MULTIPLE FUNCTION DISPERSANT VISCOSITY INDEX IMPROVER
The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional
Application No. 61/799,192, filed on March 15, 2013.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel multiple function dispersant viscosity index
improvers comprising a polymer backbone grafted with at least a first functional group
associated with sludge and varnish control and at least a second functional group associated with
soot handling performance and viscosity control. The present invention also relates to methods
for manufacturing the novel multiple function dispersant viscosity index improvers and
lubricating oil compositions containing the novel multiple function dispersant viscosity index
improvers.
2. Description of the Related Art
Conventional lubricating oils contain a variety of additives, each of which is used to
control specific performance characteristics of the lubricating oil.
One common group of lubricating oil additives are dispersant viscosity index improvers
having functional groups associated with sludge and varnish control. Among those additives
known in the art to be useful as dispersant viscosity index improvers having functional groups
associated with sludge and varnish control are polyolefins grafted with nitrogen-containing
and/or oxygen-containing monomers. For example, U.S. Patent No. 5,523,008 describes a
dispersant viscosity index improver comprising N-vinylimidazole grafted onto a polyolefin
backbone. U.S. Patent No. 5,663,126 describes a polyolefin having one or more of Nvinylimidazole,
4-vinylpyridine, or other ethylenically-unsaturated nitrogen-containing and/or
oxygen-containing monomers grafted to the polyolefin backbone.
Polyolefins grafted with nitrogen-containing and/or oxygen-containing monomers have
been prepared by dissolving the selected polyolefin in a solvent, which is typically a lubricating
oil base stock, and then mixing the polyolefin solution with a graftable monomer and an organic
peroxide as an initiator at conditions effective to graft the graftable monomer to the polyolefin
backbone. As described in U.S. Patent No. 5,523,008, for example, the initiator can be added
before, with or after the graftable monomer, but is desirably added so that the amount of
unreacted initiator which is present at any given time is preferably a small fraction of the entire
charge. The initiator may be introduced into the reactor in several discrete charges, or at a steady
rate over an extended period. The organic peroxide initiators used in these processes create an
inherently dangerous manufacturing environment.
The lubricating oil base stocks typically used as solvents for the grafting reaction are
those having a low content of aromatics. As described in U.S. Patent No. 5,663,126, for
example, the base oil should disperse or dissolve the components of the reaction mixture without
materially participating in the reaction or causing side reactions to an unacceptable degree.
Thus, aromatic constituents are desirably kept to low levels (if present at all), since aromatic
materials may be reactive with each other or other reaction components in the presence of
initiators. The reaction components may thus either be wasted or produce unwanted by-products,
unless the presence of aromatic constituents is small. For this reason Group II base stocks,
which are essentially free of unsaturated aromatics, but which are expensive in comparison to
Group I base stocks, are typically used as the solvent for the grafting reaction.
Another common group of lubricating oil additives are dispersant viscosity index
improvers having functional groups associated with soot handling performance and viscosity
control. Among those additives known in the art to be useful as dispersant viscosity index
improvers having functional groups associated with soot handling performance and viscosity
control are polyolefins grafted with the reaction product of an acylating agent and an amine.
U.S. Patent No. 4,320,019 describes dispersant viscosity index improvers prepared by first
grafting a polyolefin with an acylating agent to form an acylating reaction intermediate and then
further reacting the acylating reaction intermediate with an amine. U.S. Patent No. 7,371,713
describes dispersant viscosity index improvers having functional groups associated with soot
handling performance and viscosity control being prepared by first reacting an acylating agent,
such as maleic anhydride, with an amine, such as an aromatic amine, and then grafting the
product of that reaction onto a polyolefin.
Each additive is a separate component of the formulated lubricating oil and thus increases
the cost of the formulated lubricating oil. Thus, it is beneficial to have a multi-functional
additive that controls more than one performance characteristic of the lubricating oil. To that
end, U.S. Patent Application Publication No. 2008/0293600 describes a multifunctional grafted
polymer containing two functional groups grafted to a polymer backbone. A first functional
group is associated with sludge and varnish handling and comprises ethylenically unsaturated,
aliphatic or aromatic monomers having 2 to about 50 carbon atoms and containing oxygen and/or
nitrogen. A second functional group is associated with soot handling performance and viscosity
control and comprises the reaction product of an acylating agent and an amine.
As described in U.S. Patent Application Publication No. 2008/0293600, the process for
preparing the multifunctional graft polymer is important. To achieve good performance with
respect to both soot handling and sludge and varnish control, it is important to first graft an
acylating agent, such as maleic anhydride, onto the polymer backbone, forming a polymer
containing acyl groups, for example, succinic anhydride groups. Next, the monomer or monomer
grouping associated with sludge and varnish handling, for example N-vinylimidazole, is grafted
onto the polymer backbone. Finally, the amine or amines capable of undergoing a reaction with
the acyl group is introduced and reacted with the acylated polymer thereby imparting soot
handling performance to the graft polymer.
The multiple function dispersant viscosity index improvers of embodiments of the
present invention provide numerous benefits over the multi-functional additives described in
U.S. Patent Application Publication No. 2008/0293600. To prepare the multi-functional additive
described in U.S. Patent Application Publication No. 2008/0293600, two different substituents
are grafted to the polymer backbone. First, an acylating agent, such as maleic anhydride, is
grafted to the polymer backbone. This grafting reaction typically involves the use of an initiator,
such as an organic peroxide, and is typically performed in a Group II lubricating base oil.
Second, the functional group associated with sludge and varnish handling, for example, Nvinylimidazole,
is grafted directly to the polymer backbone. This grafting reaction also typically
involves the use of an initiator, such as an organic peroxide, and is typically performed in a
Group II lubricating base oil.
On the other hand, using embodiments of the present invention, only one substituent may
be grafted to the polymer backbone. It has been found that the functional group associated with
sludge and varnish handling may be the reaction product of an acylating agent and an amine.
Accordingly, multiple function dispersant viscosity index improvers may be prepared using only
one grafting reaction - the grafting of an acylating agent, such as maleic anhydride, to the
polymer backbone. The grafted acylating agent may then be reacted with two different amines in
order to produce the first and second functional groups. Thus, it has been found that multiple
function dispersant viscosity index improvers may be prepared while minimizing the use of
organic peroxide initiators and Group II lubricating base oils. As a result, it has been found that
multiple function dispersant viscosity index improvers may be prepared at lower cost and in a
safer and more environmentally friendly manufacturing environment.
SUMMARY OF THE INVENTION
It has been found that the current method and composition are useful for providing a
multiple function dispersant viscosity index improver comprising a grafted polymer having two
different functional groups grafted to the polymer backbone, one functional group being
associated with sludge and varnish handling and another functional group being associated with
soot handling performance and viscosity control.
In one embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer has a Rapid ADT response of at least about 8.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer has at least about 5 moles of each functional group per mole of polymer backbone.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The first functional group and the second
functional group are present in a molar ratio between 1:1.5 and 1.5:1.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in a Sequence VG Engine Test.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of at least
8.9.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in a Peugeot XUD1 1 Screener Engine Test.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in a DV4 Test.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in both a Sequence VG Engine Test and a DV4Test.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in both a Sequence VG Engine Test and a Peugeot XUD1 1 Screener
Engine Test.
In another embodiment, there is provided a multiple function dispersant graft polymer
comprising two different functional groups, each directly grafted to a polymer backbone having
graftable sites. The first functional group comprises the reaction product of an acylating agent
and a first amine, the first amine comprising an aromatic primary amine, and the second
functional group comprises the reaction product of an acylating agent and a second amine, the
second amine comprising an aliphatic primary amine. The multiple function dispersant graft
polymer, when present in base oil in an amount of about 0.80% solids by weight or below,
produces a passing result in both a Sequence VG Engine Test and a Peugeot XUD1 1 Screener
Engine Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer having a
Rapid ADT response of at least about 8.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer having at
least about 5 moles of each functional group per mole of polymer backbone.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer having
the first functional group and the second functional group present in a molar ratio between 1:1.5
and 1.5:1.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in a Sequence VG Engine Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces an
Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces an
Average Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in a Peugeot XUD1 1 Screener Engine Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in a DV4 Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in both a Sequence VG Engine Test and a DV4Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group. The
method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in both a Sequence VG Engine Test and a Peugeot XUD1 1 Screener Engine Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) reacting a polymer backbone having graftable sites and
an acylating agent having at least one point of olefinic unsaturation to form a graft polymer
reaction product having acyl groups available for reaction, (b) reacting the reaction product of
step a with a first amine comprising an aromatic primary amine to form a graft polymer reaction
product having a first functional group and acyl groups available for reaction, and (c) reacting
the reaction product of step b with a second amine comprising an aliphatic primary amine to
form a graft reaction product having a first functional group and a second functional group.
The method may be carried out so as to obtain a multiple function dispersant graft polymer that,
when present in base oil in an amount of about 0.80% solids by weight or below, produces a
passing result in both a Sequence VG Engine Test and a Peugeot XUD1 1 Screener Engine Test.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) obtaining a graft polymer having acyl groups available
for reaction, (b) reacting the graft polymer of step a with a first amine comprising an aromatic
primary amine in a solvent comprising a base oil that has an aromatic content of at least 7% by
weight, to form a graft polymer reaction product having a first functional group and acyl groups
available for reaction, and (c) reacting the reaction product of step b with a second amine
comprising an aliphatic primary amine in a solvent comprising a base oil that has an aromatic
content of at least 7% by weight, to form a graft reaction product having a first functional group
and a second functional group.
In another embodiment, there is provided a method of making a multiple function
dispersant graft polymer comprising (a) obtaining a graft polymer having acyl groups available
for reaction, (b) reacting the graft polymer of step a with a first amine comprising an aromatic
primary amine in a solvent comprising a base oil that has an aromatic content of at least 10% by
weight, to form a graft polymer reaction product having a first functional group and acyl groups
available for reaction, and (c) reacting the reaction product of step b with a second amine
comprising an aliphatic primary amine in a solvent comprising a base oil that has an aromatic
content of at least 10% by weight, to form a graft reaction product having a first functional group
and a second functional group.
In another embodiment, there is provided a lubricating oil comprising a lubricating base
oil and between about 0.05 to about 10% by composition weight of the multiple function
dispersant graft polymer of the present invention. In another embodiment, there is provided a
lubricating oil comprising a lubricating base oil and between about 0.3 to about 1.0% by
composition weight of the multiple function dispersant graft polymer of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A clear conception of the advantages and features of one or more embodiments will
become more readily apparent by reference to the exemplary, and therefore non-limiting,
embodiments illustrated in the drawings:
Figure 1 is an FT-IR Spectrum identifying a multiple function graft polymer prepared in
accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the invention will be described in connection with one or more preferred
embodiments, it will be understood that the invention is not limited to those embodiments. On
the contrary, the invention includes all alternatives, modifications and equivalents as may be
included within the spirit and scope of the appended claims.
Polymers
A wide variety of polyolefins, polyesters, and styrene-butadiene copolymers (any of
which may or may not have pendant unsaturation) are contemplated for use as a polymer
backbone for grafting. Examples of such polyolefins and polyesters include homopolymers,
copolymers, terpolymers, and higher such as, but not limited to, polyethylene, polypropylene,
ethylene-propylene copolymers, polymers containing two or more monomers, polyisobutene,
polymethacrylates, polyacrylates, polyalkylstyrenes, partially hydrogenated polyolefins of
butadiene and styrene and copolymers of isoprene, such as polymers of styrene and isoprene.
EPDM (ethylene/propylene/diene monomer) polymers, ethylene-propylene octene terpolymers
and ethylene-propylene ENB terpolymers, are also contemplated for use herein. The use of
mixtures of polyolefins, mixtures of polyesters, or mixtures of styrene-butadiene polymers is also
contemplated. The use of chemical and physical mixtures of polyolefins, polyesters, and/or
styrene-butadiene polymers is also contemplated.
The polyolefins contemplated herein may have weight average molecular weights of
from about 10,000 to about 750,000, alternatively from about 20,000 to about 500,000.
Preferred polyolefins may have polydispersities from about 1 to about 15. The polyesters
contemplated herein may have weight average molecular weights of from about from about
10,000 to about 1,000,000, alternatively from about 20,000 to about 750,000.
Particular materials contemplated for use herein include ethylene/propylene/diene
polyolefins containing from about 30% to about 80% ethylene and from about 70% to about 20%
propylene moieties by number, optionally modified with from 0% to about 15% diene
monomers. Several examples of diene monomers are 1,4-butadiene, isoprene, 1,4-hexadiene,
dicyclopentadiene, 2,5-norbornadiene, ethylidene-norbornene, the dienes recited in U.S. Pat. No.
4,092,255, the disclosure of which is incorporated herein by reference in its entirety, at column 2,
lines 36-44, or combinations of more than one of the aforementioned polymers. Other materials
contemplated are polymers derived from mixed alkylacrylates or mixed alkylmethacrylates or
combinations thereof.
Specific materials which are contemplated for use herein include the VISNEX
polyolefins which are polyolefins comprised of ethylene and propylene sold by Mitsui
Petrochemical Industries, Ltd., Tokyo, Japan; also the family of PARATONE polyolefins, such
as Paratone 8910, and Paratone 8941, comprised primarily of ethylene and propylene, marketed
by Chevron Oronite Company, L.L.C., headquartered in Houston, Tex.; also contemplated are
Infineum SV200, Infineum SV250, Infineum SV145, Infineum SV160, Infineum SV300, and
Infineum SV150, which are olefin copolymers based on ethylene and/or propylene and/or
isoprene marketed by Infineum International, Ltd., Abingdon, UK. or Infineum USA LP, Linden,
N.J.; elastomers available from DSM are also contemplated, as are polymers marketed under the
DUTRAL name by Polimeri Europa, of Ferrara, Italy such as CO-029, CO-034, CO-043, CO-
058, TER 4028, TER 4044, TER 4049 and TER 9046. The Uniroyal line of polymers marketed
by Crompton Corporation of Middlebury, Conn under the ROYALENE name such as 400, 501,
505, 512, 525, 535, 556, 563, 580 HT are also contemplated. Styrene-butadiene polymers, such
as Lubrizol®7408, sold by The Lubrizol Corporation, headquartered in Wickliffe, Ohio, are also
contemplated. Also contemplated for use are polymers such as Viscoplex 3-700, a polyalkyl
methacrylate and Viscoplex 2-602, a dispersant mixed polymer which consists of polyalkyl
methacrylate coreacted with olefin copolymer.
Combinations of the above materials, and other, similar materials are also contemplated.
Acylating Agents
The acylating agent has at least one point of olefinic unsaturation in its structure.
Usually, the point of olefinic unsaturation will correspond to—HC=CH— or —HC=CH 2.
Acylating agents where the point of olefinic unsaturation is a, b to a carboxy functional group
are very useful. Olefinically unsaturated mono-, di-, and polycarboxylic acids, the lower alkyl
esters thereof, the halides thereof, and the anhydrides thereof represent typical acylating agents
in accordance with embodiments of the present invention. Preferably, the olefinically
unsaturated acylating agent is a mono- or dibasic acid, or a derivative thereof such as anhydrides,
lower alkyl esters, halides and mixtures of two or more such derivatives. "Lower alkyl" means
alkyl groups having one to seven carbon atoms.
The acylating agent may include at least one member selected from the group consisting
of monounsaturated C4 to C50, alternatively C4 to C2o, alternatively C4 to C10 , dicarboxylic acids,
monocarboxylic acids, and anhydrides thereof (that is, anhydrides of those carboxylic acids or of
those monocarboxylic acids), and combinations of any of the foregoing acids and/or anhydrides.
Suitable acylating agents include acrylic acid, crotonic acid, methacrylic acid, maleic
acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic
anhydride, mesaconic acid, glutaconic acid, chloromaleic acid, aconitic acid, methylcrotonic
acid, sorbic acid, 3-hexenoic acid, 10-decenoic acid, 2-pentene-l,3,5-tricarboxylic acid, cinnamic
acid, and lower alkyl (e.g., Ci to C4 alkyl) acid esters of the foregoing, e.g., methyl maleate, ethyl
fumarate, methyl fumarate, and the like. The acylating agents may include the unsaturated
dicarboxylic acids and their derivatives; especially maleic acid, fumaric acid, maleic anhydride,
and combinations thereof.
Amines for forming functional groups associated with soot handling performance
Amines suitable for imparting soot handling performance are those having an aromatic
primary amine which is capable of undergoing a condensation reaction with an appropriate
acylating agent. Amines comprising more than one aromatic group and/or a functional group,
such as nitrogen or oxygen, that provides the amine with a degree of polarity may be useful for
imparting soot handling performance. One or more amines may be used. Some examples of
amines that are suitable for imparting soot handling performance include aniline; N,N-dimethylp-
phenylenediamine; 1-naphthylamine; N-phenyl-p-phenylenediamine (also known as 4-
aminodiphenylamine or ADPA); m-anisidine; 3-amino-4-methylpyridine; 4-nitroaniline; and
combinations thereof.
Amines for forming functional groups associated with sludge and varnish control
Amines suitable for imparting sludge and varnish control performance are those having
an aliphatic primary amine which is capable of undergoing a condensation reaction with an
appropriate acylating agent and having a degree of polarity (such as may be provided by a
nitrogen or oxygen group). One or more amines may be used. Some examples of amines that
are suitable for imparting sludge and varnish control performance include 2,2-dimethyl-l,3-
dioxolane-4-methanamine; n-(3-aminopropyl) imidazole; N-(3-aminopropyl)-2-pyrrolidinone; 2-
picolylamine; and combinations thereof.
Amounts of each functional group on the graft polymer
In order to be effective for both soot handling and sludge and varnish control, a multiple
function dispersant graft polymer should comprise at least a minimum amount of a first
functional group associated with soot handling performance and at least a minimum amount of a
second functional group associated with sludge and varnish control.
It is contemplated that the minimum effective amount of a first functional group
associated with soot handling performance is at least about 4 moles functional group per mole of
starting polymer, alternatively at least about 5 moles functional group per mole of starting
polymer, alternatively at least about 6 moles functional group per mole of starting polymer,
alternatively at least about 7 moles functional group per mole of starting polymer, alternatively at
least about 8 moles functional group per mole of starting polymer.
It is contemplated that the minimum effective amount of a second functional group
associated with sludge and varnish control is at least about 4 moles functional group per mole of
starting polymer, alternatively at least about 5 moles functional group per mole of starting
polymer, alternatively at least about 6 moles functional group per mole of starting polymer,
alternatively at least about 7 moles functional group per mole of starting polymer, alternatively at
least about 8 moles functional group per mole of starting polymer.
If either functional group is present on the graft polymer in an amount below the
minimum effective amount, the graft polymer may be unsuitable as a multiple function
dispersant viscosity index improver as contemplated by the present disclosure.
The maximum amount of the first functional group that may be present on a graft
polymer is limited only by the amount of acyl groups on the polymer backbone, which is limited
by the amount of graftable sites on the polymer backbone (it should also be taken into account
that some of the acyl groups should be reacted to form the second functional group). At some
point, however, the formation of additional functional groups associated with soot handling
performance may become inefficient or unnecessary. Thus, in embodiments, a graft polymer
comprises the first functional group associated with soot handling performance in an amount
between 4 moles functional group per mole of starting polymer and 15 moles functional group
per mole of starting polymer, alternatively between 5 moles functional group per mole of starting
polymer and 15 moles functional group per mole of starting polymer, alternatively between 6
moles functional group per mole of starting polymer and 15 moles functional group per mole of
starting polymer, alternatively between 7 moles functional group per mole of starting polymer
and 15 moles functional group per mole of starting polymer, alternatively between 8 moles
functional group per mole of starting polymer and 15 moles functional group per mole of starting
polymer, alternatively between 9 moles functional group per mole of starting polymer and 15
moles functional group per mole of starting polymer, alternatively between 4 moles functional
group per mole of starting polymer and 12 moles functional group per mole of starting polymer
alternatively between 5 moles functional group per mole of starting polymer and 12 moles
functional group per mole of starting polymer, alternatively between 6 moles functional group
per mole of starting polymer and 12 moles functional group per mole of starting polymer,
alternatively between 7 moles functional group per mole of starting polymer and 12 moles
functional group per mole of starting polymer, alternatively between 8 moles functional group
per mole of starting polymer and 12 moles functional group per mole of starting polymer,
alternatively between 9 moles functional group per mole of starting polymer and 12 moles
functional group per mole of starting polymer.
The maximum amount of the second functional group that may be present on a graft
polymer is limited only by the amount of acyl groups on the polymer backbone, which is limited
by the amount of graftable sites on the polymer backbone (it should also be taken into account
that some of the acyl groups should be reacted to form the first functional group). At some point,
however, the formation of additional functional groups associated with sludge and varnish
control may become inefficient or unnecessary. Thus, in embodiments, a graft polymer
comprises the second functional group associated with sludge and varnish control in an amount
between 4 moles functional group per mole of starting polymer and 15 moles functional group
per mole of starting polymer, alternatively between 5 moles functional group per mole of starting
polymer and 12 moles functional group per mole of starting polymer, alternatively between 6
moles functional group per mole of starting polymer and 12 moles functional group per mole of
starting polymer, alternatively between 7 moles functional group per mole of starting polymer
and 12 moles functional group per mole of starting polymer, alternatively between 8 moles
functional group per mole of starting polymer and 12 moles functional group per mole of starting
polymer, alternatively between 9 moles functional group per mole of starting polymer and 12
moles functional group per mole of starting polymer.
In order that the graft polymer may comprise each of the soot handling functional group
and the sludge and the varnish control functional group in effective amounts, the graft polymer
may comprise the soot handling functional group and the sludge and varnish control functional
group in a molar ratio between about 1.5 to 1 and 1 to 1.5, alternatively between about 1.4 to 1
and 1 to 1.4, alternatively between about 1.3 to 1 and 1 to 1.3, alternatively between about 1.2 to
1 and 1 to 1.2, alternatively between about 1.1 to 1 and 1 to 1.1. Alternatively, the graft polymer
comprises the soot handling functional group and the sludge and varnish control functional group
in a ratio of about 1:1.
More particularly, the functional group associated with soot handling may make up
between 40% and 60% of the total moles of functional groups on the graft polymer, alternatively
between 41% and 59%, alternatively between 42% and 58%, alternatively between 43% and
57%, alternatively between 44% and 56%, and alternatively between 45% and 55% of the total
moles of functional groups on the graft polymer. Similarly, the functional group associated with
sludge and varnish control may makes up between 40% and 60% of the total moles of functional
groups on the graft polymer, alternatively between 41% and 59%, alternatively between 42% and
58%, alternatively between 43% and 57%, alternatively between 44% and 56%, and alternatively
between 45% and 55% of the total moles of functional groups on the graft polymer.
If either functional group is present in a percentage of the total functional groups on the
graft polymer that is too low, the graft polymer will likely contain that functional group in an
amount that falls below the minimum effective amount. Accordingly, such a graft polymer may
be unsuitable as a multiple function dispersant viscosity index improver as contemplated by the
present disclosure.
Free-Radical Initiators
Broadly, any free-radical initiator capable of operating under the conditions of the
reaction between the acylating agent and the polymer is contemplated for use. Representative
initiators are disclosed in U.S. Pat. No. 4,146,489, the disclosure of which is incorporated herein
by reference in its entirety, at column 4, lines 45-53. Specific "peroxy" initiators contemplated
include alkyl, dialkyl, and aryl peroxides, for example: di-i-butyl peroxide (abbreviated herein as
"DTBP"), dicumyl peroxide, i-butyl cumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di(ibutylperoxy)
hexane, and 2,5-dimethyl-2,5-di(i-butylperoxy)hexyne-3. Also contemplated are
peroxyester and peroxyketal initiators, for example: i-butylperoxy benzoate, i-amylperoxy
benzoate, i-butylperoxy acetate, i-butylperoxy benzoate, di-i-butyl diperoxyphthalate, and tbutylperoxy
isobutyrate. Also contemplated are hydroperoxides, for example: cumene
hydroperoxide, i-butyl hydroperoxide, and hydrogen peroxide. Also contemplated are azo
initiators, for example: 2-i-butylazo-2-cyanopropane, 2-i-butylazo-l-cyanocyclohexane, 2,2'-
azobis(2,4-dimethylpentane nitrile), 2,2'-azobis(2-methylpropane nitrile), 1,1'-
azobis(cyclohexanecarbonitrile), and azoisobutyronitrile (AIBN). Other similar materials are
also contemplated such as, but not limited to, diacyl peroxides, ketone peroxides and
peroxydicarbonates. It is also contemplated that combinations of more than one initiator,
including combinations of different types of initiators, may be employed.
Solvents
Either polar or non-polar solvents or process fluids may be used. Such solvents facilitate
materials handling as well as promote the uniform distribution of reactants. The process fluids
useful here include volatile solvents which are readily removable from the grafted polymer after
the reaction is complete. Solvents which may be used are those which can disperse or dissolve
the components of the reaction mixture and which will not participate appreciably in the reaction
or cause side reactions to a material degree. Several examples of solvents of this type include
straight chain or branched aliphatic or alicyclic hydrocarbons, such as n-pentane, n-heptane, iheptane,
n-octane, i-octane, nonane, decane, cyclohexane, dihydronaphthalene,
decahydronaphthalene and others. Specific examples of polar solvents include aliphatic ketones
(for example, acetone), aromatic ketones, ethers, esters, amides, nitrites, sulfoxides such as
dimethyl sulfoxide, water, and the like. Non-reactive halogenated aromatic hydrocarbons such
as chlorobenzene, dichlorobenzene, trichlorobenzene, dichlorotoluene and others are also useful
as solvents. Combinations of solvents, such as -of polar and non-polar solvents, are also
contemplated for use in the present invention.
The solvents and process fluids useful here also include base stocks which are suitable for
incorporation into a final lubricating oil product. Any base stock may be used which can
disperse or dissolve the components of the reaction mixture without materially participating in
the reaction or causing side reactions to an unacceptable degree. Hydroisomerized and
hydrocracked base stocks, base stocks containing low or moderate levels of aromatic
constituents, and fluid poly-a-olefins are contemplated for use herein. For the grafting reaction,
aromatic constituents are desirably kept to low levels since aromatic materials may be reactive
with each other or other reaction components in the presence of initiators. The use of base stocks
having aromatic constituents, while being less than optimum for the grafting reaction, is
contemplated under this disclosure. These include base stocks containing less than 50%
aromatics, alternatively less than 30% aromatics, alternatively less than 25% aromatics,
alternatively less than 20% aromatics, alternatively less than 10% aromatics or alternatively less
than 5% aromatics.
Suitable base stocks of this kind contemplated include those marketed by ExxonMobil
Corp. such as the Group I, 100 SUS, 130 SUS, or 150 SUS low pour solvent neutral base oils,
and the Group II EHC base stocks. Representative base stocks include those marketed by
PetroCanada, Calgary, Alberta, such as HT 60 (P 60 N), HT 70 (P 70 N), HT 100 (P 100 N), and
HT 160 (P 160 N) are also contemplated as well as RLOP stocks such as 100 N and 240 N sold
by Chevron USA Products Co. In general, Group I, Group II, Group III, Group IV and Group V
base stock categories are contemplated for use. Aromatic-free base stocks such as poly-alphaolefins
("PAO") may also be used.
The aromatic content in the process fluid may be from about 0 to about 50 weight
percent, alternatively, from about 0 to about 25 weight percent, alternatively, from about 0 to
about 15 weight percent, alternatively from about 0 to about 10 weight percent, alternatively
from about 0 to about 5 weight percent.
The aromatic content of the process fluid used in the condensation reactions of the
amines with the acyl groups is far less important, as the condensation reactions take place
without the need for a free-radical initiator. Accordingly, the danger of aromatic materials
reacting with each other or other reaction components is not present. In embodiments of the
present invention base stocks having higher aromatic contents, such as at least about 5% by
weight, may be used. Alternatively, base stocks having an aromatic content of at least about 6%
by weight may be used. Alternatively, base stocks having an aromatic content of at least about
7% by weight may be used. Alternatively, base stocks having an aromatic content of at least
about 8% by weight may be used. Alternatively, base stocks having an aromatic content of at
least about 9% by weight may be used. Alternatively, base stocks having an aromatic content of
at least about 10% by weight may be used. Alternatively, base stocks having an aromatic content
of at least about 12% by weight may be used. Alternatively, base stocks having an aromatic
content of at least about 15% by weight may be used. Group I base oils generally have higher
aromatic contents within the above ranges. The use of base stocks having higher aromatic
contents may provide significant savings in raw material expenses, rendering the multiple
function dispersant viscosity index improver and the process of making the multiple function
dispersant viscosity index improver disclosed herein more economical than conventional
lubricating oils.
Method of Preparation of Multiple Function Dispersant Viscosity Index Improver
To prepare a multi-function graft polymer which displays both good soot handling and
sludge and varnish control, the respective functional groups which impart these performance
characteristics are grafted onto the same polymer backbone.
The reaction sequence is important as the reaction order is a determinant of the amount of
each functional group on the graft polymer and, hence of performance. To achieve good
performance with respect to both soot handling and sludge and varnish control, an acylating
agent, such as maleic anhydride, is grafted onto the polymer forming a graft polymer reaction
product having acyl groups available for reaction, for example, a polymer containing succinic
anhydride groups. Next, an amine reactant that is useful for forming the functional group
associated with soot handling is introduced and reacted with the acyl groups of the graft polymer
reaction product, e.g. succinic anhydride (SA) groups. Finally, am amine reactant that is useful
for forming the functional group associated with sludge and varnish control is introduced and
reacted with the acyl groups of the graft polymer reaction product, e.g. succinic anhydride (SA)
groups. More than one type of reactant may be used in any given step, so the reactants may
comprise one or more graftable polymers, one or more graftable acylating agents, one or more
amines capable of undergoing reaction with the acyl groups to form a functional group
associated with soot handling, and/or one or more amines capable of undergoing reaction with
the acyl groups to form a functional group associated with sludge and varnish control are
contemplated.
It is important that the amine reactant that is useful for forming the functional group
associated with soot handling is introduced and reacted with the acyl groups of the graft polymer
prior to the introduction of the amine reactant that is useful for forming the functional group
associated with sludge and varnish control because the aromatic amines that are useful for
forming the soot handling functional group have a significantly lower reaction rate with the acyl
groups of the graft polymer than the aliphatic amines that are useful for forming the sludge and
varnish control functional group. By reacting the aromatic amines first, one ensures that there
are sufficient un-reacted acyl groups on the graft polymer with which the aromatic amines may
react. This ensures that an effective amount of soot handling functional groups may be
incorporated onto the polymer. Because the aliphatic amines that are useful for forming the
sludge and varnish control functional group have a significantly higher reaction rate, the aliphatic
amines are able to react with the remaining un-reacted acyl groups in order to provide an
effective amount of sludge and varnish control functional groups. The high reaction rate of the
aliphatic amines provides the additional benefit that the acyl groups on the polymer backbone
may be fully reacted via a condensation reaction, such that no un-reacted acyl groups are present
on the multiple function dispersant viscosity index improver.
Although not being bound by any theory of operation, where the aliphatic amine that is
useful for forming the sludge and varnish control functional group is introduced and reacted with
the graft polymer containing acyl groups prior to the aromatic amine that is useful for forming
the soot handling function group, one may not achieve an effective amount of soot handling
functional group on the graft polymer. Additionally, because of the typically low reaction rates
of the aromatic amines that are generally useful for forming the soot handling functional group,
the resulting graft polymer may contain un-reacted acyl groups. Similarly, if one were to
provide a mixture comprising both the aliphatic amine that is useful for forming the sludge and
varnish control functional group and the aromatic amine that is useful for forming the soot
handling functional group, the graft polymer reaction product may not contain an effective
amount of a soot handling functional group.
Using the method described herein, only one free-radical grafting reaction is performed
(the grafting of the acylating agent to the polymer backbone). The remainder of the reaction
comprises condensation reactions between the two different amines and acyl groups on the
polymer backbone. Accordingly, the use of a free-radical initiator, such as an organic peroxide,
is required only for the first reaction step. It is also contemplated that the grafting of an acylating
agent to the polymer backbone may be performed by an upstream supplier, which would allow
one to produce a multiple function dispersant viscosity index improver through the reaction of
two different amines with the acylated polymer, as described herein, without having to store and
use a potentially harmful free-radical initiator. Grafting of an acylating agent by an upstream
supplier would also allow for one to produce a multiple function dispersant viscosity index
improver through the reaction of two different amines with the acylated polymer, as described
herein, in a less expensive base stock solvent that need not be essentially free of aromatics (such
as a Group I base stock). Thus, one may avoid the use of an expensive aromatic-free base stock
solvent (such as a Group II base stock).
The multi-functional graft polymer of the present invention may be prepared in solution
or by melt blending, or by a combination of melt blending and reaction in solution.
Preparation in Solution
Preparation of the multi-functional graft polymer in solution is generally carried out as
follows. The polymer to be grafted is provided in fluid form. For example, the polymer may be
dissolved in a solvent, which may be a hydrocarbon base oil suitable for use in a lubricating
composition or any other suitable solvent. The polymer solution is then heated to an appropriate
reaction temperature. A graftable acylating agent is then introduced and grafted onto the
polymer using an initiator such as a peroxide molecule, thereby forming an acylated polymer.
For example, when the acylating agent is maleic anhydride, a polymer having succinic anhydride
groups is formed. Next, an amine that is capable of undergoing reaction with the acyl groups of
the acylated polymer to form a functional group associated with soot handling is introduced to
the solution comprising the acylated polymer and reacted for a suitable amount of time. Finally,
an amine that is capable of undergoing reaction with the remaining acyl groups of the acylated
polymer to form a functional group associated with sludge and varnish control is introduced to
the solution and reacted for a suitable amount of time.
More particularly, the polymer solution is placed into a suitable reactor such as a resin
kettle and the solution is heated, under inert gas blanketing, to the desired reaction temperature,
and the reaction is carried out under an inert gas blanket. At a minimum, the reaction
temperature should be sufficient to consume essentially all of the selected initiator during the
time allotted for the reaction of the acylating agent and the polymer backbone. For example, if
di-i-butyl peroxide (DTBP) is used as the initiator, the reaction temperature should range from
about 145° C. to about 220° C , alternatively from about 155° C. to about 210° C , alternatively
from about 160° C. to about 200° C , alternatively from about 165° C. to about 190° C ,
alternatively from about 165° C. to about 180° C , alternatively greater than about 170° C ,
alternatively greater than about 175° C. Different initiators work at different rates for a given
reaction temperature. Therefore, the choice of a particular initiator may require adjustment of
reaction temperature or time. Once a temperature is adopted, the temperature is typically
maintained constant throughout the entire sequence of processes required in the preparation of
the graft polymer (although no further initiator is needed). However, the solution may be
allowed to cool to, for example, room temperature following the grafting of the acylating agent
to the polymer backbone.
The acylating agent is added to the polymer solution and dissolved. The contemplated
proportions of the acylating agent to polymer are selected so that an effective percentage will
graft directly onto the polymer backbone. The minimum mole ratio of acylating agent to
polymer is as follows: at least about 1 mole, alternatively at least about 2 moles, alternatively at
least about 3 moles, alternatively at least about 4 moles, alternatively at least about 5 moles,
alternatively at least about 6 moles, alternatively at least about 7 moles, alternatively at least
about 8 moles, alternatively at least about 9 moles, alternatively at least about 10 moles,
alternatively at least about 11 moles, alternatively at least about 12 moles, alternatively at least
about 13 moles, alternatively at least about 14 moles, alternatively at least about 15 moles,
alternatively at least about 20 moles, alternatively at least about 25 moles, alternatively at least
about 30 moles, alternatively at least about 40 moles, alternatively at least about 50 moles,
alternatively at least about 60 moles, alternatively at least about 70 moles, alternatively at least
about 74 moles of the graftable acylating agent per mole of the starting polymer. The
contemplated maximum molar proportion of the graftable acylating agent to the starting polymer
is as follows: at most about 10 moles, alternatively at most about 12 moles, alternatively at most
about 15 moles, alternatively at most about 20 moles, alternatively at most about 22 moles,
alternatively at most about 24 moles, alternatively at most about 25 moles, alternatively at most
about 26 moles, alternatively at most about 28 moles, alternatively at most about 30 moles,
alternatively at most about 40 moles, alternatively at most about 50 moles, alternatively at most
about 60 moles, alternatively at most about 74 moles of the graftable acylating agent per mole of
the starting polymer.
The graftable acylating agent may be introduced into the reactor all at once, in several
discrete charges, or at a steady rate over an extended period. The desired minimum rate of
addition of the graftable acylating agent to the reaction mixture is selected from: at least about
0.01%, alternatively at least about 0.05%, alternatively at least about 0.1%, alternatively at least
about 0.5%, alternatively at least about 1%, alternatively at least about 2%, alternatively at least
about 3%, alternatively at least about 4%, alternatively at least about 5%, alternatively at least
about 10%, alternatively at least about 20%, alternatively at least about 50%, alternatively at
least about 100% of the necessary charge of graftable acylating agent per minute. Any of the
above values can represent an average rate of addition or the minimum rate of addition. The
desired maximum rate of addition is selected from: at most about 1%, alternatively at most about
2%, alternatively at most about 5%, alternatively at most about 10%, alternatively at most about
20%, alternatively at most about 50%, alternatively at most about 100% of the necessary charge
of graftable acylating agent per minute. Any of the above values can represent an average rate of
addition or the maximum rate of addition. When added over time, the graftable acylating agent
can be added as discrete charges, at an essentially constant rate or at a rate which varies with
time.
The graftable acylating agent may be added as a neat liquid, in solid or molten form, or
cut back, i.e. diluted, with a solvent. While it may be introduced neat, it is preferably cut back
with a solvent to avoid localized concentrations of the acylating agent as it enters the reactor. In
an embodiment, it is substantially diluted with the process fluid (reaction solvent). The
monomer can be diluted by at least about 5 times, alternatively at least about 10 times,
alternatively at least about 20 times, alternatively at least about 50 times, alternatively at least
about 100 times its weight or volume with a suitable solvent or dispersing medium.
An initiator is added to the solution comprised of polymer and acylating agent. The
initiator can be added before, with or after the graftable acylating agent. When adding the
initiator, it may be added all at once, in several discrete charges, or at a steady rate over an
extended period. Preferably, the initiator may be added so that, at any given time, the amount of
unreacted initiator present is much less than the entire charge or, more preferably, only a small
fraction of the entire charge. In one embodiment, the initiator may be added after substantially,
most or the entire graftable acylating agent has been added, so that there is an excess of both the
graftable acylating agent and the polymer during essentially the entire reaction. In another
embodiment, the initiator may be added along with, or simultaneously with, the graftable
acylating agent, either at essentially the same rate (measured as a percentage of the entire charge
added per minute) or at a somewhat faster or slower rate, so that there is an excess of polymer to
unreacted initiator and unreacted acylating agent. For this embodiment, the ratio of unreacted
initiator to unreacted acylating agent remains substantially constant during most of the reaction.
The contemplated proportions of the initiator to the graftable acylating agent and the
reaction conditions are selected so that most, and preferably all, of the graftable acylating agent
will graft directly onto the polymer, rather than forming dimeric, oligomeric, or homopolymeric
graft moieties or entirely independent homopolymers. The contemplated minimum molar
proportions of the initiator to the graftable acylating agent are from about 0.02:1 to about 2:1,
alternatively from about 0.05:1 to about 2:1. No specific maximum proportion of the initiator is
contemplated, though too much of the initiator may degrade the polymer, cause problems in the
finished formulation and increase cost and, therefore, should be avoided.
The desired minimum rate of addition of the initiator to the reaction mixture is selected
from: at least about 0.005%, alternatively at least about 0.01%, alternatively at least about 0.1%,
alternatively at least about 0.5%, alternatively at least about 1%, alternatively at least about 2%,
alternatively at least about 3%, alternatively at least about 4%, alternatively at least about 5%,
alternatively at least about 20%, alternatively at least about 50% of the necessary charge of
initiator per minute. Any of the above values can represent an average rate of addition or the
minimum rate of addition. The desired maximum rate of addition of the initiator to the reaction
mixture is selected from: at most about 0.5%, alternatively at most about 1%, alternatively at
most about 2%, alternatively at most about 3%, alternatively at most about 4%, alternatively at
most about 5%, alternatively at most about 10%, alternatively at most about 20%, alternatively at
most about 50%, alternatively at most about 100% of the necessary charge of initiator per
minute. Any of the above values can represent an average rate of addition or the maximum rate
of addition. When the initiator is added over time, the initiator can be added as discrete charges,
at an essentially constant rate or at a rate which varies with time.
While the initiator can be added neat, it is preferably cut back with a solvent to avoid
high localized concentrations of the initiator as it enters the reactor. In an embodiment, it is
substantially diluted with the process fluid (reaction solvent). The initiator can be diluted by at
least about 5 times, alternatively at least about 10 times, alternatively at least about 20 times,
alternatively at least about 50 times, alternatively at least about 100 times its weight or volume
with a suitable solvent or dispersing medium.
Once the grafting of the acylating agent to the polymer has proceeded to the extent
required by the particular reactants, the next step in the preparation of the graft polymer may be
undertaken immediately or the solution may be stored and the next step in the preparation of the
graft polymer may be undertaken at a later time.
The next step in the preparation of the graft polymer is the conversion of a percentage of
the acyl groups of the acylated polymer, e.g. the succinic anhydride substituents, into the soot
handling functional group via a condensation reaction with a first amine reactant or reactants.
The solution may be maintained either at an elevated temperature, such as the temperature
appropriate for carrying out the grafting reaction, or the temperature may be decreased to, for
example, room temperature. If the reactor temperature is decreased, the amine reactant may be
introduced into the reactor all at once and blended into the polymer solution. The reactor
temperature is then raised to a suitable temperature to carry out the reaction between the acylated
polymer and the amine reactant. Alternatively, the reactor may be maintained at an elevated
temperature, in which case the amine reactant is preferably fed to the reactor relatively slowly
allowing for the reaction between the acylated polymer and the amine reactant. The reactants are
maintained at temperature until the reaction with the amine is substantially complete. The inert
blanket may be maintained during this stage of preparation of the graft polymer.
The contemplated proportions of the first amine reactant to polymer are selected so that
an effective percentage will react with the acyl group, e.g., a succinic anhydride group.
The first amine reactant may be introduced into the reactor in several (or, alternatively,
many) discrete charges, or at a steady rate over an extended period, or at a rate which varies with
time, or all at once. That is, the rate of addition of amine reactant is as follows: at least about
0.2%, alternatively at least about 0.5%, alternatively at least about 1%, alternatively at least
about 2%, alternatively at least about 3%, alternatively at least about 4%, alternatively at least
about 5%, alternatively at least about 20%, alternatively at least about 50%, alternatively at least
about 100% of the necessary charge of amine reactant per minute. Any of the above values can
represent an average rate of addition or the minimum value of a rate which varies with time.
The final step in the preparation of the graft polymer is the conversion of a percentage of
the remaining acyl groups of the acylated polymer, e.g. the succinic anhydride substituents, into
the sludge and varnish control functional group via a condensation reaction with a second amine
reactant or reactants. The solution may be maintained either at an elevated temperature, such as
the temperature appropriate for carrying out the previous condensation reaction, or the
temperature may be decreased to, for example, room temperature. If the reactor temperature is
decreased, the amine reactant may be introduced into the reactor all at once and blended into the
polymer solution. The reactor temperature is then raised to a suitable temperature to carry out
the reaction between the acylated polymer and the amine reactant. Alternatively, the reactor may
be maintained at an elevated temperature, in which case the amine reactant is preferably fed to
the reactor relatively slowly allowing for the reaction between the acylated polymer and the
amine reactant. The reactants are maintained at temperature until the reaction with the amine is
substantially complete. The inert blanket may be maintained during this stage of preparation of
the graft polymer.
The contemplated proportions of the second amine reactant to polymer are selected so
that an effective percentage will react with the acyl group, e.g., a succinic anhydride group.
The second amine reactant may be introduced into the reactor in several (or, alternatively,
many) discrete charges, or at a steady rate over an extended period, or at a rate which varies with
time, or all at once. That is, the rate of addition of amine reactant is as follows: at least about
0.2%, alternatively at least about 0.5%, alternatively at least about 1%, alternatively at least
about 2%, alternatively at least about 3%, alternatively at least about 4%, alternatively at least
about 5%, alternatively at least about 20%, alternatively at least about 50%, alternatively at least
about 100% of the necessary charge of amine reactant per minute. Any of the above values can
represent an average rate of addition or the minimum value of a rate which varies with time.
Preferably, the reaction between the second amine reactant and the remaining, i.e.
unreacted, acyl groups of the acylated polymer is carried out so that all of the unreacted acyl
groups of the acylated polymer are reacted with the second amine. Accordingly, the reaction is
preferably carried out so that the graft polymer reaction product will not contain any unreacted
acyl groups on the polymer backbone. Rather all of the grafted acyl groups are converted into
either a functional groups associated with soot handling or a functional group associated with
sludge and varnish control.
After the reaction has gone essentially to completion, the heat may be removed and the
reaction product allowed to cool in the reactor with mixing or removed prior to cooling.
Preparation by Melt-Reaction
The reaction can be carried out under polymer melt reaction conditions in an extrusion
reactor, a heated melt-blend reactor, a Banbury mill or other high-viscosity material blenders or
mixers, for example, an extruder. (The term extruder used in this specification should be
understood as being exemplary of the broader class of blenders or mixers which may be used for
melt-blending according to the present invention.)
To carry out the melt reaction, it is desirable to establish suitable process design
parameters for the reactive extruder to insure that the unit is capable of achieving the operating
parameters and conditions needed in order to generate the desired product or products. The
operating conditions and parameters appropriate for carrying out reactive extrusion include, but
are not limited to, criteria for the reactant addition ports, the reactant feed systems which include
feed rate controllers and monitors, the polymer feed hopper, the polymer handling and feed
system which includes feed rate controllers and monitors, the extruder design which includes,
among others, the screw design and its size, barrel diameter and length, die configuration and
open cross-section, systems for heating the extruder and controlling extruder temperature, such
as, barrel temperature and die temperature, screw speed, and both pre-extrusion and postextrusion
conditions. The precise conditions are established by those skilled in the art to meet
the product targets. It should be noted that during its operation, the extruder can be maintained
under, essentially, aerobic conditions, or may be purged or blanketed with an inerting material to
create anaerobic operating conditions.
The appropriate reactant feed concentrations and conditions may be based upon the
teachings presented in the present specification for the solvent based grafting reaction. These
include the appropriate feed rates, concentrations and conditions of the polymer or polymers, the
acylating agent or agents, the initiator or initiators, and the amine reactants. Examples of the
concentrations and conditions referred to include, among others, the relative concentrations of
the acylating agent to both the polymer and the initiator and of the relative concentration of both
the first amine reactant to the acylating agent and the second amine reactant to the acylating
agent. The contemplated minimum and maximum molar proportions are, in general, the same as
those previously identified for the solvent based reactions.
While the reactants may be added neat, in some embodiments, the reactants may be
introduced "cut-back" or diluted with solvent in order to avoid localized regions of elevated
species concentration. Representative solvents include base oils conventionally used in lubricant
compositions, as defined in this specification, mineral spirits, volatile, as well as non-volatile,
solvents, polar solvents and other solvents known to those skilled in the art. The concentration
of reagent, relative to solvent may range from about 1wt % to about 99 wt . In general, the
concentrations and conditions for carrying out the reaction of the acylating agent and the
polymer via reactive extrusion are chosen in order to promote grafting of the acylating agent
directly onto the polymer, as compared with reacting to form dimeric, oligomeric, or
homopolymeric graft moieties or, even, independent homopolymers.
In carrying out the graft reaction of the acylating agent and the polymer, the polymer,
essentially as a solid, is fed to the extruder at a constant rate and brought to its melt condition.
The graftable acylating agent and initiator are metered into the extruder at a constant rate. This
may be done either through the same feed port as that of the polymer or through specific reactant
feed ports. That is, the graftable reactant and initiator may be fed, essentially together with the
polymer into the same extruder zone, or alternatively, delivery of the graftable reactant and
initiator may be somewhat delayed, by being introduced downstream from the polymer into a
zone separated from the polymer feed hopper by appropriate screw seal elements.
With respect to the initiator, it may be introduced, either before, together with, or after
the graftable acylating agent, namely, either into the same extruder zone or into different zones
established by appropriate seal elements. These screw elements may be located either in front of
or after the respective zones into which the graftable reactant is fed. The feed rates of graftable
acylating agent and of initiator and their concentrations relative to polymer are adjusted to yield
the desired product composition. In addition to the graftable acylating agent, the two different
amines that are capable of reacting with the acylating agent may be fed to the extruder
downstream from the grafted polymer to complete the preparation of the multi-function graft
polymer.
In an embodiment, the graftable acylating agent is grafted onto the polymer via extrusion
and then the amine condensation reactions are carried out in solution. Because the condensation
reactions do not suffer from the same interferences from aromatics in the solvent as the freeradical
graft reaction, the condensation reactions may be performed in a base oil having a higher
aromatic content. Thus, in this embodiment, the multi-function graft polymer may be produced
in the absence of expensive Group II base oil solvent.
The melt reaction product may be used either neat, as a "solid" or dissolved in an
appropriate solvent. In an embodiment, the grafted polymer product is dissolved in an
appropriate solvent of base stock in order to facilitate handling of the graft polymer and to
facilitate lubricant blending using the graft product.
Lubricating Oil Compositions
The lubricating oil compositions of embodiments of the present invention may comprise
the following ingredients in the stated proportions:
A. from about 60% to about 99% by weight, alternatively from about 65% to about 99% by
weight, alternatively from about 70% to about 99% by weight, of one or more base oils
(including base oil carried over from the making of the grafted polymer);
B. from about 0.02% solids to about 10% solids by weight, alternatively from about 0.05% solids
to about 10% solids by weight, alternatively from about 0.05% solids to about 5% solids by
weight, alternatively from about 0.15% solids to about 2.5% solids by weight, alternatively from
about 0.15% solids to about 2% solids by weight, alternatively from 0.25% solids to about 2%
solids by weight, alternatively from 0.3% solids by weight to 1.5% solids by weight,
alternatively from 0.3% solids by weight to 1.0% solids by weight, alternatively from 0.4%
solids by weight to 0.7% solids by weight, alternatively from 0.4% solids by weight to 0.6%
solids by weight of one or more of the grafted polymers made according to this specification
(i.e., not including base oil carried over from the making of the grafted polymer);
C. from 0.0% solids to 2.0% solids by weight, alternatively from about 0.0% solids to about
1.0% solids by weight, alternatively from about 0.05% solids to about 0.7% solids by weight,
alternatively from about 0.1% solids to about 0.7% solids by weight, of conventional viscosity
index improvers;
D. from 0.0% to about 15% by weight, alternatively from about 0.2% to about 10% by weight,
alternatively from about 0.5% to about 8% by weight, or alternatively from about 0.7% to about
6%, of one or more conventional dispersants;
E. from 0.0% to about 10% by weight, alternatively from about 0.3% to 10% by weight,
alternatively from about 0.3% to 8% by weight, alternatively from about 0.5% to about 6% by
weight, alternatively from about 0.5 to about 4% by weight, of one or more detergents;
F. from 0.0% to about 5% by weight, alternatively from about 0.00% to 5% by weight,
alternatively from about 0.01% to 5% by weight, alternatively from about 0.04% to about 3% by
weight, alternatively from about 0.06% to about 2% by weight, of one or more anti-wear agents;
G. from 0.00% to 5% by weight, alternatively from about 0.01% to 5% by weight, alternatively
from about 0.01% to 3% by weight, alternatively from about 0.05% to about 2.5% by weight,
alternatively from about 0.1% to about 2% by weight, of one or more anti-oxidants; and
H. from about 0.0% to 4% by weight, alternatively from about 0.0% to 3% by weight,
alternatively from about 0.005% to about 2% by weight, alternatively from about 0.005% to
about 1.5% by weight, of minor ingredients such as, but not limited to, friction modifiers, pour
point depressants, and anti-foam agents.
The percentages of D through H may be calculated based on the form in which they are
commercially available. The function and properties of each ingredient identified above and
several examples of ingredients are summarized in the following sections of this specification.
Base Oils: Any of the petroleum or synthetic base oils previously identified as process
solvents for the graftable polymers of the present invention can be used as the base oil. Indeed,
any conventional lubricating oil, or combinations thereof, may also be used.
Multiple Function Grafted Polymers: The multiple function grafted polymers can be
used in place of part, or all, of the viscosity index improving polymers conventionally used in
such formulations. They can also be used in place of part or all of the agents used to control soot,
sludge and varnish that are conventionally used in such formulations, as they possess soot
handling and dispersancy properties.
Conventional Viscosity Index Improvers: The conventional viscosity index improvers
can be used in the formulations. These are conventionally long-chain polyolefins. Several
examples of polymers contemplated for use herein include those suggested by U.S. Pat. No.
4,092,255, the disclosure of which is incorporated herein by reference in its entirety, at column 1,
lines 29-32: polyisobutenes, polymethacrylates, polyalkylstyrenes, partially hydrogenated
copolymers of butadiene and styrene, amorphous polyolefins of ethylene and propylene,
ethylene-propylene diene polymers, polyisoprene, and styrene-isoprene.
Conventional Dispersants: Dispersants help suspend insoluble engine oil oxidation
products, thus preventing sludge flocculation and precipitation or deposition of particulates on
metal parts. Suitable dispersants include alkyl succinimides such as the reaction products of oilsoluble
polyisobutylene succinic anhydride with ethylene amines such as tetraethylene
pentamine and borated salts thereof. Such conventional dispersants are contemplated for use
herein. Several examples of dispersants include those listed in U.S. Pat. No. 4,092,255 at column
1, lines 38-41: succinimides or succinic esters, alkylated with a polyolefin of isobutene or
propylene, on the carbon in the alpha position of the succinimide carbonyl. These additives are
useful for maintaining the cleanliness of an engine or other machinery.
Detergents: Detergents to maintain engine cleanliness can be used in the present
lubricating oil compositions. These materials include the metal salts of sulfonic acids, alkyl
phenols, sulfurized alkyl phenols, alkyl salicylates, naphthenates, and other soluble mono- and
dicarboxylic acids. Basic (vis, overbased) metal salts, such as basic alkaline earth metal
sulfonates (especially calcium and magnesium salts) are frequently used as detergents. Such
detergents are particularly useful for keeping the insoluble particulate materials in an engine or
other machinery in suspension. Other examples of detergents contemplated for use herein
include those recited in U.S. Pat. No. 4,092,255, at column 1, lines 35-36: sulfonates, phenates,
or organic phosphates of polyvalent metals.
Anti-Wear Agents: Anti-wear agents, as their name implies, reduce wear of metal parts.
Zinc dialkyldithiophosphates and zinc diaryldithiophosphates and organo molybdenum
compounds such as molybdenum dialkyldithiocarbamates are representative of conventional
anti-wear agents.
Anti-Oxidants: Oxidation inhibitors, or anti-oxidants, reduce the tendency of lubricating
oils to deteriorate in service. This deterioration can be evidenced by increased oil viscosity and
by the products of oxidation such as sludge and varnish-like deposits on the metal surfaces. Such
oxidation inhibitors include alkaline earth metal salts of alkylphenolthioesters having preferably
C5 to C12 alkyl side chains, e.g., calcium nonylphenol sulfide, dioctylphenylamine, phenyl-alphanaphthylamine,
phospho sulfurized or sulfurized hydrocarbons, and organo molybdenum
compounds such as molybdenum dialkyldithiocarbamates. Use of conventional antioxidants may
be reduced or eliminated by the use of the multiple function grafted polymer of the present
invention.
Minor Ingredients: Many minor ingredients which do not prevent the use of the present
compositions as lubricating oils are contemplated herein. A non-exhaustive list of other such
additives includes pour point depressants, rust inhibitors, as well as extreme pressure additives,
friction modifiers, seal swell agents, antifoam additives, and dyes.
Example 1
In a first step, a polymer polyolefin polymer backbone comprising acyl groups is
prepared. To a twin screw intermeshing extruder is added EniChem CO-043 ethylene/propylene
copolymer at a rate of 1300 lbs/hr. After addition of the polymer to the extruder, processing
begins by the conversion of the solid polymer to a melt. Once a melt is achieved, maleic
anhydride (MAH) is injected to the extruder as a liquid at a rate of 18.2 lbs/hr. Once the MAH
has been fully incorporated into the melt, a peroxide DHBP is injected to the extruder at a rate of
1.80 lbs/hr. Note that the peroxide has been diluted in mineral oil at a ratio of 5:1. The dilution
of the peroxide is necessary to aid in the mixing and distribution of the initiator.
The reaction mixture is further processed in the extruder to complete the reaction. The
reaction is terminated by vacuum stripping of unreacted MAH, DHBP, and peroxide byproducts.
The product is finished by underwater pellitization and then air dried and packaged. The
resulting product is ethylene/propylene copolymer having grafted acyl groups. The grafted
polymer contains about 1.40 wt maleic anhydride.
Example 2
In a second step, the grafted polymer of Example 1 was reacted with two different
amines, in sequence, to provide functional groups associated with both soot handling and sludge
and varnish control. A 1000 ml glass reactor vessel with an electric heating mantle,
thermometer, stirrer, and a gas inlet was charged with 500 grams of a 12.5% maleic anhydride
grafted ethylene-propylene polymer solution. The solution was prepared by dissolving 62.5
grams of the grafted polymer of Example 1 in 437.5 grams of FHR-150 base stock. The gas inlet
permits the gas to be fed either below or above the solution surface. The solution was heated to
170° C and maintained at this temperature throughout the process. During heating, the polymer
solution was purged with an inert gas (C0 2) fed below the surface of the solution. Once the
solution was maintained at 170° C, the C0 2 was fed above the polymer solution; this blanket gas
flow was maintained throughout the rest of the preparation of grafted polymer.
A solution of 20% 4-aminodiphenylamine (ADPA), obtained from Flexsys America,
(#921141), and 80% triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. 4.10 grams of the ADPA solution was weighed out and added to the heated graft
polymer solution in a single shot. The reactants were allowed to react for about one hour. After
the ADPA reaction was complete, a sample of l-(3-aminopropyl)-imidazole obtained from
Sigma Aldrich (#272264) was weighed out to comprise .735g grams of l-(3-aminopropyl)-
imidazole, and added in a single shot to the heated solution. The solution was allowed to react
for about one hour to complete the reaction.
The reaction product contained approximately 9.4 moles of imidazole and 7.13 moles of
ADPA per mole of polymer, and obtained a full conversion of maleic anhydride based on FT-IR
spectra. The reaction product is further described in Table 1.
TABLE 1
Example 3
The grafted polymer of Example 1 was reacted with two different amines, in sequence, to
provide functional groups associated with both soot handling and sludge and varnish control.
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted ethylene-propylene
polymer solution. The solution was prepared by dissolving 62.5 grams of the grafted polymer of
Example 1 in 437.5 grams of FHR-150 base stock. The gas inlet permits the gas to be fed either
below or above the solution surface. The solution was heated to 170° C and maintained at this
temperature throughout the process. During heating, the polymer solution was purged with an
inert gas (C0 2) fed below the surface of the solution. Once the solution was maintained at 170°
C, the C0 2 was fed above the polymer solution; this blanket gas flow was maintained throughout
the rest of the preparation of grafted polymer.
A solution of 20% 4-aminodiphenylamine (ADPA), obtained from Flexsys America,
(#921141), and 80% triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. 4.70 grams of the ADPA solution was weighed out and added to the heated graft
polymer solution in a single shot. The reactants were allowed to react for about one hour.
After the ADPA reaction was complete, a sample of l-(3-aminopropyl)-imidazole obtained from
Sigma Aldrich (#272264) was weighed out to comprise .735g grams of l-(3-aminopropyl)-
imidazole, and added in a single shot to the heated solution. The solution was allowed to react
for about one hour to complete the reaction.
Comparative Example 3
As in Example 3, the grafted polymer of Example 1 was reacted with two different
amines, in sequence, to provide functional groups associated with both soot handling and sludge
and varnish control. This time, however, the sequence of the reaction was reversed.
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted ethylene-propylene
polymer solution. The solution was prepared by dissolving 62.5 grams of the grafted polymer of
Example 1 in 437.5 grams of FHR-150 base stock. The gas inlet permits the gas to be fed either
below or above the solution surface. The solution was heated to 170° C and maintained at this
temperature throughout the process. During heating, the polymer solution was purged with an
inert gas (CO 2) fed below the surface of the solution. Once the solution was maintained at 170°
C, the C0 2 was fed above the polymer solution; this blanket gas flow was maintained throughout
the rest of the preparation of grafted polymer.
A sample of l-(3-aminopropyl)-imidazole obtained from Sigma Aldrich (#272264) was
weighed out to comprise .735g grams of l-(3-aminopropyl)-imidazole, and added in a single shot
to the heated graft polymer solution. The solution was allowed to react for about one hour.
After the API reaction was complete, a solution of 20% 4-aminodiphenylamine (ADPA),
obtained from Flexsys America, (#921141), and 80% triethylene glycol di-2-ethylhexoate,
obtained from Hatco, #5238, was prepared. 4.70 grams of the ADPA solution was weighed out
and added to the heated solution in a single shot. The solution was allowed to react for about one
hour to complete the reaction.
The reaction products of Example 3 and Comparative Example 3 were examined by FTIR
and Nitrogen Testing to determine the concentration of each functional group on each of the
reaction products. The results are displayed in Table 2.
TABLE 2
Example 4
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted ethylene-propylene
polymer solution. The solution was prepared by dissolving 62.5 grams of Lz7065C,
(manufactured by the Lubrizol Corp., Cleveland, OH) grafted with 1.4% maleic anhydride in
437.5 grams of FHR-150 base stock. The gas inlet permits the gas to be fed either below or
above the solution surface. The solution was heated to 170° C and maintained at this temperature
throughout the process. During heating, the polymer solution was purged with an inert gas (C02)
fed below the surface of the solution. Once the solution was maintained at 170° C, the C02 was
fed above the polymer solution; this blanket gas flow was maintained throughout the rest of the
preparation of grafted polymer.
A solution of 20% 4-Aminodiphenylamine (ADPA), obtained from Flexsys America,
#921141, and 80% Triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. This calculated out to 4.10 grams of the ADPA solution. The solution was allowed to
react for 1 hour after addition of ADPA. After the ADPA reaction was complete, A sample of 1-
(3-aminopropyl)-imidazole obtained from Sigma Aldrich #272264 was weighed out .735g grams
of l-(3-aminopropyl)-imidazole, which was added in one shot to the heated solution. The
solution was allowed to react for 1 hour to complete the reaction.
The resultant product contained approximately 9.4 moles of imidazole and 7.13 moles of
ADPA per mole of polymer, and subsequently obtained full conversion of maleic anhydride with
ADPA based on FT-IR spectra.
Example 5
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted styrene-butadiene
polymer solution. The solution was prepared by dissolving 62.5 grams of Lz7408, (manufactured
by the Lubrizol Corp., Cleveland, OH) grafted with 1.4% maleic anhydride in 437.5 grams of
FHR-150 base stock. The gas inlet permits the gas to be fed either below or above the solution
surface. The solution was heated to 170° C and maintained at this temperature throughout the
process. During heating, the polymer solution was purged with an inert gas (C02) fed below the
surface of the solution. Once the solution was maintained at 170° C, the C02 was fed above the
polymer solution; this blanket gas flow was maintained throughout the rest of the preparation of
grafted polymer.
A solution of 20% 4-Aminodiphenylamine (ADPA), obtained from Flexsys America,
#921141, and 80% Triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. This calculated out to 4.10 grams of the ADPA solution. The solution was allowed to
react for 1 hour after addition of ADPA. After the ADPA reaction was complete, A sample of 1-
(3-aminopropyl)-imidazole obtained from Sigma Aldrich #272264 was weighed out .735g grams
of l-(3-aminopropyl)-imidazole, which was added in one shot to the heated solution. The
solution was allowed to react for 1 hour to complete the reaction.
The resultant product contained approximately 9.4 moles of imidazole and 7.13 moles of
ADPA per mole of polymer, and subsequently obtained full conversion of maleic anhydride with
ADPA based on FT-IR spectra.
Example 6
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted styrene-isoprene
polymer solution. The solution was prepared by dissolving 62.5 grams of Lz7308, (manufactured
by the Lubrizol Corp., Cleveland, OH) grafted with 1.4% maleic anhydride in 437.5 grams of
FHR-150 base stock. The gas inlet permits the gas to be fed either below or above the solution
surface. The solution was heated to 170° C and maintained at this temperature throughout the
process. During heating, the polymer solution was purged with an inert gas (C02) fed below the
surface of the solution. Once the solution was maintained at 170° C, the C02 was fed above the
polymer solution; this blanket gas flow was maintained throughout the rest of the preparation of
grafted polymer.
A solution of 20% 4-Aminodiphenylamine (ADPA), obtained from Flexsys America,
#921141, and 80% Triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. This calculated out to 4.10 grams of the ADPA solution. The solution was allowed to
react for 1 hour after addition of ADPA. After the ADPA reaction was complete, A sample of 1-
(3-aminopropyl)-imidazole obtained from Sigma Aldrich #272264 was weighed out .735g grams
of l-(3-aminopropyl)-imidazole, which was added in one shot to the heated solution. The
solution was allowed to react for 1 hour to complete the reaction.
The resultant product contained approximately 9.4 moles of imidazole and 7.13 moles of
ADPA per mole of polymer, and subsequently obtained full conversion of maleic anhydride with
ADPA based on FT-IR spectra.
Example 7
A 1000 ml glass reactor vessel with an electric heating mantle, thermometer, stirrer, and a
gas inlet was charged with 500 grams of a 12.5% maleic anhydride grafted polyalkylmethacrylate
polymer solution. The solution was prepared by dissolving 62.5 grams of Viscoplex
3-700, (manufactured by the Evonik, Corp. Horsham, PA) grafted with 1.4% maleic anhydride in
437.5 grams of FHR-150 base stock. The gas inlet permits the gas to be fed either below or
above the solution surface. The solution was heated to 170° C and maintained at this temperature
throughout the process. During heating, the polymer solution was purged with an inert gas (C02)
fed below the surface of the solution. Once the solution was maintained at 170° C, the C02 was
fed above the polymer solution; this blanket gas flow was maintained throughout the rest of the
preparation of grafted polymer.
A solution of 20% 4-Aminodiphenylamine (ADPA), obtained from Flexsys America,
#921141, and 80% Triethylene glycol di-2-ethylhexoate, obtained from Hatco, #5238, was
prepared. This calculated out to 4.10 grams of the ADPA solution. The solution was allowed to
react for 1 hour after addition of ADPA. After the ADPA reaction was complete, A sample of 1-
(3-aminopropyl)-imidazole obtained from Sigma Aldrich #272264 was weighed out .735g grams
of l-(3-aminopropyl)-imidazole, which was added in one shot to the heated solution. The
solution was allowed to react for 1 hour to complete the reaction.
The resultant product contained approximately 9.4 moles of imidazole and 7.13 moles of
ADPA per mole of polymer, and subsequently obtained full conversion of maleic anhydride with
ADPA based on FT-IR spectra.
Examples 8 to 115
The procedure of Examples 4 to 7 was carried out using a number of different polymers,
acylating agents, amines suitable for imparting soot handling performance, and amines suitable
for imparting sludge and varnish control.
As noted, polymers contemplated for use include
Al. Paratone 8910
A2. Paratone 8941
A3. Infineum SV200,
A4. Infineum SV250,
A5. Infineum SV145,
A6. Infineum SV160,
A7. Infineum SV300
A8. Infineum SV150,
A9. DUTRAL CO-029,
A10. DUTRAL CO-034,
All. DUTRAL CO-043,
A12. DUTRAL CO-058,
A13. DUTRAL TER 4028,
A14. DUTRAL TER 4044,
A15. DUTRAL TER 4049
A16. DUTRAL TER 9046.
A17. ROYALENE 400,
A18. ROYALENE 501,
A19. ROYALENE 505,
A20. ROYALENE 512,
A21. ROYALENE 525,
A22. ROYALENE 535,
A23. ROYALENE 556,
A24. ROYALENE 563,
A25. ROYALENE 580 HT
A26. Lubrizol®7408
A27. Viscoplex 3-700
A28. Viscoplex 2-602
As noted, suitable acylating agents include
Bl. acrylic acid,
B2. crotonic acid,
B3. methacrylic acid,
B4. maleic acid,
B5. maleic anhydride,
B6. fumaric acid,
B7. itaconic acid,
B8. itaconic anhydride,
B9. citraconic acid,
BIO. citraconic anhydride,
Bll. mesaconic acid,
B12. glutaconic acid,
B13. chloromaleic acid,
B14. aconitic acid,
B15. methylcrotonic acid,
B16. sorbic acid,
B17. 3-hexenoic acid,
B18. 10-decenoic acid,
B19. 2-pentene-l,3,5-tricarboxylic acid,
B20. cinnamic acid
B21. methyl maleate,
B22. ethyl fumarate,
B23. methyl fumarate
As noted, amines suitable for imparting soot handling performance include
CI. aniline;
C2.N,N-dimethyl-p-phenylenediamine;
C3. 1-naphthylamine;
C4. N-phenyl-p-phenylenediamine
C5.m-anisidine;
C6. 3-amino-4-methylpyridine;
C7.4-nitroaniline
As noted, amines suitable for imparting sludge and varnish control performance include
D1. 2,2-dimethyl- 1,3-dioxolane-4-methanamine;
D2. N-(3-aminopropyl) imidazole;
D3. N-(3-aminopropyl)-2-pyrrolidinone;
D4. 2-picolylamine
Example No. Polymer Acylating agent First amine Second amine
34 All B4 C6 D3
35 All B4 C6 D4
36 All B5 C6 Dl
37 All B5 C2 D2
38 All B5 C6 D3
39 All B5 C6 D4
40 All B6 C6 Dl
4 1 All B6 C6 D2
42 All B6 C6 D3
43 All B6 C6 D4
44 A26 B4 CI Dl
45 A26 B4 CI D2
46 A26 B4 CI D3
47 A26 B4 CI D4
48 A26 B5 CI Dl
49 A26 B5 CI D2
50 A26 B5 CI D3
5 1 A26 B5 CI D4
52 A26 B6 CI Dl
53 A26 B6 CI D2
54 A26 B6 CI D3
55 A26 B6 CI D4
56 A26 B4 C2 Dl
57 A26 B4 C2 D2
58 A26 B4 C2 D3
59 A26 B4 C2 D4
60 A26 B5 C2 Dl
6 1 A26 B5 C2 D2
62 A26 B5 C2 D3
Example No. Polymer Acylating agent First amine Second amine
63 A26 B5 C2 D4
64 A26 B6 C2 Dl
65 A26 B6 C2 D2
66 A26 B6 C2 D3
67 A26 B6 C2 D4
68 A26 B4 C6 Dl
69 A26 B4 C6 D2
70 A26 B4 C6 D3
7 1 A26 B4 C6 D4
72 A26 B5 C6 Dl
73 A26 B5 C2 D2
74 A26 B5 C6 D3
75 A26 B5 C6 D4
76 A26 B6 C6 Dl
77 A26 B6 C6 D2
78 A26 B6 C6 D3
79 A26 B6 C6 D4
80 A27 B4 CI Dl
8 1 A27 B4 CI D2
82 A27 B4 CI D3
83 A27 B4 CI D4
84 A27 B5 CI Dl
85 A27 B5 CI D2
86 A27 B5 CI D3
87 A27 B5 CI D4
88 A27 B6 CI Dl
89 A27 B6 CI D2
90 A27 B6 CI D3
9 1 A27 B6 CI D4
Example No. Polymer Acylating agent First amine Second amine
92 A27 B4 C2 Dl
93 A27 B4 C2 D2
94 A27 B4 C2 D3
95 A27 B4 C2 D4
96 A27 B5 C2 Dl
97 A27 B5 C2 D2
98 A27 B5 C2 D3
99 A27 B5 C2 D4
100 A27 B6 C2 Dl
101 A27 B6 C2 D2
102 A27 B6 C2 D3
103 A27 B6 C2 D4
104 A27 B4 C6 Dl
105 A27 B4 C6 D2
106 A27 B4 C6 D3
107 A27 B4 C6 D4
108 A27 B5 C6 Dl
109 A27 B5 C2 D2
110 A27 B5 C6 D3
111 A27 B5 C6 D4
112 A27 B6 C6 Dl
113 A27 B6 C6 D2
114 A27 B6 C6 D3
115 A27 B6 C6 D4
ADT Testing
The ADT test is used to determine the capacity of a graft polymer to disperse sludge in a
typical mineral oil.
In summary, the ADT test is carried out as follows: A sample of the graft polymer is
dissolved in Exxon 130N base oil to give a solution containing 0.25% weight of graft polymer
solids. Separately, 10 ml of Exxon 130N base oil is put into each of a series of six test tubes in a
test tube rack. 10 ml of the graft polymer solution is then added to the base oil in the first test
tube in the series. The base oil and graft polymer solution in the first test tube are mixed until
homogeneous, giving a solution which contains one half of the concentration of graft polymer
contained in the original solution. From this first tube, 10 ml are decanted and poured into the
second tube. The contents of the second tube are further diluted by a factor of 2. This process of
sequential dilution is continued through the series of tubes, successively producing solutions
with 1/4, 1/8, 1/16, and 1/32 of the concentration of graft polymer contained in the first tube.
A standardized quantity of sludge solution, simulating the sludge in the crankcase of an
internal combustion engine, is introduced and mixed well in each of the above prepared
solutions. The tubes are allowed to stand at room temperature for 24 hours (or, in some cases, for
a shorter or longer period, as indicated in the test results). The tubes of each set are examined in
front of a light source to determine which tube is the first in the series to exhibit sediment
(fallout), this being associated with sludge which is not successfully dispersed. The ADT result is
graded as follows:
Number of Tubes with no First fallout in tube
sediment number ADT Result
0 1 FAIL
1 2 1
2 3 2
3 4 4
4 5 8
5 6 16
6 -- 32
The ADT result is reported to the nearest power of two because the concentration of the grafted
dispersant polyolefin solution is halved in each successive tube.
The Rapid ADT test is an accelerated version of the ADT test method described above.
The test is carried out as described for the 24-hour test, except that the test tubes are initially kept
in an oven for 90 minutes at 60° C. The tubes are graded in the same manner as before to
determine the rapid ADT value of the graft polymer solution. After this accelerated test, the
tubes can be maintained for an additional 24 and 48 hours at room temperature to record longerterm
results.
A dispersant viscosity index improver having a higher ADT value would be able to
disperse the insoluble material in a lubricating oil composition when less of the dispersant is
used in the oil. Thus, a dispersant viscosity index improver having a higher ADT value would be
a better dispersant than one having a lower ADT value.
Since the ADT Test evaluates the capacity of a graft polymer to disperse sludge, the
compositional variable of primary importance is the concentration of the "sludge control"
functional group, the reaction product between the aliphatic amine and the acylated polymer.
The amount, or concentration, of the "sludge control" functional group is effective to provide a
multiple function dispersant viscosity index improver that has a high ADT response.
The multiple function dispersant viscosity index improvers of embodiments of the
present invention preferably have a Rapid ADT response of at least about 2. The multiple
function dispersant viscosity index improvers of embodiments of the present invention more
preferably have a Rapid ADT response of at least about 4. The multiple function dispersant
viscosity index improvers of embodiments of the present invention more preferably have a Rapid
ADT response of at least about 8. The multiple function dispersant viscosity index improvers of
embodiments of the present invention more preferably have a Rapid ADT response of at least
about 16. The multiple function dispersant viscosity index improvers of embodiments of the
present invention more preferably have a Rapid ADT response of at least about 32.
The multiple function dispersant viscosity index improvers of embodiments of the
present invention may have a Rapid ADT response between about 2 and 32. Alternatively, the
multiple function dispersant viscosity index improvers of embodiments of the present invention
have a Rapid ADT response between about 4 and 32. Alternatively, the multiple function
dispersant viscosity index improvers of embodiments of the present invention have a Rapid ADT
response between about 8 and 32. Alternatively, the multiple function dispersant viscosity index
improvers of embodiments of the present invention have a Rapid ADT response between about
16 and 32.
Sequence VG Engine Test
To confirm that the dual-monomer graft polymer of the present invention is capable of
controlling sludge and varnish, blended oils are being tested using the Sequence VG Engine Test.
This engine test is designed to evaluate how well an engine oil inhibits sludge and varnish
formation. The test is carried out using a Ford 4.6 liter, spark ignition, four stroke, eight-cylinder
V-configuration engine. The test is carried out for a total of 216 hours. The test procedure calls
for oil leveling and sampling every 24 hours. At the end of the test, the engine parts are rated,
with respect to engine cleanliness, in terms of sludge and varnish. The performance targets for
the various test parameters evaluated in the Sequence VG Engine Test, listed in Table 2,
represent either maximum or minimum values.
Since the Sequence VG Engine Test evaluates the capacity of a lubricating oil additive to
control sludge and varnish, the compositional variable of primary importance is the
concentration of the "sludge and varnish control" functional group, i.e. the reaction product
between the aliphatic amine and the acylated polymer. The aliphatic amine, and hence the
"sludge and varnish control" functional group, is selected so as to be effective to provide a
multiple function dispersant viscosity index improver that, when present in reasonable amounts
in a base oil, produces a passing result in a Sequence VG Engine Test.
Further, the amount of the "sludge and varnish control" functional group that is grafted to
the polymer backbone, i.e. the concentration of the "sludge and varnish control" functional
group, is effective to provide a multiple function dispersant viscosity index improver that, when
present in reasonable amounts in base oil, produces a passing result in a Sequence VG Engine
Test.
For example, the multiple function dispersant viscosity index improver, when present in
base oil in an amount of about 0.05% solids by weight or below, produces a passing result in a
Sequence VG Engine Test. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.10% solids by weight or below,
produces a passing result in a Sequence VG Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.15% solids
by weight or below, produces a passing result in a Sequence VG Engine Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.20% solids by weight or below, produces a passing result in a Sequence VG Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.25% solids by weight or below, produces a passing result in a Sequence
VG Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.30% solids by weight or below, produces a passing
result in a Sequence VG Engine Test. Alternatively, the multiple function dispersant viscosity
index improver, when present in base oil in an amount of about 0.35% solids by weight or below,
produces a passing result in a Sequence VG Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.40% solids
by weight or below, produces a passing result in a Sequence VG Engine Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.45% solids by weight or below, produces a passing result in a Sequence VG Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.50% solids by weight or below, produces a passing result in a Sequence
VG Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.55% solids by weight or below, produces a passing
result in a Sequence VG Engine Test. Alternatively, the multiple function dispersant viscosity
index improver, when present in base oil in an amount of about 0.60% solids by weight or below,
produces a passing result in a Sequence VG Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.65% solids
by weight or below, produces a passing result in a Sequence VG Engine Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.70% solids by weight or below, produces a passing result in a Sequence VG Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.80% solids by weight or below, produces a passing result in a Sequence
VG Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.90% solids by weight or below, produces a passing
result in a Sequence VG Engine Test. Alternatively, the multiple function dispersant viscosity
index improver, when present in base oil in an amount of about 1.0% solids by weight or below,
produces a passing result in a Sequence VG Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 1.5% solids
by weight or below, produces a passing result in a Sequence VG Engine Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 2.0% solids by weight or below, produces a passing result in a Sequence VG Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 2.5% solids by weight or below, produces a passing result in a Sequence
VG Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 3.0% solids by weight or below, produces a passing
result in a Sequence VG Engine Test. Preferably, the multiple function dispersant viscosity
index improver, when present in base oil in an amount between 0.4 and 0.7% solids by weight,
produces a passing result in a Sequence VG Engine Test.
In some embodiments, it might be that a multiple function dispersant viscosity index
improver, when used in a particular amount in base oil, does not pass the entirety of the
Sequence VG Engine Test, but nevertheless demonstrates either strong sludge control properties
or strong varnish control properties.
For example, the multiple function dispersant viscosity index improver, when present in
base oil in an amount of about 0.05% solids by weight or below, produces an Average Engine
Sludge, as measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
0.10% solids by weight or below, produces an Average Engine Sludge, as measured via a
Sequence VG Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity
index improver, when present in base oil in an amount of about 0.15% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.20% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.25% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.30% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.35% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.40% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.45% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.50% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.55% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.60% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.65% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.70% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.80% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.90% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 1.0% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 1.5% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 2.0% solids by weight or below, produces an Average Engine Sludge, as
measured via a Sequence VG Engine Test, of at least 8. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 2.5% solids
by weight or below, produces an Average Engine Sludge, as measured via a Sequence VG
Engine Test, of at least 8. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 3.0% solids by weight or below,
produces an Average Engine Sludge, as measured via a Sequence VG Engine Test, of at least 8.
In an embodiment, the multiple function dispersant viscosity index improver, when present in
base oil in an amount between 0.4 and 0.7% solids by weight, produces an Average Engine
Sludge, as measured via a Sequence VG Engine Test, of at least 8.
For example, the multiple function dispersant viscosity index improver, when present in
base oil in an amount of about 0.05% solids by weight or below, produces an Average Engine
Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
0.10% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.15% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.20% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.25% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.30% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.35% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.40% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.45% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.50% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.55% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.60% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.65% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.70% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.80% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.90% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 1.0% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 1.5% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 2.0% solids by weight or below, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 2.5% solids by weight or below, produces an Average Engine Varnish, as measured via a
Sequence VG Engine Test, of at least 8.9. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 3.0% solids by weight
or below, produces an Average Engine Varnish, as measured via a Sequence VG Engine Test, of
at least 8.9. In one embodiment, the multiple function dispersant viscosity index improver, when
present in base oil in an amount between 0.4 and 0.7% solids by weight, produces an Average
Engine Varnish, as measured via a Sequence VG Engine Test, of at least 8.9.
To confirm that the multiple function dispersant viscosity index improver is capable of
controlling sludge and varnish, two engine oils were blended and tested using the Sequence VG
Engine Test, a test, as noted, designed to evaluate an oil's ability to control sludge and varnish.
The first oil - the baseline oil - contained a conventional dispersant viscosity modifier. The
composition of the baseline oil is shown in Table 3, below. The second oil - the test oil - was
blended so as to contain the multiple function dispersant viscosity index improver prepared in
Example 2. The multiple function dispersant viscosity index improver is present in the second
oil blend in an amount of about 0.5 % solids by weight. The composition of the test oil is shown
in Table 4, below.
TABLE 3
TABLE 4
Total: 100.000%
The results of the Sequence VG Engine Test are shown in Table 5. The performance targets, i.e.
passing limits, for the various test parameters evaluated in the Sequence VG Engine Test, listed
in Table 5, represent either maximum or minimum values. Hence, an Average Engine Sludge of
7.25 for the Baseline Oil is a failing result since the minimum requirements for passing the test is
8. The Baseline Oil also failed to meet the minimum requirement for the Rocker Arm Cover
Sludge test parameter. The lubricating oil composition comprising the multiple function
dispersant viscosity index improver prepared in Example 2 met every performance target of the
Sequence VG test, including Average Engine Sludge and Average Engine Varnish.
TABLE 5
Peugeot XUD 11 Screener Engine Test
The capability of the multiple function dispersant viscosity index improver to control soot
and viscosity increase may be demonstrated using the Peugeot XUD1 1 Screener Engine Test.
The Peugeot XUD 11 Screener Engine Test is a test designed to evaluate the influence of
combustion soot on engine oil performance at medium temperatures with emphasis upon soot
induced engine oil viscosity increase.
It is carried out using a Peugeot XUD1 1 BTE 2.1 liter, inline, four-cylinder turbocharged
automotive diesel engine. The engine test is run for approximately 20-25 hours with oil
additions made and oil samples collected approximately every 5 hours. The following parameters
are measured: soot loading (or soot suspended) in the oil at the end of the test, viscosity increase
at 100° C at the end of test, and the extrapolated viscosity increase at 100° C at a soot loading of
3%. Relative improvement in performance is indicated by a relative increase in the percentage
of soot in the oil and by relative decreases in both the end of test viscosity and the viscosity
increase extrapolated to 3% soot.
Since the Peugeot XUD1 1 Screener Engine Test evaluates soot handling and viscosity
control, the compositional variable of primary importance is the concentration of the "soot
handling" functional group, the reaction product between the aromatic amine and the acylated
polymer. The aromatic amine, and hence the "soot handling" functional group, is selected so as
to be effective to provide a multiple function dispersant viscosity index improver that, when
present in reasonable amounts in a base oil, produces a passing result in the Peugeot XUD1 1
Screener Engine Test. The amount of the "soot handling" functional group that is grafted to the
polymer backbone, i.e. the concentration of the "soot handling" functional group, is preferably
effective to provide a multiple function dispersant viscosity index improver that, when present in
reasonable amounts in base oil, produces a passing result in the Peugeot XUD1 1 Screener
Engine Test.
For example, the multiple function dispersant viscosity index improver, when present in
base oil in an amount of about 0.05% solids by weight or below, produces a passing result in a
Peugeot XUD1 1 Screener Engine Test. Alternatively, the multiple function dispersant viscosity
index improver, when present in base oil in an amount of about 0.10% solids by weight or below,
produces a passing result in a Peugeot XUD1 1 Screener Engine Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.15% solids by weight or below, produces a passing result in a Peugeot XUD1 1 Screener
Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.20% solids by weight or below, produces a passing
result in a Peugeot XUD1 1 Screener Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.25% solids
by weight or below, produces a passing result in a Peugeot XUD1 1 Screener Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.30% solids by weight or below, produces a passing result in a Peugeot
XUD1 1 Screener Engine Test. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.35% solids by weight or below,
produces a passing result in a Peugeot XUD1 1 Screener Engine Test. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
0.40% solids by weight or below, produces a passing result in a Peugeot XUDl 1 Screener
Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.45% solids by weight or below, produces a passing
result in a Peugeot XUDl 1 Screener Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.50% solids
by weight or below, produces a passing result in a Peugeot XUDl 1 Screener Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.55% solids by weight or below, produces a passing result in a Peugeot
XUDl 1 Screener Engine Test. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.60% solids by weight or below,
produces a passing result in a Peugeot XUDl 1 Screener Engine Test. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
0.65% solids by weight or below, produces a passing result in a Peugeot XUDl 1 Screener
Engine Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.70% solids by weight or below, produces a passing
result in a Peugeot XUDl 1 Screener Engine Test. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.80% solids by weight
or below, produces a passing result in a Peugeot XUDl 1 Screener Engine Test. Alternatively,
the multiple function dispersant viscosity index improver, when present in base oil in an amount
of about 0.90% solids by weight or below, produces a passing result in a Peugeot XUDl 1
Screener Engine Test. Alternatively, the multiple function dispersant viscosity index improver,
when present in base oil in an amount of about 1.0% solids by weight or below, produces a
passing result in a Peugeot XUDl 1 Screener Engine Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 1.5% solids
by weight or below, produces a passing result in a Peugeot XUDl 1 Screener Engine Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 2.0% solids by weight or below, produces a passing result in a Peugeot
XUDl 1 Screener Engine Test. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 2.5% solids by weight or below,
produces a passing result in a Peugeot XUDl 1 Screener Engine Test. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
3.0% solids by weight or below, produces a passing result in a Peugeot XUD1 1 Screener Engine
Test. In one embodiment, the multiple function dispersant viscosity index improver, when
present in base oil in an amount between 0.4 and 0.7% solids by weight, produces a passing
result in a Peugeot XUD1 1 Screener Engine Test.
For example, a multiple function dispersant viscosity index improver of embodiments of
the present invention will produce results that are similar to those achieved by the graft polymercontaining
blend labeled as Blend-2 in Table 1 of published application U.S. 2008/0293600 Al,
incorporated herein by reference.
Peugeot DV4TD Medium Temperature Dispersivity Test
The capability of the multiple function dispersant viscosity index improver to control soot
and viscosity increase may be demonstrated using the Peugeot DV4TD Medium Temperature
Dispersivity Test ("DV4 Test"). The DV4 Test is a procedure for evaluating the effect of
combustion soot on engine oil viscosity increase. The procedure simulates high-speed highway
service in a diesel-powered passenger car using a fixture that comprises an engine dynamometer
procedure stand with a Peugeot DV4 TD/L4 four-cylinder in-line, common rail diesel engine
installed. The engine undergoes a ten hour run-in and is then operated continuously for 120
hours.
The lubricating oil is measured for kinematic viscosity at 100 °C, soot content, and iron
content at 24-hour intervals during the procedure. The final oil drain is used in conjunction with
intermediate samples to interpolate the absolute viscosity at 6% soot. The absolute viscosity
increase of the lubricating oil is then calculated by taking the absolute viscosity increase at 6%
soot and subtracting the viscosity of the fresh oil. This value is then compared against an ACEA
performance requirement value to determine whether the lubricating oil passed the DV4 Test. If
the absolute viscosity increase of the lubricating oil (at 100 °C, 6% soot) is less than or
equivalent to the ACEA performance requirement value, the lubricating oil is deemed to have
passed the DV4 Test. The ACEA performance requirement value for a given DV4 Test is
determined from the test results of two reference oils, one having a very low viscosity increase at
100 °C, 6% soot and one having a very high viscosity increase at 100 °C, 6% soot. Both the
absolute viscosity increase and the ACEA performance requirement are measured in mm /s.
Since the DV4 Test evaluates soot handling and viscosity control, the compositional
variable of primary importance is the concentration of the "soot handling" functional group, the
reaction product between the aromatic amine and the acylated polymer. The aromatic amine,
and hence the "soot handling" functional group, is selected so as to be effective to provide a
multiple function dispersant viscosity index improver that, when present in reasonable amounts
in a base oil, produces a passing result in the DV4 Test. The amount of the "soot handling"
functional group that is grafted to the polymer backbone, i.e. the concentration of the "soot
handling" functional group, is preferably effective to provide a multiple function dispersant
viscosity index improver that, when present in reasonable amounts in base oil, produces a
passing result in the DV4 Test.
For example, the multiple function dispersant viscosity index improver, when present in
base oil in an amount of about 0.05% solids by weight or below, produces a passing result in a
DV4 Test. Alternatively, the multiple function dispersant viscosity index improver, when
present in base oil in an amount of about 0.10% solids by weight or below, produces a passing
result in a DV4 Test. Alternatively, the multiple function dispersant viscosity index improver,
when present in base oil in an amount of about 0.15% solids by weight or below, produces a
passing result in a DV4 Test. Alternatively, the multiple function dispersant viscosity index
improver, when present in base oil in an amount of about 0.20% solids by weight or below,
produces a passing result in a DV4 Test. Alternatively, the multiple function dispersant
viscosity index improver, when present in base oil in an amount of about 0.25% solids by weight
or below, produces a passing result in a DV4 Test. Alternatively, the multiple function
dispersant viscosity index improver, when present in base oil in an amount of about 0.30% solids
by weight or below, produces a passing result in a DV4 Test. Alternatively, the multiple
function dispersant viscosity index improver, when present in base oil in an amount of about
0.35% solids by weight or below, produces a passing result in a DV4 Test. Alternatively, the
multiple function dispersant viscosity index improver, when present in base oil in an amount of
about 0.40% solids by weight or below, produces a passing result in a DV4 Test. Alternatively,
the multiple function dispersant viscosity index improver, when present in base oil in an amount
of about 0.45% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.50% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.55% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.60% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.65% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.70% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.80% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 0.90% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 1.0% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 1.5% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 2.0% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 2.5% solids by weight or below, produces a passing result in a DV4 Test.
Alternatively, the multiple function dispersant viscosity index improver, when present in base oil
in an amount of about 3.0% solids by weight or below, produces a passing result in a DV4 Test.
In one embodiment, the multiple function dispersant viscosity index improver, when present in
base oil in an amount between 0.4 and 0.7% solids by weight, produces a passing result in a DV4
Test.
It can be seen that the described embodiments provide a unique and novel multiple
function dispersant graft polymer that has a number of advantages over those in the art. While
there is shown and described herein certain specific structures embodying the invention, it will
be manifest to those skilled in the art that various modifications and rearrangements of the parts
may be made without departing from the spirit and scope of the underlying inventive concept
and that the same is not limited to the particular forms herein shown and described except insofar
as indicated by the scope of the appended claims. All references mentioned in this description,
including publications, patent applications, and patents, are incorporated by reference in their
entirety. In addition, the materials, methods, and examples described are only illustrative and not intended to be limiting.

What is claimed:
1. A multiple function dispersant graft polymer comprising two different functional groups,
each directly grafted to a polymer backbone having graftable sites, in which:
a first functional group comprises the reaction product of an acylating agent and a first
amine, the first amine comprising an aromatic primary amine; and
a second functional group comprises the reaction product of an acylating agent and a
second amine, the second amine comprising an aliphatic primary amine;
wherein the multiple function dispersant graft polymer has at least about 5 moles of each
of said functional groups per mole of polymer backbone.
2. The multiple function dispersant graft polymer of claim 1, wherein the multiple function
dispersant graft polymer has a Rapid ADT response of at least about 8.
3. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the first functional group and the second functional group are present in a molar ratio
between 1:1.5 and 1.5:1.
4. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the multiple function dispersant graft polymer, when present in a base oil in an amount
of about 0.80% solids by weight or below, produces a passing result in a Sequence VG Engine
Test.
5. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the multiple function dispersant graft polymer, when present in a base oil in an amount
of about 0.80% solids by weight or below, produces a passing result in a Peugeot XUD1 1
Screener Engine Test.
6. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the multiple function dispersant graft polymer, when present in a base oil in an amount
of about 0.80% solids by weight or below, produces a passing result in a DV4 Test.
7. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein said second amine is selected from the group consisting of 2,2-dimethyl-l,3-dioxolane-
4-methanamine; N-(3-aminopropyl)imidazole; N-(3-aminopropyl)-2-pyrrolidinone; 2-
picolylamine, and combinations thereof.
8. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein said first amine is selected from the group consisting of aniline; N,N-dimethyl-pphenylenediamine;
1-naphthylamine; N-phenyl-p-phenylenediamine (also known as 4-
aminodiphenylamine or ADPA); m-anisidine; 3-amino-4-methylpyridine; 4-nitroaniline; and
combinations thereof.
9. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein said acylating agent is selected from the group consisting of maleic acid, fumaric acid,
maleic anhydride, and combinations thereof.
10. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein said polymer backbone having graftable sites is selected from the group consisting of
olefin polymers, olefin copolymers, polyesters, and styrene-butadiene copolymers.
11. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein said multiple function dispersant graft polymer has a Rapid ADT response of at least
about 16.
12. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the first functional group provides the multiple function dispersant graft polymer with a
soot handling performance attribute and the second functional group provides the multiple
function dispersant graft polymer with a sludge and varnish control performance attribute.
13. The multiple function dispersant graft polymer of any one of the preceding claims,
wherein the first amine is 4-aminodiphenylamine and the second amine is N-(3-
aminopropyl)imidazole.
14. A method of making the multiple function dispersant graft polymer of claim 1,
comprising:
(a) reacting a polymer backbone having graftable sites and an acylating agent having
at least one point of olefinic unsaturation to form a graft polymer reaction product having acyl
groups available for reaction;
(b) reacting the reaction product of step (a) with a first amine comprising an aromatic
primary amine to form a graft polymer reaction product having a first functional group and acyl
groups available for reaction; and
(c) reacting the reaction product of step (b) with a second amine comprising an
aliphatic primary amine to form a graft reaction product having a first functional group and a
second functional group.
15. The method of claim 14, wherein the graft reaction product of step (c) comprises the first
functional group and the second functional group in a molar ratio between 1:1.5 and 1.5:1.
16. The method of any one of claims 14 to 15, wherein said second amine is selected from
the group consisting of 2,2-dimethyl-l,3-dioxolane-4-methanamine; N-(3-
aminopropyl)imidazole; N-(3-aminopropyl)-2-pyrrolidinone; 2-picolylamine; and combinations
thereof.
17. The method of any one of claims 14 to 16, wherein said first amine is selected from the
group consisting of aniline; N,N-dimethyl-p-phenylenediamine; 1-naphthylamine; N-phenyl-pphenylenediamine
(also known as 4-aminodiphenylamine or ADPA); m-anisidine; 3-amino-4-
methylpyridine; 4-nitroaniline; and combinations thereof.
18. The method of any one of claims 14 to 17, wherein said acylating agent is selected from
the group consisting of maleic acid, fumaric acid, maleic anhydride, and combinations thereof.
19. The method of any one of claims 14 to 18, wherein said polymer backbone having
graftable sites is selected from the group consisting of olefin polymers, olefin copolymers,
polyesters, and styrene-butadiene copolymers.
20. The method of any one of claims 14 to 19, wherein the first amine is 4-
aminodiphenylamine and the second amine is N-(3-aminopropyl)imidazole.
21. The method of any one of claims 14 to 20, wherein the polymer backbone and the
acylating agent are melt-reacted; the product of step (a) and the first amine are reacted in solvent;
and the product of step (b) and the second amine are reacted in solvent.
22. The method of claim 21, wherein the solvent comprises a base oil having at least about
7% by weight aromatics.
23. The method of claim 22, wherein the solvent comprises a base oil having at least about
10% by weight aromatics.
24. The method of claim 21, wherein the solvent comprises a Group I base oil.
25. The method of any one of claims 14 to 20, wherein the polymer backbone and the
acylating agent are melt-reacted; the product of step (a) and the first amine are melt-reacted; and
the product of step (b) and the second amine are reacted in a solvent.
26. The method of any one of claims 14 to 20, wherein the polymer backbone and the
acylating agent are melt-reacted; the product of step (a) and the first amine are melt-reacted; and
the product of step (b) and the second amine are melt-reacted.
27. The method of any one of claims 14 to 20, wherein the polymer backbone and the
acylating agent are reacted in a solvent; the product of step (a) and the first amine are reacted in a
solvent; and the product of step (b) and the second amine are reacted in a solvent.
28. A method of making a multiple function dispersant graft polymer comprising:
(a) obtaining a graft polymer having acyl groups available for reaction;
(b) reacting the graft polymer of (a) with a first amine comprising an aromatic
primary amine in a solvent comprising a base oil that has an aromatic content of at least 7% by
weight, to form a graft polymer reaction product having a first functional group and acyl groups
available for reaction; and
(c) reacting the reaction product of step (b) with a second amine comprising an
aliphatic primary amine in a solvent comprising a base oil that has an aromatic content of at least
7% by weight, to form a graft reaction product having a first functional group and a second
functional group.
29. The method of claim 28, wherein said second amine is selected from the group consisting
of 2,2-dimethyl-l,3-dioxolane-4-methanamine; N-(3-aminopropyl)imidazole; N-(3-
aminopropyl)-2-pyrrolidinone; 2-picolylamine, and combinations thereof.
30. The method of any one of claims 28 and 29, wherein said first amine is selected from the
group consisting of aniline; N,N-dimethyl-p-phenylenediamine; 1-naphthylamine; N-phenyl-pphenylenediamine
(also known as 4-aminodiphenylamine or ADPA); m-anisidine; 3-amino-4-
methylpyridine; 4-nitroaniline; and combinations thereof.
31. A lubricating oil comprising
a . a lubricating base oil; and
b. between about 0.05 to about 10% by composition weight of the multiple function
dispersant graft polymer of any one of claims 1 to 13.
32. The lubricating oil of claim 3 1 comprising from 0.3 to about 1.0% by composition weight
of the multiple function dispersant graft polymer.