FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
METHOD OF MANUFACTURING AN ARTICLE BY INJECTION MOULDING, USE
OF A COMPATIBILIZER IN A POLYMER RESIN, AND POLYMER RESIN
2. APPLICANT(S)
(a) NAME
(b) NATIONALITY
(c) ADDRESS
IMERYS MINERALS LIMITED
UNITED KINGDOM Company
PAR MOOR CENTRE,
PAR MOOR ROAD,
PAR CORNWALL PL24 2SQ,
UNITED KINGDOM
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL
The following specification describes
invention
COMPLETE (√)
The following specification particularly
describes the invention and the manner in
which it is to be performed
4. DESCRIPTION (Description shall start from next page)
5. CLAIMS (not applicable for provisional specification. Claims should start with
the preamble – “I/We claim” on separate page)
6. DATE AND SIGNATURE ( to be given on the last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification
on the separate page)
Note:
* Repeat boxes in case of more than one entry
* To be signed by the applicant(s)or the authorized registered patent agent
* Name of the applicant should be given in full, family name in the beginning
* Complete address of the applicant should be given stating with postal index no. /
code, state and country
* Strike out the column which is/are not applicable
This form is digitally signed.
TECHNICAL FIELD
The present invention is directed to a method of manufacturing an article by injection
moulding, to use of a compatibilizer in an article, to use of a compatibilizer in a
polymer resin, and to a polymer resin.
BACKGROUND OF THE INVENTION
In recent years, the recycling of polymer waste material has come to the fore.
However, the recycling of polymer waste material has presented challenges which
are not necessarily encountered during the preparation of polymer compositions
derived from virgin polymer.
As the need to recycle polymer waste materials increases, there is a continuing need
for the development of new methods and compositions for the economically viable
processing of polymer waste materials into high quality polymer resins and articles of
manufacture, such as a portable waste or refuse container, for example, a
wheelie bin.
SUMMARY OF THE INVENTION
According to a first aspect, there is provided a method of manufacturing an article by
injection moulding, the method comprising injection moulding an article from a
polymer resin, wherein the polymer resin comprises different types of recycled
polymer and a compatibilizer comprising inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, and wherein the
polymer resin has a MFI @ 2.16 kg/190 oC of equal to or greater than 3.0 g/10 min.
According to a second aspect, there is provided a use of a compatibilizer in an
article, wherein the article is manufactured by injection moulding a polymer resin
comprising the compatibilizer, to eliminate tiger stripes, or to reduce tiger stripes
compared to an article comprising the polymer resin absent the compatibilizer and/or
compared to an article which is manufactured by injection moulding a polymer resin
in which the compatibilizer has been replaced by a polymer-based compatibilizer,
wherein the compatibilizer comprises inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, wherein the
polymer resin comprises different types of recycled polymer and wherein the polymer
resin comprising the compatibilizer has a MFI @ 2.16 kg/190 oC of equal to or
greater than 3.0 g/10 min.
According to a third aspect, there is provided a use of a compatibilizer in a polymer
resin to (i) eliminate the occurrence of tiger stripes in an article manufactured from
the polymer resin by injection moulding, or (ii) reduce the occurrence of tiger stripes
compared to an article manufactured from the polymer resin absent the
compatibilizer and/or compared to an article which is manufactured by injection
moulding a polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer, wherein the compatibilizer comprises inorganic
particulate material and a surface treatment agent on a surface of the inorganic
particulate material, wherein the polymer resin comprises different types of recycled
polymer and wherein the polymer resin comprising the compatibilizer has a MFI @
2.16 kg/190 oC of equal to or greater than 3.0 g/10 min.
According to a fourth aspect, there is provided a use of a compatibilizer in an article,
wherein the article is manufactured by injection moulding a polymer resin comprising
the compatibilizer, to:
(A) provide a balance of toughness and stiffness which is superior compared to (i)
an article which is manufactured by injection moulding the polymer resin
absent the compatibilizer, or (ii) an article which is manufactured by injection
moulding a polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article;
wherein:
the compatibilizer comprises inorganic particulate material and a surface treatment
agent on a surface of the inorganic particulate material, wherein the polymer resin
comprises different types of recycled polymer and wherein the polymer resin
comprising the compatibilizer has a MFI @ 2.16 kg/190 oC of equal to or greater than
3.0 g/10 min.
According to a fifth aspect, there is provided a use of a compatibilizer in a polymer
resin from which an article is manufactured by injection moulding to:
(A) provide a balance of toughness and stiffness which is superior compared to (i) an
article which is manufactured by injection moulding the polymer resin absent the
compatibilizer, or (ii) an article which is manufactured by injection moulding a
polymer resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article;
wherein:
the compatibilizer comprises inorganic particulate material and a surface treatment
agent on a surface of the inorganic particulate material, wherein the polymer resin
comprises different types of recycled polymer and wherein the polymer resin
comprising the compatibilizer has a MFI @ 2.16 kg/190 oC of equal to or greater than
3.0 g/10 min.
According to a sixth aspect, there is provided a polymer resin suitable for use in the
manufacture of an article therefrom by injection moulding, wherein the polymer resin
comprises a mixture of different recycled polymers and from about 5 wt. % to about
20 wt. % compatibilizer comprising inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, based on the total
weight of the polymer resin, wherein the polymer resin has a MFI @ 2.16 kg/190 ºC
of equal to or greater than 3.0 g/10 min, and wherein the polymer resin comprises at
least about 50 wt. % recycled polyethylene, based on the total weight of the polymer
composition, and from about 10 wt. % to about 30 wt. % recycled polypropylene,
based on the total weight of the polymer resin.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a photograph of an article that has been manufactured by injection
moulding a polymer resin comprising a polymer-based compatibilizer.
Figure 2 is a photograph of an article that has been manufactured by injection
moulding a polymer resin according to the present invention.
DESCRIPTION OF THE INVENTION
Manufacturing plastics from mixed polymer feeds, such as recycled polymers, can
be challenging owing to incompatibilities between different polymer times, e.g.,
immiscibility between polyethylene and polypropylene. Efforts to improve
compatibility can be hampered owing to a tension between different mechanical
properties of plastics made from such mixed polymer feeds. More particularly, it can
be challenging to balance properties such as strength and stiffness in the final
product, such as those formed by injection moulding. The present inventors have
surprisingly found that a balance or optimization of mechanical properties such as
strength and stiffness is achievable through use of compatabilizers comprising an
inorganic particulate material and a surface treatment agent on a surface of the
inorganic particulate material.
Polymer resin
The polymer resin of the present invention comprises different types of recycled
polymer and a compatibilizer comprising inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material.
In certain embodiments, the polymer resin comprises polyethylene and
polypropylene, or a mixture of different types of polyethylene (e.g., HDPE, LDPE
and/or LLDPE) and polypropylene, or a mixture of different types of HDPE and
polypropylene.
In certain embodiments, the polymer resin comprises polypropylene in an amount of
no more than about 90 wt.%, for example, no more than about 80 wt.%, or no more
than about 70 wt.%, or no more than about 60 wt.%, or no more than about 50 wt.%,
or no more than about 40 wt.%, or no more than about 35 wt.%, or no more than
about 30 wt.%.
Unless otherwise stated, the amounts of polymer resin components described herein
are based on the total weight of the polymer resin.
In certain embodiments, the polymer resin comprises from 20-40 % by weight
polypropylene, for example, from 20-35 % by weight polypropylene, or from 23-30 %
by weight polypropylene, or 23-28 % by weight polypropylene.
In certain embodiments, all of the polypropylene in the polymer resin is recycled
polypropylene.
In certain embodiments, all or at least a portion of, for example, at least 50 %, or at
least 75 %, or at least about 90 %, or at least 90 %, or at least 95 %, or at least 99
%, or at least 99.9 % of the polypropylene is derived from a mixed recycled
polyolefin stream comprising polypropylene.
In certain embodiments, the polymer resin comprises polyethylene in an amount of
at least about 10 wt.%, for example, at least about 20 wt.%, or at least about 30
wt.%, or at least about 40 wt.%, or at least about 50 wt.%, or at least about 60 wt.%.
In certain embodiments, the polymer resin comprises a major amount of
polyethylene, wherein a major amount is defined as an amount in excess of 50 wt.%.
In certain embodiments, the polymer resin comprises polyethylene in an amount of
no more than about 90 wt.%, for example, no more than about 80 wt.%, or no more
than about 75 wt.%, or no more than about 60 wt.%, or no more than about 50 wt.%,
or no more than about 40 wt.%, or no more than about 30 wt.%. In certain
embodiments, the polymer resin comprises polyethylene in an amount of about 50-
80 wt.%, for example, about 60-75 wt.%.
The polyethylene may comprise at least two different types of polyethylene, for
example, at least two different types of recycled polyethylene, for example, a
recycled HDPE and at least one other type of polyethylene, e.g., HDPE, from
another recycled source.
In certain embodiments, the polymer resin comprises a mixture of different types of
polyethylene, e.g., HDPE, LDPE and/or LLDPE. Generally, HDPE is understood to
be a polyethylene polymer mainly of linear, or unbranched, chains with relatively high
crystallinity and melting point, and a density of about 0.96 g/cm3 or more. Generally,
LDPE (low density polyethylene) is understood to be a highly branched polyethylene
with relatively low crystallinity and melting point, and a density of from about 0.91
g/cm3 to about 0.94 g/cm3. Generally, LLDPE (linear low density polyethylene) is
understood to be a polyethylene with significant numbers of short branches,
commonly made by copolymerization of ethylene with longer-chain olefins. LLDPE
differs structurally from conventional LDPE because of the absence of long chain
branching.
In certain embodiments, the polymer resin comprises two different types of HDPE,
wherein each type of HDPE is present in an amount of from 20 to 40 wt.% based on
the total weight of the polymer resin. In certain embodiments the first type of HDPE
is present in an amount of from 20 to 30 wt.%, and the second type of HDPE is
present in an amount of from 30 to 40 wt.%. In certain embodiments, both types of
HDPE are derived from recycled polymer sources, such as post-consumer polymer
waste.
In certain embodiments, at least 75 % by weight, for example; 90-99 % by weight, of
the polymer in the polymer resin is a mixture of polyethylene and polypropylene, for
example, a mixture of HDPE and polypropylene (based on the total weight of
polymer in the resin composition). In certain embodiments, all of the polymer in the
polymer resin is polyethylene or polypropylene.
In certain embodiments, the HDPE, when present, is a mixture of HDPE from
different sources, for example, from different types of post-consumer polymer waste,
e.g., recycled blow-moulded HDPE and/or recycled injection moulded HDPE.
In certain embodiments, all or at least a portion of (e.g., at least 50 %, or at least 75
%, or at least about 90 %, or at least 90 %, or at least 95 %, or at least 99 %, or at
least 99.9 %) the polymeric component of the polymer resin is derived from polymer
waste, for example, post-consumer polymer waste, post-industrial polymer waste,
and/or post-agricultural waste polymer. In certain embodiments, all or at least a
portion of (e.g., at least 50 %, or at least 75 %, or at least about 90 %, or at least 90
%, or at least 95 %, or at least 99 %, or at least 99.9 %) the polymeric component of
the polymer resin is or is derived from, recycled post-consumer polymer waste.
In certain embodiments, the polyethylene, for example, HDPE, has an MFI @ 2.16
kg/190 oC of equal to or less than about 5.0 g/min, for example, from about 1.0 g/min
to 5.0 g/min, or from about 2.0 g/min to about 5.0 g/min, or from about 3.0 g/min to
about 5.0 g/min. In certain embodiments in which the polymer resin comprises two
more types of polyethylene, for example, two or more types of HDPE, the MFI @
2.16 kg/190 oC of the two or more polyethylenes may vary by no greater than about
3.0 g/min, for example, by no more than about 2.0 g/min, or by no more than about
1.5 g/min.
In certain embodiments, the polypropylene has an MFI @ 2.16 kg/190 oC of equal to
or greater than about 5.0 g/min, for example, from about 5.0 g/10 min to about 10
g/min, or from about 5.0 g/min to about 9.0 g/min, or from about 5.0 g/min to about
8.0 g/min, or from about 5.0 g/min to about 7.5 g/min, or from about 5.5 g/min to
about 7.0 g/min, or from about 6.0 g/min to about 7.0 g/min.
In certain embodiments, the polymer resin comprises no more than about 20 % by
weight of virgin polymer, based on the total weight of the resin composition, for
example, no more than about 10 % by weight of virgin polymer, or no more than
about 5 % by weight of virgin polymer, or no more than about 1 % by weight of virgin
polymer, or no more than about 0.1 % by weight of virgin polymer.
In certain embodiments, the polymer resin is substantially free of virgin polymer, for
example, the polymer resin is free of virgin polymer.
In certain embodiments, all of the polymer in the resin composition is recycled
polymer, e.g., derived from polymer waste such as, for example, post-consumer
waste.
In certain embodiments, the polymer resin (i.e., comprising the compatibilizer and
additional optional components) has a density of greater than about 0.925 g/cm3, for
example, equal to or greater than about 0.95 g/cm3, or equal to or greater than about
0.975 g/cm3, or equal to or greater than about 1.00 g/cm3. In certain embodiments,
the density is no greater than about 1.25 g/cm3, for example, no greater than about
1.10 g/cm3, or no greater than about 1.05 g/cm3. Density may be determined in
accordance with ISO 1183.
For use in certain applications, for example, a wheelie bin application, the polymer
resin must meet specific requirements in terms of, for example, MFI (melt flow
index). One such requirement is that the polymer resin must have a MFI @ 2.16
kg/190 oC of equal to or greater than 3.0 g/10 min.
MFI, as referred to herein, is determined in accordance with ISO 1133.
The polymer resin of the present invention has a MFI @ 2.16 kg/190 oC of equal to
or greater than 3.0 g/10 min. In certain embodiments, the polymer resin has a MFI
@ 2.16 kg/190 oC of equal to or greater than about 3.1 g/10 min, for example, equal
to or greater than about 3.2 g/10 min, or equal to or greater than about 3.3 g/10 min,
or equal to or greater than about 3.4 g/10 min, or equal to or greater than about
3.5 g/10 min.
In certain embodiments, the polymer resin has a MFI @ 5.0 kg/230 oC of equal to or
greater than about 5 g/10 min, for example, equal to or greater than about 6 g/10
min, or equal to or greater than about 6.5 g/10 min, or equal to or greater than about
6.7 g/10 min, or equal to or greater than about 6.9 g/10 min.
In certain embodiments, the polymer resin comprises from 40-95 % by weight
polypropylene, for example, from 60-95 % by weight polypropylene, or from 65-95 %
by weight polypropylene. In certain embodiments, the polymer resin comprises from
40-70 % by weight polypropylene, for example, from 60-70 % by weight
polypropylene, or from 65-70 % by weight polypropylene. In such embodiments, the
polymer resin may comprise a peroxide-containing additive, for example, a peroxidecontaining
additive in the amounts described herein. In such embodiments, the
polymer resin may comprise up to about 30 % by weight polyethylene, for example,
from about 20-30 % by weight polyethylene, or from about 20-25 % by weight
polyethylene. The polyethylene may be HDPE. In such embodiments, all of the
polypropylene and polyethylene may be recycled polypropylene and polyethylene.
In such embodiments, the polypropylene may have an MFI @ 2.16 kg/190 oC of
equal to or greater than 5.0 g/10 min, for example from about 5.0 g/10 min to about
10 g/min, or from about 5.0 g/min to about 8.0 g/min, or form about 6.0 g/min to
about 7.0 g/min. In such embodiments, the polyethylene, for example, HDPE, may
have an MFI @ 2.16 kg/190 oC of equal to or less than about 2.0 g/min, for example,
equal to or less than about 1.0 g/min, or from about 0.1 g/min to about 0.8 g/min, or
from about 0.2 g/min to about 0.7 g/min, or from about 0.4 g/min to about 0.6 g/min.
In certain embodiments, the resin composition further comprises antioxidant, for
example, in an amount of less than about 5 wt.%, for example, less than about 1
wt.%. In certain embodiments, the resin composition further comprises antioxidant,
for example, in an amount of from about 0.1-1 wt.%, or from about 0.1-0.5 wt.%, or
about 0.3 wt.%.
In certain embodiments, the polymer resin comprises a mixture of different recycled
polymers and from about 5 wt. % to about 20 wt. % compatibilizer comprising
inorganic particulate material and a surface treatment agent on a surface of the
inorganic particulate material, based on the total weight of the polymer resin, wherein
the polymer resin has a MFI @ 2.16 kg/190 oC of equal to or greater than 3.0 g/10
min, and wherein the polymer resin comprises at least about 50 wt. % recycled
polyethylene (which may be a mixture of at least two different types of HDPE), based
on the total weight of the polymer composition, and from about 10 wt. % to about 30
wt. % recycled polypropylene, based on the total weight of the polymer composition,
and optionally up to about 10 wt. % impact modifier, and optionally up to about 1.0
wt. % antioxidant. In this embodiment the polymer resin is suitable for use in the
manufacture of an article therefrom by injection moulding. In certain embodiments,
the polymer resin comprises from about 50-70 wt. % polyethylene (which may be a
mixture of at least two different types of HDPE), 20-30 wt. % polypropylene, 5-15 wt.
% compatabilizer, and optionally from about 1-7.5 wt. % impact modifier, and
optionally up to about 0.5 wt. % antioxidant.
The polymer resin, as defined herein, may be prepared by any known suitable
manufacturing method. In certain embodiments, the polymer resin is prepared via
melt mixing the relevant blend of components with an extruder, such as a Coperion
ZSK18 twin-screw extruder (18 mm diameter). The screw speed may be set to 800
rpm and the feed rate at 8.0 kg/hr. In such embodiments, the hot extrudates may
then be immediately quenched in water and pelletized.
Compatibilizer
The polymer resin of the invention comprises a compatibilizer comprising inorganic
particulate material and a surface treatment agent on a surface of the inorganic
particulate material.
The compatibilizer may be present in the polymer resin in an amount ranging from
about 1 % up to about 45 % by weight, based on the total weight of the polymer
resin. For example, from about 2 % to about 40 % by weight, or from about 3 % to
about 35 % by weight, or from about 4 % to about 30 % by weight, or from about 5 %
to about 30 % by weight, or from about 5 % to about 25 % by weight, or from about 5
% to about 20 % by weight, or from about 5 % to about 15 % by weight, or from
about 5 % to about 10 % by weight, or from about 7 % to about 13 %, or from about
8 % to about 12 % by weight, based on the total weight of the polymer resin.
The surface treatment agent (i.e., coupling modifier) may be present in the polymer
resin in an amount of from about 0.01 % by weight to about 4 % by weight, based on
the total weight of the polymer resin, for example, from about 0.02 % by weight to
about 3.5 % by weight, or from about 0.05 % by weight to about 1.4 % by weight, or
from about 0.1 % by weight to about 0.7 % by weight, or from about 0.15 % by
weight to about 0.7 % by weight, or from about 0.3 % by weight to about 0.7 % by
weight, or from about 0.5 % by weight to about 0.7 % by weight, or from about 0.02
% by weight to about 0.5 %, or from about 0.05 % by weight to about 0.5 % by
weight, or from about 0.1 % by weight to about 0.5 % by weight, or from about 0.15
% by weight to about 0.5 % by weight, or from about 0.2 % by weight to about 0.5 %
by weight, or from about 0.3 % by weight to about 0.5 % by weight, based on the
total weight of the polymer resin.
In certain embodiments, the surface treatment agent comprises a first compound
including a terminating propanoic group or ethylenic group with one or two adjacent
carbonyl groups. The surface treatment agent may be coated on the surface of the
inorganic particulate. A purpose of the surface treatment agent (e.g., coating) is to
improve the compatibility of the inorganic particulate material and the polymer matrix
with which it is to be combined, and/or improve the compatibility of two or more
different polymers in a or the polymer resin by cross-linking or grafting the different
polymers. In recycled polymer resins comprising recycled and optionally virgin
polymer, the inorganic particulate material coating may serve to cross-link or graft
the different polymers. Without wishing to be bound by theory, it is believed that
coupling involves a physical (e.g., steric) and/or chemical (e.g., chemical bonding,
such as covalent or van der Waals) interaction between the polymers and the
surface treatment agent.
In one embodiment, the surface treatment agent (i.e., coupling modifier) has a
formula (1):
A-(X-Y-CO)m(O-B-CO)nOH (1)
wherein
A is a moiety containing a terminating ethylenic bond with one or two adjacent
carbonyl groups;
X is O and m is 1 to 4 or X is N and m is 1;
Y is C1-18-alkylene or C2-18-alkenylene;
B is C2-6-alkylene; n is 0 to 5;
provided that when A contains two carbonyl groups adjacent to the ethylenic group,
X is N.
In an embodiment, A-X- is the residue of acrylic acid, optionally wherein (O-B-CO)n is
the residue of δ-valerolactone or ε-caprolactone or a mixture thereof, and optionally
wherein n is zero.
In another embodiment, A-X- is the residue of maleimide, optionally wherein (O-BCO)
n is the residue of δ-valerolactone or ε-caprolactone or a mixture thereof, and
optionally wherein n is zero.
Specific examples of coupling modifiers are β-carboxy ethylacrylate, β-
carboxyhexylmaleimide, 10-carboxydecylmaleimide and 5-carboxy pentyl maleimide.
Exemplary coupling modifiers and methods of preparation are described in US-A-
7732514, the entire contents of which is hereby incorporated by reference.
In another embodiment, the coupling modifier is β-acryloyloxypropanoic acid or an
oligomeric acrylic acid of the formula (2):
CH2=CH-COO[CH2-CH2-COO]nH (2)
wherein n represents a number from 1 to 6.
In an embodiment, n is 1, or 2, or 3, or 4, or 5, or 6.
The oligomeric acrylic acid of formula (2) may be prepared by heating acrylic acid in
the presence of 0.001 to 1% by weight of a polymerization inhibitor, optionally under
elevated pressure and in the presence of an inert solvent, to a temperature in the
range from about 50 ºC to 200 ºC. Exemplary coupling modifiers and their methods
of preparation are described in US-A-4267365, the entire contents of which is hereby
incorporated by reference.
In another embodiment, the coupling modifier is β-acryloyloxypropanoic acid. This
species and its method of manufacture is described in US-A-3888912, the entire
contents of which is hereby incorporated by reference.
The surface treatment agent/coupling modifier is present in the compatibilizer in an
amount effective to achieve the desired result. This will vary between coupling
modifiers and may depend upon the precise composition of the inorganic particulate.
For example, the coupling modifier may be present in an amount equal to or less
than about 5 wt. % based on the total weight of the compatibilizer, for example equal
to or less than about 2 wt. % or, for example equal to or less than about 1.5 wt. %.
In an embodiment, the coupling modifier is present in the compatibilizer in an amount
equal to or less than about 1.2 wt.% based on the total weight of the compatibilizer,
for example equal to or less than about 1.1 wt. %, for example equal to or less than
about 1.0 wt. %, for example, equal to or less than about 0.9 wt. %, for example
equal to or less than about 0.8 wt. %, for example equal to or less than about 0.7 wt.
%, for example, less than or equal to about 0.6 wt. %, for example equal to or less
than about 0.5 wt %, for example equal to or less than about 0.4 wt. %, for example
equal to or less than about 0.3 wt. %, for example equal to or less than about
0.2 wt. % or, for example less than about 0.1 wt. %. Typically, the coupling modifier
is present in the compatibilizer in an amount greater than about 0.05 wt. %. In
further embodiments, the coupling modifier is present in the compatibilizer in an
amount ranging from about 0.1 to 2 wt. % or, for example, from about 0.2 to about
1.8 wt. %, or from about 0.3 to about 1.6 wt. %, or from about 0.4 to about 1.4 wt. %,
or from about 0.5 to about 1.3 wt. %, or from about 0.6 to about 1.2 wt. %, or from
about 0.7 to about 1.2 wt. %, or from about 0.8 to about 1.2 wt. %, or from about 0.8
to about 1.1 wt. %.
In certain embodiments, a compound/compounds including a terminating propanoic
group or ethylenic group with one or two adjacent carbonyl groups is/are the sole
species present in the surface treatment agent.
In certain embodiments, the surface treatment agent additionally comprises a
second compound selected from the group consisting of one or more fatty acids and
one or more salts of fatty acids, and combinations thereof.
In one embodiment, the one or more fatty acids is selected from the group consisting
of lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid,
lignoceric acid, cerotic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic
acid, elaidic acid, vaccenic acid, linoleic acid, linoelaidic acid, α-linolenic acid,
arachidonic acid, eicosapentaenoic, erucic acid, docosahexaenoic acid and
combinations thereof. In another embodiment, the one or more fatty acids is a
saturated fatty acid or an unsaturated fatty acid. In another embodiment, the fatty
acid is a C12-C24 fatty acid, for example, a C16-C22 fatty acid, which may be saturated
or unsaturated. In one embodiment, the one or more fatty acids is stearic acid,
optionally in combination with other fatty acids.
In another embodiment, the one or more salts of a fatty acid is a metal salt of the
aforementioned fatty acids. The metal may be an alkali metal or an alkaline earth
metal or zinc. In one embodiment, the second compound is calcium stearate.
The second compound, when present, is present in the compatibilizer in an amount
effective to achieve the desired result. This will vary between coupling modifiers and
may depend upon the precise composition of the inorganic particulate. For example,
the second compound may be present in an amount equal to or less than about 5 wt.
% based on the total weight of the compatibilizer, for example equal to or less than
about 2 wt. % or, for example equal to or less than about 1 wt. %. In an
embodiment, the second compound is present in the compatibilizer in an amount
equal to or less than about 0.9 wt.% based on the total weight of the compatibilizer,
for example equal to or less than about 0.8 wt. %, for example equal to or less than
about 0.7 wt. %, for example, less than or equal to about 0.6 wt. %, for example
equal to or less than about 0.5 wt %, for example equal to or less than about 0.4 wt.
%, for example equal to or less than about 0.3 wt. %, for example equal to or less
than about 0.2 wt. % or, for example equal to or less than about 0.1 wt. %. Typically,
the second compound, if present, is present in the compatibilizer in an amount
greater than about 0.05 wt. %. The weight ratio of the coupling modifier to the
second compound may be from about 5:1 to about 1:5, for example, from about 4:1
to about 1:4, for example, from about 3:1 to about 1:3, for example, from about 2:1 to
about 1:2 or, for example, about 1:1. The amount of coating, comprising the first
compound (i.e., the coupling modifier) and the second compound (i.e., the one more
fatty acids or salts thereof), may be an amount which is calculated to provide a
monolayer coverage on the surface of the inorganic particulate. In embodiments, the
weight ratio of the first compound to the second compound is from about 4:1 to about
1:3, for example from about 4:1 to about 1:2, for example from about 4:1 to about
1:1, for example from about 4:1 to about 2:1, for example, from about 3.5:1 to about
1:1, for example from about 3.5:1 to 2:1 or, for example, from about 3.5:1 to about
2.5:1
In certain embodiments, the surface treatment agent does not comprise a compound
selected from the group consisting of one or more fatty acids and one or more salts
of a fatty acid.
In certain embodiments, the surface agent is or comprises an organic linker on a
surface of the inorganic particulate. The organic linker has an oxygen-containing
acid functionality. The organic linker is a basic form of an organic acid. By “basic
form” is meant that the organic acid is at least partially deprotonated, e.g., by
dehydrating an organic acid to form the corresponding oxyanion. In certain
embodiments, the basic form of an organic acid is the conjugate base of the organic
acid. The organic acid (and, thus, the organic linker) comprises at least one carbon
carbon double bond.
In certain embodiments, the organic linker is a non
embodiments, has a molecular mass of no greater than about 400 g/mol. By “non
polymeric” is meant a species which (i) is not formed by the polymerization of
monomeric species, and/or (ii) has a relatively low molecular mass, e.g., a molecular
mass of less than about 1000 g/mol, for example, a molecular mass of no greater
than about 400 g/mol, and/or (iii) comprises no more than 70 carbon atoms in a
carbon chain, for example, no more than about 25 carbon atoms in a carbon chain.
In certain embodiments, the non
greater than about 800 g/mol, or
about 500 g/mol, or no greater than about 400 g/mol, or no greater than about 300 g/
mol, or no greater than about 200 g/mol. Alternatively or additionally, in certain
embodiments, the non-polymeric spe
atoms, or no more than about 40 carbon atoms, or no more than about 30 carbon
atoms, or no more than about 25 carbon atoms, or no more than about 20 carbon
atoms, or no more than about 15 carbon atoms.
In certain embodiments, the compatibilizer comprises particulate and an organic
linker (serving as the coupling modifier) on a surface of the particulate, the
compatibilizer being obtained by at least partially dehydrating an organic acid having
an oxygen-containing acid functionality and comprising at least one carbon
double bond in the presence of the particulate.
An exemplary organic acid is a carboxylic acid, and its basic form a carboxylate, e.g.,
and
containing at least one carbon
an oxyanion) is depicted in resonance form. The carboxylate group is an example of
non-polymeric species and, in certain
ymeric” non-polymeric species has a molecular mass of no
no greater than about 600 g/mol, or no greater than
species comprises no more than about 50 carbon
n g , respectively, wherein R is an unsaturated C
carbon-carbon double bond. The carboxylate group (which is
carbonpolymeric
nonymeric”
cies carbon-carbon
C2+ group
a conjugate base. In certain embodiments, R is an unsaturated C3+ group, or an
unsaturated C4+ group, or an unsaturated C5+ group.
Without wishing to be bound by theory, it is believed that the basic form of the acid
functionality coordinates/associates with the surface of the particulate, and the
organic tail having at least one carbon-carbon double bond coordinates/associates
with the different polymer species in the resin composition. Thus, the compatibilizer
serves to cross-link or graft the different polymer types, with the organic linker acting
as coupling modifier, wherein the coupling involves a physical (e.g., steric) and/or
chemical (e.g., chemical bonding, such as covalent or van der Waals) interaction
between the different polymers and between the polymers and the particulate. The
overall effect is to enhance the compatibility of the different polymer types in the
polymer resin which, in turn, may enhance processing of the polymer resin and/or
one or more physical properties (e.g., one or more mechanical properties) of an
article of manufacture, such as a portable waste or refuse container, for example, a
wheelie bin, made from the polymer resin. The surface of the particulate may serve
to balance the anionic charge of the organic linker. Further, the compatibilizing
effect may enable greater quantities of particulate to be incorporated without
adversely affecting the processability of the polymer blend and/or the physical
properties of the articles made from the polymer blend. This, in turn, may reduce
costs because less polymer (recycled or otherwise) is used.
In certain embodiments, the organic linker is the conjugate base of an organic acid,
for example, a carboxylate or phosphate or phosphite or phosphinate or amino acid.
In certain embodiments, the organic linker is a carboxylate. In alternate
embodiments, the organic linker includes a maleimide ring (e.g., with an amide
carboxylate functionality coordinates/associates with the surface of the particulate
and a carbon-carbon double bond coordinates/associates with the different polymer
species in the polymer resin).
In certain embodiments, the organic linker comprises at least one carbon atom in
addition to the carbon-carbon double bond. In certain embodiments, the organic
linker comprises at least two carbon atoms, or at least three carbon atoms, or at
least four carbon atoms, or at least five carbon atoms in addition to the carbon18
carbon double bond. In certain embodiments, the organic linker comprises at least
six carbon atoms, for example, a chain of at least six carbon atoms, including the at
least one carbon-carbon double bond. In certain embodiments, the organic linker
comprises only one carbon-carbon double bond. In certain embodiments, the
organic linker comprises two carbon-carbon double bonds. In certain embodiments,
the organic linker comprises three carbon-carbon double bonds. The moieties about
the at least one carbon-carbon double bond may be arranged in a cis or trans
configuration. The carbon-carbon double bond may be a terminal group or may be
internal to the molecule, i.e., within the chain of carbon atoms.
In certain embodiments, the organic linker is:
(1) CH2=CH-(CH2)a-Z
and/or
(2) CH3-(CH2)b-CH=CH-(CH2)c-Z
wherein a is equal to or greater than 3;
wherein b is equal to or greater than 1, and c is equal to or greater than 0, provided
that b + c is at least 2; and
wherein Z is a carboxylate group, a phosphate group, a phosphite or a phosphinate
group.
In certain embodiments, a is from 6 to 20, for example, from 6 to 18, or 6 to 16, or 6
to 14, or 6 to 12, or 6 to 10, or 7 to 9. In certain embodiments, a is 8.
In certain embodiments, b and c are each independently from 4 to 10, for example,
each independently from 5 to 11, or from 5 to 10, or from 6 to 9, or from 6 to 8. In
certain embodiments, b and c are both 7.
In certain embodiments, when the organic linker is of formula (1), Z is a carboxylate
group. In such embodiments, the compatibilizer may consist essentially of, or
consist of, particulate (e.g., mineral particulate) and the organic linker of formula (1)
and wherein Z is a carboxylate group.
In certain embodiments, when the organic linker is of formula (2), Z is a carboxylate
group. In such embodiments, the compatibilizer may consist essentially of, or
consist of, particulate (e.g., mineral particulate) and the organic linker of formula (2)
and wherein Z is a carboxylate group.
In certain embodiments, the organic linker is a mixture of formula (1) and formula (2),
optionally wherein Z is, in each case, a carboxylate group. In such embodiments,
the compatibilizer may consist essentially of, or consist of, particulate (e.g., mineral
particulate) the organic linker of formula (1) and wherein Z is a carboxylate group,
and the organic linker of formula (2) and wherein Z is a carboxylate group.
In certain embodiments, the organic acid is an unsaturated fatty acid or derived from
an unsaturated fatty acid. In certain embodiments, when the organic acid is an
unsaturated fatty acid, the compatibilizer consists essentially of, or consists of,
particulate (for example, mineral particulate) and organic linker. In such
embodiments, the unsaturated fatty acid may be selected from one of myristoleic
acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, linoleic
acid, linoelaidic acid, α-linolenic acid, arachidonic acid, eicosapentaenoic acid,
erucuc acid and docosahexanoic acid. In such embodiments, the unsaturated fatty
acid may be oleic acid, i.e., in certain embodiments, the compatibilizer comprises
particulate (for example, mineral particulate) and the basic form of oleic acid. In
certain embodiments, the compatibilizer consists of particulate (for example, mineral
particulate) and the basic form of oleic acid.
In certain embodiments, the organic acid is derived from an unsaturated fatty acid.
In certain embodiments, the organic acid is undecylenic acid, i.e., the organic linker
is the basic form of undecylenic acid. In certain embodiments, the compatibilizer
consists of particulate (for example, mineral particulate) and the basic form of
undecylenic acid.
The inorganic particulate material
The inorganic particulate material may, for example, be an alkaline earth metal
carbonate or sulphate, such as calcium carbonate, magnesium carbonate, dolomite,
gypsum, a hydrous kandite clay such as kaolin, halloysite or ball clay, an anhydrous
(calcined) kandite clay such as metakaolin or fully calcined kaolin, talc, mica, perlite
or diatomaceous earth, or magnesium hydroxide, or aluminium trihydrate, or
combinations thereof.
A preferred inorganic particulate material is calcium carbonate. Hereafter, the
invention may tend to be discussed in terms of calcium carbonate, and in relation to
aspects where the calcium carbonate is processed and/or treated. The invention
should not be construed as being limited to such embodiments.
The particulate calcium carbonate used in the present invention may be obtained
from a natural source by grinding. Ground calcium carbonate (GCC) is typically
obtained by crushing and then grinding a mineral source such as chalk, marble or
limestone, which may be followed by a particle size classification step, in order to
obtain a product having the desired degree of fineness. Other techniques such as
bleaching, flotation and magnetic separation may also be used to obtain a product
having the desired degree of fineness and/or colour. The particulate solid material
may be ground autogenously, i.e. by attrition between the particles of the solid
material themselves, or, alternatively, in the presence of a particulate grinding
medium comprising particles of a different material from the calcium carbonate to be
ground. These processes may be carried out with or without the presence of a
dispersant and biocides, which may be added at any stage of the process.
Precipitated calcium carbonate (PCC) may be used as the source of particulate
calcium carbonate in the present invention, and may be produced by any of the
known methods available in the art. TAPPI Monograph Series No 30, "Paper
Coating Pigments", pages 34-35 describes the three main commercial processes for
preparing precipitated calcium carbonate which is suitable for use in preparing
products for use in the paper industry, but may also be used in the practice of the
present invention. In all three processes, a calcium carbonate feed material, such as
limestone, is first calcined to produce quicklime, and the quicklime is then slaked in
water to yield calcium hydroxide or milk of lime. In the first process, the milk of lime
is directly carbonated with carbon dioxide gas. This process has the advantage that
no by-product is formed, and it is relatively easy to control the properties and purity
of the calcium carbonate product. In the second process the milk of lime is
contacted with soda ash to produce, by double decomposition, a precipitate of
calcium carbonate and a solution of sodium hydroxide. The sodium hydroxide may
be substantially completely separated from the calcium carbonate if this process is
used commercially. In the third main commercial process the milk of lime is first
contacted with ammonium chloride to give a calcium chloride solution and ammonia
gas. The calcium chloride solution is then contacted with soda ash to produce by
double decomposition precipitated calcium carbonate and a solution of sodium
chloride. The crystals can be produced in a variety of different shapes and sizes,
depending on the specific reaction process that is used. The three main forms of
PCC crystals are aragonite, rhombohedral and scalenohedral, all of which are
suitable for use in the present invention, including mixtures thereof.
Wet grinding of calcium carbonate involves the formation of an aqueous suspension
of the calcium carbonate which may then be ground, optionally in the presence of a
suitable dispersing agent. Reference may be made to, for example, EP-A-614948
(the contents of which are incorporated by reference in their entirety) for more
information regarding the wet grinding of calcium carbonate. The inorganic
particulate, e.g., calcium carbonate, may also be prepared by any suitable dry
grinding technique.
In some circumstances, additions of other minerals may be included, for example,
one or more of kaolin, calcined kaolin, wollastonite, bauxite, talc, titanium dioxide or
mica, could also be present.
When the inorganic particulate material is obtained from naturally occurring sources,
it may be that some mineral impurities will contaminate the ground material. For
example, naturally occurring calcium carbonate can be present in association with
other minerals. Thus, in some embodiments, the inorganic particulate material
includes an amount of impurities. In general, however, the inorganic particulate
material used in the invention will contain less than about 5% by weight, preferably
less than about 1% by weight, of other mineral impurities.
Unless otherwise stated, particle size properties referred to herein for the inorganic
particulate materials are as measured by the well known conventional method
employed in the art of laser light scattering, using a CILAS 1064 instrument (or by
other methods which give essentially the same result). In the laser light scattering
technique, the size of particles in powders, suspensions and emulsions may be
measured using the diffraction of a laser beam, based on an application of Mie
theory. Such a machine provides measurements and a plot of the cumulative
percentage by volume of particles having a size, referred to in the art as the
‘equivalent spherical diameter’ (e.s.d), less than given e.s.d values. The mean
particle size d50 is the value determined in this way of the particle e.s.d at which
there are 50% by volume of the particles which have an equivalent spherical
diameter less than that d50 value. The term d90 is the particle size value less than
which there are 90% by volume of the particles.
The d50 of the inorganic particulate may be less than about 100 μm, for example,
less than about 80 μm for example, less than about 60 μm for example, less than
about 40 μm, for example, less than about 20 μm, for example, less than about 15
μm, for example, less than about 10 μm, for example, less than about 8 μm, for
example, less than about 6 μm, for example, less than about 5 μm, for example, less
than about 4, for example, less than about 3 μm, for example less than about 2 μm,
for example, less than about 1.5 μm or, for example, less than about 1 μm. The d50
of the inorganic particulate may be no greater than about 2.5 μm, for example, no
greater than about 1.0 μm or no greater than about 0.75 μm. The d50 of the
inorganic particulate may be greater than about 0.5 μm, for example, greater than
about 0.75 μm greater than about 1 μm, for example, greater than about 1.25 μm or,
for example, greater than about 1.5 μm. The d50 of the inorganic particulate may be
in the range of from 0.5 to 20 μm, for example, from about 0.5 to 10 μm, for example,
from about 1 to about 5 μm, for example, from about 1 to about 3 μm, for example,
from about 1 to about 2 μm, for example, from about 0.5 to about 2 μm or, for
example, from about 0.5 to 1.5 μm, for example, from about 0.5 to about 1.4 μm, for
example, from about 0.5 to about 1.4 μm, for example, from about 0.5 to about 1.3
μm, for example, from about 0.5 to about 1.2 μm, for example, from about 0.5 to
about 1.1 μm, for example, from about 0.5 to about 1.0 μm, for example, from about
0.6 to about 1.0 μm, for example, from about 0.7 to about 1.0 μm, for example about
0.6 to about 0.9 μm, for example, from about 0.7 to about 0.9 μm.
The d90 (also referred to as the top cut) of the inorganic particulate may be less than
about 150 μm, for example, less than about 125 μm for example, less than about
100 μm for example, less than about 75 μm, for example, less than about 50 μm, for
example, less than about 25 μm, for example, less than about 20 μm, for example,
less than about 15 μm, for example, less than about 10 μm, for example, less than
about 8 μm, for example, less than about 6 μm, for example, less than about 4 μm,
for example, less than about 3 μm or, for example, less than about 2 μm.
Advantageously, the d90 may be less than about 25 μm.
The amount of particles smaller than 0.1 μm is typically no more than about 5% by
volume.
The inorganic particulate may have a particle steepness equal to or greater than
about 10. Particle steepness (i.e., the steepness of the particle size distribution of
the inorganic particulate) is determined by the following formula:
Steepness = 100 x (d30/d70),
wherein d30 is the value of the particle e.s.d at which there are 30% by volume of the
particles which have an e.s.d less than that d30 value and d70 is the value of the
particle e.s.d. at which there are 70% by volume of the particles which have an e.s.d.
less than that d70 value.
The inorganic particulate may have a particle steepness equal to or less than about
100. The inorganic particulate may have a particle steepness equal to or less than
about 75, or equal to or less than about 50, or equal to or less than about 40, or
equal to or less than about 30. The inorganic particulate may have a particle
steepness from about 10 to about 50, or from about 10 to about 40.
The inorganic particulate is treated with a surface treatment agent, i.e., a coupling
modifier, such that the inorganic particulate has a surface treatment on its surface.
In certain embodiments, the inorganic particulate is coated with the surface
treatment agent.
In certain embodiments, the inorganic particulate material of the compatabilizer is
calcium carbonate, for example, GCC.
According to certain aspects and embodiments thereof, the polymer resin is
substantially free of, i.e., does not comprise, a peroxide-containing additive, for
example, di-cumyl peroxide or 1,1-Di(tert-butylperoxy)-3,3,5-trimethylcyclohexane .
Alternatively, in certain aspects and embodiments thereof, the polymer resin
comprises a peroxide-containing additive, for example, di-cumyl peroxide or 1,1-
Di(tert-butylperoxy)-3,3,5-trimethylcyclohexane. The peroxide-containing additive
may not necessarily be included with the surface treatment agent/coupling modifier
and instead may be added during the compounding of the compatibilizer and the
polymer, as described below. In some polymer systems, e.g., those containing
polyethylene (e.g., HDPE), the inclusion of a peroxide-containing additive may
promote cross-linking of the polymer chains. In other polymer systems, e.g.,
polypropylene, the inclusion of a peroxide-containing additive may promote polymer
chain scission. The peroxide-containing additive may be present in an amount
effective to achieve the desired result. This will vary between coupling modifiers and
may depend upon the precise composition of the inorganic particulate and the
polymer. For example, the peroxide-containing additive may be present in an
amount equal to or less than about 1 wt. % based on the weight of the polymer in the
polymer resin to which the peroxide-containing additive is to be added, for example,
equal to or less than about 0.5 wt. %, for example, 0.1 wt %, for example equal to or
less than about 0.09 wt. %, or for example equal to or less than about 0.08 wt. % or
for example, equal to or less than about 0.06 wt. %, equal to or less than about 0.05
wt. %, equal to or less than about 0.04 wt. %, equal to or less than about 0.03 wt. %,
equal to or less than about 0.02 wt. %, or equal to or less than about 0.01 wt. %,.
Typically, the peroxide-containing additive, if present, is present in an amount
greater than about 0.001 wt. % based on the weight of the polymer in the polymer
resin, for example, equal to or greater than about 0.005 wt. %, or equal to or greater
than about 0.075 wt. %, or equal to or greater than about 0.01 wt. %.
The compatibilizer may be prepared by combining the inorganic particulate, surface
treatment agent/coupling modifier and optional peroxide-containing additive and
mixing using conventional methods, for example, using a Steele and Cowlishaw high
intensity mixer, preferably at a temperature equal to or less than 80 ºC. The
compound(s) of the surface treatment agent/coupling modifier may be applied after
grinding the inorganic particulate, but before the inorganic particulate is added to the
optionally recycled polymer composition. For example, the surface treatment
agent/coupling modifier may be added to the inorganic particulate in a step in which
the inorganic particulate is mechanically de-aggregated. The surface treatment
agent/coupling modifier may be applied during de-aggregation carried out in a milling
machine.
The compatibilizer may additionally comprise an antioxidant. Suitable antioxidants
include, but are not limited to, organic molecules consisting of hindered phenol and
amine derivatives, organic molecules consisting of phosphates and lower molecular
weight hindered phenols, and thioesters. Exemplary antioxidants include Irganox
1010 and Irganox 215, and blends of Irganox 1010 and Irganox 215. Alternatively,
such antioxidants may be added to the resin composition separately from the
compatibilizer. Alternatively, a portion of the total required amount of antioxidant
may be present in both the compatibilizer and added separately from the
compatibilizer to the resin composition.
Secondary filler
In certain embodiments, the resin composition comprises filler in addition to the
compatibilizer when present, i.e., one or more secondary filler components. The
secondary filler component may not be treated with a surface treatment
agent/coupling modifier. In certain embodiments, the secondary filler component is
not treated with a surface treatment agent/coupling modifier. Such additional
components, where present, are suitably selected from known filler components for
polymer compositions. For example, the inorganic particulate used in the functional
filler may be used in conjunction with one more other known secondary filler
components, such as for example, carbon black and/or talc.
In certain embodiments, the resin composition comprises carbon black as a
secondary filler component. The carbon black may function as colorant and/or UV
stabiliser.
In certain embodiments, the weight ratio of compatibilizer to secondary filler
component is from about 1:1 to about 20:1, for example, from about 5:1 to about
15:1, or from about 7.5:1 to about 12.5:1, for example, about 10:1. In certain
embodiments, the inorganic particulate of the functional filler is calcium carbonate,
for example, ground calcium carbonate, and the secondary filler component is
uncoated carbon black. When a secondary filler component is used, it may be
present in an amount of from about 0.1 % to about 5 % by weight of the polymer
composition, for example, from about 0.5 % to about 4 % by weight, or from about
0.5 % to about 3 % by weight, or from about 0.5 % to about 2.5 % by weight, or from
about 0.5 % to about 2 % by weight, or from about 0.5 % to about 1.5 % by weight,
or from about 0.75 % to about 1.25 % by weight of the resin composition.
The secondary filler component(s) may also serve to increase the density of the
resin composition.
In certain embodiments, the secondary filler is present in an amount of at least about
0.5 % by weight, based on the total weight of the resin composition, for example,
from about 0.5 % by weight to about 10 % by weight, or from about 0.5 % by weight
to about 5.0 % by weight, or from about 0.5 % by weight to about 2.5 % by weight.
Impact modifier
In certain embodiments, the polymer resin comprises an impact modifier, for
example, up to about 20 % by weight of an impact modifier, based on the total
weight of the polymer resin, for example, from about 0.1 % by weight to about 20 %
by weight, or from about 0.5 % by weight to about 15 % by weight, or, for example,
for example, in an amount of less than about 10 % by weight, or from about 1 % by
weight to about 10 % by weight, or from about 2 % by weight to about 5 % by weight,
or from about 1 % by weight to about 10 % by weight, or from about 1 % by weight to
about 7.5 % by weight, or from about 1.5 wt.% to about 3.0 wt.%, or from about 2 %
by weight to about 6 % by weight, or from about 2 % by weight to about 5 % by
weight of an impact modifier, based on the total weight of polymer resin.
In certain embodiments, the impact modifier is an elastomer, for example, a
polyolefin elastomer. In certain embodiments, the polyolefin elastomer is a
copolymer of ethylene and another olefin (e.g., an alpha-olefin), for example, octane,
and/or butene and/or styrene. In certain embodiments, the impact modifier is a
copolymer of ethylene and octene. In certain embodiments, the impact modifier is a
copolymer of ethylene and butene.
In certain embodiments, the impact modifier is a recycled (e.g., post industrial)
impact modifier.
In certain embodiments, the impact modifier, for example, polyolefin copolymer as
described above, such as an ethylene-octene copolymer, has a density of from
about 0.80 to about 0.95 g/cm3 and/or a MFI of from about 0.2 g/10 min (2.16
kg@190 °C) to about 30 g/10 min (2.16 kg@190 °C), for example, from about 0.5
g/10 min (2.16 kg@190 °C) to about 20 g/10 min (2.16 kg@190 °C), or from about
0.5 g/10 min (2.16 kg@190 °C) to about 15 g/10 min (2.16 kg@190 °C), or from
about 0.5 g/10 min (2.16 kg@190 °C) to about 10 g/10 min (2.16 kg@190 °C), or
from about 0.5 g/10 min (2.16 kg@190 °C) to about 7.5 g/10 min (2.16 kg@190 °C),
or from about 0.5 g/10 min (2.16 kg@190 °C) to about 5 g/10 min (2.16 kg@190 °C),
or from about 0.5 g/10 min (2.16 kg@190 °C) to about 4 g/10 min (2.16 kg@190 °C),
or from about 0.5 g/10 min (2.16 kg@190 °C) to about 3 g/10 min (2.16 kg@190 °C),
or from about 0.5 g/10 min (2.16 kg@190 °C) to about 2.5 g/10 min (2.16 kg@190
°C), or from about 0.5 g/10 min (2.16 kg@190 °C) to about 2 g/10 min (2.16 kg@190
°C), or from about 0.5 g/10 min (2.16 kg@190 °C) to about 1.5 g/10 min (2.16
kg@190 °C). In such or certain embodiments, the impact modifier is an ethyleneoctene
copolymer having a density of from about 0.85 to about 0.86 g/cm3.
Exemplary impact modifiers are polyolefin elastomers made by DOW under the
Engage(RTM) brand, for example, Engage (RTM) 8842. In such embodiments, the
compounded polymer blend may additionally comprise an antioxidant, as described
herein. In such embodiments, the impact modifier may be present in an amount of
less than about 10 wt.%, for example, from about 1 wt. % to about 7.5 wt. %., or from
about 1.5 wt. % to about 3.0 wt. %.
In certain embodiments, the impact modifier is a copolymer based on styrene and
butadiene, for example, a linear block copolymer based on styrene and butadiene.
In such embodiments, the impact modifier may have a MFI of from about from about
1 to about 5 g/10min (200˚C @ 5.0kg), for example, from about 2 g/10min (200˚C @
5.0kg) to about 4 g/10min (200˚C @ 5.0kg), or from about 3 g/10min (200˚C @
5.0kg) to about 4 g/10min (200˚C @ 5.0kg). In such embodiments, the linear block
copolymer may be a recycled linear block copolymer.
In certain embodiments, the impact modifier is a copolymer based on styrene and
isoprene, for example, a linear block copolymer based on styrene and isoprene. In
such embodiments, the impact modifier may have a MFI of from about from about 5
to about 20 g/10min (230˚C @ 2.16), for example, from about 8 g/10min (230˚C @
2.16kg) to about 15 g/10min (230˚C @ 2.16kg), or from about 10 g/10min (230˚C @
2.16kg) to about 15 g/10min (230˚C @ 2.16kg). In such embodiments, the linear
block copolymer may be recycled.
In certain embodiments, the impact modifier is a triblock copolymer based on styrene
and ethylene/butene. In such embodiments, the impact modifier may have a MFI of
from about 15 g/10min (200˚C @ 5.0kg) to about 25 g/10min (200˚C @ 5.0kg), for
example, from about 20 g/10min (200˚C @ 5.0kg) to about 25 g/10min (200˚C @
5.0kg).
MFI may be determined in accordance with ISO 1133.
In certain embodiments, there is crosslinking between the impact modifier and one or
more polymers of the polymer resin, for example, in embodiments in which the
impact modifier is a linear block copolymer based on styrene and butadiene, or on
styrene and isoprene, and/or the resin composition comprises PE. In some
embodiments, the impact modifier may be miscible in the polymer blend.
In certain embodiments, the impact modifier is an optionally recycled styrenebutadiene-
styrene block copolymer (rSBS). In such embodiments, the rSBS may be
present in the resin composition in an amount of from about 2 % to about 5 % by
weight, based on the total weight of resin composition.
Methods of manufacture
The resin composition may be made by a method comprising compounding the
polymer components, for example, polyethylene, and propylene, with the
compatabilizer and other optional additives.
In certain embodiments, the method comprises providing a recycled mixed polyolefin
feed comprising polypropylene and polyethylene, optionally combining the recycled
mixed polyolefin feed with other sources of polyethylene and/or polypropylene, and
compounding.
The relative amounts of polyethylene, polypropylene and any other polyolefin source
may be selected to produce a resin composition as described herein.
In certain embodiments, the method comprises preparing, providing or obtaining the
compatibilizer, and compounding with the mixture of different polymer types. The
compatibilizer may be prepared by mixing the inorganic particulate material with the
surface treatment agent/coupling in suitable amounts, as described herein, and at a
temperature of no more than about 80 °C.
In certain embodiments, the resin composition comprises a secondary filler
component and/or impact modifier (e.g., rSBS) and/or antioxidant, which may be
added prior to or during compounding of the resin composition and compatibilizer.
Compounding per se is a technique which is well known to persons skilled in the art
of polymer processing and manufacture. It is understood in the art that
compounding is distinct from blending or mixing processes conducted at
temperatures below that at which the constituents become molten.
Compounding may be carried out using a twin screw compounder, for example, a
Baker Perkins 25 mm twin screw compounder. The polymers and compatibilizer and
other optional additives may be premixed and fed from a single hopper.
Alternatively, at least the polymers and compatibilizer may be fed from separate
hoppers. The resulting melt may be cooled, for example, in a water bath, and then
pelletized. In certain embodiments, the temperature during compounding is elevated
relative to the temperature at which the compatabilizer is prepared. In certain
embodiments, the temperature during compound ranges from about 150-250 °C, for
example, from about 160-240 °C, or from about 170-230 °C, or from about
170-220 °C, or from about 170-220 °C, or from about 200-250 °C. In certain
embodiments, the temperature during compounding is sufficient to cause thermomechanical
degradation of the polyolefins (e.g., recycled polyolefins) and to generate
sufficient macro-radical fragments to react with the surface treated inorganic
particulate material.
The compounded compositions may further comprise additional components, such
as slip aids (for example Erucamide), process aids (for example Polybatch® AMF-
705), mould release agents and antioxidants. Suitable mould release agents will be
readily apparent to one of ordinary skill in the art, and include fatty acids, and zinc,
calcium, magnesium and lithium salts of fatty acids and organic phosphate esters.
Specific examples are stearic acid, zinc stearate, calcium stearate, magnesium
stearate, lithium stearate, calcium oleate and zinc palmitate. Slip and process aids,
and mould release agents may be added in an amount less than about 5 wt. %
based on the weight of the masterbatch.
Other embodiments
In certain embodiments, the resin composition does not comprise 24 % by weight
polypropylene.
In certain embodiments, the resin composition does not comprise 56 % by weight
HDPE.
In certain embodiments, the resin composition does not comprise 24 % by weight
polypropylene and 56 % by weight polypropylene.
In certain embodiments, the resin composition does not comprise 20 % by weight
surface treated calcium carbonate, optionally wherein: the calcium carbonate is a
ground calcium carbonate having a d50 of 0.8 μm, and/or the amount of surface
treatment according to formula (1) applied to the calcium carbonate is calculated to
give a monolayer coverage on the surface.
In certain embodiments, the resin composition is not a polymer composition
designated as Composition A. Composition A is a polymer composition comprising
20 % by weight surface treated calcium carbonate, 56 % HDPE and 24 %
polypropylene, wherein:
(i) the surface treated calcium carbonate is a ground calcium carbonate (d50 =
0.8 μm) coated with a coupling modifier according to formula (1), wherein the
amount of surface treatment applied to the calcium carbonate is calculated to
give monolayer coverage on the surface
(ii) the composition is prepared using a Baker Perkins 25 mm twin screw
compounder, and
(iii) the HDPE and PP are from a recycled mixed polyolefin feed comprising
HDPE and PP, which is derived from injection moulded materials.
In certain embodiments, the polymeric resin is not in the form of a polymeric fibre.
In certain embodiments, the article is not a polymeric fibre.
Articles of manufacture
The polymer resin of the invention, as defined herein, may be used to manufacture
an article by injection moulding of said polymer resin. In certain embodiments, the
present invention is directed to methods of manufacturing an article by injection
moulding, the method comprising injection moulding an article from the polymer resin
of the present invention, as defined herein.
Any known method of injection moulding that is suitable for preparing an article in
accordance with the invention may be used. In certain embodiments, an Arburg
Allrounder 320M is used to prepare the injection moulded article, and the mouldings
may subsequently be conditioned for a minimum of 40hrs at 23oC at a relative
humidity of 50%.
In certain embodiments, the article is a portable waste or refuse container, for
example, a wheelie bin, or a part of a component thereof.
In certain embodiments, the article of manufacture is a plastic pallet.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has different and/or improved mechanical properties
compared to (i) an article comprising the polymer resin absent the compatibilizer
and/or (ii) an article made from the polymer resin in which the compatibilizer has
been replaced by a polymer-based compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has one or more of the following:
a) reduced tiger stripes, compared to (i) an article comprising the polymer resin
absent the compatibilizer and/or (ii) an article made from the polymer resin in which
the compatibilizer has been replaced by a polymer-based compatibilizer, or is free of
tiger stripes;
b) a flexural modulus which is greater than an article made from the polymer resin in
which the compatibilizer has been replaced by a polymer-based compatibilizer, as
determined in accordance with ISO 178;
c) a flexural modulus of at least about 900 MPa, for example, from about 900 MPa to
about 1200 MPa, as determined in accordance with ISO 178;
d) an impact strength which is greater than an article comprising the polymer resin
absent the compatibilizer, as determined in a Izod notched impact test at 23 oC ± 2
oC in accordance with ISO 180;
e) an impact strength which is greater than (i) an article comprising the polymer resin
absent the compatibilizer, as determined in a Izod notched impact test at 23 oC
± 2 oC in accordance with ISO 180 and/or a flexural modulus which is greater than
(ii) an article made from the polymer resin in which the compatibilizer has been
replaced by a polymer-based compatibilizer, as determined in accordance with ISO
178;
f) an impact strength of at least about 4.0 kJ/m2, for example, from about 4.0 kJ/m2 to
about 20 kJ/m2, as determined in a Izod notched impact test at 23 oC ± 2 oC in
accordance with ISO 180.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has reduced tiger stripes, compared to (i) an article
comprising the polymer resin absent the compatibilizer and/or (ii) an article made
from the polymer resin in which the compatibilizer has been replaced by a polymerbased
compatibilizer, or is free of tiger stripes.
Injection-moulded plastics, often when involving long flow lengths, can exhibit visible
defects called tiger stripes. Thus, the term “tiger stripes” means defects which are
present in the form of bands that are visible on the surface of an injection moulded
article. The stripes are typically alternating bands, for example, light and dark bands
or glossy and dull bands, that are present on a surface of the injection moulded
article, due to unstable flow front and for example because of insufficient joining of
immiscible polymer resins.
In certain embodiments, the compatibilizer, as defined herein, can be used in the
manufacture of an article by injection moulding the polymer resin, as defined herein,
to eliminate tiger stripes, or to reduce tiger stripes, compared to (i) an article
comprising the polymer resin absent the compatibilizer and/or (ii) an article made
from the polymer resin in which the compatibilizer has been replaced by a polymerbased
compatibilizer.
In certain embodiments, the compatibilizer, as defined herein, can be used in the
polymer resin, as defined herein, to (i) eliminate the occurrence of tiger stripes in an
article manufactured from the polymer resin by injection moulding, or (ii) reduce the
occurrence of tiger stripes compared to an article manufactured from the polymer
resin absent the compatibilizer and/or an article made from the polymer resin in
which the compatibilizer has been replaced by a polymer-based compatibilizer.
In certain embodiments, use of the polymer resin, as defined herein, in the
manufacture of an article by injection moulding of the polymer resin, can reduce the
visible presence of tiger stripes by at least 50 %, or by at least 75 %, or by at least
90 %, or by at least 99%. In certain embodiments, use of the polymer resin, as
defined herein, in the manufacture of an article by injection moulding of the polymer
resin can eliminate the visible presence of tiger stripes in the manufactured article.
In certain embodiments, the article manufactured as defined herein may have
improved tiger stripe properties, for example, improved visual tiger stripe properties
compared to (i) an article manufactured from the polymer resin absent the
compatibilizer and/or (ii) an article made from the polymer resin in which the
compatibilizer has been replaced by a polymer-based compatibilizer. In certain
embodiments, article manufactured as defined herein may have visibly reduced tiger
striping, for example, a reduced number of tiger stripes or tiger stripes that are less
visible, compared to (i) an article manufactured from the polymer resin absent the
compatibilizer or (ii) an article made from the polymer resin in which the
compatibilizer has been replaced by a polymer-based compatibilizer.
The effect of the compatabilizer in the polymer resin upon the presence of tiger
stripes can visibly be seen in Figures 1 and 2.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has a flexural modulus which is greater than an
article made from the polymer resin in which the compatibilizer has been replaced by
a polymer-based compatibilizer, as determined in accordance with ISO 178.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has a flexural modulus of at least about 880 MPa,
for example, of at least about 900 MPa, or of at least about 925 MPa, or of at least
about 950 MPa. In certain embodiments, the article manufactured by injection
moulding of the polymer resin as defined herein, has a flexural modulus from about
900 to about 1200 MPa, for example, from about 925 to about 1175 MPa.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has a flexural modulus that is at least about 2%
greater, for example at least about 5% greater, or at least about 10% greater,
compared to an article made from the polymer resin in which the compatibilizer has
been replaced by a polymer-based compatibilizer. In certain embodiments, the
article manufactured by injection moulding of the polymer resin as defined herein,
has a flexural modulus that is at least about 50 MPa greater, for example, at least
about 75 MPa greater, or at least about 85 MPa greater, compared to an article
made from the polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has a flexural modulus that is comparable to an
article comprising the polymer resin absent the compatibilizer, for example, the
flexural modulus may be no more than 10% lower than an article comprising the
polymer resin absent the compatibilizer. In certain embodiments, the article
manufactured by injection moulding of the polymer resin as defined herein, has a
greater flexural modulus compared to an article comprising the polymer resin absent
the compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has a flexural modulus which is comparable to, or
greater than, (i) an article comprising the polymer resin absent the compatibilizer, as
determined in accordance in a Izod notched impact test at 23 oC ± 2 oC in
accordance with ISO 180 and/or a flexural modulus which is greater than (ii) an
article made from the polymer resin in which the compatibilizer has been replaced by
a polymer-based compatibilizer, as determined in accordance with ISO 178.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is greater than an
article comprising the polymer resin absent the compatibilizer, as determined in a
Izod notched impact test at 23 oC ± 2 oC in accordance with ISO 180.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is at least 0.1 kJ/m2
greater, for example, at least 0.2 kJ/m2 greater, or at least 0.5 kJ/m2 greater, or at
least 1 kJ/m2 greater, or at least 1.3 kJ/m2 greater, compared to an article comprising
the polymer resin absent the compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is at least 1% greater,
for example, at least 3% greater, or at least 5% greater, or at least 10% greater, or at
least 25% greater, compared to an article comprising the polymer resin absent the
compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength of at least about 4.0 kJ/m2,
for example, at least about 4.2 kJ/m2, for example, at least about 5.0 kJ/m2, or at
least about 6.0 kJ/m2, for example, from about 4.2 kJ/m2 to about 20 kJ/m2, for
example, about 4.2 kJ/m2 to about 10 kJ/m2, or about 4.2 kJ/m2 to about 7.0 kJ/m2,
or from about 5.0 kJ/m2 to 7.0 kJ/m2, or from about 6.0 kJ/m2 to about 7.0 kJ/m2.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is comparable to an
article made from the polymer resin in which the compatibilizer has been replaced by
a polymer-based compatibilizer. In certain embodiments, the article manufactured
by injection moulding of the polymer resin as defined herein, has an impact strength
which is no more than about 50% lower, for example, no more than about 40%
lower, or no more than about 30% lower, compared to an article made from the
polymer resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is greater than (i) an
article comprising the polymer resin absent the compatibilizer, and/or has an impact
strength which is comparable to (ii) an article made from the polymer resin in which
the compatibilizer has been replaced by a polymer-based compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is greater than (i) an
article comprising the polymer resin absent the compatibilizer, as determined in
accordance in a Izod notched impact test at 23 oC ± 2 oC in accordance with ISO 180
and/or a flexural modulus which is greater than (ii) an article made from the polymer
resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer, as determined in accordance with ISO 178.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength of at least about 4.0 kJ/m2
and a flexural modulus of at least about 900 MPa, for example, an impact strength of
at least about 4.3 kJ/m2 and a flexural modulus of at least about 950 MPa.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength of from about 4 kJ/m2 to
about 7 kJ/m2 and a flexural modulus of from about 900 MPa to about 1200 MPa, for
example, an impact strength of from about 4.3 kJ/m2 to about 6.5 kJ/m2 and a
flexural modulus of from about 950 MPa to about 1175 MPa.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is at least 0.1 kJ/m2
greater, for example at least 0.2 kJ/m2 greater, than (i) an article comprising the
polymer resin absent the compatibilizer and/or a flexural modulus which is at least 50
MPa greater, for example at least 80 MPa greater, than (ii) an article made from the
polymer resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is greater than, for
example, at least 0.1 kJ/m2 greater, or at least 0.2 kJ/m2 greater, than an article
comprising the polymer resin absent the compatibilizer and/or a flexural modulus
which is comparable to, for example, no more than 10% lower than, or is greater
than, an article comprising the polymer resin absent the compatibilizer.
In certain embodiments, the article manufactured by injection moulding of the
polymer resin as defined herein, has an impact strength which is comparable to, for
example no more than 50% less than or no more than 30% less than, an article
made from the polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer and/or a flexural modulus which is greater than an
article made from the polymer resin in which the compatibilizer has been replaced by
a polymer-based compatibilizer.
In certain embodiments, articles manufactured in accordance with the present
invention have an improved balance of impact strength and flexural modulus
properties, for example, an optimum balance of impact strength and flexural modulus
properties compared to (i) an article comprising the polymer resin absent the
compatibilizer and/or (ii) an article made from the polymer resin in which the
compatibilizer has been replaced by a polymer-based compatibilizer.
In certain embodiments the manufactured article is a portable waste or refuse
container, for example, a wheelie bin, or a part or component thereof, and said
article has an improved, optionally an optimum, balance of impact strength and
flexural modulus properties of the manufactured article compared to (i) an article
comprising the polymer resin absent the compatibilizer and/or (ii) an article made
from the polymer resin in which the compatibilizer has been replaced by a polymerbased
compatibilizer.
The impact strength properties of an article correspond to the toughness of an article
i.e., the greater the impact strength of an article, the greater its toughness.
The flexural modulus properties of an article correspond to the stiffness of an article
i.e., the greater the flexural modulus of an article, the greater its stiffness.
An article such as a portable waste or refuse container, for example, a wheelie bin,
require a balance in toughness and stiffness properties in order for optimal
performance and properties.
In certain embodiments, the compatibilizer as defined herein can be used in an
article, wherein the article is manufactured by injection moulding a polymer resin, as
defined herein, comprising the compatibilizer to:
(A) provide a balance of toughness and stiffness which is superior compared to (i)
an article which is manufactured by injection moulding the polymer resin
absent the compatibilizer, or (ii) an article which is manufactured by injection
moulding a polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article.
In certain embodiments, the compatibilizer as defined herein is used in a polymer
resin, as defined herein, from which an article is manufactured by injection moulding
to:
(A) provide a balance of toughness and stiffness which is superior compared to (i)
an article which is manufactured by injection moulding the polymer resin
absent the compatibilizer, or (ii) an article which is manufactured by injection
moulding a polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article.
In certain embodiments, an article manufactured from the polymer resin by injection
moulding has a tensile modulus and/or tensile stress at yield, as determined in
accordance with ISO 527-2, which is greater than an article manufactured from a
polymer resin in which the compatabilizer has been replaced by a polymer-based
compatibilizer.
In certain embodiments, the polymer-based compatibilizer is a copolymer. In certain
embodiments, the polymer-based compatibilizer is a polypropylene-based olefin
block copolymer.
The polymer resin of the invention, as defined herein, may be used to manufacture
an article by a technique other than injection moulding, for example, extrusion of said
polymer resin.
EXAMPLES
Example 1
Seven polymer resins were prepared as shown in Table 1 below, each comprising
mixture of two types of HDPE and polypropylene (PP). All polymer resins were
prepared via melt mixing with a Coperion ZSK18 twin-screw extruder (18 mm
diameter). The screw speed was set to 800 rpm, and the feed rate at 8.0 kg/h. The
hot extrudates were immediately quenched in water and pelletized. Samples A and
1 are comparative examples since they were prepared without the surface treated
inorganic particulate material.
Table 1.
Sample HDPE 1
[wt.-%]
HDPE 2
[wt.-%]
PP
[wt.-
%]
Surface
treated
inorganic
particulate
material
[wt.-%]
Polymer
based
compatibilizer
Impact
Modifier
[wt.-%]
Antioxidant
[wt.-%]
A 36.24 31.23 27.23 - 5.0 - 0.3
1 37.90 32.90 28.90 - - - 0.3
2 35.40 30.40 26.40 7.5 - - 0.3
3 34.56 29.57 25.57 10.0 - - 0.3
4 33.73 28.73 24.74 12.5 - - 0.3
5 34.06 29.07 25.07 10.0 - 1.5 0.3
6 33.73 28.73 24.74 10.0 - 2.5 0.3
HDPE 1 has an MFI (g/10 min 2.16 kg @ 190 oC) of 3.3; HDPE 2 has an MFI (g/10
min 2.16 kg @ 190 oC) of 4.6; PP has an MFI (g/10 min 2.16 kg @ 190 oC) of 6.4.
Example 2
Melt Flow Index (MFI) properties of the seven polymer resin samples were tested.
MFI is the output rate in grams that occurs in 10 minutes when a fixed pressure is
applied to the melt via a piston and a load of total mass of 2.16 kg at the melt
blending temperature of 190°C and 230°C. MFI was tested in accordance with ISO
1133. The MFI properties of the polymer resin samples 1-7 is provided in Table 2
below.
Table 2.
A 1 2 3 4 5 6
MFI (g/10min)
2.16 kg @ 190 oC
4.0 4.2 3.9 3.7 3.7 3.5 3.8
MFI (g/10min)
5.0 kg @ 230 oC
6.28 7.2 7.0 7.0 7.1 6.9 7.0
Example 3
Injection moulded samples were prepared from the seven polymer resins, that were
prepared in Example 1, using Arburg Allrounder 320M, and mouldings were
conditioned for a minimum of 40hrs at 23˚C and a relative humidity of 50% prior to
the test, in accordance with Procedure A of Practice D618 (40/23/50).
Each injection moulded sample subsequently underwent the following mechanical
property tests.
Flexure testing:
Flexure tests were carried out at room temperature using Tinius Olsen Benchtop
flexure test, in accordance with ISO 178. The flexure test results are provided in
Table 3 below.
Tensile testing:
Tensile tests were carried out at room temperature using Tinius Olsen Benchtop
tensile tester, and the results supplied correspond to an average of 8 measurements
for each blend, in accordance with ISO 527-2. Table 3 below shows the tensile
stress at yield (MPa) and tensile modulus (MPa) of each injection moulded sample.
Impact testing:
Charpy notched impact tests may be carried out at -20 ± 2°C and 23 ± 2°C using
Instron Ceast 9340 falling-weight impact tester, in accordance with ISO 179. Izod
notched impact tests were carried out at 23 oC ± 2 oC, in accordance with ISO 180.
The results supplied in Table 3 below correspond to an average of complete break
measurements for each blend.
Table 3.
A 1 2 3 4 5 6
Flexural Modulus (MPa) 864.3 1012.5 1052.4 1115.7 1170.9 1032.5 955.9
Izod Impact Strength,
Notch @ 23 oC, Complete
break (kJ/m2)
7.3 4.1 - 4.3 - 5.4 6.5
Tensile Modulus (MPa) 930.0 1070.0 1140.0 1130.0 1160.0 1040.0 994.0
Tensile Stress @ Yield
(MPa)
21.9 24.6 23.4 23.9 24.0 23.0 22.5
WE CLAIM:
1. A method of manufacturing an article by injection moulding, the method
comprising injection moulding an article from a polymer resin, wherein the
polymer resin comprises different types of recycled polymer and a
compatibilizer comprising inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, and
wherein the polymer resin has a MFI @ 2.16 kg/190 oC of equal to or greater
than 3.0 g/10 min.
2. Use of a compatibilizer in an article, wherein the article is manufactured by
injection moulding a polymer resin comprising the compatibilizer, to eliminate
tigers stripes, or to reduce tiger stripes compared to an article comprising the
polymer resin absent the compatibilizer and/or compared to an article which is
manufactured by injection moulding a polymer resin in which the
compatibilizer has been replaced by a polymer-based compatibilizer, wherein
the compatibilizer comprises inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, wherein the
polymer resin comprises different types of recycled polymer and wherein the
polymer resin comprising the compatibilizer has a MFI @ 2.16 kg/190 oC of
equal to or greater than 3.0 g/10 min.
3. Use of a compatibilizer in a polymer resin to (i) eliminate the occurrence of
tiger stripes in an article manufactured from the polymer resin by injection
moulding, or (ii) reduce the occurrence of tiger stripes compared to an article
manufactured from the polymer resin absent the compatibilizer and/or
compared to an article which is manufactured by injection moulding a polymer
resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer, wherein the compatibilizer comprises inorganic particulate
material and a surface treatment agent on a surface of the inorganic
particulate material, wherein the polymer resin comprises different types of
recycled polymer and wherein the polymer resin comprising the compatibilizer
has a MFI @ 2.16 kg/190 oC of equal to or greater than 3.0 g/10 min.
4. Use of a compatibilizer in an article, wherein the article is manufactured by
injection moulding a polymer resin comprising the compatibilizer, to:
(A) provide a balance of toughness and stiffness which is superior compared
to (i) an article which is manufactured by injection moulding the polymer
resin absent the compatibilizer, or (ii) an article which is manufactured by
injection moulding a polymer resin in which the compatibilizer has been
replaced by a polymer-based compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article;
wherein:
the compatibilizer comprises inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, wherein
the polymer resin comprises different types of recycled polymer and
wherein the polymer resin comprising the compatibilizer has a MFI @ 2.16
kg/190 oC of equal to or greater than 3.0 g/10 min.
5. Use of a compatibilizer in a polymer resin from which an article is
manufactured by injection moulding to:
(A) provide a balance of toughness and stiffness which is superior compared
to (i) an article which is manufactured by injection moulding the polymer
resin absent the compatibilizer, or (ii) an article which is manufactured by
injection moulding a polymer resin in which the compatibilizer has been
replaced by a polymer-based compatibilizer, or
(B) optimize the balance between the toughness and stiffness of the article;
wherein:
the compatibilizer comprises inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate material, wherein
the polymer resin comprises different types of recycled polymer and
wherein the polymer resin comprising the compatibilizer has a MFI @ 2.16
kg/190 oC of equal to or greater than 3.0 g/10 min.
6. Method or use according to any preceding claim, wherein the polymer resin
comprises polyethylene and polypropylene, or a mixture of different types of
polyethylene (e.g., HDPE, LDPE and/or LLDPE) and polypropylene, or a
mixture of different types of HDPE and polypropylene.
7. Method or use according to any preceding claim, wherein the polymer resin
comprises polypropylene in an amount of no more than about 90 wt.%, for
example, no more than about 40 wt.%.
8. Method or use according to any preceding claim, wherein the polymer resin
comprises polyethylene in an amount of at least about 10 wt.%, for example,
at least about 60 wt.%.
9. Method or use according to any preceding claim, wherein the polymer resin is
free of virgin polymer.
10. Method or use according to any preceding claim, wherein the polymer resin
further comprises an impact modifier, for example, in an amount of less than
about 10 wt.%, for example, from about 1 wt. % to about 7.5 wt. %., or from
about 1.5 wt. % to about 3.0 wt.%.
11. Method or use according to any preceding claim, wherein the compatibilizer is
present in an amount of from about 5 wt. % to about 20 wt.%, for example,
from about 8 wt. % to about 12 wt. %.
12. Method or use according to any preceding claim, wherein the inorganic
particulate has a d50 of no greater than about 2.5 μm, for example, no greater
than about 1.0 μm or no greater than about 0.75 μm.
13. Method or use according to any preceding claim, wherein the surface
treatment agent comprises or is a compound having a formula (1):
A-(X-Y-CO)m(O-B-CO)nOH (1)
wherein
A is a moiety containing a terminating ethylenic bond with one or two adjacent
carbonyl groups;
X is O and m is 1 to 4 or X is N and m is 1;
Y is C1-18-alkylene or C2-18-alkenylene;
B is C2-6-alkylene; n is 0 to 5;
provided that when A contains two carbonyl groups adjacent to the ethylenic
group, X is N.
14. Method or use according to claim 13, wherein the compound is selected from
ß-carboxy ethylacrylate,ß-carboxyhexylmaleimide,10-carboxydecylmaleimide,
5-carboxy pentyl maleimide and ß-acryloyloxypropanoic acid.
15. Method or use according to any preceding claim, wherein the compatibilizer
comprises inorganic particulate material and an organic linker on a surface of
the particulate, wherein the organic linker has an oxygen-containing acid
functionality, and wherein the organic linker is a basic form of an organic acid.
16. Method or use according to any preceding claim, wherein the inorganic
particulate is calcium carbonate, for example, ground calcium carbonate.
17. Method or use according to any preceding claim, wherein the polymer resin
further comprises an antioxidant in an amount of less than about 5 wt.%, for
example, less than about 1 wt.%.
18. Method or use according to any preceding claim, wherein the article is a
portable waste or refuse container, for example, a wheelie bin, or a part or
component thereof.
19. A polymer resin suitable for use in the manufacture of an article therefrom by
injection moulding, wherein the polymer resin comprises a mixture of different
recycled polymers and from about 5 wt. % to about 20 wt. % compatibilizer
comprising inorganic particulate material and a surface treatment agent on a
surface of the inorganic particulate material, based on the total weight of the
polymer resin, wherein the polymer resin has a MFI @ 2.16 kg/190 ºC of
equal to or greater than 3.0 g/10 min, and wherein the polymer resin
comprises at least about 50 wt. % recycled polyethylene, based on the total
weight of the polymer composition, and from about 10 wt. % to about 30 wt. %
recycled polypropylene, based on the total weight of the polymer resin.
20. Polymer resin according to claim 19, further comprising an impact modifier, for
example, in an amount of less than about 10 wt. %, based on the total weight
of the polymer resin, for example, from about 1.0 wt. % to about 7.5 wt. %.
21. Polymer resin according to claim 19 or 20, further comprising antioxidant, for
example, in an amount of less than about 5 wt. %, based on the total weight
of the polymer resin, for example, from about 0.1 wt. % to about 1.0 wt. %.
22. Polymer resin according to anyone of claims 19-21, wherein the inorganic
particulate material has d50 of no greater than about 2.5 μm, for example, no
greater than about 1.0 μm, or no greater than about 0.75 μm.
23. A polymer resin according to any one of claims 19-22, wherein the surface
treatment agent comprises or is a compound having a formula (1):
A-(X-Y-CO)m(O-B-CO)nOH (1)
wherein
A is a moiety containing a terminating ethylenic bond with one or two adjacent
carbonyl groups;
X is O and m is 1 to 4 or X is N and m is 1;
Y is C1-18-alkylene or C2-18-alkenylene;
B is C2-6-alkylene; n is 0 to 5;
provided that when A contains two carbonyl groups adjacent to the ethylenic
group, X is N.
24. A polymer resin according to claim 23, wherein the compound is selected
from ß-carboxy ethylacrylate, ß-carboxyhexylmaleimide,
10-carboxydecylmaleimide, 5-carboxy pentyl maleimide and
ß-acryloyloxypropanoic acid.
25. A polymer resin according to any one of claims 19-24, wherein the
compatibilizer comprises inorganic particulate material and an organic linker
on a surface of the particulate, wherein the organic linker has an oxygencontaining
acid functionality, and wherein the organic linker is a basic form of
an organic acid.
26. A polymer resin according to any one of claims 19-25, wherein the inorganic
particulate is calcium carbonate, for example, ground calcium carbonate.
27. An article manufactured by injection moulding a polymer resin according to
any one of claims 19-26, or obtainable by the method according to any one of
claims 1-18.
28. Article according to claim 27, wherein the article has one or more of the
following:
a) reduced tiger stripes, compared to (i) an article comprising the polymer
resin absent the compatibilizer and/or (ii) an article made from the polymer
resin composition in which the compatibilizer has been replaced by a
polymer-based compatibilizer, or is free of tiger stripes;
b) a flexural modulus which is greater than an article made from the polymer
resin in which the compatibilizer has been replaced by a polymer-based
compatibilizer, as determined in accordance with ISO 178;
c) a flexural modulus of at least about 900 MPa, for example, from about 900
MPa to about 1200 MPa, as determined in accordance with ISO 178;
d) an impact strength which is greater than an article comprising the polymer
resin absent the compatibilizer, as determined in accordance in a Izod
notched impact test at 23 oC ± 2 oC in accordance with ISO 180;
e) an impact strength which is greater than (i) an article comprising the
polymer resin absent the compatibilizer, as determined in accordance in a
Izod notched impact test at 23 oC ± 2 oC in accordance with ISO 180
and/or a flexural modulus which is greater than (ii) an article made from
the polymer resin in which the compatibilizer has been replaced by a
polymer-based compatibilizer, as determined in accordance with ISO 178;
f) an impact strength of at least about 4.0 kJ/m2, for example, from about 4.0
kJ/m2 to about 20 kJ/m2, as determined in a Izod notched impact test at 23
oC ± 2 oC in accordance with ISO 180.
29. Article according to any one of claims 27 or 28, wherein the article is a
portable waste or refuse container, for example, a wheelie bin, or a part or
component thereof.