FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
RESIN COMPOSITION AND ARTICLE
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 resin composition, to a cable or cable
protection comprising or formed from said resin composition, to a rotomolded article
comprising or formed from a resin composition, to uses of said resin composition, to
the use of a recycled mixed polyolefin stream comprising at least polypropylene and
polyethylene in the manufacture of an article having an ESCR of at least about at
least about 50 hours, to a method of making an article having an ESCR of at least
about at least about 50 hours, to a method of making a resin composition, to a
method of making cable or cable protection, and to a method of making a
rotomolded article.
BACKGROUND OF THE INVENTION
There is an ever increasing demand to recycle and re-use polymer materials since
this provides cost and environmental benefits. As the need to recycle polymer waste
materials increase, there is a continuing need for the development of new ways to
utilise recycled polymer materials.
SUMMARY OF THE INVENTION
According to a first aspect, the present invention is directed to a resin composition
comprising:
at least 5 % by weight, or at least 10 % by weight, or at least 15 % by weight
polypropylene (PP),
at least about 40 % by weight of non-PP polymer,
at least about 1 % by weight of a compatabilizer comprising inorganic particulate
material and a surface treatment agent on a surface of the inorganic particulate,
wherein the resin composition is substantially free of a peroxide-containing additive.
According to a first aspect 1(a), the present invention is directed to a resin
composition comprising, based on the total weight of the resin composition:
greater than about 50% by weight polypropylene (PP), or at least about 75 % by
weight PP,
up to about 30 % by weight polyethylene, or up to about 25 % by weight
polyethylene, or free of polyethylene,
at least about 1 % by weight of a compatabilizer comprising inorganic particulate
material and a surface treatment agent on a surface of the inorganic particulate,
wherein the resin composition is substantially free of a peroxide-containing additive.
In certain embodiments of the first aspect 1(a), the resin composition has a MFI @
190 °C/2.16 kg of at least about 3.0 g/10 mins. In this and other embodiments, the
resin composition comprises at least about 85 % by weight PP and is substantially
free of polyethylene.
According to a second aspect, the present invention is directed to a cable or cable
protection comprising or formed from the resin composition according to the first
aspect or first aspect 1(a).
According to a second aspect 2(a), the present invention is directed to an article of
manufacture comprising or formed from the resin composition according to the first
aspect or first aspect 1(a).
According to a third aspect, the present invention is directed to a rotomolded article
comprising or formed from a resin composition according to the first aspect or first
aspect 1(a).
According to a third aspect 3(a), the present invention is directed to an injected
moulded article comprising of formed from a resin composition according to the first
aspect or first aspect 1(a).
According to a fourth aspect, the present invention is directed to the use of a resin
composition according to the first aspect in the manufacture of cable or cable
protection.
According to a fourth aspect 4(a), the present invention is directed to the use of a
resin composition according to the first aspect (1a) in the manufacture of an article,
for example, a plastic pallet.
According to a fifth aspect, the present invention is directed to the use of a resin
composition according to the first aspect to enhance the resistance to weathering or
ESCR of a cable or cable protection formed therefrom.
According to a sixth aspect, the present invention is directed to the use of a recycled
mixed polyolefin stream comprising at least polypropylene and polyethylene in the
manufacture of an article having an ESCR of at least about at least about 50 hours,
for example, at least about 150 hours, or at least about 250 hours, or at least about
400 hours, or at least about 500 hours, as may be determined in accordance with
ASTM D1693-01 under Condition B.
According to a seventh aspect, the present invention is directed to a method of
making an article having an ESCR of at least about at least about 50 hours, for
example, at least about 150 hours, or at least about 250 hours, or at least about 400
hours, or at least about 500 hours, as may be determined in accordance with ASTM
D1693-01 under Condition B, said method comprising forming said article from a
resin composition which is derived from a mixed recycled polyolefin stream
comprising polypropylene and polyethylene.
According to an eighth aspect, the present invention is directed to a method of
making a resin composition according to the first aspect, comprising compounding
the polypropylene and non-PP polymer, for example, polyethylene, with the
compatabilizer and other optional additives other than a peroxide-containing additive.
According to an eighth aspect 8(a), the present invention is directed to a method of
making a resin composition according to the first aspect 1(a), comprising
compounding the polypropylene and optional polyethylene, with the compatabilizer
and other optional additives other than a peroxide-containing additive.
According to a ninth aspect, the present invention is directed to a method of making
cable or cable protection, the method comprising extruding a resin composition
according to the first aspect to form said cable or cable protection.
According to a ninth aspect 9(a), the present invention is directed to a method of
making an article, for example, a plastic pallet, the method comprising injection
moulding a resin composition according to the first aspect 1(a) to form said article,
for example, said plastic pallet.
According to a tenth aspect, the present invention is directed to a method of making
a rotomolded article according to the third aspect, comprising forming the article by
rotation moulding a resin composition according to the first aspect.
DESCRIPTION OF THE INVENTION
The resin composition provides an effective polyolefin blend compatabilizer.
Typically, this involves a two step process. Without wishing to be bound by theory,
first, the surface treatment agent/coupling modifier reacts with the surface of the
inorganic particulate at relatively low temperatures, and then the surface treated
inorganic particulate is combined (at relatively higher temperatures) with the mixed
polyolefin blend (comprising polypropylene (PP) and non-PP such as polyethylene
(e.g., high density polyethylene (HDPE)), for example, by compounding, making its
way to, and reacting with macro-radical fragments. Thermo-mechanical degradation
of the polyolefinic components occurs during the combining (e.g., compounding)
process generating the macro-radical fragments. PP may be degraded due to chain
scission in the beta position, while the non-PP component, such as polyethylene,
may crosslink due to macro-radical recombination. Typically, a relatively small
amount of a peroxide-containing additive is added to catalyse the reactive extrusion
process (for example, dicumyl peroxide decomposes when heated to form alkoxy
radicals that, in turn, abstract hydrogen from the polymer backbone, forming polymer
radicals, and polyolefins are prone to chain scission reactions in the presence of free
radicals). Surprisingly, it has been found that resins having a relatively high PP
content (e.g., polyethylene contaminated with PP) and having good or even
improved mechanical/physical properties (e.g., elongation at break, impact strength
and Environmental Stress Crack Resistance (ESCR)) can be obtained in the
absence peroxide-containing additive. In this respect, and without wishing to be
bound by theory, thermo-mechanical degradation of recycled polyolefins during the
combining (e.g., compounding process) generates sufficient macro-radical fragments
to react with the surface treated inorganic particulate material, which serves to
decrease the interfacial tension between the immiscible polyolefin components, thus
enabling enhanced mechanical physical properties, even in the absence of peroxidecontaining
additive. Moreover, it has surprisingly been found that the addition of a
peroxide-containing additive, such as dicumyl peroxide, leads to a significant drop in
mechanical properties such as tensile stress and impact strength properties,
suggesting that there is an optimum macro-radical level quite dependent upon the
thermal history of the polyolefin. Thus, it has surprisingly been found that
mechanical properties may be improved by excluding peroxide-containing additives,
such as dicumyl peroxide, from resin compositions, such as those comprising
relatively high amounts of recycled polypropylene.
In certain embodiments, a stoichiometric amount of macro-radicals fragments is
generated in order to react with the surface treated inorganic particulate (i.e., one
pendant reactive double bond reacts with one macro-radical).
Resin composition
In certain embodiments, based on the total weight of the resin composition, the resin
composition comprises
at least 15 % by weight polypropylene (PP),
at least about 40 % by weight of non-PP polymer,
at least about 1 % by weight of a compatabilizer comprising inorganic particulate
material and a surface treatment agent on a surface of the inorganic particulate,
and is substantially free of a peroxide-containing additive.
In certain embodiments, the resin composition comprise less than 24 % by weight
polypropylene, for example, less than 23 % by weight polypropylene, or less than 22
% by weigh polypropylene, or less than 21 % by weight polypropylene, or less than
20 % polypropylene, or equal to or less than about 19. % by weight polypropylene.
In certain embodiments, the resin composition comprises from 16-19 % by weight
polypropylene, for example, from 17-18 % by weight polypropylene, or about 17 %
by weight polypropylene, for example about 17.0 % by weight polypropylene.
In certain embodiments, all of the polypropylene is recycled polypropylene.
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 polypropylene is derived from a mixed recycled polyolefin stream
comprising polypropylene and at least a portion of the non-PP polymer of the resin
composition.
In certain embodiments, the non-PP polymer comprises, consists essentially of, or
consists of, polyethylene. 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, 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 resin composition 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 resin composition is or derived from recycled post-consumer polymer waste.
In certain embodiments, the resin composition comprises at least about 50 % by
weight polyethylene, for example, from about 50-75 % by weight polyethylene, or
from about 60-75 % polyethylene, or from 65-75 % by weight polyethylene.
In certain embodiments, the resin composition 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/cm. 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, at least 75 % by weight, for example; 90-99 % by weight, of
the polymer in the resin composition 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, 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 accordance with the first aspect 1(a), the resin composition comprises greater
than about 50 % by weight polypropylene (PP), for example, at least about 60 % by
weight, or at least about 65 % by weight, or at least about 70 % by weight, or at least
about 75 % by weight, or at least about 80 % by weight, or at least about 85 % by
weight PP, based on the total weight of the resin composition. In this and other
embodiments, the resin composition may comprise up to about 30 % by weight of a
non-PP polymer such as polyethylene (PE), for example, up to about 20 % by weight
PE, or up to about 10 % by weight PE, or up to about 5 % by weight PE, or up to
about 2 % by weight PE, or up to about 1 % PE, or up to about 0.5 % by weight PE,
or up to about 0.1 % by weight PE. In certain embodiments, and other than impact
modifier when present, the resin composition is free of polymer other than PP. In
other words, in certain embodiments, excluding any impact modifier that may be
present, the polymer component of the resin composition is 100 % PP.
In certain embodiments, the resin composition 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 resin composition 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 ISO1183.
In certain embodiments, the resin composition has, in the absence of peroxidecontaining
additive, a MFI (melt flow index) of at least about 2 g/10 min (5.0 kg@190
°C), for example, at least about 3 g/10 min (5.0 kg@190 °C), or at least about 4 g/10
min (5.0 kg@190 °C), or at least about 5 g/10 min (5.0 kg@190 °C), or at least about
6 g/10 min (5.0 kg@190 °C). In certain embodiment, the resin composition has a
MFI of no greater than about 10 g/10 min (5.0 kg@190 °C), for example, no greater
than about to 8 g/10 min (5.0 kg@190 °C), or no greater than about 6 g/10 min (5.0
kg@190 °C), or no greater than about 4 g/10 min (5.0 kg@190 °C). MFI may be
determined in accordance with ISO 1133.
In certain embodiments, for example, certain embodiments of the first aspect 1(a),
the resin composition has, in the absence of a peroxide-containing additive, a MFI of
at least about 3.0 g/10 min (2.16 kg@190 °C), for example, at least about 4.0 g/10
min (2.16 kg@190 °C), or at least about 5.0 g/10 min (2.16 kg@190 °C), or at least
about 6.0 g/10 min (2.16 kg@190 °C). In certain embodiment, the resin composition
has a MFI of no greater than about 10 g/10 min (2.16 kg@190 °C), for example, no
greater than about to 8.0 g/10 min (2.16 kg@190 °C).
In certain embodiments, as described herein, the resin composition comprises a
secondary filler, for example, carbon black, for example, from about 0.1-5 % by
weight carbon black, for example, 0.5-2.0 % by weight carbon black.
In certain embodiments, as described herein, the resin composition comprises an
impact modifier, for example, from about 1-20 % by weight impact modifier, or from
about 2-10 %, or from about 2-7 %, or from about 2-5 % by weight of an impact
modifier.
In certain embodiments, the resin composition comprises antioxidant, for example,
up to about 5 % by weight antioxidant, or from about 0.1-1 % by weight antioxidant,
or from about 0.1-0.5 % by weight antioxidant.
In certain embodiments, the resin composition consists essentially of:
at least 15 % by weight polypropylene, for example, from 15 % by weight to less than
20 % by weight polypropylene,
from 50-75 % by weight by weight polyethylene, for example, HDPE
from 5-35 % by weight compatabilizer, for example, 5-15 % by weight
compatabilizer, optionally wherein the inorganic particulate is calcium carbonate,
optionally having a d50 of less than about 1 μm,
from 0.1-4 % by weight carbon black, for example, from 0.5-2.0 % by weight carbon
black,
from 1-10 % by weight impact modifier, for example, 2-5 % impact modifier, such as
rSBS, and
up to 5 % by weight of additional additives other than a peroxide-containing additive,
for example, 0.1-1 % by weight antioxidant.
In certain embodiments, the resin composition consists of:
from 15 % by weight to less than 20 % by weight polypropylene,
from 50-75 % by weight by weight polyethylene, for example, 60-75 % by weight
polyethylene, for example, 65-75 % by weight polyethylene
from 5-35 % by weight compatabilizer, for example, 5-15 % by weight
compatabilizer,
from 0.5-2 % by weight carbon black,
from 1-10 % by weight impact modifier, for example, from 2 to 5 % by weight impact
modifier, and
up to 2 % by weight antioxidant, for example, from 0.1-0.5 % by weight antioxidant
with the proviso that the total weight of components in the resin sum to 100 %.
In certain embodiments, the resin composition consists essentially of:
at least 50 % by weight PP, for example, at least 65 % by weight PP
from 15-25 % by weight PE,
from 2-10 % by weight compatabilizer,
from 2-10 % by weight impact modifier, and
up to about 5 % by weight of additional additives other than a peroxide-containing
additive, for example, 0.1-1.0 % by weight antioxidant.
In certain embodiments, the resin composition consists of:
from 60-70 % by weight PP,
from 20-25 % by weight PE,
from 3-7 % by weight compatabilizer,
from 3-7 % by weight impact modifier, and
up to 2 % by weight antioxidant, for example, 0.1-0.5.0 % by weight antioxidant, with
the proviso that the total weight of components in the resin sum to 100 %, and
optionally
an MFI of from about 3.0-4.0 g/10 min (2.16 kg@190 °C).
In certain embodiments, the resin composition consists essentially of:
at least 80 % by weight PP, for example, at least 85 % by weight PP
is free of polyethylene,
from 2-10 % by weight compatabilizer,
from 2-10 % by weight impact modifier, and
up to about 5 % by weight of additional additives other than a peroxide-containing
additive, for example, 0.1-1.0 % by weight antioxidant.
In certain embodiments, the resin composition consists of:
from 85-95 % by weight PP, for example, from 88-92 % by weight PP
is free of polyethylene,
from 3-7 % by weight compatabilizer,
from 3-7 % by weight impact modifier, and
up to 2 % by weight antioxidant, for example, 0.1-0-5.0 % by weight antioxidant, with
the proviso that the total weight of components in the resin sum to 100 %, and
optionally
an MFI of from about 5.0-7.0 g/10 min (2.16 kg@190 °C).
In such embodiments, including those consisting essentially of, or consisting of,
various components, the polypropylene and at least a portion of the polyethylene,
when present, is derived from a recycled mixed polyolefin source, and at least a
portion of the polyethylene is derived from another recycled source.
In such embodiments, all of the polypropylene and polyethylene may be recycled
polypropylene and polyethylene, optionally wherein the impact modifier, when
present, may be derived from recycled polymer.
In such embodiments, 90-100 % by weight of all polymer in the resin composition,
other than impact modifier (which may be rSBS), may be polypropylene and, when
present, polyethylene.
In such embodiments, all of the polymer in the resin may be recycled polymer.
Compatabilizer
The resin composition comprises at least about 1 % by weight of a compatabilizer.
The compatabilizer comprises an inorganic particulate and surface treatment agent
on a surface of the inorganic particulate.
The compatabilizer may be present in the resin composition in an amount ranging
from about 1 % up to about 45 % by weight, based on the total weight of the resin
composition. 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 8 % to about 12 % by
weight, based on the total weight of the resin composition. The compatabilizer may
be present in amount less than or equal to about 40% by weight of the polymeric
fibre, for example, less than or equal to about 35% by weight, or less than or equal to
about 30 % by weight, or less than or equal to about 25 % by weight, or less than or
equal to about 20 % by weight, or less than or equal to about 15 % by weight, or less
than or equal to about 10 % by weight, based on the total weight of the resin
composition.
In certain embodiments, for example, certain embodiments of the first aspect 1(a),
the compatabilizer may be present in the resin composition in an amount ranging
from about 1 % by weight to about 10 % by weight, based on the total weight of the
resin composition, for example, from about 2-10 % by weight, or from about 2-8 % by
weight, or from about 3-7 % by weight, or from about 4-6 % by weight, or about 5 %
by weight.
The surface treatment agent (i.e., coupling modifier) may be present in the resin
composition in an amount of from about 0.01 % by weight to about 4 % by weight,
based on the total weight of the resin composition, 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 resin composition.
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 filler 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 recycled resin composition by cross-linking or grafting
the different polymers. In recycled polymer resin compositions comprising recycled
and optionally virgin polymer, the functional filler 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-B15
CO)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 there methods of preparation are described in USA-
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C to 200C. 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 compatabilizer 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 compatabilizer, 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 compatabilizer in an
amount equal to or less than about 1.2 wt.% based on the total weight of the
compatabilizer, 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 compatabilizer in an amount greater than about
0.05 wt. %. In further embodiments, the coupling modifier is present in the
compatabilizer 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 compatabilizer 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 compatabilizer, 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 compatabilizer in an amount
equal to or less than about 0.9 wt.% based on the total weight of the compatabilizer,
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 compatabilizer 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 carboncarbon
double bond.
In certain embodiments, the organic linker is a non-polymeric species and, in certain
embodiments, has a molecular mass of no greater than about 400 g/mol. By “nonpolymeric”
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-polymeric species has a molecular mass of no
greater than about 800 g/mol, or no greater than about 600 g/mol, or no greater than
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 species comprises no more than about 50 carbon
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
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
a conjugate base. In certa
unsaturated C4+ group, or an unsaturated C
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 par
organic tail having at least one carbon
with the different polymer species in the resin composition. Thus, the compatibilizer
serves to cross-link or graft the different polymer types, with the o
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 parti
overall effect is to enhance the compatibility of the different polymer types in the
polymer blend which, in turn, may enhance processing of the polymer blend and/or
one or more physical properties (e.g., one or more mechanical properties) of
article of manufacture made from the polymer blend. 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.
dehydrating an organic acid having
, respectively, wherein R is an unsaturated C
carbon-carbon double bond. The carboxylate group (which is
certain embodiments, R is an unsaturated C
C5+ group.
carbon-carbon double bond coordinates/associates
organic linker acting
ut carbon-carbon
C2+ group
in C3+ group, or an
particulate, and the
rganic particulate. The
an
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 an a carbon-carbon double bond coordinates/associates with the different
polymer species in the polymer blend).
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 carboncarbon
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 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 that 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 resin composition 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 resin composition
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 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 resin
composition 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. %. Typically, the peroxidecontaining
additive, if present, is present in an amount greater than about 0.01 wt. %
based on the weight of the polymer in the resin composition.
The compatabilizer 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C. 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/couling modifier may be applied during de-aggregation carried out in a milling
machine.
The compatabilizer 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
compatabilizer. Alternatively, a portion of the total required amount of antioxidant
may be present in both the compatabilizer and added separately from the
compatabilizer to the resin composition.
Secondary filler
In certain embodiments, the resin composition comprises filler in addition to the
compatabilizer 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.
Impact modifier
In certain embodiments, the resin composition comprises an impact modifier, for
example, up to about 20 % by weight of an impact modifier, based on the total
weight of the filled 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 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 8 % by weight, 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 resin composition.
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 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 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 resin composition, 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 is
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
polypropylene and, when present, non-PP polymer, for example, polyethylene, with
the compatabilizer and other optional additives other than a peroxide-containing
additive.
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 in the absence of peroxide containing additive.
The relative amounts of polypropylene, non-PP (e.g., polyethylene) 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 polymer or 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 (e.g., carbon black) 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 thermo-mechanical
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.
Polymer articles, for example, cable or cable protection or rotomoulded product, may
then be formed by any suitable technique, for example, by extrusion or rotational
moulding, using conventional techniques known in the art, as will be readily apparent
to one of ordinary skill in the art.
Likewise, polymer articles such as plastic pallets may then be formed by any suitable
method, for example, by injection moulding, using conventional techniques known in
the art, as will be readily apparent to one of ordinary skill in the art.
The articles which may be formed from the resin composition are many and various.
In certain embodiments, the article is cable or cable protection.
In certain embodiments, the cable is an electric or optical cable, and/or the cable
protection is suitable for use in or as an electric or optical cable.
In certain embodiments, the cable or cable protection is compliant with any one or
more of International Standard IEC 60502-2 (second edition, 2005-03), IEC 60811-1-
1 (Edition 2.1, 2001-07), IEC 60811-2-1 (Edition 2.1, 2001-11).
In certain embodiments, the cable comprises a metallic conductor (e.g., wire), an
insulating layer about the conductor, optionally a metallic sheath about the insulating
layer, and an outer layer comprising or formed from the resin composition, i.e., the
outer layer is the cable protection.
In certain embodiments, the cable or cable protection has one or more of the
following:
Densityy of at least 0.95 g/cm3 (which may be determined in accordance with
ISO1183);
Hardness of from about 55-60 Shore D;
Elongation at break of at least about 300 %;
Tensile strength of at least 18 MPa; and/r
Carbon balck conten of about 2.5 %
In certain embodiments, the article, for example, cable or cable protection, has an
ESCR of at least about at least about 50 hours, for example, at least about 150
hours, or at least about 250 hours, or at least about 500 hours, or at least about 750
hours, or at least about 100 hours, or at least about 1500 hours, or at least about
2000 hours, or at least about 2500 hours, or at least about 3000 hours, or at least
about 3500 hours, or at least about 4000 hours, or at least about 4500 hours, or at
least about 5000 hours, or at least about 6000 hours, or at least about 7000 hours,
or at least about 8000 hours, or at least about 9000 hours, or at least about 10,000
hours.
ECSR is a mechanical failure by cracking of a polymer material which occurs in a
surface active environment. These are caused by the combined presence of
stresses and the surface active agent. The surface active agent does not chemically
attack the polymeric components or modify the fracture mechanism. The active
environment only accelerates the stress cracking process.
In certain embodiments, ECSR is determined in accordance with ASTM D1693-01
under Condition B. According to this method, ten rectangular-shaped specimens are
cut from a moulded plaque prepare with standard methods, for example, in
accordance with Procedure C of Annex 1 of Practice D4703 (see section 8.1 of
ASTM D1693-01), to the dimensions given in Condition B of ASTM D1693-01.
Condition B is typically used for materials having a density greater than about 0.925
g/cm3. Test pieces may be conditioned in accordance with Procedure A of Practice
D618 (a minimum of 40 hours at 23 °C and a relative humidity of 50 %) – see
section 9.1 of ASTM D1693-01.
In accordance with ASTM D1693-01, after 50 % of the test pieces have failed the
time to failure (F50) is taken. This time to failure, measured in hours, is used to
determine and compare the polymers resistance to cracking.
According to certain embodiments, there is provided of making an article having an
ESCR of at least about at least about 50 hours, for example, at least about 150
hours, or at least about 250 hours, or at least about 400 hours, or at least about 500
hours, or at least about 750 hours, or at least about 100 hours, or at least about
1500 hours, or at least about 2000 hours, or at least about 2500 hours, or at least
about 3000 hours, or at least about 3500 hours, or at least about 4000 hours, or at
least about 4500 hours, or at least about 5000 hours, or at least about 6000 hours,
or at least about 7000 hours, or at least about 8000 hours, or at least about 9000
hours, or at least about 10,000 hours, as may be determined in accordance with
ASTM D1693-01 under Condition B, said method comprising forming said article
from a resin composition which is derived from a mixed recycled polyolefin stream
comprising polypropylene and polyethylene.
In other embodiments, said recycled mixed polyolefin stream used to manufacture
an article, for example, cable or cable protection, having an ESCR of at least about
at least about 50 hours, for example, at least about 150 hours, or at least about 250
hours, or at least about 400 hours, or at least about 500 hours, or at least about 750
hours, or at least about 100 hours, or at least about 1500 hours, or at least about
2000 hours, or at least about 2500 hours, or at least about 3000 hours, or at least
about 3500 hours, or at least about 4000 hours, or at least about 4500 hours, or at
least about 5000 hours, or at least about 6000 hours, or at least about 7000 hours,
or at least about 8000 hours, or at least about 9000 hours, or at least about 10,000
hours, as may be determined in accordance with ASTM D1693-01 under Condition B
In certain embodiments, the resin composition comprises at least about 15 % by
weight polypropylene and at least about 40 % by weight polyethylene, at least about
1 % by weight of compatabilizer comprising inorganic particulate material and a
surface treatment agent on a surface of the inorganic particulate, and comprises or
does not comprise a peroxide-containing additive.
In certain embodiments, the article of manufacture is an article that may be
manufactured by injection moulding. In certain embodiments, the article of
manufacture is a plastic pallet.
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.
In certain embodiments, the polymer resin comprises less than 70 % by weight
polypropylene, for example, less than 60 % by weight polypropylene, or less than 50
% by weight polypropylene, or less than 40 % by weight polypropylene, or less than
30 % by weight polypropylene, or less than 20 % by weight polypropylene.
In certain embodiments, for example, embodiments in which resin composition
comprises HDPE, the resin composition comprises greater than 20 % by weight
polypropylene, based on the total weight of the resin composition.
For the avoidance of doubt, the present application is directed to the subject-matter
described in the following numbered paragraphs:
1. A resin composition comprising, based on the total weight of the composition:
greater than about % by weight polypropylene (PP), or at least about 75 % by weight
PP
up to about 30 % by weight polyethylene (PE), or up to about 25 % by weight PE, or
is free of PE,
at least about 1 % by weight of a compatabilizer comprising inorganic particulate
material and a surface treatment agent on a surface of the inorganic particulate,
wherein the resin composition is substantially free of a peroxide-containing additive.
2. Resin composition according to numbered paragraph 1, comprising at least about
75 % by weight PP, for example, at least about 85 % by weight PP.
3. Resin composition according to numbered paragraph 2, comprising at least about
85 % by weight PP.
4. Resin composition according to numbered paragraph 3, wherein the resin
composition is free of PE.
5. Resin composition according to numbered paragraph 1 or 2, comprising from
about 20-25 % by weight PE.
6. Resin composition according to any preceding numbered paragraph, wherein all
of the PP, or all of the PP and PE, is recycled.
7. Resin composition according to any preceding numbered paragraph, wherein the
non-PP polymer, when present, comprises, consists essentially of, or consists of,
PE, for example, recycled HDPE.
9. Resin composition according to any preceding numbered paragraph, comprising
a secondary filler
10. Resin composition according to any preceding numbered paragraph, comprising
an impact modifier, for example, from about 1-20 % by weight impact modifier.
11. Resin composition according to any preceding numbered paragraph, comprising
antioxidant, for example, up to about 5 % by weight antioxidant.
12. Resin composition according to any preceding numbered paragraph, wherein
the resin composition consists essentially of:
at least 50 % by weight PP, for example, at least 65 % by weight PP
from 15-25 % by weight PE,
from 2-10 % by weight compatabilizer,
from 2-10 % by weight impact modifier, and
up to about 5 % by weight of additional additives other than a peroxide-containing
additive, for example, 0.1-1.0 % by weight antioxidant.
13. Resin composition according to numbered paragraph 12, wherein the resin
composition consists of:
from 60-70 % by weight PP,
from 20-25 % by weight PE,
from 3-7 % by weight compatabilizer,
from 3-7 % by weight impact modifier, and
up to 2 % by weight antioxidant, for example, 0.1-0.5.0 % by weight antioxidant, with
the proviso that the total weight of components in the resin sum to 100 %, and
optionally
an MFI of from about 3.0-4.0 g/10 min (2.16 kg@190 °C).
14. Resin composition according to any one of numbered paragraphs 1-11, wherein
the resin composition consists essentially of:
at least 80 % by weight PP, for example, at least 85 % by weight PP
is free of polyethylene,
from 2-10 % by weight compatabilizer,
from 2-10 % by weight impact modifier, and
up to about 5 % by weight of additional additives other than a peroxide-containing
additive, for example, 0.1-1.0 % by weight antioxidant.
15. Resin composition according to numbered paragraph 14, wherein the resin
composition consists of:
from 85-95 % by weight PP, for example, from 88-92 % by weight PP
is free of polyethylene,
from 3-7 % by weight compatabilizer,
from 3-7 % by weight impact modifier, and
up to 2 % by weight antioxidant, for example, 0.1-0.5.0 % by weight antioxidant, with
the proviso that the total weight of components in the resin sum to 100 %, and
optionally
an MFI of from about 5.0-7.0 g/10 min (2.16 kg@190 °C).
16. Resin composition according to any preceding numbered paragraph, wherein all
of the PP and, when present, PE is recycled, and wherein the impact modifier, when
present, is derived from recycled polymer.
17. Resin composition according to any preceding numbered paragraph, wherein
90-100 % by weight of all polymer in the resin composition, other than impact
modifier, is PP and, when present, PE.
18. Resin composition according to any preceding numbered paragraph, wherein all
of the polymer in the resin is recycled polymer.
19. Resin composition according to any preceding numbered paragraph, wherein
the resin has an MFI of at least about 3.0 g/10 min (2.16 kg @ 190 C).
20. Resin composition according to any preceding numbered paragraph, wherein
the surface treatment agent comprises a first 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.
21. Resin composition according to numbered paragraph 20, wherein the first
compound is selected from ß-carboxy ethylacrylate, ß-carboxyhexylmaleimide,
10-carboxydecylmaleimide, 5-carboxy pentyl maleimide and ß-acryloyloxypropanoic
acid.
22. Resin composition according to any one of numbered paragraphs 1-19, wherein
the compatabilizer 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.
23. An article of manufacture comprising or formed from the resin composition
according to any preceding numbered paragraph.
24. Article according to numbered paragraph 23, wherein the article is a plastic
pallet.
25. Use of a resin composition according to any one of numbered paragraphs 1-22
in the manufacture of an article of manufacture.
26. Use according to numbered paragraph 25, wherein the article is a plastic pallet.
27. A method of making a resin composition according to any one of numbered
paragraph 1-22, comprising compounding the PE and, when present, non-PP
polymer, for example, polyethylene, with the compatabilizer and other optional
additives other than a peroxide-containing additive.
28. A method according to numbered paragraph 27, 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 in accordance with numbered paragraph 27.
29. A method of making a plastic pallet, the method comprising injection moulding a
resin composition according to any one of numbered paragraphs 1-22 to form said
plastic pallet, optionally wherein the method further comprises making the resin
composition in accordance with numbered paragraphs 27 or 28.
EXAMPLES
Example 1
Six polymer resins were prepared as shown in Table 1 below. All polymer resins
were prepared via melt mixing with a Coperion ZSK18 twin-screw extruder. 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.
Melt Flow Index (MFI) properties of the six polymer resin samples were determined.
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. MFI was tested in accordance with ISO 1133. The
MFI properties of the polymer resin samples 1-6 is provided in Table 1 below.
Injection moulded samples were prepared from the six 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 1 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 1 below shows the tensile
stress at yield (MPa) and break (%) of each injection moulded sample.
Impact testing:
Charpy notched impact tests were carried out at -20 ± 2°C using an Instron Ceast
9340 falling-weight impact tester, in accordance with ISO 179-2. The results supplied
in Table 1 below correspond to an average of complete break measurements for
each blend.
Table 1.
Formulations
1 2 3 4 5 6
Recycled HDPE (wt. %) 22.425 22.42 22.415 - - -
Recycled PP (wt. %) 67.275 67.27 67.265 89.70 89.69 89.68
Compatabilizer (wt. %) 5.0 5.0 5.0 5.0 5.0 5.0
Impact modifier (wt. %) 5.0 5.0 5.0 5.0 5.0 5.0
Dicumyl Peroxide (wt. %) - 0.01 0.02 - 0.01 0.02
Anti-oxidant (wt. %) 0.3 0.3 0.3 0.3 0.3 0.3
Total (wt. %) 100 100 100 100 100 100
Test Results
Flexural Modulus (MPa) 929.5 915.8 901.9 953.0 932.0 946.6
Charpy Impact Strength,
Unnotch @-20oC, Complete
Break (KJ/m2)
87.6 67.8 58.2 42.5 31.9 30.7
Tensile Stress @ Yield
(MPa)
20.8 20.9 20.6 21.2 20.5 20.4
Tensile Strain @ Break (%) 187.0 101.5 66.1 117.0 55.1 46.6
MFI, 2.16 kg @ 190oC, (g/10
min)
3.31 4.03 3.88 5.43 5.85 6.25
WE CLAIM:
1. A resin composition comprising:
at least 15 % by weight polypropylene (PP),
at least about 40 % by weight of non-PP polymer,
at least about 1 % by weight of a compatabilizer comprising inorganic
particulate material and a surface treatment agent on a surface of the
inorganic particulate,
wherein the resin composition is substantially free of a peroxidecontaining
additive.
2. Resin composition according to claim 1, comprising less than 24 % by
weight polypropylene, for example, less than 23 % by weight
polypropylene.
3. Resin composition according to claim 1, comprising from 16-19 % by
weight polypropylene.
4. Resin composition according to claim 2, comprising from 17-18 % by
weight polypropylene.
5. Resin composition according to claim 3 comprising about 17 % by weight
polypropylene, for example 17.0 % by weight polypropylene.
6. Resin composition according to claim 4, wherein all of the polypropylene is
recycled polypropylene.
7. Resin composition according to any preceding claim, wherein the non-PP
polymer comprises, consists essentially of, or consists of, polyethylene,
optionally wherein the polyethylene comprises 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.
8. Resin composition according to any preceding claim, comprising at least
about 50 % by weight polyethylene, for example, from about 50-75 % by
weight polyethylene.
9. Resin composition according to any preceding claim, comprising a
secondary filler, for example, carbon black, for example, from about 1-4 %
by weight carbon black.
10. Resin composition according to any preceding, comprising an impact
modifier, for example, from about 1-20 % by weight impact modifier.
11. Resin composition according to any preceding, comprising antioxidant, for
example, up to about 5 % by weight antioxidant.
12. Resin composition according to any preceding claim, wherein the resin
composition consists essentially of:
from 15 % by weight to less than 20 % by weight polypropylene,
from 50-75 % by weight by weight polyethylene,
from 5-35 % by weight compatabilizer,
from 0.1-4 % by weight carbon black,
from 1-10 % by weight impact modifier, and
up to 5 % by weight of additional additives other than a peroxidecontaining
additive, for example, antioxidant.
13. Resin composition according to any preceding claim, wherein the resin
composition consists of:
from 15 % by weight to less than 20 % by weight polypropylene,
from 50-75 % by weight by weight polyethylene, for example, 60-75 %
by weight polyethylene
from 5-35 % by weight compatabilizer, for example, 5-15 % by weight
compatabilizer,
from 0.5-2 % by weight carbon black,
from 1-10 % by weight impact modifier, for example, from 2 to 5 % by
weight impact modifier, and
up to 2 % by weight antioxidant,
with the proviso that the total weight of components in the resin sum to
100 %.
14. Resin composition according to any preceding claim, wherein all of the
polypropylene and polyethylene is recycled polypropylene and
polyethylene, optionally wherein the impact modifier, when present, is
derived from recycled polymer.
15. Resin composition according to any preceding claim, wherein 90-100 % by
weight of all polymer in the resin composition, other than impact modifier,
is polypropylene and polyethylene.
16. Resin composition according to any preceding claim, wherein all of the
polymer in the resin is recycled polymer.
17. Resin composition according to any preceding claim, wherein the surface
treatment agent comprises a first 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.
18. Resin composition according to claim 17, wherein the first compound is
selected from ß-carboxy ethylacrylate, ß-carboxyhexylmaleimide,
10-carboxydecylmaleimide, 5-carboxy pentyl maleimide and
ß-acryloyloxypropanoic acid.
19. Resin composition according to any one of claim 1-16, wherein the
compatabilizer 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.
20. Cable or cable protection comprising or formed from the resin composition
according to any preceding claim.
21. Cable or cable protection according to claim 20 having an enhanced
resistance to weathering.
22. Cable or cable protection according to claim 20 or 21, having an
Environmental Stress Crack Resistance (ESCR) of at least about 50
hours, for example, at least about 150 hours, or at least about 250 hours,
or at least about 400 hours, or at least about 500 hours, as may be
determined in accordance with ASTM D1693-01 under Condition B.
23. A cable or wire comprising, for example, encased by, cable protection
according to claim 20, 21 or 22.
24. A rotomolded article comprising or formed from a resin composition
according any one of claims 1-19.
25. Use of a resin composition according to any one of claims 1-19 in the
manufacture of cable or cable protection.
26. Use of a resin composition according to any one of claim 1-19 to enhance
the resistance to weathering or ESCR of a cable or cable protection
formed therefrom.
27. Use of a recycled mixed polyolefin stream comprising at least
polypropylene and polyethylene in the manufacture of an article having an
ESCR of at least about at least about 50 hours, for example, at least about
150 hours, or at least about 250 hours, or at least about 400 hours, or at
least about 500 hours, or at least about 10000 hours, as may be
determined in accordance with ASTM D1693-01 under Condition B.
28. A method of making an article having an ESCR of at least about at least
about 50 hours, for example, at least about 150 hours, or at least about
250 hours, or at least about 400 hours, or at least about 500 hours, or at
least about 1000 hours, as may be determined in accordance with ASTM
D1693-01 under Condition B, said method comprising forming said article
from a resin composition which is derived from a mixed recycled polyolefin
stream comprising polypropylene and polyethylene.
29. Use or method according to claim 25 or claim 26, wherein the resin
composition comprises at least about 15 % by weight polypropylene and at
least about 40 % by weight polyethylene, at least about 1 % by weight of
compatabilizer comprising inorganic particulate material and a surface
treatment agent on a surface of the inorganic particulate, wherein the resin
composition comprises or does not comprise a peroxide-containing
additive.
30. A method of making a resin composition according to any one of claims 1-
19, comprising compounding the polypropylene and non-PP polymer, for
example, polyethylene, with the compatabilizer and other optional
additives other than a peroxide-containing additive.
31. A method according to claim 31, 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 in accordance with claim 30.
32. A method of making cable or cable protection, the method comprising
extruding a resin composition according to any one of claims 1-19 to form
said cable or cable protection, optionally wherein the method further
comprises making the resin composition in accordance with claims 30 or
31.

33. A method of making a rotomolded article according to claim 24, comprising
forming the article by rotation molding a resin composition according to
any one of claims 1-19.