F O R M 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
COMPOSITIONS FOR INJECTION MOULDING
2. APPLICANT(S)
(a) NAME
(b) NATIONALITY
(c) ADDRESS
(a) NAME
(b) NATIONALITY
(c) ADDRESS
(a) NAME
(b) NATIONALITY
(c) ADDRESS
HERRING, George, Birks
UNITED KINGDOM National
19 Dunnon Road,
Hartlepool TS25 4EF,
UNITED KINGDOM
MOLDOVAN, Daniel, Gene
AMERICAN National
796 South Crest Road,
Chattanooga, TN 37404,
U.S.A.
REBIH, Fatima
UNITED KINGDOM National
16 Pagoda Drive,
Duporth,
St. Austell, Cornwall PL26 6AW,
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
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TECHNICAL FIEILD
The present invention is directed to the use of a filled polymer resin in the manufacture of an
article therefrom by injection moulding, to a method of manufacturing an article by injection
moulding a filled polymer resin, to a method for enabling or improving the injection
mouldability of a polymer resin comprising recycled polymer, wherein the polymer resin
comprises recycled polymer and functional filler, to the use of a functional filler in a polymer
resin comprising recycled polymer to improve the injection mouldability of the polymer resin,
to an article of manufacture obtained by injection moulding a filled polymer resin, and to a
filled polymer resin.
BACKGROUND OF THE INVENTION
There is an ever increasing demand to recycle and re-use polymer materials since this
provides cost and environmental benefits. However, the reprocessing of recycled polymer
waste presents challenges which are not necessarily encountered during processing of
polymer compositions derived from virgin polymer. For example, recycled polymers may be
unsuitable for injecting moulding.
As the need to recycle polymer waste materials increases, there is a continuing need for the
development of new compositions for the economically viable processing of polymer waste
materials into high quality articles of manufacture.
SUMMARY OF THE INVENTION
According to a first aspect, the present invention is directed to the use of a filled polymer
resin in the manufacture of an article therefrom by injection moulding, wherein the polymer
resin comprises recycled polymer and functional filler, wherein the function filler comprises
an inorganic particulate which (i) is surface treated and/or (ii) has a d50 of less than about 2.5
µm, and wherein the filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin during
injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent MFI of
the filled polymer resin during injection moulding; and/or
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(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, for example, less than about
2.0 g/10 min, and optionally:
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin HDPE
resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10 min, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE polymer
resin having a MFI of 8.0 g/10 mins @ 2.16 kg/190 °C.
According to a second aspect, the present invention is directed to a method of
manufacturing an article by injection moulding, the method comprising injection moulding an
article from a filled polymer resin, wherein the filled polymer resin comprises recycled
polymer and functional filler, wherein the function filler comprises an inorganic particulate
which (i) is surface treated and/or (ii) has a d50 of less than about 2.5 µm, and wherein the
filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin during
injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent MFI of
the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, for example, less than about
2.0 g/10 min, and optionally:
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin HDPE
resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10 min, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE polymer
resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
According to a third aspect, the present invention is directed to the use of a functional filler in
a polymer resin comprising recycled polymer MFI to improve the injection mouldability of the
polymer resin, wherein the function filler comprises an inorganic particulate which (i) is
surface treated and/or (ii) has a d50 of less than about 2.5 µm.
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According to a fourth aspect, the present invention is directed to a method for enabling or
improving the injection mouldability of a polymer resin comprising recycled polymer, the
method comprising filling the polymer resin with a functional filler, forming a filled polymer
resin, and manufacturing an article of manufacture from the filled polymer resin by injection
moulding, wherein the function filler comprises an inorganic particulate which (i) is surface
treated and/or (ii) has a d50 of less than about 2.5 µm, and wherein the filled polymer resin
has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin during
injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent MFI of
the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, for example, less than about
2.0 g/10 mins, and
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin HDPE
resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10 mins, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE polymer
resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
According to a fifth aspect, the present invention is directed to an article of manufacture
obtained by injection moulding a filled polymer resin as defined in any of the first, second,
third or fourth aspects.
According to a sixth aspect, the present invention is directed to a filled polymer resin suitable
for use in the manufacture of an article therefrom by injection moulding, wherein the polymer
resin comprises recycled polymer and functional filler, wherein the function filler comprises
an inorganic particulate which (i) is surface treated and/or (ii) has a d50 of less than about 2.5
µm, and wherein the filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin during
injection moulding; and/or
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(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the MFI of the filled
polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, for example, less than about
2.0 g/10 min, and optionally:
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin HDPE
resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10 min, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE polymer
resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
DETAILED DESCRIPTION OF THE INVENTION
Conventional wisdom is that a polymer resin must have a certain minimum Melt Flow Index
(MFI) for it to be suitable for injection moulding. Surprisingly, however, it has been found
that a polymer resin comprising recycled polymer and having a relatively low MFI (i.e.,
relative to the MFI of conventional virgin polymer resin used in injection moulding) can be
injected moulded providing functionally and aesthetically acceptable articles of manufacture
by filling the polymer resin with a functional filler. The filled polymer resin derived from
recycled polymer may perform better even than virgin polymer resin. Without wishing to be
bound by theory, it is believed that the polymer resin having a relatively low MFI under
testing behaves differently than expected during injection moulding – it injection moulds as it
if had a much higher MFI than the MFI measured under testing. It is currently believed that
shear thinning effects take place. This surprising finding enables greater utility of recycled
polymers previously thought unsuitable for injection moulding, and may provide cost and
environmental benefits as injection moulded articles, particularly thin-walled articles of
manufacture, can be manufactured from a greater variety of recycled polymers (including
mixed polymer), which is normally cheaper than virgin resin, and means reliance on virgin
polymers may be reduced and utility of recycled polymers increased, which is
environmentally desirable. Further, the inclusion of filler provides additional cost and
environmental benefits as less polymer is used. The filler is functionalised through
incorporation of a surface treatment and/or by controlling particle size.
As such, by “functional filler” is a meant a filler material which enhances the processability by
injection moulding of a polymer resin comprising recycled polymer. The functional filler
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comprises inorganic particulate which (i) is surface treated and/or (ii) has a d50 of no greater
than about 2.5 µm. In certain embodiments, functional filler comprises inorganic particulate
having a d50 of no greater than about 2.5 µm which is surface treated. In certain
embodiments, the enhancement in processability may be assessed by comparison with:
(i) the polymer resin absent the functional filler; and/or
(ii) the polymer resin filled with a filler which is not surface treated and/or has a d50
greater than 2.5 µm; and/or
(iii) virgin polymer resin having an MFI of at least 2.0 g/10 mins @ 2.16 kg/190° C, or at
least 2.5 g/10 mins @ 2.16 kg/190° C, or from 2.0 g/10 mins to about 30 g/10 mins
@ 2.16 kg/190° C, or from 2.5 g/10 mins to about 30 g/10 mins @ 2.16 kg/190° C;
and/or
(iv) a virgin polymer resin having an MFI of at least 2.0 g/10 mins @ 2.16 kg/190° C, or at
least 2.5 g/10 mins @ 2.16 kg/190° C, or from 2.0 to about 30 g/10 mins @ 2.16
kg/190° C, or from 2.5 g/10 mins to about 30 g/10 mins @ 2.16 kg/190° C, and which
is filled with the functional filler; and/or
(v) a virgin polymer resin having an MFI of at least 2.0 g/10 mins @ 2.16 kg/190° C, or at
least 2.5 g/10 mins @ 2.16 kg/190° C, or from 2.0 g/10 mins to about 30 g/10 mins
@ 2.16 kg/190° C, or from 2.5 g/10 mins to about 30 g/10 mins @ 2.16 kg/190° C,
which is filled with a filler which is not surface treated and/or has a d50 greater than
2.5 µm; and/or
(vi) a virgin polymer resin having a comparable MFI; and/or
(vii) a virgin polymer resin having a comparable MFI and which is filled with the functional
filler; and/or
(viii) a virgin polymer resin having a comparable MFI and which is filled with a filler which
is not surface treated and/or has a d50 greater than 2.5 µm; and/or
(ix) an unfilled virgin HDPE polymer resin having a MFI of 8.0. g/10 mins @ 2.16
kg/190°C.
Processability metrics include:
(1) the Spiral Flow Number (SFN) of the filled polymer resin (SFN is discussed in greater
detail below)
(2) the surface finish of the article formed by injection moulding; and/or
(3) the colour of the article formed by injection moulding; and/or
(4) cycle time; and/or
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(5) peak injection pressure (average and/or range, at equivalent MFI); and/or
(6) mould filling (i.e., flowability into and in the mould); and/or
(7) weight range across 32 shots; and/or
(8) de-moulding capability.
The filler polymer resin may be used in the manufacture of an article therefrom by injection
moulded, or in a method of manufacturing an article by injection moulding. In certain
embodiments, the function filler is used to enable or improve the injection mouldability of a
polymer resin comprising recycled polymer, or is used in a method for enabling or improving
the injection mouldability of a polymer resin comprising recycled polymer. The use or
method comprises filling the polymer resin with functional filler and manufacturing an article
of manufacture therefrom by injection moulding.
In certain embodiments, the article of manufacture is processed from the filled polymer resin
at a melt temperature of from about 190 °C to about 250 °C, for example, from about 200 °C
to about 240 °C, or from about 205 °C to about 235 °C, or from about 210 °C to about 230
°C, or from about 215 °C to about 230 °C, or from about 220 °C to about 230 °C. Suitable
barrel and feed throat temperature settings will be selected depending on the melt
temperature.
In certain embodiments, the peak pressure average during injection moulding is from about
500 to 2000 bar, for example, from about 750 to 2000 bar, or from about 750 to about 1500
bar, or from about 750 to about 900 to about 1400 bar, or from about 900 to about 1300 bar,
or from about 900 to about 1100 bar, of from about 1100 bar to about 1300 bar. Additionally
or alternatively, the peak injection pressure range may be equal to or less than about 7.0
bar, for example, equal to or less than about 6.5 bar, or equal to or less than about 6.0 bar,
or equal to or less than about 5.5 bar, or equal to or less than about 5.0 bar, or equal to or
less than about 4.5 bar, or equal to or less than about 4.0 bar, or equal to or less than about
3.5 bar, or equal to or less than about 3.0 bar, or equal to or less than about 2.5 bar.
In certain embodiments, the cycle time (during injection moulding) to produce an article of
manufacture is at least about 10 % shorter than the cycle time to produce a like article of
manufacture from an unfilled HDPE virgin polymer resin under the same processing
conditions, for example, at least about 20 % shorter, or at least about 30 % shorter than the
cycle time to produce a like article of manufacture from an unfilled HDPE virgin polymer
resin under the same processing conditions. In certain embodiments, the cycle time is at
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least 10 % shorter to no more than about 40 % shorter, or at least about 15 % shorter to no
more than about 35 % shorter than the cycle time to produce a like article of manufacture
from an unfilled HDPE virgin polymer resin under the same processing conditions.
In certain embodiments, the cycle time to produce an article of manufacture is equal to or
less than about 30 s, for example, equal to or less than about 25 s, or equal to or less than
about 20 s, or equal to or less than about 15 s, or equal to or less than about 14 s, or equal
to or less than about 13 s, or equal to or less than about 12 s, or equal to or less than about
11 s, or equal to or less than about 10 s. In such embodiments, the said cycle times may be
at least about 10 % shorter than the cycle time to produce a like article of manufacture from
an unfilled HDPE virgin polymer resin under the same processing conditions, for example, at
least about 20 % shorter, or at least about 30 % shorter than the cycle time to produce a like
article of manufacture from an unfilled HDPE virgin polymer resin under the same
processing conditions. In certain embodiments, the cycle time is at least 10 % shorter to no
more than about 40 % shorter, or at least about 15 % shorter to no more than about 35 %
shorter.
In certain embodiments, the weight range across 32 shots (during injection moulding) is less
than 0.008 g for an average shot weight of between 3.25 g and 4.0 g, for example, equal to
or less than 0.007 g, or equal to or less than 0.006 g, or equal to or less than about 0.005 g
for an average shot weight of between 3.25 and 4.0 g.
In certain embodiments:
the melt temperature is from about 190 °C to about 250 °C, for example, from about 200 °C
to about 240 °C, or any other melt temperature or range of melt temperature described
herein;
the cycle time is (i) is at least about 10 % shorter than the cycle time to produce a like article
of manufacture from an unfilled HDPE virgin polymer resin under the same processing
conditions, for example, at least about 20 % shorter, or at least about 30 % shorter, and/or
(ii) equal to or less than about 30 s, for example, equal to or less than about 15 s, or any
other cycle time or range of cycle time described herein;
the peak pressure average during injection moulding is from about 500 to 2000 bar, for
example, from about 750 to 2000 bar, or any other peak pressure average or range of peak
pressure average described herein.
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The filled polymer resin has a MFI @ 2.16 kg/190° C which is relatively low and which, prior
to this invention, would not have been expected to be suitable for injection moulding. MFR
may be determined in accordance with ISO 1133, for example, ISO 1133-1:2011 (e.g., by
the mass-measurement method).
In certain embodiments, the filled polymer resin has a MFI of less than about 2.5 g/10 mins
@ 2.16 kg/190° C, for example less than about 2.0 g/10 min @ 2.16 kg/190° C. In certain
embodiments, the filled polymer resin has a MFI which is equal to or less than about 2.4
g/10 min @ 2.16 kg/190° C, or equal to or less than about 2.25 g/10 min @ 2.16 kg/190° C,
or equal to or less than about 2.0 g/10 min @ 2.16 kg/190° C, or equal to or less than about
1.75 g/10 mins @ 2.16 kg/190° C, or equal to or less than about 1.5 g/10 mins, or equal to or
less than about 1.0 g/10 mins, or equal to or less than about 0.75 g/10 mins, or equal to or
less than about 0.50 g/10 mins, or equal to or less than about 0.35 g/10 mins, or equal to or
less than about 0.20 g/10 mins. In certain embodiments, the filled polymer resin has a MFI
of at least about 0.05 g/10 mins @ 2.16 kg/190° C, for example, at least about 0.10 g/10
mins @ 2.16 kg/190° C, or at least about 0.15 g/10 mins @ 2.16 kg/190° C, or at least about
0.20 g/10 mins @ 2.16 kg/190° C.
In certain embodiments, the filled polymer resin has a MFI of from about 1.0 g/10 mins @
2.16 kg/190° C to less than 2.5 g/10 min @ 2.16 kg/190° C, for example, from about 1.25
g/10 mins @ 2.16 kg/190° C to less than 2.5 g/10 mins @ 2.16 kg/190° C, or from about 1.5
g/10 mins @ 2.16 kg/190° C to less than 2.5 g/10 mins @ 2.16 kg/190° C, or from about
1.75 g/10 mins @ 2.16 kg/190° C to less than 2.5 g/10 mins @ 2.16 kg/190° C, or from
about 2.0 g/10 mins @ 2.16 kg/190° C to less than g/10 mins @ 2.16 kg/190° C.
In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C which is lower
than the MFI of the filled polymer resin during injection moulding. In certain embodiments,
the MFI during injection moulding is determined under the following conditions (using a
Plaque Mould & Demag Ergotec Injection Moulding Machine, for example, a Demag
Ergotech 150t System Servo Hydraulic Injection Moulding Machine):
Melt temperature: 220 °C;
Back pressure: 90 bar
Decompression Distance: 8 mm at 30 mm/s
Screw diameter: 25 mm
Screw Surface Speed: 700 mm/s
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Injection Speed: 70 mm/s
Dosing stroke: as required to achieve 100 % visual fill with no Holding Stage
Holding Pressure: as required to achieve a flat continuous surface finish
Holding Time: 2.0 s
Cooling Time: 6.0 s
Clamp Force: 70t
Mould temperature: 25 °C
Hot Tip Temperature: 10 °C above Melt Temperature
Exemplary injection moulding machines include Demag Ergotec Injection Moulding Machine,
an E-motion Engel injection moulding machine, for example, an Engel 55t Servo Electric/
injection moulding machine, or a Sumitomo SE180DU System 180t Servo Electric injection
moulding machine.
In certain embodiments, the injection moulding process comprises:
a mould temperature of from about 15 °C to about 40 °C, for example, from about 20 °C to
about 30°C, or from about 23 °C to about 27 °C, or about 25 °C; and/or
a back pressure of from about 50 bar to about 150 bar; and/or
a screw diameter of from about 20 mm to about 40 mm; and/or
a screw surface speed of from about 500 mm/s to about 1000 mm/s; and/or
an injection speed of from about 50 mm/s to about 100 mm/sand/or;
a holding time of from about 1.0 s to about 5.0 s; and/or
a cooling time of from about 30-70 % of cycle time, for example, from about 2.0 s to about 20
s; and/or
a clamp force of from about 50t to about 150t; and/or
a hot temperature of +/- 20 °C of melt temperature, for example, up to about 20 °C above
melt temperature, or up to about 15 °C above melt temperature.
In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C which is at least
3.0 g/10 mins lower than the apparent MFI of the filled polymer resin during injection
moulding, for example, at least about 3.5 g/10 mins lower, or at least about 4.0 g/10 mins
lower, or at least about 4.5 g/10 mins lower, or at least about 5.0 g/10 mins lower, or at least
about 5.5 g/10 mins lower, or at least about 6.0 g/10 mins lower than the apparent MFI of the
filled polymer resin during injection moulding. For example, in certain embodiments, the
filled polymer has a MFI @ 2.16 kg/190°C of equal to or less than about 1.0 g/10 mins and
an apparent MFI during injection moulding of at least about 4 g/10 mins @ 2.16 kg/190°C,
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for example, an apparent MFI during injection moulding of at least about 5 g/10 mins @ 2.16
kg/190°C. In certain embodiments, the filled polymer has a MFI @ 2.16 kg/190°C of equal
to or less than about 0.5 g/10 mins, and an apparent MFI during injection moulding of at
least about 4 g/10 mins @ 2.16 kg/190°C, for example, an apparent MFI during injection
moulding of at least about 5 g/10 mins @ 2.16 kg/190°C. By “apparent MFI” is meant that
the filled polymer resin has a processability by injection moulding which is indicative of a MFI
which is higher than the MFI determined @ 2.16 kg/190°C in accordance with ISO 1133
(e.g., ISO 1133-1:2011), e.g., a filled polymer resin having a MFI of 0.5 g/10 mins @ 2.16
kg/190°C processes as if its MFI is at least about 3.5 g/10 mins @ 2.16 kg/190°C, or at least
about 4.0 g/10 mins @ 2.16 kg/190°C, or at least about 4.5 g/10 mins @ 2.16 kg/190°C, or
at least about 5.0 g/10 mins @ 2.16 kg/190°C, or at least about 5.0 g/10 mins @ 2.16
kg/190°C. In certain embodiments, the apparent MFI is no more than about 8.0 g/10 @ 2.16
kg/190°C higher, for example, no more than about 7.5 g/10 @ 2.16 kg/190°C higher, or no
more than about 7.0 g/10 @ 2.16 kg/190°C higher.
In certain embodiments, the filled polymer resin, for example, a filled polymer resin having
an MFI of less than about 0.5 g/10 mins @ 2.16 kg/190°C processes (by injection moulding)
similarly to an unfilled HDPE virgin resin having an MFI of from about 5-6 g/10 mins @ 2.16
kg/190°C.
Additionally or alternatively, the filled polymer resin may be characterized in terms of Spiral
Flow Number (SFN). The spiral flow test provides a measure of the processability of
polymer resin under the more “real life” shear rates seen in the injection moulding process.
The SFN is a measure of the length of flow for the tested resin. SFN is determined by
injection moulding the polymer resin under the following conditions (using a Spiral Flow
Mould and Engel 55t Servo Electric/E-motion injection moulding machine):
Melt temperature: 220 °C;
Back pressure: 90 bar
Screw Surface Speed: 550 mm/s
Injection time: 1 s or 2 s
Injection Speed: 30 mm/s or 15 mm/s
Mould temperature: 25 °C
The spiral flow test is conducted using a spiral mould of appropriate dimensions. Nominal
dimensions of the spiral flow mould, sometimes referred to as spiral cavity channel, may be
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from 500 mm – 1500 mm in length (e.g., from 700 - 1000 mm), from 4 to 8 mm in width (e.g.,
about 6.35 mm) and from about 0.8 to about 3 mm in depth (e.g., about 1.57 mm).
In certain embodiments, the SFN of the filled polymer resin is at least about 350 mm, for
example, at least about 375 mm, or at least about 400 mm, or at least about 410 mm, or at
least about 420 mm, or at least about 430 mm, or at least about 440 mm, or at least about
450 mm. In certain embodiments, the SFN is from about 350 mm to about 500 mm, for
example, from about 375 mm to about 475 mm, or from about 400 to about 475 mm, or from
about 425 mm to about 475 mm, or from about 440 mm to about 460 mm. In such
embodiments, the injection time may be 2 s and the injection speed 15 mm/s. In such
embodiments, the peak pressure average during injection moulding may be from about 1500
to 2000 bar, for example, from about 1750 to 2000 bar, or from about 1800 to about 1950
bar, or from about 1850 to about 1950 bar, or any other peak pressure average or range of
peak pressure average described herein. In such embodiments, the melt temperature may
be from about 190 °C to 250 °C, for example, from about 200 °C to about 240 °C, or any
other melt temperature or range melt temperatures described herein.
In certain embodiments, the filler polymer resin has a spiral flow number (SFN) which is
greater than the SFN of a comparable unfilled virgin HDPE polymer resin having an
equivalent MFI @ 2.16 kg/190 °C.
In certain embodiments, the filler polymer resin has a SFN which is at least 80 % of the SFN
of an unfilled HDPE virgin polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, for
example, at least about 85 % of the SFN of an unfilled HDPE virgin polymer resin having a
MFI of 8 g/10 mins @ 2.16 kg/190 °C, or at least about 90 % of the SFN of an unfilled HDPE
virgin polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C of less than
about 2.5 g/10 mins @ 2.16 kg/190° C, for ex example, less than about 2.0 g/10 min and (a)
a SFN which is comparable to an unfilled virgin HDPE resin having a MFI @ 2.16 kg/190°C
of at least about 5.0 g/10 min, and/or (b) a SFN which is at least 80 % of the SFN of an
unfilled virgin HDPE polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, for
example, at least about 85 % of the SFN of an unfilled HDPE virgin polymer resin having a
MFI of 8 g/10 mins @ 2.16 kg/190 °C, or at least about 90 % of the SFN of an unfilled HDPE
virgin polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
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In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C of less than
about 2.5 g/10 mins @ 2.16 kg/190° C, for example, less than about 2.0 g/10 min and a SFN
which is comparable to an unfilled virgin HDPE resin having a MFI @ 2.16 kg/190°C of at
least about 5.0 g/10 min.
In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C of less than
about 2.5 g/10 mins @ 2.16 kg/190° C, for example, less than about 2.0 g/10 min and a SFN
which is at least 80 % of the SFN of an unfilled virgin HDPE polymer resin having a MFI of 8
g/10 mins @ 2.16 kg/190 °C, for example, at least about 85 % of the SFN of an unfilled
HDPE virgin polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, or at least about
90 % of the SFN of an unfilled HDPE virgin polymer resin having a MFI of 8 g/10 mins @
2.16 kg/190 °C.
In certain embodiments, the filled polymer resin has a MFI @ 2.16 kg/190°C of less than
about 2.5 g/10 mins @ 2.16 kg/190° C, for examples, less than about 2.0 g/10 min, a SFN
which is comparable to an unfilled virgin HDPE resin having a MFI @ 2.16 kg/190°C of at
least about 5.0 g/10 min, and a SFN which is at least 80 % of the SFN of an unfilled virgin
HDPE polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, for example, at least
about 85 % of the SFN of an unfilled HDPE virgin polymer resin having a MFI of 8 g/10 mins
@ 2.16 kg/190 °C, or at least about 90 % of the SFN of an unfilled HDPE virgin polymer
resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
In certain embodiments, the filled polymer resin is characterised in terms of a ratio of its MFI
@ 21/6 kg/190 °C to its MFI @ 2.16 kg/190 °C, referred to herein after as R-MFI,. This is
indicative of the distribution of molar mass in a given polymer sample. The larger the R-MFI,
the broader the molecular weight distribution. For example, a monodisperse polymer where
all the chain lengths are equal has a R-MFI of 1. As noted, the R-MFI is calculated as the
ratio of the MFI @ 21/6 kg/190 °C to the MFI @ 2.16 kg/190 °C, i.e.,
R-MFI = (MFI @ 21.6 kg)/(MFI @ 2.16 kg) (1)
Additionally or alternatively, the filled polymer resin may be characterised in terms of the
difference between the MFI @ 21.6 kg/190 °C and the MFI @ 2.16 kg/190 °C, i.e.,
ΔMFI = (MFI @ 21.6 kg/190 °C) – (MFI @ 2.16/190 °C kg) (2)
14
In certain embodiments, the filled polymer resin has a R-MFI of at least about 100 and/or a
ΔMFI of at least about 40.0. In such embodiments, the filled polymer resin may have a MFI
@ 2.16 kg/190 °C of less than about 1.5 g/10 mins, or less than about 1.0 g/10 mins, or less
than about 0.75 g/10 mins, or less than about 0.50 g/10 mins, or less than about 0.35 g/10
mins, or less than about 0.20 g/10 mins.
In certain embodiments, the R-MFI is at least about 125, for example, from about 150 to
about 500, or from about 150 to about 450, or from about 150 to about 400, or from about
150 to about 350, or from about 200 to about 350, or from about 250 to about 350, or from
about 300 to about 350. Additionally or alternatively, ΔMFI is at least about 41.0, or at least
about 42.0, or at least about 43.0, or at least about 44.0, or at least about 45.0, or at least
about 46.0, or at least about 47.0, or at least about 48.0, or at least about 49.0, or at least
about 50.0, or at least about 51.0, or at least about 52.0, or at least about 53.0, or at least
about 54.0, or at least about 55.0, or at least about 56.0, or at least about 57.0. In certain
embodiments, ΔMFI is no greater than about 70, for example, no greater than about 65.0, or
no greater than about 60.0. In such embodiments, the filled polymer resin may have a MFI
@ 2.16 kg/190 °C of less than about 1.5 g/10 mins, or less than about 1.0 g/10 mins, or less
than about 0.75 g/10 mins, or less than about 0.50 g/10 mins, or less than about 0.35 g/10
mins, or less than about 0.20 g/10 mins.
In certain embodiments, the filled polymer resin has a broader molecular weight distribution
than an unfilled virgin HDPE polymer resin. As such, at a given MFI @ 2.16 kg/190 °C, the
filled polymer resin may have a higher R-MFI than an unfilled virgin HDPE polymer resin.
In certain embodiments, the viscosity of the filled polymer resin decreases more rapidly at
higher shear rate compared to an unfilled virgin HDPE polymer resin. As such, at a given
MFI @ 2.16 kg/190 °C, the viscosity of the filled polymer resin will decrease more rapidly
when subjected to an ever increasing shear rate compared to the viscosity decrease of an
unfilled virgin HDPE resin subjected to the same increasing shear rate.
In certain embodiments, the filled polymer resin comprises at least about 50 % by weight
recycled polymer (based on the total weight of polymer in the filled polymer resin), for
example, at least about 60 % by weight, or at least about 70 % by weight, or at about 80 %
by weight, or at least about 95 % by weight, or at least about 99 % by weight recycled
polymer. In certain embodiments, recycled polymer constitutes substantially all, i.e., about
100 % by weight, of the polymer of the filled polymer resin.
15
In certain embodiments, the filled polymer resin comprises no more than about 20 % by
weight of virgin polymer (based on the total weight of polymer in the filled polymer resin), for
example, no more than about 15 % by weight of virgin polymer, or no more than about 10 %
by weight of virgin polymer, or no more than 5 % by weight of virgin polymer, or no more
than about 2 % by weight of virgin polymer, or no more than about 1 % by weight of virgin
polymer, or no more than about 0.5 % by weight of virgin polymer, or no more than about 0.1
% by weight of virgin polymer.
In certain embodiments, the filled polymer resin is free of virgin polymer.
In certain embodiments, the filled polymer resin comprise a mixture of polymer types, for
example, a mixture of polyethylene and polypropylene, or a mixture of different types of
polyethylene, e.g., HDPE, LDPE and/or LLDPE, or a mixture of different types of
polyethylene and polypropylene. In certain embodiments, the filled polymer resin comprises
a mixture of polymer types which individually have a MFI of greater than or less than about
2.0 g/10 mins @ 2.16 kg/190 °C) provided the filled polymer resin as a whole has a MFI of
less than 2.5 g/10 mins @ 2.16 kg/190 °C, for example, less than 2.0 g/10 mins @ 2.16
kg/190 °C, or less than about 1.5 g/10 mins @ 2.16 kg/190 °C, or less than about 1.0 g/mins
@ 2.16 kg/190 °C, or less than about 0.5 g/10 mins @ 2.16 kg/190 °C. In certain
embodiments, at least 75 % by weight of the filled 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 filled polymer resin), for example, from 75 % to about 99 % of a
mixture of polyethylene and polypropylene, for example, a mixture of HDPE and
polypropylene. In such embodiments, HDPE may constitute from about 50 % to about 95 %
by weight of the filled polymer resin (based on the total weight of the polymer of the filled
polymer resin), for example, from about 60 % to about 90 % by weight, or from about 70 %
to about 90 % by weight, of from about 70 % to about 85 % by weight, or from about 70 % to
about 80 % by weight, or from about 75 % to about 80 % by weight of the filled polymer resin
(based on the total weight of the polymer of the filled polymer resin).
In certain embodiments, the HDPE is 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.
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
16
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, the filled polymer resin comprises up to about 20 % by weight of
polymers other than HDPE such as, for example, LDPE, LLDPE and polypropylene, any or
all of which may be recycled from polymer waste, e.g., post-consumer polymer waste. In
certain embodiments, the recycled polymer comprises up to about 20 % by weight
polypropylene, based on the total weight of the recycled polymer, for example, from about 1
% to about 20 % by weight, or from about 5 % to about 18 % by weight, or from about 10 %
to about 15 % by weight, or from about 12 to about 14 % by weight polypropylene.
In certain embodiments, the polymer component of the filled polymer resin, other than any
impact modifier which may be present, is a mixture of polyethylene and polypropylene, for
example, a mixture of recycled polyethylene and polypropylene, for example, polyethylene
and polypropylene derived from a recycled mixed polyolefin feedstock consisting of
polyethylene and polypropylene. In such embodiments, the filled polymer resin may
comprise up to about 30 % by weight of recycled polypropylene, based on the total weight of
the filled polymer resin, for example, up to about 25 % by weight polypropylene, or up to
about 20 % by weight polypropylene, or up to about 15 % by weight polypropylene, or up to
about 12.5 % by weight polypropylene, or up to about 10 % by weight polypropylene, or up
to about 7.5 % by weight polypropylene, or up to about 5 % by weight polypropylene. In
certain embodiments, the filled polymer resin comprises at least about 4 % by weight
polypropylene, for example, at least about 6 % by weight polypropylene, or at least about 8
% by weight polypropylene, or at least about 10 % by weight polypropylene, or at least about
12 % by weight polypropylene, based on the total weight of the filled polymer resin. In such
embodiments, the polyethylene may be HDPE.
In certain embodiments, filled polymer resin has a density of greater than about 1.00 to
equal to or less than about 1.05 g/cm3
. Density may be determined in accordance with
ISO1183.
In certain embodiments, the functional filler comprises an inorganic particulate having a d50
of no greater than about 2.5 µm and/or a surface treatment agent on the surface of the
17
inorganic particulate. In certain embodiments, the inorganic particulate has a d50 of from
about 0.1 µm to about 2.0 µm, for example, from about 0.1 µm to about 1.5 µm, or from
about 0.1 µm to about 1.0 µm, or from about 0.2 to about 0.9 µm, or from about 0.2 µm to
about 0.7 µm, or from about 0.3 µm to about 0.7 µm, or from about 0.4 to about 0.6 µm, or
from about 0.5 to about 0.6 µm. The particle sizes described herein pertain to the inorganic
particulate absent any surface treatment agent.
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.
In certain embodiments, the inorganic particulate does not have a surface treatment on its
surface.
In certain embodiments, 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.
The purpose of the surface treatment agent is to improve the compatibility of the inorganic
particulate and the polymer matrix with which it is to be combined, and/or improve the
compatibility of different polymers in the recycled polymer. In recycled polymer resins the
surface treatment may serve to cross-link or graft the different polymers. In certain
embodiments, the surface treatment agent serves as a coupling modifier, wherein 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/or between the polymers and the
surface treatment agent.
18
In other aspects and embodiments of the present invention, the coating additionally or
alternatively comprises a compound selected from the group consisting of one or more fatty
acids and one or more salts of fatty acids, for example, stearic acid or calcium stearate.
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.
The surface treatment agent, when present, may comprise an O- or N-containing acid
functionality, for example, a compound including a hydrocarbyl unsaturation and an Oand/or N-containing acid functionality. In certain embodiments, the hydrocarbyl unsaturation
is one or more ethylenic groups, at least one of which may be a terminal group. The acid
functionality may comprise a carboxylic acid, carboxy, carbonyl and or ester functionality.
19
In certain embodiments, the surface treatment agent comprises a compound having a
saturated hydrocarbyl group and an O- or N-containing acid functionality, for example, a
carboxylic acid, carboxy, carbonyl and or ester functionality.
In certain embodiments, the surface treatment comprises both a compound including a
hydrocarbyl unsaturation and an O- and/or N-containing acid functionality, and compound
having a saturated hydrocarbyl group and an O- or N-containing acid functionality.
In certain embodiments, the functional filler and, hence, the filled polymer resin does not
comprise both of a compound including a hydrocarbyl unsaturation and an O- and/or Ncontaining acid functionality, and a compound having a saturated hydrocarbyl group and an
O- or N-containing acid functionality.
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 compound having a saturated hydrocarbyl group and an O- or
N-containing acid functionality is a saturated fatty acid, or a metal salt thereof, or a mixture of
such fatty acids and/or salts. In certain embodiments, surface treatment agent comprise
stearic acid, optionally in combination with other fatty acids.
In certain embodiments, the compound including a hydrocarbyl unsaturation and an Oand/or N-containing acid functionality is a carboxylic acid or carboxylate, for example, a
propanoic group, or an acrylic acid or acrylates, or an imide. Specific examples of coupling
modifiers are β-carboxy ethylacrylate, β-carboxyhexylmaleimide, 10-carboxydecylmaleimide
and 5-carboxy pentyl maleimide.
In certain embodiments, the compound including a hydrocarbyl unsaturation and an Oand/or N-containing acid functionality is an unsaturated fatty acid, or a metal salt thereof, or
a mixture of such fatty acids and/or salts.
In certain embodiments, the surface treatment agent comprises one or more of a C1-C18, C2-
C18 and C2-5 alkylene group. In certain embodiments, said group or groups bridges between
a hydrocarbyl unsaturation, for example, a terminal ethylenic group and an O- and/or Ncontaining acid functionality. In such embodiments, the O- and/or N-containing acid
20
functionality may be a carboxylic acid or carboxylate, for example, a propanoic group, or an
acrylic acid or acrylates, or an imide.
The functional filler may be present in the filled polymer resin in an amount ranging from
about 1 % up to about 70 % by weight, based on the total weight of the filled polymer resin.
For example, from about 2 % to about 60 % by weight, or from about 3 % to about 50 % by
weight, or from about 4 % to about 40 % by weight, or from about 5 % to about 30 % by
weight, or from about 6 % to about 25 % by weight, or from about 7 % to about 20 % by
weight, or from about 8 % to about 15 % by weight, or from about 8 % to about 12 % by
weight, based on the total weight of the filled polymer resin. The functional filler may be
present in amount less than or equal to about 80% by weight of the filled polymer resin, for
example, less than or equal to about 70% by weight, or less than or equal to about 60 % by
weight, or less than or equal to about 50 % by weight, or less than or equal to about 40 % by
weight, or less than or equal to about 30 % by weight, or less than or equal to about 20 % by
weight, or less than or equal to about 50 % by weight, based on the total weight of the filled
polymer resin.
The surface treatment agent (i.e., coupling modifier) of the functional filler may be present in
an amount of from about 0.01 % by weight to about 4 % by weight, based on the total weight
of the filled 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 filled polymer resin.
Additionally or alternatively, the surface treatment agent may be present in an amount equal
to or less than about 5 wt. % based on the total weight of the functional filler, 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 surface treatment agent is present in the functional filler in an amount
equal to or less than about 1.2 wt.% based on the total weight of the functional filler, 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
21
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 surface treatment agent is present in the functional filler in an amount greater
than about 0.05 wt. %. In further embodiments, the surface treatment agent is present in the
functional filler 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. %.
The filled polymer resin may additionally comprise a peroxide-containing additive. In an
embodiment, the peroxide-containing additive comprises di-cumyl peroxide or 1,1-Di(tertbutylperoxy)-3,3,5-trimethylcyclohexane. The peroxide-containing additive may not
necessarily be included with the surface treatment agent and instead may be added during
the compounding of the functional filler and the recycled polymers, as described below. In
some polymer systems, e.g., those containing 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 filled 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. %. Typically, the peroxidecontaining additive, if present, is present in an amount greater than about 0.01 wt. % based
on the weight of the filled polymer resin. In certain embodiments, the filled polymer resin
comprises from about 0.01 wt. % to about 0.05 wt. % of a peroxide-containing additive, for
example, di-cumyl peroxide or 1,1-Di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, for
example, from about 0.01 wt. % to about 0.05 wt. %, or from about 0.01 wt. % to about 0.03
wt. %, or from about 0.0125 wt. % to about 0.0275 wt. %, or from about 0.015 wt. % to about
0.025 wt. %, or from about 0.0175 wt. % to about 0.0225 wt. %, or from about 0.018 wt. % to
about 0.022 wt. %, or from about 0.019 wt. % to about 0.021 wt. %, or about 0.02 wt. %. In
22
such embodiments, the filled polymer resin may have a MFI of less than about 2.5 g/10 mins
@ 2.16 kg/190°C, for example, from about 1.0 g/10 mins @ 2.16 kg/190°C to about 2.5 g/10
mins @ 2.16 kg/190°C, for example, equal to or less than about 1.5 g/10 mins@ 2.16
kg/190°C, or equal to or less than about 1.0 g/10 mins@ 2.16 kg/190°C, or equal to or less
than about 0.5 g/10 mins @ 2.16 kg/190°C
In certain embodiments, the filled polymer resin comprises from about 0.015 wt. % to about
0.025 wt. % of the peroxide-containing additive, for example, di-cumyl perxoide.
In such embodiments, inclusion of a relatively minor amount of peroxide-containing additive
may serve to modify, for example, enhance, one or more mechanical properties of injected
moulded parts formed from the filled polymer resin, for example, filled polymer resin
comprising recycled polyethylene and up to about 20 wt. % of optionally recycled
polypropylene, based on the total weight of the filled polymer resin, for example, from about
2-15 wt. % of optionally recycled polypropylene, or from about 3-15 wt. %, or 4-14 wt. %, or
2-10 wt.%, or 3-9 wt.%, or 4-8 wt. %, or 7-15 wt.%, or 8-15 wt.% of optionally recycled
polypropylene. In certain embodiments, all of the polypropylene is recycled polypropylene,
which may be derived from a recycled mixed polyolefin feedstock comprising polyethylene
and polypropylene. Without wishing to be bound by theory, it is believed that a balance of
enhanced mechanical properties is obtainable by optimizing the level of peroxide-containing
additive in relation to the relative amounts of polyethylene, polypropylene and functional
filler. This also demonstrates the ability of the functional filler to decrease the interfacial
tension between normally immiscible polymer types, e.g., polyethylene and polypropylene,
and enhancing mechanical properties.
Mechanical properties include one or more of elongation at break, flexural modulus, ultimate
tensile stress (UTS) and Charpy (unnotched) Impact Strength. Tensile properties, e.g.,
elongation at break and UTS, may be determined in accordance with ISO527-2, at room
temperature, using a Tinius Olsen Benchtop tensile tester, and based on average of eight
measurements for each test piece. Charpy Impact Strength may be determined at -20 °C ±_
2 °C in accordance with ISO179-2 using an Instron Ceast 9340 falling-weight impact tester.
Flexural modulus may be determined in accordance with ISO 178.
In certain embodiments, the injected moulded part has an elongation at break of at least
about 15 %, for example, at least about 25 %, or at least about 50 %, or at least about 75 %,
or at least about 100 %, or at least about 150 %, or at least about 200 %, or at least about
23
250 %, or at least about 300 %, or at least about 325 %, or at least about 340 %. In certain
embodiments, the elongation at break is no greater than about 500 %, or no greater than
about 450 %, or no greater than about 400 %.
In certain embodiments, the injected moulded part has a UTS of from about 15-30 MPa, for
example, from about 20-30 MPa, or from about 20-25 MPa, or from about 20-23 MPa, or
from about 20-22 MPa, or from about 20-21 MPa.
In certain embodiments, the injected moulded part has a flexural modulus of at least about
750 MPa, for example, at least about 800 MPa, or at least about 850 MPa, or at least about
900 MPa, or from about 900-1250 MPa, or from about 900-1200 MPa, or from about 900-
1150 MPa, or from about 900-1100 MPa, or from about 900-1050 MPa, or from about 900-
1000 MPa, or from about 925-975 MPa.
In certain embodiments, an injected moulded part form from the filled polymer resin has one
or more of:
(a) an elongation at break of at least about 300 %, for example, when the injected
moulded part is formed from a filled polymer resin comprising at least 8 wt. %
polypropylene, and optionally no more than about 12 wt. % functional filler;
(b) a UTS of at least about 20 MPa, for example, from about 20-22MPa;
(c) a flexural modulus of at least about 900 MPa; and
(d) a Charpy Impact Strength of at least about 40 kJ/m2
(20 °C ± 2 °C), for example, at
least about 80 kJ/m2
(-20 °C ± 2 °C).
In certain embodiments, for example, embodiments having one or more of (a), (b), (c) and
(d) above, the injected moulded part is formed from a filled polymer resin comprising:
from about 0.015 wt. % to about 0.025 wt. % of the peroxide-containing additive, for
example, dicumyl peroxide,
a polypropylene content of at least about 8 wt. %, for example, from about 8-15 wt.%,
the balance of the polymer component being polyethylene, optionally wherein the
polypropylene and polyethylene are derived from the same recycled mixed polyolefin source,
from about 8-12 wt. % functional filler,
an MFI of less than 2.5 g/10 mins @ 2.16 kg/190°C, for example, from about 2.0 - 2.45 g/10
mins @ 2.16 kg/190°C
and optionally up to about 2 wt. % carbon black and up to about 0.5 wt. % antioxidant;
24
and having:
an elongation at break of at least about 300 %,
and optionally:
a UTS of from about 20-25 MPa, and/or
a flexural modulus of at least about 900 MPa, for example, from about 920-1250 MPa, or
from about 920-980 MPa, and/or
a Charpy Impact Strength of at least about 80 kJ/m2
(-20 °C ± 2 °C), for example, from about
80-90 kJ/m2
(-20 °C ± 2 °C).
In such embodiments, the functional filler may be ground calcium carbonate having a d50 of
from about 0.5-1.5 µm, for example, from about 0.5-1.0 µm, or from about 0.6-1.0 µm, or
from about 0.7-0.9 µm, or about 0.8 µm, which is surface treated with a compound according
to formula (1).
The functional filler may be prepared by combining the inorganic particulate, surface
treatment agent 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
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 may be added to the inorganic particulate in a step in which the inorganic particulate is
mechanically de-aggregated. The surface treatment agent may be applied during deaggregation carried out in a milling machine.
The functional filler 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. The amount of antioxidant may range
from about 0.01 % by weight to about 5 % by weight, based on polymer content, for
example, from about 0.05 % by weight to about 2.5 % by weight, or from about 0.05 % by
weight to about 1.5 % by weight, or from about 0.05 % by weight to about 1.0 % by weight,
or from about 0.05 % by weight to about 0.5 % by weight, or from about 0.05 % by weight to
about 0.25 % by weight, or from about 0.05 % by weight to about 0.15 % by weight based on
polymer content.
25
In certain embodiments, the filled polymer resin composition comprises (for example, up to
about 5 wt. %, based on the total weight of the filled polymer resin) a secondary filler
component other than the functional filler. The secondary filler may be in certain
embodiments an uncoated inorganic particulate material, such as for example, the inorganic
particulate materials described herein. In certain embodiments, the secondary filler is
carbon black, for example, from about 0.1- 5.0 wt. % carbon black, or from about 0.5-4.0 wt.
%, or from about 0.5-1.5 wt. %, or from about 1.0-3.0 wt. %, or from about 1.5-2.5 wt. %, or
about 2.0 wt. %, or about 1.0 wt. %, based on the total weight of the filled polymer resin.
The aforementioned amounts may also apply to secondary filler other than carbon black.
In certain embodiments, the filled 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 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 12.5
% by weight, or from about 2 % by weight to about 12. % % 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 1 % by weight to about 6 % by weight, or from about 1 % by weight to about 4 % by
weight of an impact modifier, based on the total weight of the filled 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 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, 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
26
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 ethylene-octene
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 resin 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 certain embodiments, the impact modifier is a triblock copolymer based on styrene and
ethylene/butene. In such embodiments, the impact modifier may have a MFR 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).
The articles of manufacture that are obtained by injection moulding a filled polymer resin as
described herein are many and various.
In certain embodiments, the article of manufacture is the form of one of the following: panels
(e.g., automotive panels), pallets, pipes, doors, shutters, awnings, shades, signs, frames,
window casings, mobile phone casings, pails, backboards, wallboards, flooring, tiles, railroad
ties, forms, trays, tool handles, stalls, bedding, dispensers, staves, totes, barrels, boxes,
packing materials, baskets, racks, casings, binders, dividers, walls, mats, frames,
bookcases, sculptures, chairs, tables, desks, art, toys, games, wharves, piers, boats, masts,
septic tanks, substrates, computer housings, above- and below-ground electrical casings,
PCB covers, furniture, picnic tables, tents, playgrounds, benches, shelters, sporting goods,
bedpans, plaques, trays, hangers, servers, pools, insulation, caskets, bookcovers, canes,
crutches, luggage buckle and clips, pump parts, and the like.
In certain embodiments, the article of manufacture, or a part thereof, comprises a wall
having a thickness of no more than about 5.0 mm, for example, no more than about 4.0 mm,
27
or no more than 3.0 mm, or no more than about 2.0 mm, or no more than about 1.5 mm, or
no more than about 1 mm. In certain embodiments, the article of manufacture, or a part
thereof, has a wall thickness of from about 1.0 mm to about 3.0 mm, for example, from about
1.5 mm to about 3.0 mm. It is surprising that such relatively thin-walled parts may be
injected moulding from recycled polymer resins.
EXAMPLES
Example 1 – preparation of polymer resins
Filled polymer resins were prepared by compounding. These were as follows:
Sample A – recycled HDPE + 15 wt. % of an uncoated ground calcium carbonate having a
d50 of 0.54 µm.
Sample B – a mixture of recycled HDPE and PP + 10 wt. % of a surface treated ground
calcium carbonate (d50 = 0.8 µm), and having a MFI of 0.29 g/10 mins @ 2.16 kg/190 °C.
Sample C – a mixture of recycled HDPE and PP + 10 wt. % of a surface treated ground
calcium carbonate (d50 = 0.8 µm) + 2.5 wt. %% of an ethylene-octene copolymer as impact
modifier, and a MFI of 0.15 g/10 mins @ 2.16 kg/190 °C.
Sample D – an unfilled virgin HDPE polymer resin having a MFI of 8.0 g/10 mins @ 2.16
kg/190 °C. This is included for comparative purposes.
Example 2 – injection moulding process
A mobile phone surround was prepared from each sample by injection moulding using a
Sumitomo SE180DU System 180t Servo Electric Injection Moulding Machine (Sumitomo
SE180DU C360 with a 32 mm standard engineering screw design).
Conditions:
Melt temperature: 220°C.
Barrel temperature profile: 220-225-225-220-215°C
Feed throat temperature: 70°C
Back Pressure: 90bar
28
Decompression Distance: 8mm at 30mm/s
Screw Surface Speed: 700mm/s
Injection Speed: 70mm/s
Dosing Stroke: as required to achieve 100% visual fill with no Holding Stage
Holding Pressure: as required to achieve a flat continuous surface finish
Holding Time: 2.0 seconds
Cooling Time: 6.0 seconds
Clamp Force: 100t
Mould Temperature: 25°C
Between each sample blend test the injection unit and hot runner system were purged clean
with HDPE.
Results are summarised in Tables 1 and 2.
Table 1.
Injection
Time
Average
Peak
Injection
Pressure
Average (bar)
Peak
Injection
Pressure
Range (bar)
Cycle
Time
(seconds
)
Sample A 0.33 1334 3.6 11.6
Sample B 0.32 1219 2.3 11.6
Sample C 0.32 1230 2.7 11.5
Sample D 0.29 997 7.0 17.6
All times recorded are in seconds, all pressures in bar-specific
Table 2.
Average Shot Weight
(g)
Weight Range
Across 32 Shots (g)
Sample A 3.940 0.036
Sample B 3.714 0.005
Sample C 3.713 0.007
Sample D 3.456 0.008
Example 3 – analysis of Spiral Flow Number (SFN)
The SFN of Samples B, C and D were determined by injection moulding the polymer resin
under the following conditions (using a Spiral Flow Mould and Engel 55t Servo Electric/Emotion injection moulding machine):
29
Melt temperature: 220 °C;
Back pressure: 90 bar
Screw Surface Speed: 550 mm/s
Injection time: 1 s or 2 s
Injection Speed: 30 mm/s or 15 mm/s
Mould temperature: 25 °C
Results are summarized in Tables 3A and 3B.
Table 3A.
Sample B Sample C
Injection
Time/Speed
1 second @
30 mm/s
2 second @
15 mm/s
1 second @
30 mm/s
2 second @
15 mm/s
SFN (mm) 403 455 416 444
Peak Injection
Pressure (bar)
1873 1904 1834 1888
Table 3B.
Sample D
Injection
Time/Speed
1 second @ 30
mm/s
2 second @
15mm/s
SFN (mm) 470 495
Peak Injection
Pressure (bar)
1335 1242
Example 4
A series of filled polymer resin were prepared as described in Table 4 below. Recycled
mixed polyolefin source A had a MFI of 4.01 g/10 mins @ 2.16 kg/190 °C, and recycled
polyolefin source B had a MFI of 3.71 g/10 mins @ 2.16 kg/190 °C, i.e., that is before
compounding with surface treated ground calcium carbonate (d50 = 0.8 µm) functional filler
and the other components.
All samples were perepared via melt mixing with a Coperion ZSK twin-screw extruder. The
barrel was maintained at 200, 205, 210, 215, 225, 235 and 240 °C from hopper to die. The
30
screw speed was set to 800 rpm, and the feed rate at 8.0 kg/hour. The hot extrudes were
immediately quenched in water and pelletized. Test speciments, for mechanica testing,
were then produced by injection moulding. Test specimens were prepared usinga an Arburg
Allrounder 320M, and mouldings were conditioned for a minimum of 40 hours at 23 °C and a
relative humiudity of 50 % prior to the test, in accordance with Procedure A of ASTM D618
(20/23/50).
Table 4
Sample Recycled
mixed
polyolefin
source A
(wt.-%)
Recycled
mixed
polyolefin
source B
(wt.-%)
Functional
filler (wt.-
%)
CB
(wt.-%)
A/O
(wt.-%)
DCP
(wt.-%)
PP
Content
(wt.-%)
1 88.680 - 10 1.0 0.3 0.02 5.41
2 88.660 - 10 1.0 0.3 0.04 5.51
3 83.680 - 15 1.0 0.3 0.02 5.65
4 83.660 - 15 1.0 0.3 0.04 6.89
5 - 88.680 10 1.0 0.3 0.02 8.79
6 - 88.660 10 1.0 0.3 0.04 8.54
7 - 83.680 15 1.0 0.3 0.02 9.59
8 - 83.660 15 1.0 0.3 0.04 13.58
CB = Carbon black; A/O = antioxidant; DCP = di-cumyl peroxide, PP = Polypropylene.
Mechanical testing of each test specimen, and the MFI of the compounded resins prior to
injection moulding, is summarized in Table 5.
Elongation at break and UTS were carried out at room temperature using a Tinius Olsen
Benchtop tensile tester, with results corresponding to an average of eight measurements for
each sample, in accordance with ISO572-2.
Flexural modulus was tested in accordance with ISO 178.
31
Charpy unnotchhed impact tests were carried out at -20 °C ±2 °C using a Intron Ceast 9340
falling-weight impact tester, in accordance with ISO179-2. The results provided correspond
to an average of complete break measurements for each sample.
Table 5.
Sample
1 2 3 4 5 6 7 8
MFI (g/10min, 2.16
kg@190oC)
2.26 2.08 2.38 1.67 2.35 1.39 2.22 1.48
UTS (MPa) 22.5 23.0 23.0 23.1 21.4 21.7 21.5 21.9
Break Elongation
(%)
28.1 27.6 16.4 19.9 348 304 121 175
Flexural Modulus
(MPa)
1091.1 1087.8 1202.6 994.3 948.1 947.8 1001.8 991.2
Charpy Impact
Strength (KJ/m2
, -
20oC ± 2oC)
48.9 67.1 49.5 71.5 86.2 72.9 54.4 51.4
32
WE CLAIM:
1. Use of a filled polymer resin in the manufacture of an article therefrom by injection
moulding, wherein the polymer resin comprises recycled polymer and functional filler,
wherein the function filler comprises an inorganic particulate which (i) is surface
treated and/or (ii) has a d50 of less than about 2.5 µm, and wherein the filled polymer
resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin
during injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent
MFI of the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, and optionally:
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin
HDPE resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10
min, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE
polymer resin having a MFI of 8.0 g/10 mins @ 2.16 kg/190 °C.
2. A method of manufacturing an article by injection moulding, the method comprising
injection moulding an article from a filled polymer resin, wherein the filled polymer
resin comprises recycled polymer and functional filler, wherein the function filler
comprises an inorganic particulate which (i) is surface treated and/or (ii) has a d50 of
less than about 2.5 µm, and wherein the filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin
during injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent
MFI of the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, and optionally:
33
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin
HDPE resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10
min, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE
polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
3. Use of a functional filler in a polymer resin comprising recycled polymer to improve
the injection mouldability of the polymer resin, wherein the function filler comprises
an inorganic particulate which (i) is surface treated and/or (ii) has a d50 of less than
about 2.5 µm.
4. A method for enabling or improving the injection mouldability of a polymer resin
comprising recycled polymer, the method comprising filling the polymer resin with a
functional filler, forming a filled polymer resin, and manufacturing an article of
manufacture from the filled polymer resin by injection moulding, wherein the function
filler comprises an inorganic particulate which (i) is surface treated and/or (ii) has a
d50 of less than about 2.5 µm, and wherein the filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin
during injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the apparent
MFI of the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 mins, and
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin
HDPE resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10
mins, and/or
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE
polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
5. Use or method according to any preceding claim, wherein an or the article of
manufacture is processed from the filled polymer resin at a melt temperature of from
about 200 °C to about 240 °C.
34
6. Use or method according to any preceding claim, wherein the cycle time to produce
an or the article of manufacture is at least about 10 % shorter than the cycle time to
produce a like article of manufacture from an unfilled HDPE virgin polymer resin, for
example, at least about 20 % shorter, or at least about 30 % shorter than the cycle
time to produce a like article of manufacture from an unfilled HDPE virgin polymer
resin.
7. Use or method according to any preceding claim, wherein: (i) the peak pressure
average during injection moulding is from about 1000 to 2000 bar, and/or (ii) the peak
injection pressure range is equal to or less than about 5.0 bar.
8. Use or method according to any preceding claim, wherein the weight range across
32 shots is less than 0.008 g for an average shot weight of between 3.25 g and 4.0 g.
9. Use or method according to any preceding claim, wherein filled polymer resin has a
MFI of less than 2.5 g/10 mins @ 2.16 kg/190°C, for example, equal to or less than
about 2.0 g/10 mins @ 2.16 kg/190°C, or equal to or less than about 1.5 g/10 mins
@ 2.16 kg/190°C, or equal to or less than about 1.0 g/10 mins @ 2.16 kg/190°C, or
equal to or less than about 0.5 g/10 mins @ 2.16 kg/190°C.
10. Use or method according to any preceding claim, wherein the filled polymer resin has
a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 mins and: (a) a SFN which is
comparable to an unfilled virgin HDPE resin having a MFI @ 2.16 kg/190°C of at
least about 5.0 g/10 min, and/or (b) a SFN which is at least 80 % of the SFN of an
unfilled virgin HDPE polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, for
example, at least about 90 % of SFN of an unfilled virgin HDPE polymer resin having
a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
11. Use or method according to claim 10, wherein the filled polymer resin has a MFI
equal to or less than about 2.0 g/10 mins @ 2.16 kg/190°C, for example, equal to or
less than about 1.5 g/10 mins@ 2.16 kg/190°C, or equal to or less than about 1.0
g/10 mins@ 2.16 kg/190°C, or equal to or less than about 0.5 g/10 mins @ 2.16
kg/190°C.
12. Use or method according to any preceding claim, wherein the filled polymer resin has
a R-MFI of at least about 100, wherein:
35
R-MFI = (MFI @ 21.6 kg)/(MFI @ 2.16 kg), and optionally
wherein (MFI @ 21.6 kg) – (MFI @ 2.16 kg) is at least about 40.
13. Use or method according to any preceding claim, wherein the filled polymer resin has
a SFN of at least about 350 mm, for example, at least about 400 mm, or at least
about 450 mm.
14. Use or method according to any preceding claim, wherein the filled polymer resin
comprises at least about 50 % by weight recycled polymer (based on the total weight
of polymer in the filled polymer resin).
15. Use or method according to any preceding claim, wherein the filled polymer resin
comprises a mixture of polymer types, for example, a mixture of polyethylene and
polypropylene, or a mixture of different types of polyethylene, e.g., HDPE, LDPE
and/or LLDPE, or a mixture of different types of polyethylene (e.g., HDPE, LDPE
and/or LLDPE) and polypropylene
16. Use or method according to any preceding claim, wherein the filled polymer resin is
free of virgin polymer.
17. Use or method according to any preceding claim, wherein the function filler is an
uncoated inorganic particulate having a d50 of no greater than about 1.0 µm, for
example, no greater than about 0.75 µm.
18. Use or method according to any one of claims 1-17, wherein the function filler
comprises or is a surface-treated inorganic particulate, optionally wherein the
inorganic particulate has a d50 of from about 0.1 to 2.5 µm, for example, from about
0.1 to about 1.0 µm.
19. Use or method according to claim 18, wherein the inorganic particulate is surfacetreated with a surface treatment agent is a compound including a hydrocarbyl
unsaturation and an O- and/or N-containing acid functionality, and/or a compound
having a saturated hydrocarbyl group and an O- or N-containing acid functionality.
36
20. Use or method according to any preceding claim, wherein the inorganic particulate is
calcium carbonate, for example, ground calcium carbonate.
21. Use or method according to any preceding claim, wherein the filled polymer resin
comprises an impact modifier and/or a peroxide-containing additive.
22. An article of manufacture obtained by injection moulding a filled polymer resin as
defined in any preceding claim.
23. The article of manufacture according to claim 22, wherein the article has a wall
having a thickness of no more than about 3 mm, for example, from about 1 mm to
about 3 mm.
24. The article according to claim 22 or 23 having one or more of: (a) an elongation at
break of at least about 300 %, (b) a UTS of at least about 20 MPa, for example, from
about 20-22MPa, (c) a flexural modulus of at least about 900 MPa, and (d) a Charpy
Impact Strength of at least about 40 kJ/m2
(20 °C ±_ 2 °C), for example, at least
about 80 kJ/m2
(-20 °C ±_ 2 °C).
25. A filled polymer resin suitable for use in the manufacture of an article therefrom by
injection moulding, wherein the polymer resin comprises recycled polymer and
functional filler, wherein the function filler comprises an inorganic particulate which (i)
is surface treated and/or (ii) has a d50 of less than about 2.5 µm, and wherein the
filled polymer resin has:
(1) a MFI @ 2.16 kg/190°C which is lower than the MFI of the filled polymer resin
during injection moulding; and/or
(2) a MFI @ 2.16 kg/190°C which is at least 3 g/10 mins lower than the MFI of
the filled polymer resin during injection moulding; and/or
(3) a MFI @ 2.16 kg/190°C of less than about 2.5 g/10 min, and optionally:
(a) a Spiral Flow Number (SFN) which is comparable to an unfilled virgin
HDPE resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10
min, and/or
37
(b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE
polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C.
26. Filled polymer resin according to claim 25, wherein filled polymer resin has a MFI of
less than 2.5g/10 mins @ 2.16 kg/190°C, for example, equal to or less than about 2.0
g/10 mins@ 2.16 kg/190°C, or equal to or less than about 1.5 g/10 mins@ 2.16
kg/190°C, or equal to or less than about 1.0 g/10 mins @ 2.16 kg/190°C, or equal to
or less than about 0.5 g/10 mins @ 2.16 kg/190°C.
27. Filled polymer resin according to claim 25or 26, wherein the filled polymer resin has a
MFI @ 2.16 kg/190°C of less than about 2.5 g/10 mins, for example, equal to or less
than about 2.0 g/10 mins@ 2.16 kg/190°C, and: (a) a SFN which is comparable to an
unfilled virgin HDPE resin having a MFI @ 2.16 kg/190°C of at least about 5.0 g/10
min, and/or (b) a SFN which is at least 80 % of the SFN of an unfilled virgin HDPE
polymer resin having a MFI of 8 g/10 mins @ 2.16 kg/190 °C, for example, at least
about 90 % of SFN of an unfilled virgin HDPE polymer resin having a MFI of 8 g/10
mins @ 2.16 kg/190 °C.
28. Filled polymer resin according to claim 27, wherein the filled polymer resin has a MFI
equal to or less than about 1.0 g/10 mins@ 2.16 kg/190°C, or equal to or less than
about 0.5 g/10 mins @ 2.16 kg/190°C.
29. Filled polymer resin according to any one of claims 25-28, wherein the filled polymer
resin has a R-MFI of at least about 100, wherein:
R-MFI = (MFI @ 21.6 kg)/(MFI @ 2.16 kg), and optionally
wherein (MFI @ 21.6 kg) – (MFI @ 2.16 kg) is at least about 40.
30. Filled polymer resin according to any one of claims 25-29, wherein the filled polymer
resin has a SFN of at least about 350 mm, for example, at least about 400 mm, or at
least about 450 mm.
31. Filled polymer resin according to any one of claims 25-30, wherein the filled polymer
resin comprises at least about 50 % by weight recycled polymer (based on the total
weight of polymer in the filled polymer resin).
38
32. Filled polymer resin according to any one of claims 25-31, wherein the filled polymer
resin comprises a mixture of polymer types, for example, a mixture of polyethylene
and polypropylene, or a mixture of different types of polyethylene, e.g., HDPE, LDPE
and/or LLDPE, or a mixture of different types of polyethylene (e.g., HDPE, LDPE
and/or LLDPE) and polypropylene
33. Filled polymer resin according to any one of claims 25-32, wherein the filled polymer
resin is free of virgin polymer.
34. Filled polymer resin according to any one of claims 25-33, wherein the function filler
is an uncoated inorganic particulate having a d50 of no greater than about 1.0 µm, for
example, no greater than about 0.75 µm.
35. Filled polymer resin according to any one of claims 25-33, wherein the function filler
comprises or is a surface-treated inorganic particulate, optionally wherein the
inorganic particulate has a d50 of from about 0.1 to 2.5 µm, for example, from about
0.1 to about 1.0 µm.
36. Filled polymer resin according to any one of claims 25-35, wherein the inorganic
particulate is surface-treated with a surface treatment agent selected from a
compound including a hydrocarbyl unsaturation and an O- and/or N-containing acid
functionality, and/or a compound having a saturated hydrocarbyl group and an O- or
N-containing acid functionality.
37. Filled polymer resin according to any one of claims 25-365, wherein the inorganic
particulate is calcium carbonate, for example, ground calcium carbonate.
38. Filled polymer resin according to any one of claims 25-37, wherein the filled polymer
resin comprises an impact modifier.
39. Use, method, article or filled polymer resin according to any preceding claim, wherein
the filled polymer resin comprises from about 0.01 wt. % to about 0.05 wt. % of a
peroxide-containing additive, for example, di-cumyl peroxide or 1,1-Di(tertbutylperoxy)-3,3,5-trimethylcyclohexane, based on the total weight of the filled
polymer resin.
39
40. Use, method, article or filled polymer resin according to claim 39, wherein the filled
polymer resin comprises from about 0.015 wt. % to about 0.025 wt. % of the
peroxide-containing additive.
41. Use, method article or filled polymer resin according to any preceding claim, further
comprising up to about 3 wt. % carbon black, and up to about 0. 5wt. % antioxidant,
based on the total weight of the filled polymer resin.
42. Use, method, article or filled polymer resin according to any preceding claim, wherein
the polymer component of the filled polymer resin, other than impact modifier when
present, consists of polyethylene (e.g., HDPE) and polypropylene derived from a
recycled mixed polyolefin feed.