U.S. patent application number 09/562956 was filed with the patent office on 2002-11-21 for engineered polyolefin materials with enhanced properties.
Invention is credited to Drewniak, Marta, Her, Jhy-Yuan, Srinivasan, Satchit, Szczepaniak, Edward.
Application Number | 20020173581 09/562956 |
Document ID | / |
Family ID | 24248487 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020173581 |
Kind Code |
A1 |
Drewniak, Marta ; et
al. |
November 21, 2002 |
Engineered polyolefin materials with enhanced properties
Abstract
A polyolefin blend is presented having a propylene containing
polymer as a base component, a portion of which is functionalized
with a hydrophilic moiety; a toughening component of polymer
selected from the group consisting of (A) a copolymer of ethylene
and an alpha olefin and (B) a terpolymer of ethylene, an alpha
olefin and a diene; an interfacial modifier in the form of an
elastomeric block copolymer; and a filler. The functionalized
portion of the propylene containing polymer is present in an amount
sufficient to ensure dispersion of the filler within the
semi-cystalline portion of the blend; the toughening agent is
present in an amount sufficient to enhance low temperature impact
properties of the blend but less than about 40 weight percent, the
interfacial modifier is present in an amount sufficient to assist
in adhesion between the polymer components of the blend but less
than about 30 weight percent, and the filler is present in an
amount sufficient to enhance blend strength and hardness but less
than about 40 weight percent. Also included is an article of
manufacture containing the polyolefin blend described and a method
for making such an article of manufacture by molding the described
polyolefin blend into the configuration and shape of the article of
manufacture, and the use of such articles as automobile
components.
Inventors: |
Drewniak, Marta;
(Carrollton, TX) ; Her, Jhy-Yuan; (Euless, TX)
; Srinivasan, Satchit; (Carrollton, TX) ;
Szczepaniak, Edward; (Arlington, TX) |
Correspondence
Address: |
WINSTON & STRAWN
PATENT DEPARTMENT
1400 L STREET, N.W.
WASHINGTON
DC
20005-3502
US
|
Family ID: |
24248487 |
Appl. No.: |
09/562956 |
Filed: |
May 3, 2000 |
Current U.S.
Class: |
524/504 ;
524/505; 525/71 |
Current CPC
Class: |
C08L 51/06 20130101;
C08L 23/10 20130101; C08L 23/04 20130101; C08L 23/16 20130101; C08L
53/02 20130101; C08L 23/10 20130101; C08L 2666/04 20130101; C08L
23/10 20130101; C08L 2666/24 20130101; C08L 23/16 20130101; C08L
2666/04 20130101; C08L 23/16 20130101; C08L 2666/24 20130101 |
Class at
Publication: |
524/504 ;
524/505; 525/71 |
International
Class: |
C08L 051/04; C08L
023/00; C08L 023/26; C08L 023/14 |
Claims
What is claimed is:
1. A polyolefin blend comprising: a base component of a propylene
containing polymer, a portion of which is functionalized with a
hydrophilic moiety; a toughening component of polymer selected from
the group consisting of (A) a copolymer of ethylene and an alpha
olefin and (B) a terpolymer of ethylene, an alpha olefin and a
diene; an interfacial modifier in the form of an elastomeric block
copolymer; and a filler, wherein the functionalized portion of the
propylene containing polymer is present in an amount sufficient to
ensure dispersion of the filler within the semicrystalline portion
of the blend, the toughening agent is present in an amount
sufficient to enhance low temperature impact properties of the
blend but less than about 40 weight percent; the interfacial
modifier is present in an amount sufficient to assist in adhesion
between the polymer components of the blend but less than about 30
weight percent, and the filler is present in an amount sufficient
to enhance blend strength and hardness but less than about 40
weight percent.
2. The blend of claim 1, wherein the propylene containing polymer
is a semicrystalline polypropylene polymer and the blend has an
Izod impact strength at minus 30.degree. C. of at least about 1
ft-lb/in, a flexural modulus of at least about 175 kpsi, a melt
flow rate of at least about 16 dg/min at 230.degree. C. and 2.16
kg, and a peel strength of at least about 700 N/m measured in 180
degree peel.
3. The blend of claim 1, wherein the propylene containing polymer
is a semicrystalline polypropylene polymer and the blend has an
Izod impact strength at minus 30.degree. C. of at least about 1.5
ft-lb/in, a flexural modulus of at least about 190 kpsi, the
Rockwell R hardness of at least about 70, a shrinkage of no greater
than about 8 mil/inch and a peel strength of at least about 900-N/m
measured in 180 degree peel.
4. The blend of claim 1, wherein the base component comprises a
first propylene containing polymer of polypropylene or a copolymer
of propylene and another alpha olefin and a second propylene
containing polymer that is functionalized with a hydrophilic
monomer.
5. The blend of claim 4, wherein the hydrophilic monomer is maleic
anhydride, an acrylate or combinations thereof.
6. The blend of claim 1, wherein the block copolymer comprises two,
three or four block components.
7. The polyolefin based composition of claim 1, wherein the block
copolymer contains blocks of styrene/(ethylene-butylene)/styrene,
styrene/(ethylene-propylene) /styrene, styrene/(ethylene-butylene),
styrene/(ethylene-propylene), styrene/butene/styrene,
styrene/butene,
styrene/(ethylene-propylene)/styrene/(ethylene-propylene),
styrene/butadiene or styrene/isoprene.
8. The blend of claim 1, wherein: the propylene containing polymer
is present in an amount of about 33 to 75 weight percent and at
least 0.5% of this component is functionalized; the toughening
component is present in an amount of about 1 to 25 weight percent;
the interfacial modifier is present in an amount of about 1 to 30
weight percent; and the filler is present in an amount of about 1
to 30 weight percent.
9. The blend of claim 1, wherein: the propylene containing polymer
is present in an amount of about 33 to 75 weight percent and at
least 5% to 50% of this component is functionalized; the toughening
component is present in an amount of about 10 to 20 weight 5
percent; the interfacial modifier is present in an amount of about
3 to 18 weight percent; and the filler is present in an amount of
about 8 to 20 weight percent.
10. The blend of claim 4, wherein: the propylene containing polymer
is present in an amount of about 40 to 60 weight percent; the
propylene containing polymer that is functionalized with a
hydrophilic monomer is present in an amount of 1 to 20 weight
percent; the interfacial modifier is present in an amount of about
1 to 25 weight percent; the toughening component is present in an
amount of about 1 to 30 weight percent; and the filler is present
in an amount of about 1 to 30 weight percent.
11. The blend of claim 4, wherein: the propylene containing polymer
is present in an amount of about 40 to 60 weight percent; the
propylene containing polymer that is functionalized with a
hydrophilic monomer is present in an amount of 1 to 20 weight
percent; the interfacial modifier is present in an amount of about
3 to 18 weight percent; the toughening component is present in an
amount of about 10 to 20 weight percent; and the filler is present
in an amount of about 8 to 20 weight percent.
12. An article of manufacture comprising a molded polyolefin blend
having the composition of claim 1.
13. An article of manufacture comprising a molded polyolefin blend
having the composition of claim 4.
14. An automotive product component comprising the article of claim
12.
15. An automotive product component comprising the article of claim
13.
16. A method for making an article of manufacture comprising the
step of molding the polyolefin blend of claim 1 into a desired
configuration and shape of the article of manufacture.
17. A method for making an article of manufacture comprising the
step of molding the polyolefin blend of claim 4 into a desired
configuration and shape of the article of manufacture.
18. A method for making a molded automotive product comprising the
step of molding the polyolefin blend of claim 1 into a desired
configuration and shape of an article of manufacture and utilizing
the article of manufacturer as an automotive component.
19. A method for making a molded automotive product comprising the
step of molding the polyolefin blend of claim 4 into a desired
configuration and shape of an article of manufacture and utilizing
the article of manufacturer as an automotive component.
Description
FIELD OF THE INVENTION
[0001] The invention relates to polyolefin blends which have
superior physical properties including enhanced toughness at high
reinforcement levels for high performance use in molded articles
such as automotive vehicle bumpers or the like. The invention also
relates to molded articles as well as to methods for producing
them.
BACKGROUND ART
[0002] In numerous applications, such as many in the automotive
industry, a polymeric material that exhibits a good balance of
toughness and rigidity is desired. These properties tend to occur
inversely however, and efforts to enhance one will often result in
deterioration in the other. Special polymeric materials have been
developed that overcome this problem to some degree.
[0003] European Patent Application 0794225-A1 discloses
thermoplastic resin compositions comprising polypropylene, a
styrene containing elastomer and talc wherein an acceptable balance
of toughness and rigidity is reported. The disclosure stresses the
importance of the proportions of each component used to achieve
this balance.
[0004] In PCT Application WO97/38050, a similar balance of
properties is reported for a thermoplastic resin comprising an
ethylene-propylene based polymer composition, an ethylene-alpha
olefin copolymer based rubber and/or a rubber containing vinyl
aromatic compounds and talc. Another example of a composition with
an acceptable balance of toughness and rigidity is reported in
Japanese Patent Application 10-219040-A for a resin composition
consisting of a polyolefin based resin and a block copolymer based
on aromatic vinyl and butadiene monomer units.
[0005] A comparative study of mechanical properties of compositions
like those disclosed in the foregoing references is reported in
Kiyoo Kato et al. New Developments in Styrenic Block Copolymers
(SEBS) for Polypropylene Modification, Fifth International
Conference, "TPO's in Automotive '98", Oct. 12-14, 1998, Novi,
Mich. There is confirmation therein that a good balance of
toughness and rigidity is exhibited by such compositions. Kato and
his colleagues also report results from a related morphological
study in this same paper, and it can be concluded from these
results that the styrene based components in these compositions
promote toughness at least by segregating at the interface of the
other components and entangling with polymer chains in the various
phases.
[0006] Despite these prior art formulations, there remains a need
to obtain other polymeric materials with a good balance of
toughness and rigidity, and the present materials satisfy this
need.
SUMMARY OF THE INVENTION
[0007] The present invention relates to polyolefin blends
comprising a base component of a propylene containing polymer, a
portion of which is functionalized with a hydrophilic moiety; a
toughening component of polymer selected from the group consisting
of (A) a copolymer of ethylene and an alpha olefin and (B) a
terpolymer of ethylene, an alpha olefin and a diene; an interfacial
modifier in the form of an elastomeric block copolymer; and a
filler. In these blends, the functionalized polypropylene is
present in an amount sufficient to ensure dispersion of the filler
with the semicrystalline portion of the blend. This permits a
higher weight fraction of the filler within the polypropylene
phase, leading to superior reinforcement. The toughening agent is
present in an amount sufficient to enhance low temperature impact
properties of the blend, the interfacial modifier is present in an
amount sufficient to assist in adhesion between the polymer
components of the blend, and the filler is present in an amount
sufficient to enhance blend strength and hardness.
[0008] Another aspect of the present invention is a method for
making an article of manufacture comprising the step of molding the
described polyolefin blend into a desired configuration and shape
of the article of manufacture. The resultant molded articles and
their use as automotive components are further aspects of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The present invention relates to polymer blends of
engineered polyolefin based materials that include various
preferred combinations of: (1) a base component of polypropylene or
a copolymer of propylene and another alpha olefin; (2) a component
of propylene containing polymer that is functionalized with
hydrophilic monomer(s); (3) a toughening component of (A) a
copolymer of ethylene and another alpha olefin or (B) a terpolymer
of ethylene, another alpha olefin and a diene; (4) an interfacial
modifier in the form of an elastomeric block copolymer; and (5) a
treated or untreated mineral filler. These blends surprisingly
exhibit high balanced levels of toughness and rigidity previously
unobtainable in the art.
[0010] It has also been found that the polyolefin materials of the
present invention have, at the same time, unexpectedly high
dimensional stability, hardness (and therefore scratch resistance)
and good paintability, while still possessing a good melt flow
rate. All these properties are obtained at significantly higher
reinforcement levels than other polyolefin materials with similar
toughness. This overall combination of properties is desirable for
parts or molded articles used in many industries, notably, the
automotive.
[0011] The component usually in the largest proportion in the
polyolefin based composition of the present invention is the base
component of the propylene containing polymer. This polymer is
preferably a homopolymer of propylene or a copolymer of propylene
and another alpha olefin. This material is most often
characterizable as semi-crystalline in compositions according to
the present invention. "Semi-crystalline" means that the
crystallinity is at least 30% and preferably is 50% or greater.
[0012] Suitable types of homopolymers of propylene include highly
isotactic polypropylenes. An acceptable copolymer of propylene is
ethylene-propylene copolymer. It is preferred that this component
make up at least about 33 to 75 weight percent of the overall
composition, preferably 40 to 60 weight percent and more preferably
45 to 55 weight percent.
[0013] It is possible for a portion of the propylene containing
polymer to be functionalized, such as by reaction of the propylene
containing polymer with a compound that contains hydrophilic groups
or moieties such as hydroxyl functionality. These compounds would
be added in an amount sufficient to functionalize between about 0.5
and 50% of the propylene containing polymer, preferably between
about 5 and 40% and most preferably between about 8 and 30%. Such
reaction may be carried out in situ during extrusion. It is
preferred, however, to add the functionalized propylene containing
polymer as a separate component. Functionalized polypropylene makes
up about 1 to 20 weight percent of the overall composition,
preferably 3 to 15 weight percent and more preferably 5 to 13
weight percent.
[0014] Suitable hydrophilic monomers for use in functionalization
include organic compounds that contain one or more hydroxyl groups
and anhydrides of carboxylic acids such as phthalic anhydride,
maleic anhydride and itaconic anhydride. Other examples of suitable
functionalizing compounds include vinyl chloride, silanes,
acrylonitrile, styrene, styrene derivatives such as styrene
co-hydroxypropylene, methacrylate, acrylic acid, acrylates, vinyl
pyridine, vinyl acetates, alkyl or glycidyl methacrylates, 2-vinyl
pyridine, methacrylic ester derivatives containing aromatic amines
or phenols, citraconic anhydride, maleic
anhydride-trimethylopropane ester, acrylamide, vinyl caprolactam
and divinylbenzene. Combinations of functionalizing compounds can
be used such as methacrylate/vinyl acetate mixtures or acrylic
acid/methacrylic acid mixtures. Preferably, maleic anhydride,
acrylate or combinations thereof are used.
[0015] This functionalized propylene containing polymer enhances
dispersion of the mineral filler in the composition, preferentially
into the semi-crystalline portion of the blend, and increases
interfacial interactions leading to surprisingly superior
reinforcement without negatively affecting toughness. It is
believed that this functionalized propylene containing polymer in
combination with the other polymers in the overall composition
permits good adhesion to the particles of mineral filler also
present and thus, the unexpectedly superior level of toughness
observed at high levels of reinforcement. Preferably, this
component is semi-crystalline as defined above.
[0016] Also present in the polyolefin composition of the present
invention is a toughening component of (A) a copolymer of ethylene
and another alpha olefin or (B) a terpolymer of ethylene, another
alpha olefin and a diene. This component adds toughening properties
to the composition and contributes to the good impact resistance of
the blends. Like many of the other components of the overall
composition of the present invention, it is most often
semi-crystalline as defined above.
[0017] Possible alpha olefins present in this component besides the
ethylene already named include any C.sub.3 to C.sub.18 olefin,
preferably a C.sub.3 to C.sub.10 olefin, with propylene, butene or
octene being preferred and octene being most preferred. When dienes
are used, any C.sub.4 to C.sub.18 alkene can be used. An example of
a preferred diene for use in making terpolymers is ethylidene
norbornene. It is preferred that this toughening component make up
from about 1 to 25 weight percent of the overall composition, more
preferably 5 to 25 weight percent, and even more preferably 10 to
20 weight percent.
[0018] When a terpolymer is used, the amount of diene in the
terpolymer in not critical and values as low as 0.5% are useful.
Typically, the diene content of the terpolymer will be from about 3
to 20%, and preferably from 7 to 15%.
[0019] Another component in the polyolefin based material of the
present invention is an interfacial modifier. This is preferably a
thermoplastic elastomer comprising a styrenic block copolymer. This
component contributes to the compatibilizing effect of the filler
with the other polymer components as well as significantly
improving adhesion between the polymeric phases. This leads to the
high toughness of the overall composition while improving
rigidity.
[0020] Acceptable styrenic block copolymers include copolymers of
styrene, ethylene and another alkene. Preferred copolymers contain
blocks of styrene/(ethylene-butene)/styrene,
styrene/(ethylene-propylene)/styrene, styrene/(ethylene-butene),
styrene/(ethylene-propylene), styrene/butene/styrene,
styrene/butene, styrene/butadiene and styrene/isoprene. The
preferred copolymers are those having at least three blocks or a
pair of two repeating blocks. For example, repeating
styrene/butadiene or styrene/(ethylene-propylene) blocks are
desirable, with the most preferred copolymer being one made up of
styrene/(ethylene-propylene)/styrene/(ethylene-propylene) blocks.
It is also preferred that the styrenic block copolymer component
make up from about 1 to 30 weight percent of the overall
composition, more preferably 2 to 20 weight percent and even more
preferably 3 to 18 weight percent.
[0021] There is also present in the polyolefin composition of the
present invention a mineral filler. Higher levels of mineral filler
are seen as allowing for increased stiffness and control of
shrinkage, especially under the influence of the other components
in the composition of the present invention.
[0022] The mineral filler can be a treated or untreated inorganic
material. Preferred fillers include talc, calcium carbonate,
wollastonite, alumina trihydrate, barium sulfate, calcium sulfate,
carbon blacks, metal fibers, boron fibers, ceramic fibers,
polymeric fibers, kaolin; glass, ceramic, carbon or polymeric
microspheres; silica, mica, glass fiber, carbon fiber and clay with
talc being most preferred. It is also preferred that the mineral
filler be present in an amount of from about 1 to 30 weight percent
of the overall composition more preferably 5 to 25 weight percent
and most preferably 8 to 20 weight percent.
[0023] The polyolefin material of the present invention will
preferably have an Izod impact strength at minus 30 degrees Celsius
of at least 1 ft-lb/in, a flexural modulus of at least 175 kpsi, a
melt flow rate of at least 15 dg/min at 230 degrees Celsius and
2.16 kg, and a peel strength of at least 700 N/m measured in 180
degree peel. More preferably, the material will have an Izod impact
strength at minus 30 degrees Celsius of greater than 1.5 ft-lb/in,
a flexural modulus greater than 190 kpsi, a melt flow rate of at
least 20 dg/mil at 230 degrees Celsius and 2.16 kg, a Rockwell R
hardness of at least 70, a shrinkage of no greater than about 8
mil/inch and a peel strength of at least about 900 N/m measured in
180 degree peel. These properties are those as measured according
to the methods given in the examples to follow; such standards are
to be taken as defining these properties when interpreting the
claims. Such properties are understood at least to act as implicit
recitations of composition when stated in the claims.
[0024] Given the good balance of toughness and rigidity in the
materials of the present invention, as well as other excellent
properties noted previously, this polyolefin material is suitable
for many specialized applications. For example, this material can
be shaped into components used in many interior and exterior
automobile parts. Shaping as used herein could include molding
and/or extruding, with the injection molding of a blend of the
recited components being preferred. The resultant molded articles
are highly useful for applications such as automobile door panels
and bumpers.
[0025] The polyolefin based composition of the present invention
may be prepared in one or two steps. In a two step method,
components (1), (2) and (5) of the overall composition are melt
blended and optionally along with stabilizers and /or additives
using an extruder or other mixing equipment. The resulting
masterblend is then melt blended with components (3) and (4) of the
overall composition, and optionally along with stabilizers and/or
additives; this second step can be performed using continuous or
batch mixing equipment. Alternately, both of the steps in the two
step method can be performed sequentially using a twin screw
extruder effectively making for a one step approach. The following
examples in Table I are illustrative of compositions of the present
invention:
1 TABLE I Examples Component/(wt % or physical property) 1 2 3 4 5
HIPP.sup.1 -- -- -- 53 -- HIPP.sup.2 46 46 46 -- 43.5 PP-MA.sup.3
-- 10 -- 10 -- PP-AA.sup.4 10 -- 10 -- 9.5 SEPSEP.sup.5 11 11 17 11
13 Poly(ethylene-co-octene).sup.6 17 17 11 17 19 FILLER.sup.7 16 16
16 9 15 HARDNESS.sup.8 70 73 71 79 76 FLEXURAL MODULUS.sup.9 238
258 219 259 192 MFR.sup.10 22 23 19 23 16 DENSITY.sup.11 1.00 1.00
1.01 0.96 0.99 IMPACT @-30C.sup.12 D D D D D DUCTILITY INDEX.sup.13
0.38 0.39 0.35 0.40 0.31 IZOD IMPACT TEST @-30C.sup.14 2.09 1.67
2.15 1.48 >5.31 MOLD SHRINKAGE.sup.15 7.0 7.5 8.0 9.2 8.0 PEEL
STRENGTH.sup.16 >1500 890 1150 1000 1130 Notes: .sup.1HIPP -
HIPP EOD 97-13 from Fina; highly isotactic polypropylene, MFR (at
230 C, 2.16 kg) = 70 dg/min, ASTM D-1238. .sup.2HIPP - VB 35-125
from Amoco; highly isotactic polypropylene, MFR (at 230 C, 2.16 kg)
= 125 dg/min, ASTM D-1238. .sup.3PP-MA - Polybond 3150 from
Uniroyal; polypropylene functionalized with maleic anhydrate (MA),
MFR (at 230 C, 2.16 kg) = 50 dg/min, ASTM D-1238; MA concentration
= 0.5%. .sup.4PP-AA - Polybond 1002 from Uniroyal; polypropylene
functionalized with acrylic acid (AA), MFR (at 230 C, 2.16 kg) = 20
dg/min, ASTM D-1238; AA concentration = 6%. .sup.5SEPSEP - Kraton
G-1730M from Shell; multi-block copolymer
(styrene/ethylene-propylene/styrene/ethylene-propyl- ene or
SEPSEP); MFR (at 230C, 2.16kg) = 4.2 dg/min; styrene content = 23%.
.sup.6Poly(ethylene-co-octene) - Engage 8180 from Dow-DuPont
Elastomers; C2= 72%; MFR (at 190C, 2.16 kg) = 0.5 dg/min, ASTM
D-1238; molecular weight distribution = 2. .sup.7FILLER - Ultra
Talc 609 from Luzenac; particle size = 0.9 micron. .sup.8Rockwell R
HARDNESS measured according to ASTM D-785. .sup.9kpsi measured
according to ASTM D-790. .sup.10dg/min at 230C and 2.16 kg as
measured according to ASTM D-1238. .sup.11g/cm.sup.3. .sup.12D =
Ductile Failure; B = Brittle Failure measured according to ASTM
D-3763. .sup.13Ductility Index is measured by using the impact test
according to ASTM 3763. It is calculated from the equation: DI =
(T-U)/T
[0026] where:
[0027] DI is Ductility Index
[0028] T represents total energy at the point at which the probe
has broken through the specimen. That is, the point at which the
force applied to the specimen by the probe drops to zero.
[0029] U represents ultimate energy. That is, the energy at the
point at which the force exerted by the probe on the specimen is at
maximum as determined from the force- position curve of force
applied by the probe to the specimen versus the position of the
probe.
[0030] The DI values for each of 3-5 specimens are averaged and
reported as DI.
[0031] 14. ft-lb/in measured according to ASTM D-256.
[0032] 15. mils/inch. measured according to ASTM standard
D-955.
[0033] 16. N/m measured in 180 degree peel.
[0034] The peel strength is the force (N/m) required to peel the
paint off a substrate and is a measure of adhesive strength of the
coating of the substrate.
[0035] In determining the peel strength, an injection molded
plaque, formed from the composition in question of size 4.times.6
inches and 1/8 inch thick, is partially coated with adhesion
promoter and entirely with the topcoat, both of the type used in
the automotive industry for coating polyolefinic materials, to
enable lifting the topcoat from that portion of the plaque which is
not coated with the adhesion promoter.
[0036] Cuts through the topcoat coating are made using a sharp
knife and a metal template to form two or three one cm wide strips.
The one cm wide strips are slowly peeled from those portions of the
plaque which are free of the adhesion promoter. A piece of
polyester tape is placed on the peeled off strip to form a "handle"
with which the strip is peeled further. The prepared plaque is
placed into an Instron Model 1130 Tensile Tester.
[0037] The force required to peel the strip from the plaque is
recorded as a function of the length of peeled off strip along the
plaque. The peeling speed is two inches per minute. The average
force in the entire peel is reported as the measure of adhesion
strength per one cm of width of the peel. That is, in units
N/m.
[0038] Comparative Examples A, B, and C of Table II below should be
compared with Example 1 of the present invention as they are the
same except that one different component is removed in A, B, and C
as compared to Example 1. D and E represent prior art compositions
not containing styrenic block copolymers.
2 TABLE II Comparative Examples Prior Art Component/(wgt % or
physical property) A B C D E HIPP.sup.1 56 46 46 54 54 PP-AA.sup.2
-- 10 10 -- -- SEPSEP.sup.3 11 28 -- -- --
Poly(ethylene-co-octene).sup.4 17 -- 28 -- --
Poly(ethylene-co-octene).sup.5 -- -- -- 10 --
Poly(ethylene-co-butene).sup.6 -- -- -- 20 -- EPR.sup.7 -- -- -- --
30 FILLER.sup.8 16 16 16 16 16 HARDNESS.sup.9 64 71 70 70 34
FLEXURAL MODULUS.sup.10 233 212 243 247 243 MFR.sup.11 25 22 16 27
19 DENSITY.sup.12 1.0 1.01 0.99 1.0 1.01 IMPACT @-30C.sup.13 D B B
B B DUCTILITY INDEX.sup.14 0.38 0.34 0.20 0.05 0.04 IZOD IMPACT
TEST @-30C.sup.15 1.72 2.05 1.5 1.06 0.74 MOLD SHRINKAGE.sup.16 8.7
8.5 7.8 8.5 8.2 PEEL STRENGTH.sup.17 460 950 1170 300 180 Notes:
.sup.1HIPP - VB 35-125 from Amoco; highly isotactic polypropylene,
MFR (at 230 C, 2.16 kg) = 125 dg/min, ASTM D-1238. .sup.2PP-AA -
Polybond 1002 from Uniroyal; polypropylene functionalized with
acrylic acid (AA), MFR (at 230 C, 2.16 kg) = 20 dg/min, ASTM
D-1238; AA concentration = 6%. .sup.3SEPSEP - Kraton G-1730M from
Shell; multi-block copolymer
(styrene/ethylene-propylene/styrene/ethylene-propyl- ene or
SEPSEP); MFR (at 230 C, 2.16kg) = 4.2 dg/min; styrene content =
23%. .sup.4Poly(ethylene-co-octene) - Engage 8180 from Dow-DuPont
Elastomers; C2 = 72%; MFR (at 190 C, 2.16 kg) = 0.5 dg/min, ASTM
D-1238; molecular weight distribution = 2.
.sup.5Poly(ethylene-co-octene) - Engage 8200 from Dow-DuPont
Elastomers; C2 = 76%; MFR (at 190 C, 2.16 kg) = 5.0 dg/min, ASTM
D-1238; molecular weight distribution 2.
.sup.6Poly(ethylene-co-butene) - Exact 4033 from Exxon Co.;
produced using Kaminsky catalyst, and having C2 = 80%; MFR (at 190
C, 2.16 kg) = 0.8 dg/min, ASTM D-1238; molecular weight
distribution = 2. .sup.7EPR - Dutral CO-54 from Enichem;
poly(ethylene-co-propylene); C2 = 50%, C3 = 50%, Mooney Viscosity
at 100.degree. C. = 35; molecular weight distribution = 4.6.
.sup.8FILLER - Ultra Talc 609 from Luzenac; particle size = 0.9
micron. .sup.9Rockwell R HARDNESS measured according to ASTM D-785.
.sup.10kpsi measured according to ASTM D-790. .sup.11dg/min at 230
C and 2.16 kg as measured according to ASTM D-1238.
.sup.12g/cm.sup.3. .sup.13D = Ductile Failure; B = Brittle Failure
measured according to ASTM D-3763. .sup.14See note 13 following
Table I. .sup.15ft-lb/in measured according to ASTM D-256.
.sup.16mils/inch. measured according to ASTM standard D-955.
.sup.17See note 16 following Table I. The above description and
examples should not be taken so as to unnecessarily limit the scope
of the invention.
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