Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
Polyvinyl halide (inclusive o-f vinyl halide homopolymers as
well as copolyrners of vinyl halide ~lith up to about fifty percent
of olefinic comonomer copolymerizable with the vinyl halide) is a
widely used moldable thermoplastic having a number of favorable
technological properties. However polyvinyl halide, e.g. vinyl
chloride homopolymer, breaks on impact very eas;ly at ambient
temperature and at still lower or suh-ambient temperatures. Thus
at ambient temperature, i.e. at about 20 C., correspond~ng to about
69 F., the notched Izod impact resistance of the aforementioned
vinyl halide homo- and copolymers is only of the order o~ about
0.4 to less than about 1 ft-lb./in. At sub-ambien~ temperatures,
e.g. down to -20 F. or lower, the notched Izod impact resistance
of these polymers becomes vanishingly small or ne~ligible. Gen-
erally the ambient temperature impact resistance of conventionalvinyl halide polymers is enhanced by rnechanically blending the
vinyl halide with a minor proportion, i.e. less than 50%, of an
impact enhancing polymeric additive, conventionaliy termed a poly-
vinyl halide impact modifier. The aforementioned impact modifiers
moderately enhance the ambient temperature impact resistance of
vinyl halide polymers, i.e. generally raise the ambient temperature
notched Izod impact resistance of the polymer to about 2 to 10
ft-lbs/in. ;
The polymeric additives employed as such modifiers include
~5 polymeric compositions consisting essentially of methyl methacry~
late, 1,3-butadiene and styrene monomer units (which are known
generally as "MBS" polymers) as well as polymeric compositions con-
sisting essentially of acrylonitrile, 1,3-butadiene and styrene
monomer units (which are known generlcally as "ABS" polymers). Un-
fortunately the fore~oing polymeric additives, when prepared for
use as polyvinyl halide impact modifiers are rela~ively costly.
This is especially so if a blend of the polyvinyl halide and the
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impact modifier which is transparent or transluscent is desired.
In such instances, the M5S or ABS impact modifier must be prepared
or synthesized under careful control so as to have about the same
refractive index as the vinyl halide resin (which is generally
about 1.52-1.55) and thereby maintain the transparency or trans-
luscency of the vinyl halide resin.
Accordingly, it would be technologically desirable to replace
a portion of the MBS or ABS polymer in an MBS- or ABS-modified
polyvinyl halide composition by a polymer which meets the require-
ments for impact modification and which, desirably, is also readily
available at a refractive index about the same as that of polyvinyl
halide.
A readily available class of polymersl namely the block thermo-
plastic elastomers of a hydrocarbon alkadiene of 4 to 10 carbon
atoms and a mono-alkenyl-substituted aromatic compound of the ben-
zene or naphthalene series containing up to 20 carbons ~as typified
by the block polymers of l,3-butadiene or isoprene and styrene) is
known to have a refractive index about that of the polyvinyl halides
(as indicated by "Modern Plastics Encyclopedia 1974-1975", Vol. 51,
No. lOA, October 1974, page 563, entry 35 at the fourth and seventh
vertical columns). However, as shown in the Examples set forth
below, these block polymers are found in general to be incompatible
with polyvinyl h'alide. Such incompatibility of polymeric components
in a vinyl halide polymer blend can impair the impact resistance of
the blend, as well as the transparency or transluscency of the
blend and often results in formation, on molding of the blend, of a
solid exudate on the surface of the molded blend which imparts an
undesirable rough or lumpy handle to the composition.
While the aforementioned MBS or A~S polymeric impact modifier
additives moderately enhance the impact resistance of vinyl halide
homo- and copolymers, these impact modifiers are relatively in-
effective in imparting a satisfactory sub-ambient temperature
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impact resistance to the polymer, i.e. the -20 F. notched, Izod
impact r~sistance of -the pol~nler containing the impact modifier is
well belo~l 1 ft-lb./in. and usually is about 0.4 to 0.5 ft-lb/in.
It has been discovered that polymerization of vinyl halide
(or a monomer mixture oF vinyl halide and copolymerizable ethy-
lenically unsaturated comonomers) in t:he presence of a hydrocarbon
polyolefin elastomer results in a polymer product (a vinyl halide-
graft-polyolefin polymer) which contains vinyl halide polymer
chains bound, i.e. grafted, at random points along the chain of
the trunk olefin polymer as well as ungrafted vinyl halide polymer.
The graft polymer product, especially the graft polymer product
prepared by a liquid phase bulk polymerization reaction, has a sub-
stantially enhanced impact resistance at both ambient temperature
and sub-ambient temperatures compared to the aforementioned con-
ventional, i.e. ungrafted, vinyl halide polymers even when thelatter are blended with a conventional polyvinyl halide impact
modifying polymer additive. The bulk polymerization-prepared
graft polymer product is even distin~uished from the corresponding
graft polymer prepared by a non-bulk polymerization technique, e.g.
suspension polymerization, by an enhanced impact resistance at both
low and ambient temperature and by breakage by the desirable ductile
breakage mode rather than by an undesirable brittle breakage mode.
Although the ~forementioned graFt polymer possesses a sub-
ambient low temperature impact resistance substantially greater
than that of conventional impact modifier-containing vinyl halide
polymer compositions, the low temperature impact resistance of the
graft polymer is found to decrease on ageing. Thus, for examples
a molded article of the graft polymer, on ageing at ambient temper-
ature for about one month or longer (or at an elevated temperature
for proportionally shorter periods), tends to lose a significant
amount, e.g. up to 35%, of its original high low temperature impact
resistance. This loss of low temperature impact resistance on
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ageing is a particularly serious disadvan-tage when the graft polymer
is employed in outdoor applications in a temperate climate wherein
sub-ambient temperatures of the order 0 F. to -20 F. or even
lower are often encountered during winter months (subsequent to
summer months wherein the graft polymer is subjected to relatively
high temperatures, e.g. of the order of 80~ - 100 F. or even
higher, which serve to accelerate the ageing loss of low temper-
ature impact resistance).
SUMM~RY OF THE INVENTION
The invention, in accordance with one embodiment th~reof, is
directed to an irnproved -thermoplastic composition which is capable
of being molded to an impact resistant article and which comprises
a blend of a vinyl halide polymer wherein a major proportion of the
monomer units are vinyl halide monomer residues; a polymeric impact
modifier for polyvinyl halide selected from the group consisting of
(1) a polymer wherein the major proportion o~ the monomer units are
methyl methacrylate, 1,3-butadiene and styrene residues and (2) an
ABS polymer which has about the same refractive index as said vinyl
halide polymer. According to the improvement of the invention the
blend also comprises a block thermoplastic elastomer wherein the
major proportion of the monomer units are residues of a mono-
alkenyl-substitute~ arene of the benzene or naphthalene series of
8 to 20 carbon atoms and a conjugated alkadiene hydrocarbon of 4
to 10 carbon atoms. The block polymer is normally incompatible
with said vinyl halide polymer. The vinyl halide polymer is present
in a major proportion in the blend, and the polymeric impact modi-
fier and the block polymer taken together is present in a minor
proportion in the blend. Desirably the weight ratio of said block
polymer to said MBS polymer is about 1:5 to about 5:1.
The present impact modifier-block polymer-vinyl halide polymer
compositions, when molded under conventional conditions of temper-
eture and pressure, are capable of providing molded produc-s having
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an impact resistance generally greater than those of the corres-
ponding composition o-F pol~/inyl halide modified with ~lBS or ABS
polymer alone and of the corresponding composition (i.e. generally
an incompatlble mixture) of the polyvinyl halide modified with the
block polymer alone. In other words, the combined presence of the
MBS or ABS polymer and the block polymer component with the poly-
vinyl halide according to the inYention, in general, synergisti-
cally enhances the impact resistance of the polyvinyl halide. The
components of the polyblend of the invention are inter-compatible
eYen on the molding and do not separate as individual solid phases.
Accordingly, the formation of solid exudates (o-f deleterious un-
attractive rough handle) on the surface of the present composit10ns
does not occur on molding. In general, the combination of MBS or
ABS polymer and the block polymer as an impact modifier for poly-
vinyl halide according to the invention meets or surpasses all ofthe requirements generally desired in a polyvinyl halide-impact
modifier.
In another embodiment, the invention is directed to an improve-
ment in a vinyl halide-graft-hydrocarbon polyolefin polymer compo-
sition capable of being molded to an impact~resistant article
wherein, as the improvement, the composition comprises the afore-
mentioned block thermoplastic elastomerg the proportion of block
elastomer being about 1% to 20% based on the colnbined weight of the
graft polymer and the block elastomer.
The addition of the block elastomer to the gra~t polymer accord-
1ng to the invention results in a composition which gains in low
temperature impact resistance-l e,g. impact resistance ~t sub-
ambient temperature down to temperatures as low as -20 F. or lower,
upon ageing of the composition (e.g. at ambient temperature for 1 or
more months or under a corresponding accelerated ageing period of
48 hours at 65 C.).
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Although the non-aged molded blend of the gra-ft polymer and
the block elastomer of the invention has a low or sub-ambient tem-
perature impact resistance substantially lower than that of the
corresponding composition containing only the graFt polymer, age-
ing of the graFt polymer-block elastomer mixture enhances the low
temperature impact resistance to a value greater than that achieved
on ageing the graft polymer in absence of the block polymer addi-
tive. In preferred graft polymer-block polymer compositions of the
invention as described below, the low temperature impact resistance
is enhanced to a value substantially corresponding to the irnpact re-
sistance of the corresponding non-aged composition containing the
unmodified graft polymer, i.e. the impact resistance at low temper-
ature, e.g. -20F., oF such preferred compositions of the invention,
after ageing, is no more than about 3-12% less than that oF the non-
aged, unmodified graft polymer composition. In other words the ad-
dition of the block elastomer to the graft polymer according to a
preferred embodiment oF the invention provides, in effect, stabil-
ization of low temperature impact resistance of the graft polymer.
It is noteworthy that the enhancement of low temperature im-
pact resistance on ageing which is accomplished by the addition of
the block polymer to the graFt polymer does not occur with block
thermoplastic elastomer additives which are the hydrogenated deri-
vatives of the present block thermoplastic elastomers, i.e. deriva-
tives of the present block elastomers, wherein the diene-derived
monomer residues of the elastomer are hydrogenated to saturate the
ethylenic unsaturation in the diene residues. Such hydrogenated
block thermoplastic elastomers (manufactured under the general de-
signation Kraton* G) when incorporated in the present vinyl halide
graft polymers product a loss of low temperature impact resistance
on ageing (as is illustrated by the results o-F Example 35 below).
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The incorporation of the presen-t block polymer into the vinyl
halide graft pol~mer to provide age-enhancement of low temperatllre
impact resistance according to the inven-tion does not deleteriously
affect, to any substantial extent, the other desirable properties of
the graft polymer such as the heat distortion temperature and the
thermal stability of the molten polymer (as measured in a Brabender
Plastograph). If desired, the present block polymer-vinyl halide
graft polymer compositions may contain impact resistance enhanc~ng
additives such as the aforementioned ABS or MBS polymeric addit~ves.
DETAILED DESCRIPTION OF THE INVENTION AND THE
_ _ PREFERRED EMBODIMENTS THEREOF
In the present compositions comprising block polymer, an MBS or
ABS impact modif;er and polyvinyl halide, the desired proportion of
block polymer and ABS or MBS additive and the ratio of the block
polymer to the ABS or MBS additive to provide optimum impact-resis-
tance will vary somewhat depending upon the particular ABS or MBS
additive and block polymer employed. The combination of the ABS or
MBS constituent and the block polymer constituent is generally
present in a minor proportion in the blend of the invention, i.e. is
2~ in the range oF about one to less than about fifty weight percent,
preferably is in the range of about 5 to about 20 weight percent,
and especially is in the range of about 8 to about lS weight percent.
Similarly the vinyl halide polymer is present in a major proportion,
i.e. constitutes more than about 50 weight percent to about 99 weight
percent of the blend, and preferably is present at about 80 to about
95 weight percent concentration, especially at about 85 to about 92
weight percent concentration.
T achieve synergistic enhancement of impact resistance accord-
ing to the invention, the weight ratio of the block polymer to the
MBS polymeric additive is about 1:5 to about 5:1 and preferably is
about 1:4 to about 4:1.
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The weight ratio o-F block polymer to the AB5 polymer, i.e.
additive can vary over a wide range, but is desirably about 1:5
to about 5:1 and preferably is about 1:4 to about 4:1.
In the compositions of the invention which comprise a vinyl
halide-graft-polymer composition modified with the block thermo-
plastic elastomer the proportion of the block thermoplastic elas-
torner which is employed to provide enhancement of low temperature
impact resistance upon ageing in accordance with the invention i5
generally of the order of about 1% to about 20%. Preferably about
1% to about 15%, and especially about 2% to about 10% of the block
polymer based on the combined weight of the vinyl halide graft poly-
mer component and the block polymer component is employed.
THE POLYVINYL HALIDE COMPONENT
The vinyl halide polymer employed as a component in the present
composition can be made by any of the known polymerization processes
used for preparation of these polymer, e.g. vapor phase, emulsion,
suspension, solution or bulk liquid phase polymerization. Conven-
iently vinyl halide polymers prepared by the bulk liquid phase
polymerization mode are employed.
An especially desirable bulk-liquid phase-polymerized polyvinyl
halide for use in the invention is obtained by free radical addition
polymerization in two reaction stages, i.e. a first stage employing
high speed, high shear agitation until conversion of monomer or mono-
mers to polymer is about 3 to 15% and a second stage employing low
speed, low shear agitation until polymerization is complete. This
technique is disclosed in US Patent 3, 522, 227 and British Patent
1,047,489.
The polyvinyl halide resin contemplated for use in the inven-
tion is a rigid resin, i.e. a resin containing less than about 10
percent plasticizer or none at all. Typically, the resin i5 a
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readily available commercial resin which is processes at a tempe-
rature on the order oF about 350F. or even hi~her. While vinyl
chloride is the preferred vinyl halide monomer reactant used in
prepar;ng the v;nyl halide polymers o~ the invention, other suitable
vinyl halide monomers useful in the invention are the alpha-halo-
substituted ethylenically unsaturated comPounds which, like vinyl
chloride, are capable of entering into an addition polymerization
reaction, for example, vinyl fluoride~ vinyl bromide, vinyl iodide,
vinylidene fluoride, vinylidene chloricle, vinylidene bromide~ vinyl-
idene iodide and the like. Vinyl halide polymers derived Prom
polymer;zat;on of two, three or more different v;nyl hal;cle mono-
mers can also be used. It ;s to be understood that the polyvinyl
halide resin, as contemplated for use in this invention, can be a
modified resin, e.g., a copolymer resin of vinyl halide with a
minor amount i.e. less than 50 weight percent of the total ~onomer
mixture, of a comonomer, e.g. of vinyl acetate, or preferably a
copolymer resin prepared by copolymerizing vinyl halide monomer
with from about 1 to about 30 weight percent of a comonomer co-
polymerizable with the vinyl hal;de. Thus, while the polyvinyl
halide component of the invention is preferably comprises totally
o~ vinyl chloride homopolYmer, or other vinvl halide homooolvmer,
the present invention is also intended to include copolymers
thereof as DreviouslY described. Suitable ethylenically unsaturated
comonomer materials which can be used to form the base vinyl halide
copolymers ~i.e. vinyl halide bipolymers, terpolymers, tetrapoly-
mers and higher copolymers, interpolymers, and the like), by the
- reaction with vinyl halide include the followîng monoolefinic
compounds: ethylene, propylene, butene-1,4,4-dimethylbutene~
decene-l, styrene and its nuclear alpha-alkyl or aryl substituted
3Q derivatives, e.g., o-, m- or p-methyl, ethyl, or butyl styrene;
and halogenated styrenes such as alpha-chlorostyrene~ monoole
finically unsaturated esters including vinyl esters, e.g. vinyl
acetate, vinyl stearate~ vinyl benzoate, vinyl-p-chlorobenzoates,
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alkyl methacrylate, e.g., methyl~ e-thyl, propyl and stearyl metha-
acrylate, alkyl crotonates, e.g. octyl crotonate; alkyl acrylates,
e.g., methyl, 2-ethyl hexyl, stearyl acrylates; hydroxy-ether and
tertiary butyla~ino acrylates, e.g. 2-ethoxy ethyl acrylate, iso-
propenyl esters, e.g., isopropenyl acetate, isoproPenyl halides,e.g., isopropenyl chloridei vinyl esters of halogenated acids,
e.g., vinyl alpha-chloroacetate, and vinyl alpha-bromoprop;onate;
allyl and methallyl esters, e.g., allyl chloride, allyl cyanide;
allyl chlorocarbonate, allyl nitrate, allyl formate and allyl
acetate and the corresponding methallyl compounds~ esters of
alkenyl alcohols, e.g., beta-ethyl allyl alcohol; halo-alkyl
acrylates, e.g., methyl and ethyl alpha-chloroacrylates; alkyl
alpha-cyanoacrylates, e.g., methyl alpha-cyanoacrylate; itaconates,
e.g., monomethyl itaconate, diethyl itaconate, alcohol (C-3 to C-8)
itaconates; maleates, e.g., monomethyl maleate~ diethyl maleate,
alcohol (C-3 to C-8) maleates; and fumarates, e.g., monomethyl
fumarate, diethyl fumarate, alcohol (C-3 to C-8) fumarates, and
diethyl glutaconate; monolefinically unsaturated organic nitriles
including, for example, furmaronitrile, acrylonitrile, metha-
acrylonitrile, l,l-dicyanopropene-l, and oleonitrile; monoole-
finically unsaturated carboxylic acids including, for example,
acrylic acid, methacrylic acid, cinnamic acid, maleic, and itaconic
acids, maleic anhydride and the like. Amides of these acidsl such
as acrylamide, are also useful. Vinyl alkyl ethers and vinyl ethers~
e.g., vinyl methyl ether, vinyl ethyl ether, vinyl 2-chloroethyl
ether, vinyl cetyl ether, and the like, and vinyl sulfides, e.g.
vinyl beta-chloroethyl sulfide, vinyl beta-ethoxyethyl sulfide
and the like can also be included as can diolefinicaliy unsaturated
hydrocarbons containing two olefinic groups in conJugated relation
and the halogen derivatives thereof, e.g., butadiene-1,3-, 2-
~ethyl-butadiene-1,3; 2,3-dichlorobutadiene-1,3; and 2-bromo-
butadiene-1~3 and the like.
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lHE VINYL HALIDE-GRAFT-POLYOLEFIN
POLYMER COMPONENT _
When the vinyl halide polymer component of the invention is
a copolymer, said copolymer can also be a graft copolymer of a
vinyl halide (or of vinyl halide and comonomer copolymerizable
therewith) and a polyolefin rubber i.e. elastomer, which is
characterized by being soluble, partially soluble, or dispersible
at ambient or room temperature and pressure in vinyl halide monomer.
The latter known vinyl halide graft copolymers ar~ obtained by
polymerizing a mixture of vinyl halide monomer with one or more
ethylenically unsaturated comonomers of the type described above
(or desirably, a vinyl halide monomer alone) in the presence of the
olefin trunk polymer reactant. The polyolefin elastomer or rubber
is a homopolymerg bipolymer, terpolymer, tetrapolymer or higher
copolymer (especially a homo- or bipolymer of aliphatic olefinic
monomers. The olefin polymers can also contain the residue o~ a
aliphatic hydrocarbon polyene, e.g. a non-conjugated, linear or
cyclic diene, of 14 to 18 carbon atoms as a monomer unit,
The aforementioned olefin homopolymers can be obtained by poly-
20 merization of a suitable monomer such as ethene, propene, i.e. pro- -
pylene, butene-l, isobutene, octene, or 5-methylhexene-1.
i~ Suitable comonomers for use in preparing the polyolefins are
those utilized to prepare the olefin homopolymers as listed above,
such as propene or butene-l with ethene and the like. Suitable
,
termonomers are those utilized to prepare homopolymers and co-
polymers as disclosed above such as propene, ethene and the like
as well as a polyene. Especially suitable polyene-derived ter-
i and higher co-polymers can be prepared from olef~n monomer mixtures~
containing up to 15 percent, preferably up to about 6 percent by
weight, of the polyene Cpreferably non-conjugated), e.g. 1,4-hexa-
diene, dicyclopentadiene, ethylidene norbornene, cyclooctadiene and
other dienes with linear or cyclic chains. The polyolefin used may
also be a halogenated polyolefin, e.g. a chlorinated, brominated or
fluorinated polyolefin but a hydrocarbon polyole~in trunk polymer, ~ i
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i.e. a polyolefin wherein the carbon atoms are substituted solely
with hydrogen, is preferred.
The polyolefins used are characterized by being soluble, par-
tially soluble or dispersible at ambien-t temperature and pressure
5 in vinyl chloride monomer, and in having, typically, monomeric
units of 2 to 8 carbon atoms. The weight average molecular weight
of the olefin polymers, copolymers, terpolymers, and tetrapolymers
can vary from about 50,000 to about 1,0()0,000 and higher, but pre-
ferably is about 50,000 to about 300,000. Preferred as polyolefin
rubbers for use in preparing vinyl halide graft polymers for use in
the invention are ethene-propene polyolefin elastomers and ethene-
propene-diene polyolefin elastomers.
The vinyl halide-graft copolymers of the polyolefin elastomers
are prepared by polymerizing the vinyl halide in the presence of
about 0.05 to about 20% preferably about 1 to about 20~, based on
the weight of vinyl halide monomer of the above-described polyole-
fin rubber. Preparation of such vinyl halide-polyolefin graft co-
polymer according to emulsion and suspension polymerization tech-
niques is described in G. Natta et al., US Patent 3,812,204.
Preparation of such vinyl halide-polyoleFin graft copolymer by
vapor phase and solution polymerization techniques are described,
respectively, in J. Dumoulin et al., US Patent 3,7~9,083 and F.M.
Rugg et al., US Patent 2,947,719. Conveniently, the preparation
of the vinyl halide-polyolefin graft copolymers useful as the poly-
vinyl halide component of the compositions of the invention is ef-
fected by a bulk liquid phase polymerization technique as described
by A. Takahashi, US Patent 4,071,582; Canadian application Serial
No. 290,991, filed November 16, 1977, now Canadian Patent 1,109,181;
and by L. E. Walker, US Patents 4,007,235 and 4,067,928.
It is to be understood that the above-described vinyl halide-
polyolefin graft copolymers possess an impact resistance substantially
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greater than the impact resistance oF conventional (i e. ungrafted)
vinyl halide homopolymers and copolymers. Nevertheless, the impact
resistance properties of such graft copolymers is generally further
improved by blending with the present MBS or ABS polymer, i.e. addi-
tive and block polymer in accordance with the invention.
A vinyl halide-graft-polyolefin polymer composition wherein
the polyolefin is a hydrocarbon polyolefin is the substrate em-
ployed when it is desired to provide the vinyl halide graft polymer
compositions of the invention which are resistant to loss of low
temperature impact resistance on ageing.
THE METHYL METHACRYLATE-1,3-8UTADIENE-STYRENE
POLYMER (MBS POLYMER) COMPONENT
The methyl methacrylate-1,3-butadiene-styrene polymers employed
as components of the compositions of the invention constitute a read-
ily available class of polymers (generally proprietary polymers)
which are manu-factured to have a re-fractive index about that of poly-
vinyl halide and which are widely employed as impact modifiers for
polyvinyl halide resins. The MBS polymers as manufactured for use
as polyvinyl halide impact modification agents are generally graft
polymers prepared by polymerizing methyl me~hacrylate (and option-
ally, in minor proportion to the methacrylate monomer, ethylenically
unsaturated comonomers copolymerizable therewith such as acryloni-
trile or styrene) in the presence of a polybutadiene or a polybu-
tadiene-styrene trunk polymer rubber, as described in L. I. Nass
Ed. "Encyclopedia of PVC'', M. Dekker, Inc., Vol. 2, 1977, page 613,
Section 2(a). It is well understood that a wide variety of grafting -
conditions and choice of comonomers can be employed in the prepara-
tion of the MBS-impact modifiers. Typical graft polymerization se-
quences and/or comonomers for use with the methacrylate monomer in
preparation of the MBS polymer modifiers are disclosed in the follow-
ing patents: ~
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K. Saito et al., US Patent 3,~70,052; K. Saito et al., US Patent
3,651,177; K. Saito et al., US Patent 3,287,443; S.S. Feuer, US
Patent 2,943,074; L.E. Daly, US Patent 2,018,26~; L.A. Beer, US
Patent 3,444,269; A.C. Condon, US Patent 3,445,416; T. Tanaka et
al., US Patent 3,652,483; S. Yonezu et al., US Patent 3,~52,727;
T. Tanaka et al., US Patent 3,657,39t); S. Koyanagi et al., US
Patent 3,717,68~; Y. Amagi et al., U'i Paten-t 3,775,514; T.J.G.
Lonning, US Patent 3,780,134; T. Tanaka et al., US Patent 3,842,1 4LI;
H. Kumabe et al., US Patent 3,907,928; F.E. Love, US Patent
3,922,320; N. Murayama et al., US Pat:ent 4,021,509; F. Ide et al.,
US Patent 4,041,106 and S. Koyanagi et al., German Offenlegung-
shrift 2,0647297 issued July 1, 1971.
Proprietary MBS polymers manuFactured as impact modification
additives for vinyl halide polymers incl~de Acryloid-~ KM229, KM
607-N and KM611 of Rohm and Haas Co. (described in R.P. Petrich,
Polymer Eng. and Sci., July 1973, Vol. 13, No. 4, pages 248~258
and in J.T. Lut~, Jr., Adv. in Chem. Ser. No. 134, 1974, pages
61-72, as well as Kane Ace~ B-12 and B-22 manufactured by
Kanegafuchi Chemical Industry Co. The latter proprietary MBS
polymer, i.e. Kane Ace~'; B-22, which provides an especially good
result when employed as the MBS polymer component of the inven-
tion, is prepared in accordance with the technology of the above-
mentioned US Patents 3,387,443; 3,651,177 and 3,670,052 of K.
Saito et al.
THE ACRYLONITRILE-1,3-BUTADIENE-STYRENE
POLYMER (ABS POLYMER) C MPONENT _
The acrylonitrile-1,3-butadiene-styrene polymers employed as
components oF the composition oF the invention constitute a readily
available class of polymers (generally proprietary polymers) which
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are widely employed as impact modifiers for polyvinyl halide resins.
If desired, they are available at about the same refractive index
as vinyl halide resins. As recognized by the art the ABS polymers
comprise either (1) a mixture of a copolymer of styrene and acrylo-
nitrile (typically, at a monomer ratio of 60 to 80:40 to 20 styrene;
acrylonitrile) with a minor amount (e.g. 10~ to 40% by weight) of a
copolymer oF acrylonitrile and butadiene (typically at a monomer
ratio of 5 to 40:95:5) or (2) a mixture of a copolymer of styrene
and acrylonitrile (typically at a monomer ra-tio of 60 to 80:40 to
20) with a minor amount (typically 10% to 40%) of a graft of the
latter styrene-acrylonitrile copolymer onto polybutadiene.
The ABS polymers are more particularly described in R.E.
Gallagher, US Patent 3,988,393 and W.C. Calvert, Australian Patent
220,155 (issued April 11, 19~7).
THE BLOCK POLYMER COMPONENT
The block elastomer component of the compositions of the inven-
tion is a thermoplastic block polymer wherein the major proportion
of the monomer units are derived from (1) a mono-alkenyl-substituted
arene (i.e. aromatic compound) of the benzene or naphthalene series
containing 8 to 20 carbons and (2) a conjugated hydr-ocarbon alka-
diene of 4 to 10 carbon atoms. Minor amounts of other monomers may
be present in the block polymer as described herein below.
The monoalkenyl arene of the benzene or naphthalene series
employed as a monomer in preparing the block polymer constituent of
the present composition can be, for example, styrene; o-, m- or p-
methyl styrene; o-, m-, or p-n-butyl-styrene; m-isopropyl-st.yrene;
p-t-butyl-styrene; p-octyl-styrene; 2,3-dimethyl styrene; 3-ethyl
styrene; alpha methyl-styrene; p-n-dodecyl-styrene; p-methoxy-
styrene; m-n-octylstyrene; l-vinyl-2-n-octyl naphthalene; l-vinyl-
2-isopropyl-naphthalene; 1-vinyl-2-methoxy-naphthalene or mixtures
thereof. The carbon-to-carbon double bond in the side chain of the
:
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- 17 -
alkenyl arene is in alpha, beta position with respect to the aromatic
nucleus. Preferably the monoalkenyl-substituted arene is a hydro-
carbon and -the alkenyl group is the vinyl group, CH2=CII-. PreFerably
also the monoalkenyl-substituted arene is a compound o~ the benzene
series, especially an alkenyl-substituted compound of the ben~ene
series containing up to 12 carbon atoms. Block polymers prepared
usiny styrene as the mono-alkenyl-substituted aromatic monomer are
especially preferred.
The conjugated hydrocarbon alkadiene monomer used to prepare
~ the block polymer constituent of the present composition can be,
for example, 1,3-butadiene; isoprene; 2,3 dimethyl-butadiene; 2-n-
butyl~l,3-butadiene; 1,3-cyclohexadiene; 2-n-hexyl-1,3-butadiene;
1,3-pentadiene; 1,3-hexadiene; 1,3-decadiene; 2-isopropyl-1,3-buta-
diene, 2-t-butyl-1,3-butadiene; 1,3-cyclodecadiene; Z~4-octadiene;
or mixtures of the foregoing cyclic or open chain alkadiene hydro-
carbons. Preferably the alkadiene monomer employed in the block
polymer constituent of the present composition is an open chain
alkadiene and especially is l,3-butadiene or isoprene.
While it is preferred that all of the monomer units of the
present block polymer constituent consist of residues of the fore-
going alkadiene and mono-alkenyl-substitutPd arenes, it is under-
stood that, i~ desired, minor proportions of the residues of other
ethylenically unsaturated compounds copolymerizable with the alka-
diene and the alkenyl-substituted aromatic monomer can be present
also as comonomer units, for example residues of vinyl pyridine,
acrylonitrile, lower alkyl esters of acrylic acid ~wherein the term
lower alkyl indicates a straight or branched alkyl group of 1 to 6
carbon atoms, e.g. methyl), methacrylonitrile, and vinyl carboxy-
lates, e.g. vinyl acetate.
The weight ratio o~ the mono-alkenyl-substituted aromatic
compound residue to the alkadiene residue can vary over a wide rarge.
However, because of their ready availability, the block polymers
i .
:
::
1134~37'~L
- 18 -
preferably employed in the invention have a ~leight ratio of mono-
alkenyl-substituted arene residue -to alkadiene residue in the range
of about 1:1 to about 1:10, pre~erably o-F about 1:1.5 to about I:6
and especially of about 1:1.5 to 1:2.3.
The block polymers of the invention are generally prepared by
a sequential polymerization of the monomer reactants employing an
anionic addition polymerization technique. The reaction is generally
carried out in the presence of a catalyst for anionic polymerizat~on,
typically an organo lithium catalyst such as n-butyl lithium; (Under
the latter reaction conditions a block copolymer is ~ormed substan-
tially to the exclusion of formation of a conventional copolymer,
i.e. a random, network, or graft copolymer, of the aforementioned
monomers). The polymerization reaction is e~fected in an inert
atmosphere under substantially anhydrous conditions. The polymer-
ization can be carried out in the absence or presence of an inert
reaction mixture diluent or solvent such as an ether devoid o~
functional groups containing active hydrogen, e.g. tetrahydrofuran,
or an aromatic hydrocarbon such as benzene~ toluene, xylene and
the like. Use of an ether solvent is especially advantageous.
The preparation of the aforementioned block polymers is more
particularly described in L. M. Potter, U.S. Patent 3,140,182;
R. N. Cooper, U.S. Patent 3,030,846; R. P. Selinski, U.S. Patent
3,287,333; K. J. Silberberg, U.S. Patent 3,380,863, at Col. 3,
lines 5-28 and Col. 5, lines 10-40; R. A. Hinton, U.S. Patent
3,452,119; J. K. Craver and R. W. Tess Ed. "Applied Poly~er
Science", Organic Coating and Plastics Chemistry Div. o~ American
Chem. Soc., 1975, pages 394-429, M. Morton Ed. "Rubber Technology",
Van Nostrand-Rheinhold Co., Second Edition, 1973, pages 188, 515-
~ 533 and D. C. Allport et al. Ed. "Block Copolymers", Wiley
-~ 30 (Halstead Press), 1973, pages 81-87, G. Holden et al., 3,265,765;
; - R. L. Huxtable et al., U.S. Patent 3,1987774; R. E. Dollinger,
U.S. Patent 3,297~793; R. E. Dollinger et al., U.S. Patent
.
,
:
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- 19 -
3,35~,7~3, Encyclopedia of Polymer Science and Technology, Vol. 15,
J. Wiley and Sons, 1971 (Supplement) "Styrene-Diene Block Polymers",
pages 50~-530; and Encyclopedia of Polymer Science and Technology,
Supplement, Vol. 2, J. Wiley and Sons, 1977, pages 129-132.
The aForementioned block polymers can be linear block polymers
composed of two homopolymeric segments or blocks (termed a diblock
polymer) or three (termed a triblock polymer) or more homopolymeric
segments. In the triblock polymers, generally the residues of the
mono-alkenyl arene constitute the end block while the residues of
-the alkadiene constitute the interior block. The block polymers
of the invention can be graded or tapered block polymers wherein,
for example, one polymer segment or block o-F the polymer begins
with a particular monomer unit and gradually incorporates another
monomer unit until at the end, said block is totally composed of
the second monomer units. In general, in such tapered or graded
block polymers (as in the aforementioned triblock polymers) mono-
alkenyl arene residues constitute the end blocks while the alka-
diene residues constitute the interior block or blocks.
Block polymers oF a mono-alkenyl-substituted aromatic hydro-
carbon monomer (e.g. styrene) and a hydrocarbon alkadiene (e.g.
1,3-butadiene or isoprene) containing tapered blocks are more
particularly described at page 395 of the aforementioned Craver
and Tess textbook reference; at pages 83-84 of the aforementioned
Allport et al. textbook reference and the aforementioned US Patent
of Holden et al., 3,265,765.
The block thermoplastic elastomers of the invention can also
be of star-like or radial polymeric structure wherein 2, 3, 4 or
more homopolymeric blocks (advantageously alkadiene blocks) radi-
ate from another, central homopolymeric block (advantageously the
mono-alkenyl arene block). The latter radial block polymers can
be prepared by charging a small amount of a coupling agent
,
,.
~3~
- 20 -
(e.g. a polyfunctional alkenyl arene compound such as 1,4-divinyl
benzene or a poly-functional inorganic compound such as silicon te-
trachloride) to the partially reacted reaction mass of the afore-
mentioned anionic polymerization (whic:h has already sufficiently
reacted to form a diblock polymer).
The preparation of b'lock polymers having a star or radial
configuration is described by the Craver and Tess textbook refer-
ence at pages 395 (Table 11), 421, ancl 422 (Table Vl); by pages
131-132 of the aforementioned article of The Encyclopedia of
Polymer Science and Technology, Supplement, Vol. 2; by N. Platzer,
.
Chemtech, October 1977, pages 634-641, especially page 637, Column
1, lines 33-35 and Figure 2; by the anonymous article entitled
"New Rubber is Backed by Stars", Chemical Week, June 11, 1975,
page 35; and especially by R.P. Zelinski et al., US Patcnts
3,078,254 and 3,281,383.
It is emphasized that the aforementioned Figure 2 of the
Platzer reference graphically indicates the substantial distinc-
tions between the present block copolymers and corresponding con-
ventional copolymers (including random, network and graft copolymers). ;
The distinctive physical, mechanical and especially processing pro-
perties which distinguish the present thermoplastic block elastomers
from conventional elastomers prepared from the same monomers as are
employed in block polymers are more particularly discussed in the ;
aforementioned Morton textbook reference.
Block copolymers of styrene and 1,3-butadiene or of styrene
and isoprene are readily available as proprietary polymers manu- ''
; factured under the designation "Kraton"~'; by Shell Chemical Co. and
under the designation "Solprene"* by Phi'llips Petroleum Co. As in-
dicated by the fourth and sixth horizontal lines of the aforemen-
30 tioned Table Vl of page 422 of the Craver and~Tess textbook
reference, the Kraton* copolymers are linear b10ck polymers (non-
hydrogenated) of styrene and l,3-butadiene or isoprene whereas the
.,, ,:~
trademark
:
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- 21 -
Solprene copolymers are radial block polymers or are block polymers
containing a tapered block wherein the monomer units are derived
from styrene and l,3-butadiene.
OPTIONAL ADDITIVES
The compositions of the invention may a1so contain various
functional additives, which additives are conventional in the pre-
paration of vinyl halide molding compositions. Typically these
additives include thermal and/or light stabilizers, as well as
external and internal lubricants, and processing aids for the
polyvinyl halide or vinyl halide graft polymer.
Stabilizers suitable for use in making the vinyl halide poly-
mer compositions of the invention include all of the materials
known to stabilize polyv7nyl halide against the degradation action
oF heat and/or light. They include all classes of known stabili-
zers, both organic and inorganic such as metal salts of mineral
acids, salts of organic carboxylic acids, e.g. carboxylic acids
of 6 to 18 carbon atoms, organo-tin compounds, epoxides, amine
compounds and organic phosphites. Conveniently an organo-tin
compound such as a methyl tin mercaptide is employed as stabilizer.
I 20 A more detailed description of suitable stabilizers, lubri-
cants and processing aids for incorporation into the compositions
of the invention is presented in Belgian Patent 855,764 issued
December 16, 1977.
Additional classes of additives known for use in polyvinyl
halide resins which can be added optionally to the composition
of the invention in addition to the aforementioned stabilizers,
lubricants and processing aids include pigments, dyes and fillers
as described in L.R. Brecker, Plastics Engineering, March 1976,
"Additives 76", pages 3-4.
In general the amount of each type of the aforementioned op-
tional additive employed in the present composition is about 0.01
,
:
~3~
- 22 -
to about 5 weight percent, preferably about 0.1 to about 3 weight
percent based on the total resin composition.
The compositions of the invention are essentially of the
rigid vinyl halide resin type which contain no more than about
10 weight percent oF a plasticizer for vinyl halide graft polyrner
and preferably are free of said plasticiziny additive. Typical
suitable plasticizer additives (which are generally organic com-
pounds) conventionally employed in polyvinyl halide compositions
include, for example, the esters of aliphatic alcohols of medium
chain length, e.g. of 7 to 11 carbon atoms, with phenyl dicarbox-
ylic acids, e.g. di-n-octyl phthalate and di-isononyl phthalate
as well as organic phosphate esters such as cresyl-diphenyl-phos-
phate and octyl di-phenyl-phosphate. The chemical structure and
technology of plasticizers conventionally employed in polyvinyl
halide compositions is more particularly discussed in L.R. Brecker,
op. cit. page 5.
The compositions of the invention can be prepared by milling
and mixing techniques conventional for preparing conventional
impact-modified vinyl halide polymer polyblends. e.g. conventional
MBS or ABS polymer-modi-Fied polyvinyl halide. Generally the com-
ponent polymers (and, if desired, the above-described optianal
additives) are added as a particulate solid mixture to a roll
mill or a Banbury type mixer and milled at an elevated temperature
conventional for processing rigid vinyl halide polymer compositions.
The resultant polymer blend obtained as product from the milling
and mixing operation is molded by either an injection or compres-
sion molding technique to articles of particular desired shapes at
elevated temperature and pressure conditions which are conventional
in molding rigid polyvinyl halide compositions. Desirably when an
MBS- or ABS-modified vinyl halide polymer is employed as the blend
substrate, a compression molding technique is employed to prepare
the aforementioned articles which can be in various shapes including
bars, plates, rings, rods, as well as sheets and films.
. .
:' ,' ' ' ' , " ' ,, ':
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- 23 -
The following examples further illustrate the various aspects
oF the invention but are not intended to limit it. Various modi-
fications can be made in the invention without departing from the
spirit and scope thereof. Where not otherwise specified in this
specification and claims, temperatures are given in degrees centi-
grade, and all parts, ratios and percentages are by weight.
EXA~PLE 1
A particulate solid mixture of 100 parts of a vinyl chloride
homopolymer which is prepared by bulk liquid phase polymerization
and has a Notched Izod impact resistance (ASTM Test D-256) in the
range of about 0.4 to less than 1 ft.-lbs./in., 6.5 parts of a pro-
prietary methyl methacrylate-1,3-butacliene-styrene polymer conven-
tionally employed for impact resistance-enhancement of vinyl halide
polymers (manufactured by Kanegafuchi Chem. Ltd. under the designa-
15 tion Kane Ace* B-22), 6.5 parts of a proprietary styrene-1,3-buta-
diene radial block polymer containing about 40~ styrene and about
60~ 1,3-butadiene (manufactured by Phillips Petroleum Co. under
the designation Solprenet: 414-P), 2.85 parts of an acrylic polymer
processing aid conventionaily employed in processing vinyl halide
resins (manufactured by Rohm and Haas Corp. under the designation
Acryloid~'~ K-12C-ND), 1.14 parts of a proprietary short chain paraf-
fin wax conventionally employed as an internal lubricant in molding
vinyl halide polymers (manufactured by Cincinnati-Milacron Co.
under the designation Advawax~ 140), 0.23 parts of a proprietary
was which is a derivative long chain (28-32 carbon atoms) montan
wax acid which contains a diester of a dihydric alcohol and which
.
is conventionally employed as an external lubricant (having some
internal lubricant function) in molding vinyl halide polymers (man-
ufactured by American Hoechst Corp. under~the designation Wax E~';)
and 1.8 parts of a proprietary methyl-tin mercaptide conventionally
employed as a heat stabilizer in vinyl halide polymers
`
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.,
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- 24 -
(manufactured by Cincinnati-Milacron Co. under the designation
TM-181) is added to the rolls of an Amil Mill opera-tiny under the
following conditions:
Front Roll Temperature 355 - 360~F
Back Roll Temperature 330 - 335F
Roll Speed 48 ft./min.
The ~usion time of the mixture,in the mill is about 10-15 seconds.
The mixture remains on the mill rolls for about 5 minutes with the
appearance of the bands of the mixture on the rolls being satis-
factory. The mixture is delivered ~rom the mill as a sheet which
is allowed to cool to about ambient temperature (about 20).
The resultant polyblend is compression malded as bars 6 inches
in length, 6 inches in width and 1/8 inch in thickness employing
a large Carver Press which operates under the following sequence
of temperature and pressure cond;tions: 3 minutes at 350F., 1000
psi; 2 minutes at 350F., 30,000 to 32,000 psi; and 2 minutes at
ambient temperature 30,000 to 32,000 psi.
The resultant molded bar samples are cut to provide bar samples
of 1/2 inch width which are notched and tested for Notched Izod
Impact resistance at ambient temperature and 20F. substantially
in accord with ASTM Test D-256. The results of this test and
appearance of the molded bar articles are presented in Table I
below.
EXAMPLES 2-9
Z5 In a series of Examples 2-9, the procedure of Example 1 is
repeated substantially as described except that the amounts charged
of the methacrylate polymer component, i.e. the MBS additive, and
the block polymer component are varied or, in some instances, either
the MBS poiymer or the block polymer is omitted. The results of
these examples are summarized in Table I below.
,
,
: .: . . . . . . . ................. . . .. . .
"! .,~. ,, '!: ''
~3~ 4
c c~ .. " V . ~ ,~
L O _S ~ L 'L L U~ L S o
O ~ 2~ ) 0 ~ ~ ~
1.~1 ~ :~ ~a ~ 3 ~ ~ 3 V~ " -- ' ~ 111 O
._ a~ 3 ~ 3 x 3~ cn a~
Cl. O 0 Vl ~ L L ~~a 0 0 L U L ~ o
'tQ ,o ._ L O ~ L E - -- ~ E ~ E ~ cJ E
vv ~_C __C ~ V V ~ ~v ~ .~
~ -- ~ ~ ~V~ ~ 0 ~~ --~ ~-- ~ C ~ ~
0~c
_oo ~ ~ ~ LO
U~1 O O O O O O O O O ILI '~
C ~ O
~ ~ ocC ~ 4_~
~~ 1_ c~ o {~ Q.
~ L.I ~ ~ co 0- ~ d cn ~ i ~ c
j~ I V~ ~ L
04-
o o E
o
~O'~UD ~ I~ 00, O O O ~ CO O .,_
~ ~ ~5! L ~--
~ 0 ~ ~
o : a E
O ~ O L~ O IL O O~ OD I L
1~_ L ~ c~ O O O a a
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L ~ O O ~ ~
. ,:
,' ' ' ' ,'''', ' ~ . " ' ,, ' " , ' '. ' ~': :' , '`' ' ' , , '.', ','.,',
3~
- 26 -
Comparison of the ambient temperature impact resistance results
of Examples 1-3 (~Ihich illustra-te the compGsitions o-f the invention
and which contain block polymer to ME3S polymer in a ratio of about
1:1 to 4:1 with the ratio of styrene to butadiene in the block
polymer being about 2:3) with the corresponding impac-t resistance
results of Control Examples 5-6 (which omit the block polymer com-
ponent), on the one hand, and of Control Examples 7-9 (wh;ch omit
the MBS polymer), on the other hand, indicate that the impact re-
sistance of the composition OT the invention is synerg;stically
enhanced by the combined presence, according to the lnvent1On, of
- both the block polymer and the MBS polymer in a vinyl halide resin
blend.
Control Examples 8-9 further illustrate that the block polymer
additive by itself in a vinyl halide resin is incompatible with the
.15 vinyl halide polymer as especially indicated by the formation of a
transparency-impairing surface exudate on the products of these Ex-
amples. Control Example 4 illustrates a vinyl halicle containing
both an MBS polymer and block polymer wherein, however, the ratio of
the latter two additives is outside the ratio of the invention. In
the latter Examp1e the ambient temperature impact resistance of the
: product is not synergistically enhanced by the Joint presence in
vinyl halide polymer of both the MBS polymer and the block polymer.
Moreover, the polymer components of the Example 4 product are in-
: compatible with each other as indicated by the sur~ace solid exudate
~5 in the Example 4 product.
EXAMPLES 10-16
A series of illustrative and Control Examples 10-16 similar to
these described above in Examples 1-9 is performed employing the
procedure of Example 1, substantially as described, except that the :
block polymer employed is a proprietary radial styrene-1,3-butadiene
block polymer containing about 30% styrene and about 70~O (manufac-
tured by Phillips Petroleum Co. under the designation Solprene
; 411-P). The results of these Examples are presented in lable II:
below.
: ~ .
374
- 27 -
~ o ~ ~ o
V o
~o ~ L 0 3 o u v
C o,~ , t ~,.' o
L~ o ,~ L ~ V V .~ ~ E ~_ ,a U
. ~ ~.~ ,, ~ ~ ,~, "': 8. "' O
~ ~ ~ -- ~ V~ ~ o.
l - -
L CO C~ C~
~ ~ o o o c~ ~ o
~: L
QC~ O
1~~l LL
.~1 8--Ln o ~
~
#:1 O ~ E
j~: ,
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0 0
o V C Ln o Ln o ~ ~o o~
O_ -- E Ln 1~ ~:0 0 Ir~ ~ O
: V C:n o
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C
,
L~ Ll .,:
LLI O L~ Ln ~ :~J _ O O O
'LO
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L o _ ~ o
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Compositions of the invention in Tahle II, i.e. the product of
Examples 10, 11 and 12 (~hich have about 1:1 to about 4:1 ratio of
block po'lymer to MBS polymer wi-th the ratio of styrene to butadiene
in the block polymer being about 1:2.3) are seen to have an enhanced
ambient temperature impact resistance compared to that obtainable
~at corresponding concentrations~ in polyvinyl halide-methacrylate
polymer compositions devoid of block polymer (of the typé illust-
rated in Control Examples 5 and 6 above), polyvinyl halide block
polymer compositions devoid of MBS polymer (the products of Control
Examples '14-16) or polyvinyl halide compositions containing both
MBS polymer and block polymer but at a ratio of the latter two
polymeric addit;ves outside that of the invention (the product of
Control ~xample 13j. The polyvinyl halide compositions of Table
II which contain block polymer but no MBS polymer (the products of
Control Examples 14-163 and the polyvinyl halide composition of
Table II which contains MBS polymer and b'lock polymer at a ratio
other than that of the invention (the product of Control Example
13) are seen to have inferior optical properties compared to the
products of the invention illustrated in Examples 10, 11 and 12.
Moreover the polymer component of the products of Control Examples
13-16 are incompat;ble with each other as indicated by the presence
of substantial solid exudate on the surface of the products.
EXAMPLES 17-2?
In Examples 179 19 and 21 the results of which are set forth
in Table III below the procedure of Example 1 is repeated substan-
ially as described above'employing several different proprietary
block polymers of a mono-alkenyl substituted arene and an alkadiene
; according to the invention (t'ne particu'lar block polymer employed ' ' '
being identified in the footnotes of the Table). Examples 18, 20
and 22 (the results of which are also presented in Table III) are
Control Examples corresponding, respectively, to aforementioned
Examples 17, 19 and 21 wherein the MBS polymer component is omitted.
'
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- 29 -
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. 3~ e ~ c ~ ~ ~ ~ ~ ~ o c
a c ~ d CJ ~ ~ O ~ O
U _ X CL aJ U _ CL ~ X L _ 1'~ , O
0 ~ -a V ~ o.~ ~ L e ~d éa
~ ~ ~e - ~ ~ ~ e o n~ L ~ ~Je v ~ e ,a , t cn
L~ ~ ^ o ~ u~ O --~,v ~ _ v~ v o ~ ~ ~
o ~ ~ e O _ ~ r ~ _
2 C X ~ Vl e ~ ~c u~ ~ .,~ ~e O u .~ ~o c e ae~ a~ e ~
O ,3 aJ ~ o ~ ~e 'L ' ~ '~ ~e' ~ ~ a~ o sJ
9 ~-- ~ ~ ' o L ' ' '' e s ~ o v c
3: ~ o o v~ v~ ~ o ~ ~ e ~ s c., I ~ .a
~o ~ .7 o
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c o~ r~ ~ ~ ~ ~ ~ ~ ~ ~e
o ~ o o o o o o ~ e L o Cl
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~ L~ ~ ~C~ ::L.O 0~ ~
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I:TI O Ll~ O 11'~ 0 U~ O ~ ~1) 10 ~ U~ Ir)
0 3: C r- r~ _ e o. e
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I c- E u~ o u o ~ o ~ v . ~, .
2.~ l o~ o ~ o ~ `
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llJ ~ ~ _~
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3
The products illustrative of the invention in Table III, i.e.
the products of Examples 17, 19 and 21, wherein the ratio of block
polymer to MBS polymer is about 1:1, have enhanced optical proper-
ties (i.e. transparency or translucency) compared to the products
of the corresponding Control Examples 18, 20 and 22 wherein the
MBS polymer is omitted. The latter Control Example products also
have a solid exudate in their surface which is substantially ab-
sent in the products of Examples 17, 19 and 21. These results
further substantiate the incompatibility of the block polymer of
the invention with vinyl halide polymer when the MBS polymer is
omitted.
Comparison of the ambient temperature impact resistance re-
sults of the products of Examples 17, 19 and 21 with those oF the
i corresponding vinyl halide polymer compositions containing the MBS
i 15 polymer but no block polymer (i.e. the products of above-discussed
Control Examples 5 and 6) and with those oF the corresponding vinyl
halide compositions containing the block polymer but no MBS polymer
(i.e. the product of the appropriate Control Example in Examples 18,
20 and 22) indicates that the ambient temperature impact resistance
of the products of Examples 17, 19 and 21 is enhanced synergistically.
EXAMPLE 2 3
1:
1~ A particulate solid mixture of 100 parts of a vinyl chloride
1~ homopolymer which is prepared by bulk liquid phase polymerization
and has a Notched Izod impact resistance (ASTM Test D-256) in the
range as described in Example 1, 6.5 parts oF a proprietary ABS
(acrylonitrile-1,3-butadiene-styrene) polymer conventionally em-
ployed for impact resistance-enhancement of vinyl halide polymers
(manufactured by Marbon Division, Borg Warner Corporation under
~; ~ the designation Marbon Blendex~L 401), 6.5 parts of the proprietary
styrene-1,3-butadiene radial block polymer of Example 1, 2.85 parts
of the acrylic polymer processing aid containing abou-t 13~, ethyl
acrylate and 87% methyl methacrylate monomer residues employed in
~ ~ *trademark
:: :: ~ :
,.. ,, ,,,,, . .: .... ~. . .. .
I - 31 -
! Example 1, 1.14 parts of the proprietary short chain paraffin wax,
0.23 parts o~ the proprietary ~lax derivative is conventionally
employed as an external lubricant in molding vinyl halide polymers
which is described in Example 1 and 1.8 parts of the proprietary
methyl-tin mercaptide heat stabilizer of Example 1 is added to the
rolls of a Farrell Mill operating under the following conditions:
Front Roll Temperature 360F.
Back Roll Temperature 240F.
Roll Speed ~8 ft./min.
10 After fusion, the mixture remains on the mill rolls ~or about 5
minutes with the appearance of the bands of the mixture on the
rolls being satisfactory. The mixture is delivered from the mill
as a sheet which is allowed to cool to about ambient temperature
(about 20).
The resultant polyblend is compression molded into sample bars
6 inches in length, 6 inches in width and 1/8 inch in thickness
employing a large Carver Press and tested for Notched Izod Impact
resistance at ambient temperature and -20F. substantially as
described in Example 1. The results of this test and appearance
20 of the molded bar articles are presented in Table IV below.
;~ EXAMPLES 24-30
In a series of Examples 24-25 the procedure of Example 23 is
~j~ repeated substantially as described employing different block
polymers as follows:
:
:~ 25 Example 24 - the radial block polymer containing 70% -~
1,3-butadiene and 30% styrene of Example 10
~ Example 25 - the triblock polymer containing 86% isoprene; ~ and 14% styrene of Example 17.
In series of Control Examples 26-30 the procedure o-f Example
30 23 is repeated substantial1y as described with either the ABS
polymer or the block polymer being omitted. I-n Example 26, the
proportion of the ABS polymer is varied while in Examples 28-30,
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. - 32
the block polymer is varied. The block polymer employed in Control
~ Examples 28, 29 and 30 correspond to the block polymers used in
;~ Examples 23, 24 and 25, respectively. The results of all of these
Examples are compared uith those oF Example 23 in Table IY bel~vl.
.
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A comparison of the ambient temperature impact resistance
results of Example 23 (which illustrates the composition of the
invention) with those of the Control Examples 26-28 indicates that
the impact resistance of the composition of the invention is syn-
ergistically enhanced by the combined presence, according to theinvention, of both the block polymer and the ABS polymer.
Control Examples 28-30 further illustrate that the block
polymer additive by itself in a vinyl halide resin is incompatible
with the vinyl halide resin as especially indicated by the Forma-
tion of a solid exudate on the sur-Face of the products of these
Examples.
EXAMPLE 31
To a small heated Prodex Henschel mixer operating at about
3800 rpm and 130F., there is added 1500 g. of a vinyl chloride-
graft-polyolefin polymer (9~ graft polymer content) wherein the
polyolefin is an ethylene-propylene-ethylidene norbornene terpoly-
mer which has been prepared by bulk free radical liquid phase
polymerization substantially as described in aforementioned
Canadian application Serial No. 290,991, filed November 16, 1977.
After the mixing operation has proceeded for 5 minutes, the tem-
perature of the mass is 150F. and there is added 45 g. of a pro-
; prietary monohydrous tribasic lead sulfate stabilizer conventional-
- ly employed for vinyl halide polymers (manufactured by National
;~ Lead Co. under the designation Tribase AG*) and 15 g. oF a propri-
etary dibasic lead stearate stabilizer conventionally employed for
vinyl halide polymers (manufactured by National Lead Co. under the
designation DS-207). After the mixing has proceeded for an addi-
tional two minutes, the temperature of the mixture is about 160F.
:
and there is added to the mix~ure 30 g. of the proprietary proces-
sing aid copolymer of ethylacrylate (13%) and methy methacrylate
(87~) employed in Example 1. After the mixing operation has pro-
ceeded for an additional 5 minutes, the temperature of the mixture
is 190F. and there is added to the mixture 15 g. of a proprietary
organic
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74
- 35 -
lubricant conventionally employed for external lubrication of vinyl
halide po1ymers (manufactured by American Hoechst Corp. under the
designation XL-165). After the mixing operation has been carried
out for an additional 3 minutes, i.e. for a total mixing time of
15 minutes, the temperature of the mixture is 210F. and the
mixture is discharged from the mixing apparatus and allowed to cool
to ambient temperature.
The resultant mixture is divided into three equal portions
which are reserved for milling according to the follow;ng pro-
cedure.
To a Farrell Mill operating at the following conditions:Front Roll Temperature 355 ~ 360F.
Back Roll Temperature 330 - 335F.
Speed 48 r.p.m.
there is added 25 g. of the proprietary radical block thermoplastic
elastomer of 1,3-butadiene and styrene, employed in Example 10.
The elastomer is milled for 5 minutes and then one of the a-fore-
mentioned portions of the above-described mixture is added to the
mill. The resultant mixture is milled ~or about 5 minutes and
then is sheeted from the mill. The foregoing milling procedure
is repeated with the two remaining portions of the mixture from
the Prodex-Henschel mixer so that a total of 75 9. of the block
elastomer is blended with the vinyl chloride graft polymer.
The sheets obtained from the milling operation are combined
and pulverized in a Rapid Granulator. The heat distortion tempe-
rature at 264 psi of the resultant mixture is measured in accord-
ance with ASTM Test D-648. Also the equilibrium torque and the
hea~ stability of the molten mixture in a Brabender Plastograph
operating at 204 and 63 r.p.m. is determined.
The pulverulent mixture is charged to an Arburg 200 Injection
Molding machine operating at the following cylinder temperature
settings, Zone 3 - 320F., ~one 2 - 350F., and Zone 1 - 370F.,
a mold temperature of 100F. and an injection pressure of 15,000
.
:. : :
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- 36 -
psi to obtain impact test bar samples 5 inches in length, 1/2
inch in width and 1/8 inch thickness. Some of -these samples are
immediately tested for impact resistance (according'to the Notched
Izod Impact Resistance Test of ASTM D-256) at bo-th ambient tempe-
rature i.e. about 20C. and sub-ambient temperature. i.e. -~0F.
The remaining portion of bar samples are subjected to accel~rated
ageing by being heated in a forced clraft oven at 65 for about 48
hours. The aged bars are then tested for impact resistance at
-20F. according to the aforementioned procedure of this Example.
The results of the foregoing Example are reported in Table V below.
~XAMPLE 32
.. ... .
The procedure oF Example 31 is repeated substantial'ly as
described except that the b'lock thermoplastic elastomer employed
is the proprietary radial block copolymer of 1,3-butadiene and
styrene of Example 1. The results of this Example are compared
with those of Example 31 in Table V below.
EXAMPLE 33
-
The procedure of Example 31 is repeated substantially as
described except that the block thermoplastic elastomer employed
is the proprietary triblock copolymer of isoprene and styrene
contlaining 86X isoprene and 14% styrene of Example 17. The resu'lts
of this Example are compared with those of Examples 31 and 32 in
the Table V below.
EXAMPLE 34 (Control)
. . .
The procedure of Example 31 is repeated substantially as
described except that,the thermop,lastic b,lock elastomer ls omitted.
The results of this Example are compared with those of the pre-
ceeding Examples in Table V below.
.
EXAMPLE 35 (Comparative)
In a Comparative Example the procedure of Example 31 is re-
peated substantially as described except that in place of the block
'
.
thermoplastic elastomer of Example 31 there is ernployed a proprie-
tary triblock thermoplastic elastomer of l,3-butadiene and styrene
which has been selectively hydrogenated to remove ethylenic unsatu-
ration in the butadiene residue block (so that the elastomer is, in
effect, a triblock polymer having polystyrene end blocks and a mid-
block of l-butylene-ethylene copolymer as a result of the hydrogen-
ation). The latter hydrogenated thermoplastic block elastomer (the
general structure of which is illustrated in Figure 7, page 131 of
"The Encyclopedia of Polymer Science and Technology" Supplement,
Vol. 2, op cit) is manufactured by Shell Chemical Co. under the
designation Kraton GX-6521. The results oF this Example are also
set forth in Table V below.
Examples 36-38 (Comparative)
The procedure of Example 31 is repeated substantially as de-
scribed in Comparative Examples 36-38 wherein the thermoplastic
block elastomer of Example 31 is replaced by different thermoplas-
tic elastomers not having a block configuration as follows:
Example 36 - a proprietary cross-linked acrylonitrile-1,3-
butadiene copolymer containing 41% acrylonitrile
conventionally employed as a vinyl halide poly-
mer additive (manufactured by B.F. Goodrich ~-~
Chemical Co. under -the designation Hycar* 1411)
Example 37 - a proprietary acrylonitrile-1,3-butadiene copoly-
mer containing about 33% acrylonitrile (manufac- ~-
tured by B.F. Goodrich Chemical Co. under the
designation Hycar* 1452P-50) -~
Example 38 - a proprietary acrylonitrile-styrene copolymer ~`
(manufactured by Dow Chemical Co. under the de~
signation Tyril~
The resul~s oF these Comparative Examples are compared with
those of Examples 31-35 in Table V below.
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A comparison of the results of the illustrative examples of
the invention, i.e. Examples 31-33 with Control Example 3~ (con-
taining unmodified vinyl halide graft: polymer) ind;cates that while
the addition of the present thermoplastic block elastomers according
to the invention to the vinyl halide graft polymer results in an
initial lowering of the low temperature impact resistance compared
to that of the graft polymer, the low temperature impact resistance
of the compositions of the invention increases on accelerated ageing
(substantially equ;valent to ageing at ambient temperature for about
l month or 10nger~. Compar;son of the results of the aforementioned
illustrative Examples with those of the comparative Examples, i.e.
Examples 35-38, indicates that other thermoplastic elastomer addi-
tives (including non-block polymers and a block polymer hav;ng
structural features distinctive from the additives of the invention
as in the block elastomer additive of Example 35) do not impart age-
enhancement of low temperature impact res;stance to the graft polymer
composition as does the block thermoplastic addit;ve of the invention.
Comparison of the data of vertical columns 33, 34 and 35 of the
Illustrative Examples and the corresponding data of Control Example
34 indicates that the fusion time and heat stabiliky (Brabender
Plastograph data~ and the heat distortion temperature of the graft
polymer are not dim;nished substantially by the admixture of the
graft polymer w;th the block thermoplastic elastomer oF the inventian.
Compar;son of the amb;ent temperature ;mpact res;stance of the products
of the Illustrative Examples with that of the product of the Control
Example ind;cates that the add;tive of the ~inven~ion does not sub-
stantially d;minish the ambient temperature impact resistance of
the graft polymer on admixture with the graft polymer according to
the invention.
The invention has been described in the above specification and
illustrated by reference to specific embodiments in the illustrative -
examples. However~ it is to be understood that these embodiments
are not intended to limit the invention since changes and modifications
in the specific details disclosed hereinabove can be made without de-
parting from the scope or spirit of the invention.
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