CA1340065C - Graft copolymers and blends thereof with polyolefins - Google Patents

Abstract

A novel graft copolymer capable of imparting to a polyolefin when blended therewith high tensile modulus and high sag resistance without increasing melt viscosity, and a method of making the same. The graft copolymer is a polyolefin having a relatively high weight-average molecular weight methacrylate polymer grafted thereto. The graft copolymer is formed by dissolving or swelling a non-polar polyolefin in an inert hydrocarbon solvent, heating to dissolve the polyolefin, and while stirring the mixture, adding a methacrylate monomer, together with an initiator to produce a constant, low concentration of radicals, to form a graft copolymer with a high molecular weight polymer chain covalently bonded or grafted to the polyolefin backbone. The graft copolymer can be separated from the solvent, isolated by volatilizing the solvent, for example in a devolatilizing extruder, and extruded into a desired shape such as a sheet, tube or the like. This graft copolymer can be blended with a polyolefin matrix. The blend exhibits improved physical properties in the melt, upon cooling, and in the solid state, and is useful in cast and oriented films, solid extruded rod and profile, foamed rod, profile and sheet, blown bottles and the like. The graft copolymer further improves compatibility in a wide range of polymer blends.

Description

i34006~

Fiel ~ of the Invention This invention relates broadly to a novel graft copolymer capable of imparting to a polyolefin, when blended therewith, high tensile modulus and high resistance to sagging without increasing melt viscosily, and to a method of making the same.
More particularly, the invention relates to a polymerized olefin having grafted thereto, by covalent bonding, a polymeric methacrylate chain of relatively high molQcu~ weight. The methacrylate chain has a weight average molecular weight (Mw) of at least 20,000 and advantageously between about 30,000 and 150,000.
In the method of manufacturing the grafted copolymer, a non-polar polyolefin, ple~ral ly polypropylene or polyethylene, is introduced into an inert hydrocarbon solvent which dissolves (or swells) the polyolefin, by heating to a temperature at which the polyolefin is dissolved. While agitating the solution, methyl methacrylate (MMA) monomer, together with an initiator which generates a constant, low radical flux concentration sufficient to initiate polymerization of the monomer at the temperature of the solution and the formation of the covalent bond, is gradually added. The polyolefin with a side-chain grafted thereto is ll,er~a~ler separated from the solvent by volatilizing the solvent, preferably in a devolatili~ extruder. The graft polymer is then blended with a suitable polyolefin such as polypropylene or polyethylene, and extruded into a desired shape.

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R~cK~r~ l INn ~F THF INVFNTION

Non-polar polyolefins, especi~lly polypropylene and polyethylene and mixtures in various low-density, high-density, and linear low-density form, are major articles of commerce for a wide variety of uses.
Nevertheless, there exist specialty needs for which the marketplace has not provided a s~tis~r-otol~r answer. Among these are to overcome the difficulty of ll.~rmoforming and processing of the polyolefin, especially unfilled, in a molten or semi-molten form (subst~ntially above its melting point); the polymer tends to sag readily under its own weight because it o exhibits an undesirably low stiffness, and to form shapes of grossly non-uniform thicknesses upon thermoforming. Attempts to correct same by increasing the molecular weight lead to difficulties in processing the higher molecular weight polymer not encountered with the lower molecular weight grades.
For the isot~tic polymer of butene-1, known also as polybutylene, the low melting point has made difficult the crystallizing of the polymer after processing and obtaining the enhanced performance and handling properties crystallization imparts. Satisfactory nucleators have not appeared in the marketplace.

Means have also been sought to improve the toughness or impact strength of polypropylene, for instance. Use of copolymers or ethylene-prowlene rubber modified polypropylene has improved toughness, but at the cost of even lower stiffness values, and lower values of heat distortion resistance. It would be desirable to combine impact performance of the copolymers with stiffness and heat distortion behavior of the ho~opolymer polypropylene resin.
Grafting of monomers careble of vinyl polymerization, such as styrene, methyl methacrylate, and the like, onto polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymers, and . ,... . . ., ,. . . ~ .

1~40l~6~

ethylene-propylene-diene terpolymers has been studied almost since the discovery of routes to prd.,~tical preparation of such backbones.
Grafting onto solid polymer by vapor-phase polymerization, by reaction in an extruder, by peroxi~l~lion of the olefinic backbone, and grafting onto pendant double bonds are all routes which have been attempted.
There still exists a need for a route which allows for grafts of relatively high molecular weight, with relatively good grafting efficiency (i.e., lov.-er~d fo""alion of un~tlached polymer molecules), freedom from gel, and a practical means for preparing and isolating the graft polymer in o an efficient and lower~ost mannsr.
Blends of two or more polymers have often been made, for example in attempts to combine desirable properties of the individual polymers into the blend, to seek unique properties in the blend, or to produce less costly polymer products by including less expensive or scrap polymers in the blend. Co~lpAt~ polymers tend to form blends that contain small domains of the individual polymers; in the case of ~miscible~ polymers these occur at the molecular scale, resulting in properties usually considered characteristic of a single polymer. These may include occurrence of a single glass-transition temperature and optical clarity. Such blends are frequently termed ~alloys." Compatible polymers that are not strictly miscible, as described above, nevertheless tend to form blends with properties that approach those of the miscible blends. Such properties as tensile strength, which rely upon adhesion of the domains to one another, tend not to be degraded when compA~ible polymers are blended.
Unfortunately many polymers are poorly compatible with one another. Poor co~ ,atibility cannot necess~rily be predicted accurately for a given pol~",er co",bination, but in general it may be expected when non-polar polymers are blended with more polar polymers. Poor coi"p~tibility in a blend is apparent to those skilled in the art, and often 13400fi~

evidences itself in poor tensile strength or other physical properties, es~:~"y when compared to the component polymers of the blend.
Microscopic evidence of poor compAtibility may also be present, in the form of large, poorly adhered domains of one or more polymer cG,-,ponants in a matrix of another polymer component of the blend.
More than one glass-transilion temperature may be observed, and a blend of otherwise transparent polymers may be opaque because the domain sizes are large enough to scatter visible light.
Much research has been directed toward finding ways to increase o the compatibiUty of poorly compatible polymers when blended.Appr~,achas that have been used include adding to the blend polymers which show compatibility with the other, mutually incompatible polymers; such added polymers act as a bridge or interface between the incompatible components, and often decrease domain size.
Chlorinated polyethylene has been used as such an additive polymer, espedally in blends of polyolefins with other, poorly compatible polymers.
Graft polymers, as of incompatible polymers A onto B, are known to aid in blending polymers A and B. Such graft polymers may also serve to aid in blending other incompatible polymers C and D, where A
and C are cG",palible and B and D are compatible.
What has also been difficult to predict in polymer science is the extent to which such a graft polymer will be effective in enhancing desirable properties of the blend over those of the incompatible blend alone. Conse~ ently, those skilled in the art have had to treat each combination of graft polymer and other component polymers of a given blend as a spQ~ case, and determine experimentally whether an improvement in such properties as tensile strength could be obtained by adding a specific graft polymer to a specific blend.

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pFI FVANT ART

U.S. Patent No. 4,094,927 describes copolymers of higher alkyl m~,~l,aclylates with (meth)acrylic acid as melt strength additives, foam slal,ili~ers, and processing aids for polypropylene. Such polymers, however, are not fully cG.~,pali~le with polypropylene and the additive will tend to plate out and foul equipment during such operations as melt calendering.
U.S. Patent No. 4,409,345 describes polyolefin modified with a polymerizable unsaturated carboxylic ester in affording improved o p,ucessing of mixtures of polypropylene, high density polyethylene, and finely divided vegetable fibers. The patent appears only to demonstrate reinforcement by the fibers which are bonded to the polyolefin by the graft copolymer. All examples are limited to "grafts~ of maleic anhydride or acrylic acid, wherein the material grafted is of a molecular weight cGr.dspGnding to a small number of monomer units.
South African Patent No. 826,440 describes "improved melt viscosity~ (higher melt viscosily under low shear conditions while retaining the low melt viscosily at high shear rheology behavior of the unmodified polypropylene) and improved thermoforming characteristics for blends of polypropylene with certain salts of acid-modified propylene polymers.
U.S. Patent No. 4,370,450 describes modification of polypropylene with polar vinyl monomers by polymerization in aqueous suspension containing a swelling agent at temperatures above 85~C

2~ with a radical chain initiator having a half-life of at least 2 hours in the temperature range 80-135~C. The patent does not desc,ibe direct solution grafting, stating such yields ~only relatively low degrees of grafting~. Hydrocarbons are listed as examples of swelling agents.

U.S. Patent No. 4,161,452 describes only grafts of unsaturated carboxylic acids or anhydrides and esters of (meth)acrylic acid onto ethylene/propylene copolymers in solution in the presence of a free-radical initiator c~p~hle of hydrogen abstraction at temperatures between 60 and 220~C. An oil soluble polymer is required.
U.S. Patent No. 4,595,726 describes graft copolymers of C2-C6 alkyl "~tl,ac,ylates onto polypropylene via a solvent-free vapor-phase pol~",eri~dtion wherein the molecular weight of the graft and the number of ~ t6~ chains are controlled to yield the desired (although o undefined) length and number of chains for utility in adhesive applications between polypropylene and more polar substrates. The patent diccloses that similar grafts can be made from methyl methacrylate, but do not exhibit the desired adhesive properties. The patent requires polyme,i~tiGn below the softening point of polypropylene, which is not defined in their patent, which is known to be IowGr~.l by the presence of monomers, and for which no temperature higher than 1 40~C is exemplified, and in the absence of solvent. There is no indication or suggestion that a relatively high molecular weight chain is covalently g.dll~ to the polyolefin. Moreover, the radical flux generated appears to be too high to form a high molecular weight, e.g.
greater than 20,000, chain.
U.S. Patent No. 4,692,992 describes grafting at temperatures betwGen 60 and 160~C while maintaining the olefin polymer dissolved in a solvent which is a mixture of a hydrocarbon and a ketonic solvent, the grafted polymer pr~cipilaling upon cooling the reacted mixture below 40~C. n~nctiQn co,~ditions for achieving high molecular weight or the advantage in conducting the reaction in the presence only of a solvent of low chain transfer activity are not disclosed.
U.S. Patent No. 3,86~,~65 only describes melting of polyolefins in an extruder, followed by g.dfling of unsaturated acids to achieve 13qO065 ~improved rheology~ as defined in South African Patent No. 826440, supra.
U.S. Patent No. 3,886,227 discloses (but does not exemplify for the esters) grafting of unsaturated acids and esters to form a material useful as a modifying agent for polypropylene. The grafting is conducted in an extruder, and they also disclose that the molecular wei~ht of the backbone polypropylene polymer be lowered by degla~atiGn during the grafting process, conducted at a temperatur above 200~C. It describe6 blending with polypropylene and the resulting modification found, such as nucleation, lack of warpage on molding, and the like. Although improvement in heat distortion temperature is noted, there is no disclosure of improved rheological performance at the tel"perdtures required for thermoforming and the like.
Japanese Kokai 59-164347 describes grafts of unsaturated acids or their derivatives (including esters) at very low graft levels (10-5 to 10-8 g equivalents per gram of polyolefin), blends of the grafts with polyolefins, and their use in affecting surface tension in the molten state of the polyolefin while not affecting high-shear viscosity, making the blends useful in, e.g. blow molding of bottles.
Kallitis et al., FIIr. Pr~ymer J.. 27, 1 17 (1987) describes ethylene-propylene polymers as nucleating agents for polybutylene. They do not cJesc,ibe or su~gest the utility of the polypropylene/methacrylic grafts of this invention.
Reike and Moore, in U. S. Patent No. 2,987,501, disclose grafts of polymers of vinyl monomers onto polyethylene or polypropylene by oxidizing the polyolefin with fuming nitric acid or nitrogen tetroxide, followed by heating the aclivated polyolefin with the vinyl monomer.

13400fi~i The reference exemplifies grafting methyl methacrylate onto polyethylene and polypropylene.
Japanese Kokai 223250/87 dicclQses compatibilizing a polyolefin and a polyamide using a reaction product of an unsaturated carboxylic acid or its derivative y- fled onto a mixture of polyolefin and polyamide, that is, the re&,tion product is formed in the presence of a mixture of two or more polymers. The amount of acid or derivative reacted with the trunk poly.-,ers is less than 10%, and it is clear from the only examples present, which utilize unsaturated acids which do not homopolymerize, that what o is attached or grafted are low-molecular-weight moieties,. They disclose reaction conditions, including relatively low levels of unsaturated acid and relatively high levels of peroxide, which would lead one away from achieving the molecular weights of the grafted chains disclosed below as part of the present invention. A particular modifier disclQsed by this reter~nce, formed by rea~ti"g two non-polymerizable acids with a mixture of four trunk polymers, affe~ts the compatibility of the polyamide and polyolefin. However, the comparative data suggest that a reaction of the acids onto polypropylene alone is not an effective compatibilizer for the two resins, and shows that graft polymers of low levels of low molecular unsaturated acids or derivatives are not effective in compatibilizing polyamides with polyolefins.
Japanese Kokai 86040/87 directed to polymer adhesives, ~;scloses an olefin polymer ~I,esive modified with a carboxylic or carboxylic anhydride group, further reacted with a polyolefin having alcohol functionality, and still further reacted with an aromatic acid halide.
Boutevin et al., in Ar~ew~ndte l~ kromolekular Chemie. Vol. 162, page 175 (1988), .J;~,lose the preparation of a graft polymer of poly(methyl methacrylate) onto a polyethylene trunk by ozonolysis of a low-density polyethylene followed by heating the activated polyethylene in the presence of methyl methacrylate. They disclQse grafts of methyl 13400~S

methacrylate having a number-average molecular weight up to 21400 and the use of such grafts as polymeric emulsifiers or c~",p~ibilizers for mixtures of low-density polyethylene and poly(vinyl chloride). They report that the co,llpat;biliz d mixture has a distinct increase in the stress required to break it and a decrease in the domain sizes in the blend.
They also report apprer~ ls degradation of the polyethylene molecular weight when it is ozonked prior to grafting. This reference does not deal with higher molecular weights nor does it provide any indication that the graft polymer might be effective in reducing sag of a polyolefin matrix polymer or otherwise imparting desirable rheological effects to a polymer.
Thus the art has described means for preparing grafts of methyl methacrylate homo- and copolymers upon polyolefin substrates but has not recognized the advantages of the polymerization process herein described for a rapid efficient prodlJction of novel high molecular weight grafts without gel and with ease of product isolation. The art teaches that certain grafts may be blended with polyolefins but has not recognized the unexl~e~1~1 utility of the novel graft polymers of this invention as having positive effects on both low-shear melt and solid-state properties espec~ y with little or no effect on the high-shear performance. The art also has not reco~ni~e.~ or identified the positive effects on sag resistance imparted by the present grafts.
It is thus an object of this invention to provide an improved process for the manufacture of novel graft polymers of methacrylic esters onto '5 polyolefin subsb~es. Another object is to provide graft copolymers of at least one chain of ",etl,a.;lJ~lale polymer of relatively high molecular weight i.e. at least ~0 000 onto a polyolefin homo- or copolymer substrate. Yet another object is to provide such graft copolymers which serve as compatibilizing agents for blends of polymers which are otherwise poorly cor"patibb. It is a further object to provide blends of the .,. ~ ... .~ . ...

13100~5 graft copolymer with a polyolefin matrix which exhibit improved physical performance in the melt, upon cooling, and in the sold state.
Further objects and advantages of this invention will appear as this speci~i~lion progresses.

.~UMMARY OF THF INVFNTION

Broadly, the aforesaid objects and advantages are accomplished by grafting onto a non-polar polyolefin trunk in solution, at least one chain which is of a polymer having a weight average molecular weight greater than about 20,000, and present in a weight ratio with the polyolefin of from about 1:9 to 4:1. The graft polymer is derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2 = C(CH3)COOR, whera R may be alkyl, aryl, substituted or unsubstituted, and less than 20%, based on the total monomer weight, of an acrylic or styrenic monomer copolymerizable with the methacrylic ester. This is accomplished by adding the methacrylate monomers to a solution of the polyolefin together with an initiator which generates a constant, low radical concen~ralion, or radical ~flux", at the solution temperature. These r~ initiate polymerization of the monomer and cause formation of a covalent bond with the trunk.
The resulting copolymer product, hereinafter referred to as concentrate, may be blended with polyolefin either as a result of the manner by which it is made, or after it is made. It may be extruded into a desired shape sither directly, or after pelletization. In either case, the resulting blended product exhibits a relatively high tensile modulus and high sag resistance ~vithout an increase in melt viscosi~y, as compared with similar ungrafted polymers, viz: polyolefins without a high molecular weight chain or chains covalently bonded thereto.

The concentrate may also be blended with other polymers than polyolefins, and particularly with mixtures of two or more polymers which are poorly con-patible with one another, and which may or may not include polyolefins, to improve the compatibility of the resulting mixture.
The invention also relates to a process of making such a copolymer having a relatively high weight-average molecular weight (Mw) polymer chain. Briefly, the prt,cess according to this invention involves dissolving or swelling the polyolefin in an inert hydrocarbon solvent, and heating to dissolve the polyolefin, i.e. at least about 1 40~C.
While agitating the solution, a monomer is introduced, together with an initiator which generates a constant, low radical flux at the temperature of the solution; the radicals initiate polymerization of the monomer and formation of a covalent bond therewith on the polyolefin trunk. The reacted mixture may be allowed to solidify by removal of the solvent. The resultant product, the concentrate, consists of the polyolefin with the chain grafted thereto, unreacted polymer, i.e. polyolefin without the chain, and ungra~leJ methacrylic ester polymer. It may be pelletized, blended with another polyolefin and extruded into desired shape. Alternatively the reaction mixture may be extruded directly in a devolatilizing extruder to volatilize the solvent and residlJel monomer, and thereafter blended with a polyolefin and extruded to form article in such form as sheets, tubes and the like.

nFTAII Fn nF~;:CRlPTlON

In the following, LDPE is low-density polyethylene, usually branched, of density of about 0.91 to about 0.94 g/cc; HDPE is high-density polyethylene of a density above about 0.95 g/cc; LLPDE is linear low-density polyethylene of density about 0.91 to about 0.95 g/cc; EPDM
inc4~des nubber terpolymers of ethylene, propylene, and a non-1~40~65 conjug~ted diene monomer, such as 1,4-hexadiene or ethylidenenorbornene.
The term "polar suL.st,ate~ or ~non-polar polymer, as used herein, is difficult to define in quant;ld~ive terms. By "non-polar" is meant polymers which are predominantly formed from monomer units of mono-or di-olefins. ~Polar~, as generally underslood in the polymer art, would refer to monomers or polymers which contain an oxygen, nitrogen, or sulfur-containing functionality. Thus, methyl methaclylate, acrylonitrile, and vinyl phenyl sulfone are ~polar~ monomers, whereas polypropylene is a ~non-polar polymer.
The polymers to be modified in the grafting process include the non-polar olefin polymers and copolymers. Included are polypropylene, polyethylene (HDPE, LDPE, and LLDPE), polybutylene, ethylene-propylene copolymers at all ratios of ethylene and propylene, EPDM
terpolymers at all ratios of othylene and propylene and with diene monomer contents up to 10%, poly(l-butene), polymethylpentene, ethylene-vinyl acelale copolymers with vinyl acetate contents up to 25%, ethylene-methyl acrylate copolymers, ethylene-methyl methacrylate copolymers, and ethylene-ethyl acrylate copolymers. Also included are mixtures of these polymers in all ratios.
Usable graft copolymers include those with ratios of polyolefin:acrylic polymer or copolymer that vary from 20:80 to 80:20.
The molsculer weight of the polyolefin polymer which forms the trunk of the graft copolymer should be high enough to give a large amount of non-polar polymer when grafted, but low enough so that most of the graft copolymer has one acrylic polymer chain grafted to each polyolefin trunk chain. A polyolefin trunk having a molecular weight of about 200,000-800,000 Mw is e.speci~lly preferred, but polyolefins having a mo'ec~ weight of about 50,000-200,000 can be used with some 1 3 i O ~ fiS

beneficial effect. In ~eneral, a ~raft copolymer imparts greater mslt-rheolo~y i.,-prove...~nt to ~ hi~h-molecular-weight polyolefin. This is especially true when the polyolefin tnunk of the graft copolymer is of relatively low molecular weight.
Me~t flow rate (mfr) is well known to correlate well wiih weight-average molQcu'~ wei~ht. The profer.dd range of mfr values for the polyolefin trunks used in preparin~ the ~rafl copolymers of the present invention are from about 20 to about 0.6 ~/10 minutes as measured by ASTM Standard Method ~1238.
0 The pre~er-dd .,.o,~o,--er is methyl methacrylate. As much as 100%
of this, or of other 2 to 4 carbon alkyl methacrylates, can be used. Up to 20% of hi~h alkyl, such as dodecyl and the like, aryl, such as phsnyl and the like, alkaryl, and such as benzyl and the like, and/or cycloalkyl, such as cyclohexyl and the like, methacrylates can be used. In addition, up to j 20% (preferably less than 10%) of the following monomers can be incorporated with the .netl~clylate esters which form the major portion of the monomer: methacrylic acid, methacrylamide, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkoxyalkyl ~"etl)acrylates, such as ethoxyethyl methacrylate and the like, alkylthioalkyl methacrylates, swh as ethylthioethyl methacrylate and the like, methacrylamide, t-butylaminoethyl ~~,~ll-acrylate, dimethylaminoethyl methacrylate, dimethyla,--~ ~oprupyl methacrylamide, glycidyl methacrylate, methacryloxypropyltlietl.oxysilane, acrylate ~,~o,-G,-,ers tsuch as ethyl acrylate, butyl acrylate and the like), styrene, acrylonitrile, t 25 acrylamide, acrylic acid, acryloxypropionic acid, vinyl pyridine, snd ~vinylpyrrolidone. In addition, as much as 5% of maleic anhydride or itaconic add rnay be~l~sed. It is important that the chain t~,~sfer of the poly,..erizing chains to its own polymer be minimal relative to transfer with the polyolefin chains for the efficient prod~ction of homogeneous non-3o ~elled graft polymer in ~ood yield.

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1~40~5 The molecu'~r weight of the acrylic graft as measured by the weight average molecular weight of the un~rafted co-prepared acrylic polymer may be about 20,000 to 200,000. The preferred range is 30,000 to 150,000.
The process of graft polymerizing the monomer leads to the prodoction of ungrd~leJ and y~ ecl material. The amount of grafted ",dte,ial is in the range of 5% to 50% of the total acrylic polymer or copolymer pro~uced The graft copolymer is prepared in a process that polymerizes the monomer in the presence of the non-polar polyolefin.
The process is con~u~ted in a solvent which swells or dissolves the non-polar polymer. The solvent is also one that has no or low chain transfer ability. Examples include non-branched and branched aliphatic hydrocarbons, chlorobenzene, benzene, t-butylbenzene, anisole, cyclohexane, naphthas, and dibutyl ether. Preferably, the solvent is easy to remove by extrusion devolatilization, and therefore has a boiling point below 200~C, preferably below about 150~C. To avoid excessive pressure, a boiling point above about 1 00~C is also preferred.
The final solids content (which includes polyolefin and acrylic polymer) depends on the viscosity and the ability to mix well. The practical limits are 20% to 70% but the solids content can be as high as is consistent with good mixing for economy. Preferably, the solids content falls in the range of about 35% to about 60%.
A gradual addition or multicharge addition of the monomer is preferred. Optionally, the monomer charge need not be the same throughout, for example, the last 0-20% may contain all of the monomer used in minor amount to concentrate that monomer in one portion of the polymer.
The temperature during the polymerization can be in the range 110 to 200~C but the p~efe~ d range is 130 to 175~C. Especially 1 3 4 0 0 ~

preferred is 145 to 160~C. The pressure can be atmospheric to supGr~t",ospheric, or as high as 2100 kPa or whatever is necessery to keep the reaction mixture in the liquid phase at the polymerization temperature.
The unreacted monomer concentration should be kept low during the reaction. This is controlled by balancin~ the radical flux and the monomer feed co"dilions.
For polymerization, oil-soluble thermal free-radical initiators are used. Those that work in this process are those with a one hour half life o at about 60~ to about 200~C. The preferred ones have a one hour half life in the range 90 to 170~C. Suitable free radical initiators include peroxy initiators such as t-butyl peroxypivalate, lauroyi peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-~thyl hexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, acetyl peroxide, succinic acid peroxide, t-butyl perocto~te, benzyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxymaleic acid, I-hydroxy-l-hydroperoxydicyclohexyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, t-butyl peroxycrotonate, 2,2-bis(t-butylperoxybutane), t-butylperoxy isopropyl carbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, t-butyl pefacetate, methyl ethyl ketone peroxide, di-t-butyl diperoxyphthalate, t-butyl perbenzoate, dicumyl peroxide, 2,5,dimethyl-2,5-di(t-butylperoxy)hexane, 2,4-pentanedione peroxide, di-t-butyl peroxide, 2,5,-dimethyl-2,5-di(t-butylperoxy)-hexyne-3, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, t-butyl hydroperoxide, t-butyl cumyl peroxide, p-menthane hydroperoxide and azo-bis-isobutyronitrile.
The initiator is introdlJced together with the monomer during the polymerization in a manner to maintain a fairly constant radical flux during most of the polymo.i2alion. This is done to achieve the correct l~qo~ s high molecul~ weight, a high graft efficiency, the desired molecular wei~ht distribution, and freedom from gel.
Radical flux can be defined as the calculated rate of formation of free radicals, expressed in equivalent of r~diG~ls per liter per minute.
While not being c~r~hlQ of being measured experimentally, this may be calculated from the known rate of deco",?osilion of the free radical initiator present at any time, and its inslanlaneous concentration.
Decomposition rates for in~tiators are determined from published literature, and the concentration is either a known constant, as in continuous feed of initiator, or can be c-'cul~ted (for a single charge of initiator) from the known decomposition rate constant and the time elapsed since feed.
Good results are achieved when a uniform radical flux is ",aintained and the radical flux is c~lcul~ted to be in the range 0.00001 to 0.0005 equivalents of radicals per liter p~r minute. The preferred range is 0.00002 to 0.0002 equivalents of radicals per liter per minute.
The radical flux is dependent on the specific initiator utilized, its concentration and rate of decomposition, and the reaction temperature chosen. The rate of .Je~,nposition can be found in tabulated data, such as in ~The Polymer H~ k", 2nd Edition, ed. Brandrup and îmmergut, Wiley and Sons, New York (1975), or provided by the manufacturer.
Even if the exact rate constant at the temperature of interest is not known, often activation ener~ies are supFlied from which the rate can be ~Icul~ted The radical flux is:
Radical flux = 2(kd)(60)(1) where kd is that rate eonstant for decomposition of the particular initiator in units of inverse seconds, and I the concentration of the initiator in moUliter. In a batch reaction, I steadily decreases from lo~ the initial charge, and the radical flux is not constant. When initiator is continuously .. .. .. .. ,~ ~ , , , ,. ~, , .

13~06~
fed, a calculation must be made to determine the instantaneous concentration of initiator, but the value is much more constant than in a batch reaction, espec~~"y with careful control of initiator feed.
The process may be run in a semi-continuous or continuous manner. Monomer, solvent, and initiator may be added by means similar to those descnbed above. Polymer may be separately dissolved in solvent and added at a rate essentially equivalent to that of product removal, or polymer may be melted and added as a solid to the reaction by means of an extruder.
o After the polymerization, a hold time may be used. Then the mixture is devolatilized to remove solvent and any unreacted monomer.
Acceptable devolatilizing devices include a devolatilizing extruder, a rotary film evaporator, or any other convenient stripping device as known in the art. The polymerization reaction mixture may be conveyed to the devolatilization appar~t.ls as a batch or continuously.
Prior to, during, or after the devolatilization step, appropriate additives may be admixed into the graft copolymer solution/suspension which are desi~d to be present in the isolated gra~t copolymer. If such additives do not affect the grafting reaction, they may be added prior to, during, or after the polymerization process. Such additives may also be added when the graft copolymer is blended with the matrix polymer.
Such additives may include stabilizers against light or heat, such as benzotriazoles, hindered amines, alkyl polysulfides such as dialkyl disulfides, and the like, lub~cants, or plasticizers; flame retardants; and the like. Preferred is the addition of a disulfide, such as di-n-dodecyl disulfide or di-t-dodecyl disulfide and the like at levels between about 0.001% to about 0.05~h by weight of graft polymer, based on the weight of graft copolymer plus matrix polymer, to stabilize the acrylic portion of the graft copolymer against thermal degradation during melt processing while admixing into the matrix or blending and extruding.

A second class of stabilizer is the tris(polyalkylhydroxybenzyl)-s-tri~inetriones. Preferred is tris-(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-s-triazine-(1H, 3H, 5H)-trione, at levels from about 0.001 to about 0.1%
by weight, based on the total polymer weight.
Stability may also be imparted to the acrylic portion of the graft copolymer by including an alkylthioalkyl (meth)acrylate, preferably ethylthioethyl ",e~l,a~rylate, with the acrylic monomer or monomers during the graft polymsrization.
The product is then isolated by stranding, cooling, chopping, o drying, and bagging, or other known collection techniques.
The polyolefin and the graft copolymer concentrate may be blended by mixing the dry feed materials and extruding either directly to form a film, sheet or the like, or by collecting the blend and reprocessing it into the desired article, or by adding the polyolefin in the course of the devolatilization.
Polyolefins are often produced with one or more stabilizers to prevent degradation of the polymer appearance or physical properties during prucessing and/or end use. Such stabilizers may include metal salts such as metal stearates, which act as acid acceptors, hindered phenols, which act as anti-oxidants, and sulfur-containing organic esters or derivatives, added as heat stabilizers. Examples of such additives, which are usually pr~,crielary to the supplier, are metal stearates, 2,6-dimethylphenolic compounds, and thiodiesters of long-chain alcohols.
Polyolefins may also contain light stehili~ers, such as hindered amines, benzotriazoles, and the like. All of the polyolefins used in the present examples are thought to contain small amounts of these proprietary st~hili~ers.
One way to specify the blend composition is that at least about 0.2% of the total formulation (polyolefin plus graft copolymer) should be 13400fi.~

chemically grafted acrylic polymer or copolymer within the molecular weight limits specified. The l"axi",um amount is about 10% grafted acrylic polymer, with up to about 5% g.~ll6d acrylic polymer being preferred for cost opti"~ization and optimization of most properties of the blend.
Optionally, the blend of concentrate and polyolefin may be further I"Gdif;ed by the introduçtion of fillers, both inorganic and organic, fibers, impact modifiers, colorants, stabilizers, flame retardants, and/or blowing agents.
Blowing agents may be gases, such as nitrogen or carbon dioxide, admixed with the polymer melt in the extruder and allowed to expand upon extrusion. More often, blowing agents are solids which liberate gases, usually nitrogen, at a specific melt temperature, and which are mixed into the melt, or blended from a pre-compounded mixture of the blowing agent dispersed in a polymeric matrix. The melt temperatures for the polyoleffns are typically in the range of about 200 to about 230~C, although other temperatures may be used, depending on the specific blowing agent. Solid blowing agents include azo compounds such as azodicarbonamides, azoisobutyronitrilss, hydroazo compounds, or compounds containing the nitroso group.
The blend of the graft copolymer and polyolefin is useful in thermoforming, film making (espe~"y blowing and extruding), blow molding, fiber spinning, acid and basic dyeing, foaming, extrusion (sheet, pipe, and profile), coextrusion (multilayer film, sheet, preforms, and parisons, with or without the use of tie layers), hot melt adhesives, calendering, and extrusion coating (for the preparation of polymer/fabric, carpet, foil, and other multiiayer constructions). Such graft copoly-"era, especi~lly with small amounts of copolymerized acid functionality, ars useful when blended with polyolefins for improved printability. The grafts 13~0065 themselves may bs used as tis layers between otherwise incompatible polymers.
In extrusion, the graft copolymer is useful, especially with LLDPE, at reduction of melt fracture without an effect on the melt flow rate. Unlike the additives of U.S. Patent No. 4,094,297, the present additives do not plate out when the ,.,~;fie(l polyolefin is extruded for extended times.
When polypropylene is modified with the graft copolymers of the present invention, it may be employed in the manufacture of many useful objects, such as extrusion- or injection-blown bottles for packaging of o food.stuffs, aqueous solutions such as intravenous feeds, hot-filled items such as ketchup, or extruded articles in profile form such as clips, scrapers, window and door casings and the like. The foamed articles may be used as substitutes for wood in moldings, for packaging materials, for insulation or sound-deadening materials, for food containers, and other rigid-article applications. Films may be used in many protective or wrapping applications, such as for food packaging, blister packaging of consumer goods, and the like.
The graft copolymers of the present invention are useful in preparing polyolefin fibers, espec~ y polypropylene fibers; they are esreci~lly useful when the graft copolymer is formed from a polypropylene trunk. Polypropylene is relatively easy to process into fibers having high strength and toughness.
Polypropylene fibers show certain deficiencies which include difficulty in dyeing and poor long-term dimensional stability. Grafts containing functional sites capable of accepting dys may be prepared by the present pr~cess~by inc~i~,orating low levels of dye-accepting monomers, such as methacrylic acid, dimethylaminoethyl methacrylate, N-vinylpyridine, and the like. The improved sag resistance noted for the 1~400Gi present graft polymers in a polypropylene matrix should correspond to improvements in creep resistance of the fiber.
Polypropylene may be formed into fibers by slitting tape from extruded film to form large-denier, coarse fibers, by extruding monotilaments into large~enier fibers with a controlled cross-sectional size, or by extruding multifilaments through a spinnerette to produce bundles of small-denier fibers. In all cases, the fibers may be draw-textured. As an example, small-denier polypropylene fiber bundles may be extruded from a 25.4-mm, single-screw extruder having a screw o length-to-diamster ratio of 24:1, such as that supplied by Killion Extruders Corp. of Cedar Grove, New Jersey and equipped with a static mixer, metering pump and spinnerette assembly with multiple orifices.
Using such equipment the extruded polypropylene would be passed thought a cooling bath and then over a ssries of godets (metal rolls with heating or coolTng capability) to orient the polymer or quench existing orientation.
Polypropylene fibers may be used for, among other things, strapping, netting (including fish nets), slit tape, rope, twine, bags, carpet backing, foamed ribbon, upholstery, rugs, pond liners, awnings, swimming-pool covers, tarpaulins, lawn-furniture webbing, shades, bristles, sutures, cigarette filters, nonwoven fabrics, such as for tea bags, bed sheets, bandages, diaper liners and the Iike, and for doll hair, apparel and tho like.
The graft copolymer of the present invention may also be used to improve the compatibility of polymers in blends whsre they would othen~ise be poorly compatible. The graft copolymer is incorporated into such blends, pr~for~bly at levels of from about 0.2 to about 10 %, prefer~bly from about 0.5 to about 5%, and more preferably from about 0.8 to about 2.5%, to achieve the desired improvement in compatibility.
Higher levels of the graft copolymer may be used, but increases above 1340~6;
the preferred level generally show only small improvements in co",pa~ibility.
As noted above, compatibility is not easily predicted. As a general rule non-polar polymers are poorly compatible with more polar polymers, but poorly comp~tible blends may also be found experimentally among polar~polar or non-polar-non-polar blends. Examples of the non-polar polymers are olefinic polymers such as high- and low-density polyethylene and linear low-density polyethylene, polypropylene including atactic polypropylene, poly-1-butene, poly-iso-butylene, o ethylene-propylene rubber, ethylene-acrylic acid copolymer, ethylene-propylene-diene terpolymer rubber, ethylene-vinyl acetate copolymer, poly (ethylene-propylene), polymethylpentenes, and ionomers such as polymers of ethylene with metal-salt-neutralized acrylic acid.
Relatively more polar polymers, called polar polymers for the purposes of this d;~clQsure, include acrylonitrile-butadiene-styrene polymer, acetal polymers, polyarylates, acrylic-styrene copolymers, acrylonitrile-styrene-acrylic polymers, acrylonitrile-styrene polymers modified with ethylene-propylene rubber, cellulosics, polyester-polyether block copolymers, polyesters such as polybutylene terephthalate and !O polyethylene tarephtl,alate, and including liquid-crystal polyesters, polyetheramides, polyetheretherketones, polyetherimides, polyethersulfones, ethylene-vinyl alcohol copolymers, polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride and fluoride, styrene polymers such as polystyrene, high-impact polystyrene, styr~ne-acrylonitrile copolymers, styrene-butadiene copolymers, styrene-maleic anhydride copolymers, alkyl-substituted styrenes copolymerized with styrene alone or with the additional monomers !isted for styrene, polyphenylene ether, polyphenylene sulfide, polysulfone, polyurethane, polyamides, i.e., nylons sueh as nylon 6, nylon 6-6, nylon 6-9, nylon 6-10, o nylon 6-12, nylon 11, nylon 12, amorphous nylons, polyamideimide, l~lq~65 polycaprolactone, polyglutarimide, poly(methyl methacrylate), other C~ to C8 poly(alkyl (meth)acrylates) and polycarbonates. The acrylic polymers refer.~d to above are polymers containing at least 50 weight percent, and prefer~~bly at least 80 weight percent, of mers of acrylic acid and/or methacrylic acid (referred to collectively as (meth)acrylic acid) or their esters, preferably their alkyl esters and more preferably their alkyl esters in which the alkyl ~roup contains from one to eight, preferably one to four, carbon atoms. The remaining mers are those from one or more monomers copolymerizabl~ with the (meth)acrylic acid or ester by free-o radical polymerization, preferably vinylaromatic monomers, vinyl esters or vinyl nitriles, and more preferably mers of styrene or acrylonitrile.
In the examples which follow, polymer concentrates and polymer blends were tested using standard procedures which are summarized below.
Unreacted monomer in the reaction mixture prior to solvent removal or subsequent to extruder devolatilization was determined using a gas chromatographic technique.
The coll3cted volatiles were analyzed by gas chromatography on a 25 meter CP wax 57 CB wall coated open tubular fused silica column at 40~C. A co-"p~iison of the major signals for the solvent with the MMA
signal was used to ~Jeter",ine the amount of residual monomer in the reactor and ll,GrG~ore give a measure of conversion immediately. A more accurate measure of conversion was obtained by a C,H,O analysis of the graft copolymer. The carbon content was used to calculate EPDM or polypropylene content by interpolating between the carbon content of EPDM (85.49%) or ~olypropylene (85.87%) and acrylic polymer (60.6%).
The graft copolymers are analyzed by solvent extraction to remove the ungrafted (meth)acrylic portion, whose molecular weight is then determined by gel permeation chromatographic techniques. A technique 1~40~6~

for separatin~ the ~raft copolymer from ungrafted polyolefin is not available. Forconce.lt~t~s, 0.8-1.3 9 of polymerwas placed in a centrifu~e tube with 17 crn3 of xylene. The tube was shaken overni~ht.
Then the tube was placed in an oil bath set at 138~C. The tubes were periodically taken from th~ bath and shaken until all polymer had dissol~od. The fact that all dissolved ind~ es that no crosslinhng occurred. Th~ tubes wer~ cooled durir~ which time the polyprowlene - co-,tainin~ subst~nces pr~pit~le. Then the tubes were centrifuged at 15 000 rpm for 2 hours and the xylene solution was removed with care not to remove any floats. The molecular wei~ht of the acrylic polymer extracted by the xylens was determined by gel per-"e~tion chromalo~r.lph~r. The pr.~cedure was rsFs~ted on the resulting plug to extract ~IdiliG,~al (meth)a¢rylate. The value l~helled % graft is the pGItion of the (meth)acryli¢ polymer fo,l"eJ which remains with the polyolefin plug after repeated exl,~.tion. The co",posilion is determined from the carbon analysis of this plug.
- The polypropylene concentrate and any additives were blended in the melt on a 7.6 cm by 17.8 cm electric mill with a minimum ~ap of 3.8 mm set at 1 90~C. Once the material had tluxed, it was mixed an ~dditional 3 minutes. Higher temperatures wer~ used for hi~her viscosity materials (for example, mfr-0.5-2 material was done at 195-21 0~C).
While still hot, the material was either co"~ression molded or cut into small chunks (about 1-2 cm in each dimension) for ~ranulation (5 mm screen). It is of inler~st that the additives of the present inventiGn cont,ibute to easy release from hot metal surfaces such as mill rolls ~Haake Rheocordlbowls etc.
Millin~ of poly~thylene was done in a similar manner except that the HDPE blends were milled at 200~C and the LLDPE blends were milled at 170~C.

* Trademark ~ .

134006a A 2.5 cm~Killionnextruder was used for extrusion blending. A two stage screw was used at 150 rpm, with all three zones set for 190~C. The on~strand die was also set at the same temperature. A vacuum vent was used. The strand wal; cooW in water and pelletized. The extrusion rate was 4.5 ko per hour.
Melt bbnding in a''Haake Rhsocord'~a batch melt mixer) was done on 50 9 sampbs at 1 90~C or at 21 0~C and 100 rpm in air. Mixing was continued for three minutes after peak torque was reached. Sample size was 50 ~rams.
, 10 The po~olefin blends were compression molded in an electrically heated carverSress 15 x 15 cm or"Farrel'press 30.5 x 30.5 cm. The samples were moWed between aluminum plates with an appropriate spacer to provide the req~red thickness 0.25-3.8 mm. In one method the hot melt was taken directly from the mill roll and placed between two aluminum sheets. This was then placed in the press set at 1 90~C and presse.J at high pressure ~68-91 metric tonnes for the Farrel press and 6820 kg for th~"Carver'pre6s). Aner three minutes the mold was placed in an unheated press at high pressure for three minutes. In the other procedure, ~ranulated material or pellets produced from an extrusion, Haake, or milling operation were dried and then compression molded.
The pruc~Jure used was the same as for molding a melt except that a 5 minute preheat was used while ."aintaining a slight pressure on the press. This was tolbwed by the high pressure molding in the hot and cold presses. A hot press of 1 90~C was usually sufficient for mfr~4 -25 polypropylenes, but higher viscosity polypr~p~lenes would split during sag testing unlsss higher molding temperatures were used (195-210~C).
Polyetl,~l~ne was molded in a similar manner except that HDPE
was molded at 170~C and LLDPE at 150~C.

* Trad~ark (each instance) .
~.''';

1~4006.~

Injection molding of polypl.JpylGne was perform~d on i Newbury *
injection moldin~ machin~ in an AST~I tamily moW. Material to be moWed was dried for 16 hours at 60~C. The first barrel zone was set for 204~C, and the other two barrel zones and the noz71e were set hr 21 8~C.
The ram time was set for 3 seconds and the cycle of 15 secGnds for injection and 45 seconds overall was used. The injection pressure was 2100 kPa and the back pressure was 690 kPa. The screw speed was 100 rpm. Both mold platens were sst tor 60~C.
The sag tests are pe.~r",6-1 on a co",pr~ssion molded sheet 10 x o 10 x 0.15 cm. This sheet was clamped in a frame with a 7.6-cm-square opening. There were metal rulers attached to the front and back of the frame for use in measuring sag. The frame and sheet were placed in a hot, forced air oven (typically at 190~C). The amount of sag of the centsr of the sheet was then r~ Jed as a function of time. Typically, the sag was first recorded at 2.5 cm but for slow saggin~ materials sa~s as low as 16 mm were r~cor.leJ. Data was recoh~e~l up to 10.2 cm of sag or for 30 minutes, whichever occurred first.
The term ~slope~ refers to the slope of a plot of the natural logarithm of the sa~ in ce"ti",eler:, vsrsus time, resultin~ in 8 straight line.A hi~h slope indicates that the materisl sags quickly while a low slope indicates that it sa~s sbwly. The advantage of comparing slopss in this manner is that it eliminate~ any differences in oven cooling when the sample is introdvce~ (due to differ~nces in ths time the oven is open, room temperatures, etc.).
Crude thermoforming was done in ths laboratory to illustrate this melt stren~th effect. A sh~et of polypropybne or modified polypropylene was heated in a forcéd air oven at 190~C, removed from the oven, placed over a female mold, and subjected to vacuum.

* TrA~ TLA rk .~., 1~4006~

The capillary flow data were measured on a Sieglaff McKelvey rheo"~GtGr. Ths flows were recorded at ten shear rates (1 to 100-redpr~al secondj) at each te~ er~t~Jre. The data was fit to the power bw, i.e., visoosi~y~k(temp~rature)~(shear rate)~, and the values at 1 and 1000 redprocal secor,~ls were calculated from this best fit e~luAtion. The parallel plate vi~sity ref~rs to measurements on the'~heometrics"*
Dynamic Spe~o"-eter, ~rcJed at a strain of 5%.
Differential scanning calorimeter (DSC) measurements of melting and nucleation were pe~r"-~ on a duPont instrument. A value of 59 caUg was used for the heat of cryst~ tion and psr cent crystallinity was corr~t~ for the presence of the melt additive. The nuc'e-~ion temperature was measured in an experiment in which the polypropylene was melted at 200~C for 2 minutes and then cooled at 1 0~C/min. The temperature at which peak crys'~ -~on occurred is called the nudeation temperature. The isothermal crystel';~tion time was recorded by cooling the molten pol$~n~pylene quickly to 127~C and the exotherm recorded with time.
The physical properties of the polypropylene homopolymer and ~medium i."pa~t' copolymsr are determined on extruded and injection moWed sampbs, although similar results have been observed in milled and compression molded samples. In cenain examples below are described spe~ ed oqulpment for preparing foamed sheet, rod or proffle, extruded rod or tubing, fibers, cast film, mono~Yi~lly o,iented and biaxially orientod film, and injection blow-molded bottles or hollow '2~ containers.
The examples are intended to illustrate the present invention and not to limit it except as it is limited by the claims. All percentages are by wei~ht unless o~l,elwise specifieJ and all r~ag6nts are of good commerdal quality unless otherwise specified.

* Trader[ ark ~'.

. .

13~006.;

This example illu~tr~tes prepar~tion of a Graft Copolymer (GCP) of Po'y~ro~"rlene (PP) Methyl Methacrylate (MMA) and Ethyl Acrylate (EA).
A polypropylene-acrylic ~ran copolymer is made by polymerizing a 5% ethyl acrylate (EA) - 9S% methyl methacrylate (MMA) n,GnG",er mixture in the presence of polypropyl~ne (wei~ht ratio of poly~r~pylene:monomer . 0.67:1). Radicals ar0 generated from di-tertiary-butyl pdn~xwe (DTBPO) at the rate of 0.00010 moles per liter per ' minute (radical flux). Monomer and initiator are fed over 60 minutes and the theoretical (100% conversion) solids at the end of the reaction is 55%.
A 6.6 liter reactor e~uipped with a double heJical agitator (115 rpm) was char~ed with 1780 9 of an inert hydrocarbon solvent mixture of 2-methylalkanes havin~ 6-12 C-atoms and 880 9 polypropylene (mfr~4) and hsated to 1 75~C. After 2 hours the temperature was J~c~eased to 1 55~C and the batch was stirred for 1 additional hour. Over a two minute - period two solutions were aWed. The first consi! le~l of t.04 9 of di-t-butyl peroxide in 21 9 of the hydrocarbon solvent. The second consisted of 0.06 ~ ot di-t-butyl peroxide in 2.1 9 of ethyl acr~rlate and 42 ~ of methyl methacrylate. For the next 58 minutes at the same feed rate a feed of 1.87 9 of di-t-butyl peroxid~ and 62 g of ethyl acrylate in 1215 ~ of methyl methacrylate was added at the same feed rate as the second fQed. This feed schedule results in a radical flux of 0.00010 durin~ the feed tirne.
After the feed was complete the rtldcliG.) was held at 1 55~C for an additional 15 minutes. Then it was devol~b';~s~ by passing through a 30-mm"Werner rf~iderer'l3xtruder wTth two vacuum vents at 200-250~C.
The concantldt~ product (¢oncentrate) is a mixture wherein the elemental analysis showed that the con,posTlion is 56% (meth)acrylate. Extraetivs results showed 15.9% of the poly."erTzed (meth)acrylic monomers were ~rd~l~l, and the Mw of the Imeth)acrylic polymer was 91 S00. The * Trade Telrk 1~006~

concentrate may be blended with other thermoplastic polymers such as polypropylene.
The following Table shows the efficiency of the above concentrate blended at different levels in improving sag rssistance of a polypropylene homopolymer having a melt flow rate (mfr=4) of four.

T~RI F I

Wt. % of sag sample sag at concentrate slope, thickness 17 min timeto in blend ,min-~ ( mm) (cm) sa~ ~.5cm 0 0 0.18 1.75 2.29 39 min 1 .5 0.12 1 .45 6.1 0 6.0 2.5 0.1 2 1 .70 4.57 6.8 3.3 0.06 1.78 3.05 11.4 5.0 0.045 1.73 1.27 13.1 7.5 0.030 1.75 1.02 ----FXAMPI FS ~ - 51 A polypropylene-acrylic graft copolymer is made by polymerizing a 5% ethyl acrylate (EA) - 95% methyl methacrylate (MMA) monomer mixture in the presence of polypropylene (weight ratio of polypropylene:monom0r . 0.67:1). Radicals were generated from di-tertiary-butyl peroxide (DTBPO) at the rate of 0.00010 moles per liter per minute (radical flux). Monomer and initiator were fed over 60 minutes and the theoretical (100% conversion) solids at the end of the reaction was 52.5%.
A 6.6 liter reactor e~ pped with a pitched-blade turbine agitator (375 rpm) was charged with 1880 9 hydrocarbon solvent and 840 9 134~06~

polypropylene and heated to 1 55~C. The mixture was stirred for 3 hours. Over a two minlne period two solutions were ~dded The flrst consisted of 1.06 ~ of di-t-butyl pero~tide In 21 9 of hyJ,~carbon solvent, as in Exampb 1. The second co,)si~ted of 0.06 ~ of di-t-butyl peroxide in 2.1 9 of ethyl acrylate and 40 ~ of methyl methacrylate. For the next 58 minutes a feed of 1.8J 9 of di-t-butyl peroxide and 61 9 of ethyl acrylate in 1157 9 of methyl i"etl-a~late was added at the same feed rate as the second feed. This feed schedule should produce a radical flux of 0.00010 during th~ feed time. Afterthe feed was complete, the reaction was held at 1704C for an ~Jitional 15 minutes. Then it was devolatilized by passing through a 30-mm'~Hernsr-Pfleiderel"extruder with vacuum vents at 200-250~C. The concentrate showad that the cGmpo6ition is 51% acryJate.
A~hJ)t;s~al polypropylene-acrylic ~raft copolymers (Examples 2-51 ) were prepared by th~ procedure of this Example and ev~4J~ted as 3.5% blends in polypropylene (mfr=4) as melt strength additives. The following TabJe illu~l.ala~ the polym~fization con-litions for the concentrate and the percent acrylic polymer pr~50nl in the concentrate with the sag r~sTst~nce of the bbnd with the polypropylene.
In the f~llowin~ Table ll, DTBPO is di(t-butyl)peroxide, TBPB is t-butyl perbenzoate, and DDBH is 2,5-dim~thyl-2,5-di(t-butylperoxy)hexane .

* Trademark .,, , ~, ., . .. , . " . , , , , ~ , .. . . . .. .

13~006a T~RI F ll sa~ % fecd rad- %EA
slope acrylic init- solids polymer time, ical in E2~ min-~ in conc j~Q~ % temp.~C min flux Con~ 0.15-0.18 -- ---- ----- ------ --- ---- ---0.03-0.05 56 DTBPO 55 155 60 0.00010 5 2 0.06 51 DTBPO 52.5 155 60 0.00010 5 3 0.06 52 DTBPO 55 155 60 0.00010 5 4 0.045 55 DTBPO 55 150 60 0.00010 5 0.08 57 DTBPO 55 145 60 0.00010 5 6 0.05 57 DTBPO 57 150 60 0.00010 5 7 0.10 49 DTBPO 55 150 60 0.00007 5 8 0.06 53 DTBPO 55 150 60 0.00015 5 9 0.06 55 DTBPO 55 150 60 0.00010 10 0.11 53 DTBPO 55 150 60 0.00010 0 11 0.056 48 DTBPO 55 155 60 0.00010 10 12 0.07 51 DTBPO 50 150 60 0.00010 5 13 0.11 58 DTBPO 55 145 120 0.00007 5 14 0.10 57 TBPB 55 145 120 0.00007 5 0.09 56 TBPB 55 150 120 0.00010 5 16 0.12 54 TBPB 55 150 120 0.00007 5 17 0.13 55 TBPB 55 150 120 0.00015 5 18 0.06 55 DTBPO 55 150 120 0.00007 5 19 0.06 49 TBPB 55 150 60 0.00010 5 0.10 51 TBPB 55 150 120 0.00010 5 21 0.14 57 TBPB 56 150 120 0.00010 5 22 0.13 51 TBPB 55 150 60 0.00010 5 23 0.15 55 TBPB 55 150 120 0.00010 0 24 0.15 56 DDBH 55 150 120 0.00010 5 O fi i TARI F ll (~ontinlled) sag % feed rad- %EA
slope acrylic init- solids polymer time, ical in in conc j~Q~ % temp.~C min 0.14 57 TBPB 55 150 120 0.00015 5 26 0.09 51 TBPB 55 150 60 0.00010 5 27 0.15 54 DDBH 55 150 120 0.00010 0 28 0.11 51 DDBH 55 155 120 0.00010 5 29 0.10 53 DTBPO 50 150 120 0.00007 5 0.10 54 DTBPO 50 150 120 0.00005 5 31 0.15 53 DTBPO 50 150 120 0.00005 5 32 0.10 51 DTBPO 55 150 120 0.00007 5 33 0.12 55 TBPB 55 1 50 120 0.00007 5 34 0.18 55 DDBH 55 150 120 0.00007 5 0.07 53 DTBPO 55 150 120 0.00005 5 36 0.09 51 DTBPO 55 150 120 0.00010 5 37 0.14 51 TBPB 55 1 50 120 0.00005 5 38 0.10 37 DTBPO 55 155 60 0.00010 5 39 0.11 - 43 DTBPO 55 155 120 0.00007 5 0.08 48 DTBPO 55 155 120 0.00005 5 41 0.10 47 DTBPO 55 155 120 0.00007 5 42 0.07 48 DTBPO 55 155 60 0.00010 5 43 0.10 43 DTBPO 55 155 120 0.00005 5 44 0.10 50 DTBPO 55 155 120 0.00007 5 0.10 54 DTBPO 55 150 120 0.00010 5 46 0.10 54 DTBPO 55 150 1 20 0.00007 5 47 0.07 54 DTBPO 55 150 120 0.00005 5 48 0.08 56 DTBP055 150 120 0.00007 5 49 0.08 55 DTBPO 55 145 120 0.00007 5 T~RI F ll (contin~led) .. . . "., . , ~ ~ , . . .. ..

134006~

sag % feed rad- %EA
slope acrylic init- solids polymer time ical in ~x. ~Q-1 in conc j~Q~ % temp.~C min 0.09 56 DTBPO 55 145 120 0.00005 5 51 0.08 55 DTBPO 55 145 120 0.00010 5 Control = PP with no concentrate The calculated percent of grafted acrylic polymer and the mlo'ecul~r weight (Mw) of ungrafted acrylic material are tabulatsd below in Table lll on certain samples where the ungrafted acrylic polymer was separated from the concenllate by extraction.

% Acrylic Polymer Fx~m~le (~r~fted to PP ~

2 12.3 107,000 10.6 119,000 11 29.8 71,800 14.8 43.000 46 10.7 62,600 47 21.7 87,300 Note: (Mw = weight average molecular weight) FXAMPI F !'i:~ - 54 This example shows a larger scale preparation of a polypropylene-acrylic graft copolymer made by polymerizing a 5% ethyl acrylate (EA) - 95%
methyl ~"~tl,ac"rlate (MMA) monomer mixture in the presence of polypropylene (weight ratio of polypropylene:monomer= 0.67:1). R~di~lC were generated 0 6 a from di-tertiary-butyl peroxide (DTBPO) at the rate of 0.000065 moles per liter per minute (radical flux). Monomer and initiator were fed over 122 minutes and the theoretical (100% conversion) solids at the end of the reaction was 47%.
A 380 liter reactor e~luipped with a back-slope turbine agitator was charged with 102.3 kg of the hydrocarbon solvent and 36.4 kg of mfr=4 polypropylene homopolymer and heated to 150~C over 4 hours. Two solutions were added over a twenty minute pefiod. The first consisted of 82 9 of di-tertiary-butyl peroxide in 826 g of the hydrocarbon solvent. The second consisle-l of 454 9 of EA and 8.6 kg of MMA. Addition of the first solution was then continuedo at a lower rate to feed an additional 82 g of di-tertiary-butyl peroxide and 826 g of the hydrocarbon solvent over 90 minutes. At the same time the monomer ~ddition of 2.3 kg of EA and 47.5 kg of MMA was continued over 102 minutes - (ending 12 minutes after the initiator feed had finished). The reaction was held at 150~C for an additional 15 minutes. Then an additional 23 kg of hydrocarbon solvent was pumped in over 30 minutes. The reaction mixture was then devolatilized by passing through a 20-mm Welding Engineers twin-screw extruder at 200 rpm and 200-250~C over 14 hours. This concentrate is Ex. 52.
Similar preparations labelled 53 and 54 were synthesized with changes in feed time and radical flux as indicated. The following Table IV shows the improvement in sag resistance when concentrates of Example 52, 53 and 54 are blended with polypropylene of mfr=4:

~ ., . . , , , . . ,~

13~006~
T~RI F IV

% Weight Conc Sag Fraction in Slope Acrylic Init- Polymer Feed Rad.
E~, Blend min-~ in conc. ~QC Solids ~ Time Con. none 0.19 ---52 2.5 0.11 0.6 DTBPO 47 150 122 0.000065 3.5 0.10 53 3.5 0. 11 0.6 DTBPO 45 150 90 0.00007 5.0 0.10 54 3.5 0.15 0.6 DTBPO 49 1 50 78 0.00008 5.0 0.09 This example and Table V demonstrate the unsxpected advantage of the concentrate of Example 4 in the improvement of sag resistance for both high density polyethylene (HDPE) and linear low density polyethylene (LLDPE). Data for HDPE are for polymers of two different mfr values (4 and 8) and are obtained at 1 50~C, The LLDPE
values are on a single resin having a density of 0.917 g/cc, but at two differenttemperatures. Comparison molded polyethylene samples prepared for this test had a significant increase in gloss over the unmodified control.

l t~ fi ~i TARI F V

Time to ~. Minutes Pob/~hyleneWt-%~itive Tem~~t' 508 mm 7R:) mm HDPE mfr=8 0 150 8.7 9.3 3 5 15.8 30.0 31.4 HDPE mfr=4 0 150 8.0 9.0 3.5 10.5 12.0 26.0 --LLDPE mfr=2 0 170 5.3 6.0 17.7 21.4 LLDPE mfr=2 0 180 4.6 5.2 8.5 10.0 ~- FXAMPI F 56 A polyethylene-acrylic graft copolymer concentrate was synthesi~ecl in a manner similar to that previously described for polypropylene-acrylic graft copolymers. The polyethylene-acrylic graft copolymer concentrate was made by polymerizing a 100% methyl metl,ac~ylate (MMA) monomer mixture in the presence of polyethylene (wei~ht ratio of polyatl,ylene:monomer= 0.5:1). Radicals were generalecl from di-tertiary-butyl peroxide (DTBPO) at the rate of 0.00010 moles per liter per minute (radical flux). Monomer and initiator were fed over 60 minutes a~d the theoretical (100% conversion) solids at the end of the reaction was 55%.
A 6.6 liter reactor s~u;rped with a double helical agitator (115 rpm) was char~ed with 1760 9 hydrocarbon solvent and 725 9 1~4036~
polyethyl0ne (mfrs4, density=0.95) and heated to 1 50~C. The mixture was stirred for 3 hours. Over a two minute period two solutions were added. The first consist~ of 1.63 9 of di-t-butyl peroxide in 48 g of methyl ~,.ethacrylate. For the next 58 minutes a feed of 1.73 9 of di-t-butyl peroxide in 1401 9 of methyl methacrylate was added at the same feed rate as the second feed. This feed schedule should produce a radical flux of 0.00010 during the feed time. After the feed was complete the reaction was held at 1 50~C for an additional 15 minutes.
Then it was devolatilized by passing through a 30-mm Werner-Pfleiderer extruder with vacuum vents at 200-250~C, The elemental analysis showed that the concentrate contained 64% (meth)acrylate.

This example shows that both polyethylene-acrylic graft polymer and polypropylene-acrylic graft polymer concentrate were effective at reducing the sag of HDPE. The blend of concentrate with HDPE mfr=4 and density=0.95 was milled at 220~C and the hot material from the mill was molded at 21 0~C. Sags. were measured by the same procedure used for polypropylene sheet except that an oven temperature of 1 50~C
was used.

TABI F Vl Concentrate Sag Slope25.4 mm Sag 76.2 mm Sag of FY~m~l~le %Conc. ~1 (min) (min) Control none 0.57 7.4 9.4 56 5% 0.27 9.0 13.0 56 10% 0.11 10.0 19.8 4 5% <0.015 15.0 30 min to 31.7 mm .. . ~ , ,~ . ,.

13~0Q65 FxAMpl F 58 This example shows that the polyethylene and polypropylene graft copolymer concentrates are effective in improving sag resistance of HDPE while ungrafted acrylic polymer of similar Mw is not. Addition of as much as 5% of a comrnercial acrylic molding powder poly(methyl methacrylate), Mw 105.000. designal~d ~A") showed no decrease in sag rate while 3% poly(methyl ",etl,aclylate) present as the graft copolymer concentrate resu!ted in large reductions of sag rate.
The specific concentrate used in part of this study was synthesized O in the following manner. The polypropylene-acrylic graft copolymer was made by polymerizing a 5% ethyl acrylate (EA) - 95% methyl methacrylate (MMA) monomer mixture in the presence of polypropylene of mfr=0.4 (weight ratio of polypropylene:monomer= 0.67:1). Radicals were generated from di-tertiary-butyl peroxide (DTBPO) at the rate of 0.00007 moles per liter per minute (radical flux). Monomer and initiator wsre fed over 120 minutes and the theoretical (100% conversion) solids at the end of the reaction was 55%.
A 6.6 liter reactor equi~ped with a pitched-blade turbine agitator (375 rpm) was charged with 1780 9 of the hydrocarbon solvent and 880 9 polypropylene (mfrØ4) and heated to 160~C. The mixture was stirred for 2 hours and then the temperature was dec,~ased to 150~C for one hour. Over a two minute period two solutions were added. The first cGnsisled of 1.22 9 of di-t-butyl peroxide in 20 9 of the hydloc~r~on solvent. The second consisted of 0.0002 mg of monomethyl ether of hydroquinone (MEHQ) and 0.05 9 of di-t-butyl peroxide in 1.1 9 of ethyl acrylate and 21 9 of methyl methacrylate. For the next 1 18 minutes a feed of 13 mg MEHQ and 2.70 9 of di-t-butyl peroxide in 66 9 of ethyl acrylate and 1253 9 of methyl methacrylate was added at the same feed 9~S
rate as the second feed. This feed schedule should produce a radical flux of 0.00007 durin~ the feed time. After the feed was complete the reaction was held at 150~C for an a.lditional 15 minutes. Then it was devol~ e.J by passing through a 30 mm Werner-Pfleiderer extruder with two vacuum vents at 200-250~C. The elemental analysis showed that the con~snll~le cont~;ned 53% (meth)acrylate.
The blends of HDPE (mfr=7, densityØ95) and graft copolymer concentrate was milled at 200~C and the hot materials were formed into sheets from the mill at 170~C. Sags were measured by the same o ploceJure used for polypropylene sheet except that an oven temperature of 150~C was used.

T~RI F Vll Concentrate Sag Slope25.4mm 50.8 mm Fx~ ple I Qvel ~i~1 ~ ~rnin) ~ (mirl) Control none 0.59 7.4 8.7 A 3.0% 0.58 7.1 8.3 A 5.0% 0.54 7.6 9.0 56 5.0% 0.27 -- 10.3 4 2.0% 0.28 8.2 10.2 4 3.5% 0.056 9.4 15.8 4 5.0% 0.038 10.4 31.4 58 3.5% 0.37 7.4 9.2 58 5.0% 0.30 8.1 10.0 1~036~
FXAMpl F 59 The concentlate of Example 4 was blended with LLDPE and the results of evaluating the sa~ resistance improvements are shown below in Table Vlll. The blend of modifier and LLDPE was milled at 1 70~C and the hot material from the mill was milled at 150~C. Sag resistance was measured by the same pr~c~ure used for polypropylene sheet at the temperature listed.
~A~ is an LLDPE havin~ an mfr=2.3 and a density of 0.92, recG"""ended for casting and extnuding applications.
~B~ is an LLDPE having an mfr=1 and a density of 0.92, recGn,i"ended for blow molding and extrusion applications.

T,ARI F Vlll Sag Sag Slope25.4mm 101.6 mm I l npF Concentr~te Temp. mirt1_ sag (min) sa~ (min) A none 1 80~C 0.58 3.4 5.6 A 5% Ex. 4 180~C 0.24 5.2 10.6 A none 1 70~C 0.54 3.9 6.4 A 5% Ex. 4 1 70~C 0.096 9.5 23.0 B none 1 50~C --- 7.8 15.6 B 5%Ex.4 150~C --- 33.7minat19mm FXAMPl F 60 This example iilustrates improved sa~ mG.lilic~tion and increased nuc's~tion temperature for polybutylene, when blended with the concentrate. Polybutylene, injection grade, mfrs4, with and without 2.44 wt. % of the concentrate of Example 20 were milled at 1 90~C and 13~00fit~

pressed into pl~ques of about 1.7 mm thickness. Times were measured for various distances of sag at 1 45~C. DSC curves were used (heaVcool time = 20~C/min). A higher crystallization temperature relates to increased speed of nu~'3~tion and solidification of the heated polymer.

T~RI F IX

Weight Percent Time to .cag (rnin:cQ~) n.~c Te~rAtllre. oc Concentr~te ~5.4 mm 50.8 mm 101.6 mm ~ Crystallize Control (0) 5:20 7:50 10:23 128 45 2.44 wt % 7:24 15:53 ~30 129 55 This ex&.--ple describes the preparation of a concentrate of polypropylen~acrylic graft copolymer made by polymerizing 5% ethyl ! 5 acrylate (EA) - 95% methyl ~-,elhaclylate (MMA) monomer mixture in the presence of an equal amount of polypropylene. R~dic~ls were 96ner~dled from di-tertiary-butyl peroxide (DTBPO) at the rate of 0.00017 moles per liter per minute (radical flux). Monomer and initiator were fed over 30 minutes and the l~)eoretical (100% conversion) solids at the end of the reaction was 50%.
A 6.6 liter reactor equipped with a double helical agitator (115 rpm) was charged with 1980 9 of the hydrocarbon solvent and heated to 1 70~C. 1000 9 of polypropylene (mfr.5) was fed to the reactor via a melt extruder set a~ 200~C at a rate of about 10 9 per minute. After 45 minutes hold at 1 70~C the addition of monomer and initiator solutions was begun. Over a two minute period two solutions were added. The first consisted of 0.44 9 of di-t-butyl peroxide in 21 9 of the hydrocarbon 13~J6.~

sol~rent. The second consisted of 0.11 9 of di-t-butyl peroxide in 1.3 9 of ethyl acrylate and 65 9 of methyl mell,acr~lale. For the next 28 minutes a feed of 1.59 9 of di-t-butyl peroxide and 19 9 of ethyl acrylate in 914 9 of methyl methacrylate was added at the same feed rate as the second feed. This feed schedule should produce a radical flux of 0.00017 during the feed. After the feed was complete the reaction was held at 170~C for an additional 15 minutes. Then it was devolatilized by passing throu~h a 3~mm Wemer Plleider~r extruder with vacuum vents at 200-250~C. The elemental analysis (carbon content) showed o that the con~snl-~te contained 35% (meth)acrylate.
A sheet of polypropylene (mfr=4) with and without the concentrate of this example was heated in a forced air oven to 1 90~C, removed from the oven and immediately placed over a female mold and subjected to vacuum. The top and bottom comer measurements were the average of the 8 measurements in mm at the corner of each of the four side faces of the box. The top and bottom center measurements were the average of the 4 measurements in mm at the center of the edge of the 4 faces of the box. These measurements are summarized in Table X and demonstrate smaller wall thickness va-iations when the concentrate is present.

TARI F X

WAI I THI~,KNF~ VARIATION IN THFRM~-F~RMFn PARTS

Top Top Bottom Bottom Poly~ro~ylene Center Corner Center Corner unmodified 1.14mm 0.88 mm 0.75 mm 0.025 mm 5% Ex. 61 0.97 mm 0.97 mm 0.35 mm 0.21 mm 13~0q~;

FXAMPl F f;~

This example demor,slraled the ur.~xpected higher nucleation te..,pcr~ture anJ shorter time for crystallization imparted by addition of the polymeric concentrate of Examples 1 and 52 to polypr~pylene of mfr.4. The nucleation te-"par~tLJre was measured while cooling at 10~Clmin the melting te.~,perdture was measured while h eating at 20~C/min and the crystaHization time was measured isothermally at 127~C or 1 30~C. The extent of crystallization was reported for both cooling and melting measu~ei"ents. Comparison was made with o un~rd~ PMMA of similar Mw.

TA~I F Xl Temp. of crystallization (~C) 127 127 130 130 130 130 130 Percent Concentrate 0 5 0 1.1 2.2 3.9 7.8 PolymerConcentrate of Example - 52 - 52 52 PMMAPMMA
Crystallization Time, min. 16.3 3.6 24.5 3.7 3.0 8.1 10.6 Nucl~- ~io.)Temperature,~C 105 112 107 118 118 112 110 % Crystallinity 39 40 41 46 42 42 41 Melting Temperature, ~C 165 166 169 170 168 170 168 % C~ystallinity 41 44 44 44 46 46 44 FXAMpl F 63 This example del"Gnsll~ted the lower equilibrium torque and improven,onl in time to flux for blend~ of the concenl-dte of Example 1 with polypropylene of mfr.4 usin~ the Haake Rhaocord'*The test conditions are ~JesclibeJ above. Peak torque at flux was also re~uce~

TrAtl~lArk 0~5 T~Rl F Xll Wt.-%
Concentrate in Time to flux Equilibrium Torque poly~ro~ylene (seconds) ~meter~r~rns ~t 21 5c FXAMpl F 64 This example shows that a propylene-acrylic graft copolymer concentrate may be used to improve the sag resistance of an acrylic o sheet. About 20 parts of the graft polymer of Example 1 was milled with 100 parts of a commercial acrylic molding pow1er of Mw 105,000 and co"~plession moWed. Sag tests indic~te~ that the sheet containing the concenl,ate may be heated to about 5-1 0~C higher before flow equivalent to that of the unmodified sheet was observed.

FxAMpl FS 65 - 66 Graft copolymer concentrates were prepared according to the process deso-ilJ~ in Exarnples 52-54, using the conditions shown in Table Xlll.

l?~ lOnfi5 T~RI F Xlll Monomer Feed Concentrate % Acrylic Init- Time Radical of FY:3~ In t',onc. jj~Q~ SolidsTem~. ~C (min) _EI~

A 55 DTBPO 50% 150 120 0.00010 B 55 DTBPO 50% 150 120 0.00007 Concentrates A and B were blended together at a weight ratio of 2.8:1 to form concentrate C. As indicated in Table XIV, concentrate C
was blended at the 4% level with polypropylene and the indicated amounts of di-t-dodecyl disulfide (DTDDS) and extruded. The sag results for these blends are given in Table XIV below.

TARI F XIV

FY~rn~le % Concentr~te DTnDS Sa~ Slope in min-~

4 none 0.07 66 4 0.03% 0.05 67 4 0.3% 0.03 Stabilizing the conconl-dle during processing, as by using the DTDDS, is seen to produce even more sig,)iticant improvement in melt slr~n~h.

This example further demonstrates that the graft copolymer has little effect on the high-shear viscosily but a pronounced effect on low-shear viscosil~ in polypropylene.

134006~

The graft copolymer of Example 1 was admixed at the five weight-percent level with an injection-molding grade of propylene homopolymer, mfr=4, as in Example 63. ~api~l~ry and parallel-plate viscosities were measured at various temperatures under conditions .Jescribed above, under both low and high shear conditions. The results shown in Table XV below demon~,ate the incr~ase in low shear viscosity, especially at temperatures below about 210 ~C, with essentially no effect on viscosity at high shear rate.

T~RI F XV
Conditions: I nW She~r Hi~h She~r Amount of Graft Polymer: O % 5 % O % 5%
Test Te~er~tllre C~pill ry Viscosity (a) 180 ~C 94000 133000 1900 2000 C~rill''ry Viscosity (a) 190 ~C 80000 110000 1900 1600 Capillary Viscosity (a) 210 ~C 57000 75000 1200 1100 Parallel Plate Viscosity(b) 190 ~C 630dO 99000 2100 2100 Parallel Plate Viscosity (b) 210 ~C 54000 58000 1800 1800 Parallel Plate Viscosity (b) 230 ~C 37000 39000 1500 1400 Shear Conditions:
a: Low Shear=1.0 sec-~; high shear= 1000 sec-~
b: Low Shear=0.1 sec-~; high shear= 500 sec-1 This exa."ple shows improved stabili~alion to weight loss on heating by use of a disulfide or a substituted tri~ine stabilizer. A
polypropylene-acrylic graft copolymer similar to that of Example 4 was blended with stabilizers on the mill roll. The graft copolymer (98 grams) 1340D~S

was fluxed on the mill at 1 95~C. The sl~bil;~er (2 ~rams) was added and blended in tor 2 minutes. The ~~le~ial was removed from the mill, cut into chunks, and granul~ed One or more of these stabilized versions were then let down in a similar manner in additional ~raft copolymer to produce ~raft copolymer stabilized at the 100-5000 ppm level. The results on the TGA of s~bi~ tiol) are shown in the table.
Weight loss (%) is the tcmperature at which the particular pa~cent weight loss is observed, utilizing a DuPont ThermoGravimetric Analyzer *
at a heating rate of 20~C in nitrogen. Althou~h nons of the st~hili~ers were deleterious to stability, only those desi~nated 2 and 7 exhibited si~r,ificsnt stability advantages.
The stabilizers studied were:

1. DLTDP (dilauryl thiodipropionate);
2. TNPP (l-isnony4Jha~yl phosphite);
3."1rganox'~010 (tetrakis(methylene(3,~di-t-butyl-4-hydroxy-hydrocinn~" ,ale))methane);
4. DTDDS (di-t-dodecyWisulfide);
5."1~afo~"188 (tris-(2,4~i-t-butylphenyl)phosphite);

6." W~slon"*818 (di ~ea.yl pentaerythritol diphosphite);

7."Cyanox 1790 (tris~4-t-buty1-3-hydroxy-2,6~imethylbenzy1)-s-bia~;ne-2,4,~(1 H,3H,5H)-trione;

8. " Irganox '~ 076 (octadecyl 3,Wi-t-buty~4-hydroxyhydrocinna" ,ale);

9. Topano~ CA (3~ ~ensate of ~,.,~tl"~l 6 t-butylphonol with crotonahJel ,yde.

* l.,.~..-.rk (ea~h instance).

1.~40~5 T~RI F XVI

WEIGHT LOSS
STABILIZER (PPM) TEMPERATURE
_______ ---------------------------- ~DEGREES C) 1 % 10 %

13gO065 TARI F X~ ;ontinllGtt) WEIG~T LOSS
STAaILIZER ~PPM) TEMPERATURE
(DEGREES C) 1 2 3 4 5 6 7 8 9 - - __________ 1 % 10 %

2000 600 278 . 321 1~4006~

This example illusl.~les the preparation of a larger amount of graft eopolymer to be used in many of the folbwing studies. The process and eG",~osition of Example 52 was tollowed with some variations. Several preparations were combined. In all but the last of these preparations, radieals are generated at the rate of 0.000070 moles per liter per minute (radical flux).Monomer and initiator are fed over 120 minutes and the theoretical (100%) conversion) solids at the end of the rea~,1iol~ is 50%.
A 380-liter reactor equipped with a pitched-blade turbine agitator was eharged with 86.4 kg of the hydrocarbon solvent an~ 34.5 kg of polypropylene homopolymer, mfr=4. After deoxygenating (applying vacuum to degas, followed by pressurizing with nitrogen to atmospherie pressure) through three cyeles, it was pressurized to 103 kPa with nitrogen and heated to 1 50~C over 2 hours. A pressure of 241 kPa was maintained while the batch was held at 1 50~C for 3 hours. Two solutions were added over a fifteen minute period. The first consisled of 59 9 of DTBPO in 841 9 of the hydrocarbon solvent. The second consisled of 0.32 kg of ethyl acrylate and 6.14 kg of methyl methacrylate. Addition of the first solution was then continued at a lower rate to feed an AchJ;tional 103 9 of DTBPO and 1479 9 of the hydrocarbon solvent over 105 minutes. At the same time the monomer addition of 2.26 kg of ethyl acrylate and 43.0 kg of methyl methacrylate was continued over 105 minutes.
neP--,tion exotherm incr~ased the temperature to about 1 60~C. After the feed was complete, 5 kg of the hydrocarbon solvent was fed into the reaction mixture.
25 . The reaction mixture was held in the reaction kettle for an additional 30 minutes. It was then trans~er,dd to a second kettle which was also under pressure at 1 50~C. During the transfer a solution of 80 g of di-tertiary dodecyl disulfide in 320 9 of the hydrocarbon solvent was added to the second kettle.
Also during this transfer three 4.53 kg portions of the hydrocarbon solvent were ... . . ,. ,. .~

134006,j' fed into the reaction kettle. Material in this second kettle was fed to a 20.3-mm We~ing Engineers twin-screw sxtruder where devol~ on occurred.
During the devolatilization the next batch was prepared in the reaction kettle. It was transferred to the extruder feed kettle while extrusion continued.
In this manner several batches were made in a semi-batch~ manner that is L~lc~ ise in the reactor with continuous feed to the extruder.
In the final prep&r~tion of the blend radical flux was 0.000050 (42 9 DTBPO + 858 g of the hydrocarbon solvent in the first feed 73 9 DTBPO +
1502 9 of the hydrocarbon solvent in the second feed).
o The final blend designated Example 69 was prepared by blending pellets from 13 batches prepared as described and one batch of the final variant. All sarnples from individual batches gave acceptable sag resistance when tested in polypropylene.

FxAMpl F 70 The following example illustrates that improved stability can be imparted to the graft copolymers of the present invention by copolymerization of an alkylthioalkyl monomsr spccifically ethylthioethyl methacrylate.
The stability of graft copolymers prepared with alternate monomer cG",positions was also evaluated. All were prepared according to the pr~.c6dure for Example 4 except that the monomer co",position varied and the product was isol~ted by ev&pGIvdtil)g solvent instead of by devolatilizing in anextruder. The monomer compositions and the TGA resuKs are summarized in the table below. The al~brel,iation EA indicates ethyl acrylate; MMA methyl ~"etl,aclylate; ETEM~= ethylthioethyl methacrylate and MA= methyl acrylate.
Weight loss (%) is the temperature at which the particular percent weight loss is observed utilizing a DuPont ThermoGravimetric Analyzer at a heating rate of 20~C in nitrogen.

1~41106a I~IF XVîl Grafted Acrylic Temperature at Which Noted Percent Weight Poly~r T.o~.~ O~llr~ ~y T~.~ AnA 1 yc ~ Q ~~~) 1 % ~ % 5 % 10 %

95% MMA, 5% EA 221 274 307 333 95% MMA, 5% EA + 260 289 314 346 O.05% ETEMA

95% MMA, 5% EA + 281 305 335 360 O.25% ETEMA

95% MMA, 5% MA . 254 290 317 325 FXAMPlF 71 This example illustrates that an altemative Ille~llGJ reported for the preparation of ",eU,a~lylic ester//polyolefin graft copolymers does not produce a po~rmer useful in il"~ro~ resistance to sa~ging of po~propylene. Exampb2OfU.S. Patent 2,987,501 was repeated, wherein linear low-density polyethylene hG",opoly..ler (mtr~2.3) was immersed in fuming nitric acid for 30 minutes at 70~C, removed, washed with water, and dried. Thie treated polyethylene was then suspended over refluxing - methyl ",ethacrylate for 4 hours. The polymer was exl,~ct~ with methyl ethyl ke~one, as taught in the reference, to remove ungrafted poly(methyl ",etl,ac~ylate). The ",olQ~ul~ weight of the ungrafted polymer was determined by ~el permeation chro")at6~.~phy to be Mw=430,000, Mn ~ 70,000.

13~0065 T~RI F XVIII

Weight of Weight before Weight after Weight polyethylene, reaction (after reaction and of polymer ~. n~trAt~on), g. e~tr~ct;on. g extr~cte~
3.397 3.48 5.964 4.40 Thus, the graft copolymer ferrl,ed was 43~/O PMMA and 57% PE. The total sample prior to exl~action was 67% PMMA, 33% PE, and the efficiency of yr~ing of the PMMA was 63.1%.
The resultant graft polymer, from which the ungrafted polymer had not been removed, was blended at the 4% level into the polypropylene resin of mfr=4 used as a standard for testing sag resistance. The graft copolymer of thisexample did not disperse well, and visible, large, unJispersed fragments were seen. The sag value (0.31 ) was worse than for the unmodified resin (0.18) or for resin modified with an equivalent amount of the graft copolymer of Example 69 (0-02)-The graft copolymer of this example was also milled into linear low-density polyethylene (mfr 2.3) in the manner taught in Example 59. Poor dispersion in polyethylene was also noted, with large chunks of the u(,cl;spersed modifier visible. Sag resistance was determined at 150~C as in Example 59; sag for the unmodified control (by the sag slope test) was 0.39, and for the graft copolymer of this example, 0.23. By comparison, sag when using the graft copolymer of Example 4 would be expect~ to be well below 0.10.

- - 13400~a FXAMPI F.Ci 7~

This example illustrates prepz.r~tion of blends of graft eopolymer with polyprop~lene resins to form pellets useful for further proc~ssing into extrudedor molded artieles.
The gratt eopolymer of Exampl- 69, not separated from any un~rafted polypr~pylene or acrylie poly...er, was used as 3.2-mm long pellets eut from an extruded strand.
The poly~.,u~,ylene resins used wer~nAristeeh'~1-4020F (Aristeeh Chemieal CG.~Gr~tion, Pittsburgh, PA),'~i~-lG,lt'~523 (Himont Corporation Wilmington, Delaware), and'~exene" 14S4A (Rexene Corporation Dallas, TX).
Characte.ialics are shown in Table Xlll; the term ~eopolymer in the table means a eopoly-"ar with ethylene.
The ~raft copoly.,-Er was blended at 5% with the polypropylene resins by tumbling. The blend was then extruded into strands through a""~3an 60-"*
mm, twin-serew extruder equipped with screws of 32:1 len~th/diameter ratio;
the al-ands were cooled and choppe~ into pellets. Various feed rates and serew speeds were utilized. Conditions for the unmodified and modified resins used to obtain large-seale samples are sum"-ancsJ in Table XIY. Sag tests as de~,il,ed in Example 1 were con~ucte~ on several other samples of ",odified resin pr~eesced under varying conditions, and the results were comparable to those r~po,l~ bebw in Table XIX.

* Trad~~mark (ea~h instance).

.
~ .
,~ '.
. ~

T~RI F XIX

Rlen~.~ of PolyDropyl~ne With Meth~yl MethAcrylAte Gr~ft Copolymer An-l Control s Ex. 69 ExampleGraft, P~IYDr~PYl~ne MAtrix Resin Sag phr ~Am~ MFR Co~osition 72 -- Aristech TI-4020F 2 copolymer 0.23 73 5 0.02 74 -- Himont 6523 4 homopolymer0.36 0.11*

76 -- Rexene 14S4A 4 copolymer 0.35 77 5 0.14 ~ Sample tore on testing; other blends processed at slightly different conditions gave sags of 0.06 to 0.09.

T~r~l F XX

Process~n~ C~n~tt;on~ for Pr~-Rl~n~ of T~hle XIX

Example: 72 73 74 ~ 76 77 Modifier: -- 5% -- S% -- 5%

Feed Rate, kg/hr ~Set)90.7 181.4 90.7 181.4 181.4 181.4 Feed Rate (actual)90.2 185 89.8 181.4 178.7 182.3 Screw Speeds 101 200 100 200 200 Drive Amp~ 103 121 97 111 112 112 Kg-m/sl 1258 3033 1184 2811 2~11 2811 Head PresQure (kPa)21372758 1448 2068 2275 2206 Barrel Temps. (~C) Zone 1 163 163 163 163 163 163 Zones 2 - 8 204 204 204 204 204 204 Die 204 204 204 204 204 204 Melt Temp. ~C 213 222 208 216 217 217 .

1 - Power applied to extruder screw.

;

This example illustrates preparations ot blends of graft copolymer with other pobrpropylene resins on difterent compoundin~ equipment to form pellets usetul for turther pr)cessin~ into film or profile. Th~!Amoco- *
6214 is a film ~rade polypropylene resin containin~ a clarifier. The ~- Eastman 4E1 1--ls an impact-extrusion grade propylene-ethylene-copoly-"er resin used in profile extrusion. In the present case both 1%
and 5% by wei~ht of the graft copolymer ,les~-ibed in Example 69 were used to torm the blends.

* TL~ ~rk ** Tr;~Apm 3rk ;r ~ ' ' ' ' -- .

. .. . . ..... ~.~ . . , .. . .. ~ ,.. . . .. . .. ..

The two polymers were tumble blended, and the mixtures ted to an 83 mm'~emer-Ptleiderer'~o-r~tatin~, intermeshing, twin-screw extruder of 24/1 W ratio. The pelbts were continuously ted to the extnJder by means ot art~Acrisorr~loss-in-weight teeder, melted and mixed in the extruder, extruded throu~h a 33-strand die, cooled in a water trough, dried, pelletized, and packa~ed. The machine cor,ditions for the individual l~lcl)es are as follows:

T~RLF Xxl Co~Dos;tions of Rlen~.c An~ ~Atr;Y Polymers ~x~m~le% ~i fi~r ~trix Poly~er ! 78 -- "Eastman"4Ell Copolymer 81 -- "Amoco 6214"Homopolymer * Tr~A ~ rk T~RI F XXII

Pre~r~tive Con~it;o~s for VArious Rlen~.~ of T~hle XXI
TP~er~ture, ~C
Ex.79 Zone set point/~ct-l~l Con~tions Z-2 235 / 216 TORQUE- 73-75 %

Z-4 213 / 302 VACUUM- 380 mm Hg Z-5 235 / 221 MELT TEMP.- 227~C (STRANDS) Z-6(DIE) 227 / 227 RATE- 150 kg/hr Z-7~DIE) 238 / 241 Ex. 80 Zone set ~oint/~.tl~l Con~it;ons Z-2 235 / 216 TORQUE- 73-75 %

Z-4 213 / 302 VACUUM- 355-380 mm Hg Z-5 235 / 232 MELT TEMP.- 205-207~C
Z-6 241 / 241 RATE- 218 kg/hr Ex. 82 Zone set ~o;nt/~ctu~l Con~itio~s Z-2 296 / 304 TORQUE- 50-53 %

Z-4 252 / 316 VACUUM- 203 - 253 mm Hg Z-5 293 / 293 MELT TEMP.- 223~C
Z-6 266 / 232 RATE- 116 kg/hr . ,. . , " ., , ~, . ~ ,.

1 3 1 0 ~

Ex. 83 Zone qet point/A~tl-~l ron~t~on~

Z-l 288 / 28S RPM- 90 Z-2 293 / 272 TORQUE- 50-56 %

Z-4 224 / 310 VACUUM- 304 - 329 mm Hg Z-S 266 / 249 MELT TEMP.- 226~C
Z-6 266 / 229 RATE- 122 kg/hr FXAMplF.~ 84-87 This example illustrates the use of a graft copolymer of the present invention in the prepar~tion of bottlss from polypropylene ,-,alenals.
The graft polymer of Example 69 was blended at various levels up to 5% by wsight with either of two commercial polyplopylenes used for blow moWing of bottles The matrix poly...er of Example 84 was a propylene lancJon) copoly."er believed to contain 2-4 % ethylene, supplied by ~na Oil & Chemical Co., Dallas, TX, as"Fina'7231, mfr~2.
The matrix polymer of Example 86 was a propyl~ne homopolymer, mfr~2, supplied by Quantum Chemical, USI Division, Rolling Meadows, IL as~l~orchem~200GF. Blends were made by tumblin~ the resins.

Samples were injection blow molded on a"Joma~machine, model 40, (Jomar Corporation, Pleasantville, NJ). The resin blend, in melt form, was injl~cted into a four-cavity mold (two cavities being bbcked off) over a core pin with an air hole at the end to form an i.lflatable puison. The mold was heated and was designed to produce a pd~ler-, at the far end which will ailow a cap to be ~tlacl,ed after molding.
Ten,pcr~t~lres of the mold were cont,~"ed at the bottle neck, bottle walls, and bottle bottom. The parisons wore conveyed to a seconJ

, ., * ~ll,.r~. .. ;3rk (each instance) .

station where ~hey were ;ntlal~ to torm the bottb shape, and then to a third station where they were cooied and re,-~v~:l. Bottles, which were a 103.5 ml spice bottie, were judged versus non-modified controls for surface 91OSS, ciarity, unifu-l--i~y of thickness, wall sl~.lytil, and the like,as well as to the ease of molding.
T~RI F XXU¦

Molding Conditions for Bottles T~er~tllres. ~C.
I ~XA~pl e BeslnGr~ft~% ~ Q~Qm ~all ~k 84 84 ___ 243 77.7 104 48.9 84Ex. 69, 5% 249 82.2 110 48.9 86 86 --- 243 77.7 104 48.9 87 86Ex. 69, 5% 249 82.2 110 48.9 When bottles from Example 85 were compared with their controls from Exampb 84, a sli~ht improvement in 9bss, notable increase in conlac.t clarity, and noticoable i",pro1~ol,~nt in stiffness were observed.
Similar adva,.l~es over the control were seen with at a 1% level of the ~raft poiymer with the matrix resin of Example 84. The clarity effect was not seen with bottles from Example 87 over control Example 86.
For re~ons not fully under~toGJ, the same additive at 5% was cbbterious to the for,..~tion of bottles from ho,.-opolymer or copolymer of hi~her mett flow rate, even wrth a,~prop~iate adjustments in pr. ~ssin~ temperatures; much of the probbm was Assoc-~lscl with poor Jispcr;,;on of the modifier. Such poor dispersion has not been 2~ seen in other cG,-"~ounding, pr~s.sing or testin~ operations. A slightly stiffer bottle of i.l,pro~d gloss could be bbwn with the ~raft polymer additive at 0.5 weight percent, relative to a control with no additive .

. ~ :
, . ....... ...

~ 1340065 A pre-blend (Example 73) of 5% graft copolymer with another mfr.2 high-impact copolymer yielu~d bonles with severe ~"alelial non-unifo"";ty. A dry bbnd of 0.5% graft copolymer with this same resin (the resin of Example 72) gave bottles with improved gloss and contacl clarity.

FXAMpl F~: ~R- 94 These examples illustrate the utility of a graft polymer of the present invention in the preparation of polyp,opylene foam and foamed sheet. In the examples a ho".Gpolymer of polypropylene (Example 72) - 10 mfr.2 a pre-blend (Example 73) of that polypropylene with a m~ll,acrylate//polypropylsne graft copolymer, and a mixture of the Example73 pre-blend witlh 1% talc (d~si~nsl~ Example 88) wer employed; into all pellets were b'~nJed A"~pacet"40104 to inco",or~te a blowing agent."A",p~~t'~lowing agent is a 10%-active proprietary chemical blowing agent dispersed in polyethylene. It is supplied by A,npacet CG".Gralion, 250 South Terrace Avenue Mt. Vemon NY
,.
10550. When 10 parts of Ampacet are blended there is 1 part pn:~p,ietary blowing a~ent in the formulation.
The polymer mixture was p,ocessed in a 25.4-mm single-screw extruder produced by KilJion Extruders Corporation, utilizing a 24:1 bn~th/diameter screw of 4:1 cG,-"~,ess;on ratio, and a 1-mm-diameter rod die. Extrusion conditions are summarized below. The unmodified polymer exhibited severe fluctl ~a~ions in die pressure (6900 - 12 400 kPa); the blend contalnin~ 5 parts of the graft copolymer could be extruded at a constant di~ pressure. In both cases ~ood cell unifo,-"il~r was observed. Uniform larger cells were noted in the gratt-polymer-modified blend when the amount ot active foa",in~ ingredient * Tr~l~rk ~' was increased to 2%. The presence of 1% talc in the modified polyolefin produced the best cell stnJcture and fastest line speed.
Foam densities of the rods were measured according to ASTM
Standard Method D-792 M~thocl A-L. Although the unmodified matrix polymer pro~uc~ the lowest-density foam the modified polymer foams in ~eneral had a regular foam~ell structure.
The three ",ale,ials were also processed on a similar line with a 202-mm cast ~Im die and a heated collecting roll to yield foamed sheet;
here no significant differences in plocess;,-g were seen among the three resin blends. The individual sample preparations and results are shown in Tab~e XXIV below.

T~RI F XXIV

Type: Rod Rod Rod Sheet Sheet Sheet Sample:Ex. 89 Ex. 90 Ex. 91 Ex. 92Ex. 93Ex. 94 Poly~r Qf:F.x . 7~F.X. 73 ~x. 88 F.x . ~1~x . 73 F.x . 73 Talc, wt% -- -- 1 -- -- --Foaming agent,wt %
Extruder rpm80 80 80 75 75 75 Melt temp.,~C214 208 209 227 227 227 Melt pressure, 70-kg/cm2 127 127 140 56 42 42 Puller speed, 13 15 23 meters/min Sample Density, 0.469 0.6640.733 g/cm3 ... . ... . .. . ~ . .

1~ lOOfi5 FXAMPI F.~ 95 - 98 This example illustrates the utility of a ~raft copolymer of ~olypr~pylenel/methyl m4~hacrylate in lhe prep~r~tTon of blown ~olypr~pylene film. Film was blown from the control polypropylene hG.~poly.. ar of Example 74, the pre-blend of Example 75 which contained 5 wei~ht percent of the ~raft copoly--ler of Example 69, and dry blends of the polypropylene of Exampb 74 wlth 1 and with 5 parts of the graft cop~y-oer of example 69.
Blown fflm was pro~ce~ on a'l<illion"blown film line (Killion Extruders Co., Cedar Grove, NJ), which consfsts of a 25.4-mm, single-o screw extruder operatin~ d a melt temperature of about 216~C., a 50-mm spiral ~anJIel die, air input for producin~ a bubble, and a Killion vertical-blown -film tower. The blown-film tower contains two nip rolls for collapsin~ the bubble and a means tor pullin~ the film through the nip rolls. The die and pull sp~eds are adjusted to produce tilm about 5.6 mm thick (two thicknesses) and either 108 or 165 mm wide, the blow-up ratios being 2.125 and 3.25 respe~ ely, at respecti~e top nip speeds of 7.65 and 5.94 meters/minute.

T~hle XXV

Film of Materials Thickness 20 E~am~

. .
Ex. 95 Ex. 74; no GCP 0.051 - 0.066 Ex. 96 Ex. 75; 5% GCP, Cmpd. 0.056 - 0.064 Ex. 97 Ex. 74; 5% GCP, Dry Blend 0;051 - 0.058 Ex. 98 Ex. 74; 1 % GCP, Dry Blend 0.051 - 0.058 * TrAA~I'lA l~k Himont 6523, mfr=4, homopoly..,er polypropylene was blown into 0.02~mm-thick fflm (singb layer) as Example 95 (control). The bubble was slightly lop~icle.J, and the frostline (onset of crystallization) was at an angle to the die. A lopsided bubble results in less uniform film thicknesses With 5% of the graft copolymer of Ex. 69 present, the bubble of Example 96 was stebil;~J, the frostline lovolled, and the frostline moved closer to the die. Both 108- and 1 65-mm, lay-flat films were produced Although some fluctue~ion in die pressure was noted when forming the latter film, it had the most stable bubble.
This increase in bubble stability was also observed with the 1%
and 5% dry blends of Examples 97 and 98. No significant differences in film appearance was observed between the 5% precompounded blsnds and the dry blends.
The modified films had decreased film see-through clarity.
Contact clarity remained urlchanged. No difference in edge-roll color was observed between modified and ur,i"GJified film.
The ~openability~ of neat and ",Gdified film was tested. Although a very ~u~lit~tive test (the collarsed film is snapped between the fingers and one feels how well it opens), no difference between the unmodified and ",G.Jified resins was observed.

FXAMpl FS 99 -104 The experime!lts illustrate the use of the graft polymer of the present invention in producing polypropylene cast film. A single-screw extruder, manufactured by Killion Co., was e~uippe~ with a 3.81-cm screw of 24/1 length/diameter ratio, a 20.~cm x 0.635-mm cast film die, 1~40065 a chill roll and a torque winder for the film, was utilized. The extruder melt temperature was 226~C. The melt was extnuded through the die and onto the chill rolls, the take-up speed being ~djusted to produce film of various thicknesses. Film thicknesses was measured, as was ~neck-in~, an undesirable shrinkage of width. Film stiffness and edge roll color were measured rluAIit~ively. Film thicknesses were adjusted incrbasing line speed of the torque winder and lowering the extruder output by reducing screw speed.

T~RI F XXVI

Filmof Starting Material Form ~amQ~

Ex. 99 Ex. 74 Unmodified Ex. 100 Ex. 75 Pre-blend; 5% GCP
Ex. 101 Ex. 74 and Ex. 69 Dry blend; 5% GCP
Ex. 102 Ex. 81 Unmodified Ex. 103 Ex. 82 Pre-blend; 1% GCP
Ex. 104 Ex. 83 Pre-blend; 5% GCP

GCP = grafl copolymer of Example 69 Films of the co"~osition of Example 99 were uniform and consistent at thicknesses of from 0.25 mm to below 2.5 mm. Example 100 pro~uc~ ~cep~le film of improved edge color and with less film neck-in. Example 101 also pro~uced less neck-in, but did not i",pro~/o edge color. Both "~ifie~ versions yi~lded stiffer films at equivalent thickness versus the control, allowing the film to be wound more easily.
The opacity of the film inc,.,asecl with the ~dilion of the grafl polymer.

With Examples 102 to 104, the neck-in differences were not noted when the graft copolymer sdditive was present. The films at both 1 and S weight percent graft copolymer were stiffer than the un",Gdiried control (Examples 103 and 104 versus Example 102).

This example illuslr~les that bi~xielly oriented film can be prepared from a polypropylene resin containing 5% of the polypropylene/methyl methacrylate graft copolymer. Under the limited condiliGns tested, which were optimum for the unmodified resin, no di~lin~ advantage could be seen for the additive. At identical extrusion and MW (machine direction orientation) conditions, the modified resins couW not achieve and maintain the line speeds possible with the unmodified resin during the TDO (transverse direction orientation).
The control resin was Example 81, mfr=2.2, high~larity homopolymer marketed for film use. Pre-compounded resins were Examples 82 and 83, containing respectively 1% and 5% of the graft copolymer of Example 69 (under the extrusion conditions, a dry blend of 5 parts graft copolymer of Ex. 69 with the matrix resin of Example 81 gave very poor dispersion, leading to many gels and frequent film breaks). The blends were processed in a 50.8-mm, Davis-Standard single-screw extruder which conveyed the melt through a 0.48-meter die and onto a 1.02-meter casting roll. An air knife was used to blow the extrudate onto the casling roll. The casling roll r~ta~ed through a water bath to completely quench the sheet. The sheet then was conveyed into the MDO, supplied by Marshall and Williams Co., Providence, Rl, and comprising a series of heated nip rolls, moving at speeds which cause monoaxial orientation.

After the MDO, the film p~ssed through a slitter to cut the film to the proper width and then onto a winder. These rolls were used to feed the film into the TDO, which is an oven with three heating zones, rolls for conveying the film forward, and clamps to grip and laterally expand the film.
The film from Example 81 (unmodified resin) was drawn both 4.75:1 and 5.0:1 in the MDO, and couW be drawn 9:1 in the TDO. The ur""~ified 4.75:1 MDO resin could maintain a TDO line speed of 8.69 meters/minute; the unmod~fied 5.0:1 MDO resin could maintain a line speed of 6.85 meters/minute .
The film from Example 82 (1% graft copolymer) could receive a MDO of 4.75:1 and TDO of 9:1 and maintain a 6.85-meters/minute TDO
line speed. Frequent film breakage was encountered at higher MDO
and higher line spseds. This biaxially oriented film appeared to be slightly more op~que than the biaxially oriented film from Example 80.
No difference between the edge roll colors of film from Examples 81 and 82 was observed for MDO film.
The films from Example 83 received MDO's of 4.75:1, 5.0:1, and 5.25:1 at a TDO of 9:1. The best film was obtained with a line speed of 6.85 meters/minute and with the lowest MDO; tearing would occur under more stressed conditions. Films from Example 83 were noticeably more op~us and the frost line appeared sooner than with the control film of Example 81.

FXAMpl F 106 This example illustrates a profile extrusion trial using polypropylene modified with a graft copolymer of the present invention.
A single-screw extruder was e~uipped with a die and appropriate cooling, pulling, and sizing equipment to form a profile in the shape of a solid rod with l,Gri~ontal tlanges. The rod diameter was 4.83 cm., flan~,iGS 2.67 crn. (e~lendad beyond rod), and flange thickness 1.52 cm.
With un.--~itied resin (Tenite 4E11 copoly.--er, Easlll.an Chemical, as described in ExampJe 78), sy...--.elry was difficult to ~--aintain Tn the profile without sag or distortion. When blends of Example 79 and 80 (1 and 5% ~raft copolymer, respec(i~ely) were employed, the maintenance of shape was i---p~ed.

This example illustrates the use of a graft copolymer blend of the present invention in the ,-~odifioation of polypropylene to produce improved plastic tubing. The polymers used were the unmodified resins and the resins compounded with 5% of the graR copolymer of Ex. 69, as d&~-il~cJ in Examples 72 to 77.
A 25.4-mm, single-screw'Killion"Extruder (Killion Extruders Co., Cedar Grove, NJ) was equipped with a screw of 24J1 l~ngth/diameter ratio, a tubing die with an outer die diameter of 11.4 mm. and a variable inner diameter, leadin~ to a 0.2~metar-long wder trough for cooling, an air wipe, and a puller and cutter. Conditions and observations are shown in Table below. Ovality is the ratio of smallest outer diameter to largest outer diameter, as measured by calipers; a value of 1 means the tube is unif~ round.
When tubing of good ovalit,v was produced from the u-""Gdifiad resin, the mapr eff~t of the additive was i",pru;0ment in tubing stiffness.
With the resin of Example 72, where ovality was dimcult to control at A~epteble output rates, the ~"GJi~ resin (Example 73) improved ovality as well as stiffness.

* Tradem~rk 68 . ~' '''. .

13~0065 ~le XXVII

Tllhin~ Pre~re~l from Polypro~ylene ar~-l M~lifiefl Polypropylene Polymer Melt Melt Inner Ovality Temperature, Pressure, Diameter ~C kPa(a) mm(~) Ex. 72 217 8270 8.1 0.75 Ex. 73 214 6890 8.1 0.88 (b) Ex. 74 185 9650 8.1 0.97 Ex.75 197 6890 8.1 (c) 0.77 Ex.76 184 6890 8.1 (d) 0.92 Ex.77 180 8270 8.1 (d) 090 (b,e) (a) Extrusion rate equivalent for paired un",Gdified and ~I~ified resin.
(b) Modified extrudate tube stiffer.
5 (c) Higher melt tsmperature required to avoid ~sharkskin" on tubing.
(d) With this hi~her mfr resin, re~uced melt te,l-peral.lre and higher puller speed led to tubing of lower outer diameter.
(e) Modified tubing more op~lue.

FXAMPI F!:: 108- 109 -' 20 This example illust,ales the preparation of pre-compounded blends containing talc. The talc used is a white, soft, platy talc of particle size less than 40 ~mj known as'~antal'hIM-45 90 (Canada Talc Industries Umited, Madoc, Ontario). It was ussd at the 20% level. The polypropylene used was a hG",opoly...er of mfr.4, known as~ "Gnr*
6523. The graft copoly",~ir was ir~G.~,or~tsd at the 5-weight-percent * T~At-.,~rk ?
~, 13~0065 level and was the graft copolymer of Example 69. The compounding/preparation of these samples was carried out on a 30-mm Werner-Pfleiderer co-rotating, twin-screw extruder. The materials were tumble blsnded prior to the compounding.

TARI F XXVIII

Blend % Talc Modifier Matrix Polymer Example 108 (control) 20 Cantal --- 80% Himont 6523 Example 109 20 Cantal 5% Example 75% Himont 6523 The preparative conditions for the blends are given in Table XXIX.
The extruder was operated at 200 rpm, with no vacuum, at rates of 4.5 -4.6 kg/hour, and 85-86% torque.

T~RI F XXIX

Fxtn ~Qr 7f-ne Settin~s. ~C
FY~le 108 F~ lQ 109 Zone set ~int/~c~ual set ~inV~tual Z~ 240/ 239 240/ 239 Z-8 (die) 225/ 239 225/ 239 Melt 239 243 ~4~065 FXAMPI F~:; 110 ~

These examples teach the injection molding of polypropylene of various compositions and melt flow rates, the polypropylenes containin~ a graft copolymer of the present invention. In two examples, a 20% loadin~ of platy talc is also present.
Polypropylene may be injection molded into useful objQcts by employing a reciprocating-screw, injection-molding machine such as that of Arburg Maschien Fabrik, I ossb~rg, Federal Rep~blic of Germany, Model 221-51-250. In the preparation of test samples, the extruder is equipped with an ASTM mold which forms the various test pieces. The conditions chosen for molding were unchanged throughout the various matrix and modified matrix polymers, and no difficulties in molding were noted. Table XXX describes the blends which are molded; Table XXXI teaches the molding conditions; Table XXXII reports modulus values, Table XXXIII Dynatup impact data, and Table XXXIV heat distortion temperature values for the modified polymers and their controls.
In the following list of injection-molded polymers and blends, all samples contain 1 or 5 weight percent of the graft copolymer of Example 69. The polypropylene matrix resins are described in earlier examples; HP is homopoiymer, CP is copolymer, the number is the mfr value. The blends with talc are described in Examples 108 and 109.
All materials were pre-blended in the melt, excspt where a dry blend from powder was directly molded. (C) is an unmodified control; (CT) is a control with talc, ~ut no ~raft copolymer All test Illetllods were by ASTM standard methods: flexural modulus and stress are by ASTM Standard Method D 790, heat .. , .... ~ ~, 13 10~65 distortion temperature under load is by ASTM Standard Method D 648 and Dynatup impact is by ASTM Standard Method D 3763.
Table XXX also includes the melt flow rates (mfr) for the ur""Gdi~ied and pre-compounded blends. In most cases the melt flow rate is unchanged or slightly decreased in the presence of the graft copolymer so that the melt viscosily under these intermediate-shear conditions is not extensively incleaseJ. The melt flow rate is by ASTM
Standard Method D-1238 cGndilion L (230~C. 298.2 kPa) and has units of grams extruded/10 minutes.

1~40065 T~RI F XXX

Fx~le Matrix ~.r~ % Talc.% n~-Rlend? mfr 74 (C) HP,4 -- -- -- 4.40,4.06 HP,4 5 -- -- 6.07 110 HP,4 5 -- YES
108 (CT) HP,4 -- 20 ~~
109 HP,4 5 20 --76 (C) CP,4 -- -- -- 4.47 77 CP,4 5 -- -- 3.75 111 CP,4 5 -- YES
72 (C) CP,2 -- -- -- 2.37 73 CP,2 5 -- -- 2.02 112 CP,2 5 -- YES
78 (C) CP -- -- -- 2.92 79 CP 1 -- -- 2.04 CP 5 -- -- 2.12 81 (C) CP -- -- -- 2.33 82 CP 1 -- -- 3.81 83 CP 5 -- -- 2.16 1~40065 T~RI F

Cylind~ t~ nr~ res. ~C ~Settin~ma~cllr~
Feed -216/216 Meterin~ -216/216 Compression -216/216 Nozzle 216/216 Mold Temperatures, ~C
Stationary -49/49 Movsable -49/49 Cycle time, secor,ds Injection fonNard -14 Mold Open -0.5 Cure -14 Total Cycle -0.5 Mold Closed -1.2 Machine readings:
Screw speed (rpm) - 400 B~k pressure (kPa) -172 Injection (1st stage)(kPa) - 861 The flexural modulus data from Table XXXII indicate the :,linanin~
effect of the graft cop~ly-.-er. Results are in me~r~A~ s (mPa).

,~
.

13~0065 T~RI F XXXII

FLEXURAL STRESS
Example MODULUS ~at max) mP~ mP~

74 (C) 1470.6 43.8 1744.4 47.5 110 1783.1 46.9 108 (CT) 2768.0 52.0 109 2867.0 54.5 Table XXXIII su"""~.izes Dynatup impact data (in Joules) at various t~-"pGr~ures for the blends and controls tested. The data indicate, in general, slightly improved impact for the pre-blended materials, a deterioration in impact strength on molding dry blends of graft copolymer and matrix polymer, and an increase in impact slrenyll, for the taic-modified bbnd also containing the graft copolymer.

134096~
T~l F XXXIII

Dynatup Impact (joulss) at TestTem~r~llre ~C
Fy~rnple 2~ 15 74 (C) 4.9i2.7 4.4i1.5 3.8iO.3 2.6i. 41 5.7i3.4 4.6iO.8 2.7i1.5 3.4il.09 110 3.4i1.1 2.0iO.5 1.9i1.0 1.5i. 41 108 (CT) 3.0iO.5 3.4iO.8 4.2il.6 5.0i2.5 109 l.9iO.5 4.1i2.3 4.8il.8 5.0i2. 5 76 (C) 40.0iO.5 77 43.9iO.4 111 14.0i6.4 72 (C) 37.9i1.8 73 43.1i10.3 112 32.4i9.5 78 (C) 36.7iO.4 79 36.3i1.1 37.1iO.7 81~ (C) 13.3ilO.7 ---- 3.3iO.8 2.7iO.2 82 4.9iO.7 ---- 3.0i1.4 3.0iO.8 83 7.6i3.7 ---- 3.3iO.8 3.5+1.1 The large standard deviation at room temperature is suspect.

Table XXXIV presents heat distortion and hardness values for one series. The modifiéd polymer appears to exhibit a slightly higher heat distortion temperature and hardness, although there are inconsisl6ncies noted. The Rockwell hardness values represent 1340~65 separate dete""inalions on two samples of the ",ale.ial trom the indic~ted example.

T~RI F XXXIV

Heat Deflection Ternperature Rockwell Hardness Example ~ ~rlMinl ~e At "~ IQ
-- 411 kP~ 1645 kP~
74 (C) 110.9 61.0 58.4 56.5 113.8 63.3 60.7 59.3 110 117.3 68.7 57.9 46.9 108 (CT) 128.2 76.8 57.3 64.7 109 124.7 81.9 65.4 63.7 This example illusl~tes the effect of the ",ol~aJlar weight of the polyprop~lene tnJnk component of the graft copolymer on the sag ",~ificalion of polypropylenes of various molscular weights. Graft copolymers were prepar~d from p~h,p~p~lene of various melt flow rates. All modifiers were prepar~cl as in Exampb 58. The 35 mfr polypropylene ~ lo,lt P~701~*was run at 6~% solids. The 12 mfr polypropylene ~himorlt Pro-fax 6323) was nun at 60% solids. The 4 mfr polypr."~ylene (Himont Pro-fax 6523) and the 0.8 mfr polypropylene *

'~Himont Pro-fax"6723) were run at 55% solids. The molecular weights - for the polypropylene base resins, where known, are ~iven in Table XXXV, bebw.
These were ev~ tsd as melt ~Ir~,~tl, ;""~,o~ors at 4% by weight in several of these same polypropylenes. Sttu~ard mill and press conditions were used for all blends, except the 0.8 mfr/0.8 mfr ?7 * T.~ ~rk r l~OOfiS
polypropylene blends which were milled at 215~C and presssd at 21 5~C. Sag rates were measured by the standard procedures. The sag slope at 190~C is reported in Table XXXVI, below.

T~RI F Xxxv M~-~FR D~t~ for polyprQ~yl ~n~ e Res;n Molecular-Weight WP;~ht-Aver~e ~le~l]l~r Welght x 105 .Sol~r~P l? ~fr PP 4 mfr PP 0.8 ~fr PP
(a) 3 4.3 7.1 ~b) 2.45 3.05 3.5,4.7 (c) 0.27* 0.45* --Source of Molecular-Weight Value: a) Supplier's data. b) Sheehan et al, J. Appl. Polymer Sci., 8, 2359 ~1964). c) Mays et al, lbid., 34, 2619 ~1987).
* These values are nl~mher-Aver~e molecular weight.

T~RI F XXXVI

Slope At 190~C for Olefin Rlen~ min-~) polyprQDyl~n~ h~.~e r~c'n (96~) ~;f;er (4%)35 mfr PP1~ ~fr PP 4 ~fr PP0.8 ~fr PP
none 1.6 0.52 0.25 0.099 35 mfr PP based 1.8 0.52 0.23 0.074 12 mfr PP based 1.2 0.41 0.034 < 0.02 4 mfr PP based1.0 0.16 0.022< 0.02 0.8 mfr PP based 0.64 0.16 0.031 << 0.02 In all cases except where a high-melt-flow base resin was modified with a graft polymer having a trunk of high-flow-rate (low-moleaJI~-weight~ polypropylene, sag improvement was observed. The molecular weight for the resin of mfr=35 is not accurately known; it is .. .".u . ,. .. ~ .. ." , .. . .

believed to be made by thermal/oxidative pr~ssing of a higher oclJl-r weight resin. Such a process wouW both lower the moiecular weight and narrow the originally broad molecular-weight distribution.

FX~MPI F 1 14 This example illustrates the effectiveness of the graft copolymers of the present invention as compatibilizing agents for polymers that are othenrJise poorly compatible. In this example a polyolefin, a polar polymer, and the graft copolymer of the present invention were compounded in an intermeshing, co-rotating, twin-screw extruder (Baker-Perkins MPCN 30) with a screw length-to-diameter ratio of 10:1.
The cG"~ounder was run at 200 rpm and temperatures were adjusted to accomr"Gdate the polyrners in the blend and achieve a good melt.
The melt temperature in the compounding zone is recorded in the second column of the table. The melt was fed directly to a 38-mm, single-screw, pelletizing extruder with a length-to-diameter ratio of 8:1.
The melt temperature in the transition zone between the compounding and the pe"~ti~ing extruder is shown in column 3 of Table XXXVIII, below. The melt was extruded into strands through a die, cooled in a water bath, and cut into pellets.
Table XXXVII below summarizes the polymers which were used in the blends of the present example, while Table XXXIX shows that the graft copolymer has little effect upon the tensile strength of the unblended polymers, that is, it does not act to a significant degree as a toughening agent. In the 5~lhse~luent tables, Tables XL and XLI, improvement in tensile strength of the blended polymers indicates an increase in co,.,patibility of the blended polymers with one another in the presence of the graft copolymers of the present invention.

1~006~

Under the proper co."pounding coficlilions, an increase in comp~ibility may also praduce a decrease in the size of polymer domains in the blend. Scanning electron micr~.~copy confirms that in some of these examples, sigr,ificant domain-size reductions occur when the graft copolymer is added. For example, the polypropylene domains average 2 micrometers in the 70 PMMA / 30 PP blend of example 114.
The addition of 5 phr co",palibilizer reduced the domain size to 0.5 llm.
The addilion of 15 phr con"~alibilizer reduce~ the domain size to 0.43 m. Although not all ot the domain sizes were reduced, several others were reduced by 10-30% bythe addition of 5 phrcGi"palil,ilizer. This is a further suggestion that the cGi"palibilizer is acting on the inle,face of the polymer domains rather than on the individual polymers.
Table XLI summarizes the comp~tibi';~ing effect of the graft copolymers upon the various polymer blends.

T~RIF Xxxvll poly~rs Use~ ~ n the Rl ~n~ Fx~ es Other Polymer and Designation Grade Spec. Specifi-in T~hles pro~llcer ~esi~n~t;on ~r~V. ~Ations SAN Monsanto '~ustran"~AN 33 1.07 mfr~l4 Styrene-Acrylonitrile ASTM D 1238 Polymer Cond.(I) PA66 DuPont "Zytell'~01 1.14 mp-255~C
Nylon 6-6 ~D2117) ¦ PET Eastman IlKodapa~ PET 1.4 mp-245~C
Polyethylene Kodak 7352 (DSC), Terephthalate iv~0.74 EVOH EVAL Co. "Eva~'EP-E105 1.14 44 mole% E, Ethylene Vinyl of America mp-164 C, Alcohol Copolymer mfr~5.5 (190~C, 2160 g) PC General "Lexan"121 1.20 mfr~l6.5 Polycarbonate Electric ASTM D 1238 Plastics Cond. (O) 1 PVC Georgia SP-7107* 1.35 PolyvinylChloride Gulf Corp.

PMMA Rohm and "Plexiglas~ 1.18 mfr=15 Poly~Methyl Haas Co.
Methacrylate) EP Exxon "Vistalo~l719 0.89 54 Mooney Ethylene Propylene (D-1646) Copolymer HDPE Phillips "Marlex"* 0.950 mfr=4 High-Density 66 Co. HMN 5060 Polyethylene PP Hlmont "Pro-faxl'6523 0.903 mfr~4 Polypropylene EVA DuPont ~Elvax"650 0.933 12% VA
Ethylene Vinyl Acetate mfr~8 * Tr~Fm~rk (each instance).
.~

13~006a TARI F XXXVII ~nntin~lA-l) Other Polymer and Designation Grade Spec. Specifi-1n T~hles pro~llcer nes~gr~At~on Grav. ~At;ons LLDPE Exxon n Escorene "* 0.926 mfr~12 Linear Low-Density LL-6202 Polyethylene PS Huntsman PS-203 1.06 mfr=8 Polystyrene Chemical ~crystal) PBT General " Valox' 6120 Poly(butylene Electric terephthalate) PA6 Allied " Capronn8253 1.09 mp=21~C
Nylon 6 Signal ABS Dow " Magnum"341 1.05 mfr=5 Acrylonitrile- Chemical Butadiene-Styrene Resin PC/PBT General nXenoy "~101 1.21 Polycarbonate/ Electric Poly~butylene tere-' phthalate alloy ¦!

* Tr ~ ~rk (each ~nstance.
~

r ~
~,. .

1~4006:~
T~Rl F XXXVIII

melt t~m~er~t~res ~~C) ~Qm~olln~er trAnsit ~ on The pelbts were dried and inj~ction mol~ed on a reciprocatin~-screw injaction ",~lclin~ machina '(New ~ritair~Model 7~) into test specimens.

*rrad~rk .

13~006~

T~RI F XXXIX

.ffect of Co~tihilizer on polymer Tens;le Str~ngth Te~s;le Strength.~ Shown in ~egAP~sc~ls (~P~) snm~t;hili7er concentr~tion pOly~r 0 ~hr 5 Dhr 15 Dhr PMMA 65.44 64.7961.27 SAN 71.91 62.7455.89 EVOH 68.78 66.2163.78 PA66 64.82 64.6866.60 PET 58.26 59.3359.72 PVC 45.25 44.9745.22 PC 62.63 63.0563.70 HDPE 22.59 22.6624.14 PP 33.02 34.0333.95 EP 4.79 5.50 5.84 LLDPE10.91 11.8012.99 EVA 8.64 8.67 8.17 13~00~5 T~RI F Xl TPns;le Stre~gth.~ (MPA) of RlPn~.~ of polyolefins An~ pol~r Polymers 30% pol Ar ~ol y~Pr 55% pol ~r ~ol ym~L 80% pol ~r ~ol ymer polar poly~Pr 0phr ~h~ 15~hx O~hr ~h~ hL Q~hL ~h~ 15Dhr ~~--~----------------- HDPE -----------------------* PMMA 25.26 27.00 30.26 31.42 38.30 39.54 50.78 53.77 55.55 * SAN 25.77 28.09 30.57 34.71 41.51 38.33 51.88 55.08 51.23 * EVOH 26.57 26.80 27.74 33.18 38.00 39.58 49.24 51.32 50.79 PA66 26.94 28.85 29.72 38.34 38.11 38.33 61.22 65.62 69.23 PET 25.97 28.61 30.98 37.70 37.93 40.09 50.23 51.72 50.91 PVC 20.89 22.92 24.86 19.91 23.67 27.34 26.18 30.72 34.87 PC 25.66 28.80 30.93 31.11 35.20 38.53 55.61 50.41 51.92 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ p p _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ * PMMA34.02 35.37 37.81 40.23 43.45 45.84 46.40 53.70 56.6 * SAN33.67 38.76 41.05 37.67 47.65 46.08 41.11 54.12 51.81 * EVOH32.85 37.40 38.56 35.01 44.65 45.60 42.73 53.38 52.57 PA6632.06 40.29 40.38 42.72 52.17 51.10 64.71 67.84 66.15 PET32.93 33.80 35.15 39.47 43.81 43.64 37.67 53.12 54.04 PVC36.32 37.68 39.35 35.28 37.87 40.79 30.88 40.00 42.56 PC33.82 36.68 39.09 36.69 40.13 44.64 42.38 46.24 51.64 ~~~~~~~~~~~~~-~-------- EP ------------------------PMMA8.20 10.87 12.51 19.99 24.17 27.81 42.47 44.59 46.93 SAN8.10 12.53 14.11 22.14 28.82 28.15 45.92 50.68 44.58 EVOH12.19 12.04 11.69 24.92 24.66 23.17 41.29 42.39 42.70 PA6613.04 13.a4 12.36 27.62 27.98 26.33 40.87 48.77 43.48 PET7.94 8.40 11.13 20.22 20.43 22.27 33.72 37.00 38.87 PVC6.17 9.05 12.88 12.93 18.28 19.22 25.50 28.41 30.60 PC10.31 12.05 13.66 23.10 24.34 25.60 40.18 41.79 42.76 1340~65 TARI F ~tl ~ntin~
T~ns; le Strerlgth~ ~P~) of Rl~n~ of polyoleflns ?n~l pol~r PoLymers 30% ~olAr ~olyIn~r 55% pol~r ~olyln~r 80% ~ol~r Dolylner polar ~ol y~r Ophr 5~hr ;L~ ODhr 5Dhr lSDhr Q~ 15phr ~~~~~~~~~~~~~-~------ LLDPE -----------------------PMMA 15.23 18.63 20.90 24.88 30.68 32.84 48.95 55.36 54.14 SAN 15.78 21.08 22.57 26.50 35.76 36.71 47.52 56.92 48.84 EVOH 16.83 17.26 18.26 30.02 31.74 31.87 51.83 50.71 52.29 PA66 17.93 17.99 19.98 29.67 28.49 25.23 64.65 67.55 67.26 PET 15.33 18.09 20.35 25.53 28.23 30.78 45.02 46.16 42.87 PVC 14.72 14.12 15.73 12.45 18.09 20.50 25.99 30.54 33.69 PC 13.64 19.20 18.48 19.22 27.83 30.46 38.45 40.59 38.86 ------------------------------- EVA ---------------------------PMMA10.57 11.28 14.38 23.06 21.10 28.31 45.99 47.02 50.87 SAN12.40 13.62 15.22 27.97 27.29 29.35 48.94 52.01 46.14 EVOH13.13 13.97 16.59 32.41 28.65 35.43 50.97 50.28 48.81 PA6614.15 13.54 14.42 27.36 24.59 26.92 40.75 38.35 31.60 PET14.55 14.35 12.31 21.22 23.90 26.45 43.20 43.91 48.44 PVC7.69 8.28 10.25 13.40 14.29 18.17 19.22 23.76 28.12 PC14.05 14.54 13.52 19.78 21.79 24.85 39.26 40.55 41.46 - polar polymer levels are 20, 45,and 70% instead of 30, 55 and 80%.

13~006.7 T~RI F Xl I
Effect of Compatibilizer on Tensile Strength of Blends of Polyolefins and Polar Polymers Incre~se in Tensile Strength (~PA) fr~m the Com~tib;lizer 30% pol~r polym~r 55% Dol~r polym~L 80% pol~r polymer polar poly~r5 phr 15 phr 5 phr 15 phr 5 phr 15 Dhr ----------------------- HDPE -----------------------PMMA 1.74 5.01 7.38 8.12 2.99 4.77 SAN 2.32 4.80 6.80 3.63 3.21 -0.64 *EVOH 0.23 1.17 4.81 6.39 2.08 1.54 PA66 1.90 2.77 -0.23 -0.01 4.40 8.00 PET 2.65 5.01 0.23 2.39 1.48 0.68 PVC 2.03 3.97 3.76 7.43 4.54 8.69 PC 3.14 5.27 4.10 7.42 -5.20 -3.69 _ _ _ _ _ _ .
*PMMA 1.35 3.79 3.22 5.61 7.29 10.22 SAN 5.09 7.38 9.98 8.41 13.02 10.i0 - *EVOH 4.56 5.72 9.64 10.59 10.65 9.83 PA66 8.23 8.32 9.45 8.38 3.13 1.44 PET 0.86 2.22 4.34 4.17 15.44 16.37 PVC 1.36 3.03 2.59 5.51 9.11 11.68 PC 2.86 5.27 3.43 7.94 3.85 9.26 .. , .. .... ,. , ~ ... ... . ..

1340~6S
T~RI F )~ ontin~

Incre~se in T~n~ile Strength ~YP~) from the Co~t;h;l;zer 30% po1~r poly~r 55% pol~r poly~r 80% pol~r polymer polar polym~r5 phr 15 phr 5 phr 15 phr 5 phr 15 phr ------------------------ EP ------------------------PMMA2.66 4.30 4.18 7.82 2.12 4.46 SAN4.43 6.01 6.68 6.01 4.76 -1.34 EVOH-0.15 -0.50 -0.27 -1.75 1.10 1.41 PA660.01 -0.68 0.36 -1.29 7.90 2.61 PET0.46 3.19 0.21 2.05 3.29 5.16 PVC2.86 6.71 5.35 6.29 2.91 5.10 PC1.74 3.35 1.24 2.50 1.61 2.59 ---------------------- LLDPE -----------------------PMMA3.40 5.67 5.80 7.96 6.42 5.19 SAN5.31 6.80 9.26 10.21 9.40 1.32 EVOH0.43 1.43 1.72 1.85 -1.12 0.45 PA660.06 2.05 -1.19 -4.44 2.90 2.61 PET2.76 5.01 2.70 5.25 1.14 -2.14 PVC-0.59 1.01 5.64 8.05 4.56 7.70 PC5.56 4.85 8.61 11.24 2.14 0.41 ----------------------- EVA ------------------------PMMA0.71 3.81 -1.95 5.25 1.03 4.87 SAN1.22 2.81 -0.68 1.38 3.07 -2.80 EVOH0.83 3.45 -3.75 3.02 -0.68 -2.16 PA66-0.61 0.27 -2.77 -0.44 -2.40 -9.15 PET-0.20 -2.25 2.68 5.23 0.70 5.24 PVC0.59 2.56 0.89 4.76 4.54 8.89 PC0.49 -0.53 2.01 5.07 1.30 2.20 ~ - polar polymer levels are 20, 45 and 70% insle~l of 30, 55 and 80%.

1~400 6 .~
T~RI F Xl ll Con~tibili7~tion Fffect E~E PP E;E~ LLPI)~
PMMA +~+ +++l +~+ +~ ++~
SAN +++ +++ +++ +~+ ++
EVOH ++ +++l o o ++
PA66 ++ +++l + + o PET + ++l ++ ++ ++
PVC +++ +++ +++ ++l ++
PC ++ +++l + ++ +

+++ - compatibilization at all three polyolefin-polar polymer ratios (not necessarily at all co""~dlibilizer levels) I + - compatibiP~tion at two of the three polyolefin-polar polymer levels + - compatibilk~tion at one of the two polyolefin-polar polymer levels 15 ~ - no compatibilization seen at any polyolefin-polar polymer ratio at any co",p~libilizer level (1 ) - additional evidence for compatibilization in the reduction of domain size by 1 0-80%

The co",patil)ilizing sffect on selected additional polymsr pairs was eve~u~ted in the following example. The blends were compounded molded and tested for tensile strer~th as previously de~ribed. The results in Table XLIII again indicate that the co",~tibilizer has minimal or a negative effect on the polar polymers but a positive effect on the polar / nonpolar polymer blends. A large tensile sl-er"Jtl, improvemsnt is seen for the ABS / PP blend. Smaller but significant improve,ne.~ls are seen for the blends of PP with PA6 and with PC / PBT. With the PS blends ev~4J~ted the effect was negligible.

134006.~

T~RI F ~
tensll~ str~ngth.~ (~P~) polar polymer + blend1 +
15 phr 15 phr polar nonpolar polar graft graft polyr~r pol~8L pnlym~L copolym8~_ hl en~l cQDol ym~r PBT PP 43.02 45.11 36.96 38.96 PA6 PP 56.11 51.67 43.50 47.04 PS PP 45.26 40.45 38.88 37.36 PS HDPE 45.26 40.45 36.48 33.76 ABS PP 51.25 52.25 32.25 42.55 PC/PBT PP 51.77 51.79 38.99 41.88 1 - blend in all cases refers to 55 parts by weight polar polymer and 45 parts by weight nonpolar polymer.

The effsct of the gratt copolymer on multi-component blends such as those representative of commingled scrap polymers are shown in Table XLIV. In all cases a significant increase in tensile strength is observed when the co",~ bili~er is present.

13~0DG5 T~RIF XLIV

cGil~Alihili7~tion of Mllllic~ nt Rl~n~c Tensile pol~r P~ly~r~ N~ol~r Poly~r~ tihil;?~r Strength HDPE T.T.DpF. ~

12 7 5 33.5 33.5 9 none 16.27 12 7 5 33.5 33.5 9 5 17.67 12 7 5 33.5 33.5 9 15 21.77 12 8 - 35 35 10 none 18.62 12 8 - 35 35 10 5 19.98 12 8 - 35 35 10 15 22.16 12 - 6 36 36 10 none 17.06 12 - 6 36 36 10 5 i9.21 12 - 6 36 36 10 15 21.91 This example further illusl,~tes co"~p~ti~ tion of polymer blends using graft co~o~.llera of the present invention.
Blends of ethybne-vinyl alcohol copolymer (Kuraray EP-F101A), polypn~pllene ~Himon~6523) and ~raft copoly"ler were milled on a 7.62-cm X 1 7.78~m electric mill at 204~C to flux plus three minute~.
The stocks were pres~ at 204~C and 103 MPa for three minutes (Carver Press, 12.7-cm X 12.7~m X 3.175-mm mold)and at room temperature and 103 MPa for three minutes. Two graft copolyn,er~
were used in thTs exampb. Tne fTrst (Gratt Copolymer A) was a polypropylene - acrylic graft copolymer pr~pa~ecl ~rom mfr.4 polypropylene hG",opolymer (100 parts) and a 93:2:5 mixture of methyl * Tr~rk A~
.~ .

methaerylate:ethyl acrylate:methaerylie aeid (100 parts). Polymerization was done in Isopar E solvent at 1 60~C at 50% solids over one hour with a di-t-butyl peroxide radiaal flux of 0.00012. The product isolated eontained 44% aerylate. The second graft eopolymer (Graft Copolymer B) was a polypropylene - aerylie graft eopolymer prepared from mfr=4 propylene homopolymer (100 parts) and a 95:5 mixture of methyl ",ell,ac~ylate:ethyl aerylate (150 parts). roly",erization was done in Isopar E solvent at 1 55~C at 60% solids. The feed time was 60 minutes and the radieal flux was 0.00010. The product eontained 53% aerylate.
AWition of the graft copolymer results in an inerease in tensile sl,en~
and modulus.

T~RI F Xl V

Co,l,~7~i~ n of FVOH ~nrl PolYpropylene notched graft Izod tensile tensile EVAL PPcopolymer tensile strength modulus (gr~m~ r~m~) (gr~m.~) (J/m) (~P~) l~P~) 0 21 29.85 2570 51 21 48.06 3190 52 22 46.75 3270 0 18 21.37 1930 15l 18 29.79 2140 152 13 30.41 2030 1 - Graft Copolymer A (see text above).
2 - Graft Copolymer B (see text above).

While ths invention has been described with reference to specific examples and applications, other modifications and uses for the invention will be apparent to those skilled in the art without departing from the spirit and scope of the invention defined in the appended claims.

Claims (60)

1. A graft copolymer capable of imparting to a polyolefin when blended therewith a relatively high tensile modulus and high resistance to sagging without increasing melt viscosity, the copolymer comprising:
(a) an non-polar polyolefin trunk selected from the group consisting of polyethylene, polypropylene, polybutylene, poly(4-methylpentene), copolymers of said olefins with each other, and one or more copolymers of said olefins with 1-alkenes, vinyl esters, vinyl chloride, (meth)acrylic ester, and (meth)acrylic acid, said trunk having a weight average molecular weight between about 50,000 and 1,000,000; and (b) at least one methacrylate chain grafted with a covalent bond to said trunk having a weight ratio with said trunk of from about 1:9 to about 4:1, said chain being a polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain having a weight average molecular weight of from about 20,000 to 200,000.

2. A copolymer as claimed in claim 1 wherein the molecular weight of the methacrylate chain is between about 30,000 and 150,000.

3. A copolymer as claimed in claim 4 wherein the molecular weight of the trunk is about 100,000 to 400,000.

4. A copolymer as claimed in claim 1, 2 or 3 wherein the methacrylic ester is methyl methacrylate.

5. A copolymer as claimed in claim 1, 2 or 3 wherein the polyolefin trunk is polypropylene.

6. A copolymer as claimed in claim 1, 2 or 3 wherein the polyolefin trunk is polypropylene and the methacrylate chain is a methyl methacrylate polymer.

7. A polymer blend comprising:
(a) a polyolefin: and (b) a graft copolymer having a non-polar polyolefin trunk selected from the group consisting of polyethylene, polypropylene, polybutylene, poly(4-methylpentene), copolymers of said olefins with each other, and copolymers of said olefins with 1-alkenes, vinyl esters, vinyl chloride, (meth)acrylic esters, and (meth)acrylic acid, said trunk having a weight average molecular weight between about 50,000 and 1,000, 000; and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight-average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; said polyolefin (a) being the matrix for the blend.

8. The polymer blend as claimed in claim 7 wherein the blend is a concentrate comprising from about 5 to about 50% of the graft copolymer, based on the weight of the blend.

9. The polymer blend as claimed in claim 8 wherein the polyolefin trunk is polypropylene.

10. The polymer blend as claimed in claim 7 wherein the graft copolymer constitutes about 5% of the total polymer.

11. The polymer blend as claimed in claim 7 wherein the graft copolymer is between about 0.2% and 5% of the total blend.

12. The polymer blend as claimed in claim 11 wherein at least 80% of the polymer blend is polypropylene.

13. The polymer blend as claimed in claim 12 wherein the polyolefin trunk is polypropylene.

14. The polymer blend as claimed in claim 11 wherein at least 80% of the polymer blend is polyethylene.

15. The polymer blend as claimed in claim 11 wherein at least 80% of the polymer blend is polybutylene.

16. The polymer blend as claimed in claim 11 wherein at least 80% of the polymer blend is a copolymer of at least 80% propylene with ethylene.

17. The polymer blend as claimed in claim 11 including about 0.001 to about 0.05 weight percent of an alkyl polysulfide.

18. The polymer blend as claimed in claim 17 wherein the alkyl polysulfide is di-t-dodecyl disulfide.

19. The polymer blend as claimed in claim 7 wherein the blend additionally comprises ungrafted methacrylate polymer derived from at least 80% of a monomer of a methacrylic ester of formula CH2=C(CH3)COOR, wherein R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said ungrafted methacrylate polymer having a weight-average molecular weight of from about

20,000 to 200,000.

20. The polymer blend as claimed in claim 19 wherein at least 80% of the polymer blend is the ungrafted methacrylate polymer.

21. A process for preparing a graft copolymer concentrate capable of imparting to a polyolefin when blended therewith relatively high tensile modulus and high resistance to sagging without increasing the melt-viscosity, comprising the steps of:
(a) introducing a non-polar polyolefin selected from the group consisting of polypropylene, polyethylene, polybutylene, poly(4-methylpentene), copolymers of said olefins, and one or more copolymers of said olefins with one or more 1-alkenes, vinyl esters, vinyl chloride, (meth)acrylic esters, and (meth)acrylic acid into a reactor vessel containing an inert solvent, said polyolefin having a weight average molecular weight between about 50,000 and 1,000,000;

(b) heating the polyolefin mixture to a temperature at which the polyolefin dissolves;
(c) adding with agitation at least about 80%, based on the total monomer weight, of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl or substituted aryl or alkaryl and not more than about 20% based on the total monomer weight of an acrylic or styrenic monomer copolymerizable with the methacrylic ester to the polyolefin solution in the reactor vessel;
(d) adding to the mixture in the reactor vessel an initiator which produces a low and constant radical flux for a time sufficient to produce a methacrylate chain polymer having a weight average molecular weight of between about 20,000 and 200,000 which is covalently bonded to the polyolefin; and (e) removing the solvent to isolate the graft copolymer concentrate.

22. A process as claimed in claim 21 wherein the concentrate is extruded into a desired shape.

23. A process as claimed in claim 21 wherein the concentrate is blended with an additive and extruded into a desired shape.

24. A process as claimed in claim 21 wherein the methacrylic ester monomer is methyl methacrylate.

25. A process as claimed in claim 21 wherein the solvent is removed in a devolatilizing extruder.

26. A process as claimed in claim 21 wherein the solvent is a hydrocarbon solvent.

27. A process as claimed in claim 21 wherein the initiator is an oil soluble, thermal free radical initiator having a one hour half life of from about 60°C
to about 200°C.

28. A process as claimed in claim 27 wherein the initiator has a one hour half life between 90°C and 170°C.

29. A process as claimed in claim 21 wherein the constant radical flux at the temperature in the reaction vessel is between about 0.00001 and about 0.0005 equivalents of radicals per liter per minute.

30. A process as claimed in claims 28 or 29 wherein the initiator is a peroxy initiator.

31. A process for imparting to a polyolefin a relatively high tensile modulus and high resistance to sagging without increasing its melt viscosity, the process comprising blending the graft copolymer concentrate of claim 8 with the polyolefin.

32. A process as claimed in claim 31 wherein the temperature to which the polyolefin-concentrate blend mixture is heated for blending is at least 150°C, and an alkyl polysulfide is incorporated into the blend prior to heating.

33. A process as claimed in claim 32 wherein the alkyl polysulfide is di-t-dodecyl disulfide.

34. A process as claimed in claim 32 wherein the blend mixture includes 0.001 to 0.05 weight percent of the polysulfide.

35. The process as claimed in claim 31 wherein the polyolefin comprises at least 80% of the blended polyolefin and concentrate.

36. The process as claimed in claim 35 wherein the polyolefin is polyethylene.

37. The process as claimed in claim 35 wherein the polyolefin is polypropylene.

38. The process as claimed in claim 35 wherein the polyolefin is polybutylene.

39. The process as claimed in claim 35 wherein the polyolefin is a blend of polyethylene and polypropylene.

40. The process as claimed in claim 35 wherein the polyolefin is a blend of polypropylene and polybutylene.

41. An extruded, calendered or molded product using the polymer blend of any one of claims 11, 12, 13, 14, 15 or 16.

42. An extruded product in the form of a hollow tube, said product being a blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight-average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1, said polypropylene (a) being the matrix for the blend; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

43. An extruded product in the form of a fiber, said product being a blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight-average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

44. The product of claim 43 wherein the polymer of the fiber is oriented.

45. An extruded product in the form of a sheet or film, said product being a blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer have a weight average molecular weight ranging from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1;
and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

46. The product of claim 45 wherein the polymer of the film is monoaxially oriented.

47. The product of claim 45 wherein the polymer of the film is biaxially oriented.

48. A molded product in the form of a hollow container, said product being a blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight average molecular weight in the range of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

49. The product of claim 48 wherein the hollow container is formed by extrusion blow molding.

50. The product of claim 48 wherein the hollow container is formed by injection blow molding.

51. An extruded product shaped into a solid profile, said product being a blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20%of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight-average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

52. An extruded, calendered or molded product comprising a foamed blend of (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80%of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend.

53. The product of claim 52 wherein the product is further shaped into a foamed profile.

54. A polymer blend comprising (a) from about 80% to about 99.8% by weight of the total blend of polypropylene; and (b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a polypropylene trunk, said polypropylene trunk having a weight average molecular weight between about 50,000 and 1,000,000, and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1; and optionally, (c) at least one additive selected from fillers, fibers, impact modifiers, colorants, stabilizers, flame retardants, and blowing agents, and mixtures thereof, in an amount of up to 19.8% by weight of the blend, said additive constituting the balance (if any) of said blend, said at least one additive including a blowing agent, said polypropylene (a) being the matrix for said blend.

55. The polymer blend of claim 54 wherein the blowing agent is an agent which liberates nitrogen at a melt processing temperature of from about 200 to about 230°C.

56. The polymer blend of claim 55 wherein the blowing agent is present in an amount of from about 1 to about 2 weight percent of the total polymer blend.

57. The graft copolymer of claim 1 wherein the substituted alkyl group is alkyl thioalkyl.

58. The graft copolymer of claim 57 wherein the alkyl thioalkyl group is ethyl thioethyl.

59. A polymer blend comprising (a) a polyolefin;
(b) from about 0.2 to about 5% of the total blend weight of a graft copolymer having a non-polar polyolefin trunk selected from the group consisting of polyethylene, polypropylene, polybutylene, poly(4-methylpentene), copolymers of said olefins with each other, and copolymers of said olefins with l-alkenes, vinyl esters, vinyl chloride, (meth)acrylic esters, and (meth)acrylic acid, said trunk having a weight average molecular weight between about 50,000 and l,000,000; and covalently bonded to said trunk a methacrylate chain polymer derived from at least about 80% of a monomer of a methacrylic ester of the formula CH2=C(CH3)COOR, where R is alkyl, aryl, substituted alkyl, substituted aryl, or substituted alkaryl, and less than about 20% of an acrylic or styrenic monomer copolymerizable with the methacrylic ester, said methacrylate chain polymer having a weight average molecular weight of from about 20,000 to 200,000, and being present in a weight ratio with said trunk of from about 1:9 to about 4:1, and c) from about 0.001 to about 0.1% by weight of the total polymer blend of a tris(polyalkyl-hydroxybenzyl)-s- triazinetrione;
said polyolefin (a) being the matrix for said blend.

60. The polymer blend of claim 59 wherein the tris(polyalkylhydroxybenzyl)-s-triazinetrione is tris-(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-s-trriazine-(lH,3H,5H)-trione.