Rubber-modified dicarboxylic acid imide copolymers

Claim 1

A process for preparing a rubber-modified copolymer comprising (a) 5 to 40 weight percent of an elastomer and (b) 95 to 60 weight percent of a copolymer containing from 1 to 50 mole percent of an imide derivative of an ethylenically unsaturated dicarboxylic acid and 99 to 50 mole percent of one or more monomers copolymerizable therewith, said process comprising: a. forming an aqueous suspension of (1) a rubbermodified copolymer comprising (a) 5 to 40 weight percent of an elastomer selected from the group consisting of homopolymers of conjugated 1,3-dienes, copolymers of said 1,3-dienes with up to 50 mole percent of one or more monoolefinically unsaturated monomers copolymerizable therewith, ethylenepropylene-diene terpolymer rubbers, acrylate-diene copolymer rubbers, and mixtures thereof, and (b) 95 to 60 weight percent of a copolymer in discrete particulate form containing 1 to 50 mole percent of a dicarboxylic moiety selected from the group consisting of an ethylenically unsaturated dicarboxylic acid, an ethylenically unsaturated dicarboxylic anhydride and an ethylenically unsaturated dicarboxylic acid half acid derivative, and mixtures thereof and 99-50 mole percent of one or more monomers copolymerizable therewith selected from the group consisting of a vinyl aryl monomer, an aliphatic alpha-monoolefin, an alkyl vinyl ether, a conjugated diolefin, an unsaturated nitrile, an acrylic monomer and mixtures thereof and (2) aqueous ammonia or an aqueous amine selected from the group consisting of alkyl amines having 1 to 4 carbon atoms in the alkyl group, allyl amine, ethanolamine, aniline, benzylamine, α,ω-alkylene diamines having 2 to 6 carbon atoms in the alkylene group, and arylene diamines in an amount sufficient to react stoichiometrically with the dicarboxylic moiety; b. heating said suspension with agitation in a closed system at a temperature of between 125° and 200° C. at autogenous pressure for 0.5 to 48 hours to allow reaction between the ammonia or amine and the dicarboxylic moiety; and c. separating the rubber-modified copolymer in discrete particulate form from the aqueous medium.