Patent GB-834346-A (GB)
Title: Impact-resistant synthetic resinous compositions
IPC: C08L25/00
Filed: 1957-09-20
Abstract: An impact-resistant synthetic resinous composition comprises a polymer derived from ethylenically-unsaturated material, which is hard at room temperature and 3 to 50% by weight of a substantially saturated cross-linked polymer, derived from ethylenically unsaturated material, which is rubber-like at room temperature. Hard polymers specified are those of styrene, vinyl chloride, vinyl acetate, cyclohexyl and decalyl vinyl ethers, acrylonitrile, methyl, decalyl and cyclohexyl methacrylates and chlorbutyl, hexyl and decalyl acrylates, in particular polymers of styrene and its alkyl and halogen derivatives and copolymers of styrene with methyl methacrylate or acrylonitrile.  Rubber-like polymers specified are those of isobutylene and acrylic esters and vinyl ethers derived from alcohols such as ethyl, propyl, n-butyl, isobutyl, amyl, hexyl and ethylhexyl alcohols, the methyl, ethyl, propyl, n-butyl, isobutyl and ethylhexyl monoethers of ethylene, propylene, butylene and hexamethylene glycols and copolymers of such monomers with each other or with styrene or acrylonitrile.  The rubber-like polymers may be obtained in cross-linked form either (a) by the use in the preparation of the polymer of a small quantity of a poly-unsaturated comonomer, such as the divinyl ethers of ethylene, propylene, butylene and hexamethylene glycols, the diacrylic and dimethacrylic esters of the above glycols, divinyl benzene, diallyl fumarate, allyl methacrylate, diallyl phthalate and oxalate and triallyl cyanurate, or (b) by the use of rubber-like polymers containing reactive groups which are used in a cross-linking reaction, such groups being introduced either by copolymerization with small amounts of monomers containing such groups, such as acrylic and methacrylic acids, acrylamide, methacrylamide, maleic anhydride, 1,4-butane - diol monoacrylate, 1,4 - butane - diol monovinyl ether and isocyanato-alkyl, aminoalkyl and epoxyalkyl acrylates and vinyl ethers, or by chemical after-treatment of the polymers, for example by the partial saponification of acrylate or vinyl ester polymers. Where the rubber-like polymer contains reactive groups cross-linking may be effected by means of (i) an appropriate polyfunctional agent such as a polybasic acid, a polyhydric alcohol, a polyester with a high hydroxyl number or a polyisocyanate, (ii) the use of a mixture of rubber-like polymers containing complementary reactive groups, or (iii) by the use of a hard polymer which contains groups capable of reacting with the groups in the rubber-like polymer.  The resultant cross-linked products may be rendered thermoplastic by mechanical degradation at elevated temperature. The mixtures of polymers may be made by mixing the preformed polymers of by mixing the rubber-like polymer with the monomer or monomers forming the hard polymer, polymerization then being effected by bulk, solution, bead or emulsion techniques.  In addition to describing the preparation of the above-mentioned polymer mixtures the examples describe also the preparation, by various means, of the hard and the rubber-like polymers. Specification 759,860 is referred to.