GB815839A - Process for making copolymers of monovinylbenzene compounds and unsaturated alkydresins - Google Patents

Abstract

Tough, mouldable resin compositions are prepared by mixing (A) 60 to 99 per cent of at least one monovinyl aromatic compound of the benzene series and (B) 40 to 1 per cent of at least one polymerizable high molecular weight linear elastic polyester having a second order transition temperature below room temperature and which is the reaction product of a minor amount of (1) an organic diisocyanate or diketene and a major amount of (2) a lower molecular weight polyester derived from (a) a mixture of dicarboxylic acids comprising an ethylene-a ,b -dicarboxylic acid and (b) excess of at least one glycol, optionally mixed with (3) a polyester derived from glycols and dicarboxylic acids free from ethylenic unsaturations, the amount of ethylene-a ,b -dicarboxylic acid being 0.0845 to 1.5 per cent by weight of the composition and 1 to 3 mole. per cent of the acids, and heating to effect polymerization. Specified monovinyl compounds are styrene, p-methylstyrene, m-methylstyrene, p-ethylstyrene, p-isopropylstyrene, 2,4 - dimethylstyrene, p - chlorostyrene, 2-chloro - 4 - methylstyrene and 2,4 - dichlorostyrene which may be partially prepolymerized. The polyesters may be derived from maleic, fumaric, citraconic, chloromaleic, adipic, b -methyl adipic, pimelic, suberic, azelaic, sebacic, phthalic and terephthalic acids or their anhydrides, acid chlorides or esters of low molecular weight monohydric alcohols, and 1,2-propylene glycol, 2,2 - dimethyl propanediol - 1,3, ethylene glycol, trimethylene glycol, hexamethylene glycol and decamethylene glycol, at least one of the reactants preferably having a branched carbon chain. The polyesters may also comprise long chain hydroxy aliphatic carboxylic acid radicals, e.g. of 12-hydroxystearic acid. Specified coupling materials are ethylene diisocyanate, trimethylene diisocyanate, tetra-methylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, meta-toluene diisocyanate, 1,5-naphthalene diisocyanate, 2,9-dimethyl - 1,9 - decadiene - 1,10 - dione, 3,10-dicarbonyl-2,11-dodecanedione and carbon sub-oxide. Preferably (B) is prepared by coupling saturated linear polyesters with polyesters containing a higher proportion of unsaturated dicarboxylic acid than the desired mean. The polymerizable compositions may contain plasticizers, mould lubricants, colouring agents, opacifiers, pearlescents and fillers and may be polymerized, optionally in the presence of nonreactive solvents and peroxy catalysts, e.g. benzoyl peroxide, cumene hydroperoxide, ascaridol and tert-butyl peroxide, on a rising temperature schedule. The compositions may be used as laminating resins, coating materials, casting and potting agents and for impregnating porous and fibrous structures.