GB1297983A - - Google Patents

Abstract

1297983 Cellular vinyl chloride polymers PRODUITS CHIMIQUES PECHINEYSAINT-GOBAIN 17 April 1970 [18 April 1969] 18534/70 Heading C3C Cellular vinyl chloride polymers are made by mixing at least one vinyl chloride polymer with a blowing agent consisting of at least one nitrogen-containing compound of the formula in which X is an oxygen or sulphur atom or an imino group; R 1 is a hydrogen atom or a C 1-6 alkyl or C 2-5 acyl group, or a substituted or unsubstituted carbamoyl group; R 2 is a hydrogen atom or a C 1-6 alkyl group and R 3 is a hydrogen atom, a C 1-6 alkyl or C 2-5 acyl group, a substituted or unsubstituted carbamoyl group, or a saturated C 2-6 aliphatic ester group, and at least one compound selected from C 3-10 saturated straight or branched chain aliphatic acids which may or may not be substituted by one or more cyano, chloro, bromo, aryl, aryloxy or chloroaryloxy radicals, and C 3-18 saturated cycloaliphatic acids, and anhydrides of either of said classes of acids, and gelling, shaping and expanding the polymer(s), the operations being carried out in the absence of any other blowing agent and in any order, provided that any combination thereof may be carried out simultaneously and that the expansion must take place in a final stage. In examples mixtures of polyvinyl chloride and/or a vinyl chloride/vinyl acetate copolymer with zinc oxide, butylbenzyl phthalate, dibasic lead sulphate, phosphite or stearate, tribasic lead sulphate, dioctyl phthalate, ethylene glycol methacrylate, cumene hydroperoxide and/or cadmium and zinc octoates were made cellular by expanding with a blowing agent comprising urea, biuret or acetylurea together with adipic, malonic, succinic, dodecanedioic or propionic acid or succinic anhydride.