GB1301587A - - Google Patents

Abstract

1301587 Cellular vinyl chloride polymers PRODUITS CHIMIQUES PECHINEYSAINT-GOBAIN 17 April 1970 [18 April 1969] 18533/70 Heading C3C A cellular vinyl chloride polymer is 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; R 3 is a hydrogen atom or a C 1-6 alkyl or C 2-5 acyl group, a substituted or unsubstituted carbamoyl group, or a saturated aliphatic ester group containing not more than 6 carbon atoms, and at least one compound selected from straight and branched chain C 3-12 unsaturated aliphatic acids which have an α or # ethylenic or acetylenic bond and which may or may not be substituted by one or more halogen atoms or phenyl or phenoxy groups, and C 6-12 aromatic acids which may or may not be substituted by one or more halogen atoms, and anhydrides of either of said classes of acids, 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 the examples mixtures of polyvinyl chloride and/or vinyl chloride-vinyl acetate copolymer with zinc oxide, butylbenzyl phthalate, di- or tri-basic lead stearate, cadmium octoate, zinc octoate, dioctyl phthalate, dibasic lead phosphite, tribasic lead sulphate, ethyleneglycol dimethacrylate and/or cumene hydroperoxide were made cellular by expanding with a blowing agent comprising urea, biuret or acetylurea together with maleic, fumaric, acrylic, crotonic or benzoic acids, or maleic or phthalic anhydrides.