| 摘要 |
1,241,704. Vinyl halide polymers. STAUFFER CHEMICAL CO. 10 Oct., 1968 [7 Nov., 1967], No. 48021/68. Heading C3G. A vinyl halide polymer is prepared by freeradical polymerization of a monomer composition containing at least 50% by weight of a monomer of formula wherein Z is hydrogen or halogen and Hal means halogen, in the presence of (1) an aliphatic mercaptan compound in an amount based on -SH equivalence of from 0.000075 to 0.05 equivalence -SH per mole of monomer in said monomer composition and (2) from 0.01 to 1% by weight based on the total weight of monomer in said composition of a polymerizable, organosolvent soluble, unsaturated diene elastomer. The diene elastomer is a natural or synthetic rubber containing at least 3 carbon-carbon double bonds per molecule. In Examples 1 to 13 and 19, vinyl chloride is polymerized in an aqueous suspension containing a styrene-butadiene copolymer and a blend of pentaerythritol tetra, tri, di and mono (3-mercaptopropionate)s. Similar processes are employed in the other examples, in which the mercaptan and diene elastomer are as follows: (14) trimethylolpropane tri(3-mercaptopropionate) and polybutadiene, (15) tetramercaptopentaerythritol and hydroxyl-terminated liquid polybutadiene, (16) 1,3,5-trimercaptocyclohexane and butadiene-acrylonitrile copolymer, (17) dipentaerythritol hexa(3-mercaptopropionate) and isobutylene-butadiene copolymer, and (18) polyvinyl thiol and styrene-butadiene-acrylonitrile copolymer.
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