| 摘要 |
1,125,728. Graft polymer compositions. KANEGAFUCHI CHEMICAL INDUSTRY CO. Ltd. 12 Nov., 1965 [25 Jan., 1965], No. 48141/65. Heading C3G. A thermoplastic polymeric composition is prepared by a method comprising the steps of: I-adding (a) from 0À5 to 10 parts by weight of a formaldehyde-sulphoxylic salt and (b) 0À01 to 3 parts of a peroxidic compound, before the stage at which the polymerization of methyl methacrylate with the butadiene polymer particles is substantially completed, to an aqueous dispersion containing from 20 to 70 parts of a butadiene polymer and a supplemental additional emulsifier if necessary, which polymer comprises at least 50% of butadiene and consists of particles more than 80% of which are less than 0À2 micron in diameter, II-adding monomeric methyl methacrylate and substantially completely polymerizing the same with the butadiene polymer, III-adding to the resulting product a vinyl aromatic compound in monomeric form and polymerizing it to form an interpolymer, and IV-blending the interpolymer with a vinyl chloride polymer or vinyl copolymer which contains more than 70% of vinyl chloride and less than 30% of monoolefinic compounds copolymerized therewith to form the thermoplastic composition, the sum of the monomeric materials being equal to from 80 to 30 parts by weight, of which the methyl methacrylate accounts for from 10 to 80% and the vinyl aromatic monomer accounts for from 90 to 20%, the monomeric methyl methacrylate being added while more than 80% of the butadiene polymer particles are below 0À2 micron in size. An additional amount of peroxidic compound may be added in step III. Suitable sulphoxylic salts are zinc and sodium formaldehyde sulphoxylates. The preparation of compositions comprising (1) a butadiene-styrene rubber grafted with methyl methacrylate and styrene and (2) polyvinyl chloride or a vinyl chloride-vinyl acetate copolymer and, optionally, tin mercaptide and butyl stearate is described, the peroxidic compound used being cumene hydroperoxide or isopropylbenzene hydroperoxide. |
