| 摘要 |
1,150,488. Polymerizing vinyl chloride. SHIN-ETSU CHEMICAL INDUSTRY CO. Ltd. 22 May, 1967 [30 May, 1966], No. 23594/67. Heading C3P. Vinyl chloride is polymerized in alkaline aqueous emulsion in the presence of 0À01-5% of a suspending agent, 0À01-5% of a nonionic surfactant and 0À5-20% of an inert, organic solvent based on the weight of monomer. There may also be present comonomers such as vinyl acetate, vinyl ethers, acrylic or methacrylic acid and their esters, vinyl aromatics, olefins, maleic acid, or vinylidene halide. The suspending agent is starch, gelatine, tragacanth gum, alkyl- or hydroxyalkyl-cellulose, polyvinyl alcohol, polyacrylate, vinyl acetate-maleic acid copolymer, bentonite, talc, barium sulphate or calcium carbonate. As surfactants may be used polyoxyethylene alkyl ether, ester or alkaryl ether, sorbitan ester, polyoxyethylene-propylene glycol ether or -sorbitan ester or fatty acid monoglyceride. Suitable solvents boil below 200‹ C. and include alcohols, hydrocarbons, ketones, esters, ethers and halocarbons or halohydrocarbons. Alkaline substances are added, e.g. sodium or potassium hydroxide, carbonate or alcoholate, sodium acetate or phosphate or calcium or ammonium hydroxide; examples use a pH of 11-12À5. A peroxide or azo catalyst is used, e.g. lauroyl peroxide.
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