| 摘要 |
1,194,260. Polymerizing vinyl chloride. A.C.S.A. APPLICAZIONI CHIMICHE S.p.A. 25 Sept., 1967 [24 Sept., 1966 (2); 13 April, 1967], No. 43592/67. Heading C3P. Vinyl chloride is polymerized or copolymerized in bulk (including the use of minor amounts of diluent) at below 0‹ C. in the presence as catalyst of (a) an organic hydroperoxide, (b) sulphur dioxide and (c) an alcoholate of a Group I or II metal or aluminium and a C 1 -C 6 linear or branched chain alkanol in which the molar ratio RO: SO 2 is not greater than 2. The hydroperoxide is used in an amount of 0À01- 3% by wt. of monomers, sulphur dioxide up to 3% such that the molar ratio to hydroperoxide is 15: 1 to 1: 15 and the alcoholate 0À01-5%. The alcoholate is added in solution, preferably also containing the sulphur dioxide e.g. in an alcohol, nitrile, chloroalkane, ester or tetrahydrofuran. A minor amount of a hydrocarbon or halohydrocarbon diluent may be added. Comonomers used in examples are methyl acrylate and vinyl acetate. Products have a degree of sydiotacticity above 1.8 and a Tg value above 95‹ C. and have a sulphonic acid end group. |
