| 摘要 |
1,174,877. Polymerizing vinyl chloride. MONSANTO CO. 16 Aug., 1968 [18 Aug., 1967], No. 39249/68. Heading C3P. Vinyl chloride is polymerized or copolymerized by (a) mixing water, an emulsifying agent and a redox catalyst comprising sulphate and sulphite and an activating metal ion, (b) allowing these to interact for 10 minutes to 3 hours and (c) adding monomer and polymerizing; narrow range particle size are reproducibly obtained. Emulsifiers are ammonium, sodium or potassium alkyl sulphates. The catalyst may be a mixture of ammonium, sodium or potassium persulphate with a bisulphite, sodium formaldehyde sulphoxylate, sulphur dioxide, a thiosulphite, or diethyl sulphite; the activating metal may be a trace-impurity in water. A buffer such as sodium bicarbonate is also added. The mixture is preferably heated to 40-60‹ C. for 15-45 mins. and the monomer then added. In one example a copolymer with vinyl acetate is produced.
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