| 摘要 |
1,133,328. Suspension polymerization. DOW CHEMICAL CO. 23 Feb., 1966 [1 March, 1965], No. 7850/66. Heading C3P. Vinyl monomers, e.g. styrene, are suspension polymerized by incorporating in an aq. suspension of the monomer (1) a thixotropic paste of one or more inorganic suspension stabilizing agents of average particle size 0À5 Á and water in a weight ratio of 1 : 2 to 2 : 1, the stabilizing agent being 0À1-2% by wt. of the monomer, (2) one or more surface active agents which are anionic or amphoteric having both carboxyl and amino groups in amount of 0À01-2% by wt. of the suspension and (3) a protective colloid in amount of 0À0001-0À005% by wt. of the suspension, and heating the mixture. The stabilizing agent may be tricalcium phosphate and calcium carbonate, or a phosphate of barium, boron, strontium, magnesium, aluminium, zinc or cadmium; a silicate of aluminium or magnesium, magnesium carbonate or oxide or barium oxalate or sulphate. The surface active agent may be sodium (beta-, nonyl- or butyl-) naphthalene sulphonate or the partial sodium salt of N- lauryl imino dipropionic acid or N-lauryl amino propionic acid. The protective colloid may be sodium polyacrylate. A polymerization catalyst, e.g. a mixture of benzoyl peroxide, azobisisobutyronitrile and tert. butyl peroxide may be used.
|
