| 摘要 |
A water-insoluble monomer which contains at least one C=C bond and water are emulsified with 0.1-30% of emulsifier to a reversed emulsion of the water-in-oil type which is then dispersed in an aqueous medium and the dispersion is polymerized with 0.1-5% of a free radical catalyst. The monomer may be styrene, an ester of methacrylic or acrylic acid with an aliphatic saturated C1-6 monohydric alcohol, styrene alkylated in the nucleus or side chains, vinyl acetate or propionate or butyrate, vinyl or vinylidene chloride, isoprene, 2,3-dimethyl butadiene or chloroprene. The monomers may be cross-linked with divinylbenzene, glycol dimethacrylate, hexahydro-triacrylyl-1, 3, 5- triazine, triallyl cyanurate or maleic acid-ethylene or butylene glycol polyesters, or copolymerized with each other or maleic acid cyclohexyl semiester or fumaric diester. The monomers may be used in bulk or in an organic solvent immiscible with water. The ratio of monomer to water may be from 100:5 to 1:80 and of emulsion to aqueous phase may be from 3:1 to 1:50. The emulsifier may be an alkaline earth or alkali metal salt of a C12-20 fatty acid, or a polymer obtained by grafting 1-50 parts of a monovinyl compound, e.g. styrene, vinyl esters, acrylates or methacrylates, with 1-2 parts of a poly-alkylene oxide of molecular weight at least 500, a reaction product of a copolymer of an a , b -ethylenically unsaturated dicarboxylic acid or its semi-ester and an alkylene oxide wherein at least 10% of the carboxyl groups are esterified, fatty acid esters, non-ionic emulsifiers. The free radical catalyst may be Redox systems containing persalts or H2O2 and sulphur compounds or amines, nitrogen compounds, peroxides, hydroperoxides. The dispersing agent may be polyvinyl alcohol, styrene-maleic acid copolymers, carboxymethyl cellulose or Mg(OH)2. Specification 928,621 is referred to. |
