GB1174391A - Dispersion Polymerisation. - Google Patents

Abstract

1,174,391. Polymer dispersions. IMPERIAL CHEMICAL INDUSTRIES Ltd. 20 Jan., 1967 [31 Jan., 1966], No. 4180/66. Headings C3G and C3P. A dispersion of a polymer in an organic liquid is prepared by polymerizing an ethylenically unsaturated monomer in the liquid in the presence of a stabilizing preformed amphipathic graft copolymer, comprising a polymeric component which is solvated by the liquid and a polymeric component which is non-solvated by the liquid, the copolymer being substantially free of ungrafted non-solvated component. The stabilizer may be prepared by adding a random mixture of the graft copolymer and its ungrafted non-solvatable and solvatable components to the liquid in which the dispersion is to be formed and removing the insoluble, non- solvatable component by centrifugation. Alternatively, the graft copolymer is prepared free of ungrafted components by grafting on to a polymer non-solvatable in the said liquid at least 3 polymeric chains which are solvatable, or vice versa, said grafting being carried out in a liquid in which both graft components are soluble. In Example 1, a copolymer of lauryl methacrylate and glycidyl methacrylate is reacted with methacrylic acid, prior to being grafted with a mixture of methyl methacrylate and methacrylic acid. The resulting solution is added to an aliphatic hydrocarbon medium, which is then clarified by filtration or centrifugation prior to polymerization therein of methyl methacrylate and methacrylic acid to produce a polymer dispersion. In Example 2, a methyl methacrylate-glycidyl methacrylate copolymer is reacted with thioglycollic acid and grafted with lauryl methacrylate, the resulting graft copolymer being employed as a stabilizer as in Example 1. The graft copolymer in Example 3 is produced by grafting hydroxyethyl methacrylate on to a styrene-glycidyl methacrylate copolymer reacted with methacrylic acid and is used as a stabilizer in the production of a dispersion of polystyrene. In Example 4, a methyl methacrylate-methacrylic acid copolymer is reacted with glycidyl methacrylate, grafted with lauryl methacrylate and used in the production of a dispersion of methacrylic acidmethyl methacrylate copolymer by a two-stage process employing azobisdiisobutyronitrile as catalyst and octyl mercaptan as modifier. Similarly, copolymer dispersions are produced in Examples 5 to 7, the graft copolymer stabilizers employed being (5) a methyl methacrylateundecenyl methacrylate copolymer grafted with lauryl methacrylate, (6) as in Example 2 and (7) a methyl methacrylate-methacrylyl chloride copolymer treated with ultra-violet light, tertiary butyl peroxide and pyridine prior to grafting with 2-ethylhexyl acrylate. In Example 8, a vinyl acetate-glycidyl methacrylate copolymer is reacted with acrylic acid and grafted with vinyl octoate, the resulting copolymer being employed as stabilizer in the production by a two-stage process of a dispersion of vinyl acetate-acrylic acid copolymer in aliphatic hydrocarbon.