| 摘要 |
1363432 Vinyl ester copolymer compositions IMPERIAL CHEMICAL INDUSTRIES Ltd 17 Nov 1971 [25 Nov 1970] 56071/70 Heading C3P An aqueous dispersion of a random copolymer of monomers (a) 50 to 95% by weight of a vinyl ester of a saturated C 1 -C 18 aliphatic monocarboxylic acid, e.g. vinyl acetate, (b) 5 to 45% by weight of a C 2 -C 12 alkyl ester of acrylic or methacrylic acid (e.g. ethyl, butyl or 2 ethyl hexyl acrylate and (c) 0À5 to 8% by weight of a glycidyl ester of a monocarboxylic ethylenically unsaturated acid (e.g. glycidyl acrylate or methacrylate), the weight per cent of monomers being based on the total weight of monomers used, is prepared by the emulsion polymerization of not more than 10% by weight (based on total monomer weight) of monomer (a) or a mixture of monomers (a) and (b) to form a primary dispersion which is further co-polymerized by emulsion polymerization with a mixture of the remaining monomers. Not more than 2% by weight of an ethylenically unsaturated carboxylic acid (e.g. acrylic acid) may also be present in the monomer mixture. Anionic surfactants and colloids, e.g. polyvinyl alcohol or hydroxyethyl cellulose may be present. The dispersions may be used as coating compositions. In the examples a seed dispersion of polyvinyl acetate is prepared to which is added simultaneously (a) a mixture of vinylacetate, 2-ethylhexylacrylate and glycidylmethacrylate to acrylic acid and (b) a mixture of water, ammonium nonyl phenol polyglycol ether sulphate, a condensate of ethylene oxide with nonyl phenol, ammonium persulphate and sodium tetraborate to give a dispersion of pH 5À5 of a polymer of 0À3 Á particle size. Also in comparative examples the glycidyl methacryl. ate was omitted or added after the other monomers. The product dispersions, adjusted to pH 8-9 with NH 3 and containing TiO 2 were applied to hardboard. |
