Patent ES-316120-A1 (ES)
Title: Polymer dispersions and dispersants
IPC: C08F2/08
Filed: 1965-08-04
Abstract: Dispersions of polymer particles in an organic liquid in which the polymer is insoluble are prepared by polymerizing an ethylenically unsaturated monomer in the liquid which contains a dispersion stabilizer, the latter being a polymeric substance comprising a polymeric backbone which is non-solvated by the liquid and attached thereto, on average, at least 5 side chains which are solvated by the liquid, the molecular weight of the side chains being at least 500 and the weight ratio of the attached side chains to the backbone being from 0.5: 1 to 5: 1 respectively. In the dispersion stabilizer, the side chains may be attached to the backbone by a condensation reaction involving, for example, the formation of ester, ether, amide or urethane links preferably, however, the stabilizer is formed by copolymerizing in solution in an organic solvent an ethylenically unsaturated monomer, which provides the backbone, and a chain-like macromonomer (molecular weight at least 500) having only one terminal ethylenically unsaturated group per molecule, which provides the side chains, the macromonomer being of different polarity to the resulting backbone. In examples the stabilizers are prepared by (1) copolymerizing the reaction product of 12-hydroxystearic acid dimer and glycidyl methacrylate with methyl methacrylate in a hydrocarbon solvent using benzoyl peroxide catalyst together with primary octyl mercaptan, (2) copolymerizing the reaction product of poly-12-hydroxystearic acid and glycidyl methacrylate with methyl methacrylate and methacrylic acid in ethyl/butyl acetate using azodiisobutyronitrile catalyst, (3) solution polymerizing the methacrylate ester of a commercial mixture of C8-C10 aliphatic alcohols using 4,41-azobis-(cyanovaleric acid) catalyst together with thioglycollic acid, esterifying the terminal carboxyl groups of the product with glycidyl methacrylate, and copolymerizing the ester product with methyl methacrylate and methacrylic acid in ethyl acetate using azobis(isobutyronitrile) catalyst, (4) interesterifying the terminal carboxyl group of poly-12-hydroxystearic acid with vinyl acetate (to introduce a terminal vinyl group into the polymer chain) and copolymeriizing the product with vinyl acetate and acrylic acid in ethyl/butyl acetate using azodiisobutyronitrile catalyst, (5) solution polymerizing methyl methacrylate using 4,41-azobis(cyanovaleric acid) together with thioglycollic acid, terminally esterifying as in (3), and copolymerizing the ester product with vinyl pyrrolidone, (6) copolymerizing the terminal ester product obtained in (5) with dimethylaminoethyl methacrylate using azodiisobutyronitrile catalyst. Use of some of these particular stabilizers is illustrated wherein methyl methacrylate and methacrylic acid are copolymerized in a solvent in the presence of azodiisobutyronitrile with or without primary octyl mercaptan. The stabilizer of process (4) is suitable for polymeriizing vinyl acetate in aliphatic hydrocarbon.ALSO:In Example 1, 12-hydroxystearic acid dimer is esterified with glycidyl methacrylate by refluxing in solution in an aliphatic hydrocarbon (b.p. 100-120 DEG C.) in the presence of hydroquinone (polymerization inhibitor) and a tertiary base catalyst.