Patent GB-1231614-A (GB)
IPC: C08L33/02
Filed: 1968-07-02
Abstract: 1,231,614. Polymer dispersions. BALM PAINTS Ltd. 2 July, 1968 [6 July, 1967], No. 31475/68. Headings C3G and C3P. Stabilized dispersions of particles of synthetic polymer is an inert organic liquid in which the polymer is insoluble are prepared by forming the particles in the liquid in the presence, in solution in the liquid, of a polymeric stabilizer comprising an anchoring component which associates with the particles of disperse polymer and a solvated component which provides a stabilizing steric barrier around the particles; and reacting the stabilizer with the particles of polymer in order to covalently link the stabilizer to the polymer. The covalent links between stabilizer and polymer can be produced by (a) copolymerization of ethylenically unsaturated groups in the monomer from which the polymer is derived and in the stabilizer, (b) reaction between chemically reactive groups in the stabilizer and complementary reactive groups in the polymer, or (c) reaction between chemically reactive groups in a bridging compound and complementary reactive groups in the stabilizer and the polymer. Coalesced films can be formed from the polymer dispersions at temperatures below the glass transition temperature of the polymer. Preferably the disperse polymer is an addition polymer derived from one or more ethylenically unsaturated monomers, e.g. vinyl chloride, vinylidene chloride, vinyl acetate, alkyl (meth)acrylates, diesters of maleic or itaconic acid, styrene, α- methylstyrene and vinyltoluene, and, where required, also from reactive monomers, e.g. maleic acid or anhydride, itaconic acid, acid esters of maleic or itaconic acid, glycidyl (meth)- acrylate, hydroxyalkyl (meth)acrylates, (meth)- acrylamide, dimethylaminoethyl methacrylate, vinylidene carbonate and N-carbamylmaleimide. Suitable stabilizers are described in Specifications 1,123,611, 1,122,397 and 1,143,404. The inert liquid may optionally include a component which is a solvent or plasticizer for the disperse polymer and has lower volatility than the non-solvent. The dispersions may optionally include pigments, thickeners, pigment dispersants and light-degradation stabilizers. In examples the following polymer dispersions are prepared in aliphatic hydrocarbon non- solvents: (a) polymethyl methacrylate using a copolymerizable stabilizer obtained by condensing poly(12-hydroxy-stearic acid) with glycidyl methacrylate, copolymerizing the condensate with methyl methacrylate and glycidyl methacrylate and treating the copolymer product with methacrylic acid; (b) methyl methacrylate/ butyl methacrylate/glycidyl methacrylate terpolymer using as stabilizer either (i) a copolymerizable stabilizer as used in (a) or (ii) a chemically reactive stabilizer which is the untreated copolymer product of the condensate, methyl methacrylate and glycidyl methacrylate as described in (a) in conjunction with hexamethylene diamine as reactive bridging agent; (c) methyl methacrylate/maleic anhydride copolymer using a chemically reactive stabilizer, which is similar to stabilizer (ii) in (b) except that the condensate is copolymerized with methyl methacrylate and maleic anhydride, in conjunction with ethylene glycol or hexamethylene-diamine as reactive bridging agent; (d) methyl methacrylate/# -hydroxyethyl methacrylate copolymer using either (i) a reactive stabilizer which is a copolymer of the condensate described in (a) with methyl methacrylate and #-hydroxyethyl methacrylate, in conjunction with toluene diisocyanate as reactive bridging agent or (ii) a reactive stabilizer which is the reaction product of a stabilizer as used in (b)(ii) and methylamine, in conjunction with toluene diisocyanate as reactive bridging agent.