Patent GB-1248972-A (GB)
Title: Stable dispersions of crosslinkable polymers
IPC: C08F2/08
Filed: 1968-10-21
Abstract: 1,248,972. Polymer dispersions. BALM PAINTS Ltd. 21 Oct., 1968 [27 Oct., 1967], No. 49732/68. Heading C3P. A stable dispersion of particles of a crosslinkable derivative of an addition polymer in an inert, substantially non-polar organic liquid in which the derivative is insoluble is prepared by (a) dispersion polymerizing an ethylenically unsaturated monomer in said inert organic liquid in the presence of a stabilizer comprising anchoring and solvating components, as described in Specification 1,143,404 or 1,231,614, to produce a dispersion of insoluble polymer having a molecular weight greater than 50,000 and containing on average at least one chemically reactive group per polymer molecule and (b) reacting with the disperse polymer so prepared at least one ethylenically unsaturated component bearing a complementary chemically reactive group, said unsaturated component being additionally an autoxidative component (i.e. a component which can be attacked by oxygen to subsequently provide free radicals to initiate addition polymerization) or a component which will enter into free radical initiated addition reactions. The organic liquid is essen tially hydrocarbon in character (aliphatic and/ or aromatic) and may optionally include a minor proportion (e.g. less than 30% by weight of total liquid) of an ester, ketone or alcohol. The monomer polymerized in step (a) may include vinyl chloride, vinyl acetate, vinylidene chloride, alkyl (meth)acrylates, di-alkyl maleates or itaconates, styrene, α-methyl styrene or vinyl toluene; to provide the reactive group(s) a monomer such as maleic anhydride (acid), itaconic acid, acid esters of maleic or itaconic acid, glycidyl (meth)acrylate, hydroxyalkyl (meth)- acrylates, (meth)acrylamide, dimethylaminoethyl methacrylate, vinylidene carbonate or N- carbamyl maleimide can be used. The unsaturated component bearing the complementary group for use in (b) may be autoxidative, e.g. an alcohol or acid bearing a chain-like entity derived from a drying oil, or a vinyl-substituted dioxolane or dioxane; or it may be an addition polymerizable compound such as (meth)acrylic acid, glycidyl (meth)acrylate, cinnamic acid, allyl alcohol or glycerol mono- or di-allyl ether. In examples, the stabilizers used are obtained by (a) condensing 12-hydroxystearic acid self polyester with glycidyl methacrylate (to form monomer A) and copolymerizing the condensation product with methyl methacrylate and methacrylic acid, (b) copolymerizing monomer A with methyl methacrylate and glycidyl methacrylate, (c) modifying the product of (b) by reaction with methacrylic acid, and (d) copolymerizing maleic anhydride and styrene, and treating the product with a secondary fatty amine (C 16 -C 18 ). The following monomers are dispersion polymerized in the examples: (1) methyl methacrylate-maleic anhydride subsequently reacted with #-hydroxyethyl methacrylate, (2) methyl methacrylate-maleic anhydride subsequently reacted with ethylene glycol monoallyl ether, (3) vinyl acetate-maleic anhydride subsequently reacted with #-hydroxyethyl acrylate and ethylene glycol monoallyl ether, (4) methyl methacrylate-glycidyl methacrylate subsequently reacted with methacrylic acid, (5) methyl methacrylate-glycidyl methacrylate subsequently reacted with tall oil fatty acid, (6) methyl methacrylate-glycidyl methacrylate subsequently reacted with tall oil fatty acid, and (7) styrene-methyl methacrylate maleic anhydride subsequently reacted with #- hydroxyethyl acrylate. The polymer dispersions are particularly useful in the production of surface-coatings.