Patent GB-948493-A (GB)
Title: Improvements in thermoset compositions based on carboxy polymers and epoxide resins
IPC: C09D163/00
Filed: 1960-04-29
Abstract: Solvent-thinned resinous compositions which when heat-converted form thermoset non-adhesive compositions comprise (a) a polyepoxide (b) a carboxy copolymer which comprises an alpha-beta monounsaturated carboxylic acid containing up to 4 carbon atoms and a monoethylenically unsaturated monomer free of carboxyl groups which is copolymerisable therewith, the copolymer containing 1 to 30% by weight of acid, and (c) a soluble alkylated aldehyde-amine or alkylated aldehyde-amide condensate, the composition comprising 0.7 to 2 equivalents of polyepoxide per equivalent of carboxy copolymer and the amount of condensate being 5 to 50% by weight of total copolymer-polyepoxide-aldehyde condensate composition. The epoxy resin may be a glycidyl polyether of a polyhydric alcohol or phenol, e.g. bisphenol-A, or an epoxy ester, e.g. 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate and bis(3,4-epoxy-6-methylcyclohexylmethyl) suberate or it may be the diglycidyl ether of trimethylolpropane, dicyclopentadiene diepoxide, the bisepoxycyclopentyl ether of ethylene glycol or an epoxidised drying oil, e.g. epoxidised soya oil. The carboxy copolymer may be derived from acrylic, methacrylic or crotonic acid copolymerised with other monomers or mixtures of monomers which may be styrene, halostyrenes, cyanostyrene, dialkylstyrenes, isopropenyltoluene, vinylnaphthalene, a -methylstyrenes, acrylic, methacrylic and crotonic esters of saturated alcohols, acrylonitrile, methacrylonitrile or unsaturated alcohol esters of unsaturated monocarboxylic acids. Many such monomers are specified. The condensates may be alkylated aldehyde condensates of melamine, urea benzoguanamine and other aminotriazines and aminodiazines. The solvent may be mixtures of xylene, butanol, 2-ethoxyethyl acetate and/or methyl isobutyl ketone. The compositions may be cured by heating alone or in the presence of the catalysts described in Specification 948,491.  In the examples the following copolymers (in which parts are by weight) are prepared by solution polymerisation using, as a catalyst, benzoyl peroxide: 72/20/8 styrene/methyl acrylate/acrylic acid; 70/20/10 and 42/42/16 vinyltoluene/methyl acrylate/methacrylic acid; 65/20/15 and 55/20/25 vinyltoluene/ethyl acrylate/acrylic acid and 85.7/14.3 vinylacetate/crotonic acid.ALSO:Coating compositions which are solvent-thinned resinous compositions and which on heat-conversion yield thermoset non-adhesive compositions comprising (a) a polyepoxide, (b) a p carboxy copolymer which comprises an alpha-beta monounsaturated carboxylic acid containing up to 4 carbon atoms and a monoethylenically unsaturated monomer free from carboxyl groups which is copolymerizable therewith, the copolymer containing 1-30% by weight of acid, and (c) a soluble alkylated aldehyde-amine or alkylated aldehyde-amide condensate, the composition comprising 0,7-2 equivalents of polyepoxide per equivalent of carboxy copolymer and the amount of condensate being 5-50% by weight of the total polyepoxide-copolymer-condensate composition, and containing optionally a curing catalyst are drawn down in films on glass and tin plates.  The coatings are cured by heating.