Patent GB-925856-A (GB)
Title: Coating compositions
IPC: C09D125/14
Filed: 1961-10-13
Abstract: Surfaces may be sprayed with an organic solvent solution of (A) a solution copolymer derived from (1) 10 to 50% by weight of monoethylenically unsaturated ester having at least one terminal aliphatic hydrocarbon chain of 6 to 20 carbon atoms, (2) 10 to 60% by weight of styrene and or vinyltoluene and (3) monoethylenically unsaturated carboxylic acid in an amount providing from 4 to 23,5 equivalents per cent of free carboxyl, any balance of the copolymer being derived from other ethylenically unsaturated monomer; (B) an epoxy compound having at least one terminal 1,2-epoxy group or having at least one alicyclic ring containing at least one 1,2-epoxy group, in an amount providing at least 0,2 epoxy equivalents per carboxyl in (A); and (C) 3 to 15% by weight of (A) and (B) of a C3 to C8 alkylated urea-formaldehyde resin.  The coatings are cured by baking and are recoatable.  They may contain pigments, e.g. titanium dioxide.ALSO:Coating compositions comprise a solution of (1) a solution copolymer derived from (a) 10 to 50% by weight of monoethylenically unsaturated ester having at least one terminal aliphatic hydrocarbon chain of 6 to 20 carbon atoms, (b) 10 to 60% by weight of styrene and/or vinyltoluene and (c) monoethylenically unsaturated carboxylic acid in an amount providing from 4 to 23,5 equivalents per cent of free carboxyl, any balance of the copolymer being derived from other ethylenically unsaturated monomer; (2) epoxy compound having at least one terminal 1,2-epoxy group or having at least one alicyclic ring containing at least one 1,2-epoxy group, in an amount providing at least 0,2 epoxy equivalents per carboxyl in (1); and (3) 3 to 15% by weight, based on the combined weight of (1) and (2), of the solvent soluble reaction product of urea and formaldehyde reacted with a C3 to C8 alcohol, in an organic solvent. The copolymer (1) may be derived from (a) esters such as 2-ethylhexyl acrylate and vinyl 2-ethylhexoate; (c) acids such as acrylic and maleic acids or monoesters of dicarboxylic acids, such as monobutyl maleate and (d) other monomers such as methyl methacrylate by solution polymerization in the presence of chain terminating agents, such as mercaptans, and free radical producing catalysts such as peroxides, hydroperoxides and N,N-azodiisobutyronitrile.  Many monomers and catalysts are specified.  Many epoxy compounds are specified including mono-epoxides such as styrene oxide and phenyl glycidyl ether and polyepoxides such as glycidyl polyethers of polyhydric phenols, phenol-aldehyde condensates and polyhydric alcohols, butadiene dioxide, vinylcyclohexene dioxide, poly(allyl glycidyl ether), copolymers including a proportion of glycidyl acrylate, glycidyl methacrylate or allyl glycidyl ether with various acrylate or methacrylate esters or other copolymerizable monomers, and 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate.  Many solvents are specified both for the solution polymerization reaction and for the compositions including hydrocarbons such as benzene and methylnaphthalene, alcohols such as ethanol, ketones such as acetone, esters such as ethyl acetate, ether alcohols such as ethylene glycol monoethyl ether, butyrolactone, and diacetone alcohol.  Mixtures of such solvents may also be used.  The compositions may also contain additives such as titanium dioxide, petrolatum and polyethylene wax. Coatings produced from the compositions are cured by baking and are recoatable.  Examples are given of the compositions and of the preparation of the copolymers.