GB798604A - Improvements in or relating to liquid coating compositions - Google Patents

Abstract

A liquid coating composition, the dry coating of which is characterized by water-blister resistance, comprises an air-drying organic filmforming material and a particulate waterinsoluble polymeric reaction product of at least one polyanionic linear polymer and at least one polycationic linear polymer, combined in subsubstantially chemically equivalent amounts through a plurality of ionic cross-linkages. The term "polyanionic linear polymer" is defined as a linear polymer the anion of which is polymeric and contains a plurality of lateral substituents having anionic negative charges, e.g. polyacrylic acid or sodium polyacrylate; "polycationic linear polymer" is defined similarly with relation to cations, e.g. polymeric polyquaternary ammonium salts. Suitable polyanionic polymers are polyacrylic, polymethacrylic, polyethacrylic and poly-alpha-chloroacrylic acid, copolymers of methacrylic or acrylic acid with methyl methacrylate, vinyl acetate, styrene, 1,3-butadiene and acrylonitrile, hydrolysed copolymers of maleic anhydride with ethylene, propylene, isobutylene, styrene, vinyl acetate, vinyl chloride or methyl acrylate, polyvinylsulphonic acid, polyphosphoric acids obtained by reacting orthophosphoric acid with polymers containing epoxy groups, polymers derived from naturally occurring materials such as lignic, alginic, pectinic, arabic and polygalacturonic acids and carboxymethyl cellulose, and the sodium, potassium and ammonium salts of the above materials. Suitable polycationic polymers are the polymeric quaternary ammonium salts of beta-dimethylaminoethyl or betadiethylaminoethyl acrylate or methacrylate or of copolymers thereof with lower alkyl acrylates or methacrylates, or of beta-di-n-butyl-aminoethylmethacrylate, beta - dicyclohexylaminoethyl methacrylate, 4 - (beta - methacryloxyethyl) morpholine, 1 - (beta - methacryloxyethyl) piperidine, 2 - (diethylamino) cyclohexyl methacrylate, triethanolamine monomethacrylate and beta-dimethylaminoethylacrylate, polyvinylamines, polyvinylpyridines, polyvinylquinolines, hydrogenated 1,3-butadiene/acrylonitrile and 1,3 - butadiene/methacrylonitrile copolymers, polyamines obtained by reductive amination of ethylene/carbon monoxide copolymers, polyethyleneimine, poly-N-methylene imine, linear polyamides containing intralinear tertiary amino groups, reaction products of vinyl ketone polymers with ammonia or primary amines, polymeric amines resulting from the reaction of ammonia or an amine with a polymer containing epoxy groups, quaternary ammonium salts of the above mentioned polymers, or quaternary ammonium salts prepared by reacting alpha, omega - dihalides with N,N,N1,N1-tetraalkyl diamines or by reacting tertiary amines with halogenated polymers such as chlorinated polyvinyl toluene. The polyanionic and polycationic polymers may also contain additional functional groups, such as epoxy, hydroxy, mercapto, halogeno, carbalkoxy and amido groups, capable of bringing about covalent cross-linking between the two polymers, or covalent cross-linking may be accomplished by reaction with a polyfunctional reagent such as alkylene diahlides, aralkylene dihalides, ethylene oxide, propylene oxide, formaldehyde, dimethylolurea, dimethylolmelamine, dimethylolurea, dimercaptans and glycols. The air-drying organic film-forming material may be linseed, tung, perilla, soya or oitica oil in its natural, refined or bodied form, an alkyd resin modified therewith or with fatty acids derivable therefrom, a synthetic ester such as a drying or semi-drying oil fatty acid ester of pentaerythritol, sorbitol or an epichlorohydrin-diphenylol condensate, a gumcontaining varnish based on such synthetic esters or glyceride oils, or a drying oil polymer of butadiene-1,3. Other ingredients normally used in coating compositions may be incorporated, such as titanium dioxide, zinc oxide and magnesium silicate pigments, lead or manganese naphthenate driers, ammonium stearate or mineral spirits.