GB925038A - Water-soluble coating compositions - Google Patents

Abstract

A water-soluble resinous composition capable of air-drying into water-insoluble form comprises a water-soluble salt of the reaction product of a drying oil, maleic anhydride, acrylic and/or methacrylic acid and at least one ethylenically unsaturated monomer which is free from carboxylic acid and anhydride groups. The salts may be formed from an alkali metal or ammonium hydroxide or an amine e.g. diethylamine, dimethylamine, triethanolamine, ethylene diamine, triethylamine, morpholine, 2-amino-gamma-methyl-1-propanol and di-isopropylamine. Drying oils specified are linseed, soya, dehydrated castor, safflower and tall oils. Specified monomers are vinyl toluene, styrene, alpha C1-4 alkyl styrenes, alkyl acrylates and methacrylates and mixtures thereof. The preferred procedure is to react the oil and maleic anhydride and then to add the acid and monomer, preferably incrementally. The formation of the reaction product may be catalysed by benzoyl or di-t-butyl peroxide or cumene hydroperoxide. Neutralisation is usually effected by adding the base in aqueous solution which may also include glycol monoethyl ether or ethyl, butyl or amyl alcohol. The resulting aqueous composition may include an air-drying catalyst e.g. cobalt or lead naphthenate, which is usually added with a wetting agent, and may be used to coat wood, paper, metals and alloys e.g. steel, aluminium and tinplate, fabrics, and films of synthetic thermo-plastic or setting material e.g. polyethylene glycol terephthalate.ALSO:A water-soluble resinous composition capable of air-drying into water-insoluble form comprises a water-soluble salt of the reaction product of a drying oil, maleic anhydride, acrylic and/or methacrylic acid and at least one ethylenically unsaturated monomer which is free from carboxylic acid and anhydride groups. The salts may be formed from an alkali metal or ammonium hydroxide or an amine, e.g. diethylamine, dimethylamine, triethanolamine, ethylene diamine, triethylamine, morpholine, 2-amino-gamma-methyl-1-propanol and di-isopropylamine. Drying oils specified are linseed, soya, dehydrated castor, safflower and tall oils. Specified monomers are vinyl toluene, styrene, alpha C1-4 alkyl styrenes, alkyl acrylates and methacrylates and mixtures thereof. The preferred procedure is to react the oil and maleic anhydride and then to add the acid and monomer, preferably incrementally. The formation of the reaction product may be catalysed by benzoyl or di-t-butyl peroxide or cumene hydroperoxide. Neutralization is usually effected by adding the base in aqueous solution which may also include glycol monoethyl ether or ethyl, butyl or amyl alcohol. The resulting aqueous composition may include an air-drying catalyst, e.g. cobalt or lead naphthenate, which is usually added with a wetting agent, and may be used to coat wood, paper, metals and alloys, e.g. steel, aluminium and tinplate, fabrics, and films of synthetic thermoplastic or setting material, e.g. polyethylene glycol terephthalate.