Patent GB-832111-A (GB)
Title: Improvements in or relating to coating compositions
IPC: C08L61/00
Filed: 1957-10-08
Abstract: A coating composition comprises a mixture of an aqueous dispersion of a copolymer of (1) 20 to 70 parts by weight of at least one vinyl benzene monomer, (2) 1 to 20 parts by weight of at least one a -olefinic monocarboxylic acid with a methylene group double-bonded to the a -carbon atom, and (3) an ester of an a -olefinic monocarbonylic acid as in (2) with a saturated aliphatic monohydric alcohol of from 1-8 carbon atoms in an amount to make up 100 parts of a monomer mixture, and for each 100 parts by weight of copolymer, from 5 to 300 parts of a water-dilutable heat-reactive formaldehyde condensation resin. The monomers are dispersed in water polymerized and the formaldehyde resin added.  Styrene, a -methyl styrene, and vinyl toluene; acrylic and methacrylic acids, a -ethyl, a -propyl, a -isopropyl and a -butyl acrylic acids; and methyl, ethyl, propyl, isopropyl, butyl, octyl, 2-ethyl hexyl, cyclohexyl, methyl a -ethyl and butyl a -ethyl acrylates and methyl, ethyl, and butyl methacrylates are mentioned.  The formaldehyde resins include phenol, urea, melamine, and urea/melamine formaldehyde resins and coalescing agents such as tetramethylene sulphone, cyclic ethylene carbonate, dimethyl formamide, dimethyl acetamide, alkyl monoethers of ethylene glycol or diethylene glycol and diacetone alcohol; plasticizers; stabilizers; extenders and pigments such as titanium dioxide, zinc oxide, calcium metasilicate, barytes and china clay may be added. Storage stability is improved by the adjustment of pH to at least 7 by a neutralizing agent.  The compositions may be used as an impregnant or a protective, insulating or primer coating applicable to wood, fibres, and sheet metal such as aluminium, copper and bonderized steel.  The coatings are dried and cured at temperatures up to 600 DEG  F.  In examples, bonderized steel sheet was flow coated or spray-coated and baked for 20 minutes at 350 DEG  F. and 30 minutes at 300 DEG  F., respectively, and second-coated with a white alkyd enamel or an enamel with a vehicle containing 70% non-drying oil alkyd and 30% butylated urea-formaldehyde resin which was in turn baked for 30 minutes at 300 DEG  F., to give a combined coating of excellent crack, abrasion and scratch resistance.ALSO:A coating composition comprises a mixture of an aqueous dispersion of a copolymer of (1) 20 to 70 parts by weight of at least one vinyl benzene monomer, (2) 1 to 20 parts by weight of at least one a -olefinic monocarboxylic acid with a methylene group double bonded to the a -carbon atom and (3) an ester of an a -olefinic monocarboxylic acid as in (2) with a saturated aliphatic monohydric alcohol of from 1-8 carbon atoms, in an amount to make up 100 parts of a monomer mixture, and for each 100 parts by weight of copolymer, from 5 to 300 parts of a water-dilutable heat-reactive formaldehyde condensation resin. The monomers are dispersed in water, polymerized and the formaldehyde resin added.  Styrene, a -methyl styrene, and vinyl toluene; acrylic and methacrylic acids, a -ethyl, a -propyl, a -isopropyl and a -butyl acrylic acids; and methyl, ethyl, propyl, isopropyl, butyl, octyl, 2-ethyl hexyl, cyclohexyl, methyl a -ethyl and butyl a -ethyl acrylates and methyl, ethyl and butyl methacrylates are mentioned and the polymerization is carried out at elevated temperatures in aqueous emulsion containing dispersing agents such as sodium lauryl sulphate, polyoxyethylene and polyoxypropylene, colloidal silica, non-ionic organic phosphates and magnesium montmorillonite clay; and catalysts such as sodium bisulphite and potassium persulphate, inorganic and organic peroxides and salts of inorganic peroxides and azonitriles.  The formaldehyde resins include, phenol, urea, melamine and urea-melamine formaldehyde resins and coalescing agents such as tetramethylene sulphone, cyclic ethylene carbonate, dimethyl formamide, dimethyl acetamide, alkyl monoethers of ethylene glycol or diethylene glycol and diacetone alcohol, plasticizers, stabilizers, extenders and pigments such as titanium dioxide, zinc oxide, calcium metasilicate, barytes and china clay may be added.  Storage stability is improved by the adjustment of pH to at least 7 by a neutralizing agent such as ammonia, monoethanolamine, triethanolamine, n-butyl amine, methyl, dimethyl and trimethyl amine, morpholine, and picoline.  The compositions are applied as coatings or impregnants by conventional methods and may be dried and cured at temperatures up to 600 DEG  F.