GB1350400A - Coatings - Google Patents

Abstract

1350400 Coating compositions ROHM & HAAS CO 22 June 1971 [23 June 1970] 29111/71 Heading C3P Aqueous coating compositions comprise 30 to 70 weight per cent non-volatiles and contain (1) a binder at least 50 weight per cent of which is constituted by a water-insoluble "vinyl" addition emulsion polymer of average particle size 0À01 to 3 microns, and (2) 1 to 50 weight per cent based on the total binder solids of a waterinsoluble cationic emulsion copolymer of (i) 5 to 70 weight per cent of monoethylenically unsaturated compounds having amine and/or quaternary ammonium groups at least 50 per cent of which are in cationic form, (ii) 0 to 50 weight per cent of polyethylenically unsaturated cross-linking agent having at least two non- conjugated double bonds, and (iii) to make 100 per cent at least one monoethylenically unsaturated neutral or non-ionic monomer, the dispersion further comprising anions containing one or more of boron, chromium, molybdem or tungsten. The binder may comprise as "vinyl" polymer a vinyl, acrylic or methacrylic ester polymer or polymer of an unsaturated hydrocarbon. Further constituents of the binder may be the copolymer salt of film-forming, alkyd, aminoplast and epoxy resins, casein and starch. The copolymer salts may be derived from vinyl pyridines; and aminoalkyl ethers, thioethers, acrylates, methacrylates, acrylamides and methacrylamides; which may be quaternized before or after polymerization. The polymers may be prepared by emulsion polymerization and compounded with surfactants, antifoam agents, preservatives and pigments to provide non- staining paints. Many suitable materials are specified and examples describe aqueous dispersions of dimethylaminoethyl methacrylate/ methyl methacrylate/ethylene glycol diimethacrylate, 4-vinylpyridine/methyl methacrylate/ ethylene glycol dimethacrylate, dimethylaminoethyl vinyl sulphide/vinyl acetate/methyl methacrylate/dibutyl maleate and 2-bromoethyl methacrylate/methyl methacrylate copolymers, the third being cross-linked with diglycidyl phthalate and the last with tetramethyl ethylenediamine, quaternized with ethylene oxide, 1,4-dichlorobutene-2, benzyl chloride, methyl bromide or methyl iodide; containing counterions derived from chromic, tungstic or molybdic anhydrides, zinc dichromate, or boric acid; and the incorporation of the products in paints comprising methyl methaorylate/ butyl acrylate/methacrylic acid copolymer dispersions, surface active agents, antifoam agents, ethylene glycol, sodium salt of diisobutylene/ maleic anhydride copolymer, titanium dioxide, silica, hydroxyethyl cellulose and optionally strontium chromate or barium metaborate.