Patent GB-761928-A (GB)
Title: Acrylic interpolymers and coating compositions containing same
IPC: C09D133/20
Filed: 1954-07-13
Abstract: Interpolymers are made by subjecting to polymerizing conditions in an aqueous medium a mixture comprising, for a total of 100 parts: (1) 30-80 parts of acrylonitrile; (b) 2-15 parts of an alpha-olefinic monocarboxylic acid selected from the group consisting of acrylic, methacrylic, ethacrylic, phenyl acrylic and crotonic acids; (c) 15-65 parts of an ester of an acid of the above group with a saturated aliphatic monohydric alcohol of 1 to 8 carbon atoms, and optionally (d) 1-25 per cent, per 99-75 per cent of (a), (b) and (c), of allyl glycidyl ether or an ester of 2,3-epoxypropanol-1 with one of the above olefinic monocarboxylic acids.  Polymerization may be carried out in the presence of a catalyst such as a mixture of potassium persulphate and sodium bisulphite, inorganic and organic peroxides and azonitrile catalysts, emulsifiers such as sodium "Lorol" (Registered Trade Mark) sulphate, and chain terminators such as dodecyl mercaptan. At the end of the polymerization reaction the heated interpolymer dispersions may be freed from residual monomer, and also concentrated, by blowing with air.  The aqueous interpolymer dispersions are used as coating compositions, for which purpose they are preferably rendered alkaline by the addition of ammonia or an amine.  The dispersions may be modified by the addition of pigments such as titanium dioxide, coalescing agents such as dimethyl formamide, dimethyl acetamide, ethylene carbonate, tetramethylene sulphone, alkyl monoethers of ethylene glycol or diethylene glycol, and diacetone alcohol, and other resinous filmformers, in particular water-dilutable thermosetting resins such as phenol/formaldehyde, urea/formaldehyde, urea - melamine/formaldehyde, melamine/formaldehyde and acetone/formaldehyde resins.  The interpolymer coating compositions may be used as wire enamels, sidewall tyre paints, as coatings to metallic and non-metallic substrates and in coating flexible substrates of rubber, leather, paper and textile fabrics. After application the coatings may be heated to effect coalescence of the interpolymer particles, the curing of any heathardenable aldehyde resin present, and, in the case of interpolymers derived from glycidyl monomers, cross-linking by reaction between the epoxy groups and carboxyl groups present in the interpolymer.  Coating compositions containing interpolymers not derived from glycidyl monomers may be modified with cross-linking agents capable of reacting with the carboxyl groups of the interpolymers such as glycerine, diamines, polyvinyl alcohol, vinyl cyclohexene diepoxide, an epoxy polyether resin derived from bisphenol and epichlorhydrin, and imidobisisopropylamine.ALSO:Metal surfaces are coated by applying thereto coating compositions comprising an aqueous dispersion of an interpolymer derived from, for a total of 100 parts, (A) 30 to 80 parts of acrylonitrile, (B) 2 to 15 parts of an alpha-olefinic monocarboxylic acid selected from acrylic, methacrylic, ethacrylic, phenyl acrylic and crotonic acids, (C) 15 to 65 parts of an ester of an acid of the above group with a saturated aliphatic monohydric alcohol of 1 to 8 carbon atoms, and optionally (D) 1 to 25 per cent per 99 to 75 per cent of (A), (B) and (C), of allyl glycidyl ether or an ester of 2, 3-epoxypropanol-1 with one of the above acids.  The coating compositions may be modified by the addition of pigments such as titanium dioxide, coalescing agents such as dimethyl formamide, dimethyl acetamide, ethylene carbonate, tetramethylene sulphone, alkyl monoethers of ethylene or diethylene glycol, and diacetone alcohol, and other resinous film-formers, in particular water-dilutable thermosetting resins such as phenol/formaldehyde, urea/formaldehyde, urea-melamine/formaldehyde melamine/formaldehyde and acetone/formaldehyde resins.  The resinous dispersions are applied to the surfaces of metallic objects, such as wires and panels, followed by heat-treatment, which coalesces the particles of resin and produces a coherent coating.