Patent GB-1146700-A (GB)
Title: Production of coloured synthetic polymer coatings on metallic surfaces by electrodeposition
Inventor: WILHELM HANS
IPC: C09D133/06
Filed: 1966-05-19
Abstract: 1,146,700. Electrochemical coating compositions containing coloured copolymers. BADISCHE ANILIN- & SODA-FABRIK A.G. 19 May, 1966 [20 May, 1965], No. 22311/66. Heading C3P. [Also in Division C7] A coloured synthetic polymer coating is formed on a metal surface by anodic deposition from an aqueous solution or dispersion of an anionic polymer followed by stoving, the polymer containing copolymerized units comprising by weight 100 parts total provided by (a) 10 to 70 parts of an ester of acrylic and/or methacrylic acid with a C 1  to C 20  monohydric alcohol; (b) 2 to 15 parts of an α-ethylenically unsaturated C 3  to C 8  carboxylic acid, at least half of the acid groups being in an amine or ammonium salt form; (c) 1 to 25 parts of an ethylenically unsaturated monomer having a chromophore group and containing the skeleton of an azo or anthraquinone dye; and (d) 0À5 to 40 parts of N-methylolacrylamide and/or N-methylolmethacrylamide and/ or an ether of one of these with a C 1  to C 10  monhydric alcohol and/or 0À5 to 20 parts of an ethylenically unsaturated alcoholic hydroxy compound bearing no amido groups, with or without one or more other ethylenically unsaturated monomers, the total amount of (d) being 0À5 to 60 parts. Numerous examples of suitable components are referred to. In particular reference is made to for (a) alkyl esters; for (b) acrylic, methacrylic, maleic and fumaric acids; for (c) derivatives of acrylamide, ethyl acrylate and vinyl-sulphonamide; and for (d) C 1  to C 10  alkyl ethers of the two specified N-methylol amides, amido groupfree C 3  to C 20  ethylenically unsaturated alcoholic hydroxy compounds such as hemiesters of acrylic acid and/or methacrylic acid with alkane diols, allyl alcohol, monovinyl ethers of diols such as ethanediol and butane-1:4-diol, hydroxy derivatives of bicyclo-[2:2:1]-heptene- 2, up to 45 parts styrene, up to 15 parts C 1  to C 4  dialkyl esters of maleic and fumaric acids, up to 20 parts vinyl esters, e.g. of acetic and propionic acids, up to 12 parts acrylonitrile and/or methacrylonitrile, up to 20 parts acrylamide and/or methacrylamide, and up to 30 parts of derivatives of urea and triazine such as N-acryloylurea and N-acryloylmelamine. Other water-soluble or water-dispersable binders such as aminoplasts, phenoplasts, epoxy resins and alkyd resins may be included in the solution or dispersion in amounts up to the weight of the salt of the copolymer, the water content being 20 to 95% by weight. Pigments, antifoaming agents, flow assistants and other coating agents may also be present. A coating composition suitable for production of a stoved coating on a sheet steel car body part comprises a dispersion in water of a xylene solution of a copolymer formed from (a) Z-ethylhexyl acrylate, (b) acrylic acid, (c) 4-(N-ethyl-N-acryloyloxyethyl)- amino-azobenzene, and (d) n-butylether of N- methylolmethacrylamide, 4 - hydroxybutyl acrylate and styrene, the copolymer being partially neutralized with N:N-dimethyl.N-(#- hydroxyethyl)-amine and may optionally contain rutile TiO 2 . The coating can be stoved by heating at 130-250‹ C.