GB1139432A - Production of synthetic polymer coatings on articles by electrodeposition - Google Patents

Abstract

1,139,432. Anionic copolymer compositions. BADISCHE ANILIN- & SODA - FABRIK A.G. 20 May, 1966 [21 May, 1965], No. 22523/66. Heading C3P. [Also in Division C7] An aqueous solution or dispersion of an anionic copolymer which may be anodically deposited on a conducting surface on a non- conducting article includes a copolymer containing : (a) 10 to 70 parts by weight of units of an ester of acrylic and/or methacrylic acid with a C 1 to C 20 monohydric alcohol; (b) 2 to 15 parts by weight of units of an α,#- ethylenically unsaturated carboxylic acid having 3 to 6 C atoms (e.g. acrylic, methacrylic, maleic or fumaric), a part or all of said units being in the form of ammonium or amine salts ; and (c) 0À5 to 75 parts by weight of units of at least one other ethylenically unsaturated monomer, 0À5 to 40 parts by weight being N- methylol amide of acrylic and/or methacrylic acid and/or an ether of these amides with a C 1 to C 10 monohydric alcohol. The copolymer may be formed by adding amine or ammonia to a copolymer formed from components (a) and (c) above together with 2 to 15 parts by weight of an α,#-ethylenically unsaturated carboxylic acid having 3 to 6 C atoms or by direct copolymerization of components (a), (b) and (c). In examples the copolymer comprises units of (a) 2-ethylhexylacrylate, (b) N: N- dimethyl - N - (# - hydroxyethyl) - amine salt of acrylic acid, and (c) the n-butanol ether of N - methylolacrylamide, 4 - hydroxybutyl acrylate and styrene. A pigment such as titanium dioxide may be included in the solution or dispersion, together if desired with a solvent such as n-butanol. The electrodeposited coating is heated to harden it. Examples of other copolymerizable units (c) mentioned are alkane diol mono (meth)acrylates, allyl alcohol, monovinyl ethers of diols, hydroxy-bicyclo-heptenecompounds, styrene, dialkyl (C 1 to C 4 ) esters of maleic or fumaric acid, vinyl esters of saturated aliphatic carboxylic acids, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and urea and triazine derivatives, e.g. the N-acryloyl or N-methacryloyl derivatives of urea or melamine. Additional binders may be included in the coating compositions, e.g. aminoplasts, phenoplasts, epoxide resins, alkyd resins or mixtures of these materials. The pH of the coating composition is maintained in the range 7 to 10À5 by the addition of acid or base.