GB1535275A - Electrocoating baths - Google Patents

Abstract

1535275 Electrocoating baths DE SOTO Inc 15 Jan 1976 [10 Feb 1975] 01603/76 Headings C3M and C3R Electrocoating baths comprise aqueous media having dispersed therein with the aid of a base 2 to 20 weight per cent of resin solids comprising (A) an ether-hydroxy ester carboxylic acid polymer which is an adduct of a stoichiometric deficiency of monoepoxide with a copolymer of (1) 5 to 75 weight per cent of the copolymer of an ethylenically unsaturated hydroxy functional polyether containing 1À2 to 2À0 ethylenically unsaturated groups per molecule and being an epoxy-free reaction product of a polyepoxide with oleyl alcohol, (2) the balance of the copolymer comprising copolymerizable monoethylenically unsaturated monomers including carboxy functional monomer in an amount of at least 10 weight per cent of the copolymer; and (B) 5 to 40weightper cent of the resin solids of a heat-hardening formaldehyde condensate. (A) may be prepared by reacting a bisphenol diglycidyl ether with oleyl alcohol in the presence of a catalyst, e.g. boron trifluoride etherate, copolymerizing the product with carboxy-functional monomers together with vinyl aromatic and/or unsaturated ester monomers and optionally acrylamide or hydroxyalkyl acrylate monomers, and reacting with a monoepoxide containing at least 12 carbon atoms. Preferred condensates are aminoplasts, and the resins may be dispersed with the aid of amine bases, e.g. triethylamine and triethanolamine. The medium may contain watermiscible organic solvents. In an example the diglycidyl ether of bisphenol A is reacted with oleyl alcohol and the product copolymerized with styrene and acrylic acid, reacted with C 14-16 olefin epoxides and dispersed with dialkanolamines in an aqueous medium together with a benzoquanamine/formaldehyde resin.