Patent ID: 7494716
Filing Date: 2009-02-24
Classification: C08G,C09D,Y10T

Abstract:
1. A process of preparing an aqueous anodic electro-dipcoating bath comprising the steps of: A) preparing an acid epoxy ester having an acid number of 10-50 by reacting in the presence of at least one aliphatic alcohol having 1-6 carbon atoms, wherein said at least one aliphatic alcohol is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, n-butanol, sec-butanol, tert-butanol, and hexanol: B) neutralising free acid functions of the acid epoxy ester prepared in Step A; and blending with at least one film-forming binder selected from the group consisting of polyacrylate resins, polyester resins, polyurethane resins and mixtures thereof and C) diluting the composition prepared in Steps A and B with fully deionised water to provided the anodic electro-dipcoating bath having a 1 to 15 wt. % binder solids content of the acid epoxy ester; wherein the polyester resin of step B) is derived from reactants consisting of a polycarboxylic acid, polyol and optional dialkyl ester; said polycarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids, cycloaliphatic dicarboxylic acids, aromatic dicarboxylic acids, tribasic carboxylic acids, tetrabasic carboxylic acids, anhydrides of any of said acids and any mixtures thereof; said polyol selected from the group consisting of dihydric alcohols, polyols having 3-4 hydroxyl groups and any mixtures thereof and said dialkyl ester being incorporated into the polyester by transesterification; and whereby the anodic electro-dipcoating bath being used for electrocoating vehicles or parts thereof.