CATHODICALLY DEPOSITABLE AQUEOUS DIPPING VARNISH COMPOSITION

摘要

The invention relates to a cathodically depositable aqueous electro-dip lacquer coating composition containing as synthetic resin binder (A) from 50 to 99% by weight, based on the total quantity of synthetic resin binder, of one or more amino-1,2-epoxy resins, the amino-1,2-epoxy resin or-where several amino-1,2-epoxy resins are present-the mixture of amino-1,2-epoxy resins (a) having an average molecular weight (Mn) of from 700 to 10,000, (b) containing per 1000 molecular weight units from 0.2 to 3.6 lateral or terminal ethylenic double bonds corresponding to a hydrogenation iodine number of from 5 to 90, (c) containing primary and/or secondary alcoholic hydroxyl groups corresponding to a hydroxyl number of from 30 to 450 and (d) having an amine number of from 30 to 150, (B) from 1 to 50% by weight of a substantially non-acid polyester of a polycarboxylic acid containing at least two terminal or lateral, saturated and/or unsaturated beta -hydroxy ester groups per molecule and having an average molecular weight of from about 1500 to 10,000, and (C) soluble and/or insoluble transesterification catalysts for the thermal crosslinking of (A) and (B) at temperatures above 140 DEG C. The invention also relates to the use of the coating composition for cathodic deposition from a lacquer bath onto electrically conductive surfaces.