Water dispersible binders for cationic electrocoating finishes and a process for their preparation

摘要

The invention relates to water-dispersible binders for cationic electrocoating finishes, which binders are reaction products ofP P(A) low molecular weight epoxide resins containing aromatic groups and having an epoxide equivalent weight of below 375, P P(B) aliphatic and/or alicyclic polyfunctional alcohols and/or carboxylic acids having a molecular weight of below 350,P P (C) if appropriate up to 60% by weight, relative to the total binder, of polyfunctional alcohols, carboxylic acids and/or SH compounds having a molecular weight of 500-5,000 andPP(D) primary, secondary and/or tertiary amines and/or salts thereof or a sulfide/acid mixture or a phosphine/acid mixture, the reaction product of A and B containing 10- 45% of aromatic groups, calculated as the phenylene group. By means of the binders, a higher layer thickness is obtained in electrocoating.