Process for the preparation of water dilutable binders for cationic electrocoating finishes using monofunctionally modified polyepoxides

摘要

The invention relates to water-dilutable binders for cationic electrocoating finishes. For the preparation of the binders, a di-epoxide compound, together with at least one mono-epoxide compound if desired, is converted by a polyaddition, carried out at 100 to 195 C. and initiated by a monofunctionally reacting initiator carrying either an alcoholic OH group, a phenolic OH group or an SH group, to form an epoxy resin which then subsequently is modified withPP(A) primary and/or secondary amines or their salts and/or the salt of a tertiary amine, a sulfide/acid mixture or a phosphine/acid mixture and with, if desired,PP(B) a polyfunctional alcohol, a polycarboxylic acid, a polysulfide or a polyphenol.