Modified epoxy resin/amine adduct by reacting polyamine/monoepoxide modifier, polyepoxy resins and amines

Claim 1

Cathodically depositable paint binders based on modified epoxy resins/amine adducts wherein said binders contain 5% to 30% by weight, based on the modified epoxy resin/amine adduct, of a modifier of general formula ##STR5## wherein R 1 represents the same or different groups ##STR6## R 2 represents the same or different groups ##STR7## R 3 represents the group ##STR8## R 4 represents a hydrogen atom or a methyl group, n and m are integers between 2 and 8 but, in the case of R 2 , n is an integer between 8 and 20, and which has been reacted with at least 2 mol of polyepoxy resins at least one member selected from the group consisting of a primary alkylamine, secondary dialkylamine, primary alkanolamine and a secondary dialkanolamine; and a primary-tertiary alkyldiamine to form an epoxy resin/amine adduct which is free from epoxide groups, waterdilutable after neutralization with acids and has a molecular weight of 4,000 to 16,000, by the weight method, or 1,500 to 3,000, by the counting method, a glass transition temperature of +20° C. to +45° C., and an amine number of at least 20 mg KOH/g.