Self-crosslinking heat-curable binder

A self-cross-linking heat-curable binder based on an organic synthetic resin which contains amino groups and esterified carboxyl groups and is water-dilutable due to neutralization with acids, in which the esterified carboxyl groups are activated in the alcohol component and are .beta.-hydroxylalkyl ester groups or carbalkoxymethyl ester groups and said organic synthetic resin is an epoxy resin which has been prepared by reacting a polyglycidyl ester or ether with a compound which carries two groups which are reactive toward epoxy groups and at least one of said esterified carboxyl groups to give an intermediate produce having terminal epoxy groups, and reacting said terminal epoxy groups having open rings with a compound selected from the group consisting of primary amines, secondary amines, ketimines having a hydrogen atom on the nitrogen atom, and aminoalcohols blocked at the nitrogen atom or a polyurethane resin which has been prepared by reacting a diisocyanate with a compound which carries two groups which are reactive toward isocyanate groups and at least one of said esterified carboxyl groups to give an intermediate product having terminal isocyanate groups, and reacting said terminal isocyanate groups with a compound selected from the group consisting of primary amines, secondary amines, ketimines having a hydrogen atom on the nitrogen atom, aldimines having a hydrogen atom on the nitrogen atom, and aminoalcohols blocked at the nitrogen atom.