Thermosetting binders for cathodic deposition in electrodeposition paints

Abstract

Process of producing, and binders water soluble upon neutralization with acids which are depositable at the cathode of an electrodeposition system and can be crosslinked through thermic polymerization without additional crosslinking components characterized in that (A) 1 mole of an isocyanate having the formula OCN--R--(NCO).sub.n, in which R is an aromatic, aliphatic or cycloaliphatic hydrocarbon radical and n is 1 or 2, is reacted at from 0.degree.-50.degree. C., with (a) from 0.1 to 0.5 moles, if n=1, or 0.1 to 1.0 moles, if n=2, of a tertiary dialkylalkanol amine, and subsequently with (b) from 0.5 to 0.9 moles, if n=1, or 1.0 to 1.9 moles, if n=2, of a compound carrying one free hydroxy group and 1-3 CH.sub.2 =CR.sub.1 groups, where R.sub.1 =H or CH.sub.3, and (B) the intermediate resulting from (A) carrying an average of 1 free isocyanate group is reacted at from 10.degree.-100.degree. C., with the hydroxy groups of an epoxy resin/amine adduct until an isocyanate value of 0 is obtained, the quantities between the components being chosen in order that the final product, in 1000 molecular weight units, carries at least 0.5 chain end or side chain double bonds and at least 0.15 basic nitrogen atoms. The reaction proceeds in a single kettle to produce compounds having superior dispersibility and stability in water, and are easily applied as a binder.

Dependencies are inferred from the claim text.