Coating compsns. contg. melamine-formaldehyde resin copolymers - with polyurethanes from modified ester polycondensates

摘要

Water-dilutable or -dispersible COOH gps. contg. melamine/HCHO-polyurethane copolymer resins are prepd. by reacting (1) polycondensation products on alkyd resin basis, modified by polymerisable monomers and contg. free COOH gps. at sec. and/or tert. C atoms and having other functional, i.e. Zerewitinoff-active, H atoms towards isocyanates, with (2) diisocyanates and (3) melamine/HCHO resins. The resins are used for stoving lacquer binders as opt. pigment. and/or filler-contg. aq. dispersions for coating compsns. applied to paper, cardboard, Fe, steel and non-Fe metal sheets. Lacquers may be applied electrophoretically to metal sheets and stoved at 80-200 (100-160) degrees C for 10-80 (20-60) min.