| abstract |
The present invention relates to heat-curable coating compositions containing A) a prepolymer having an average of 2-4 ketoxime-blocked NCO groups, having an average moleculer weight of 500-15,000 and prepared from aliphatic, cycloaliphatic and aromatic polyisocyanates and one or more polyhydroxy components which contain 0 to 30% by weight of ethylene oxide units and B) a crosslinking agent of the formula (* CHEMICAL STRUCTURE *) wherein R and R1 represent H or C1-C4-alkyl, the ratio of equivalents of blocked NCO groups in A) to NH2 groups in B) being 1.35:1 to 0.95:1, characterized in that at least one of the polyhydroxy compounds used for the preparation of the prepolymer contains, in stable dispersion, a polyurethane, a polyurethane-urea and/or a polyurea, which is substantially free from NCO groups, hydroxyl groups and amino groups and which are synthesized from aromatic, aliphatic and/or cycloaliphatic diisocyanates and from diamines, hydrazine and/or diols, provided that at least one of these components carries a radical having hydrophilic characteristics. The present invention also relates to the use of these coating compositions in a process for the coating, particularly water vapor-permeable coating, of substrates, preferably textile sheet-like structures and leather. |