Resinous polyurethane coating lacquers prepared from polyisocyanate, water, and polyhydroxyl reaction products, and process for their preparation

Polyurethane coating compositions are prepared by reacting organic polyisocyanates with compounds containing at least two isocyanate-reactive hydrogen atoms in a solvent in the presence of at least 0,5%, by weight of the polyisocyanate of water. The solvent may be a hydrocarbon, a chlorinated hydrocarbon, an ether, or a ketone such as acetone, ethyl methyl ketone and cyclohexanone, or a mixture of such solvents. The polyisocyanate may be tolylene-2,4-diisocyanate, or mixtures of tolylene-2,4-and -2,6-diisocyanates, diphenylmethane diisocyanates, 4,41-diisocyanato-3-methyldiphenylmethane, m- and p-phenylene diisocyanates, chlorophenylene-2,4-diisocyanate, 2,4,6-triisocyanatotoluene, 4,41,411-triphenylmethane-triisocyanate, 2,4,41-triisocyanatodiphenyl ether, polymers of for example tolylene-2,4-diisocyanate containing isocyanurate rings, urethane polyisocyanates and mixtures of such compounds. The compounds reactive therewith are polyesters, polyesteramides and polyethers. Examples are given.