Moisture-curing surface coating compositions of isocyanate-ended polyurethanes containing epoxy groups

An organic polyisocyanate containing isocyanurate rings and epoxy groups is obtained by reacting together a condensation product of epichlorhydrin and diphenylolpropane with an excess of polyisocyanate containing isocyanurate rings. Preferably 3-6 isocyanate groups should be provided for each isocyanate reactive group. The polyisocyanates of the invention may be used for coating substrates when dissolved in an organic solvent which does not react with the isocyanate; the coatings are allowed to dry, optionally with heating. Pigments, fillers, flame-proofing agents, surfactants, catalysts and antioxidants may be present. A suitable isocyanate containing isocyanurate rings, which may be used as a starting material, is described in Example 1 of Specification 954,095.