Novel low viscosity prepolymers with low diisocyanate monomer content for moisture cure coatings

摘要

The present invention provides a urethane prepolymer and method of making said prepolymer useful in forming a moisture curable coating on an object. The prepolymer of the present invention is made by the process comprising reacting a HDI-uretidione with a polyol such that a moisture-curable urethane prepolymer having a viscosity at 25° C. less than about 3000 cP is formed. Moreover, the HDI-uretidione and the polyol are of sufficient amounts that the reaction index is at least about 2. The present invention also provides a method of coating a substrate with the prepolymer of the present invention.