Patent No. U.S. 7,737,243 B2
E. I. du Pont de Nemours and Company has obtained a patent for urea-containing polyisocyanate adduct mixture consisting essentially of the reaction product of at least one aliphatic isocyanate trimer; and at least one cycloaliphatic isocyanate trimer in the presence of a urea-forming agent; and wherein the mole ratio of the aliphatic to cycloaliphatic trimer is in the range of from 1:2 to 1:10 and the reaction product has a molecular weight average of from 500 to 3000 and an isocyanate functionality of at least 4.