Process for the preparation of isocyanates or isocyanate mixtures useful for the preparation of polyurethane foams

摘要

Isocyanates or isocyanate mixtures which are substantially free of color-imparting components are made by treating the isocyanate with hydrogen in the presence of a catalyst at a pressure of from about 3 to about 150 bar, a temperature of from about 100 to about 180 DEG C. for from about 15 minutes to about 4 hours. These isocyanates are particularly useful for the preparation of light-colored polyurethane rigid foams.