A PROCESS FOR THE PREPARATION OF HIGHLY PURE AROMATIC DIURETHANES AND/OR POLYURETHANES

摘要

Mo3814 LeA 28,779 A PROCESS FOR THE PREPARATION OF HIGHLY PURE AROMATIC DIURETHANES AND/OR POLYURETHANES This invention relates to a process for the preparation of highly pure aromatic diurethanes and/or polyurethanes by reaction of the corresponding aromatic diamines and/or polyamines with unsubstituted carbamates with the release of ammonia. The reaction is carried out in the presence of excess carbamates. The resultant reaction mixture is freed from any solvents used, and the formed aromatic diurethanes and/or polyurethanes are purified by extraction with water.