Process for the production of crosslinked plastics of high molecular weight

Claim 1

A METHOD FOR MAKING A POLYURETHANE WHICH COMPRISES REACTING A MEMBER SELECTED FROM THE GROUP CONSISTING OF A POLYHYDRIC POLYALKYLENE ETHER AND AN HYDROXYL TERMINATED POLYTHIOETHER, SAID GROUP MEMBER HAVING A MOLECULAR WEIGHT OF AT LEAST ABOUT 500 WITH AN ORGANIC POLYISOCYANATE IN A REACTION MIXTURE CONTAINING AN EXCESS OF THE POLYISOCYANATE TO FORM AN -NCO TERMINATED ADDUCT, EACTING THE ADDUCT WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF AMMONIA, HYDRAZINE, ALIPHATIC DIAMINES, AROMATIC DIAMINES, CYCLOALIPHATIC DIAMINES, N,N,DIHYDROXYETHYL UREA, DICYANDIAIDE, AND N,N,DIHYDROXYETHYL MELAMINE IN A REACTION MIXTURE CONTAINING AN EXCESS OF THE SAID GROUP MEMBER AND THEREAFTER REACTING THE SECOND ADDUCT HAVING TERMINAL NH2 GROUPS WITH FORMALDEHYDE.