| abstract |
METHOD OF PREPARING POLYURETHANES BY TIME-LAPSE CATALYSIS WHICH COMPRISES: (A) THROUGHLY MIXING A REACTION MEDIUM CONTAINING: (1) AN ORGRANIC POLYISOCYANATE, (2) ABOUT 3.5-1.5 EQUIVALENT, PER EQUIVALENT OF ORAGANIC POLYISOCYANATE, OR AN ORGANIC POLYHYDROXY COMPOUND, (3) ABOUT 0.0001 TO 0.1 MOLE, PER EQUIVALENT OF ORGANIC POLYISOCYANATE, OF A CURE RATE CATALYST FOR THE POLYUREATHANE REACTION CONSISTING ESSENTIALLY OF AMINE-FREE ORGANO-TINE CURE RATE CATAYLST FOR THE POLYURETHANE REACTION, (4) AT LEAST ABOUT 0.1 MOLE, PER MOLE OF AMINEFREE ORGANO-TIN CATALYST, OF A TIME-LAPSE MODIFIER SELECTED FROM THE GROUP CONSISTING OF (A) B-DICARBONYL COMPOUNDS HAVING AN ENOL CONTENT OF AT LEAST ABOUT 4% AND A DISCATBONYL ANGLE OF NOT GREATER THAN ABOUT 120 DEGREES, (B) A-HYDROXY KETONES, (C) FUSED AROMATIC B-HYDROXY KETONES IN WHICH THE HYDROXYL GROUP IS ATTACHED TO A CARBON BETA TO THE KETO GROUP IN AN ADJACENT RING, AND (D) B-HYDROXY NITROGEN-HETEOCYCLIC FUSED AROMATIC IN WHICH THE HYDROXYL GROUP IS ATTACHED TO A CARBON BETA TO THE NITROGEN IN AN ADJACENT RING, (B) APPLYING THE REACTION MIXTURE, AND (C) ALLOWING THE APPLIED REACTION MIXTURE TO CURE AT AMBIENT TEMPERATURE. |