Abstract 1. A PROCESS FOR THE PREPARATION OF POLYURETHANE ELASTOMERS IN THE FORM OF GRANULES OR POWDERS BY REACTING AN ESSENTIALLY ANHYDROUS LINEAR DIHYDROXY COMPOUND, A DIISOCYANATE AND A CHAIN EXTENDER, THE IMPROVEMENT COMPRISING REACTING THE LINEAR DIHYDROXY COMPOUND WITH A MOLAR EXCESS OF DIISOCYANATE TO THE FORMATION OF A PREPOLYMER, SAID PRE-POLYMER BEING DISSOLVED IN A CHEMICALLY INERT AND ANHYDROUS SOLVENT, ADDING TO THE RESULTING SOLUTION THE CHAIN EXTENDER IN A SLIGHT MOLAR DEFICIT RELATIVE TO THE ABOVE-MENTIONED MOLAR EXCESS OF DIISOCYANATE, THEN ADDING A VOLTILE TERTIARY AMINE AS A CATALYST AND ALLOWING THE REACTION TO PROCEED UNTIL THE INITIALLY CLEAR SOLUTION GRADUALLY PASSES INTO A DISPERSION, AND THEN SUBJECTING SAID DISPERSION TO A STEAM TREATMENT WHILE VAPORIZING THE CATALYST AND THE SOLVENT, AND SEPARATING THE THE RESULTING POLYURETHANE FROM THE AQUEOUS PHASE OBTAINED.
A PROCESS FOR THE PREPARATION OF POLYURETHANE ELASTOMERS IN THE FORM OF GRANULES OR POWDERS BY REACTING AN ESSENTIALLY ANHYDROUS LINEAR DIHYDROXY COMPOUND, A DIISOCYANATE AND A CHAIN EXTENDER, THE IMPROVEMENT COMPRISING REACTING THE LINEAR DIHYDROXY COMPOUND WITH A MOLAR EXCESS OF DIISOCYANATE TO THE FORMATION OF A PREPOLYMER, SAID PRE-POLYMER BEING DISSOLVED IN A CHEMICALLY INERT AND ANHYDROUS SOLVENT, ADDING TO THE RESULTING SOLUTION THE CHAIN EXTENDER IN A SLIGHT MOLAR DEFICIT RELATIVE TO THE ABOVE-MENTIONED MOLAR EXCESS OF DIISOCYANATE, THEN ADDING A VOLTILE TERTIARY AMINE AS A CATALYST AND ALLOWING THE REACTION TO PROCEED UNTIL THE INITIALLY CLEAR SOLUTION GRADUALLY PASSES INTO A DISPERSION, AND THEN SUBJECTING SAID DISPERSION TO A STEAM TREATMENT WHILE VAPORIZING THE CATALYST AND THE SOLVENT, AND SEPARATING THE THE RESULTING POLYURETHANE FROM THE AQUEOUS PHASE OBTAINED.
Claim 2
Dependent Claim
133 words
A PROCESS FOR THE PREPARATION OF POLYURETHANE ELASTOMERS IN THE FORM OF GRANULES OR POWDERS BY REACTING AN ESSENTIALLY ANHYDROUS LINEAR DIHYDROXY COMPOUND, A DIISOCYANATE AND A CHAIN EXTENDER, THE IMPROVEMENT COMPRISING REACTING THE LINEAR DIHYDROXY COMPOUND WITH A MOLAR EXCESS OF DIISOCYANATE TO THE FORMATION OF A PREPOLYMER, SAID PRE-POLYMER BEING DISSOLVED IN A CHEMICALLY INERT AND ANHYDROUS SOLVENT, ADDING TO THE RESULTING SOLUTION THE CHAIN EXTENDER IN A SLIGHT MOLAR DEFICIT RELATIVE TO THE ABOVE-MENTIONED MOLAR EXCESS OF DIISOCYANATE, THEN ADDING A VOLTILE TERTIARY AMINE AS A CATALYST AND ALLOWING THE REACTION TO PROCEED UNTIL THE INITIALLY CLEAR SOLUTION GRADUALLY PASSES INTO A DISPERSION, AND THEN SUBJECTING SAID DISPERSION TO A STEAM TREATMENT WHILE VAPORIZING THE CATALYST AND THE SOLVENT, AND SEPARATING THE THE RESULTING POLYURETHANE FROM THE AQUEOUS PHASE OBTAINED.