Polyurethane resins

Claim 1

METHOD WHICH COMPRISES THE STEPS OF (I) SIMULTANEOUSLY REACTING AT A TEMPERATURE BETWEEN ABOUT 10 AND 200*C., (A) A LACTONE HAVING AT LEAST FOUR CARBON ATOMS IN THE RING WITH (B) A DIFUNCTIONAL COMPOUND OF THE GROUP CONSISTING OF DIHYDRIC ALCOHOLS, DIPHENOLS, DIMERCAPANS, MERCAPTO ALCOHOLS, WATER AND HYDROGEN SULFIDE, AND (C) A MONOMERIC VICINAL EPOXIDE, THE PROPORTIONS OF SAID REACTANTS BEING SUCH AS TO FORM A MIXTURE OF LINEAR POLYESTERS HAVING TERMINAL HYDROXYL GROUPS AND MOLECULAR WEIGHTS IN THE RANGE OF ABOUT 400 TO ABOUT 10,000 (II) REACTING SAID MIXTURE OF LINEAR POLYESTERS WITH A 30 TO 60% MOLAR EXCESS OF ORGANIC DIISOCYANATE AT A TEMPERATURE UP TO ABOUT 300*C. TO FORM A MIXTURE OF SUBSTANTIALLY LINEAR POLYESTER-POLYURETHANE DIISOCYANATES; AND (III) REACTING SAID MIXTURE OF LINEAR POLYESTER-POLYURETHANE DIISOCYANATES WITH AN AMOUNT OF A POLYFUNCTIONAL COMPOUND IN EXCESS OF THAT REQUIRED FOR REACTING WITH ALL OF THE ISOCYANATE GROUPS OF THE SAID MIXTURE OF LINEAR POLYESTER-POLYURETHANE DIISOCYANATES, SAID POLYFUNCTIONAL COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF WATER AND ORGANIC COMPOUNDS HAVING AT LEAST TWO REACTIVE SITES SELECTED FROM THE GROUP CONSISTING OF ALCOHOLIC HYDROXYL, PRIMARY AMINO, SECONDARY AMINO, AND CARBOXYL GROUPS TO FORM A NON-HARDENING GUM STOCK.