Polyurethane resins from lactone polyesters

Claim 1

METHOD WHICH COMPRISES THE STEPS OF I. REACTING A LACTONE HAVING AT LEAST SEVEN CARBON ATOMS, AT LEAST SIX CARBON ATOMS BEING IN THE RING, AT A TEMPERATURE BETWEEN ABOUT 50 AND 300*C., WITH AN AMOUNT OF ORGANIC BIFUNCTIONAL INITIATOR HAVING TWO REACTIVE SITES SELECTED FROM THE GROUP CONSISTING OF ALCOHOLIC HYDROXYL, PRIMARY AMINO AND SECONDARY AMINO GROUPS SUFFICIENT TO FORM A LINEAR POLYESTER HAVING TERMINAL HYDROXYL GROUPS, A HYDROXYL NUMBER BETWEEN ABOUT 40 AND 60, AND AN ACID NUMBER NOT IN EXCESS OF 10, II. REACTING THE SAID LINEAR POLYESTER WITH A 30 TO 60% MOLAR EXCESS OF ORGANIC DIISOCYANATE AT A TEMPERATURE UP TO ABOUT 300*C. TO FORM A SUBSTANTIALLY LINEAR POLYESTERPOLYURETHANE DIISOCYANATE, AND III. REACTING THE SAID LINEAR POLYESTER-POLYURETHANE DIISOCYANATE WITH AN AMOUNT OF A POLYFUNCTIONAL COMPOUND IN EXCESS OF THAT REQUIRED FOR REACTING WITH ALL OF THE ISOCYANATE GROUPS OF THE SAID LINEAR POLYESTER-POLYURETHANE DIISOCYANATE, 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 MILLABLE GUM PRODUCT.