Conserving polyol in fusion cooking of polymeric polyesters

Claim 1

A METHOD OF PREPARING A POLYMERIC POLYESTER FROM AN ESTERIFICATION MIXTURE CONSISTING ESSENTIALLY OF (A) AT LEAST ONE POLYOL SELECTED FROM THE CLASS CONSISTING OF ETHYLENE GLYCOL, PROPYLENE GLYCOL, BUTYLENE GLYCOL, DIETHYLENE GLYCOL, DIPROPYELENE GLYCOL, TRIPROPYLENE GLYCOL, TRIETHYLENE GLYCOL AND GLYCERINE, AND (B) A CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF MALEIC ANYDRIDE, PHTHALIC ANHYDRIDE, ENDOMETHYLENETRETRACHLOROPHTHALIC ANHYDRIDE, TETRACHLOROPHTHALIC ANYDRIDE, TETRAHYDROPHTHALIC ANHYDRIDE, SUCCINIC ANHYDRIDE, ADIPIC ACID, ISOPHTHALIC ACID, TEREPHTHALIC ACID, FUMARIC ACID, MALEIC ACID AND SUCCINIC ACID, BY FUSION COOK, WHICH METHOD COMPRISES: (1) HEATING SAID MIXTURE IN A REACTION ZONE AND IN THE SUBSTANTIAL ABSENCE OF SOLVENTS TO A TEMPERATURE TO EFFECT ESTERIFICATION REACTION BETWEEN COMPONENTS (A) AND (B) TO FORM SAID POLYMERIC POLYESTER, ATTENDED BY EVOLUTION OF AND EVAPORATION OF WATER, AND ALSO TO EVAPORATE A PORTION OF POLYOL, (2) PASSING INERT GAS THROUGH SAID MIXTURE AT A RATE DETERMINED BY THE FORMULA: C.F.M.=1+K G, WHEREIN C.F.M. EQUALS CUBIC FEET OF SAID INERT GAS PER MINUTE, K IS A CONSTANT HAVING A VALUE WITHIN A RANGE OF 0.001 TO 0.04 AND G IS GALLONS OF BATCH, TO REMOVE SUBSTANTIALLY ALL OF THE WATER AS VAPOR AS IT IS EVOLVED AND TO TAKE UP VAPORS OF SAID POLYOL, (3) PASSING THE MIXTURE OF INERT GAS AND WATER VAPORS DIRECTLY FROM THE REACTION ZONE TO A SEPARATE ZONE OF PARTIAL CONDENSATION WHEREIN THEY ARE COOLED TO A TEMPERATURE IN A RANGE FROM SLIGHTLY ABOVE THE BOILING POINT OF WATER TO ABOUT 240*F. WHEREBY TO CONDENSE OUT ANY VAPORS OF POLYOL WITHOUT CONDENSING WATER VAPOR, AND MAINTAING SAID ZONE OF PARTIAL CONDENSATION SUBSTANTIALLY FREE OF WATER OF CONDENSATION, (4) RETURNING THE POLYOL CONDENSED IN SAID ZONE OF PARTIAL CONDENSATION DIRECTLY TO SAID ESTERIFICATION MIXTURE IN THE REACTION ZONE WHILE PERMITTING THE INERT GAS AND WATER VAPOR IN THE ZONE OF PARTIAL CONDENSATION TO PASS OUT OF THE SYSTEM WITHOUT CONDENSATION OF THE WATER VAPOR, AND (5) CONTINUING TO RETURN SAID POLYOL FROM THE ZONE OF PARTIAL CONDENSATION OF THE ZONE OF ESTERIFICATION AND TO PASS SAID INERT GAS CONTAINING THE VAPORS TO WATER FROM THE ZONE OF PARTIAL CONDENSATION UNTIL EVOLUTION OF WATER SUBSTANTIALLY CASES AND SAID ESTERIFICATION MIXTURE HAS BEEN CARRIED TO THE DESIRED STAGE AND A POLYMERIC POLYESTER OF DESIRED ACID VALUE AND VISCOSITY IS OBTAINED.

Claim 2

A METHOD OF PREPARING A POLYMERIC POLYESTER FROM AN ESTERIFICATION MIXTURE CONSISTING ESSENTIALLY OF (A) AT LEAST ONE POLYOL SELECTED FROM THE CLASS CONSISTING OF ETHYLENE GLYCOL, PROPYLENE GLYCOL, BUTYLENE GLYCOL, DIETHYLENE GLYCOL, DIPROPYELENE GLYCOL, TRIPROPYLENE GLYCOL, TRIETHYLENE GLYCOL AND GLYCERINE, AND (B) A CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF MALEIC ANYDRIDE, PHTHALIC ANHYDRIDE, ENDOMETHYLENETRETRACHLOROPHTHALIC ANHYDRIDE, TETRACHLOROPHTHALIC ANYDRIDE, TETRAHYDROPHTHALIC ANHYDRIDE, SUCCINIC ANHYDRIDE, ADIPIC ACID, ISOPHTHALIC ACID, TEREPHTHALIC ACID, FUMARIC ACID, MALEIC ACID AND SUCCINIC ACID, BY FUSION COOK, WHICH METHOD COMPRISES: (1) HEATING SAID MIXTURE IN A REACTION ZONE AND IN THE SUBSTANTIAL ABSENCE OF SOLVENTS TO A TEMPERATURE TO EFFECT ESTERIFICATION REACTION BETWEEN COMPONENTS (A) AND (B) TO FORM SAID POLYMERIC POLYESTER, ATTENDED BY EVOLUTION OF AND EVAPORATION OF WATER, AND ALSO TO EVAPORATE A PORTION OF POLYOL, (2) PASSING INERT GAS THROUGH SAID MIXTURE AT A RATE DETERMINED BY THE FORMULA: C.F.M.=1+K G, WHEREIN C.F.M. EQUALS CUBIC FEET OF SAID INERT GAS PER MINUTE, K IS A CONSTANT HAVING A VALUE WITHIN A RANGE OF 0.001 TO 0.04 AND G IS GALLONS OF BATCH, TO REMOVE SUBSTANTIALLY ALL OF THE WATER AS VAPOR AS IT IS EVOLVED AND TO TAKE UP VAPORS OF SAID POLYOL, (3) PASSING THE MIXTURE OF INERT GAS AND WATER VAPORS DIRECTLY FROM THE REACTION ZONE TO A SEPARATE ZONE OF PARTIAL CONDENSATION WHEREIN THEY ARE COOLED TO A TEMPERATURE IN A RANGE FROM SLIGHTLY ABOVE THE BOILING POINT OF WATER TO ABOUT 240*F. WHEREBY TO CONDENSE OUT ANY VAPORS OF POLYOL WITHOUT CONDENSING WATER VAPOR, AND MAINTAING SAID ZONE OF PARTIAL CONDENSATION SUBSTANTIALLY FREE OF WATER OF CONDENSATION, (4) RETURNING THE POLYOL CONDENSED IN SAID ZONE OF PARTIAL CONDENSATION DIRECTLY TO SAID ESTERIFICATION MIXTURE IN THE REACTION ZONE WHILE PERMITTING THE INERT GAS AND WATER VAPOR IN THE ZONE OF PARTIAL CONDENSATION TO PASS OUT OF THE SYSTEM WITHOUT CONDENSATION OF THE WATER VAPOR, AND (5) CONTINUING TO RETURN SAID POLYOL FROM THE ZONE OF PARTIAL CONDENSATION OF THE ZONE OF ESTERIFICATION AND TO PASS SAID INERT GAS CONTAINING THE VAPORS TO WATER FROM THE ZONE OF PARTIAL CONDENSATION UNTIL EVOLUTION OF WATER SUBSTANTIALLY CASES AND SAID ESTERIFICATION MIXTURE HAS BEEN CARRIED TO THE DESIRED STAGE AND A POLYMERIC POLYESTER OF DESIRED ACID VALUE AND VISCOSITY IS OBTAINED.