Conserving polyol in the cooking of polyesters of polybasic acids and polyhydric alcohols in the absence of solvents

Claim 1

A METHOD OF PREPARING A POLYMERIC POLYESTER FROM AN ESTERIFICATION MIXTURE CONTAINING ESSENTIALLY OF (A) AT LEAST ONE POLYOL SELECTED FROM THE CLASS CONSISTING OF ETHYLENE GLYCOL, PROPYLENE GLYCOL, BUTYLENE GLYCOL, DIETHYELENE GLYCOL, DIPROPYLENE GLYCOL, TRIETHYLENE GLYCOL, TRIPROPYLENE GLYCOL AND GLYCEROL, AND (B) AT LEAST ONE CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF MALEIC ANHYDRIDE, PHTHALIC ANHYDRIDE, ENDOMETHYLENETETRACHLOROPHTHALIC ANHYDRIDE, TETRACLOROPHATHALIC ANHYDRIDE, TETRAHYDROPHTHALIC ANHYDRIDE, SUCCINIC ANHYDRIDE, ADIPIC ACID, ISOPHTHALIC ACID, TEREPHTHALIC ACID, FUMARIC 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 THE EVOLUTION OF AND EVAPORATION OF WATER, AND ALSO TO EVAPORATE A PORTION OF THE POLYOL, PASSING INERT GAST THROUGH SAID MIXTURE AT A RATE TO REMOVE SUBSTANTIALLY ALL OF THE WATER AS VAPOR AS IT IS EVOLVED AND TO TAKE UP VAPORS OF SAID POLYOL, (2) PASSING THE RESULTANT GASEOUS MIXTURE OF INERT GAS, WATER VAPOR AND POLYOL VAPOR THROUGH A FRACTIONATING ZONE, PROVIDING AT LEAST ONE THEORETICAL PLATE OF SEPARATION AND THE LOWER PORTION OF WHICH IS MAINTAINED AT A TEMPERATURE IN A RANGE OF ABOUT 240* F. TO 440*F. WHILE THE TOP THEREOF IS MAINTAINED AT A TEMPERATURE ABOVE 212*F. AND BELOW 430*F., AND THE TEMPERATURE IN THE UPPER PART OF THE ZONE BEING BELOW THAT IN THE BOTTOM OF SAID ZONE AND BEING BELOW THE BOILING POINT OF THE POLYOL BEING USED THE FRACTIONATING ZONE BEING MAINTAINED ESSENTIALLY FREE OF WATER IN LIQUID STATE, (3) PASSING THE VAPORS FROM THE FRACTIONATING ZONE THROUGH 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. SUFFICIENTLY WHEREBY TO CONDENSE OUT ANY VAPORS TO POLYOL WITHOUT CONDENSING WATER VAPOR, AND RETURNING THE POLYOL CONDENSED IN SAID ZONE OF PARTIAL CONDENSATION, THROUGH SAID FRACTIONATING ZONE TO SAID ESTERISFICTION MIXTURE IN THE REACTION ZONE WHILE PERMITTING SAID GAS AND SAID WATER VAPOR IN THE ZONE OF PARTIAL CONDENSATION TO PASS OUT OF THE SYSTEM WITHOUT CONDENSATION OF THE WEATER VAPOR, AND (4) CONTINUING TO RETURN SAID POLYOL FROM THE ZONE OF PARTIAL CONDENSATION TO THE ZONE OF ESTERIFICATION AND TO PASS SAID INERT GAS THROUGH THE ESTERIFICATION MIXTURE UNTIL EVOLUTION OF WATER SUBSTANTIALLY CEASES AND SAID ESERIFICATION MIXTURE HAS BEEN CARRIED TO THE DESIRED STATE AND A POLYESTER OF DESIRED ACIE VALUE AND VISCOSITY IS OBTAINED.

Claim 2

A METHOD OF PREPARING A POLYMERIC POLYESTER FROM AN ESTERIFICATION MIXTURE CONTAINING ESSENTIALLY OF (A) AT LEAST ONE POLYOL SELECTED FROM THE CLASS CONSISTING OF ETHYLENE GLYCOL, PROPYLENE GLYCOL, BUTYLENE GLYCOL, DIETHYELENE GLYCOL, DIPROPYLENE GLYCOL, TRIETHYLENE GLYCOL, TRIPROPYLENE GLYCOL AND GLYCEROL, AND (B) AT LEAST ONE CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF MALEIC ANHYDRIDE, PHTHALIC ANHYDRIDE, ENDOMETHYLENETETRACHLOROPHTHALIC ANHYDRIDE, TETRACLOROPHATHALIC ANHYDRIDE, TETRAHYDROPHTHALIC ANHYDRIDE, SUCCINIC ANHYDRIDE, ADIPIC ACID, ISOPHTHALIC ACID, TEREPHTHALIC ACID, FUMARIC 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 THE EVOLUTION OF AND EVAPORATION OF WATER, AND ALSO TO EVAPORATE A PORTION OF THE POLYOL, PASSING INERT GAST THROUGH SAID MIXTURE AT A RATE TO REMOVE SUBSTANTIALLY ALL OF THE WATER AS VAPOR AS IT IS EVOLVED AND TO TAKE UP VAPORS OF SAID POLYOL, (2) PASSING THE RESULTANT GASEOUS MIXTURE OF INERT GAS, WATER VAPOR AND POLYOL VAPOR THROUGH A FRACTIONATING ZONE, PROVIDING AT LEAST ONE THEORETICAL PLATE OF SEPARATION AND THE LOWER PORTION OF WHICH IS MAINTAINED AT A TEMPERATURE IN A RANGE OF ABOUT 240* F. TO 440*F. WHILE THE TOP THEREOF IS MAINTAINED AT A TEMPERATURE ABOVE 212*F. AND BELOW 430*F., AND THE TEMPERATURE IN THE UPPER PART OF THE ZONE BEING BELOW THAT IN THE BOTTOM OF SAID ZONE AND BEING BELOW THE BOILING POINT OF THE POLYOL BEING USED THE FRACTIONATING ZONE BEING MAINTAINED ESSENTIALLY FREE OF WATER IN LIQUID STATE, (3) PASSING THE VAPORS FROM THE FRACTIONATING ZONE THROUGH 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. SUFFICIENTLY WHEREBY TO CONDENSE OUT ANY VAPORS TO POLYOL WITHOUT CONDENSING WATER VAPOR, AND RETURNING THE POLYOL CONDENSED IN SAID ZONE OF PARTIAL CONDENSATION, THROUGH SAID FRACTIONATING ZONE TO SAID ESTERISFICTION MIXTURE IN THE REACTION ZONE WHILE PERMITTING SAID GAS AND SAID WATER VAPOR IN THE ZONE OF PARTIAL CONDENSATION TO PASS OUT OF THE SYSTEM WITHOUT CONDENSATION OF THE WEATER VAPOR, AND (4) CONTINUING TO RETURN SAID POLYOL FROM THE ZONE OF PARTIAL CONDENSATION TO THE ZONE OF ESTERIFICATION AND TO PASS SAID INERT GAS THROUGH THE ESTERIFICATION MIXTURE UNTIL EVOLUTION OF WATER SUBSTANTIALLY CEASES AND SAID ESERIFICATION MIXTURE HAS BEEN CARRIED TO THE DESIRED STATE AND A POLYESTER OF DESIRED ACIE VALUE AND VISCOSITY IS OBTAINED.