Polyester resins and method of making same

Claim 1

IN THE PREPARATION OF THERMOPLASTIC POLYESTERS FROM DISCARBOXYLIC ACID ANHYDRIDES AND MONOEPOXIDES, THE PROCESS FOR PREPARING BRANCH CHAIN POLYESTERS HAVING END GROUPS WHICH DO NOT REACT WITH EACH OTHER DURING PREPARATION, COMPRISING A COMPOUND WHICH ACTS AS A REACTION INITIATOR WHICH IS A MONOMER, A POLYMER OR A COPOLYMER HAVING AT LEAST THREE FUNCTIONAL CONSTITUENTS OF THE GROUP CONSISTING OF CARBOXYL RADICALS, PHENOLIC RADICALS OR COMBINATIONS THEREOF, THE NUMBER OF SUCH GROUPS BEING EQUAL TO THE NUMBER OF BRANCH CHAINS DESIRED, REACTING THE INITIATOR, THE ANHYDRIDE AND THE MONOEPOXIDE BY HEATING THE REACTANTS AT AN ELEVATED TEMPERATURE BELOW 150*C. SUFFICIENT TO BRING ABOUT A REACTION OF THE ANHYDRIDE WITH THE ALCOHOLIC HYDROXYL GROUP FORMING CARBOXYL GROUPS, THE REACTION OF MONOEPOXIDE WITH THE PHENOLIC HYDROXYL GROUPS TO FORM ALCOHOLIC HYDROXYL GROUPS, AS WELL AS A REACTION OF MONOEPOXIDE WITH THE CARBOXYL GROUPS ALSO FORMING ALCOHOLIC HYDROXYL GROUPS AND MAINTAINING THE TEMPERATURE BELOW THAT AT WHICH THE CARBOXY-HYDROXY REACTION TAKES PLACE SO THAT END GROUPS OF POLYESTER CHAINS GROWING BY THE SUCCESSIVE ADDITION OF ANHYDRIDE AND MONOEPOXIDE TO THE INITIATOR, DO NOT REACT WITH EACH OTHER AND FORM WATER, SAID MONOEPOXIDE BEING FREE OF SUBSTITUENTS CAPABLE OF REACTING WITH AN ACID ANHYDRIDE.