Process for preparing anhydride polymers and resulting product

Claim 1

A METHOD FOR PREPARING POLYMERS HAVING A PLURALITY OF RECURRING ALPHA-METHYLENE GLUTARIC ANHYDRIDE GROUPS AS PART OF THE MAIN CHAIN THEREOF, COMPRISING TREATING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS A MEMBER SELECTED FROM THE CLASS CONSISTING OF (A) (1) AT LEAST ONE SUBSTANTIALLY ANHYDROUS MONOMERIC MONOCARBOXYLIC ACID HAVING FROM 3 TO 13 CARBON ATOMS AND A TERMINAL CH2= GROUP IN A POSITION BETA TO THE CARBOXYL GROUP AS THE SOLE ALIPHATIC CARBON-TO-CARBON UNSATURATION AND CONTAINING ONLY THE ELEMENTS CARBON, HYDROGEN, OXYGEN AND NOT MORE THAN 1 HALOGEN IN THE ALPHA POSITION, (2) MIXTURES OF A MAJOR PROPORTION OF (1) WITH AT LEAST ONE OTHER MONOOLEFINIC MONOMER WHICH IS COPOLYMERIZABLE WITH (U), (3) MIXTURES OF (1) AND 901 TO 30% BY WEIGHT BASED ON SAID (1) OF A POLYUNSATURATED MONOMER WHICH IS COPOLYMERIZABLE WITH SAID (1), AND (4) MIXTURES OF (2) WITH .01 TO 30% BY WEIGHT BASED ON SAID (2) OF A POLYUNSATURATED MONOMER WHICH IS COPOLYMERIZABLE WITH SAID (2), IN THE PRESENCE OF A FREE RADICAL CATALYST AND A POLYMERIZING TEMPERATURE, AND (B) POLYMERS OF SAID (A) AT AN ELEVATED TEMPERATURE, WITH (C) AT LEAST ONE MOLE OF A DEHYDRATING AGENT PER MOLAR EQUIVALENT OF CARBOXYL IN SAID (A) AND (B), SAID DEHYDRATING AGENT BEING SELECTED FROM THE CLASS CONSISTING OF NON-POLYMERIZABLE CARBOXYLIC ANHYDRIDES OF ACIDS HAVING AT LEAST 2 CARBON ATOMS AND UP TO ABOUT 18 CARBON ATOMS, ACID HALIDES OF SAID NON-POLYMERIZABLE ACIDS, PHOSPHORUS HALIDES, PHOSPHOROUR OXYHALIDES, SULFUR OXYHALIDES, WHEREIN THE HALOGEN OF SAID DEHYDRATING AGENT HAS AN ATOMIC WEIGHT OF FROM ABOUT 35.5 TO ABOUT 80 AND P2O5 SAID (B) BEING TREATED FOR A TIME SUFFICIENT TO CONVERT AT LEAST ABOUT 35% OF THE CARBOXYL GROUPS TO ANHYDRIDE GROUPS ON THE MAIN POLYMER CHAIN.

Claim 2

A METHOD FOR PREPARING POLYMERS HAVING A PLURALITY OF RECURRING ALPHA-METHYLENE GLUTARIC ANHYDRIDE GROUPS AS PART OF THE MAIN CHAIN THEREOF, COMPRISING TREATING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS A MEMBER SELECTED FROM THE CLASS CONSISTING OF (A) (1) AT LEAST ONE SUBSTANTIALLY ANHYDROUS MONOMERIC MONOCARBOXYLIC ACID HAVING FROM 3 TO 13 CARBON ATOMS AND A TERMINAL CH2= GROUP IN A POSITION BETA TO THE CARBOXYL GROUP AS THE SOLE ALIPHATIC CARBON-TO-CARBON UNSATURATION AND CONTAINING ONLY THE ELEMENTS CARBON, HYDROGEN, OXYGEN AND NOT MORE THAN 1 HALOGEN IN THE ALPHA POSITION, (2) MIXTURES OF A MAJOR PROPORTION OF (1) WITH AT LEAST ONE OTHER MONOOLEFINIC MONOMER WHICH IS COPOLYMERIZABLE WITH (U), (3) MIXTURES OF (1) AND 901 TO 30% BY WEIGHT BASED ON SAID (1) OF A POLYUNSATURATED MONOMER WHICH IS COPOLYMERIZABLE WITH SAID (1), AND (4) MIXTURES OF (2) WITH .01 TO 30% BY WEIGHT BASED ON SAID (2) OF A POLYUNSATURATED MONOMER WHICH IS COPOLYMERIZABLE WITH SAID (2), IN THE PRESENCE OF A FREE RADICAL CATALYST AND A POLYMERIZING TEMPERATURE, AND (B) POLYMERS OF SAID (A) AT AN ELEVATED TEMPERATURE, WITH (C) AT LEAST ONE MOLE OF A DEHYDRATING AGENT PER MOLAR EQUIVALENT OF CARBOXYL IN SAID (A) AND (B), SAID DEHYDRATING AGENT BEING SELECTED FROM THE CLASS CONSISTING OF NON-POLYMERIZABLE CARBOXYLIC ANHYDRIDES OF ACIDS HAVING AT LEAST 2 CARBON ATOMS AND UP TO ABOUT 18 CARBON ATOMS, ACID HALIDES OF SAID NON-POLYMERIZABLE ACIDS, PHOSPHORUS HALIDES, PHOSPHOROUR OXYHALIDES, SULFUR OXYHALIDES, WHEREIN THE HALOGEN OF SAID DEHYDRATING AGENT HAS AN ATOMIC WEIGHT OF FROM ABOUT 35.5 TO ABOUT 80 AND P2O5 SAID (B) BEING TREATED FOR A TIME SUFFICIENT TO CONVERT AT LEAST ABOUT 35% OF THE CARBOXYL GROUPS TO ANHYDRIDE GROUPS ON THE MAIN POLYMER CHAIN.