Preparation of polymers containing carboxy groups from polymers of acrylamide

Claim 1

THE METHOD OF PRODUCING A POLYMER OF ACRYLAMIDE IN WHICH POLYMER FROM 10 TO 70 PERCENT OF THE AMIDE GROUPS INITIALLY PRESENT THEREIN HAVE BEEN CONVERTED INTO ALKALI-METAL CARBOXYLATE GROUPS, SAID METHOD COMPRISING HEATING AN AQUEOUS SOLUTION AT A TEMPERATURE RANGING FROM NEAR THE REFLUX TEMPERATURE AT ATMOSPHERIC PRESSURE TO A TEMPERATURE BELOW THE DECOMPOSITION TEMPERATURE OF THE STARTING ACRYLAMIDE POLYMER AND OF HYDROLYSIS PRODUCTS THEREOF, SAID SOLUTION COMPRISIGN (1) AN ACRYLAMIDE POLYMER CONTAINING AMIDE GROUPS SELECTED FROM THE CLASS CONSISTING OF THOSE REPRESENTED BY THE FORMUALS -CONH2 -CONHR AND -CONRR'', WHERE R AND R'' EACH REPRESENTS A LOWER ALKYL RADICAL, SAID POLYMER HAVNG AN AVERAGE MOLECULAR WEIGHT WITHIN THE RANGE OF FROM ABOUT 3000 TO ABOUT 250,000 AN THE MONOMER THEREOF HAVING A HYDROGEN ATOM ATTACHED DIRECTLY TO ITS ALPHA CARBON ATOM, AND (2) AN AMOUNT OF AN ALKALI-METAL HYDROXIDE WHICH IS CHEMICALLY EQUIVALENT TO THAT REQUIRED FOR EFFECTING THE DESIRED PERCENTAGE OF CONVERSION OF THE AID AMIDE GROUPS TO ALKALI-METAL CARBOXSYLATE GROUPS, AND STOPPING THE REACTION WHEN THE DESIRED PERCENTAGE OF CONVERSION HAS BEEN EFFECTED.

Claim 2

THE METHOD OF PRODUCING A POLYMER OF ACRYLAMIDE IN WHICH POLYMER FROM 10 TO 70 PERCENT OF THE AMIDE GROUPS INITIALLY PRESENT THEREIN HAVE BEEN CONVERTED INTO ALKALI-METAL CARBOXYLATE GROUPS, SAID METHOD COMPRISING HEATING AN AQUEOUS SOLUTION AT A TEMPERATURE RANGING FROM NEAR THE REFLUX TEMPERATURE AT ATMOSPHERIC PRESSURE TO A TEMPERATURE BELOW THE DECOMPOSITION TEMPERATURE OF THE STARTING ACRYLAMIDE POLYMER AND OF HYDROLYSIS PRODUCTS THEREOF, SAID SOLUTION COMPRISIGN (1) AN ACRYLAMIDE POLYMER CONTAINING AMIDE GROUPS SELECTED FROM THE CLASS CONSISTING OF THOSE REPRESENTED BY THE FORMUALS -CONH2 -CONHR AND -CONRR'', WHERE R AND R'' EACH REPRESENTS A LOWER ALKYL RADICAL, SAID POLYMER HAVNG AN AVERAGE MOLECULAR WEIGHT WITHIN THE RANGE OF FROM ABOUT 3000 TO ABOUT 250,000 AN THE MONOMER THEREOF HAVING A HYDROGEN ATOM ATTACHED DIRECTLY TO ITS ALPHA CARBON ATOM, AND (2) AN AMOUNT OF AN ALKALI-METAL HYDROXIDE WHICH IS CHEMICALLY EQUIVALENT TO THAT REQUIRED FOR EFFECTING THE DESIRED PERCENTAGE OF CONVERSION OF THE AID AMIDE GROUPS TO ALKALI-METAL CARBOXSYLATE GROUPS, AND STOPPING THE REACTION WHEN THE DESIRED PERCENTAGE OF CONVERSION HAS BEEN EFFECTED.