Method for preparing polyampholytes by esterifying a carboxyl group containing polymer with an nu, nu-dialkyl formamide complex of an aminoalcohol

Claim 1

A PROCESS FOR PREPARING POLYAMPHOLYTES WHICH COMPRISES ESTERIFYING AN ALKALI-SOLUBLE, CARBOXYL GROUP-CONTAINING ESSENTIALLY LINEAR POLYMER BY HEATING SAID POLYMER WITH AN ESSEITIALLY ANHYDROUS ORGANIC SOLUTION CONTAINING LESS THAN A STOICHIOMETRICALLY EQUIVALENT QUANTITY OF AN N,N-DIALKYLFORMAMIDE COMPLEX OF A MONOHYDRIC ALIPHATIC AMINOALCOHOL TO A TEMPERATURE AT WHICH SUBSTANTIALLY ALL OF THE HYDROXYL GROUPS OF THE AMINOALCOHOL WILL REACT WITH THE CARBOXYL GROUPS OF THE ALKALI-SOLUBLE POLYMER; SAID ORGANIC SOLVENT BEING FREE OF (1) FUNCTIONAL GROUPS REACTIVE WITH THE N,N-DIALKYLFORMAMIDE COMPLEX OF THE MONOHYDRIC ALIPHATIC AMINOALCOHOL AND (2) FUNCTIONAL GROUPS REACTIVE WITH THE ALKALI-SOLUBLE POLYMER; SAID ALKALI-SOLUBLE, CARBOXYL GROUP-CONTAINING POLLYMER BEING SELECTED FROM THE GROUP CONSISTING OF HOMOPOLYMERS OF HOMOPOLYMERIZABLE ALPHA, BETA-ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS AND INTERPOLYMERS OF (A) A MONOMER OF THE GROUP CONSISTING OF ALPHA,BETA-ETHYLENICALLY UNSATURATED MONOCARBOXYLIC ACIDS, ALPHA,BETA-ETHYLENICALLY UNSATURATED DICARBOXYLIC ACIDS, ANHYDRIDES OF ALPHA, BETA-ETHYLENICALLY UNSATURATED DICARBOXYLIC ACIDS AND MIXTURES THEREOF AND, (B) AN INTERPOLYMERIZABLE MONOMER OF THE GROUP CONSISTING OF VINYL HALIDES, VINYLIDENE HALIDES, MONO- AND DI-OLEFINIC HYDROCARBONS CONTAINING 2-5 CARBON ATOMS, VINYL ESTERS OF CARBOXYLIC ACIDS, ESTERS OF ALPHA,BETA-ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS, VINYL AROMATIC HYDROCARBONS, VINYL ETHERS AND MIXTURES THEREOF.