Process for preparing water-soluble copolymers of acrylic acids and n-vinyl heterocyclic monomers in a halogenated hydrocarbon

Claim 1

IN A PROCESS FOR PREPARING A COPOLYMER OF (A) AN ACRYLIC ACID SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ACID, METHACRYLIC ACID AND A-ETHYLACRYLIC ACID AND (B) AN N-VINYLHETEROCYCLIC MONOMER SELECTED FROM THE GROUP CONSISTING OF: (1) N-VINYL-2-OXAZOLIDINONES OF THE GENERAL FORMULA: 3-(CH2=CH-),4,5-DI(R-)-2-OXAZOLIDINONE WHEREIN EACH R INDIVIDUALLY IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND C1-C2 ALKYL RADICALS, (2) N-VINYL-3-MORPHOLINONES OF THE GENERAL FORMULA: 2,5,6-TRI(R''-),4-(CH2=CH-)-3-MORPHOLINONE WHEREIN EACH R'' INDIVIDUALLY IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND C1-C4 ALKYL RADICALS, (3) N-VINYL-2-PYRROLIDONE, AND (4) N-VINYL-2-PIPERIDONE, BY A FREE RADICAL VINYL ADDITION POLYMERIZATION IN A LIQUID MEDIUM AT 20*-140*C., THE IMPROVEMENT MEDIUM A C1-C4 ESSENTIALLY IN USING AS THE POLYMERIZATION MEDIUM A C1-C4 HALOGENATED ALIPHATIC HYDROCARBON CONTAINING FROM 1 TO 4 BROMINE OR CHLORINE ATOMS AND HAVING A NORMAL BOILING POINT BETWEEN 20* AND 140*C.