Granted Patent B2

US 6,894,110 · App. 10/207,516 · Granted May 17, 2005

Abstract

Claims (14)

1. A method of preparing a dispersion in an aqueous salt solution of discrete particles of a water-soluble polymer having pendant amine groups comprising

a) polymerizing under free radical forming conditions one or more monomers including a vinylamide monomer of formula

H 2 C═CR 2 NRC(O)R 1

wherein R, R 1 and R 2 are independently selected from hydrogen, C 1 -C 20 alkyl groups, aryl groups and alkylaryl groups in an aqueous solution of an anionic salt in the presence of one or more water-soluble stabilizer polymers selected from the group consisting of poly(vinyl alcohol), partially hydrolyzed poly(vinyl acetate), hydrolyzed poly(vinyl acetate/N-vinyl formamide), poly(vinyl alcohol/acrylamide), poly(diallyldimethyl ammonium chloride), poly(dimethylaminoethyl acrylate methyl chloride quaternary salt), poly(dimethylaminoethyl methacrylate methyl chloride quaternary salt), poly(dimethylaminoethyl acrylate benzyl chloride quaternary salt), poly (dimethylaminoethyl methacrylate benzyl chloride quaternary salt), poly(diallyldimethyl ammonium chloride/dimethyaminoethyl acrylate methyl chloride quaternary salt), poly(diallyldimethylammonium chloride/dimethylaminoethyl methacrylate methyl chloride quaternary salt), poly(diallyldimethylammonium chloride/dimethylaminoethyl acrylate benzyl chloride quaternary salt), and poly(diallyldimethyl ammonium chloride/dimethylaminoethyl methacrylate benzyl chloride quaternary salt) to form a dispersion in an aqueous salt solution of discrete particles of a water-soluble polymer having pendant amide groups;

b) stirring and heating the dispersion of step a) to a temperature of about 50° C. to about 90° C.; and

c) bubbling HCl gas or ammonia gas through the stirred and heated dispersion to effect the desired amount of hydrolysis of pendant amide groups to pendant amine groups.

2. The method of claim 1 wherein the vinylamide monomers are selected from the group consisting N-vinyl formamide, N-methyl-N-vinylacetamide and N-vinyl acetamide.

3. The method of claim 1 wherein the water-soluble polymer having pendant amine groups comprises about 1 to about 99 mole percent vinylamide monomers and about 99 to about 1 mole percent of one or more monomers selected from the group consisting of copolymerized with one or mote monomers selected from the group consisting of acrylic acid and salts thereof, methacrylic acid and salts thereof, C 1 -C 10 N-alkyl acrylamide, C 1 -C 10 N,N-dialkyl acrylamide, C 1 -C 10 N-alkyl methacrylamide, C 1 -C 10 N, N-dialkyl methacrylamide, N-aryl acrylamide, N,-N-diaryl acrylamide, N-aryl methacrylamide, N-N-diaryl methacrylamide, N-arylalkyl acrylamide, N,N-diallylalkyl acrylamide, N-arylalkyl methacrylamide, N,N-diarylalkyl methacrylamide, maleic anhydride, itaconic acid, vinyl sulfonic acid, styrene sulfonic acid, sodium acrylamido methyl propane sulfonic acid, maleic acid, vinyl acetate, diallyldimethyl ammonium chloride, vinyl pyrrolidinone, acrylonitrile, dimethylaminoethyl acrylate methyl chloride quaternary salt, dimethylaminoethyl acrylate benzyl chloride quaternary salt, dimethylaminoethyl acrylate methyl sulfate quaternary salt, dimethylaminoethyl acrylate cetyl chloride quaternary salt, dimethylaminoethyl methacrylate cetyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminoethyl methacrylate methyl sulfate quaternary salt.

4. The method of claim 1 wherein the dispersion in an aqueous salt solution of discrete particles of a water-soluble polymer having pendant amide groups comprises poly(N-vinylformamide).

5. The method of claim 1 wherein the dispersion in an aqueous salt solution of discrete particles of a water-soluble polymer having pendant comprises poly(N-vinylacetamide).

6. The method of claim 1 wherein the anionic salt is selected from the group consisting of ammonium, alkali metal and alkaline earth metal halides, sulfates, phosphates, nitrates and combinations thereof.

7. The method of claim 4 wherein the stabilizer is poly(vinyl alcohol).

8. The method of claim 5 wherein the stabilizer is poly(vinyl alcohol).

9. The method of claim 1 wherein the stabilizer is poly(vinyl alcohol) having a molecular weight of 1,000 to 5,000,000.

Assignments (6)