Methods for synthesizing polyvinyl amine (PVA) type flocculating and coagulating agents, novel agents thus obtained, uses thereof and improved paper types thus obtained

Patent 6797785 Issued on September 28, 2004. Estimated Expiration Date:

March 9, 2020. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Linear basic polymers, their preparation and their use
Patent #: 4421602
Issued on: 12/20/1983
Inventor: Brunnmueller , et al.

Bi-phase initiator system for water-in-oil emulsion polymers
Patent #: 4739008
Issued on: 04/19/1988
Inventor: Robinson , et al.

Process for the synthesis of oligomeric vinylamines
Patent #: 5280077
Issued on: 01/18/1994
Inventor: Carroll, et al.

Preparation of finely divided, water-soluble polymers containing vinylamine units
Patent #: 5290880
Issued on: 03/01/1994
Inventor: Moench, et al.

Process for the preparation of stable water-in-oil emulsions of hydrolyzed polymers of N-vinyl amides and the use thereof
Patent #: 5739190
Issued on: 04/14/1998
Inventor: Hartmann, et al.

Poly(vinylamine)-based superabsorbent gels and method of manufacturing the same Patent #: 6121409
Issued on: 09/19/2000
Inventor: Mitchell, et al.

Inventors

Assignee

SNF S.A.

Application

No. 09926245 filed on 03/09/2000

US Classes:

525/328.2, Polymer derived from monomer containing nitrogen other than: unsubstituted ammonium, acrylonitrile, acrylamide, methylolacrylamide and the corresponding methacryl materials525/340, Chemical treating agent contains a phosphorus atom525/369Metal hydroxide

Examiners

Primary: Lipman, Bernard

Attorney, Agent or Firm

Arent Fox, PLLC

Foreign Patent References

44 09 903 DE 09/01/1991
40 07 310 DE 09/01/1995
197 10 212 DE 09/01/1998
0 295 614 EP 12/01/1988

International Class

C08F 812

Abstract

The invention relates to a process of synthesis at low temperature of polymers of the PVA (polyvinylamine) type on the basis the monomer vinylformamide. The polymerization claimed for the invention begins at around 0° C., is initiated by an original combination of redox and azoic catalysts, and is conducted under more or less normal pressure. The polymerization is conducted in water and is followed by direct hydrolysis. A powdered cationic PVA of high molecular weight is thereby obtained. The process may also be conducted in an emulsion at an initiation temperature of around 15° C. Application of PVAs as flocculants and coagulants in the paper, water treatment, petroleum and parapetroleum, and, similar industries.