Process for the preparation of copolymers

US4722958A · kind A · utility

Assignee

• Cassella Aktiengesellschaft · DE

Inventors

• Josef Sauer · Alzenau, DE
• Friedrich Engelhardt · Frankfurt, DE
• Kerstine Rabas · Frankfurt am Main, DE
• Ulrich Karsunky · Brechen, DE
• Wolfram Schidlo · Hofheim, DE
• Jochen M. Quack · Eppstein, DE
• Alwin Reng · Kelkheim, DE
• Werner Skrypzak · Liederbach, DE

Key dates

• Filing date: Jan 29, 1987
• Grant date: Feb 2, 1988
• Expiry date: Jan 29, 2007

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61Q5/06
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

Process for the preparation of copolymers from acrylamide and acrylic or methacrylic acid, wherein to prepare 100 parts by weight of the copolymer, (A) 10-90 parts by weight of acrylamide, (B) 90-100 parts by weight of acrylic acid and/or methacrylic acid or of a salt thereof, (C) 0-40 parts by weight of another copolymerizable monomer and (D) 0-5 parts by weight of a copolymerizable crosslinking agent which has two or more olefinic double bonds are polymerized in an alcohol having 1-4 carbon atoms by precipitation polymerization such that 10-90% by weight of the alcohol, 10-90% by weight of the total amount of monomers (A), (B) and (C) together with 100% by weight of the crosslinker substance are initially mixed, polymerization is started with 10-100% by weight of the initiator and then the remainder of the solvent, monomers, crosslinking agent and initiator to make up to 100% is metered in, as individual components or as a mixture, after the polymerization has started.