Preparation of insoluble polymer powders which are only slightly swellable

US4658002A · kind A · utility

Assignee

• BASF SE

Inventors

• Chung-Ji Tschang · Bad Dürkheim, DE
• Karlheinz Messmer · Bad Dürkheim, DE
• Walter Denzinger · Speyer, DE

Key dates

• Filing date: Sep 18, 1985
• Grant date: Apr 14, 1987
• Expiry date: Sep 18, 2005

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F26/10
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Insoluble polymer powders which are only slightly swellable are prepared by polymerization of N-vinylpyrrolidone or a mixture of (a) an N-vinylcarboxamide, acrylamide, methacrylamide, acrylic acid, methacrylic acid, acrylates, methacrylates and/or a vinyl ester and (b) from 0.1 to 10% by weight, based on the total amount of monomers, of, as a crosslinking agent, a compound possessing two or more ethylenically unsaturated double bonds, in a powder bed in the presence of a heat-transfer medium and in the absence of oxygen and polymerization initiators, at from 90.degree. to 220.degree. C., the powder state being maintained, the reaction mass being circulated and the heat-transfer medium evaporated from the polymerization zone. The resulting polymers are used as adsorbents, as formulation assistants for crop protection agents or as ion exchangers.