The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1987
Filed:
Sep. 18, 1985
Chung-Ji Tschang, Bad Durkheim, DE;
Karlheinz Messmer, Weisenheim, DE;
Walter Denzinger, Speyer, DE;
Basf Aktiengesellschaft, Ludwigshafen, DE;
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.