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:
Mar. 03, 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 and are based on N-vinylpyrrolidone are prepared by polymerization of N-vinylpyrrolidone or a mixture of this with copolymerizable monomers and from 0.1 to 10% by weight, based on the total amount of monomers, of a crosslinking agent in a powder bed in the presence of a heat-transfer medium, which is inert to the reactants, and in the absence of oxygen and polymerization initiators, at from 90.degree. to 220.degree. C., while maintaining the powder state, circulating the reaction mass and evaporating the heat-transfer medium from the polymerization zone. The resulting insoluble polymers which are only slightly swellable are used as adsorbents or formulation assistants for fertilizers and crop protection agents.