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. 31, 1992
Filed:
Oct. 31, 1990
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C08J / ;
U.S. Cl.
CPC ...
521 56 ; 521146 ;
Abstract
In the preparation of expandable styrene polymers by polymerizing styrene, if desired together with up to 50% by weight of other monomers, in aqueous suspension with addition of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent and, if desired, conventional additives in effective amounts before, during or after the polymerization, foaming is reduced if the aqueous phase contains from 0.05 to 0.3% by weight of polyvinylpyrrolidone having a K value of from 100 to 150 as protective colloid.