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:
Feb. 21, 1984
Filed:
Jun. 04, 1982
Hans G Keppler, Weinheim, DE;
BASF Aktiengesellschaft, , DE;
Abstract
A process for the preparation of styrene homopolymers or copolymers by suspension polymerization of monomers which contain dissolved styrene polymers from a preceding suspension polymerization, in the presence of sparingly soluble metal phosphates as suspension stabilizers, wherein, before the polymerization is started, the monomer phase is dispersed in an aqueous phase, containing a dissolved mineral acid, preferably phosphoric acid, at from 10.degree. to 80.degree. C. for from 5 to 120 minutes, after which the sparingly soluble metal phosphate is formed in situ in the aqueous phase. The process is particularly suitable for the preparation of expandable styrene polymers, in which case a volatile blowing agent is added to the suspension before, during or after polymerization.