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. 23, 1993
Filed:
Jul. 05, 1991
Applicant:
Inventors:
Assignee:
Huels Aktiengesellschaft, Marl, DE;
Primary Examiner:
Int. Cl.
CPC ...
C08J / ;
U.S. Cl.
CPC ...
521 56 ; 521146 ; 521147 ; 526 87 ;
Abstract
Expandable styrene polymer of controlled particle size is prepared by polymerizing styrene and optionally polymerizable comonomers in a stirred aqueous suspension in the presence of monomer-soluble free radical initiator and dispersant to the extent that at least 70%, based on the total monomer, of the monomers are polymerized in the aqueous suspension initially to a conversion of at least 70% by weight; and then adding the remaining monomer, initiator and optional copolymerizable monomer and additives to the polymerization medium over one to three hours.