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:
Jan. 30, 1979
Filed:
Jan. 06, 1978
Applicant:
Inventor:
Louis A Cutter, Pittsburgh, PA (US);
Assignee:
United States Steel Corporation, Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08F / ; C08F / ; C08F / ;
U.S. Cl.
CPC ...
526 73 ; 526 78 ; 526 87 ; 526228 ; 526346 ; 526909 ; 526910 ; 260886 ;
Abstract
Crystal polystyrene with improved flow properties useful in injection molding is prepared in a two-stage process in which a first portion of monomer is polymerized in the presence of about 0.3 to about 2.0% peroxide initiator to convert about 70 to 95% of the monomer present to polymer having a number average molecular weight of 20,000 to 50,000 and a weight average of 50,000 to 100,000; then adding the rest of the monomer thereby reducing the catalyst concentration to generate a second moiety of polymer so that the final product has a weight average molecular weight of 150,000-300,000, and a number average of 50,000-70,000.