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. 19, 1991
Filed:
Feb. 09, 1990
Applicant:
Inventors:
Brian A Stern, Evans, GA (US);
Richard Layton, Augusta, GA (US);
Assignee:
Amoco Corporation, Chicago, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528194 ; 528176 ; 528179 ; 528180 ; 528271 ;
Abstract
Process for preparing polyarylates comprising the steps of (a) prepolymerizing a diester of Bisphenol-A with at least one aromatic dicarboxylic acid to form a prepolymer having a melting point of at least about 200.degree. C. and being fluid at the polymerization temperature; followed by (b) polycondensing said prepolymer under agitation until it is substantially transformed into a powdery solid; maintaining said agitation to keep the powdery solid in a polydispersed solid state; and continuing the polymerization below the agglomeration temperature of the polymerizing solid, until the desired molecular weight is reached.