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:
Oct. 04, 1988
Filed:
Jun. 08, 1987
Applicant:
Inventors:
Daniel J Brunelle, Scotia, NY (US);
Thomas L Evans, Clifton Park, NY (US);
Thomas G Shannon, Schenectady, NY (US);
Assignee:
General Electric Company, Schenectady, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528371 ; 528196 ; 528201 ; 528370 ;
Abstract
Cyclic polycarbonate mixtures containing units derived from spirobiindane bisphenols, preferably 6,6'-dihydroxy-3,3,3',3'-tetramethylspirobiindane are prepared from the corresponding bischloroformates or mixtures thereof with bisphenols. They may be homopolymeric or copolymeric; cyclic oligomer mixtures are preferred. Such oligomers may be converted to linear polycarbonates having high glass transition temperatures.