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:
Jun. 05, 1990
Filed:
Oct. 26, 1988
Applicant:
Inventors:
Assignee:
Rohm GmbH, Darmstadt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; C07C / ;
U.S. Cl.
CPC ...
568727 ; 568722 ; 568728 ;
Abstract
A method for making aromatic bisphenols such as 9,9-bis-(4-hydroxyphenyl)fluorene by reacting an aromatic ketone, for example a diaryl ketone or diaryl diketone, with a phenol in the present of an insoluble strongly acidic cationic ion exchange resin as an acidic condensation catalyst, which latter may be used in the presence of a co-catalyst containing sulfur.