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:
Sep. 22, 1992
Filed:
Feb. 11, 1992
Winfried Orth, Hassloch/Pfalz, DE;
Emmerich Pastorek, Hemsbach, DE;
Wolfgang Weiss, Neckarhausen, DE;
Hans W Kleffner, Battenberg/Pfalz, DE;
Rutgerswerke AG, , DE;
Abstract
In a process for the preparation of 9,9-bis-(4-hydroxyphenyl)-fluorene by condensing fluorenone and phenol in a molar ratio of 1:4 to 1:8 at 30.degree. to 90.degree. C. in the presence of gaseous hydrogen chloride and .beta.-mercapto-propionic acid catalyst, the improvement comprising distilling water of reaction and dissolved hydrochloric acid from the completed reaction mixture, dissolving the distillation residue in a nitrile, separating the crystallized adduct of nitrile and 9,9-bis-(4-hydroxphenyl)- fluorene from the nitrile and optionally dissociating the adduct to recover high purity 9,9-bis-(4-hydroxphenyl)- fluorene.