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:
Jul. 17, 1990
Filed:
Nov. 28, 1988
Applicant:
Inventors:
Assignee:
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
568724 ; 568727 ; 568728 ; 568750 ;
Abstract
The process for preparing 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) by reacting acetone with phenol and decomposing the resultant adduct of bisphenol A and phenol is well known. However, the quality of bisphenol A thus obtained is not always satisfactory. In the process of this invention, the adduct is washed with phenol recovered by decomposing an adduct of bisphenol A and phenol, and then bisphenol A is prepared by decomposing the washed adduct. The bisphenol A prepared by the process of this invention has an extremely high quality and is suitable for the preparation of polycarbonate used for optical parts.