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:
Aug. 21, 1990
Filed:
Feb. 17, 1989
Applicant:
Inventors:
Assignee:
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
568724 ; 568722 ; 568727 ;
Abstract
A process for crystallizing the adduct of bisphenol A with phenol from a phenol solution in the presence of water comprises controlling the concentration of bisphenol A in said solution by removing portion of the phenol from said solution or adding phenol to said solution according to feedback control based on the measurement of solution density to obtain an adjusted solution, and feeding the adjusted solution to the crystallizer in which its inside wall is kept at a temperature higher than that of the adjusted solution, provided the temperature difference being smaller than 5.degree. C. The crystallized adduct has a uniform particle size and a high purity.