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. 12, 1982
Filed:
May. 26, 1981
Applicant:
Inventors:
Glen R Ladewig, Angleton, TX (US);
Feng-Chih Chang, Angleton, TX (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
568724 ; 568749 ; 568753 ;
Abstract
A method of purifying bisphenols by (1) crystallizing the crude bis from a single liquid phase containing water, bis and an organic solvent, (2) stripping the remaining mother liquor (containing the impurities) of solvent and water, and (3) mixing it with phenol, (4) contacting the mixture of phenol and mother liquor with a cation exchange resin to convert the impurity to the desired product, (5) stripping the phenol and (6) recycling the remainder to the initial crystallizing step.