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. 10, 1989
Filed:
Jan. 25, 1988
Applicant:
Inventors:
Gerhard Schaefer, Heidelberg, DE;
Heinz Eilingsfeld, Frankenthal, DE;
Peter Neumann, Wiesloch, DE;
Michael Stumpp, Ludwigshafen, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
568 34 ;
Abstract
A process for the isolation of 4,4'-dichlorodiphenyl sulfone from a mixture of dichlorodiphenyl sulfones in which the ratios of the masses of 2,4'-dichlorodiphenyl sulfone and 3,4'-dichlorodiphenyl sulfone to the mass of 4,4'-dichlorodiphenyl sulfone are respectively from 0.5% to 20% and from 0.5% to 30% by treating the mixture with an alkanol at temperatures of from 20.degree. C. to 250.degree. C., cooling, and separating the pure 4,4'-dichlorodiphenyl sulfone that precipitates.