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. 03, 1989
Filed:
Jan. 25, 1988
Applicant:
Inventors:
Gerhard Schaefer, Heidelberg, DE;
Peter Neumann, Wiesloch, DE;
Assignee:
Dresser Industries, Inc., Dallas, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
568 34 ;
Abstract
A process for the preparation of 4,4-dichlorodiphenyl sulfone by heating a mixture of (a) chlorobenzene, (b) chlorosulfonic acid or sulfur trioxide, and (c) thionyl chloride or phosgene to temperatures up to 220.degree. C., more than the stoichiometric amount (based on the amount of chlorobenzene) of chlorosulfonic acid or sulfur trioxide and less than the stoichiometric amount of thionyl chloride or phosgene being employed.