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:
Nov. 02, 1982
Filed:
Dec. 22, 1980
Applicant:
Inventors:
Georg Grigoleit, Dorsten, DE;
Kurt Matern, Duisburg, DE;
Helmut Kohler, Mulheim an der Ruhr, DE;
Gerd Collin, Duisburg, DE;
Assignee:
Rutgerswerke Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549 49 ;
Abstract
A process for the production of thionaphthene by dissociation of thionaphthene sulfonic acid such as obtained, for example, in the partial sulfonation of naphthalene fractions of coal tar, characterized in that the density of the reaction mixture is maintained essentially constant during the entire duration of the dissociation reaction and the thionaphthene formed is not removed by azeotropic distillation; a product of high purity is obtained in high yield in a substantially reduced reaction time.