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:
Jul. 20, 1976
Filed:
Oct. 08, 1974
Kurt Gengnagel, Offenbach, Main, DT;
Theodor Papenfuhs, Frankfurt am Main, DT;
Hoechst Aktiengesellschaft, Frankfurt am Main, DT;
Abstract
The process for the preparation of tolutriazoles by diazotation of toluylene-o-diamines and subsequent ring closure to form the tolutriazole ring, was improved and the tolutriazoles are now obtained in a simpler way and in a pure form. The improvement comprises dissolution of the tolutriazoles without preceding isolation after their synthesis by means of an alkaline agent, preferably a sodium hydroxide solution of 20 - 33% strength, and subsequent precipitation at a pH of from 4.5 to 6 by addition of a mineral acid, preferably nitric acid or hydrochloric acid, and avoids a subsequent technically complicated and expensive purification process as well as the use of organic solvents. The tolutriazoles obtained according to this novel process are sufficiently pure for the use as corrosion inhibition.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile