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. 09, 1979
Filed:
May. 22, 1978
Applicant:
Inventor:
Richard P Carr, Cincinnati, OH (US);
Assignee:
The Sherwin-Williams Company, Cleveland, OH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; C07D / ;
U.S. Cl.
CPC ...
203-6 ; 203 38 ; 203 62 ; 203 91 ; 548257 ;
Abstract
A method for purifying benzotriazole, tolyl-triazole or mixtures of the two is disclosed. The method includes the steps of vacuum distillation of crude triazole and collection of the condensate. The crude triazole contains color bodies, diazotizable impurities which are color body precursors, or both. The color of the distilled triazole is improved by adding to the crude triazole, prior to vacuum distillation, an amount of formaldehyde sufficient for reaction with an appreciable proportion of the color bodies, the color body precursors, or both.