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:
Aug. 31, 1982
Filed:
Jan. 05, 1981
Roland A Winter, Armonk, NY (US);
Martin Dexter, Briarcliff Manor, NY (US);
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
Substituted 2-nitro-2'-hydroxyazobenzenes are prepared by adding an aqueous mineral acid solution of a diazotized o-nitroaniline to a strongly alkaline lower alkanol or aqueous lower alkanol solution of a substituted phenol, containing sufficient alkali metal hydroxide to assure a pH value substantially over 11 and an excess of hydroxyl ion in the reaction mixture even after all the acidic diazonium salt solution is added, wherein the reaction solvent mixture is at least 50% by weight of lower alkanol, at a reaction temperature between -15.degree. C. and +30.degree. C. The o-nitroazobenzenes obtained are intermediate products useful in the manufacture of benzotriazole UV absorbers.