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:
Jan. 17, 1984
Filed:
Apr. 23, 1982
Erich Hammerschmidt, Bergisch Gladbach, DE;
Horst Behre, Odenthal, DE;
Bruno Kruger, Cologne, DE;
Adolf Winkler, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
The invention relates to a process for the preparation of 1-benzoylamino-8-hydroxynaphthalene-4,6-disulphonic acid (benzoyl-K acid) by reacting 1-amino-8-hydroxynaphthalene-4,6-disulphonic acid (K acid) with benzoylating agents, according to which process mixtures of aminonaphtholdisulphonic acid isomers are used instead of pure K acid, which mixtures contain over 40% by weight of K acid, relative to the total amount of diazotizable compounds in the mixture of isomers, and in which no other single isomer has a proportion which exceeds 10% by weight of the total amount of diazotizable compounds in the mixture of isomers.