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. 18, 1983
Filed:
Jul. 28, 1981
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process is provided for the preparation of naphthalene-1,3-5,-trisulphonic acid from 1,5-disulphonated naphthalene, which comprises sulphonating 1,5-disulphonated naphthalene, in the form of a mixture which has been obtained by mixing naphthalene and SO.sub.3 in the presence of an inert solvent at temperatures in the range of -40.degree. to +20.degree. C., the ratio of SO.sub.3 added to naphthalene added having been in the range of 2.5 to 10 mols of SO.sub.3 per mol of naphthalene during the entire addition, at 60.degree. to 110.degree. C. in anhydrous sulphuric acid with oleum, with prior or concurrent separation of the inert solvent. The resulting product is a known intermediate for the formation of azo dyestuffs.