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:
Jun. 01, 1982
Filed:
Apr. 07, 1980
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549 56 ;
Abstract
A transparent pigmentary form of 4,4',7,7'-tetrachlorothioindigo is prepared by oxidizing the leuco compound of tetrachlorothioindigo in aqueous alkaline suspension, in the presence of a dithionite, at from 20.degree. to 100.degree. C., with simultaneous exposure to shearing forces. Preferably, the oxidation is carried out in the presence of a surfactant. The pigment obtained gives brilliant, transparent full-shade colorations, while white reductions have a deep pure reddish hue.