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:
Sep. 11, 1979
Filed:
Feb. 03, 1978
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
544339 ; 260 4221 ;
Abstract
An .alpha.-indanthrone pigment having improved tinctorial and technological properties is produced by swelling .gamma.-indanthrone in sulfuric acid of from 73 to 80 percent strength by weight at from 20.degree. to 50.degree. C. in the presence of from 0.1 to 20% by weight, based on indanthrone, of a hydroxylammonium salt, a hydrazinium salt, amidosulfonic acid, urea, a salt of urea, formaldehyde or paraformaldehyde or a mixture of these. After precipitation in water which may or may not contain a surfactant, at below 50.degree. C., an .alpha.-indanthrone pigment of high tinctorial strength is obtained, which gives clear and pure colorations and is easily dispersible.