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:
Feb. 28, 1995
Filed:
Aug. 19, 1993
Applicant:
Inventors:
Hiroki Inoue, Osaka, JP;
Iwao Sakaguchi, Hyogo, JP;
Katsutoshi Numano, Osaka, JP;
Toshiaki Kishimoto, Osaka, JP;
Yoshiaki Hayashi, Osaka, JP;
Keisuke Ito, Osaka, JP;
Assignee:
Sumimoto Chemical Company, Limited, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
552212 ; 552211 ;
Abstract
Crude 4,4'-diamino-l,l'-dianthraquinonyl-3,3'-disulfonic acids or salts thereof are purified by subjecting an aqueous solution containing the crude products to salting-out using inorganic salts, the aqueous solution being adjusted within a range of from acid to neutral region, whereby a product usable as such for the production of 4,4'-diamino-1,1'-dianthraquinonyl red pigments having excellent pigmentary properties is obtained in high yields with industrial advantages.