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. 06, 1996
Filed:
Oct. 26, 1994
Osamu Shiromaru, Tokyo, JP;
Hitoshi Sugamo, Tokyo, JP;
Toyo Ink Manufacturing Co., Ltd., Tokyo, JP;
Abstract
A process for the production of a dis-azo pigment which is excellent in sanitary condition and almost free of a residual coupler component and decomposition products derived from the residual coupler component, and has a reduced aromatic amine content, and a dis-azo pigment produced by the said process, the process comprising the steps of (a) coupling-reacting a solution of a tetrazonium salt of benzidine with a slurry of acetoacetanilide of which the amount is stoichiometrically excess relative to an amount of said tetrazonium salt, to prepare a dis-azo pigment slurry, and (b) adding a halogen to the dis-azo pigment slurry to treat the acetoacetanilide in said slurry.