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:
Mar. 04, 1980
Filed:
Jan. 10, 1978
Applicant:
Inventors:
Assignee:
Sumitomo Chemical Company, Limited, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260582 ; 260205 ; 260208 ;
Abstract
Highly pure p-phenylenediamine can advantageously be prepared on a commercial scale by separating and removing o-aminoazobenzene produced as a by-product in the step of producing p-aminoazobenzene, from the product mixture before p-aminoazobenzene is reduced in a process for preparing p-phenylenediamine which comprises preparing p-aminoazobenzene from aniline by way of diazoaminobenzene and then reducing p-aminoazobenzene.