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. 23, 1988
Filed:
Oct. 14, 1986
Takanari Nawata, Tokyo, JP;
Shuzabu Sakaguchi, Ibaraki, JP;
Toshiaki Kohzaki, Ibaraki, JP;
Osamu Aoki, Chiba, JP;
Norio Takeda, Saitama, JP;
Yoshiyuki Aoki, Ibaraki, JP;
Masafumi Shimpo, Tokyo, JP;
Abstract
A process for continuously preparing benzophenone-azines comprising oxidizing benzophenone-imines with molecular oxygen or a molecular oxygen-containing gas in the presence of a copper halide catalyst is disclosed. The oxidation reaction is carried out in a multistage system under an oxygen partial pressure gradually decreasing from the former stage to the latter stage and at a conversion gradually decreasing from the former stage to the latter stage, while controlling the conversion so that the molar ratio of the benzophenone-imines to the copper halide in the final stage be maintained at 1 or more. By the process, the continuous reaction can stably be performed at a high conversion of the benzophenone-imines without involving insolubilization and sedimentation of the catalyst.