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.

Date of Patent:
Mar. 24, 1998

Filed:

Mar. 10, 1997
Applicant:
Inventors:

Keigo Nishihira, Ube, JP;

Shuji Tanaka, Ube, JP;

Yuki Nishida, Ube, JP;

Hirofumi Ii, Ube, JP;

Satoru Fujitsu, Ube, JP;

Katsumasa Harada, Ube, JP;

Ryoji Sugise, Ube, JP;

Koichi Kashiwagi, Ube, JP;

Takashi Doi, Ube, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
558274 ; 558271 ; 558272 ;
Abstract

A diaryl carbonate with a high degree of purity is produced at a high yield by (A) subjecting (a) a diaryl oxalate and a phenol compound or (b) an alkylaryl oxalate to transesterification reaction in one or two stages in the presence of a catalyst to prepare a diaryl oxalate, while removing a by-product from the reaction system; (B) collecting the diaryl oxalate from the resultant reaction product mixture of the step (A); (C) subjecting the diaryl oxalate to a decarbonylation reaction, preferably in the presence of a phosphorous compound-containing catalyst, to convert the diaryl oxalate to a corresponding diaryl carbonate, while removing a reaction by-product comprising carbon monoxide from the reaction system; and (D) collecting the diaryl carbonate from the reaction product mixture of the step (C).


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