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:
Oct. 25, 2011
Filed:
Jul. 23, 2009
Shinsuke Fukuoka, Tokyo, JP;
Hironori Miyaji, Tokyo, JP;
Hiroshi Hachiya, Tokyo, JP;
Kazuhiko Matsuzaki, Tokyo, JP;
Shinsuke Fukuoka, Tokyo, JP;
Hironori Miyaji, Tokyo, JP;
Hiroshi Hachiya, Tokyo, JP;
Kazuhiko Matsuzaki, Tokyo, JP;
Asahi Kasei Chemicals Corporation, Tokyo, JP;
Abstract
An aromatic polycarbonate that is obtained by transesterification between a high-purity diphenyl carbonate and an aromatic dihydroxy compound. A specific industrially useful process for the production of a high-purity diaryl carbonate in which a diaryl carbonate having low contents of intermediate boiling point and high boiling point impurities is produced is disclosed. As a starting material, a reaction mixture containing an alkyl aryl carbonate obtained through a transesterification reaction between a dialkyl carbonate and an aromatic monohydroxy compound is used. The process in which separation by distillation is carried out uses three distillation columns in a specified order. Moreover, it is particularly preferable if a reactive distillation column and the three distillation columns, each of which has a specified structure, and the three distillation columns are each operated under specified distillation conditions.