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. 12, 2010
Filed:
Aug. 24, 2005
Shinsuke Fukuoka, Tokyo, JP;
Hiroshi Hachiya, Tokyo, JP;
Kazuhiko Matsuzaki, Tokyo, JP;
Hironori Miyaji, Tokyo, JP;
Shinsuke Fukuoka, Tokyo, JP;
Hiroshi Hachiya, Tokyo, JP;
Kazuhiko Matsuzaki, Tokyo, JP;
Hironori Miyaji, Tokyo, JP;
Asahi Kasei Chemicals Corporation, Tokyo, JP;
Abstract
According to the present invention, there are provided a high boiling point material separating column A and a diphenyl carbonate purifying column B each comprising a continuous multi-stage distillation column having specified structures, and there is provided a specific process that enables a high-purity diphenyl carbonate which is important as a raw material of a high-quality and high-performance polycarbonate to be produced stably for a prolonged period of time on an industrial scale of not less than 1 ton/hr from a reaction mixture containing the diphenyl carbonate using an apparatus in which these two continuous multi-stage distillation columns are connected together.