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:
Aug. 28, 2018
Filed:
Dec. 10, 2015
Idemitsu Kosan Co., Ltd., Tokyo, JP;
IDEMITSU KOSAN CO., LTD., Tokyo, JP;
Abstract
A method of producing a polycarbonate, including: introducing a tertiary amine into a reaction process; and performing interfacial polycondensation between an alkali aqueous solution of a dihydric phenol and phosgene in the presence of an organic solvent, in which: (i) a portion into which the tertiary amine is introduced comprises at least a tertiary amine storage tank, a tertiary amine supply pipe, and a diluent solvent supply pipe; (ii) the portion further includes a pressure control valve in the tertiary amine supply pipe on an upstream side of a merging portion with the diluent solvent supply pipe; and (iii) when a pressure Pof an inside of the tertiary amine storage tank pressurized by a pressurization gas and a pressure Pin a portion ranging from an outlet of the storage tank to an upstream side of the pressure control valve, a relationship of P≤Pis satisfied.