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:
Jul. 29, 2025
Filed:
Sep. 15, 2020
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Shun Ishikawa, Ibaraki, JP;
MITSUBISHI GAS CHEMICAL COMPANY, INC., Tokyo, JP;
Abstract
The present application addresses the problem of providing a new method for producing a polycarbonate resin having excellent properties. This problem has been solved by providing a method for producing a polycarbonate resin containing a constituent unit derived from an aromatic dihydroxy compound represented by formula (1). The method includes polymerizing the aromatic dihydroxy compound represented by formula (1). During the polymerization, a raw material substance is used in which the concentration of compounds represented by formula (2), which are impurities, is 80 ppm or less relative to the total weight of the aromatic dihydroxy compound represented by formula (1) and the compounds represented by formula (2). (In formula (1) and formula (2), Rto R, X, a, b, m and n are as described in the description of the present application.)