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:
Jun. 10, 2025
Filed:
Mar. 19, 2020
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Kazuyoshi Uera, Tokyo, JP;
Kohei Kamatani, Tokyo, JP;
Keisuke Tomita, Tokyo, JP;
Hisato Akimoto, Tokyo, JP;
MITSUBISHI GAS CHEMICAL COMPANY, INC., Tokyo, JP;
Abstract
A method for producing a polycarbonate copolymer which has siloxane constituent units represented by any of formulae (1-1) to (1-4) and prescribed polycarbonate constituent units, the method having a polymerization step for polymerizing a silane-based compound selected from among a prescribed diaryloxysilane compound, a prescribed dialkoxysilane compound and a prescribed silicon compound, a carbonate compound and a diol compound such as an aromatic diol compound or an alicyclic diol compound in the presence of a transesterification catalyst. The polymerization step is carried out in a molten state under reduced pressure while removing alcohols derived from the carbonate compound.