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. 25, 2024
Filed:
Mar. 25, 2020
Nof Corporation, Tokyo, JP;
Shota Sasaki, Kawasaki, JP;
Yuichi Takahashi, Kawasaki, JP;
Atsushi Sato, Kagawa, JP;
Tsuyoshi Takehana, Kawasaki, JP;
Toshihiko Hagihara, Kawasaki, JP;
NOF CORPORATION, Tokyo, JP;
Abstract
A method for producing a terminal carboxyl group-containing polyethylene glycol, which includes the following steps 1 and 2. Step 1: In a solution containing a polyethylene glycol having a hydroxyl group, an inorganic base 0.5 to 4 times the polyethylene glycol in mass, an aprotic solvent and water, mass of the water being 5 to 20 meq with respect to the inorganic base and mass of the water in the solution being 2,000 ppm or less, a compound of the formula (1) is reacted with the polyethylene glycol to obtain a polyethylene glycol ester: wherein X represents a leaving group, a represents an integer of 4 to 9, and Rrepresents a hydrocarbon group having 1 to 4 carbon atoms; Step 2: The polyethylene glycol ester is hydrolyzed to obtain a terminal carboxyl group-containing polyethylene glycol.