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. 25, 2020
Filed:
Mar. 22, 2018
Nof Corporation, Tokyo, JP;
Midori Hirai, Kawasaki, JP;
Hiroki Yoshioka, Kawasaki, JP;
NOF CORPORATION, Tokyo, JP;
Abstract
A purification method of a polyethylene glycol compound having one carboxyl group. In the method, an aqueous solution of the compound having a pH of 8 to 11 is prepared, the aqueous solution and a mixed organic solvent are mixed at a temperature of 15° C. or more and 50° C. or less and the mixture is separated into an organic layer and an aqueous layer. In the mixed organic solvent, a ratio of solvent I is from 25 to 60% by mass, and a ratio of solvent II is from 75 to 40% by mass. Solvent I is a hydrocarbon, solvent II is a halogenated hydrocarbon, a mixing ratio Y (organic solvent I/organic solvent II), a temperature T (° C.) at mixing and a weight average molecular weight M of the compound satisfy a relationship of 3.11×10M+0.084≤Y−0.0135T≤−1.77×10M+0.404.