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:
Sep. 22, 2020
Filed:
Mar. 01, 2018
Agc Inc., Chiyoda-ku, JP;
Tamaki Chinsoga, Chiyoda-ku, JP;
Takuo Nishio, Chiyoda-ku, JP;
Yasushi Yamaki, Chiyoda-ku, JP;
Takayuki Kaneko, Chiyoda-ku, JP;
AGC Inc., Chiyoda-ku, JP;
Abstract
To provide a production method whereby an ion exchange membrane for alkali chloride electrolysis can be obtained which has high current efficiency, little variation in current efficiency and high alkaline resistance. This is a method for producing an ion exchange membranehaving a layer (C)containing a fluorinated polymer (A) having carboxylic acid type functional groups, by immersing an ion exchange membrane precursor film having a precursor layer (C') containing a fluorinated polymer (A′) having groups convertible to carboxylic acid type functional groups, in an aqueous alkaline solution comprising an alkali metal hydroxide, a water-soluble organic solvent and water, and converting the groups convertible to carboxylic acid type functional groups to carboxylic acid functional groups, wherein the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the aqueous alkaline solution (100 mass %); the temperature of the aqueous alkaline solution is at least 40° C. and less than 80° C.; and the proportion of structural units having carboxylic acid type functional groups in the fluorinated polymer (A) is from 13.0 to 14.50 mol % in all structural units (100 mol %) in the fluorinated polymer (A).