Production method for ion exchange membrane for alkali chloride electrolysis, and production method for alkali chloride electrolysis apparatus

Patent metadata

Field	Value
Publication number	US-2018186950-A1
Application number	US-201815909013-A
Country	US
Kind code	A1
Filing date	Mar 1, 2018
Priority date	Sep 8, 2015
Publication date	Jul 5, 2018
Grant date	—

Abstract

To provide a method whereby it is possible to efficiently produce an ion exchange membrane for alkali chloride electrolysis, which has high current efficiency and high alkali resistance at the time of electrolyzing an alkali chloride. This is a method for producing an ion exchange membrane 1 for alkali chloride electrolysis, having a layer (C) 12 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 subjecting the groups convertible to carboxylic acid type functional groups to hydrolysis treatment to convert them to carboxylic acid type functional groups, wherein the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %); the proportion of structural units having carboxylic acid type functional groups in the fluorinated polymer (A) is from 14.00 to 14.50 mol %; and the resistivity in the layer (C) 12 is from 3.0×10 3 to 25.0×10 3 Ω·cm.

First claim

What is claimed is:

1 . A production method for an ion exchange membrane for alkali chloride electrolysis, which is a method for producing an ion exchange membrane for alkali chloride electrolysis having a layer containing a fluorinated polymer having carboxylic acid type functional groups, by immersing an ion exchange membrane precursor film having a precursor layer containing a fluorinated polymer having groups convertible to carboxylic acid type functional groups, in an alkaline aqueous solution containing an alkali metal hydroxide, a water-soluble organic solvent and water, and subjecting the groups convertible to carboxylic acid type functional groups to hydrolysis treatment to convert them to carboxylic acid type functional groups, wherein
the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %), the proportion of structural units having the carboxylic acid type functional groups in the fluorinated polymer having the carboxylic acid type functional groups, is from 14.00 to 14.50 mol %, in all structural units (100 mol %) in the fluorinated polymer having the carboxylic acid type functional groups, and the resistivity in the layer containing the fluorinated polymer having the carboxylic acid type functional groups is from 3.0×10 3 to 25.0×10 3 Ω·cm.

2 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , wherein the water content of the layer containing the fluorinated polymer having the carboxylic acid type functional groups is from 3.5 to 11.5 mass %.

3 . A production method for an ion exchange membrane for alkali chloride electrolysis, which is a method for producing an ion exchange membrane for alkali chloride electrolysis having a layer containing a fluorinated polymer having carboxylic acid type functional groups, by immersing an ion exchange membrane precursor film having a precursor layer containing a fluorinated polymer having groups convertible to carboxylic acid type functional groups, in an alkaline aqueous solution containing an alkali metal hydroxide, a water-soluble organic solvent and water, and subjecting the groups convertible to carboxylic acid type functional groups to hydrolysis treatment to convert them to carboxylic acid type functional groups, wherein
the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %), the proportion of structural units having the carboxylic acid type functional groups in the fluorinated polymer having the carboxylic acid type functional groups, is from 14.00 to 14.50 mol %, in all structural units (100 mol %) in the fluorinated polymer having the carboxylic acid type functional groups, and the water content of the layer containing the fluorinated polymer having the carboxylic acid type functional groups is from 3.5 to 11.5 mass %.

4 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , wherein the concentration of the alkali metal hydroxide is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %).

5 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 3 , wherein the concentration of the alkali metal hydroxide is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %).

6 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , wherein the concentration of the water-soluble organic solvent is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

7 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 3 , wherein the concentration of the water-soluble organic solvent is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

8 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 4 , wherein the concentration of the alkali metal hydroxide is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

9 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 5 , wherein the concentration of the alkali metal hydroxide is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

10 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 6 , wherein the concentration of the alkali metal hydroxide is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

11 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 7 , wherein the concentration of the alkali metal hydroxide is from 5 to 50 mass % in the alkaline aqueous solution (100 mass %).

12 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , wherein the alkali metal hydroxide is sodium hydroxide or potassium hydroxide.

13 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 3 , wherein the alkali metal hydroxide is sodium hydroxide or potassium hydroxide.

14 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , wherein the water-soluble organic solvent is at least one member selected from the group consisting of aprotic water-soluble organic solvents, alcohols and aminoalcohols.

15 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 3 , wherein the water-soluble organic solvent is at least one member selected from the group consisting of aprotic water-soluble organic solvents, alcohols and aminoalcohols.

16 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 14 , wherein the water-soluble organic solvent is at least one member selected from the group consisting of dimethyl sulfoxide, methyl alcohol, ethyl alcohol, propyl alcohol, 1-methoxy-2-propanol, triethanolamine, diethanolamine, isopropanolamine, triisopropanolamine, dimethylaminoethanol and diethylaminoethanol.

17 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 15 , wherein the water-soluble organic solvent is at least one member selected from the group consisting of dimethyl sulfoxide, methyl alcohol, ethyl alcohol, propyl alcohol, 1-methoxy-2-propanol, triethanolamine, diethanolamine, isopropanolamine, triisopropanolamine, dimethylaminoethanol and diethylaminoethanol.

18 . The production method for an ion exchange membrane for alkali chloride electrolysis according to claim 1 , which is a method for producing an ion exchange membrane for alkali chloride electrolysis further having a layer containing a fluorinated polymer having sulfonic acid type functional groups, wherein
the ion exchange membrane precursor film further has a precursor layer containing a fluorinated polymer having groups convertible to sulfonic acid type functional groups, the ion exchange membrane precursor film is immersed in the alkaline aqueous solution, and the groups convertible to carboxylic acid type functional groups are subjected to hydrolysis treatment and converted to carboxylic acid type functional groups, and at the same time, the groups convertible to sulfonic acid type functional groups are subjected to hydrolysis treatment and converted to sulfonic acid type functional groups.

19 . The prod

Assignees

• Asahi Glass Co Ltd

Inventors

• Chinsoga Tamaki
• Nishio Takuo
• Yamaki Yasushi
• Kaneko Takayuki

Classifications

• C08J5/22

  Films, membranes or diaphragms · CPC title

• C08J5/2293 Primary

  After-treatment of fluorine-containing membranes · CPC title

• C08J2300/102

  containing halogen atoms · CPC title

• C25B1/46

  in diaphragm cells · CPC title

• C25B1/34

  Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis · CPC title