Agc Inc.

Asahi Glass Company, Limited

Yasushi Yamaki

Takuo Nishio

Takayuki Kaneko

Hiromitsu Kusano

Tamaki Chinsoga

Tatsuya Miyajima

Kosuke Sumikura

Satoru Hommura

Kazuo Umemura

Takumi Okuyama

Takayuki Endo

Shintaro Hayabe

Osamu Homma

The present invention provides composite particles which are capable of forming an ion exchange membrane with fewer defects and an ion exchange membrane. The composite particles according to the present invention comprise pellets comprising a fluorinated polymer having groups convertible to ion exchange groups, and a powder held on the pellet surface which comprises a polymer, wherein the powder has an average particle diameter of at least 1 μm and at most 1,000 μm, and the ratio of the average particle diameter of the pellets to the average particle diameter of the powder is 2 to 4,500.

Composite particles and ion exchange membrane

The present invention provides an ion exchange membrane can improve the current efficiency of a redox flow battery without a drop in voltage efficiency, when used in the redox flow battery. The ion exchange membrane of the present invention is an ion exchange membrane comprising a fluorinated polymer having sulfonic acid functional groups, wherein the difference (D−Dc) between the distance D between ionic clusters and the diameter Dc of ionic clusters as measured by the small angle X-ray scattering is 0.60 nm or more, and the ion exchange capacity of the fluorinated polymer is 0.95 meq/gram dry resin or more.

Ion exchange membrane suitable for redox flow battery

An ion exchange membrane containing a fluorinated polymer, wherein in a case where by Raman spectroscopy, polarized light orthogonal to the thickness direction of the ion exchange membrane is irradiated to obtain a spectrum chart, whereby the ratio of the peak area a2 of Raman shift 680 to 760 cmto the peak area al of Raman shift 1,025 to 1,095 cmis taken as A1, and by Raman spectroscopy, to a cross section in the thickness direction of the ion exchange membrane, polarized light parallel with the thickness direction is irradiated to obtain a spectrum chart, whereby the ratio of the peak area b2 of Raman shift 920 to 1,025 cmto the peak area b1 of Raman shift 1,025 to 1,095 cmis taken as B1, B1/A1 is at least 1.05.

Ion exchange membrane and method for producing dry ion exchange membrane

The present invention provides a strong polymer electrolyte membrane which can provide a water electrolyzer operable at low electrolysis voltage. The polymer electrolyte membrane of the present invention comprises a fluorinated polymer and a woven fabric, wherein the weight of the woven fabric is from 20 to 95 g/m, and the warp and weft of the woven fabric independently have a denier of from 30 to 100.

Polymer electrolyte membrane, membrane electrode assembly and water electrolyzer

To provide an ion exchange membrane for alkali chloride electrolysis for which membrane strength is increased while membrane resistance is reduced to reduce electrolysis voltage during alkali chloride electrolysis and which prevents peeling between layers (S) and a layer (C). The ion exchange membrane for alkali chloride electrolysis comprises a layer (C) which comprises a fluorinated polymer having carboxylic acid functional groups, at least two layers (S) which comprise a fluorinated polymer having sulfonic acid functional groups, and a reinforcing material, wherein the layers (S) include a layer (Sa) and a layer (Sb), the layer (Sa) is a layer which is adjacent to the layer (C), the layer (Sb) is a layer which is not adjacent to the layer (C), the reinforcing material is disposed in the layer (Sb) substantially in parallel to the layer (Sb) in a state not in contact with the layer (Sa), and the ion exchange capacity of the layer (Sa) is lower than the ion exchange capacity of the layer (Sb).

Ion exchange membrane for alkali chloride electrolysis and alkali chloride electrolysis apparatus

To provide an ion exchange membrane for alkali chloride electrolysis which has a low membrane resistance and which is capable of reducing the electrolysis voltage during the alkali chloride electrolysis, while increasing the membrane strength. An ion exchange membranefor alkali chloride electrolysis wherein a reinforcing materialobtained by weaving with reinforcing yarnsand sacrificial yarnsis embedded in a fluoropolymer having ion exchange groups, the ion exchange membranecomprises elution holes () formed by eluting at least a portion of a material of the sacrificial yarns, and in a cross section perpendicular to the length direction of the yarns, the total area (S) obtained by adding the cross-sectional area of an elution holeand the cross-sectional area of a sacrificial yarnremaining in the elution holeis from 500 to 1,200 &#x3bc;m, and the number (n) of elution holesbetween adjacent reinforcing yarnsis at least 10.

Ion exchange membrane for alkali chloride electrolysis, and alkali chloride electrolysis apparatus

To provide an ion exchange membrane for alkali chloride electrolysis which is a membrane having a high water permeability and being capable of maintaining a low electrolysis voltage while suppressing the amount of water supplied to a cathode chamber to be minimum, and which is capable of forming an aqueous alkali hydroxide solution having a high caustic alkali quality. The ion exchange membrane for alkali chloride electrolysis comprises a layermade of a fluorinated polymer having carboxylic acid functional groups, and a layerA and a layerB made of a fluorinated polymer having sulfonic acid functional groups, wherein a reinforcing materialcontaining reinforcing threadsis disposed between the layerA and the layerB, the thickness when dried, of the layeris from 9 to 28 &#x3bc;m, the layerB includes a layer having an ion exchange capacity of from 1.3 to 2.5 meq/g, the thickness when dried, of the layerB is from 6 to 100 &#x3bc;m, the layerA includes a layer having an ion exchange capacity of from 0.9 to 1.25 meq/g, and the thickness when dried, of the layerA is from 40 to 110 &#x3bc;m.

Ion exchange membrane for alkali chloride electrolysis, method for its production and alkali chloride electrolysis apparatus

To provide an ion exchange membrane for alkali chloride electrolysis which has high membrane strength and low membrane resistance, thereby capable of reducing the electrolysis voltage during alkali chloride electrolysis. In this ion exchange membrane () for alkali chloride electrolysis, a reinforcing materialformed by weaving reinforcing yarnsand sacrificial yarnsis disposed in a layer (S), and layer (S)has elution portionsformed by elution of at least portions of the sacrificial yarns. In a cross section perpendicular to reinforcing yarns of the warp, the average distance (d1) from the center of a reinforcing yarnto the center of the adjacent reinforcing yarn, the total area (P) obtained by adding the cross-sectional area of an elution portionand the cross-sectional area of a sacrificial yarnremaining in the elution portion, the number (n) of elution portions between adjacent reinforcing yarns, and the ion exchange capacity of a layer (Sa) located on the most anode side in the layer (S)during alkali chloride electrolysis, are controlled to be within specific ranges, respectively.

Ion exchange membrane for alkali chloride electrolysis, production method, and alkali chloride electrolysis apparatus

To provide a process for producing an ion exchange membrane for electrolysis which has a low membrane resistance and which is capable of reducing the electrolysis voltage during the electrolysis, even if the membrane strength is increased, an ion exchange membrane for electrolysis, a precursor membrane of an ion exchange membrane for electrolysis, and an electrolysis apparatus. In a fluorinated polymer having groups convertible to ion exchange groups, a reinforcing fabricA formed by weaving covered yarnseach comprising a reinforcing fabricand a sacrificial material covering at least a portion of the outer peripheral surface of the reinforcing yarn, to produce a precursor membrane of an ion exchange membrane, and from the precursor membrane, at least a portion of the sacrificial material in the reinforcing fabric is eluted to form a reinforcing material and at the same time, the groups convertible to ion exchange groups are converted to ion exchange groups, to produce an ion exchange membrane for electrolysis.

Process for producing ion exchange membrane for electrolysis, and ion exchange membrane for electrolysis

To provide an ion exchange membrane for alkali chloride electrolysis, which has low membrane resistance and which reduces the electrolysis voltage during alkali chloride electrolysis, even if the spacing between reinforcing yarns is made narrow to increase the membrane strength. This ion exchange membranefor alkali chloride electrolysis comprises a fluoropolymer containing ion exchange groups; a reinforcing material embedded in the fluoropolymer and formed of reinforcing yarns and optionally contained sacrificial yarns; and elution holes of the sacrificial yarns present between the reinforcing yarns, wherein in a cross section perpendicular to the length direction of the reinforcing yarns forming the reinforcing material, the average distance (d1) from the center of a reinforcing yarnto the center of the adjacent reinforcing yarnis from 750 to 1,000 &#x3bc;m, the total area (S) obtained by adding the cross-sectional area of an elution holeand the cross-sectional area of a sacrificial yarnremaining in the elution holeis from 500 to 5,000 &#x3bc;mper elution hole, and the number n of elution holesbetween adjacent reinforcing yarnsis from 4 to 6.

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&#x2032;) 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&#xb0; C. and less than 80&#xb0; 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).

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

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 membranefor alkali chloride electrolysis, having 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&#x2032;) 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)is from 3.0&#xd7;10to 25.0&#xd7;10&#x3a9;&#xb7;cm.

To provide an ion exchange membrane for alkali chloride electrolysis whereby it is possible to make the electrolysis voltage low and the current efficiency high at the time of performing electrolysis of an alkali chloride; a method for its production; and an alkali chloride electrolysis apparatus using it. The ion exchange membrane for alkali chloride electrolysis has a layer (C) comprising a fluorinated polymer having carbonic acid functional groups, and a layer (S) comprising a fluorinated polymer having sulfonic acid functional groups; a reinforcing material containing reinforcing threads is disposed in the layer (S); and when measured after the ion exchange membrane for alkali chloride electrolysis is immersed and held in a 32 mass % sodium hydroxide aqueous solution warmed at 90&#xb0; C. for 16 hours and subsequently immersed in a 32 mass % sodium hydroxide aqueous solution at 25&#xb0; C. for 3 hours, the AC resistance value A of the layer (S) and the AC resistance value B of the layer (C) satisfy the following formulae at the same time: 1(&#x3a9;&#xb7;cm)&#x2264;A&#x2264;10(&#x3a9;&#xb7;cm) and 200(&#x3a9;&#xb7;cm)&#x2264;B&#x2264;450(&#x3a9;&#xb7;cm).

To provide a method capable of efficiently producing an ion exchange membrane for alkali chloride electrolysis 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&#x2032;) 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, wherein 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 the layer (C), the value of resistivity is from 4.0&#xd7;10to 25.0&#xd7;10&#x3a9;&#xb7;cm, and the variation in resistivity is at most 4.0&#xd7;10&#x3a9;&#xb7;cm, and the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the alkaline aqueous solution.

To provide a cation exchange membrane which is less susceptible to swelling or elongation during electrolysis of a potassium chloride aqueous solution even without permitting water absorption or swelling immediately prior to mounting it in an electrolyzer, and a method whereby it possible to stably produce a potassium hydroxide aqueous solution without necessity to conduct an operation for water absorption or swelling immediately prior to mounting the membrane in the electrolyzer. A cation exchange membrane comprising a polymer having cation exchange groups, wherein in cations (100 mol %) contained in the cation exchange membrane, the total of potassium ions and sodium ions is at least 99 mol %, and in the total (100 mol %) of potassium ions and sodium ions contained in the cation exchange membrane, the potassium ions are 80-98 mol % and the sodium ions are 20-2 mol %.

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Chiyoda-ku, Japan

Yasushi Yamaki