Agc Inc.

Asahi Glass Company, Limited

Hiromitsu Kusano

Yasushi Yamaki

Takayuki Kaneko

Takuo Nishio

Kazuo Umemura

Tetsuji Shimohira

Satoru Hommura

Susumu Saito

Yoshiaki Higuchi

Takayuki Endo

To provide a method for producing pellets from which an ion exchange membrane excellent in stability of the electrolysis voltage can be formed, pellets, and an ion exchange membrane. The method for producing pellets of the present invention is a method for producing pellets, which comprises extruding a melt containing a fluorinated polymer having groups convertible to ion exchange groups from a die of a melt-extruder to obtain a strand containing the fluorinated polymer, and cutting the strand to obtain pellets containing the fluorinated polymer,

Method for producing pellets

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

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 a method for producing a fluorinated cation exchange membrane, by which a fluorinated cation exchange membrane having a high effect to suppress attachment of the gas to the surface on the cathode side and having an excellent resistance to dropping of inorganic particles from a gas-releasing layer provided on the cathode side can be obtained. A method for producing a fluorinated cation exchange membranefor electrolysis comprising, on at least the cathode side, a layer (&#x3b1;1)containing a perfluorocarbon polymer (A) having carboxylic acid groups or precursor groups of carboxylic acid groups, and a gas-releasing layer (&#x3b1;2)provided on the cathode side of the layer (&#x3b1;1), which comprises applying to the surface of the layer (&#x3b1;1)a coating liquid containing inorganic particles having an average secondary particle size of from 0.5 to 1.5 &#x3bc;m, a binder and a dispersion medium in a mass ratio of the binder to the total mass of the inorganic particles and the binder of from 0.15 to 0.3, to form the gas-releasing layer (&#x3b1;2)

Production method for fluorinated cation exchange membrane

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 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 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 %.

Cation exchange membrane and method for producing potassium hydroxide aqueous solution

A reinforced electrolyte membrane having an electrolyte membrane containing a fluoropolymer having ion exchange groups, reinforced by a woven fabric made of a reinforcing thread and a sacrificial thread, where the sacrificial thread remains in the electrolyte membrane, a void is formed between the sacrificial thread and the electrolyte membrane, and 2000 &#x3bc;m&#x3c;A&#x3c;6000 &#x3bc;mand 0.3&#x2266;B/A&#x3c;1.0 are satisfied, where A is the total of a cross-sectional area of the sacrificial thread and a cross-sectional area of the void, and B is the cross-sectional area of the sacrificial thread.

Reinforced electrolyte membrane and process for producing same

To provide an ion exchange membrane for alkaline chloride electrolysis having a low electric resistance and further having a sufficient mechanical strength. To employ an ion exchange membrane containing a polymer having units (U1). Q, Q=a perfluoroalkylene group or the like; R, R=a perfluoroalkyl group or the like; X=an oxygen atom or the like; a=0 or the like; Y=a fluorine atom or the like; r=0 or 1; and M=a hydrogen atom or an alkali metal atom.

Ion-exchange membrane for alkaline chloride electrolysis

A cation exchange membrane which shows suppressed deterioration of the strength of the membrane in the upper portion of an electrolytic cell when the membrane is employed in the electrolytic cell and used for a long term, which can perform electrolysis with good production efficiency, and which can be produced simply with low cost; its production process and; such an electrolytic cell; are provided. A cation exchange membrane to be used for an electrolytic cell, which has a laminate structure comprising a first layer containing a fluoropolymer having sulfonic groups and a second layer containing a fluoropolymer having carboxylic groups and adjacent to the first layer, and which has a rectangular shape with a constant thickness;

Cation exchange membrane, production process thereof and electrolytic cell using the same

An electrolyte membrane characterized by comprising a porous body formed from a melt-moldable fluororesin and having interconnected pores and an ion exchange resin with which the interconnected pores are filled, is provided. Specifically, the porous body is formed, for example, from an ethylene/tetrafluoroethylene copolymer, a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene/[CF&#x2550;CF&#x2014;(OCFCFY)&#x2014;O&#x2014;(CF)&#x2014;SOH] copolymer (wherein Y is a fluorine atom or a trifluoromethyl group, a is an integer of 0 to 3, b is an integer of from 0 to 12, and c is 0 or 1, provided that when b=0, C=0), or the like. An electrolyte membrane reinforced by such a porous body has high mechanical strength even if it is thin, and is excellent in dimensional stability when hydrated, and a polymer electrolyte fuel cell with a membrane-electrode assembly having the electrolyte membrane provides a high output and is excellent in durability.

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Chiyoda-ku, Japan

Hiromitsu Kusano