Abstract: An ion-exchange membrane method electrolytic cell comprising a coil cushion arranged between a conductive plate and a cathode in a cathode chamber, and further an ion-exchange membrane arranged in contact with the cathode. The conductive plate is not perforated, and the coil cushion is arranged so that its axial direction is in agreement with the vertical direction of electrolytic cell. Preferably the coil cushion is made of a metal coil and has an impact resilience of 7-17 kPa. The cathode preferably has supported electrode catalyst and is made of an expanded metal with strands of 0.1-1.0 mm width and 0.1-1.0 mm thickness, and having SW of 0.5-5.0 mm and LW of 1.0-10 mm, and 48-60% open area. The electrolytic cell is energy-saving, and damage thereof can be avoided over a long period, and elevation of voltage and reduction of current efficiency with time can be minimized.

Abstract: Provided is a method of preventing reverse current flow through an ion exchange membrane electrolyzer, which method is capable of preventing a reverse current from being generated after stopping operation of the ion exchange membrane electrolyzer. A method of preventing reverse current flow through an ion exchange membrane electrolyzer 100, the ion exchange membrane electrolyzer 100 having an anode chamber 107 housing an anode, a cathode chamber 110 housing a cathode, an anode solution-supplying manifold 121 to feed anode solution to the anode chamber 107, and a cathode solution-supplying manifold 124 to feed cathode solution to the cathode chamber 110.

Abstract: Disclosed is an electrolysis method, whereby sodium chloride concentration of an aqueous caustic soda solution formed through electrolysis in a two-chamber ion-exchange membrane sodium chloride electrolytic cell, which is equipped with a gas diffusion electrode as a cathode and divided into an anode chamber containing an anode and a cathode gas chamber containing the cathode that are partitioned by an ion-exchange membrane, is lowered. In a two-chamber ion-exchange membrane electrolytic cell (1) using a gas diffusion electrode (7), electrolysis is performed while reducing the pressure difference between the liquid pressure in the anode chamber and the gas pressure in the cathode gas chamber, i.e.

Abstract: The current invention is to provide an oxygen gas diffusion cathode for brine electrolysis which reduces an initial electrolysis voltage and is excellent in the durability against short-circuit, and an electrolytic cell and an electrolytic method using the same. The oxygen gas diffusion cathode for brine electrolysis includes a gas diffusion layer 13 and a reaction layer 14 on one surface of an electro-conductive substrate 12, and an electro-conductive layer 15 on the opposite surface thereof. The present oxygen gas diffusion cathode reduces the resistance of the electro-conductive substrate 12 and supplies uniform current by mounting the electro-conductive layer 15.

Abstract: Provided are an elastic cushion member and an ion exchange membrane electrolyzer using the same, which elastic cushion member can be installed even in an ion exchange membrane electrolyzer having such a small gap between an electrode and an electrode current collecting plate that a conventional elastic cushion member cannot be arranged therein. An elastic cushion member (10) has a pair of corrosion-resistant metal thin plates (11) arranged at a distance in parallel fashion and a fixing member (12) which fixes the pair of corrosion-resistant metal thin plates (11) and comprises a metal elastic body (13) wound between the pair of corrosion-resistant metal thin plates (11). The fixing member (12) is attached to the pair of corrosion-resistant metal thin plates (11) in a manner that enables detachment of the fixing member therefrom. The metal elastic body (13) is preferred to be a metal coil body.

Abstract: Provided is a cell for ion exchange membrane electrolysis obtained by improving the performance in electrolysis of an existing bipolar cell for ion exchange membrane electrolysis, in which a cathode partition wall and a rigid cathode being connected together by a plurality of intermediating V-shaped springs, by a simple method. It is a cell for ion exchange membrane electrolysis which is separated by an ion exchange membrane (7) into an anode chamber (1) having a rigid anode (1a) and an anode partition wall (1b) and a cathode chamber (2) having a rigid cathode (2a) and a cathode partition wall (2b), the rigid cathode (2a) and the cathode partition wall (2b) being connected together by a plurality of intermediating V-shaped springs (3).

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein the ion exchange membrane and a cathode chamber inner space in which the gas diffusion electrode is disposed are separated by a liquid retaining member, the outer periphery of the liquid retaining member is held in a void formed in a gasket or a cathode chamber frame constituting the cathode chamber, or the outer periphery and the end face of the outer periphery of the liquid retaining member are sealed, or the outer periphery of the liquid retaining member is joined to and integrated with the gasket.

Abstract: The present invention relates to an apparatus to produce oxidizing agent-rich sulfuric acid by electrolysis of sulfuric acid. More specifically, it relates to the apparatus by which dilute sulfuric acid of the specified temperature and concentration is formed within the electrolysis system and then, by electrolysis of the formed dilute sulfuric acid, electrolytic sulfuric acid containing richly oxidizing agent is formed at a high efficiency and safely under the temperature control.

Abstract: Provided are: a method of measuring the total concentration of oxidizing agents, by which the total concentration can be determined in a single measurement with simple operations even in an evaluation solution containing multiple components such as persulfuric acid, perosulfate and hydrogen peroxide; a simple and inexpensive concentration meter for measuring the total concentration of oxidizing agents; and a sulfuric acid electrolysis device comprising the concentration meter. The method according to the present invention is a method of measuring the total concentration of oxidizing agent(s) in an evaluation solution containing at least one oxidizing agent. The method comprises at least the steps of: heat-treating the evaluation solution at 50 to 135° C.; and detecting hydrogen peroxide in the thus heat-treated evaluation solution.

Abstract: An ion-exchange membrane method electrolytic cell comprising a coil cushion arranged between a conductive plate and a cathode in a cathode chamber, and further an ion-exchange membrane arranged in contact with the cathode. The conductive plate is not perforated, and the coil cushion is arranged so that its axial direction is in agreement with the vertical direction of electrolytic cell. Preferably the coil cushion is made of a metal coil and has an impact resilience of 7-17 kPa. The cathode preferably has supported electrode catalyst and is made of an expanded metal with strands of 0.1-1.0 mm width and 0.1-1.0 mm thickness, and having SW of 0.5-5.0 mm and LW of 1.0-10 mm, and 48-60% open area. The electrolytic cell is energy-saving, and damage thereof can be avoided over a long period, and elevation of voltage and reduction of current efficiency with time can be minimized.

Abstract: The present invention provides an electrically conductive diamond electrode comprising an electrically conductive substrate and an electrically conductive diamond layer coated on the surface of the electrically conductive substrate, featuring that: 1) the thickness of the electrically conductive diamond layer is 1˜25 ?m, 2) the potential window fulfills Equation (1) and 3) the ratio (A/B) of the diamond component A and the non-diamond component B by the Raman spectroscopic analysis fulfills Equation (2). 2.1V?potential window?3.5V??(1) 1.5<A/B?6.5??(2) A: Intensity at the wave number 1300 cm?1 by the Raman spectroscopic analysis B: Intensity at the wave number 1500 cm?1 by the Raman spectroscopic analysis.

Abstract: A cleaning method includes: producing an oxidizing solution by electrolysis of sulfuric acid; and cleaning a workpiece with the oxidizing solution. The oxidizing solution is heated by heat of mixing to clean the workpiece. A method for manufacturing an electronic device includes: producing a workpiece; producing an oxidizing solution by electrolysis of sulfuric acid; and cleaning the workpiece with the oxidizing solution. The oxidizing solution is heated by heat of mixing to clean the workpiece.

Abstract: The present invention relates to a conductive diamond electrode, comprising a substrate having a plurality of convex and concave part disposed over the entire surface of the conductive diamond electrode, and a diamond film coated on the surface of said substrate, wherein the width of each convex part of said convex and concave part is in a range from 0.2 mm to 1 mm. The present invention can provide a conductive diamond electrode, applying a thin film of conductive diamond and a thick substrate, being less expensive than a self-supported type conductive diamond electrode and also having mechanical strength enough to be used in the zero-gap electrolysis, functioning stably for a long time with smooth water supply or gas liberation, and an ozone generator using the conductive diamond electrode.

Abstract: An apparatus for electrolyzing sulfuric acid, the apparatus comprising an electrolytic cell comprising a cathode chamber having a cathode and an anode chamber having an anode, the cathode chamber and the anode chamber being separated by a diaphragm, a sulfuric acid tank configured to store the sulfuric acid, a supply pipe connecting the sulfuric acid tank to an inlet port of the anode chamber, a connection pipe connecting an outlet port of the cathode chamber to the inlet port of the anode chamber, a first supply pump provided on the supply pipe and configured to supply the sulfuric acid from the sulfuric acid tank to the cathode chamber through the supply pipe, and a drain pipe connected to an outlet port of the anode chamber and configured to supply to a solution tank a solution containing an oxidizing agent generated by electrolysis in the anode chamber.

Abstract: The present invention provides an ozone generator comprising an anode and a cathode provided on each side of a fluororesin type cation exchange membrane, the anode being a conductive diamond electrode having conductive diamond on the surface, wherein water is supplied to an anode compartment, DC current is supplied between the anode and the cathode to electrolyze water to evolve ozone from the anode compartment and hydrogen from a cathode compartment, the conductive diamond electrode comprising a substrate having a plurality of convexo-concave and a conductive diamond film coated on the surface of the substrate is applied as the conductive diamond electrode, and a close packed layer of ion exchange resin particles or the fluororesin type cation exchange membrane with notch is closely adhered to the surface of the anode side of the fluororesin type cation exchange membrane.

Abstract: Sulfuric acid electrolysis process wherein; a temperature of electrolyte containing sulfuric acid to be supplied to an anode compartment and a cathode compartment is controlled to 30 degree Celsius or more; a flow rate F1 (L/min.) of the electrolyte containing sulfuric acid to be supplied to said anode compartment is controlled to 1.5 times or more (F1/Fa?1.5) a flow rate Fa (L/min.) of gas formed on an anode side as calculated from Equation (1) shown below and a flow rate F2(L/min.) of said electrolyte containing sulfuric acid to be supplied to said cathode compartment is controlled to 1.5 times or more (F2/Fc?1.5) a flow rate Fe (L/min.) of gas formed on a cathode side as calculated from Equation (2) shown below. Fa=(I×S×R×T)/(4×Faraday constant)??Equation (1) Fe=(I×S×R×T)/(2×Faraday constant)??Equation (2) I: Electrolytic current (A) S: Time: 60 second (Fixed) R: Gas constant (0.082 1·atm/K/mol) K: Absolute temperature (273.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein the ion exchange membrane and a cathode chamber inner space in which the gas diffusion electrode is disposed are separated by a liquid retaining member, the outer periphery of the liquid retaining member is held in a void formed in a gasket or a cathode chamber frame constituting the cathode chamber, or the outer periphery and the end face of the outer periphery of the liquid retaining member are sealed, or the outer periphery of the liquid retaining member is joined to and integrated with the gasket.

Abstract: [Problems] The liquid pressure of an anode chamber in a two-chamber ion exchange membrane electrolytic cell using a gas diffusion electrode are different among one another depending on depths so that the liquid pressures are applied on an anode or an ion exchange membrane, thereby introducing damage or deformation of the elements. [Means for Solving] A cushion material 10 is accommodated between a cathode gas chamber back plate 9 and a gas diffusion electrode 7 of an ion exchange membrane electrolytic cell 1 such that a repulsive force of the cushion material at the bottom part of the cathode gas chamber is larger than that at the top part. The excessive pressure applied to an ion exchange membrane is suppressed to prevent the generation of scratches or the like by decreasing the repulsive force of the cushion material toward the top in accordance with a differential pressure between an anode chamber pressure and a cathode gas chamber pressure.

Abstract: The cleaning method by electrolytic sulfuric acid and the manufacturing method of semiconductor device comprising: the process in which the first sulfuric acid solution is supplied from outside to the sulfuric acid electrolytic cell to form the first electrolytic sulfuric acid containing oxidizing agent in the sulfuric acid electrolytic cell; the process in which the second sulfuric acid solution, which is higher in concentration than said the first sulfuric acid solution previously supplied, is supplied from outside to said sulfuric acid electrolytic cell; said the second sulfuric acid solution and the first electrolytic sulfuric acid are mixed in said sulfuric acid electrolytic cell; and electrolysis is performed to form the cleaning solution comprising the second electrolytic sulfuric acid containing sulfuric acid and oxidation agent in said sulfuric acid electrolytic cell and the process in which cleaning treatment is performed for the cleaning object with said cleaning solution.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion-exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein in a cathode gas chamber formed between a back plate of the cathode chamber and one side of the gas diffusion electrode opposite to the electrolytic surface, a gas-permeable elastic member is disposed between the gas diffusion electrode and the back plate, and the elastic member forms a conductive connection between the gas diffusion electrode and the back plate by making contact with corrosion-resistant conductive layers formed on the surfaces of a plurality of conductive members which are joined to the back plate.