Abstract: A solid electrolytic capacitor is obtained by a method which includes dissolving a polymerizable material for being converted into a conductive polymer in a water-soluble organic solvent to obtain a solution, adding the solution to water while homogenizing the solution to obtain a sol, immersing an anode body having a dielectric layer in the surface of the anode body in the sol, and applying voltage using the anode body as a positive electrode and a counter electrode as a negative electrode placed in the sol to electropolymerize the polymerizable material. An electropolymerizable liquid for producing a conductive polymer, the liquid composed of a sol comprising water, a water-soluble organic solvent, and a polymerizable material for being converted into the conductive polymer.

Abstract: Disclosed is a solid electrolytic capacitor element including a dielectric layer, a first conductive polymer semiconductor layer, a second conductive polymer semiconductor layer and a conductor layer, formed in that order, on a tungsten anode body having an externally protruding lead wire, and the thickness of the thickest portion of the second conductive polymer semiconductor layer on the lower surface opposite the upper surface from which the lead wire protrudes is thinner than the thickness of the thickest portion of the second conductive polymer semiconductor layer on the side surfaces, and the thickness of the second conductive polymer semiconductor layer on the lower surface is greater than 2 ?m and less than 15 ?m.

Abstract: A solid electrolytic capacitor is obtained by a method which includes dissolving a polymerizable material for being converted into a conductive polymer in a water-soluble organic solvent to obtain a solution, adding the solution to water while homogenizing the solution to obtain a sol, immersing an anode body having a dielectric layer in the surface of the anode body in the sol, and applying voltage using the anode body as a positive electrode and a counter electrode as a negative electrode placed in the sol to electropolymerize the polymerizable material. An electropolymerizable liquid for producing a conductive polymer, the liquid composed of a sol comprising water, a water-soluble organic solvent, and a polymerizable material for being converted into the conductive polymer.

Abstract: A solid electrolytic capacitor is obtained by a method comprising dissolving a polymerizable material for being converted into a conductive polymer in a water-soluble organic solvent to obtain a solution, adding the solution to water while homogenizing the solution to obtain a sol, immersing an anode body having a dielectric layer in the surface of the anode body in the sol, and applying voltage using the anode body as a positive electrode and a counter electrode as a negative electrode placed in the sol to electropolymerize the polymerizable material. An electropolymerizable liquid for producing a conductive polymer, the liquid composed of a sol comprising water, a water-soluble organic solvent, and a polymerizable material for being converted into the conductive polymer.

Abstract: A method for finely powdering tungsten powder, which includes: a process for classifying a material tungsten powder into a fine powder having a relatively small average particle diameter and a coarse powder having a relatively large average particle diameter; an oxidation process for forming an oxide film on the particle surface of the coarse powder; and an alkali treatment process for removing the oxide film formed in the oxidation process and a natural oxide film formed on the fine powder with an alkali aqueous solution. Also disclosed is a method for producing ultrafine tungsten powder, which includes obtaining tungsten powder having an average particle diameter of 0.04 to 0.4 ?m and a BET specific surface area of 5 to 15 m2/g by the above method for finely powdering.

Abstract: A capacitor element sequentially including a dielectric layer containing an amorphous tungsten oxide, a layer coating a part or all of the dielectric layer and containing a crystalline tungsten oxide, a semiconductor layer and a conductor layer on a tungsten-containing anode body. The capacitor element is manufactured by a method including a sintering step of forming an anode body by sintering a formed body of a tungsten powder; a step of forming a dielectric layer by subjecting the anode body to a chemical conversion treatment; a step of forming a crystalline tungsten oxide layer on the dielectric layer; a step of forming a semiconductor layer for forming a semiconductor layer; and a step of forming a conductor layer for forming a conductor layer; in this order.

Abstract: A method for finely powdering tungsten powder, which includes dispersing tungsten powder in an aqueous solution containing an oxidizing agent to form an oxide film in the surface of the tungsten powder and removing the oxide film with an alkaline aqueous solution. Also disclosed is a method for producing fine tungsten powder, which includes obtaining tungsten powder having an average particle size of 0.05 to 0.5 ?m by a process including the above method for finely powdering. Also disclosed is a tungsten powder having an average particle size of 0.05 to 0.5 ?m, in which the dMS value (product of an average particle size d (?m), true density M (g/cm3) and BET specific surface area S (m2/g)) is within the range of 6±0.8.

Abstract: A carbon paste including a carbon powder, a resin, and an oxygen releasing oxidizer. The amount of the oxidizer is 3 to 30 parts by mass based on 100 parts by mass of the total amount of the carbon powder and the resin. A solid electrolytic capacitor element is prepared by a method which includes making a valve-action metal powder sintered to obtain an anode body, electrolytically oxidizing a surface of the anode body to chemically convert the surface into a dielectric layer, electrolytic polymerization to form a semiconductor layer of an electro conductive polymer on the dielectric layer, applying the carbon paste onto the semiconductor layer, and drying and hardening the carbon paste to form a carbon layer.

Abstract: A method for producing a solid electrolytic capacitor element, which includes, in the following order, a sintering step of sintering a valve-acting metal to form an anode body, a chemical conversion step to form a dielectric layer on the surface layer of the anode body, a step of forming a semiconductor layer comprising a conductive polymer by immersing the anode body in a solution of monomers of a conductive polymer to thereby polymerize the monomers, and a step of forming a conductor layer on the anode body. The method is characterized in conducting the step of forming a semiconductor layer under the condition where photopolymerization of the monomers of the conductive polymer is not caused.

Abstract: A method for producing an anode body in a capacitor, which includes making a molded body by molding a tungsten powder and making an anode body by sintering the molded body, which includes a step of bringing the tungsten powder or the molded body thereof into contact with a solution of a silicon compound before sintering the molded body so as to adjust the silicon content in the anode body to 0.05 to 7 mass %.

Abstract: A method for finely powdering tungsten powder, which includes dispersing tungsten powder in an aqueous solution containing an oxidizing agent to form an oxide film in the surface of the tungsten powder and removing the oxide film with an alkaline aqueous solution. Also disclosed is a method for producing fine tungsten powder, which includes obtaining tungsten powder having an average particle size of 0.05 to 0.5 ?m by a process including the above method for finely powdering. Also disclosed is a tungsten powder having an average particle size of 0.05 to 0.5 ?m, in which the dMS value (product of an average particle size d (?m), true density M (g/cm3) and BET specific surface area S (m2/g)) is within the range of 6±0.8.

Abstract: The present invention provides an anode body for capacitors, which is formed of a sintered body that is obtained by sintering a powder mixture of a tungsten powder and a tungsten trioxide powder, and wherein the ratio of the tungsten trioxide powder to the total amount of the tungsten powder and the tungsten trioxide powder is 1 to 13 mass %. The present invention is able to reduce the number of semiconductor layer formation wherein polymerization of a semiconductor precursor is carried out a plurality of times on a dielectric layer. Consequently, a solid electrolytic capacitor element, in which a semiconductor layer that is composed of a conductive polymer is formed on a dielectric layer that is formed on the outer surface layer and the inner surface layer of the fine pores of a tungsten sintered body, can be produced efficiently.

Abstract: An anode body for a capacitor and method for producing the same, which method includes compressing a powder mixture containing a tungsten powder and a high-oxygen-affinity metal powder into a compact with a wire rod planted therein, and firing the compact into a sintered compact. The high-oxygen-affinity metal has an oxygen affinity higher than that of tungsten. The content of the high-oxygen-affinity metal powder in the powder mixture is regulated so that the content of the high-oxygen-affinity metal in the sintered compact is 0.1 to 3% by mass based on the mass of the tungsten in the sintered compact. The wire rod includes tantalum or niobium. Also disclosed is an electrolytic capacitor including the anode body.

Abstract: A method for producing a capacitor element, which includes aging process A of applying a voltage of ? to ? of the chemical formation voltage to the capacitor element having an electrically conductive layer formed on an anode body under conditions of a temperature of 15 to 50° C. and a humidity of 75 to 90% RH; or a method for producing a capacitor element including, before the above-mentioned process A, process B of retaining the capacitor element having an electrically conductive layer formed on the anode body at a temperature more than 50° C. and 85° C. or less and a humidity of 50 to 90% RH.

Abstract: Disclosed is a solid electrolytic capacitor element including a dielectric layer, a first conductive polymer semiconductor layer, a second conductive polymer semiconductor layer and a conductor layer, formed in that order, on a tungsten anode body having an externally protruding lead wire, and the thickness of the thickest portion of the second conductive polymer semiconductor layer on the lower surface opposite the upper surface from which the lead wire protrudes is thinner than the thickness of the thickest portion of the second conductive polymer semiconductor layer on the side surfaces, and the thickness of the second conductive polymer semiconductor layer on the lower surface is greater than 2 ?m and less than 15 ?m.

Abstract: A method for manufacturing a tungsten capacitor element, which includes: a sintering process for forming an anode body by sintering a tungsten powder or a molded body thereof, a chemical conversion process for forming a dielectric layer on the surface layer of the anode body, a process for forming a semiconductor layer on the dielectric layer, a post-chemical conversion process for repairing the defects generated on the dielectric layer, a non-aqueous electrolysis process for conducting electrolysis operation by immersing the anode body in a solution of a non-aqueous solvent containing an oxidizing agent, and a process of forming a conductor layer on the anode body, in this order.

Abstract: A method for manufacturing a tungsten capacitor element, which includes: a sintering process for forming an anode body by sintering a tungsten powder or a molded body thereof, a chemical conversion process for forming a dielectric layer on the surface layer of the anode body, a process for forming a semiconductor layer on the dielectric layer, a post-chemical conversion process for repairing the defects generated on the dielectric layer, a non-aqueous electrolysis process for conducting electrolysis operation by immersing the anode body in a solution of a non-aqueous solvent containing an oxidizing agent, and a process of forming a conductor layer on the anode body, in this order.

Abstract: A carbon paste including a carbon powder, a resin, and an oxygen releasing oxidizer. The amount of the oxidizer is 3 to 30 parts by mass based on 100 parts by mass of the total amount of the carbon powder and the resin. A solid electrolytic capacitor element is prepared by a method which includes making a valve-action metal powder sintered to obtain an anode body, electrolytically oxidizing a surface of the anode body to chemically convert the surface into a dielectric layer, electrolytic polymerization to form a semiconductor layer of an electro conductive polymer on the dielectric layer, applying the carbon paste onto the semiconductor layer, and drying and hardening the carbon paste to form a carbon layer.

Abstract: A method for finely powdering tungsten powder, which includes: a process for classifying a material tungsten powder into a fine powder having a relatively small average particle diameter and a coarse powder having a relatively large average particle diameter; an oxidation process for forming an oxide film on the particle surface of the coarse powder; and an alkali treatment process for removing the oxide film formed in the oxidation process and a natural oxide film formed on the fine powder with an alkali aqueous solution. Also disclosed is a method for producing ultrafine tungsten powder, which includes obtaining tungsten powder having an average particle diameter of 0.04 to 0.4 ?m and a BET specific surface area of 5 to 15 m2/g by the above method for finely powdering.

Abstract: A method for producing an anode body in a capacitor, which includes making a molded body by molding a tungsten powder and making an anode body by sintering the molded body, which includes a step of bringing the tungsten powder or the molded body thereof into contact with a solution of a silicon compound before sintering the molded body so as to adjust the silicon content in the anode body to 0.05 to 7 mass %.