Abstract: The aim of the present invention is to provide a metal powder for an electroconductive paste with which a low-resistance electrode film can be formed. One embodiment of the present invention relates to a platinum-containing or platinum-alloy-containing metal powder for an electroconductive paste, the metal powder including a metal element or metal elements other than Pt, wherein the metal elements other than Pt include at least Ca, and may further include Al and Zr, and the total content of the Ca, Al and Zr among the metal elements other than Pt is 10-900 mass ppm.

Abstract: The present invention aims at providing an electrode having more sufficient electrode activity and electrical conductivity as a sensor electrode for various gas sensors than conventional sensor electrodes. The present invention relates to a gas sensor electrode including a platinum-containing layer having mixed and dispersed therein a conductive particle phase composed of Pt or a Pt alloy and a ceramic particle phase, and a ceramic layer containing a ceramic material, wherein the platinum-containing layer and the ceramic layer are porous, and the porosity of the ceramic layer as measured by image analysis of a cross-sectional SEM appearance is from 1 to 40% and the average pore size of the ceramic layer is from 0.1 to 5 ?m.

Abstract: The present invention is to provide a metal paste capable of forming electrodes which have sufficient electrode activity and electroconductivity as compared with conventional ones and are useful as the sensor electrodes of various gas sensors. The present invention relates to a metal paste for gas sensor electrode formation formed by dispersing conductive particles including Pt or a Pt alloy and ceramic powder into a solvent and the metal paste further includes inorganic-oxide particles including alumina and insoluble organic particles or carbon or diamond powder, the ceramic powder including a ceramic powder having a particle diameter of 0.5 ?m or larger in an amount of 10-80% by mass based on the whole ceramic powder.

Abstract: To be provided is a metal paste from which an electrode having high electrode activity as a sensor electrode of various gas sensors can be produced. The present invention is a metal paste for forming a gas sensor electrode obtained by dispersing a conductive particle including Pt or a Pt alloy and a ceramic powder including zirconia or stabilized zirconia, or any of zirconia and stabilized zirconia and one or more oxides of La, Ce, Pr, Nd, Sm, and Hf in a solvent, the metal paste further including an inorganic oxide particle containing alumina and an insoluble particle that is insoluble in the solvent, in which 0.5 or more to 3.0 mass % or less of the inorganic oxide particle and 1.0 to 5.0 mass % of the insoluble particle are dispersed based on the mass of the solid content of the conductive particle, the ceramic powder, the inorganic oxide particle, and the insoluble particle.

Abstract: To be provided is a metal paste from which an electrode having high electrode activity as a sensor electrode of various gas sensors can be produced. The present invention is a metal paste for forming a gas sensor electrode obtained by dispersing a conductive particle including Pt or a Pt alloy and a ceramic powder including zirconia or stabilized zirconia, or any of zirconia and stabilized zirconia and one or more oxides of La, Ce, Pr, Nd, Sm, and Hf in a solvent, the metal paste further including an inorganic oxide particle containing alumina and an insoluble particle that is insoluble in the solvent, in which 0.5 or more to 3.0 mass % or less of the inorganic oxide particle and 1.0 to 5.0 mass % of the insoluble particle are dispersed based on the mass of the solid content of the conductive particle, the ceramic powder, the inorganic oxide particle, and the insoluble particle.

Abstract: The present invention relates to a gas sensor electrode including a conductive particle phase made of Pt or Pt alloy and a ceramic particle phase being mixed and dispersed, wherein a rate of content of the ceramic particle phase is 6.0 to 22.0 mass %, and a void ratio is 2.5 to 10.0%, and a dispersion degree of the conductive particle phase per length of 25 ?m on the electrode surface is 0.60 to 0.85 ?m, and a dispersion degree of the conductive particle phase in the electrode cross section per length of 100 ?m in a direction parallel to the electrode surface is 2.0 to 4.0 ?m. This electrode can be produced by firing a metal paste made by dispersing, in a solvent, a conductive particle having a core/shell structure in which a core particle such as Pt is covered with a ceramic shell and ceramic powder. The gas sensor electrode according to the present invention has a high electrode activity.

Abstract: To be provided is a metal paste from which an electrode having high electrode activity as a sensor electrode of various gas sensors can be produced. The present invention is a metal paste for forming a gas sensor electrode obtained by dispersing a conductive particle including Pt or a Pt alloy and a ceramic powder including zirconia or stabilized zirconia, or any of zirconia and stabilized zirconia and one or more oxides of La, Ce, Pr, Nd, Sm, and Hf in a solvent, the metal paste further including an inorganic oxide particle containing alumina and an insoluble particle that is insoluble in the solvent, in which 0.5 or more to 3.0 mass % or less of the inorganic oxide particle and 1.0 to 5.0 mass % of the insoluble particle are dispersed based on the mass of the solid content of the conductive particle, the ceramic powder, the inorganic oxide particle, and the insoluble particle.

Abstract: The present invention relates to a technique for recovering and recycling a platinum paste. The present invention provides a method for recovering a metal powder from a platinum paste formed by mixing a solid component composed of a metal powder including at least a platinum powder or a platinum alloy powder and an organic component including at least an organic solvent, the method including removing the organic component by heating the platinum paste at a recovery temperature set in a temperature range of 300° C. or higher and 500° C. or lower. The recovered metal powder can be recycled into a platinum paste equivalent to a new product by mixing the metal powder with a solvent etc.

Abstract: An object of the present invention is to provide a conductive fine particle for producing a metal paste that can produce an electrode film having a low resistance, and a metal paste utilizing the conductive fine particle. The present invention is a conductive particle for electrode formation having a core/shell structure, and the conductive particle comprises a core particle made of Pt or a Pt alloy and having a particle diameter of 10 to 200 nm, and a shell made of a ceramic containing Al2O3 or ZrO2 and covers at least a part of the core particle, wherein the ceramic constituting the shell is added in an amount of 0.5 to 15% by weight based on the core particle to cover the core. The core particle is preferably Pt or a Pt alloy alloyed with Pd, Au, Ag, or Rh.

Abstract: The present invention is an electroconductive particle for forming an electrode including a precious metal particle including Pt or a Pt alloy and having an average particle diameter of 50 to 150 nm, a first ceramic particle including Al2O3 or ZrO2 dispersed in the precious metal particle and having an average particle diameter of 5 to 50 nm, and a second ceramic particle including Al2O3 or ZrO2 bonded to an outer periphery of the precious metal particle and having an average particle diameter of 5 to 50 nm. The sum of the volume of the first ceramic particle and the volume of the second ceramic particle is preferably 2 to 40 vol % based on the whole electroconductive particle. A metal paste containing the electroconductive particle according to the invention is one from which an electrode film of low resistance and excellent durability can be manufactured and further excellent in adherence and conformability to a substrate.

Abstract: To be provided is a metal paste from which an electrode having high electrode activity as a sensor electrode of various gas sensors can be produced. The present invention is a metal paste for forming a gas sensor electrode obtained by dispersing a conductive particle including Pt or a Pt alloy and a ceramic powder including zirconia or stabilized zirconia, or any of zirconia and stabilized zirconia and one or more oxides of La, Ce, Pr, Nd, Sm, and Hf in a solvent, the metal paste further including an inorganic oxide particle containing alumina and an insoluble particle that is insoluble in the solvent, in which 0.5 or more to 3.0 mass % or less of the inorganic oxide particle and 1.0 to 5.0 mass % of the insoluble particle are dispersed based on the mass of the solid content of the conductive particle, the ceramic powder, the inorganic oxide particle, and the insoluble particle.

Abstract: The present invention relates to a gas sensor electrode including a conductive particle phase made of Pt or Pt alloy and a ceramic particle phase being mixed and dispersed, wherein a rate of content of the ceramic particle phase is 6.0 to 22.0 mass %, and a void ratio is 2.5 to 10.0%, and a dispersion degree of the conductive particle phase per length of 25 ?m on the electrode surface is 0.60 to 0.85 ?m, and a dispersion degree of the conductive particle phase in the electrode cross section per length of 100 ?m in a direction parallel to the electrode surface is 2.0 to 4.0 ?m. This electrode can be produced by firing a metal paste made by dispersing, in a solvent, a conductive particle having a core/shell structure in which a core particle such as Pt is covered with a ceramic shell and ceramic powder. The gas sensor electrode according to the present invention has a high electrode activity.

Abstract: An object of the present invention is to provide a conductive fine particle for producing a metal paste that can produce an electrode film having a low resistance, and a metal paste utilizing the conductive fine particle. The present invention is a conductive particle for electrode formation having a core/shell structure, and the conductive particle comprises a core particle made of Pt or a Pt alloy and having a particle diameter of 10 to 200 nm, and a shell made of a ceramic containing Al2O3 or ZrO2 and covers at least a part of the core particle, wherein the ceramic constituting the shell is added in an amount of 0.5 to 15% by weight based on the core particle to cover the core. The core particle is preferably Pt or a Pt alloy alloyed with Pd, Au, Ag, or Rh.

Abstract: The present invention is an electroconductive particle for forming an electrode including a precious metal particle including Pt or a Pt alloy and having an average particle diameter of 50 to 150 nm, a first ceramic particle including Al2O3 or ZrO2 dispersed in the precious metal particle and having an average particle diameter of 5 to 50 nm, and a second ceramic particle including Al2O3 or ZrO2 bonded to an outer periphery of the precious metal particle and having an average particle diameter of 5 to 50 nm. The sum of the volume of the first ceramic particle and the volume of the second ceramic particle is preferably 2 to 40 vol % based on the whole electroconductive particle. A metal paste containing the electroconductive particle according to the invention is one from which an electrode film of low resistance and excellent durability can be manufactured and further excellent in adherence and conformability to a substrate.

Abstract: An object of the present invention is to provide a conductive fine particle for producing a metal paste that can produce an electrode film having a low resistance, and a metal paste utilizing the conductive fine particle. The present invention is a conductive particle for electrode formation having a core/shell structure, and the conductive particle comprises a core particle made of Pt or a Pt alloy and having a particle diameter of 10 to 200 nm, and a shell made of a ceramic containing Al2O3 or ZrO2 and covers at least a part of the core particle, wherein the ceramic constituting the shell is added in an amount of 0.5 to 15% by weight based on the core particle to cover the core. The core particle is preferably Pt or a Pt alloy alloyed with Pd, Au, Ag, or Rh.

Abstract: An object of the present invention is to provide a conductive fine particle for producing a metal paste that can produce an electrode film having a low resistance, and a metal paste utilizing the conductive fine particle. The present invention is a conductive particle for electrode formation having a core/shell structure, and the conductive particle comprises a core particle made of Pt or a Pt alloy and having a particle diameter of 10 to 200 nm, and a shell made of a ceramic containing Al2O3 or ZrO2 and covers at least a part of the core particle, wherein the ceramic constituting the shell is added in an amount of 0.5 to 15% by weight based on the core particle to cover the core. The core particle is preferably Pt or a Pt alloy alloyed with Pd, Au, Ag, or Rh.