Dowa Electronics Materials Co., Ltd.

Yoshiyuki Michiaki

Masahiro Yoshida

Kenichi Inoue

Atsushi Ebara

Hiroshi Kamiga

Yoshichika Horikawa

Kozo Ogi

Yuki Kaneshiro

Kyoso Masuda

Shin Hamada

Takuma Honda

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dxof not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

Copper powder and method for producing same

While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700&#xb0; C. (preferably 350 to 650&#xb0; C. and more preferably 450 to 600&#xb0; C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 &#x3bc;m and a crystallite diameter Dxof not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

A silver powder which has a small content of carbon and which is difficult to be agglutinated, and a method for producing the same. While a molten metal, which is prepared by melting silver to which 40 ppm or more of copper is added, is allowed to drop, a high-pressure water is sprayed onto the molten metal to rapidly cool and solidify the molten metal to produce a silver powder which contains 40 ppm or more of copper, 0.1% by weight or less of carbon and 0.1% by weight or less of oxygen and wherein the particle diameter (D50 diameter) corresponding to 50% of accumulation in volume-based cumulative distribution of the silver powder, which is measured by means of a laser diffraction particle size analyzer, is in the range of from 1 &#x3bc;m to 15 &#x3bc;m, the average particle diameter (SEM diameter) of single particles being in the range of from 1 &#x3bc;m to 8 &#x3bc;m when it is measured by means of a field emission scanning electron microscope (SEM), the ratio (SEM diameter/D50 diameter) of the SEM diameter to the D50 diameter being in the range of from 0.3 to 1.0.

Silver powder and method for producing same

There is provided a silver powder which has a small average particle diameter and a small thermal shrinkage percentage, and a method for producing the same. While a molten metal of silver heated to a temperature (1292 to 1692&#xb0; C.), which is higher than the melting point (962&#xb0; C.) of silver by 330 to 730&#xb0; C., is allowed to drop, a high-pressure water is sprayed onto the molten metal of silver (preferably at a water pressure of 90 to 160 MPa) to rapidly cool and solidify the molten metal of silver to powderize silver to produce a silver powder which has an average particle diameter of 1 to 6 &#x3bc;m and a shrinkage percentage of not greater than 8% (preferably not greater than 7%) at 500&#xb0; C., the product of the average particle diameter by the shrinkage percentage at 500&#xb0; C. being 1 to 11 &#x3bc;m&#xb7;% (preferably 1.5 to 10.5 &#x3bc;m&#xb7;%).

An object of the present invention is to provide metal powder that can be used to form an external electrode, which is excellent in solder wettability and solder leach resistance while having a layer structure with fewer layers than in the related art and, furthermore, is excellent in electrical conductivity. This silver-coated alloy powder comprises a coating layer on a surface of an alloy core particle containing copper, nickel, zinc, and inevitable impurities, the coating layer containing silver.

Silver-coated alloy powder, electrically conductive paste, electronic part, and electric device

There is provided a silver powder, which is able to obtain a conductive paste having a high thixotropic ratio and a high Casson yield value and which is able to form a conductive pattern having a low resistance, and a method for producing the same. An aliphatic amine such as hexadecylamine is added to a silver powder, the surface of which is coated with a fatty acid such as stearic acid, to be stirred and mixed to form the aliphatic amine on the outermost surface of the silver powder while allowing the fatty acid to react with the aliphatic amine to form an aliphatic amide such as hexadecanamide between the fatty acid and the aliphatic amine.

Provided is a catalyst having the ability to combust PM at relatively low temperatures and having high HC and CO removal (conversion) efficiency even at the above operating temperature. In the catalyst composition, at least one kind of platinum group element selected from Pt, Rh, and Pd is dispersed in and supported by a platinum group-supporting carrier containing at least one kind of element selected from Zr, Al, Y, Si, Bi, Pr, and Tb, and the platinum group-supporting carrier is supported on the surface of a Ce oxide containing Ce as an essential component. The catalyst composition has both PM combustion activity and gas purification activity.

Method for producing catalyst composition, catalyst composition, diesel particulate filter using the same, and exhaust gas purification system

A composite oxide for an exhaust gas purification catalyst is provided which can burn PM in diesel engine exhaust gas at low temperatures and has a good S desorption property. The composite oxide for an exhaust gas purification catalyst is composed of Ce, Bi, Pr, R, and oxygen in a molar ratio of Ce:Bi:Pr:R=(1&#x2212;x&#x2212;y&#x2212;z):x:y:z. The ratios of Ce, Bi, Pr, and R satisfy 0&#x3c;x+y+z&#x2266;0.5 and preferably 0&#x3c;x&#x2266;0.1, 0&#x3c;y&#x2266;0.25, and 0&#x3c;z&#x2266;0.3. Particularly, when R is Zr, the composite oxide exhibits a good S desorption property at a temperature of about 600&#xb0; C. and can recover its catalytic activity at low temperatures. Therefore, the exhaust gas purification catalyst is suitable as a PM combustion catalyst.

Composite oxide for exhaust gas purification catalyst, method for manufacturing the same, coating material for exhaust gas purification catalyst, and filter for diesel exhaust gas purification

An oxidation catalyst is provided which is capable of combusting PM in a diesel engine exhaust gas at a low temperature and which has low degradation due to heat generated during combustion (i.e., has high heat resistance). A composite oxide for an exhaust gas purification catalyst is formed from Ce, Bi, R, R', and oxygen, and when the molar ratios of Ce, Bi, R, and R&#x2032; are expressed as Ce:Bi:R:R&#x2032;=(1&#x2212;x&#x2212;y&#x2212;z) :x:y:z, it satisfies 0&#x3c;x&#x2266;0.4, 0&#x3c;y&#x3c;1.0, and 0&#x3c;z&#x2266;0.5. Since this composite oxide has no change in its BET value even when treated at a high temperature, and can withstand a high amount of sulfur poisoning, retrogradation due to poisoning is low. Therefore, this exhaust gas purification catalyst is suitable as a PM combustion catalyst.

Complex oxide for exhaust gas purification catalyst, production method thereof, coating material for exhaust gas purification catalyst, and diesel exhaust gas purification filter

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Tokyo, Japan

Yoshiyuki Michiaki