Harima Chemicals, Incorporated

Ulvac, Inc.

Denso Corporation

National Institute of Advanced Industrial Science and Technology

Toshiba Corporation

Sagami Chemical Research Center

Sijtechnology, Inc.

Yorishige Matsuba

Daisuke Itoh

Noriaki Hata

Masayuki Ueda

Yoshihisa Misawa

Masaaki Oda

Toshihiro Suzuki

Noriyuki Abe

Hideyuki Gotoh

Norimichi Saito

Katsuhisa Osako

Akihito Izumitani

Kiyosi Kondo

Kazuhiro Murata

Hiroshi Yokoyama

Takuo Kikuchi

Masashi Totokawa

Kazuki Tateyama

Hisao Kondo

Masahiro Hayashi

Kazunaga Yazawa

Masao Segawa

Hideyuki Goto

Naoto Shioi

Katsuhisa Oosako

Yasunari Ukita

Kazuo Hosoya

Hiroshi Saito

Hiroharu Nishigaki

Masashi Isozaki

Daisuke Sugimori

Tetsuya Tsutsumi

The present invention provides a process for simply and easily producing fine metal particles or fine metal oxide particles in the form of a dry powder which can be used as extremely fine particles in a good dispersion state without causing coagulation for a long time even if not stored in a dispersion solvent. Fine metal particles or fine metal oxide particles in the form of a dry powder are prepared using a dispersion in which fine metal particles or fine oxide metal particles having a surface oxidation film are dispersed in an organic solvent in a stable state, while once covering the particle surface with covering agent molecules containing, at a terminal, a functional group having an oxygen atom, a nitrogen atom, or a sulfur atom as a group capable of forming a coordinative bond with metal, and by removing the dispersion solvent, washing and removing excess covering agent molecules with a polar solvent without damaging the covering agent molecule layer covering the fine particle surface, finally evaporating the polar solvent used for washing and drying.

Fine metal particles and fine metal oxide particles in dry powder form, and use thereof

According to the present invention, a metal nanoparticle dispersion suitable to multiple layered coating by jetting in the form of fine droplets is prepared by dispersing metal nanoparticles having an average particle size of 1 to 100 nm in a dispersion solvent having a boiling point of 80&#xb0; C. or higher in such a manner that the volume percentage of the dispersion solvent is selected in the range of 55 to 80% by volume and the fluid viscosity (20&#xb0; C.) of the dispersion is chosen in the range of 2 mPa&#xb7;s to 30 mPa&#xb7;s, and then when the dispersion is discharged in the form of fine droplets by inkjet method or the like, the dispersion is concentrated by evaporation of the dispersion solvent in the droplets in the course of flight, coming to be a viscous dispersion which can be applicable to multi-layered coating.

Metal nanoparticle dispersion usable for ejection in the form of fine droplets to be applied in the layered shape

The present invention provides a conductive metal paste, available for fabrication of a metal fine particle sintered product layer, which has excellent adhesion to a surface of an underlying substrate such as a glass substrate and also has good conductivity. The conductive metal paste according to the present invention contains, per 100 parts by mass of the metal fine particles whose average particle size is 1 to 100 nm, 10 to 60 parts by mass in total of one or more compounds which are used in a coating molecular layer on a surface of a metal fine particle and which have a group capable of coordinate bonding to a metal element contained in the metal fine particles via a lone pair held by a nitrogen, oxygen, or sulfur atom, and also contains one or more metal compounds which are reduced by heating up to 250&#xb0; C. or higher to be able to precipitate a metal atom such that a total amount of metals contained in the metal compound is within a range from 0.3 to 7 parts by mass, and further, 100 to 500 parts by mass of an amine-based solvent capable of dissolving the metal compounds blended per 10 parts by mass in total of metals in the metal compounds, wherein all of these components are uniformly dissolved and dispersed in an organic solvent used as a dispersion solvent for the metal fine particles.

Conductive metal paste

The present invention provides a process for forming a copper fine particle sintered product type of a fine-shaped electric conductor showing superior electroconductivity, which comprises steps of drawing a fine pattern with the use of a dispersion containing the copper fine particles having a surface oxide film layer, conducting a treatment for reducing the copper fine particles with the surface oxide film layer or copper oxide fine particles included in the pattern at a comparatively low temperature, and baking the resultant copper fine particles. Specifically, the process carries out the processes of; applying a dispersion containing the copper fine particles having the surface oxide film layer thereon or the copper oxide fine particles with an average particle diameter of 10 &#x3bc;m or smaller onto a substrate; and then performing a series of the heat treatment steps of heating the particles in the coated layer at temperature of 350&#xb0; C. or lower under an atmosphere containing a vapor and a gas of a compound having reducibility to reduce the oxide film by a reduction reaction which used the compound having reducibility as a reducing agent, subsequently repeating a heat treatment combining an oxidizing treatment of a short time with a re-reducing treatment, and sintering the resultant copper fine particles with each other to form a layer of the sintered product.

Method for forming fine copper particle sintered product type of electric conductor having fine shape, and process for forming copper fine wiring and thin copper film by applying said method

The present invention provides a conductive adhesive agent capable of being diluted with a solvent to give good coating workability and allowing formation of a conductive joint excellent in both thermal conductivity and electrical conductivity by inhibiting a gas generated when a binder resin is heat-cured after attachment of a part. The conductive adhesive agent according to the present invention is a conductive adhesive agent wherein, based on 100 parts by weight of silver powder having an average particle diameter of micrometers, which is used for a conductive medium, e.g. as a main component, 1 to 10 parts by weight of silver fine particles having an average particle diameter of nanometers is used in combination therewith and 5 to 15 parts by weight of thermosetting resin as a binder resin component and 10 parts or less by weight of solvent for adjustment of a fluid viscosity are blended therein as essential components, and by selection of such a blending ratio, generation of a gas component during heating and curing of the thermosetting resin to prevent formation of voids, and at the same time, fabrication of a conductive joint excellent in thermal conductivity and electrical conductivity is achieved.

Conductive adhesive agent with ultrafine particles

This invention provides a low-temperature sintering conductive paste for high density circuit printing which can form a fine circuit having good adhesive force, a smooth surface and low resistance when applied on a substrate and then baked; the conductive paste of the invention uses, as conductive media, in combination with metal fillers having an average particle diameter of 0.5 to 20 &#x3bc;m, ultrafine metal particles having an average particle diameter of not larger than 100 nm, which are set in the state that the surfaces thereof are coated with one compound or more having a group comprising a nitrogen, oxygen, or sulfur atom and capable of coordinate-bonding by a lone pair existing in the atom, as a group capable of coordinate-bonding to a metal element contained in the ultrafine metal particles, and are dispersed uniformly in a resin composition comprising a heat curable resin component, an organic acid anhydride or a derivative thereof or an organic acid, and one or more organic solvent; and thereby it enables low-temperature sintering of the ultrafine metal particles during a heat treatment at a low temperature.

Electroconductive metal paste and method for production thereof

To provide a method for producing a sensing film for gas sensors by sintering particles comprising a metal or a metal oxide on a substrate, where the sensing film for gas sensors having excellent sensor properties such as sensitivity and responsibility can be easily and simply formed. A nano-meter order particle (), a dispersant () for preventing aggregation of the particles (), and a scavenger () for trapping the dispersant () at the sintering are mixed in a solvent () to prepare a paste body (), and this paste body () is coated on a base material and fired, thereby forming a sensing film.

Production method of gas sensor

[Object] A fatty acid-related polyunsaturated compound can be selectively purified using an industrially operable successive method under moderate conditions. [Content] A highly purified fatty acid-related polyunsaturated compound is obtained by a process comprising steps of forming a complex with silver on account of the high degree of unsaturation of the fatty acid-related polyunsaturated compound, isolating the complex from other fats on account of the hydrophilicity of the complex and then applying dissociating procedures to the complex to obtain the fatty acid-related polyunsaturated compound as a target substance on account of the hydrophobicity of the fatty acid-related polyunsaturated compound. As to the procedures for dissociation, addition of a dissociating agent and reduction of silver are disclosed. As to the dissociating agent, various compounds which produce insoluble composition with silver other then water are disclosed. Furthermore, an apparatus appropriately used to carry out this method is also disclosed.

Method of purifying polyunsaturated aliphatic compounds

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Tsukuba, Japan

Yorishige Matsuba