Dowa Electronics Materials Co., Ltd.

The University of Tokyo

Dowa Mining Co., Ltd.

Dowa Holdings Co., Ltd.

The University of Shiga Prefecture

Pchem Associates, Inc.

Tokohu University

Tohoku University

Kimitaka Sato

Shinya Sasaki

Kenichi Inoue

Kazuyuki Matsumoto

Shin-ichi Ohkoshi

Shunsuke Sakurai

Takatoshi Fujino

Shiro Kuroki

Hirotoshi Saito

Daisuke Kodama

Hidefumi Fujita

Taro Nakanoya

Taku Okano

Michael A Mastropietro

Tetsu Yonezawa

Kazuhito Hashimoto

Kazuyuki Tohji

Asuka Namai

Hiromasa Miyoshi

Gregory A Jablonski

Yutaka Hisaeda

Kozo Ogi

Jhon Lehman Cuya Huaman

Jeyadevan Balachandran

Yoshitsugu Hirokawa

Shohei Ida

Balachandran Jeyadevan

Shin-Ichi Ohkoshi

To provide thin and long silver nanowires covered with an organic protective agent containing a less amount of impurities, the silver nanowires having good dispersibility in an ink having an alcohol added thereto. Silver nanowires containing covered thereon a copolymer composition containing one or more kinds of a copolymer having a vinylpyrrolidone structural unit, and having a sulfur content Sppm of 2,000 ppm or less and a residual vinylpyrrolidone monomer content ratio VPobtained from an NMR spectrum of 6.0% or less, the silver nanowires having an average diameter of 30 nm or less and an average length of 10 &#x3bc;m or more.

Silver nanowires and method for producing same, and silver nanowire ink and transparent conductive film

A method for producing silver nanowires, containing reduction-precipitating silver in the form of wire in an alcohol solvent having dissolved therein a silver compound, the deposition being performed in the alcohol solvent having dissolved therein a chloride, a bromide, an alkali metal hydroxide, an aluminum salt, and an organic protective agent, the molar ratio Al/OH of the total Al amount of the aluminum salt dissolved in the solvent and the total hydroxide ion amount of the alkali metal hydroxide dissolved therein being from 0.01 to 0.40, the molar ratio OH/Ag of the total hydroxide ion amount of the alkali metal hydroxide dissolved in the solvent and the total Ag amount of the silver compound dissolved therein being from 0.005 to 0.50.

Method for producing silver nanowires, silver nanowires, and ink using same

Silver nanowires having a thin and long shape that exhibit excellent dispersibility in an aqueous solvent having an alcohol added thereto are provided by silver nanowires having an average diameter of 50 nm or less and an average length of 10 &#x3bc;m or more, covered with a copolymer of a maleimide-based monomer and vinylpyrrolidone. The silver nanowires can be produced by a method for producing silver nanowires, containing reductively depositing silver in a wire form in an alcohol solvent having dissolved therein a silver compound, the deposition being performed in the solvent having dissolved therein a copolymer of a maleimide-based monomer and vinylpyrrolidone.

Silver nanowires, method for producing same, and ink

A silver conductive film is formed on a substrate in a continuous roll-to-roll system by applying a fine silver particle dispersing solution, which contains 30 to 70 wt % of fine silver particles dispersed in a water based dispersing medium, to a halide, such as a chlorine compound, which is applied to the substrate, by flexographic printing, and thereafter, heating the substrate at 60 to 200&#xb0; C. for 0.1 to 5 seconds in an infrared (IR) heating open, which is installed on the printing path, to carry out calcination.

Method for producing silver conductive film

Provided is a silver micropowder coated with a protective material and capable of more drastically reducing the sintering temperature than before. The silver micropowder comprises silver particles processed to adsorb hexylamine (CH&#x2014;NH) on the surfaces thereof and having a mean particle diameter Dof from 3 to 20 nm or an X-ray crystal particle diameter Dof from 1 to 20 nm. The silver micropowder has the property of forming a conductive film having a specific resistivity of not more than 25 &#x3bc;&#x3a9;&#xb7;cm when it is mixed with an organic medium to prepare a silver coating material and when a coating film formed of it is fired in air at 120&#xb0; C. Even when fired at 100&#xb0; C., it may form a conductive film having a specific resistivity of not more than 25 &#x3bc;&#x3a9;&#xb7;cm. The silver micropowder can be produced by mixing a silver particle dispersion, as monodispersed in an organic medium, of silver particles coated with a primary amine A having an unsaturated bond and having a molecular weight of from 200 to 400, and hexylamine, and then keeping the mixture at 5 to 80&#xb0; C. with stirring to thereby form precipitated particles.

Silver micropowder, silver ink, silver coating, and methods for production of these materials

A silver nanoparticle composition is provided which is possible to be sintered through sintering at a low temperature in a short time and to form silver electro conductive film and wiring which is favorable for adhesion to a substrate and low in resistance, and articles using the same are provided. The silver nanoparticle composition is provided, wherein a main component of a solvent is water, a pH of the composition is within a range of 5.3 to 8.0, a silver nanoparticle included in the composition is protected by an organic acid or a derivative thereof, and the content of the organic acid or the derivative thereof with respect to silver is 2 to 20% by mass.

Low-temperature sintered silver nanoparticle composition and electronic articles formed using the same

Provided are silver nanoparticles having a good affinity (that is, dispersibility) for y-butyrolactone (CHO), an organic solvent which has a relatively high boiling point though having a relatively small molecular weight, and has a low viscosity and a low surface tension and which has little irritating odor. The above problems are solved by providing a silver micropowder excellent in affinity for at least y-butyrolactone, which comprises silver particles processed to adsorb at least one of 1,4-dihydroxy-2-naphthoic acid (CHO) and gallic acid (CHO) on the surfaces thereof and having an X-ray crystal particle diameter Dof from 1 to 40 nm, preferably from 1 to 15 nm. The invention also provides a silver ink obtained by dispersing silver particles processed to adsorb an organic compound having a carboxyl group on the surfaces thereof and having an X-ray crystal particle diameter Dof from 1 to 40 nm, preferably from 1 to 15 nm (or having a mean particle diameter D, as measured through TEM microscopy, of from 3 to 40 nm, preferably from 4 to 15 nm), in y-butyrolactone.

Silver micropowder having excellent affinity for polar medium, and silver ink

Provided is a method for producing a silver fine powder covered with an organic substance, which comprises a step of mixing (i) a dispersion of silver particles covered with a protective material Xthat comprises an organic compound having an unsaturated bond and having a molecular weight of from 150 to 1000 in a liquid organic medium A, (ii) a protective material Xthat comprises an organic compound of which the number of the carbon atoms constituting the carbon skeleton is smaller than that of the organic compound to constitute the protective material X, and (iii) a liquid organic medium B of which the ability to dissolve the protective material Xtherein is higher than that of the liquid organic medium A, thereby promoting the dissolution of the protective material Xin the liquid organic medium B and the adhesion of the protective material Xto the surface of the silver particles. Accordingly, the invention provides an industrial, large-scale mass-production system for a silver fine powder covered with a protective material having a low molecular weight, of which the sintering temperature can be greatly lowered.

Method for production of silver fine powder covered with organic substance, and silver fine powder

Provided is a method for producing a silver particle powder excellent in the dispersibility in a liquid organic medium having a low polarity, which comprises reducing a silver compound in an alcohol having a boiling point of from 80&#xb0; C. to 200&#xb0; C. or in a polyol having a boiling point of from 150 to 300&#xb0; C., at a temperature of from 80&#xb0; C. to 200&#xb0; C. under reflux while maintaining the stream having a Reynolds number of not more than 3.70&#xd7;10. The stream having a Reynolds number of not more than 3.70&#xd7;10can be maintained by stirring with a stirring power of not more than 5.68&#xd7;10W. According to the method, a silver particle powder having good low-temperature sinterability and good dispersibility and suitable for use for microwiring formation can be obtained at a high yield.

Method for producing silver particle powder

Used is a sample holder for MALDI mass spectrometry, which has a CuO secondary particle as a laser-beam-absorbing matrix and in which the secondary particle comprises an aggregate of CuO primary particles having an average particle diameter of 100 nm or smaller and has an uneven surface arising from the shape formed by the primary particles constituting the outermost surface of the secondary particle. As the CuO secondary particle, usable is one derived from a CuO powder produced by baking basic copper carbonate in air at 200 to 300&#xb0; C., and the basic copper carbonate is produced in a process of mixing an aqueous ammonium hydrogencarbonate solution and an aqueous copper nitrate solution. The CuO secondary particle has an average particle diameter of, for example, from 0.3 to 10 &#x3bc;m.

Sample holder for maldi mass spectrometric analysis, and mass spectrometric analysis method

Sample holder for MALDI mass spectrometric analysis, and mass spectrometric analysis method

Disclosed is a magnetic material comprising a crystal of &#x3b5;-GaFeO(wherein 0&#x3c;x&#x3c;1) prepared by substituting a part of Gaion sites of an &#x3b5;-FeOcrystal with Feions and having X-ray diffraction peaks corresponding to the crystal structure of &#x3b5;-FeO. The coercive force of the magnetic material lowers in accordance with the Ga content thereof, and the saturation magnetization thereof has a maximum value.

Magnetic material

Disclosed is a magnetic crystal for electromagnetic wave absorbing materials, having a structure of &#x3b5;-MFeOwith 0&#x3c;x&#x3c;1, which has the same space group as that of an &#x3b5;-FeOcrystal and which is derived from an &#x3b5;-FeOcrystal by substituting a part of the Fe site therein with M. In this, M is a trivalent element having an effect of lowering the coercive force Hc of &#x3b5;-FeOcrystal by the substitution. Concretely, the element M includes Al and Ga. An electromagnetic wave absorber having a packed structure of particles having such a substituent element M-added 'M-substituted &#x3b5;-FeOcrystal' as the magnetic phase may control the electromagnetic wave absorption peak frequency depending on the degree of substitution with the element M, and for example, the invention gives an electromagnetic wave absorber applicable to a 76 GHz band for on-vehicle radars.

Magnetic crystal for electromagnetic wave absorbing material and electromagnetic wave absorber

A silver particle dispersion liquid comprising a silver particle powder having an average particle diameter (D) of 50 nm or less, the surface of the particle being covered with an organic protective material, dispersed in a non-polar or small polar liquid organic medium having a boiling point of 60 to 300&#xb0; C., wherein the organic protective material is an amine compound having one or more unsaturated bonds in one molecule. The silver particle dispersion liquid can be produced by reducing a silver compound in a liquid including one or more alcohol or polyol acting as a reducing agent, wherein the reduction reaction is conducted in the presence of an amine compound having a molecular weight of 100 to 1,000 and having one or more unsaturated bonds in one molecule.

Growing community of inventors

Okayama, Japan

Kimitaka Sato