Denka Company Limited

Denki Kagaku Kogyo Kabushiki Kaisha

Tateho Chemical Industries Co., Ltd.

Shuji Sasaki

Yasuhisa Nishi

Kohki Ichikawa

Mitsuyoshi Iwasa

Junichi Nakazono

Tomoaki Chikazawa

Yoshihisa Osaki

Yuzo Nakamura

Junya Nitta

Norihisa Nakashima

Shinji Yamano

Kazutoshi Sugita

Noriyuki Kashiwamura

Takahisa Mizumoto

Shotaro Tanoue

Miki Yamamoto

Ryoma Yamaguma

Hiroaki Yoshigai

Koji Miyazaki

A high-purity barium titanate powder according to the present invention has a Clconcentration of 20 ppm or less, an electric conductivity of extracted water of 70 &#x3bc;S/cm or less, and an average particle diameter of 1 &#x3bc;m to 30 &#x3bc;m.

High-purity barium titanate powder, method for producing same, resin composition, and fingerprint sensor

A powder mixture including spherical barium titanate particles and spherical oxide particles and having an average particle diameter of 2 &#x3bc;m or more and 30 &#x3bc;m or less, wherein the spherical oxide particles have an average particle diameter of 0.05 &#x3bc;m or more and 1.5 &#x3bc;m or less, and the spherical oxide particles are contained in an amount of 0.02% by mass or more and 15% by mass or less based on the powder mixture. The spherical oxide particles are preferably amorphous silicon dioxide particles and/or aluminum oxide particles. According to the present invention, it is possible to provide a spherical barium titanate-based powder which enables to prepare a high dielectric resin composition with which reduced wire sweep amount and burr are achieved.

Powder mixture

Provided is an external additive for toner, which is suitable for producing a toner having excellent storage stability and chargeability. A silica fine powder suitable for being added to the external additive for toner is also provided. The silica fine powder has a specific surface area of 15 m/g or more and 90 m/g or less, a loose bulk density of 0.09 g/cmor more and 0.18 g/cmor less, a carbon content of 0.25 wt % or more and 0.90 wt % or less, and a hydrophobicity of 60% or more and 75% or less. It is preferable that a ratio (A)/(B) of the loose bulk density of the silica fine powder after surface treatment (A) to a loose bulk density of the silica fine powder before the surface treatment (B) be 1.05 or more and 1.60 or less.

Silica fine powder and use thereof

The present invention herein provides silica powder which can be incorporated into a sealing material at a high content to thus give a sealing material having excellent moldability. The silica powder at least has, in the volume-based frequency distribution of particle size as determined by the laser diffraction-scattering technique, a maximum frequency value for a mode peakpresent in a particle size range extending from 1 to 4 &#x3bc;m and a maximum frequency value for a mode peakpresent in a particle size range extending from 15 to 55 &#x3bc;m, wherein the maximum frequency value for the mode peakis greater than that for the mode peak, the mode peakhas a shoulder, and the content of particles whose particle size ranges from 15 to 55 &#x3bc;m is larger than that of particles whose particle size ranges from 1 to 4 &#x3bc;m.

Silica powder and use thereof

The present invention herein provides fine inorganic hollow powder having a high hollowness rate, which can be incorporated into, for instance, a low dielectric rubber or resin composition. The inorganic hollow powder has an average hollowness rate of higher than 70% by volume and an average particle size ranging from 3 to 20 &#x3bc;m and the powder preferably has an average hollowness rate ranging from 75 to 85% by volume, an average particle size ranging from 5 to 15 &#x3bc;m, a maximum particle size of not more than 25 &#x3bc;m, a specific surface area of not more than 10 m/g, an average sphericity degree of not less than 0.90 and a purity of not less than 99% by mass. The inorganic hollow powder can be prepared by a method comprising the steps of forming a flame using a burner provided with at least a triplet-tubular portion comprising, in order from the outermost side, a combustion-improving gas-supply pipe, a combustible gas-supply pipe and an inorganic raw powder-supply pipe assembled together; injecting, into the flame at a high discharge speed, inorganic raw powder having a specific particle size through the inorganic raw powder-supply pipe, while the powder is entrained with a carrier gas having a specific relative humidity, to thus subject the powder to a heat-treatment.

Inorganic hollow particle, process for producing the same, and composition containing the same

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Omuta, Japan

Shuji Sasaki