National Institute for Materials Science

Denka Company Limited

Teijin Limited

National Institute of Materials Science

Dmitri Golberg

Yoshio Bando

Takashi Kawasaki

Go Takeda

Chunyi Zhi

Chengchun Tang

Fumihiro Kurokawa

Seitaro Kobayashi

Hiroaki Kuwahara

Yihua Gao

Yashio Bando

Zongwen Liu

Yang Huang

A boron nitride fine particle has low major diameter/thickness (aspect) ratio, high purity and high crystallinity, and also has an average particle diameter of 0.05 to 2.0 &#x3bc;m, a graphitization index of 3 or less, and a total oxygen content of 0.20% by mass or less, with an average value of a major diameter/thickness ratio of scaly particles being 6.0 or less. A method of producing a boron nitride fine particle includes introducing ammonia and an alkoxide borate at an ammonia/alkoxide borate molar ratio of 1 to 5 in a reaction vessel in an inert gas atmosphere for heating at 800 to 1,350&#xb0; C. within 30 seconds thereby obtaining a boron nitride precursor, and then heating the boron nitride precursor at 1,650 to 2,200&#xb0; C. for at least 0.5 hour in an inert gas atmosphere.

Boron nitride fine particles and production method thereof

A spherical boron nitride fine particle suited for use as a highly thermoconductive filler or the like has an average particle diameter of 0.01 to 1.0 &#x3bc;m, an orientation index of 1 to 15, a boron nitride purity of 98.0% by mass or greater, and an average circularity of 0.80 or greater. A method of producing a spherical boron nitride fine particle includes reacting ammonia with an alkoxide borate at an ammonia/alkoxide borate molar ratio of 1 to 10 in an inert gas stream at 750&#xb0; C. or higher within 30 seconds, then applying heat treatment to a reaction product in an atmosphere of ammonia gas or a mixed gas of ammonia gas and an inert gas at 1,000 to 1,600&#xb0; C. for at least 1 hour, and further firing the reaction product in an inert gas atmosphere at 1,800 to 2,200&#xb0; C. for at least 0.5 hour.

Spherical boron nitride fine particles and production method thereof

Spherical boron nitride nanoparticles having an average particle diameter of less than 50 nm is obtained by a method of synthesizing spherical boron nitride nanoparticles including the following steps; heating a mixture of boric acid ester and nitrogen gas in ammonia gas and argon gas to form reaction product; crystallizing reaction product to form precursor of spherical boron nitride nanoparticles; and, heating the precursor in inert gas.

Spherical boron nitride nanoparticles and synthetic method thereof

A boron nitride fiber paper having a very small fiber diameter and exhibiting excellent heat resistance, mechanical properties and heat conductivity. The fiber paper is composed of a fiber assembly which contains boron nitride fibers having a fiber diameter of not more than 1 &#x3bc;m in an amount of not less than 40 wt %.

Boron nitride-based fiber paper and manufacturing process thereof

By preliminarily measuring the gallium temperature and the length change of a temperature sensing element comprising a carbon nanotube having a continuous column of gallium contained therein, then heating the temperature sensing element installed in a subject to increase the temperature thereof in air, removing the temperature sensing element subjecting to measure the gallium length, and substituting the measured gallium length in a formula, the temperature is measured accurately over a wide temperature range in a micrometer size or less environment.

Temperature measuring method using micro temperature sensing element

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Tsukuba, Japan

Dmitri Golberg