Denka Company Limited

National Institute for Materials Science

Denki Kagaku Kogyo Kabushiki Kaisha

Go Takeda

Yoshitaka Taniguchi

Takashi Kawasaki

Yoshio Bando

Dmitri Golberg

Fumihiro Kurokawa

Seitaro Kobayashi

Naoto Hirosaki

Masayoshi Ichikawa

Tomohiro Nomiyama

Ryo Yoshimatsu

Suzuya Yamada

Ryozo Nonogaki

Takemi Oguma

Hisayuki Hashimoto

Michiharu Nakashima

To provide a boron nitride powder having excellent heat conductivity and high particle strength. Provided is a boron nitride powder which comprises bulky boron nitride formed such that scaly primary particles of hexagonal boron nitride are aggregated to form bulky particles, and which has the following characteristics (A) to (C):

Boron nitride powder, method for producing same, and heat-dissipating member produced using same

A surface-treated aggregated boron nitride powder is prepared by using the boron nitride powder as the raw material, adding an oxidizer to the boron nitride aggregated grains, wet-pulverizing or wet-crushing the grains for surface modification treatment of the particles and allowing reaction of the particles with a metal coupling agent. The surface-treated boron nitride aggregated grains are formed by aggregation of hexagonal h-BN primary particles; (B) have any one or more of Si, Ti, Zr, Ce, Al, Mg, Ge, Ga, and V in an amount of 0.1 atm % or more and 3.0 atm % or less in its composition on the surface of 10 nm; (C) have a crushing strength of 5 MPa or more; and (D) have an average particle diameter of 20 &#x3bc;m or more and 100 &#x3bc;m or less.

Surface-treated aggregated boron nitride powder, aggregated boron nitride powder, and thermally conductive resin composition

A boron nitride powder includes boron nitride aggregated grains that are formed by aggregation of scaly hexagonal boron nitride primary particles, the boron nitride powder having the following characteristic properties (A) to (C): (A) the primary particles of the scaly hexagonal boron nitride have an average long side length of 1.5 &#x3bc;m or more and 3.5 &#x3bc;m or less and a standard deviation of 1.2 &#x3bc;m or less; (B) the boron nitride aggregated grains have a grain strength of 8.0 MPa or more at a cumulative breakdown rate of 63.2% and a grain strength of 4.5 MPa or more at a cumulative breakdown rate of 20.0%; and (C) the boron nitride powder has an average particle diameter of 20 &#x3bc;m or more and 100 &#x3bc;m or less. Also provided are a method for producing the same and a thermally conductive resin composition including the same.

Boron nitride aggregated grain

The present invention provides a spherical boron nitride fine powder and the other superior in filling property into resin. The present invention relates to a spherical boron nitride fine powder having the following characteristics (A) to (C):

Spherical boron nitride fine powder, method for manufacturing same and thermally conductive resin composition using same

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

A blue phosphor having an emission peak wavelength different from that of conventional blue phosphors, a method for producing the same, and a high-intensity luminescent device using the phosphor are provided. The phosphor of the present invention is represented by a general formula MeReAlSiON(Me may contain one or more elements selected from Mg, Ca, Sc, Y, and La as second elements, provided that Sr or Ba is contained as an essential first element, and Re may contain one or more elements selected from Mn, Ce, Tb, Yb, and Sm as second elements, provided that Eu is contained as an essential first element), where the composition ratio represented by a, b, c, d, e, and f has the following relations: a+b=1, 0.005&#x3c;b&#x3c;0.25, 1.60&#x3c;c&#x3c;2.60, 2.50&#x3c;d&#x3c;4.05, 3.05&#x3c;e&#x3c;5.00, and 2.75&#x3c;f&#x3c;4.40.

Phosphor, method for producing the same, and luminescent device using the same

&#x3b2;-SiAlON represented by a general formula SiAlONwith Eu dissolved therein, whose spin density corresponding to absorption g=2.00&#xb1;0.02 at 25&#xb0; C. obtained by the electron spin resonance method is equal to or lower than 6.0&#xd7;10spins/g. A method of manufacturing the &#x3b2;-SiAlON includes: a mixing step of mixing &#x3b2;-SiAlON materials; a baking step of baking the &#x3b2;-SiAlON having undergone the mixing step; a heating step of increasing the ambient temperature of the materials having undergone the mixing step from 1500&#xb0; C. to a baking temperature of the baking step at a rate equal to or lower than 2&#xb0; C./min.; an annealing step of annealing the &#x3b2;-SiAlON having undergone the baking step; and an acid treatment step of acid-treating the &#x3b2;-SiAlON having undergone the annealing step. The objective of the present invention is to provide &#x3b2;-SiAlON capable of achieving high luminescent efficiency, a method of manufacturing the &#x3b2;-SiAlON, and a light-emitting device using the &#x3b2;-SiAlON.

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Machida, Japan

Go Takeda