Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Advanced Industrial Science and Technology

Isao Harada

Naruyuki Iwanaga

Toshihiko Nishitsuji

Akio Kikkawa

Sadaichi Komohara

Makoto Aritsuka

Hisashi Hokonohara

Toshiaki Yamaguchi

Hiroyuki Hyakutake

Yukihiro Yoda

Yoshihiro Tsuzikawa

Tosiaki Yamaguti

Nobuhiko Fujieda

Masato Yamazaki

Kimiyasu Sato

Kohichi Haruta

Shigeo Kanayama

Kenshi Mitsuishi

Koji Watari

Atsuhisa Mimoto

Masao Tanaka

Jin-yu Qiu

Nobuhiko Koto

Yuji Hotta

The present invention is to produce an aluminum nitride powder which is turned into a sintered body at a temperature of not more than 1600&#xb0; C., thereby obtaining a sintered aluminum nitride in which the density and thermal conductivity are high and which can be properly used as a substrate material. Using a vapor phase reaction apparatus shown in FIG., ammonia gas was fed from a reactorheated at from 300 to 500&#xb0; C. and maintained at that temperature by a heating sectionvia a feeding tubewhile being regulated by a flow regulator. At the same time, while being regulated by the flow regulator, nitrogen gas containing an organic aluminum compound is fed via a feeding tubeto obtain an aluminum nitride powder. The aluminum nitride powder is subjected to a heat treatment at from 1100 to 1500&#xb0; C. in a reducing gas atmosphere and/or an inert gas atmosphere to obtain an aggregate aluminum nitride powder. The aggregate aluminum nitride powder is subjected to a mechanical treatment to obtain an aluminum nitride powder in which the specific surface area value is not less than 30 m/g and a ratio of an average particle diameter to a particle diameter in terms of the specific surface area is not more than 10.

Aluminum nitride powder, method for producing the same and use thereof

A metal container to be filled with a halogen containing gas, with the inner surface processed with a polishing agent. The gas has a reduced purity decline by the increase of the water content or impurities from the inner surface of the container which is absorbed by the gas over the passage of time. The inner surface processing method is improved such that the value of dividing the area of the Si2s peak by the area of the Fe2ppeak in the X-ray photoelectron spectrum of the gas container inner surface with the inner surface process with a polishing agent applied is 0.3 or less.

Processing method for high pressure gas container and halogen containing gas filled in said container

An agent for treating an exhaust gas, which is a mixture of a solid metal oxide and a solid metal carbonate as a main component, the metal being selected from the group of metal elements consisting of Mn, Fe, Ni, Cu and Zn. The agent is made of a molded article obtained by granulation, pelletization or extrusion of the mixture, and can be used in a process of treating an exhaust gas, capable of reducing the concentration of the exhaust gas containing a low concentration of a metal hydride gas and/or an organometallic gas to at least 0.5 ppm or lower.

Agent for and process of treating exhaust gas

There is provided with a method of treating an exhaust gas comprising the steps of loading into a column an exhaust gas treating agent containing as a main component a metal of which surface is fluorinated previously; passing through the column the exhaust gas containing nitrogen trifluoride as a component to be treated; and contacting the exhaust gas with the exhaust gas treating agent. And the exhaust gas treating agent is also provided.

Exhaust gas treating agent and a method of treating exhaust gas using

A process is provided by the present invention for the preparation of a partially-substituted fluorosilane represented by the following formula: SiH.sub.n F.sub.4-n wherein n stands for an integer of 1 to 3. The process comprises converting a corresponding partially-substituted chlorosilane represented by the following formula: SiH.sub.n Cl.sub.4-n wherein n has the same meaning as defined above into the partially-substituted fluorosilane by halogen replacement while using a fluorinating agent. The fluorinating agent is zinc fluoride having a water content not higher than 0.2 wt. %. Preferably, the size of crystallites in the direction of a (110) plane of the zinc fluoride is at least 500 .ANG..

Process for the preparation of partially-substituted fluorosilane

Method for purifying nitrogen trifluoride gas

An electrolytic cell for the production of a nitrogen trifluoride gas by a molten salt electrolysis comprises electrodes, partition plates, bottom surface, liquid surface of an electrolytic bath and lids, at least some of these members being in a particular distance relationship.

Electrolytic cell

This invention relates to a process for obtaining a high purity nitrogen trifluoride gas which is used as a dry etching agent for semiconductors or a cleaning gas for CVD apparatus, etc., particularly to a process for removing oxygen difluoride. This is a process for purifying a nitrogen trifluoride gas by, after removing hydrogen fluoride from a nitrogen trifluoride crude gas, contacting with at least one aqueous solution containing one selected from the group consisting of sodium thiosulfate, hydrogen iodide and sodium sulfide.

Process for purifying nitrogen trifluoride gas

Method of liquefying and condensing nitrogen trifluoride and a method of

The method for preparing a gaseous metallic floride is here disclosed which comprises reacting a metal or its oxide with a fluorine gas or nitrogen trifluoride gas, the aforesaid method being characterized by comprising the steps of mixing the metal or its oxide with a molding auxiliary comprising a solid metallic fluoride which does not react with fluorine and nitrogen trifluoride; molding the resulting mixture under pressure; and contacting the molded pieces with the fluorine gas or nitrogen trifluoride gas, while the molded pieces are heated.

Method for preparing gaseous metallic fluoride

A process of the present invention can effectively decompose, particularly, dinitrogen difluoride present in a nitrogen trifluoride gas to remove it from the gas. This process for purifying the nitrogen trifluoride gas is characterized by comprising the step of heating the nitrogen trifluoride gas containing at least dinitrogen difluoride as an impurity at a temperature of 150.degree. C. to 600.degree. C. in a metallic vessel the inner wall of which is lined with a solid fluoride, or in a packing layer of the solid fluoride in the vessel.

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Yamaguchi, Japan

Isao Harada