Kochi University

Sumitomo Metal Mining Company, Ltd.

Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Sangi

Koito Manufacturing Company, Ltd.

Toyo Denka Kogyo Co., Ltd.

Idemitsu Kosan Company, Limited

Japan Agency for Marine-Earth Science and Technology

National University Corporation Kochi University

Kochi University, National University Corporation

Kazumichi Yanagisawa

Hideki Ohara

Shin-ichi Heguri

Osamu Ikeda

Tomoaki Yoneyama

Yohei Kudo

Junhao Zhang

Shin-Ichi Heguri

Yoshitomo Ozaki

Sumio Kamiya

Kazuyuki Takaishi

Ayumu Onda

Wuxing Zhang

Noboru Otake

Yumiko Matsuura

Tatsuo Shou

Yukinobu Kato

Jun Kubo

Yu Shinomiya

Masaru Ishii

Hide Sakaguchi

Arito Sakaguchi

Masoud Sakaki

Harumi Kimura

Nan Li

Shuhei Ogo

Satoko Inuzuka

Isao Matsushita

A method of producing an apatite crystal includes the steps of preparing an apatite single crystal expressed by the general formula M(PO)X (Mbeing at least atomic element selected from the group consisting of divalent alkaline-earth metals and Eu, and X is at least one atomic selected from the group consisting of halogens); placing the apatite single crystal into a space controllable to a predetermined atmosphere; supplying water vapor into the space; and heating such that the atmosphere in the space is within a 1000&#xb0; C. to 1400&#xb0; C. range.

Method of producing apatite crystal, and apatite crystal

Provided is an efficient method for producing nickel powder from a solution containing a nickel ammine complex, the method including adding seed crystals to a solution containing a nickel ammine complex and subjecting the resulting mixture to hydrogen reduction under high temperatures and high pressures to produce nickel powder, which makes it possible to maintain the quality of the nickel powder produced and reduce the amount of the seed crystals used. The method for producing nickel powder is characterized by adding seed crystals and a dispersant having an anionic functional group to the solution containing a nickel ammine complex to form a mixture slurry, and subjecting the mixture slurry to pressurized hydrogen reduction treatment by blowing hydrogen into the mixture slurry in a high temperature and high pressure atmosphere to cause a reduction reaction, thereby reducing the nickel ammine complex in the mixture slurry to obtain nickel powder.

Method for producing nickel powder

Provided is nickel powder obtained by adding seed crystals to a nickel ammine complex solution and performing hydrogen reduction reaction under high temperatures and high pressures, wherein the nickel powder does not produce dust during handling, and a container can be efficiently filled with the nickel powder. The method for producing nickel powder includes: adding seed crystals and a surfactant having a nonionic or anionic functional group to a solution containing a nickel ammine complex to forma mixed slurry; and subjecting the mixed slurry to hydrogen reduction under high temperature and high pressure conditions in a pressure vessel to obtain nickel powder from the mixed slurry.

Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially comprises: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

Provided is a method for producing nickel powder from a nickel ammine sulfate complex solution, comprising treatment steps of: (1) a seed crystal production step of producing nickel powder having an average particle size of 0.1 to 5 &#x3bc;m; (2) a seed crystal addition step of adding the nickel powder obtained in the step (1) as seed crystals to form a mixed slurry; (3) a reduction step of forming a reduced slurry containing nickel powder formed by precipitation of a nickel component in the mixed slurry on the seed crystals; and (4) a growth step of performing solid-liquid separation to separate and recover the nickel powder as a solid phase component and then blowing hydrogen gas into a solution prepared by adding the nickel ammine sulfate complex solution to the recovered nickel powder to grow the nickel powder to form high purity nickel powder.

Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially includes: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, a dispersant containing a sulfonate and an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

Using conventional synthesis methods, when an unsaturated carboxylic acid or a derivative thereof is synthesized from a hydroxycarboxylic acid or a derivative thereof by a dehydration reaction using a catalyst, the yield has been low. Accordingly, an object of the present invention is to provide a catalyst capable of synthesizing unsaturated carboxylic acids or derivatives thereof by a dehydration reaction that produces a high yield. The synthetic catalyst comprises an apatite compound containing an alkali metal in a crystal structure thereof, and the invention further includes methods for synthesizing an unsaturated carboxylic acid and/or a derivative thereof. The methods comprise contacting the aforementioned synthetic catalyst with the hydroxycarboxylic acid and/or a derivative thereof, so as to synthesize the unsaturated carboxylic acid and/or a derivative thereof by a dehydration reaction.

Synthesis catalyst and synthesis method for unsaturated carboxylic acid and/or derivative thereof

This invention provides a fine particle composite comprising fine particles of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re) and conductive fine particles via a step of preparing a solvent mixture from a compound containing conductive carbon powder, at least one compound containing an element selected from among molybdenum (Mo), rhodium (Rh), ruthenium (R), and rhenium (Re), and sulfur (S) and a step of conducting a hydrothermal or solvothermal reaction at a pressure and temperature that convert the solvent mixture into a supercritical or subcritical water or solvent.

Fine particle composite, method for producing the same, catalyst used for solid polymer fuel cell, and solid polymer fuel cell

This invention provides a fine particle composite comprising fine powder of a sulfide or sulfide complex comprising a given element. The fine particle composite is obtained by a method for producing a fine particle composite comprising fine powder of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re). Such method comprises steps of: preparing a solvent mixture from at least one compound containing an element selected from among molybdenum (Mo), rhodium (Rh), ruthenium (Ru), rhenium (Re), and sulfur (S); and subjecting the solvent mixture to a hydrothermal or solvothermal reaction. The resulting fine particle composite comprises fine particles of a sulfide or sulfide complex comprising at least one element selected from the group consisting of molybdenum (Mo), rhodium (Rh), ruthenium (Ru), and rhenium (Re).

Single-crystal fine powder of sulfide or sulfide complex and method for preparing the same

An appropriate catalyst is found for synthesis of an unsaturated carboxylic acid and/or a derivative thereof using as a raw material compound a hydroxycarboxylic acid and/or a derivative thereof that can easily be synthesized from a polysaccharide such as biomass-derived cellulose, and an efficient method for synthesizing the unsaturated carboxylic acid and/or the derivative thereof is provided. This method is a method for synthesizing an unsaturated carboxylic acid and/or a derivative thereof, wherein an apatite compound is used as a catalyst to synthesize the unsaturated carboxylic acid and/or the derivative thereof from a biomass-derived hydroxycarboxylic acid and/or a derivative thereof by a dehydration reaction.

Method for synthesizing unsaturated carboxylic acid and/or derivative of same

The present invention is intended to provide a catalyst which is for synthesizing butanol from ethanol at a high selectivity and which comprises strontium phosphate apatite having the Sr/P atomic ratio of 1.5-2.0, and the synthesis method.

Catalyst and alcohol synthesis method

According to the present invention, a fluorescent powder composed mainly of an acicular or fibrous zinc oxide single crystal with an aspect ratio of 5 or higher is produced by the following steps: A zinc oxide single crystal powder can be produced at low cost without the need for a pulverization step or a similar step and high-density orientation can be realized by such crystal powder. Such crystal powder is most suitable for light emitting devices, display devices, fluorescent lamps, and the like.

Fluorescent powder, process for producing the same, and light emitting device, display device, and fluorescent lamp containing fluorescent powder

This invention provides a method for producing calcite-type calcium carbonate single crystal available for optical elements, which can be carried out under relatively low temperature and low pressure conditions. The crystal growth process which comprises; a first step of filling a sealed pressure container of an autoclave with solvent and calcium carbonate as a raw material for growth, a second step of dissolving the starting rate in the solvent under predetermined conditions of pressure and temperature, a third step of crystallizing the calcium carbonate on a seed crystal suspended in the upper portion of the pressure container, on account of the difference of solubility caused by temperature gradient in the container; the method is characterized by that the aqueous solution of ammonium salt of mono-carboxylic acid is used as the solvent. The ammonium salt of mono-carboxylic acid is selected from the ammonium salts of carboxylic acid of whose alkyl group has 1 to 6 carbons, such as ammonium salts of acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid (equal to caproic acid), and heputanic acid (equal to enantic acid).

Growing community of inventors

Kochi, Japan

Kazumichi Yanagisawa