公开(公告)号：JPH08198615A

公开(公告)日：1996-08-06

申请号：JP2134895

申请日：1995-01-13

Applicant: AGENCY IND SCIENCE TECHN

Inventor： TAJIRI KOJI ,  IGARASHI KAZUO ,  NISHIO TOSHIYUKI

IPC: C01B33/158 ,  C01B33/16

Abstract: PURPOSE: To produce silica aerogel having high transparency. CONSTITUTION: Isopropanol is substd. for the liq. phase of wet silica gel and supercritical drying is carried out using the isopropanol as a medium to produce the objective hydrophobic silica aerogel having high transparency. This silica aerogel is used as it is or heat treatment is further carried out at 300-600 deg.C for several hr in an oxidizing atmosphere, e.g. in the air to obtain hydrophilic silica aerogel having higher transparency than the hydrophobic silica aerogel.

公开(公告)号：JPH05296662A

公开(公告)日：1993-11-09

申请号：JP12137692

申请日：1992-04-15

Applicant: AGENCY IND SCIENCE TECHN

Inventor： TAJIRI KOJI ,  IGARASHI KAZUO ,  NISHIO TOSHIYUKI

IPC: F26B25/16 ,  F26B5/04

Abstract: PURPOSE:To improve a yield of production of aerogel during an ultra critical drying operation by a method wherein a thin protection plate of metal is arranged over an entire upper region of a dried item as well as a circumference just below a pipe of an upper lid in order to prevent liquid from various pipes fixed to the upper lid from being badly influenced. CONSTITUTION:A high pressure container for ultra critical drying operation is used for manufacturing a porous member having a high porosity without producing any shrinkage by removing liquid phase material in gel substances such as jelly composed of solid phase and liquid phase under higher temperature and higher pressure than those at the liquid phase critical point after the liquid phase is changed to a ultra critical fluid. Pipes 14 such as a fluid inlet or outlet pipe, a pressure gauge pipe and a safety valve pipe and the like are fixed to the upper lid 2 of the high pressure container. A disk-like metallic closing plate 17 is fixed to a rear surface of the upper lid 2 in order to prevent the uniform aerogel structure being dripped onto the upper part of the dried item within the container from the pipes 14 and then the liquid flowed down from the pipes 14 is prevented from being applied to the dried item.

公开(公告)号：JPH10256528A

公开(公告)日：1998-09-25

申请号：JP7460497

申请日：1997-03-10

Applicant: AGENCY IND SCIENCE TECHN

Inventor： MURAKAMI JUNICHI ,  OI YUTAKA ,  YOSHIMURA KAZUNORI ,  IGARASHI KAZUO ,  TANEMURA SAKAE ,  GOTO MASAHIRO

IPC: B22F9/02 ,  B22F1/02 ,  B22F9/14 ,  C23C14/00 ,  C23C14/35 ,  C30B23/00 ,  H01L21/285 ,  H01L29/06 ,  H01L29/66

Abstract: PROBLEM TO BE SOLVED: To provide a method for generating layer aluminum fine particles and an application to a single electron tunneling quantum device. SOLUTION: Metal aluminum is supplied into mixed gas of helium and steam of 1×10 to 3×10 Torr by sputtering metal aluminum by discharging argon gas, aggregation is generated, then discharged into vacuum to generate single crystal covered on a surface layer with aluminum, thereby forming spherical metal aluminum fine particles (layered aluminum fine particles). The particles are carried on a flow of the helium gas, discharged into vacuum via an aperture, and deposited directly on a board to generate layered aluminum particles of a particle size of 5 to 500nm. The vicinity of an outlet of particle generation source is cooled by the nitrogen or a distance between an aluminum target and the aperture is set to 30 to 50mm, thereby generating the layered aluminum fine particles. Further, single electron tunneling quantum device element using the layered aluminum fine particles obtained by the method is set.

公开(公告)号：JPH10279328A

公开(公告)日：1998-10-20

申请号：JP9807397

申请日：1997-03-31

Applicant: AGENCY IND SCIENCE TECHN

Inventor： TAJIRI KOJI ,  NISHIO TOSHIYUKI ,  IGARASHI KAZUO ,  OI YUTAKA

IPC: B01D11/00 ,  B01J13/00 ,  C01B33/16 ,  C03C17/25

Abstract: PROBLEM TO BE SOLVED: To provide an aerogel firmly joined to a glass by dipping the glass on which the aerogel is to be produced in a soln. such as a hydrofluoric acid soln. capable of etching the glass surface, cleaning the glass, pouring a mixture liquid of the start source material for a wet gel onto the surface without exposing the glass surface to air to produce a wet gel, and then subjecting the wet gel to supercritical drying. SOLUTION: A glass is dipped in a soln. such as a hydrofluoric acid soln. or acid ammonium fluoride soln. which corrodes the glass surface, and then the glass is cleaned. Then without exposing the glass surface to air, a reaction liquid as an aerogel precursor is made to flow on the surface to cause gelation or polymn. on the glass surface to produce a wet gel adhered to the glass. Then the produced wet gel is subjected to supercritical drying. As for the reaction liquid as the aerogel precursor, for example, a mixture liquid of alkoxide silicate or its oligomer and water and alcohol is used, and if necessary, with addition of alkali or acid as a catalyst.

公开(公告)号：JPH10152322A

公开(公告)日：1998-06-09

申请号：JP32604796

申请日：1996-11-20

Applicant: AGENCY IND SCIENCE TECHN

Inventor： MURAKAMI JUNICHI ,  OI YUTAKA ,  YOSHIMURA KAZUNORI ,  IGARASHI KAZUO ,  TANEMURA SAKAE ,  GOTO MASAHIRO

IPC: B01J21/04 ,  B01J32/00 ,  B01J35/10 ,  B01J37/00 ,  C01F7/42 ,  C23C14/00

Abstract: PROBLEM TO BE SOLVED: To provide a method of formation of θ-alumina particles which has large surface areas and is useful as a carrier of metal catalyst, and a catalyst carrier. SOLUTION: This method of formation of θ-alumina particles of 5-200nm diameter comprises spattering metal aluminum powder by electric discharge in argon gas, feeding the aluminum into a gaseous mixture of helium and water to form fine θ-alumina particles by coagulation while controlling the particle size by growing the particles by using metal tubes or reducing particle size by cooling with liquid nitrogen, and depositing the particles on a substrate, thus producing alumina particles of 20nm or less size which has a large surface area and is useful as a carrier of metal catalysts.

公开(公告)号：JPH06227809A

公开(公告)日：1994-08-16

申请号：JP3474493

申请日：1993-01-29

Applicant: AGENCY IND SCIENCE TECHN

Inventor： TAJIRI KOJI ,  IGARASHI KAZUO ,  NISHIO TOSHIYUKI

IPC: C01B33/16 ,  C01B33/159

Abstract: PURPOSE:To readily obtain a silica aerogel in which the surface having characerstics different from those of the silica aerogel is coated with a metallic oxide over a wide range of density. CONSTITUTION:This method for coating the surface of a silica aerogel with a metallic oxide comprises immersing a wet gel of silica obtained by hydrolyzing a silicon alkoxide in an alcohol, then removing the misture in the alcohol, subsequently adding a metallic compound condensable with hydroxyl group on the surface of the silica thereto, condensing the metallic compound with the hydroxyl group, further removing the unreacted metallic compond and the subjecting the resultant wet gel to the supercritical drying treatment. This silica aerogel obtained by this method has the surface coated with the metallic oxide.