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公开(公告)号：JP2003252622A
公开(公告)日：2003-09-10
申请号：JP2002055876
申请日：2002-03-01
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： IKEGAMI TAKAYASU , RI TSUGUMITSU , MORI TOSHIYUKI
Abstract: PROBLEM TO BE SOLVED: To provide an acicular ceria powder with a nano-sized diameter suitable as a catalyst or catalyst carrier. SOLUTION: The production method for an acicular ceria particle having the diameter of 15 nm or less is characterized by mixing an aqueous solution of cerium salt having a concentration of 0.01 mol/l to its saturated one with an aqueous solution of ammonium carbonate of the concentration of 1-7.5 mol/l in such a way that the ratio of the cerium salt to ammonium carbonate is 5 or more, aging within a temperature range of from 50 to 85°C to synthesize ammonium cerium carbonate expressed by the formula, (NH 4 ) x Ce(OH) y (CO 3 ) z -tH 2 O (wherein, 0.10≤x COPYRIGHT: (C)2003,JPO
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Patent Agency Ranking
公开(公告)号：JP2002201023A
公开(公告)日：2002-07-16
申请号：JP2000399046
申请日：2000-12-27
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： IKEGAMI TAKAYASU , RI TSUGUMITSU , MORI TOSHIYUKI
IPC: C01F17/00
Abstract: PROBLEM TO BE SOLVED: To obtain a nano-ceria powder of practical use having an average particle size of 100 nm or less with no or few coagulation at a low cost. SOLUTION: This method f or producing a nano-ceria powder having an average particle size of 100 nm or less with no or few coagulation comprises the steps of mixing an organic solvent containing an acidic salt of cerium dissolved by 0.01 to 1 mol/L with water content of 8 wt.% or less and an organic solvent containing an organic base dissolved by 0.1 mol/L or more with water content of 8 wt.% or less, generating a precipitate of individually separated primary particles of at least either of cerium hydroxide and hydrated ceria, separating the precipitate from the liquid phase, drying and calcining.
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公开(公告)号：JP2001270714A
公开(公告)日：2001-10-02
申请号：JP2000086173
申请日：2000-03-27
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： IKEGAMI TAKAYASU , RI TSUGUMITSU , MORI TOSHIYUKI , RI SHOKIN
Abstract: PROBLEM TO BE SOLVED: To obtain an yttrium-aluminum-garnet(YAG) powder having a small primary particle diameter without aggregation. SOLUTION: An aqueous solution of basic salts of yttrium and aluminum is dropped into an aqueous solution of a basic salt containing carbonic acid at a concentration within the range of 0.1-2.5 mol/L and the pH is regulated to 7.4-9 under conditions in which sulfate ions are present to form a precipitate having a composition which is an amorphous phase according to X-rays and corresponds to a mixture of yttrium carbonate with dawsonite in 3:5 ratio of the yttrium carbonate to dawsonite. The resultant aqueous solution containing the formed precipitate is then filtered before crystalline yttrium carbonate is formed from the precipitate. Furthermore, the precipitate is then washed and calcined to provide the YAG powder.
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公开(公告)号：JP2006347826A
公开(公告)日：2006-12-28
申请号：JP2005177077
申请日：2005-06-17
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： RI TSUGUMITSU , ISHIGAKI TAKAMASA
IPC: C01G23/053 , C09K11/08 , C09K11/67
Abstract: PROBLEM TO BE SOLVED: To provide a titanium dioxide particle capable of generating the fluorescence based on a rare-earth element with a high efficiency, viz. a titanium dioxide particle in which a rare-earth element is substituted for a titanium site, and its manufacturing method. SOLUTION: The method for manufacturing the rare-earth element-doped titanium dioxide particle comprises a process for preparing a liquid precursor containing a titanium source and a rare-earth metal source in which an amount of the rare-earth element in the rare-earth metal source is in a range over 0 at% to 5.0 at%, a process for generating a thermal plasma, and a process for feeding the liquid precursor into the thermal plasma. COPYRIGHT: (C)2007,JPO&INPIT
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公开(公告)号：JP2002154870A
公开(公告)日：2002-05-28
申请号：JP2000348042
申请日：2000-11-15
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： IKEGAMI TAKAYASU , RI TSUGUMITSU , MORI TOSHIYUKI , RI SHOKIN
IPC: C04B35/443 , C01F7/16
Abstract: PROBLEM TO BE SOLVED: To provide a method for producing easily sinterable spinel powder. SOLUTION: An aqueous acidic salt solution containing magnesium ions and aluminum ions mixed in such a ratio as to obtain spinel is dropped into a basic aqueous solution adjusted to 35-80 deg.C again temperature and >=pH 10.5 and containing >=0.2 mol/l carbonate ions and ammonium ions to precipitate a precursor comprising a mixture of ammonium dawsonite hydrate and hydrotalcite, this precipitate is separated by filtration, washed and calcined at 900-1,400 deg.C to produce easily sinterable spinel powder. This spinel powder is compacted and sintered at 1,500-1,900 deg.C under
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公开(公告)号：JP2001270775A
公开(公告)日：2001-10-02
申请号：JP2000086084
申请日：2000-03-27
Applicant: NAT INST FOR MATERIALS SCIENCE
Inventor： IKEGAMI TAKAYASU , RI TSUGUMITSU , MORI TOSHIYUKI , RI SHOKIN
Abstract: PROBLEM TO BE SOLVED: To produce a yttrium-aluminum-garnet transparent sintered body that can be used as a laser host material, light-emitting tube for discharge lamps, an observation window, an element material for detector using fluorescence. SOLUTION: An acidic aqueous solution of yttrium and aluminum salts is dripped into a carbonate-including basic aqueous solution in the 0.1 m/l-2.5 m/l concentration range, then the pH is adjusted to 7.4-9 in the presence of sulfate ion to precipitate the composition that has an amorphous phase, when observed with X-rays, and has the composition corresponding to 3/5 ratio of yttrium carbonate to dawsonite. The precipitated mixture is filtered before crystalline yttrium carbonate is formed from the precipitated, the precipitate is washed and calcined to a YAG powder. Then, the YAG powder is formed and the formed product is fired. In a preferred embodiment, the filtered amorphous precipitate is calcined at 800-1,300 deg.C to form the YAG powder with primary particle sizes of 40-400 nm.
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