# US 8,771,618 B2 · Method for producing alkali metal niobate particles, and alkali metal niobate particles

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- Number: US 8,771,618 B2
- Document ID: US8771618B2
- Status: Granted
- Kind: B2
- Application number: 13/262,770
- Filed: 2010-04-05
- Published: 2012-03-15
- Granted: 2014-07-08
- Earliest claimed: 2009-04-09
- Assignees: Sakai Chemical Industry Co., Ltd.; Tohoku University; Fuji Ceramics Corporation
- Applicants: Atsushi Muramatsu; Kiyoshi Kanie; Atsuki Terabe; Yasuhiro Okamoto; Hideto Mizutani; Satoru Sueda; Hirofumi Takahashi
- Inventors: Atsushi Muramatsu; Kiyoshi Kanie; Atsuki Terabe; Yasuhiro Okamoto; Hideto Mizutani; Satoru Sueda; Hirofumi Takahashi
- Web page: https://patentgrep.com/patent/US8771618B2

## CPC

- C01D 1/02: Oxides
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- C01D 13/00: Compounds of sodium or potassium not provided for elsewhere
- C01G 1/02: Oxides
- C01G 33/00: Compounds of niobium
- C04B 35/495: based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
- H10N 30/097: by sintering
- H10N 30/8542: {Alkali metal based oxides, e.g. lithium, sodium or potassium niobates}
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2004/03: obtained by SEM
- C01P 2004/38: cube-like
- C01P 2004/39: parallelepiped-like
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2004/62: Submicrometer sized, i.e. from 0.1-1 micrometer
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C04B 2235/3201: Alkali metal oxides or oxide-forming salts thereof
- C04B 2235/3255: Niobates or tantalates, e.g. silver niobate
- C04B 2235/5292: Flakes, platelets or plates
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- C04B 2235/656: characterised by specific heating conditions during heat treatment
- C04B 2235/77: Density
- Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.]
- C01D: COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides C01B17/22; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; phosphides C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Disclosed are a method of producing fine particulate alkali metal niobate in a liquid phase system, wherein the size and shape of the particulate alkali metal niobate can be controlled; and fine particulate alkali metal niobate having a controlled shape and size. One of specifically disclosed is a method of producing a substantially rectangular cuboid particulate alkali metal niobate represented by MNbO3 (1), wherein M represents one element selected from alkaline metals, including specific four steps. Another one of specifically disclosed is particulate alkali metal niobate represented by the formula (1) having a substantially rectangular cuboid shape, wherein the substantially rectangular cuboid shape has a longest side and a shortest side, the length of the longest side represented by an index Lmax is 0.10 to 25 μm, and the length of the shortest side represented by an index Lmin is 0.050 to 15 μm.

## Claims

### Claim 1

A method of producing particulate alkali metal niobate represented by the following formula (1):
MNbO3 (1)
wherein M represents one element selected from alkaline metals, the particulate alkali metal niobate having a substantially rectangular cuboid shape,
the method comprising the steps of:
(a) mixing a niobium-containing solution with an alkaline solution having a concentration of 0.1 to 30 mol/L, to prepare a suspension;
(b) allowing the suspension to stand still for 12 to 48 hours at a temperature between 80° C. and 150° C.;
(c) performing a solvothermal reaction of the suspension at a temperature between 150° C. and 300° C. for 1 to 12 hours; and
(d) separating the particulate alkali metal niobate from a reaction mixture.

### Claim 2 (depends on 1)

The method according to claim 1,
wherein M in the formula (1) is Na, and the alkaline solution is NaOH.

### Claim 3 (depends on 1)

The method according to claim 1,
wherein M in the formula (1) is K, and the alkaline solution is KOH.

### Claim 4 (depends on 1)

The method according to claim 1,
wherein the niobium-containing solution includes:
niobium oxide and/or niobium halide;
a solvent selected from the group consisting of water, ethylene glycol, and polyethylene glycol; and
an acid.