Method of producing spherical oxide powder

• US 7,374,704 B2
• Filed: 07/26/2002
• Issued: 05/20/2008
• Est. Priority Date: 07/27/2001
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Chiba, Ikuka, Okamoto, Shigeo, Sogabe, Tomohiro, Che, Shenglei
• Primary Examiner(s): LOPEZ, CARLOS N
• Application Number:
  US10/483,315
• Publication Number:
  US 20040180991A1
• Time in Patent Office: 2,125 Days
• Field of Search: 264 13- 15
• US Class Current: 264/13
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/145 After-treatment of oxides or hydroxides, e.g. pulverising, drying, decreasing the acidity
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 23/006 Alkaline earth titanates
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/52 highly monodisperse size distribution
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C04B 2235/3203 Lithium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3236 Alkaline earth titanates
• CPC Class Codes: C04B 2235/3241 Chromium oxides, chromates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3244 Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3251 Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3262 Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
• CPC Class Codes: C04B 2235/3275 Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
• CPC Class Codes: C04B 2235/3287 : Germanium oxides, germanates or oxide forming salts thereof, e.g. copper germanate
• CPC Class Codes: C04B 2235/3298 : Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
• CPC Class Codes: C04B 2235/528 : Spheres
• CPC Class Codes: C04B 2235/5296 : with a defined aspect ratio, e.g. indicating sphericity spherical constituents C04B2235/528
• CPC Class Codes: C04B 2235/5436 : micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5481 : Monomodal
• CPC Class Codes: C04B 35/468 : based on barium titanates
• CPC Class Codes: C04B 35/4682 : based on BaTiO3 perovskite phase
• CPC Class Codes: C04B 35/62655 : Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: H01B 3/10 : metallic oxides ceramics H01B3/12
• CPC Class Codes: H05K 1/0373 : containing additives, e.g. fillers H05K1/036 takes precedence

Abstract

The present invention provides a production method of spherical oxide powder which includes a feeding step in which a granular powder composed of an oxide composition is fed into a combustion flame together with a carrier gas; a melting step in which said fed granular powder is melted in said combustion flame to obtain a melt; and a solidifying step in which said melt is solidified by being moved and placed outside said combustion flame.

Claims

1. A production method of spherical oxide powder comprising:

a feeding step in which a granular powder composed of an oxide composition is fed into a combustion flame together with a carrier gas;

a melting step in which said fed granular powder is melted in said combustion flame to obtain a melt; and

a solidifying step in which said melt is solidified by being moved and placed outside said combustion flame, to form a spherical oxide powder,

wherein said spherical oxide powder obtained through said solidifying step is 1 to 10 μ

m in mean particle size and 0.9 or above in sphericity, and

wherein said melt is solidified in said solidifying step under temperatures corresponding to a plurality of heating means wherein said temperatures gradually decrease along a traveling direction of said melt.

2. A production method of a spherical oxide powder according to claim 1, wherein said granular powder is composed of the same oxide as in said spherical oxide powder obtained through said solidifying step.

3. A production method of a spherical oxide powder according to claim 1, wherein said granular powder is composed of plural kinds of compound particles.

4. A production method of a spherical oxide powder according to claim 1, wherein said spherical oxide powder obtained through said solidifying step is constituted by a dielectric material composed of a composite oxide.