Claims
- 1. A method for the preparation of ultra-fine spherical particles of a metal oxide having an average particle diameter of 40 nm or smaller comprising vaporizing a vaporizable metal to form a concentration of 0.06 to 10% by volume and decomposing the vaporizable metal compound by heating to a temperature not exceeding 600.degree. C. in the presence of water vapor in an amount in the range of from 30 to 120 moles per mole of vaporized metal compound to give ultra-fine particles of a metal oxide, the decomposition being immediately followed by cooling by direct quenching with a cooling medium to a temperature not exceeding 100.degree. C. and at which coalescence of the ultra-fine particles of the metal oxide no longer takes place.
- 2. The method for the preparation according to claim 1 wherein the vaporizable metal compound is selected from the group consisting of titanium alkoxides, titanium halides, zirconium halides, organic zirconium compounds and alkoxides of rare earth metals.
- 3. The method for the preparation according to claim 1 wherein the decomposition of the vaporizable metal compound is performed in the absence of an oxygen-containing gas in the atmosphere.
- 4. The method for the preparation according to claim 1 wherein the metal oxide is titanium oxide or zirconium oxide.
- 5. The method of claim 1 wherein the vaporizable metal compound is heated to a temperature of 250.degree. to 450.degree. C. to decompose said compound.
- 6. The method of claim 1 wherein the concentration of the vaporizable metal compound is 0.1 to 10% by volume.
- 7. The method of claim 1 wherein the vaporizable metal compound is heated for decomposition for 0.1 to 10 seconds.
- 8. The method of claim 7 wherein the heating time is 0.1 to 5 seconds.
Priority Claims (2)
Number |
Date |
Country |
Kind |
60-41828 |
Mar 1985 |
JPX |
|
60-71639 |
Apr 1985 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 928,280, filed Oct. 23, 1986 now abandoned.
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Date |
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3297414 |
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Jun 1964 |
|
3796793 |
Metzer et al. |
Jun 1978 |
|
4241042 |
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Dec 1980 |
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FRX |
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JPX |
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Aug 1979 |
JPX |
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Jun 1984 |
JPX |
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Jun 1984 |
JPX |
60-166025 |
Aug 1985 |
JPX |
0186418 |
Sep 1985 |
JPX |
58-172233 |
Oct 1988 |
JPX |
Non-Patent Literature Citations (1)
Entry |
Funaki et al., "Study on the Preparation of TiO.sub.2 by Hydrolysis of TiC.sub.14 " p. 64. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
928280 |
Oct 1986 |
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