Claims
- 1. Alumina particles obtained from aluminum chloride by a gas phase method, said alumina having a crystalline form of an amorphous or transition alumina, with primary particles thereof having an average particle diameter of approximately 5 to 100 nm, and secondary particles, resulting from the aggregation of said primary particles, having an average particle diameter of approximately 150 to 800 nm.
- 2. Alumina particles obtained from aluminum chloride by a gas phase method, said particles having a crystalline form of δ or θ or a mixed form thereof.
- 3. The alumina particles as claimed in claim 1 or 2, wherein the particles having a secondary particle diameter larger than 45 μm are contained in an amount of about 0.05% by mass or less.
- 4. A process for producing alumina particles as claimed in claim 1 or 2, comprising vaporizing aluminum chloride and oxidizing the vaporized aluminum chloride with an oxidizing gas to produce alumina particles, wherein the aluminum chloride-containing gas (material gas) and the oxidizing gas are introduced into a reactor each at an ejecting flow velocity of about 10 m/sec or more, the ratio of the flow velocity of oxidizing gas to the flow velocity of material gas is approximately from 0.2 to less than 10, and the amount of oxidizing gas is about 1 or more times the amount of oxidizing gas necessary for stoichiometrically oxidizing aluminum chloride.
- 5. The process for producing alumina particles as claimed in claim 4, wherein the aluminum chloride vaporized gas and the oxidizing gas are preheated to about 500° C. or more before the oxidation.
- 6. The process for producing alumina particles as claimed in claim 4, wherein the vaporized aluminum chloride gas contains approximately from 5 to 90% by volume of aluminum chloride.
- 7. The process for producing alumina particles as claimed in claim 4, wherein the ratio of oxygen to water vapor in the oxidizing gas is from 0 to about 90% by volume of oxygen to from about 10 to 100% by volume of water vapor and the sum total of oxygen and water vapor is from about 10 to 100% by volume.
- 8. The process for producing alumina particles as claimed in claim 4, wherein the high-temperature oxidation is performed with a reactor residence time of about 1 sec or less.
- 9. Alumina particles obtained by the production process of alumina particles claimed in claim 4.
- 10. Alumina particles obtained by the production process of alumina particles claimed in claim 5.
- 11. Alumina particles obtained by the production process of alumina particles claimed in claim 6.
- 12. Alumina particles obtained by the production process of alumina particles claimed in claim 7.
- 13. Alumina particles obtained by the production process of alumina particles claimed in claim 8.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-369555 |
Dec 1999 |
JP |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part (CIP) application under 35 U.S.C. §120 of U.S. patent application Ser. No. 09/891,456 filed on Jun. 27, 2001 and PCT/JP00/09231 filed on Dec. 26, 2000 and designating U.S., claiming benefit pursuant to 35 U.S.C. §119(e)(1) of the filing date of the Provisional Application No. 60/214,795 filed on Jun. 28, 2000 pursuant to 35 U.S.C. §111(b).
Provisional Applications (1)
|
Number |
Date |
Country |
|
60214795 |
Jun 2000 |
US |
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
09891456 |
Jun 2001 |
US |
Child |
10179268 |
Jun 2002 |
US |
Parent |
PCT/JP00/09231 |
Dec 2000 |
US |
Child |
10179268 |
Jun 2002 |
US |