Powder having multilayered film on its surface and process for preparing the same
US5985466A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 10, 1997 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Sep 10, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12181
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A powder having metal oxide films on its surface is obtained in which the films have a heightened refractive index and which hence shows a high reflectance and has a bright color. A powder is obtained which has a reduced number of metal oxide films on the surf ace and hence has a small particle diameter. A powder having a multilayered film on the surface which comprises a base particle having on the surface thereof a multilayered film comprising at least a metal oxide film formed by the hydrolysis of a metal alkoxide, and in which the multilayered film has undergone a heat treatment. A process for producing any of the above powders which comprises dispersing a base particle into a solution of a metal alkoxide, hydrolyzing the metal alkoxide to obtain a metal oxide and deposit a film of the metal oxide on the surface of the base particle, conducting the foregoing steps two or more times to form a multilayered film, and performing a heat treatment in at least the final step, and in which the multilayered film is regulated so as to have an appropriate combination of constituent materials and appropriate film thicknesses to change the interference colors of the multilayered film and th…
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