US 5,985,466 A · Powder having multilayered film on its surface and process for preparing the same

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 thus impart a bright color to the powder.

Claims40

Dependent claims

A powder having a multilayered film on its surface which comprises base particle having provided thereon a multilayered film (a) comprising at least a metal oxide film formed by hydrolyzing a metal alkoxide, and (b) is treated by heating.

A process for producing a powder having a multilayered film on its surface 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;
drying the metal oxide film;
subsequently heat-treating the dried metal oxide film to form a heat-treated metal oxide film;
and
conducting the above steps at least once to form a multilayered film.

3 more elements

A process for producing a powder having a multilayered film on its surface 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;
drying the metal oxide film to form a dried metal oxide film;
conducting the above steps at least once to form a multilayered film;
and
heat-treating the multilayered film as a final step.

3 more elements

A process for producing a powder having a multilayered film on its surface 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 above steps at least once to form a multilayered film;
drying the multilayered film;
and
heat-treating the dried multilayered film.

3 more elements

Dependencies are inferred from the claim text.

Powder having multilayered film on its surface and process for preparing the same

Life of this patent

Powder having multilayered film on its surface and process for preparing the same

Life of this patent

Abstract

Claims40