Methods and apparatus for producing enhanced interference pigments

A method of forming a powdered pigment material, comprising the steps of:

• directing a powdered substrate material comprising a TiO2-coated interference mica into a vacuum chamber containing a coating material vaporization source;
• generating a coating material vapor comprising titanium from the coating material vaporization source in a dry vacuum process carried out at a temperature of less than about 200° C.;
• exposing the powdered substrate material to the coating material vapor in a substantially uniform manner;
• and
• depositing a thin coalescence film of coating material on the powdered substrate material to form a powdered pigment material, the thin coalescence film of coating material substantially replicating a surface microstructure of the powdered substrate material.

A powdered pigment material, comprising:

• a plurality of inorganic core flakes;
• a first coating layer of a high refractive index dielectric material substantially surrounding each of the core flakes and having an observable surface microstructure;
• and
• a second coating layer of a light absorbing material substantially surrounding the first coating layer, the second coating layer substantially replicating the surface microstructure of the first coating layer, the light absorbing material selected from the group consisting of oxides, sub-oxides, nitrides, borides, sulfides, carbides, carbon, and combinations thereof.

A coating apparatus for depositing a thin coalescence film on a powdered substrate material, comprising:

• a vacuum chamber;
• a coating material vaporization source disposed within the vacuum chamber;
• and
• a vibrating bed capable of holding a powdered substrate material and exposing the substrate material in a substantially uniform manner to coating material vapor produced by the vaporization source, the vibrating bed including a rotatable container for holding the powdered substrate material, and a vibrator that is operatively connected to the container for producing a substantially helical motion of the substrate material in the container.

A coating apparatus for depositing a thin coalescence film on a powdered substrate material, comprising:

• a vacuum chamber;
• a coating material vaporization source disposed within the vacuum chamber;
• and
• a vibrating conveyor coater capable of circulating a powdered substrate material and exposing the substrate material in a substantially uniform manner to coating material vapor produced by the vaporization source, the vibrating conveyer coater including a plurality of conveyors that are overlapping arranged in a closed pattern so that the powdered substrate material effectively moves from one conveyor to an adjacent conveyer.

A coating apparatus for depositing a thin coalescence film on a powdered substrate material, comprising:

• a vacuum chamber defined by an elongated coating tower structure;
• a plurality of coating material vaporization sources in communication with the vacuum chamber;
• means for supplying a powdered substrate material to the vacuum chamber to produce a coated substrate material;
• a ledged tray device disposed alone the length of the tower structure on an opposing side from the vaporization sources, the ledged tray device configured such that the powdered substrate material runs downward thereover and through the vacuum chamber;
• and
• means for collecting the coated substrate material.

A coating apparatus for depositing a thin coalescence film on a powdered substrate material, comprising:

• a vacuum chamber defined by an elongated coating tower structure that is tilted with respect to a vertical position;
• a plurality of coating material vaporization sources in communication with the vacuum chamber;
• means for supplying a powdered substrate material to the vacuum chamber to produce a coated substrate material;
• a ledged tray device disposed along the length of the tower structure on an opposing side from the vaporization sources, the ledged tray device configured such that the powdered substrate material runs downward thereover and through the vacuum chamber;
• and
• means for collecting the coated substrate material.

A powdered pigment material, comprising:

• a plurality of inorganic core flakes;
• a first coating layer of a high refractive index dielectric material substantially surrounding each of the core flakes and having an observable surface microstructure;
• and
• a second coating layer of a light absorbing material comprising titanium and substantially surrounding the first coating layer, the second coating layer substantially replicating the surface microstructure of the first coating layer.