Diffractive pigment flakes and compositions
AssigneeFlex Products, Inc.
InventorsAlberto Argoitia, Richard A. Bradley, Jr.
Life of this patent
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Abstract
Diffractive pigment flakes include single layer or multiple layer flakes that have a diffractive structure formed on a surface thereof. The multiple layer flakes can have a symmetrical stacked coating structure on opposing sides of a reflective core layer, or can be formed with encapsulating coatings around the reflective core layer. The diffractive pigment flakes can be interspersed into liquid media such as paints or inks to produce diffractive compositions for subsequent application to a variety of objects. The diffractive pigment flakes can be formed with a variety of diffractive structures thereon to produce selected optical effects.
Claims25
A diffractive composition, comprising:
- a pigment medium;
- and
- a plurality of diffractive pigment flakes dispersed in the pigment medium, the pigment flakes having a multilayer structure comprising:
- a central reflector layer having a first major surface, and an opposing second major surface;
- a first dielectric layer overlying the first major surface of the reflector layer;
- and
- a second dielectric layer overlying the second major surface of the reflector layer;
- wherein the pigment flakes have a diffraction grating pattern thereon with at least about 1,400 grating lines per mm and a grating depth of at least about 150 nm.
A coated article comprising:
- an object having a surface;
- a diffractive coating layer overlying at least a portion of the surface, the coating layer comprising a diffractive composition comprising:
- a pigment medium;
- and
- a plurality of diffractive pigment flakes dispersed in the pigment medium, the pigment flakes having a diffraction grating pattern thereon with at least about 1,400 grating lines per mm and a grating depth of at least about 150 nm;
- wherein the coating layer has a substantially continuous tone iridescent diffractive effect observable under a mixture of diffuse and directional illumination.
An optical security device comprising:
- a first region;
- a second region;
- and
- an assembly of diffractive pigment flakes in at least one of the first or second regions, the pigment flakes having a diffractive structure comprising a sequence of substantially equally spaced linear features that provides for a decrease in a zero order diffracted light beam and a sufficient increase in a first or higher order diffracted light beam such that the appearance of the security device is dominated by the dispersion of light by first or higher order reflections.
Dependencies are inferred from the claim text.