Diffractive effect pigments having a reflective core and semiconductor coatings
AssigneeEckart America Corporation
InventorDevin Schmitt
Life of this patent
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Abstract
Disclosed herein is a flaky diffractive effect pigment having a diffractive structure and comprising a flake of a highly reflective material having a first major interface and opposed to this first interface a second major interface, and at least one side surface and directly adjacent on one or of both of these major interfaces a layer of a semiconducting material having a bandgap of 0.7 to 2.5 eV. The diffractive effect pigment may be further coated with a coating which is optically non-active in the visible wavelength region.
Claims20
A flaky diffractive effect pigment having a diffractive structure and a 3-layer stack consisting of a core of a flake of a highly reflective material having a first major interface and opposed to this first interface a second major interface, and at least one side surface and directly adjacent on both of these major interfaces a layer of a semiconducting material having a bandgap of 0.1 to 2.5 eV, wherein the layers of the semiconductor material have an average primary thickness in the range from 10 to 100 nm and wherein the total primary thickness of the effect pigment is in a range of 35 to below 300 nm.
A method of making a flaky diffractive effect pigment using a PVD process comprising:
- (a1) applying a release layer to a linearly movable flexible substrate,
- (a2) introducing a diffractive structure into the release layer, preferably by embossing, and
- (a3) depositing a first semiconductor layer onto the release layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition (PVD), and
- (a4) depositing a metal layer onto the first semiconductor layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition
- (a5) depositing a second semiconductor layer onto the metal layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition
- or
- (b1) applying a release layer to a linearly movable flexible substrate,
- (b2) depositing a first semiconductor layer onto the release layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition (PVD), and
- (b3) depositing a metal layer onto the first semiconductor layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition
- (b4) depositing a second semiconductor layer onto the metal layer on the linearly movable flexible substrate, in a vacuum chamber having a vapor-deposition section, by means of physical vapor deposition
- (b5) introducing a diffractive structure onto and/or into any of the structures of step (b2) to (b4), and
- c) stripping the material stack from the flexible substrate in a solvent,
- the resulting flaky diffractive effect pigment having a diffractive structure and a 3-layer stack consisting of a core of a flake of a highly reflective material having a first major interface and opposed to this first interface a second major interface, and at least one side surface and directly adjacent on both of these major interfaces a layer of a semiconducting material having a bandgap of 0.1 to 2.5 eV, wherein the layers of the semiconductor material have an average primary thickness in the range from 10 to 100 nm and wherein the total primary thickness of the effect pigment is in a range of 35 to below 300 nm.
15-16. (canceled)
Dependencies are inferred from the claim text.