Composition including a color shifting pigment and a color filter

Patent metadata

Field	Value
Publication number	US-11680175-B2
Application number	US-201916702191-A
Country	US
Kind code	B2
Filing date	Dec 3, 2019
Priority date	Dec 3, 2018
Publication date	Jun 20, 2023
Grant date	Jun 20, 2023

Abstract

A composition including a first color shifting pigment having a first color shift that extends from a starting color at normal through a plurality of colors as a viewing angle is increased to a final color, wherein the first color shift rotates counterclockwise relative to, and about, an origin of the L*a*b* color space; and a color filter that transmits a portion of the first color shift of the first color shifting pigment and absorbs a remainder of the first color shift of the first color shifting pigment; wherein the composition has a second color shift different from the first color shift; and wherein the second color shift has a first portion that rotates counterclockwise relative to the origin and a second portion that rotates clockwise relative to the origin is disclosed. A security device including the composition is included. A method of making the composition and a method of authenticating the security device are also disclosed.

First claim

What is claimed is:

1. A composition comprising:
a first color shifting pigment having a property of a first color shift that extends from a starting color at normal through a plurality of colors as a viewing angle is increased to a final color, wherein the first color shift rotates counterclockwise relative to, and about, an origin of the L*a*b* color space; and
a color filter having the ability to transmit a portion of the first color shift of the first color shifting pigment and having the ability to absorb a remainder of the first color shift of the first color shifting pigment;
wherein the composition has a property of a second color shift different from the first color shift;
wherein the second color shift has a first portion that rotates counterclockwise relative to the origin and a second portion that rotates clockwise relative to the origin, and
wherein the color filter does not transmit colors having a wavelength less than about 530 nm.

2. The composition of claim 1 , wherein the first color shifting pigment includes at least the following layers: a reflector layer, a spacer layer, and an absorber layer.

3. The composition of claim 1 , wherein each of the starting color and the final color of the first color shifting pigment are different from each of a starting color and a final color of the composition, respectively.

4. The composition of claim 3 , wherein the starting color of the composition has a higher chromaticity value as compared to the starting color of the first color shifting pigment.

5. The composition of claim 1 , wherein the second color shift of the composition is shorter in length than the first color shift of the first color shifting pigment.

6. The composition of claim 1 , wherein the second color shift does not rotate about the origin.

7. The composition of claim 1 , wherein the second color shift includes a small change in chroma over a length of the entire second color shift.

8. The composition of claim 1 , wherein the color filter is applied as a layer on the first color shifting pigment.

9. The composition of claim 2 , wherein the color filter is included in at least one layer of the first color shifting pigment, wherein the at least one layer is chosen from the reflector layer, the spacer layer, and the absorber layer.

10. The composition of claim 1 , wherein the second color shift extends over a range of viewing angle from about 10 degrees to about 90 degrees.

11. The composition of claim 1 , wherein the second color shift extends over a range of hue from about 30 degrees to about 360 degrees.

12. The composition of claim 1 , wherein the color filter is an organic dye.

13. The composition of claim 1 , wherein the color filter is a nanosized pigment.

14. The composition of claim 1 , wherein the first color shifting pigment includes a magnetic layer.

15. A security device comprising,
a substrate; and the composition of claim 1 .

16. The security device of claim 15 , wherein the first coloring shifting pigment is in the form of a flake with the color filter as a layer on the flake, and wherein the flake is positioned parallel to a surface of the substrate.

17. A method of making a composition comprising:
selecting a first color shifting pigment having a property of a first color shift that extends from a starting color at normal through a plurality of colors as a viewing angle is increased to a final color at perpendicular to normal, wherein the first color shift rotates counterclockwise relative to, and about, an origin of the L*a*b* color space;
selecting a color filter having the ability to transmit a portion of the first color shift of the first color shifting pigment and having the ability to absorb a remainder of the first color shift of the first color shifting pigment; and
combining the first color shifting pigment and the color filter to form a composition;
wherein the composition has a property of a second color shift different from the first color shift; and
wherein the second color shift has a first portion that rotates counterclockwise relative to the origin and a second portion that rotates clockwise relative to the origin, and
wherein the color filter does not transmit colors having a wavelength less than about 530 nm.

18. The method of claim 17 , wherein the color filter is applied as a layer on the first color shifting pigment, which is in a form of a flake.

19. The method of claim 17 , wherein the color filter is included in at least one layer of the first color shifting pigment, wherein the at least one layer is chosen from the reflector layer, the spacer, and the absorber layer.

20. A method of authenticating a security device, comprising:
viewing, at a normal angle, an article imprinted with a composition,
wherein the composition includes a first color shifting pigment having a first color shift that extends from a starting color at normal through a plurality of colors as a viewing angle is increased to a final color at perpendicular to normal, wherein the first color shift rotates counterclockwise relative to, and about, an origin of the L*a*b* color space; and a color filter that transmits a portion of the first color shift of the first color shifting pigment and absorbs a remainder of the first color shift of the first color shifting pigment; and
viewing, at a viewing angle, the imprinted article;
wherein the composition has a second color shill different from the first color shift; and
wherein the second color shift has a first portion that rotates counterclockwise relative to the origin and a second portion that rotates clockwise relative to the origin, and
wherein the color filter does not transmit colors having a wavelength less than about 530 nm.

Assignees

• Viavi Solutions Inc

Inventors

• Delst Cornelis Jan
• Kohlmann Paul Thomas

Classifications

• B42D25/378

  Special inks · CPC title

• B42D25/369

  Magnetised or magnetisable materials · CPC title

• B42D25/373

  Metallic materials · CPC title

• C09D5/29 Primary

  for multicolour effects · CPC title

• C01P2006/63

  a* (red-green axis) · CPC title