# US 8,147,932 B2 · Black-to-color shifting security element

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- Number: US 8,147,932 B2
- Document ID: US8147932B2
- Status: Granted
- Kind: B2
- Application number: 11/912,348
- Filed: 2006-04-05
- Published: 2009-11-12
- Granted: 2012-04-03
- Earliest claimed: 2005-05-04
- Assignees: Sicpa Holding SA
- Inventors: Claude-Alain Despland; Albert Stichelberger; Edgar Müller; Pierre Degott
- Web page: https://patentgrep.com/patent/US8147932B2

## CPC

- B42D 25/29: Securities; Bank notes
- B42D 25/328: Diffraction gratings; Holograms
- B42D 25/364: Liquid crystals
- B42D 2033/26
- B42D 2035/24
- Y10S 428/916: Fraud or tamper detecting
- Y10T 428/24802: Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
- B42D: BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention discloses a security element for a banknote, a document of value, right or identity, a ticket, a label, a branded good identifier, or a tax banderole. The element comprises a combination of a coating containing at least one optically variable pigment having a substantial viewing-angle dependent color variation, with at least one selective spectral absorbing material, which blocks out visible spectral components reflected by the optically variable pigment at orthogonal incidence. The security element appears black when viewed at orthogonal angle, and colored when viewed at grazing angle.

## Claims

### Claim 1

Security element for a banknote, a document of value, right or identity, a ticket, a label, a branded good identifier, or a tax banderole, comprising
i) a coating containing at least one optically variable pigment having a substantial viewing-angle dependent color variation, selected from the group consisting of vacuum-deposited thin-film interference pigments, interference-layer coated particles, and cholesteric liquid crystal pigments; and
ii) at least one selective spectral absorbing material embodied as a compound or a mixture of compounds selected form the group consisting of soluble organic dyes, insoluble organic pigments, and insoluble inorganic pigments; wherein said selective spectral absorbing material has spectral absorption properties such that it substantially blocks out the visible spectral components reflected by said optically variable pigment at orthogonal incidence, and does not absorb all spectral components reflected by said optically variable pigment under oblique incidence,
the security element thereby exhibiting a black appearance when viewed at orthogonal angle, and a colored appearance when viewed at grazing angle.

### Claim 2 (depends on 1)

Security element according to claim 1, wherein said optically variable pigment is a multilayer interference pigment comprising reflecting, dielectric and absorbing layers.

### Claim 3 (depends on 1)

Security element according to claim 1, wherein the selective spectral absorbing material is in the coating containing the optically variable pigment.

### Claim 4 (depends on 1)

Security element according to claim 1, wherein the selective spectral absorbing material is in a coating composition applied on top of at least part of the coating containing the optically variable pigment.

### Claim 5 (depends on 1)

Security element according to claim 1, wherein the selective spectral absorbing material is provided in a foil or decal applied on top of at least part of the coating containing the optically variable pigment.

### Claim 6 (depends on 1)

Security element according to claim 1, additionally comprising at least one material selected from the group consisting of luminescent materials, magnetic materials, and infrared absorbing materials.

### Claim 7 (depends on 1)

Security element according to claim 1, further comprising indicia.

### Claim 8 (depends on 1)

Security document, comprising at least a first security element according to claim 1.

### Claim 9 (depends on 8)

Security document according to claim 8, wherein said security document is selected from the group of documents consisting of banknotes, documents of value, right, or identity, labels, branded good identifiers, and tax banderoles.

### Claim 10 (depends on 1, 8)

Security document according to claim 8, further comprising a second security element according to claim 1 in juxtaposition to said first security element, wherein said two security elements form a geometameric color pair exhibiting a black appearance at orthogonal view and two different colors at grazing view.

### Claim 11 (depends on 8)

Security document according to claim 8, further comprising, in the vicinity of said first security element, a non-color-shifting element having a similar black or dark appearance at orthogonal view.

### Claim 12 (depends on 1)

Method of use of a security element according to claim 1, as a protection against counterfeit and illegal reproduction, on a banknote, a document of value, right, or identity, a label, a branded good identifier, or a tax banderole, said method comprising the step of applying said security element on said banknote, a document of value, right, or identity, a label, a branded good identifier, or a tax banderole.