SECURITY ELEMENT FORMED FROM AT LEAST TWO MATERIALS PRESENT IN PARTIALLY OR FULLY OVERLAPPING AREAS, ARTICLES CARRYING THE SECURITY ELEMENT, AND AUTHENTICATION METHODS

• US 20190126659A1
• Filed: 12/13/2016
• Published: 05/02/2019
• Est. Priority Date: 12/17/2015
• Status: Active Grant

• Current Assignee: Sicpa Holding SA
• Original Assignee: Sicpa Holding SA
• Inventors: DORIER, Jean-Luc, MILOS-SCHOUWINK, Mia, RAEMY, Xavier Cedric
• Granted Patent: US 10,457,087 B2
• Time in Patent Office: Days
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/382 absorbing or reflecting infrared light
• CPC Class Codes: B42D 25/387 absorbing or reflecting ultraviolet light
• CPC Class Codes: B42D 25/405 Marking
• CPC Class Codes: C09D 11/033 characterised by the solvent
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/101 Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• CPC Class Codes: C09D 11/106 containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09D 11/30 Inkjet printing inks
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09D 11/54 Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G06K 19/06028 using bar codes
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06103 the marking being embedded in a human recognizable image, e.g. a company logo with an embedded two-dimensional code
• CPC Class Codes: G06K 7/1413 1D bar codes
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1443 locating of the code in an image
• CPC Class Codes: G07D 2207/00 Paper-money testing devices
• CPC Class Codes: G07D 7/003 : using security elements using digital security elements G07D7/004
• CPC Class Codes: G07D 7/12 : Visible light, infrared or ultraviolet radiation
• CPC Class Codes: G07D 7/1205 : Testing spectral properties

Abstract

Security element comprising a first material MAT1 and a second material MAT2 formed in or on a substrate, in such a manner that areas occupied by MAT1 and MAT2 overlap partially or fully,

the first material MAT1 comprising a phosphorescent pigment (donor), the second material MAT2 comprising a fluorescent dye or pigment (acceptor),

wherein the phosphorescent pigment present in MAT1 is capable of emitting phosphorescence radiation in at least one first phosphorescence emission wavelength range λ1e upon excitation by electromagnetic radiation falling within a phosphorescence excitation wavelength range λ1a, and

the fluorescent dye or pigment present in MAT2 is capable of emitting fluorescence radiation in at least one second fluorescence emission wavelength range λ2e upon excitation by electromagnetic radiation falling within an fluorescence excitation wavelength range λ2a of the fluorescent dye or pigment, and

said first phosphorescence emission wavelength range λ1e of the phosphorescent pigment present in MAT1 overlaps with the excitation wavelength range λ2a of the fluorescent dye or pigment present in MAT2, so that after irradiation of the security element with electromagnetic radiation within the phosphorescence excitation wavelength range λ1a the emission of fluorescence radiation in the emission wavelength range λ2e is observable.

Claims

1. A security element comprising a first material MAT1 and a second material MAT2, which are formed in or on a substrate, in such a manner that areas occupied by MAT1 and MAT2 overlap partially or fully so that there are three areas recognizable:

an area wherein MAT1, but not MAT2 is provided, an area wherein MAT2, but no MAT1 is provided, and an area wherein both MAT1 and MAT2 are provided,

the first material MAT1 comprising a phosphorescent pigment (donor),

the second material MAT2 comprising a fluorescent dye or pigment (acceptor), wherein the phosphorescent pigment present in MAT1 is capable of emitting phosphorescence radiation in at least one first phosphorescence emission wavelength range 80 1e upon excitation by electromagnetic radiation falling within a phosphorescence excitation wavelength range λ

1a, and

the fluorescent dye or pigment present in MAT2 is capable of emitting fluorescence radiation in at least one second fluorescence emission wavelength range λ

2e upon excitation by electromagnetic radiation falling within an fluorescence excitation wavelength range λ

2a of the fluorescent dye or pigment, and

said first phosphorescence emission wavelength range λ

1e of the phosphorescent pigment present in MAT1 overlaps with the excitation wavelength range λ

2a of the fluorescent dye or pigment present in MAT2, so that after irradiation of the security element with electromagnetic radiation within the phosphorescence excitation wavelength range λ

1a. the emission of fluorescence radiation in the emission wavelength range λ

2e is observable.

2. The security element according to claim 1, wherein MAT1 is an ink applicable by gravure printing, offset printing, intaglio printing, pad printing, flexographic printing or screen printing, and MAT2 is an ink applicable by inkjet printing.

3. The security element according to claim 1, wherein MAT2 is comprised in a digital code, such as a QR code, dot-matrix code or bar code.

4. The security element according to claim 1, wherein MAT2 is comprised in a serial code or product code, or wherein MAT2 is item-specific.

5. The security element according to claim 1, wherein MAT1 and MAT2 are present in the form of layers on a substrate, and MAT2 is provided directly on MAT1, or wherein MAT1 is provided directly on MAT2.

6. The security element according to claim 1, wherein MAT1 is comprised in the substrate and MAT2 is provided directly on the substrate, or wherein MAT2 is comprised in the substrate and MAT1 is provided directly on the substrate.

7. The security element according to claim 6, wherein the substrate comprising MAT1 or MAT2 is selected from one or more of glass, ceramics, plastics, paper, and cardboard.

8. The security element according to claim 1, wherein one or both of MAT1 and MAT2 is/are not visually distinguishable from the substrate by the naked eye.

9. The security element according to claim 1, wherein one or both of MAT1 and MAT2 is/are provided in the form of a pattern, indicia, symbol or logo.

10. The security element according to claim 9, wherein MAT1 is provided in the form of a pattern, indicia, symbol or logo, and wherein MAT2 is provided in the form of a code, which may or may not be item-specific.

11. The security element according to claim 1, wherein the area wherein MAT1 is provided entirely includes the area wherein MAT2 is provided.

12. The security element according to claim 1, wherein λ

1a-max <

λ

1e-max <

λ

2e-max, wherein λ

1a-max, λ

1e-max, and λ

2e-max denote the wavelengths of the excitation and emission peaks in the respective excitation and emission wavelength regions of the phosphorescent pigment present in MAT1 and the fluorescent dye or pigment present in MAT2.

13. A method for authenticating a security element as defined in claim 1, which comprises the steps

i. irradiating the security element with a light source in the wavelength range λ

1a for a given time to excite the phosphorescent pigment in MAT1 to emit phosphorescence radiation in the wavelength range λ

1e;

ii. after the given time has elapsed, subsequently detecting a response emitted by a region of a spatial overlap of the security element within the wavelength range λ

_2e and

iii. judging the authenticity of the security element on the basis of the response in the wavelength range λ

^2e.

14. The authentication method according to claim 13, wherein step iii. comprises a sub-step iii.a of extracting a value related to at least one parameter associated with the emission in the wavelength region 80_2e and a sub-step iii.b of determining whether the extracted value corresponds within a certain level of confidence to a value that is characteristic for an authentic security element.

15. The authentication method according to claim 14, wherein the parameter is associated with the intensity of the observed emission in the wavelength region λ

_2e.

16. The authentication method according to claim 15, wherein the parameter is associated with the decay time of the phosphorescent pigment.

17. The authentication method according to claim 13, wherein the method additionally comprises steps for acquiring an image of the security element in the wavelength range λ

_2e upon illumination in the wavelength range λ

_2a, and processing the acquired image.

18. The authentication method according to claim 16, which further comprises generating a digital correlation mask from said image.

19. An authentication apparatus for authenticating a security element, wherein the security element comprises a first material MAT1 and a second material MAT2 formed in or on a substrate, in such a manner that areas occupied by MAT1 and MAT2 overlap partially or fully so that there are three areas recognizable:

an area wherein MAT1, but not MAT2 is provided, an area wherein MAT2, but no MAT1 is provided, and an area wherein both MAT1 and MAT2 are provided,

the first material MAT1 comprising a phosphorescent pigment (donor),

second material MAT2 comprising a fluorescent dye or pigment (acceptor),

wherein the phosphorescent pigment present in MAT1 is capable of emitting phosphorescence radiation in at least one first phosphorescence emission wavelength range λ

1e upon excitation by electromagnetic radiation falling within a phosphorescence excitation wavelength range λ

1a, and

the fluorescent dye or pigment present in MAT2 is capable of emitting fluorescence radiation in at least one second fluorescence emission wavelength range λ

2e upon excitation by electromagnetic radiation falling within. an fluorescence excitation wavelength range) λ

2a of the fluorescent dye or pigment, and

said first phosphorescence emission wavelength range λ

1e of the phosphorescent pigment present in MAT1 overlaps with the excitation wavelength range λ

2a of the fluorescent dye or pigment present in MAT2, so that after irradiation of the security element with electromagnetic radiation within the phosphorescence excitation wavelength range λ

1a. the emission of fluorescence radiation in the emission wavelength range λ

2e is observable, and the security element is authenticated with the method described in claim 13, wherein the apparatus comprises a radiation source for performing step i, a detector for performing step ii and a processing unit for performing step iii.

20. The authentication apparatus according to claim 19, comprising

a first radiation source for emitting substantially in the wavelength range λ

1a for irradiating the phosphorescent pigment in MAT1;

an imager selectively sensitive in the wavelength range λ

2e for capturing images of the security element;

a computing device for storing and processing the captured images under the first radiation source and for comparing the processed image result with a set of predefined stored rules to judge whether the security element is authentic.

21. The authentication apparatus according to claim 19, further comprising a second light source emitting substantially in the wavelength range λ

2a for irradiating the fluorescent dye or pigment in MAT2.

22. The authentication apparatus according to claim 19, wherein said computing device is furthermore arranged for decoding information in a digital code.

23. A commercial good of value or security document comprising the security element according to claim 1.

24. A process for producing a security element according to claim 1, which comprises

providing a first material MAT1 and a second material MAT2 in or on a substrate, in such a manner that the areas occupied by MAT1 and MAT2 overlap fully or partially so that there are three areas recognizable:

an area wherein MAT1, but not MAT2 is provided, an area wherein MAT2, but no MAT1 is provided, and an area wherein both MAT1 and MAT2 are provided,

the first material MAT1 comprising a phosphorescent pigment (donor),

the second material MAT2 comprising a fluorescent dye or pigment (acceptor),

wherein the phosphorescent pigment present in MAT1 is capable of emitting phosphorescence radiation in at least one first phosphorescence emission wavelength range λ

1e upon excitation by electromagnetic radiation falling within a phosphorescence excitation wavelength range λ

1α

, and

the fluorescent dye or pigment present in MAT2 is capable of emitting fluorescence radiation in at least one second fluorescence emission wavelength range λ

2e upon excitation by electromagnetic radiation falling within an fluorescence excitation wavelength range λ

2 α

of the fluorescent dye or pigment, and said first phosphorescence emission wavelength range 80 1e of the phosphorescent pigment present in MAT1 overlaps with the excitation wavelength range λ

2a of the fluorescent dye or pigment present in MAT2, so that after irradiation of the security element with electromagnetic radiation within the phosphorescence excitation wavelength range λ

1α

the emission of fluorescence radiation in the emission wavelength range λ

2e is observed.