Optically variable security threads and stripes

Patent metadata

Field	Value
Publication number	US-9701152-B2
Application number	US-201214424783-A
Country	US
Kind code	B2
Filing date	Aug 29, 2012
Priority date	Aug 29, 2012
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

Security threads or stripes include a substrate and i) a first optically variable layer imparting a first different color impression at different viewing angles, ii) a second optically variable layer imparting a second different color impression at different viewing angles, iii) a first color constant layer having a color matching the color impression of the first or second optically variable layer at a first viewing angle, iv) a second color constant layer having a color matching the color impression of the first or second optically variable layer at a second viewing angle, and v) one or more material-free regions, wherein the first optically variable layer, the second optically variable layer, the first color constant layer, the second color constant layer and the one or more material-free regions are jointly visible from one side of the security thread or stripe.

First claim

The invention claimed is:

1. A security thread or stripe comprising a substrate and:
i) a first optically variable layer imparting a first differing color impression at different viewing angles and being made of an optically variable composition comprising a plurality of optically variable pigments;
ii) a second optically variable layer imparting a second differing color impression at different viewing angles and being made of an optically variable composition comprising a plurality of optically variable pigments;
iii) a first color constant layer having a color matching the color impression of the first or second optically variable layer at a first viewing angle and being made of a color constant composition comprising a binder and a plurality of inorganic pigments, organic pigments or mixtures thereof;
iv) a second color constant layer having a color matching the color impression of the first or second optically variable layer at a second viewing angle and being made of a color constant composition comprising a binder and a plurality of inorganic pigments, organic pigments or mixtures thereof; and
v) one or more material-free regions,
wherein the first differing color impression is different from the second differing color impression,
wherein the first optically variable layer and the second optically variable layer either comprise one or more gaps in the form of indicia or comprise indicia made of the optically variable compositions,
wherein the substrate is a metalized material comprising a further indicia comprising clear text,
wherein the further indicia is disposed in register with the one or more material-free regions, and
wherein the first optically variable layer, the second optically variable layer, the first color constant layer, the second color constant layer, the one or more material-free regions, and the clear text are jointly visible from one side of the security thread or stripe.

2. The security thread or stripe according to claim 1 , wherein the first optically variable layer is disposed on top of the first color constant layer and/or the second color constant layer, and the second optically variable layer is disposed on top of the first color constant layer and/or the second color constant layer.

3. The security thread or stripe according to claim 1 , wherein the first optically variable layer is in direct contact with the first color constant layer and/or the second color constant layer, and the second optically variable layer is in direct contact with the first color constant layer and/or the second color constant layer.

4. The security thread or stripe according to claim 1 , wherein the first viewing angle under which the first color constant layer has a color matching the color impression of the first or second optically variable layer is the same as the second viewing angle under which the second color constant layer has a color matching the color impression of the first or second optically variable layer.

5. The security thread or stripe according to claim 1 , wherein the first viewing angle under which the first color constant layer has a color matching the color impression of the first or second optically variable layer is different from the second viewing angle under which the second color constant layer has a color matching the color impression of the first or second optically variable layer.

6. The security thread or stripe according to claim 1 , wherein at least a part of the plurality of optically variable pigments consists of thin film interference pigments, magnetic thin film interference pigments, interference coated pigments, cholesteric liquid crystal pigments and mixtures thereof.

7. The security thread or stripe according to claim 6 , wherein the thin film interference pigments comprise a Fabry-Perot absorber/dielectric/reflector/dielectric/absorber multilayer structure.

8. The security thread or stripe according to claim 7 , wherein the reflector layer of the multilayer structure is selected from the group consisting of metals, metal alloys, and combinations thereof; and/or the dielectric layers of the multilayer structure are independently selected from the group consisting of magnesium fluoride (MgF 2 ), silicium dioxide (SiO 2 ), and mixtures thereof; and/or the absorber layers of the multilayer structure are independently selected from the group consisting of chromium, nickel, metal alloys, and mixtures thereof.

9. The security thread or stripe according to claim 7 , wherein the Fabry-Perot absorber/dielectric/reflector/dielectric/absorber multilayer structure is a multilayer structure of Cr/MgF 2 /Al/MgF 2 /Cr.

10. The security thread or stripe according to claim 7 , wherein the magnetic thin film magnetic interference pigments comprise a 5-layer Fabry-Perot absorber/dielectric/reflector/dielectric/absorber multilayer structure wherein the reflector and/or the absorber is a magnetic layer.

11. The security thread or stripe according to claim 10 , wherein the magnetic thin film magnetic interference pigments comprise a 7-layer Fabry-Perot absorber/dielectric/reflector/magnetic/reflector/dielectric/absorber multilayer structure.

12. The security thread or stripe according to claim 11 , wherein the 7-layer Fabry-Perot absorber/dielectric/reflector/magnetic/reflector/dielectric/absorber layer is a multilayer structure of Cr/MgF 2 /Al/Ni/Al/MgF 2 /Cr.

13. The security thread or stripe according to claim 10 , wherein the reflector layers of the multilayer structure are independently selected from the group consisting of metals, metal alloys, and combinations thereof; and/or the dielectric layers of the multilayer structure are independently selected from the group consisting of magnesium fluoride (MgF 2 ), silicium dioxide (SiO 2 ), and mixtures thereof; and/or the absorber layers of the multilayer structure are selected from the group consisting of chromium, nickel, metal alloys, and mixtures thereof, and/or the magnetic layer of the multilayer structure is selected from the group consisting of nickel (Ni), iron (Fe) and cobalt (Co), and mixtures thereof.

14. The security thread or stripe according to claim 1 , wherein the substrate is selected from the group consisting of plastics, polymers, composite materials, metals, and mixtures thereof.

15. The security thread or stripe according to claim 1 , further comprising one or more protective layers.

16. The security thread or stripe according to claim 1 , further comprising one or more additional layers selected from the group consisting of adhesive layers, lacquers, machine readable layers, hiding layers, and combinations thereof.

17. The security thread or stripe according to claim 16 , wherein the machine readable layer comprises a machine readable material selected from the group consisting of magnetic materials, luminescent materials, electrically conductive materials, infrared-absorbing materials, and mixtures thereof.

18. The security thread or stripe according to claim 1 , wherein the first optically variable layer and the second optically variable layer consist of radiation curable compositions, thermal drying compositions, or any combination thereof.

19. The security thread or stripe according to claim 1 , wherein the indicia are selected from the group consisting of symbols, alphanumeric symbols, motifs, geometric patterns, letters, words, numbers, logos, drawings, and combinations thereof.

20. The security thread or stripe according to claim 1 , having a width between about 0.5 mm and about 30 mm.

21. A

Assignees

• Ritter Gebhard
• Degott Pierre
• Ye Zhongdong
• Sun Fangyi
• Wang Weiru
• Hu Chunhua
• Li Xiang
• Sicpa Holding Sa
• China Banknote Printing & Minting Corp
• Zhongchao Special Security Technology Co Ltd
• China Banknote Sicpa Security Ink Co Ltd

Inventors

• Ritter Gebhard
• Degott Pierre
• Ye Zhongdong
• Sun Fangyi
• Wang Weiru
• Hu Chunhua
• Li Xiang

Classifications

• D21H21/42 Primary

  Ribbons or strips (filaments D21H15/06) · CPC title

• B42D25/00

  Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof (printing processes to produce identification or security features B41M3/14) · CPC title

• B42D25/351

  Translucent or partly translucent parts, e.g. windows · CPC title

• B42D25/355 Primary

  Security threads · CPC title

• D21H21/44

  Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods · CPC title