Methods for printing tactile security features

Patent metadata

Field	Value
Publication number	US-9616699-B2
Application number	US-201314406903-A
Country	US
Kind code	B2
Filing date	Apr 16, 2013
Priority date	Jun 11, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A process for manufacturing a security feature having a tactile pattern, said method including applying on a substrate a radiation-curable basecoat composition by a process selected from inkjet, offset, screen printing, flexo printing and rotogravure; at least partially or fully radiation-curing the radiation-curable basecoat composition so as to obtain a radiation-cured basecoat; applying on the radiation-cured basecoat a radiation-curable topcoat composition in a form of indicia by a process of screen printing, flexo printing or rotogravure; radiation-curing said radiation-curable topcoat composition so as to form a radiation-cured topcoat. The radiation-curable basecoat composition and/or the radiation-curable topcoat composition includes one or more machine readable feature substances independently selected from cholesteric liquid crystal pigments, luminescent compounds, infrared-absorbing compounds, magnetic compounds and mixtures thereof. The radiation-cured basecoat has a surface energy at least 15 mN/m less than the surface energy of the radiation-cured topcoat.

First claim

The invention claimed is:

1. A process for manufacturing a security feature comprising a tactile pattern, said method comprising:
applying on a substrate a radiation-curable basecoat composition by a process selected from the group consisting of inkjet, offset, screen printing, flexo printing and rotogravure;
at least partially radiation-curing said radiation-curable basecoat composition so as to obtain a radiation-cured basecoat;
applying on the radiation-cured basecoat a radiation-curable topcoat composition in a form of indicia by a process selected from the group consisting of screen printing, flexo printing and rotogravure; and
radiation-curing said radiation-curable topcoat composition so as to form a radiation-cured topcoat,
wherein at least one of the radiation-curable basecoat composition and the radiation-curable topcoat composition comprises one or more machine readable feature substances independently selected from the group consisting of cholesteric liquid crystal pigments, luminescent compounds, infrared-absorbing compounds, magnetic compounds and mixtures thereof, and
wherein the radiation-cured basecoat has a surface energy at least 15 mN/m less than the surface energy of the radiation-cured topcoat.

2. The process according to claim 1 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition are UV-Vis-curable compositions.

3. The process according to claim 1 , wherein the substrate is selected from the group consisting of paper-containing materials, plastic or polymer substrates, composite materials, metals, metalized materials and combinations thereof.

4. The process according to claim 1 , wherein at least one of the radiation-curable basecoat composition and the radiation-curable topcoat composition comprises one or more machine readable feature substances and the other of the radiation-curable basecoat composition and the radiation-curable topcoat composition comprises one or more overt security feature substances selected from the group consisting of iridescent pigments, thin-film interference pigments, magnetic or magnetizable thin-film interference pigments, interference-layer coated particles, holographic pigments, thermochromic pigments, photochromic pigments, metameric materials, and mixtures thereof.

5. The process according to claim 4 , wherein the other of the radiation-curable basecoat composition and the radiation-curable topcoat composition additionally comprises one or more machine readable feature substances.

6. The process according to claim 1 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition independently comprise:
a binder compound selected from the group consisting of epoxy(meth)acrylates, (meth)acrylated oils, polyester(meth)acrylates, aliphatic or aromatic urethane(meth)acrylates, silicone(meth)acrylates, amino(meth)acrylates, acrylic(meth)acrylates, cycloaliphatic epoxides, vinyl ethers and mixtures thereof; and
one or more photoinitiators.

7. The process according to claim 6 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition independently further comprise a second binder compound selected from the group consisting of monomeric acrylates.

8. The process according to claim 6 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition independently further comprise the one or more machine readable feature substance and/or the one or more security feature substances.

9. The process according to claim 6 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition independently further comprise one or more additives selected from the group consisting of fillers, antifoaming agents, photosensitizers, photostabilizers, emulsifiers, and mixtures thereof.

10. The process according to claim 1 , wherein:
the radiation-curable topcoat composition comprises one or more machine readable feature substances selected from the group consisting of cholesteric liquid crystal pigments, and
the radiation-curable basecoat composition comprises one or more overt security feature substances selected from the group consisting of iridescent pigments, thin-film interference pigments, magnetic or magnetizable thin-film interference pigments, and mixtures thereof.

11. The process according to claim 1 , wherein:
the radiation-curable topcoat composition comprises one or more machine readable feature substances selected from the group consisting of cholesteric liquid crystal pigments, and
the radiation-curable basecoat composition comprises one or more machine readable feature substances selected from the group consisting of cholesteric liquid crystal pigments.

12. The process according to claim 11 , wherein the cholesteric liquid crystal pigments in the radiation-curable topcoat composition and the cholesteric liquid crystal pigments in the radiation-curable basecoat composition are different in terms of circularly polarized light.

13. The process according to claim 1 , wherein:
the radiation-curable topcoat composition comprises one or more machine readable feature substances selected from the group consisting of luminescent compounds, and
the radiation-curable basecoat composition comprises one or more overt security feature substances selected from the group consisting of iridescent pigments, thin-film interference pigments, magnetic or magnetizable thin-film interference pigments, and mixtures thereof.

14. The process according to claim 1 , wherein:
the radiation-curable topcoat composition comprises one or more machine readable feature substances selected from the group consisting of luminescent compounds, and
the radiation-curable basecoat composition comprises one or more machine readable feature substances selected from the group consisting of cholesteric liquid crystal pigments.

15. The process according to claim 1 , wherein the radiation-curable basecoat composition and the radiation-curable topcoat composition are metameric inks.

16. The process according to claim 1 , wherein the radiation-curable basecoat composition comprises one or more surface additives.

17. The process according to claim 16 , wherein the one or more surface additives are in an amount from about 1 to about 25 weight percent, the weight percent being based on a total weight of the radiation-curable basecoat composition.

18. The process according to claim 1 , wherein the tactile pattern has a peak to valley distance of at least 20 μm.

19. A use of the security feature formed according to the process of recited in claim 1 for the protection of a security document against counterfeiting or fraud.

20. A security document comprising a security feature having the tactile pattern, wherein the security feature is formed according to the process of claim 1 .

21. The process according to claim 1 , wherein the at least partially radiation-curing said radiation-curable basecoat composition comprises fully radiation-curing said radiation-curable basecoat composition.

22. A security feature comprising a substrate and a tactile pattern of a radiation-cured basecoat and a radiation-cured topcoat, said radiation-cured topcoat being in the form of indicia and at least partially covering said radiation-cured basecoat,
wherein at least one of said radiation-cured basecoat and said radiation-cured topcoat comprises at least one machine-readable feature substance independently select

Assignees

• Sicpa Holding Sa

Inventors

• Garnier Christophe
• Vuilleumier Lucien
• Degott Pierre

Classifications

• B41M3/14 Primary

  Security printing {(securities B42D25/29)} · CPC title

• B42D25/364

  Liquid crystals · CPC title

• B41M3/148

  Transitory images, i.e. images only visible from certain viewing angles · CPC title

• B41M1/04

  Flexographic printing · CPC title

• B41M1/12

  Stencil printing; Silk-screen printing · CPC title