IR-absorbing Intaglio ink

• US 8,362,130 B2
• Filed: 11/18/2011
• Issued: 01/29/2013
• Est. Priority Date: 11/25/2005
• Status: Active Grant

• Current Assignee: Sicpa Holding SA
• Original Assignee: Sicpa Holding SA
• Inventors: Demartin Maeder, Marlyse, Despland, Claude-Alain, Mueller, Edgar, Degott, Pierre
• Primary Examiner(s): NGUYEN, VU ANH
• Application Number:
  US13/300,097
• Publication Number:
  US 20120065313A1
• Time in Patent Office: 438 Days
• Field of Search: 524/417, 524/443
• US Class Current: 524/417
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: C09D 11/03 characterised by features other than the chemical nature of the binder
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: Y10S 283/904 Credit card
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24835 including developable image or soluble portion in coating or impregnation [e.g., safety paper, etc.]
• CPC Class Codes: Y10T 428/24934 including paper layer

Abstract

Pasty ink for the engraved steel die printing process, having a viscosity value above 3 Pa·s, preferably above 5 Pa·s at 40° C., and comprising an infrared absorbing material, wherein said infrared absorbing material is a transition element compound whose IR-absorption is a consequence of electronic transitions within the d-shell of transition element atoms or ions.

Claims

1. IR-absorbing ink for an engraved steel die printing process, comprising:

a polymeric organic binder and an IR-absorbing material,

said ink having a pasty consistency with a viscosity value at 40°

C. of at least 3 Pa·

s, wherein said IR-absorbing material comprises a transition element compound, and wherein infrared absorption of the IR-absorbing material is a consequence of electronic transitions within the d-shell of transition element atoms or ions,

said IR-absorbing material is present in a concentration from 10% to 50% by weight of the ink, and contains IR-absorbing transition element atoms or ions at a concentration of at least 10% by weight, and absorbs in the near infrared range (700 to 1100 nm), and has a CIE (1976) diffuse reflectance lightness (L*) value greater than 70 as measured on the neat powder, and is transparent in some range between 1100 and 2500 nm.

2. The IR-absorbing ink according to claim 1, wherein said ink has a pasty consistency with a viscosity value at 40°

C. of at least 5 Pa·

s.

3. The IR-absorbing ink according to claim 1, wherein said transition element atoms or ions comprise at least one atom selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu.

4. The IR-absorbing ink according to claim 1, wherein said transition element atoms or ions comprise at least one ion selected from the group of ions consisting of Ti³⁺, VO²⁺, Cr⁵⁺, Fe²⁺, Ni²⁺, Co²⁺, and Cu²⁺.

5. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material comprising said IR-absorbing transition element atoms or ions is a glass, in which there is a coordination of the transition element atoms or ions to phosphate and/or fluoride anions present in the glass.

6. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material comprising IR-absorbing transition element atoms or ions comprises a glass, and said glass is a phosphate-and/or fluoride-comprising glass.

7. The IR-absorbing ink according to claim 1, wherein said infrared absorbing material comprising said IR-absorbing transition element atoms or ions is a crystalline compound, being composed of one or more cations and one or more anions.

8. The IR-absorbing ink according to claim 7, wherein said anion is selected from the group consisting of phosphate (PO₄³⁻

), hydrogenophosphate (HPO₄²⁻

), pyrophosphate (P₂O₇⁴⁻

), metaphosphate (P₃O₉³⁻

), polyphosphate, silicate (SiO₄⁴⁻

), the condensed polysilicates;

titanate (TiO₃²⁻

), the condensed polytitanates, vanadate (VO₄³⁻

), the condensed polyvanadates, molybdate (MoO₄²⁻

), tungstate (WO₄²⁻

), the condensed polytungstates, fluoride (F⁻

), oxide (O²⁻

), and hydroxide (OH⁻

).

9. The IR-absorbing ink according to claim 7, wherein said infrared absorbing material is selected from the group of compounds consisting of copper (II) fluoride (CuF₂), copper hydroxyfluoride (CuFOH), copper hydroxide (Cu(OH)₂), copper phosphate (Cu₃(PO₄)₂*2H₂O), anhydrous copper phosphate (Cu₃(PO₄)₂), the basic copper(II) phosphates, copper(II) pyrophosphate (Cu₂(P₂O₇)*3H₂O), anhydrous copper(II) pyrophosphate (Cu₂(P₂O₇)), copper(II) metaphosphate (Cu₃(P₃O₉)₂), iron(II) fluoride (FeF₂*4H₂O), anhydrous iron(II) fluoride (FeF₂), iron(II) phosphate (Fe₃(PO₄)₂*8H₂O, Vivianite), lithium iron(II) phosphate (LiFePO₄, Triphylite), sodium iron(II) phosphate (NaFePO₄, Maricite), iron(II) silicates (Fe₂SiO₄, Fayalite;

Fe_xMg_2-xSiO₄, Olivine), iron(II) carbonate (FeCO₃, Ankerite, Siderite);

nickel(II) phosphate (Ni₃(PO₄)₂*8H₂O), titanium(III) metaphosphate (Ti(P₃O₉)), Ca₂Fe(PO₄)₂*4H₂O, (Anapaite), and MgFe(PO₄)F, (Wagnerite).

10. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material includes IR-absorbing transition element atoms or ions bound to a component of said polymeric organic binder of said ink.

11. The IR-absorbing ink according to claim 10, wherein said polymeric organic binder of said ink contains specific binding sites for transition element ions.

12. The IR-absorbing ink according to claim 11, wherein said transition element ions are Cu²⁺ and/or Fe²⁺.

13. The IR-absorbing ink according to claim 11, wherein said binding sites are phosphate groups which are cross-linked into, or grafted onto a polymer backbone.

14. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material is an IR-absorbing complex of a transition element atom or ion and a binding site contained in the polymer.

15. The IR-absorbing ink according to claim 14, wherein said IR-absorbing complex of a transition element atom or ion and a binding site contained in the polymer is an organic thioruea-copper(II) complex dissolved in said binder.

16. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material has a CIE (1976) diffuse reflectance lightness (L*) value higher than 80, as measured on the neat powder.

17. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material contains IR-absorbing transition element atoms or ions at a concentration of 20% or more by weight.

18. The IR-absorbing ink according to claim 1, wherein said IR-absorbing material contains IR-absorbing transition element atoms or ions at a concentration of 40% or more by weight.

19. The IR-absorbing ink according to claim 1, comprising said IR-absorbing material in a concentration in the range from 20% to 50% by weight of the ink.

20. The IR-absorbing ink according to claim 1, comprising an organic compound as an additional IR-absorber.

21. The IR-absorbing ink according to claim 20, wherein said additional IR-absorber displays a narrower IR-absorption peak than the transition metal based IR-absorbing material.

22. A method of producing an IR-absorbing ink for an engraved steel die printing process according to claim 1, comprising combining the polymeric organic binder and the IR-absorbing material.

23. A method according to claim 22, wherein the ink has a pasty consistency with a viscosity value at 40°

C. of at least 5 Pa·

s.

24. The method according to claim 22, wherein the transition element atoms or ions comprise at least one atom selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, and Cu.

25. The method according to claim 22, wherein the transition element atoms or ions comprise at least one ion selected from the group of ions consisting of Ti³⁺, VO²⁺, Cr⁵⁺, Fe²⁺, Ni²⁺, Co²⁺, and Cu²⁺.

26. The IR-absorbing ink according to claim 9, wherein the basic copper(II) phosphates comprise Cu₂(PO₄)₂(OH) (Libethenite), Cu₃(PO₄)₂(OH)₃ (Cornetite), Cu₅(PO₄)₃(OH)₄ (Pseudomalachite), and CuAl₆(PO₄)₄(OH)₈.5H₂O (Turquoise).