Luminescent borates, materials and articles incorporating such borates, and methods and apparatus for their production and use in article authentication

• US 9,074,137 B2
• Filed: 11/08/2012
• Issued: 07/07/2015
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kane, James, Rapoport, William Ross, Lau, Carsten
• Primary Examiner(s): Bryant, Casey
• Application Number:
  US13/672,109
• Publication Number:
  US 20130119274A1
• Time in Patent Office: 971 Days
• US Class Current: 1/1
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: B42D 2033/20 Coloured material; Pigments or inks
• CPC Class Codes: B42D 25/00 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 Class Codes: B42D 25/21 for multiple purposes
• CPC Class Codes: B42D 25/23 Identity cards
• CPC Class Codes: B42D 25/24 Passports
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/373 Metallic materials
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09F 3/00 Obtaining spirits of turpentine
• CPC Class Codes: C09K 11/778 Borates
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

Embodiments include luminescent materials and associated production methods. The material includes a crystal borate having a first substitutable element, neodymium substituted for the first substitutable element at a first substitution percentage of at least about 20 percent, and ytterbium substituted for the first substitutable element at a second substitution percentage. The material also may include chromium substituted for a second substitutable element. The material also may include a medium within which particles of the borate are incorporated. The medium, with the luminescent material particles, may form a security feature of an article. Embodiments of methods for identifying whether such a luminescent material is incorporated with an article include exposing a portion of the article to excitation in a chromium absorption band, and determining whether a detected emission produced by the article as a result of the excitation indicates an ytterbium emission after termination of the exposing step.

Claims

1. A luminescent material comprising:

a borate having a crystal structure and including a substitutable element;

neodymium substituted for the substitutable element at a first substitution percentage of at least about 20 percent; and

ytterbium substituted for the substitutable element at a second substitution percentage.

2. The luminescent material of claim 1, wherein the borate has a formula MeX₃B₄O₁₂, and wherein:

Me is the substitutable element, which is selected from a group consisting of yttrium, lanthanum, gadolinium, lutetium, and a mixture thereof,

X is an element selected from a group consisting of aluminum, scandium, and gallium,

B is boron, and

O is oxygen.

3. The luminescent material of claim 2, further comprising chromium substituted for X at a third substitution percentage up to 100 percent.

4. The luminescent material of claim 1, wherein the borate has the formula YAl₃B₄O₁₂, where Y is the substitutable element yttrium, Al is aluminum, B is boron, and O is oxygen.

5. The luminescent material of claim 1, wherein the borate has the formula LaAl₃B₄O₁₂, where La is the substitutable element lanthanum, Al is aluminum, B is boron, and O is oxygen.

6. The luminescent material of claim 1, wherein the borate has the formula GdAl₃B₄O₁₂, where Gd is the substitutable element gadolinium, Al is aluminum, B is boron, and O is oxygen.

7. The luminescent material of claim 1, wherein the first substitution percentage is in a range of about 50 to about 95 percent, and the second substitution percentage is in a range of about 5 to about 50 percent.

8. The luminescent material of claim 7, wherein the first substitution percentage is in a range of about 80 to about 90 percent, and the second substitution percentage is in a range of about 10 to about 20 percent.

9. The luminescent material of claim 1, wherein the borate has a crystal structure selected from a group consisting of a monoclinic Huntite-like structure, a rhombohedral Huntite-like structure, and a mixed Huntite-like structure.

10. The luminescent material of claim 1, wherein the borate is in a form of particles, and the luminescent material further comprises a medium within which the particles are incorporated, wherein the medium is selected from a group consisting of an ink, an ink additive, a glue, a liquid, a gel, a polymer, a slurry, a plastic, plastic base resin, a glass, a ceramic, a metal, a textile, wood, fiber, paper pulp, and paper.

11. The luminescent material of claim 1, wherein the luminescent material is in a powder form, and the luminescent material comprises particles with a particle size of less than 10 microns.

12. An article comprising:

a security feature that includes;

a medium, and

particles of a luminescent borate dispersed in the medium, the luminescent borate comprising a borate having a crystal structure and including a substitutable element, neodymium substituted for the substitutable element at a first substitution percentage of at least about 20 percent, and ytterbium substituted for the substitutable element at a second substitution percentage.

13. The article of claim 12, wherein the borate has a formula MeX₃B₄O₁₂, wherein:

Me is the substitutable element, which is selected from a group consisting of yttrium, lanthanum, gadolinium, lutetium, and a mixture thereof,

X is an element selected from a group consisting of aluminum, scandium, and gallium,

B is boron, and

O is oxygen.

14. The article of claim 13, wherein the borate further comprises chromium substituted for X.

15. The article of claim 12, wherein the article is an article selected from a group consisting of an identification card, a driver'"'"'s license, a passport, identity papers, a banknote, a check, a document, a paper, a stock certificate, a packaging component, a credit card, a bank card, a label, a seal, a postage stamp, a token, a liquid, a human, an animal, and a biological sample.