Method of authenticating polymers, authenticatable polymers, methods of making authenticatable polymers and authenticatable articles, and articles made there from

• US 20050109984A1
• Filed: 11/26/2003
• Published: 05/26/2005
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: Philippe Schottland, Radislav Potyrailo
• Inventors: Schottland, Philippe, Potyrailo, Radislav
• Granted Patent: US 7,094,364 B2
• Time in Patent Office: Days
• US Class Current: 252/299.10
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G07D 7/12 Visible light, infrared or ultraviolet radiation
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 23/281 by changing the physical properties of the record carrier
• CPC Class Codes: G11B 7/2433 Metals or elements of Groups 13, 14, 15 or 16 of the Periodic Table, e.g. B, Si, Ge, As, Sb, Bi, Se or Te
• CPC Class Codes: G11B 7/2472 cyanine
• CPC Class Codes: G11B 7/248 porphines; azaporphines, e.g. phthalocyanines
• CPC Class Codes: G11B 7/252 of layers other than recording layers
• CPC Class Codes: G11B 7/2534 polycarbonates [PC]
• CPC Class Codes: G11B 7/2542 consisting essentially of organic resins
• CPC Class Codes: G11B 7/2578 consisting essentially of inorganic materials
• CPC Class Codes: G11B 7/258 of reflective layers
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 436/13 Tracers or tags

Abstract

In one embodiment, a method for authenticating that a test polymer is an authenticatable polymer is disclosed wherein the authenticatable polymer comprises a substrate polymer and a thermochromic compound, the thermochromic compound having a first signal at a first temperature and at an authenticating wavelength, and a second signal at an authenticating temperature and the authenticating wavelength, the first and second signals being different, and the authenticating temperature being greater than the first temperature, the method comprising subjecting the test polymer to a stimulus sufficient to raise a portion of the test polymer to the authenticating temperature to create a heated portion, determining a test signal of the heated portion of the test polymer at the authenticating wavelength, and authenticating that the test polymer is an authenticatable polymer if the test signal is the same as an authenticating signal of the authenticatable polymer.

Claims

1. A method of authenticating that a test polymer is an authenticatable polymer, wherein the authenticatable polymer comprises a substrate polymer and a thermochromic compound, the thermochromic compound having a first signal at a first temperature and at an authenticating wavelength, and a second signal at an authenticating temperature and the authenticating wavelength, the first and second signals being different, and the authenticating temperature being greater than the first temperature, the method comprising

subjecting the test polymer to a stimulus sufficient to raise a portion of the test polymer to the authenticating temperature to create a heated portion,

determining a test signal of the heated portion of the test polymer at the authenticating wavelength, and

authenticating that the test polymer is an authenticatable polymer if the test signal is substantially the same as an authenticating signal of the authenticatable polymer.

2. The method of claim 1 wherein the step of determining the test signal further comprises measuring at least one of reflection, emission, fluorescence, or luminescence.

3. The method of claim 2 wherein the step of determining the test signal further comprises using an analytical technique that is at least one of fluorescence spectroscopy, luminescence spectroscopy, vibrational spectroscopy or electronic spectroscopy.

4. The method of claim 3 wherein the step of determining the test signal further comprises using an analytical technique that is at least one of fluorescence spectroscopy or luminescence spectroscopy.

5. The method of claim 1 wherein the thermochromic compound is present in the authenticatable polymer in an amount of no more than about 10 weight percent, based on the authenticatable polymer.

6. The method of claim 5 wherein the thermochromic compound is present in the authenticatable polymer in an amount of less than about 5 weight percent, based on the authenticatable polymer.

7. The method of claim 6 wherein the thermochromic compound is present in the authenticatable polymer in an amount of less than about 2 weight percent, based on the authenticatable polymer.

8. The method of claim 7 wherein the thermochromic compound is present in the authenticatable polymer in an amount of less than about 1 weight percent, based on the authenticatable polymer.

9. The method of claim 8 wherein the thermochromic compound is present in the authenticatable polymer in an amount of at least 0.005 weight percent, based on the authenticatable polymer.

10. The method of claim 1 wherein the thermochromic compound is present in the authenticatable polymer in an amount that does not provide a visually retrievable thermochromic response.

11. The method of claim 1 wherein the substrate polymer is polycarbonate.

12. The method of claim 1 wherein the authenticating wavelength is at least one of an excitation wavelength, a maximum excitation wavelength, or a range of excitation wavelengths.

13. The method of claim 12 wherein the authenticating wavelength is an excitation wavelength of from 250 nm to 800 nm.

14. The method of claim 12 wherein the test signal is a least one of at least one of intensity of fluorescence, shape of a fluorescence peak, location of a fluorescence peak, duration or decay of fluorescence over time or after removal of a heat source, the ratio of fluorescence intensity at at least two different wavelengths and combinations thereof.

15. The method of claim 1 wherein the stimulus is a direct stimulus.

16. The method of claim 15 wherein the stimulus is a heat source that transfers thermal energy via a heated fluid.

17. The method of claim 1 wherein the stimulus is an indirect stimulus.

18. The method of claim 17 wherein the stimulus comprises a source of electromagnetic radiation.

19. The method of claim 18 wherein the authenticatable polymer further comprises a component that absorbs electromagnetic radiation and converts it to heat.

20. The method of claim 19 wherein the authenticatable polymer comprises a NIR absorber.

21. The method of claim 1 wherein the authenticatable polymer further comprises an amplification compound and the authenticating signal of the authenticatable polymer is greater than the second signal of the thermochromic compound as a result of the amplification compound.

22. The method of claim 21 wherein the amplification compound is at least one of an organic fluorophore, an inorganic fluorophore, an organometallic fluorophore, or a luminescent nanoparticle.

23. The method of claim 21 wherein the amplification compound is present in the authenticatable polymer in an amount of about 10⁻

18 to about 2 weight percent, based on the weight of the authenticatable polymer.

24. An authenticatable polymer comprising

a substrate polymer, and

a thermochromic compound having a first signal at a first temperature and at an authenticating wavelength, and a second signal at an authenticating temperature and the authenticating wavelength, the first and second signals being different, and the authenticating temperature being greater than the first temperature,

wherein the thermochromic compound is present in the authenticatable polymer in an amount of from 0.001 to 0.50 weight percent, based on the weight of the authenticatable polymer.

25. The authenticatable polymer of claim 24 wherein the thermochromic compound is present in an amount of less than 0.50% by weight, based on the weight of the authenticatable polymer.

26. The authenticatable polymer of claim 24 wherein the thermochromic compound is present in an amount of about 0.005 to 0.4% by weight, based on the weight of the authenticatable polymer.

27. The authenticatable polymer of claim 24 wherein the authenticatable polymer further comprises an amplification compound and the authenticating signal of the authenticatable polymer is greater than the second signal of the thermochromic compound as a result of the amplification compound.

28. The authenticatable polymer of claim 27 wherein the amplification compound is at least one of an organic fluorophore, an inorganic fluorophore, an organometallic fluorophore, or a luminescent nanoparticle.

29. The authenticatable polymer of claim 27 wherein the amplification compound is present in the authenticatable polymer in an amount of about 10⁻

18 to about 2 weight percent, based on the weight of the authenticatable polymer.

30. A method of making an authenticatable polymer, comprising incorporating together a substrate polymer and a thermochromic compound to provide an authenticatable polymer, wherein the thermochromic compound is incorporated in an amount of from 0.001 to 0.50 weight percent, based on the weight of the authenticatable polymer.

31. A method of making an authenticatable article, comprising

providing the authenticatable polymer of claim 30, and

forming an authenticatable article from the authenticatable polymer.

32. The method of claim 31 wherein forming the article from the authenticatable polymer comprises melting the authenticatable polymer.

33. The method of claim 32 further comprising extruding or molding the authenticatable polymer.

34. The method of claim 33 wherein said molding comprises injection molding the authenticatable polymer.

35. The method of claim 31 wherein the authenticatable article is an optical disk.

36. An authenticatable article made by the method of claim 31.

37. The authenticatable article of claim 36 that is an optical disk.

38. The authenticatable article of claim 37 having one substrate made from the authenticatable polymer.

39. The authenticatable article of claim 38 wherein the substrate made from the authenticatable polymer is a read through substrate.

40. The authenticatable article of claim 37 having two substrates made from the authenticatable polymer.