Differentially cured materials and process for forming same

• US 20020051866A1
• Filed: 08/10/2001
• Published: 05/02/2002
• Est. Priority Date: 08/18/2000
• Status: Active Grant

• Current Assignee: Orafol Americas Inc. (Orafol Europe GmbH)
• Original Assignee: Reflexite
• Inventors: Mullen, Patrick W.
• Granted Patent: US 7,250,122 B2
• Time in Patent Office: Days
• US Class Current: 428/156
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 35/0894 provided with masks or diaphragms
• CPC Class Codes: B29C 35/10 for articles of indefinite length
• CPC Class Codes: B29D 11/00 Producing optical elements, e.g. lenses or prisms grinding or polishing of optical elements B24B; constructional form of optical elements G02B; optical parts of spectacles G02C7/00
• CPC Class Codes: B29D 11/00605 Production of reflex reflectors
• CPC Class Codes: B29K 2105/243 Partially cured
• CPC Class Codes: B29K 2995/003 Reflective
• CPC Class Codes: B29L 2011/0083 Reflectors
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/12 Reflex reflectors
• CPC Class Codes: G03F 7/001 Phase modulating patterns, e.g. refractive index patterns
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

A structure includes a layer which includes a first cured portion and a second cured portion which are formed from a same light curable material. The first cured portion is cured to a first amount, and the second cured portion is cured to a second amount. The first amount is sufficiently different than the second amount to result in a visible discontinuity on the surface of the structure.

A method for forming a pattern in a radiation curable material includes providing between a radiation source and the radiation curable material, a pattern that can block a portion of the radiation from the radiation source. The material is cured with radiation from the radiation source to form a pattern in the radiation curable material.

Claims

1. A structure comprising:

a layer which includes a first cured portion and a second cured portion which are formed from a same light curable material, said first cured portion is cured to a first amount and said second cured portion is cured to a second amount, said first amount is sufficiently different than the second amount to result in a visible discontinuity on the surface of the structure.

2. The structure of claim 1 wherein said layer is connected to a base.

3. The structure of claim 2 wherein said layer and said base are formed of the same material.

4. The structure of claim 1 wherein said first amount is sufficiently different than the second amount to result a difference in the thickness of the first portion and the thickness of the second portion that is in a range of between about 0.05 and 2.0 micrometers.

5. The structure of claim 1 wherein said light curable material is selected from a group consisting of polyesters, urethanes, epoxy acrylates and methacrylates.

6. The structure of claim 1 wherein the base is formed from a material selected from the group consisting of polyester, polycarbonate, polyurethane, acrylic and polyvinyl chloride.

7. The structure of claim 1 wherein said layer includes linear prisms.

8. The structure of claim 1 wherein said layer includes a lenticular structure.

9. The structure of claim 1 wherein said layer includes a cube-corner prism.

10. The structure of claim 1 wherein said layer includes a sub-wavelength structure.

11. The structure of claim 1 wherein said first cured portion is configured to represent a logo, geometric forms or alphanumerics.

12. The structure of claim 1 wherein said first cured portion has an index of refraction that is different than the index of refraction of the second cured portion.

13. The structure of claim 1 wherein said first cured portion has a density that is different than the density of the second cured portion.

14. The structure of claim 1 wherein said base and said layer include the same light curable material.

16. The method of claim 15 wherein the radiation source emits ultraviolet light.

17. The method of claim 12 wherein the radiation curable material is selected from polyesters, urethanes, epoxy acrylate and methacrylates.

18. The method of claim 15 wherein the pattern is configured in the form of a logo, geometric form, or alphanumerics.

19. The method of claim 15 wherein the blocking pattern is formed on a separate film.

20. The method of claim 15 wherein the radiation curable material is connected to a base film.

21. The method of claim 20 wherein the blocking pattern is removably placed on the base film.

22. A structure formed by the method of claim 15.

24. The pattern transfer structure of claim 23 wherein said radiation source can emit ultraviolet light.

25. The pattern transfer structure of claim 23 wherein said radiation curable material is selected from a material consisting of polyester, epoxy acrylates, urethanes and methacrylates.

26. The pattern transfer structure of claim 23 wherein the pattern is configured in the form of a logo, geometric forms and alphanumerics.

28. The structure of claim 27 wherein said first cured portion has an index of refraction that is different than the index of refraction of the second cured portion.

29. The structure of claim 27 wherein said first cured portion has a density that is different than the density of the second cured portion.

15. A method for forming a pattern in a radiation curable material, comprising:

a) providing between a radiation source and the radiation curable material, a blocking pattern that can block a portion of the radiation from the radiation source; and

b) curing the material with radiation from the radiation source through the blocking pattern to form a pattern in the radiation curable material.

23. A pattern transfer structure, comprising:

a) a radiation source for emitting radiation;

b) a radiation curable material that can be cured by the radiation; and

c) a pattern for blocking a portion of the radiation, said pattern disposed between the radiation source and the radiation curable material during the curing of the material such that a pattern is formed in the material.

27. A method for forming a prism structure comprising:

a) providing a prism mold;

b) placing a radiation curable material in the mold;

c) providing between a radiation source and the radiation curable material, a pattern that can block a portion of the radiation curable material; and

d) curing the radiation curable material with radiation from the radiation source to form a pattern in the radiation curable material.

30. A prism structure comprising:

a) a base;

b) a prism array connected to said base, said prism array includes a first cured portion and a second cured portion which are formed from a same radiation curable material, said first cured portion has a first index of refraction value and said second cured portion has a second index of refraction value which is sufficiently different from said first index of refraction value to result in a visible discontinuity on the surface of the structure.