Antireflection film

• US 6,379,788 B2
• Filed: 11/20/1998
• Issued: 04/30/2002
• Est. Priority Date: 02/19/1998
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jones, Robert L., Nagarkar, Pradnya V., Choi, Hyung-Chul, Smyth, William K.
• Primary Examiner(s): DIXON, MERRICK L
• Application Number:
  US09/197,006
• Publication Number:
  US 20010049024A1
• Time in Patent Office: 1,257 Days
• Field of Search: 428/421, 428/422, 428/483, 428/333, 428/215, 428/434, 428/472, 428/699, 428/336, 428/339, 428/332, 427/162, 427/164, 427/163.4
• US Class Current: 428/333
• CPC Class Codes: G02B 1/111 using layers comprising organic materials
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component

Abstract

An antireflection film comprises a transparent substrate carrying on one surface a polymeric antireflection layer, this antireflection layer having a refractive index at least about 0.02 lower than that of the substrate and being formed from a cured polymer comprising repeating units derived from a fluoroalkene, an alkyl acrylate or methacrylate and a polyfunctional acrylate monomer. No inorganic antireflection layer is present between the substrate and the polymeric antireflection layer.

Claims

1. An antireflection film comprising a substantially transparent substrate bearing a polymeric antireflection layer, the antireflection layer forming one outer surface of the antireflection film and having a refractive index at least approximately 0.02 less than that of the substrate over the wavelength range of 400 to 700 nm, the antireflection layer being formed from a cured polymer comprising repeating units derived from a fluoroalkene, an alkyl acrylate or methacrylate and a polyfuctional acrylate monomer, there being no inorganic antireflection layer present between the substrate and the polymeric antireflection layer.

2. An antireflection film according to claim 1 wherein the antireflection layer has a refractive index at least approximately 0.05 less than that of the substrate over the wavelength range of 400 to 700 nm.

3. An antireflection film according to claim 1 wherein the substrate has a refractive index of at least approximately 1.60 over the wavelength range of 400 to 700 nm.

4. An antireflection film according to claim 1 wherein the substrate comprises an organic polymer.

5. An antireflection film according to claim 4 wherein the organic polymer is a polyester or a polyphenylene polymer.

6. An antireflection film according to claim 5 wherein the polymer comprises poly(ethylene terephthalate).

7. An antireflection film according to claim 1 wherein the substrate comprises glass.

8. An antireflection film according to claim 1 having a hard coat disposed between the substrate and the polymeric antireflection layer, the hard coat having a refractive index higher than that of the substrate.

9. An antireflection film according to claim 1 wherein the polymeric antireflection layer comprises repeating units derived from vinylidene fluoride and/or tetrafluoroethylene.

10. An antireflection film according to claim 1 wherein the polymeric antireflection layer comprises repeating units derived from methyl methacrylate.

11. An antireflection film according to claim 1 wherein the polymeric antireflection layer comprises repeating units derived from dipentaerythritol pentaacrylate.

12. An antireflection film according to claim 1 wherein the polymeric antireflection layer has a thickness in the range of from about 20 to about 200 nm.

13. An antireflection film according to claim 12 wherein the polymeric antireflection layer has a thickness in the range of from about 60 to about 130 nm.

14. An antireflection film according to claim 1 wherein the polymeric antireflection layer has an outer portion enriched in the alkyl acrylate or methacrylate and an inner portion enriched in the fluoroalkene.

15. A process for providing a polymeric antireflection film on a substantially transparent substrate, the substrate being free from inorganic antireflection layers, the process comprising:

depositing a layer of a curable composition on the substrate, the curable composition comprising a polymer of a fluoroalkene, a polymer of an alkyl acrylate or methacrylate, and a polyfunctional acrylate monomer; and

effecting free radical curing of the deposited curable composition to form a polymeric antireflection layer having a refractive index at least approximately 0.02 less than that of the substrate over the wavelength range of 400 to 700 nm.

16. A process according to claim 15 further comprising depositing a hard coat on the substrate before the polymeric antireflection layer is deposited thereon, the hard coat having a refractive index higher than that of the substrate, the curable composition being deposited on top of the hard coat.

17. A process according to claim 15 wherein the curing of the curable composition is conducted in air.

18. A process according to claim 15 wherein the substrate has a refractive index of at least approximately 1.60 over the wavelength range of 400 to 700 nm.

19. A process according to claim 15 wherein the substrate comprises an organic polymer.

20. A process according to claim 19 wherein the organic polymer is a polyester or a polyphenylene polymer.

21. A process according to claim 20 wherein the polymer comprises poly(ethylene terephthalate).

22. A process according to claim 15 wherein the substrate comprises glass.

23. A process according to claim 15 wherein the curable composition comprises a polymer of vinylidene fluoride and/or tetrafluoroethylene.

24. A process according to claim 15 wherein the curable composition comprises dipentaerythritol pentaacrylate.

25. A process according to claim 15 wherein the polymeric antireflection layer formed has a thickness in the range of from about 20 to about 200 nm.

26. A process according to claim 25 wherein the polymeric antireflection layer formed has a thickness in the range of from about 60 to about 130 nm.

27. An image-receiving element adapted to receive dye and thereby form an image, the image-receiving element comprising:

a substantially transparent polymeric substrate;

an image-receiving layer disposed on the polymeric substrate and containing at least one mordant for a dye; and

a polymeric antireflection layer disposed on the opposed surface of substrate from the image-receiving layer and having a refractive index at least approximately 0.02 less than of the polymeric substrate over the wavelength range of 400 to 700 nm, the antireflection layer being formed from a cured polymer comprising repeating units derived from a fluoroalkene, an alkyl acrylate or methacrylate and a polyfunctional acrylate monomer.

28. A photographic product for forming a diffusion transfer image and comprising:

a photosensitive element comprising at least one photosensitive layer having associated therewith an image dye-providing material, the photosensitive element being such that upon its exposure to light and contact with an alkaline developing composition, an image dye is released from non-exposed regions of the photosensitive element; and

an image-receiving element in superposed relationship with the photosensitive element so as to receive image dye released from the photosensitive element and thereby form an image, the image-receiving element bearing, on its surface remote from the photosensitive element, a polymeric antireflection layer having a refractive index at least approximately 0.02 less than that of the image-receiving element over the wavelength range of 400 to 700 nm, the antireflection layer being formed from a cured polymer comprising repeating units derived from a fluoroalkene, an alkyl acrylate or methacrylate and a polyfunctional acrylate monomer.

29. An image display device comprising:

means for receiving data representing an image; and

a screen capable of generating light to produce a visual image corresponding to the data received by the data receiving means, the screen having an outer surface through which the visual image can be viewed,

the outer surface of the screen being provided with a polymeric antireflection layer having a refractive index at least approximately 0.02 less than that of the screen over the wavelength range of 400 to 700 nm, the antireflection layer being formed from a cured polymer comprising repeating units derived from a fluoroalkene, an alkyl acrylate or methacrylate and a polyfunctional acrylate monomer.