Optical film for display devices

• US 20040091643A1
• Filed: 11/12/2002
• Published: 05/13/2004
• Est. Priority Date: 11/12/2002
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Nair, Mridula, Jones, Tamara K., Sedita, Joseph S., Rakes, Gary A., Houghtaling, Bradley M.
• Granted Patent: US 7,252,864 B2
• Time in Patent Office: Days
• US Class Current: 428/1.33
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/035 Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/111 using layers comprising organic materials
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: Y10S 430/106 Binder containing
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/254 Polymeric or resinous material

Abstract

Disclosed is an optical film that comprises certain radiation cured (meth)acrylate binders and, desirably, irregular semicrystalline asymmetric particles.

Claims

1. An optical film comprising a layer containing irregular semicrystalline asymmetric particles in a radiation cured binder.

2. The optical film of claim 1 wherein the radiation cured binder comprises polyfunctional acrylic compounds derived from polyhydric alcohols.

3. The optical film of claim 2 wherein the radiation cured binder comprises a repeating group selected from ethoxylated trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.

4. The optical film of claim 2 wherein the radiation cured binder comprises a repeating group selected from pentaerythritol tetra(meth)acrylate and pentaerythritol tri(meth)acrylate.

5. The optical film of claim 1 wherein the radiation cured binder comprises acrylate and methacrylate oligomers derived from low-molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, polyurethane resin.

6. The optical film of claim 1 wherein the radiation cured binder comprises a urethane acrylate compound.

7. The optical film of claim 1 wherein the radiation cured binder comprises an aliphatic urethane acrylate derived from isophorone diisocyanate.

8. The optical film of claim 1 wherein the radiation cured binder comprises a polyurethane acrylate derived from an aliphatic polyester polyol.

9. The optical film of claim 1 wherein the particles comprise micronized irregular polyamide or copolyamide polymer particles.

10. The optical film of claim 1 wherein the particles have an average size of between 2 and 20 micrometers.

11. The optical film of claim 1 wherein said particles are present in at least 2% by weight of the layer.

12. The optical film of claim 1 wherein said particles are present in an amount of less than 50% by weight of the layer.

13. The optical film of claim 1 additionally containing a silicone acrylate lubricant.

14. The optical film of claim 13 wherein the silicone acrylate lubricant is a methacryloxy-functional silicone polyether copolymer.

15. The optical film of claim 1 wherein said film has a pencil hardness of greater than 2 H.

16. The optical film of claim 1 wherein said film has a hardness of between 2 H and 8 H.

17. The optical film of claim 1 wherein said film is deposed upon a transparent polymeric support.

18. The optical film of claim 17 wherein said support is selected from the group consisting of triacetyl cellulose, polyethylene terephthalate, diacetyl cellulose, acetate butyrate cellulose, acetate propionate cellulose, polyether sulfone, polyacrylic based resins, polyurethane based resin, polyester, polycarbonate, aromatic polyamide, polyolefins, polymers derived from vinyl chloride, polyvinyl alcohol, polysulfone, polyether, polynorbornene, polymethylpentene, polyether ketone, and (meth)acrylonitrile.

19. The polymeric support of claim 17 wherein said support is triacetyl cellulose.

20. The optical film of claim 1 wherein the transmission haze is less than 50.

21. The optical film of claim 1 wherein the 60 degree gloss is less than 130.

22. The optical film of claim 1 wherein the total light transmission is greater than 90 percent.

41. An LCD display comprising the optical film of claim 1.

43. A touch screen display comprising the optical film of claim 1.

23. An optical film comprising a layer containing a radiation cured binder derived from a mixture of (meth)acrylate derivatives of pentaerythritol functionalized aliphatic urethanes.

24. An optical film of claim 23 wherein the mixture comprises pentaerythritol tetra(meth)acrylate and pentaerythritol tri(meth)acrylate functionalized aliphatic urethanes.

25. The optical film of claim 23 wherein the radiation cured binder is derived from isophorone diisocyanate.

42. An LCD display comprising the optical film of claim 23.

44. A touch screen display comprising the optical film of claim 23.

26. A coating dispersion comprising a radiation curable urethane acrylate oligomer, irregular semicrystalline asymmetric particles, a radiation sensitive curing agent, and an organic solvent.

27. The coating dispersion of claim 26 wherein said organic solvent comprises an ester solvent or an aromatic hydrocarbon.

28. The coating dispersion of claim 26 wherein said the radiation sensitive curing agent comprises a UV sensitive curing initiator.

29. A method of forming an optical film comprising providing a flexible transparent polymeric support, applying to the support a coating of radiation curable binder comprising polyfunctional acrylic compounds, irregular semicrystalline asymmetric particles in an organic solvent, and radiation curing said the coating to form a layer.

30. The method of claim 29 wherein the coating additionally contains a silicone acrylate.

31. The method of claim 30 wherein the radiation curable binder comprises a repeating group selected from ethoxylated trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.

32. The method of claim 29 wherein the radiation curable binder comprises a repeating group selected from pentaerythritol tetra(meth)acrylate and pentaerythritol tri(meth)acrylate.

33. The method of claim 29 wherein the radiation curable binder comprises acrylate and methacrylate oligomers derived from low-molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, polyurethane resin.

34. The method of claim 29 wherein the radiation curable binder comprises a urethane acrylate containing compound.

35. The method of claim 29 wherein the radiation curable binder comprises an aliphatic urethane acrylate derived from isophorone diisocyanate.

36. The method of claim 29 wherein the radiation curable binder comprises a polyurethane acrylate derived from an aliphatic polyester polyol.

37. The method of claim 29 wherein the particles comprise micronized irregular polyamide or copolyamide polymer particles.

38. The method of claim 29 wherein the particles have an average size of between 2 and 20 micrometers.

39. The method of claim 29 wherein said particles are present in an amount of at least 2% by dry weight of the layer.

40. The method of claim 29 wherein said particles are present in an amount of less than 50% by dry weight of the layer.