Coating for Optical Discs

• US 20090196160A1
• Filed: 10/17/2006
• Published: 08/06/2009
• Est. Priority Date: 10/17/2005
• Status: Abandoned Application

• Current Assignee: Eques Coatings
• Original Assignee: Eques Coatings
• Inventors: Crombach, Berend
• Application Number:
  US12/083,741
• Publication Number:
  US 20090196160A1
• Time in Patent Office: Days
• US Class Current: 369/283
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 9/04 Ingredients treated with organic substances treated with macromolecular compounds C08K9/08
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: G11B 7/2534 polycarbonates [PC]
• CPC Class Codes: G11B 7/2545 containing inorganic fillers, e.g. particles or fibres
• CPC Class Codes: G11B 7/259 based on silver

Abstract

An energy-curable flowable coating composition comprising a surface treated inorganic nanoparticle, a photoinitiator, and at least one energy-curable monomer, oligomer or resin. The energy-curable flowable coating can be used as a covering layer of optical discs, and is especially suited for use as a 100 micron cover layer of a Blu-Ray disc, having enhanced scratch resistance and reduced shrinkage.

Claims

1-20. -20. (canceled)

21. An energy-curable flowable coating composition comprising:

a surface treated inorganic nanoparticle,

a photoinitiator, and

at least one energy-curable monomer, oligomer or resin.

22. A composition according to claim 21, in which the viscosity of the final formulation is between 100 mPa·

s and 10,000 mPa·

s.

23. A composition according to claim 21, in which the viscosity of the final formulation is between 500 mPa·

s and 5,000 mPa·

s.

24. A composition according to claim 21, in which the viscosity of the final formulation is higher than 700 mPa·

s but lower than 3.000 mPa·

s.

25. A composition according to claim 21, in which said nanoparticles are comprised of silica, alumina, zirconia, a metal, a compound of a metal, or a ceramic.

26. A composition according to claim 25, in which said nanoparticles have a particle size of from 5 to 80 nm.

27. A composition according to claim 25, in which the nanoparticles have a particle size from 9 to 60 nm.

28. A composition according to claim 21, in which the nanoparticle is surface treated with a material having a reactive functional group, such as an epoxy-, (meth)acrylate- or isocyanate group.

29. A composition according to claim 28, in which said nanoparticles have a particle size of from 15 to 30 nm.

30. A composition according to claim 21, in which the amount of nanoparticles is from 15 to 50% by weight of the entire composition.

31. A composition according to claim 21, in which the amount of nanoparticles is from 20 to 40% by weight of the entire composition.

32. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition has a transparency greater than 85% at a the wavelength of 405 nm.

33. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition has a transparency greater than 85% at a the wavelength of 650 nm.

34. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition has a shrinkage after curing of less than 7%.

35. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition has a pencil hardness of at least 4H.

36. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition indentation hardness is under a indentation depth of 5 μ

m, in accordance with Philips Electronics test standard U;

PHV 623-93/487.

37. A composition according to claim 21, wherein the composition may be cured to an optical disc by exposure to energy, and further wherein the cured composition has a gloss loss after the Taber abrasion test of from 2 to 10%.

38. An optical disc comprising:

a substrate;

a reflective layer,

a coating layer comprised of a inorganic nanoparticle, a photoinitiator, and

at least one energy-curable monomer, oligomer or resin.

39. An optical disc according to claim 38, in which said nanoparticles of the coating layer are comprised of silica, alumina, zirconia, a metal, a compound of a metal, or a ceramic.

40. An optical disc according to claim 39, in which said nanoparticles have a particle size of from 5 to 80 nm.

41. An optical disc according to claim 39, in which the nanoparticles are surface treated with a material having a reactive functional group, such as an epoxy-, (meth)acrylate- or isocyanate group.

42. An optical disc according to claim 38, wherein the photoiniator of the coating layer is selected from the group consisting of hydroxycyclohexyl phenyl ketones, benzophenone and its derivatives, acyl phosphine based materials, sulphonium salts, thianthrenium salts;

iodonium salts, phenacyl sulphonium salts, and thioxanthonium salts.

43. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a thickness of from 20 to 150 □

m.

44. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a transparency greater than 85% at a the wavelength of 405 nm.

45. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a transparency greater than 85% at a the wavelength of 650 nm.

46. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a shrinkage after curing of less than 7%.

47. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a pencil hardness of at least 4H.

48. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a indentation hardness under an indentation depth of 5 μ

m, in accordance with Philips Electronics test standard U;

PHV 623-93/487.

49. An optical disc according to claim 38, wherein the coating layer is cured to the reflective layer by exposure to energy, and further wherein the coating layer has a gloss loss after the Taber abrasion test of from 2 to 10%.