Carbon Nanotube-Based Curable Coating Composition Providing Antistatic Abrasion-Resistant Coated Articles

• US 20090169870A1
• Filed: 12/27/2007
• Published: 07/02/2009
• Est. Priority Date: 12/27/2007
• Status: Abandoned Application

• Current Assignee: Essilor International SA
• Original Assignee: Essilor International SA
• Inventors: Zheng, Haipeng
• Application Number:
  US11/965,394
• Publication Number:
  US 20090169870A1
• Time in Patent Office: Days
• US Class Current: 428/332
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 17/008 comprising a mixture of materials covered by two or more of the groups C03C17/02, C03C17/06, C03C17/22 and C03C17/28
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: C09D 5/00 Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced electrically insulating plastics, resins or waxes H01B3/30; Filling pastes
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 1/16 having an anti-static effect, e.g. electrically conducting coatings
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

The present invention relates to a curable composition, providing, upon curing, an abrasion-resistant, transparent, antistatic coating, comprising carbon nanotubes and a binder comprising at least one epoxysilane compound, preferably an epoxyalkoxysilane, and optionally fillers such as nanoparticles of non electrically conductive oxides and/or additional binder components such as tetraethoxysilane. The invention further relates to optical articles comprising a substrate, and, starting from the substrate, an abrasion- and/or scratch-resistant coating, and an antistatic coating formed by depositing directly onto said abrasion- and/or scratch-resistant coating the above referred curable composition. The obtained optical articles exhibit antistatic properties, high optical transparency with about 91-92% of transmittance, low haze and improved abrasion resistance.

Claims

1-21. -21. (canceled)

22. A curable composition, providing, upon curing, an abrasion-resistant, transparent, low haze, antistatic coating, comprising:

a) carbon nanotubes, and

b) a binder comprising at least one compound of formula;

R_n′

Y_mSi(X)<sub>4-n′

-m</sub>  

 

(I)

or a hydrolyzate thereof, in which the R groups are identical or different and represent monovalent organic groups linked to the silicon atom through a carbon atom, the Y groups are identical or different and represent monovalent organic groups linked to the silicon atom through a carbon atom and containing at least one epoxy function, the X groups are identical or different and represent hydrolyzable groups or hydrogen atoms, m and n′

are integers such that m is equal to 1 or 2 and n′

+m=1 or 2.

23. The curable composition of claim 22, wherein the Y groups are independently groups of formulae III and/or IV:

24. The curable composition of claim 22, wherein the compound of formula I is an epoxytrialkoxysilane of formula V or VI:

25. The curable composition of claim 22, wherein the binder further comprises at least one compound of formula:

R_nSi(Z)_4-n  

 

(II)

or a hydrolyzate thereof, in which the R groups are identical or different and represent monovalent alkyl groups, the Z groups are identical or different and represent hydrolyzable groups or hydrogen atoms, and n is an integer equal to 0, 1, or 2.

26. The curable composition of claim 22, further comprising a filler.

27. The curable composition of claim 26, wherein the filler comprises nanoparticles.

28. The curable composition of claim 27, wherein the nanoparticles have a diameter ranging from 2 to 100 nm.

29. The curable composition of claim 28, wherein the nanoparticles have a diameter ranging from 5 to 50 nm.

30. The curable composition of claim 27, wherein the nanoparticles comprise at least one of Al₂O₃, TiO₂, SiO₂, ZrO₂, Sb₂O₅, Ta₂O₅, SnO₂, zinc oxide, indium Si₃N₄, and/or MgF₂.

31. The curable composition of claim 26, wherein the ratio of (theoretical dry extract weight of fillers)/(theoretical dry extract weight of the composition) is from 25 to 80%.

32. The curable composition of claim 22, wherein the ratio of (theoretical dry extract weight of compound of formula I)/(theoretical dry extract weight of the composition) is from 20 to 100%.

33. The curable composition of claim 22, wherein the ratio of (theoretical dry extract weight of compound of formula II)/(theoretical dry extract weight of the composition) is from 15 to 60%.

34. The curable composition of claim 22, wherein the ratio of (weight of carbon nanotubes)/(theoretical dry extract weight of binder) is from 0.00025 to 0.01.

35. The curable composition of claim 22, wherein the carbon nanotubes are present in an amount ranging from 0.002 to 0.015% based on the total weight of the composition.

36. The curable composition of claim 22, wherein the composition comprises less than 1% by weight electrically conductive fillers based on the total weight of the composition.

37. The curable composition of claim 36, wherein the composition comprises 0% by weight electrically conductive fillers based on the total weight of the composition.

38. An optical article comprising a substrate, and, starting from the substrate:

an abrasion- and/or scratch-resistant coating; and

an antistatic coating formed by depositing directly onto said abrasion- and/or scratch-resistant coating a curable composition of claim 22.

39. The optical article of claim 38, wherein the thickness of the antistatic coating is from 50 nm to 2 μ

m.

40. The optical article of claim 38, wherein the abrasion- and/or scratch-resistant coating is a (meth)acrylate based coating or silicon-containing coating.

41. The optical article of claim 38, wherein the abrasion- and/or scratch-resistant coating has a thickness of at least 1 μ

m.

42. The optical article of claim 38, further defined as a lens or lens blank.

43. The optical article of claim 38, further defined as having a charge decay time ≦

500 milliseconds.

44. The optical article of claim 38, further defined as having a relative light transmission factor in the visible spectrum Tv higher than 90%.

45. A process for preparing the optical article of claim 38, comprising:

providing an optical article comprising a substrate;

applying onto the surface of the substrate an abrasion- and/or scratch-resistant coating;

depositing directly onto said abrasion- and/or scratch-resistant coating a curable composition of claim 22; and

curing said composition.