Method of preparing nano-structured surface coatings and coated articles

• US 7,892,606 B2
• Filed: 10/06/2004
• Issued: 02/22/2011
• Est. Priority Date: 05/20/2003
• Status: Expired due to Fees

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Inventors: Currie, Edwin, Gan, Keqi, Meijers, Guido J. W., Thies, Jens C.
• Primary Examiner(s): LIGHTFOOT, ELENA TSOY
• Application Number:
  US10/958,657
• Publication Number:
  US 20060019114A1
• Time in Patent Office: 2,330 Days
• Field of Search: 427/162, 427/402, 427/407.1, 427/493, 427/495, 427/508, 427533-535
• US Class Current: 427/402
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 2217/425 consisting of a porous layer
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4584 Coating or impregnating of particulate or fibrous ceramic material C04B20/10, C04B35/628 take precedence
• CPC Class Codes: C04B 41/483 Polyacrylates
• CPC Class Codes: C04B 41/4842 Fluorine-containing polymers
• CPC Class Codes: C04B 41/81 Coating or impregnation
• CPC Class Codes: C08F 220/10 Esters
• CPC Class Codes: C08K 3/20 Oxides; Hydroxides graphene oxides C08K3/042
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 9/08 Ingredients agglomerated by treatment with a binding agent
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: Y10T 428/249967 Inorganic matrix in void-containing component
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer

Abstract

The invention relates to new processes for the preparation of antireflective coatings and coated substrates, as well as articles produced by these processes. These coatings can include one or more layers made of materials which form nano-structured and/or nano-porous surfaces. The process can include applying a cross-linkable hard coat to a substrate, partially curing or cross-linking the hard coat, and then applying a second coat carried by a solvent or mixture of solvents capable of swelling the partially cured hard coat. The second coat is then cross-linked and grafted to the hard coat to produce a durable coated substrate with antireflective properties.

Claims

1. A process for applying an antireflective coating to a substrate comprising the steps of:

a) applying a first coating to the substrate, said first coating being a radical cross-linkable hard coat consisting essentially of an acrylate-based diluent,

b) partially cross-linking the first coating to achieve a percent relative reacted acrylate unsaturation (% Relative RAU) of less than about 90%,

c) providing a second coating, said second coating being cross-linkable and being carried in a solvent capable of partially swelling the first coating,

d) applying the second coating and solvent to the partially cross-linked first coating, and

e) cross-linking the second coating.

2. The process of claim 1, wherein step b) comprises partially cross-linking the first coating by exposure to a dose of UV radiation that is insufficient to cause substantially complete cross-linking of the first coating.

3. The process of claim 1, wherein step b) comprises partially cross-linking the first coating by exposure to UV radiation in the presence of an amount of oxygen sufficient to inhibit complete cross-linking of the first coating.

4. The process of claim 1 in which the second coating comprises a nano-porous, antireflective layer.

5. The process of claim 1 in which the second coating is substantially completely cross-linked and thereby grafted to the first coating.

6. The process of claim 1 further comprising the step of heating the second coating prior to or during the step of cross-linking the second coating.

7. The process of claim 1 further comprising the step of thermally treating the second coating after the step of cross-linking the second coating.

8. The process of claim 1 in which the solvent is selected from the group consisting of methanol, isopropyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl acetate, cyclohexanone, isobutyl isobutyrate, 2-heptanone, cyclopentanone, ethyl acetate, ethanol, acetone, diisobutyl ketone, methyl amyl ketone, n-butanol, isobutanol, sec-butanol, toluene, and xylene.

9. The process of claim 8 in which the solvent is methyl isobutyl ketone, methyl ethyl ketone, or 1-methoxy-2-propanol.

10. The process of claim 1 in which the first and second coatings include a photo-initiator.

11. The process of claim 10 in which the first coating includes a type one photo-initiator.

12. The process of claim 10 in which the second coating includes a synergist and a photo-initiator.

13. The process of claim 1, wherein step b) is practiced to partially cure the first composition to a % Relative RAU of less than about 80%.

14. The process of claim 1, wherein step b) is practiced to partially cure the first composition to a % Relative RAU of less than about 70%.