High refractive index, durable hard coats

• US 7,491,441 B2
• Filed: 12/30/2004
• Issued: 02/17/2009
• Est. Priority Date: 12/30/2004
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Kolb, Brant U., Pokorny, Richard J., Olson, David B., Mader, Roger A.
• Primary Examiner(s): Jackson; Monique R
• Application Number:
  US11/026,573
• Publication Number:
  US 20060147702A1
• Time in Patent Office: 1,510 Days
• Field of Search: None
• US Class Current: 428/328
• CPC Class Codes: C08F 222/102 of dialcohols, e.g. ethylene glycol di(meth)acrylate or 1,4-butanediol dimethacrylate
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/061 Polyesters; Polycarbonates
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/005 Modified block copolymers
• 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: 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 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

The development of new compositions and new aromatic sulfur acrylate monomers results in improved hardcoat films, and improved optical films that contain the hard coat films. The films provide improved display systems when incorporated thereon. The combination of functionalized zirconia nanoparticles with multifunctional acrylate crosslinkers and high index of refraction aromatic sulfur acrylates, about 1.58 or greater, produces abrasion resistant hard coats that have relatively high refractive indices.

Claims

1. A display system comprising a hard coat layer coupled to a substantially transparent substrate, the hard coat layer comprising:

functionalized zirconia nanoparticles;

at least one acrylate crosslinking agent; and

at least one aromatic sulfur acrylate monomer selected from the group of compounds defined by the following formula;

2. The display system of claim 1 wherein said acrylate crossliniking agent is multifunctional and said aromatic sulfur acrylate exhibits an index of refraction of at least 1.58 or greater.

3. The display system of claim 1 wherein said aromatic sulfur acrylate is selected from the group consisting of acrylic acid 2-acryloyloxymethyl-3-(naphthalene-2-ylsulfanyl)-2-(naphthalene-2-ylsulfanylmethyl)-propyl ester and acrylic acid 2-acryloyloxymethyl-3 -phenylsulfanyl-2-phenylsulfanylmethyl-propyl ester.

4. The display system of claim 1 further comprising a low refractive index layer coupled to said hardcoat layer.

5. The display system of claim 4 wherein said low refractive index layer has a refractive index no greater than 1.5.

6. The display system of claim 4 wherein said hardcoat layer has a refractive index of at least 1.58.

7. The display system of claim 1 wherein the hard coat layer further comprises a photoinitiator.

8. The display system of claim 1 wherein said hard coat has an abrasion resistance no greater than 3.0% haze as determined by modified ASTM F 735-94.

9. The display system of claim 1 wherein the hard coat layer comprises a multifunctional acrylate with a functionality of at least 3.

10. The display system of claim 9 wherein said multifunctional acrylate is pentaerythritol triacrylate.

11. A coating composition comprising:

an aromatic sulfur acrylate selected from the group of compounds defined by the following formula;

12. The composition of claim 11 wherein said zirconia nanoparticles have a diameter measuring about 10-30 nanometers.