Antiglare coating and articles

• US 20060046078A1
• Filed: 08/26/2004
• Published: 03/02/2006
• Est. Priority Date: 08/26/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Bottari, Frank J., Cairns, Darran R., Richter, Paul J.
• Granted Patent: US 7,294,405 B2
• Time in Patent Office: Days
• US Class Current: 428/447
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/478 Silica
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: G02B 5/0226 having particles on the surface
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24364 with transparent or protective coating
• CPC Class Codes: Y10T 428/2438 Coated
• CPC Class Codes: Y10T 428/24405 Polymer or resin [e.g., natural or synthetic rubber, etc.]
• 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 428/31 Surface property or characteristic of web, sheet or block
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

The present invention relates to articles comprising an antiglare layer, coating compositions suitable for making antiglare layers, methods of making an antiglare article, and methods of making antiglare coating compositions. In some embodiments the article is a (e.g. illuminated) display article such as a touch screen. The antiglare layer comprises aggregate inorganic oxide particles in a cured inorganic polymer matrix.

Claims

1. A touch screen comprising an antiglare layer, an active layer underlying the antiglare layer, and a glass substrate underlying the active layer wherein the antiglare layer comprises aggregate inorganic oxide particles in a cured inorganic polymer matrix and the aggregate inorganic oxide particles form surface structures ranging in size from greater than 2 micrometers to about 100 micrometers.

2. The touch screen of claim 1 wherein the touch screen has a reflected haze of at least 150.

3. The touch screen of claim 1 wherein the touch screen has a reflectance of less than 10%.

4. The touch screen of claim 1 wherein the touch screen has a transmission of at least 80%.

5. The touch screen of claim 1 wherein the touch screen has a scratch resistance as determined by the Nanoscratch Test of at least 10 mN.

6. The touch screen of claim 1 wherein the touch screen has a time to failure as determined by the Polishing Test of at least 2 hours for a 1 micrometer antiglare layer.

7. The touch screen of claim 1 wherein the silica particles have a mean particle size ranging from about 0.05 micrometers to about 0.15 micrometers.

8. The touch screen of claim 1 wherein the surface structures have an average maximum dimension of at least about 10 micrometers.

9. The touch screen of claim 5 wherein the surface structures have an average maximum dimension of at least about 20 micrometers.

10. The touch screen of claim 1 wherein the inorganic oxide is selected from the group consisting of silica, ceria, alumina, zirconia, titania and mixtures thereof.

11. The touch screen of claim 1 wherein the inorganic particles consist of silica.

12. The touch screen of claim 1 wherein the cured inorganic polymer matrix is derived from an organosilane.

13. The touch screen of claim 12 wherein the cured inorganic polymer matrix is derived from silicon alkoxide.

14. The touch screen of claim 11 wherein the organosilane is derived from a sol-gel process.

15. The touch screen of claim 1 wherein the surface layer has a total surface area and the surface structures comprise at least 20% of the total surface area.

16. The touch screen of claim 1 wherein the surface layer has a total surface area and the surface structures comprise at least 30% of the total surface area.

17. The touch screen of claim 1 wherein the surface layer has a total surface area and the surface structures comprise at least 40% of the total surface area.

18. The touch screen of claim 1, further comprising a silicon oxide layer disposed between the transparent conductive layer and the antiglare layer.

19. The touch screen of claim 1, wherein the active element comprises a transparent conductive layer disposed between the glass substrate and the antiglare layer.

20. The touch screen of claim 19, wherein the transparent conductive layer comprises a transparent conductive oxide.

21. The touch screen of claim 1 further comprising a liquid crystal silane surface layer.

22. An article comprising an antiglare layer wherein the antiglare layer comprises aggregate inorganic oxide particles in a cured inorganic polymer matrix, wherein the aggregate inorganic oxide particles form surface structures ranging in size from greater than 2 micrometers to about 100 micrometers.

23. The article of claim 22 wherein the article is a display panel.

24. The article of claim 22 wherein the article is selected from the group comprising computer monitors, television screens, optical filters, picture frames, windows, mirrors, solar collector cover plates, optical lenses, and windshields for vehicles.

25. A coating composition comprising a organosilane and flocculated inorganic oxide particles ranging in size from greater than 2 micrometers to about 100 micrometers.

26. The coating composition of claim 25 wherein the inorganic oxide particles are present in a concentration of less than 1.5 wt-%.

27. A method of making an antiglare article comprising:

providing a transparent substrate;

coating the substrate with the coating composition of claim 25;

and

heating the coating composition.

28. The method of claim 27 wherein the substrate is selected from glass, polycarbonate, polymethylmethacrylate, and cellulose acetate butyrate.

29. A method of making an antiglare coating composition comprising providing an inorganic polymer precursor and colloidal inorganic oxide particles having a mean particle size ranging from 0.05 micrometers to 0.15 micrometers;

and forming an inorganic polymer solution concurrently with flocculating colloidal inorganic oxide aggregates ranging in size from greater than 2 micrometers to 100 micrometer.

30. The method of claim 29 wherein the colloidal inorganic oxide particles are present in an amount of less than 1.5 wt-%.

31. The method of claim 29 wherein the method comprises the addition of acid.

32. The method of claim 29 wherein the method comprises the addition of sodium acetate.

33. An article comprising an antiglare layer wherein the article has a transmitted haze of less than 30, transmission of at least 80%, clarity of at least 70, and a scratch resistance as determined by the Nanoscratch Test of at least 10 mN.

34. The article of claim 33 wherein the haze is less than 5%.

35. The article of claim 33 wherein the transmission is at 90%.

36. The article of claim 33 wherein the clarity is at least 80%