Laminated glass articles and methods of making thereof

• US 8,007,913 B2
• Filed: 02/06/2007
• Issued: 08/30/2011
• Est. Priority Date: 02/10/2006
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Mashewske, Monica J., Lapp, Josef C., Coppola, Frank T.
• Primary Examiner(s): McNeil; Jennifer C
• Assistant Examiner(s): ROBINSON, LAUREN E
• Application Number:
  US11/702,858
• Publication Number:
  US 20070190340A1
• Time in Patent Office: 1,666 Days
• Field of Search: 428/213, 428/432, 428/426, 428/428, 428/688
• US Class Current: 428/426
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: C03B 17/02 Forming molten glass coated with coloured layers; Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• CPC Class Codes: C03C 17/02 with glass C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 3/091 containing aluminium

Abstract

Disclosed are laminated glass articles and methods of making the same.

Claims

1. A laminated glass sheet comprising a central core that comprises a core glass and an external skin that comprises a skin glass wherein:

(a) the skin glass has a strain point greater than or equal to 700°

C. and a melting temperature that is less than or equal to 1,665°

C.;

(b) when measured by a gradient boat technique, the skin glass has a liquidus viscosity that is in the range of 15,000-80,000 poise and the core glass has a liquidus viscosity that is greater than 100,000 poise so that the core glass is more stable with respect to devitrification during formation by a fusion overflow downdraw process than the skin glass; and

(c) the laminated glass sheet is formed by a double fusion overflow downdraw process so that the central core has a rejoin surface and the external skin has a fire-polished surface.

2. The laminated glass sheet article of claim 1, wherein the external skin is adjacent to the central core.

3. The laminated glass sheet article of claim 1, wherein the skin glass has a liquidus viscosity of from 20,000 to 50,000 poises as measured by a gradient boat technique, wherein the glass article is made by fusion drawing.

4. The laminated glass sheet article of claim 1, wherein the laminated glass sheet has an average coefficient of thermal expansion less than 40×

10<sup>−

7</sup>/°

C. over the temperature range of from 0°

C. to 300°

C.

5. The laminated glass sheet article of claim 1, wherein the skin glass is alkali free.

6. The laminated glass sheet article of claim 1, wherein the skin glass is alkali free and comprises in mole percent on an oxide basis:

7. The laminated glass sheet article of claim 1, wherein the skin glass is alkali free and comprises in mole percent on an oxide basis:

8. The laminated glass sheet article of claim 1, wherein the skin glass is alkali free and comprises an alkali free glass comprising in mole percent on an oxide basis:

9. The laminated glass sheet article of claim 1, wherein the sheet has a thermal compaction less than 20 ppm.

10. An electronic device comprising the laminated glass sheet of claim 1.

11. A liquid crystal display comprising the laminated glass sheet of claim 1.

12. The laminated glass sheet of claim 1, further comprising a thin film transistor on at least one fire-polished surface of the external skin.

13. The laminated glass sheet of claim 12, wherein the thin film transistor comprises poly-crystalline silicon.

14. A method for producing a laminated glass sheet of claim 1, comprising applying the external skin to at least one exposed surface of the central core.

15. The laminated glass sheet of claim 1 wherein the strain point of the skin glass is greater than 740°

C.

16. The laminated glass sheet of claim 1 wherein the liquidous viscosity of the core glass is greater than 350,000 poise.

17. The laminated glass sheet of claim 1 wherein the strain point of the skin glass is greater than 740°

C. and the liquidous viscosity of the core glass is greater than 350,000 poise.

18. The laminated glass sheet of claim 1 wherein, when measured by compaction, the skin glass is more thermally stable than the core glass.