GLASS PLATE AND METHOD FOR MANUFACTURING SAME

• US 20200131074A1
• Filed: 03/12/2018
• Published: 04/30/2020
• Est. Priority Date: 03/22/2017
• Status: Active Grant

• Current Assignee: Nippon Electric Glass Company Limited
• Original Assignee: Nippon Electric Glass Company Limited
• Inventors: SAITO, Atsuki
• Granted Patent: US 11,753,329 B2
• Time in Patent Office: Days
• CPC Class Codes: C03B 17/06 Forming glass sheets
• CPC Class Codes: C03B 17/064 by the overflow downdraw fusion process; Isopipes therefor
• CPC Class Codes: C03B 5/027 by passing an electric current between electrodes immersed in the glass bath, i.e. by direct resistance heating
• CPC Class Codes: C03B 5/43 Use of materials for furnace walls, e.g. fire-bricks
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/11 containing halogen or nitrogen
• CPC Class Codes: H10K 50/00 Organic light-emitting devices integrated devices or assemblies of multiple devices H10K59/00, H10K65/00; organic semiconductor lasers H01S5/36
• CPC Class Codes: H10K 77/10 Substrates, e.g. flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A glass sheet of the present invention has a content of Li₂O+Na₂O+K₂O of from 0 mol % to less than 1.0 mol % and a content of B₂O₃ of from 0 mol % to less than 2.0 mol % in a glass composition, has a β-OH value of less than 0.20/mm, and has a thermal shrinkage ratio of 20 ppm or less when increased in temperature from normal temperature at a rate of 5° C./min, kept at a temperature of 500° C. for 1 hour, and decreased in temperature at a rate of 5° C./min.

Claims

1. A glass sheet, which has a content of Li₂O+Na₂O+K₂O of from 0 mol % to less than 1.0 mol % and a content of B₂O₃ of from 0 mol % to less than 2.0 mol % in a glass composition,

which has a β

-OH value of less than 0.20/mm, and

which has a thermal shrinkage ratio of 20 ppm or less when increased in temperature from normal temperature at a rate of 5°

C./min, kept at a temperature of 500°

C. for 1 hour, and decreased in temperature at a rate of 5°

C./min.

2. The glass sheet according to claim 1, wherein the glass sheet has a content of B₂O₃ of from 0 mol % to less than 1.0 mol % in the glass composition, and has a β

-OH value of 0.15/mm or less.

3. The glass sheet according to claim 1, wherein the glass sheet has a thickness of from 0.03 mm to 0.6 mm, and comprises as a glass composition, in terms of mol %, 60% to 75% of SiO₂, 8% to 16% of Al₂O₃, 0% to less than 2.0% of B₂O₃, 0% to less than 1.0% of Li₂O+Na₂O+K₂O, 1% to 7% of MgO, 2% to 10% of CaO, 0% to 5% of SrO, 0% to 7% of BaO, 0% to less than 0.050% of As₂O₃, and 0% to less than 0.050% of Sb₂O₃.

4. The glass sheet according to claim 1, wherein the glass sheet has a content of Fe₂O₃ of 10 ppm or more and less than 100 ppm on a molar basis in the glass composition.

5. The glass sheet according to claim 1, wherein the glass sheet has a content of Na₂O of 100 ppm or more and less than 600 ppm on a molar basis in the glass composition.

6. The glass sheet according to claim 1, wherein the glass sheet has a strain point of 710°

C. or more.

7. The glass sheet according to claim 1, wherein the glass sheet has a liquidus temperature of 1,300°

C. or less.

8. The glass sheet according to claim 1, wherein the glass sheet has a temperature at a viscosity of 10^2.5 dPa·

s of 1,680°

C. or less.

9. The glass sheet according to claim 1, wherein the glass sheet comprises a formed joined surface on a center portion in a thickness direction.

10. The glass sheet according to claim 1, wherein the glass sheet is used as a substrate of an OLED device.

14. The glass sheet according to claim 2, wherein the glass sheet has a thickness of from 0.03 mm to 0.6 mm, and comprises as a glass composition, in terms of mol %, 60% to 75% of SiO₂, 8% to 16% of Al₂O₃, 0% to less than 2.0% of B₂O₃, 0% to less than 1.0% of Li₂O+Na₂O+K₂O, 1% to 7% of MgO, 2% to 10% of CaO, 0% to 5% of SrO, 0% to 7% of BaO, 0% to less than 0.050% of As₂O₃, and 0% to less than 0.050% of Sb₂O₃.

11. A method of producing a glass sheet, comprising:

a blending step of blending a glass batch so as to obtain glass comprising as a glass composition, in terms of mol %, 60% to 75% of SiO₂, 8% to 16% of Al₂O₃, 0% to less than 2.0% of B₂O₃, 0% to less than 1.0% of Li₂O+Na₂O+K₂O, 1% to 7% of MgO, 2% to 10% of CaO, 0% to 5% of SrO, 0% to 7% of BaO, 0% to less than 0.050% of As₂O₃, and 0% to less than 0.050% of Sb₂O₃;

a melting step of heating the resultant glass batch through application of a current with a heating electrode to obtain molten glass; and

a forming step of forming, by an overflow down-draw method, the resultant molten glass into a glass sheet having a β

-OH value of less than 0.20/mm, and having a thermal shrinkage ratio of 20 ppm or less when increased in temperature from normal temperature at a rate of 5°

C./min, kept at a temperature of 500°

C. for 1 hour, and decreased in temperature at a rate of 5°

C./min.

12. The method of producing a glass sheet according to claim 11, wherein the melting step comprises heating the resultant glass batch through application of a current with a molybdenum electrode to obtain the molten glass.

13. The method of producing a glass sheet according to claim 11, wherein the forming step comprises forming the resultant molten glass into a glass sheet having a thickness of from 0.03 mm to 0.6 mm.

15. The method of producing a glass sheet according to claim 12, wherein the forming step comprises forming the resultant molten glass into a glass sheet having a thickness of from 0.03 mm to 0.6 mm.