Low CTE, ion-exchangeable glass compositions and glass articles comprising the same

• US 9,868,664 B2
• Filed: 02/27/2013
• Issued: 01/16/2018
• Est. Priority Date: 02/29/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Gomez, Sinue, Kiczenski, Timothy James, Mauro, John Christopher, Schaut, Robert Anthony, Smedskjaer, Morten Mattrup, Venkataraman, Natesan
• Primary Examiner(s): Bolden, Elizabeth A
• Application Number:
  US14/380,446
• Publication Number:
  US 20150030827A1
• Time in Patent Office: 1,784 Days
• CPC Class Codes: B32B 17/00 Layered products essentially comprising sheet glass, or glass, slag, or like fibres
• CPC Class Codes: B32B 2307/308 Heat stability dimensional stability B32B2307/734
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• 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: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 2204/00 Glasses, glazes or enamels with special properties
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: C03C 4/18 for ion-sensitive glass
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

Glass compositions and glass articles comprising the glass compositions are disclosed. In one embodiment, a glass composition includes from about 65 mol. % to about 70 mol. % SiO2; from about 9 mol. % to about 14 mol. % Al₂O₃; and from about 0 mol. % to about 11 mol. % B₂O₃ as glass network formers. The glass composition also includes from about 5 mol. % to less than 10 mol. % alkali oxide R₂O, wherein R is at least one of Li, Na, and K. The glass composition also includes from about 3 mol. % to about 11 mol. % of divalent oxide MO, wherein M is at least one of Mg, Ca, Ba, SrO and Zn. The glass composition has a coefficient of thermal expansion which is less than or equal to 55×10-⁷/° C. and is amenable to strengthening by ion-exchange. The glass composition is well suited for use as the glass cladding layers of a laminated glass article.

Claims

1. A glass composition comprising:

from about 65 mol. % to about 70 mol. % SiO₂;

from about 9 mol. % to about 14 mol. % Al₂O₃;

from 0 mol. % to about 11 mol. % B₂O₃;

from about 5 mol. % to less than 10 mol. % alkali oxide R₂O, wherein R is at least one of Li, Na, or K;

from 7 mol. % to about 10 mol. % divalent oxide MO, wherein M is at least one of Mg, Ca, Ba, Sr, or Zn, and a concentration of ZnO is from 0 mol. % to about 3 mol. %;

an average coefficient of thermal expansion less than or equal to 55×

10<sup>−

7</sup>/°

C.; and

a liquidus viscosity greater than or equal to 35 kPoise;

wherein a compressive stress in a glass article formed from the glass composition is greater than or equal to 400 MPa following ion-exchange in a 100% KNO₃ salt bath at 410°

C. for 8 hours.

2. The glass composition of claim 1, wherein the glass composition comprises:

from about 65 mol. % to about 68 mol. % SiO₂;

from about 10 mol. % to about 13 mol. % Al₂O₃;

from about 6 mol. % to about 9 mol. % B₂O₃;

from about 6 mol. % to less than 9 mol. % alkali oxide R₂O; and

from about 7 mol. % to about 10 mol. % of divalent oxide MO, wherein M is at least one of Mg, Ca, or Zn.

3. The glass composition of claim 1, wherein a concentration of B₂O₃ is less than 7 mol. %.

4. The glass composition of claim 1, wherein a concentration of divalent oxide MO is less than 9 mol. %.

5. The glass composition of claim 1, wherein the divalent oxide MO comprises MgO and CaO and a concentration of MgO (mol. %) is greater than a concentration of CaO (mol. %).

6. The glass composition of claim 1, wherein the divalent oxide MO comprises MgO and CaO and a concentration of MgO is greater than 5 mol. % and a concentration of CaO is less than 5 mol. %.

7. The glass composition of claim 1, wherein the glass composition is ion-exchange strengthened.

8. A glass article comprising:

a glass core layer disposed between a first glass cladding layer and a second glass cladding layer, wherein the first glass cladding layer and the second glass cladding layer are formed from the glass composition of claim 1.

9. The glass article of claim 8, wherein a concentration of B₂O₃ in the first glass cladding layer and the second glass cladding layer is less than about 7 mol. %.

10. The glass article of claim 8, wherein a concentration of the divalent oxide MO in the first glass cladding layer and the second glass cladding layer is less than 9 mol. %.

11. The glass article of claim 8, wherein the divalent oxide MO comprises MgO and CaO and a concentration of MgO (mol. %) is greater than a concentration of CaO (mol. %).

12. The glass article of claim 8, wherein the divalent oxide MO comprises MgO and CaO and a concentration of MgO is greater than 5 mol. % and a concentration of CaO is less than 5 mol. %.

13. The glass article of claim 8, wherein the first glass cladding layer and the second glass cladding layer are ion-exchange strengthened.

14. The glass article of claim 8, wherein the first glass cladding layer and the second glass cladding layer have a compressive stress greater than or equal to 400 MPa.

15. The glass article of claim 8, wherein:

the glass core layer has an average core coefficient of thermal expansion CTE_core; and

the first glass cladding layer and the second glass cladding layer have an average cladding coefficient of thermal expansion CTE_clad which is less than the average core coefficient of thermal expansion CTE_core.

16. The glass article of claim 15, wherein the average cladding coefficient of thermal expansion CTE_clad is less than or equal to 55×

10<sup>−

7</sup>/°

C. in a temperature range from 20°

C. to 300°

C.

17. The glass article of claim 8, wherein a first surface of the glass core layer is directly adjacent the first glass cladding layer, and wherein a second surface of the glass core layer is directly adjacent the second glass cladding layer.

18. The glass article of claim 8, wherein a diffusive layer is disposed between at least one of the first glass cladding layer or the second glass cladding layer and the glass core layer.

19. The glass article of claim 18, wherein the average coefficient of thermal expansion of the diffusive layer has a value between that of an average core coefficient of thermal expansion of the glass core layer and an average cladding coefficient of thermal expansion of the at least one of the first glass cladding layer or the second glass cladding layer.