High CTE opal glass compositions and glass articles comprising the same

• US 9,701,570 B2
• Filed: 02/27/2013
• Issued: 07/11/2017
• Est. Priority Date: 02/29/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Smedskjaer, Morten Mattrup, Mauro, John Christopher, Venkataraman, Natesan
• Primary Examiner(s): Bolden, Elizabeth A
• Application Number:
  US14/380,574
• Publication Number:
  US 20150010739A1
• Time in Patent Office: 1,595 Days
• 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: B32B 2307/30 having particular thermal properties
• CPC Class Codes: B32B 2315/08 Glass
• CPC Class Codes: B32B 2451/00 Decorative or ornamental articles wall paper B32B2607/02
• CPC Class Codes: B32B 7/027 Thermal properties
• 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 2204/00 Glasses, glazes or enamels with special properties
• CPC Class Codes: C03C 3/112 containing fluorine
• CPC Class Codes: C03C 3/118 containing aluminium
• CPC Class Codes: C03C 4/005 for opaline glass
• CPC Class Codes: C03C 4/02 for coloured glass
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

Opal glass compositions and glass articles comprising the same are disclosed. In one embodiment, a glass composition includes 55 mol. % to 70 mol. % SiO₂ and 9 mol. % to 15 mol. % Al₂O₃ as glass network formers. The glass composition also includes 10 mol. % to 15 mol. % alkali oxide M₂O, wherein M is at least one of Na and K. The glass composition also includes 2 mol. % to 8 mol. % divalent oxide RO, wherein R is at least one of Zn, Ca, and Mg. As an opalizing agent, the glass composition may also include 8.5 mol. % to 16 mol. % F⁻. The glass composition may also include 0 mol. % to 0.3 mol. % SnO₂ as a fining agent and from about 0 mol. % to about 6 mol. % of colorant. The glass composition is free from As and compounds containing As.

Claims

1. A glass composition comprising:

from about 55 mol. % to about 70 mol. % SiO₂;

from 9 mol. % to about 15 mol. % Al₂O₃;

from about 10 mol. % to about 15 mol. % alkali oxide M₂O, wherein M is at least one of Na or K;

from about 2 mol. % to about 5.5 mol. % divalent oxide RO, wherein R is at least one of Zn, Ca, or Mg;

from about 12.5 mol. % to about 16 mol. % F⁻

;

from 0 mol. % to about 0.5 mol. % SnO₂; and

from 0 mol. % to about 6 mol. % of colorant;

wherein the glass composition is free from As and compounds containing As and is opalized as a result of phase separation during formation or with a post-formation heat treatment.

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

from about 58 mol. % to about 64 mol. % SiO₂;

from about 10 mol. % to about 12 mol. % Al₂O₃; and

from about 11 mol. % to about 13 mol. % M₂O.

3. The glass composition of claim 1, wherein a concentration of the colorant is less than or equal to 2 mol. %.

4. The glass composition of claim 1, wherein the colorant is selected from the group consisting of Fe₂O₃, Cr₂O₃, Co₃O₄, CuO, Au, and V₂O₅.

5. The glass composition of claim 1, wherein the glass composition comprises from about 10 mol. % to about 15 mol. % Na₂O.

6. The glass composition of claim 1, further comprising B₂O₃.

7. The glass composition of claim 1, further comprising from about 2 mol. % to about 5 mol. % B₂O₃.

8. The glass composition of claim 1, wherein the glass composition comprises from about 2 mol. % to about 5.5 mol. % ZnO.

9. The glass composition of claim 1, further comprising from about 0.1 mol. % to about 0.3 mol. % SnO₂.

10. The glass composition of claim 1, further comprising an average coefficient of thermal expansion of greater than or equal to 75×

10<sup>−

7</sup>/°

C. averaged over a temperature range from 20°

C. to 300°

C.

11. A glass article comprising:

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

12. The glass article of claim 11, 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.

13. The glass article of claim 12, wherein the average core coefficient of thermal expansion CTE_core is greater than or equal to 75×

10<sup>−

7</sup>/°

C. averaged over a temperature range from 20°

C. to 300°

C.

14. The glass article of claim 11, wherein the first glass cladding layer and the second glass cladding layer are formed from ion-exchangeable glass.

15. The glass article of claim 11, wherein the first glass cladding layer and the second glass cladding layer are compressively stressed.

16. The glass article of claim 11, 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.

17. The glass article of claim 11, 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, and 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.

18. The glass article of claim 11, wherein the colorant is selected from the group consisting of Fe₂O₃, Cr₂O₃, Co₃O₄, CuO, Au, and V₂O₅.

19. The glass article of claim 11, wherein the glass core layer comprises:

from about 58 mol. % to about 64 mol. % SiO₂;

from about 10 mol. % to about 12 mol. % Al₂O₃; and

from about 11 mol. % to about 13 mol. % M₂O.

20. The glass article of claim 11, wherein the glass composition comprises from about 2 mol. % to about 5.5 mol. % ZnO.