Glass article and method for forming the same

• US 10,710,927 B2
• Filed: 08/20/2018
• Issued: 07/14/2020
• Est. Priority Date: 03/13/2014
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Amosov, Alexey Sergeyevich, Boek, Heather Debra, Coppola, Frank, Dejneka, Matthew John, Mauro, John Christopher, Venkataraman, Netesan, Weller, Mark Owen
• Primary Examiner(s): Herring, Lisa L
• Application Number:
  US16/105,586
• Publication Number:
  US 20180354845A1
• Time in Patent Office: 694 Days
• Field of Search: None
• 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 15/02 for making a smooth surface
• CPC Class Codes: C03C 17/02 with glass C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 2218/355 Temporary coating
• 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 3/093 containing zinc or zirconium
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

A method includes forming a glass article. The glass article includes a core and a clad adjacent to the core. The core includes a first glass composition. The clad includes a second glass composition different than the first glass composition. A degradation rate of the second glass composition in a reagent is greater than a degradation rate of the first glass composition in the reagent.

Claims

1. A glass article comprising:

a core comprising a core glass composition; and

a clad adjacent to the core and comprising a clad glass composition comprising SiO₂, Al₂O₃, B₂O₃, and at least one alkali metal oxide selected from the group consisting of Li₂O, Na₂O, K₂O, Rb₂O, Cs₂O, and combinations thereof;

wherein a concentration of SiO₂ in the clad glass composition is about 45 mol % to about 60 mol %;

wherein a coefficient of thermal expansion (CTE) of the clad glass composition is about 50×

10<sup>−

7</sup>°

C. to about 95×

10<sup>−

7</sup>°

C.;

wherein a liquidus viscosity of the clad glass composition is at least about 50 kP; and

wherein a degradation rate of the clad glass composition in a reagent is greater than a degradation rate of the core glass composition in the reagent.

2. The glass article of claim 1, wherein the clad glass composition is substantially free of As and Cd, and a ratio of the degradation rate of the clad glass composition in the reagent to the degradation rate of the core glass composition in the reagent is at least about 10.

3. The glass article of claim 1, wherein the clad glass composition comprises about 13 mol % to about 19 mol % Al₂O₃, about 5 mol % to about 23 mol % B₂O₃, and about 3 mol % to about 21 mol % Na₂O.

4. The glass article of claim 1, wherein the reagent comprises a 50 vol % aqueous HCl solution, and the degradation rate of the clad glass composition in the reagent expressed in terms of percent weight loss after contact by the reagent at 60°

C. in an ultrasonic bath for 30 min, is about 0.9% to about 29%.

5. The glass article of claim 1, wherein the clad comprises a first cladding layer and a second cladding layer, and the core comprises a core layer disposed between the first cladding layer and the second cladding layer.

6. The glass article of claim 5, wherein the core layer comprises an inner core layer, a first outer core layer disposed between the first cladding layer and the inner core layer, and a second outer core layer disposed between the second cladding layer and the inner core layer, and wherein each of the first outer core layer and the second outer core layer comprises the core glass composition.

7. The glass article of claim 5, wherein the core layer comprises an inner core layer, a first outer core layer disposed between the first cladding layer and the inner core layer, and a second outer core layer disposed between the second cladding layer and the inner core layer, and wherein each of the first cladding layer, the first outer core layer, the second cladding layer, and the second outer core layer comprises a lower CTE than the inner core layer.

8. The glass article of claim 5, wherein the core layer comprises an inner core layer, a first outer core layer disposed between the first cladding layer and the inner core layer, and a second outer core layer disposed between the second cladding layer and the inner core layer, and wherein each of the first cladding layer and the second cladding layer comprises a higher degradation rate in the reagent than each of the first outer core layer and the second outer core layer.

9. The glass article of claim 5, further comprising a thickness of from about 0.05 mm to about 3 mm, wherein a ratio of a thickness of the core layer to a combined thickness of the first cladding layer and the second cladding layer is at least about 1.

10. The glass article of claim 1, wherein the CTE of the clad glass composition is less than a CTE of the core glass composition.

11. The glass article of claim 1, wherein a strain temperature of the clad glass composition is less than a strain temperature of the core glass composition.

12. The glass article of claim 1, wherein contacting the glass article with the reagent for about 0.1 hr to about 10 hr causes the clad to be at least partially removed from the core and exposes an outer surface of the core.

13. The glass article of claim 1, wherein the glass article is a molded glass article with a non-planar shape.

14. The glass article of claim 1, comprising an ion exchanged region at an interface between the clad and the core.

15. The glass article of claim 1, wherein the clad glass composition comprises about 55 mol % to about 59 mol % SiO₂, about 12 mol % to about 16 mol % Al₂O₃, about 13 mol % to about 17 mol % B₂O₃, and about 12 mol % to about 16 mol % Na₂O.

16. The glass article of claim 1, wherein the clad glass composition comprises about 47 mol % to about 51 mol % SiO₂, about 13 mol % to about 17 mol % Al₂O₃, about 17 mol % to about 21 mol % B₂O₃, about 13 mol % to about 17 mol % Na₂O, and 0 mol % to about 4 mol % CaO.

17. A display, an automotive glazing, or an architectural panel comprising the glass article of claim 1.

18. A glass article comprising:

a core comprising a core glass composition; and

a clad adjacent to the core and comprising a clad glass composition;

wherein a degradation rate of the clad glass composition in a reagent is greater than a degradation rate of the core glass composition in the reagent and wherein a portion of the clad is removed to expose a portion of the core wherein the reagent comprises a 50 vol % aqueous HCl solution, and the degradation rate of the clad glass composition in the reagent expressed in terms of percent weight loss after contact by the reagent at 60°

C. in an ultrasonic bath for 30 min, is about 0.9% to about 29%.

19. A glass article comprising:

a core comprising a core glass composition; and

a clad adjacent to the core and comprising a clad glass composition;

wherein a degradation rate of the clad glass composition in a reagent is greater than a degradation rate of the core glass composition in the reagent and wherein a portion of the clad is removed to expose a portion of the core,

wherein the clad glass composition comprises about 45 mol % to about 60 mol % SiO₂, at least one alkali metal oxide selected from the group consisting of Li₂O, Na₂O, K₂O, Rb₂O, Cs₂O, and combinations thereof, a coefficient of thermal expansion (CTE) of from about 50×

10<sup>−

7</sup>/°

C. to about 95×

10<sup>−

7</sup>/°

C., and a liquidus viscosity of at least about 50 kP.