Fusion formable lithium aluminosilicate glass ceramic

Patent metadata

Field	Value
Publication number	US-9440878-B2
Application number	US-201414185202-A
Country	US
Kind code	B2
Filing date	Feb 20, 2014
Priority date	Feb 28, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A down-drawable glass ceramic. The glass ceramic has a composition which yields a liquidus viscosity that enables formation of the parent glass by down-draw techniques such as fusion-draw and slot-draw methods. The resulting glass ceramic is white or translucent in appearance with high strength achieved through heat treatment of the fusion-formed glass.

First claim

The invention claimed is:

1. A glass ceramic, the glass ceramic comprising:
from about 72 wt % to about 85 wt % SiO 2 , from about 7 wt % to about 11 wt % Al 2 O 3 , from about 4.3 wt % to about 6.5 wt % Li 2 O, and from about 4 wt % to about 9 wt % K 2 O;
a lithium silicate crystallized component and a lithium aluminum silicate crystallized component; and
a residual glass component, wherein the glass ceramic has a composition located within an area defined by a ternary eutectic of β-spodumene-lithium disilicate-tridymite in the SiO 2 —Al 2 O 3 —Li 2 O system and a binary eutectic of orthoclase-tridymite in the SiO 2 —Al 2 O 3 —K 2 O system, and wherein the ternary eutectic and binary eutectic occur at temperatures of less than about 1000° C.

2. The glass ceramic of claim 1 , further comprising up to 2.6 wt % Na 2 O.

3. The glass ceramic of claim 1 , further comprising up to about 5 wt % BaO.

4. The glass ceramic of claim 1 , further comprising up to about 3.0 wt % ZnO.

5. The glass ceramic of claim 1 , further comprising from about 0.1 wt % to about 5.0 wt % P 2 O 5 .

6. The glass ceramic of claim 1 , further comprising 0.0001 wt % to about 0.1 wt % of at least one noble metal.

7. The glass ceramic of claim 6 , wherein the at least one noble metal comprises silver, and wherein the glass ceramic further comprising at least one of 0.005 wt % to about 0.5 wt % CeO 2 , 0.005 wt % to about 0.5 wt % SnO 2 , and 0.005 wt % to about 0.5 wt % Sb 2 O 3 .

8. The glass ceramic of claim 1 , wherein the glass ceramic is formed from a glass having a liquidus viscosity of at least about 100 kpoise.

9. The glass ceramic of claim 8 , wherein the glass ceramic is formed from a glass having a liquidus viscosity of at least about 150 kpoise.

10. The glass ceramic of claim 1 , wherein the residual glass component comprises at least 20 wt % of the glass ceramic.

11. The glass ceramic of claim 10 , wherein the residual glass component has a quartzofeldspathic composition.

12. The glass ceramic of claim 1 , wherein the lithium aluminum silicate crystalline component has a beta spodumene crystal structure or a beta quartz crystal structure.

13. A method of making a glass ceramic, the method comprising:
a. down-drawing a glass, the glass comprising from about 72 wt % to about 85 wt % SiO 2 , from about 7 wt % to about 11 wt % Al 2 O 3 , from about 4.3 wt % to about 6.5 wt % Li 2 O, and from about 4 wt % to about 9 wt % K 2 O, wherein the glass has a liquidus viscosity of at least about 100 kP; and
b. heating the glass to form the glass ceramic, wherein forming the glass ceramic includes crystallizing a lithium silicate component and a lithium aluminosilicate component, and wherein the glass ceramic includes a residual glass component, the residual glass component comprising an alkali aluminosilicate glass that comprises at least one of sodium and potassium, wherein the glass ceramic has a composition located within an area defined by a ternary eutectic of β-spodumene-lithium disilicate-tridymite in the SiO 2 —Al 2 O 3 —Li 2 O system and a binary eutectic of orthoclase-tridymite in the SiO 2 —Al 2 O 3 —K 2 O system, and wherein the ternary eutectic and binary eutectic occur at temperatures of less than about 1000° C.

14. The method of claim 13 , wherein the step of down-drawing the glass comprises slot-drawing the glass.

15. The method of claim 13 , wherein the step of down-drawing the glass comprises fusion-drawing the glass.

16. The method of claim 13 , further comprising ion exchanging the glass or the glass ceramic.

17. The method of claim 13 , wherein heating the glass to form the glass ceramic comprises heating the glass at a temperature in a range from about 600° C. to about 900° C.

Assignees

• Corning Inc

Inventors

• Beall George Halsey
• Boek Heather Debra
• Mayolet Alexandre Michel
• Weller Mark Owen

Classifications

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title

• C03C14/004

  the non-glass component being in the form of particles or flakes · CPC title

• C03C10/0027 Primary

  containing SiO2, Al2O3, Li2O as main constituents · CPC title

• C03B17/064

  by the overflow downdraw fusion process; Isopipes therefor · CPC title

• C03C10/00

  Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition · CPC title