White, opaque, βspodumene glass-ceramic articles with tunable color and methods for making the same

Patent metadata

Field	Value
Publication number	US-9546106-B2
Application number	US-201514751746-A
Country	US
Kind code	B2
Filing date	Jun 26, 2015
Priority date	Jun 30, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

Crystallizable glasses, glass-ceramics, IXable glass-ceramics, and IX glass-ceramics are disclosed. The glass-ceramics exhibit β-spodumene ss as the predominant crystalline phase. These glasses and glass-ceramics, in mole %, include: 62-75 SiO 2 ; 10.5-18 Al 2 O 3 ; 5-14 Li 2 O; 2-12 B 2 O 3 ; and 0.4-2 Fe 2 O 3 . Additionally, these glasses and glass-ceramics can exhibit the following criteria:

a
⁢

⁢
ratio
⁢

:

⁢

[

Li
2

⁢
O

+

Na
2

⁢
O

+

K
2

⁢
O

+
MgO
+
ZnO

_

]

⁢

[

Al
2

⁢

O
3

]

between 0.8 to 1.5.

The glass-ceramics also exhibit colors at an observer angle of 10° and a CIE illuminant F02 determined with specular reflectance of a* between −0.5 and 0.5, b* between −2.5 and +2, and L* between 90 and 93.

First claim

We claim:

1. A glass-ceramic article comprising:
a composition, in mole %, comprising:
i) SiO 2 in a range from about 62 to about 75,
ii) Al 2 O 3 in a range from about 10 to about 18,
iii) Li 2 O in a range from about 5 to about 14,
iv) B 2 O 3 in a range from about 2 to about 12,
v) Fe 2 O 3 in a range from about 0.4 to about 2,
vi) MgO in a range from 0 to about 8,
vii) ZnO in a range from 0 to about 4,
viii) TiO 2 in a range from about 2 to about 5,
ix) Na 2 O in a range from 0 to about 5,
x) K 2 O in a range from 0 to about 4,
wherein a ratio of the mole sum total [Li 2 O+Na 2 O+K 2 O+MgO+ZnO]/moles of [Al 2 O 3 ] in a range from about 0.8 to about 1.5, and
wherein β-spodumene is the predominant crystalline phase.

2. The glass-ceramic article of claim 1 , wherein the glass-ceramic article comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
a) CIE a* in a range from about −0.5 to about 0.5;
b) CIE b* in a range from about −2.5 to about 2; and
c) CIE L* in a range from about 90 to about 93.

3. The glass-ceramic article of claim 1 , wherein the composition comprises Fe 2 O 3 in a range from about 0.5 to about 2 mole %.

4. The glass-ceramic article of claim 1 , further comprising a compressive stress layer formed by ion-exchange.

5. The glass-ceramic article of claim 4 , wherein the compressive stress layer has a compressive stress of at least 300 MPa and a depth of layer (DOL) of at least about 2% of an overall thickness of the article.

6. The glass-ceramic article of claim 1 , wherein the composition further comprises:
xi) SnO 2 in a range from about 0.05 to about 0.5.

7. A process for making a glass-ceramic comprising:
a) heating a crystallizable glass at a rate in a range from about 1° C./min to about 10° C./min to a nucleation temperature in a range from about 700° C. and 810° C., wherein, in mole %, the crystallizable glass comprises:
i) SiO 2 in a range from about 62 to about 75,
ii) Al 2 O 3 in a range from about 10 to about 18,
iii) Li 2 O in a range from about 5 to about 14,
iv) B 2 O 3 in a range from about 2 to about 12, and
v) Fe 2 O 3 in a range from about 0.4 to about 2, and

b) maintaining the crystallizable glass at the nucleation temperature to produce a nucleated crystallizable glass;
c) heating the nucleated crystallizable glass at a rate in a range from about 1° C./min to about 10° C./min to a crystallization temperature of in a range from about 850° C. to about 1200° C.; and
d) maintaining the nucleated crystallizable glass at the crystallization temperature to produce a glass-ceramic having β-spodumene as a predominant crystalline phase.

8. The process of claim 7 , wherein the glass-ceramic article comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
a) CIE a* in a range from about −0.5 to about 0.5;
b) CIE b* in a range from about −2.5 to about 2; and
c) CIE L* in a range from about 90 to about 93.

9. The process of claim 8 , wherein a correlation between a* and b* exists, as a function of crystallization temperature, wherein a plot of a* vs. b* has a slope of delta b*/delta a* between about 8 and about 22.

10. The process of claim 9 , wherein a correlation between b* and L* exists, as a function of crystallization temperature, wherein a plot of b* vs. L* has a slope of delta L*/delta b* of between about 0.75 and about 1.25.

11. The process of claim 9 , further comprising selecting the crystallization temperature to tune the color based on the correlation between a* and b*.

12. The process of claim 10 , further comprising selecting the crystallization temperature to tune the color based on the correlation between a* and b* and the correlation between b* and L*.

13. The process of claim 7 , wherein the crystallizable glass further comprises:
vi) MgO in a range from 0 to about 8,
vii) ZnO in a range from 0 to about 4,
viii) TiO 2 in a range from about 2 to about 5,
ix) Na 2 O in a range from 0 to about 5,
x) K 2 O in a range from 0 to about 4, and
xi) SnO 2 in a range from about 0.05 to about 0.5, and
xii) a ratio of the mole sum total [Li 2 O+Na 2 O+K 2 O+MgO+ZnO]/moles of [Al 2 O 3 ] in a range from about 0.8 to about 1.5.

14. A process for making a glass-ceramic comprising:
a) heating a nucleated crystallizable glass at a rate in a range from about 1° C./min to about 10° C./min to a crystallization temperature of in a range from about 850° C. to about 1200° C., wherein, in mole %, the nucleated crystallizable glass comprises:
i) SiO 2 in a range from about 62 to about 75,
ii) Al 2 O 3 in a range from about 10 to about 18,
iii) Li 2 O in a range from about 5 to about 14,
iv) B 2 O 3 in a range from about 2 to about 12,
v) Fe 2 O 3 in a range from about 0.4 to about 2, and

b) selecting the crystallization temperature to tune the color based on a correlation between a* and b*, wherein:
i) the color is presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
(1) CIE a* in a range from about −0.5 to about 0.5;
(2) CIE b* in a range from about −2.5 to about 2; and
(3) CIE L* in a range from about 90 to about 93; and

ii) based on the correlation between a* and b*, as a function of crystallization temperature, a plot of a* vs. b* has a slope of delta b*/delta a* of between about 8 and about 22; and

 maintaining the nucleated crystallizable glass at the crystallization temperature to produce a glass-ceramic having β-spodumene as a predominant crystalline phase.

15. The process of claim 14 , wherein based on a correlation between b* and L*, as a function of crystallization temperature, a plot of b* vs. L* has a slope delta L*/delta b* of between about 0.75 and about 1.25.

16. The process of claim 15 , further comprising selecting the crystallization temperature to tune the color based on the correlation between a* and b* and the correlation between b* and L*.

17. The process of claim 14 , further comprising ion exchanging the glass ceramic to form a compressive stress layer.

18. The process of claim 17 , wherein the compressive stress layer has a compressive stress of at least 300 MPa and a depth of layer (DOL) of at least about 2% of an overall thickness of the glass-ceramic.

19. The process of claim 14 , wherein the crystallizable glass further comprises:
vi) MgO in a range from 0 to about 8,
vii) ZnO in a range from 0 to about 4,
viii) TiO 2 in a range from about 2 to about 5,
ix) Na 2 O in a range from 0 to about 5,
x) K 2 O in a range from 0 to about 4, and
xi) SnO 2 in a range from about 0.05 to about 0.5, and
xii) a ratio of the mole sum total [Li 2 O+Na 2 O+K 2 O+MgO+ZnO]/moles of [Al 2 O 3 ] in a range from about 0.8 to about 1.5.

20. A glass-ceramic article comprising:
a) a composition, in mole %, comprising:
i) SiO 2 in a range from about 62 to about 75,
ii) Al 2 O 3 in a range from about 10 to about 18,
iii) Li 2 O in a range from about 5 to about 14,
iv) B 2 O 3 in a range from about 2 to about 12,
v) a metal oxide selected from group consis

Assignees

• Corning Inc

Inventors

• Fu Qiang
• Smith Charlene Marie

Classifications

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C10/0054 Primary

  containing PbO, SnO2, B2O3 · CPC title

• C03C10/0027 Primary

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

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• C03C3/093 Primary

  containing zinc or zirconium · CPC title