Chemically strengthened glass

Patent metadata

Field	Value
Publication number	US-11136264-B2
Application number	US-202017124183-A
Country	US
Kind code	B2
Filing date	Dec 16, 2020
Priority date	Apr 20, 2017
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

A chemically strengthened glass obtained by chemically strengthening a lithium-containing aluminosilicate glass, when representing a sheet thickness of the chemically strengthened glass by t (μm) and an internal stress at a depth×(μm) from a surface of the chemically strengthened glass by σ(x) (MPa), has a value of a ratio C=rE/rElimit being greater than or equal to 0.7 and less than 1.0 where rE (kJ/m2) is calculated from Expression (3) described above and rElimit=16×t/1000+3.

First claim

The invention claimed is:

1. A chemically strengthened glass obtained by chemically strengthening a lithium-containing aluminosilicate glass, wherein representing a sheet thickness of the chemically strengthened glass by t (μm) and an internal stress at a depth x (μm) from a surface of the chemically strengthened glass by σ(x) (MPa), the chemically strengthened glass has a value of a ratio C=rE/rE limit being greater than or equal to 0.7 and less than 1.0 where rE (kJ/m 2 ) is calculated from a following Expression (3) and rE limit =16×t/1000+3,

rE
=

2
×

∫
DOL

t
/
2

⁢



σ
⁡

(
x
)



⁢
dx
×

(

t
-

2
×
DOL

)

1000
×
t

(
3
)

wherein rE limit is expressed in kJ/m 2 ,
and a stress value at a half depth of a DOL value of the glass is 10% or less, with respect to a surface stress value,
where DOL represents a depth (μm) of a compressive stress layer of the chemically strengthened glass.

2. The chemically strengthened glass as claimed in claim 1 , wherein DOL representing the depth of the compressive stress layer is greater than or equal to 85 μm.

3. The chemically strengthened glass as claimed in claim 1 , wherein a position at which a half value (HW) of a surface compressive stress CS is less than 8 μm.

4. The chemically strengthened glass as claimed in claim 1 , wherein a surface compressive stress CS is greater than or equal to 600 MPa.

5. The chemically strengthened glass as claimed in claim 1 , wherein DOL representing the depth of the compressive stress layer is greater than or equal to 90 μm.

6. The chemically strengthened glass as claimed in claim 1 , wherein DOL representing the depth of the compressive stress layer is greater than or equal to 95 μm.

7. The chemically strengthened glass as claimed in claim 1 , wherein the sheet thickness t is less than or equal to 1500 μm.

8. The chemically strengthened glass as claimed in claim 1 , wherein DOL representing the depth of the compressive stress layer is greater than or equal to 100 μm.

9. A chemically strengthened glass obtained by chemically strengthening a lithium-containing aluminosilicate glass, wherein representing a sheet thickness of the chemically strengthened glass by t (μm) and an internal stress at a depth x (um) from a surface of the chemically strengthened glass by σ(x) (MPa),
the chemically strengthened glass has a value of a ratio C=rE/rE ii being greater than or equal to 0.7 where rE (kJ/m 2 ) is calculated from a following Expression (3) and rE limit =16×t/1000+3,

rE
=

2
×

∫
DOL

t
/
2

⁢



σ
⁡

(
x
)



⁢
dx
×

(

t
-

2
×
DOL

)

1000
×
t

(
3
)

wherein rE limit is expressed in kJ/m 2 ,
and a position at which a half value (HW) of a surface compressive stress CS is less than 8 μm,
where DOL represents a depth (μm) of a compressive stress layer of the chemically strengthened glass,
the number of broken pieces is less than 15 when the chemically strengthened glass having the size of 50 mm×50 mm is broken by a tip part of an indenter having a facing angle of 60° which perpendicularly presses against the surface of the chemically strengthened glass under a static load, and
wherein the surface compressive stress CS is greater than or equal to 600 MPa.

10. The chemically strengthened glass as claimed in claim 9 , wherein a stress value at a half depth of a DOL value of the glass is 10% or less, with respect to a surface stress value.

11. The chemically strengthened glass as claimed in claim 9 , wherein C=rE/rE limit is greater than or equal to 0.84.

12. The chemically strengthened glass as claimed in claim 9 , wherein C=rE/rE limit is greater than or equal to 0.9.

13. The chemically strengthened glass as claimed in claim 9 , wherein DOL is greater tha

Assignees

• Agc Inc

Inventors

• Ogami Satoshi

Classifications

• C03C21/002 Primary

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

• C03C4/00

  Compositions for glass with special properties · CPC title