Glass sheet capable of having controlled warping through chemical strengthening

Patent metadata

Field	Value
Publication number	US-10377660-B2
Application number	US-201615577870-A
Country	US
Kind code	B2
Filing date	May 19, 2016
Priority date	Jun 8, 2015
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A float glass sheet having a boron- and lithium-free glass composition comprising the following in weight percentage, expressed with respect to the total weight of glass:
65≤SiO 2 ≤78% 5≤Na 2 O≤20% 1≤K 2 O<8% 1≤Al 2 O 3 <6% 2≤CaO<10% 0≤MgO≤8%; K 2 O/(K 2 O+Na 2 O) ratio which is from 0.1 to 0.7; wherein the glass sheet has:

0.01
<



(

Na
2

⁢
O

)

air

(

Na
2

⁢
O

)

tin

-
1.03



≤
3.

The glass sheet may be a chemically-temperable soda-silica type glass composition suitable for mass production that shows reduced or controlled increased warping effect.

First claim

The invention claimed is:

1. A float glass sheet comprising the following in weight percentage, expressed with respect to the total weight of glass:
65≤SiO 2 ≤78%;
5≤Na 2 O≤20%;
1≤K 2 O<8%;
1≤Al 2 O 3 <6%;
2≤CaO<10%;
0≤MgO≤8%; and
K 2 O/(K 2 O+Na 2 O) ratio of from 0.1 to 0.7,
wherein the glass sheet has:

0.01
<



(

Na
2

⁢
O

)

air

(

Na
2

⁢
O

)

tin

-
1.03



≤
3

,

 and
wherein the glass sheet is boron- and lithium-free.

2. A float glass sheet according to claim 1 , wherein the composition comprises total iron (expressed in the form of Fe 2 O 3 ) in a content ranging from 0.002 to 1.7% by weight.

3. A float glass sheet according to claim 2 , wherein the composition comprises total iron (expressed in the form of Fe 2 O 3 ) in a content ranging from 0.002 to 0.06% by weight.

4. A float glass sheet according to claim 3 , wherein the composition comprises total iron (expressed in the form of Fe 2 O 3 ) in a content ranging from 0.002 to 0.02% by weight.

5. A float glass sheet according to claim 1 , wherein the composition comprises an alumina content such that 1≤Al 2 O 3 ≤4 wt %.

6. A float glass sheet according to claim 5 , wherein the composition comprises an alumina content such that : 2≤Al 2 O 3 ≤3 wt %.

7. A float glass sheet according to claim 1 , wherein the composition comprises : 5≤CaO<10 wt %.

8. A float glass sheet according to claim 1 , wherein the composition comprises : 1≤K 2 O<6 wt %.

9. A float glass sheet according to claim 1 , wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio of from 0.1 to 0.5.

10. A float glass sheet according to claim 1 , wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio of from 0.2 to 0.5.

11. A float glass sheet according to claim 1 wherein the composition comprises a K 2 O/(K 2 O+Na 2 O) ratio of from 0.2 to 0.4.

12. A float glass sheet according to claim 1 , wherein the glass sheet has:

(

Na
2

⁢
O

)

air

(

Na
2

⁢
O

)

tin

≤
1.

13. A float glass sheet according to claim 1 , wherein R (CS 465° C. /CS 420° C. ) is from 0.76 to 0.92.

14. A float glass sheet according to claim 1 , wherein the glass sheet has a thickness of less than 1.5 mm.

15. A float glass sheet according to claim 1 , wherein the glass sheet has a thickness of less than 0.7 mm.

16. A float glass sheet according to claim 1 , wherein the float glass sheet is chemically tempered.

17. An electronic device comprising the float glass sheet according to claim 16 .

18. An electronic device comprising the float glass sheet according to claim 1 .

19. A float glass sheet comprising the following in weight percentage, expressed with respect to the total weight of glass:
65≤SiO 2 ≤78%;
5≤Na 2 O≤20%;
1≤K 2 O<8%;
3≤Al 2 O 3 <6%;
2≤CaO<10%;
0≤MgO≤8%; and
K 2 O/(K 2 O+Na 2 O) ratio of from 0.1 to 0.7,
wherein the glass sheet has:

0.02
<



(

Na
2

⁢
O

)

air

(

Na
2

⁢
O

)

tin

-
1.03



≤
3

,

 and
wherein the glass sheet is boron- and lithium-free.

Assignees

• Agc Glass Europe

Inventors

• Lambricht Thomas
• Dogimont Audrey
• Degand Aline
• Scheyvaerts Florence

Classifications

• C03C21/002

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

• C03C3/087 Primary

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C23/008 Primary

  comprising a lixiviation step · CPC title

• C03C21/00

  Treatment of glass, not in the form of fibres or filaments, by diffusing ions or metals in the surface · CPC title