Chemically temperable glass sheet

Patent metadata

Field	Value
Publication number	US-11718552-B2
Application number	US-201916680006-A
Country	US
Kind code	B2
Filing date	Nov 11, 2019
Priority date	Dec 9, 2014
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

The invention relates to a glass sheet having a boron-, strontium- and lithium-free glass composition comprising the following in weight percentage, expressed with respect to the total weight of glass:65≤SiO2≤78%8≤Na2O≤15%1≤K2O<6%1≤Al2O3<6%2≤CaO<10%0≤MgO≤6%;as well as a K2O/(K2O+Na2O) ratio which is ranging from 0.1 and 0.7. The invention corresponds to an easy chemically-temperable soda-lime-silica type glass composition, which is more suited for use in electronic devices applications.

First claim

The invention claimed is:

1. A chemically tempered glass sheet comprising the following in weight percentage, expressed with respect to a 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%;

total iron content expressed as Fe 2 O 3 of from 0.06<Fe 2 O 3 ≤1.7%, and
a K 2 O/(K 2 O+Na 2 O) ratio which is from 0.1 to 0.7,
wherein the glass sheet is boron, strontium, and lithium free.

2. The glass sheet according to claim 1 , wherein the glass sheet comprises total iron as follows:
0.06<Fe 2 O 3 ≤0.6% by weight.

3. The glass sheet according to claim 2 , wherein the glass sheet comprises total iron as follows:
0.06<Fe 2 O 3 ≤0.2% by weight.

4. The glass sheet according to claim 1 , wherein the glass sheet comprises:
5≤CaO<10 wt %.

5. The glass sheet according to claim 1 , wherein the glass sheet comprises:
3≤K 2 O≤6 wt %.

6. The glass sheet according to claim 1 , wherein the glass sheet comprises a low alumina content such that:
1≤Al 2 O 3 ≤4 wt %.

7. The glass sheet according to claim 6 , wherein the glass sheet comprises:
2≤Al 2 O 3 ≤3 wt %.

8. The glass sheet according to claim 1 , further comprising the following in weight percentage, expressed with respect to the total weight of glass:
<0.1% ZrO 2 ;
<0.1% BaO;
<0.1% SnO; and
<0.1% ZnO.

9. The glass sheet according to claim 1 , wherein the glass sheet comprises a colorant other than iron of between 0.001 and 0.075 wt %.

10. The glass sheet according to claim 1 , wherein the glass sheet comprises colorants other than iron, cobalt or chromium oxides in an amount less than 0.005 wt %.

11. The glass sheet according to claim 1 , wherein the glass sheet comprises a K 2 O/(K 2 O+Na 2 O) ratio ranging from 0.2 to 0.4.

12. A cover glass for a portable electronic device, comprising the glass sheet of claim 1 .

13. The glass sheet according to claim 1 , wherein the glass sheet has a compressive stress of at least 400 MPa and a Depth of Layer of at least 10 μm at CS 460° C. .

14. The glass sheet according to claim 1 , having a ratio R of at least 0.76 wherein R═CS 465° C. /CS 420° C. and CS 465° C. refers to immersion of the glass sheet in a KnO 3 bath at 465° C. for 480 minutes and CS 420° C. refers to immersion of the glass sheet in a KnO 3 bath at 420° C. for 220 minutes.

15. The glass sheet according to claim 1 , wherein the glass sheet was formed by a float process.

16. A chemically tempered glass sheet comprising the following in weight percentage, expressed with respect to a total weight of glass:
65≤SiO 2 ≤78%;
5≤Na 2 O≤20%;
3≤K 2 O<8%;
3<Al 2 O 3 <6%;
5≤CaO<10%;
0≤MgO≤8%; and
a K 2 O/(K 2 O+Na 2 O)ratio from 0.2 to 0.5,
wherein the glass sheet is boron, strontium, and lithium free.

17. The glass sheet according to claim 16 , wherein the glass sheet comprises a colorant other than iron of from 0.001 to 0.075 wt %.

18. The glass sheet according to claim 16 , wherein the Mass sheet comprises cobalt and/or chromium oxides in a total content of between 0.001 and 0.025 wt %.

19. A chemically tempered glass sheet comprising the following in weight percentage, expressed with respect to a 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
a K 2 O/(K 2 O+Na 2 O) ratio which is from 0.4 to 0.7,
wherein the glass sheet is boron, strontium, and lithium free, and
wherein the glass sheet comprises cobalt and/or chromium oxides in a total content of between 0.001 and 0.025 wt %.

Assignees

• Agc Glass Europe

Inventors

• Lambricht Thomas

Classifications

• C03C3/087 Primary

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

• C03C21/002

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

• C03C4/18

  for ion-sensitive glass · CPC title