Glass sheet having a high transmission in the infrared

1. A glass sheet having a composition that comprises, in an amount expressed in percentages by total weight of glass:

SiO 2

  55-85%

Al 2 O 3

   0-30%

B 2 O 3

   0-20%

Na 2 O

   0-25%

CaO

   0-20%

MgO

   0-15%

K 2 O

   0-20%

BaO

   0-20%

Total iron (expressed in Fe 2 O 3 form)

0.002-0.04%;

said composition furthermore comprising at least two components from chromium, selenium, copper, cerium and manganese; the chromium (expressed in Cr 2 O 3 form) being in a maximum content of 0.02% by weight; the selenium (expressed in Se form) being in a maximum content of 0.08% by weight; the copper (expressed in CuO form) being in a maximum content of 0.04% by weight; the cerium (expressed in CeO 2 form) being in a maximum content of 0.8% by weight; the manganese (expressed in MnO form) being in a maximum content of 1.6% by weight;

wherein the composition is zinc-free and Sb 2 O 3 is not present;

wherein the composition has an absorption coefficient at a wavelength of 1050 nm lower than 5 m −1 ; and

wherein the composition is according to the formula:

[10.02*(Cr 2 O 3 /Fe 2 O 3 )+4*(Se/Fe 2 O 3 )+2.73*(CuO/Fe 2 O 3 )+0.7*(CeO 2 /Fe 2 O 3 )+0.23*(MnO/Fe 2 O 3 )+0.11*(Sb 2 O 3 /Fe 2 O 3 )]≥A;

A being equal to 0.30.

2. The glass sheet according to claim 1 , wherein the composition comprises a total iron content (expressed in Fe 2 O 3 form) from 0.002 to 0.02% by weight relative to the total weight of the glass.

3. The glass sheet according to claim 2 , wherein the composition comprises a total iron content (expressed in Fe 2 O 3 form) from 0.002 to less than 0.014% by weight relative to the total weight of the glass.

4. The glass sheet according to claim 1 , wherein the composition comprises an Fe 2+ content (expressed in FeO form) lower than 10 ppm.

5. The glass sheet according to claim 1 , wherein the composition comprises an Fe 2+ content (expressed in FeO form) lower than 5 ppm.

6. The glass sheet according to claim 1 , wherein the glass sheet is free of CeO 2 .

7. The glass sheet according to claim 1 , wherein the glass sheet is free of boron, lithium, strontium, and cobalt.

8. The glass sheet according to claim 1 , wherein A is equal to 0.6.

9. The glass sheet according to claim 8 , wherein A is equal to 0.9.

10. The glass sheet according to claim 1 , wherein the composition comprises:

a Cr 2 O 3 /Fe 2 O 3 ratio≤0.5;

an Se/Fe 2 O 3 ratio≤2;

a CuO/Fe 2 O 3 ratio≤1.2;

a CeO 2 /Fe 2 O 3 ratio≤20; and —an MnO/Fe 2 O 3 ratio≤40.

11. The glass sheet according to claim 10 , wherein the composition comprises:

a Cr 2 O 3 /Fe 2 O 3 ratio≤0.25;

an Se/Fe 2 O 3 ratio≤1;

a CuO/Fe 2 O 3 ratio≤0.6;

a CeO 2 /Fe 2 O 3 ratio≤10; and —an MnO/Fe 2 O 3 ratio≤20.

12. The glass sheet according to claim 1 , wherein the composition is according to the formula:

[2*(Cr 2 O 3 /Fe 2 O 3 )+0.5*(Se/Fe 2 O 3 )+0.83*(CuO/Fe 2 O 3 )+0.05*(CeO 2 /Fe 2 O 3 )+0.025*(MnO/Fe 2 O 3 )+0.05*(Sb 2 O 3 /Fe 2 O 3 )]≤B;

B being equal to 2.

13. The glass sheet according to claim 1 that has an absorption coefficient at a wavelength of 850 nm lower than 5 m −1 .

14. A touch screen or touch panel or touch pad, comprising at least one glass sheet according to claim 1 defining a touch surface.

15. The touch screen or touch panel or touch pad according to claim 14 that uses FTIR or PSD optical technology.

16. A device comprising the glass sheet according to claim 1 that employs infrared radiation propagating essentially inside said sheet.

17. The device according to claim 16 , wherein the infrared radiation propagates by total internal reflection.

18. A glass sheet having a composition that comprises, in an amount expressed in percentages by total weight of glass:

SiO 2

  55-85%

Al 2 O 3

   0-30%

B 2 O 3

   0-20%

Na 2 O

   0-25%

CaO

   0-20%

MgO

   0-15%

K 2 O

   0-20%

BaO

   0-20%

Total iron (expressed in Fe 2 O 3 form)

0.002-0.04%;

said composition furthermore comprising at least two components from chromium, selenium, copper, cerium, manganese and antimony; the chromium (expressed in Cr 2 O 3 form) being in a maximum content of 0.02% by weight; the selenium (expressed in Se form) being in a maximum content of 0.08% by weight; the copper (expressed in CuO form) being in a maximum content of 0.04% by weight; the cerium (expressed in CeO 2 form) being in a maximum content of 0.8% by weight; the manganese (expressed in MnO form) being in a maximum content of 1.6% by weight; the antimony (expressed in Sb 2 O 3 form) being in a maximum content of 0.8% by weight;

wherein the composition is according to the formula:

[2*(Cr 2 O 3 /Fe 2 O 3 )+0.5*(Se/Fe 2 O 3 )+0.83*(CuO/Fe 2 O 3 )+0.05*(CeO 2 /Fe 2 O 3 )+0.025*(MnO/Fe 2 O 3 )+0.05*(Sb 2 O 3 /Fe 2 O 3 )]≤B;

B being equal to 0.25.

19. A glass sheet having a composition that comprises, in an amount expressed in percentages by total weight of glass:

SiO 2

  55-85%

Al 2 O 3

   0-30%

B 2 O 3

   0-20%

Na 2 O

   0-25%

CaO

   0-20%

MgO

   0-15%

K 2 O

   0-20%

BaO

   0-20%

Total iron (expressed in Fe 2 O 3 form)

0.002-0.04%;

said composition furthermore comprising at least two components from chromium, selenium, copper, and manganese; the chromium (expressed in Cr 2 O 3 form) being in a maximum content of 0.02% by weight; the selenium (expressed in Se form) being in a maximum content of 0.08% by weight; the copper (expressed in CuO form) being in a maximum content of 0.04% by weight; the manganese (expressed in MnO form) being in a maximum content of 1.6% by weight;

wherein the composition is zinc-free, and Sb 2 O 3 and CeO 2 are not present.

20. The glass sheet according to claim 19 that has an absorption coefficient at a wavelength of 1050 nm lower than 5 m −1 .