Filter gas
The invention relates to a filter glass comprising Na 2 O and K 2 O and the following (in % by weight on an oxide basis): P 2 O 5 58-68 Al 2 O 3 5-10 CuO 8-15 V 2 O 5 0.05-1 SiO 2 <2 F <1 Total R′O (R′ = Mg, Ca, Sr, Ba) 0-11 Total R 2 O (R = Li, Na, K) 3-17.
1. Filter glass comprising Na 2 O and K 2 O and the following (in % by weight on an oxide basis):
P 2 O 5
58-68
Al 2 O 3
5-10
CuO
8-15
V 2 O 5
0.05-1
SiO 2
<2
F
<1
Total R′O (R′ = Mg, Ca, Sr, Ba)
0-11
Total R 2 O (R = Li, Na, K)
3-17
wherein a ratio of K 2 O (in % by weight)/Na 2 O (in % by weight) is >1.
2. Filter glass according to claim 1 , wherein the filter glass contains K 2 O in an amount of from 3 to 10% by weight and Na 2 O in an amount of from 0.1 to 8% by weight.
3. Filter glass according to claim 1 , wherein the total R 2 O is at least 4% by weight and at most 15% by weight.
4. Filter glass according to claim 1 , wherein the ratio of K 2 O (in % by weight)/Na 2 O (in % by weight) is >1.1.
5. Filter glass according to claim 1 , wherein the filter glass contains MgO in an amount of at most 5% by weight and the total proportion of R′O is at least 1% by weight.
6. Filter glass according to claim 1 , wherein the content of CuO is at least 9% by weight and at most 14% by weight.
7. Filter glass according to claim 1 , wherein the content of CuO is at least 10% by weight and at most 13% by weight.
8. Filter glass according to claim 1 , wherein V 2 O 5 is present in an amount of at least 0.2% by weight.
9. Filter glass according to claim 1 , wherein V 2 O 5 is present in an amount of at least 0.5% by weight and at most 0.75% by weight.
10. Filter glass according to claim 1 , wherein the filter glass further comprises La 2 O 3 at a content of at least 0.5% by weight and at most 3.5% by weight.
11. Filter glass according to claim 1 , wherein the glass is free of one or more components selected from the group consisting of B 2 O 3 , SiO 2 , CaO, BaO, SrO, ZnO, ZrO 2 , Nb 2 O 5 , Y 2 O 3 , Yb 2 O 3 , Gd 2 O 3 , WO 3 , Fe 2 O 3 , PbO, CoO, Cr, Mn, Ni, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm.
12. Filter glass according to claim 1 , wherein the glass has, at a sample thickness of 0.11 mm, an internal transmission τ i at a wavelength of 400 nm of more than 85%.
13. Filter glass according to claim 1 , wherein the filter glass has a coefficient of thermal expansion (α 20-300 ) of at least 9.5×10 −6 /K and at most 13×10 −6 /K.
14. Filter glass according to claim 1 , wherein the filter glass has a transformation temperature of more than 400° C.
15. Filter comprising a filter glass, the filter glass comprising Na 2 O and K 2 O and the following (in % by weight on an oxide basis):
P 2 O 5
58-68
Al 2 O 3
5-10
CuO
8-15
V 2 O 5
0.05-1
SiO 2
<2
F
<1
Total R′O (R′ = Mg, Ca, Sr, Ba)
0-11
Total R 2 O (R = Li, Na, K)
3-17
wherein a ratio of K 2 O (in % by weight)/Na 2 O (in % by weight) is >1.
16. Filter according to claim 15 , wherein the filter glass has a coating on at least one of its surfaces.
17. Filter glass according to claim 1 , wherein the ratio of K 2 O (in % by weight)/Na 2 O (in % by weight) is <2.
18. Filter glass according to claim 1 , wherein the glass has, at a sample thickness of 0.11 mm, an internal transmission τ i at a wavelength of 400 nm of at least 87.5%.
19. Filter glass having, at a sample thickness of 0.11 mm, an internal transmission τ i at a wavelength of 400 nm of more than 85%, and a T 50 value in the range 625 nm to 640 nm, wherein the filter glass is a vanadium oxide containing phosphate-glass comprising CuO at a content of 8-15% by weight and comprising La 2 O 3 at a content of 0.1-4% by weight.
20. Filter glass having, at a sample thickness of 0.11 mm, an internal transmission τ i at a wavelength of 400 nm of more than 85%, and a T 50 value in the range 625 nm to 640 nm, wherein the filter glass is a vanadium oxide containing phosphate-glass comprising CuO at a content of 8-15% by weight, wherein a ratio of K 2 O (in % by weight)/Na 2 O (in % by weight) is >1.
21. Filter glass according to claim 19 , comprising Na 2 O and K 2 O and the following (in % by weight on an oxide basis):
P 2 O 5
58-68
Al 2 O 3
5-10
V 2 O 5
0.05-1
SiO 2
<2
F
<1
Total R′O (R′ = Mg, Ca, Sr, Ba)
0-11
Total R 2 O (R = Li, Na, K)
3-17.
22. Filter glass according to claim 20 , comprising Na 2 O and K 2 O and the following (in % by weight on an oxide basis):
P 2 O 5
58-68
Al 2 O 3
5-10
V 2 O 5
0.05-1
SiO 2
<2
F
<1
Total R′O (R′ = Mg, Ca, Sr, Ba)
0-11
Total R 2 O (R = Li, Na, K)
3-17.
23. Filter glass according to claim 22 , further comprising La 2 O 3 at a content of 0.1-4% by weight.
24. Filter glass according to claim 19 , wherein the content of V 2 O 5 is in the range 0.05-1% by weight.
25. Filter glass according to claim 20 , wherein the content of V 2 O 5 is in the range 0.05-1% by weight.