Alkaline-earth aluminosilicate glass and use thereof
The invention relates to an alkaline-earth aluminosilicate glass with the following composition (in wt. %, based on oxide content): SiO 2 >58-62; B 2 O 3 0 5.5; Al 2 O 3 13.5 17.5; MgO 0-7; CaO 5.5-14; SrO 0-8, BaO 6-14; ZrO 2 0-2; CeO 2 0.001 0.5; TiO 2 0.01-2. The glass is particularly suitable for use as a bulb material for halogen light bulbs.
1. An alkaline-earth aluminosilicate glass substantially free of alkali metal oxides and having a composition (in % by weight, based on oxide) of
SiO 2
>58-62
B 2 O 3
0-5.5
Al 2 O 3
13.5-17.5
MgO
0-7
CaO
5.5-14
SrO
0-8
BaO
6-14
ZrO 2
0-2
CeO 2
0.001-0.5
TiO 2
0.01-2 .
2. The alkaline-earth aluminosilicate glass as claimed in claim 1 , having a composition (in % by weight, based on oxide) of
SiO 2
59-62
B 2 O 3
3-5.5
Al 2 O 3
13.5-15.5
MgO
2.5-5
CaO
8.2-10.5
BaO
8.5-9.5
ZrO 2
0-1
CeO 2
0.001-0.2
TiO 2
0.01-2 .
3. The alkaline-earth aluminosilicate glass as claimed in claim 1 , having a composition (in % by weight, based on oxide) of
SiO 2
>58-62
B 2 O 3
0-1
Al 2 O 3
14-17.5
MgO
0-6
CaO
5.5-14
SrO
0-8
BaO
6-14
ZrO 2
0-1
CeO 2
0.001-0.2
TiO 2
0.01-2 .
4. The alkaline-earth aluminosilicate glass as claimed in claim 1 , having a composition (in % by weight, based on oxide) of
SiO 2 >58-62
SiO 2
>58-62
B 2 O 3
0.2-0.7
Al 2 O 3
15-17.5
MgO
0-<1
CaO
5.5-14
SrO
0-8
BaO
6-10
ZrO 2
0.05-1
CeO 2
0.001-0.2
TiO 2
0.01-2 .
5. The alkaline-earth aluminosilicate glass as claimed in claim 1 , wherein the CeO 2 content is between 0.01% by weight and 0.2% by weight.
6. The alkaline-earth aluminosilicate glass as claimed in claim 1 , wherein the TiO 2 content is between 0.01 and 1% by weight.
7. The alkaline-earth aluminosilicate glass as claimed in claim 1 , wherein apart from inevitable impurities it is free of iron oxides.
8. The alkaline-earth aluminosilicate glass as claimed in claim 1 , having a spectral transmittance between λ=500 nm and λ=1500 nm of >0.9 mm for a specimen thickness of 1.0 mm.
9. The alkaline-earth aluminosilicate glass of claim 5 , wherein the CeO 2 content is 0.01-0.1% by weight.
10. The alkaline-earth aluminosilicate glass of claim 6 , wherein the TiO 2 content is 0.03-0.8% by weight.
11. The alkaline-earth aluminosilicate glass of claim 6 , wherein the TiO 2 content is 0.1-0.8% by weight.
12. The alkaline-earth aluminosilicate glass of claim 9 , wherein the TiO 2 content is 0.03-0.8% by weight.
13. The alkaline-earth aluminosilicate glass of claim 9 , wherein the TiO 2 content is 0.1-0.8% by weight.
14. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 1 .
15. In a method for manufacturing bulbs for halogen lamps, the improvement comprising forming said bulb from a molten composition according to claim 1 .
16. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 2 .
17. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 3 .
18. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 4 .
19. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 7 .
20. In a halogen lamp comprising a glass bulb, halogen gas, filaments and terminals, the improvement wherein the bulb has a composition according to claim 13 .