Glass and use of a glass for glass-metal bonds
The glass of the glass-metal bond contains the following ingredients in the following amounts: SiO 2 , 72-80 wt %; B 2 O 3 , 4-<6 wt %; Al 2 O 3 , 2-5 wt %; Na 2 O, 4-7 wt %; K 2 O, 0-3 wt %; CaO, 2.5-8 wt %; MgO, 0-2 wt %; BaO, 0-4 wt %; TiO 2 , 0-5 wt %; CeO 2 , 0-2 wt %; Fe 2 O 3 , 0-0.1 wt %; F, 0-2 wt %; and the ratio of the sum total amount of Al 2 O 3 and B 2 O 3 (in mol %) to the sum total amount of MgO, CaO and BaO (in mol %) in the glass is less than 5. The glass-metal bond advantageously includes a KOVAR® alloy and the glass of the aforesaid composition and connects the glass envelope tube with an inner metal absorber tube in a tube collector.
1. A glass-metal bond comprising a metal or metal alloy and a glass tube bonded to the metal or to the metal alloy, wherein said glass tube consists of a glass containing the following ingredients in the following amounts:
SiO 2
72-80
wt %
B 2 O 3
4-<6
wt %
Al 2 O 3
2-5
wt %
Na 2 O
4-7
wt %
K 2 O
0-3
wt %
CaO
2.5-8
wt %
MgO
0-2
wt %
BaO
0-4
wt %
TiO 2
0-5
wt %
CeO 2
0-2
wt %
Fe 2 O 3
0-0.1
wt %
F
0-2
wt %; and
wherein a ratio of a sum total amount of Al 2 O 3 and B 2 O 3 in mol % to a sum total amount of MgO, CaO and BaO in mol % in the glass is less than 5.
2. The glass-metal bond according to claim 1 , wherein a sum total amount of CaO, MgO, BaO, SrO and ZnO in said glass is >3 wt %.
3. The glass-metal bond according to claim 1 , wherein said glass contains the following ingredients in the following amounts:
SiO 2
75-80
wt %
B 2 O 3
4.5-<6
wt %
Al 2 O 3
2-4.5
wt %
Na 2 O
5.5-7
wt %
K 2 O
0-2
wt %
CaO
>2.5-8
wt %
MgO
0-2
wt %
TiO 2
0-5
wt %
CeO 2
0-2
wt %
Fe 2 O 3
0-0.1
wt %
F
0-2
wt %.
4. The glass-metal bond according to claim 1 , wherein the glass contains 50-200 ppm Fe 2 O 3 .
5. The glass-metal bond according to claim 1 , wherein the glass contains 100-150 ppm Fe 2 O 3 .
6. The glass-metal bond according to claim 1 , wherein the glass consists of the said ingredients.
7. The glass-metal bond according to claim 1 , wherein the glass is bonded to the metal alloy and the metal alloy has the following ingredients in the following amounts: Ni, 28-30 wt %; Co, 16-18 wt %; C, up to 0.05 wt %; and Fe, remaining balance.
8. A glass containing the following ingredients in the following amounts:
SiO 2
72-80
wt %
B 2 O 3
4-<6
wt %
Al 2 O 3
2-5
wt %
Na 2 O
4-7
wt %
K 2 O
0-3
wt %
CaO
2.5-8
wt %
MgO
0-2
wt %
BaO
0-4
wt %
TiO 2
0-5
wt %
CeO 2
0-2
wt %
Fe 2 O 3
0-0.1
wt %
F
0-2
wt %;
wherein a ratio of a sum total amount of Al 2 O 3 and B 2 O 3 in mol % to a sum total amount of MgO, CaO and BaO in mol % is less than 5.
9. The glass according to claim 8 , wherein a sum total amount of CaO, MgO, BaO, SrO and ZnO is >3 wt %.
10. The glass according to claim 8 , containing the following ingredients in the following amounts:
SiO 2
75-80
wt %
B 2 O 3
4.5-<6
wt %
Al 2 O 3
2-4.5
wt %
Na 2 O
5.5-7
wt %
K 2 O
0-2
wt %
CaO
>2.5-8
wt %
MgO
0-2
wt %
TiO 2
0-5
wt %
CeO 2
0-2
wt %
Fe 2 O 3
0-0.1
wt %
F
0-2
wt %.
11. The glass according to claim 8 , containing 50-200 ppm Fe 2 O 3 .
12. The glass according to claim 8 , containing 100-150 ppm Fe 2 O 3 .
13. A cover glass in a photovoltaic product, wherein said cover glass has a composition according to claim 8 .
14. A substrate glass in a photovoltaic product, wherein said substrate glass has a composition according to claim 8 .
15. A superstrate glass in a photovoltaic product, wherein said superstrate glass has a composition according to claim 8 .