Boron aluminosilicate glass
View Patent ↗A short optical glass is disclosed which is particularly suited for the applications imaging, projection, telecommunication, optical information technology and/or laser technology, also particularly suited for fiber applications (light guides or imaging guides). Preferably, the glass has a refractive index of 1.54≦n d ≦1.62 and an Abbe coefficient of 48≦v d =57. It further has good attenuating and ion exchange characteristics, good chemical stability and good crystallization stability. The glass comprises 35 to 50 wt.-% SiO 2 , 0.1 to 6 wt.-% B 2 O 3 , 0.1 to 7 wt.-% Al 2 O 3 , 0.1 to 4 wt.-% P 2 O 5 , 4 to 24 wt.-% R 2 O (alkali oxides), 6 to 14.5 wt.-% BaO, 0 to 12 wt.-% other RO (alkaline earth oxides), 14 to 25 wt.-% ZnO, 0 to 5 wt.-% La 2 O 3 , 0 to 10 wt.-% ZrO 2 , wherein R 2 O is an alkali oxide, RO is an alkaline earth oxide other than BaO, wherein Li 2 O is 6 wt.-% at the most, wherein the glass does not contain any GeO 2 , SnO, SnO 2 , AgO, Sb 2 O 3 and, preferably, no rare earth oxides, and wherein the glass may be molten while adding suitable purifying agents.
1. A boron aluminosilicate glass comprising at least the following components (in wt.-%):
SiO 2
40 to 47
B 2 O 3
0.1 to 6
Al 2 O 3
0.1 to 4
P 2 O 5
0.1 to 4
Li 2 O
0 to 2
Na 2 O
2 to 7
K 2 O
>6.5 to 11
MgO
0 to 5
CaO
0. to 6
BaO
6 to 14
ZnO
20 to 25
La 2 O 3
0 to 1.5
ZrO 2
1 to 7.
wherein said glass is free of lead, and
wherein said glass is an optical glass.
2. The boron aluminosilicate of claim 1 comprising (in wt.-%):
SiO 2
42 to 47
B 2 O 3
0.1 to 5
Al 2 O 3
0.1 to 2
P 2 O 5
0.5 to 3
Na 2 O
3 to 6
K 2 O
>6.5 to 10
CaO
1 to 5
BaO
6 to 12
ZnO
20 to 25
ZrO 2
3 to 7,
to 1 wt-% of refining agents.
3. The boron aluminosilicate glass of claim 1 , wherein said glass is an optical glass having a retractive index n d between 1.54 and 1.62.
4. The boron aluminosilicate glass of claim 1 , wherein said glass is an optical glass having an Abbe number between 48 and 57.
5. The boron aluminosilicate glass of claim 1 , wherein said glass is an optical glass having a refractive index n d between 1.54 and 1.62 and an Abbe number between 48 and 57.
6. A boron aluminosilicate glass comprising at least the following components (in wt.-%):
SiO 2
38 to 45
B 2 O 3
0.1 to 6
Al 2 O 3
0.1 to 4
P 2 O 5
0.1 to 4
Li 2 O
>2 to 6
Na 2 O
2 to 7
K 2 O
2 to 6.5
MgO
0 to 5
CaO
0.5 to 6.5
BaO
6 to 14.5
ZnO
14 to <20
La 2 O 3
>1.5 to 5
ZrO 2
1 to 7;
wherein said glass is an optical glass that is free of lead.
7. The boron aluminosilicate of claim 6 , comprising the following components (in wt.-%):
SiO 2
38 to 43
B 2 O 3
0.1 to 5
Al 2 O 3
0.5 to 3
P 2 O 5
0.5 to 3
Li 2 O
>2 to 6
Na 2 O
3 to 6
K 2 O
3 to 6.5
CaO
2 to 6.5
BaO
8 to 14.5
ZnO
14 to 19
La 2 O 3
>1.5 to 3
ZrO 2
2 to 5,
up to 1 wt,-% of refining agents.
8. A boron aluminosilicate glass comprising (in wt.-%):
SiO 2
35 to 50
B 2 O 3
0.1 to 7
Al 2 O 3
0.1 to 7
P 2 O 5
0.1 to 4
R 2 O
4 to 24
RO
0 to 12
BaO
6 to 14.5
ZnO
14 to 25
La 2 O 3
0 to 5
ZrO 2
0 to 10,
wherein R 2 O is an alkali oxide, RO is an alkaline earth oxide apart from BaO, wherein the amount of Li 2 O is 6 wt.-% maximum and wherein the glass, apart any unintended contaminants, does not contain any GeO 2 , SnO 2 , AgO or any rare earth metals and wherein said glass is an optical glass that is free of lead.
9. The boron aluminosilicate of claim 8 which comprises up to 1 wt.-% of refining agents.
10. The boron aluminosilicate glass of claim 9 wherein said refining agents comprise at least one component selected from the group formed by Sb 2 O 3 , As 2 O 3 , SnO, NaCl, So 4 2− and F − .
11. The boron aluminosilicate glass of claim 10 , wherein the portion of RO in the total weight is smaller than the portion of BaO.
12. The boron aluminosilicate glass of claim 8 comprising (in wt.-%):
SiO 2
35 to 50
B 2 O 3
0.1 to 7
Al 2 O 3
0.1 to 7
P 2 O 5
0.1 to 4
Li 2 O
0 to 6
Na 2 O
2 to 7
K 2 O
2 to 11
MgO
0 to 5
CaO
0.5 to 6.5
BaO
6 to 14.5
ZnO
14 to 25
La 2 O 3
0 to 5
ZrO 2
1 to 10
refining agents in common amounts.
13. The boron aluminosilicate glass of claim 8 , comprising at least the following components (in wt.-%):
SiO 2
38 to 47
B 2 O 3
0.1 to 6
Al 2 O 3
0.1 to 4
P 2 O 5
0.1 to 4
Li 2 O
0 to 6
Na 2 O
2 to 7
K 2 O
2 to 11
MgO
0 to 5
CaO
0.5 to 6.5
BaO
6 to 14.5
ZnO
14 to 25
La 2 O 3
0 to 5
ZrO 2
1 to 7.
14. The boron aluminosilicate glass of claim 8 having a refractive index n d of 154≦n d ≦162.
15. The boron aluminosilicate glass of claim 8 having an Abbe number of 48≦v d ≦57.
16. A boron aluminosilicate glass comprising (in wt.-%):
SiO 2
35 to 50
B 2 O 3
0.1 to 7
Al 2 O 3
0.1 to 7
P 2 O 5
0.1 to 4
R 2 O
4 to 24
RO
0 to 12
BaO
6 to 14.5
ZnO
14 to 25
La 2 O 3
0 to 5
ZrO 2
0 to 10,
wherein R 2 O is an alkali oxide, RO is an alkaline earth oxide apart from BaO, wherein the amount Li 2 O is 6 wt.-% maximum,
wherein said glass is free or lead, and
wherein said glass is an optical class.
17. The boron aluminosilicate glass of claim 16 , wherein said glass comprises 4 to 12 wt.-% of K 2 O.
18. The boron aluminosilicate glass of claim 16 , wherein said glass is an optical glass having a refractive index n d between 1.54 and 1.62
19. The boron aluminosilicate class of claim 16 , wherein said glass is an optical glass having an Abbe number between 48 and 57.
20. The boron aluminosilicate glass of claim 16 , wherein said glass is an optical glass having a refractive index n d between 1.54 and 1.62 and an Abbe number between 48 and 57.
21. The boron aluminosilicate glass of claim 20 , wherein said class comprises 4 to 12 wt.-% of K 2 O.