UV-radiation absorbing glass with reduced absorption of visible light and methods of making and using same
View Patent ↗The method for making UV-absorbing glass, which transmits in a visible range, includes melting raw materials to form a melt and producing the melt under oxidative conditions. The UV-absorbing glass is free of PbO and has the following composition (in % by weight): SiO 2 , 55-79; B 2 O 3 , 3-25; Al 2 O 3 , 0-10; Li 2 O, 0-10; Na 2 O, 0-10; K 2 O, 0-10; MgO, 0-2; CaO, 0-3; SrO, 0-3; BaO, 0-3; ZnO, 0-3; ZrO 2 , 0-3; CeO 2 , 0-1; Fe 2 O 3 , 0-1; WO 3 , 0-3; Bi 2 O 3 , 0-3; MoO 3 , 0-3; with Σ Li 2 O+Na 2 O+K 2 O=0.5 to 16 and Σ MgO+CaO+SrO+BaO+ZnO=0-10. The melt composition is characterized by including 0.1 to 10 % TiO 2 and from 0.01-10 % As 2 O 3 . The glass made by the method and its properties are also disclosed. The glass is useful in lamps, LCD displays, monitors and glass-to-metal seals with molybdenum, tungsten and Fe—Co—Ni alloys.
1. A method of making a UV-absorbing glass, which transmits in a visible range, said method comprising melting raw materials to form a melt and producing said melt under oxidative conditions,
wherein said melt is free of PbO and has the following composition:
SiO 2
55-79%
by weight
B 2 O 3
3-25%
by weight
Al 2 O 3
0-10%
by weight
Li 2 O
0-10%
by weight
Na 2 O
0-5%
by weight
K 2 O
0-10%
by weight,
Wherein Σ Li 2 O + Na 2 O + K 2 O
0.5-16%
by weight,
MgO
0-2%
by weight
CaO
0-3%
by weight
SrO
0-3%
by weight
BaO
0-3%
by weight
ZnO
0-3%
by weight,
Wherein Σ MgO + CaO + SrO +
0-10%
by weight,
BeO + ZnO
ZrO 2
0-3%
by weight
CeO 2
0-1%
by weight
Fe 2 O 3
0-1%
by weight
WO 3
0-3%
by weight
Bi 2 O 3
0-3%
by weight
MoO 3
0-3%
by weight
TiO 2
0.1-10%
by weight
As 2 O 3
0.01-2%
by weight.
2. The method as defined in claim 1 , wherein said melt contains at least 50 ppm Fe 2 O 3 .
3. The method as defined in claim 1 , wherein said SiO 2 and/or said raw material contains greater than 100 ppm Fe 2 O 3 .
4. The method as defined in claim 1 , wherein said oxidative conditions are produced by addition of alkali nitrates and/or alkaline earth nitrates.
5. The method as defined in claim 1 , wherein said raw material contains up to a maximum of 6 percent by weight of alkali nitrates and/or alkaline earth nitrates in order to produce said oxidative conditions.
6. The method as defined in claim 1 , wherein said melt contains up to a maximum of 100 ppm chloride.
7. The method as defined in claim 1 , wherein said melt contains from 0.01 to 1 percent by weight of said As 2 O 3 as refining agent.
8. A UV-radiation absorbing glass with minimal absorption in the visible range, said UV-radiation absorbing glass being free of PbO and having the following composition:
SiO 2
55-79%
by weight
B 2 O 3
3-25%
by weight
Al 2 O 3
0-10%
by weight
Li 2 O
0-10%
by weight
Na 2 O
0-5%
by weight
K 2 O
0-10%
by weight,
wherein Σ Li 2 O + Na 2 O + K 2 O
0.5-16%
by weight,
MgO
0-2%
by weight
CaO
0-3%
by weight
SrO
0-3%
by weight
BaO
0-3%
by weight
ZnO
0-3%
by weight,
wherein Σ MgO + CaO + SrO + BaO + ZnO
0-10%
by weight,
ZrO 2
0-3%
by weight
CeO 2
0-1%
by weight
Fe 2 O 3
0-1%
by weight
WO 3
0-3%
by weight
Bi 2 O 3
0-3%
by weight
MoO 3
0-3%
by weight
TiO 2
0.1-10%
by weight
As 2 O 3
0.01-2%
by weight;
wherein 95% of any titanium present is in a +4 oxidation state.
9. The UV-radiation absorbing glass as defined in claim 8 , containing at least 50 ppm Fe 2 O 3 .
10. The UV-radiation absorbing glass as defined in claim 8 , containing from 55 to 79% by weight of said SiO 2 , from 10 to 25% by weight of said B 2 O 3 , from 0.5 to 10 percent by weight of said Al 2 O 3 , from 0.1 to 1% by weight of said As 2 O 3 and from 1 to 16% by weight of said Σ Li 2 O+Na 2 O+K 2 O.
11. The UV-radiation absorbing glass as defined in claim 8 , containing from 62 to 69% by weight of said SiO 2 , from 18 to 20% by weight of said B 2 O 3 , from 2 to 3 percent by weight of said Al 2 O 3 , from 0.2 to 1% by weight of said Li 2 O, from 0.2 to 1.5% by weight of said Na 2 O, from 6 to 8% by weight of said K 2 O, from 0.2 to 1% by weight of said ZnO, from 0.1 to 10 percent by weight of said TiO 2 and from 0.01 to 1 percent by weight of said As 2 O 3 .
12. The UV-radiation absorbing glass as defined in claim 8 , containing from 69 to 75% by weight of said SiO 2 , from 15 to 18% by weight of said B 2 O 3 , from 0.5 to 2 percent by weight of said Al 2 O 3 , from 0 to 0.5% by weight of said Li 2 O, from 3 to 5% by weight of said Na 2 O, from 0.5 to 3% by weight of said K 2 O, from 0 to 1% by weight of said ZnO, from 0.1 to 10 percent by weight of said TiO 2 and from 0.01 to 1 percent by weight of said As 2 O 3 .
13. The UV-radiation absorbing glass as defined in claim 8 , further comprising up to a maximum of 0.01 percent by weight of at least one metal oxide selected from the group consisting of PdO, PtO 3 , PtO 2 , PtO, RhO 2 , Rh 2 O 3 , IrO 2 and Ir 2 O 3 .
14. A glass-to-metal seal comprising an UV-absorbing glass and at least one metal component made of at least one metal, said at least one metal being selected from the group consisting of molybdenum, tungsten and iron-cobalt-nickel alloys, and wherein said UV-absorbing glass is defined in claim 8 .
15. A lighting device comprising UV-absorbing glass, said UV-absorbing glass being free of PbO and having a composition comprising:
SiO 2
55-79%
by weight
B 2 O 3
3-25%
by weight
Al 2 O 3
0-10%
by weight
Li 2 O
0-10%
by weight
Na 2 O
0-10%
by weight
K 2 O
0-10%
by weight,
wherein Σ Li 2 O + Na 2 O + K 2 O
0.5-16%
by weight,
MgO
0-2%
by weight
CaO
0-3%
by weight
SrO
0-3%
by weight
BaO
0-3%
by weight
ZnO
0-3%
by weight,
wherein Σ MgO + CaO + SrO + BaO + ZnO
0-10%
by weight,
ZrO 2
0-3%
by weight
CeO 2
0-1%
by weight
Fe 2 O 3
0-1%
by weight
WO 3
0-3%
by weight
Bi 2 O 3
0-3%
by weight
MoO 3
0-3%
by weight
TiO 2
0.1-10%
by weight
As 2 O 3
0.01-1%
by weight;
wherein 95% of any titanium present is in a +4 oxidation state.
16. The lighting device as defined in claim 15 , consisting of a gas discharge lamp, fluorescence lamp or a Xenon lamp.
17. A display device comprising UV-absorbing glass, said UV-absorbing glass being free of PbO and having a composition comprising:
SiO 2
55-79%
by weight
B 2 O 3
3-25%
by weight
Al 2 O 3
0-10%
by weight
Li 2 O
0-10%
by weight
Na 2 O
0-10%
by weight
K 2 O
0-10%
by weight,
wherein Σ Li 2 O + Na 2 O + K 2 O
0.5-16%
by weight,
MgO
0-2%
by weight
CaO
0-3%
by weight
SrO
0-3%
by weight
BaO
0-3%
by weight
ZnO
0-3%
by weight,
wherein Σ MgO + CaO + SrO + BaO + ZnO
0-10%
by weight,
ZrO 2
0-3%
by weight
CeO 2
0-1%
by weight
Fe 2 O 3
0-1%
by weight
WO 3
0-3%
by weight
Bi 2 O 3
0-3%
by weight
MoO 3
0-3%
by weight
TiO 2
0.1-10%
by weight
As 2 O 3
0.01-1%
by weight;
wherein 95% of any titanium present is in a +4 oxidation state.
18. The display device as defined in claim 17 , consisting of a computer monitor, a telephone display or a liquid crystal display.
19. A UV-radiation absorbing glass with minimal absorption in the visible range and with a composition consisting of:
SiO 2
55-79%
by weight
B 2 O 3
3-25%
by weight
A1 2 O 3
0-10%
by weight
Li 2 O
0-10%
by weight
Na 2 O
0-5%
by weight
K 2 O
0-10 %
by weight,
wherein Σ Li 2 O + Na 2 O + K 2 O
0.5-16%
by weight,
MgO
0-2%
by weight
CaO
0-3%
by weight
SrO
0-3%
by weight
BaO
0-3%
by weight
ZnO
0-3%
by weight,
wherein Σ MgO + CaO + SrO + BaO + ZnO
0-10%
by weight,
ZrO 2
0-3%
by weight
CeO 2
0-1%
by weight
Fe 2 O 3
0-1%
by weight
WO 3
0-3%
by weight
Bi 2 O 3
0-3%
by weight
MoO 3
0-3%
by weight
TiO 2
0.1-10%
by weight
As 2 O 3
0.01-2%
by weight
Fe 2 O 3
0 to 1500
ppm
at least one metal oxide selected from the
0 to 0.1%
by weight;
group consisting of PdO, PtO 2 , PtO 3 , PtO,
RhO 2 , Rh 2 O 3 , IrO 2 and Ir 2 O 3
wherein 95% of any titanium present is in a +4 oxidation state.
20. The UV-radiation absorbing glass as defined in claim 19 , wherein said Fe 2 O 3 is present in an amount of at least 100 ppm and said TiO 2 is present in an amount of from 0.5-10 percent by weight.
21. The UV-radiation absorbing glass as defined in claim 19 , wherein said at least one metal oxide selected from the group consisting of PdO, PtO 3 , PtO 2 , PtO, RhO 2 , Rh 2 O 3 , IrO 2 and Ir 2 O 3 is present in an amount of from 0.1 ppm to 0.1% by weight. ;