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US5045509A
Expired / Lapsed
US
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UV-transparent glass
Assignee: Schott AG
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Filing: 1989-01-19
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Granted: 1991-09-03
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Expires: 2009-01-19
Abstract
Abstract The invention relates to a glass which is transparent to UV radiation and which, for a thickness of 1 mm and the wavelength of 253.7 nm has a transmission of at least 75%, a linear coefficient of thermal expansion of 3.8x10-6 to 4.5x10-6K-1 in the temperature range from 20 DEG to 300 DEG C. and a hydrolytic resistance of <120 mu g of Na2O/g according to DIN 12 111. The new glass has the synthesis composition, calculated on an oxide basis, of -SiO2 64 to 66.5 percent by weight -B2O3 20 to 22.5 percent by weight -Al2O3 4 to 6 percent by weight -Li2O 0.4 to 1 percent by weight -Na2O 1.0 to 3.5 percent by weight -K2O 1.0 to 2.5 percent by weight -CaO 0.35 to 0.8 percent by weight -BaO 0.5 to 2.0 percent by weight -F- 0.5 to 2.0 percent by weight - SIGMA Li2O + Na2O + K2O 3.8 to 5.5 percent by weight - SIGMA CaO + BaO 1.0 to 2.5 percent by weight -one or more 0.2 to 2.0 percent by weight -non-oxidizing -refining agents -one or more 0.05 to 0.3 percent weight. -reducing agents -
Inventors
- 👤 Werner Kiefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:01
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C4/00; C03C4/0085; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/905
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
155 words
A glass transparent to UV radiation, which, for a thickness of 1 mm and the wavelength of 253.7 nm, has a transmission of at least 75%, a linear coefficient of thermal expansion of 3.8×10 -6 to 4.5×10 -6 K -1 in the temperature range from 20° to 300° C., and a hydrolytic resistance of <120 μg of Na 2 O/g according to DIN 12 111, and having a synthesis composition, calculated on an oxide basis, of ______________________________________
SiO.sub.2 64 to 66.5
B.sub.2 O.sub.3 20 to 22.5
Al.sub.2 O.sub.3 4 to 6
Li.sub.2 O 0.4 to 1
Na.sub.2 O 1.0 to 3.5
K.sub.2 O 1.0 to 2.5
CaO 0.3 to 0.8
BaO 0.5 to 2.0
F.sup.- 0.5 to 2.0
Σ Li.sub.2 O + Na.sub.2 O + K.sub.2 O
3.8 to 5.5
Σ CaO + BaO 1.0 to 2.5
one or more 0.2 to 2.0
non-oxidizing
refining agents
one or more 0.05 to 0.3.
reducing agents
______________________________________
Claim 2
Dependent Claim
155 words
A glass transparent to UV radiation, which, for a thickness of 1 mm and the wavelength of 253.7 nm, has a transmission of at least 75%, a linear coefficient of thermal expansion of 3.8×10 -6 to 4.5×10 -6 K -1 in the temperature range from 20° to 300° C., and a hydrolytic resistance of <120 μg of Na 2 O/g according to DIN 12 111, and having a synthesis composition, calculated on an oxide basis, of ______________________________________
SiO.sub.2 64 to 66.5
B.sub.2 O.sub.3 20 to 22.5
Al.sub.2 O.sub.3 4 to 6
Li.sub.2 O 0.4 to 1
Na.sub.2 O 1.0 to 3.5
K.sub.2 O 1.0 to 2.5
CaO 0.3 to 0.8
BaO 0.5 to 2.0
F.sup.- 0.5 to 2.0
Σ Li.sub.2 O + Na.sub.2 O + K.sub.2 O
3.8 to 5.5
Σ CaO + BaO 1.0 to 2.5
one or more 0.2 to 2.0
non-oxidizing
refining agents
one or more 0.05 to 0.3.
reducing agents
______________________________________
Claim 3
Dependent Claim
12 words
A UV-transparent glass of claim 1, wherein NaCl is the refining agent.
Claim 4
Dependent Claim
12 words
A UV-transparent glass of claim 1, wherein sugar is the reducing agent.
Claim 5
Dependent Claim
13 words
A UV-transparent glass of claim 1, wherein aluminum powder is the reducing agent.
Claim 6
Dependent Claim
11 words
A UV-transparent glass of claim 1, which is essentially Fe free.
Claim 7
Dependent Claim
12 words
A UV-transparent glass of claim 1, which is essentially Fe +3 free.
Claim 8
Dependent Claim
11 words
A UV-transparent glass of claim 1, which is oxidizing agent free.
Claim 9
Dependent Claim
20 words
In an EP-ROM comprising a window of highly UV-transparent glass, the improvement wherein said glass is one of claim 1.
Claim 10
Dependent Claim
16 words
An EP-ROM of claim 8 wherein said window is sealed to Al 2 O 3 .
Claim 11
Dependent Claim
22 words
In a UV-transparent lamp comprising a UV-transparent glass sealed to a metal, the improvement wherein said glass is one of claim 1.
Claim 12
Dependent Claim
10 words
A lamp of claim 10, wherein said metal is tungsten.
Claim 13
Dependent Claim
30 words
In a UV-transparent glass to metallic element seal, the improvement wherein the glass is one of claim 1 and the metallic element is tungsten or Al 2 O 3 .
Claim 14
Dependent Claim
28 words
A UV transparent glass of claim 1, wherein for a thickness of 1 mm and the wavelength of 253.7 nm, the transmission falls within the range of 85-87%.
Claim 15
Dependent Claim
25 words
A UV transparent glass of claim 1, wherein for a thickness of 1 mm and the wavelength of 253.7, the transmission is greater than 83%.
Claim 16
Dependent Claim
20 words
A UV-transparent glass to Al 2 O 3 pressurized glazing, the improvement wherein the glass is one of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |