US4526874A
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Optical light weight glass with a refractive index of >1.70, an Abbe index of >22 and a density of <3.5 G/CM3
Assignee: Schott AG
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Filing: 1983-04-27
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Granted: 1985-07-02
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Expires: 2003-04-27
Abstract
Abstract An optical glass with the familiar optical position of n d >1.70 and v d >22, which differs from the familiar optical glasses of the optical position due to its lower density and good chemical stability, and is composed of (in percent by weight): SiO 2 25-42, TiO 2 15-35, B 2 O 3 0.5-7, BaO 3-13, CaO 1-3, Nb 2 O 5 1-20, GeO 2 0-2, Al 2 O 3 0-4, Na 2 O 7.5-15, Li 2 O 0-9, K 2 O 2-10, SrO 0-6, ZnO 0-5, ZrO 2 0-3, and WO 3 0-3.
Inventors
- 👤 Danuta Grabowski geb. Marszalek
- 👤 Ludwig Ross
- 👤 Volkmar Geiler
- 👤 Karl Mennemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:42
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C3/062; C03C3/064; C03C3/066; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/901; Y10S501/903
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
176 words
An optical glass having a refractive index of 1.74-1.79, an Abbe number of 25-29 and a density of 3.1-3.3 g/cm 3 , with crystallization stability sufficiently good to enable the glass to be produced in 100 liter crucible melts and chemical stability characterized by having an acid resistance of >100 hrs. for removal of 0.1 μm, from a polished layer with 0.5N HNO 3 and an alkali resistance of >120 hrs. for removal of 0.1 μm from a polished layer with NaOH at pH 10, containing not more than 1.5 percent by weight ionic fluorine and not more than 2 percent by weight SnO 2 , consisting essentially of the following composition, in percent by weight: ______________________________________
SiO.sub.2 3.0.-35
GeO.sub.2 .0.-1
B.sub.2 O.sub.3 .0..5-3
Al.sub.2 O.sub.3 .0.-2
Li.sub.2 O .0.-3
Na.sub.2 O 7.5-13
K.sub.2 O 4-6
total alkali metal oxides
12-18
MgO .0.-2
CaO 1-3
SrO .0.-2
BaO 7-13
ZnO .0.-2
total alkaline earth oxides
8-15
TiO.sub.2 2.0.-3.0.
ZrO.sub.2 .0.-3
Nb.sub.2 O.sub.5 7-19 and
WO.sub.3 .0..2-2,
______________________________________ wherein the SiO 2 :TiO 2 ratio is 1-1.75.
Claim 2
Dependent Claim
176 words
An optical glass having a refractive index of 1.74-1.79, an Abbe number of 25-29 and a density of 3.1-3.3 g/cm 3 , with crystallization stability sufficiently good to enable the glass to be produced in 100 liter crucible melts and chemical stability characterized by having an acid resistance of >100 hrs. for removal of 0.1 μm, from a polished layer with 0.5N HNO 3 and an alkali resistance of >120 hrs. for removal of 0.1 μm from a polished layer with NaOH at pH 10, containing not more than 1.5 percent by weight ionic fluorine and not more than 2 percent by weight SnO 2 , consisting essentially of the following composition, in percent by weight: ______________________________________
SiO.sub.2 3.0.-35
GeO.sub.2 .0.-1
B.sub.2 O.sub.3 .0..5-3
Al.sub.2 O.sub.3 .0.-2
Li.sub.2 O .0.-3
Na.sub.2 O 7.5-13
K.sub.2 O 4-6
total alkali metal oxides
12-18
MgO .0.-2
CaO 1-3
SrO .0.-2
BaO 7-13
ZnO .0.-2
total alkaline earth oxides
8-15
TiO.sub.2 2.0.-3.0.
ZrO.sub.2 .0.-3
Nb.sub.2 O.sub.5 7-19 and
WO.sub.3 .0..2-2,
______________________________________ wherein the SiO 2 :TiO 2 ratio is 1-1.75.
Claim 3
Dependent Claim
14 words
A glass according to claim 1 further comprising 0.5-5 percent by weight of PbO.
Claim 4
Dependent Claim
18 words
A glass according to claim 1 further comprising 1-3 percent by weight of La 2 O 3 .
Claim 5
Dependent Claim
18 words
A glass according to claim 1 further comprising 1-5 percent by weight of Y 2 O 3 .
Claim 6
Dependent Claim
38 words
A glass according to claim 1 further comprising 1-2 percent by weight of Bi 2 O 3 , 1-4 percent by weight of Gd 2 O 3 and 1-2 percent by weight of Ta 2 O 5 .
Claim 7
Dependent Claim
15 words
A glass according to claim 1 further containing 0.2-1.5 percent by weight of fluorine ions.
Claim 8
Dependent Claim
20 words
A glass according to claim 1 further containing 0.2-2 percent by weight of SnO 2 in order to increase transmission.
Claim 9
Dependent Claim
20 words
A glass according to claim 1 further containing not more than 2 percent by weight of other unnamed glass-forming oxides.
Claim 10
Dependent Claim
165 words
An optical glass having a refractive index of about 1.7455-1.7892, an Abbe number of about 25.54-28.76, a density of about 3.12-3.30 g/cm 3 , with crystallization stability sufficiently good to enable the glass to be produced in 100 liter crucible melts and chemical stability characterized by having an acid resistance of >100 hrs. for removal of 0.1 μm from a polished layer with 0.5N HNO 3 and an alkali resistance of >120 hrs. for removal of 0.1 μm from a polished layer with NaOH at pH 10, containing not more than 1.5 percent by weight ionic fluorine, consisting essentially of, in percent by weight: ______________________________________
SiO.sub.2 31.00-35.10
B.sub.2 O.sub.3 0.5-2.85
SnO.sub.2 0-1
NaF 0-1.00
Na.sub.2 O 7.88-12.00
K.sub.2 O 5.30-5.55
total alkali metal oxides
13.93-17.53
PbO 0-0.60
CaO 1.06-2.01
BaO 6.24-12.44
total alkaline earth oxides
7.90-14.21
TiO.sub.2 20.18-29.16
Nb.sub.2 O.sub.5 8.5-18.56
La.sub.2 O.sub.3 0-1.0
WO.sub.3 0.10-1.92
Y.sub.2 O.sub.3 0-1.0
Gd.sub.2 O.sub.3 0-1.0
As.sub.2 O.sub.3 0.10-0.20
______________________________________ wherein the SiO 2 :TiO 2 ratio is 1.13-1.74.
Claim 11
Dependent Claim
165 words
An optical glass having a refractive index of about 1.7455-1.7892, an Abbe number of about 25.54-28.76, a density of about 3.12-3.30 g/cm 3 , with crystallization stability sufficiently good to enable the glass to be produced in 100 liter crucible melts and chemical stability characterized by having an acid resistance of >100 hrs. for removal of 0.1 μm from a polished layer with 0.5N HNO 3 and an alkali resistance of >120 hrs. for removal of 0.1 μm from a polished layer with NaOH at pH 10, containing not more than 1.5 percent by weight ionic fluorine, consisting essentially of, in percent by weight: ______________________________________
SiO.sub.2 31.00-35.10
B.sub.2 O.sub.3 0.5-2.85
SnO.sub.2 0-1
NaF 0-1.00
Na.sub.2 O 7.88-12.00
K.sub.2 O 5.30-5.55
total alkali metal oxides
13.93-17.53
PbO 0-0.60
CaO 1.06-2.01
BaO 6.24-12.44
total alkaline earth oxides
7.90-14.21
TiO.sub.2 20.18-29.16
Nb.sub.2 O.sub.5 8.5-18.56
La.sub.2 O.sub.3 0-1.0
WO.sub.3 0.10-1.92
Y.sub.2 O.sub.3 0-1.0
Gd.sub.2 O.sub.3 0-1.0
As.sub.2 O.sub.3 0.10-0.20
______________________________________ wherein the SiO 2 :TiO 2 ratio is 1.13-1.74.
References Cited (Backward Citations)
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JPS5316718A
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US4149895A
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DE2824982A1
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JPS55126549A
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US4390638A
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| 3.5 Years (Year 4) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
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