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US4343908A
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Optical glass having nD =1.63±(1.5×10-2), vD =59.5±1.0 with a high chemical stability and a low tendency to crystallization
Assignee: Schott AG
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Filing: 1980-12-29
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Granted: 1982-08-10
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Expires: 2000-12-29
Abstract
Abstract An optical glass having nD=1.63+/-(1.5x10-2), vD=59.5+/-1.0, a high chemical stability and a low tendency to crystallization is provided, consisting essentially of (in percent. by weight): -SiO2 23-27 -B2O3 24-30 -SrO 18-31 -La2O3 10-16 -Al2O3 2-4 -BaO 0-10 -CaO 0-5 -ZnO 0-6 -Y2O3 0-5 -ZrO2 0-2 -Li2O, Na2O and/or K2O 0-1.5 -As2O3 and/or Sb2O3 0-1 -F and/or Cl 0-1, - wherein the sum of SiO2+B2O3 is 50-53, the weight ratio SiO2:B2O3 is 0.8-1.0, the sum SrO+BaO is 26-31, and the sum ZnO+La2O3 is 12-17.
Inventors
- 👤 Marga Faulstich
- 👤 Volmar Geiler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:20
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/064; C03C3/068; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
107 words
An optical glass having n D =1.63±(1.5×10 -2 ), v D =59.5±1.0, a high chemical stability and a low tendency to crystallization, and consisting of (in percent. by weight): ______________________________________
SiO.sub.2 23-27
B.sub.2 O.sub.3 24-30
SrO 18-31
La.sub.2 O.sub.3 10-16
Al.sub.2 O.sub.3 2-4
BaO 0-10
CaO 0-5
ZnO 0-6
Y.sub.2 O.sub.3 0-5
ZrO.sub.2 0-2
Li.sub.2 O, Na.sub.2 O and/or K.sub.2 O
0-1.5
As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3
0-1
F and/or Cl 0-1,
wherein the sum of
SiO.sub.2 + B.sub.2 O.sub.3 is
50-53,
the weight ratio
SiO.sub.2 :B.sub.2 O.sub.3 is
0.8-1.0,
the sum
SrO + BaO is 26-31,
and the sum
ZnO + La.sub.2 O.sub.3 is
12-17.
______________________________________
Claim 2
Dependent Claim
107 words
An optical glass having n D =1.63±(1.5×10 -2 ), v D =59.5±1.0, a high chemical stability and a low tendency to crystallization, and consisting of (in percent. by weight): ______________________________________
SiO.sub.2 23-27
B.sub.2 O.sub.3 24-30
SrO 18-31
La.sub.2 O.sub.3 10-16
Al.sub.2 O.sub.3 2-4
BaO 0-10
CaO 0-5
ZnO 0-6
Y.sub.2 O.sub.3 0-5
ZrO.sub.2 0-2
Li.sub.2 O, Na.sub.2 O and/or K.sub.2 O
0-1.5
As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3
0-1
F and/or Cl 0-1,
wherein the sum of
SiO.sub.2 + B.sub.2 O.sub.3 is
50-53,
the weight ratio
SiO.sub.2 :B.sub.2 O.sub.3 is
0.8-1.0,
the sum
SrO + BaO is 26-31,
and the sum
ZnO + La.sub.2 O.sub.3 is
12-17.
______________________________________
Claim 3
Dependent Claim
87 words
An optical glass of claim 1 having the following properties: ______________________________________
range
______________________________________
chemical stability
(a) acid class, class f better than 5c
(b) erosion of 0.1μ in min. in
more than 6 min.
standard acetate, pH 4.5
(c) stain test class F1 3-4
(d) thickness of layer <0.24
destroyed after 1 hour
in a solution, pH 5.6
(e) climatic change better than
stability after 30 hrs
class 4
(f) stray light ≦4.5%
crystallization tendency
(g) essentially no devitrification
(h) crystal growth rate of
≦1.2 μ/min.
______________________________________
Claim 4
Dependent Claim
17 words
An optical glass of claim 1 having the following property: acid class, class f: better than 5c.
Claim 5
Dependent Claim
25 words
An optical glass of claim 1 having the following property: erosion of 0.1μ m in min. in standard acetate, pH 4.5.: more than 6 min.
Claim 6
Dependent Claim
15 words
An optical glass of claim 1 having the following property: stain test class Fl: 3-4.
Claim 7
Dependent Claim
23 words
An optical glass of claim 1 having the following property: thickness of layer destroyed after 1 hour in a solution, pH 5.6: <0.24.
Claim 8
Dependent Claim
20 words
An optical glass of claim 1 having the following property: climatic change stability after 30 hours: better than class 4.
Claim 9
Dependent Claim
13 words
An optical glass of claim 1 having the following property: stray light: ≦4.5%.
Claim 10
Dependent Claim
10 words
An optical glass of claim 1 having essentially no devitrification.
Claim 11
Dependent Claim
14 words
An optical glass of claim 1 having a crystal growth rate of ≦1.2 μ/min.
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) | 1985-08-09 | 1986-02-08 | 1986-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-09 | 1990-02-08 | 1990-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-09 | 1994-02-08 | 1994-08-10 | $7700.00 | Window Closed / Lapsed |