US4447550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead aluminoborofluorosilicate moldable glasses
Assignee: Corning Glass Works
•
Filing: 1983-06-13
•
Granted: 1984-05-08
•
Expires: 2003-06-13
Abstract
Abstract The instant invention is directed to optical glass compositions capable of being shaped under the combined action of temperature and pressure in a mold so as to obtain articles having surfaces exhibiting highly precise reproduction of the mold walls. The inventive glasses demonstrate softening points not exceeding 500 DEG C., refractive indices between about 1.65-1.82, Abbe number between about 27-39, and consist essentially, in weight percent, of -SiO2 8-20 -B2O3 5-20 -PbO 50-70 -Al2O3 1-11 -F 2-7 -
Inventors
- 👤 Dominique L. J. Leroy
- 👤 Jean-Pierre Mazeau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:42
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/901; Y10S501/903
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
68 words
A moldable optical glass of the lead aluminoborofluorosilicate type having an index of refraction between about 1.65-1.82, an Abbe number between about 27-39, a softening point not exceeding 500° C., good chemical durability in a moist atmosphere, and high stability which consists essentially, expressed in terms of weight percent on the oxide basis, of ______________________________________
SiO.sub.2
8-20
B.sub.2 O.sub.3
5-20
PbO 50-70
Al.sub.2 O.sub.3
1-11
F 2-7
______________________________________
Claim 2
Dependent Claim
68 words
A moldable optical glass of the lead aluminoborofluorosilicate type having an index of refraction between about 1.65-1.82, an Abbe number between about 27-39, a softening point not exceeding 500° C., good chemical durability in a moist atmosphere, and high stability which consists essentially, expressed in terms of weight percent on the oxide basis, of ______________________________________
SiO.sub.2
8-20
B.sub.2 O.sub.3
5-20
PbO 50-70
Al.sub.2 O.sub.3
1-11
F 2-7
______________________________________
Claim 3
Dependent Claim
23 words
A glass according to claim 1 consisting essentially of ______________________________________
SiO.sub.2
8-18
B.sub.2 O.sub.3
5-17
PbO 60-70
Al.sub.2 O.sub.3
4-8
F 4-7
______________________________________
References Cited (Backward Citations)
US2393448A
Cited
US2461878A
Cited
US2642633A
Cited
US3888692A
Cited
US3653933A
Cited
US4109054A
Cited
US4123731A
Cited
US4146655A
Cited
US4348484A
Cited
US4285730A
Cited
US4362819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |