Patent US3765913A successfully refreshed from Google Patents.
US3765913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phototropic glass
Assignee: Nippon Sheet Glass Co Ltd
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Filing: 1972-01-25
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Granted: 1973-10-16
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Expires: 1992-01-25
Abstract
Abstract A transparent and durable phototropic glass comprising a borosilicate glass body containing therein microcrystals of silver halide, copper oxide and lanthanum oxide, and process for making the phototropic glass which comprises melting a batch for the said glass body, forming and cooling the molten glass, heat treating said glass to cause the silver halide to crystallize, and cooling the glass.
Inventors
- 👤 Y Murakami
- 👤 M Kume
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:55
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/04; C03C4/06
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
30 words
The glass according to claim 1, wherein the amount of PbO present is 0.7 - 5.7 mole percent and the amount of CaO present is less than 10.0 mole percent.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |