US4093468A
Expired / Lapsed
US
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Process to obtain transparent colorless and glass-ceramics so obtained
Assignee: Corning Glass Works
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Filing: 1977-03-23
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Granted: 1978-06-06
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Expires: 1997-03-23
Abstract
Abstract The invention relates to glass-ceramics.
Inventors
- 👤 Marius Charles Boitel
- 👤 Serge Andre Maurice Renault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:30
CPC Classifications
C; C03; C03C; C03C10/00; C03C1/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
69 words
Sensibly colourless transparent glass-ceramics wherein beta-quartz solid solution constitutes the predominant crystal phase having base compositions within the Li 2 O-Al 2 O 3 -SiO 2 field which contain, on the basis of oxides and as calculated from the batch, about 0.5-6% by weight TiO 2 , an amount of Fe 2 O 3 up to about 500 ppm, and about 0.03-0.75% by weight Nd 2 O 3 .
Claim 2
Dependent Claim
69 words
Sensibly colourless transparent glass-ceramics wherein beta-quartz solid solution constitutes the predominant crystal phase having base compositions within the Li 2 O-Al 2 O 3 -SiO 2 field which contain, on the basis of oxides and as calculated from the batch, about 0.5-6% by weight TiO 2 , an amount of Fe 2 O 3 up to about 500 ppm, and about 0.03-0.75% by weight Nd 2 O 3 .
Claim 3
Dependent Claim
44 words
Sensibly colourless transparent glass-ceramics according to claim 1 having base compositions consisting essentially, in weight percent on the basis of oxides and as calculated from the batch, of about 3-4% Li 2 O, 15-25% Al 2 O 3 , and 60-70% SiO 2 .
References Cited (Backward Citations)
US3928229A
Cited
US4018612A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |