US4009042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent, infra-red transmitting glass-ceramics
Assignee: Corning Glass Works
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Filing: 1976-01-15
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Granted: 1977-02-22
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Expires: 1996-01-15
Abstract
Abstract The instant invention relates to the production of highly-crystalline, transparent glass-ceramic articles wherein the predominant crystal phase is a beta-quartz solid solution and which demonstrate transmittances of infra-red radiations up to about 80% at a wavelength of 3.5 microns in bodies having thickness dimensions of about 4 mm. The articles of the invention have compositions within a very narrow area of the Li 2 O--Al 2 O 3 --SiO 2 field, nucleated with TiO 2 , and wherein some of the silica is replaced with AlPO 4 . Minor additions of ZrO 2 enhance the chemical durability of the articles and, if desired, coloring agents can be added to yield colored, transparent, crystalline articles.
Inventors
- 👤 Hermann L. Rittler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:51
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0018; C03C10/0027; C03C4/00; C03C4/10; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/904
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
A transparent glass-ceramic article exhibiting a coefficient of thermal expansion (R.T. to 300° C.) less than about 10 × 10.sup. -7 /° C., excellent detergent durability, an infra-red transmittance at a wavelength of 3.5 microns through a polished plate of about 4 mm. thickness greater than 40%, and wherein the crystal phase consists essentially of beta-quartz solid solution, which consists essentially, by weight on the oxide basis, of about 3-4% Li 2 O, 20-30% Al 2 O 3 , 50-65% SiO 2 , 3-7% TiO 2 , 1.5-3% ZrO 2 , and 2-5% P 2 O 5 , and wherein additional alkali metal oxides, the alkaline earth metal oxides, and B 2 O 3 are essentially absent.
Claim 2
Dependent Claim
117 words
A transparent glass-ceramic article exhibiting a coefficient of thermal expansion (R.T. to 300° C.) less than about 10 × 10.sup. -7 /° C., excellent detergent durability, an infra-red transmittance at a wavelength of 3.5 microns through a polished plate of about 4 mm. thickness greater than 40%, and wherein the crystal phase consists essentially of beta-quartz solid solution, which consists essentially, by weight on the oxide basis, of about 3-4% Li 2 O, 20-30% Al 2 O 3 , 50-65% SiO 2 , 3-7% TiO 2 , 1.5-3% ZrO 2 , and 2-5% P 2 O 5 , and wherein additional alkali metal oxides, the alkaline earth metal oxides, and B 2 O 3 are essentially absent.
References Cited (Backward Citations)
US3282712A
Cited
US3642504A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |