US5275979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colored glasses and method
Assignee: Corning Inc
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Filing: 1992-10-30
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Granted: 1994-01-04
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Expires: 2012-10-30
Abstract
Abstract Thermally induced color is developed in a glass article containing a silver halide crystal phase by including in the glass batch a thermal reducing agent, retaining the thermal reducing agent in its lower valence state while meltinq the batch and forming the glass article and subsequently heat treating the article to partially reduce the silver halide crystal phase.
Inventors
- 👤 Nicholas F. Borrelli
- 👤 David W. Morgan
- 👤 Michel Prassas
- 👤 Dennis W. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:34
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/02; C03C14/00; C03C14/006; C03C3/00; C03C3/04; C03C3/076; C03C3/11; C03C2214/00; C03C2214/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
157 words
A glass article that exhibits a permanent color throughout its body, that, as melted, consists essentially of R 2 O, Al 2 O 3 , B 2 O 3 , and SiO 2 with Ag and at least one halogen, selected from the group consisting of Cl and Br, dissolved in the glass, and that has present at least one thermal reducing agent in its lowest valence state, the thermal reducing agent being selected from the group consisting of SnO 2 , Sb 2 O 3 , and As 2 O 3 , and being present in an amount no greater than about l cation %, the glass after heat treatment having AgCl and/or AgBr crystals and silver metal particles dispersed throughout the glass, the thermal reducing agent being at least partially oxidized to its higher valence state by electron transfer to the silver to produce silver metal and thereby impart a permanent color to the glass.
Claim 2
Dependent Claim
157 words
A glass article that exhibits a permanent color throughout its body, that, as melted, consists essentially of R 2 O, Al 2 O 3 , B 2 O 3 , and SiO 2 with Ag and at least one halogen, selected from the group consisting of Cl and Br, dissolved in the glass, and that has present at least one thermal reducing agent in its lowest valence state, the thermal reducing agent being selected from the group consisting of SnO 2 , Sb 2 O 3 , and As 2 O 3 , and being present in an amount no greater than about l cation %, the glass after heat treatment having AgCl and/or AgBr crystals and silver metal particles dispersed throughout the glass, the thermal reducing agent being at least partially oxidized to its higher valence state by electron transfer to the silver to produce silver metal and thereby impart a permanent color to the glass.
Claim 3
Dependent Claim
84 words
A glass article in accordance with claim 1 wherein the glass composition as calculated in cation percent consists essentially of 35-70% SiO 2 , 2-12% Al 2 O 3 , 20-35% B 2 O 3 , 8-30% R 2 O selected from 0-20% Li 2 O, 0-20% Na 2 O, and 0-12% K 2 O, 0.01-1% of a thermal reducing agent from the group SnO 2 , Sb 2 O 3 and As 2 O 3 , 0.25-1% Cl+Br, 0.10-0.5% Ag and 0-0.1% CuO.
Claim 4
Dependent Claim
11 words
A glass in accordance with claim 1 that exhibits photochromic characteristics.
Claim 5
Dependent Claim
16 words
A glass in accordance with claim 1 wherein the thermal reducing agent is SnO 2 .
Claim 6
Dependent Claim
18 words
A glass in accordance with claim 1 wherein the thermal reducing agent is Sb 2 O 3 .
Claim 7
Dependent Claim
25 words
A glass in accordance with claim 1 wherein the thermal reducing agent content is at least 0.01% but not over 1% of the glass composition.
Claim 8
Dependent Claim
12 words
A glass in accordance with claim 1 wherein the halogen is chlorine.
Claim 9
Dependent Claim
17 words
A glass in accordance with claim 1 wherein the halogen is a mixture of chlorine and bromine.
References Cited (Backward Citations)
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US4134747A
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US4240836A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-03 | 1997-07-05 | 1998-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-03 | 2001-07-05 | 2002-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-03 | 2005-07-05 | 2006-01-04 | $7700.00 | Window Closed / Lapsed |