US4084974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making light-absorbing glass-ceramic articles
Assignee: Corning Glass Works
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Filing: 1977-07-22
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Granted: 1978-04-18
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Expires: 1997-07-22
Abstract
Abstract Light-absorbing glass-ceramic articles comprising beta-spodumene and/or beta-quartz as the principal crystal phase and exhibiting blue-to-black coloration are provided by adding a glass reducing agent to a titanium-containing lithium aluminosilicate glass batch for the parent glass.
Inventors
- 👤 George H. Beall
- 👤 Hermann L. Rittler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:07
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
A method for producing a light-absorbing glass-ceramic article exhibiting blue-to-black coloration wherein beta-quartz and/or beta-spodumene constitutes the principal crystal phase which comprises the steps of: (a) compounding a batch for a lithium aluminosilicate glass which is thermally crystallizable to beta-quartz or beta-spodumene, said batch including a source of TiO 2 as a nucleating agent and a glass reducing agent in an amount at least sufficient to reduce at least some of the Ti +4 species present in the batch to Ti +3 species at batch melting temperatures, wherein the glass reducing agent is a carbonaceous reducing agent selected from the group consisting of carbon, sugar and starch; (b) melting the batch to form a glass melt containing Ti +3 species and forming a glass article from the melt; and (c) heat-treating the glass article to obtain crystallization in situ thereof to a light-absorbing glass-ceramic article exhibiting blue-to-black coloration and comprising beta-quartz and/or beta-spodumene as the principal crystal phase and Ti +3 species as a colorant.
Claim 2
Independent Claim
165 words
A method for producing a light-absorbing glass-ceramic article exhibiting blue-to-black coloration wherein beta-quartz and/or beta-spodumene constitutes the principal crystal phase which comprises the steps of: (a) compounding a batch for a lithium aluminosilicate glass which is thermally crystallizable to beta-quartz or beta-spodumene, said batch including a source of TiO 2 as a nucleating agent and a glass reducing agent in an amount at least sufficient to reduce at least some of the Ti +4 species present in the batch to Ti +3 species at batch melting temperatures, wherein the glass reducing agent is a carbonaceous reducing agent selected from the group consisting of carbon, sugar and starch; (b) melting the batch to form a glass melt containing Ti +3 species and forming a glass article from the melt; and (c) heat-treating the glass article to obtain crystallization in situ thereof to a light-absorbing glass-ceramic article exhibiting blue-to-black coloration and comprising beta-quartz and/or beta-spodumene as the principal crystal phase and Ti +3 species as a colorant.
Claim 3
Dependent Claim
27 words
A method in accordance with claim 1 wherein the lithium aluminosilicate glass is a glass in the Li 2 O-MgO-ZnO-Al 2 O 3 -SiO 2 composition field.
Claim 4
Dependent Claim
28 words
A method in accordance with claim 1 wherein the glass reducing agent is added to the batch in an amount constituting about 0.5-2% by weight of the batch.
Claim 5
Dependent Claim
13 words
A light-absorbing glass-ceramic article produced in accordance with the method of claim 1.
References Cited (Backward Citations)
US1919264A
Cited
US3634111A
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US3854919A
Cited
US3788997A
Cited
US4030903A
Cited
US4009042A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |