US4192665A
Expired / Lapsed
US
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Rapidly crystallized beta-spodumene glass-ceramic materials
Assignee: Corning Glass Works
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Filing: 1977-09-07
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Granted: 1980-03-11
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Expires: 1997-09-07
Abstract
Abstract Glasses in the Li2O-Al2O3-SiO2-MgO-ZnO-TiO2 composition field, additionally containing PbO and/or one of B2O3, Na2O and P2O5 are rapidly crystallized to beta-spodumene glass-ceramics at temperatures not exceeding 1000 DEG C. to provide white, opaque glass-ceramic products exhibiting both low thermal expansion and good chemical durability.
Inventors
- 👤 Kenneth Chyung
- 👤 John E. Megles, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:57
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045; C03B; C03B32/00; C03B32/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
270 words
A method for producing a white, opaque, chemically durable, low-expansion glass-ceramic material comprising beta-spodumene solid solution as the principal crystal phase which comprises the steps of: (a) selecting for crystallization a glass having a composition falling within one of Ranges I and II below, wherein: Range I includes compositions consisting essentially, in weight percent, of about 63-67%, SiO 2 , 18-21% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 1.5-4.0% PbO, 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0-2% total of B 2 O 3 +Na 2 O+P 2 O 5 , and Range II includes compositions consisting essentially, in weight percent, of about 68-71% SiO 2 , 16-18% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0.2-2.2% total of B 2 O 3 +Na 2 O+P 2 O 5 ; and (b) converting the selected glass to a glass-ceramic material utilizing a crystallization heat treatment comprising heating the glass to a nucleation temperature in the range of about 750°-800° C. for a time in the range of about 1-4 hours to develop crystal nuclei throughout the volume of the glass, followed by heating the glass to a crystallization temperature in the range of about 900°-1000° C. for a time not exceeding about 2 hours, whereby a white, opaque, chemically durable, low-expansion glass-ceramic material comprising beta-spodumene solid solution as the principal crystal phase is provided.
Claim 2
Independent Claim
270 words
A method for producing a white, opaque, chemically durable, low-expansion glass-ceramic material comprising beta-spodumene solid solution as the principal crystal phase which comprises the steps of: (a) selecting for crystallization a glass having a composition falling within one of Ranges I and II below, wherein: Range I includes compositions consisting essentially, in weight percent, of about 63-67%, SiO 2 , 18-21% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 1.5-4.0% PbO, 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0-2% total of B 2 O 3 +Na 2 O+P 2 O 5 , and Range II includes compositions consisting essentially, in weight percent, of about 68-71% SiO 2 , 16-18% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0.2-2.2% total of B 2 O 3 +Na 2 O+P 2 O 5 ; and (b) converting the selected glass to a glass-ceramic material utilizing a crystallization heat treatment comprising heating the glass to a nucleation temperature in the range of about 750°-800° C. for a time in the range of about 1-4 hours to develop crystal nuclei throughout the volume of the glass, followed by heating the glass to a crystallization temperature in the range of about 900°-1000° C. for a time not exceeding about 2 hours, whereby a white, opaque, chemically durable, low-expansion glass-ceramic material comprising beta-spodumene solid solution as the principal crystal phase is provided.
Claim 3
Dependent Claim
82 words
A method in accordance with claim 1 wherein the glass selected for crystallization has a composition consisting essentially, in weight percent on the oxide basis, of about 63-67% SiO 2 , 18-21% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 1.5-4.0% PbO, 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0-2% total of B 2 O 3 +Na 2 O+P 2 O 5 .
Claim 4
Dependent Claim
80 words
A method in accordance with claim 1 wherein the glass selected for crystallization has a composition consisting essentially, in weight percent on the oxide basis, of about 68-71% SiO 2 , 16-18% Al 2 O 3 , 3.0-5.0% Li 2 O, 1.0-2.5% MgO, 0.4-2.5% ZnO, 4.0-5.0% TiO 2 , 0-1.0% B 2 O 3 , 0-1.0% Na 2 O, 0-2.0% P 2 O 5 , and 0.2-2.2% total of Na 2 O+B 2 O 3 +P 2 O 5 .
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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) | 1983-03-11 | 1983-09-10 | 1984-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-11 | 1987-09-10 | 1988-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-11 | 1991-09-10 | 1992-03-11 | $7700.00 | Window Closed / Lapsed |