US3926602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass-ceramic articles with reflective surfaces
Assignee: Corning Glass Works
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Filing: 1974-06-19
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Granted: 1975-12-16
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Expires: 1994-06-19
Abstract
Abstract This invention is concerned with the production of glass-ceramic articles from glasses within the Li2O-FeO-Al2O3-SiO2 system which, when nucleated with TiO2 or a combination of TiO2 and ZrO2 and exposed to carefully-defined heat treatments, will crystallize in situ to bodies having highly-durable integral surfaces exhibiting distinctly metallic lusters. The lustrous surfaces are reflective to visible light and, when developed upon previously polished surfaces, can produce mirror-like finishes with good color and spatial reproduction of reflected images. On slightly irregular or non-planar surfaces as, for example, fractured or as-poured surfaces, an appearance similar to metal plating is observed.
Inventors
- 👤 Ronald L Andrus
- 👤 Richard F Reade
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:03
CPC Classifications
C; C03; C03B; C03B32/00; C03B32/02; C03C; C03C10/00; C03C10/0018; C03C10/0027
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
170 words
A METHOD FOR MAKING A GLAS-CERAMIC ARTICLE COMPOSED OF A BODY PORTION AND A HIGHLY-DURABLE, INTEGRAL SURFACE LAYER EXHIBITING A REFLECTIVE, METALLIC LUSTER, SAID BODY PORTION CONSISTING ESSENTIALLY OF BETA-QUARTZ SOLID SOLUTION CRYSTALS DISPERSED WITHIN A GLASSY MATRIX AND SAID INTEGRAL SURFACE LAYER CONSISTING ESSENTIALLY OF HEMATITE (ALPHA-FE2O3) CRYSTALS DISPERSED WITHIN A GLASSY MATRIX, COMPRISING THE STEPS OF: A. MELTING A BATCH FOR A GLASS CONSISTING ESSENTIALLY, IN WEIGHT PERCENT ON THE OXIDE BASIS, OF ABOUT 0.5-3.5% FEO, 3-6% LI2O, 16-21% AL2O3, 65-75% SIO2, AND 1.5-7% RO2, WHEREIN RO2 CONSISTS OF 1.5-6% TIO2 AND 0-3% ZRO2; B. SIMULTANEOUSLY COOLING THE MELT TO AT LEAST WITHIN THE TRANSFORMATION RANGE AND FORMING A GLASS ARTICLE OF A DESIRED CONFIGURATION THEREFROM; C. EXPOSING SAID GLASS ARTICLE TO A TEMPERATURE BETWEEN ABOUT 850*-1025*C. FOR A PERIOD OF TIME SUFFICIENT TO TO CAUSE THE GROWTH OF BETA-QURTZ SOILD SOLUTION CRYSTALS IN SITU IN SAID BODY PORTION AND THE GROWTH OF HEMATITE (ALPHA-FE2O3) CRYSTALS IN SITU IN SAID SURFACE LAYER; AND D. COOLING TO ROOM TEMPERATURE.
Claim 2
Independent Claim
170 words
A METHOD FOR MAKING A GLAS-CERAMIC ARTICLE COMPOSED OF A BODY PORTION AND A HIGHLY-DURABLE, INTEGRAL SURFACE LAYER EXHIBITING A REFLECTIVE, METALLIC LUSTER, SAID BODY PORTION CONSISTING ESSENTIALLY OF BETA-QUARTZ SOLID SOLUTION CRYSTALS DISPERSED WITHIN A GLASSY MATRIX AND SAID INTEGRAL SURFACE LAYER CONSISTING ESSENTIALLY OF HEMATITE (ALPHA-FE2O3) CRYSTALS DISPERSED WITHIN A GLASSY MATRIX, COMPRISING THE STEPS OF: A. MELTING A BATCH FOR A GLASS CONSISTING ESSENTIALLY, IN WEIGHT PERCENT ON THE OXIDE BASIS, OF ABOUT 0.5-3.5% FEO, 3-6% LI2O, 16-21% AL2O3, 65-75% SIO2, AND 1.5-7% RO2, WHEREIN RO2 CONSISTS OF 1.5-6% TIO2 AND 0-3% ZRO2; B. SIMULTANEOUSLY COOLING THE MELT TO AT LEAST WITHIN THE TRANSFORMATION RANGE AND FORMING A GLASS ARTICLE OF A DESIRED CONFIGURATION THEREFROM; C. EXPOSING SAID GLASS ARTICLE TO A TEMPERATURE BETWEEN ABOUT 850*-1025*C. FOR A PERIOD OF TIME SUFFICIENT TO TO CAUSE THE GROWTH OF BETA-QURTZ SOILD SOLUTION CRYSTALS IN SITU IN SAID BODY PORTION AND THE GROWTH OF HEMATITE (ALPHA-FE2O3) CRYSTALS IN SITU IN SAID SURFACE LAYER; AND D. COOLING TO ROOM TEMPERATURE.
Claim 3
Dependent Claim
35 words
A method according to claim 1 wherein said glass article is first exposed to a temperature between about 750*-850*C. for about 1-6 hours and thereafter to a temperature between about 850*-1025*C. for about 1-8 hours.
Claim 4
Dependent Claim
21 words
A method according to claim 1 wherein said FeO is less than about 1% such that said glass-ceramic article exhibits transparency.
Claim 5
Dependent Claim
22 words
A method according to claim 1 wherein said surface layer of said glass-ceramic article is no more than several thousand angstroms thick.
Claim 6
Independent Claim
200 words
A method for making an opaque glass-ceramic article composed of a body portion and a highly-durable, integral surface layer exhibiting a reflective, metallic luster, said body portion consisting essentially of beta-spodumene solid solution crystals dispersed within a glassy matrix and said integral surface layer consisting essentially of hematite (alpha-Fe2O3) crystals dispersed within a glassy matrix, comprising the steps of: a. melting a batch for a glass consisting essentially, in weight percent on the oxide basis, of about 0.5-3.5% FeO, 3-6% Li2O, 16-21% Al2O3, 65-75% SiO2, and 1.5-7% RO2, wherein RO2 consists of 1.5-6% TiO2 and 0-3% ZrO2; b. simultaneously cooling the melt to at least within the transformation range and formIng a glass article of a desired configuration therefrom; c. exposing said glass article to a temperature between about 850*-1025*C. for a period of time sufficient to cause the growth of beta-quartz solid solution crystals in situ in said body portion and the growth of hematite (alpha-Fe2O3) crystals in situ in said surface layer; d. exposing said crystallized article to a temperature of at least 1050*C. for a period of time sufficient to convert said beta-quartz solid solution crystals to beta-spodumene solid solution crystals; and e. cooling to room temperature.
Claim 7
Independent Claim
200 words
A method for making an opaque glass-ceramic article composed of a body portion and a highly-durable, integral surface layer exhibiting a reflective, metallic luster, said body portion consisting essentially of beta-spodumene solid solution crystals dispersed within a glassy matrix and said integral surface layer consisting essentially of hematite (alpha-Fe2O3) crystals dispersed within a glassy matrix, comprising the steps of: a. melting a batch for a glass consisting essentially, in weight percent on the oxide basis, of about 0.5-3.5% FeO, 3-6% Li2O, 16-21% Al2O3, 65-75% SiO2, and 1.5-7% RO2, wherein RO2 consists of 1.5-6% TiO2 and 0-3% ZrO2; b. simultaneously cooling the melt to at least within the transformation range and formIng a glass article of a desired configuration therefrom; c. exposing said glass article to a temperature between about 850*-1025*C. for a period of time sufficient to cause the growth of beta-quartz solid solution crystals in situ in said body portion and the growth of hematite (alpha-Fe2O3) crystals in situ in said surface layer; d. exposing said crystallized article to a temperature of at least 1050*C. for a period of time sufficient to convert said beta-quartz solid solution crystals to beta-spodumene solid solution crystals; and e. cooling to room temperature.
Claim 8
Dependent Claim
55 words
A method according to claim 5 wherein said glass article is first exposed to a temperature between about 750*-850*C. for about 1-6 hours, thereafter exposed to a temperature between about 850*-1025*C. for about 1-8 hours, and then exposed to a temperature of at least 1050*C. for at least 3 hours but less than 16 hours.
Claim 9
Dependent Claim
22 words
A method according to claim 5 wherein said surface layer of said glass-ceramic article is no more than several thousand angstroms thick.
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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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |