US3849097A
Expired / Lapsed
US
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Method for continuously hot forming strong laminated bodies
Assignee: Corning Glass Works
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Filing: 1972-03-27
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Granted: 1974-11-19
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Expires: 1992-03-27
Abstract
Abstract This invention relates to sound, high strength, laminated articles of glass, glass-ceramic, glass and glass-ceramic materials. Such articles are made by means of a continuous hotforming process wherein glasses are melted for the individual layers and these layers are then simultaneously fused together and shaped into a laminated structure of a desired configuration. The individual layers are formed with a composition and temperature so as to place the surface layers in compression because of expansion and viscosity characteristics. Where a glass-ceramic article is desired, the laminated glass structure is subsequently heat treated in a particular manner to cause the glass to crystallize in situ.
Inventors
- 👤 J Giffen
- 👤 D Duke
- 👤 J Macdowell
- 👤 J Megles
- 👤 W Dumbaugh
- 👤 J Flannery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:52
CPC Classifications
C; C03; C03C; C03C4/00; C03B; C03B17/00; C03B17/02; C03B27/00; C03C10/00; C03C10/0036; C03C10/0045; C03C10/0054; C03C17/00; C03C17/02; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/085; C03C3/087; C03C3/089; C03C3/091; C03C2204/00; C03C2204/04
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
158 words
A METHOD FOR CONTINUOUSLY HOT-FORMING A STRONG LAMINATED GLASS ARTICLE CONSISTING OF A TENSILELY-STRESSED CORE PORTION AND A COMPRESSIVELY-STRESSED SURFACE LAYER FUSED THERETO AND SUBSTANTIALLY ENVELOPING SAID CORE PORTION SUCH THAT THE FUSED GLASS SURFACE BETWEEN SAID CORE PORTION AND SAID SURFACE LAYER IS ESSENTIALLY DEFECT-FREE AND WHEREIN THE COEFFICIENT OF THERMAL EXPANSION OF SAID SURFACE LAYER AT THE SETTING POINT IS AT LEAST ABOUT 15X10**7/*C. LESS THAN THE COEFFICIENT OF THERMAL EXPANSION OF SAID CORE PORTION WHICH COMPRISES THE STEPS OF: A. MELTING A GLASS FORMING BATCH FOR EACH SAID ORE PORTION AND SAID SURFACE LAYER; B. ESSENTIALLY SIMULTANEOUSLY BRINGING SAID MOLTEN BATCHES TOGETHER WHILE IN THE FLUID STATE AND COMBINING THEM INTO A LAMINATED GLASS ARTICLE AT AN ELEVATED TEMPERATURE SUCH THAT SAID CORE PORTION HAS A VISCOSITY GREATER THAN AND UP TO SIX TIMES GREATER THAN SAID SURFACE AND FUSING SAID CORE PORTION AND SURFACE LAYER TOGETHER SUCH THAT AN INTERFACE THEREBETWEEN IS ESSENTIALLY DEFECT-FREE.
Claim 2
Independent Claim
158 words
A METHOD FOR CONTINUOUSLY HOT-FORMING A STRONG LAMINATED GLASS ARTICLE CONSISTING OF A TENSILELY-STRESSED CORE PORTION AND A COMPRESSIVELY-STRESSED SURFACE LAYER FUSED THERETO AND SUBSTANTIALLY ENVELOPING SAID CORE PORTION SUCH THAT THE FUSED GLASS SURFACE BETWEEN SAID CORE PORTION AND SAID SURFACE LAYER IS ESSENTIALLY DEFECT-FREE AND WHEREIN THE COEFFICIENT OF THERMAL EXPANSION OF SAID SURFACE LAYER AT THE SETTING POINT IS AT LEAST ABOUT 15X10**7/*C. LESS THAN THE COEFFICIENT OF THERMAL EXPANSION OF SAID CORE PORTION WHICH COMPRISES THE STEPS OF: A. MELTING A GLASS FORMING BATCH FOR EACH SAID ORE PORTION AND SAID SURFACE LAYER; B. ESSENTIALLY SIMULTANEOUSLY BRINGING SAID MOLTEN BATCHES TOGETHER WHILE IN THE FLUID STATE AND COMBINING THEM INTO A LAMINATED GLASS ARTICLE AT AN ELEVATED TEMPERATURE SUCH THAT SAID CORE PORTION HAS A VISCOSITY GREATER THAN AND UP TO SIX TIMES GREATER THAN SAID SURFACE AND FUSING SAID CORE PORTION AND SURFACE LAYER TOGETHER SUCH THAT AN INTERFACE THEREBETWEEN IS ESSENTIALLY DEFECT-FREE.
Claim 3
Dependent Claim
41 words
from 0 to 9% CaO d. from 0.25 to 3.0% MgO; e. from 3 to 6% TiO2; and f. from 0 to 5percent total of at least one compound selected from the group consisting of CdO, ZnO, As2O3, K2O, and B2O3.
Claim 4
Dependent Claim
41 words
from 0 to 9% CaO d. from 0.25 to 3.0% MgO; e. from 3 to 6% TiO2; and f. from 0 to 5percent total of at least one compound selected from the group consisting of CdO, ZnO, As2O3, K2O, and B2O3.
Claim 5
Dependent Claim
24 words
The method as recited in claim 1 wherein the liquidus temperature of the glasses is lower than the temperature for shaping the laminated structure.
Claim 6
Dependent Claim
23 words
The method as recited in claim 1 wherein the core portion is from 2 to 4 times as viscous as the adhered layer.
Claim 7
Dependent Claim
73 words
The method as recited in claim 1 wherein the coefficient of thermal expansion of the core portion is between about 60 and 110 X 10 7/*C. and the coefficient of thermal expansion of the adhered layer is between about 30 and 80 X 10 7/*C. with the expansion of the adhered layer being at least 15 X 10 7/*C. less than that of the core portion at the setting point of the system.
Claim 8
Dependent Claim
82 words
A method as recited in claim 1 wherein said laminated structure is formed from a three-ply sheet having a core ply and two adhered plies, each ply selected from the group consisting of a clear glass, a spontaneous opal glass, a heat treatable opal glass, and a thermally-crystallizable glass, wherein: a. the core ply is substantially enveloped by the two adhered plies; and b. the viscosity of the core ply is from about 1 to 6 times that of the adhered plies.
Claim 9
Dependent Claim
29 words
The method as recited in claim 5 wherein below the maximum heat treating temperature the viscosity of the adhered plies is greater than the viscosity of the core ply.
Claim 10
Dependent Claim
104 words
The method as recited in claim 5 wherein the adhered glass plies consist essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 50 to 65% SiO2; b. from 10 to 20% Al2O3; c. from 5 to 25% CaO; d. from 0 to 12% MgO; e. from 0 to 10% B2O3; f. from 0 to 12percent total of at least one compound selected from the group consisting of BaO, SrO, ZnO, and La2O3; and g. from 0 to 5 percent total of at least one compound selected from the group consisting of Li2O, Na2O, K2O, TiO2, and ZrO2.
Claim 11
Dependent Claim
172 words
The method as recited in claim 5 wherein the core ply is a clear alkali aluminosilicate glass consisting essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 50 to 75% SiO2; b. from 10 to 30% Al2O3; c. from 5 to 25percent total alkali metal oxide with Na2O comprising at least one-half of the total alkali metal oxide and with from 0 to 6% K2O; d. from 0 to 20 percent total alkaline earth metal oxide; e. from 0 to 10 percent total of at least one compound selected from the group consisting of La2O3, TiO2, ZrO2, Nb2O5, ZnO, CdO, GeO2, PbO, Bi2O3, CeO2, and B2O3; f. from 0 to 2 percent of at least one compound selected from the group consisting of As2O3 and Sb2O3; g. from 0 to 1.5 percent chloride; and h. from 0 to 5 percent total of at least one coloring oxide selected from the group consisting of the oxides of Cr, Mn, Fe, Co, Cu, Nd, V, and Ni.
Claim 12
Dependent Claim
86 words
The method as recited in claim 5 wherein the core ply is a clear alkaline earth aluminosilicate glass consisting essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 40 to 60% SiO2; b. from 5 to 15% Al2O3; c. from 20 to 50% BaO; d. from 0 to 25% SrO; and e. from 0 to 10% total, of at least one compound selected from the group consisting of La2O3, B2O3, CaO, MgO, TiO2, ZrO2, PbO, ZnO, CdO, and P2O5.
Claim 13
Dependent Claim
172 words
The method as recited in claim 5 wherein the core ply is a spontaneous opal glass consisting essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 50% to 75% SiO2; b. from 3% to 20% Al2O3; c. from 0% to 3% total alkali metal oxide with Na2O comprising at least 1/3 of the total alkali metal oxide and with from 0 % to 8% K2O; d. from 0% to 20% total alkaline earth metal oxide; e. from 0% to 10% total of at least one compound selected from the group consisting of La2O3, TiO2, ZrO2, Nb2O5, ZnO, CdO, GeO2, PbO, Bi2O3, CeO2, and B2O3; f. from 0% to 2% of at least one compound selected from the group consisting of As2O3 and Sb2O3; g. from 0% to 1.5% chloride; h. from 0% to 5% total of at least one compound selected from the group consisting of the oxides of Cr, Mn, Fe, Co, Cu, Nd, V, and Ni; and i. from 3% to 8% fluoride.
Claim 14
Dependent Claim
87 words
The method as recited in claim 5 wherein the core ply is a heat-treatable opal glass consisting essentially, of, in weight percent on the oxide basis as calculated from the batch: a. from 50 to 70% SiO2; b. from 15 to 25% Al2O3; c. from 7 to 14% Na2O; d. from 5 to 12% ZnO; e. from 2.5 to 7% fluoride; and f. from 0 to 3 percent total of at least one compound selected from the group consisting of As2O3, CaO, MgO, B2O3, Li2O, and BaO.
Claim 15
Dependent Claim
55 words
The method as recited in claim 11 wherein the laminated structure having the heat treatable opal glass core ply is exposed to temperatures between about 500*C. and 650*C. for at least 10 minutes and then exposed to temperatures between about 650*C. and 850*C. for at least 10 minutes to cause the core ply to opalize.
Claim 16
Dependent Claim
86 words
The method as recited in claim 5 wherein the core ply is a thermally-crystallizable glass consisting essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 44 to 61% SiO2; b. from 19 to 23% Al2O3; c. from 10 to 14% Na2O; d. from 7 to 10% ZnO; e. from 3 to 6% fluroide; and f. from 0 to 3 percent total of at least one compound selected from the group consisting of As2O3, CaO, MgO, B2O3, Li2O, and BaO.
Claim 17
Dependent Claim
81 words
The method as recited in claim 13 wherein the laminated structure having the thermally-crystallizable glass core ply is exposed to temperatures between about 500*-650*C. for at least 10 minutes, thereafter the laminate is exposed to temperatures between about 650*-750*C. for at least 10 minutes and finally the laminate is exposed to temperatures between about 750*C. and 850*C. for at least 10 minutes to cause the glass core ply to be crystallized in situ to a zinc orthosilicate nucleated, nepheline-type glass-ceramic ply.
Claim 18
Dependent Claim
52 words
The method as recited in claim 5 wherein the core ply is a thermally-crystallizable glass consisting essentially of, in weight percent on the oxide basis as calculated from the batch: a. from 50 to 65% SiO2; b. from 20 to 30% Al2O3; c. from 15 to 20% total Na2O and CaO with
Claim 19
Dependent Claim
62 words
The method as recited in claim 15 wherein the laminated structure having the thermally-crystallizable glass core ply is exposed to temperatures between about 700*-750*C. for at least 10 minutes and thereafter the laminate is exposed to temperatures between about 750*-850*C. for at least 10 minutes to cause the glass core ply to be crystallized in situ to a tintania-nucleated, nepheline-type glass-ceramic ply.
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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) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |