GLASS LAMINATED BODIES COMPRISING A TENSILELY STRESSED CORE AND A COMPRESSIVELY STRESSED SURFACE LAYER FUSED THERETO

• US 3,673,049 A
• Filed: 10/07/1970
• Issued: 06/27/1972
• Est. Priority Date: 10/07/1970
• Status: Expired due to Term

• Current Assignee: David A. Duke, James E. Flannery, James W. Giffen, John E. Megles, John F. Macdowell, William H. Dumbaugh Jr
• Original Assignee: David A. Duke, James E. Flannery, James W. Giffen, John E. Megles, John F. Macdowell, William H. Dumbaugh Jr
• Inventors: Duke, David A., Dumbaugh, William H. Jr., Flannery, James E., MacDowell, John F., Megles, John E., Giffen, James W.
• Primary Examiner(s): Burnett, Robert F.
• Assistant Examiner(s): Gil, Joseph C.
• Application Number:
  US05/078,763
• Time in Patent Office: 629 Days
• Field of Search: 161/1,43,193,166,164,165 65/41,114,145,121 106/54,39DV,48,52,53,39R 117/123A,124A,125
• US Class Current: 428/213
• CPC Class Codes: C03B 17/02 Forming molten glass coated with coloured layers; Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts
• CPC Class Codes: C03B 27/00 Tempering or quenching glass products
• CPC Class Codes: C03C 10/0018 containing SiO2, Al2O3 and monovalent metal oxide as main constituents
• CPC Class Codes: C03C 17/02 with glass C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 2204/04 Opaque glass, glaze or enamel
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 4/00 Compositions for glass with special properties
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

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. 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.

Claims

2. A high strength laminate according to claim 1 wherein a. the coefficient of thermal expansion of the compressively stressed adhered layer is between 30-80 X 10 7/* C.;

and b. the coefficient of thermal expansion of the tensilely stressed core portion is between 60-110 X 10 7/* C.

3. A high strength laminate according to claim 1 consisting of a three-ply sheet having a core ply and two adhered plies.

4. A high strength laminate according to claim 3 wherein the ratio of the thickness of the tensilely-stressed ply to the total thickness of the compressively-stressed plies adjacent thereto is less than 30:

1.

5. A high strength laminate according to claim 3 wherein the adhered plies are glass and 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 12% 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.

6. A high strength laminate according to claim 3 wherein the core ply is a clear alkaline earth metal 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.

7. A high strength laminate according to claim 3 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 25 percent total alkali 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.

8. A high strength laminate according to claim 3 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 3 to 20% total alkali metal oxide with Na2O comprising from at least one-third of the total alkali metal oxide and with from 0 to 8% 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;

h. from 0 to 5 percent 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 percent fluoride.

9. A high strength laminate according to claim 3 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 percent 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.

10. A high strength laminate according to claim 3 wherein the core ply is a zinc orthosilicate-nucleated nepheline-type glass-ceramic 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 percent 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.

11. A high strength laminate according to claim 3 wherein the core ply is a titania-nucleated, nepheline-type glass-ceramic 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 percent total Na2O and CaO with (1) from 9 to 20% Na2O, and (2) from 0 to 9% CaO;

d. from 0.25 to 3% MgO;

e. from 3 percent to 6 percent TiO2; and

f. from 0 to 5 percent total of at least one compound selected from the group consisting of CdO, ZnO, As2O3, K2O, and B2O3.

12. A high strength glass-ceramic laminate comprising a tensilely-stressed surface layer fused to and substantially enveloping said core portion such that the fused surface between said core portion and said surface layer is essentially defect-free wherein:

a. the ratio of the thickness of sAid core portion to the total thickness of said surface layer is at least about 10;

1;

b. the thickness of said surface layer is at least about 0.002 inch; and

c. the coefficient of thermal expansion of said surface layer is at least about 5 X 10 7/* C. less than the coefficient of thermal expansion of said core portion.

13. A high strength laminate according to claim 12 consisting of a three-ply sheet having a core ply and two adhered plies.

14. A high strength laminate according to claim 13 wherein the ratio of the thickness of the tensilely stressed ply to the total thickness of the compressively stressed plies adjacent thereto is less than 30:

1.

15. A high strength laminate according to claim 13 wherein:

a. the tensilely-stressed core ply is a glass-ceramic selected from the group consisting of beta-spodumene solid solution and rutile, anatase and nepheline solid solution; and

b. the compressively-stressed adhered plies are a glass-ceramic selected from the group consisting of beta-quartz solid solution, beta-spodumene solid solution, and rutile, cordierite and beta-eucryptite solid solution.