Beta-quartz glass ceramics with controlled transmission and methods of making same

• US 9,650,286 B2
• Filed: 05/16/2012
• Issued: 05/16/2017
• Est. Priority Date: 05/16/2011
• Status: Active Grant

• Current Assignee: Eurokera S.N.C. (Corning Incorporated)
• Original Assignee: Eurokera S.N.C. (Corning Incorporated)
• Inventors: Comte, Marie Jacqueline Monique, Lismonde, Michel Jean Gerard, Melscot-Chauvel, Isabelle Marie
• Primary Examiner(s): Auer, Laura
• Application Number:
  US14/117,383
• Publication Number:
  US 20150197444A1
• Time in Patent Office: 1,826 Days
• CPC Class Codes: C03B 32/02 Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles C03B27/012 takes precedence
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 10/0054 containing PbO, SnO2, B2O3
• CPC Class Codes: C03C 2204/00 Glasses, glazes or enamels with special properties
• CPC Class Codes: C03C 3/083 containing aluminium oxide or an iron compound
• CPC Class Codes: C03C 3/085 containing an oxide of a divalent metal
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 4/02 for coloured glass
• CPC Class Codes: C03C 4/10 for infrared transmitting glass

Abstract

Beta-quartz glass-ceramics containing in their composition neither arsenic oxide nor antimony oxide and having a controlled transmission curve, articles made using the glass-ceramics, including cooktops, and precursor glasses of such glass-ceramics.

Claims

1. A glass-ceramic of the lithium aluminosilicate type, containing a beta-quartz solid solution as the predominant crystalline phase and having for a thickness of 4 mm:

an integrated optical transmission, T_v, in the visible range, between 0.8 and 2%,

an optical transmission at 625 nm of more than 3.5%

an optical transmission at 950 nm between 50 and 70%, and

an optical transmission at 1,600 nm between 65 and 75%, wherein the optical transmissions are measured after a ceramming that comprises (in sequence);

(a) heating to 650°

C., (b) heating from 650°

C. to 820°

C. at a heating rate of 5°

C./min, (c) heating from 820°

C. to T_max at a heating rate of 15°

C./min and holding at T_max for about 7 to 10 minutes; and

(d) cooling from T_max at an oven cooling rate, wherein T_max is between about 920°

C. and about 970°

C.,

wherein the composition of the glass-ceramic, expressed as percentages by weight of oxides, contains;

SnO₂ 0.3-0.6

V₂O₅ 0.025-0.060

Cr₂O₃ 0.01-0.04

Fe₂O₃ 0.05-0.15

As₂O₃+Sb₂O₃<

0.1, and

wherein the composition further comprises as base oxides expressed as percentages by weight of oxides;

2. The glass-ceramic according to claim 1, the composition of which contains:

SnO₂ 0.36-0.6,

V₂O₅ 0.025-0.045

Cr₂O₃ 0.01-0.04

Fe₂O₃ 0.05-0.15

As₂O₃+Sb₂O₃<

0.05.

3. The glass-ceramic according to claim 1, the composition of which contains:

SnO₂ 0.34-0.39

V₂O₅ 0.028-0.041

Cr₂O₃ 0.013-0.016.

4. The glass-ceramic according to claim 1, the composition of which contains 0.07≦

Fe₂O₃<

0.12.

5. The glass-ceramic according to claim 1, the composition of which is free of F and of Br, except for inevitable traces.

6. The glass-ceramic according to claim 1, the composition of which comprises at least 98% by weight of SnO₂, V₂O₅, Cr₂O₃, Fe₂O₃ and of said base oxides, with As₂O₃+Sb₂O₃<

1000 ppm.

7. An article comprising a glass-ceramic according to claim 1.

8. A lithium aluminosilicate glass precursor, the composition of said glass corresponding to the glass-ceramic according to claim 1.

9. The glass-ceramic according to claim 1, the composition of which contains:

SnO₂ 0.3-0.4,

V₂O₅ 0.025-0.045, and

Cr₂O₃ 0.01-0.03.