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

Patent metadata

Field	Value
Publication number	US-9650286-B2
Application number	US-201214117383-A
Country	US
Kind code	B2
Filing date	May 16, 2012
Priority date	May 16, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

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.

First claim

We claim:

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:
SnO 2 0.3-0.6
V 2 O 5 0.025-0.060
Cr 2 O 3 0.01-0.04
Fe 2 O 3 0.05-0.15
As 2 O 3 +Sb 2 O 3 <0.1, and
wherein the composition further comprises as base oxides expressed as percentages by weight of oxides:

SiO 2
60-72

Al 2 O 3
18-23

Li 2 O
2.5-4.5

MgO
0-3

ZnO
1-3

TiO 2
1.5-4  

ZrO 2
  0-2.5

BaO
0-5

SrO
0-5

with BaO + SrO
0-5

CaO
0-2

Na 2 O
  0-1.5

K 2 O
  0-1.5

P 2 O 5
0-5

B 2 O 3
 0-2,

and
further wherein the composition contains less than 200 ppm of CoO.

2. The glass-ceramic according to claim 1 , the composition of which contains:
SnO 2 0.36-0.6,
V 2 O 5 0.025-0.045
Cr 2 O 3 0.01-0.04
Fe 2 O 3 0.05-0.15
As 2 O 3 +Sb 2 O 3 <0.05.

3. The glass-ceramic according to claim 1 , the composition of which contains:
SnO 2 0.34-0.39
V 2 O 5 0.028-0.041
Cr 2 O 3 0.013-0.016.

4. The glass-ceramic according to claim 1 , the composition of which contains 0.07≦Fe 2 O 3 <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 SnO 2 , V 2 O 5 , Cr 2 O 3 , Fe 2 O 3 and of said base oxides, with As 2 O 3 +Sb 2 O 3 <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:
SnO 2 0.3-0.4,
V 2 O 5 0.025-0.045, and
Cr 2 O 3 0.01-0.03.

Assignees

• Comte Marie Jacqueline Monique
• Melscoët-Chauvel Isabelle Marie
• Lismonde Michel Jean Gerard
• Eurokera

Inventors

• Comte Marie Jacqueline Monique
• Melscoët-Chauvel Isabelle Marie
• Lismonde Michel Jean Gerard

Classifications

• C03C4/02

  for coloured glass · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C10/0054

  containing PbO, SnO2, B2O3 · CPC title

• C03C10/0027 Primary

  containing SiO2, Al2O3, Li2O as main constituents · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title