Non-opaque arsenic-free beta-spodumene glass ceramic exhibiting brown-grey coloration

Patent metadata

Field	Value
Publication number	US-10160685-B2
Application number	US-201715416034-A
Country	US
Kind code	B2
Filing date	Jan 26, 2017
Priority date	Feb 28, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Methods, compositions, and articles provide for LAS-type glass-ceramics having specific thermo-mechanical, optical and coloration characteristics to yield generally brown-grey products. The glass-ceramic materials may include as colorants iron oxide, vanadium oxide, chromium oxide, cobalt oxide, nickel oxide and/or cerium oxide.

First claim

The invention claimed is:

1. A method, comprising:
melting a load of vitrifiable raw materials;
fining the load to obtain molten glass;
cooling the molten glass to a temperature sufficient to shape it into a desired shape; and
ceramming of the glass in the desired shape at a maximum temperature between about 960° C. to about 1060° C., to produce a lithium aluminosilicate glass-ceramic material containing beta-spodumene as a predominant crystalline phase, wherein the glass-ceramic material comprises:
60-72% SiO 2 , 18-23% Al 2 O 3 , and 2.5-4.5% Li 2 O; and
0.05-0.20% V 2 O 5 , 0.15-0.30% Fe 2 O 3 , 0.015-0.030% Cr 2 O 3 , 0-0.05% CoO, 0-0.3% NiO, and 0-0.2% CeO 2 ;

wherein the glass-ceramic material, exhibits a brown-grey color with an optical transmittance for a wavelength of 62.5 nm of greater than 2.0% as measured using an illuminant D65, 2° observer test on 4 mm thick glass-ceramic.

2. The method of claim 1 , wherein at least one of:
a green-red hue (a*) of the glass-ceramic is between about −3 to +4,
a blue-yellow hue (b*) of the glass-ceramic is between about −10 to +4, and
said hue is measured in reflection using an illuminant D65, 10° observer test.

3. The method of claim 1 , wherein a lightness L* of the glass-ceramic is between about 15-40 measured in reflection using an illuminant D65, 10° observer test.

4. The method of claim 1 , wherein an integrated visible transmission (Tl) of the glass-ceramic is between about 0.3% to about 6%, wherein said integrated visible transmission (Tl) is measured using an illuminant D65, 2° observer test on 4 mm thick glass-ceramic.

5. The method of claim 1 , wherein an optical transmission of the glass-ceramic, measured at about 625 nm, is higher than about 3.5%, and wherein said optical transmission is measured using an illuminant D65, 2° Observer test on 4 mm thick glass-ceramic.

6. The method of claim 1 ; wherein an optical transmission of the glass-ceramic, measured at about 950 nm, is between about 35-75%, and, wherein said optical transmission is measured using an illuminant D65, 2° observer test on 4 mm thick glass-ceramic.

7. The method of claim 1 , wherein an infra-red optical transmission of the glass-ceramic, measured at about 1600 nm, is greater than 45%, wherein said optical transmission is measured using an illuminant D65, 2° observer test on 4 mm thick glass-ceramic.

8. The method of claim 1 , wherein the glass-ceramic material is substantially free of As 2 O 3 and Sb 2 O 3 .

9. The method of claim 8 , wherein the glass comprises (in weight %): 0-2.5% ZrO 2 , and 1.5-4% TiO 2 .

10. The method of claim 8 , wherein the glass comprises (in weight %): 0-3% MgO, 0-3% ZnO, BaO, 0-2% CaO, 0-1.5% K 2 O, 0-1.5% Na 2 O.

11. The method of claim 8 , wherein the glass comprises (in weight %): 0-0.6% SnO 2 .

Assignees

• Eurokera

Inventors

• Comte Marie Jacqueline Monique
• Jousseaume Cécile
• Lehuede Philippe
• Plevacova Kamila

Classifications

• C03C4/02

  for coloured glass · CPC title

• H05B3/74

  Non-metallic plates {, e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits} · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C3/085

  containing an oxide of a divalent metal · CPC title

• C03C10/0027 Primary

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