Soda-lime-silica glass-ceramic material
View Patent ↗The invention relates to a glass-ceramic material having SiO 2 , Na 2 O and CaO as main components and comprising crystalline particles of SiO 2 dispersed homogeneously in the volume of an amorphous matrix. Such a material has good mechanical strength, in particular good resistance to scratch propagation and allows improved tempering. This material furthermore has a pleasant aesthetic appearance.
1. A sheet comprising a glass-ceramic material, comprising:
an amorphous matrix comprising, based on a total weight of the glass-ceramic material:
from 60 to 85% of SiO 2 ;
from 1 to 25% of Na 2 O;
from 1 to 25% of CaO;
less than 500 ppm by weight of the element lithium; and
crystalline particles consisting essentially of SiO 2 ,
wherein the crystalline particles are dispersed homogeneously in a volume of the amorphous matrix, and
wherein the sheet comprising a glass-ceramic material is free of the element fluorine.
2. The sheet comprising a glass-ceramic material of claim 1 , being free of the element lead.
3. The sheet comprising a glass-ceramic material of claim 1 , wherein the crystalline particles are in the form of an SiO 2 polymorph.
4. The sheet comprising a glass-ceramic material of claim 1 , wherein the crystalline particles are in the form of cristobalite.
5. The sheet comprising a glass-ceramic material of claim 1 , having a brittleness, measured by Vickers indentation, of less than 6.5 μm −0.5 .
6. The sheet comprising a glass-ceramic material of claim 1 , having a coefficient of thermal expansion (CTE), measured for a temperature variation ranging from 25 to 300° C., greater than 100×10 −7 /° C.
7. An article, comprising:
the sheet of claim 1 .
8. The sheet comprising a glass-ceramic material of claim 1 , being free of the element boron.
9. The sheet comprising a glass-ceramic material of claim 1 , wherein the amorphous matrix contains a maximum of 15% by weight of elements other than SiO 2 , Na 2 O, and CaO.
10. A sheet comprising a glass-ceramic material, comprising:
an amorphous matrix comprising, based on a total weight of the glass-ceramic material:
from 60 to 85% of SiO 2 ;
from 1 to 25% of Na 2 O;
from 1 to 25% of CaO;
less than 500 ppm by weight of the element lithium; and
crystalline particles consisting essentially of SiO 2 ,
wherein the crystalline particles are dispersed homogeneously in a volume of the amorphous matrix, and
wherein the crystalline particles have a size between 5 nm and 500 μm.
11. The sheet comprising a glass-ceramic material of claim 10 , wherein the crystalline particles have a size between 5 nm and 500 nm.
12. The sheet comprising a glass-ceramic material of claim 10 , wherein the crystalline particles have a size between 500 nm and 500 μm.
13. A sheet comprising a glass-ceramic material, comprising:
an amorphous matrix comprising, based on a total weight of the glass-ceramic material:
from 60 to 85% of SiO 2 ;
from 1 to 25% of Na 2 O;
from 1 to 25% of CaO;
less than 500 ppm by weight of the element lithium;
less than 500 ppm by weight of the element fluorine; and
crystalline particles consisting essentially of SiO 2 ,
wherein the crystalline particles are dispersed homogeneously in a volume of the amorphous matrix.
14. The sheet comprising a glass-ceramic material of claim 13 , wherein the crystalline particles have a size between 5 nm and 500 nm.
15. The sheet comprising a glass-ceramic material of claim 13 , wherein the crystalline particles have a size between 500 nm and 500 μm.