Glass-ceramic materials, precursor glass thereof and process for making the same
AssigneeEurokera
InventorMarie Jacqueline Monique Comte
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Abstract
The invention relates to: a method of preparing glass-ceramics of β-quartz and/or of β-spodumene; a method of preparing articles made from said glass-ceramics; novel glass-ceramics of β-quartz and/or of β-spodumene; articles made from said novel glass-ceramics; and lithium aluminosilicate glasses, which are precursors of such novel glass-ceramics. The present invention relates to the use, as agent for fining the glass-ceramic glass precursor, of fluorine and at least one oxide of a multivalent element.
Claims10
A glass-ceramic containing a solid solution of β-quartz or of β-spodumene or solid solutions of β-quartz and β-spodumene, as main crystalline phase(s), the composition of which, expressed as percentages by weight of oxides, essentially consists of:
- SiO2
- 60-72
- Al2O3
- 18-23
- Li2O
- 2.5-4
- MgO
- 0.5-2
- ZnO
- 1-3
- TiO2
- 1.5-3.5
- ZrO2
- 0-2.5
- BaO
- <2
- SrO
- 0-2
- CaO
- 0-2
- Na2O
- 0-1.5
- K2O
- 0-1.5
- P2O5
- 0-5
- B2O3
- 0-3
- F
- 0.05-1,
- advantageously 0.05-0.3;
- and at least one oxide of a multivalent element selected from the group consisting of SnO2, V2O5, CeO2, MnO2 and Fe2O3, wherein each respective one of said at least one multivalent element oxide comprises at least 0.15% of the glass-ceramic, such that the sum of said multivalent element oxide(s) comprises 0.2-2% of the glass ceramic, wherein SnO2, if included, comprises 0.15-0.7% of the glass-ceramic, and barium oxide is present in an amount up to 2%.
A glass-ceramic containing a solid solution of β-quartz or of β-spodumene or solid solutions of β-quartz and β-spodumene, as main crystalline phase(s), the composition of which, expressed as percentages by weight of oxides, essentially consists of:
- SiO2
- 65-70
- Al2O3
- 18-19.8
- Li2O
- 2.5-3.8
- MgO
- 0.55-1.5
- ZnO
- 1.2-2.8
- TiO2
- 1.8-3.2
- BaO
- 0-1.4
- SrO
- 0-1.4
- with BaO + SrO
- 0.4-1.4
- with MgO + BaO + SrO
- 1.1-2.3
- ZrO2
- 1.0-2.5
- Na2O
- 0-<1.0
- K2O
- 0-<1.0
- with Na2O + K2O
- 0-<1.0
- with 2.8Li2O + 1.2ZnO/5.2MgO
- >1.8
- F
- 0.05-1,
- advantageously 0.05-0.3;
- and at least one oxide of a multivalent element selected from the group consisting of SnO2, V2O5, CeO2, MnO2 and Fe2O3, wherein each respective one of said at least one multivalent element oxide comprises at least 0.15% of the glass-ceramic, such that the sum of said multivalent element oxide(s) comprises 0.2-2% of the glass ceramic, and SnO2, if included, comprises 0.15-0.7% of the glass-ceramic.
A glass-ceramic containing a solid solution of β-quartz or of β-spodumene or solid solutions of β-quartz and β-spodumene, as main crystalline phase(s), the composition of which, expressed as percentages by weight of oxides, essentially consists of:
- SiO2
- 65-70
- Al2O3
- 18-20.5
- Li2O
- 2.5-3.8
- MgO
- 0.55-1.5
- ZnO
- 1.2-2.8
- BaO
- 0-1.4
- SrO
- 0-1.4
- with BaO + SrO
- 0.4-1.4
- with MgO + BaO + SrO
- 1.1-2.3
- Na2O
- 0-<1
- K2O
- 0-<1
- with Na2O + K2O
- 0-<1
- with (2.8 Li2O + 1.2 ZnO)/5.2 MgO
- >1.8
- TiO2
- 1.8-3.5
- ZrO2
- 0.8-1.6
- with
-
-
- TiO
- 2
- ZrO
- 2
- >2.2
- F
- 0.05-1,
- advantageously 0.05-0.3;
- and at least one oxide of a multivalent element selected from the group consisting of SnO2, V2O5, CeO2, MnO2 and Fe2O3, wherein each respective one of said at least one multivalent element oxide comprises at least 0.15% of the glass-ceramic, such that the sum of said multivalent element oxide(s) comprises 0.2-2% of the glass ceramic, and SnO2, if included, comprises 0.15-0.7% of the glass-ceramic.
Dependencies are inferred from the claim text.