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US 6,664,203 B2Granted
Alkali free glass, production method therefor, and flat display panel using the same
AssigneeNippon Sheet Glass Co., Ltd.
InventorsYukihito Nagashima, Yoshikazu Toshikiyo
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Abstract
The present invention can provide an alkali free glass containing as a refining agent, a tin oxide and at least one selected from the group consisting of a cerium oxide, a manganese oxide, a tungsten oxide, a tantalum oxide and a niobium oxide.
Claims8
An alkali-free glass comprising:
- (A) a composition including:
- 50 to 70 wt % of SiO2;
- 7.5 to 20 wt % of Al2O3;
- 10 to 15 wt % of B2O3;
- 0 to 5 wt % of ZnO;
- and
- 5 to 30 wt % of at least one of MgO, CaO, SrO and Bao, in which an amount of MgO is 0 to 8 wt %, an amount of CaO is 0 to 10 wt %, an amount of SrO is 0 to 8 wt % and an amount of BaO is 0 to 15 wt %;
- wherein the composition shows a temperature for a viscosity at 102 dPas being equal to or higher than 1,615 ° C., and the composition does not substantially contain each of ZrO2 and an alkali metal oxide;
- (B) total tin oxide in an amount of 0.1 to 2 wt %, as a refining agent, based on the weight of the composition (A);
- and
- (C) at least one of total cerium oxide, total manganese oxide, total tungsten oxide, total tantalum oxide and total niobium oxide in an amount of 0.1 to 1 wt %, as a refining agent, based on the weight of the composition (A).
8 more elements
A method for producing an alkali-free glass, comprising the steps of:
- (i) preparing a glass batch comprising:
- in terms of an oxide
- 50 to 70 wt % of SiO2;
- 7.5 to 20 wt % of Al2O3;
- 10 to 15 wt % of B2O3;
- 0 to 5 wt % of ZnO;
- and
- 5 to 30 wt % in total of at least one of MgO, CaO, SrO and BaO, in which an amount of MgO is 0 to 8 wt %, an amount of CaO is 0 to 10 wt %, an amount of SrO is 0 to 8 wt % and an amount of BaO is 0 to 15 wt %,
- wherein the glass batch shows a temperature for a viscosity at 102 dPas being equal to or higher than 1,615° C., and the glass batch does not substantially contain each of ZrO2 and an alkali metal oxide;
- (ii) melting the glass batch;
- and
- (iii) forming the melted batch,
- wherein SnO2 and at least one of CeO2, MnO2, WO3, Ta2O5 and Nb2O5 are added to the glass batch as a refining agent in amounts of 0.1 to 2 wt % and 0.1 to 1 wt %, respectively, based on the weight of the glass batch.
10 more elements
Dependencies are inferred from the claim text.