| 摘要 |
The present invention relates to a production method for a non-alkali glass, containing putting glass raw materials in a melting furnace, heating to a temperature of 1,350 to 1,750° C. to prepare a molten glass, and forming the molten glass into a sheet shape by float method, in which the heating in the melting furnace concurrently utilizes heating by combustion flame of burners and electrical heating of the molten glass by heating electrodes arranged so as to be dipped in the molten glass in the melting furnace, and in which when electrical resistivity at 1,350° C. of the molten glass is represented by Rg (Ωcm) and electrical resistivity at 1,350° C. of a refractory constituting the melting furnace is represented by Rb (Ωcm), the glass raw materials and the refractory are selected so as to achieve Rb>Rg. |
| 主权项 |
1. A production method for a non-alkali glass, comprising mixing glass raw materials so as to have the following glass composition, putting it in a melting furnace, heating to a temperature of 1,350 to 1,750° C. to prepare a molten glass, and forming the molten glass into a sheet shape,
wherein the heating in the melting furnace concurrently utilizes heating by combustion flame of burners and electrical heating of the molten glass by heating electrodes arranged so as to be dipped in the molten glass in the melting furnace, and wherein when electrical resistivity at 1,350° C. of the molten glass is represented by Rg (Ωcm) and electrical resistivity at 1,350° C. of a refractory constituting the melting furnace is represented by Rb (Ωcm), the glass raw materials and the refractory are selected so as to achieve Rb>Rg: in terms of mol % on the basis of oxides thereof:SiO266 to 70,Al2O312 to 15,B2O30 to 1.5,MgOmore than 9.5 and 13 or less,CaO4 to 9,SrO0.5 to 4.5,BaO0 to 1,ZrO20 to 2; and comprising an alkali metal oxide in an amount of 600 to 2,000 ppm, wherein MgO+CaO+SrO+BaO is 17 to 21, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, MgO/(MgO+CaO) is 0.40 or more, and MgO/(MgO+SrO) is 0.60 or more. |
