METHOD FOR MANUFACTURING LOW ALKALI GLASS PLATE, AND LOW ALKALI GLASS PLATE

WIPO Patent Application WO/2021/261446

A1

The present invention provides a low alkali glass plate that has a high strain point and excellent bubble quality, and a method for manufacturing the same.　This method for manufacturing a low alkali glass plate comprises: a batch preparation step for preparing a starting material batch so as to give a low alkali glass that comprises, as a glass composition in terms of mass%, 50-70% of SiO2, 15-25% of Al2O3, 1.8-4.5% of B2O3, 0-10% of MgO, 0-10% of CaO, 0-10% of SrO, 0-15% of BaO, 0-5% of ZnO, 0-1% of ZrO2, 0-5% of TiO2, 0-10% of P2O5 and 0.1-0.5% of SnO2; a melting step for melting the starting material batch thus prepared; a clarification step for clarifying the melted glass; and a shaping step for shaping the clarified glass into a plate, said method being characterized in that, when the content of B2O3 is referred to as x (mass%) and the β-OH value of the obtained low alkali glass plate is referred to as y (/mm), then the content of B2O3 and the β-OH value are adjusted so as to establish the relational expression y=ax+b (wherein 0.03