Manufacturing method of non-alkali glass substrate and non-alkali glass substrate

摘要

Provided are a non-alkali glass substrate having a high distortion point and excellent foam quality, and a method for manufacturing the same. As the glass composition, SiO250 to 70%, Al2O315 to 25%, B2O34.5 or more to 12%, MgO to 10%, CaO to 0 to 15%, SrO to 0 to 10%, BaO to 0 to 15%, by mass%, A batch preparation step for preparing a raw material batch so as to form a non-alkali glass containing ZnO 0 to 5%, ZrO 20 to 5%, TiO 20 to 5%, P2O 50 to 15%, and SnO 20 to 0.5%, and a prepared raw material. Including a melting step of melting the batch, a clarification step of clarifying the molten glass, and a molding step of forming the clarified glass into a plate shape, the bubble diameter of the obtained glass starts to increase from the maximum temperature in the clarification step. It is characterized in that the raw material batch is melted so that the temperature is lowered.