METHOD FOR PRODUCING GLASS SUBSTRATE AND GLASS SUBSTRATE PRODUCTION APPARATUS

摘要

PROBLEM TO BE SOLVED: To suppress a contamination of a foreign material formed from platinum or platinum alloy evaporated from a refiner used in a production process of a glass substrate in the production of the glass substrate.SOLUTION: In the production of a glass substrate, refining including defoaming for discharging the foam from a molten glass to a vapor phase space by heating the molten glass is carried out while raw materials of glass is melted to form the molten glass and the molten glass is passed in a refiner including a heated long tubing consisting of platinum or platinum alloy with the vapor phase space being formed, in which the tube of the refiner is formed so that the vapor phase space does not exist at a portion of the tube of which temperature is equal to or less than the coagulation temperature of volatile platinum contained in the vapor phase space at least in part.