Patent ID: 8887528

Claim:
A process for producing a surface-treated glass plate having a plurality of concave portions on a surface of a glass plate, the method comprising: providing a glass plate having a strain point; heating the glass plate in a range from the strain point (°C.) to the strain point +250 (°C.); exposing the heated glass plate to an atmosphere containing water in a concentration of 0.01 to 20 g/L so as to form a hydrated layer only on a surface of the heated glass plate to generate a phase separation which separates to a high SiO 2 phase and a high alkaline-containing phase in the hydrated layer: wherein exposing the heated glass plate to the atmosphere generates phase separation from the surface to 1 μm or less of the heated glass plate; wherein the temperature of the glass plate when exposing the heated glass plate to the atmosphere is from the strain point of the glass to the strain point +250° C.; and washing the glass plate to remove the high alkaline- containing phase; wherein the plurality of concave portions having a range of average open pore diameter/depth of 10/100 to less than 1000/50 are formed on the surface of the glass plate after washing the glass plate.