Glass sheet with porous coating film and method of producing same

A coated glass sheet comprising:

• a glass sheet;
• and
• a coating film provided on at least one principal surface of the glass sheet and having a smooth surface,
• wherein the coating film comprises:
• closed pores;
• and a matrix,
• the coating film is substantially free of open pores open at the surface of the coating film,
• a transmittance gain is 2.5% or more, the transmittance gain being calculated by subtracting an average transmittance of the glass sheet as determined by applying light having wavelengths of 380 to 1100 nm to the glass sheet in the absence of the coating film on the surface of the glass sheet from an average transmittance of the coated glass sheet as determined by applying light having the wavelengths to the coated glass sheet,
• the closed pores, when viewed in a cross-section along a thickness direction of the coating film, include first closed pores that are approximately elliptical isolated pores and second closed pores each formed of two or more approximately elliptical pores connected to each other,
• the first closed pores and the approximately elliptical pores forming the second closed pores each have a major axis with a length of 30 to 80 nm and a minor axis with a length of 20 to 30 nm and are arranged so that the major axes extend along the surface of the coating film,
• the matrix of the coating film comprises silica as a main component,
• the silica is derived from a product of hydrolysis and condensation of a silicon alkoxide, and
• the silicon alkoxide consists of a silicon alkoxide having one or two alkyl groups directly bonded to a silicon atom.