PURPOSE: To obtain the subject glass by blending soda-lime-silica-based preform glass with whole iron, FeeO3, FeO, TiO2 and whole cerium in a specific ratio and making the ratio of FeO to whole iron in a given ratio.
CONSTITUTION: Soda-lime-silica-based preform glass (e.g. composition comprising 68-74wt.% SiO2, 0.5-3wt.% Al2O3, 3-5wt.% MgO, 6-10wt.% CaO, 10-16wt.% Na2O and 0-1wt.% SO3) is blended with 0.53-0.70wt.% calculated as Fe2O3 of whole iron 0.35-0.50wt.% Fe2O3, 0.16-0.24wt.% FeO, 0.2-0.4wt.% TiO2 and 0.5-0.8wt.% calculated as CeO2 of whole cerium and the weight of FeO calculated as Fe2O3 is 30-40wt.% the weight of whole iron calculated as Fe2O3 to give a raw material, which is fed to a furnace heated and melted at about 1,500°C and vitrified. Then the glass is clarified and molded to give the, objective glass having 1,7-7mm thickness, ≤50% sunlight transmittance (4mm) and ≤18% ultraviolet light transmittance (4mm).
KAMEI FUMIO
KONDO AKIRA
