GREY GLASS COMPOSITION FOR PRODUCTION OF WINDOWS

摘要

The subject of the invention is a gray glass composition of the soda-lime-silicate type having an overall light transmission under illuminant A (T_LA) greater than 67% for a glass thickness equal to 3.85 mm, which comprises the constituents below within the following limits by weight: SiO₂ 64-75% Al₂O₃ 0-5% B₂O₃ 0-5% CaO 5-15% MgO 0-5% Na₂O 10-18% K₂O 0-5% and the coloring agents below within the following limits by weight: Fe₂O₃ 0.25-0.65% and preferably 0.5-0.65% CoO less than 20 ppm, preferably less than or equal to 15 ppm NiO 40-250 ppm and preferably 70-150 ppm Se 0-5 ppm where Fe₂O₃ is the total iron.