COMPOSITION OF GREY GLASS Russian patent published in 2011 - IPC C03C3/95 

FIELD: construction.

SUBSTANCE: glass composition contains the main glass composition, including the following components: SiO₂ from 65 to 75 wt %, Na₂O from 10 to 20 wt %, CaO from 5 to 15 wt %, MgO from 0 to 5 wt %, Al₂O₃ from 0 to 5 wt %, K₂O from 0 to 5 wt % and BaO from 0 to 1 wt % and a pigment and a property-changing part of the composition, including total iron from 0.25 to 0.9 wt %, Cr₂O₃ from 6 parts/million to 400 parts/million, Er₂O₃ from 0.3 to 3.0 wt %, and TiO₂ from 0.1 to 0.8 wt %. Besides, the glass composition has the value of oxidation-reduction ratio within the range from 0.15 to 0.62.

EFFECT: provision of Lta value equal or more than 65 %, TSET of less or equal to 57 %, and SAE UV of less or equal to 47 %.

13 cl, 4 tbl