Sodium/calcium glass composition having a green/yellow colour with high ultraviolet radiation absorption

摘要

Sodium/calcium glass composition having a green/yellow colour with high ultraviolet radiation absorption containing from 65 to 68% of SiO2, from 0 to 5% of Al2O3, from 6 to 13% of CaO, from 0 to 6% of MgO, from 10 to 15% of Na2O, from 0 to 5% of K2O, also containing Fe2O3, Cr2O3 and sulphur as colouring components, characterised in that: - the sulphur is partly in the form of sulphide and partly in the form of SO3, and the ratio between sulphide sulphur and SO3 sulphur is more than 1.5, - the concentration of Fe2O3 is greater than 0.6%, and - the concentration of Cr2O3 is less than 0.08%.