COLOURLESS INORGANIC GLASSES WITH A SHARP OPTICAL ABSORPTION CUTOFF BETWEEN 370 AND 425 nm; PRODUCTS FROM SAID GLASSES

摘要

The present invention represented by _{cationic%, 23-73% SiO 2, 15-45} % B 2 O 3, 0-24% Al 2 O 3, 0-12% Li 2 O, 0-20% Na 2 O, 0 _{-12% K 2 O, 0.25-5%} CaO + BaO + SrO, 0.125-1% Cu 2 O, 0-1% CdO, 0-5% ZrO 2, 0-1.75% Cl, 0-2% Br , and essentially of a composition of 0-2% F, and when the Cl, Br and F content is expressed as% by weight of the total composition is Cl + Br 0.25-2% and a large weight percentage of bromine than the weight content of chlorine ( Br Cl);_{SnO 2, As 2 O 3,} Sb 2 O 3 and obtain the appropriate amount of a reducing agent preferably selected from the mixtures thereof having a copper mainly in the form of copper ions (Cu ⁺⁾ of the glass, and thus does not have a red or blue-green; Has a residual yellow minimized in accordance with standard T51-067 (NF); Containing copper halides or copper cadmium halides, and relates to colorless inorganic glasses of the type having a sharp optical absorption blocking between 370nm to 425nm.