Very fast fading photochromic glass.

摘要

The present invention relates to photochromic glasses exhibiting a darkened luminous transmittance at 40°C below 35 %and a five-minute fading rate at 40°C of at least 40 units of transmittance and a darkened transmittance at 25°C below 25 % and a five-minute fading rate at 25°C of at least 35 units of transmittance consist essentially, by weight, of:
<TableDetails id="tabla01" num="0001"><Image id="ia01" he="47" wi="45" file="IMGA0001.TIF" imgContent="table" imgFormat="TIFF" inline="no" /></TableDetails>wherein the levels of Ag, Br, Cl and CuO represent values as analysed in the glass.