Patent ID: 10358378

Abstract:
It is an object of the present invention to provide near infrared cutoff filter glass having a high transmittance in a visible light range and a low transmittance in a near infrared light range and being excellent in the devitrification resistance, even though the concentration of Cu components in the glass is high for forming a thin plate.A near infrared cutoff filter glass, which comprises, as represented by cation percentage: P5+ 30 to 50%, Al3+ 5 to 20%, R+ 20 to 40% (wherein R+ is the total amount of Li++Na++K+), R′2+ 5 to 30% (wherein R′2+ is the total amount of Mg2++Ca2++Sr2++Ba2++Zn2+), Cu2+ 3 to 15% and comprises, as represented by anion percentage: O2− 30 to 90% and F− 10 to 70%, wherein (Li++Na++K+)/(P5++Al3+) is from 0.45 to 1.0, and (Sr2++Ba2++Cu2+)/(Al3++Mg2++Ca2+) is from 0.5 to 1.0.