| 摘要 |
PROBLEM TO BE SOLVED: To produce infrared absorption glass excellent in infrared absorptivity and capable of efficiently being sealed even in heated with the outer edge part of an infrared beam spot by specifying infrared transmissivity at a specific wavelength and by specifying chlorine content in glass. SOLUTION: This glass has <=10% infrared transmissivity at 1,050 nm wavelength at 0.5 mm thickness, <=150 ppm chlorine content, pref. <=5,000 ppm iron content and importantly (85-100)×10-7/ deg.C coefficient of linear thermal expansion at 30-380 deg.C. The glass pref. contains 60-75 wt.% SiO2, 1-10 wt.% Al2O3, 0-10 wt.% B2O3, 3.5-10 wt.% RO (R is at least one kind selected from the group consisting of Ca, Mg, Ba, Sr and Zn), 0.5-5 wt.% Li2O, 8-17 wt.% (Na2O+K2O) and 2-10 wt.% Fe3O4. |
