| 摘要 |
<p>The purpose/object of the present invention is to provide ultraviolet light-transmitting glass which has excellent transmittance in the ultraviolet region of 300 nm or less. Ultraviolet light-transmitting glass of the present invention contains, in wt% in terms of oxides, 10-40% of SiO2, 10-40% of B2O3, 2-7% of Al2O3, 0-5% of Li2O, 0-8% of Na2O, 0-8% of K2O (provided that Li2O + Na2O + K2O = 0-10%), 0-40% of CaO, 0-40% of BaO, 0-10% of ZnO (provided that CaO + BaO + MgO + SrO + ZnO = 1-40%), 0-17% of Y2O3, 0-18% of ZrO2, 0-15% of La2O3 (provided that at least one of Y2O3, ZrO2 or La2O3 is contained) and 0-0.5% of Sb2O3. By having fine crystals deposit, a sample of the ultraviolet light-transmitting glass having a thickness of 2.0 mm has a transmittance at 250 nm of 60% or more.</p> |
