| 摘要 |
1,208,020. Glass compositions. ERNST LEITZ G.m.b.H. 20 Dec., 1967 [31 Dec., 1966], No. 57785/67. Heading C1M. An I.R.-transparent glass comprises by wt.: GeO 2 , 10-50%; Bi 2 O 3 and/or Tl 2 O 3 , total 50-80%; up to 5% GeO 2 may be replaced by PbF 2 ; the balance, if any, consisting of other compatible constituents. Up to 33% of PbO and/or PbF 2 may be present. The glass may have R.I. > 1.8400 in the I.R. |
