Oxidic glasses containing metal nitride fluorides

摘要

In the production of oxidic, nitrogen-containing glasses whose chemical and physical properties have been improved by partial replacement of oxygen by nitrogen, oxide-analogous compounds of metal nitride fluorides are added to the powdered starting glasses in order to increase the optical refraction and hardening properties to a greater extent than is possible just by replacing oxygen by nitrogen with the aid of nitrides. The better solubility of oxide-analogous metal nitride fluorides in oxidic glass melts and the possibility of carrying out the melting without using a protective gas give advantages for the product through a higher nitrogen content without dark shades and for the process for the preparation of the product through the omission of the protective gas. The nitrogen content can be increased two-fold, for example from the content by weight of 3% to 6% or more.