Process for forming glass or glass ceramic and for making suitable mould

摘要

Production of a mold for hot deformation of glass or glass ceramics comprises producing the mold as a glass ceramic mold from a starting glass by casting and converting into a keatite glass ceramic with a predominant keatite mixed crystal phase by heat treatment. Independent claims are also included for the following: (1) process for molding glass or glass ceramic; (2) mold produced by the above method; and (3) molded body made from a glass or glass ceramic.