| 摘要 |
PROBLEM TO BE SOLVED: To obtain dies having a nitride which prevents the fusion of the dies to glass at the time of forming the glass as protective films and suitable for use in the production of an optical lens by a reheating-pressing method by forming nitrogen compd. films having a specified concn. of oxygen on the surfaces of dies for forming glass. SOLUTION: The dies have nitrogen compd. films having <8 at.% concn. of oxygen on the surfaces. The base material of the dies is preferably silicon carbide, a cemented carbide or silicon nitride. The nitrogen compd. effective for protective films is, e.g. boron nitride, aluminum nitride, titanium nitride or chromium nitride. In order to form the films, magnetron sputtering or vacuum deposition is adopted. It is preferable that the films are formed in an atmosphere of hydrogen and annealed in the atmosphere or treated with hydrogen plasma. The films may be formed in 500-30,000Åthickness in a high vacuum of <=10<-7> Torr.
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