| 摘要 |
PURPOSE:To obtain a molding tool which permits easy working, is resistant to surface roughening by oxidation and does not weld to glass by forming a Pt-Au alloy layer in the form of a film onto the surfaces of base plates of the molding tool which are made of WC and are worked to a plunger die of a lens shape. CONSTITUTION:Softened glass 4 to be molded is press-molded between an upper die 1 and lower die 2 which are formed slidable on the inside peripheral faces of guide dies 3 and have a desired die surface shape to obtain the glass lens. The base plates 1a, 2a of the upper and lower dies 1, 2 of the molding tool for the glass tool constituted in the above-mentioned manner are made of WC and are subjected to an HIP treatment to increase the density thereof and after the base plates are worked to the prescribed circular columnar shape, the end faces are finished to an optical mirror surface having a concave spherical shape. The Pt-Au alloy is formed by sputtering, etc., in the form of the film onto the above-mentioned end faces to provide surface layers 1b, 2b thereto. The film thickness of the Pt-Au alloy is adequately in a 50-3,000Angstrom range and the compsn. thereof is adequately 99-46wt% Pt and 1-54% Au.
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