| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical disk base with good characteristics by devising a method for controlling mold clamping force or compression force immediately before cooling process is completed and avoiding inferiority of mold releasing of a molded base and deterioration of characteristics of the base as the result in a method for molding the optical disk base in which at the same time when thickness is made thin, good mechanical characteristics and such characteristics as transferring properties are required and as the result, inferiority of mold release operation and deterioration of characteristics of the molded base are easily generated. SOLUTION: A method for molding by which a thin optical disk base such as a DVD is molded by means of an injection molding process or an injection compression molding process is predicated on a method for molding in which the maximum mold clamping pressure or the maximum compression force (P1) is suddenly decreased to a pressure (P2) and cooling is performed while the pressure (P2) is held and by performing a pressure decreasing operation wherein the pressure (P2) is suddenly decreased to a low pressure (P3) in a short time where the cooling process is completed and just before mold opening action is started, pressure fluctuation in the molded base is solved and the molded base is uniformly released from a stamper.
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