| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for molding an optical disk characterized by low scattering in double refraction rate and no double transfer. SOLUTION: A substrate for an information recording medium is formed by arranging a stamper having a rugged pattern to be transferred to a substrate formed on one inner surface of a mold composed of a moving die and a fixed die in an injection molding machine equipped with a toggle linking mechanism, injecting and filling a melt resin made of a thermosetting resin material into a cavity formed between the other inner surface of the mold, compression molding is carried out with a set compression force for the first stage and at least a step higher set compression force. In such case, the set compression force for the first stage is set at a lower pressure in terms of the resin pressure than a resin pressure which occurs when a melt resin is injected, and at least a step higher set compression force is set at resin pressure higher in terms of the resin pressure than a peak resin pressure which occurs at the time of injection, and the retaining time of the set compression force for the first stage is set between 1 second and four seconds. |
