METHOD FOR MANUFACTURING DISK PLATE

摘要

PROBLEM TO BE SOLVED: To provide a technique for stably molding a disk plate from polycarbonate.

SOLUTION: When molding a disk plate of a 120mm in outer diameter and 1.1 to 1.2mm thick from a polycarbonate resin by coupling a 90 to 10 mole% dihydroxy-compound expressed by a general formula (1), and a 90 to 10 mole% dihydroxy-compound expressed by a general formula (2), a resin is to be used as the polycarbonate resin, exhibiting melt viscosity η (unit : poise) of 200<η<2500 in the range of shear rate γ (unit : sec-1) of 6×102<γ<6.1×103at 300°C.

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