To obtain a material which satisfies both a superior moldability and a low brefringence efficiency by using a polycarbonate resin derived from three kinds of bisphenols and having a specific composition and a specific limiting viscosity.
The molding material for optical recording media has structural units expressed by formulae I, II and III, including a unit of the formula I by 5-50 mol.% in the total structural units and having a limiting viscosity of 0.30-0.50 dl/g. Preferably, 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spiroindane, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisphenol and 2,2-bis(4-hydroxyphenyl) propane deriving the formulae I-III respectively are reacted with phosgene to obtain the material. A polymerization degree is adjusted by a univalent phenol with the use of an acid binder such as pyridine or the like, a solvent such as methylene chloride or the like, and a catalyst of quaternary ammonium and tertiary amine. Particularly, the material is suitable to writable optical disks and magneto-optic disks.
MASUMOTO MITSUHIKO
HONDA NORIAKI
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