| 摘要 |
PURPOSE: To obtain the subject molding material containing structural units having a fluorene structure, excellent in heat resistance, moldability, etc., reduced in birefringence, and useful for optical recording media such as compact disks and laser disks. CONSTITUTION: This molding material comprises a polycarbonate having an intrinsic viscosity of 0.30-0.50dl/g and comprising fluorene structure-having structural units of formula I (R1 -R4 are H, F, Cl, Br, 1-5C alkyl, 6-12C aryl, 7-17C aralkyl, etc.) and structural units of formula II (R5 -R8 are H, F, Cl, Br, I, 1-5C alkyl, 6-12C aryl, 7-17C aralkyl, etc.; X is -S-, -O-, etc.) wherein the structural units of formula I are 5-40mol.%, preferably 15-30mol.%, in the whole structural units. The structural units of formula II is preferably derived from 2,2-bis(4-hydroxyphenyl)propane, and the structural units of formula I is also preferably derived from 9,9-bis(4-hydroxyphenyl)fluorene, etc. |
