Patent ID: 6747080
Filing Date: 2004-06-08
Classification: C08K,G11B,Y10T

Abstract:
A polycarbonate resin composition for the production of a substrate for an optical information medium, comprising:100 parts by weight of a polycarbonate resin (A) comprising a plurality of aromatic polycarbonate main chains, and 0.0005 to 1.0 part by weight of a mold release agent (B), wherein said polycarbonate resin composition exhibits a relative viscosity (&eegr;r) within the range of from 1.17 to 1.19, said relative viscosity (&eegr;r) being defined as the ratio (&eegr;/&eegr;o) of viscosity value (&eegr;) of a methylene chloride solution of said polycarbonate resin composition to viscosity value (&eegr;o) of methylene chloride, wherein the concentration of the polycarbonate resin composition in said methylene chloride solution is 0.005 g/cm3 and each of said viscosity values (&eegr;) and (&eegr;o) is measured at 25Â° C., and wherein said relative viscosity (&eegr;r) of the polycarbonate resin composition and a melt index (MI) of the polycarbonate resin composition as measured at 280Â° C. under a load of 2.16 kg in accordance with JIS K 7210 satisfy the following formulae (I) and (II): &eegr;r&gE;âˆ’0.0723 log MI+1.316â€ƒâ€ƒ(I) and &eegr;r&lE;âˆ’0.0723 log MI+1.324â€ƒâ€ƒ(II).