| 摘要 |
PURPOSE:To obtain a substrate which retains transparency, heat resistance, and mechanical properties, is improved in photoelastic coefficient, etc., and is suited for use as a structural material of an optical part or as a functional material by reacting a specific precursor with a chain terminator. CONSTITUTION:A dihydric phenol consisting mainly of 1,1-bis(4- hydroxyphenyl)-3,3,5-trimethylcyclohexane is reacted with a carbonate precursor and a chain terminator 45mol% or more of which is represented by the formula (wherein R is an aliphatic hydrocarbon group which may contain a 1-10C ether group; R' is a 1-10C aliphatic hydrocarbon group or a halogen; m is 4-20; n is 2-18; and p is 0-4) to obtain a polycarbonate resin which is a product of the reaction of an (un)substituted hydroxyaralkyl alcohol with a lactone. This polycarbonate satisfies the equations 0.23<=etasp<=0.37 and 30<=N<=60, wherein etasp is the specific viscosity of the polycarbonate and N is the content (mold) of the lactone units based on the sum of the dihydric phenol units and the lactone units. This polycarbonate is melted and molded into a substrate. |
