| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin provided with a low photoelastic constant and flowability suitable for molding at a high degree and capable of exhibiting negative birefringence, and an optical film using it. <P>SOLUTION: In the polycarbonate resin, a molar ratio (A/B) of a repeating unit represented by a repeating unit represented by formula (A) and an aliphatic carbonate repeating unit (B) is in the range of 60/40-90/10 and a specific viscosity measured in a methylene chloride solution at 20°C is 0.20-1.50. The optical film indicating the negative birefringence using the polycarbonate resin is provided. In formula, R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>, R<SB>4</SB>, R<SB>5</SB>and R<SB>6</SB>each independently represents a hydrogen atom or a 1-10C hydrocarbon group, R<SB>1</SB>and R<SB>2</SB>may be bonded to form a carbon ring or a heterocyclic ring, R<SB>4</SB>and R<SB>5</SB>may be bonded to form a carbon ring or a heterocyclic ring, and m and n represent the same or different integer of 1-4. In formula (B), R<SB>7</SB>represents a 2-18C alkyl group or a 4-20C cycloalkylene group and may contain oxygen, nitrogen and sulfur, and r represents an integer of 0 or 1. <P>COPYRIGHT: (C)2011,JPO&INPIT |
