To improve adhesion/adhesive properties with another member by forming a film or a sheet having high appearance and shape stability without a wrinkle or a warp, providing a process which can remove the residual solvent of the film or the sheet and high transparency and heat resistance obtained by the process, improving destructive characteristics in forming of the film or the sheet by a solution casting process with a cycloolefin addition polymer.
The film or the sheet for an optical material is obtained by dissolving the cycloolefin addition polymer of a specific structure by using a mixed solvent containing a solvent (I) for dissolving the polymer at 25°C and having a boiling point at 1 atm or lower of 130°C or lower and a solvent (II) for not dissolving the polymer at a boiling point at 1 atm or lower of 150°C or lower for dissolving the polymer at 25°C as a cast solvent, and depositing the film by a solution casting process.
TSUBOUCHI TAKASHI
OSHIMA NOBORU
