PURPOSE: To enhance the refractive index vertical to the film face with a single layer by using a film formable polymer contg. specified plural repeating units in a specified ratio as the main component.
CONSTITUTION: A film formable polymer consisting of 100-10mol% repeating unit shown by formula I and 0-90mol% repeating unit shown by formula II is used as the main component. In the formulas I and II, Ar is a 6-15C univalent aromatic group, a part or the whole of the hydrogens of the aromatic group can be substituted by 1-4C alkyl, halogen group, nitro group or nitrile group, and X1 to X4 are respectively hydrogen atom or halogen group and can be the same or different. Among such films, the film consisting of a polymer, wherein the Ar in the formula I is a phenyl group contg. a substituent having ≥0.2 Hammett value σ, is most preferable.
WATANABE TOSHIYUKI
IWATA KAORU
TEIJIN LTD