RAW FILM FOR RETARDATION FILM, RETARDATION FILM, AND LIQUID CRYSTAL DISPLAY

摘要

PROBLEM TO BE SOLVED: To provide a retardation film including a polypropylene resin having high transparency and less retardation irregularity.

SOLUTION: A raw film for a retardation film includes a propylene-based copolymer selected from a propylene-based random copolymer and a propylene-based block copolymer. The film contains smectic crystals by not less than 90% in the whole crystals in the propylene-based copolymer constituting the film, and has an in-plane retardation of 50 nm or less and a thickness of 30 to 200 μm. The propylene-based copolymer shows such properties that when a film consisting of the copolymer is stretched at a pulling rate of 100 mm/min at a temperature as to result in a stress at 200% strain of 0.8±0.1 MPa, a parameter (A) calculated by formula (1) defined in relation to the obtained stress-strain curve is in the range from 0.0007 to 0.1.

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