MANUFACTURING PROCESS OF ORIENTED FILM, RETARDATION FILM, CIRCLE POLARIZING PLATE, AND LIQUID CRYSTAL DISPLAY

摘要

PROBLEM TO BE SOLVED: To provide a wide-width and long oriented film which has no nonuniformity of the thickness in a width direction and dispersion in an orientation direction, is excellent in optical performance, and slants the axis of orientation in the range of a predetermined angle to a wind-up direction.

SOLUTION: A manufacturing process comprises the process of orienting a long non-oriented film including a thermoplastic resin in a direction perpendicular to its direction of travel to obtain a first oriented film having an angle of orientation of 0°≤θ1≤1° to a width direction and a birefringence Δn in the range of 0.001 to 0.003, and the process of obtaining a second oriented film having an angle of orientation θ2 in the range of 40°<θ2<50° to the wind-up direction by reorienting it in a tenter so as to satisfy each condition of (1) 1.0≤R2/R1≤2.0, (2) 0°≤θo≤θi≤6° and (3) 4°≤θo(max)+θi(max)≤7° while extending the first oriented film in a direction of an angle of 10°<θ<60° to the wind-up direction.

COPYRIGHT: (C)2008,JPO&INPIT