| 摘要 |
A cellulose acylate film is provided to obtain an optical film which has optical anisotropy and a large Re and is capable of being directly adhered to a polarizing film, and to allow production of a high-quality polarizing plate particularly useful as a retardation film. A cellulose acylate film has X-ray diffraction intensities satisfying the following formulae (I) to (III) and a half-width of the peak at 2[theta]2 is 3 deg. or less: 0.40<=Ic/(Iam+Ic)<=0.65 (I); Iam=I1 + {(I3-I1) / (2[theta]3 - 2[theta]1) * (2[theta]2 - 2[theta]1)} (II); and Ic=I2-Iam (III). In the formulae, when it is assumed that [theta] is the Bragg angle, 2[theta]1 represents 2[theta] where the intensity becomes the minimum in a range of 2[theta] of 4-5 deg.; 2[theta]2 represents 2[theta] where the intensity becomes the maximum in a range of 2[theta] of 5-10 deg.; 2[theta]3 represents 2[theta] where the intensity becomes the minimum in a range of 2[theta] of 14-16 deg.; I1 represents a diffraction intensity at 2[theta]1; I2 represents a diffraction intensity at 2[theta]2; and I3 represents a diffraction intensity at 2[theta]3. |
