| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase difference film that has an appropriate expression of phase difference (retardation) and has a sufficiently-small variation in phase difference against a variation in environmental humidity, and to provide a manufacturing method thereof. <P>SOLUTION: A phase difference film containing acetylcellulose includes an optically anisotropic layer a, and an optically isotropic layer b and an optically isotropic layer c that are laminated on both sides of the optically anisotropic layer a. The optically anisotropic layer a contains acetylcellulose whose acetyl substitution degree is within a range of 1.5 to 2.3. And, when setting a thickness of the optically anisotropic layer a as d<SB POS="POST">a</SB>, and setting each thickness of the optically isotropic layers b and c as d<SB POS="POST">b</SB>and d<SB POS="POST">c</SB>, relational expressions of 3.0>d<SB POS="POST">b</SB>and d<SB POS="POST">c</SB>>1.0×d<SB POS="POST">a</SB>are formed, and a total thickness d(=d<SB POS="POST">a</SB>+d<SB POS="POST">b</SB>+d<SB POS="POST">c</SB>) of the laminated layers is within a range of 30 to 55 μm. <P>COPYRIGHT: (C)2012,JPO&INPIT |
