| 摘要 |
Provided are an optical film using a cellulose derivative, useful in an image display device, such as a liquid crystal display or the like, a retardation film and a polarization film using the optical film, and a liquid crystal display having excellent view angle characteristics by using these films, while the optical film uses a cellulose derivative resin in which some hydrogen atoms of hydroxy groups of cellulose are substituted with three or more kinds of substituents. |
| 主权项 |
1. An optical film comprising a cellulose ester resin in which some hydrogen atoms of hydroxyl groups of cellulose are substituted with two kinds of acyl groups selected from an acetyl group and a propionyl group, or an acetyl group and a butyryl group, and some hydrogen atoms of the other hydroxyl groups not substituted with the acyl groups are substituted with substituents selected from Chemical Formula 1 or Chemical Formula 2: (In Chemical Formula 1, R1, R2 and R3 each are independently selected from the group consisting of H, (C1-C10)alkyl, and (C6-C30)aryl; and the alkyl and aryl may be further substituted with at least one of (C1-C10)alkyl, halogen, nitro, cyano, hydroxyl, amino, (C6-C30)aryl, (C2-C10)alkenyl, (C3-C20)cycloalkyl, 5-membered to 7-membered heterocycloalkyl containing at least one atom selected from N, O, and S, or (C4-C30)heteroaryl containing at least one atom selected from N, O, and S), (In Chemical Formula 2, R4 and R5 each are independently selected from the group consisting of (C1-C10)alkyl and (C6-C30)aryl; and the alkyl and aryl may be further substituted with at least one of (C1-C10)alkyl, halogen, nitro, cyano, hydroxyl, amino, (C6-C30)aryl, (C2-C10)alkenyl, (C3-C20)cycloalkyl, 5-membered to 7-membered heterocycloalkyl containing at least one atom selected from N, O, and S, or (C4-C30)heteroaryl containing at least one atom selected from N, O, and S), wherein the optical film includes a cellulose ester resin in which substitution degrees of the acyl groups satisfy Equations 1 and 3, or Equations 2 and 4 below and a substitution degree of a substituent selected from Chemical Formula 1 or Chemical Formula 2 is 0.01˜1.0:
1.9≦DSac+DSpr<2.8 [Equation 1]1.9≦DSac+DSbu<2.8 [Equation 2]1.8≦DSpr<2.7 [Equation 3]1.6≦DSbu<2.7 [Equation 4] (In Equations 1 to 4, DSac means substitution degree of acetyl group, DSpr means substitution degree of propionyl group, and DSbu means substitution degree of butyryl group). |
