The optical film of the present invention is an optical film including a thermoplastic resin, in which the optical film has a moisture permeability of 70 g/m2/day or less (in terms of a film thickness of 40 μm), and contains a moisture permeability-reducing compound having a molecular weight of 200 or more and satisfying Formula (1) described below. Formula (1) A/B≤0.9 (A represents a moisture permeability of an optical film in a case in which 10 mass % of the moisture permeability-reducing compound is added to the mass of the thermoplastic resin, and B represents a moisture permeability of an optical film in a case in which the thermoplastic resin is included and the moisture permeability-reducing compound is not added.)
本发明的光学薄膜是一种包括热塑性
树脂的光学薄膜,其中光学薄膜的透湿性为 70 克/平方米/天以下(以薄膜厚度为 40 微米计),并含有分子量为 200 以上且满足下述式(1)的透湿性降低化合物。式(1)A/B≤0.9(A 表示在热塑性
树脂的质量中添加 10 质量%的透湿性降低化合物时光学薄膜的透湿性,B 表示包含热塑性
树脂且不添加透湿性降低化合物时光学薄膜的透湿性)。