| 摘要 |
<p>A birefringent film, a polycyclic compound, a coating liquid, and an image display device are provided to prevent cracks from being generated in the birefringent film even when the birefringent film is exposed to a high-temperature environment or a high-temperature and high-humidity environment for a long time. A birefringent film has a transmittance of 85% or more at the wavelength of 590 nm. In the birefringent film, a refractive index ellipsoid shows a relationship of nx>=nz>ny, wherein nx and ny denote refractive indices in directions perpendicular to each other within a plane of the birefringent film, and nz denotes a refractive index in a thickness direction of the birefringent film. In the birefringent film, an in-plane birefringence at the wavelength of 590 nm(Deltanxy) is 0.01 or more. The birefringent film has a thickness of 10 um or less. The birefringent film contains a lyotropic liquid crystalline polycyclic compound, which has an acenaphtho quinoxaline derivative unit in a molecular structure. The molecular weight of lyotropic liquid crystalline polycyclic compound is bigger than 500.</p> |
