LIQUID CRYSTAL COMPOUND, POLYMERIZABLE LIQUID CRYSTAL COMPOSITION, OPTICALLY ANISOTROPIC MATERIAL, OPTICAL ELEMENT AND OPTICAL INFORMATION RECORDING/PLAYBACK DEVICE

摘要

A liquid crystal compound having a good durability against light, a polymerizable liquid crystal composition and an optically anisotropic material are provided. Further, an optical element having a good durability against light and an optical information writing/reading device employing such an element are provided. The liquid crystal compound is represented by a general formula CH 2 =CR 1 -COO-(L) k -E 1 -E 2 -(E 3 ) m -R 2 . E 1 is preferably a trans-2,6-decahydronaphthalene group and E 2 is preferably a trans-1,4-cyclohexylene group. A phase difference plate 4 produced by employing the compound has a good durability against light, and accordingly, it is possible to achieve an optical head device employing a blue laser as a light source 1 and being suitable for large capacity writing/reading.