POLARIZING PLATE AND IMAGE DISPLAY DEVICE

PROBLEM TO BE SOLVED: To provide a polarizing plate excellent in thermal durability and optical characteristics.SOLUTION: The polarizing plate of the present invention has a retardation film comprising a cellulose ester, a polyene-based polarizer, a polarizer protective film in contact with the polyene-based polarizer, and a hard coat layer disposed on a surface of the retardation film. The retardation film has a slow axis and shows an in-plane retardation Roof 80 nm or more and 160 nm or less at a wavelength of 550 nm. The slow axis forms an angle θ of 30° or more and 60° or less with respect to the longitudinal direction of the retardation film, and an angle of 30° or more and 60° or less with respect to an absorption axis of the polyene-based polarizer. A difference |ΔL-ΔL| between a dimensional change rate ΔLin the slow axis direction within the plane of the retardation film when the retardation film is stored in an environment of 105°C and 0% RH for 60 minutes, and a dimensional change rate ΔLof the retardation film in a direction perpendicular to the slow axis, is 0.01% or more and 0.30% or less.SELECTED DRAWING: Figure 1 【課題】熱耐久性及び光学特性に優れた偏光板を提供する。【解決手段】本発明の偏光板は、セルロースエステルを含有する位相差フィルムと、ポリエン系偏光子と、前記ポリエン系偏光子に接する偏光子保護フィルムと、前記位相差フィルムの表面に設けられたハードコート層とを有し、前記位相差フィルムは、遅相軸を有し、かつ波長５５０ｎｍにおける面内位相差Ｒｏ550が８０ｎｍ以上１６０ｎｍ以下であり、前記遅相軸は、前記位相差フィルムの長尺方向に対する角度θが３０°以上６０°以下であり、かつ前記ポリエン系偏光子の吸収軸に対する角度が３０°以上６０°以下であり、前記位相差フィルムを１０５℃の温度・相対湿度０％ＲＨの環境下に６０分間保管した前後の位相差フィルム面内の遅相軸方向の寸法変化率ΔＬθと、前記位相差フィルムの遅相軸に垂直な方向の寸法変化率ΔＬθ+90との差｜ΔＬθ−ΔＬθ+90｜が０．０１％以上０．３０％以下である。【選択図】図１