Barrier film for wavelength conversion sheet, wavelength conversion sheet, backlight, and liquid crystal display device using barrier film, and method for selecting barrier film for wavelength conversion sheet

Abstract

Provided is a barrier film for a wavelength conversion sheet that, when applied to a wavelength conversion sheet, can suppress in-plane uneven brightness of the wavelength conversion sheet. A barrier film for a wavelength conversion sheet, the barrier film including a first base material film, a second base material film, a barrier layer, a primer layer, and an adhesive layer positioned between the first base material film and the second base material film, wherein the barrier film satisfies the following condition 1: <Condition 1> A surface of the barrier film on a side having the primer layer with respect to the adhesive layer is defined as a surface 1; an elevation of the surface 1 is measured at intervals of 1 mm to obtain elevation data about the surface 1; a contour curve of the surface 1 determined by the elevation data is defined as a contour curve 1; at least a part of the surface 1 has at least one irregularity 1 having a height difference between an adjacent peak and valley of 0.001 mm or more and 0.600 mm or less in the contour curve 1 in a predetermined direction; when a height difference and a width of the irregularity 1 are defined as H [mm] and W [mm], respectively, the following expression (1): H/W≤1.5×10(1) is satisfied.