Acrylic resin film and method for manufacturing same, polarizing plate protective film, and polarizing plate and liquid crystal display device including polarizing plate protective film

The purpose of the present invention is to provide an acrylic resin film having high water resistance and heat resistance, as well as high brittleness. This acrylic resin film includes a copolymer (I) including structural units derived from an aromatic vinyl compound (A) and structural units derived from a cyclic acid anhydride (B) at least a portion of the structural units derived from the cyclic acid anhydride (B) being decyclized.