Manufacturing method of polarizing plate protective film, polarizing plate protective film, polarizing plate, and liquid crystal display device

A process for producing a cellulose-ester-resin-containing protective film for polarizers through film formation by melt casting. The protective film diminishes long-period optical unevenness and suffers no unevenness even after long-term storage. Also provided are a protective film for polarizers, a polarizer employing the film, and a liquid-crystal display. The process for producing a protective film for polarizers is a process for producing by the melt casting method a polarizer-protective film containing a cellulose ester resin. The process for producing a protective film for polarizers is characterized in that the protective film contains at least one compound selected among compounds represented by the following general formula (I) and compounds having an acrylate or methacrylate group and a phenolic hydroxy group in the same molecule and that the protective film extruded from a casting die at a draw ratio of 10-30 during film formation by melt casting is transferred while holding/pressing it between a touch roll having an elastic surface and a cooling roll.