PROTECTIVE FILM FOR POLARIZING PLATE, METHOD FOR PRODUCTION OF FILM, POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY ELEMENT

摘要

Disclosed is a method for production of a film, which comprises the steps of: extruding a molted material containing a cellulose resin on a cooling roll from a die in a film-like form at a draw ratio ranging from 10 to 30 inclusive; pressing the extruded molted film on the cooling roll with a touch roll; and transferring the molted film while solidifying the film on the cooling roll, wherein the touch roll has a metal-made outer cylinder, an inner cylinder, and a space for accommodating a cooling medium between the metal-made outer cylinder and the inner cylinder and also has a touch roll linear pressure ranging from 1 to 15 kg/cm inclusive during pressing with the touch roll. A protective film for a polarizing plate, a polarizing plate and a liquid crystal display element can be provided which are free from the concern of formation of light-dark lines or spot-shaped unevenness caused by die lines formed upon displaying an image using a liquid crystal display element and are formed using a cellulose ester resin by a melt film casting method.