| 摘要 |
Provided is a method for producing an optical film which suffers neither flatness deterioration nor film breakage and is free from problems concerning undulating undulation and partial light leakage. The process for optical film production comprises laminating a cellulose ester resin layer (A) to an acrylic resin layer (B) by coextrusion. The process is characterized in that the cellulose ester resin layer (A) contains 55 to 99 mass % cellulose ester resin and the acrylic resin layer (B) contains 55 to 99 mass % acrylic resin, that the web is conveyed while keeping the layer (A) and the layer (B) in contact with the surface of a first cooling roll and the surface of a second cooling roll, respectively, and that when the surface temperature of the first cooling roll and the surface temperature of the second cooling roll are expressed by Ta (° C.) and Tb (° C.), respectively, then the Ta (° C.) and Tb (° C.) satisfy the following relationship (1). (Ta−80)° C.<Tb(° C.)<(Ta−5)° C.  Relationship (1) |
