Laminated polyolefin films and methods of production thereof by coextrusion

A laminated polyolefin film with two or more layers is produced by coextrusion. An outer-layer forming material is prepared by with olefin resin containing specified kinds of non-ionic surfactant and salt of organic sulfonic acid in a specified amount and at a specified ratio. In the production of the laminated polyolefin film by coextrusion, this outer-layer forming material is used to form either one or both of the outer layers if the laminated film is to have three or more layers and to form only one of the outer layers if the laminated film is to have only two layers.