METHOD FOR MANUFACTURING UNSTRETCHED SHEET FOR MOLDING FILM CONTAINING CAVITIES AND FILM CONTAINING CAVITIES

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an unstretched sheet for molding a film containing cavities in which a non-compatible polymer is uniformly dispersed regardless of the content of the non-compatible polymer and a homogeneous film internally containing a large number of cavities.

SOLUTION: This method for manufacturing an unstretched sheet for molding a film containing cavities is characterized in that a matrix polymer and a polymer which is non-compatible with the former are melted and mixed inside an extruder, then the mixture is made to pass through an extension fluid mixer with a series of chambers partitioned by slits and extruded from a die to obtain the unstretched sheet. In addition, the film containing cavities is manufactured by stretching the unstretched sheet obtained by the described manufacturing method in at least a monoaxial direction.

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