POLYMER RESIN FILM, AND AIR PERMEABLE FILM, SOUND PERMEABLE FILM, ACOUSTIC RESISTOR, AIR PERMEABLE FILM MEMBER, SOUND PERMEABLE FILM MEMBER, ACOUSTIC RESISTOR MEMBER, AND ACOUSTIC EQUIPMENT PROVIDED WITH SAID POLYMER RESIN FILM, AND METHOD FOR MANUFACTURING POLYMER RESIN FILM

摘要

A polymer resin film of the present disclosure has a plurality of through holes extending through the thickness of the polymer resin film. The through holes penetrate a substrate structure of the resin film. The through holes have openings formed in both a first principal surface and a second principal surface of the film. The through holes have a shape in which the area of a cross-section perpendicular to a direction in which the through holes extend is constant from the first principal surface of the film to the second principal surface of the film or increases from the first principal surface toward the second principal surface. The openings in the first principal surface have a diameter of 3 µm or more and 80 µm or less. A variation in a porosity defined by the openings in the first principal surface is 10% or less. A variation in the density (number/cm 2 ) of the openings in the first principal surface is 1000 openings/cm 2 or less. The polymer resin film of the present disclosure is a polymer membrane having air permeability through its thickness, and unevenness of the air permeability in the polymer resin film is smaller than in conventional membranes.