Polymer resin film, and air-permeable membrane, sound-permeable membrane, acoustic resistor, air-permeable membrane member, sound-permeable membrane member, acoustic resistor member, and audio device that include the polymer resin film, and method for producing the 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.