POLYMER FILM, WATERPROOF SOUND-TRANSMITTING MEMBRANE, WATERPROOF SOUND-TRANSMITTING MEMBER, ELECTRONIC DEVICE, CASE FOR ELECTRONIC DEVICE, WATERPROOF SOUND-TRANSMITTING STRUCTURE, WATERPROOF VENTILATION MEMBRANE, WATERPROOF VENTILATION MEMBER, WATERPROOF VENTILATION STRUCTURE, ADSORPTION SHEET, METHOD FOR ADSORBING WORK OBJECT TO ADSORPTION UNIT, METHOD FOR MANUFACTURING CERAMIC CAPACITOR, OPTICAL FILM, OPTICAL MEMBER AND COMPOSITION

摘要

This polymer film has through-holes extending from one main surface to the other main surface. The through-holes are straight holes each having a linearly extending central axis, and have a shape in which the area of the cross section perpendicular to the direction in which the central axis extends increases from one main surface of the polymer film toward the other main surface thereof. This polymer film has paths in the thickness direction, has a structure that does not exist in the prior art, and can be used in various applications including a waterproof sound-transmitting membrane, a waterproof ventilation membrane, and an adsorption sheet. The ratio of the opening diameter a of the through-hole in the one main surface to the opening diameter b of the through-hole in the other main surface, i.e., a/b, is, for example, 80% or less.