Abstract:
A water-proof air-permeable filter (1) includes: a resin film (2) having formed therein a plurality of through pores (21); a treated layer (3) having hydrophobicity and oil repellency, and formed on at least one of both surfaces in the thickness direction of the resin film (2) such that the treated layer (3) has openings (31) at positions corresponding to the through pores (21); and a loop-shaped double-sided tape (4) stuck to an edge region of one of both surfaces in the thickness direction of the resin film (2), with the treated layer (3) interposed therebetween.
Abstract:
A water-proof air-permeable filter (1) includes: a resin film (2) having formed therein a plurality of through pores (21); and a treated layer (3) having hydrophobicity and oil repellency, and formed on at least one of both surfaces in the thickness direction of the resin film (2) such that the treated layer (3) has openings (31) at positions corresponding to the through pores (21). The through pores (21) each have a predetermined size larger than or equal to 0.01 μm and smaller than or equal to 10 μm, and are uniformly distributed such that a density of the through pores falls within specific limits included in a range from 10 to 1×108 pores/mm2.
Abstract:
The method of the present disclosure includes: (I) irradiating a polymer film (1) with an ion beam composed of ions (2) accelerated in a cyclotron so as to form a polymer film that has collided with the ions in the beam; and (II) chemically etching the polymer film formed in the irradiation (I) so as to form openings (4b) and/or through holes (4a) corresponding to tracks (3) left by the colliding ions in the polymer film. In the irradiation (I), a beam current value of the ion beam is detected upstream and/or downstream of the polymer film in a path of the ion beam, and an irradiation conditioning factor in the irradiation of the polymer film with the ion beam is controlled based on the detected beam current value so that the polymer film can be irradiated with the ions at a predetermined irradiation density. The method of the present disclosure is suitable for industrial production of porous polymer films.
Abstract:
The polymer film of the present invention has through holes extending from one principal surface of the polymer film to the other principal surface of the polymer film. The through holes are straight holes having a central axis extending straight, and have a shape in which the area of a cross-section perpendicular to the direction of the central axis increases from the one principal surface of the polymer film toward the other principal surface. This polymer film has passages in its thickness direction, has an unconventional structure, and can be used in various applications, such as in a waterproof sound-permeable membrane, in a waterproof gas-permeable membrane, and in a suction sheet. The ratio a/b of the opening diameter a of the through holes at the one principal surface to the opening diameter b of the through holes at the other principal surface is 80% or is less than 80%.
Abstract:
The method of the present disclosure is a method for producing a porous polymer film including: irradiating a strip-shaped polymer film with an ion beam while moving the polymer film transversely to the ion beam, so as to form a polymer film that has collided with ions in the beam; and chemically etching the formed polymer film so as to form openings and/or through holes corresponding to tracks left by the colliding ions in the polymer film. The ion beam (11) with which the polymer film is irradiated is obtained by folding a tail of an original beam (51) inwardly toward a center of the original beam by nonlinear focusing. The original beam is composed of ions accelerated in a cyclotron and has a cross-sectional intensity distribution profile in which an intensity is maximum at the center of the original beam and continuously decreases from the center toward the tail of the original beam, and the profile is an intensity distribution profile in a cross section perpendicular to a direction of the original beam.