Porous structure for ventilation stopper

Abstract

The present invention provides an air-permeable porous structural body that can be used for a vent plug or the like and imposes a low environmental load in waste treatment or the like after use, and also provides a vent plug using the porous structural body. Further, the invention provides an air-permeable porous structural body that can be molded by injection molding that has high productivity. The porous structural body has an overall structure entirely occupied by a structure composed of an infinite number of spherical or ellipsoidal cavities having a diameter of 1 μm to 100 μm. Holes are open in cavity walls and the cavity is linked to another cavity by the holes. The inside of the porous structural body is constituted by communicating open passages that pass in a meandering fashion between the inlet and outlet of the porous structural body and are composed of a plurality of cavities that are joined with each other in a chain configuration, and chain closed passages that are composed of one cavity or a plurality of cavities and connected to the communicating open passages. Further, 50 to 60% of the cavities per unit cube are cavities having a diameter of less than 10 μm.

Dependencies are inferred from the claim text.