Abstract: An electret includes an electret layer. The electret layer is formed by subjecting a composite film in which inorganic dielectric particles are dispersed and held in a base film to a polarization treatment. The inorganic dielectric particles are mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more.

Abstract: An electret includes a substrate and an electret layer formed above a surface of the substrate. The electret layer is a composite metal compound containing two or more different metal elements, and is obtained by subjecting a thin film mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more to a polarization treatment.

Abstract: A production method for a resin molding (1) inserted a 1st plate (10) having many through holes (10a) and a 2nd plate (11) having many through holes (11a), which are arranged in parallel and facing each other during a manufacturing process, comprising a 1st plate process and a 2nd plate process. The 1st plate process in which, the 1st plate (10) moves to the 2nd plate (11) side from a 1st plate start position (U0) and returns a 1st plate end position (P3) near the 1st plate start position (U0) in a cavity filled with a molten resin (4) kept to a high pressure. The 2nd plate process in which, the 2nd plate (11) moves to the 1st plate (10) side from a 2nd plate start position (V0) and returns a 2nd plate end position (P4) near the 2nd plate start position in the cavity. This makes it possible to spread the molten resin (4) to even a shielded area with a reciprocal plate motion.

Abstract: In a method of forming a synthetic resin structure integral with two-dimensional steel fabric, a warp and woof are made from a steel metal, and these wires are woven in a planar configuration to provide a two-dimensional steel fabric which is then pressed into a flat structure. Two flat structures are set at a metallic mold die, into which a synthetic resin is injected so as to form a synthetic resin body integral with the flat structures. This makes it possible to secure a sufficient space between the flat structures, and spread the synthetic resin fully into the flat structures so as to reinforce a surface of the synthetic resin body with durability and high rigidity. Through the toughness, strength and price of the steel metal, it is possible to provide a marketability with products manufactured by using the present method.

Abstract: In a method of forming a synthetic resin structure integral with two-dimensional steel fabric, a warp and woof are made from a steel metal, and these wires are woven in a planar configuration to provide a two-dimensional steel fabric which is then pressed into a flat structure. Two flat structures are set at a metallic mold die, into which a synthetic resin is injected so as to form a synthetic resin body integral with the flat structures. This makes it possible to secure a sufficient space between the flat structures, and spread the synthetic resin fully into the flat structures so as to reinforce a surface of the synthetic resin body with durability and high rigidity. Through the toughness, strength and price of the steel metal, it is possible to provide a marketability with products manufactured by using the present method.