Abstract: Provided is a surface treated calcium carbonate filler for resins, which comprises calcium carbonate particles, the surface of which has been treated with at least one surface active agent (A) selected from the group consisting of saturated fatty acids, unsaturated fatty acids, alicyclic carboxylic acids, resin acids, and salts thereof and with at least one compound (B) having the ability to chelate alkaline earth metals, the compound (B) being selected from the group consisting of phosphonic acids, polycarboxylic acids, and salts thereof. The surface treated calcium carbonate filler for resins of the present invention deteriorates little with time, has satisfactory dispersibility in resins, and can give a sheet or film which has a satisfactory balance among durability, weatherability, strength, and thermal stability, and is useful as a battery separator or a light reflector.

Abstract: Provided is a surface treated calcium carbonate filler for resins, which comprises calcium carbonate particles, the surface of which has been treated with at least one surface active agent (A) selected from the group consisting of saturated fatty acids, unsaturated fatty acids, alicyclic carboxylic acids, resin acids, and salts thereof and with at least one compound (B) having the ability to chelate alkaline earth metals, the compound (B) being selected from the group consisting of phosphonic acids, polycarboxylic acids, and salts thereof. The surface treated calcium carbonate filler for resins of the present invention deteriorates little with time, has satisfactory dispersibility in resins, and can give a sheet or film which has a satisfactory balance among durability, weatherability, strength, and thermal stability, and is useful as a battery separator or a light reflector.

Abstract: A fine pore formation agent for a porous resin film is provided which comprises inorganic particles satisfying (a) 0.1?D50?1.5 (?m) (D50: average particle diameter of particles in 50% cumulative total by weight from the larger particle side by micro-track FRA), (b) Da?20 (?m) (Da: maximum particle diameter by micro-track FRA), (c) 3?Sw?60 (m2/g) (Sw: BET specific surface area measured by nitrogen adsorption method), (d) Ir?1.0×105 (?·cm) (Ir: volume resistivity (?·cm). The fine pore formation agent for a porous resin film is capable of providing a resin composition giving a porous resin film useful in uses for electric parts such as capacitors and battery separators.

Abstract: A fine pore formation agent for a porous resin film is provided which comprises inorganic particles satisfying (a) 0.1?D50?1.5 (?m) (D50: average particle diameter of particles in 50% cumulative total by weight from the larger particle side by micro-track FRA), (b) Da?20 (?m) (Da: maximum particle diameter by micro-track FRA), (c) 3?Sw?60 (m2/g) (Sw: BET specific surface area measured by nitrogen adsorption method), (d) Ir?1.0×105 (?·cm) (Ir: volume resistivity (?·cm). The fine pore formation agent for a porous resin film is capable of providing a resin composition giving a porous resin film useful in uses for electric parts such as capacitors and battery separators.

Abstract: A filler for porous films is provided which is easy to be mixed with a resin, has good dispersibility in a resin, and provides a porous film useful for a light reflector of, for example, a liquid crystal display and a lighting apparatus and a porous film useful for a diaphragm (separator) between electrodes of a battery. A filler comprises inorganic particles surface treated with a surfactant (A) and a compound (B) having a chelating function to an alkaline earth metal.