Abstract: A siloxane polymer contains a silsesquioxane unit and a linear siloxane unit in its main chain and has a cage-type silsesquioxane structure in its side chain. A highly transparent and flexible film having a small linear thermal expansion coefficient is produced by utilizing the cohesion force (physical crosslinking) of the cage-type silsesquioxane in the side chain. The siloxane polymer has repeating units respectively represented by formulae (1) and (4), and has terminal groups respectively represented by formulae (5L) and (5R) at its right and left terminals, wherein A represents a structure shown below.

Abstract: Provided is a microporous membrane that is suitable for a battery separator, and has good low-temperature characteristics of a battery. The microporous membrane that is suitable for the battery separator, and has good low-temperature characteristics of the battery can be provided by forming the microporous membrane formed of a thermoplastic resin, in which ion resistance is 0.20 or less, reaction resistance is 0.45 or less and total resistance is 0.60 or less.

Abstract: Provided is an organic-inorganic composite membrane for a multilayer heat-resistant separator material, having smoothness, maintenance of microporous characteristics of a substrate film, and adhesion between a substrate and a heat-resistant layer in a well-balanced manner. The organic-inorganic composite membrane is provided with the heat-resistant layer containing inorganic heat-resistant particles and an organic solvent-soluble binder on at least one surface of the substrate film formed of a microporous membrane made of polyolefin, in which the inorganic heat-resistant particles contain small particles F(a) having an average particle size less than 0.2 micrometer and large particles F(b) having an average particle size of 0.2 micrometer or more.

Abstract: The objective of the present disclosure is to show a multilayered heat-resistant separator element having minimized warpage and curling. The present disclosure is a multilayered heat-resistant separator element obtained by laminating an inorganic heat-resistant layer on at least one surface of a substrate film comprising a polyolefin microporous membrane having an elongation of 2% or less when tensioned at 10 N/mm2 at 100° C., the curl height of the multilayered heat-resistant separator element not exceeding 10 mm. During manufacturing of the multilayered heat-resistant separator element, the inorganic heat-resistant layer is dried and solidified at a temperature of 80 to 120° C. and a tensile force of 4-10 N/mm2.

Abstract: The present invention addresses the problem of providing an organic-inorganic composite film that is useful as a separator material. The problem is addressed by an organic-inorganic composite film characterized in that a heat-resistant layer that contains inorganic heat resistant particles and a binder is provided on at least one surface of a base material film comprising a polyolefin microporous film, said organic-inorganic composite film satisfying all of the following conditions (A), (B), and (C): Condition (A): a?1.5 (a: density of heat resistant layer (g/m2/?m), condition (B): 12.74?b (b: peel strength (N) of base material film and heat resistant layer), condition (C): c?20 (c: represents the percentage change in air permeability (%) calculated from the following equation. Percentage change in air permeability (%)=|(air permeability of organic-inorganic composite film)?(air permeability of base material film)|÷(air permeability of base material film)×100).

Abstract: To provide a composite porous film in which thermal shrinkage is satisfactorily suppressed even when temperature exceeds a melting temperature of a polyolefin resin, adhesion between a microporous membrane and a heat-resistant layer is improved, and dropout of an inorganic filler is suppressed. The composite porous film is composed of the heat-resistant layer formed of the inorganic filler and a binder, and the microporous membrane formed of the polyolefin resin, and the composite porous film having a primary particle size of the inorganic filler in the range of 5 nanometers to 100 nanometers.

Abstract: To provide a composite porous film in which thermal shrinkage is satisfactorily suppressed even when temperature exceeds a melting temperature of a polyolefin resin, adhesion between a microporous membrane and a heat-resistant layer is improved, and dropout of an inorganic filler is suppressed. The composite porous film is composed of the heat-resistant layer formed of the inorganic filler and a binder, and the microporous membrane formed of the polyolefin resin, and the composite porous film having a primary particle size of the inorganic filler in the range of 5 nanometers to 100 nanometers.