Abstract: The invention offers a microporous modified-polytetrafluoroethylene membrane that is a microporous membrane having a significantly small pore diameter and narrow pore-diameter distribution and that can remove microscopic foreign particles at high efficiency when used as a filtration membrane.

Abstract: Provided is a method for producing a porous polytetrafluoroethylene film having good chemical resistance, good heat resistance, a high porosity, and good dimensional stability. The method for producing a porous polytetrafluoroethylene film includes a stretching step of stretching a sheet-like molded body composed of a fluororesin containing polytetrafluoroethylene as a main component in a longitudinal direction and/or a lateral direction at a temperature lower than a melting point of the fluororesin to make a porous fluororesin film, and, after the stretching step, an annealing step of holding the porous fluororesin film in a shape-fixed state, and maintaining the porous fluororesin film at a temperature lower than the melting point of the fluororesin but not lower than a temperature 30° C. lower than the melting point for 1 to 20 hours.

Abstract: A porous polytetrafluoroethylene composite includes a porous polytetrafluoroethylene film, a porous support layer that supports the porous polytetrafluoroethylene film, an adhesive layer bonded to the porous polytetrafluoroethylene film, and a porous reinforcement layer bonded to the adhesive layer, in which the adhesive layer is a layer composed of a fluororesin having a melting point, or a glass transition point when a melting point is not clearly defined, of lower than 260° C.

Abstract: A porous polytetrafluoroethylene film comprising a fluororesin containing polytetrafluoroethylene as a main component, wherein an envelope surface area of resin fibers included per film having an area of 1 m2 and a thickness of 25 ?m is 4,000 m2 or more, and a melting point peak is 333° C. or lower.

Abstract: Provided are a fluororesin microporous membrane having a narrow pore-size distribution and a smaller difference between a mean flow pore size and a maximum pore size, a method for producing the fluororesin microporous membrane, and a filter element that uses the fluororesin microporous membrane. The fluororesin microporous membrane is a porous membrane obtained by forming fluororesin particles into a membrane having a particular shape and particular dimensions, baking the fluororesin particles together by heating the membrane to a melting point of the membrane or higher, and then stretching the membrane. The fluororesin particles each have a structure in which a heat of fusion of a fluororesin constituting an outer surface portion of the particle is lower than a heat of fusion of polytetrafluoroethylene constituting an inside portion of the particle.

Abstract: There are provided a fluororesin thin film which is composed of a fluororesin, which has a thickness of 20 ?m or less and a Gurley's number of 300 seconds or more, and which includes no defects, such as voids and/or cracks; a method for manufacturing the fluororesin thin film in which after a fluororesin dispersion including a dispersing medium and a fluororesin powder dispersed therein is applied on a flat and smooth foil, the dispersing medium is dried, and the fluororesin powder is sintered; the fluororesin dispersion; a fluororesin composite including a porous base material and the fluororesin thin film; a manufacturing method thereof, a porous fluororesin composite formed by stretching the fluororesin composite; and a separation membrane element using the porous fluororesin composite.

Abstract: The invention offers a porous polytetrafluoroethylene membrane, which is a porous resin membrane produced by the following steps: preparing multiple types of polytetrafluoroethylene each having a different quantity of heat of fusion; using each of the multiple types of polytetrafluoroethylene to form a membrane composed of a fluororesin consisting mainly of polytetrafluoroethylene; heating each membrane to its melting point or above to bake it, so that multiple types of nonporous resin membranes are produced; stacking the multiple types of nonporous resin membranes in the order of the magnitude of the quantity of heat of fusion of the polytetrafluoroethylene used to produce each of the nonporous resin membranes; bonding the stacked membranes with each other; and stretching the bonded membranes to form the porous resin membrane. The porous polytetrafluoroethylene membrane has a mean flow pore diameter of 50 nm or less.

Abstract: A redox flow cell membrane includes a porous membrane that has a mean flow pore size of not more than 100 nm, that has a thickness of not more than 500 ?m, and that has an air flow rate of not less than 0.1 ml/s·cm2. When the redox flow cell membrane is used for a V—V-based redox flow cell, the porous membrane preferably has a mean flow pore size of not more than 30 nm.

Abstract: A tetrafluoroethylene resin molded article obtained by fusing PTFE by heating a tetrafluoroethylene resin by heating, and then executing a gradual cooling or a cooling including a holding at a temperature equal to or higher than 313° C. and lower than 321° C. for 10 minutes or longer, and having, when heated to 365° C., then cooled to 245° C. with a rate of ?1° C./min, and then heated to 365° C. with a rate of 10° C./min, a heat of fusion which, within a range from 296 to 343° C., is equal to or larger than 32 J/g and less than 47.8 J/g, a porous article obtained by expanding the molded article, and a composite article, a filter, an impact deformation absorber and a sealing material utilizing the molded article or the porous article.

Abstract: The invention offers a microporous modified-polytetrafluoroethylene membrane that is a microporous membrane having a significantly small pore diameter and narrow pore-diameter distribution and that can remove microscopic foreign particles at high efficiency when used as a filtration membrane.

Abstract: A composite structure comprising two polytetrafluoroethylene porous layers and a framework structural member having a plurality of gaps or openings, the framework structural member being disposed between the two polytetrafluoroethylene porous layers, wherein the composite structure is structured such that the polytetrafluoroethylene porous layers are united together by being adhered with each other through the gaps or openings of the framework structural member and such that the respective polytetrafluoroethylene porous layers (A1) and (A2) are united with the framework structural member closely along the surfaces of the respective constituent elements of the framework structural member in such a manner as to wrap the respective elements. The method of manufacturing the composite structure is characterized in that it includes a step of applying pressure through a mass of fine particles.

Abstract: A production process of a perforated porous resin base, comprising Step 1 of impregnating the porous structure of a porous resin base with a liquid or solution; Step 2 of forming a solid substance from the liquid or solution impregnated; Step 3 of forming a plurality of perforations extending through from the first surface of the porous resin base having the solid substance within the porous structure to the second surface in the porous resin base; and Step 4 of melting or dissolving the solid substance to remove it from the interior of the porous structure, and a production process of a porous resin base with the inner wall surfaces of the perforations made conductive, comprising the step of selectively applying a catalyst only to the inner wall surfaces of the perforations to apply a conductive metal to the inner wall surfaces.

Abstract: An expanded porous polytetrafluoroethylene film having residual strain of at most 11.0% as measured after a load required to indent a rod, which is in a columnar form that its outer diameter is at least 2 mm and at least 1.9 times as much as the thickness of the film, and has a smooth plane perpendicular to its axis at a free end surface thereof and a modulus of longitudinal elasticity of at least 1.0×104 kgf/mm2, up to 20% of the film thickness at a strain rate of 100%/min from the free end surface is applied repeatedly 20 times, and a production process of the porous film, in which a step of compressing an expanded porous polytetrafluoroethylene film having a high draw ratio is provided.

Abstract: A method of manufacturing a perforated porous resin substrate, the method including the following steps: Step 1 of forming at least one perforation penetrating in the thickness direction from a first surface to a second surface in a porous resin substrate made of a resin material containing a fluoropolymer; Step 2 of etching treatment conducted by putting an etchant containing an alkali metal in contact with the wall face of each perforation; and Step 3 of putting an oxidizable compound or a solution thereof in contact with a degenerative layer generated by the etching treatment, and thereby removing the degenerative layer. A method of manufacturing a porous resin substrate in which electrical conductivity is afforded to the wall face of the perforation.

Abstract: There are provided a fluororesin thin film which is composed of a fluororesin, which has a thickness of 20 ?m or less and a Gurley's number of 300 seconds or more, and which includes no defects, such as voids and/or cracks; a method for manufacturing the fluororesin thin film in which after a fluororesin dispersion including a dispersing medium and a fluororesin powder dispersed therein is applied on a flat and smooth foil, the dispersing medium is dried, and the fluororesin powder is sintered; the fluororesin dispersion; a fluororesin composite including a porous base material and the fluororesin thin film; a manufacturing method thereof a porous fluororesin composite formed by stretching the fluororesin composite; and a separation membrane element using the porous fluororesin composite.

Abstract: Disclosed are expanded polytetrafluoroethylene products, such as porous polytetrafluoroethylene tubes, having high axial tear strength and a process for their production. Each expanded polytetrafluoroethylene product has a microstructure, which comprises fibrils and nodes interconnected with each other by the fibrils, and has an axial tear strength of not lower than 6,000 gf/mm as calculated in accordance with the following formula: L/[T×(V/100)] where L (gf) is an axial tear load, T (mm) is a wall thickness, and V (%) is a volume ratio of resin. The process for the production of the expanded polytetrafluoroethylene product includes a high-speed extrusion step.

Abstract: An object of the present invention is to provide a method for manufacturing a porous material in which complicated and fine through portions, recessed portions, and the like have been patterned. It is to provide a patterned porous molded product or nonwoven fabric, in which a plated layer has been selectively formed on the surfaces of the through portions and the recessed portions. With the invention, a mask having through portions in a pattern is placed on at least one side of the porous molded product or the nonwoven fabric. A fluid or a fluid containing abrasive grains is sprayed from above the mask, thereby to form through portions or recessed portions, or both of them, to which the opening shape of each through portion of the mask has been transferred, in the porous molded product or the nonwoven fabric.

Abstract: The present invention is directed to an anisotropic conductive film and manufacturing methods thereof, in which an electrically insulative porous film made of synthetic resin is used as a base film and in which conductive parts capable of being provided with conductiveness in the film thickness direction are formed independently at plural positions of the base film by adhering conductive metal to resinous parts of porous structure in such a manner as piercing through from a first surface to a second surface.

Abstract: A composite structure comprising two polytetrafluoroethylene porous layers and a framework structural member having a plurality of gaps or openings, the framework structural member being disposed between the two polytetrafluoroethylene porous layers, wherein the composite structure is structured such that the polytetrafluoroethylene porous layers are united together by being adhered with each other through the gaps or openings of the framework structural member and such that the respective polytetrafluoroethylene porous layers (A1) and (A2) are united with the framework structural member closely along the surfaces of the respective constituent elements of the framework structural member in such a manner as to wrap the respective elements. The method of manufacturing the composite structure is characterized in that it includes a step of applying pressure through a mass of fine particles.

Abstract: An expanded porous polytetrafluoroethylene film having residual strain of at most 11.0% as measured after a load required to indent a rod, which is in a columnar form that its outer diameter is at least 2 mm and at least 1.9 times as much as the thickness of the film, and has a smooth plane perpendicular to its axis at a free end surface thereof and a modulus of longitudinal elasticity of at least 1.0×104 kgf/mm2, up to 20% of the film thickness at a strain rate of 100%/min from the free end surface is applied repeatedly 20 times, and a production process of the porous film, in which a step of compressing an expanded porous polytetrafluoroethylene film having a high draw ratio is provided.