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: 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: In a filter for microfiltration, a filtration layer is protected so as not to be damaged. A porous multi-layer filter, which is a laminated body of three porous stretched PTFE sheets that have been biaxially stretched in the longitudinal and transverse directions, includes a filtration layer as a middle layer, a protection layer stacked on one surface of the filtration layer on the liquid-to-be-treated inflow side, and a support layer stacked on another surface of the filtration layer, in which the one surface and the other surface of the filtration layer are fusion-bonded to the protection layer and the support layer at boundaries therebetween, pores of the protection layer and pores of the support layer three-dimensionally communicate with pores of the filtration layer, and the mean pore size of pores of the filtration layer is smaller than the mean pore size of pores of each of the protection layer and the support layer.

Abstract: Provided is a porous multilayer filter which can trap ultrafme particles and in which permeability is high and treatment can be performed at a high flow rate. A porous multilayer filter is characterized by including a support layer 2 composed of a porous expanded PTFE sheet, and a filtration layer 3 composed of a porous expanded PTFE sheet which is different from that of the support layer 2, wherein at least a liquid-to-be-treated inflow surface of the filtration layer 3 is subjected to hydrophilization treatment, the filtration layer 3 and the support layer 2 are fusion-bonded to each other at a boundary therebetween to form a multilayer structure, pores of the support layer 2 three-dimensionally communicate with pores of the filtration layer 3, and pores surrounded by a fibril skeleton of the filtration layer 3 are smaller than pores of the support layer 2.

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: A porous multilayered hollow fiber for outer side pressed filtration is made of a multilayer comprising a supporting layer constituted of the thickness of an expanded porous polytetrafluoroethylene tube, and a filtration layer provided on the outer surface of the supporting layer, wherein pores surrounded by fibrous frameworks in the filtration layer are smaller than those of the supporting layer, and the mean of the maximum fibril length (L) of the fibrous frameworks surrounding each pore in the outer surface of the filtration layer is designed to be small such that (X) and (Y) fall within the range on the XY plane, where (X) is a particle diameter of particles captured when the particle trapping ratio is equal to or more than 90% in the case where the filtration is done under an elevated pressure of 0.1 MPa, and (Y) is a value designated as RFL obtained by dividing (L) by (X).

Abstract: A porous multilayered hollow fiber for outer side pressed filtration is made of a multilayer comprising a supporting layer constituted of the thickness of an expanded porous polytetrafluoroethylene tube, and a filtration layer provided on the outer surface of the supporting layer, wherein pores surrounded by fibrous frameworks in the filtration layer are smaller than those of the supporting layer, and the mean of the maximum fibril length (L) of the fibrous frameworks surrounding each pore in the outer surface of the filtration layer is designed to be small such that (X) and (Y) fall within the range on the XY plane, where (X) is a particle diameter of particles captured when the particle trapping ratio is equal to or more than 90% in the case where the filtration is done under an elevated pressure of 0.1 MPa, and (Y) is a value designated as RFL obtained by dividing (L) by (X).