Sumitomo Electric Fine Polymer, Inc.

Hajime Funatsu

Fumihiro Hayashi

Atsushi Uno

Kazuaki Ikeda

Shinichi Kanazawa

Hiroyuki Tsujiwaki

Tooru Morita

Itsumu Furumoto

Kiyoshi Ida

There are provided a fluororesin thin film which is composed of a fluororesin, which has a thickness of 20 &#x3bc;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.

Manufacturing methods for a porous fluororesin composite

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). Thus, the degradation of flow rate due to the elapse of time can be prevented, since solid particles to be separated do not enter into pores, and clogging and blockade of the pores do not occur even in the case of filtering a solution of high turbidity. As a result, it is possible to recover filtration property easily by performing back-wash reverse filtration and to maintain excellent filtration property for a long time.

Porous multilayered hollow fiber and filtration module, and method of manufacturing porous multilayered hollow fiber

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Osaka, Japan

Hajime Funatsu