Toray Industries, Inc.

Takahiro Tokuyama

Harutoki Shimura

Yohei Adachi

Masayuki Hanakawa

Hiroho Hirozawa

Yoshiki Nishiguchi

Kohei Kuraoka

Kenta Iwai

Hiroki Tomioka

Koichi Takada

Takafumi Ogawa

Rina Iizuka

Yoko Hasegawa

A novel membrane is provided in which the permeate flow rate is not prone to decrease even when the membrane is used to process seawater with high salt concentration and high heavy metal ion concentration. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer coating the separation function layer, wherein the separation function layer contains a crosslinked polymer amide which is a condensate of polyfunctional aromatic amine and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer including a polyether moiety and a carbonic acid polymer moiety.

Composite semipermeable membrane and composite semipermeable membrane element

By having a coating layer, this composite semipermeable membrane has fouling resistance easily maintainable before and after contact with acid, and enables stable operation over a long period of time. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer arranged on the separation function layer, wherein the separation function layer contains a crosslinked aromatic polyamide which is a polycondensate of polyfunctional aromatic amines and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer having the structure (I) in the description.

The present invention relates to a layered semipermeable membrane satisfying the conditions below. (A) The maximum peak intensity between 3700 and 2900 cmis 0.08 or greater in the difference spectrum between an IR spectrum measured at 25&#xb0; C. and 97% relative humidity and an IR spectrum measured at 25&#xb0; C. and 3% relative humidity. (B) The peak top wavenumber between 3700 and 2900 cmof the aforementioned difference spectrum is 3400 cmto 3550 cm. (C) The N1s peak has a maximum value at 401 eV or greater in X-ray photoelectron spectroscopy in which X-rays are radiated to a coat layer.

Layered semipermeable membrane

An object of the present invention is to provide a multilayer separation membrane having excellent performance on both removal of suspended solids in water and adsorptive removal of metal ions in water. A multilayer separation membrane of the present invention includes: a porous adsorption layer including substantially a polymer having chelating functional groups; and a porous clarification layer, and the porous clarification layer is disposed neater to a raw water-side than the porous adsorption layer.

Multilayer separation membrane

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Shiga, Japan

Takahiro Tokuyama