Toray Industries, Inc.

Kiyohiko Takaya

Takao Sasaki

Masahiro Kimura

Masakazu Koiwa

Kentaro Takagi

Hiroki Tomioka

Koji Nakatsuji

Takafumi Ogawa

Harutoki Shimura

Yutaro Suzuki

Masaki Higashi

Yoshie Marutani

Takashi Yoshino

Tomoko Mitsuhata

Takeharu Inoue

A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 &#x3bc;m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/&#x3bc;m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Composite semipermeable membrane

Provided is a semipermeable membrane having at least a separating functional layer, wherein azo compounds are retained in the separating functional layer, and the separating functional layer has a yellow index of 10 to 40. Also provided is a method of producing the semipermeable membrane. The present invention provides a semipermeable membrane having not only high water permeability but also high rejection performance even for substances that are nondissociative in the neutral range, such as boric acid, and showing high durability and a manufacturing method therefor.

Semipermeable membrane and manufacturing method therefor

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Otsu, Japan

Kiyohiko Takaya