Toyo Boseki Kabushiki Kaisha

Mitsuru Suzuki

Isamu Yamamoto

Makoto Ohno

Seiji Watanuki

Hidehiko Sakurai

Kazutake Okamoto

Tohru Uenishi

Hideo Sato

Yasuhiro Shiota

A cellulose acetate membrane composed of a mixture comprising a cellulose triacetate and a cellulose diacetate and having an improved heat stability, which does not substantially show a melting peak of cellulose diacetate but substantially shows a melting peak of cellulose triacetate, in a differential thermal analysis. By mixing a cellulose triacetate and a cellulose diacetate at an appropriate ratio, crystallization or orientational crystallization of each component due to a high pressure stream sterilization can be avoided and a cellulose acetate membrane with improved water permeability and sieving coefficient of myoglobin after a high pressure steam sterilization can be obtained.

Cellulose acetate hemodialysis membrane

A cellulose acetate membrane composed of a mixture comprising a cellulose triacetate and a cellulose diacetate and having an improved heat stability, which does not substantially show a melting peak of cellulose diacetate but substantially shows a melting peak of cellulose triacetate, in a differential thermal analysis. By mixing a cellulose triacetate and a cellulose diacetate at an appropriate ratio, crystallization or orientational crystallization of each component due to a high pressure steam sterilization can be avoided and a cellulose acetate membrane with improved water permeability and sieving coefficient of myoglobin after a high pressure steam sterilization can be obtained.

A hollow fiber membrane made of a cellulose ester having a membrane thickness of not more than 75 .mu.m, and having void volume (x, % by volume) of the membrane and a rate of ultrafiltration (y, ml/m.sup.2.hr.mmHg) satisfying the following formula:

Cellulose ester hollow fiber membrane for plasma separation

Growing community of inventors

Otsu, Japan

Mitsuru Suzuki