Cellulose acetate semipermeable membrane and process for producing the cellulose acetate semipermeable membrane

摘要

To provide a cellulose acetate semipermeable membrane having a high filtration rate and high mechanical strength and which is hardly degraded by microorganisms, the present invention provides a cellulose acetate semipermeable membrane containing a cellulose acetate having an alpha-cellulose content of not less than 99% by weight, a 6 wt/vol % viscosity of 20 to 220 mPa.s at 25±1° C. and an acetylation degree of 58 to 62%. The cellulose acetate semipermeable membrane is suitable particularly as a hollow fiber membrane.