Hydrophilic vinylidene fluoride porous hollow fiber membrane and method for producing the same

摘要

Provided is a vinylidene fluoride porous hollow fiber membrane excellent in fouling resistance due to reduced organic substance absorbance, preferably having preferable pore structures to enable to have high permeability, high fractionation performance, and good process controllability. The membrane includes a vinylidene fluoride resin and 0.5 to 10% by weight of a hydrophilic resin, having a ratio Pi/Po of 2.5 to 50 where Pi and Po denote an average pore size on inner surface and an average pore size on outer surface , respectively, and having a pure water permeation rate satisfying the following formula: FLUX d / FLUX w × 100 ‰¥ 40.0 wherein FLUX d represents a pure water permeation rate (L/m 2 /hr/98 kPa) of the hollow fiber membrane in a dry state, and FLUX W represents a pure water permeation rate (L/m 2 /hr/98 kPa) of the hollow fiber membrane in a wet state.