Patent ID: 7504034

Claim:
A method of producing a hollow fiber membrane comprising: discharging a polyvinylidene fluoride solution comprising a polyvinylidene fluoride resin and a poor solvent at a temperature above a phase separation temperature into a cooling bath at a temperature below the phase separation temperature to coagulate the polyvinylidene fluoride resin, wherein the crystallization temperature of the polyvinylidene fluoride solution is in the range of 40° C. to 120° C., the average cooling rate of the polyvinylidene fluoride solution when the temperature of the polyvinylidene fluoride solution reaches the crystallization temperature during cooling is in the range of 2×10 3 ° C./min to 10 6 ° C./min, and the temperature Ts of a spinneret for discharging the polyvinylidene fluoride solution into the cooling bath and the crystallization temperature Tc satisfy the relationship Tc≦Ts≦Tc+90.