| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a hollow fiber membrane good in process stability and hardly causing yarn break in drawing treatment of an undrawn hollow fiber. SOLUTION: This method for producing a composite hollow fiber membrane by extruding a melted crystalline polymer from a spinning nozzle to spin an undrawn hollow fiber, and drawing the spun hollow fiber, comprises subjecting the undrawn hollow fiber to an annealing treatment in a nitrogen atmosphere before drawing the hollow fiber, or carrying out the steps prior to the step for extruding the crystalline polymer to provide the undrawn hollow fiber in the nitrogen atmosphere, and further subjecting the obtained undrawn hollow fiber to the annealing treatment in the nitrogen atmosphere before drawing the hollow fiber.
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