Polyimide separator having a three-dimensional ordered macropore structure and its manufacturing method

摘要

PROBLEM TO BE SOLVED: To provide: a polyimide separator having a three-dimensional regularly arranged macropore structure superior in mechanical strength without the need for highly toxic hydrogen fluoride nor an acid treatment which would worsen a separator film strength; and a method for manufacturing the polyimide separator.SOLUTION: A method for manufacturing a polyimide separator in which a plurality of macropores uniform in shape and size are regularly arranged in three-dimensional directions comprises the steps of: mixing a mixture of polyamic acid, ethylene glycol, and nonionic detergent in N,N-dimethyl acetamide with polymer particles which can be pyrolyzed in a temperature range higher than 370°C and up to a decomposition temperature of a polyimide and which have a glass transition point lower than a glass transition point of the polyimide to prepare a slurry; forming a film from the slurry; and performing a heat treatment on the film at a temperature higher than 370°C and up to the decomposition temperature of the polyimide under an inert gas atmosphere of 10 vol.% or less in oxygen concentration to turn the polyamic acid to polyimide, and pyrolyze and remove the polymer particles.SELECTED DRAWING: Figure 4