COMPOSITE POLYMER ELECTROLYTE MEMBRANE AND ITS PRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a composite polymer electrolyte membrane for giving superior mechanical strength and generating performance to a solid polymer fuel cell, and its producing method. SOLUTION: The composite polymer electrolyte membrane is formed of a sulfonate of a polyallylene polymer consisting of 5-70 mol% aromatic compound units having electron attractive groups in main chains and 30-95 mol% aromatic compound units having no electron attractive groups in main chains. It contains a base material selected from the sulfonate and having an ion exchange capacity of 1.5 meq/g or more and less than 3.0 meq/g, preferably of 1.7 meq/g or more and less than 2.5 meq/g, and a reinforcing material having an ion exchange capacity of 0.5 meq/g or more and less than 1.5 meq/g, preferably of 0.5 meq/g and less than 1.3 meq/g, at a predetermined rate. The sulfonate is such that the aromatic compound units are copolymerized at different mol ratios or the same polyallylene polymer is sulfonated in different conditions. The reinforcing material is of a fibrous or porous membrane type.