Cation exchange membrane, electrolysis vessel using the same and method for producing cation exchange membrane

A method for producing the cation exchange membrane, comprising the steps of:

• weaving two or more reinforcing core materials, a sacrifice yarn soluble in an acid or an alkali, and a dummy yarn soluble in a predetermined solvent in which the reinforcing core materials and the sacrifice yarn are insoluble, to obtain a reinforcing material having the sacrifice yarn and the dummy yarn arranged between the reinforcing core materials adjacent to each other;
• soaking the reinforcing material in the predetermined solvent to remove the dummy yarn from the reinforcing material;
• stacking the reinforcing material from which the dummy yarn is removed and a fluorine-based polymer having an ion-exchange group or an ion-exchange group precursor which can be converted into the ion-exchange group by hydrolysis, to form a membrane body having the reinforcing material;
• and
• soaking the sacrifice yarn in an acid or an alkali to remove the sacrifice yarn from the membrane body, thereby forming an elution hole in the membrane body.