AROMATIC SULFONIC ACID DERIVATIVE, AND METHOD FOR PRODUCING THE DERIVATIVE

PROBLEM TO BE SOLVED: To provide an aromatic polymer material which secures excellent proton conductivity even when an introduction quantity of sulfonic group is increased, and to provide a monomer for obtaining the polymer material.SOLUTION: The aromatic sulfonic acid derivative is represented by formula (A) (wherein X-Xeach represent a hydrogen atom or a halogen atom, and at least two of X-Xare halogen atoms; R represents the hydrogen atom, an alkali metal atom, an alkaline earth metal atom or a 1-20C hydrocarbon group; a and b each represent an integer of 1 or more, and Arand Areach represents an aromatic group).