| abstract |
A polymer having an isothianaphthene structure represented by the formula (Ia) and/or Ib): <IMAGE> wherein R1 and R2 each represents a hydrogen atom or a hydrocarbon residue having 1 to 5 carbon atoms such as methyl, methoxy and thiomethyl, with the proviso that R1 and R2 may link together to form, along with the benzene ring, a fused ring which is naphthalene; X is sulfur, selenium or tellurium; Y- represents an anion of an electrolyte; z represents a number from 0.01 to 1 showing a ratio of the anion per mol of a monomer; and n represents a number of from 5 to 500 showing a degree of polymerization. An electrochromic display wherein a high molecular weight conductive membrane formed on a conductive transparent base is used as a display base and an opposing electrode is arranged thereunder via a liquid electrolyte, which is characterized in that said high molecular weight conductive membrane is a polymer having an isothianaphthene structure and capable of being reversibly oxidized or reduced. |