Abstract: The method for the production of multilayers comprises: applying a coating solution (I) which comprises a dissolved or dispersed proton-conductive polymer and a solvent (Is) containing water in amounts from 25 to 60 wt % and an organic solvent in amounts from 75 down to 40 wt %, on an electrode, applying a coating solution (II) which comprises a dissolved or dispersed proton-conductive polymer and a solvent (IIs) containing water in amounts from 0 to less than 25 wt % and an organic solvent in amounts above 75 wt %, on the wet first coating without any drying of the first coating; and drying the coatings to form an electrolyte membrane. The methods can provide multilayers capable of satisfactory power generation properties as an electrode structure by forming an electrolyte membrane on an electrode without causing any penetration of electrolyte into the electrode.

Abstract: A polymer which has a flexible structure in its main chain and thus exhibits a high toughness and can difficultly be deteriorated in its mechanical properties and thermal properties even when sulfonated, a sulfonic acid group-containing polymer obtained by the sulfonation of the polymer, and a proton-conductive membrane having an excellent mechanical strength and durability made of the sulfonic acid group-containing polymer.

Abstract: A monomer containing an electron-withdrawing group and an electron-donative group which can be easily controlled in the upper limit of the amount of a sulfonic acid, which impairs the mechanical properties of a copolymer, and can provide a sulfonated polymer that forms a proton-conductive membrane having a high proton conductivity over a wide temperature range, an excellent mechanical strength and an excellent proton conductivity and showing inhibited swelling in hot water and an aqueous solution of methanol, and a copolymer obtained from the monomer.

Abstract: Provided are a cleaning agent for semiconductor parts, which can decrease a load on the environment and has a high cleaning effect on CMP (chemical mechanical polishing) abrasive particles, metallic impurities and other impurities left on the semiconductor parts such as semiconductor substrates after the CMP, comprising a (co)polymer having at least one kind of group selected from the group consisting of sulfonic acid (salt) groups and carboxylic acid (salt) groups, the cleaning agent further containing a phosphonic acid (salt) group-containing (co)polymer, a phosphonic acid compound or a surfactant as needed; and a method for cleaning semiconductor parts with the above cleaning agent.