METHOD OF PRODUCING PERFLUORINATED SULPHO-CATIONITE MEMBRANES THROUGH COATING FROM SOLUTION Russian patent published in 2011 - IPC C08J5/22 H01M8/10 C08J3/02 C08L27/12 

FIELD: chemistry.

SUBSTANCE: invention can be used in making membrane-electrode blocks used in different types of fuel cells, as well as in portable electronic devices etc. The membranes are obtained through coating from a 5-40% solution prepared from perfluorinated ion-exchange copolymer of tetrafluoroethylene with perfluorosulpho-containing vinyl ester and a tertiary modifying comonomer selected from a group comprising perfluoro-2-methylene-4-methyl-1,3-dioxalane and perfluoroalkylvinyl ester whose alkyl contains 1 or 3 carbon atoms, having equivalent weight of 700-900, number-average molecular weight of 1.0-4.0×10⁵, density 1.79-1.83 kg/m³, degree of crystallinity equal to 1.0-4.5%, and one or more modifying perfluorinated ion-exchange copolymers whose structure is similar to the basic perfluorinated ion-exchange copolymer with equivalent weight of 950-1600, having number-average molecular weight of 4.5-9.0×10⁵, density 1.84-1.91 kg/m³, degree of crystallinity 4.5-12.5%, structural formula: , M denotes H, Li, K, Na, a=23.57-10.53 mol %, b=74.43-81.65 mol %, c=2.0-8.0 mol % in the medium of an organic solvent at 70-120°C. The ratio of the basic perfluorinated and modifying perfluorinated ion-exchange copolymers is equal to 1.5-19. The membrane forms at 40-100°C after evaporation of the solvent.

EFFECT: improved operational properties of the membrane and simple process of making the membrane.

4 cl, 3 tbl, 18 ex