WO200049069-A1  DATABASE WPI Week 197806, Derwent Publications Ltd., London, GB; AN 1978-11509A, XP002905658 ASAHI DOW LTD.: 'Ion exchange membrane with improved oxidn, resistance - comprises sulphonated polymer base material of halogenated olefin, mono:olefinic hydrocarbon and vinyl, monomer mixts' & JP 52 156 790 A 27 December 1977;  DATABASE WPI Week 198415, Derwent Publications Ltd., London, GB; AN 1984-091637, XP002905656 & JP 59 038 242 A & PATENT ABSTRACTS OF JAPAN & JP 59 038 242 A (ASAHI KASEI KOGYO KK) 13 June 1984;  DATABASE WPI Week 199647, Derwent Publications Ltd., London, GB; AN 1996-472310, XP002905659 MITSUBISHI CHEM CORP.: 'Polyolefin cation exchange membrane prodn - comprises crosslinking sulphonic acid gp.-contg polyolefin film by electron beam irradiation, giving improved durability to oxidative degradation' & JP 8 239 494 A 17 September 1996;  DATABASE WPI Week 199927, Derwent Publications Ltd., London, GB; AN 1999-323596, XP002905657 & JP 11 116 679 A & PATENT ABSTRACTS OF JAPAN & JP 11 116 679 A (SUMITOMO CHEM CO LTD) 30 July 1999;  DATABASE FILE CAPLUS, [Online] BRACK H.P. ET AL.: 'Development of radiation-grafted membranes for fuel cell applications based on poly(ethylene-alt-tetrafluoroethylene)', XP002907346 Retrieved from stn international, accession no. 127:250520 Database accession no. 1997:582320 & POLYM. MATER. SCI. ENG., vol. 77, 1997, pages 368 - 369;  DATABASE WPI Week 198519, Derwent Publications Ltd., London, GB; AN 1985-113518, XP002905655 & JP 60 055 033 A & PATENT ABSTRACTS OF JAPAN & JP 60 055 033 A (KURORIN ENGINEERS KK) 03 August 1985;  MIKAEL PARONEN ET AL.: 'Effects of irradiation on sulfonation of poly (vinylfluoride)' J. MATER. CHEM., vol. 7, no. 12, 1997, pages 2401 - 2426, XP002928702;  T. LEHTINEN ET AL.: 'Electrochemical characterization of PVDF-based proton conducting membranes for fuel cells' ELECTROCHEMICA ACTA, vol. 43, no. 12-13, 1998, pages 1881 - 1890, XP002928701;  MIKAEL PARONEN ET AL.: 'Structure of Sulfonated (Poly(vinyl fluoride)' JOURNAL OF APPLIED POLYMER SCIENCE, vol. 73, August 1999, pages 1273 - 1284, XP002928703;  DATABASE FILE CAPLUS, [Online] BRACK H.P. ET AL.: 'Development of radiation-grafted membranes for fuel cell applications based on poly(ethylene-alt-tetrafluoroethylene)' Retrieved from stn international, accession no. 127:250520 Database accession no. 1997:582320 & POLYM. MATER. SCI. ENG., vol. 77, 1997, pages 368 - 369;  DATABASE WPI Week 197806, Derwent Publications Ltd., London, GB; AN 1978-11509A ASAHI DOW LTD.: 'Ion exchange membrane with improved oxidn, resistance - comprises sulphonated polymer base material of halogenated olefin, mono:olefinic hydrocarbon and vinyl, monomer mixts' & JP 52 156 790 A 27 December 1977;  DATABASE WPI Week 198415, Derwent Publications Ltd., London, GB; AN 1984-091637 & JP 59 038 242 A & PATENT ABSTRACTS OF JAPAN & JP 59 038 242 A (ASAHI KASEI KOGYO KK) 13 June 1984;  DATABASE WPI Week 198519, Derwent Publications Ltd., London, GB; AN 1985-113518 & JP 60 055 033 A & PATENT ABSTRACTS OF JAPAN & JP 60 055 033 A (KURORIN ENGINEERS KK) 03 August 1985;  DATABASE WPI Week 199647, Derwent Publications Ltd., London, GB; AN 1996-472310 MITSUBISHI CHEM CORP.: 'Polyolefin cation exchange membrane prodn - comprises crosslinking sulphonic acid gp.-contg polyolefin film by electron beam irradiation, giving improved durability to oxidative degradation' & JP 8 239 494 A 17 September 1996;  DATABASE WPI Week 199927, Derwent Publications Ltd., London, GB; AN 1999-323596 & JP 11 116 679 A & PATENT ABSTRACTS OF JAPAN & JP 11 116 679 A (SUMITOMO CHEM CO LTD) 30 July 1999;  MIKAEL PARONEN ET AL.: 'Structure of Sulfonated (Poly(vinyl fluoride)' JOURNAL OF APPLIED POLYMER SCIENCE, vol. 73, August 1999, pages 1273 - 1284;  See also references of EP 1177246A1;  DATABASE WPI Week 198519, Derwent Publications Ltd., London, GB; AN 1985-113518, XP002905655&JP 60 055 033 A&PATENT ABSTRACTS OF JAPAN&JP 60 055 033 A (KURORIN ENGINEERS KK) 03 August 1985;  DATABASE FILE CAPLUS, [Online] BRACK H.P. ET AL.: 'Development of radiation-grafted membranes for fuel cell applications based on poly(ethylene-alt-tetrafluoroethylene)', XP002907346 Retrieved from stn international, accession no. 127:250520 Database accession no. 1997:582320&POLYM. MATER. SCI. ENG., vol. 77, 1997, pages 368 - 369;  DATABASE WPI Week 198415, Derwent Publications Ltd., London, GB; AN 1984-091637, XP002905656&JP 59 038 242 A&PATENT ABSTRACTS OF JAPAN&JP 59 038 242 A (ASAHI KASEI KOGYO KK) 13 June 1984;  DATABASE WPI Week 199927, Derwent Publications Ltd., London, GB; AN 1999-323596, XP002905657&JP 11 116 679 A&PATENT ABSTRACTS OF JAPAN&JP 11 116 679 A (SUMITOMO CHEM CO LTD) 30 July 1999;  DATABASE WPI Week 197806, Derwent Publications Ltd., London, GB; AN 1978-11509A, XP002905658 ASAHI DOW LTD.: 'Ion exchange membrane with improved oxidn, resistance - comprises sulphonated polymer base material of halogenated olefin, mono:olefinic hydrocarbon and vinyl, monomer mixts'&JP 52 156 790 A 27 December 1977;  DATABASE WPI Week 199647, Derwent Publications Ltd., London, GB; AN 1996-472310, XP002905659 MITSUBISHI CHEM CORP.: 'Polyolefin cation exchange membrane prodn - comprises crosslinking sulphonic acid gp.-contg polyolefin film by electron beam irradiation, giving improved durability to oxidative degradation'&JP 8 239 494 A 17 September 1996EP1177246-A1  See also references of WO 0049069A1US6630518-B1  Brack et al, Poly. Mater. Sci. Eng., 77 :368-369 (1997).;  Lehtinen et al, Electrochemica Acta, 43 (12-13) :1881-1890 (1998).;  Paronen et al, J. Mater. Chem., 7 (12) :2401-2406 (1997).;  Paronen et al, J. of Appl. Polymer Sci., 73 :1273-1284 (1999).;  Savadogo, J. of New Materials for Electrochemical Systems, 1:47-66 (1998).US6902849-B2  Brack et al, Poly. Mater. Sci. Eng., 77:368-369 (1997).;  Lehtinen et al, Electrochimica Acta, 43(12-13):1881-1890 (1998).;  Paronen et al, J. Mater. Chem., 7(12):2401-2406 (1997).;  Paronen et al, J. of Appl. Polymer Sci., 73:1273-1284 (1999).;  Savadogo, J. of New Materials for Electrochemical Systems, 1:47-66 (1998).EP1177246-B1  DATABASE FILE CAPLUS, [Online] BRACK H.P. ET AL.: 'Development of radiation-grafted membranes for fuel cell applications based on poly(ethylene-alt-tetrafluoroethylene)', XP002907346 Retrieved from stn international, accession no. 127:250520 Database accession no. 1997:582320 & POLYM. MATER. SCI. ENG., vol. 77, 1997, pages 368 - 369;  DATABASE WPI Week 197806, Derwent Publications Ltd., London, GB; AN 1978-11509A, XP002905658 ASAHI DOW LTD.: 'Ion exchange membrane with improved oxidn, resistance - comprises sulphonated polymer base material of halogenated olefin, mono:olefinic hydrocarbon and vinyl, monomer mixts' & JP 52 156 790 A 27 December 1977;  DATABASE WPI Week 198415, Derwent Publications Ltd., London, GB; AN 1984-091637, XP002905656 & JP 59 038 242 A & PATENT ABSTRACTS OF JAPAN & JP 59 038 242 A (ASAHI KASEI KOGYO KK) 13 June 1984;  DATABASE WPI Week 198519, Derwent Publications Ltd., London, GB; AN 1985-113518, XP002905655 & JP 60 055 033 A & PATENT ABSTRACTS OF JAPAN & JP 60 055 033 A (KURORIN ENGINEERS KK) 03 August 1985;  DATABASE WPI Week 199647, Derwent Publications Ltd., London, GB; AN 1996-472310, XP002905659 MITSUBISHI CHEM CORP.: 'Polyolefin cation exchange membrane prodn - comprises crosslinking sulphonic acid gp.-contg polyolefin film by electron beam irradiation, giving improved durability to oxidative degradation' & JP 8 239 494 A 17 September 1996;  DATABASE WPI Week 199927, Derwent Publications Ltd., London, GB; AN 1999-323596, XP002905657 & JP 11 116 679 A & PATENT ABSTRACTS OF JAPAN & JP 11 116 679 A (SUMITOMO CHEM CO LTD) 30 July 1999;  MIKAEL PARONEN ET AL.: 'Effects of irradiation on sulfonation of poly (vinylfluoride)' J. MATER. CHEM., vol. 7, no. 12, 1997, pages 2401 - 2426, XP002928702;  MIKAEL PARONEN ET AL.: 'Structure of Sulfonated (Poly(vinyl fluoride)' JOURNAL OF APPLIED POLYMER SCIENCE, vol. 73, August 1999, pages 1273 - 1284, XP002928703;  T. LEHTINEN ET AL.: 'Electrochemical characterization of PVDF-based proton conducting membranes for fuel cells' ELECTROCHEMICA ACTA, vol. 43, no. 12-13, 1998, pages 1881 - 1890, XP002928701