{
  "$type": "site.standard.document",
  "description": "A polymer electrolyte membrane for a polymer electrolyte fuel cell, that overcomes disadvantages of the conventional polymer ion-exchange membranes including fluorine-based polymer electrolyte membranes and can maintain cell characteristics even in use over a long period of time (e.g., several…",
  "path": "/patents/1068588",
  "publishedAt": "2006-04-05T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B01D67/009",
    "NITTO DENKO CORP [JP]"
  ],
  "textContent": "A polymer electrolyte membrane for a polymer electrolyte fuel cell, that overcomes disadvantages of the conventional polymer ion-exchange membranes including fluorine-based polymer electrolyte membranes and can maintain cell characteristics even in use over a long period of time (e.g., several thousand hours). The polymer electrolyte membrane comprises a fluorine polymer substrate having grafted thereon monomers having sulfone groups as a cation-exchange group, wherein a main chain of the graft chain comprises a hydrocarbon or a partially fluorinated hydrocarbon, and sulfone groups or substituents having sulfone groups are bonded as a side chain, and wherein in element compositional ratio by ESCA, at least one surface of the polymer electrolyte membrane has O/S value of 5.0 or higher, and a surface element proportion of S is 0.4-5.0%.",
  "title": "Polymer electrolyte membrane having excellent durability"
}