| 摘要 |
The present invention provides carbon fibre paper for use as current collectors for a polymer electrolyte fuel cell, where there is no fear of a short circuit with the facing electrode occurring, and which is not damaged by the application of pressure, has a comparatively low resistance value and is also cheap. Specifically, it relates to a carbon fibre paper for a polymer electrolyte fuel cell which is characterized in that it is a carbon fibre paper which is used in a polymer electrolyte fuel cell in a state where short carbon fibres are bound with a polymer material and, taking the thickness as X mm, the thickness at the time of 2.9 MPa applied pressure as Y mm and the length of the short carbon fibre as W mm, at least 95% of the short carbon fibres excluding those of length (Y + 0.1) mm or less satisfy the relation W ≥ 5X. Taking the average length as Z mm, it is also preferred that the relation Z ≥ 5X also be satisfied. Said carbon fibre paper has a weight reduction of no more than 3% when a uniform pressure of 2.9 MPa is applied for 2 minutes in the thickness direction and then this pressure released, and the short carbon fibre diameter D ( mu m), tensile strength sigma (MPa) and tensile modulus (E) satisfy the following relation. <MATH> <IMAGE> |
