FUEL CELL GAS DIFFUSION LAYER BASE MATERIAL AND METHOD FOR PRODUCING SAME

A method for producing a fuel cell gas diffusion layer base material sequentially Includes: a water-containing sheet preparation step of preparing a water-containing sheet containing a carbon fiber, graphite particles having a particle diameter more than 120 μm as measured by a laser diffraction/scattering method, and a fibrillated organic fiber, which is to be carbonized in a subsequent carbonization step, by using a slurry containing the carbon fiber, the graphite particles, and the fibrillated organic fiber; a composite sheet preparation step of preparing a composite sheet by water-squeezing and drying the water-containing sheet; a resin impregnation step of preparing a resin impregnation sheet by impregnating the composite sheet with a carbon precursor resin to be carbonized in the subsequent carbonization step; a compression step of preparing a thinned sheet by compressing the resin impregnation sheet; and the carbonization step of heating and firing the thinned sheet in a non-oxidizing atmosphere.