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AssigneeNippon Steel Chemical Co., Ltd.
InventorsYoichi Kawano, Takayuki Kawarada, Hiroshi Ono
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This invention relates to a fuel cell separator of excellent electrical conductivity, gas impermeability and strength. The composition for a fuel cell separator of this invention comprises a resin binder with a viscosity of 0.01–0.5 Pa·s at 150° C. and a viscosity of 3 Pa·s or more at 25° C. and graphite particles at a weight ratio of 1:(5–15) and a curing accelerator. The resin binder is exemplified by an epoxy resin binder composed of an epoxy resin and a curing agent for the epoxy resin. The process for producing the fuel cell separator of this invention is practiced by kneading and molding the aforementioned composition for a fuel cell separator and curing above the curing temperature of the composition. The fuel cell separator of this invention to be obtained by the aforementioned process shows a bulk density of 1.90 g/cm3 or more, a sheet resistance (areal pressure, 0.5 MPa) of 40 m Ωcm2 or less, a gas permeability of 1×10−14 cm2 or less and a flexural strength of 30 MPa or more.
A composition for a fuel cell separator which is formulated from graphite particles and a liquid or solid resin binder with a viscosity of 0.01–0.5 Pa·s at 150° C. and a viscosity of 3 Pa·s or more at 25° C. at a weight ratio of (5–15):1, wherein the graphite particles comprise synthetic graphite particles with an average particle diameter of 50–300 μm and Kish graphite particles with an average particle diameter of less than 50 μm at a mix ratio by weight in the range from 40:60 to 90:10.
A composition for a fuel cell separator which is formulated from graphite particles and a liquid or solid resin binder with a viscosity of 0.01–0.5 Pa·s at 150° C. and a viscosity of 3 Pa·s or more at 25° C. at a weight ratio of (5–15):
A process for producing a fuel cell separator which comprises
Dependencies are inferred from the claim text.