Patent ID: 8105726

Claim:
A gas-impermeable fuel cell separator, comprising: protruding ribs each having a top surface, the protruding ribs forming a gas flow passage, said ribs and gas flow passage having a base material comprising a binder resin; and a sealing section having a top surface corresponding to a region to be bonded to a sealing component, said sealing section having a base material comprising the binder resin, wherein the separator is treated by oxidizing portions of the base material of the gas flow passage, the sealing section, and the top surfaces of the protruding ribs such that hydrophilically treated surfaces which contain hydrophilic COOH groups and OH groups are formed, and wherein the base material is exposed throughout substantially the entire top surface of the sealing section by removing the hydrophilic treatment from the top surface of the sealing section, such that the base material contains substantially no hydrophilic treatment.