US 2013/0171547 A1Published application

Fuel cell separator

AssigneeNisshinbo Chemical Inc.

InventorFumio Tanno

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Abstract

This fuel cell separator is obtained by irradiating the surface of a molded article formed by molding a composition containing graphite powder, an epoxy resin, a phenol resin, a curing accelerator, and an internal mold lubricant and is provided with the following characteristics. Accordingly, the conductivity and hydrophilicity of a fuel cell separator provided with grooves that form flow paths for gas supply and exhausting on the surface thereof can be improved, and also elutability can be reduced. Residue from laser irradiation of the surface is 5% or less by area ratio Arithmetic average roughness of surface is 0.80-1.50 μm Surface static contact angle is 15-60° Surface contact resistance is 3-7 mΩ·cm2 Ion exchanged water: under a condition of separator=9:1 (mass ratio), the conductivity after the separator has been immersed in ion exchanged water at 90° C. for 168 hours is 1.2 μS/cm or less.

Claims7

Dependent claims

A fuel cell separator obtained by laser irradiation of a surface of an article molded from a composition comprising a graphite powder, an epoxy resin, a phenolic resin, a curing accelerator and an internal mold release agent, which fuel cell separator possesses characteristics (1) to (6) below:

(1) residues from laser irradiation on a surface of the separator, expressed as an area ratio, of 5% or less;
(2) an arithmetic mean roughness Ra at the separator surface of from 0.80 to 1.50 μm;
(3) a static contact angle at the separator surface of from 15 to 60′;
(4) a contact resistance at the separator surface of from 3 to 7 mΩ·cm2;
(5) an electrical conductivity by leachate obtained after immersing the separator for 168 hours in ion-exchanged water at 90° C., under conditions where the weight ratio of ion-exchanged water to separator=9:1, of 1.2 μS/cm or less;
and
(6) changes in surface roughness after 2,000 hours of immersion in, respectively, 90° C. ion-exchanged water and 150° C. ion-exchanged water, which are each within 0.3 μm of the surface roughness prior to immersion.

4 more elements

Dependencies are inferred from the claim text.