Metallic adhesive, hydrophobic and conductive coatings that are particularly useful as paints for fuel cell bipolar plates

摘要

A solid composition, of use in particular on any type of metallic substrate as a hydrophobic, electrically conductive, metal-adhesive coating, comprises at least (% by weight of composition): as conductive filler, from 75% to 95% of electrically conductive microparticles, the weight-average size of which is between 1 μm and 100 μm; and as hydrophobic, metal-adhesive polymer matrix, from 5% to 25% of a polymer matrix denoted “P”, comprising at least 2 different polymers P1, a thermoplastic fluoropolymer, the weight-average molecular weight of which, denoted “Mw”, is between 100 000 and 1 000 000 g/mol; and P2, a thermoset resin, the glass transition temperature of which is between 30° C. and 150° C. A steel bipolar plate, especially made of stainless steel, for a fuel cell, may be coated with such a composition.