(US4459342-A)      Porous ribbed substrate for a fuel cell electrode comprises a non-ribbed layer and a ribbed layer of bulk density lower than that of the non-ribbed layer.    Pref. the respective bulk densities are 0.4-0.7 and 0.5-0.9 g/cm3. The non-ribbed layer has a thickness 1/50-1/2 of that of the substrate minus the thickness of the ribs. The substrate pref. has a bending strength of not less than 50 kg/cm2 and a porosity of 50-80%. Not less than 70% of the    are open, not less than 60% of the pores in the ribbed layer are of dia. 5-50 microns, and not less than 60% of the pores in the non-ribbed layer have a dia. of 1-30 microns.    ADVANTAGE -   High mechanical strength is achieved.    (4pp)    (DE3332625-C)      A porous, ribbed carrier material for a fuel cell electrode, comprises a ribbed layer and a non-ribbed layer.    The density of the non-ribbed layer is greater than that of the ribbed layer. The non-ribbed layer density is 0.4-0.7%/om3 while the ribbed layer density is 0.5-0.9 g/cm3.    The non-ribbed layer thickness is pref. 1/50-1/2 the thickness of the carrier mater.    ADVANTAGE -   The material is efficient and reliable, and has good mechanical strength.    (5pp)    (JP92049747-B)      The substrate consists of a ribbed layer (a) on one side of a non-ribbed layer (b) which has a higher density than layer (a). Layer (a) pref. has a density of 0.4-0.7 g/ccm. The density of layer (b) is pref. 0.5-0/9 g/ccm. Layer (b) pref. has a thickness of 1/50th to 1/2 of the thickness of the substrate without the ribs.    The substrate pref. has a bend strength of min. 4.9 MPa (50 kg/sq.cm), and a porosity of 50-80%, where min. 70% of the pores are open, and min. 60% of the pores in layer (a) are 5-50 microns in dia. In layer (b) min. 60% of the pores are 1-30 microns in dia.; and the average dia. of the pores in layer (a) is larger than the average dia. of the pores in layer (b).    By using a substrate consisting of two layers of different properties, the electrode has excellent operating characteristics in a fuel cell, e.g. good permeability to gases and low electrical resistance. (J59046763-A