(US4794043-A)      Carbon prod. comprises carbonaceous materials (I) between which are interposed flexible graphite sheets (II). (I) and (II) are joined together and the thus joined materials have been integrated by calcination, as a unitary carbon body, in an inert atmos. The joining surface of at least one of materials (I) comprises both joining parts and non-joining parts, which have an optional shape and are uniformly arranged on the joining surface. The ratio of the total area of the non-joining parts in the joining surface of materials (I), to the total area of the joining surface is from 0.20 to 0.80. The value of the difference of the rate (%) of linear expansion and contraction at calcination between two materials (I), to be subjected to mutual joining via (II), is not more than 3%.    Pref. (I) having non-joining parts is a plate having depressed parts.    ADVANTAGE -   New prod. is free from curvature, crack and exfoliation. (15pp)t    (DE3614574-C)      New carbon prod. (I) comprises carbon materials (II) between which are inserted flexible graphite films (III). (II) and (III) are bonded together, and the materials so bonded are integrated to a carbon material by calcining in an inert atmos.    The improvement is that a bonding surface of at least one of the carbon materials has: (a) bonding areas and (b) non-bonding areas, which are arranged uniformly on the bonding surface. The ratio of the total surface of areas (b) on the bonding surface of the carbon material, to the total surface of the bonding surface is 20-80%.    USE -   (I) is useful as part of an electrode substrate. (18pp)    (JP92050709-B)      Carbon production (I) has carbonaceous materials (II) bonded by flexible graphite films (III), which are integrated to a carbon component by calcination in an inert atmosphere. The areas of the bond have zone(s) bonding (II) and unbonded zone(s), which are of any shape and uniformly arranged in the area of the bond.    Preferably the zones of (III) corresponds to the unbonded zones (II) are hollow. The fraction of the total area of the unbonded zones on the bonding area of (II) is 20-80 percent of the total area of this surface. In the fuel cell electrode substrate, the distance between adjacent protrusions is maximum 10 mm. The protrusions may be quadrilateral, rectangular, round or elliptical parallel to the surface and quadrilateral, rectangular or trapezoidal perpendicular to the surface and arranged in series or alternately. The porous plates have an average density of 0.25-0.9 g/cc and gas permeability of minimum 30 cm2/h.mm H20, whilst the protrusions have an average density of 0.40-1.8 g/cc.    Calcination is carried out in an inert atmosphere at minimum 800 degree C. The difference in the rate (percent) of linear expansion and contraction of the 2 (II) to be bonded is not more than 3 percent.    USE/ADVANTAGE -   (I) is claimed as an electrode component, comprising a flat porous carbonaceous plate with protrusions bonded to another (II) through (III), especially on electrode substrate for fuel cells with one (II) as separator. The specified construction preventing stresses being focussed on the bonded areas. (J61253768-A