Abstract: In order to attain excellent electrical conductivity and molding processability, a fuel cell separator to be produced by performing press molding on a preform in which expanded graphite is used as the main raw material is improved so that the preform is produced by a papermaking method, whereby the characteristics of the mechanical strength, the flexibility, and the gas impermeability are improved, and a light and compact configuration that is preferred in the automobile use or the like can be realized.

Abstract: In order to attain excellent electrical conductivity and molding processability, a fuel cell separator to be produced by performing press molding on a preform in which expanded graphite is used as the main raw material is improved so that the preform is produced by a papermaking method, whereby the characteristics of the mechanical strength, the flexibility, and the gas impermeability are improved, and the moldability is made excellent so that a light and compact configuration that is preferred in the automobile use or the like can be realized.

Abstract: According to the invention, in a separator molded member (4A) for a fuel cell which is produced by: loading a complex compound that is configured by bonding graphite powder by means of a thermosetting resin, into a mold (14); and forming ribs (11) for forming gas passages by the resin molding process, a section of the separator molded member is formed into a stack structure in which part of flat graphite particles (14) overlap with one another in the thickness direction, whereby the gas impermeability, the mechanical strength, and the conductivity which are required in a fuel cell separator can be improved.

Abstract: According to the invention, in a separator molded member (4A) for a fuel cell which is produced by: loading a complex compound that is configured by bonding graphite powder by means of a thermosetting resin, into a mold (14); and forming ribs (11) for forming gas passages by the resin molding process, the surfaces of the ribs (11) are alkali-treated by, for example, etching by using an alkaline solution, and graphite particles (14) which are flat and soft are exposed from the top surfaces of the ribs (11) which function as a contact surface with an electrode in the separator molded member (4A), and resin defective portions (15) are formed between adjacent graphite particles (14), whereby the contact area with an electrode is enlarged, so that the performance and efficiency of the fuel cell can be improved by remarkable lowering of the contact resistance.

Abstract: According to the invention, in a separator (4) for a fuel cell which is produced by: loading a complex compound that is configured by bonding graphite powder by means of a thermosetting resin, into a mold (14); and forming ribs (11) for forming gas passages by the resin molding process, the surfaces of the ribs (11) are etched by an alkaline solution or alkali-treated, a surface resin layer which is formed on the surface of the separator (4) is removed away, and graphite particles showing a plate-like form are exposed from the surfaces of the ribs (11) which function as a contact surface with an electrode, whereby the contact resistance with an electrode is remarkably lowered, so that the performance and efficiency of the fuel cell can be improved.

Abstract: To provide a separator for a fuel cell made of graphite excellent in mechanical strength and gas impermeability as well as electric characteristic properties, a separator for a fuel cell is produced from a molded body produced by filling a graphite powder 21 whose surface is coated with resin 20 in a molding die and by pressure-molding the powder. Such a molded body is provided with excellent mechanical strength of 40 MPa of bending strength or higher, 10×10?8 cc·cm/cm2·sec·atm of gas permeability or lower, and electric property of 10×10?3 ?·cm of the volume resistance or lower even if the content of resin is decreased to as low as 10 to 24 wt. %.

Abstract: A separator for a fuel cell made of graphite may be excellent in mechanical strength and gas impermeability as well as electrical properties. A separator for a fuel cell is produced from a molded body that is produced by filling a graphite powder whose surface is coated with resin in a molding die and by pressure-molding the powder. Such a molded body provides excellent mechanical strength, gas permeability, and electrical properties even if the content of resin is decreased to as low as 10 to 24 wt. %.

Abstract: A polishing pad that can polish the surface of work pieces, such as semiconductor silicon wafers, with satisfactory results. Polishing pad 1.sub.1 is formed of a large number of resin polishing elements 11, all tubular with a very small diameter, inseparably bound together, outer peripheral surface to outer peripheral surface, with the axial direction tube end faces aligned on a plane, to form a plate structure 10 with two kinds of pores 12, 13, which are regularly positioned and run through the plate structure 10 in the thickness direction. Pad surface 1a of polishing pad 1.sub.1 is formed by the axial direction tube end faces of polishing elements 11 . . . . First pore 12 is the center pore in the polishing element 11. Second pore 13 is formed between the outer peripheral surfaces of the polishing elements 11 . . . .