Abstract: The present invention provides a carbonaceous material suitable for an electrode of a secondary cell. The carbonaceous material has a specific surface area by BET method of at least 10 m.sup.2 /g and a nitrogen/carbon atom weight ratio of 0.15 to 0.01, and is obtained by heat-treating a polyimide polymer having repeating units represented by: ##STR1## wherein R represents a 4 valent aromatic residue having at least one aromatic ring, of which each 2 valences are bonded with an adjacent carbon atom in the aromatic ring, R' represents a divalent aromatic residue having 1 to 4 aromatic rings and n is an integer of at least 2. The present invention also provides a secondary cell using the above mentioned carbonaceous material as electrode.

Abstract: An electrode comprises a porous carbon sheet comprising (a) carbon fibers and (b) a carbon matrix which comprises carbon particles and is integrally combined with the carbon fibers, having continuous through-holes. This electrode can be used as a cathode or anode for a battery. This type of electrode is prepared by depositing a phenolic resin on a phenolic resin sheet comprising phenolic resin fibers, and carbonizing the phenolic resin and the phenolic resin sheet in an oxygen-free atmosphere at temperatures in the range of 500.degree. C. to 3000.degree. C.

Abstract: Disclosed herein are composite carrier particles for electrophotography comprising 80 to 99% by weight of ferromagnetic fine particles and a phenol resin, and having a number-average particle diameter of 10 to 1,000 .mu.m, a bulk density of not more than 2.0 g /cm.sup.3, and a curved surface configuration, and a process for producing the same.

Abstract: The present invention relates to a process for producing spherical thermosetting phenolic resin particles having a size of no larger than about 1,000 microns, and the spherical thermosetting phenolic resin particles produced by this process.In accordance with the process of the present invention, a novolak resin, and a nitrogenous basic compound, and, optionally, an aldehyde, are reacted while they are suspended in an aqueous medium in the presence of a suspension stabilizer.The thermosetting phenolic resin produced by the process of the present invention not only displays superior thermal curing characteristics during molding; the cured product fabricated by molding this resin also exhibits good physical properties such as improved mechanical strength and heat resistance. Therefore, the spherical thermosetting phenolic resin particles produced by the process of the present invention can be extensively used as molding materials, binders, adhesives, and in many other applications.

Abstract: A resole resin in the form of microspherical particles whose surfaces are partly or entirely covered with a coating of a substantially water-insoluble inorganic salt and which are not larger than 500 .mu.m in size, and a process for producing such resole resin. The resole resin comprises solid particles that are highly heat reactive and can be stored in a stable manner for a prolonged period. The resin particles can be used with good results in all fields of applications (e.g., moldings, laminations and binders) where conventional phenolic resins are used.

Abstract: A process for producing microspherical cured phenolic resin particles having a particle diameter of not more than about 100 .mu.m, which comprises reacting a novolak resin, a phenol and an aldehyde in an aqueous medium in the presence of a basic catalyst and an emulsion stabilizer. Novel microspherical cured phenolic resin particles are produced by this process. The resin particles have excellent impact strength and mechanical properties, a sharp particle size distribution, and a low secondary agglomerate content, and because of these properties, are useful as an excellent modifier or filler for various plastics and rubbers.

Abstract: A resole resin in the form of microspherical particles whose surfaces are partly or entirely covered with a coating of a substantially water-insoluble inorganic salt and which are not larger than 500 .mu.m in size, and a process for producing such resole resin. The resole resin comprises solid particles that are highly heat reactive and can be stored in a stable manner for a prolonged period. The resin particles can be used with good results in all fields of applications (e.g., moldings, laminations and binders) where conventional phenolic resins are used.