Abstract: An improved acoustic diaphragm may be produced by a process which includes the steps of impregnating non-woven fabric or woven fabric of carbon fiber having a high degree of elasticity with a thermosetting resin, thermally molding it into a diaphragm shape, calcining the shaped fabric in an inert gas atmosphere to obtain a porous carbon molding, heating the porous molding to a uniform temperature, and depositing vapor phase, thermally decomposed carbon upon a surface of the porous molding. The deposited carbon is generated by thermal decomposition of a hydrocarbon-containing material introduced together with a carrier gas. The acoustic diaphragm so prepared has a dense surface layer of carbonized fiber-carbonized thermosetting resin-thermally decomposed carbon, and a porous interior of carbonized fiber bonded together by carbonized resin and the thermally decomposed carbon.

Abstract: A process for producing an acoustic diaphragm of carbonaceous material including the steps of uniformly depositing vapor phase thermally decomposed carbon generated by the thermal decomposition of a carbon-generating material introduced together with a carrier gas on the surface of a diaphragm-shaped base material and separating the obtained thermally decomposed carbon deposit from the diaphragm-shaped base material. Thus, the diaphragm is inexpensively made of a carbon material having a large E/.rho. value, high elasticity and high accuracy, without cracking.

Abstract: A process for producing a carbon product having coarse and dense structures by carbonizing moldings of a mixture of one or more types of organic polymer substance, asphalt pitches, dry distilled pitches to obtain a dense structure carbon by carbonizing in an inert gas atmosphere or with a mixture of fine particle graphite powder as required, and porous organic polymer produced in point contact between the particles by solubilizing the surface layers of the organic polymer particles to obtain coarse structure carbon by sintering in particle state by carbonizing in an inert gas atmosphere, in an inert gas atmosphere after solidification to integrally mold organic liquid composition remaining high carbon residue in a composite composition, and carbonizing the composite composition in an inert gas atmosphere.

Abstract: A process for producing an acoustic diaphragm of carbonaceous material including the steps of impregnating nonwoven fabric or woven fabric of carbon fiber having a high degree of elasticity with a thermosetting resin, thermally molding it into a diaphragm shape, calcining the shaped fabric in an inert gas atmosphere to obtain a porous carbon molding, heating the porous molding to a uniform temperature, and depositing vapor phase, thermally decomposed carbon upon a surface of the porous molding. The deposited carbon is generated by thermal decomposition of a hydrocarbon-containing material introduced together with a carrier gas. The process produces an acoustic diaphragm having a dense surface layer of carbonized fiber-carbonized thermosetting resin-thermally decomposed carbon, and a porous interior of carbonized fiber bonded together by carbonized resin and the thermally decomposed carbon.

Abstract: A coiled resistance heating element of carbonaceous or graphite material is disclosed. A simplified process which includes carbonization or graphitization of a coiled strand of an organic material is also disclosed.

Abstract: A process for producing hollow structures of carbon material having desired shape and properties of carbon by obtaining a carbon paste composition, molding portions of the hollow structure by a method selected from the group consisting of an injection molding method, an extrusion molding method, a casting method or a fluidizing method, bonding the molded portions together using a paste composition, solidifying the bonded portion by precarbonizing, the hollow structures thus provided, and then calcining in an inert gas atmosphere as required. Hollow structures of carbon materials having a rigid bond, excellent impermeability, and complicated shape can be readily accurately and inexpensively produced without working after calcining.

Abstract: Porous materials of carbon can be manufactured by introducing particles of organic polymer in a vessel of an arbitrary shape, dissolving a particle surface layer to produce point bondings between the particles, thereby producing porous materials of organic polymer, then insolubilizng or infusibilizing it, and further calcining the particles in inert gas atmosphere, thereby obtaining the porous materials of carbon fundamentally as sintered particle materials. Thus, this process permits, essentially without difficult means of managing complicated steps such as impregnating or extracting, facilitated manufacture of porous materials of carbon having a large quantity of continuous pores with ready adjustments of porosity and diameters of the pores and high strength.

Abstract: An improved process for producing hard carbonaceous sheets, which comprises uniformly dispersing as a viscous binder in fine carbon powder a mixture of relatively readily polymerizable thermosetting resins such as monomers, prepolymers or low polymers exhibiting high residual carbon yield after calcining; applying mechanical energy to the resultant mixture to induce mechanochemical phenomenon to produce molding paste composition in which said binder is uniformly rigidly bonded physicochemically to the surfaces of the primary particles of the fine powder, molding the composition by a fluid rolling method or a coating method in a film or sheet shape; infusibilizing the resultant molding; and calcining the resultant molding in an inert gas atmosphere. Thus, the hard carbonaceous sheets thus produced have small porosity, high mechanical strength, high elastic modulus, isotropy and uniform thickness of several microns to several mm using widely available and inexpensive manufacturing processes.

Abstract: A process for producing a carbon product having coarse and dense portions, the process including producing an integral porous carbon having high strength and uniform porosity distribution with dense structure carbon moldings. The carbon moldings are produced by calcining in an inert gas atmosphere a composite of (a) a green molding, a precarbonized material or a carbide and (b) chlorinated vinyl chloride resin particles, the chlorinated vinyl chloride resin producing, when carbonized in an inert gas atmosphere, a coarse structure. Dense carbon is formed by carbonizing the green molding, precarbonized material or carbide. Thus, the carbon product has coarse and dense portions.