Abstract: A process for producing a process for producing a two- or three-dimensional carbon fabric, which process includes melt-spinning (a) an optically anisotropic carbonaceous pitch having an optically anisotropic phase content of 60 to 100%, subjecting the thus- infusibilized fibers to a primary heat treatment at a temperature greater than 1000.degree. and not higher than 2500.degree. C. to produce primary heat treated fibers having a tensile strength not lower than 300 kg/mm.sup.2 and a breaking elongation in the range of 0.4% to 10%, preparing a two- or three-dimensional fabric from the primary heat treated fibers and then subjecting the two- or three-dimensional fabric to a secondary heat treatment at a temperature which is at least 50.degree. higher than the temperature used in the primary heat treatment, the temperature in the secondary heat treatment being higher than 1050.degree. C. and no higher than 3300.degree. C.

Abstract: A process of manufacturing carbon fibers of high chemical stability comprises reacting feed carbon fibers having an elastic modulus of 30.times.10.sup.3 kgf/mm.sup.2 with a compound of elements capable of forming a carbide ceramics on the carbon fibers peripherally alone or both peripherally and partially internally.

Abstract: A carbon/carbon composite is prepared by impregnating a bundle of carbon fibers with a polymer of a nitrogen-containing heterocyclic compound, carbonizing the thus-impregnated carbon fiber bundle under pressure or under pressing and, optionally, further carbonizing the thus-carbonized carbon fiber bundle at atmospheric pressure.

Abstract: A carbon/carbon composite is prepared by polymerizing a polycyclic aromatic compound in the presence of a coupling agent, then impregnating a bundle of carbon fibers with the resulting polymer, then carbonizing the thus-impregnated carbon fiber bundle under pressure or under pressing, and optionally, further carbonizing the thus-carbonized carbon fiber bundle at atmospheric pressure.

Abstract: A carbon/carbon composite is prepared by mixing 100 parts of a carbonaceous pitch with 1-45 parts by weight of at least one aromatic compound containing at least one functional group selected from nitro and hydroxyl groups, then impregnating a bundle of carbon fibers with the resulting mixture, thereafter carbonizing the thus-impregnated carbon fiber bundle under pressure or under pressing, and if necessary, further carbonizing the thus-carbonized carbon fiber bundle at atmospheric pressure.

Abstract: A carbon material having oxidation resistance is prepared by forming a fi coating constituted mainly by carbon on the surface of a carbon/carbon composite by chemical vapor deposition, then forming on said first coating a second coating of a ceramic or both a ceramic and carbon by chemical vapor deposition, and changing at least one of thermal physical properties or mechanical physical properties of carbon in said first coating continuously or step-wise.

Abstract: A pitch-based carbon fiber having a high strength is produced by (a) treating a heavy oil at a temperature of 370.degree. to 480.degree. C. and a pressure of 2 to 50 kg/cm.sup.2 ; (b) separating and removing insoluble solids from the heat-treated oil so that the insoluble solids content is not higher than 50 ppm; (c) subjecting the oil to thin film distillation at a temperature of 250.degree. to 450.degree. C., a pressure of not higher than 100 mm Hg and a film thickness of not larger than 5 mm; (d) heat-treating the resulting pitch at a temperature of 340.degree. to 450.degree. C. while passing an inert gas at atmospheric or reduced pressure to obtain an optically anisotropic pitch having a softening point of 260.degree. to 300.degree. C.

Abstract: A carbon/carbon composite having oxidation resistance is produced by filling the voids of a carbon/carbon composite comprising 10-70% by volume of carbon fibers and 5-90% by volume of a carbonaceous matrix and having a void percentage of 10-55%, with at least one of carbon and a ceramic by chemical vapor infiltration and then coating the deposit surface with a ceramic or both ceramic and carbon by chemical vapor deposition.

Abstract: A melt spinning apparatus particularly applicable to a multifilament spinning for pitch based carbon fibers. The melt spinning apparatus is provided in which a flow uniforming member is attached to a central part on a spinning side of a spinneret having circularly or concentrically arranged nozzles, the flow uniforming member having a sectional diameter at least 3 mm smaller than the diameter of the innermost row of nozzles and a length not smaller than 2 cm. The apparatus is provided with a cooling means as an outer peripheral portion below a spinning pack having an annular blowing port for blowing a cooling gas toward the spun filaments. A gap is provided between the spinning pack and the cooling means and is sealed with a heat insulator.

Abstract: A process for fabricating a carbon/carbon fiber composite characterized in that one or more kinds of fibers selected from the group consisting of a pitch fiber obtained by spinning a carbonaceous pitch, an infusiblized fiber obtained by subjecting the pitch fiber to an infusiblizing treatment, and a pre-carbonized fiber obtained by subjecting the infusiblized fiber to a pre-carbonizing fiber at 400.degree. to 800.degree. C. in an inert gas atmosphere, are woven, laminated or mix-pulverized together with a pitch-based carbon fiber, and then carbonized under the application of pressure or under pressing.

Abstract: In a process for producing carbon fibers from a carbonaceous pitch, the improvement characterized in that an end portion of infusiblized fiber or carbonized fiber to be first subjected to a carbonizing or graphitizing treatment and that of infusiblized fiber or carbonized fiber to be next subjected to the same treatment are bonded together using a composition comprising (a) at least one member selected from the group consisting of phenolic resins and pitches and (b) graphite powder, and the thus-bonded fibers are fed successively to a carbonizing apparatus or a graphitizing apparatus.

Abstract: In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the pitch fibers are subjected to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range between 0.5 and 500 cSt and removing said dimethyl polysiloxane by washing prior to the carbonization.

Abstract: Pitch for the production of carbon fibers which contains from 5 to 40% of the optically anisotropic region which is insoluble in organic solvents having a solubility parameter from 7.4 to 9.0 but is soluble in organic solvents having a solubility parameter from 9.2 to 11.0.

Abstract: Provided is a process for producing pitch carbon fibers by subjecting pitch fibers obtained by melt-spinning a carbonaceous pitch to infusibilization treatment and then to carbonization treatment or both carbonization treatment and subsequent graphitization treatment, characterized in that a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range of 12,000 to 1,000,000 cSt is applied to the fibers after the infusibilization treatment, and the infusibilized fibers with the dimethyl polysiloxane thus applied thereto are then subjected to the carbonization treatment or both the carbonization treatment and the subsequent graphitization treatment.

Abstract: Provided is a starting pitch for producing carbon fiber by heat-treating the starting pitch to obtain a precursor pitch, melt-spinning the precursor pitch, then rendering the resultant pitch fiber infusible, followed by carbonization, and further followed by graphitization if required, the starting pitch comprising a mixture of (a) 100 parts by weight of a pitch and (b) 5 to 500 parts by weight of a methanol-insoluble and benzene-soluble component contained in a heavy oil obtained in a fluid catalytic cracking of petroleum, the heavy oil having a boiling range not lower than 200.degree. C.

Abstract: A precursor pitch for the production of carton fibers is obtained by heat-treating a carbonaceous pitch in the form of a thin film having a thickness not larger than 5 mm at a temperature in the range of 250.degree. to 390.degree. C. and under a reduced pressure not higher than 100 mmHg. By melt-spinning this precursor pitch and subjecting the resultant pitch fiber to infusiblization and carbonization and, if required, to subsequent graphitization, there is obtained a high quality carbon fiber.

Abstract: Provided is a process for producing a pitch-based graphite fiber, which process comprises treating a pitch fiber in an oxidative gas atmosphere to render it infusible, said pitch fiber being obtained by melt-spinning a carbonaceous pitch, then heat-treating the infusibilized fiber at 400.degree.-750.degree. C. in an inert gas atmosphere to obtain a precarbonized fiber substantially containing oxygen, then raising the temperature to 2,000.degree.-3,000.degree. C. at a rate of 500.degree. C. or higher per minute in an inert gas atmosphere and heat-treating the precarbonized fiber at the raised temperature of 2,000.degree.-3,000.degree. C. in said inert gas atmosphere.

Abstract: A process for producing carbon fibers, comprising melt spinning a carbonaceous pitch to obtain pitch fibers, contacting the thus obtained pitch fibers with hydrobromic acid, making the thus contacted fibers infusible in an oxidizing atmosphere and then carbonizing and, if desirable, graphitizing the thus treated pitch fibers to obtain the carbon fibers.

Abstract: A starting pitch for carbon fibers is obtained by mixing (1) 100 parts by volume of a heavy fraction oil boiling at not lower than 200.degree. C. and obtained at the time of fluidized catalytic cracking of petroleum with (2) 10 to 200 parts by volume of a fraction boiling in the range of 250.degree. to 550.degree. C. obtained by distilling under reduced pressure an oil produced at the time of heat treating a starting pitch and then heat treating the resulting mixture at a temperature of from 370.degree. C. to 480.degree. C. under a pressure of from 2 to 50 Kg/cm.sup.2.G thereby to obtain the starting pitch for carbon fibers. The thus obtained starting pitch is heat treated to obtain a precursor pitch which is melt spun, infusibilized, carbonized or graphitized to obtain the carbon fibers.

Abstract: A starting pitch for carbon fibers, obtained by (A) mixing together (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of fluidized catalytic cracking of petroleum, (2) a hydrogenated oil selected from aromatic hydrocarbons of 2-10 rings having their nuclei partly hydrogenated and specific fractions boiling at 160.degree.-650.degree. C. and containing such aromatic hydrocarbons and (3) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum, to form a mixture of the oils (1), (2) and (3), and then (B) heat treating the thus formed oil mixture at 370.degree.-480.degree. C. and 2-50 Kg/cm.sup.2.G thereby to obtain the starting pitch.