Petoca, Ltd.

Takashi Maeda

Toshifumi Kawamura

Tomiji Hosotsubo

Yuji Kawabuchi

Tetsuo Yamamoto

Mesophase pitch-based activated carbon fibers which are obtained by milling infusibilized mesophase pitch fibers, as they are or after carbonizing at a temperature of 350 to 1,000.degree. C., to an average particle diameter of 5 to 50 .mu.m and then activating in the presence of an alkali metal compound. The activated carbon fibers have a pore distribution suitable for forming a electric double layer and is excellent as the material for an electrode of an electric double layer capacitor. The electric double layer capacitor having the electrode using the activated carbon fiber exhibits high discharge capacity.

Mesophase pitch-based activated carbon fibers and electric double layer

A process for preparing nitrogen-containing isotropic pitch, comprising the steps of mixing a petroleum heavy oil, a nitrating reagent and water to prepare a homogeneous dispersion, thereby contacting the petroleum heavy oil with the nitrating reagent in the homogeneous dispersion state to prepare a crude nitrated heavy oil, and subjecting the crude nitrated heavy oil to refining, thermal polymerization and vacuum distillation. According to the process of the invention, a petroleum heavy oil containing a large amount of light oil components and being liquid at ordinary temperature, from which pitch has been hardly prepared conventionally, is used as a starting material for preparing pitch, and there can be obtained nitrogen-containing isotropic pitch of homogeneity and high quality having a desired softening point of from a low softening point to a high softening point, though such pitch was unable to be obtained so far.

Process for preparing nitrogen-containing isotropic pitch and

There is disclosed a process for producing pitch-based carbon fiber which comprises melt spinning an optically isotropic pitch or a mesophase pitch to form pitch fiber; subjecting the pitch fiber to liquid-phase oxidative polymerization in a solvent in the presence of an acid catalyst and a crosslinking agent to form infusibilized fiber; and carbonizing the infusiblized fiber. The above process enables low temperature and short time infusibilizing treatment of optically isotropic pitch fiber having a low softening point which has heretofore been difficult because of failure to preserve the original fibrous shape during infusibilization, and also efficient production of mesophase pitch-based carbon fibers as well as optically isotropic pitch-based carbon fibers each being improved in physical properties.

Process for producing pitch-based carbon fiber

A process for preparing pitch for matrix wherein an optically isotropic pitch is formed into a fibrous pitch, and the fibrous pitch thus obtained is nitrated with a nitration reagent in the presence of an acid catalyst. The resulting pitch can be carbonized with a low energy, is high in carbonization yield, low in softening point and excellent in moldability and impregnability.

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Kamisu-machi, Japan

Takashi Maeda