Abstract: The purpose of the present invention is to provide a carbon black capable of efficiently covering the surface of an electrode active material and enhancing the electric current collection effect as an electroconductive agent of a secondary cell. A carbon black comprising carbon black aggregates (2) in which the ratio PPA/d of the number of primary particles (1) (PPA) and the diameter d (nm) of the primary particles (1) is 8 or higher.

Abstract: The purpose of the present invention is to provide a carbon black capable of efficiently covering the surface of an electrode active material and enhancing the electric current collection effect as an electroconductive agent of a secondary cell. A carbon black comprising carbon black aggregates (2) in which the ratio PPA/d of the number of primary particles (1) (PPA) and the diameter d (nm) of the primary particles (1) is 8 or higher.

Abstract: In the present invention, a starting material liquid including a carbon compound and a catalyst or a catalyst precursor, and a reaction vessel having a high-temperature zone heated to 900-1,300° C. are prepared. The starting material liquid is introduced into the reaction vessel, and a mixture is generated which comprises a gas including a carbon source, and catalyst microparticles dispersed in the gas. A carrier gas is then introduced in pulses into the reaction vessel, and the mixture is pushed out to the high-temperature zone. The carbon source and catalyst microparticles included in the mixture are then brought into contact with each other in the high-temperature zone, initial fibers are grown, and carbon fibers are subsequently grown in an environment in which the carrier gas is retained.

Abstract: This invention relates to a carbon black reactor comprising; a combustion zone for generating a hot combustion gas by burning a mixture of a hydrocarbon fuel and an oxygen containing gas, a reaction zone for producing a carbon black by contacting the hot combustion gas with a feedstock introduced in a plurality of divided flows to thermally decompose and/or incompletely combust the feedstock, and a quench zone for stopping a carbon black growth reaction by injection a coolant to said carbon black containing flow, and these three zones are arrayed laterally in order, wherein the cross-section shape of the feedstock introduction part in the reaction zone is not a circle nor a polygon. The carbon black reactor can produce the carbon black having same characteristics, especially the distribution of the aggregate size, as one produced by pilot-scale reactor, while its production scale is increased to the level of that of reactor actually operated.

Abstract: In a pneumatic tire, a tread portion is comprised of a rubber composition containing 30-70 parts by weight of carbon black powder having particular properties based on 100 parts by weight of rubber component.