Abstract: The present invention discloses carbon black for a tire tread having a cetyltrimethyl ammonium bromide specific surface area (CTAB) of 120 to 160 m.sup.2 /g, a dibutyl phthalate absorption number of compressed sample (24M4) of 95 to 135 ml/100 g, and a tinting strength (Tint) of 100 to 150% and exhibits an M value defined by the following formula (1) and satisfying the following formula (2): ##EQU1## wherein IA is the iodine adsorption number (mg/g), N.sub.2 SA is the nitrogen adsorption specific surface area (m.sup.2 /g), Dst is the equivalent Stokes diameter (nm) at the maximum absorbance of the distribution curve of aggregates determined by the centrifugal classification method, and .DELTA.Dst is the difference (nm) between two equivalent Stokes diameters at two points on the distribution curve of aggregates at which the absorbance is 50% of the maximum absorbance.

Abstract: Disclosed are surface-coated SiC whiskers, proceses for preparing the same, a ceramic reinforced with the same, and a process for preparing said reinforced ceramic. The surface-coated SiC whiskers are SiC whiskers (I) having a surface coated with a thin carbonaceous layer having a thickness of 7 to 100 .ANG., or SiC whiskers (II) having a surface coated with an Si.sub.3 N.sub.4 layer. The SiC whiskers (I) can be prepared by dispersing SiC whiskers in a homogeneous solution of a thermosetting resin in an organic solvent, separating the whiskers by filtration and drying it, curing the thermosetting resin, and firing the cured thermosetting resin in a non-oxidizing atmoshpere at 800.degree. to 1,600.degree. C. The SiC whiskers (II) can be prepared by dispersing SiC whiskers in a solution of an organosilicon polymer in an organic solvent, separating the whiskers by filtration and drying it, heating the whiskers coated with the organosilicon polymer in a nitriding atmoshpere at 1,200.degree. to 1,600.degree. C.

Abstract: Magnetic carbon black, a process for preparing the same, and a method of modifying magnetic carbon black are provided. The magnetic carbon black is prepared by process A in which when a hydrocarbon is supplied into a high temperature combustion gas stream formed by combustion of a fuel to prepare carbon black, an organic transition metal compound is supplied together with the hydrocarbon and, at the same time, an oxygen gas is supplied from the circumference of the hydrocarbon, process B in which a transition metal compound is supplied together with a hydrogen gas on the downstream side of the supply position of the hydrocarbon, and process C in which a hydrocarbon is supplied into a high temperature combustion gas stream on both the upstream side and the downstream side and a transition metal compound is supplied from a position between the supply positions of the hydrocarbon.

Abstract: A granular carbonaceous heat insulator comprising a carbon black pellet the surface of which is coated with a carbon layer having a dense structure is disclosed. This heat insulator is prepared by adhering a binder solution to a carbon black pellet, heating the resulting coating to remove a solvent from the binder solution and, at the same time, to cure the binder, and baking the carbon black pellet coated with the cured binder in a non-oxidizing atmosphere to carbonize the cured binder. Alternatively, the heat insulator is prepared by subjecting a carbon black pellet having specific characteristics to wet granulation in the presence of a binder solution to crush the carbon black pellet and, at the same time, to granulate the crushed pellet, thereby preparing a granulated carbon black pellet, followed by removal of the solvent from the prepared pellet, curing of the binder and baking of the cured binder in the same manner as that described above.

Abstract: A rubber composition comprising 35 to 100 parts by weight of a carbon black per 100 parts by weight of a rubber component, the carbon black having a nitrogen adsorption specific surface area (N.sub.2 SA) within a range of 70 to 185 m.sup.2 /g and an aggregate characteristic which shows a first and a second modal diameters in the aggregate equivalent Stokes diameter distribution and has a difference between the two modal diameters L (nm) to be calculated from the following equation (1) which satisfies the following formula (2):L=Dst.sub.2 -Dst.sub.1 (1)20.ltoreq.L.ltoreq.110-0.3 (N.sub.2 SA) (2)wherein Dst.sub.1 and Dst.sub.2 respectively denote the first modal diameter (nm) and the second modal diameter (nm) in the aggregate equivalent Stokes diameter distribution detetermined by a centrifugal classification method.

Abstract: A carbon black for blending in rubber is disclosed, which has a BET specific surface area (N.sub.2 SA) within a range of 65 to 84 m.sup.2 /g, an a value to be obtained according to the following calculation formula, of at least 270 and a ratio of the BET specific surface area (N.sub.2 SA) to the iodine adsorption number (IA), N.sub.2 SA/AI, within a range of 1.10 to 1.35:a=(24M4DBP).sup.2 .times.(Blackness/IA ).sup.2 .times.(Dst).sup.2 .times.10.sup.

Abstract: The present invention provides a process for preparing silicon carbide whiskers. According to the process, carbon black having the following properties (a) to (c) is blended, as a carbonaceous material, with a silicon source material, and the resulting mixture is heated in a non-oxidizing atmosphere at 1,300.degree. to 1,800.degree. C.(a) Nitrogen adsorption specific surface area: 150 to 500 m.sup.2 /g(b) Dibutyl phthalate absorption: 120 to 200 ml/100 g.(c) Tint strength (%): equal to or below a value calculated according to the following formula:0.3496.times.(nitrogen adsorption specific surface area)-0.2143.times.(dibutyl phthalate absorption)+101.

Abstract: In a process for manufacturing a whisker preform for a composite material, a dispersion of a whisker in water or an organic solvent is passed through a sieve and is filtered, and a residual wet whisker cake is dried, with or without prior compression, to produce a cake having a desired density based upon the relationship between the weight of the whisker in the dispersion and the volume of the residual whisker cake after filtration.

Abstract: The invention provides a method for preparing a SiC whisker-reinforced composite material. A matrix material such as a metal, an alloy or a plastic is introduced into a fibrous base consisting of a SiC whisker sponge-like cake. The resultant structure is compressed into a desired shape as needed. The fibrous base is prepared by heating a mixture of silica gel or ashed rice hulls with a furnace carbon black and an additional amount of NaCl as a space forming agent for forming spaces conducive to whisker growth.

Abstract: The process according to the present invention involves mixing 100 parts by weight of a silica gel, containing 6.0 to 25.0% by weight with respect to a silicon of a water-soluble compound of at least one metal selected from the group consisting of iron, nickel and cobalt, with 110 to 400 parts by weight of furnace carbon black having a structure indicated by a DBP absorption number of 50 ml/100 g or higher, and then reacting the mixture under a non-oxidative atmosphere at a temperature of 1,300.degree. to 1,700.degree. C. to produce silicon carbide whiskers.

Abstract: According to this invention, a rubber composition is provided, which comprises 100 parts by weight of a rubber component and 25 to 250 parts by weight of carbon black, which carbon black falls within the property range of an electron-microscopic average particle diameter (dn) of above 31 millimicron, an iodine adsorption number of 35 to 60 mg/g and a dibutyl phthalate absorption number (DBP) of 90 to 150 ml/100 g and further has a selected property such that the Dst mode diameter (m.mu.) is below the value (m.mu.) obtained from the following equation:Dst=2.65.times.dn+0.64.times.DBP-27.

Abstract: A rubber composition is provided which comprises 100 parts by weight of basic rubber and 25 to 250 parts by weight of furnace carbon black having the particle properties defined by an N.sub.2 SA higher than 60 m.sup.2 /g and a DBP higher than 108 ml/100 g and the following selective characteristic values.True specific gravity.ltoreq.-0.0006.times.N.sub.2 SA+1.8379Tinting strength (%).gtoreq.0.6979.times.N.sub.2 SA-0.4278.times.DBP+203.3Range of aggregate size distribution (.DELTA.Dst).gtoreq.0.6118.times.(Dst mode diameter)+30.