摘要:
A surface graphitized carbon material comprising a graphitic surface and a carbonaceous internal part. This surface graphitized carbon material can be produced by contacting a carbon material with a metal having catalytically graphitizing activity or a compound thereof to thereby cause the metal or compound thereof to be present in a surface of the carbon material and heating the carbon material at 300 to 1500.degree. C. in an inert atmosphere. By virtue of the possession of a graphitic surface and a carbonaceous internal part, the surface graphitized carbon material of the present invention simultaneously has the properties of the carbon material such that, when used in a negative electrode for lithium-ion secondary battery, a negative electrode having high charge and discharge capacities, being excellent in performance at low temperature, and facilitating a display of residual capacity can be obtained, and the properties of the graphite material such that a negative electrode whose cycle deterioration of charge and discharge capacities is slight can be obtained.
摘要:
A negative electrode material for use in lithium-ion secondary batteries, comprising milled pitch-based graphite fibers (A) obtained by graphitization at 2400.degree. C. or higher and milled pitch-based carbon fibers (B) obtained by carbonization at 550.degree. to 1300.degree. C. In this negative electrode material, it is preferred that both the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) have an average particle size of 10 to 30 .mu.m, that the ratio of milled pitch-based carbon and graphite fibers having a particle size of 5 .mu.m or less to all the milled pitch-based carbon and graphite fibers is not greater than 10% by weight and that the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) are blended at a weight ratio (A/B) of 95/5 to 40/60. A negative electrode which has a large capacity at the time of having been stabilized, exhibits a high charge and discharge efficiency at the initial stage and is excellent in charge and discharge cycle characteristics can be provided by the blending of milled pitch-based carbon fibers with milled pitch-based graphite fibers.
摘要:
Milled carbon fibers are provided which have a fiber cut surface and a fiber axis intersecting with each other at cross angles, the smaller one thereof being at least 65° on the average. The milled carbon fibers may have a specific surface area as measured by the BET method of 0.2 to 10 m2/g. The milled carbon fibers may be obtained by a process comprising melt spinning of mesophase pitch, infusibilization, milling of the infusibilized pitch fibers as obtained or after a primary heat treatment at low temperatures in an inert gas and a high-temperature heat treatment in an inert gas. Even when the graphite layer plane has achieved high-level growth, the above milled carbon fibers have low reactivity with a metal of high temperature or the like during the molding or use thereof because the proportion of reactive exposed surface of the inner portion of the fiber is small, so that the use of the milled carbon fibers can improve the mechanical strength and high-temperature heat resistance of the composite material.
摘要:
A process for providing activated carbon fibers consisting of optically anisotropic components and optically isotropic components by spinning a pitch into fibers, and infusibilizing the resulting fibers, followed by an activation treatment. The pitch for spinning is prepared by melt mixing together (A) 100 parts by weight of an optically isotropic pitch having a softening point of 230.degree.-300.degree. C. obtained by heat treatment of a pitch while blowing an oxygen containing gas into the pitch, and (B) 10-50 parts by weight of an optically isotropic pitch having a softening point of 200.degree.-270.degree. C. obtained by polymerization of naphthalene in the presence of a Lewis acid catalyst. The optically isotropic pitch (B) is further characterized as having the property of being converted into an optically anisotropic pitch by the stress occurring at the time of spinning. The carbon fibers produced by spinning the spinning pitch into fibers have a double layer structure, the surface layer exhibiting optical isotropy and the center portion exhibiting optical anisotropy. The spun fibers are infusibilized, followed by carbonization and/or graphitization.
摘要:
A replaceable gang head machine tool comprising a working unit having a driving motor mounted on a slide table adapted to be driven forwardly and rearwardly and an annular rail disposed on the machine base and carrying a plurality of gang heads adapted for being driven by an index table to selectively place a gang head in an operative position. A stockyard extends longitudinally adjacent the machine base and has a longitudinally extending runway guidably supporting a carrying truck for movement therealong and a plurality of replacement gang heads are disposed on the stockyard along the length thereof so that the replacement gang heads can replace the heads disposed on the annular rail by the carrying truck.
摘要:
Milled carbon fibers are provided which have a fiber cut surface and a fiber axis intersecting with each other at cross angles, the smaller one thereof being at least 65° on the average. The milled carbon fibers may have a specific surface area as measured by the BET method of 0.2 to 10 m2/g. The milled carbon fibers may be obtained by a process comprising melt spinning of mesophase pitch, infusibilization, milling of the infusibilized pitch fibers as obtained or after a primary heat treatment at low temperatures in an inert gas and a high-temperature heat treatment in an inert gas. Even when the graphite layer plane has achieved high-level growth, the above milled carbon fibers have low reactivity with a metal of high temperature or the like during the molding or use thereof because the proportion of reactive exposed surface of the inner portion of the fiber is small, so that the use of the milled carbon fibers can improve the mechanical strength and high-temperature heat resistance of the composite material.
摘要:
A fiber reinforced plastic pipe comprising a cylindrical inner layer formed by winding a prepreg sheet containing a thermosetting resin as a matrix and an outer layer formed by winding a thermoplastic resin sheet or tape around the inner layer, said inner and outer layers being heat cured and thermocompression bonded in one united body; and a process for manufacturing the fiber reinforced plastic pipe. When the fiber reinforced plastic pipe is manufactured, the thermosetting resin is used for forming the inner layer and the thermoplastic resin is used for forming the outer layer. Moreover, a metal coat can be firmly bonded to the surface of the outer layer. Hence, a fiber reinforced plastic pipe prominently improved in impact resistance, abrasion resistance and lightweight properties can be provided.
摘要:
A piston ring is assembled into a groove of a piston by pushing the piston ring out of a front end of a guide member. The piston ring is mounted on an outside of the guide member which has a diameter larger than an outside diameter of the piston. The pushing is carried out while maintaining a clearance which allows for the piston ring to undulate. This clearance is formed between a front end of the guide member and a plane including a groove surface which lies away from the front end of the guide member. The apparatus for assembling a set oil ring into a piston ring groove of a piston has a guide member which is larger in diameter than an outside diameter of the piston, pushing device for pushing, in sequence out of a front end of the guide member, a spacer ring and a pair of side rail rings, a restricting member which is movable back and forth in a radial direction of the guide member and which can be placed with a clearance to be formed to open into that groove portion which is formed between that groove surface of the piston ring groove which is closer to the guide member and the spacer ring assembled into the piston ring groove.
摘要:
An assembly machine including a drive unit and an assembling unit removably coupled to the drive unit so as to be driven by the drive unit to assemble an assembly such as a torque converter case with an assembly part such as a valve body unit. The machine further includes an assembly part conveyance means for supply the assembly part, an assembling unit housing means for housing a plurality of assembling units, and a changeover conveyance means. The assembly part is conveyed from the assembly part conveyance means to the assembling unit by the changeover conveyance means. At the time of the change of the type of the assembly, the assembling unit is removed from the drive unit and conveyed onto the changeover conveyance means and the direction of conveyance of the changeover conveyance means is then changed over to convey the assembling unit into the assembling unit housing means, another assembling unit housed in the housing means is conveyed out of the means onto the changeover conveyance means, and the direction of conveyance of the changeover conveyance means is then changed over again to convey the other assembling unit to the drive unit.