Abstract: A metallocene compound may be used as a catalyst component for the polymerization of olefins. The compound is stable to air and moisture so that it generates no hydrogen halide by hydrolysis and is easily handled, and it has high storage stability and high catalyst activity. Specifically, the catalyst component for the polymerization of olefins comprises a transition metal composition represented by the general formula [1] and [2]: (RaCp)m(R′bCp)M(—X—Ar—Yc)4−(m+n)  [1] R″(RdCp)(R′eCp)M(—X—Ar—Yc)2  [2] wherein M is Ti, Zr or Hf; each of (RaCp), (R′b Cp), (Rd Cp) and (R″e Cp) is a radical having the cyclopentadienyl skeleton; R″ is a radical that links (Rd Cp) and (R′e Cp); (—X—Ar—Yc) is a grouping in which the aromatic ring Ar substituted by a specified radical Y bonds to M through an oxygen or sulphur atom X.

Abstract: A metallocene compound may be used as a catalyst component for the polymerization of olefins. The compound is stable to air and moisture so that it generates no hydrogen halide by hydrolysis and is easily handled, and it has high storage stability and high catalyst activity.

Abstract: A metallocene compound may be used as a catalyst component for the polymerization of olefins. The compound is stable to air and moisture so that it generates no hydrogen halide by hydrolysis and is easily handled, and it has high storage stability and high catalyst activity. Specifically, the catalyst component for the polymerization of olefins comprises a transition metal composition represented by the general formula [1] and [2]: (Ra Cp)m(R′b Cp)M(—X—Ar—Yc)4−(m+n)  [1] R″(Rd Cp)(R′e Cp)M(—X—Ar—Yc)2  [2] wherein M is Ti, Zr or Hf; each of (Ra Cp), (R′b Cp), (Rd Cp) and (R″e Cp) is a radical having the cyclopentadienyl skeleton; R″ is a radical that links (Rd Cp) and (R′e Cp); (—X—Ar—Yc) is a grouping in which the aromatic ring Ar substituted by a specified radical Y bonds to M through an oxygen or sulphur atom X.

Abstract: The present invention relates to a metallocene compound as a catalyst component for the polymerization of olefins, said compound, is stable to air and moisture so that generates no hydrogen halide by hydrolysis and easily handled, and has a high storage stability and a high catalyst activity. Specifically, the catalyst component for the polymerization of olefins comprises a transition metal composition represented by the general formula [1] and [2]: (Ra Cp)m(R′b Cp)M(—X—Ar—Yc)4−(m+n)  [1] R″(Rd Cp) (R′e Cp)M(—X—Ar—Yc)2  [2] wherein M is Ti, Zr or Hf; (Ra Cp),(R′b Cp), (Rd Cp) and (R″e Cp ) each is a radical having the cyclopentadienyl skeleton; R″ is a radical which links (Rd Cp) and (R′e Cp); (—X—Ar—Yc) is a grouping in which the aromatic ring Ar substituted by a specified radical Y bonds to M through an oxygen or sulphur atom X.

Abstract: A process for the preparation of a high-softening-point pitch rich in mesopores having a softening point measured by temperature gradient method of 150° C. or higher, a weight loss by heating up to 300° C. of 5 wt. % or less and mesopores of 100 mm3/g or greater, in terms of minute pore volume calculated by the Dollimore-Heal method, and a process for making carbonaceous materials carrying metal thereon are disclosed. The high-softening-point pitch rich in mesopores can easily provide carbonaceous material carrying metal thereon by using no oxidizing agent such as nitric acid, and, therefore, the high-softening-point pitch rich in mesopores is especially suitable for the production of carbonaceous materials carrying metal thereon or highly crystalline graphitized carbonaceous materials in a short heating time.

Abstract: A process for manufacturing fine particles or powder of pitch with a high softening point from a heavy oil raw material which is liquid at an ambient temperature or pitch having a relatively low softening point is disclosed. Fine particles of pitch with a high softening point are useful materials and can be used as carbon materials for various applications. A characteristic feature of the process resides in the utilization of emulsion of the heavy oil raw material.

Abstract: When preparing carbon artefacts from heavy oils of petroleum or coal origin, removal of undesirable components or recovery of desirable components from raw materials or intermediates is usually required so as to improve the quality of the final products. Such removal or recovery operation is conventionally done by filtration. In the past, regeneration of filters clogged with solid carbonaceous materials inevitably formed by the filtration operations is difficult and troublesome procedures. Herein disclosed is a simple and effective process for regenerating filters clogged with solid carboneceous materials, characterized by treating the filter medium in an aqueous solution of hydrogen peroxide with heating and then optionally conducting ultrasonic washing in water or a solvent. By this simple process, clogged filters can be regenerated completely to show the same filtration performance as new filters.

Abstract: Commercially attractive continuous processes for the preparation of mesophase pitches for manufacturing high-performance carbon fibers are disclosed. One feature resides in that conversion of a pitch into a mesophase pitch is conducted continuously by using a unique continuous dispersion-heat-treating apparatus.

Abstract: Commercially attractive continuous processes for the preparation of mesophase pitches for manufacturing high-performance carbon fibers are disclosed. One feature resides in that conversion of a pitch into a mesophase pitch is conducted continuously by using a unique continuous dispersion-heat-treating apparatus.

Abstract: A process for co-production of a pitch for the manufacture of HP carbon fibers and a pitch for the manufacture of GP carbon fibers is proposed. The pitch for the manufacture of GP carbon fibers is prepared from the spent fraction not used in the production of an optically anisotropic pitch suitable for the manufacture of HP carbon fibers. The spent fraction has hitherto been discarded as a valueless material. According to the present process, a pitch for the manufacture of so-called ultra HP carbon fibers with tensile strength of over 400 Kg/mm.sup.2 and modulus of elasticity of over 60 ton/mm.sup.2 and a pitch for the manufacture of GP carbon fibers can be produced simultaneously. Both pitches have very excellent spinnability and when they are spun, they cause no fiber cut-off even at a high spinning rate of, for example, 500 m/min or 700 m/min.

Abstract: The unwanted components from coal tars should be removed at a certain stage of the process for producing homogeneous spinning pitches which are suitable for use in the production of high-performance carbon fibers from coal tars. The unwanted components can be eliminated from coal tars in a very efficient manner by the following procedures: subjecting the coal tars to distillation or flash distillation so as to separate a heavy component having a boiling point higher than a predetermined temperature, dissolving the heavy component in a monocyclic aromatic hydrocarbon solvent, and subjecting the solution to filtration or centrifugation.

Abstract: A process for the preparation of an excellent mesophase pitch suitable for use as a spinning pitch for the production of high performance carbon fibers is disclosed. The mesophase pitch can satisfy the four remarkable characteristics at the same time, i.e., a softening point of below 320.degree. C. as determined by Mettler method, a mesophase content of above 90% as examined on a polarized microscope, a quinoline insoluble content of less than 20%, and a xylene soluble content of less than 20%. The mesophase pitch is particularly homogeneous and is easily spinnable. The process can be characterized by a preliminary extraction step, a continuous heat treatment step, and an extraction step. In some cases, the preliminary extraction step can be omitted. Graphite fibers having a tensile strength of about 400 Kg/mm.sup.2 and a modulus of elasticity of above 60 ton/mm.sup.2 can be obtained from the mesophase pitch. Further, even carbon fibers prepared at a carbonization temperature of 1000.degree. C.

Abstract: When preparing carbon fibers from mesophase pitches, we usually encounter to the formation of cracks along the fiber axis. The crack formation is the most serious and troublesome problem. A simple process which can effectively prevent the crack formation comprises preparing the carbon fibers from mesophase pitches by melt spinning sufficient only to give a rotatory motion to the molten mesophase pitches just before extrusion substantially around the axis of a spinning nozzle hole. The process employs a usual nozzle plate having a pitch introducing tube and a spinning nozzle hole further containing a plug member having an outer spiral groove such as a drill point or a worm gear which is inserted within the pitch introducing tube.

Abstract: A process for an efficient preparation of a mesophase pitch is disclosed. The process is suitable for the production of high performance carbon fibers, from a coal tar or a petroleum residual oil. More particularly, the present invention relates to a process for the preparation of a homogeneous mesophase pitch which comprises a continuous thermal treatment of a heavy oil or a pitch which does not contain quinoline insoluble fractions, in the presence or absence of an aromatic oil, subsequent distillation of the thermally treated product, recovery of a pitch with extremely low quinoline insoluble contents, hydrogenation of the pitch by continuous thermal treatment in the presence of a hydrogen-donating solvent, distillation and recovery of a hydrogenation pitch, and thermal treatment of the hydrogenated pitch. The mesophase pitch prepared by the process of the present invention is suitable for the production of high performance carbon fibers.

Abstract: Until now, it has not yet been succeeded to prepare high performance carbon fibers having satisfactory strength from heavy oils of coal or petroleum origin. We now succeeded to prepare an excellent intermediate pitch which allows the preparation of high performance carbon fibers having tensile strength of higher than 300 Kg/mm.sup.2 and Young's modulus of 50 ton/mm.sup.2.The intermediate pitch can be obtained by heating a heavy oil of coal or petroleum origin in a tubular heater under a specific conditions, and then flash distilling the heater effluent in a flash distillation column under a specific condition so as to remove lighter fractions and recovering heavy fraction from the column bottom as the intermediate pitch. The process for the preparation of the intermediate pitch is simple and economical and allows continuous production without fluctuation of quality of the intermediate pitch. The intermediate pitch is also suitable for the production of higher density carbon products.