Abstract: A carbon fiber having a total content of Li, Na, Ti, Mn, Fe, Ni and Co metal elements of no more than 50 ppm and a fiber diameter of 0.001 to 2 ?m and not branched and a assembly of a plurality of the carbon fibers.

Abstract: A method of decomposing a polycarbonate with water in a supercritical or subcritical state. A high-purity dihydroxy compound which is a constituent component of the polycarbonate can be recovered at a high yield by this decomposition method. This decomposition method is environment-friendly because it does not use an organic solvent, easy to be carried out, has a high decomposition rate and rarely causes a side reaction.

Abstract: Disclosed is a fibrous activated carbon wherein fine pores in the surface of the activated carbon have diameters of 0.1-200 nm and the activated carbon is in the form of fiber having a fiber diameter of not more than 1000 nm.

Abstract: A method of decomposing a polycarbonate with water in a supercritical or subcritical state. A high-purity dihydroxy compound which is a constituent component of the polycarbonate can be recovered at a high yield by this decomposition method. This decomposition method is environment-friendly because it does not use an organic solvent, easy to be carried out, has a high decomposition rate and rarely causes a side reaction.

Abstract: A carbon fiber having a total content of Li, Na, Ti, Mn, Fe, Ni and Co metal elements of no more than 50 ppm and a fiber diameter of 0.001 to 2 ?m and not branched and a assembly of a plurality of the carbon fibers.

Abstract: A laminate which is advantageously used as an insulating layer for electronic package application and as an adhesive film for fixing a semiconductor wafer for semiconductor device application, laminates comprising the same and a process for manufacturing the above laminate. The laminate (I) comprises a base layer (A) and an adhesive layer (B) formed on one side or both sides of the layer A, the layer A is a film made of (A-1) a specific wholly aromatic polyimide (PIA-1) or (A-2) a specific wholly aromatic polyamide (PAA-2); and the layer B comprises (B-1) a specific wholly aromatic polyimide (PIB-1), (B-2) a specific wholly aromatic polyamide (PAB-2), or (B-3) a specific resin composition (RCB-3) comprising a wholly aromatic polyimide (PIB-3) and a specific wholly aromatic polyamide (PAB-3), laminates comprising the same and a process for manufacturing the above laminate.

Abstract: A carbon fiber nonwoven fabric comprising an aggregate of carbon microfibers having a fiber diameter of 0.001 to 2 ?m and a production method thereof are provided. The nonwoven fabric is useful as a substrate, precursor and material for a fuel cell electrode. The nonwoven fabric can be mixed with a resin to be used as a composite material and can carry metal to be used in a filter.

Abstract: An oriented polyimide film with a high Young's modulus, satisfactory moist heat resistance and low moisture absorptivity, and a process for its production. The polyimide film is composed mainly of a pyromellitic acid component, with a p-phenylenediamine component at between 30 mole percent and 99 mole percent and a diamine component represented by the structural unit of the following formula (II) at between 1 mole percent and 70 mole percent: (wherein ArIIa and ArIIb are each independently a C6-20 aromatic group optionally having an non-reactive substituent, and X in structural unit (II) consists of at least one group selected from among —O—, —O—ArIIc—O—, —SO2— and —O—ArIId—O—ArIIe—O—), and the polyimide film is characterized by having two perpendicular directions in which the in-plane Young's modulus is 3 GPa or greater, and having a moisture absorptivity of no greater than 3.3 wt % at 72% RH, 25° C.

Abstract: A fibrous active carbon having pores in the surface, wherein the pore diameter falls within a range of 0.1 to 200 nm, and, the active carbon is in the form of a fiber, and has a fiber diameter of less than 1000 nm or less.

Abstract: There are provided an adhesive sheet, exhibiting a specific peel strength and shear peel strength and being composed of a base material (A) comprising a fully aromatic polyimide film having a glass transition temperature of 200° C. or above and a thermal adhesive layer (C) comprising a fully aromatic polyamide having a glass transition temperature of 200-500° C., as well as a laminate composed of the sheet and a process for its production. Also provided is a method of release after treatment of the laminate composed of the adhesive sheet, to obtain a laminate having the target to-be-treated layer.

Abstract: A process for manufacturing a carbon fiber having a fiber diameter of 0.001 to 5 ?m and a narrow fiber size distribution, and a resin composition suitable for the manufacture of a carbon fiber. A resin composition comprising 100 parts by weight of a thermoplastic resin, 1 to 150 parts by weight of a carbon precursor organic compound (A) and 0.001 to 40 parts by weight of acopolymer of polymer segments (e1) and (e2) which satisfy a specific range of surface tension for the thermoplastic resin and a specific range of surface tension for the carbon precursor organic compound (A) at the same time.

Abstract: A polycarbonate composition comprising 100 parts by weight of an aromatic polycarbonate, 0.005 to 0.2 part by weight of an ester of an aliphatic monocarboxylic acid having 10 to 25 carbon atoms and an aliphatic polyhydric alcohol having 2 to 10 carbon atoms, and 0.015 to 0.3 part by weight of a first aromatic compound which is an aromatic ether, ester or carbonate compound having at least four benzene rings in the molecule, wherein the above ester is contained in the above range to ensure that the first aromatic compound is contained in a deposit on the polymer contacting surface of a metal mold in an amount of 0.5 to 3 parts by weight based on 1 part by weight of the ester when a 120 mm x 50 mm board having a thickness of 2 mm is injection molded at a cylinder temperature of 380° C., a mold temperature of 80° C., an injection speed of 200 mm/sec and a holding pressure of 3,432 kPa (35 kgf/cm2).

Abstract: To provide a high-quality polycarbonate composition comprising a polycarbonate which is free from a reduction in molecular weight by filtration, discoloration or the formation of foreign matter and obtained by using a polymer filter having a small opening size to have a low content of foreign matter. This composition comprises (A) a polycarbonate having a viscosity average molecular weight of 10,000 or more obtained by filtration in a molten state with a filter comprising an assembly of a plurality of disk filter elements having an outer diameter of 15 inches (38.1 cm) or less, an inner diameter/outer diameter ratio of 1/7 or more and an opening size of 40 &mgr;m or less, an inorganic filler (B1) and/or a thermoplastic resin (B2) other than polycarbonates.

Abstract: There is provided a technique for producing an aromatic polycarbonate which undergoes no deterioration in quality in a gear pump, has excellent hue and contains a small amount of foreign materials even when a production plant is scaled up. In producing the aromatic polycarbonate by melt-polycondensation, a molten polycondensate is fed continuously into a shaft seal portion of a self-lubricating gear pump disposed for transporting the polycondensate from a polycondensation vessel such that the following expressions: Q/S≧0.1 (cm/sec) wherein Q is a flow rate (cm3/sec) of the polycondensate, and S is a cross sectional area (cm2) of a passage provided for feeding the polycondensate to the shaft seal portion, and D≦2.9W1/3 wherein D is an internal diameter (cm) of a pipe, and W is a flow rate, are satisfied, thereby operating the gear pump. A polycondensation vessel therefor is also disclosed.

Abstract: An aromatic polycarbonate extruder which is a twin screw extruder for kneading components into a molten aromatic polycarbonate, the extruder having at least one module consisting of a kneading unit, a material seal unit, a back kneading unit and full-flight unit which are arranged from an upstream side to a downstream side and a method of kneading components into an aromatic polycarbonate by using the above extruder. The present invention also provides a kneading apparatus and method for producing an aromatic polycarbonate which has an extremely small content of foreign matter and is free from residence deterioration such as coloration, crosslinking or gelation when the aromatic polycarbonate is to be kneaded with various components.

Abstract: An aromatic polycarbonate extruder which is a twin screw extruder for kneading components into a molten aromatic polycarbonate, the extruder comprising at least one module consisting of a kneading unit, a material seal unit, a back kneading unit and a full-flight unit which are arranged from an upstream side to a downstream side and a method of kneading components into an aromatic polycarbonate by using the above extruder. The present invention can provide a kneading apparatus and method for producing an aromatic polycarbonate which has an extremely small content of foreign matter and is free from residence deterioration such as coloration, cross-linking or gelation when the aromatic polycarbonate is to be kneaded with various components.

Abstract: An aromatic polycarbonate having excellent color is obtained by keeping an aromatic dihydroxy compound and a carbonic acid diester which are raw materials for the production of an aromatic polycarbonate in consideration of the influences of storage atmosphere, temperature, temperature difference from a storage tank and residence time.

Abstract: There is provided a technique for producing an aromatic polycarbonate which undergoes no deterioration in quality in a gear pump, has excellent hue and contains a small amount of foreign materials even when a production plant is scaled up.

Abstract: A method of producing a polycarbonate or the like which is excellent in hydrolysis and heat stability such as a reduction in molecular weight at the time of molding and color retention and moldability such as releasability and transferability, rarely experiences residence deterioration such as coloring, crosslinking and gel formation and has an extremely small content of foreign matter by employing a special structure for an opening in the side surface of a horizontal cylindrical vacuum resin treating apparatus, supplying a molten polycarbonate into a unidirectional rotary intermeshing double-screw extruder under specific conditions, adding a specific agent under specific conditions and cleaning the inner surface of a production apparatus by a specific method.

Abstract: A method of cleaning the aromatic polycarbonate production unit with a carbonic acid diaryl ester at a temperature of 200 to 350° C. in an inert gas atmosphere.