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: 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 polycarbonate having excellent color, a low content of foreign substances, a low content of an OH terminal group, little quality variation and excellent moldability and a production method therefor.

Abstract: An aromatic polycarbonate resin is produced under the conditions that the flow velocity of the reaction mixture in a pipe through which a molten reaction mixture passes is a specific value or over, the viscosity-average molecular weight of the reaction mixture is 1,000 or more, the sum of the average retention times of the reaction mixture is not longer than 3 hours, the wall temperature of the pipe through which a molten reaction mixture passes is set to be higher than the temperature of the reaction mixture in the pipe, the catalyst deactivation agent is added within 2 hours after the completion of the melt polycondensation reaction, the filtration is carried out by using a filter having a specific retained particle size under a specific pressure difference, specific treated amount of the aromatic polycarbonate resin per unit area of the filter and a ratio of W (flow quantity of filtered polymer)×1,000/A (maximum area of the polymer path in the filtration vessel) falling within a specific range, etc.

Abstract: Purpose To enable the reduction of the quantities of wastes and the performance of long term continuous operation in polycarbonate production. Means for solution As a method for removing the reaction byproducts in the production of a polycarbonate resin by sucking and reducing the pressure, ejectors which use the vapor of a substance comprising the condensed liquid of the reaction byproducts as the driving source are used, and the wall temperatures of piping between a polymerization reactor and the ejectors are held at a temperature equal to the boiling point of said reaction byproducts at reduced pressure or higher.

Abstract: An aromatic polycarbonate resin is produced under the conditions that the flow velocity of the reaction mixture in a pipe through which a molten reaction mixture passes is a specific value or more, the viscosity-average molecular weight of the reaction mixture is 1,000 or more, the sum of the average retention times of the reaction mixture is not longer than 3 hours, the wall temperature of the pipe through which a molten reaction mixture passes is set to be higher than the temperature of the reaction mixture in the pipe, the catalyst deactivation agent is added within 2 hours after the completion of the melt polycondensation reaction, the filtration is carried out by using a filter having a specific retained particle size under a specific pressure difference, specific treated amount of the aromatic polycarbonate resin per unit area of the filter and a ratio of W (flow quantity of filtered polymer)×1,000/A (maximum area of the polymer path in the filtration vessel) falling within a specific range, etc.

Abstract: Aromatic polycarbonate having a reduced discoloration and improved heat stability, hue, etc. is provided by keeping a pressure in a raw material melting vessel and the linear velocity of a gas in a transporting piping in a specific range, keeping the concentration of a nitrogen-containing basic compound in a specific range, recycling a byproduct containing specific amounts of impurities, suppressing the amounts of a nitrogen-containing basic compound, metallic elements and a silicic acid derivative in the carbonic acid diester at specific values or less, prescribing the material quality of the reaction facilities, and/or forming an oxide layer at the inner wall surfaces of the reaction facilities.