Polycarbonate block copolymers are provided, which have: (A) a polyester block of chemical formula 1; and (B) a polycarbonate block derived from a dihydric phenol of chemical formula 3 compound and phosgene. The copolymers may be prepared by (1) polymerizing ester oligomers to form a compound of chemical formula 1; and (2) copolymerizing the ester oligomer obtained in (1) with a polycarbonate oligomer prepared from a dihydric phenol compound of chemical formula 3 and phosgene, in the presence of a polymerization catalyst. The block copolymer may have a viscosity average molecular weight (Mv) of 10,000 to 200,000. The thermoplastic copolymer resins have excellent heat resistance, transparency, impact strength, and fluidity, and thus can be usefully applied in various products, including office devices, electric/electronic products, and automotive interior/exterior parts;

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The invention relates to a film containing a special polycarbonate or copolycarbonate of the formula (Ia), (I-2), (I-3) or (I-4) and to the use of the film in a security document and in a layer structure.

The invention relates to a film containing a special polycarbonate or copolycarbonate of the formula (Ia), (I-2), (I-3) or (I-4) and to the use of the film in a security document and in a layer structure.

Provided is a molded body, including a polycarbonate-based resin composition containing: a polycarbonate-polyorganosiloxane copolymer (A); and at least one kind of compound (B) selected from the group consisting of an antioxidant, a dye, a release agent, a light-diffusing agent, a flame retardant, a UV absorber, a silicone-based compound, an epoxy compound, and a polyether compound, wherein the polycarbonate-polyorganosiloxane copolymer (A) contains a polycarbonate block (A-1) and a polyorganosiloxane block (A-2), and contains the polyorganosiloxane block (A-2) at a content of from 20 mass % to 70 mass %, and wherein the molded body has a durometer hardness of from 25 to 72, which is measured with a type D durometer in conformity with JIS K 6253-3:2012.

A polymeric radiation-source with customized geometries to maximize receipt of radiation into treatment areas that is formed from either radioisotopes molecularly bonded to a polymer or radioisotopes encased within a polymer.

A polymeric radiation-source with customized geometries to maximize receipt of radiation into treatment areas that is formed from either radioisotopes molecularly bonded to a polymer or radioisotopes encased within a polymer.

The purpose of the present invention is to provide: a polycarbonate resin which has a narrow molecular weight distribution and in which the formation of low molecular weight oligomers is suppressed; and a method for producing the polycarbonate resin. According to the present invention, provided are a polycarbonate resin containing a structural unit represented by general formula (1), wherein the molecular weight distribution value (Mw/Mn) is 6.0 or less, and the content of oligomers having a molecular weight of less than 1,000 is suppressed to 0.50 mass % or less; and a method for producing the polycarbonate. (In general formula (1), R.sub.1-26 represent hydrogen, fluorine, chlorine, bromine, iodine, a C1-9 alkyl group, a C6-12 aryl group, a C1-5 alkoxy group, a C2-5 alkenyl group, or a C7-17 aralkyl group). ##STR00001##

The purpose of the present invention is to provide: a polycarbonate resin which has a narrow molecular weight distribution and in which the formation of low molecular weight oligomers is suppressed; and a method for producing the polycarbonate resin. According to the present invention, provided are a polycarbonate resin containing a structural unit represented by general formula (1), wherein the molecular weight distribution value (Mw/Mn) is 6.0 or less, and the content of oligomers having a molecular weight of less than 1,000 is suppressed to 0.50 mass % or less; and a method for producing the polycarbonate. (In general formula (1), R.sub.1-26 represent hydrogen, fluorine, chlorine, bromine, iodine, a C1-9 alkyl group, a C6-12 aryl group, a C1-5 alkoxy group, a C2-5 alkenyl group, or a C7-17 aralkyl group). ##STR00001##

Provided are a polycarbonate-polyorganosiloxane copolymer having a carbon tetrachloride concentration of less than 4 ppm by mass, and the following production method for producing the polycarbonate-polyorganosiloxane copolymer. More specifically, provided is a method of continuously producing a polycarbonate-polyorganosiloxane copolymer, the method comprising the steps of: (A) continuously or intermittently taking a polymerization reaction liquid, which is obtained by polymerizing a dihydric phenol compound, a carbonate precursor, and a specific polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent, out of a reactor; (B) separating the polymerization reaction liquid taken out in the step (A) into an aqueous phase and a water-insoluble organic solvent phase; (C) washing the water-insoluble organic solvent phase separated in the step (B), followed by separation thereof into an aqueous phase and a water-insoluble organic solvent phase; (D) concentrating the water-insoluble organic solvent phase separated in the step (C); and (E) recovering part or all of the water-insoluble organic solvent removed by evaporation in the step (D), followed by distillation purification thereof in a distillation column, the water-insoluble organic solvent obtained in the step (E) being reused as at least part of the water-insoluble organic solvent in the step (A) or as an extraction solvent for the aqueous phase separated in the step (B), or as both thereof, in the step (E), the distillation purification being performed while a concentration of the polycarbonate-polyorganosiloxane copolymer in a column bottom liquid of the distillation column is controlled to 6% by mass or less.

Provided are a polycarbonate-polyorganosiloxane copolymer having a carbon tetrachloride concentration of less than 4 ppm by mass, and the following production method for producing the polycarbonate-polyorganosiloxane copolymer. More specifically, provided is a method of continuously producing a polycarbonate-polyorganosiloxane copolymer, the method comprising the steps of: (A) continuously or intermittently taking a polymerization reaction liquid, which is obtained by polymerizing a dihydric phenol compound, a carbonate precursor, and a specific polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent, out of a reactor; (B) separating the polymerization reaction liquid taken out in the step (A) into an aqueous phase and a water-insoluble organic solvent phase; (C) washing the water-insoluble organic solvent phase separated in the step (B), followed by separation thereof into an aqueous phase and a water-insoluble organic solvent phase; (D) concentrating the water-insoluble organic solvent phase separated in the step (C); and (E) recovering part or all of the water-insoluble organic solvent removed by evaporation in the step (D), followed by distillation purification thereof in a distillation column, the water-insoluble organic solvent obtained in the step (E) being reused as at least part of the water-insoluble organic solvent in the step (A) or as an extraction solvent for the aqueous phase separated in the step (B), or as both thereof, in the step (E), the distillation purification being performed while a concentration of the polycarbonate-polyorganosiloxane copolymer in a column bottom liquid of the distillation column is controlled to 6% by mass or less.