Idemitsu Kosan Company, Limited

Yukiko Nagao

Yasuhiro Ishikawa

Hiroaki Motegi

Noriyuki Kunishi

Masayuki Takahashi

Kenji Sasaki

Toshiyuki Yasuda

Kazuhiro Sekiguchi

Kota Mabuchi

Provided is a method of producing a polycarbonate-polyorganosiloxane copolymer, including a step (a) of producing a polycarbonate oligomer with an alkaline aqueous solution of a dihydric phenol, phosgene, and an organic solvent, the method further including a step of setting a content of a polycarbonate-polyorganosiloxane copolymer in the organic solvent to be introduced into the step (a) to less than 850 ppm by mass.

Method for producing polycarbonate-polyorganosiloxane copolymer

Provided is a polycarbonate resin powder, including a polycarbonate-polyorganosiloxane copolymer, in which an amount of particles each having a particle diameter of 300 &#x3bc;m or less in an entirety of the powder is 60 mass % or less.

Polycarbonate resin powder and method for transporting same

Provided is a method of producing a branched polycarbonate, including: a step (a) of subjecting an alkali aqueous solution of a dihydric phenol, phosgene, and a branching agent to a phosgenation reaction in the presence of an organic solvent to provide a reaction liquid; a step (b) of adding the alkali aqueous solution of the dihydric phenol and a polymerization catalyst to the reaction liquid obtained from the step (a) to provide a reaction liquid containing a polycarbonate oligomer; a step (c) of separating the reaction liquid containing the polycarbonate oligomer obtained in the step (b) into an organic solvent phase containing the polycarbonate oligomer and an aqueous phase; and a step (d) of causing the organic solvent phase containing the polycarbonate oligomer separated in the step (c) and the alkali aqueous solution of the dihydric phenol to react with each other to provide a reaction liquid containing the branched polycarbonate, in which a ratio (x/y) of an addition amount of the polymerization catalyst to be added in the step (b), which is represented by x mol/hr, to a chloroformate group amount of the polycarbonate oligomer in the reaction liquid obtained from the step (b), which is represented by y mol/hr, is 0.0035 or more.

Branched polycarbonate production method

Provided is a method of producing a polycarbonate that enables efficient drying of a polycarbonate powder and has no risk of deteriorating the quality of a polycarbonate molded article to be obtained. The method of producing a polycarbonate includes: a step of causing an alkali aqueous solution of a dihydric phenol and phosgene to react with each other in the presence of an organic solvent to produce an organic solvent solution containing a polycarbonate; a powdering step of powdering the organic solvent solution containing the polycarbonate to provide a polycarbonate powder; and a pre-drying step of drying the polycarbonate powder to remove the remaining organic solvent, in which a drying temperature in the pre-drying step is set to a temperature lower than the glass transition temperature of the polycarbonate containing 1.5 mass % of the organic solvent by from 5&#xb0; C. to 15&#xb0; C.

Method for producing polycarbonate

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.

Polycarbonate-polyorganosiloxane copolymer and method for continuously producing same

Provided is a method for economically and stably producing a high-quality polycarbonate-polyorganosiloxane copolymer excellent in, for example, transparency and impact resistance in a continuous manner. Specifically, provided is a method of continuously producing a polycarbonate-polyorganosiloxane copolymer, the method including a step (A) of continuously or intermittently taking a polymerization reaction liquid, which is obtained by polymerizing a dihydric phenol-based compound, a carbonate precursor, and a polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent, out of a reactor, the step (A) including the following step (a-1) and the following step (a-2), the method using a dissolution tank for dissolving the dihydric phenol-based compound in the alkaline compound aqueous solution to prepare an alkaline compound aqueous solution of the dihydric phenol-based compound to be used in each of both the step (a-1) and the step (a-2), the step (a-2) including, before mixing a polycarbonate oligomer and the dihydric phenol-based compound, mixing the alkaline compound aqueous solution and the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank: step (a-1): a step of mixing the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank and the polycarbonate precursor, followed by a reaction of the mixture in the presence of the water-insoluble organic solvent to produce the polycarbonate oligomer; and step (a-2): a step of continuously or intermittently taking the polymerization reaction liquid, which is obtained by mixing the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank, the polycarbonate oligomer obtained in the step (a-1), and the polyorganosiloxane, and polymerizing the mixture in the presence of the water-insoluble organic solvent, out of the reactor.

Method for continuous production of polycarbonate-polyorganosiloxane copolymer

The present invention provides a method for producing a polycarbonate-polyorganosiloxane copolymer economically and stably, in particular, the present invention is concerned with a method for continuous production of a polycarbonate-polyorganosiloxane copolymer including (A) a step of withdrawing a polymerization reaction solution obtained by polymerizing a dihydric phenol compound, a carbonate precursor, and a polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent continuously or intermittently from a reactor; (B) a step of separating the polymerization reaction solution withdrawn in the step (A) into an aqueous phase and a water-insoluble organic solvent phase; and (C) a step of after washing the water-insoluble organic solvent phase separated in the step (B) with an acidic aqueous solution, separating the resultant into an aqueous phase and a water-insoluble organic solvent phase, wherein the content of the polycarbonate-polyorganosiloxane copolymer in the aqueous phase separated in the step (C) is controlled to not more than 2% by mass, and a part or the whole of an extract obtained by extracting the aqueous phase separated in the step (C) with a water-insoluble organic solvent is reused for the step (A).

Provided is a polycarbonate-polyorganosiloxane copolymer having high impact resistance and excellent transparency, in particular, a high total light transmittance and a small haze, and a method of producing thereof. Specifically, provided is a polycarbonate-polyorganosiloxane copolymer, containing a main chain having a repeating unit represented by the following general formula (I) and a constituent unit represented by the following general formula (II), in which: n in the general formula (II) is 25 to 50; and the copolymer satisfies the following conditions (a) and (b): (a) a molded article having a thickness of 2 mm made of the copolymer has a total light transmittance measured based on ISO 13468 of 88% or more and a haze measured based on ISO 14782 of 0.7% or less; and (b) a molded article having a thickness of 3 mm made of the copolymer has a total light transmittance measured based on ISO 13468 of 88% or more and a haze measured based on ISO 14782 of 1.0% or less. (In the formulae, Rand Reach independently represent a halogen atom, an alkyl group or an alkoxy group, X represents a single bond, an alkylene group, an alkylidene group, a cycloalkylene group, a cycloalkylidene group, &#x2014;S&#x2014;, &#x2014;SO&#x2014;, &#x2014;SO&#x2014;, &#x2014;O&#x2014; or &#x2014;CO&#x2014;, and a and b each independently represent an integer of 0 to 4. Rto Reach independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an aryl group, Y represents a single bond, or an organic residue containing an aliphatic or aromatic moiety, and n represents an average repetition number.)

Polycarbonate-polyorganosiloxane copolymer and method for producing same

The present invention provides a method for producing a polycarbonate-polyorganosiloxane copolymer economically and stably, in particular, the present invention is concerned with a method for continuous production of a polycarbonate-polyorganosiloxane copolymer including (A) a step of withdrawing a polymerization reaction solution obtained by polymerizing a dihydric phenol compound, a carbonate precursor, and a polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent continuously or intermittently from a reactor; (B) a step of separating the polymerization reaction solution withdrawn in the step (A) into an aqueous phase and a water-insoluble organic solvent phase; and (C) a step of after washing the water-insoluble organic solvent phase separated in the step (B) with an acidic aqueous solution, separating the resultant into an aqueous phase and a water-insoluble organic solvent phase, wherein the aqueous phase separated in the step (C) is extracted with a water-insoluble organic solvent, the content of the polycarbonate-polyorganosiloxane copolymer in the obtained extract is controlled to not more than 2% by mass, and a part or the whole of the extract is reused for the step (A).

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Ichihara, Japan

Yukiko Nagao