A method for quenching a polymerisation process is described. The reaction of carbon dioxide with an epoxide in the presence of a bimetallic metal complex catalyst to produce a polymer comprises the quenching step of deactivation of the catalyst by contacting the catalyst with an acid effective to deactivate the catalyst. The deactivated catalyst may be removed from the polymer product by contacting the catalyst and polymer product with a solid phase and/or by precipitation; and the catalyst may also be optionally reactivated by contacting the deactivated catalyst with an anion. The acid may contain an anion effective to initiate the polymerisation process and effective to deactivate the catalyst and the molar ratio of acid to catalyst in the deactivation step may be less than or equal to 20:1 of the acid to catalyst mole ratio for the reaction.

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.

Polymer powders useful for additive manufacturing may be made by contacting carbon dioxide and a crystallizable polymer having at least one carbonyl, sulfur oxide or sulfone group; permeating the carbon dioxide into the polymer for a crystallizing time sufficient to induce crystallization forming an induced crystalized polymer; removing the carbon dioxide; and forming induced crystalized polymer particles having a D90 particle size of at most 300 micrometers and average particle size of 1 micrometer to 100 micrometers equivalent spherical diameter. The carbon dioxide is desirably supercritical carbon dioxide for at least a portion of the crystallizing time. The polymer powders upon heating during additive manufacturing may result in a polymer having less crystallinity or become amorphous.

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

A method of producing a polycarbonate-polyorganosiloxane copolymer, including: a step (a) of obtaining a solution containing a polycarbonate-polyorganosiloxane copolymer through use of an alkaline aqueous solution of a dihydric phenol, phosgene, a polyorganosiloxane, and an organic solvent; a step (b) of continuously or intermittently draining the solution containing the copolymer from step (a), followed by separation of the drained solution into an aqueous phase and an organic phase to provide the organic phase with copolymer; and a step (c) of concentrating the organic phase with the from step (b) to remove the organic solvent, before heating the organic phase to a boiling region in the step (c), a viscosity of the organic phase being adjusted to 70 cP or less at 35° C., the polycarbonate-polyorganosiloxane copolymer obtained by the steps (a) to (c) including a polycarbonate-polyorganosiloxane copolymer containing a specific polycarbonate block (A) and a specific polyorganosiloxane block (B).

In an embodiment, a polycarbonate polymerization process comprises interfacially polymerizing a carbonate compound and dihydroxy compound in the presence of an interfacial catalyst to form a polycarbonate and adding a viscosity reducing agent and a transesterification catalyst to polycarbonate upstream of a first filter to form an adjusted polycarbonate. The first filter can be replaced with a replacement filter and the adjusted polycarbonate can be introduced to the replacement filter. The flow can be diverted to a replacement filter. The process further comprises reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.

A method for quenching a polymerisation process is described. The reaction of carbon dioxide with an epoxide in the presence of a bimetallic metal complex catalyst to produce a polymer comprises the quenching step of deactivation of the catalyst by contacting the catalyst with an acid effective to deactivate the catalyst. The deactivated catalyst may be removed from the polymer product by contacting the catalyst and polymer product with a solid phase and/or by precipitation; and the catalyst may also be optionally reactivated by contacting the deactivated catalyst with an anion. The acid may contain an anion effective to initiate the polymerisation process and effective to deactivate the catalyst and the molar ratio of acid to catalyst in the deactivation step may be less than or equal to 20:1 of the acid to catalyst mole ratio for the reaction.

Provided is a method of manufacturing an aromatic polycarbonate resin composition with high fluidity, particularly during low shear, and a good color. An aromatic polycarbonate resin composition including: an aromatic polycarbonate resin that has a structural unit expressed by general formula (1); a aliphatic cyclic carbonate that is expressed by general formula (2) and is included at a ratio of 10 ppm-10,000 ppm; an aromatic cyclic carbonate that is expressed by general formula (3); and at least one compound selected from the group consisting of compounds expressed by general formulas (4)-(6), wherein the total content of the aromatic cyclic carbonate and the compound(s) expressed by general formula(s) (4)-(6) is 0.1 mass %-2.0 mass % by bisphenol A-converted value.

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The present invention relates to a method for separating an organozinc catalyst from a polyalkylene carbonate polymerization solution, and the method of the present invention includes: stirring and aging a polymerization solution including a polyalkylene carbonate resin, an organozinc catalyst, an alkylene oxide and a polymerization solvent; and filtering the polymerization solution after completing the aging.

A method for preparing granular polycarbonate particles is disclosed herein. In some embodiments, a method for preparing granulated polycarbonate particles includes mixing a polymerization reaction solution comprising polycarbonate and an organic solvent, and an anti-solvent solution comprising water and an anti-solvent to prepare a mixed solution, heating the mixed solution to remove the organic solvent, and drying or filtering the mixed solution to obtain granular polycarbonate particles. The granular polycarbonate particles having excellent physical properties without using a stabilizer or a surfactant can be obtain.