Abstract: A process for preparing diaryl carbonate and utilizing at least part of the process wastewater by increasing the concentration of the wastewater phases containing sodium chloride for the electrolysis by means of osmotic membrane distillation with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the diaryl carbonate production process (diphenyl carbonate process) is described.

Abstract: The invention relates to a polycarbonate composition having reduced subsequent yellowing of the mouldings produced therefrom on heat ageing and having good optical properties of the polycarbonate composition on processing.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.

Abstract: The invention relates to a UV-stabilised melt polycarbonate composition having improved melt flowability while at the same time having good optical properties and at the same time good hydrolytic stability, the composition comprising a melt polycarbonate, at least one UV absorber, at least one phosphine and optionally an aliphatic carboxylic acid ester.

Abstract: A combined process for the preparation of polycarbonate from bisphenols and diaryl carbonates, the monophenol liberated being reacted again for the preparation of the diaryl carbonate and the alkali metal halide forming in the preparation of the diaryl carbonate being converted by electrochemical oxidation, optionally over a gas diffusion electrode, into chlorine and alkali hydroxide solution, the chlorine being recycled into the preparation of the phosgene and the alkali hydroxide solution being recycled into the preparation of the diaryl carbonate.

Abstract: The invention relates to a polycarbonate composition with improved melt-flowability together with good optical properties and together with good hydrolysis resistance.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.

Abstract: The invention relates to a polycarbonate composition having reduced subsequent yellowing of the mouldings produced therefrom on heat ageing and having good optical properties of the polycarbonate composition on processing.

Abstract: The invention relates to a polycarbonate composition with improved melt-flowability together with good optical properties and together with good hydrolysis resistance.

Abstract: A combined process for the preparation of polycarbonate from bisphenols and diaryl carbonates, the monophenol liberated being reacted again for the preparation of the diaryl carbonate and the alkali metal halide forming in the preparation of the diaryl carbonate being converted by electrochemical oxidation, optionally over a gas diffusion electrode, into chlorine and alkali hydroxide solution, the chlorine being recycled into the preparation of the phosgene and the alkali hydroxide solution being recycled into the preparation of the diaryl carbonate.

Abstract: A process for preparing diaryl carbonate and utilizing at least part of the process wastewater by increasing the concentration of the wastewater phases containing sodium chloride for the electrolysis by means of osmotic membrane distillation with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the diaryl carbonate production process (diphenyl carbonate process) is described.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.

Abstract: Processes comprising: (a) reacting phosgene and a monohydroxyl aryl compound in the presence of a suitable catalyst to form a diaryl carbonate and a solution comprising an alkali chloride; (b) separating the diaryl carbonate from the solution; (c) adjusting the pH of the solution to a value of less than or equal to 8 to form a pH-adjusted solution; (d) treating the pH-adjusted solution with an adsorbent to form a treated solution; (e) subjecting at least a portion of the treated solution to electrochemical oxidation to form chlorine and an alkali hydroxide solution; and (f) recycling at least a portion of one or both of the chlorine and the alkali hydroxide solution.

Abstract: A multi stage process for the production of polycarbonates having low monomer content is disclosed. The process entails, in sequence, (i) transesterifying in the melt at least one dihydroxyaryl compound with at least one diaryl carbonate in the presence of at least one onium catalyst to produce a polycondensate that contains monomers, (ii) introducing into the polycondensate an inhibitor in an hypostoichiometric amount in relation to the catalyst and (iii) reducing in a finishing reactor the content of monomers in said polycondensate. The polycarbonate thus produced is characterized in that it contains less than 350 ppm of diphenyl carbonate, less than 40 ppm of 2,2-bis-(4-hydroxyphenyl)propane and less than 150 ppm of phenol.

Abstract: An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.

Abstract: An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.

Abstract: A multi stage process for the production of polycarbonates having low monomer content is disclosed. The process entails, in sequence, (i) transesterifying in the melt at least one dihydroxyaryl compound with at least one diaryl carbonate in the presence of at least one onium catalyst to produce a polycondensate that contains monomers, (ii) introducing into the polycondensate an inhibitor in an hypostoichiometric amount in relation to the catalyst and (iii) reducing in a finishing reactor the content of monomers in said polycondensate. The polycarbonate thus produced is characterized in that it contains less than 350 ppm of diphenyl carbonate, less than 40 ppm of 2,2-bis-(4-hydroxyphenyl)propane and less than 150 ppm of phenol.