Abstract: The invention relates to a continuous method for producing polycarbonates by transesterifying diaryl carbonates with dihydroxyaryl compounds in the presence of quaternary onium compounds. The invention also relates to polycarbonates produced thereby and products produced from said polycarbonates.

Abstract: A process for making a high molecular weight (co)polycarbonate resin is disclosed. The process entails (i) obtaining at least one member selected from the group low molecular weight residue (weight average molecular weight 15,000 to 30,000) of aromatic (co)polycarbonate production, waste of (co)polycarbonate production, remainders of (co)polycarbonate production and (co)polycarbonate recyclate (ii) melting the said member in a suitable vessel to obtain a melt and (iii) feeding the melt into a reactor optionally along with at least one bisphenol or oligocarbonate having terminal OH groups and further optionally with a transesterification catalyst, and (iv) subjecting the melt to transesterification reaction at a temperature of 250 to 350° C., at a pressure below 5 mbar and residence time of 0.02-4 hours.

Abstract: A continuous process for producing oligocarbonate is disclosed. The process entails in sequence the steps of a) reacting a dihydroxyaryl compound with a diaryl carbonate in the presence of a catalyst to obtain a melt and avoiding removal of released monohydroxyaryl compound and b) withdrawing the monohydroxyaryl compound by flash evaporation and c) heating the melt obtained under vacuum in an evaporator equipped with sump receiver and d) repeating at least once steps b) and then c) each at gradually increased temperatures and lowered pressures.

Abstract: A branched melt-polymerized polycarbonate having pronounced non-Newtonian flow behavior is disclosed. The polycarbonate is suitable for preparing molding compositions and the preparation of a variety of molded articles.

Abstract: The invention relates to a continuous method for producing polycarbonates by transesterifying diaryl carbonates with dihydroxyaryl compounds in the presence of quaternary onium compounds. The invention also relates to polycarbonates produced thereby and products produced from said polycarbonates.

Abstract: A process for the preparation of transparent copolycarbonate is disclosed. The copolycarbonate the molecular structure of which contains more than 35 mole % of units derived from dihydroxydiphenylene is prepared by the melt transesterification process wherein the final temperature of the reaction is reached in less than 40 minutes after reaching the starting temperature.

Abstract: A process for preparing a melt transesterification catalyst is disclosed. The process entails (i) obtaining a phenol adduct of phosphonium phenolatein the form of crystalline solid and (ii) storing the solid phenol adductin a closed container at relative humidity of 30 to 70 % and at temperature of −30 to 50° C. The thus prepared catalyst is suitable in the production of polycarbonate in the melt transesterification process.

Abstract: The invention relates to a novel polycarbonate and its use a material in the production of molded articles and semifinished products, especially for transparent articles such as data memories or radio compact discs, slabs, cellular sheets, films, housings, panes, especially panes for motor vehicles, diffusion glasses, but also for electrical applications or the constructions of houses.

Abstract: A thermoplastic molding composition suitable for making articles having good combination of properties is disclosed. The composition contains (A) a copolycarbonate derived from compounds of formula (I) wherein R1 to R4 independently of one another represent H, C1-C4-alkyl, phenyl, substituted phenyl or halogen, and compounds of formula (II) wherein R5 to R8 independently of the others denote H, CH3, Cl or Br and X is C1-C5-alkylene, C2-C5-alkylidene, C5-C6-cycloalkylene, C5-C10-cycloalkylidene, and (B) a homopolycarbonate derived from bisphenol A. The composition that features resistance to stress cracking and good low-temperature properties is suitable for automotive construction and exterior applications.

Abstract: The present invention provides a two-stage process for the production of polyester carbonates with aliphatic dicarboxylic acids, the polyester carbonates obtained thereby, a process for the production of extrudates and molded articles from the polyester carbonates, and the extrudates and molded articles obtained thereby.

Abstract: A process for the production of phosphonium phenolates is disclosed. The process entails reacting a phosphonium halide and phenol in an aqueous alkaline solution.

Abstract: An improvement to the melt transesterification reaction of diaryl carbonate with dihydroxy aryl compound is disclosed.

Abstract: A melt-polymerized polycarbonate is disclosed. The polycarbonate has a shear thinning ratio (y) that is defined by the limiting values of the following equation c+axb>y>−c+axb  (Q) wherein y≧1, c=0.3 to 0.1, b=14.831±0.05 to 0.02, a=0.1262±0.005 to 0.003 and x is the relative viscosity of the polycarbonate. The polycarbonate exhibits a flow behavior similar to that of a linear polycarbonate of comparable molecular weight obtained by the interface polymerization process.

Abstract: A multi-layer product comprising a coex layer and a base layer is disclosed.

Abstract: The present invention provides the use of impact resistant, stress cracking resistant copolycarbonates with particularly good low temperature properties for applications in which particularly good low temperature properties are required, e.g., for automobile construction or external applications, and new copolycarbonates themselves.

Abstract: A transesterification process for producing polyester is disclosed. In a first stage of the process there is heated, in an inert gas atmosphere, a first mixture containing at least one dihydroxy compound and at least one diaryl carbonate to form an oligocondensate. In a second stage there is added to the oligocondensate at least one dicarboxylic acid to form a second mixture. The second mixture is heated to a temperature not higher than 290° C. in the presence of a quaternary onium compound as catalyst to form polyester carbonate. Hydroxyaryl formed throughout the process is distilled-off under reduced pressure.

Abstract: A process for producing a high purity tetraphenylphosphonium phenolate that at room temperature is in liquid form is disclosed. The process entails (i) reacting tetraphenylphosphonium halide with phenol in an aqueous-alkaline solution at temperatures of up to 55° C., at a molar ratio of phenol to tetraphenylphosphonium halide ≧10:1 and at pH values of 9.5 to 11 to obtain a material system containing an organic phase and an aqueous phase and, (ii) upon completion of the reaction adding a solution of water and a sparingly soluble alcohol to separate the aqueous phase from the organic phase. The phosphonium phenolate thus produced is suitable as transesterification catalyst, in particular for solvent-free production of thermoplastic polycarbonate.

Abstract: A process for preparing a melt transesterification catalyst is disclosed. The process entails (i) obtaining a phenol adduct of phosphonium phenolatein the form of crystalline solid and (ii) storing the solid phenol adductin a closed container at relative humidity of 30 to 70% and at temperature of −30 to 50° C. The thus prepared catalyst is suitable in the production of polycarbonate in the melt transesterification process.

Abstract: A process for producing polycarbonate is disclosed. The process entails obtaining an oligocarbonate produced by transesterification of diaryl carbonate with dihydroxyaryl compound in the presence of catalysts and introducing the oliogocarbonate into a reactor that enables continuous formation of free films at a rate higher than 10. The reactor including a horizontal cylinder equipped with a heating jacket, at least one vapor outlet, a feed nozzle an outlet nozzle, a rotatable cylindrical basket having a cylindrical perforated wall and annular discs positioned at intervals around the periphery of said basket and along the length thereof, and means for rotating said basket, the interior of said basket including no central shaft, the diameter of the cylindrical basket corresponding to about ⅔ of the diameter of the horizontal cylinder, and said discs being formed of perforated sheet metal.

Abstract: The present invention provides a two-stage process for the production of polyester carbonates with aliphatic dicarboxylic acids, the polyester carbonates obtained thereby, a process for the production of extrudates and molded articles from the polyester carbonates, and the extrudates and molded articles obtained thereby.