Abstract: Disclosed are random copoly(phosphonate carbonate)s with the high molecular weight and narrow molecular weight distribution exhibiting a superior combination of properties compared to prior art.

Abstract: The invention relates to a method for regenerating acidic cation exchangers, which are used as catalysts in the reaction of phenols with aldehydes or ketones to give bisphenols, in particular to give bisphenol A, with acids, with the proviso that, in the method according to the invention, these cation exchangers experience very little mechanical damage due to swelling processes during the regeneration process.

Abstract: Disclosed are random copoly(phosphonate carbonate)s with the high molecular weight and narrow molecular weight distribution exhibiting a superior combination of properties compared to prior art.

Abstract: Disclosed are random copoly(phosphonate carbonate)s with the high molecular weight and narrow molecular weight distribution exhibiting a superior combination of properties compared to prior art.

Abstract: The present invention relates to a composition containing polycarbonate and 0.01 wt. % to less than 0.30 wt. % of polyol, polyether polyol, or combinations thereof.

Abstract: The invention relates to a method for regenerating acidic cation exchangers, which are used as catalysts in the reaction of phenols with aldehydes or ketones to give bisphenols, in particular to give bisphenol A, with acids, with the proviso that, in the method according to the invention, these cation exchangers experience very little mechanical damage due to swelling processes during the regeneration process.

Abstract: The present invention provides a polycarbonate resin produced by the continuous interfacial process characterized in that after alkaline hydrolysis with sodium hydroxide, the polycarbonate resin contains an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) said amount measured by high pressure liquid chromatography, wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen. C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, the process comprising phosgene reacting with at least one bisphenol at 8 to 17% molar excess of phosgene relative to the bisphenol.

Abstract: Processes for producing bisphenols (e.g., bisphenol A (BPA)) having a purity greater than 99.7% are described, such processes including reacting a phenol and acetone in the presence of an acidic catalyst to form a product mixture comprising a bisphenol; removing at least a portion of the bisphenol from the product mixture in the form of a bisphenol/phenol adduct by crystallization, filtration and washing to provide bisphenol/phenol adduct crystals; and removing at least a portion of the phenol from the bisphenol/phenol adduct crystals to provide the bisphenol having a purity of more than 99.7%; wherein the crystallization comprises continuous suspension crystallization and is carried out in at least three crystallization devices arranged such that the product mixture is first cooled in a first stage of the crystallization to a temperature of 50 to 70° C.

Abstract: The present invention relates to a solid sheet prepared from a composition that includes: (a) a transparent polycarbonate; and (b) transparent polymeric particles having an optical density which differs from the transparent polycarbonate matrix material. The present invention also relates to use of such a solid sheet as a diffuser sheet in flat screens.

Abstract: Flame-resistant compositions comprising: a polycarbonate; 0.01 to <0.3 wt. % of a polyol; and 0.01 to 0.8 wt. % of a salt of a metal selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof, and a compound selected from the group consisting of sulfonic acids, sulfonamides, sulfonimides and mixtures thereof; processes for preparing the same and products prepared therewith.

Abstract: Processes for producing bisphenols (e.g., bisphenol A (BPA)) having a purity greater than 99.7% are described, such processes including reacting a phenol and acetone in the presence of an acidic catalyst to form a product mixture comprising a bisphenol; removing at least a portion of the bisphenol from the product mixture in the form of a bisphenol/phenol adduct by crystallization, filtration and washing to provide bisphenol/phenol adduct crystals; and removing at least a portion of the phenol from the bisphenol/phenol adduct crystals to provide the bisphenol having a purity of more than 99.7%; wherein the crystallization comprises continuous suspension crystallization and is carried out in at least three crystallization devices arranged such that the product mixture is first cooled in a first stage of the crystallization to a temperature of 50 to 70° C.

Abstract: A continuous process for the separation of phenol is disclosed. The process includes (a) feeding a stream of material, produced while preparing bisphenol A by reacting phenol with acetone, into a distillation column containing at least 5 theoretical separation stages, b) distilling-off the phenol as a top product and discharging from the column a bottom product containing secondary components, c) continuously introducing a portion of the bottom product into a dwell-time container operating at process parameters sufficient to cause, in the presence of an acidic catalyst, at least partial isomerization of the secondary components to form an isomerized product and d) introducing the isomerized product to the distillation column. The introducing of the bottom product is at a rate that is more than 30% of the rate of feeding of the stream at temperatures greater than 190° C. and hydrodynamic dwell time of at least 120 minutes.

Abstract: The present invention relates to a solid sheet prepared from a composition that includes: (a) a transparent polycarbonate; and (b) transparent polymeric particles having an optical density which differs from the transparent polycarbonate matrix material. The present invention also relates to use of such a solid sheet as a diffuser sheet in flat screens.

Abstract: The invention relates to a method for producing polycarbonate according to the method for the transesterification of molten mass whereby bis-(hydroxyaryl) compounds (bisphenols) and diaryl carbonates are reacted by means of reactive rectification.

Abstract: A polymeric material suitable for making a substrate for optical data storage disks is disclosed. The material, preferably aromatic polycarbonate is characterized in that the potential on 95 to 100% of the total surface of a disk molded therefrom is from ?1.5 to +1.5 kV, and in that the potential on 0 to 5% of the total surface of said disk is between ?1.5 and ?2.5, and +1.5 to +2.5, and in that the potential on no more than 1% of the total surface of said disk is less than ?2.5 kV and more than +2.5 kV. The potential measurements are carried out by means of a Monroe probe at a distance of 3.5 mm from the surface of the disk, the scanning region is in each case 12 cm in the X- and Y-direction, and in each case in steps of 2 mm in the X- and in the Y-directions.

Abstract: A substrate material, preferably polycarbonate, suitable for producing transparent injection-molded coated disks is disclosed. The material is characterized in that a substrate molded therefrom has an electrical field (measured within 5 minutes of its molding and at a distance of 100 mm from the surface) of ?30 to 0 kV/m.

Abstract: A polycarbonate resin that after alkaline hydrolysis with sodium hydroxide contain an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) wherein R1 and R2 independently of one another denote hydrogen or C1-C12-alkyl, or together denote C4-C12-alkylidene, and R3 and R4 independently of one another denote hydrogen, C1-C12-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, said amount measured after alkaline hydrolysis with sodium hydroxide by high pressure liquid chromatography.

Abstract: A continuous process for the separation of phenol is disclosed. The process includes (a) feeding a stream of material containing 40 to 90% phenol, 5 to 40% bisphenol A and 5 to 40% of side products into a distillation column containing at least 5 theoretical separation stages, b) distilling-off the phenol as a top product and discharging from the column a first portion of the bottom product c) continuously introducing a second portion of the bottom product into a dwell-time container operating at process parameters sufficient to cause, in the presence of an acidic catalyst, an at least partial isomerization of the side products to form an isomerized product and d) introducing the isomerized product to the distillation column. The introducing of said portion of the bottom product is at a rate, in Kg/hour, that is more than 30% of the rate of feeding of the stream, and said process parameters include temperatures greater than 190° C. and hydrodynamic dwell time of at least 120 minutes.

Abstract: The present application relates to a process for producing high-purity bis(4-hydroxyaryl)alkanes from adducts of bis(4-hydroxyaryl)alkanes and aromatic hydroxy compounds, which are obtained by acid-catalysed reaction of the aromatic hydroxy compounds with ketones.

Abstract: The application relates to a process for producing high-purity bis(4-hydroxyaryl)alkanes from adducts of bis(4-hydroxyaryl)alkanes and aromatic hydroxy compounds, which are obtained by acid-catalysed reaction of the aromatic hydroxy compounds with ketones.