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.

Abstract: The present invention provides crystals of an adduct of a bisphenol and a phenol and methods of producing those crystals. The crystals may find use in preparing bisphenols.

Abstract: Solid particles containing 10 to 90 parts by weight of a dihydroxy compound and 10 to 90 parts by weight of a carbonic acid ester are disclosed. Also disclosed is a process for the production of these particles, an apparatus suitable for the process and a method for their use in production of polycarbonate by transesterification of carbonic acid esters with dihydroxy compounds.

Abstract: A process for producing polycarbonate is disclosed. The process entails transesterification of at least one carbonic ester with a mixture that contains dihydroxyl compound and phenol. The amount of bisphenol A in the mixture is 10 to 100 mol % relative to the amount of dihydroxyl compound and phenol is present in the mixture in an amount of 0.1 to 200% relative to the weight of bisphenol A.

Abstract: A device for exchanging a die plate of a molten bisphenol A prilling tower is described. The device comprises: (a) at least two die plates; (b) a guide which is in contact with the die plates; and (c) a drive mechanism, wherein the drive mechanism moves the die plates linearly and serially between an operating position and an exchange position along the guide. Also described is a process of automated operation of the device at the top of a bisphenol A prilling tower.

Abstract: The present invention provides crystals of an adduct of a bisphenol and a phenol and methods of producing those crystals. The crystals may find use in preparing bisphenols.

Abstract: A method for producing bisphenol A in prill form is disclosed. Molten bisphenol is top-fed into a prilling tower via a plate containing a plurality of nozzles. A gas coolant guided through a circuit is led into said tower in a counter flow direction. The prills are cooled to about room temperature, collected at the bottom of the tower and removed. Also disclosed is the device for carrying out the inventive method and the prills thus produced.

Abstract: A container made of polycarbonate resin is disclosed. The container is characterized in that the polycarbonate is prepared by the phase interface process that is characterized in that the aqueous solution of an alkali salt of a bisphenol used, contains dissolved oxygen in an amount less than 150 ppb. The process for making the container is also disclosed.

Abstract: A process for fluidizing bisphenol dust is disclosed. The process entails adding 0.1 to 10 parts by weight of water per 1 part by weight of bisphenol dust. Also disclosed is a process for preparing a bisphenol wherein the fluidized bisphenol dust according to the invention is introduced before, during or after reaction of a phenol with a carbonyl compound.

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.

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: A process of preparing bisphenol A having low residual contents of oxygen and phenol is described. The process involves: (a) melting mixed crystals of bisphenol A and phenol under a nitrogen atmosphere at a temperature of 100° C. to 120° C.; (b) feeding continuously the melt formed in step (a) into the top of a distillation unit under conditions of 120° C. to <160° C. and a pressure of >80 mbar to 200 mbar; (c) feeding contemporaneously with step (b) nitrogen into the bottom of the distillation unit; (d) allowing the melted feed material and the nitrogen feed to contact each other within the distillation unit, thereby forming a concentrated melt material having (i) a phenol content reduced to 10 to 25 wt. %, and (ii) a reduced oxygen content (e.g., an oxygen content of <1 ppm); and (e) optionally passing a stream of nitrogen through the concentrated melt material under conditions of at least atmospheric pressure, 180° C. to 220° C. and a nitrogen partial pressure of 1 to 1.

Abstract: A process for the preparation of polycarbonate resins having a low yellowness index is described. The process involves converting phosgene with a sodium bisphenolate solution by means of a phase interface process performed with the exclusion of oxygen. The sodium bisphenolate solution used in the process has a dissolved oxygen content of <150 ppb. Also described are optical data storage media prepared from the polycarbonate of the present invention.

Abstract: A process for producing bis(4-hydroxyaryl)alkane is disclosed. The process comprise in sequence the steps of (a) passing inert gas through a melt at 150 to 230° C. that contains bis(4-hydroxyaryl)alkane and other aromatic hydroxy compounds, under conditions designed to remove said other aromatic hydroxy compounds from said melt and to obtain a stream of inert gas that contains said other aromatic hydroxy compounds (b) condensing the stream obtained in (a) to remove said other aromatic hydroxy compound, and to obtain a stream of inert gas, and (c) purifying and compressing the stream of inert gas obtained in (b), and recycling to step (a).

Abstract: A process for producing bis(4-hydroxyaryl)alkane is disclosed. The process comprise in sequence the steps of (a) passing inert gas through a melt at 150 to 230° C. that contains bis(4-hydroxyaryl)alkane and other aromatic hydroxy compounds, under conditions designed to remove said other aromatic hydroxy compounds from said melt and to obtain a stream of inert gas that contains said other aromatic hydroxy compounds (b) condensing the stream obtained in (a) to remove said other aromatic hydroxy compound, and to obtain a stream of inert gas, and (c) purifying and compressing the stream of inert gas obtained in (b), and recycling to step (a).

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