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: Polycarbonate substrates having low concentration of defects are disclosed. The substrates are suitable for producing molded articles characterized by low cloudiness.

Abstract: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

Abstract: A process for the preparation of polycarbonate by the phase boundary process is disclosed. The process entails reacting at least one dihydroxydiarylalkane in the form of its alkali metal salts with phosgene in the heterogeneous phase in the presence of sodium hydroxide solution and an organic solvent. The process is characterized in that the feedstock have but low content of Fe, Cr, Ni, Zn, Ca, Mg, Al metals or homologues thereof, and in that the organic solvent is separated off, and in that the polycarbonate which is obtained is worked up. The resulting polycarbonate is particularly useful in producing transparent shaped articles.

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: Polycarbonate substrates having low concentration of defects are disclosed. The substrates are suitable for producing molded articles characterized by low cloudiness.

Abstract: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

Abstract: The present invention provides mixtures containing bisphenol A, methods for the production thereof. The mixtures of the present invention may find use in the production of polymeric materials.

Abstract: Monodisperse cation-exchangers and anon-exchangers are conditioned by a process and thereafter used as catalysts and for the production of bisphenols.

Abstract: A process for the production of 2,2-bis(4-hydroxyphenyl)propane (BPA) is disclosed. The process that entails reacting acetone with phenol in the presence of cross-linked sulfonated polystyrene resins is characterised in that BPA is separated from the reaction solution downstream of the reaction unit by means of a multi-stage vacuum distillation and a subsequent single- or multi-stage layer crystallisation. The by-product stream with accumulated by-products is returned downstream of the reaction unit.

Abstract: 2,2-bis(4-hydroxyphenyl)propane (BPA) is produced by reacting acetone and phenol in the presence of cross-linked sulfonated polystyrene resins and then separating the BPA off from the reaction solution.

Abstract: Flame-resistant, thermoplastic moulding compositions containing A) 70 to 98 parts by weight of an aromatic polycarbonate, B) 0.5 to 20 parts by weight of a graft polymer, C) 0.5 to 5 parts by weight of a mixture of C.1) 10 to 90 parts by weight, based on C, of a monophosphorus compound of formula (I) C.2) 90 to 10 wt. %, based on C, of a phosphorus compound of formula (II) D) 0.05 to 5 parts by weight of a fluorinated polyolefin with an average particle diameter of 0.05 to 1000 &mgr;m, a density of 1.2 to 2.3 g/m3 and a fluorine content of 65 to 76 wt. %.

Abstract: Polycarbonate substrates, the preparation of which is based on 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone, and their use for producing shaped articles with particularly high purity and extremely high surface brilliance and also the shaped articles which can be produced from the polycarbonate substrate are described.

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 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 invention relates to fluidised bisphenol dust consisting of bisphenol dust and water, to a method for producing the same and to a method for producing a bisphenol, whereby fluidised bisphenol dust is added during production.

Abstract: A process for the commissioning of a process for the production of 2,2-bis(4-hydroxyphenyl)propane is disclosed. The process that entails reacting phenol with acetone in the presence of sulfonated cross-linked polystyrene resins is characterized in that the commissioning takes place with an acetone concentration reduced below, and a phenol concentration increased above, that of the optimal sustained operation state, with a reduced quantitative throughput, and in that with temperature control, the reactant quantity and the acetone content of the reactor feed are subsequently increased until the sustained operating state is reached.

Abstract: The invention relates to substance mixtures, containing bisphenol A, two methods for production thereof and use thereof for production of polymeric materials.

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.