Bayer Aktiengesellschaft

Other

Michael B&ouml;diger

Frieder Heydenreich

Rainer Neumann

Michael Prein

Steffen K&uuml;hling

Franky Bruynseels

Dirk Van Meirvenne

Dieter Wittmann

Thomas Eckel

Heinrich Alberts

Gerhard Fennhoff

Rolf Lanze

Rudolf Wagner

Ren&eacute; De Cleyn

Wolfgang Ebert

Klaus Horn

Reinhold M Klipper

Ulrich Schnegg

Johan Vaes

Wolfgang Wambach

Ren&euml; De Cleyn

Nikolai Kostyszyn

Hans-Ludwig Fofonka

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.

Method of producing polycarbonates

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.

Method for producing bisphenols

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

Polycarbonate substrates

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.

Substance mixture containing bisphenol A

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.

Bisphenol production

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

Method for conditioning ion exchangers

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.

Method for the production of bisphenol-a

Flame-resistant polycarbonate moulding materials which are dimensionally stable at high temperatures and have high flow line strength

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.

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.

Fluidised bisphenol dust

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.

Initiation method of a method for producing 2,2-bis(4-hydroxyphenyl)propane

Process for the removal of dissolved oxygen from phenol

X-ray detectable molded articles prepared from polycarbonate resins are disclosed. The articles, preferably toys or medical equipment, are molded of polycarbonate the structure of which contains units derived from iodophenyl.

Growing community of inventors

League City, TX, United States of America

Michael Bödiger

Growing community of inventors

League City, TX, United States of America

Michael B&ouml;diger

Michael Bödiger