Bayer Aktiengesellschaft

Bayer Ag Konzernverwaltung Rp

Jurgen Hinz

Claus H Wulff

Kurt-Peter Meurer

Tony Van Osselaer

Christian Lindner

Rudolf Binsack

Kaspar Hallenberger

Klaus Elfert

Johan Vaes

Ignace Hooftman

Dieter Wittmann

Walter Uerdingen

Alfred Eitel

Otto Koch

Ludwig Trabert

Werner Verhoeven

Udo Rudolph

Heinrich Steude

Karola Brudermanns

Burkhard Braun

Norbert Bachem

Pol Bamelis

Frank Quaeyhaegens

Willy Van Herck

Roelof Boyens

The invention relates to a process for the purification of p,p-bisphenolate solutions such as are obtained in the production of bisphenolates from soda lye and bisphenols by extraction.

Purification of p,p-bisphenolate solutions

A process for preparing bisphenol A which has a purity of at least 99.95 wt. % of p,p-bisphenol A (BPA). Thermally stable and colour-stable BPA purified in accordance with the invention produces improved thermal and colour stability and improved optical transparency in polymers such as e.g. polycarbonates prepared therefrom.

Process for the purification of bisphenol

The invention relates to the preparation of a transparent crystalline adduct consisting of bisphenol A (75 parts) and bisphenol TMC (25 parts), which has a melting point of 144.degree. C. which is below the melting points of the pure starting compounds bisphenol A (157.degree. C.) and bisphenol TMC (208.degree. C.).

Crystalline adduct of bisphenol A and bisphenol TMC

The invention relates to a method for the purification by distillation of p,p-bisphenol A from the melt. The p,p-bisphenol A melt thus obtained is highly heat-stable, stable in storage and colour-stable, is free from high-boiling components and no longer contains any surface-active or non-distillable metal, salt, acid or polymer components and no sulphur-containing components; o,p-BPA and phenol are removed and the low-boiling components are scarcely detectable.

Method for the preparation of ultra-pure bisphenol A and the use thereof

This invention relates to an ionic exchanger modified with thiazolines, to its preparation and to its use for the preparation of condensation products, particularly bisphenols.

Ionic exchangers modified with thiazolines

The invention relates to a process for the recovery of thermoplastic polymers from aqueous dispersions by spray-drying after treatment with carboxylic acid of formula I ##STR1## wherein X is a single bond, --CH.sub.2 -- or --C.sub.2 H.sub.4 --, and

Processing of polymer dispersions by spray drying

The invention relates to an improved process for the production of polymer powders based on graft polymers and optionally rubber-elastic polymers and vinyl monomer polymers.

Polymer powders containing graft polymer

Alkyl sulphonic acid phenyl esters which are substituted by carboxylic acid esters can be obtained by reacting sulphochlorinated paraffins with hydroxy benzoic acid esters. Said compounds can be used as plasticizers for polymers.

Alkyl sulphonic acid phenyl esters substituted by carboxylic acid esters

Semipermeable membranes of sulphonated polybenz-1,3-oxazin-2,4-diones for separating or enriching organic sulphonates by the method of inverse osmosis or ultrafiltration.

Semipermeable membranes of sulphonated polybenz-1,3-oxazin-2,4-diones

Novel, sulphonated polybenz-1,3-oxazin-2,4-diones are produced by reacting polybenzoxazin diones with chlorosulphonic acid in a molar ratio of from 1:1 to 1:10.

Growing community of inventors

Krefeld, Germany

Jurgen Hinz