Bayer Aktiengesellschaft

Bayer Ag Konzernverwaltung Rp

Kurt-Peter Meurer

Claus H Wulff

Jurgen Hinz

Tony Van Osselaer

Kaspar Hallenberger

Johan Vaes

Ignace Hooftman

Werner Obrecht

Gerd Sylvester

Alfred Eitel

Rudolf Casper

Wolfgang Baade

Werner Verhoeven

Heinrich Steude

Bernhard Will

Bernhard A Wolf

Hugo Zimmermann

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

High molecular weight, gel-free ethylene/vinyl acetate copolymers may be prepared by the process of solution polymerization if a particular relationship of temperature/pressure is observed.

Solution polymerization for the preparation of gel-free ethylene/vinyl

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Leverkusen, Germany

Kurt-Peter Meurer