Bayer Aktiengesellschaft

Ralf Pakull

Gerhard Fennhoff

Volker Eckhardt

Jurgen Kirsch

Hans-Josef Buysch

Dieter Freitag

Karsten-Josef Idel

Wilfried Haese

Hans R Kricheldorf

Claus H Wulff

Hans-Rudolf Dicke

Klaus D Berg

Alfred Eitel

Joachim Genz

Hans-Rytger Kricheldorf

Bernhard Wehrle

Thomas Himmler

Pieter Ooms

Ulrich R Grigo

Karsten J Idel

Rudolf Braden

Uwe Westeppe

Otto Immel

Wolfgang Alewelt

Peter Tacke

Werner Struver

Hartmut L Ower

Ulrich Leyrer

Friedrich Bruder

J Urgen Kirsch

Volker Doring

Jurgen Engelhardt

Dierik Lubbers

Steffen Kuhlig

The invention relates to a process for the synthesis of bis-(4-hydroxyphenyl)-alkanes on ion-exchange resins or mixtures of ion-exchange resins which are modified with alkyl-SH groups, wherein the monophenols and carbonyl compounds to be used have first been purified to remove substances which can transfer alkyl groups.

Bisphenol synthesis on modified ion-exchange resins using specially

The present invention provides the use of polycarbonates containing carbonate structural units of the formula (I), ##STR1## for the production of optical articles, novel polycarbonates, which contain the structural units (I), together with a process for the production of these novel polycarbonates.

Use of special polycarbonates for the production of optical articles

A process for purifying aromatic carbonate polymers, including polycarbonates and polyestercarbonates, is disclosed. Accordingly a carbonate polymer in an organic solvent is rendered virtually free of low molecular weight components by agitation with aluminosilicate or by passing through layers of such aluminosilicate. The aluminosilicate is subsequently separated off and the carbonate polymer is isolated in known methods.

Process for the purification of polycarbonate and polyester carbonate

A method of preparing aliphatic-aromatic polycarbonate resin is disclosed. Accordingly, the method entails reacting an oligocarbonate of diphenol having chlorocarbonic acid ester terminal groups, with an aliphatic diol, in a non-aqueous solvent. The amount of solvent is such that the oligocarbonate is about 10-40% relative to the total weight of solvent, oligocarbonate and diol.

Method of preparing aliphatic-aromatic polycarbonates

A process for producing an aliphatic-aromatic polycarbonate is disclosed. The process comprise (A) reacting in an anhydrous neutral solvent (i) an oligocarbonate of diphenol with (ii) an aliphatic dicarboxylic acid, and (B) eliminating the hydrogen chloride and carbon dioxide by-products. The oligocarbonate of diphenol is characterized in that it is terminated by chlorocarbonic acid ester groups. The resins thus prepared are readily molded conventionally.

Process for the production of aliphatic-aromatic polycarbonates

A catalytic method for preparing thermoplastic carbonate polymers is disclosed. In the method according to the interfacial polycondensation process or the homogeneous solution process, resins which containing catalytically active groups are used as catalysts. The resulting resins are characterized by their color stability and temperature stability.

Method of preparing polycarbonates and polyester carbonates

The invention relates to a process for the production of bisphenols from acetone and phenols in the presence of sulfonic acid ion exchanger resins modified with alkyl-SH groups, in which 0.6 to 5% by weight H.sub.2 O is added to the mixture of phenol and acetone before the reaction.

Process for the production of bisphenols

A three-step process for the production of solventless polycarbonate is disclosed. Accordingly, a mixture of two different oligocarbonates each prepared by the interfacial method, is prepared in the first process step. In a second step, the mixture is crystallized. The third step entails polycondensation. In an additional embodiment of the invention the first step uses a mixture of one oligocarbonate with a suitable monomer.

Process for the production of solventless polycarbonate

The substituted polyheterocycles containing recurring structural units corresponding to the formula ##STR1## in which X is an oxygen atom, a sulfur atom or N-H, show good solubility in mixtures of methanesulfonic acid and methylene chloride or trifluoroacetic acid and methylene chloride. They may be used for the production of mixtures with thermoplastic polymers.

Stiff-chain polyheterocycles having improved solubility, a process for

Process for the preparation of polyaromatic compounds in which an aromatic dichloro compound, optionally in the presence of an anhydrous aprotic solvent, is reacted with metallic zinc, manganese or magnesium in the presence of a catalyst system of

Soluble polyaromatic compounds

The novel thermotropic polycarbonates having recurring structural units of the formulae ##STR1## have good mechanical properties and good processability. They can be used in conventional manner for manufacturing mouldings, filaments, fibres and films.

Copolycarbonate from mixture of polyarylene diol

The new thermotropic polyesters containing recurring structural units corresponding to the following formulae ##STR1## show excellent mechanical properties and good processibility. They may be used in the usual way for the production of moldings, filaments, fibers and films.

Thermotropic polyesters, a process for their production and their use

The thermotropic aromatic polyesters according to the invention which contain recurring units corresponding to the following formulae ##STR1## show improved resistance to chemicals, low melting points and, hence, good processibility in addition to the well-known favorable mechanical properties of liquid-crystal materials. The thermotropic aromatic polyesters are used for the production of moldings, filaments, fibers and films.

Thermotropic aromatic polyesters, a process for their production and

Thermotropic polyesterimides based on N-(.omega.-carboxyalkylene)-trimellitic acid imides and diphenols are distinguished by superior mechanical properties while at the same time being easily processible.

Thermotropic polyesterimide from N-carboxyalkylene trimellitimide having

This invention relates to a process for the preparation of polyimide esters starting from trimellitic acid anhydride and aminophenols or aminohydroxy biphenyls.

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Cologne, Germany

Ralf Pakull