Hoechst Aktiengesellschaft

Hellmuth Deckers

Frank Osan

Michael-Joachim Brekner

Harald Cherdron

Friedrich Herold

Reiner Hess

Thermoplastic cycloolefin copolymers (COCs) having high tear strength and low optical attenuation, a process for their preparation, and their use as optical waveguides (optical fibers).

Cycloolefin copolymers having high tear strength and low optical attenuation

Cycloolefin copolymers having low melt viscosity and low optical

A thermoplastically processible aromatic polyetheramide, in which the structure comprises the repeating units of the formulae

Thermoplastically processible aromatic polyetheramide from

The structure of the aromatic copolyether amide which can be processed as a thermoplastic comprises recurring units of the formulae --CO--Ar.sup.1 --CO-- (A), --NH--Ar.sup.1 --O--Ar.sup.1 --X--Ar.sup.1 --O--Ar.sup.1 --NH (B) and --NH--Ar.sup.2 --NH-- (C) in which Ar.sup.1 denotes a divalent, unsubstituted or substituted aromatic radical having 6 carbon atoms which is linked in the p-position, X represents a 2,2-propylidene link and Ar.sup.2 is identical with Ar.sup.1 or is Ar.sup.1 which is linked in the m-position, or is the --Ar.sup.1 --Z--Ar.sup.1 -- group in which Z is a direct bond or is a radical --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --SO.sub.2 --, --CO--, --O--, --CH.dbd.CH--, --CO--NH-- or --O--Ar.sup.1 --O-- or the radical ##STR1## in which R represents hydrogen or a branched or unbranched alkyl radical having 1-4 carbon atoms. The proportion of units (A) and of the sum of units (B) and (C) is each 100 mol-%, the proportion of units (C) being up to 50 mol-% and, if Z represents --SO.sub.2 --, up to 75 mol-%. The Staudinger index [.eta.] of the copolyether amide is in the range from 50 to 1000 cm.sup.3 /g, and the value of the glass transition temperature is above 200.degree. C. The copolyether amide is prepared by a low-temperature solution, solid, interface or melt condensation process. The moldings produced therefrom in the form of filaments, wires, films and other moldings are obtained by processing the pulverulent copolyether amides or their solutions.

Aromatic copolyether amide which can be processed as a thermoplastic,

The invention relates to a process for the preparation of aromatic polyethers by condensation of the reactants in the presence of a condensation agent consisting of a mixture of metal carbonates comprising (a) lithium and/or an alkaline earth metal carbonate and (b) sodium, potassium, rubidium and/or cesium carbonate. The combination of carbonates (a) and (b) according to the invention leads to a surprising increase in activity.

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Ingelheim, Germany

Hellmuth Deckers