Bayer Aktiengesellschaft

Armin Zenner

Hans-Joachim Scholl

Walter Meckel

Klaus Konig

Christian Wamprecht

Werner Rasshofer

Artur Reischl

Holger Meyborg

Hans-Joachim Kreuder

Ulrich Liman

Joachim Werner

Henning Klussmann

Wolfgang Patzold

The present invention relates to powder coating compositions wherein the binder contains copolymers which are solid below 30.degree. C., prepared from olefinically unsaturated compounds and have a weight-average molecular weight (M.sub.w) of 1500 to 75,000, a content of free hydroxyl groups of 0.2 to 6.0% by weight and a content of intramolecular carboxylic acid anhydride groups (calculated as C.sub.4 H.sub.2 O.sub.3) of 1 to 30% by weight.

Powder coating compositions containing copolymers having hydroxyl and

The present invention relates to polyurethanes with softening temperatures above 80.degree. C. which are NCO-free, which are reactive via masked isocyanates, which are essentially linear and extensively pre-lengthened, and their preparation. The polyurethanes can be used as powders which can be processed like thermoplastics and post-cured.

Reactive polyurethanes

The invention relates to an improved process for the production of polyamines containing urethane and/or urea and/or biuret and/or isocyanurate groups and, preferably, also alkylene ether, carbonate and/or acetal groups by the alkaline hydrolysis of corresponding compounds containing terminal aliphatic and/or aromatic isocyanate groups. To this end, the compounds containing terminal NCO-groups, preferably NCO-preadducts, are converted by means of selected bases into the carbamates and neutralized by introduction into equivalent quantities of acid or by the simultaneous introduction of the components in equivalent quantities into a reaction vessel, after which the polyamines are directly isolated by methods known per se. The invention also relates to the use of the polyamines obtained by the process for the production of polyurethanes.

Simplified process for the production of polyamines by the alkaline

A process for producing urethanes by reacting aromatic amino compounds with aliphatic, cycloaliphatic or araliphatic alcohols and carbon monoxide under conditions of elevated temperature and pressure characterized in that the reaction takes place in the presence of

Process for the production of urethanes

This invention relates to an improved process for the preparation of urethanes by the reaction of aromatic nitro compounds with alcohols and carbon monoxides in the presence of catalyst systems containing sulphur and/or selenium and/or compounds of these elements.

Preparation of aromatic urethanes

The instant invention relates to an improved process for the preparation of urethanes by the reaction of aromatic nitro compounds with alcohols and carbon monoxide in the presence of catalyst systems which contain selenium.

Process for the preparation of urethanes

The instant invention relates to the preparation of stable, relatively low viscosity dispersions of polyisocyanate-polyaddition products in hydroxyl containing compounds as dispersing agents. The process broadly comprises mixing an aqueous dispersion of an isocyanate-polyaddition product with a compound having at least two hydroxyl groups and having a boiling point about 100.degree. C., and thereafter at least partially distilling off the water.

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Dormagen, Germany

Armin Zenner