Bayer Aktiengesellschaft

Anton Schmitz

Wilhelm Thoma

Werner Rasshofer

Walter Schroer

Rolf Langel

The present invention is directed to a process for the preparation of finely dispersed, easily spreadable, aqueous polyurethane reactive coating compositions suitable for coating textile sheet products, artificial leather or leather by the direct or transfer coating process by

Process for the preparation of coating compositions, aqueous dispersions

This invention relates to new liquid or fluid polyamine/carbonic acid salt compositions free from crystalline content and their preparation from mixtures containing at least one aliphatic or cycloaliphatic polyamine, an aliphatic or cycloaliphatic hydroxyamine having at least one hydroxyl group and at least one amino group, and water and optionally diluents and/or conventional auxiliary agents and additives, by the addition of carbon dioxide. The proportion of polyamine to hydroxyamine is in the range of from about 95:5 to 10:90 % by weight, the quantity of water added is from about 0.01 to 5 mol of H.sub.2 O per amine equivalent (but at least 1 mol of water per mol of CO.sub.2) and the quantity of CO.sub.2 added is from about 0.01 to 0.99 mol of CO.sub.2 per amine equivalent. The invention further relates to the use of these liquid polyamine/carbonic acid salt compositions for the production of foamed polyurethane ureas, especially for coating substrates or for the production of sheet products, using prepolymers preferably containing blocked isocyanate groups and the liquid polyamine/carbonic acid salt compositions as chain lengthening agents and/or crosslinking agents and at the same time as physiologically harmless blowing agents.

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Leverkusen, Germany

Anton Schmitz