Bayer Aktiengesellschaft

Fritz Ehrhard

Walter Uerdingen

Rolf Kubens

Herbert Gebauer

Wilfried Orywol

Urea-modified bubble-free moldings based on polyisocyanate polyaddition products are made by reacting (a) an organic polyisocyanate with (b) a polyhydroxyl compound and/or polyepoxide in the presence of (c) a water chain extender in the form of an aqueous alkali aluminosilicate or an aqueous alkali-alkaline earth aluminosilicate of the zeolite type in a mold using cast resin technology. The reaction components are used in quantities such that the equivalent ratio of isocyanate to hydroxyl and/or epoxide groups is from 1.1:1 to 6.1. The chain extender is used in a quantity such that the amount of water is at least equivalent to the excess of isocyanate. These moldings may be made by a one-shot or a two-shot process. These moldings are characterized by better mechanical properties such as tensile strength and elongation than prior art moldings.

Process for the production of non-foamed moldings

The instant invention is directed to a process for the solvent-free production of solid polyurethane moldings wherein the polyisocyanate used is a polyisocyanate mixture containing from 10 to 80% by weight of 2,4'-diisocyanatodiphenylmethane.

Process for the solvent-free production of solid plastic moldings

A shaped polyurethane product having improved arc-resistance, current leakage properties and dimensional stability which adapt it to be used as an electrical insulator is made by shaping a reactive mixture containing

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Neuss, Germany

Fritz Ehrhard