Th. Goldschmidt Ag

Wilhelm Ahrens

Jurgen Fock

Ulrich Holtschmidt

Dietmar Schedlitzki

The invention relates to a hardenable adhesive, which contains as effective components at least one polyol and one polyisocyanate and/or their prepolymers as well as additionally conventional additives, such as, accelerators, gluing auxiliaries, pigments and/or fillers. It is characteristic of the inventive adhesive that it contains, as a polyol, the reaction product of a novolak of average molecular weight from 300 to 1200 with an oxirane of the general formula ##STR1## in which R.sup.1 is hydrogen, or an optionally halogenated hydrocarbon group with 1 to 4 carbon atoms or the --CH.sub.2 OR.sup.2 group, in which R.sup.2 represents an alkyl or an alkenyl group, the R.sup.1 group within the polymeric molecule being the same or different, there being added, on the average, 1 to 7 moles of the oxirane per hydroxyl group of the novolak, and the polyol and the polyisocyanate being present in such a ratio that 0.95 to 1.25 isocyanate groups of the polyisocyanate correspond to one hydroxyl group of the polyol. The inventive adhesives are liquid, adhere well to plastic surfaces and have a high peel strength. They are resistant to the effects of water and moisture.

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Essen, Germany

Wilhelm Ahrens