Ciba-geigy Corporation

Rene Huwyler

Imre Forgo

Andreas Kramer

Urs Gruber

Jacques Francois

Rudolf Brunner

Elvio Manso

Hardenable compositions comprising bismaleimides, alkenylphenols and

Prepregs which are tacky to dry to the touch can be prepared by impregnating a solid reinforcing material with a liquid, solvent-free composition containing (a) an epoxide resin, (b) a photopolymerizable compound, (c) a heat-activatable curing agent for the epoxide resin (a) and, if appropriate, a photopolymerization catalyst for the photopolymerizable compound (b), and the composition is exposed to actinic radiation. The composition solidifies thereby to give an essentially solid layer as the result of photopolymerization of the photopolymerizable compound, whereas the epoxide resin remains substantially in a heat-curable state. In accordance with the invention, a substituted or unsubstituted aliphatic, cycloaliphatic or araliphatic amine is used as the heat-activatable curing agent (c), and the photopolymerizable compound (b) is employed in such a ratio to the heat-curable component (a) that, after irradiation with actinic light, the composition can still be shaped by thermoplastic methods. The prepregs thus obtained are suitable for the production of reinforced composite materials, such as skis, tennis rackets or car body components by hot-curing.

Process for the preparation of prepregs, and the reinforced composite

Heat-curable adhesive films of variable tack can be prepared:

Process for the preparation of heat-curable adhesive films

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Aesch, Switzerland

Rene Huwyler