Ciba-geigy Corporation

Imre Forgo

Jacques Francois

Alfred Renner

Andre Schmitter

Rene Huwyler

Theobald Haug

Abdul-Cader Zahir

Bruno Schreiber

Urs Gruber

Elvio Manso

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

Storage stable curing agents for acrylate adhesives, which curing agents are miscible with an acrylate resin adhesive, are produced by the mixing together of a polymerizable monomer, a thermoplast or elastomer soluble therein, and a liquid aldehyde/amine condensation product, and subsequent homogenisation of the mixture at elevated temperature. The curing agents, which optionally contain also stabilizers and curing accelerators, can be mixed with acrylate resin adhesives in any chosen quantity ratio between 2:1 and 1:2.

Process for producing a storage-stable, miscible curing agent for

The adhesive or adhesive component according to the invention, which contains a vinyl monomer, a vinyl polymer, a compound producing free radicals, and, as an adhesion promoter, an acid amide or imide which is substituted on the nitrogen atom by a chlorosulfonated alkyl, aryl or aralkyl group, forms, together with an amine accelerator, an adhesive with which heat-, oil- and water-resistant bonds, for example of metals, polymeric materials, glass and ceramics, having very high tensile shearing strength can be obtained. The adhesive can also be converted into the form of a dried sheet, with or without carrier, and in this form can be used for bonding.

Adhesive or adhesive component containing chlorosulfonated amide or imide

According to the invention, polyaddition products containing imide groups are manufactured by reacting certain polyimides (preferably maleimides) with polycarboxylic acids in the presence of basic compounds. The preferred embodiment (C) relates to the use of catalysts as basic compounds. In particular, tertiary amines, secondary amines or mixed tertiary-secondary amines can be used. A further embodiment (D) relates to the use of primary polyamines as basic compounds. In the latter case, the polyamine participates in the polyaddition mechanism, that is to say the molecules are incorporated into the polyaddition products. In this latter case, catalysts can also be used additionally. The invention can be utilized particularly in the fields of surface protection, the electrical industry, laminating processes, and the manufacture of foamed plastics, and in the building industry.

Process for the manufacture of polyaddition products containing imide

According to the invention, polyaddition products containing imide groups are manufactured by reacting certain polyimides (preferably maleimides) with polyhydric phenols in the presence of basic compounds. The preferred embodiment (A) relates to the use of catalysts as basic compounds. In particular, tertiary, secondary or mixed tertiary-secondary amines can be used. A further embodiment (B) relates to the use of primary polyamines as basic compounds. In the latter case, the polyamine participates in the polyaddition mechanism, that is to say the molecules are incorporated into the polyaddition products. In this latter case, catalysts can also be used additionally. The invention can be utilized particularly in the fields of surface protection, the electrical industry, laminating processes and the manufacture of foamed plastics, and in the building industry.

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Birsfelden, Switzerland

Imre Forgo