Ciba-geigy Corporation

Hermann Diethelm

Bruno Schreiber

Jurgen Habermeier

Abdul-Cader Zahir

Sheik A Zahir

Ewald Forster

Peter Ruf

Wolfgang Dresen

Willi Zummerli

Cured foams with a high degree of closed cellular structure, good stability under prolonged heat exposure and good compressive strength can be produced from a hot-foamable, thermosetting epoxy resin mixture containing (a) an epoxy resin or a mixture of epoxy resins with an average epoxide content of 4.4 to 5.0 equivalents/kg and an average epoxide functionality of more than 2.0, (b) a novolak with a hydroxyl equivalent weight of 90 to 120, 0.8 to 0.95 hydroxyl equivalents of component (b) being present in the epoxy resin mixture per 1 epoxide equivalent of component (a), (c) 1.0 to 1% by weight, based on the amount of components (a) and (b), of a curing accelerator, (d) 0.5 to 10% by weight, based on the amount of components (a) and (b), of a blowing agent which splits off nitrogen above 100.degree. C. with decomposition, (e) 0.3 to 1% by weight, based on the total amount of the epoxy resin mixture, of an emulsifier, and if appropriate (f) foam modifiers.

Hot-foamable, thermosetting epoxy resin mixture

Molded bodies of thermoset material are produced from monomers, oligomers or higher pre-polymers of reactive resins by pressure reaction injection molding. The molded bodies may contain filler and/or reinforcing material. The process is carried out in a mold consisting of a first, preferably upper half mold and a second, preferably lower half mold, and an inlet socket opening downwardly into the first half mold. The mold is equipped with heating coils adapted for applying separately a lower temperature to the first half mold and a higher temperature to the second one. During the introduction and hardening phase of the reactive mixture, the first half mold is maintained at a lower temperature than the second half mold, the temperature difference amounts to about 40 to 180, and preferably 60 to 120 centigrades.

Pressure reaction injection molding process for making molded bodies of

A mixture consisting of a polymaleimide and a copolymerizable monomer or a prepolymer formed from these two compounds contains, as the polymerization catalyst, an ethane which is substituted by aromatic groups and hydroxyl groups or halogen (cf. formula II), such as benzpinacol. The mixture is stable on storage and heat-curable. It can be cured, while at the same time being shaped to give mouldings, sheet-like structures, laminates, adhesive bonds or foams, for example by casting or compression moulding.

Heat-curable mixtures, stable on storage, based on polyimides and

Aminoplast or phenoplast moulding compositions are manufactured by passing an aqueous solution of a urea-formaldehyde resin, of an optionally phenol-modified melamine-formaldehyde resin or of a phenol-formaldehyde resin into a fluidized bed drier, by spraying the resin onto fillers and drying it. The compositions are used for crockery, household articles and technical components for the electrical industry.

Process for the manufacture of aminoplast and phenoplast moulding

Storage-stable epoxide moulding compositions containing solid pre-adducts of triglycidyl isocyanurate and amine curing agents, fillers and release agents. After curing, these compositions form tracking-resistant plastics of high heat distortion point.

Storage-stable epoxide moulding compositions

Storage-Stable moulding compositions which contain solid adducts, containing epoxide groups, of triglycidyl-bis-hydantoins or triglycidyl-bis-dihydrouracils and organic compounds possessing several active hydrogen atoms, solid adducts, containing amino groups, of cycloaliphatic, heterocyclic or aromatic polyamines as curing agents, and fillers. The moulding compositions are used for the manufacture of light-stable and tracking-resistant plastics.

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Aesch, Switzerland

Hermann Diethelm