GB819809A - Improvements in and relating to epoxy resin compositions - Google Patents

Abstract

A moulding composition comprising (i) 75-20 per cent by weight of a thermosetting epihalohydrin-polyhydric compound polymer, (ii) a catalyst therefore, and (iii) at least 20 per cent by weight of a mass of unwoven continuous length metallic filaments having a diameter of 0.0005-0.025 inch is compressed and cured under pressure. (i) May be derived from epichloro- or epibromo-hydrin and diethylene glycol, 2,2 - bis - (p - hydroxyphenyl) - propane, resorcinol or a partially condensed phenolformaldehyde resin: a liquid, cold setting resin is preferred, in which case excess resin may be allowed to escape from the composition during compression. (ii) May be alkaline reacting metal oxides, polyhydric alcohols, ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, polycarboxylic acids, or the intermediate condensation product of a polyfunctional amine with an epihalohydrin polymer, e.g. of diethylene triamine with an epichlorhydrin-"bis-phenol A." (iii) May be wools derived from steel, Cu, Ag, Al, Fe, Pb or their alloys, or steel wool coated with Cu or Ag, or glass or synthetic resins or fibres coated or plated with metals. Optional ingredients include metal powders, metal plated powders, glass fabric, asbestos, fabric, chopped fabric, paper, glass fibres, Al2O3, SiO2, clays (kaolin, bentonite or "Bentone" (Registered Trade Mark)) and mica. In a preferred embodiment the metallic filaments are disposed in parallel planar relationship in layers, the longitudinal axis of the filaments in adjacent layers being neither parallel nor perpendicular to each other. In Example (3) a mixture of filaments is used, one-third being steel wool, one-third steel wool coated with Ag and one-third steel wool coated with Cu. Uses.-Tools and dies for metal and plastic moulding and forming electrodes.ALSO:In a process of making tools and dies for metal and plastic moulding and forming, the exothermic heat of reaction of a thermosetting epihalohydrin-polyhydric compound polymer is dissipated throughout the mass of the polymer by the inclusion in the mould of at least 20 per cent. by weight of a mass of unwoven continuous length metallic filaments having a diameter of 0,0005-0,025 inch. 75-20 per cent. of the moulding composition is a conventional epoxy resin, the remainder consisting of a conventional hardening catalyst therefor, and optionally, conventional fillers such as metal powders, metal plated powders, glass fabric, asbestos, fabric, chopped fabric, paper, glass fibres, Al2O3, SiO2, clays (kaolin, bentonite or Bentone (Registered Trade Mark) and mica. The metallic filaments may be wools derived from steel, Cn, Ac, Al, Fe, Pb, or their alloys, or steel wool coated with Cn or Ag, or glass or synthetic resins or fibres coated or plated with metals. In a preferred embodiment the metallic filaments are disposed in parallel planar relationship in layers, the longitudinal axis of the filaments in adjacent layers being neither parallel nor perpendicular to each other.