| 摘要 |
Particulate epoxy resin compositions comprise particles containing a solid polyfunctional epoxy resin having more than two epoxy groups per molecules and a melting-point of 130 DEG to 340 DEG F. in intimate mixture with filler particles, at least a portion of the filler particles being individually coated with a surface film of a curing agent to furnish a substantial surface area of curing agent for reaction with the resin at moulding temperatures, substantially all of the curing agent of the composition being carried on filler particles, the curing agent having a melting-point of 120 DEG to 340 DEG F. The epoxy resins specified are polyglycidyl ethers of polyhydric phenols such as novolak resins. Curing agents specified are m-phenylenediamine, p - phenylenediamine, p,p1 - methylenedianiline and 4,41 - methylenebis - (2 - chloroaniline) and mixtures thereof. Fillers specified are silica, slate, hydrated alumina, alumina, mica, calcium carbonate and aluminium powder. The compositions may also contain accelerators such as polyhydric phenols, pigments and release agents. The epoxy resin may be coated on a part of the filler. The compositions are used as moulding powders and may be in the form of preforms or tablets.ALSO:Powdered inorganic fillers are coated with epoxy resin curing agents such as solid amines and epoxy resin-amine adducts by mixing the filler with the molten curing agent in a mixer or mixing the filler with a solution of the curing agent and flashing off the solvent. The cake or agglomerate of coated particles is then pulverized. Powdered inorganic fillers are coated with epoxy resins in a similar manner. Fillers specified include silica, alumina, hydrated alumina, mica, calcium carbonate and talc.ALSO:Powdered inorganic fillers are coated with epoxy resin curing agents such as solid amines and epoxy resin amine adducts by mixing the filler with the molten curing agent in a mixer or mixing the filler with a solution of the curing agent and flashing off the solvent. The cake or agglomerate of coated particles is then pulverized. Powdered inorganic fillers are coated with epoxy resins in a similar manner. Fillers specified include slate and aluminium. |
