| 摘要 |
PURPOSE:To obtain the title composition prevented from causing the precipitation of a filler and improved in infiltrability into windings by mixing an epoxy resin with an acid anhydride, a cure accelerator, a flame retardant and a specified filler. CONSTITUTION:An epoxy resin (a) (e.g., bisphenol A epoxy resin) is mixed with 0.6-1.3 equivalents, per equivalent of the epoxy groups of component (a), of an acid anhydride (b) (e.g., methyltetrahydrophthalic anhydride), 0.1-5.0 pts.wt., per 100 pts.wt. component (b), cure accelerator (c) (e.g., 2-ethyl-4- methylimidazole), a flame retardant (d) desirably a mixture of 10-50 pts.wt., per 100 pts.wt. component (a), halogenated organic compound with 3-15 pts.wt. Sb2O3 and a filler (e) which is a mixture of a silica (i) having a particle diameter distribution of a mean particle diameter of 10-15mum and a cumulative weight of particles <=3mum of less than 15wt.% with a hydrated alumina (ii) having a particle diameter distribution of a mean particle diameter of 6-12mum and a cumulative weight of particles <3mum of less than 12wt.% in an amount to give a component (ii) to component (i) ratio of (40-80)/(60-20)wt.%. |
