| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing material which has higher flowability and can prevent the peeling caused by a thermal stress and the cracking of a sealing material layer, by using a liquid epoxy resin, a curing agent, an inorganic filler comprising a spherical amorphous silica having a specified mean particle diameter, and a coupling agent as the constituents. SOLUTION: The sealing material contains (A) a liquid epoxy resin comprising, e.g. a bisphenol A epoxy resin, (B) a curing agent selected from an acid anhydride based, an arnine based and a dicyandiamide based curing agents, in an amount sufficient to provide an equivalent ratio of component B to component A of (0.7 to 1,2):1, (C) an inorganic filler comprising a spherical amorphous silica, in an amount of 65-95 wt.%, and (D) a coupling agent such as a silane coupling agent or a titanate coupling agent, in an amount of 0.05-3 wt.% based on component C. If necessary, a cure accelerator, a surface active agent, a leveling agent, a defoaming agent, a coloring agent and the like are blended with the sealing material. The component C comprises silica particles having a mean diameter of 8-65 nm and a spectfic surface of 45-300 m2/g and containing those with a mean diameter of 0.5-30 nm in an amount sufficient to provide a weight ratio of these particles to the whole silica particles of (0.01 to 0.5):1.
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