Composition for formation of cured epoxy resin, and cured products thereof

A composition for the formation of a cured epoxy resin, the composition comprising the following components (A), (B), and (C):

• (A) an epoxy resin;
• (B) a clathrate compound of:
• 5-hydroxyisophthalic acid or 5-nitroisophthalic acid;
• and
• an imidazole compound selected from the group consisting of 2-ethyl-4-methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-undecylimidazole;
• 2-phenyl-4-methyl-5-hydroxyethylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole;
• and
• (C) a tetrakisphenol compound represented by formula (III):
• wherein:
• X represents (CH2)n1 or a p-phenylene group,
• n1 represents any integer of 0 to 3, and
• R5 to R12 each represents a hydrogen atom, a C1 to C6 alkyl group, an optionally substituted phenyl group, a halogen atom, or a C1 to C6 alkoxy group,
• wherein the composition comprises 0.01 to 1.0 mol of the imidazole compound in the component (B) with respect to 1 mol of an epoxy ring, and
• the amount of the tetrakisphenol compound is 1% by mol to 50% by mol with respect to an amount of 5-hydroxyisophthalic acid or 5-nitroisophthalic acid in the component (B).