Resin composition, resin sheet, resin cured product, and resin substrate

A resin composition comprising:

• an epoxy compound;
• a first triphenylbenzene compound represented by the following expression (1);
• and
• a second triphenylbenzene compound represented by the following expression (2),
• where R1 to R15 are each independently selected from the group consisting of a hydrogen group (—H) and a hydroxyl group (—OH) so long as two or more of R1 to R15 are hydroxyl groups,
• where R21 to R35 are each independently selected from the group consisting of a hydrogen group, a hydroxyl group, and an alkoxy group so long as at least one of R21 to R35 is a hydroxyl group, and at least one of R21 to R35 is an alkoxy group,
• wherein a ratio M (mol %) expressed by the following mathematical expression (A) is in a range of from 0.2 mol % to 16.3 mol %,
• M(mol %)=(M1/M2)×100 (A)
• where:
• M1 is the number of moles (mol) of the alkoxy group contained in the second triphenylbenzene compound, and
• M2 is a sum of the number of moles (mol) of the hydroxyl group contained in the first triphenylbenzene compound, the number of moles (mol) of the hydroxyl group contained in the second triphenylbenzene compound, and the number of moles (mol) of the alkoxy group contained in the second triphenylbenzene compound.