Novolak resin, epoxy resin, photosensitive resin composition, curable resin composition, cured substance, electronic device, production method for novolak resin, and production method for epoxy resin

A production method for a novolak resin, comprising reacting an aromatic compound with fluoral in a presence of an acid catalyst to produce a novolak resin having a partial structure represented by —C(CF3)H—, and wherein the novolak resin has a structural unit represented by General Formula (1),

• in General Formula (1),
• R1 represents a hydrogen atom or a monovalent organic group, and in a case where a plurality of R1's are present, the plurality of R1's may be the same or different from each other,
• R2 represents a monovalent substituent, and in a case where a plurality of R2's are present, the plurality of R2's are may be the same or different from each other,
• n is 0 to 2, and
• p is 1 or more, and q is 0 or more, provided that in a case where n is 0, p+q≤4 is satisfied, in a case where n is 1, p+q≤6 is satisfied, and in a case where n is 2, p+q≤8 is satisfied, and
• wherein the novolak resin has at least one structural unit selected from the group consisting of General Formulae (8), (10), and (11),
• in General Formulae (8), (10), (11),
• R1 represents a hydrogen atom or a monovalent organic group, and in a case where a plurality of R1's are present, the plurality of R1's may be the same or different from each other,
• R2 represents a monovalent substituent, and in a case where a plurality of R2's are present, the plurality of R2's may be the same or different from each other,
• l and m are each independently 0 to 3,
• R3 represents a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, these groups may be further substituted with a fluorine atom, and R3 may be linked to form a cyclic group having 3 to 10 carbon atoms, the cyclic group being saturated or unsaturated, and monocyclic or polycyclic, and in a case where a plurality of R3's are present, the plurality of R3's may be the same or different from each other.