Curable resin, curable resin composition, cured product, prepreg, laminate, and semiconductor substrate

A curable resin represented by the following formula (1):

• in formula (1), A represents any one of the following formulas (1-a), (1-c), and (1-d),
• each of the multiple Xs independently represents any one of the following formulas (1-e) to (1-g),
• each of the multiple R1s independently represents a residue obtained by removing one hydrogen atom from a C9 petroleum resin,
• each of the multiple R2 independently represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group, or a hydroxy group,
• each of the multiple s and t independently represents an integer of 0 to 3, and the sum of s and t is an integer of 0 to 3, s being the number of R1s bonded to the same aromatic ring, t being the number of R2 bonded to the same aromatic ring,
• the average value save of s is 0<save≤3, and the average value tave of t is 0≤tave≤2,
• n is the number of repetitions, and the average value nave of n is 0.1≤nave≤5,
• in formulas (1-a) to (1-d), each of the multiple R3s independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms,
• the wavy line represents a bonding site to the aromatic ring in formula (1),
• in formulas (1-e) to (1-g), the wavy lines represent the bonding sites to the oxygen atom in formula (1).