| abstract |
A phenol novolak resin having an excellent balance between the mold shrinkage of a composition containing the phenol novolak resin during heat curing and the modulus of elasticity at high temperature. A phenol novolak resin that is an alkyl phenol novolak resin produced by bonding alkyl phenol (I), in which an alkyl group having a carbon number of 4 to 8 is included as a substituent on an aromatic ring, to each other with a methylene group interposed therebetween, wherein the ratio (a)/(b) of a value (a) of integration from 146 to 148 ppm to a value (b) of integration from 146 to 153 ppm based on the 13C-NMR measurement is within the range of 0.05 to 0.30, and the area ratio of alkyl phenol (I) based on GPC measurement is within the range of 0.01% to 3.0%, a curable resin composition using the same, and a cured product thereof. |