| 摘要 |
PROBLEM TO BE SOLVED: To provide an active ester resin which gives a cured product being excellent in heat resistance, exhibiting little change in heat resistance after a thermal history, and having a low dielectric constant and a low dielectric loss tangent.SOLUTION: The active ester resin contains a trifunctional compound (x) represented by the structural formula (1) [wherein Rand Reach independently represent a hydrogen atom, a C1-C4 alkyl group, or a C1-C4 alkoxy group, and Z's are each an ester forming structure moiety (z1) or a hydrogen atom (z2)]. At least one of Z's contained in the trifunctional compound (x) is the ester forming structure moiety (z1). |
