| abstract |
This cured product is configured to exhibit both excellent heat resistance and excellent flame retardancy, while having low dielectric constant and low dielectric loss tangent. A phosphorus atom-containing compound (i), which is obtained by reacting (a1) an aromatic aldehyde that has an alkoxy group as a substituent on the aromatic nucleus with (a2) an organic phosphorus compound that has a P-H group or a P-OH group in a molecular structure, is reacted with (a3) a phenol substance, thereby obtaining (A1) a phosphorus atom-containing phenol substance; and then the thus-obtained phosphorus atom-containing phenol substance (A1) is reacted with (A2) an aromatic dicarboxylic acid, an acid anhydride thereof or a dihalide of an aromatic dicarboxylic acid, or a saturated dicarboxylic acid having 2-6 carbon atoms, an acid anhydride thereof or a dihalide of a saturated dicarboxylic acid having 2-6 carbon atoms so that some or all of the hydroxyl groups of the phenol substance (A1) form ester bonds. |