| 摘要 |
PROBLEM TO BE SOLVED: To provide a curable resin composition which has high dielectric characteristic necessary for an electrical insulation material corresponding to high frequency, furnishes a hardened material excellent in low water absorption rate and low linear expansion coefficient and is excellent in wiring embedding flatness and resin fluidity.SOLUTION: There is provided an aromatic polyester having the repeated structural units represented by formulas (a') and (b') (in the formulas, Zand Zare each independently a divalent aromatic group; and Y is an ether or ketone group), and univalent aromatic group as a terminal structural unit. The molar fractions of the structural units (a'), (b') and the terminal structural unit are 15-94%, 1-35% and 5-60%, respectively. The sum of a hydroxy equivalent value and a carboxyl equivalent value is 1,000 (g/eq) or more, and an impurity amount derived from a catalyst is 1.0 wt.% or less.SELECTED DRAWING: None |
