| abstract |
A modified phenolic resin which is an alternating copolymer of a phenol compound and a compound having a divalent connecting group and has a specific structure in which a side chain of an aromatic ring having a hydroxy group has been substituted by a group represented by the general formula (1-1). Using the modified phenolic resin as a hardener for epoxy resins gives an epoxy resin, a composition thereof, and a cured object which are excellent in adhesion and flame retardancy while retaining intact material properties inherent in conventional phenolic resins, such as gel time, glass transition temperature, moisture absorption, and mechanical properties. (1-1) (In the formula, R1 represents a C1-8 linear, branched, or cyclic hydrocarbon group.) The modified phenolic resin is useful as a hardener for epoxy resins for semiconductor encapsulation. The epoxy resin composition has excellent adhesion and high flame retardancy when used in applications such as insulation materials for electrical/electronic parts and laminates (printed wiring boards). Also provided are: a prepreg comprising this epoxy resin composition and a glass base impregnated therewith; a laminate; and an electronic-circuit substrate. |