Composition and cured product thereof

Abstract

A composition comprises: a resin component including an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying all the following conditions (1) to (4): (1) a number average molecular weight of the copolymer is 500 or more and 100000 or less; (2) the aromatic vinyl compound monomer is an aromatic vinyl compound having 8 or more and 20 or less carbon atoms, and a content of a unit of the aromatic vinyl compound monomer is 0 mass % or more and 70 mass % or less; (3) the aromatic polyene is one or more selected from polyenes having 5 or more and 20 or less carbon atoms and having a plurality of vinyl groups and/or vinylene groups in the molecule, and a content of the vinyl groups and/or the vinylene groups derived from the unit of the aromatic polyene is 1.5 pieces or more and less than 20 pieces per number average molecular weight; and (4) the olefin is one or more selected from olefins having 2 or more and 20 or less carbon atoms, and a total of units of the olefin monomer, the aromatic vinyl compound monomer, and the aromatic polyene monomer is 100 mass %; and a surface-treated silica. The volume ratio between the resin component and the silica is in the range of 98 to 15:2 to 85. A cured product of the composition has a value of the dielectric tangent obtained by resonator method at a measurement frequency of 10 GHz and/or a measurement frequency range of 25 GHz to 40 GHz of 1.2×10or less and a storage elastic modulus at 250° C. in the range of 10 MPa or more and 10 GPa or less.