Copolymer and laminate containing same

A composition in a varnish form, the composition comprising:

• an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying the following conditions (1) to (4);
• and
• a solvent:
• (1) a number average molecular weight of the copolymer is 5000 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 10 mass % or more and less than 60 mass %;
• (3) the aromatic polyene is one or more selected from polyenes having 5 or more and 20 or less carbon atoms, having a plurality of vinyl groups and/or vinylene groups in the molecule, and a content of the vinyl groups and/or vinylene groups derived from a unit of the aromatic polyene is 3.5 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, being ethylene alone, or having a mass ratio of 60 -olefin monomer components other than ethylene to an ethylene monomer component contained in the olefin, of 1/10 or less, and the total of units of the olefin monomer, the aromatic vinyl compound monomer, and the aromatic polyene monomer is 100 mass %.