Copolymer tackifying resins containing dicyclopentadine, vinyl aromatic hydrocarbon and a substituted benzene (halogen, lower alkyl, or hydroxyl) and adhesives containing these resins

Adhesive composition, essentially consisting of a tackifying resin, an adhesive base selected from the group consisting of ethylene vinyl-acetate copolymers, natural and synthetic rubbers, as well as optionally a wax or paraffin, in which the tackifying resin is a copolymer consisting essentially of dicyclopentadiene, a vinylaromatic hydrocarbon, a mono-, di- or tri-substituted benzene in which the substituents are chosen among lower alkyl, hydroxyl and halogen, and optionally a pentadiene and a C.sub.1 -C.sub.12 alkyl ester of an unsaturated carboxylic acid, in relative molar ratios of 0.7-1.5 moles of vinylaromatic compound per mole of dicyclopentadiene and 0.01-1.0 mole of substituted benzene per mole of dicyclopentadiene and 0-3 moles of pentadiene and 0-025 moles of C.sub.1 -C.sub.12 alkyl ester of unsaturated carboxylic acid per mole of dicyclopentadiene.