Modified hydrocarbon resin and hot melt adhesive composition

A modified hydrocarbon resin obtained by hydrogenating a hydrocarbon resin comprising:

• a 1,3-pentadiene monomeric unit of 20 mass % to 70 mass %,
• a C4_6 alicyclic monoolefin monomeric unit of 10 mass % to 35 mass %,
• a C4_8 acyclic monoolefin monomeric unit of 5 mass % to 30 mass %,
• an alicyclic diolefin monomeric unit of 0 mass % to 1 mass %, and
• an aromatic monoolefin monomeric unit of 0 mass % to 40 mass %,
• the modified hydrocarbon resin being characterized in that:
• a degree of hydrogenation of the olefins is within a range of 30% to 80%;
• a degree of hydrogenation of the aromatic rings, if an aromatic monomeric unit is included, is within a range of 5% to 20%;
• a weight average molecular weight (Mw) is within a range of 1,000 to 4,000;
• a Z-average molecular weight (Mz) is within a range of 2,500 to 10,000;
• a ratio (Mz/Mw) of the Z-average molecular weight to the weight-average molecular weight is within a range of 1.5 to 2.5;
• a Gardner color scale of a toluene solution of 50 mass % is 2 or lower;
• and
• a difference between pre-hydrogenation and post-hydrogenation mixed aniline point (MMAP) is 5° C. or less.