Petroleum resins generally have a softening point of 80-140°C, a relative density of 0.970-0.975, and a relative molecular mass of less than 2×10³. They are insoluble in water but readily soluble in organic solvents. They exhibit low acidity, excellent adhesion, water and chemical resistance, and adjustable viscosity and excellent thermal stability. Therefore, petroleum resins can effectively replace rosin and terpene resins as tackifiers for hot-melt adhesives and pressure-sensitive adhesives, improving wettability and adhesion. The emergence of petroleum resins also addresses the limited availability of natural rosin and terpene resins, their poor thermal stability, high cost, and susceptibility to aging. Furthermore, a 60% by weight fraction of petroleum resin can achieve the same performance as rosin-modified hot-melt adhesives.