Petroleum resin is a kind of thermoplastic resin, which is a mixture of polymer molecules with different molecular weights of the ethyl fraction, and it is not a hazardous material. The melt viscosity of petroleum resin mainly affects the wetting ability of hot melt adhesive and pressure sensitive adhesive, if the melt viscosity is too high, the wetting degree of hot melt adhesive and pressure sensitive adhesive will be reduced, and the adhesion of hot melt adhesive and the coating of pressure sensitive adhesive will become difficult, and if the melt viscosity is too low, on the one hand, the filler in the hot melt adhesive system will be caused by the settling of filler, resulting in uneven distribution of the material components, and on the other hand, it will be unfavorable for the adhesion of hot melt adhesive due to the reduction of cohesive strength.

Classification of petroleum resin
(1) Petroleum resin can be generally categorized as C5aliphatic (aliphatic), C9aromatic (aromatic hydrocarbons), DCPD (cycloaliphatic dienophthalates) and pure monomers, etc., and its constituent molecules are all hydrocarbons, so it is also called hydrocarbon resin.
(2) Petroleum resins are divided into aliphatic resins (C5), alicyclic resins (DCPD), aromatic resins (C9), aliphatic/aromatic copolymerized resins (C5/C9) and hydrogenated petroleum resins, C5 hydrogenated petroleum resins, C9 hydrogenated petroleum resins, according to the different raw materials.
Main applications of petroleum resins
(1) Paint
Paint mainly use high softening point of C9 petroleum resin, DCPD resin, C5/C9 copolymerization resin, paint to add petroleum resin can increase paint gloss, improve film adhesion, hardness, acid resistance, alkali resistance.
(2) Rubber
Rubber mainly uses low softening point of C5 petroleum resin, C5/C9 copolymerization resin and DCPD resin. Such resins and natural rubber pellets have good mutual solubility, the rubber vulcanization process does not have a major impact on the rubber, rubber in the addition of petroleum resins can play a viscosity, reinforcing, softening effect. In particular, the addition of C5/C9 copolymer resin can not only increase the adhesion between the rubber grains, but also improve the adhesion between the rubber grains and the cord, for radial tires and other high demand for rubber products.
(3) Adhesives
Petroleum resin has excellent adhesive properties. Adding petroleum resin to adhesives and pressure-sensitive tapes improves adhesive strength, acid resistance, alkali resistance, and water resistance, and effectively reduces production costs.
(4) Ink
Petroleum resins for inks are mainly high softening point C9 petroleum resins and DCPD resins. The addition of petroleum resin to ink can play a role in color spreading, fast drying, brightening effect, and improve printing performance.
(5) Asphalt
Road marking and road delineation with paint, petroleum resin on concrete or asphalt pavement has good adhesion, and wear resistance and water resistance, and inorganic substances have a good affinity, easy to coat, weathering, fast drying, high degree of solidity, and can improve the physical and chemical properties of the layer, to improve the resistance to ultraviolet light and weathering.