Hydrocarbon Resins

AbstractHydrocarbon resins are low molecular weight thermoplastic polymers synthesized via the polymerization of coal‐tar fractions, cracked petroleum distillates, terpenes, or pure olefinic monomers. In general, these polymers may be categorized as coumarone–indene, petroleum, or polyterpene resins. Coumarone–indene resins are synthesized from aromatic monomers obtained from the coking of coal. Petroleum distillates, such as piperylenes and styrene, are obtained from the vapor‐phase cracking of light to heavy petroleum naphthas and are used for the production of petroleum resins. Petroleum resins may be grouped into C‐5 aliphatic, C‐5–C‐9 aromatic modified aliphatic, cycloaliphatic diene (dicyclopentadiene), and C‐9 aromatic resins. Polyterpenes are produced from monoterpenic monomers such as limonene and β‐pinene, which are obtained from the citrus and wood industries, respectively. Most coumarone–indene, petroleum, and polyterpene resins are produced by carbocationic polymerization using Lewis acid catalysis. Cycloaliphatic diene‐based resins are typically produced via thermal polymerization techniques. The hydrogenation of hydrocarbon resins is typically accomplished using supported monometallic and bimetallic catalyst systems based on the Group VI and VIII transition elements. Uses and applications for hydrocarbon resins include adhesives, sealants, inks, paints, varnishes, plastics, and oil field applications. They are rarely used alone.