Microcrystalline wax is a petroleum refinery byproduct acquired when petrolatum or petroleum jelly is de-oiled. The product differs from other petroleum wax byproducts in that it contains a high level of branched or isoparaffinic hydrocarbons. This gives the wax a finer crystal structure than paraffin wax, for example, in addition to being tackier, darker, and melting at higher temperatures. Microcrystalline wax also possesses good elastic and adhesive qualities due to its slimmer crystal structure. The wax is used in a broad range of applications which include cosmetics, rubber compounds, candles, and metal casting.
During the refinement of lubricant oils, heavy distillates such as petrolatum are produced which are further refined to make products such as microcrystalline wax. In the case of wax production, the petrolatum, or petroleum jelly as it is more commonly known, is typically sent off-site to specialized wax refineries for further processing. Here the petrolatum undergoes a de-oiling process to make microcrystalline wax. At this point, further hydroprocessing may be considered to remove the natural odors and color from the wax. The end product is a wax of fine crystalline structure with outstanding flexibility, viscosity, temperature resistance, and adhesive qualities.
There are two common grades of the wax: laminating and hardening. Laminating grade microcrystalline wax is the softer of the two with a melting point of 140°-175°F (60°–80°C). Hardening grade wax melts at 175°– 200°F (80°–93°C) with a needle penetration rating of 25 or below in contrast to the 25 and above of the laminating grade. The clarity and color of the wax may range from a dark brown or straw color to white depending on the extent of the refinement process. The higher melting point of the hard wax makes it ideal for metal casting processes particularly in the manufacture of jewelry.
The wax is widely used in sports such as snowboarding and ice hockey where it is used as a board or puck wax and as a friction tape preservative. Its excellent lubricant qualities also make it an ideal additive for applications in the printing industry where it is used as a slip agent in printing inks. The cosmetics industry is also a regular microcrystalline wax consumer with many products featuring it as a formulation additive. It is also regularly used in its parent industry as a conditioner for several other petroleum products.
Ironically one of these is the petroleum jelly it is refined from; in this application, it is used to adjust the consistency and congealing characteristics of the petrolatum. The wax is also used extensively in the production of candles and rubber compounds, particularly those used in the tire manufacture industry. Microcrystalline wax is also a feasible byproduct of “green” hybrid petroleum refinement which should ensure the long-term prospects for this useful product.