The Microcrystalline Waxes are produced usually from distillate residues and are of following two types based on the melting point
Flexible Microcrystalline Wax : Low molecular weight, low melting point wax produced from heavy Petroleum residues of either Paraffinic or mixed base crude oils and also by refining bright slack waxes from the propane deasphalted (PDA) stocks. They can be further classified into two groups viz. Food Grade & Non-food Grade based on UV absorption test.
Hard Microcrystalline Wax : High molecular weight, high melting point wax is produced from crude oil tank bottom or fractionation of residual Microcrystalline Waxes.
Several blends with intermediate properties are also possible and marketed.
They differ from refined P. Waxes in size and structure of crystals due to difference in molecular weight. MCWs are more tougher, flexible and have high melting point & tensile strength. They are more adhesive and less lustrous and greasy. The binding properties are much better to P. Waxes thereby preventing the sweating out of the liquid.
Rubber Industry : as an additive to provide softness, lustre and weathering protective for household & industrial rubber goods.
Tyre Industry : as an ingredient of rubber compounding in tyre industry to provide protection against action of light, oxygen & ozone.
Petroleum Jelly : The unique property of MCW to bind oil with other liquids is used for manufacture of jellies required for industrial, pharmaceutical and jelly filled telecommunication cable applications. Industrial jellies are used for coating on machines, tools etc to act as a barrier against corrosion. Jellies of pharmaceutical grade are used in production of ointments and cosmetic creams.
PVC Extrusion : as external lubricants in extrusion of PVC resins.
Hot-melt Adhesives : are used in packaging, tapes, disposables, footwear.
Other uses : Wax solutions are used in the calibration of lab glassware, polishes. It is also used in cosmetics and textile finishing.
|Melting Point °C||75 – 85|
|Congealing Point °C||70 – 75|
|Needle Penetration (max) at 25°C, 1/10 mm.||25 – 35|
|Oil Content (max) % by mass||3|
|Saponification value (max)||Nil|
|Acidity (max) mg. KOH per gm.||Nil|
|Viscosity at 90°C, in cps||10 – 20|
|Specific gravity at 90°C||0.80 – 0.85|
|Refractive Index||1.445 – 1.450|
|Ash Content (max) % by mass||0.03|