Bituminous Wax Composition
The use of bitumen wax compositions as pavers and coverants for various surfaces such as roads and airports is known. Such compositions contain a mixture of aggregate and asphalt in a specified proportion and are generally laid and compacted while hot to provide a dense and durable surface.
For many applications, asphalt provides a binder for aggregate with sufficient durability and adhesion. However, for heavy duty applications, additives may be added to the asphalt to improve its mechanical properties.To this end, various additives have been proposed, including polymers such as ethylene-vinyl acetate copolymers, styrene and conjugated diene random or block copolymers (such as SBS copolymers). Recently, synthetic waxes containing synthetic aliphatic hydrocarbons have also been used in asphalt blends. Such bitumen wax blends tend to be more resistant to deformation under high load than their wax-free counterparts.
Fuels such as diesel and gasoline have a damaging effect on asphalt. These fuels tend to dissolve or soften the bituminous components of bituminous surfaces. Thus, over time, the aggregate composition of such a surface tends to become less well combined, and thus the surface tends to disintegrate.
Surprisingly, we have now discovered that waxes can be used to improve the fuel resistance of asphalt.
petroleum wax and synthetic wax, specifically is Suitable for bitumen wax composition. They are waes of softening point and melting point good in more than 50 ℃, 60 ~ 150 ℃ and 60 ~ 120℃ . Examples of petroleum waxes include paraffin and microcrystalline waxes. Such waxes are well known and are generally obtained from crude oil and/or petroleum distillates using known techniques. Paraffin is coarse grain products and is usually solid under the normal temperature (25 ℃). Microcrystalline waxes also tend to be solid at room temperature. However, in addition to being obtained from petroleum distillates, these waxes can also be found naturally, for example, in the form of ground wax. Ground wax can be refined and bleached to produce cerasus wax, which is also suitable for use as a fuel additive.
Suitable synthetic waxes include hydrocarbon waxes, such as polyethylene waxes, and better waxes obtained in the fee-tropsch process. Waxes with functional groups, such as chemically modified hydrocarbon waxes, and waxy esters and amides, may also be used.