paraffin wax

Paraffin Waxes from Petroleum

Crude oils and their products contain a large number of individual paraffin. The main physical characteristics of the most frequently occurring alkanes are listed in Table, indicating that n-pentane is already liquid and n-hexadecane solid at ambient temperature.

Paraffin

Synonyms: Hard paraffin; Paraffin wax; Paraffin waxes; Paraffin wax fume; Petroleum wax. crystalline; Poly (methylene) wax

Classification: Aliphatic organic compd.; hydrocarbon

Definition: Solid mixture of hydrocarbons obtained from petroleum fractions by solvent crystallization or by the sweating process; consists predominantly of straight-chain hydrocarbons > C20; characterized by relatively large crystals

Empirical: CnH2n+2

Properties: Colorless to wh. cyst. solid; odorless; tasteless; greasy feel; sol. in benzene, gasoline. chloroform. ether, carbon disulfide. oils; misc. with fats; insole. in water, alcohol; dens. - 0.9; m.p. 50-57 C; flash pt. (CC) 190 C

Toxicology: ACGIH TLV/TWA 2 mg/m3 (fume); TDLo (implant, rat) 120 mg/kg; primary Uses irritant; skin and eye irritant; anesthetic effect; chronic skin exposure can cause dermatitis. abnormal pigmentation. etc.; fumes cause lung damage; questionable carcinogen; experimental tumorigenic by implantation; many paraffin waxes contain carcinogens; TSCA listed

Precaution: Dangerous fire hazard; will burn above 198 C; burns with luminous flame; when heated, produces irritating fumes NFPA: Health 0, Flammability 1, Reactivity 0 Storage: Store away from heat; store in cool, dry place; refrigerate

Uses Candles; paper coating; glazing agent, protective sealant for foods; food coatings; plastics lubricant; hot-melt carpet backing; floor polishes; the masticatory substance in chewing gum; raising m.p. of ointments; antiozonant for rubber; Mfg. of varnishes: in elec. insulators: perfume extraction (from flowers); paper sizing agent; waterproofing agent for textiles, leather, paper, cork, wood: solvent for inks; emollient, visit. control agent, moisturizer, the stabilizer for cosmetics; pharmaceuticals (stiffener, tablet coating); defoamer, surf. lubricant in food-contact coatings; in cellophane for food pkg.; wood preservative for Agric. Prods. pkg.; pkg. material for irradiated foods.

Paraffin wax (petroleum)

Synonyms. Paraffin wax

Definition: A complex combination of hydrocarbons obtained by treatment of a petroleum wax fraction with natural or modified clay to remove trace amts. of polar compounds and impurities; predominantly straight chain saturated hydrocarbons

Uses: Antioxidant, dispersant, gloss aid, lubricant, internal lubricant, process aid, release agent

Trade Names: IGI 1230 Paraffin Wax-Slab; IGI 1231 Paraffin Wax-Granulated; IGI 1236 Paraffin Wax -Gran; IGI 1236 Paraffin Wax-Slab; IGI 1240 Paraffin Wax-Slab; IGI 1245 Paraffin Wax-Slab; IGI 1246 Paraffin Wax-Gran; IGI 1255 Paraffin Wax-Gran;1611343 Paraffin Wax

Wax

is of two general types: (i) paraffin wax in petroleum distillates and (ii) microcrystalline wax in petroleum residua.

Paraffin wax is a solid crystalline mixture of straight-chain (normal) hydrocarbons ranging from 20 to 30 carbon atoms per molecule, and even higher.

Paraffin wax is a solid crystalline mixture of straight-chain (normal) hydrocarbons ranging from C20 to C34 and possibly higher, that is, CH3(CH2) CH3, where n218. It is distinguished by its solid state at ordinary temperatures (25°C, 77°F) and low viscosity (35-45 SUS at 99°C, 210°F) when melted. However, in contrast to petroleum wax, petrolatum (petroleum jelly), although solid at ordinary temperatures, does, in fact, contain both solid and liquid hydrocarbons. It is essentially a low-melting, ductile, microcrystalline wax.

Microcrystalline waxes f0rm approximately 1-2% w/w of crude oil and arc valuable products having numerous applications. These waxes are usually obtained from heavy lube distillates by solvent dewaxing and from tank bottom sludge by acid clay treatment. However, these crude wax products usually contain appreciable quantity (10-20% w/w) of residual oil and, as such, are not suitable for many applications such as paper coating, electrical insulation, textile printing, and polishes.

PRODUCTION AND PROPERTIES

Production

Paraffin wax from a solvent dewaxing operation (Speight. 2014) is commonly known as slack was, and the processes employed for the production of waxes arc aimed at de-oiling the slack wax (petroleum wax concentrate).

Was "waling was originally used to separate wax fractions with various melting points from the wax obtained from shale oils. Wax sweating is Still used to some extent but is being replaced by the more convenient crystallization process. In wax sweating, a cake of slack wax is slowly warmed to a temperature at which the oil in the wax and the lower-melting waxes become fluid and drip (or sweat) from the bottom of the cake. leaving a residue of higher-melting wax. Sweated waxes generally contain small amounts of unsaturated aromatic and sulfur compounds, which are the source of unwanted color, odor, and the aisle that reduce the ability of the wax to resist oxidation; the commonly used method of removing these impurities is clay treatment of the molten wax.

Wax crystallization, like wax sweating, separates slack wax into Inactions. but instead of using the differences in melting points, it makes use of the different solubility of the wax fractions in a solvent. such as the ketone used in the dewaxing process.When a mixture of ketone and slack wax is heated, the slack wax usually dissolves completely. and it' the solution is cooled slowly, a temperature is reached at which a crop of wax crystals is formed. These crystals will all be of the same melting point. and if they arc removed by filtration, a wax fraction with a specific melting point is obtained. If the clear filtrate is further cooled, the second crop of wax crystals with a lower melting point is obtained. Thus, by alternate cooling and filtration, the slack wax can be subdivided into a large number of wax fractions, each with different melting points.

Chemically. paraffin wax is a mixture of saturated aliphatic hydrocarbons (with the general formula.Wax is the residue extracted when dewaxing lubricant oils and they have a crystalline structure with canton number greater than 12. The main characteristics of wax are (i) colorless. (ii) Odorless. (iii) translucent, and (iv) a melting point above 45°C (113°F).

Properties

Petroleum wax is of two general types: the paraffin waxes in petroleum distillates and the microcrystalline waxes in petroleum residua. The melting point of the wax is not directly related to its boiling point because waxes contain hydrocarbons of different chemical nature. Nevertheless, waxes are graded according to their melting point (ASTM 1)87, IP 55) and oil content (ASTM D721. IP In).

The melting point of paraffin was (ASTM D87. IP 55) has both direct and indirect significance in most wax utilization. All wax grades are commercially indicated in a range of melting temperatures rather than at a single value, and a range of I °C (2°F) usually indicates a good degree of refinement. Other common physical properties that help to illustrate the degree of refinement of the wax are color (ASTM D156), oil content (ASTM D721, IP 158), and viscosity (ASTM D88, ASTM D445, IP 71).

Fully refined paraffin waxes are a hard, white crystalline material derived from petroleum. Paraffin waxes are predominately composed of normal, straight-chain hydrocarbons. The water-repellent and thermoplastic properties of paraffin waxes make them ideal for many applications. Typical end uses include cereal, delicatessen, and household wrap, corrugated containers, candles, cheese and vegetable coatings, and hot melt adhesives.

Paraffin wax is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 46 and 68°C (115 and 154°F) and a density of approximately 900, is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin wax is often classed as a stable chemical since it is unaffected by most common chemical reagents but burns readily.

Microcrystalline waxes are a type of wax produced by de-oiling petrolatum, as part of the petroleum refining process. In contrast to the more familiar paraffin wax, which contains mostly unbranched alkanes, microcrystalline wax contains a higher percentage of iso-paraffin (branched) and naphthene hydrocarbons. It is characterized by the fineness of its crystals in contrast to the larger crystal of paraffin wax. It consists of high-molecular-weight saturated aliphatic hydrocarbons. It is generally darker, more viscous, denser, tackier, and more elastic than paraffin waxes, and has a higher molecular weight and melting point. The elastic and adhesive characteristics of microcrystalline waxes are related to the non-straight-chain components that they contain. The typical microcrystalline wax crystal structure is small and thin, making them more flexible than paraffin wax.