Paraffin is a kind of hydrocarbon mixture extracted from some distillate of petroleum, shale oil or other bituminous mineral oil. The main composition is solid alkanes, odorless and tasteless. It is a white or light yellow translucent solid. Paraffins are mixtures of plus-chain saturated alkanes of different molecular weights, which can be expressed by the general formula CNH2N +2. According to the physical state of paraffin wax, it can be divided into liquid paraffin wax, solid paraffin wax and microcrystalline wax. Paraffin wax has many advantages, such as low price, wide source, colorless and tasteless, stable physical and chemical properties, large latent heat of phase change, etc. Therefore, it is widely used in the fields of medicine, packaging, construction, military camouflage, industry and agriculture, etc. In recent years, there are a lot of studies on composite phase change energy storage materials.1.Melting pointParaffin wax is a mixture of hydrocarbons and therefore does not have a strict melting point as pure compounds do. The so-called melting point of paraffin refers to the temperature at which the cooling curve of the melted paraffin sample first appears stagnation period under specified conditions. All kinds of wax products are required to have good temperature resistance of paraffin wax, that is, do not melt or soften deformation at a particular temperature. Commercial paraffins are required to have a series of different melting points according to the conditions of use, the region and season of use, and the environment of use. The main factor affecting the melting point of paraffin wax is the degree of raw fraction. The melting point of paraffin wax extracted from heavier fraction is higher. In addition, oil content also has a great influence on the melting point of paraffin wax, the more oil in paraffin wax, the lower its melting point.
2. The oil content
Oil content refers to the amount of low melting point hydrocarbons contained in paraffins. High oil content will affect the color and storage stability of paraffin wax, but also reduce its hardness. Therefore, the oil-bearing wax extracted from the reduced pressure fraction needs to be deoiled by sweating or solvent method to reduce its oil content. However, most paraffin products need to contain a small amount of oil, which is beneficial to improve the gloss and demoulding properties of products.
3. The stability
Paraffin products are in modelling or besmear process, be in hot melt state for a long time, contact with air, if stability is bad, easy oxidation metamorphism, color becomes deep, give out stink even. In addition, paraffin wax also turns yellow when exposed to light during use. Therefore, paraffin wax is required to have good thermal stability, oxidation stability and light stability. The main factors affecting the stability of paraffins are trace non-hydrocarbon compounds and polycyclic aromatic hydrocarbons. To improve the stability of paraffin wax, it is necessary to deeply refine it to remove these impurities.
Application :1.GB2760-96 allows the use of gum sugar base agent, limited to 50.0g/kg. In foreign countries, it is also used in the production of glutinous rice paper, the amount of 6g/kg. Outside, widely used in food packaging materials moisture-proof, anti-stick and anti-oil, etc.
2 as the film agent, China's regulations can be used as gum gum, the maximum usage of 50g/kg.
3. Used for rubber products, awning canvas, matches, etc
4. Used in the production of synthetic fatty acids and high alcohol, also used in the manufacture of matches, candles, wax paper, waterproof agent, ointment and so on
5. Used for crayons, waxed paper, telecommunication equipment, light industry and chemical raw materials, wax model crafts, etc
6. Used as cosmetic raw material, also used in capacitors, electronic components, leather shoes and other aspects
7. White paraffin wax is mainly used as candles, crayons, wax paper, matches, general telecommunication equipment, rubber products, polishing paste and other chemical raw materials. The refined paraffin is suitable for the production and precision casting of high-frequency porcelain, carbon paper, iron pen waxed paper, cold frost and other products. Food paraffin is suitable for making food and oral medicine components, as well as demoulding, tablet pressing, polishing, etc. Food including paraffin wax suitable for food contact solution and packaging materials coating and impregnation.
8.GB2760-96 allows the use of gum sugar base agent, limited to 50.0g/kg. In foreign countries, it is also used in the production of glutinous rice paper, the amount of 6g/kg. Outside, widely used in food packaging materials moisture-proof, anti-stick and anti-oil, etc. It is suitable for making products of chewing gum, bubblegum, positive gold oil and other components, as well as wax with direct contact with food and medicine such as heat carrier, demoulding, tablet pressing and polishing by cold pressing of wax-containing fraction of petroleum or shale oil.