Paraffin is an important product of petroleum products. Some properties of paraffin wax, such as melting point, strength, elasticity, flexibility and so on, are difficult to meet the requirements. So in the 1960s and 1970s, low molecular weight polyethylene (LMPE) with a molecular weight of about 2000 was widely used abroad as the modifier of paraffin wax, thus improving the performance of paraffin wax.
Waxes used as paper coatings, crayons, carbon paper raw materials and medical ointments contained in Japanese chartered publications such as Zhao47-51083, Zhao47-45163, Zhao49-116315, and Zhao50-15484 all contain low molecular polyethylene. After the 1980s, there were reports about the addition of polyethylene to paraffin, such as the US patent 5281652, which oxidized the mixture of linear low-density polyethylene and paraffin to acid value 12-30 mg KOH/g, and then oxidized into products, which were used in fruit fresh-keeping coatings. Japanese patents Zhao63-50516 and Zhao63-51437 are high melting point paraffin wax products with a melting point of 70-85 ℃or -115℃ after extrusion or wire drawing, which transfer alkanes above 22℃ into ultra-high molecular polyethylene with a molecular weight greater than 1x 106.
According to the melting point of the target product, the composition of the additive is different. If the melting point of the target product is high melting point paraffin wax at 66 - 72℃, only additives consisting of high-pressure polyethylene are added. The melting point of the product is 75 ~84 ℃paraffin, and the additive is composed of high-pressure polyethylene and polypropylene. When the melting point of the target product is high melting point paraffin wax at 88 - 109 ℃, the additives are composed of high-pressure polyethylene, polypropylene, and the copolymer of ethylene and vinyl acetate. Therefore, the additive is a composite additive consisting of high-pressure polyethylene as the main agent and polypropylene, ethylene and vinyl acetate copolymer as the auxiliary agent.