Ethylene-vinyacetate copolymer (ethylenevinyacetatecopolymer), also known as EVA resin, is made of ethylene and vinyl acetate. EVA resin is an odorless, tasteless, non-toxic, white or light-yellow powder or granular Low melting point polymer, relative density 0.12~0.95, refractive index 1.480~1.510, brittle temperature less than -71 ℃. Because of its low crystallinity, high elasticity, rubber-like, and at the same time it contains enough polymer that plays a role in physical association. Ethylene crystallizes and thus has the characteristics of thermoplastic elastomers.

EVA resin has good softness, rubber-like elasticity, heating fluidity, good transparency and gloss, good compatibility with other compounding agents, and a wide range of compounding ingredients. A variety of hot melt adhesives with good performance and reasonable price can be prepared according to performance requirements. In addition, EVA resin has large cohesive force, small surface tension when melting, and has thermal adhesion to almost all materials. extensive attention.

The biggest disadvantage of EVA resin is that the high temperature performance is not good enough, the strength is low, and it is not resistant to fatty oil, which limits its application range. At present, the modification method of EVA has been studied, such as heating and mixing cross-linked EVA and chain-breaking butyl rubber or isobutyl rubber in the presence of organic peroxide to obtain a copolymer, which is used as a hot melt adhesive. Can significantly improve heat resistance and bond strength. For another example, EVA can be copolymerized with carboxyl compounds with better heat resistance such as maleic anhydride to improve the high temperature resistance of EVA. EVA resin is stored in a cool, ventilated and dry warehouse, fireproof and moisture-proof.