Rosin resin is the oil resin flowing out after the pine tree is cut. It is the product of tree physiological activities, mainly composed of terpenes. The newly discharged rosin is a colorless and transparent oily liquid. When exposed to the air, it thickens with the gradual volatilization of terpene compounds, and finally becomes a white or yellow solid substance - rosin. Rosin is the raw material for producing rosin and turpentine.
Hot melt adhesive (English name: Hot Glue or Hot melt adhesive) is a kind of plastic adhesive. Its physical state changes with temperature within a certain temperature range. It is solid at low temperature, while it is liquid at high temperature. Its chemical properties remain unchanged. It is non-toxic and odorless, and belongs to environmental protection chemical products. Because the product itself is solid, it is convenient for packaging, transportation, storage, solvent-free, pollution-free and non-toxic; It has the advantages of simple production process, high added value, high adhesive strength and high speed.
At present, rosin resin processed in rosin industry is mainly used in hot melt adhesive industry, so we should especially study and study it. Due to its environmental protection characteristics and the economic development of various countries, people pay more and more attention to the potential harm of various daily necessities to people, so the application range of hot melt adhesive products is becoming wider and wider, especially in Europe, the United States, Japan and South Korea in Asia, where solvent-based adhesive products are increasingly replaced by hot melt adhesive products.
The types of hot melt adhesives are also diverse, but they cannot be separated from their tracks. The overall formula is composed of basic resin, tackifier, viscosity regulator, antioxidant and other components. The main types are polyolefin hot melt adhesives, ethylene and its copolymer (EVA) hot melt adhesives, polyester hot melt adhesives, polyester (PET), polyamide hot melt adhesives, environment-friendly hot melt adhesives, pressure-sensitive hot melt adhesives and water-based hot melt adhesives. Among them, EVA type hot melt adhesives, environment-friendly hot melt adhesives (wood and paper composite), pressure-sensitive hot melt adhesives and water-based hot melt adhesives all use a large number of rosin resins with various properties. Rosin resins are used as tackifiers. The performance and cost of hot melt adhesives are adjusted by selecting different types of rosin resins, changing the proportion and compounding different tackifiers.