Quickly learn about high temperature hot melt adhesives
Polyamide resin is a linear thermoplastic resin with many repeating amide groups on the molecular main chain. Compared with other thermoplastic resins, it has a significant feature that when it is heated and cooled, the resin melts and solidifies. Occurs over a narrow temperature range. This feature allows the polyamide hot melt adhesive to quickly solidify when it is heated and melted a little while cooling into the construction. It can also make it have good bonding performance at a temperature close to the softening point.
The hydrogen on the amide group of the polyamide resin can be combined with the electron-donating carbonyl group on the other amide group segment to form a strong hydrogen bond, which increases the melting point of the resin, thereby having good flexibility, oil resistance and Adhesive properties. These properties increase with the increase of the molecular weight of the resin. Compared with ethylene-vinyl acetate copolymer hot-melt adhesives, polyamide hot-melt adhesives have higher softening points and therefore better heat resistance.
The molecular weight of polyamide resin currently used as the matrix of high temperature resistant hot melt adhesive is generally in the range of 1000-9000. The polyamide resin used as the hot melt adhesive matrix is mainly composed of dimers of unsaturated fatty acids (such as linoleic acid, soya oleic acid, tungonic acid, etc.) and diamines (such as ethylene diamine, propylene diamine, hexamethylene diamine, etc.). Amine, etc.) prepared by polycondensation.
When the polyamide resin is synthesized, different diamines are used, and the molecular weight of the obtained resin is also different, so the softening point is also different. At present, the method of mixing ethylene diamine and hexamethylene diamine is mostly used.
In the manufacturing process of high temperature resistant hot melt adhesives, polyamide resins are mainly made by copolymerizing and polymerizing dibasic acids with diamines, and then through modification, pulverization and other processes. During the processing, nitrile, hydrogenation, and And other processes, which simplifies the production process of high-temperature hot-melt adhesives and equipment requirements. The production of high-temperature hot-melt adhesive rods has easy control of raw material costs, and the manufacturing process is convenient and accurate to ensure stable product quality. , High-temperature resistant hot-melt adhesive has excellent bonding performance, high softening point, convenient storage, and convenient promotion and application.