Polyamide hot melt adhesive, also known as dimer acid polyamide hot melt adhesive, referred to as PA hot melt adhesive, is a high temperature condensation reaction between dimer acid and polyamine. It has excellent heat resistance, cold resistance, electrical properties and oil resistance. Properties, chemical resistance and medium resistance; odorless, colorless; fast curing; can bond a variety of metals and non-metals; good compatibility with other resins.
Products can be used for the bonding of fabrics, leather, wood, plastics, metals, ceramics, etc., as well as for the bonding and protection of electronic components, book binding, low-pressure injection molding, tape production and so on.
High molecular weight polyamide hot melt adhesive: good fluidity, high bonding strength, dry cleaning, water washing.
Low molecular weight polyamide hot melt adhesive: good strength and toughness, most of which are superior to EVA hot melt adhesive.
Under normal circumstances, polyamide hot melt adhesive softening point can be from about 100 ° C to more than 200 ° C, can withstand low temperatures to minus 40 ° C, high temperature resistance can reach 200 ° C, at normal temperature, the specific gravity is usually 0.97.
The basic color of polyamide hot melt adhesive is amber (yellow), but it can usually be changed to black by adding carbon black, white color is added by adding titanium white powder, and some uncommon cases are added to other pigments and converted into other colours. Color-changing polyamide hot melt adhesives are commonly used in special applications such as low pressure injection molding processes.
Since the polyamide hot melt adhesive is formed by the polymerization of acid amines, there are usually indicators for the acid value and the amine value at the ends, and the acid amine polymerization reaction is usually terminated by the end of the reaction at the other end. Therefore, in the case of the acid amine value index, the acid value is low and the amine value is low, and the high amine value is low. In a few cases where the two values are close, a balance is reached and the reaction is terminated.