Requirements for curing agents for powder coatings
Curing agents are not required in thermoplastic powder coatings, but in thermosetting powder coatings, curing agents are an essential component of the powder coating composition. Without curing agents, thermosetting powder coatings cannot be cross-linked and cured to form films with certain physical mechanics. Coatings with properties and chemical resistance. The properties of the curing agent are the main factors that determine the performance of powder coatings and films.
The curing agent should have a good chemical reaction activity with the resin. It does not react with the resin under normal temperature and melt-extrusion mixing temperature conditions, and under the baking curing conditions, it will rapidly undergo a cross-linking curing reaction with the resin to obtain an appearance flow. Coating with good flatness, good physical and mechanical properties and chemical resistance.
Considering the manufacturing process and storage stability of powder coatings, the curing agent is solid rather than liquid under normal or room temperature conditions, and is preferably a solid powder or a solid granular or flake that is easily crushed.
From the perspective of energy conservation, the crosslinking curing reaction temperature of the curing agent and the resin is low and the reaction time is short, which is conducive to low-temperature and short-term curing film formation, which can save energy and improve production efficiency.
The raw materials of the curing agent come from a wide range of sources and are inexpensive, suitable for a wide range of industrial applications.