One.Powder coatingsWhat are the main components?
Thermoplastic powder coatings are composed of thermoplastic resins, pigments, fillers, plasticizers, and stabilizers. Thermoplastic powder coatings include: polyethylene, polypropylene, polyester, polyvinyl chloride, chlorinated polyethylene, polyamide, cellulose-based, and polyester-based.
Thermosetting powder coatings are composed of thermosetting resins, curing agents, pigments, fillers, and additives. Thermosetting powder coatings include: epoxy resin systems, polyester resin systems, and acrylic resin systems.
Two. Powder coating formulation proportions
1、Key considerations for epoxy powder coating formulations
Epoxy powder is the earliest type of heat-curing powder to be developed and commercialized. Epoxy powders are divided into functional and decorative types, and decorative epoxy powders are not widely used currently. Any compound that can react with epoxy groups at a specific temperature (110～200℃) can be used as a curing agent for epoxy powder. In reality, the main types of curing agents suitable for epoxy powder include amine-based agents (such as dicyandiamide, modified or accelerated dicyandiamide), anhydrides (aromatic anhydrides, cyclic anhydrides, etc.), acyl chlorides (such as dipicolinic acid dicarboxamide, hexadicarboxamide), imidazole-based agents (often used as promoters), and organic phenolic curing agents. The appropriate curing agent should be selected based on different technical requirements, and appropriate curing promoters should also be selected to meet various actual needs and curing conditions. There are many types of curing promoters, such as acetylacetone metal salts, triphenylphosphine (TPP) and its salts, adducts of aryl isocyanates (substituted ureas), 2-phenylimidazoline, and dimethylimidazoline.
2、Epoxy/Polyester (Hybrid) Powder Coating Formulation Key Points
- Currently, it is the product with the largest production volume and the widest application in the domestic market. The formulation design is primarily based on the performance requirements and cost considerations of the coating.