What is the definition of polyester resins for HAA-based formulations? What are their core properties?
Polyester resins for HAA-based formulations are a type of polyester resin specifically formulated for use with HAA (hexamethylene adipamide hydrazine) crosslinkers. They are primarily used in the paint and coating industry as film-forming agents. Its core properties include excellent cross-linking properties. Under specific conditions (such as heating and curing agents), it can cross-link with HAA to form a three-dimensional network structure, enhancing the coating's hardness, adhesion, and chemical resistance. Secondly, it boasts excellent weather resistance. Through its molecular structure, this resin resists the erosion of environmental factors such as UV rays, heat, and humidity, ensuring long-term color stability and excellent performance, making it suitable for outdoor coatings. Furthermore, it exhibits excellent compatibility with HAA cross-linkers and other coating components (such as pigments, solvents, and additives), making it less susceptible to delamination and sedimentation, ensuring stable coating performance. Furthermore, it offers controllable viscosity, allowing the resin viscosity to be adjusted according to coating application requirements (e.g., spray or brush application), facilitating application and achieving a uniform coating.
Why have HAA-based polyester resins become a key raw material in the coatings industry?
In the coatings industry, the performance of film-forming substances directly determines coating quality. The core reason HAA-based polyester resins have become a key raw material is their synergistic effect with HAA, addressing many of the challenges of traditional coatings. Traditional coating resins (such as standard polyester resins) may suffer from insufficient coating hardness, poor chemical resistance, and weak weathering resistance. However, HAA-based polyester resins, when cross-linked with HAA, form a three-dimensional network structure that significantly improves the coating's physical and mechanical properties (such as hardness and abrasion resistance) and chemical stability (such as acid, alkali, and solvent resistance), extending the coating's service life. Furthermore, the resin's weathering resistance makes it suitable for coatings on outdoor structures (such as building facades, vehicle hulls, and outdoor furniture), addressing the issues of fading, cracking, and peeling in outdoor coatings. Furthermore, its excellent workability and compatibility allow it to be adapted to various coating formulations, meeting diverse coating requirements (such as high-gloss, matte, and anti-corrosion coatings), making it a core raw material for enhancing coating performance in the coatings industry.
What types of coatings are HAA-based polyester resins primarily used in?
What applications are they suitable for? Its primary application is in powder coatings, a core area of application. HAA-based powder coatings, composed of polyester resins and HAA crosslinkers, are widely used for coating metal materials such as aluminum doors and windows, automotive parts (such as wheels and frames), appliance housings (such as refrigerator and washing machine housings), and hardware tools. These coatings offer high hardness, strong adhesion, and scratch resistance, effectively protecting metal surfaces from corrosion and wear while enhancing the product's appearance and quality.
The second most common application is coil coatings, primarily used in the production of pre-coat finishes for color-coated steel sheets and aluminum coils. Coil coatings must maintain their integrity during subsequent coil processing (such as bending, stamping, and rolling) and withstand long-term outdoor exposure to wind and sun. HAA-based polyester resins, with their excellent flexibility and weather resistance, can withstand the deformation requirements of coil processing, preventing cracking and flakes. They also resist erosion from UV rays, heat, rain, and other environmental factors, ensuring the long-term stability and aesthetics of color-coated steel sheets and aluminum coils for applications such as building facades, rooftops, and outdoor billboards.
It also has important applications in the field of "anti-corrosion coatings," often used on surfaces susceptible to corrosion, such as chemical equipment, oil pipelines, offshore platforms, and bridge steel structures. In these environments, equipment is exposed to corrosive substances such as acidic and alkaline media, seawater, and industrial exhaust gases for long periods of time. HAA-based coatings, formed by cross-linking polyester resin with HAA, form a dense protective film that blocks contact between the corrosive media and the substrate. They also exhibit excellent chemical resistance and resistance to moisture and heat, significantly extending the service life of equipment and structures while reducing maintenance costs.
It also has applications in some systems for "original automotive paint and refinish paint," primarily as a midcoat or topcoat on automotive bodies, particularly for models requiring high hardness, gloss, and stone chip resistance. The cross-linked coating improves the paint's scratch resistance, reducing minor scratches from daily use while maintaining a long-lasting gloss and protecting the paint from corrosion caused by car wash fluids, acid rain, and other factors.
