2. High Durable Polyester HDP (the shortcomings of PE and SMP of High Durable Polyester), the British company HYDRA (now acquired by BASF) and the Swedish company BECKER developed a 60-80% weather-resistant HDP dip coating that can reach PVDF coating at the beginning of 2000, which is superior to the ordinary silicon modified polyester coating, and its outdoor weather resistance reaches 15 years. The monomer containing cyclohexane structure is used in the synthesis of high weather-resistant polymer resin to achieve the balance of flexibility, weatherability and cost of the resin, and aromatic polyols and polybasic acids are used to reduce the absorption of UV light by the resin to achieve the high weather-resistant performance of the coating. Ultraviolet absorber and steric hindrance amine (HALS}) are added into the coating formula to improve the weatherability of the paint film. The high weatherability polyester coil coating has been recognized by the market abroad, and the cost performance of the coating is very outstanding.
3. Silicone Modified Polyester (SMP)
Because polydips contain active radical - OH/- COOH, which is easy to react with other polymer compounds, in order to improve the sunlight resistance and pulverization property of PE, Silicone resin with excellent color retention and heat resistance is used for the denaturation reaction, and the denaturation ratio with P can be between 5% and 50%. SMP provides better durability of steel plate, and its anti-corrosion life can be as long as 10-12 years. Of course, its price is also higher than PE, but the adhesion and processing formability of Silicone resin to materials are not ideal, Therefore, SMP color coated steel plate is not suitable for occasions requiring multiple molding and processing, and most of it is used for the star roof and exterior wall of buildings.
4. Fluorocarbon PVDF (Polyvinylidine Fluoride)
Due to the strong bond energy between the chemical bond and the chemical bond of PVDF, the coating has very good corrosion resistance and color retention. Among the color coated steel plate coatings used in the construction industry, it is the most advanced product, and has a large molecular weight and a straight bond structure. Therefore, in addition to chemical resistance, the mechanical properties, cable resistance and heat resistance are also very special. Under general environmental protection, the corrosion protection period can be as long as 20-25 years. In recent years, fluorine-containing resins co-polymerized with trifluoroethylene and vinyl ester monomers have become popular in China, and are widely used in exterior walls and metal plates of buildings. Due to the use of easily hydrolyzed vinyl ester monomers and the lower fluorine content than PVDF (about 30%), its weatherability is somewhat different from PVDF. The PVDF content of the fluorocarbon coating produced by Baosteel is not less than 70% (the other is acrylic acid resin).