Zinc Phosphate/Imidazole Composites Built on Coordinating Construction for the Syncretic Weatherability and Corrosion Inhibition Property

Inorganic corrosion inhibitors are poorly compatible with organic resins, tending to leave defects in the cured coating, weakening the protection efficiency. Composites that combine the characteristics of organic and inorganic materials can improve this. Zinc phosphate/imidazole (ZP/IMZ) composites with a lamellar structure were designed relying on the coordination ability of imidazole, which could effectively increase the cross-linking compactness of resin and thus significantly improve the shielding effect. Additionally, the ZP/IMZ could convert high-energy ultraviolet (UV) light into low-harm visible light, which effectively improved the weathering resistance of the coating and showed good corrosion resistance, with a corrosion current density of 4.26 μA·cm–2 and a resistance of 5736.9 ohm·cm2 at 168 h of corrosion. The introduction of imidazole compensated for the defects of the zinc phosphate pigment, such as poor initial effect and inability to form dense coating, and synergized with the passivation protection film of zinc phosphate, providing ideas to design organic–inorganic corrosion inhibitors.