Study On Preparation Of New Rust Transfer Agent And Low Surface Treatment High Temperature Resistant Coating

In a high temperature environment,the equipment is more likely to be corroded.Low surface treatment and high temperature resistant coatings can save a lot of pre-treatment costs and time,and at the same time can meet the needs of repainting rusty equipment in high temperature environments.As a new type of rust-transfer agent,pyrogallic acid has excellent rust-transfer ability,but its performance is too active.It is studied to modify it with epoxy resin and apply it to low-surface and high-temperature coatings.（1）Using self-made epoxy modified silicone resin as base material,a paint with good high temperature resistance was developed.The optimized formula is:pigment and filler grinding time 50min,paint dispersion time 60min,curing agent dosage 15%,paint film thickness 300μm,pigment base ratio 3.0 and the ratio of Si O₂ and Al₂O₃ are 1:1.The optimized high temperature resistant coating has high temperature resistance up to 550°C,and has good construction performance and adhesion,but it has poor performance for low surface treatment coatings.（2）A low surface treatment coating for high chromium steel was developed.The optimum formulation was as follows:the mass ratio of base resin E-44 to curing agent was 10:3,the mass fraction of antirust pigment was 49%,the mass fraction of zinc phosphate,phosphorus iron powder and iron oxide red was 20%,20%and 9%,and the mass ratio of calcium silicate and talcum powder was 1:1.The solid content of the coating is 70%,and the color base ratio is 1.6:1.The coating and film properties meet and some properties exceed the national standard.It can be applied on the surface with rust and oil.The coating has good rheology,bright and full surface,good adhesion and mechanical properties.（3）A new rust conversion agent was developed and its application in low surface treatment coatings was explored.Pyrogallic acid was physically modified by solvent epoxy resin E-20 and waterborne epoxy resin E0430,and pyrogallic acid was chemically modified by epoxy resin E-20.Three groups of modified rust conversion agents were optimized.The three groups of rust conversion agents were added to the corresponding low-surface coatings and compared with the performance of the paint without the rust conversion agent.The results showed that the coatings with chemically modified rust conversion agents had the best performance.In the test,the corrosion current density is the smallest among the four groups.The salt spray test can reach 144h,the high temperature performance test can reach 250°C,and the other properties also meet the national standards.The prepared high temperature resistant coatings can be used at temperatures up to 550℃,but have poor performance in low surface treatment.The low surface treatment performance of the prepared high chromium steel low surface coating is good,but the high temperature resistance performance is slightly poor.The comprehensive performance of the low surface high temperature resistant coating prepared by the new chemical modified pyrogallic acid rust remover is the best.