Study On Preparation And Performance Of Silane Hybrid Membrane On The Carbon Steel Surface

The silane treated metal surface is a new surface preparation method, which hasgreat advantages such as non-pollution and excellent adhesive strength, compared tothe mature industrial application of phosphating process. So, the development ofsilane surface treatment technology has an extensive market prospect.At present, the study of the silane film on the metal surface is mainly focused ona single component silane film. The performance of the silane film is of instability,poor corrosion resistance, and also unfavorable to subsequent coating. At the sametime, the research is rarely focused on the carbon steel. Therefore, exploring thesystem of silane treatment technology on the carbon steel surface and improving thestability of the silane treatment fluid to achieve strong binding force on the surface ofthe silane film and carbon steel, improve the performance of silane film, improve thecorrosion resistance of silane film, etc., will become a problem to be solved at present.Based on tetraethyl orthosilicate TEOS and silane coupling agent KH560as themain raw material, the silane surface treatment fluid will form in the way ofhydrolytie polycondensation under certain conditions, further optimizate the process.By investigating the influence of the hydrolysis time, pH, other factors, etc., on thehydrolysis degree of silane and stability of treatment fluid, combined with the surfacemorphology, thermal stability and other testing, it is concluded that the optimaltreatment fluid composition and process conditions; Then investigating the influenceof dipping time, curing temperature, etc., on ordinary silane film and the influence ofadditives on the corrosion resistance of silane film, combined with scanning electronmicroscopy, electrochemical tests, etc., the physical and chemical properties of silanefilm are characterized; Finally, its application in organic coating is further exploredfor research.The results showed that: when the hydrolysis temperature is50℃, pH value isabout3.5, the ratio of TEOS/KH560is1:2, the ratio of isopropyl alcohol/Si is12, thereaction time is7h, the ratio of H2O/Si is7, the properties of stability and corrosionresistance of silane treatment fluid is optimal; And when dipping times is4, dippingtime is2min, dipping temperature is45℃, curing temperature is95℃, curing time is40min, the properties of adhesive force and corrosion resistance of the ordinary silanefilm is optimal; And mixed with0.05%of rare earth lanthanum and5%offilm-forming additives, the corrosion resistance of silane film can be improve about 10times, and the film-forming conditions should correspondingly change, forexample， dipping temperature is30℃, curing temperature is130℃, curing time is30min, the conditions are beneficial for energy conservation and environmentalprotection. At the same time, the performance of hybrid silane film is optimal, theadhesion and corrosion resistance can even exceed the effect of phosphating process;When coated with organic coating on the surface, the adhesion and other performanceof coating and substrate can achieve common indicators.This technology has not only realized the strong binding force of silane film, butalso improved the stability of silane treatment fluid and the corrosion resistance ofsilane film on the metal surface, so as to further improve the service life of coating,realizing environmental protection and energy saving of surface treatment industry.