Ethyl silicate zinc dust coatings

Ethyl silicate binders are mainly used in applications involving high temperatures and corrosive influences. The principal application of ethyl silicate zinc dust coatings is the protection of iron and steel against corrosion it is effective even at temperatures of up to 400 C. Examples include ships, harbor construction work, bridges, steel structures exposed to atmospheres in industrial areas, tanks, containers, pipelines, and chimneys. 

Historical Development. The importance and advantages of ethyl silicate zinc dust paints were recognized and intensively investigated in the late 1940s [2.187], [2.188]. The fundamental work of Lopata and Keithler [2.189] on the partial acid hydrolysis of tetraethyl orthosilicate and the use of the product as a zinc dust paint binder was followed by attempts to improve the application properties and quality of the coatings (e.g., by adding polyfvinyl butyral) [2.190], alkyl titanates [2.191], borate esters [2.192], or trialkyl phosphates [2.19. ]. 

Important manufacturers of ethyl silicate zinc dust paints include Ameron, Car-boline, Hempel s Marine Paints, International Paint, Jotun, Mobil Chemical, and Sigma Coatings. 

Zinc dust coatings are utilized in large quantities for the protection of structural steel, also including underwater steel construction and ship building [5.56]. Zinc dust is used in organic and inorganic binder systems (alkali silicates, ethyl silicates) [5.56, 5.105]. 

Continuous efforts have therefore been made to develop binders for one-pack paints which must be completely compatible with active pigments such as zinc dust. Mixtures of ethyl silicate and zinc can be stored for unlimited periods in the absence of water. If the hydrolysis and condensation reactions caused by atmospheric moisture can be sufficiently accelerated during application of the coating, a one-pack system can be produced. 

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