Application of Water Based Inorganic Zinc Silicate Anti-corrosive Coatings on Steel Structure

摘要

The composition, characteristic, anticorrosive mechanism and application of water based inorganic zinc silicate coatings prepared by potassium silicate and zinc powder are introduced in this paper. Zinc, employed in coating films as loading that insures the film conductivity, will form an efficient anode of a galvanic couple with steel, sacrificially corroding itself, and overriding local cell activity on the steel that becomes entirely cathodic and protected. Through the research of modification of potassium silicate by CH_3Si (OCH_3)_3, it can evidently improve flexility and adherence of coating so as to get excellent performance. It also researches the granularity, appearance, pretreatment technology of zinc powder and optimizes content of zinc in coatings. It not only has no VOC(volatile organic component) and no flash point, which contributes to a user-friendly application environment, but also shows better performance, such as hardness, and resistance to impact and abrasion of their film, and can be used in high temperature. It dries fairly quickly, usually within 15 minutes, and can be used conveniently as well. At the same time the coatings have good comprehensive properties after test. Having a life as long as 20 years, it has been used successfully in huge steel structure as long-term anticorrosive method and proves to have a promising future.