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Research status of domestic chromium-free Dacromet coating formulation

Posted on 2019-02-12 The silicone and the nano-powder treated with the nano-dispersion are dispersed into a plurality of resin cross-linked polymerized composite resins, and after being modified, the zinc powder and the aluminum powder can be obtained to have chromium-free, acid-resistant, and Magnesium alloy chromium-free Dacromet solution with the advantages of salt spray resistance, environmental protection, thin coating film, good weather resistance and impact resistance. Zhang Shuyong et al. added zinc powder, aluminum powder, deionized water, dispersant (decadiol polyoxyethylene ether or cetyl polyoxyethylene ether), phosphate (aluminum hydroxide and 85% phosphoric acid in proportion), Thickener (water-soluble methyl cellulose ether or hydroxypropyl methyl cellulose ether), sodium tripolyphosphate, polymerization initiator (35% hydrogen peroxide and / or potassium permanganate), pH regulator (zinc oxide, oxidation Calcium or calcium hydroxide) and filming aid (polyethylene glycol) are mixed according to a certain ratio, stirred evenly, and the pH is controlled at 3.5 to 5.5 to obtain a chromium-free Dacromet coating liquid. The invention is environmentally friendly and pollution-free. The corrosion performance is 7 to 10 times higher than that of electrogalvanized, and it also has the advantages of high permeability, high friction reduction, and high weather resistance. Zhu Chengfei et al. Zinc powder, aluminum powder, wetting and dispersing agent (alcohol or polyalcohol), passivating agent (phytic acid), corrosion inhibitor (sodium molybdate), water, film forming agent (manganese acetate, manganese nitrate or Manganese chloride), filming aid (silane coupling agent), forming aid (boric acid or succinic acid) and thickener (hydroxymethyl cellulose or hydroxyethyl cellulose) are prepared according to a certain ratio to obtain no Compared with the prior art, the chromium dacrox coating liquid has the advantages of no pollution, no pollution, low energy consumption and good wear resistance.
Using phosphoric acid as binder and passivating agent, rare earth is auxiliary, aluminum powder, zinc powder, 85% phosphoric acid, aluminum hydroxide, hydrogen peroxide, calcium oxide, cetyl polyoxyethylene ether, hydroxypropyl cellulose ether , ammonium cerium nitrate and ammonium nitrate are mixed according to a certain ratio, stirred evenly, and the pH is controlled to 5.5, to obtain a chromium-free Dacromet coating liquid with excellent corrosion resistance. The research shows that the addition of rare earth strontium salt effectively reduces the coating. The corrosion current of the layer has a good corrosion inhibition effect on the Dacromet coating.


Post time: Jan-13-2022