| The powder coatings is the coating that does not contain any organic solvents(VOC). It has been developed rapidly, because of their economy, environmental protection, efficiency, superior performance characteristics,especially since the1990s. China is a veritable powder coating production and consumption and powder coatings reached800,000tons in2009. The production and sales of epoxy resin is the largest one among all powder coatings and the world and China production are more than50%and60%of the total powder coatings, respectively. Thus, the epoxy powder coating in the powder coating industry occupies a vital position. Epoxy powder coating contains epoxy resin, pigments and fillers, etc.The heat-resistant of epoxy powder coating is improved by adding silicone resin and high molecular weight and high softening point epoxy resin.Epoxy resin (SM-604, SM-609), polyvinyl butyral (PVB) and TiO2were taken as raw materials, using powder mixed method for preparation of coatings. A3steel was taken as base material, and made test sample in turning and sand blasting. By pull-off test for determinating adhesion of coatings. Adhesion was taken as the evaluation target, through the L9(34) orthogonal experimental method to obtain epoxy powder coating formulations (parts by weight):SM60433.3, SM60966.7,20plasticizer, pigment and filler20. By a single factor test, to further study effects of the SM-604and SM-609ratio, PVB content and TiO2filler content to adhesion of coating, and ultimately determine the optimized epoxy resin powder coating formulation (parts by weight):SM-60425, SM-60975, PVB20, TiO220. And use the scribe of optimized formula powder coating adhesion experimental verification is performed, the results accord with the relevant standard requirements.Based on the optimized fomula,powder coating samples were made,and the powder coating product performance were tested, the results were in line with the relevant national standards.DC04steel plate was taken as base material, and painting the test plate, do the test of powder coatings,the results accord with the relevant standard requirements for powder coatings.And contrast before and after curing by infrared spectrum, IR spectrum confirms the curing reaction of the evidence.Finally, taking A3steel as base material, by phosphating, phytic acid and silane coupling agent treatment of different pretreatment methods, preparation of adhesion of test block, do the bonding strength test. The results for the use of phytic acid salt solution for surface pretreatment combined with strength and common phosphating. If phytic acid salt treatment to replace traditional phosphating pretreatment, can reduce processes,reduce energy consumption and reduce environmental pollution. |
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