| A kind of Water-borne thick epoxy intermediate coating with both goodmechanical properties and excellent anticorrosion performance was prepared, Thecoating of solid content by volume was up to64.5%. A series of factors whichaffected the performance of coating were analyzed, the paper consisted of two parts.The first part, according to the antirust mechanism of different kinds of pigmentand filler, the research focused on flake filler because of its excellent corrosionmedium screening function. Various kinds of flake filler selection was conducted inthe development of coating, and the result showed that mica flake was best suited toprepare thick epoxy intermediate coating because of its complete laminated structureand excellent corrosion resistance. Secondly, the influence of different size andvarious adding quantity of mica flake on coating properties were studied in thisexperiment, and the result showed that150mesh mica flake and when its addingquantity up to40%that of total filler which were comparatively suit for preparation ofintermediate coating. Finally, the result showed: the coating had the best performancewhen the adding quantity of epoxy emulsion up to65%that of total filler byresearching influence of pigment volume content(PVC) on the performances ofcoatings and by investigating the structure of coatings with different PVC throughSEM.In the second part, firstly, against the deficiency of the low compatibility of micaflake and epoxy resin, Silane coupling agent KH-560was used as modifier for thesurface-modification of mica flake, and the result showed that when the dosage ofsilane coupling agent KH-560was up to1.3%that of mica flake the coatingcompactness and anti-penetrant efficiency could be obviouly enhanced byinvestigating the structure of coating through SEM and FTIR. According to theperformance and construction characteristics of two-component water-borne coatingthat the ratio of epoxy emulsion to curing agent and the pot life of coating werestudied, and the result showed that the best ratio of epoxy emulsion to curing agent was10:1and the longest pot life of coating was within4hours. Thirdly, the influenceof coalescing agent on the curing and film-formation process was studied, and theresult showed that the coating had best performance when the dosage of coalescingagent up to5%that of epoxy emulsion and the Tg of epoxy resin droped about40℃.Finally, the influence of thixotropic agent on the viscosity and thixotropy of coatingwas studied, and the result showed that bentonite EW have an obvious influence on thixotropy index of intermediate coating and there was no sag formed that thethickness of wet film can reach275μm in the first coating when the dosage of EW upto0.35%that of the total amount of formulation.At last, the Water-borne thick epoxy intermediate coating with both goodmechanical properties and excellent anticorrosion performance was prepared, and theprospective performance index were reached. |
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