Preparation And Properties Of Silicon Modified Water-insoluble Epoxy Resin

Epoxy resin has a wide range of applications in the coatings, its advantage is highadhesion, good anchoring strength, good chemical characters, etc. Most conventionalepoxy is insoluble in water, so large amounts of organic solvent are used to dilute theconstruction. But volatile organic solvents could cause serious health and threatenvironmental protection. Therefore, more and more people like the water-solubleepoxy resin, but its disadvantage limit its applications in dry and poor weather. In thispaper, the water-soluble epoxy resin is modified by a self-regulating silica sol, and thenthe silicon modified water-insoluble epoxy resin is acquired, making that theperformance of the water-soluble epoxy resin is effectively improved in drying andweather resistance. The research results are as follows:The silica sol was prepared by the method of sol-gel in this article, many factorsincluding the pH value, reaction temperatures, times and reactant ratio were discussedon the performance of the modified silica sol. The parameters of preparing modifiedsilica sol were obtained as follows: the reaction time was6h, the reaction temperaturewas55℃, the pH value was between2and2.5, the molar ratio wasTEOS/EAA/H2O/KH560=1/4/2/0.25.The silicon modified water-insoluble epoxy resin was made from silica sol andwater-insoluble epoxy resin by the method of solution polymerization, which has theexcellent performance of silica sol and water-insoluble epoxy resin. The waterresistance and alkali resistance of resin film can be greatly increased when the massratio of silica sol KH560and KH570in silane coupling agents is2/0, through theinfluence silicone modified waterborne epoxy resin is the discussion of the factors. Thehardness and resistance of the resin would increase as the increasing of silica sol contentwhen the content of the silane coupling agents was invariability. But the excessive silicasol will reduce the fineness and gloss of the coating film, so the performance of theresin was best when the silica content was10%of the composite resin. Infrared spectra showed that, Si-O-Si bond and Si-O-C bond of the silicon modified water-insolubleepoxy resin significantly increased drying, solvent resistance and acid and alkaliresistance, so the defects of water-insoluble epoxy resin have effectively remedied.The glossiness, covering power and mechanical properties of the coatings could bethe best value when binder ratio of the coatings was2/0through experiments to thecoating film properties. When the ratio of dioxide and precipitated barium sulfate was0.5, the coating film has better properties. According to the results of fillers in themilling time, the dispersing time should not be more than30min.