Preparation And Study Of Properties Of Inorganic-organic Compound High Temperature Resistant Waterborne Anticorrosive Coating

In this paper, we prepared a novel and environment friendly high temperature resistant coating, whose solvent was only water. We also studied the usual anticorrosive properties of the coating. We found the coating could not only resist the severe heat and oxygen corrosion, but also the chemical medium, for example, water resistance, 5% mass concentration NaCl solution resistance, neutral salt-fog proof and 200# solvent oil and so on. The following two parts are included in this paper:In the first part, we mainly inspected its high temperature resistant property. Firstly, we chose the filtrated potassium water glass F with m equaling 3.05 as the inorganic base, which has excellent heat resistant and anti-corrosive properties. At the same time, the organic styrene-acrylic emulsion B got through soap-free emulsion polymerization was mixed together harmoniously to improve the bad water resistant and flexibility performances and accelerate the solidification of the film. The compatibility between the inorganic/organic was critical. We had found the main factors affecting our choosing the water glass were the high pH value (usually 13～14) and the impurity (Fe rust and S2-) which might conclude in the strong basicity solution and led the emusion breaking. When the blending (solids conent)ratio between them was 3:1(inorganic/organic), the coating had the best balance between high temperature resistance and mechanical behavior. The other key point was to choose an appropriate heat-resistant and crack proof filler. Thinking about our goal temperature at about 700-800℃, from a large number of inorganic minerals and frits and after a series of control experiments, we selected one kind of glass powder with the melt point of 700℃. And when its mass concentration was 5.64%, we found, after baking of 700℃, 5h or 800℃, 1h in the muffle furnace, the film still kept well. In the SEM photos, we could see that the melt frit covered the pigment and fillers and made up the caves after the organic resin volatilized. Otherwise, we prepared different kinds of coatings with different P/B (the mass ratio of pigment to base) and at last we found the 2:1 one having the best high temperature resistance and mechanical performances. Moreover, I investigated the thickness of the film and when it reached 90-120μm, the film could protect the base board well and the flexibility and the impact strength were good at same time.In the second part, we mainly studied the anticorrosive properties of the coating as improving the high temperature resistance. We had found when the styrene-acylic emulsion A which had better compatibility with water glass and better water resistance accounted for 1/3 of the whole organic emulsion and the SiO₂ sol was 5% of the inorganic film forming matter, the coating had not only an improved heat-resistance (up to 800,5h), but the film after 240h water immersion was good and there was no obvious change on the apparence. The 5% mass concentration NaCl solution resistance, neutral salt-fog proof and 200# solvent oil resistant properties were also good and could reach the solvent organosilicon high temperature paint standard. In the coating, we blended 4.93% nano-TiO2 paste and improved the anti-corrosion performance of the film. The test results showed that the water and 5% NaCl solution resistance had certain improvement. The SEM photos had proved the good compact film.In the last chapter, we controlled the new prepared high temperature resistant paint with the"Shuangshi"organosilicon ones, produced by Tianjin Zhongtai Zhiyuan Co., Ltd. Except the distance in the flexibility and impact strength( especially after high temperature baking), the green and environmentally friendly compound coating had preferable high temperature resistance and hardness.