Preparation And Properties Of Water Based Anti-corrosive And Heat Insulation Coatings

Facilities made of metal materials are easy to be damaged by long term chemical and electrochemical corrosion. Besides, the surface temperature of metallic facilities is easily to rise under the exposure of solar light, causing serious safety issues. Applying coatings with anti-corrosive and heat insulation properties to such metallic devices can protect them from corrosion and prevent heat accumulation as well. In this way, the working stability of the devices can be improved and their service life span can be prolonged. In the cases as petrochemical tanks, pipelines, outdoor facilities, high-speed trains, bridges as well as many other areas, coatings anti corrosive and heat insulation properties have great application prospects.According to the requirement for both anti-corrosive and heat insulation, waterborne multi-functional coatings are designed by using the theories of anti-corrosive and heat insulation mechanism. The influence of pigment types, size and distribution, cooperation of different pigments, pigment volume concentration(PVC) and coating colors on both heat insulation and anti corrosive properties are discussed systematically. Though persistent formula optimization, all the components in the formula can work synergistically to meet both the criteria of anti-corrosive and heat insulation for metallic application.Measurements like reflection spectra, contract angle test, neutral salt spray test and laser particle size analysis are included for characterization of the used materials and evaluation the performance of the prepared products. The results show:(1) The heat insulation ability is determined by the type of pigments used. Rutile titanium dioxide pigments show strong reflectance ability to infrared and visible light. The reflect intensity depends on the particle size and distribution. (2) The anti corrosive ability of the coatings mainly controlled by anti-corrosive pigments and PVC of the coatings. Molybdenum-modified zinc phosphate which is environmental friendly shows the best anti-corrosive performance among the family of zinc phosphate pigments we studied in the experiment. Giving an overall consideration of the requirement for both anti-corrosion and heat insulation, formulas using TiO2 and Mo-Zinc phosphate as functional pigments, waterborne Acrylic emulsion as film forming materials, have a great comprehensive performance for application. The range of coating PVC should be controlled between 20% and 30%.Finally, research on anti corrosive and heat insulation coatings is continued in the endeavor of maintaining a comfortable interior temperature for the apparatus like living-cargo containers, trains and cabins by using thermochromic coatings. The thermochromic coatings we prepared in this paper can change the color according to the surrounding temperature. The transition temperature of prepared coatings is 25℃. When the surrounding temperature is lower than 25℃, they present yellow. When the temperature gets higher than 25℃, they turn into white. The spectrum data show that comparing to coatings at low temperature, coatings at high temperature have much better solar reflective ability. Computer modeling and energy simulation are carried out to evaluate their energy saving performance in application. The result shows that thermochromic coatings can decrease the indoor energy consumption when they are used in areas which have cold winter and hot summer.