| Metal products are easy to corrode and oxidize under oil,water vapor,salt,weak acid,weak alkali,high temperature and other environmental factors,which seriously affect the use and appearance.Therefore,in order to increase the practicability of metal products,it is necessary to develop a high temperature resistant coating with high temperature resistance,anti-oxidation,acid and alkali resistance,good adhesion and good decorative appearance.As a common and water-based coating material,silica sol has a large rigidity and easy cracking,so it must be modified.Due to the high activity of silane monomer in water after hydrolysis,it is difficult to obtain one component high temperature resistant inorganic coatings.In order to be suitable for industrial production,two-component inorganic coatings are prepared.Therefore,this paper intends to use silica sol and silane monomer as modifier as base materials,through the study of the influence of pigment base ratio,additives,inorganic pigments and fillers and EE on the stability and performance of the coating,as well as the test and analysis of the physical and chemical properties of the coating,the environment-friendly water-based non expansive high temperature resistant inorganic coating was prepared.The influence factors of component a color paste,such as the amount of pigment and additives were studied,the results show that:When the ratio of pigment to base is 1:1,the performance of the coating is relatively good;When the iron chrome black content is 13.5%of the total mass of component A,the black high temperature resistant coating can be prepared;When the content of 250HBR in component A is 0.5%of pigment and filler,the viscosity of color paste is suitable;When the addition of sn-5040 in component A is 0.2%,the color paste is uniform and stable;When the dosage of AMP-95 in component A is between0.3%and 0.5%,the color paste has good storage stability.When component A and component B are mixed to prepare the coating,the amount of EE in component B directly affects the stability,application time and viscosity of the coating,and then affects the performance of the coating.The results show when the EE content is 1.5%,the coating is uniform and stable,the viscosity is suitable,and the application time is long,which is conducive to the dispersion and spraying of the coating.The curing time of the coating prepared by the optimized process is12～24 h at room temperature,and the application time is about 100 h;After spraying,surface dry at room temperature for 15～30 minutes,then heat preservation at 180℃for 2～4 h,The coating has excellent physical and chemical properties,such as temperature resistance of600℃,fire resistance of 900℃and adhesion of grade 1.In order to better explain the high temperature resistance mechanism of the coating,in this paper,the surface morphology of the coating before and after the high temperature and fire resistance test was studied,and the heat resistance process of the inorganic high temperature resistant coating was studied by means of optical microscope,XRD and FT-IR.The results show that:for temperature resistance,with the increase of temperature,some raw materials in the coating will decompose.Although these reactions will damage the integrity of the paint film to a certain extent,the silica sol film formed by cross-linking reaction in the coating has not been completely damaged,but the performance of the coating has become worse,for example,the water drainage capacity of the coating will be weakened.For the flammability,the coating is burnt at 500℃and 900℃for 30 minutes,due to the better temperature resistance of the coating and melting of the filler at the lower part of 900℃,the glass phase is formed,which makes the coating maintain a good integrity in the fire resistance test,the iron chromium black in the raw material will undergo oxidation reaction to generate red brown Fe2O3 under high temperature burning,which will make the color of the coating slightly red after the fire. |
