The Sio Aluminum Flake <sub> 2 </ Sub> Coated With Coloring

Coloring aluminum flake powder has special angle-dependent optical effects that can satisfy people's pursuit of colorful by the people's attention. Therefore, the studies of coloring aluminum flake powder are a new direction of paint and coating industry, and they have great application value and economic value. Bases on the coating of the SiO2 on the surface of aluminum flake powder, this paper studies the preparation of coloring aluminum flake powder by the deposition coating method using pigment and SiO2.This paper studies the coating of the SiO2 on the surface of aluminum flake powder by tetraorthosilicate(TEOS) sol-gel process, The coating process was affected by many factors such as the addition quantities of TEOS, the ratio of distilled water to TEOS, the addition quantities of the catalyst, reaction time, reaction temperature, and so on. The effect of SiO2-coated is measured by the hydrogen evolution testing. The results of experiments showed that, the optimum conditions including factors as below:The total reaction system is set to 100mL, aluminum flake powder 2g, the addition quantities of TEOS is about 20%, the ratio of distilled water to TEOS is 25, the catalyst (diamine) 1mL, reaction time for 12h, the reaction temperature is 40℃. The hydrogen test, size test, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and spectroscopy (EDS) were applied to analyze the SiO2/AI composite particles which were prepared under the optimum conditions. The results of experiments showed that, SiO2/AI composite particles coated with a layer of SiO2 which featured in compactness, smooth, the SiO2 of the layer's composition came into existence as amorphous, and the light can through it, so that SiO2/AI composite particles retain metallic luster of the raw aluminum flake powder also has a good hydrophilicity, good dispersion, good corrosion resistance and so on.Bases on the coating of the SiO2 on the surface of aluminum flake powder, this paper studies the preparation of coloring aluminum flake powder by the co-deposition coating method using pigment and SiO2. In this paper, coloring aluminum flake powder were prepared by two methods, the first method is co-deposition coating method using pigment and SiO2. The coloring effect was affected by the addition quantities of TEOS. The results of experiments showed that, When the addition quantities of TEOS is too small, aluminum flake powder can not be colored, the addition quantities of TEOS is more than 6mL, aluminum flake powder can be colored. Respectively, the addition quantities of TEOS is 6mL,8mL,10mL,12mL and 16mL, more addition quantities of TEOS, deeper color of coloring aluminum flake powder. When the addition quantities of TEOS is 16mL, the polymerization of TEOS is incomplete, the results of XPS analysis showed that, [Si(OSi)3OH] exists on the surface of coloring aluminum flake powder. The second method is that pigment deposited on the surface of aluminum flake powder at first, and then coated with SiO2. The results of experiments show that, in the process of pigment deposited on the surface of aluminum flake powder, the addition quantities of the additive is 3mL, pigment deposited on the surface of aluminum flake powder better. In the process of coating using SiO2, better addition quantities of the TEOS is 4mL. By comparison, in the case of less addition quantities of the TEOS, aluminum flake powder can be colored by the second approach, taking the cost savings and the maintenance of raw aluminum flake powder's characteristics into consideration, the second method is better. The hydrogen evolution test, size test, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and spectroscopy (EDS) were applied to analysis coloring aluminum flake powder, the results showed that, the surface of coloring aluminum flake powder coated with a film which consisted of silicon dioxide and pigment. The SiO2 of the layer came into existence as amorphous, pigment is does not chemical reaction, while coloring aluminum flake powder has a good hydrophilicity, good dispersibility, good corrosion resistance.