Effect of leveling agent on the appearance of the paint film

effect of the antiflow leveling agent on the appearance of theWang Yanyan 1, Shen Li 2, Chen Yuanzhen 1(1. CNOOC Changzhou Coatings and Chemical Research Institute Co., Ltd., Changzhou, Jiangsu 213016 However, the resin alone can not meet the requirements of the appearance of the paint, must be added leveling agent, etc. to improve the appearance of the paint film. Leveling agent can promote the coating in the drying process into a film to form a flat, smooth, uniform coating film, mainly by reducing the surface pressure between the coating and substrate, so that the coating and substrate has the best wetting, that is, to reduce the surface tensor gradient changes caused by solvent volatility to improve the appearance of the paint film. The compatibility and migration behavior of different types of leveling agents will directly affect the surface stress gradient of paint film, and the rational selection of leveling agent is very important to effectively improve the appearance of paint. After adding different types of leveling agents and their compositions to varnish, monochrome and complex paint, this paper compares the properties of the gloss, fog shadow and brightness of the paint film in parallel to discuss the effect of the leveling agent on the appearance of the paint film.1 Experimental part 1.1 Raw materialshydroxypropyl acrylic resins, pigments, dispersants, catalysts, acrylates leveling agents, fluorocarbon-modified acrylates leveling agents, silicone leveling agents, curing agents, etc.1. 2 Instruments HY970-265 Micro Three-Angle Gloss: BYK-GardnerGbmH; 4632 Micro Mist: BYK-Gardner GbmH; Wave-scan Dual orange peeler: BYK-Gardner GbmH; SFJ-400 sanding, dispersion, mixing multi-use machine: Shanghai Modern Environmental Engineering Technology Co., Ltd.; JA31002 Electronic Balance: Shanghai Yu Hengping Scientific Instruments Co., Ltd.1.3 Coatingthe basic formula for varnishes, monochrome and complex paints is in Table 1.formula for table 1 varnishes, monochrome paints and complex paints 1.4 experimental methods see Figure 1.2 Performance comparison of three types of leveling agents 2.1 static surface stress The results of static surface stress determination of three types of leveling agents are compared to Figure 2.can be seen from Figure 2: Silicone-type leveling agents can effectively reduce static surface stress in three types of leveling agents. In varnish systems, the static surface stress of acrylic and fluorocarbon-modified acrylates leveling agents decreased by 13.81% and 10.18%, respectively. Lower static surface stress facilitates the coating of liquid coatings to better wet the substrate and prevent hole shrinking.2.2 smoothness the paint film smoothness of the three types of leveling agents is compared to Figure 3.can be seen by Figure 3: with the increase in the amount of leveling agent, the smoothness of the paint film is enhanced, when the optimal dosage of the leveling agent is reached, continue to increase its dosage, smoothness remains unchanged. Because silicone leveling agent contains a large number of methamphetyl groups, and its chain segment is short, can effectively improve the smoothness of the paint film.3 Effect of lysate on the appearance of the paint film 3.1 Effect of the leveling agent on gloss The effect of different types of leveling agents and their compositions on the gloss of the paint film is seen in Table 2.As can be seen from Table 2: The 20-degree gloss of varnish coatings with acrylics, fluorocarbon-modified acrylics and silicone leveling agents increased by 0.3%, 1% and 3.5%, respectively. It can be seen that the silicone leveling agent works best under the same amount of addition, which is mainly related to its composition. Silicone leveling agents are mainly composed of small density, low surface stress silicone or modified silicone resin, which can form a thin and smooth single-molecule film layer on the coating surface, thus improving the gloss of the coating film. At the same amount of addition, acrylic or fluorocarbon-modified acrylic leveling agents were used with silicone leveling agents, and the 20-degree gloss of varnish paint film increased by 2% and 0.5%, respectively, compared to their individual use.effect of 3.2 leveling agent on fog shadow The effect of different types of leveling agent and its composition on the shadow value of lacquer film is seen in Table 3.Table 3 Effects of different types of leveling agents and their compositions on the fog shadow value of the lacquer film As can be seen from Table 3, the fog shadow value of the paint film was virtually unchanged with the addition of acrylates and fluorocarbon-modified acrylates. Silicone leveling agent can significantly reduce the fog shadow value of the paint film, in varnish, monochrome paint and complex paint 3 paint samples, the fog shadow value decreased by 33.3%, 32.5% and 31.5%, respectively. This is mainly related to the composition of silicone leveling agents, silicone leveling agents mainly provide pre-leveling, can effectively improve the shadow. Under parallel conditions, acrylic or fluorocarbon-modified acrylic leveling agents were used with silicone leveling agents, and the fog shadow values of the three paint films of varnish, monochrome and complex paint were lower than those of the paint film when acrylates or fluorocarbon-modified acrylates were used alone.
effects of 3.3 leveling agents on freshDifferent types of leveling agents and their compositions were added to varnishes, monochrome and complex paints, and the freshness of the contrasting paint film was tested in parallel, with the results shown in Figure 4.As can be seen from Figure 4: After adding different types of leveling agents to varnish, monochrome and complex paint, the freshness of the paint film is improved, especially the silicone leveling agent can better improve the flatness of the paint film, so that the freshness of the paint film is improved. Similarly, when acrylates or fluorocarbon-modified acrylates and silicone leveling agents are used, the freshness of the paint film is better than that of the paint film when used alone.3.4 Effect of leveling agents on long and short wave levels Adding different types of leveling agents and their compositions to varnishes, monochrome and complex paints, parallel testing and contrasting the long and short wave levels of paint film, the experimental results are found in Table 4.After the leveling agent was added, the long and short wave flow of the paint film decreased on average. However, the effect of different compositions of leveling agents on long and short wave levels is not the same. Silicone leveling agents and fluorocarbon modified acrylates leveling agents had the greatest effect on long and short wave levels, respectively. Short-wave level mainly reflects the episody of the paint film, which is affected by the Bernal vortex. According to the physics of paint film drying, Bernald vortex often forms in the early stages of solvent evaporation in paint film, so to eliminate Bernald vortex must require the addition of leveling agent in the early stage of solvent evaporation can be quickly migrated to the paint film surface, silicone leveling agent can better improve the preflow Flat, so silicone leveling agent can better improve the effect of short-wave leveling, long-wave level mainly reflects the flatness of the paint film, fluorocarbon modified acrylates leveling agent has a better surface state control ability, the substrate wetting is good, anti-shrink hole ability is strong.4 Conclusion (1) With the development of the paint industry and the improvement of the appearance requirements of the paint film, it is necessary to use leveling agent to avoid the paint film orange peel, shrink hole, floating color, flowering and other defects, improve the flatness of the paint film surface.(2) Silicone leveling agent, due to its unique structure, has the advantage of reducing the surface pressure of the paint film and improving the smoothness of the paint film.(3) Different types of leveling agents have different effects on improving the appearance of the paint film because of their different structure and composition, as seen in Table 5.