WANG Peng, CHEN Chuan-yin, LUO Wen-xing (Zhanchen New Material Group Co., Ltd., Shenzhen 518107, Guangdong, China)
Abstract: The preparation and application of waterborne sprinkle wood paint was discussed. The related technical properties, influences of raw materials and improvement plan were studied. The trend was forecasted.
With the advent of the low-carbon economy era, environmental protection and energy are the two major challenges we face in the 21st century. To cope with this challenge, the coatings industry is gradually shifting from traditional varieties with high pollution, high energy consumption, and extreme dependence on petroleum industry products to water-based coatings, Environmentally friendly, resource-saving products such as radiation-curable coatings, powder coatings, and high-solids coatings. Water-based wood coatings are one of the main varieties of industrial coatings. They refer to water-based coatings used for decoration and protection on wooden products. The product introduced in this article is also one of the waterborne wood coatings. It is often applied to the surface coating of wooden acoustics and decorative boards. The coating is similar to the effect of dripping drops. This coating not only protects the surface of the speaker from external forces, but also has Certain artistic and artistic sense. Spilled paint has a full appearance and strong decoration, which can conceal defects such as rough and uneven surfaces or mechanical damage on the surface of the object being painted. Through the selection and matching of the main film-forming substances, film-forming aids, rheological additives, etc. in the product, the three-dimensional feel and texture of the coating are improved, and the mechanical properties of the coating film are enhanced.
1 Experimental process
1.1 Equipment and materials (see Table 1)
1.2 Resin screening
The most important performance requirements of sprinkle paint are: the effect of sprinkle should be natural, round and full, the gloss is generally semi-gloss or bright, high hardness and rapid increase in hardness. If it is applied to audio coating, it must also have excellent resistance Chemical resistance, including water resistance, alcohol resistance, red wine resistance, etc. Therefore, from the perspective of formula design, the first thing to consider is the properties of the main film-forming substances, that is, the main resin Tg, fullness, gloss, physical properties, and its compatibility with color paste.It can be seen from Table 2 that the resin with a higher Tg has higher hardness, but the risk of single use is higher, cracking may occur, and the amount of film-forming additives is higher, which is not environmentally friendly. Therefore, the combination method was selected. AC and PUD not only met the requirements of hardness and fullness, but also improved the williness of the coating film. The T-2 scheme was used in this experiment, and the ratio was sample 3: sample 8 = 3: 2.
1.3 Selection of film-forming aids
The main film-forming substance is determined as the T-2 scheme in Table 2. The film-forming aids need to be selected. It is necessary to ensure an appropriate drying speed without affecting the safety of paint samples and coating films. The impact of the analysis is shown in Figures 1 to 3.
From the data in Figures 1 to 3, it can be analyzed that the selection of a suitable film-forming aid has a crucial effect on the drying and safety of the system. Excessive film-forming aids will affect the drying time of the system, and there is The risk of sticking, and the insufficient amount of addition, there will be the risk of cracking, so the selection of film-forming additives must be careful. Sometimes in order to achieve the desired effect, you can choose to use a combination of film-forming aids. In the experiment, DPnB was added with BCS. The addition amount was 5%, and the ratio was 4: 1. speed.
1.4 Selection of color paste
The basic structure of the formula was determined. The auxiliary materials need to be selected and matched. Since the spray paint is mostly black, black paste was used as the test material in the experiment. Six different manufacturers and different brands of black paste were tested. The main problems are compatibility and stability. Stability is mainly reflected in high-temperature storage coking, and sometimes it is a manifestation of system incompatibility, as shown in Figure 4.
After repeated screening, a black paste with excellent compatibility and stability was determined-N131-CN water-based black paste.1.5 Selection of additives and fillersUnder normal circumstances, additives play an auxiliary role, and rarely have a key role in the final performance of the product, such as hardness, fullness, gloss, etc., but in water-based spray paint, some additives play a role Very critical effects, such as dispersants, rheological additives, etc., directly affect the final spray point effect and gloss of the coating film. The choice of filler also plays an important role in the three-dimensional effect of the spray point, gloss, and hardness of the coating film. The tests were performed on the additives and fillers, as shown in Tables 3 and 4.
According to the test data in Tables 3 and 4, the experimentally selected formula defoaming system is BYK093 + Tego901W, which not only ensures the system’s defoaming efficiency, but also does not affect the gloss.In order to achieve the special effect of water-based spray paint, the rheological system needs to select a thickener with certain thixotropy. Among them, the performance of RM-8W can be satisfied. It must not be too high in viscosity, which will cause uneven drawing and sprinkle points, or high thixotropy, which will cause the effect of sprinkle points to become dry and not round, as shown in Figure 5.
It can be seen from Figure 5 that the effect of rheological additives on water-based spray paint is very important. Not only should a thickener suitable for the system be selected, but the amount of addition must be controlled, viscosity and thixotropy Be moderate. In addition, the selection of the filler is also particularly important. The tests were performed on several fillers, and the results are shown in Table 5.
Considering the viscosity, gloss and stability of the system, glass powder was used as filler in the experiment, and the addition of glass powder further improved the mechanical properties of the system.1.6 Formulation and performanceAccording to the above-mentioned experimental tests, a water-based spray paint formula with beautiful appearance, texture, and beautiful shape can be prepared. The specific formulas and performance parameters are shown in Tables 6 and 7.
Through the discussion in this article, it is concluded that using a suitable emulsion or finding suitable resins, adding a certain proportion of fillers, combining efficient additives and additives, and adjusting the viscosity with a suitable rheological additive, like water-based coatings. Can be beautiful, texture, round, excellent three-dimensional effect of the spray point coating, and also has excellent mechanical properties.