浅谈彩涂板用环氧底漆存在瓶颈时期

随着彩涂板行业的快速发展，开发性能优异的彩涂板涂料以满足先进、多样化产品的需求已成为国内外研究的热点。其中，制备附着力好、柔韧性好、与面漆相容性好的底漆对提高彩板涂料的性能至关重要。以电镀锌板为基材， 彩涂板经烘烤后涂有有机漆的产品为电镀锌彩涂板。由于电镀锌板的锌层很薄，锌含量通常为20/20g/m2，因此该产品不适合在室外制作墙壁和屋顶。但由于其外形美观，加工性能优良，主要用于家用电器、音响、钢制家具、室内装饰等。

With the rapid development of color coated plate industry, the development of color coated plate coatings with excellent performance to meet the needs of advanced and diversified products has become a research hotspot at home and abroad. Among them, the preparation of primer with good adhesion, flexibility and good compatibility with the top coat is very important to improve the performance of color plate coating. The product obtained by baking with the electro galvanized sheet as the substrate and coated with organic paint is the electro galvanized color coated sheet. Because the zinc layer of the electro galvanized sheet is thin and the zinc content is usually 20 / 20g / m2, the product is not suitable for making walls and roofs outdoors. However, due to its beautiful appearance and excellent processing performance, it can be mainly used for household appliances, acoustics, steel furniture, indoor decoration, etc.

Due to many influencing factors, the preparation of primer is a complex process. Recently, domestic researchers have used orthogonal experiment to determine the influence of various factors on the performance of epoxy primer, so as to reasonably determine the best formula with less steps. The prepared paint film has obvious advantages of hardness and solvent resistance, and excellent adhesion. According to experts, they focused on six influencing factors: color base ratio, amount of crosslinking agent, catalyst, defoamer, surfactant reducing agent and wetting dispersant. The selected crosslinking curing agent is urea formaldehyde resin sm-526. The experiment shows that the amount of crosslinking curing agent has the greatest impact on the adhesion of the paint film, has a great impact on the bending and MEK wiping resistance, and has no significant impact on the hardness of the paint film. Because domestic coil coatings lag behind foreign products in variety and quality, Chinese manufacturers have to adopt expensive imported coatings when producing color plates, which greatly affects the development of color plate industry in China. Therefore, experts call on the domestic industry to break through the bottleneck of epoxy primer for color coated plate as soon as possible.
At 15%, except that the hardness is the same as other 3 levels, other properties are poor; At 20%, MEK wiping resistance and bending resistance are the best, and the adhesion is general (mean 1.3); At 25%, the MEK wiping resistance and hardness of the paint film are the best, and the other two properties are poor. Considering the processability of the color plate, the researchers selected 20% of the crosslinking curing agent. Experts said that the above research has made a good start, but further research is needed to truly break through the bottleneck of epoxy primer for color coated plate. In the experiment, the effect of four dosage on hardness was not obvious (mean value was 5.0); When the amount of crosslinking curing agent is 10%, the adhesion is the best (the average value reaches 0.3), the MEK wiping resistance is relatively poor, and the bending performance is better.