Exposed to the natural environment, the steel structure building has been affected by wind, sunshine, light and rain for a long time. Soon, the wall surface appears discoloration, paint peeling, dust and other phenomena. With the passage of time and temperature change, the dust is firmly attached to the wall, and the dust accumulates, resulting in the whole building looks dirty and old.

　　与这些现象直接相关的是建筑外墙材料，即彩涂钢板的涂装体系。影响涂料体系性能的主要因素有:树脂、颜料、底漆、热反射。

　　What is directly related to these phenomena is the coating system of building exterior wall materials, i.e. color coated steel plate. The main factors that affect the performance of coating system are resin, pigment, primer and heat reflection.

　　有些有机颜料耐光性能差，不耐碱性强，在阳光、化学物质、空气污染等影响下，颜料会发生质变，有些颜料粉末会引起漆膜褪色。

　　Some organic pigments have poor light resistance and strong alkali resistance. Under the influence of sunlight, chemicals and air pollution, the pigments will undergo qualitative change, and some pigment powders will cause the paint film to fade.

　　一般彩钢板表面的油漆粉末主要是成膜树脂的老化降解，树脂和颜料在颗粒状态下从表面析出的现象。树脂的耐候性是决定漆粉质量的关键因素。粉化会导致彩钢板表面出现白色粉末，造成褪色、光泽度，从而影响建筑外观。

　　Generally, the paint powder on the surface of color steel plate is mainly the aging degradation of film-forming resin, and the phenomenon that resin and pigment are separated from the surface in particle state. The weather resistance of resin is the key factor to determine the quality of paint powder. Powdering will cause white powder on the surface of color steel plate, which will cause fading and glossiness, thus affecting the appearance of the building.

　　漆膜脱落是由于涂料树脂长期在室外使用而引起的老化现象。造成漆膜脱落的主要原因有:长期的紫外线照射、基材表面预处理的地址、油漆配方粗糙或涂面漆与底漆搭配不当。

　　The falling off of paint film is the aging phenomenon caused by the long-term outdoor use of paint resin. The main causes of paint film falling off are: long-term ultraviolet radiation, the location of substrate surface pretreatment, rough paint formula or improper matching of finish coat and primer.

　　综上所述，涂层系统必须选用的原材料，这对于避免或减少薄膜的变色和褪色是非常重要的。

　　To sum up, the coating system must select high-quality raw materials, which is very important to avoid or reduce the discoloration and fading of the film.