The basic raw material of pearlescent pigment is mica. Mica is ground into fine powders with different particle sizes, then coated with titanium dioxide to form coatings with different thickness, and then fired at a high temperature above 700 ℃ to make translucent, very stable and almost chemically inert pearlescent pigment. They are not affected by temperature during application. The flake structure will not precipitate, frost or melt in the resin. Pearlescent pigment is non-toxic, and does not contain metal components, depending on chemical principles, forming different colors. A series of pearlescent pigments of white, interference color, metallic color and gold can be obtained through the particle size and coating thickness of mica made by Kong.
Pearlescent pigment is translucent, in the application process, we must pay attention to its optical properties and make use of it to achieve good pearlescent effect. In recent decades, the application of plastic industry in the world has developed rapidly. In China's national economy also occupies an important position, with the improvement and development of plastic forming processing means, plastic products are increasingly rich and colorful. Pearlescent pigments are widely used in plastics. From artificial leather, wallpaper, plastic packaging film, cosmetics, shampoo packaging, household appliances plastic parts, to artificial pearls, plastic buttons and other plastic products, pearlescent pigments are widely used to increase the attraction. Pearlescent pigments can be applied to almost all thermoplastics and some thermosetting plastics. The concentration of pearlescent pigments used in plastics depends on the application conditions. But generally 1-2% (weight of resin) can achieve satisfactory pearlescent effect. For some film products, the concentration of pearlescent pigment should be as high as 4-8%. In addition, some low transparency plastics also need to use a higher content of pearlescent pigment or larger particles to give a special effect.
Material selection
Because the pearlescent pigment itself is translucent, and needs to rely on external light reflection to achieve good pearlescent effect, so in the selection of plastic, should try to use the material with better transparency. The following plastics are commonly used, and their common point is that they are more transparent. After adding pearlescent pigment, light can reach the surface of pearlescent pigment chip through the surface plastic, causing reflection and refraction. HDPE, LDPE, PP, EVA, PMMA, pet, PC, PVC, AK, EPT, PU, Low transparency or opaque plastics, such as GPPS, hips, ABS, etc., have no obvious pearlescent effect, but this does not mean that these plastics can not use pearlescent pigments, but the amount of pearlescent pigments is relatively large.
In terms of the choice of mixed pigments, pearlescent pigments can not be mixed with conventional opaque pigments (such as chromium, cadmium, titanium dioxide). Ordinary pearlescent pigment can be used for transparent and translucent plastic resin, the use of pearlescent pigment will bring a charming color visual effect. Pearlescent pigments are widely used in cosmetics containers, all kinds of packaging, toys, decorative materials, films and other plastic products.