Several Main Properties Of Organic Pigments For Plastics Coloring Are Introduced!
The processability and application needs of plastic products should be considered in the organic pigments for plastic coloring. The selected pigments are not only dazzling, but also colorfast and durable, which requires heat resistance, migration resistance, weather resistance, solvent resistance, etc. according to the main properties of organic pigments for plastic coloring, the following are detailed introduction:
1、 The coloring power of a pigment refers to the amount of pigment required for a certain color product, expressed as a percentage of the coloring power of the standard sample. The coloring power of pigments is not only related to their properties, but also to the dispersion of pigments. The dispersion degree mainly refers to the fineness degree of pigment. The greater the dispersion degree is, the higher the coloring power is. However, there is a maximum value beyond which the coloring power decreases.
2、 Heat resistance, the heat resistance of organic pigments for plastic coloring refers to the change of color or performance of pigments at processing and use temperatures. The pigment in PVC and PE should be able to withstand 160 ~ 180 ℃; ABS and PS should be processed at 250 ~ 280 ℃; PP, PA and pet should be above 280 ℃. When considering the heat resistance of pigments, it is also necessary to consider the heating time, because when plastics are processed into products, the processing methods are different, and the heating time is different; generally, the higher the use temperature, the shorter the heat resistance time.
3、 Migration resistance of pigment refers to the long-term contact between colored plastic products and other solid, liquid, gas and other materials or working in a certain specific environment, which may have physical and chemical reactions with the above substances, which is manifested as the migration of pigments from the interior of plastics to the free surface of products, or to the adjacent plastics or solutions.
4、 Light and weather resistance, plastic products such as safety helmet, turnover box, rolling shutter, profile and automobile plastic parts, etc. are required to have good light and weather resistance due to long-term outdoor use. The color of some pigments will change in different degrees under the illumination of light.
5、 Chemical resistance, industrial plastic products are commonly used for storing chemicals and used as pumps and pipes for transporting acid and alkali, so the acid and alkali resistance of pigments should be considered. For example, it is not suitable to use ultramarine and cadmium pigments for coloring plastic products and acid contact, and chrome yellow is not suitable for contact with alkali.
6、 Toxicity: more and more plastic products are used in our daily life, such as packing candy, various drinks, grease containers, plastic toys, etc;
7、 Mixing property: when coloring plastic products, more than two kinds of pigments are often used for color matching. Therefore, it is necessary to understand the mixing performance between them and whether the pigments react with additives and additives in plastics