How does the plastics industry choose titanium dioxide in a targeted manner?
The application of titanium dioxide in plastic products, in addition to using its high hiding power, high achromatic power and its pigment performance, it can also improve the heat resistance, light resistance, weather resistance of plastic products and protect plastic products from UV light. Attack, improve the mechanical and electrical properties of plastic products. How should we choose titanium dioxide in the plastics industry? The titanium dioxide distributors in Dongguan will introduce the following nine points in detail.
1. The color of titanium dioxide in the plastics industry
Color is an important technical indicator for marking pigments. Titanium dioxide is called "king of white pigment", and the color index of titanium dioxide is whiteness. Even titanium dioxide with the same chemical composition will have different colors due to different process routes, raw materials, equipment and technical level. Although the color light depends on the chemical composition, the more important and often decisive factor is its Particle shape, size, particle size distribution, crystal type, impurity content, etc.
2、The hiding power of titanium dioxide selection in the plastics industry
The optical nature of hiding power is caused by the difference in refractive index between the pigment and the medium surrounding it. Rutile titanium dioxide has a refractive index of 2.71 and anatase 2.55, which is the white pigment with the highest hiding power. The covering effect is mainly due to scattering caused by titanium dioxide, or absorption due to the presence of colored substances, or both of the above reasons to reduce the intensity of incident light, and a covering phenomenon occurs. Therefore, the main reason for determining the hiding power of titanium dioxide is related to the particle shape, particle size and particle size distribution of titanium dioxide in addition to the chemical composition and crystal form.
3、Coloring power of titanium dioxide selection in the plastic industry
Coloring power is an important characteristic index of titanium dioxide, that is, after titanium dioxide is mixed with another pigment, the ability of the mixture to display its own pigment can be obtained. In other words, for a white pigment, after it is mixed with a dark pigment, the lighter the color of the mixture, the stronger its coloring power (achromatic power).
4、Selection of oil absorption of titanium dioxide in the plastics industry
Oil absorption is also one of the important pigment properties of titanium dioxide, because it relates to the filling state of titanium dioxide in the vehicle, and can explain its dispersion performance in the medium. It is used in the paint industry to estimate the consistency of paints before mixing paints, to guide the formulation of paints, and to estimate their pigment volume concentration (pvc).
5、Selected chemical composition of titanium dioxide in the plastics industry
The chemical composition of titanium dioxide determines the chemical properties of titanium dioxide. It is the main sign of the difference between pigments. In addition to reflecting a series of pigment properties of pigments, such as whiteness, achromatic power, oil absorption, etc., its application The performance effect is also great, such as weather resistance, dispersion and so on.
6、The light and weather resistance of titanium dioxide selected in the plastics industry
The light resistance and weather resistance of titanium dioxide are important indicators to measure the application performance of titanium dioxide. It is meaningless to refer to its light resistance and weather resistance. This index is meaningful only after applying titanium dioxide to related application fields (such as automotive paint, profiles, etc.). Therefore, the light resistance and weather resistance of titanium dioxide refers to its light resistance and weather resistance in a certain field. In addition, the light resistance and weather resistance of titanium dioxide should be measured to ensure that the weather resistance of its application carrier is better than that of titanium dioxide. The main factors that affect the weather resistance index of titanium dioxide are its chemical composition, chemical form of coating material, crystal structure, application formula, etc.
7、The gloss of titanium dioxide in the plastics industry
The gloss of titanium dioxide is an important indicator to measure the application performance of titanium dioxide. Usually titanium dioxide has no gloss, and its glossiness is meaningless. Only after applying titanium dioxide to related application fields (such as automotive paints, inks, profiles, masterbatch, etc.), this index is meaningful.
8、Selection of volatile matter of titanium dioxide in the plastics industry
The volatile content of titanium dioxide is actually the water content. Because of the high energy and hydroxyl groups on the surface, the surface must always absorb a certain amount of water to reduce its surface energy. The amount of absorbed water is related to the surface organic treatment of titanium dioxide and the humidity and temperature of the surrounding environment where it is stored. The level of volatile matter of titanium dioxide cannot determine the quality of the product, depending on its application system. In general, the level of volatiles in the water-based system has little effect on the application, but for oily systems and polyolefin systems, the lower the volatiles, the better, because the high volatiles will affect their dispersion properties and products in the system. quality.
9、Dispersion of choice of titanium dioxide in plastics industry
Dispersibility is also called grinding dispersibility or grinding wettability. It is called water dispersibility when used in water as a medium, and it is called oil dispersibility when used in coating systems such as solvents. The dispersion index is an important application index of titanium dioxide. The quality of dispersion not only affects the indexes such as the tinting power, hiding power and oil absorption of titanium dioxide pigments, but also affects the gloss and weather resistance of coating film forming or profile forming. When grinding and dispersing in a paint production plant, the quality of the dispersibility directly affects the length of the grinding and dispersing time, which is one of the important economic indicators in the production of paint. Moreover, if the grinding time is too long, it will increase equipment pollution and make the product whiteness change. difference. In the production of plastic masterbatches or profiles, the quality of dispersion directly affects the cycle of replacing the head screen and the performance of the final product.