Application of Titanium Dioxide in Plastics
The plastic industry is the second largest user of titanium dioxide. Generally, the consumption of titanium dioxide in the plastic field accounts for 20% of the consumption of titanium dioxide in the field of application. The plastic industry has been the fastest growing area in recent years, with an average annual growth rate of 6%. In over 500 brands of titanium dioxide in the world, more than 50 are special use for plastic. Titanium dioxide is applied to plastic products, besides its high covering power, high achromatic force and other properties of pigment, to improve the heat resistance, light resistance, weathering resistance of plastic products so that the plastic products are protected from the invasion of UV light and the mechanical and electrical properties of the plastic products are improved. Because the coating of plastic is much thicker than that of paint and ink, it does not require too high volume of pigment. With its high covering power, tinting strength, the general consumption is only 1%~5%. It is used in almost all thermosetting and thermoplastic plastics, such as polyolefines (mainly low density polyethylene, polypropylene), polystyrene, ABS, PVC and so on. It can be both mixed with the resin dry powder and the liquid containing the plasticizer. Some are used to process the color master batch first.
Most titanium dioxide anatase
used in plastic are fine. Generally, the diameter of the coating-using titanium dioxide is 0.2~0.4μm. The diameter of the plastic-using titanium dioxide is 0.15~0.3μm so that it can obtain the blue base phase, which has a shading effect on the most yellow resin or the easily yellowing resin.
The plastic-using titanium dioxide generally has the organic surface treatment (polyol, or siloxane) because coating-using titanium dioxide is different from plastics-using titanium dioxide. The former is made through mixing by shearing force in low polarity resin. Titanium dioxide after organic surface treatment can disperse well under proper mechanical shearing force.