Requirements of coating for titanium dioxide performance

Coating industry is the largest user of titanium dioxide, especially rutile titanium dioxide, most of which is consumed by coating industry In 2018, the output of 1336 Enterprises above Designated Size in China's coating industry reached 17.5979 million tons, up 5.9% year on year In 2018, in terms of main business income, the total amount of Industrial Enterprises above Designated Size in 1998 reached 326.81 billion yuan, a year-on-year increase of 6.5%, realizing a total profit of 23.648 billion yuan, a year-on-year increase of 5.1% The demand for titanium dioxide is closely related to the development of the coating industry The development of the coating industry will inevitably promote the development of the titanium dioxide industry In 2018, the comprehensive output of 39 large-scale titanium dioxide enterprises in the whole process was 2.9543 million tons, an increase of 85000 tons compared with 2017, with an increase of 2.95% In the total output of 2.9543 million tons, rutile type is 2.293 million tons, accounting for 77.62%; anatase type is 507600 tons, accounting for 17.18%; other titanium dioxide products such as non pigment products are 154000 tons, accounting for 5.2% TiO2 consumed by the coating industry accounts for 58% - 60% of the total consumption of titanium dioxide pigment In China, the consumption proportion is higher, about 60% - 65% Titanium dioxide is one of the most used pigments in the coating industry, accounting for half of the cost of colorant, 90% of the total consumption of various pigments in the coating industry, and 10% ~ 25% of the cost of raw materials There are so many white pigments Why do coatings only focus on titanium dioxide for many years? The main reason is that titanium dioxide is far superior to other white pigments in various main properties See Table 1 for the main performance comparison between titanium dioxide and other white pigments It can be seen from table 1 that titanium dioxide has the highest refractive index, so it has the highest optical properties such as hiding power (opacity) and achromatic power, bright whiteness, high luster and good dispersion Theoretically speaking, in terms of covering power, rutile titanium dioxide is 5.56 times of ordinary lithopone, anatase titanium dioxide is 4.43 times of ordinary lithopone; in terms of achromatic power, rutile titanium dioxide is 6.25 times of lithopone, anatase titanium dioxide is 5.56 times of ordinary lithopone Therefore, from the perspective of application effect alone, one ton of titanium dioxide is at least equivalent to four tons of ordinary lithopone; from the perspective of service life (mainly refers to outdoor anti pulverization), the coating with titanium dioxide as pigment is three times higher than that with ordinary lithopone as pigment, which is the reason why the coating has been choosing titanium dioxide for a long time Titanium dioxide is one of the indispensable parts of the coating Its function is not only to cover and decorate, but also to improve the physical and chemical properties of the coating, improve the mechanical strength, adhesion, corrosion resistance, light and weather resistance of the coating Therefore, in the application of titanium dioxide, in addition to the base materials, solvents, additives and other aspects, and also from the pigment characteristics, paint performance and other aspects, reasonable selection of titanium dioxide for coating performance requirements and specifications Pigment grade titanium dioxide is usually used in the coating industry, and its quality requirements for titanium dioxide are as follows: first, good whiteness; two, good grinding wettability and easy dispersion; three, good weather resistance and durability; four, good chemical stability; five, small particle size, large covering power, high fading power, good opacity and glossiness The requirements of common coatings on the characteristics of titanium dioxide are shown in Table 2 Table 2 requirements for titanium dioxide characteristics of common coatings