Titanium dioxide has two types of structures: rutile type (R type) and anatase type (A type). Rutile crystal structure is dense, relatively stable, and has low optical activity, so it has good weather resistance, and at the same time, it has high hiding power and achromatic power. Therefore, it has better application performance and obtains a wider range of applications.
Titanium dioxide is not only used as a colorant in the rubber industry, but also has the functions of reinforcement, anti-aging and filling. Titanium dioxide is added to white and colored rubber products. Under sunlight, it is resistant to sunlight, does not crack, does not change color, has a large elongation rate and is resistant to acid and alkali. Titanium dioxide for rubber is mainly used for automobile tires, rubber shoes, rubber floors, gloves, sports equipment, etc., generally anatase type. But for the production of automobile tires, a certain amount of rutile products are often added to enhance the anti-ozone and anti-ultraviolet capabilities.
Titanium dioxide is also widely used in cosmetics. Because titanium dioxide is non-toxic and far superior to lead white, almost all kinds of fragrant powder use titanium dioxide to replace lead white and zinc white. Only 5%-8% titanium dioxide can be added to the fragrance powder to obtain permanent white color, which makes the fragrance more creamy, with adhesion, absorption and covering power. In gouache and cold cream, titanium dioxide can reduce the feel of greasy and transparent. Titanium dioxide is also used in various other fragrances, sunscreens, soap flakes, white soaps and toothpaste.
The enamel made of titanium dioxide has strong transparency, low quality, strong impact resistance, good mechanical properties, bright colors, and is not easy to be polluted. Titanium dioxide for food and medicine is titanium dioxide with high purity, low heavy metal content and strong covering power.
1) Relative density
Among the commonly used white pigments, titanium dioxide has the smallest relative density. Among the white pigments of the same quality, titanium dioxide has the largest surface area and the highest pigment volume.
2) Melting point and boiling point
Since the anatase type transforms into a rutile type at high temperature, the melting point and boiling point of anatase titanium dioxide do not actually exist. Only rutile titanium dioxide has a melting point and boiling point. The melting point of rutile titanium dioxide is 1850 ° C, the melting point in air is (1830 ± 15) ° C, and the melting point in oxygen-rich is 1879 ° C. The melting point is related to the purity of titanium dioxide. The boiling point of rutile titanium dioxide is (3200±300)°C, and titanium dioxide is slightly volatile at this high temperature.
3) Dielectric constant
Due to the high dielectric constant of titanium dioxide, it has excellent electrical properties. When determining some physical properties of titanium dioxide, the crystallographic direction of titanium dioxide crystals should be considered. The dielectric constant of anatase titanium dioxide is relatively low, only 48.
4) Conductivity
Titanium dioxide has semiconductor properties, its conductivity increases rapidly with temperature, and it is also very sensitive to oxygen deficiency. The dielectric constant and semiconductor properties of rutile titanium dioxide are very important to the electronics industry, and these properties can be used to produce electronic components such as ceramic capacitors.
5) Hardness
According to the scale of Mohs hardness, rutile titanium dioxide is 6 to 6.5, and anatase titanium dioxide is 5.5 to 6.0. Therefore, in chemical fiber extinction, anatase type is used to avoid abrasion of spinneret holes.
6) Hygroscopicity
Although titanium dioxide is hydrophilic, its hygroscopicity is not very strong, and the rutile type is smaller than the anatase type. The hygroscopicity of titanium dioxide has a certain relationship with the size of its surface area. Large surface area and high hygroscopicity are also related to surface treatment and properties.
