Coating Industry:
Rutile type
Titanium Dioxide, as one of the two most important types of titanium dioxide, is an excellent white pigment with high dispersion, high weather resistance, high covering power, and excellent stability. Widely used in interior and exterior latex paint, industrial coatings, composite inks, flexographic inks, laminated paper,
Plastic Masterbatch, powder coatings, etc. So, what are the physical properties of rutile type titanium dioxide?
01
relative density
The relative density of titanium dioxide is related to its crystal morphology, particle size, chemical composition, and especially the surface treatment amount. During the manufacturing process, it increases with the increase of calcination temperature and prolongation of calcination time. Among commonly used white pigments, titanium dioxide has the smallest relative density. For white pigments of the same quality, titanium dioxide has the largest surface area and the highest pigment volume. The relative density of rutile type titanium dioxide is 3.8-3.9g/cm3, while the relative density of rutile type titanium dioxide is 4.2-4.3g/cm3.
02
Melting and boiling points
Due to the fact that both rutile type and plate type titanium dioxide can transform into rutile type at high temperatures, their melting and boiling points actually do not exist. The melting point values of rutile type titanium dioxide are inconsistent in various data records. It is generally believed to be between 1800 and 1875 ℃. According to data, the melting point in air is 1830 ± 15 ℃, while in oxygen rich conditions it is 1879 ± 15 ℃. The melting point is related to the purity of titanium dioxide. The boiling point of rutile type titanium dioxide is (3200 ± 300) K.
03
Dielectric constant
Due to its high dielectric constant, titanium dioxide has excellent electrical properties. Under the action of an external electric field, the ions interact with each other, forming an extremely strong local internal electric field. Under the action of this internal electric field, the outer electron orbitals of ions undergo strong deformation, and the ions themselves also undergo significant displacement.
The trace impurities contained in the crystal form of titanium dioxide have a significant impact on the dielectric constant. The dielectric constant of the rutile type varies with the direction of the titanium dioxide crystal: when parallel to the C-axis, its dielectric constant is measured to be 180; 90 when at right angles; The average value of its powder is 114. The dielectric constant of rutile titanium dioxide is only 48.
04
conductivity
Titanium dioxide has semiconductor properties, its conductivity increases rapidly with temperature, and it is also very sensitive to hypoxia. Rutile type titanium dioxide remains an insulator at 20 ℃, but its conductivity increases by 107 times when heated to 420 ℃; The conductivity of stoichiometric titanium dioxide (TiO2) is less than 10-10s/m, while when a small amount of oxygen is lost, the conductivity of TiO2 such as TiO2 1.9995 is 10-1s/m. The electronic industry often uses the dielectric constant and semiconductor properties of rutile type titanium dioxide to produce electronic components such as ceramic capacitors.
05
hardness
If using a 10 point scale Mohs hardness meter (which only represents the hardness level of various crystals and does not represent their true ratio), the hardness of rutile titanium dioxide is 5.5-6.0, and that of rutile titanium dioxide is 6-7. The hardness is related to the crystal structure of titanium dioxide, and in production, it is related to the purity of the product and the calcination temperature. High temperatures are prone to sintering, and the hardness also increases accordingly. It is precisely because of the high hardness and difficulty in crushing of rutile type titanium dioxide that it has a higher wear rate on the spinneret hole and a greater wear on the roller, that it is not suitable for chemical fiber extinction and photographic concave printing.
06
Hygroscopicity
Although titanium dioxide has hydrophilicity, its hygroscopicity is not very strong, and the hygroscopicity of the rutile type is slightly greater than that of the rutile type. The hygroscopicity of titanium dioxide is related to the properties of the treatment agent during surface treatment, as well as to the size of its specific surface area. The hygroscopicity of titanium dioxide with a larger specific surface area is also slightly higher.
07
thermal stability
Titanium dioxide is a thermally stable compound that undergoes slight deoxygenation under strong heating under vacuum, accompanied by a dark blue color. This reaction is reversible and will return to its original white color after cooling.
