Titanium dioxide is an inorganic compound with the chemical formula of TiO2. It is a white solid or powdered amphoteric oxide with a molecular weight of 79.866. It is non-toxic, has the best opacity, the best whiteness and brightness, and is considered to be the best white pigment in the world today.
Titanium white has strong adhesion and is not easy to change chemically. It is always white. It is widely used in coatings, plastics, paper making, printing ink, chemical fiber, rubber, cosmetics and other industries. Its melting point is very high, and it is also used to make refractory glass, glaze, enamel, clay, high-temperature resistant experimental utensils, etc. Titanium dioxide can be extracted from rutile by acid decomposition or decomposed from titanium tetrachloride. There are three allotropes of titanium dioxide in nature: rutile type, anatase type and plate titanium type. In addition, there are several synthetic crystal forms.
Classification
Class I: titanium dioxide is dry ground and untreated. Class I titanium dioxide has low surface area and low oil absorption value.
Class II: Class I titanium dioxide is treated and wet ground to remove large particles, and coated with 4% silicon aluminum. It has the lowest surface area and the lowest oil absorption value.
Class III: It is a typical ultra-fine coating grade with organic coating.
Class IV: large coverage, which can also be divided into IV a and IV b, with coverage ranging from 5 to 10%. Ⅳ b is mainly used in titanium dioxide with high addition, because its opacity is better than Ⅳ a.
Performance
Rutile type titanium dioxide absorbs more radiation energy at high energy (shorter wavelength) than anatase type titanium dioxide. In other words, for rutile type titanium dioxide, in the UV-wavelength range (350-400nm) with strong killing power, its reflectivity of ultraviolet radiation is far lower than anatase type titanium dioxide. In this case, it has much less ultraviolet light to share on the surrounding film-forming materials, resins, etc., so the service life of these organics is longer, This is why rutile titanium dioxide has better weather resistance than anatase.