How to use titanium dioxide?
1.Background of Titanium Dioxide Application：
Titanium dioxide is a very important white pigment, which is widely used in coatings, plastics, paper, ink and other industries. Therefore, the application index of tio2 is extremely important.
The glossiness of an object refers to the ability of the material to reflect the projected light. The stronger the reflection ability, the greater the glossiness. In practical application, the pigment is only one of the coating groups. The pigment itself is not glossy, and the coating film is shiny.
However, the influence of the characteristics of the pigment in actual production determines the gloss of the coating film, and the appearance of the pigment determines the properties of the pigment. This is an indisputable fact. Giving pigments a complete and uniform morphology is an important aspect of improving the gloss of products.
The main reasons for affecting the gloss of titanium dioxide pigments after film formation also include its particle size, inorganic treatment and dispersibility. Under the same conditions of film treatment, improving the singleness of titanium dioxide particles can improve the dispersibility of the product, and subsequently improve the gloss of the product, but not vice versa.
At present, titanium dioxide has incomplete coating caused by uneven particle dispersion and gloss deviation caused by particle agglomeration. In this case, there is an urgent need to provide a method for improving the gloss of titanium dioxide, so that the application of this kind of titanium dioxide is more extensive.
2.The dosage and application of tio2 pigments in coatings
Tio2 has excellent optical, electrical properties and pigment application properties, so it has a wide range of use values. The physical, chemical and optical properties of Tio2 pigments are mainly determined by the original state of the pigment particles before coating and the chemical structure of the coating on the surface.
Titanium dioxide pigments generally use oxides of silicon, aluminum and zirconium as surface treatment agents, which are deposited on the surface of particles to form a coating, and the form, quantity and method of precipitation are controlled by process. Some also use organic treatment agents. Different surface treatment methods endow titanium dioxide with individual characteristics to meet the different needs of paint formulation design.
In order to meet the purpose of covering power, generally 30-40 microns of enamel can cover. The addition amount is 15-25% of the total formula; from the perspective of weather resistance and high gloss, it is necessary to use matting powder to obtain high weather resistance matte paint, and the principle of minimum tio2 addition and no other fillers is added; from the perspective of cost Consider adding other system fillers to reduce costs. The addition of other system fillers will reduce the amount of titanium dioxide added, but the problem of vividness must be balanced; for interior wall latex paints that exceed the CPVC value, the amount of Tio2 added is 2%-4%. Require.
In terms of dispersion, wetting and dispersing additives may not be used in primers or topcoats with low requirements from the perspective of formulation cost, but the phenomenon of floating color and blooming should be controlled within an acceptable range. Adding controllable flocculation additives to the primer and topcoat can control the phenomenon of floating color and blooming.
In high-grade topcoats, low molecular weight wetting and dispersing additives can be used for titanium dioxide paste, and high molecular weight wetting and dispersing additives for other organic pigment pastes are generally compatible;
if it is a fluorocarbon topcoat, it is generally necessary to use Tio2 with high dispersibility and high weather resistance, and the selection of appropriate wetting and dispersing additives, can solve the problem of floating color and blooming; if anti-corrosion primer, architectural latex paint and anti-corrosion topcoat, choose Tio2 with good dispersibility, With the help of wetting and dispersing additives, the dispersion effect can be achieved directly by using a high-efficiency high-speed disperser, which saves the grinding process.
The dosage and the variety of wetting and dispersing additives are different, so it is necessary to add the dosage according to the production requirements to achieve the best effect of the topcoat.
3. The method of titanium dioxide surface treatment
In 1916, it was produced due to the production of titanium dioxide and other problems, due to the cleaning of Fe3+ and other equipment and the control of pigment particle size. In 1930, the white powder problem developed to the point that it could not affect the production of Tio2.
Chemically generated nanoparticles, so it is found that tio2 pigments has chemical activity when used in the surface, which accelerates the development of surface treatment technology by using inorganic oxides such as A12O3 and SiO2 in large quantities. Raise, as another commonly used product of its kind, also comes in several types of surface treatments.
1) Universal titanium dioxide
The output of these general-purpose titanium dioxide(like Lomon R996) exceeds 60% of the total output of titanium dioxide. Due to its wide range of uses, it has a good effect on whiteness, tinting strength, dispersibility, weather resistance, etc., so it is very popular among users. The surface treatment of these products is generally carried out with inorganic oxides such as AI 203, AI 20 3-SiO2 or A1 2O 3-SiO2-TiO2, which account for 2 to 5% of the total.
Through the analysis of surface-treated general-purpose titanium dioxide products, it is found that the content of TiO2 pigments is about 94. The dosage of the treating agent is about 3-5%. Due to the contradiction between some characteristic indexes of Tio2 pigments, the tinting strength is reduced while the weather resistance is required to be high, and it is impossible to be perfect.
2) High weather resistance titanium dioxide
It exhibits exceptional performance in weather resistance, which is especially desirable for coatings used outdoors. The surface treatment agents used in such products are still inorganic oxides such as A12O3, SiO2, TiO2, ZrO2, and the addition amount is 7-10%. During the coating process, these oxides are deposited on the surface of TiO2 particles to form a skin-like dense film, which plays a good protective role against the natural oxidation-reduction process on the TiO2 surface.
3) Titanium dioxide coatings with high pigment volume concentration
The titanium dioxide pigment used for flat latex paint should have a sponge-like coating after treatment, and the amount of treatment agent added is 10-15%. higher than the processing capacity of Al203. After the Tio2 pigments coated with a large amount of porous Al2O3-SiO2 or aluminum silicate is crushed into a suitable particle size, the maximum covering rate can be obtained in the latex paint.
4) Titanium dioxide treated with organic matter
For some varieties, surface treatment should be performed according to the special requirements of use. For example, treatment with a small amount of organic compounds can improve the dispersion of titanium dioxide. Commonly used organic compounds are polyols, polyamines and silicone oils. When choosing an organic treatment agent, pay attention to its heat resistance, stability, and place of use.
Jinan Hongquan Titanium Industry Co., Ltd. https://www.greatspringchem.com/is located in Jinan, a beautiful spring city. The company’s scientific research personnel sincerely cooperate with well-known domestic universities and various titanium dioxide production enterprises to study and produce active titanium dioxide pigments with great concentration. Some of its products have been widely used in chemical, textile, paper, plastic, paint and other production fields.
The company’s products (like Brand Lomon titanium dioxide) have been demonstrated by well-known national experts, and the conclusion is: “technological innovation is strong, improves the performance and utilization of pigments, reduces dosage, saves resources, economic benefits, no environmental pollution, in line with national industrial promotion and development strategies”