Amount of titanium dioxide in coatings and its application

Titanium dioxide has excellent optical, electrical properties and pigment application properties, so it has a wide range of use value. The physical, chemical and optical properties of titanium dioxide pigment mainly depend on the original state of pigment particles before coating and the chemical structure of its surface coating.

Titanium dioxide pigments usually use silicon, aluminum and zirconium oxides as surface treatment agents to precipitate on the particle surface to form a coating, and process control on the form, quantity and method of precipitation. Some also use organic treatment agents. The different surface treatment methods endow titanium dioxide pigments with personalized characteristics to meet the different needs of coating formula design.

For the purpose of meeting the covering power, it is generally sufficient to cover with enamel paint of 30-40 microns. The addition amount is 15-25% of the total amount of the formula; From the point of view of weather resistance and high gloss, matt powder shall be used for matt paint to obtain high weather resistance. The principle is to add a small amount of titanium dioxide without adding any other filler; From the cost point of view, the addition of fillers from other systems will reduce the cost. The addition of fillers from other systems will reduce the amount of titanium dioxide, but the brightness should be balanced; For interior wall emulsion paint exceeding CPVC value, the addition amount of titanium dioxide is 2% - 4%, which can meet the requirements.

In terms of dispersion issues, wetting and dispersion additives may not be used in primers or topcoats with low requirements from the perspective of formula cost, but the phenomenon of floating color and blooming should be controlled within an acceptable range. Adding controllable flocculent additives to the primer and topcoat can control the phenomenon of floating color and blooming.

In high grade finish paint, titanium white slurry can use low molecular weight wetting and dispersing additives, and other organic pigment slurry can use high molecular weight wetting and dispersing additives, which are generally compatible; In case of fluorocarbon finish paint, it is generally necessary to use titanium dioxide with high dispersivity and weather resistance, and select appropriate wetting and dispersing additives to solve the problem of floating color and blooming; If anti-corrosion primer, architectural latex paint and anti-corrosion finish paint are selected, titanium dioxide with good dispersibility can be directly used with effective high-speed disperser with the help of wetting and dispersing additives to achieve the dispersion effect, eliminating the grinding process.

The dosage and variety of wetting and dispersing additives are different, so it is necessary to add the dosage according to the production needs in order to achieve the effect of using the topcoat.