Titanium dioxide for paint is the most suitable white pigment used to give whiteness and hiding power in paint and coatings, plastics and inks. The paint made of titanium dioxide has the performance of bright colors, high hiding power, strong tinting power, low dosage. It can also protect the stability of the medium, enhance the mechanical strength and adhesion of the paint film, prevent cracks, prevent the penetration of ultraviolet rays and moisture, extend the life of the paint film.
Performance And Applications of Titanium Dioxide Uses In Paint
Titanium dioxide for paint has the characteristics of high refractive index, strong achromatic power, large hiding power, good dispersion, good whiteness, non-toxic, stable physical and chemical properties. In addition, it also has excellent optical and electrical properties. Therefore, it has a wide range of uses in paint and coating, especially rutile grade TiO2.
The refractive index of rutile titanium dioxide is 2.76, and the refractive index of anatase type is 2.55. The difference between the refractive index of the pigment and medium determine is the hiding power. Their relative values can be calculated according to the formula. The reflextion coefficient of rutile titanium dioxide is 25% to 30% higher than that of anatase titanium dioxide.
In addition, rutile titanium dioxide paint has a compact structure, relatively stable, low photochemical activity, resistance to ultraviolet light, isn’t easy to pulverize outdoors. It also has better weather resistance and gloss than anatase type. Therefore, it is widely used in various outdoor coatings that need high weather resistance, such as, ships, bridges, automobiles and building. Anatase titanium dioxide paint is easy to pulverize and yellow, generally only in interior coatings or primers.
Requirements of Titanium Dioxide in Different Types of Paint
Latex paint is water-based. It doesn’t contain solvents or contains a small amount of solvents. It has the advantages of weather resistance, scrubbing and environmental protection. So it is widely used as architectural coatings. Due to the different emulsion systems used in the interior and exterior wall latex paints, the application requirements for titanium dioxide are also different. However, considering the dispersion, dispersion stability and covering power of titanium dioxide is always necessary.
Coil and Printing Iron Coating
Coil coatings are solvent-based, using a large number of alcohol ether solvents, special esters and ketone solvents. Most of them are polyester and epoxy resin systems. The strong polarity system makes titanium dioxide difficult to disperse. Since the processing process can include grinding process, it doesn’t require particularly high dispersibility of TiO2, but require high hiding power. Coil coatings generally use rutile grade titanium dioxide, the requirements for the inner back costing are relatively low.
Anticorrosive coatings are represented by marine paints, mainly epoxy resin systems, and most factories don’t use the grinding process. They are not very demanding on the comprehensive performance of titanium dioxide paint. Whether the TiO2 powder is suiatble mainly depends on its dispersibility, dispersion stability and hiding power.
Furniture paint mainly contains polyurethane and nitrocotton type, which has high requirements for the dispersibility and fineness of titanium dioxide powder.
Car paint contains high-grade and medium-low grade. The best is car paint, followed by truck and bus paint. The titanium dioxide paint for car paint is mostly special rutile grade.