What’s the position of Titanium Dioxide in inks?

Titanium dioxide is used in various types of printing ink production with big dosage proportion between 25% ~ 50%, some even more.Therefore, titanium dioxide plays an important role in the quality of printing ink.

 

1.For whiteness of ink

a). The influence of impurities of Titanium dioxide in ink.In general, if there are traces of iron, chromium, cobalt, copper and other impurities mixed in the titanium dioxide, the ink will have color cast, white degree reduced.This is because the impurity ions in titanium dioxide, especially metal ions, twisted crystal structure and loss of symmetry.Rutile type titanium dioxide with greater sensitivity of impurity ,if iron oxide content is more than 0.003% will present a color, but more than 0.009% in the anatas titanium dioxide will produce color reaction.Therefore, choosing superfine and purity titanium dioxide is very important.

b).The influence of shape, size and distribution of titanium dioxide in ink whiteness.High quality titanium dioxide particle shape is smooth, without sharp edges, if use particle surface with edges and corners, will greatly weaken the light reflection effect and reduce the ink whiteness.

Titanium pigment particle size should be controlled in 0.2 ~ 0.4 microns, which is equivalent to about half the wavelength, can obtain high scattering ability, make its appear more white.When the particle size is less than 0.1 microns, crystal is transparent, if the particle size of more than 0.5 mu m, will reduce the performance of paint light scattering,and affect the whiteness of ink.Suitable for this purpose, the requirement of titanium dioxide good particle size and uniform distribution to show good whiteness.

 

2.For covering power of ink

a).The crystal refractive index of titanium dioxide will affect the size of the covering power of ink directly.Usually, the refractive index of titanium dioxide is the best in all white pigment.For white ink, should choose titanium pigment with high refractive index, in order to enhance the hiding power of white ink.

b).The influence of particle size, particle structure and dispersibility of titanium dioxide in white ink covering power.Usually, in more than 1/2 of the visible light wavelength range, the smaller the particle size, the more smooth particle surface, the better the dispersion of titanium dioxide link in resin material, the stronger hiding power.Due to titanium dioxide has a clear crystal structure, so its refractive index is bigger than show color agent, and the greater the difference of refractive index, the stronger the covering power of the titanium dioxide used.Practice has proved, rutile titanium dioxide is better than the anatas titanium dioxide in covering power, so be widely used in printing ink production.

 

3.For tinting strength of ink

The tinting strength of titanium dioxide depends on the light scattering capacity, and have a direct impact on the ink tinting strength, the greater the scattering coefficient, the stronger the tinting strength; the higher titanium dioxide refractive index, the stronger tinting strength.Titanium dioxide is the highest refractive index products in the white pigment, and rutile type titanium pigment refractive index is higher than anatas titanium dioxide.Therefore, we suggest to choose titanium dioxide with strong scattering capabilityand high refractive index.

 

4. For dispersibility of ink

The particle shape and light reflex of tatanium dioxide depend on the performance of the titanium dioxide dispersion.If titanium dioxide particle surface is smooth, uniform reflection, the dispersivity is good, the white ink gloss and whiteness are better;Conversely, particle surface is rough, diffuse, can significantly reduce gloss, dispersion is bad, directly affect the whiteness of white ink and heat transfer performance. For this purpose, the titanium white must be treated before used.

 

To sum up, with the rapid development of packaging and publishing both at home and abroad, the market demand of ink will be increasing, as a very important white pigment in the ink, many performance and the role of titanium dioxide is not a substitute for any other material. Therefore, using of titanium pigment in the ink will increase year by year, will have big application prospect in the market.

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