Titanium dioxide in printing inks
In the ink production, different types of ink products on the quality requirements of titanium dioxide are also different. Practice has proved that rutile titanium dioxide has a better application performance, can being widely used in various types of ink preparation.
Whether the crystal shape, refractive index, or color strength, fluorescence index, rutile titanium dioxide are better than anatase titanium dioxide, therefore, rutile titanium dioxide in the ink production is widely used. In addition, in the ink preparation process but also according to the specific characteristics of various types of ink and require the choice of different properties of titanium dioxide.
(1)offset printing is based on the principle of oil and water repression, therefore, offset printing resin used in ink to have good antiemulsifying properties, but also have excellent hydrophobic, otherwise, offset printing white ink is easy to emulsify; In the outdoor print used by the offset white ink, requiring the preparation of titanium dioxide must have good light resistance and weather resistance,else white ink will turn yellow or powder.
(2) For gravure composite film inks, in order to make the printed color, beautiful, first with white ink rendering, and then color printing. To this end, the requirements of titanium dioxide must have excellent color strength and hiding power.
(3)For tin printing ink, the postpress baking temperature is about 180 ℃, and the baking time is about 120 minutes.Therefore, the white titanium powder must have excellent heat resistance, otherwise, white ink in the high temperature baking will turn yellow, loss of luster, serious will cause the printing of the scrapped.
Therefore, according to different types of ink and different printing suitability requirements, the rational use of titanium dioxide is the key to the manufacture of fine white ink. Integrated ink with titanium dioxide quality requirements, mainly in the following:
① good whiteness, durability is not yellowing, can make the color of printed matter in a variety of environments to keep bright, bright;
② good wetting, easy grinding;
③ small particles, easy to evenly dispersed in the ink link material;
④ strong hiding power, good coloring;
⑤ weather resistance, good heat resistance, chemical stability;
⑥ good water resistance.