Application of Pigment Carbon Black in Ink

Black water-based ink is a chemical product, which is synthesized by mixing water, pigment carbon black, resin, amine water and emulsion. It is pumped from the ink tank into the ink transfer system during printing. Pigment carbon black is the main pigment of black ink, and its performance directly affects the product quality of black ink and the aesthetics of printed matter. The carbon black powder we see every day is not a spherical particle, but an aggregate, its own small units, that come together during the formation process. However, the size and distribution of the original particle size is still one of the important basic properties, and it also affects the blackness and tone of the ink.

In the process of printing production, the operator hopes that the viscosity and concentration range of the water-based ink can be stably controlled, so that the product can reduce the generation of color difference. However, after 10 to 20 minutes, a dirty version is produced. Due to the influence of the surrounding environment, the pigment carbon black begins to precipitate. However, after the water, resin, and amine water gradually evaporate, the water-based ink will become thicker or even solidified, that is, pH The value has decreased while the viscosity has increased.

At present, most of the finished products on the market are produced by furnace method. As pigment carbon black, in order to improve its dispersibility, post-oxidation treatment is carried out to increase the oxygen ion content on its surface and make it easier to disperse; on the contrary, those without post-oxidation treatment product, the dispersion is much worse. The influence of pigment carbon black on the gloss of ink, the gloss of ink depends on the performance of carbon black for ink itself, the quality of aggregate dispersion, and the particle size of aggregate. For example, after high-speed dispersion, it is uniformly dispersed in the ink to achieve the fineness of the original particle size. The finer the particle size, the higher the gloss. On the contrary, if the original particle size is larger, or it is not fully dispersed, the side gloss will decrease.

Since the ink is a very thin film, the carbon black and vehicle used in the ink tend to penetrate the porous surface, allowing more of the substrate to protrude from the film. This effect is more pronounced in liquid inks than in paste inks. Post-oxidized carbon blacks will result in inks with lower viscosity and better fluidity. The reason is that the oxygen-containing compound chemically adsorbed on the surface acts like a surfactant, which makes the surface of carbon black more easily wetted, so that its dispersibility and stability after dispersion will be greatly increased. After post-oxidation treatment, the more oxygen-containing groups on the surface, the lower the PH value, but the hygroscopicity of carbon black will be greatly increased. Dispersion of black in water-based inks.