Effect of ultra-dispersant on yellow UV offset ink performance (2)

2 Results and discussion
2.1 Determination of the super-dispersant ratiothe amount of pigments, fillers, light triggers and monomers in the formula of fixed UV inks, change the dosage or ratio of ultra-dispersants, see Table 2, adjust the amount of pre-dispersion accordingly.In accordance with the ratio and dosage shown in Table 2, the ultra-dispersant Solsperse 39000 and the add-on Solsperse 22000 were added to the ink, respectively, and the effect of the compounding ratio on the flow of the ink is shown in Figure 3.As can be seen from Figure 3, there is no significant change in the flow of the ink when using the ultra-dispersant Solsperse39000 or the booster Solsperse 22000 alone. It can be seen that the separate use of Solsperse 39000 and Solsperse222000 pairs of liphenyl yellow pigments in the ink dispersion has no obvious effect; 9000 and the add-on Solsperse 22000, and its compounding ratio of 1/0.5, the flow of ink significantly increased, indicating that the pigment in the ink at this time is more dispersed. Since the booster Solsperse 22000 has similar physical and chemical properties to the yellow pigments of diphenylamine, the polar anchoring group of the Solsperse 39000 is firmly adsorbed to the pigment surface under its bridging action On the other hand, since the solvent chain of Solsperse 39000 has good affinity to the dispersion medium (UV prejudge), the wetting of pigment particles in the dispersion medium can be greatly improved, thus significantly increasing the flow of the ink. When the ratio of Solsperse 39000 and Solsperse 22000 is 1:1, there is no significant change in system flow, indicating that excessive Solsperse 22000 interference affects the dispersion effect of the Solsperse 39000 solvent chain in the prejudes. Therefore, the re-matching ratio of the ultra-dispersant Solsperse39000 and the booster Solsperse 22000 is 2:1, which can significantly improve the dispersion performance of the yellow pigment of liphenylamine in pre-embossed, and significantly improve the flow of yellow UV offset ink.2.2 Determination of the amount of ultra-dispersantin the case of pigment, filler, monomer and light trigger content unchanged, fixed super-dispersant Solsperse 39000 and the efficiencizer Solsperse222000 compound ratio of 2:1, according to the compound dosage in Table 3 to add super-dispersant, and adjust the amount of pre-dispersion accordingly.The effect of ultra-dispersant dosage on flow and coloration force is shown in Figure 4.visible from Figure 4: As the amount of ultra-dispersant increases, the coloring force of the ink shows a trend of gradually increasing and then decreasing, and the coloring force of the S-7 reaches a peak of 108%. As can be seen from the change trend of flow degree, with the increase of the amount of ultra-dispersant, the growth trend of flow degree is gradually slowing down. Combined with the relevant theory, it can be seen that the amount of ultra-dispersant is too large, not only easy to destroy the polar anchoring group on pigment adsorption and wrapping, but also lead to polymer solventization chain entangled with each other, can not produce a stable dispersion effect;can be seen from Figure 4, when the S-7 sample, i.e. the super-dispersant Solsperse39000 and the booster Solsperse 22000, has a compounding amount of 3%, the phenylasamine yellow pigment achieves optimal dispersion in the prejudgment and the ink coloration force is highest.2.3 Effect of ultra-dispersants on grinding efficiencyThe effect of ultra-dispersants on grinding efficiency is tested by matching ink samples with S-1 and S-7, respectively, as shown in Figure 5.can be seen by Figure 5: Compared with S-1, as the number of grinding times of the three-roller machine increases, the fineness of the S-7 added to the ultra-dispersant decreases rapidly, and the coloring force increases rapidly, and the fineness of the ink is reduced when grinding the third channel. The minimum value is reached at 5 m and the coloring force is 108%, while for S-1, the fineness and coloring force of the ink reach the minimum value of 10 m and the maximum value of 100% respectively when grinding the 4th channel. It can be inferred from this that the addition of ultra-dispersants to the yellow UV offset ink formulation can not only effectively improve the coloring force and reduce the fineness of the ink, but also improve the dispersion performance of pigments, can reduce the number of grinding times and grinding time, improve production efficiency.3 ConclusionIn summary, the ultra-dispersant Solsperse39000 and the add-on Solsperse22000 are matched by a 2:1 quality ratio, with the best dispersion effect when the amount is 3% of the ink quality, the yellow UV offset ink can obtain the best flow and coloring force; Ultra-dispersant is of great significance to improve the fluid properties and printing suitability of UV offset inks.