Waterless glue ink matures (2)

The use of a polymer and a highly soluble new resin is effective for obtaining a low-viscosity, high-fluidity ink, and can be used to cross-link low-viscosity resins without impairing the flowability. In the cross-linking process of the resin, a network structure is formed between the macromolecules, the internal cohesive force is increased, and the viscosity is increased. If the aluminum chelate compound gelator, the fluidity of the ink may be lost. Thus, a heat-polymerized resin composed of a rosin-modified phenolic resin and a molecular chain-length oligomer was proposed to make the resin quantified with high plasticity, thereby obtaining a low-viscosity resin binder.

(2) Improve anti-dirt

Resistance to dinging is indicated by CTI, which is related to ink viscosity, viscosity, and fluidity, and is directly proportional to viscosity and viscosity, and inversely proportional to fluidity. Therefore, it is not easy to design high-CTI inks with low viscosity, low viscosity, and good fluidity (high speed printing) ink technology.

Waterless offset printing should have anti-dirt resistance while achieving low viscosity. Therefore, the key issue in formula design of waterless offset inks is how to suppress the dirtiness of the printing plate. In general, there is a close relationship between the resistance to dinging and the viscosity of the ink, the solvent used and the density of the printing field, the structure of the printing press, and the printing speed.

1 ink anti-dirt and solvent. If the solvent in the ink is quickly wetted on the surface of the silicone, ink adhesion can be prevented. As a result, the olefin-based solvent, the naphthenic AF solvent, and the more aromatic-free No. 6 solvent exhibited small contact angles on the silica gel surface and maintained high seizure resistance.

2 ink anti-dirt and ink viscosity related. Figure 2 shows the relationship between the temperature of the dirt and the viscosity of the ink. A waterless offset printing press equipped with an ink roller cooling device, whether it is a sheet-fed or web-fed printing, usually has a layout temperature of 28 to 34°C. At this temperature, the expected anti-dirt resistance is achieved. The problem is that the viscosity of the new ink is further reduced, but the CTI does not change. Because the viscosity is low, the amount of ink on the print part is increased, which eliminates the unevenness of the dot density, thereby reducing the color turbidity of waterless offset printing. In addition, a smooth ink film can improve the multi-color overprint effect. Infiltration drying fast. Due to the use of a polymer resin and a new type of linking material, the ink has good solvent-removal properties and is fast in penetration and drying, so it can be deposited after printing.

3 high gloss. According to the improvement of ink repellency and overprintability, high-gloss printing can be obtained.

4 excellent on-board stability. As the on-board stability of the new formula ink is greatly improved, which is conducive to stable printing, Table 3 is the ink index of a new type of sheet-fed offset printing ink, in which the flow value is 30°C and the parallel plate viscometer is loaded with 115g. Stretch diameter (mm) after 60 seconds.

Sheet-fed offset printing inks have the characteristics of good fluidity, low viscosity, soft body, etc., while retaining the same anti-dirt properties as the original products. They have been tried by a number of companies and Heidelberg is also in the Quickmaster DI46. The printing was carried out to prove that it has greatly improved in terms of ink repellency, fluidity, anti-scuffing, glossiness and abrasion resistance of the ink film.