Influence of Coatings of Ink Jet Printing Paper on Printing Quality and Stability (Chinese)

2 Results and Discussion

Porous ink-jet paints are mainly composed of an insoluble inorganic pigment particle and some adhesives. It may also contain some special additives to enhance the coating performance. There are more and more reports on new materials used for porous, high-gloss inking coatings.

In this paper, three different SiO2 particles, such as Colloidal SiO2, Sintered SiO2 and SiO2, are studied and their effects on various coating properties and properties are investigated. The average particle sizes of the three SiO2 particles were 95 nm, 278 nm, and 318 nm, respectively.

2.1 Effect on coating formulation

The basic formulation of the paint is polyvinyl alcohol as an adhesive, and the ratio of pigment to adhesive is 80/20. The formulation properties of the coating are shown in Table 1. Colloidal SiO2 and sintered SiO2 have the potential to achieve high solids content at lower Brookfield viscosity.

Table 1 Coating properties

2.2 Effect on Coating Structure

The final coating structure is changed by changing the particle size of the particles. It is expected that the gloss of the coating will be inversely proportional to the particle size, and the gloss of the coating will decrease as the particle size increases. Calendering can be used to improve gloss and produce high gloss ink jet printing paper.

Figure 1 shows the gloss value of each particle before and after calendering in a hot/soft nip. As can be seen from Figure 1, sintered SiO2 has the highest gloss measurement. Its value is significantly higher than the smoke SiO2 with the same particle size, and it is further increased after calendering.

Figure 1 gloss value

Inspection of the coated surface using a scanning electron microscope (SEM) was also expected. The surface image is always consistent with the measurement of gloss. The colloidal SiO2-based coated image shows minor cracks.
(to be continued)