CZ26391U1 - Nanoparticle based inorganic ink, especially for material printing - Google Patents

Description

The technical solution relates to the composition of inorganic ink based on nanoparticles, intended especially for material printing.

BACKGROUND OF THE INVENTION

In recent years, the attention of researchers and manufacturers has turned to the promising technique of producing electronic printed materials - material printing. In particular, methods such as screen printing, inkjet printing, flexo printing, droplet printing can be used for this technology. Of these, screen printing and inkjet printing are the most important. They are valued mainly due to the quality of the deposited layer, as well as due to repeatability and the possibility of registration. These two technologies (screen printing and inkjet printing) have been successfully used to manufacture various electronic components, sensors, optical components, flexible displays and other light emitting devices.

Inkjet printing has great advantages for printing complex structures and themes. It is advantageous in comparison with screen printing, because it is not necessary to construct a new screen prior to any change of the printed motif, but the printed motif is set via the digital interface.

Material inkjet printers differ significantly from conventional user inkjet printers in terms of features. Above all, it is the precision and repeatability of mechanical shifts that allow you to work with print resolutions up to 5080 dpi. The print head can also be heated to reduce the viscosity of the polymer solution inks used for printing.

As for the process itself, during deposition, the solution (ink) containing the substance to be deposited is introduced into the printhead, where it is, for example, sprayed towards the substrate by means of mechanically deforming piezoelectric elements. A suitable profile of the electrical signals applied to the piezoelectric elements ensures that a regular stream of uniformly formed droplets of a certain volume leaves the printhead. These parameters are critical to achieving the required print quality. And their specific settings are called “waveform”.

For perfect printing, the entire printing system, namely the print head, the type of substrate on which the printed pattern is deposited, in particular the ink itself, must be taken into account. There are four main types of material printing inks: melt or state-change inks, UV-curable inks, water-based inks, and solvent-based inks.

The melt-based inks enter the system in a solid phase and are heated prior to printing, thereby rendering them liquid. The advantage of these inks lies in the very fast curing. They are mainly used to print barcodes on non-porous substrates. The disadvantage is the material limitations on thermoplastics.

UV curable inks have been used successfully for many years. However, the restriction concerns the food sector. Furthermore, their disadvantages are high costs.

Water-based inks are widespread mainly in home printers. Their advantage is the possibility of use in biological and food applications. However, these inks require porous substrates or substrates with a specially treated surface. Adhesion with a non-porous substrate is not perfect.

Solvent-based inks are widely used for large format applications with an emphasis on print quality, image resistance and substrate compatibility. They are generally considered low cost. Advantages further include compactness with different types of substrates and prompt drying (often

Accelerated heating). The disadvantages of some of these inks are the rapid evaporation of solvents, which can cause the print head nozzles to clog.

Among the most important application properties of a polymeric solvent ink are viscosity and surface tension. The disadvantage of the material inkjet printing method is its high sensitivity to these parameters, which determine the range of ink usage. The viscosity should be in a relatively narrow range (6-12) x10 ³ Pa · s and a surface tension between 30x10 ³ N · m depending on the printhead type (below 3x10 ³ Pa · s of thermal print heads). Viscosity has a major effect on blasting and deposition on a substrate, and its value depends primarily on the presence and concentration of the polymer, the solvent composition and possible coagulation. Viscosity may increase due to coagulation of the particles or, in the case of UV inks, also during storage, where the ink components may undergo polymeric reactions.

Surface tension depends primarily on the composition of the ink. The surface tension is crucial for the size and shape of the droplet and for wetting the substrate surface with ink as the droplet falls and the ink spills over the substrate. All of this greatly affects print performance and quality when using an inkjet print head. The narrow range of surface tension values is difficult to maintain, and this can have a decisive impact on the performance achieved and lower print quality, especially for functionally sensitive surface electronic structures or large format applications.

The essence of the technical solution

Said drawbacks and disadvantages of the prior art inks for material printing, when the surface tension of the ink and the associated adhesion to the substrate are concerned, largely eliminates the inorganic nanoparticle ink, in particular for the material printing, according to the invention. The essence of the invention is that the inorganic material printing ink consists of CuO nanoparticles having a concentration of 3 to 10% by weight. % in a mixture of polymer dispersants in an amount of 5 to 35 wt. and an additional amount of water up to 100 wt.

The inorganic nanoparticle ink according to the present invention preferably has copper oxide nanoparticles having a size of less than 50 nm.

The advantage of the inorganic material printing ink according to the invention is, besides the CuO deposition itself, also the fact that it achieves a rapid improvement of the blasting of the droplets from the print head and an increase of the adhesion to the substrate itself. in the area of material printing.

BRIEF DESCRIPTION OF THE DRAWINGS

Samples of the CuO layer and individual droplets printed by material printing according to the set process parameters on the waveform nozzle for inorganic material printing ink according to the technical solution are shown in the attached drawings, where:

FIG. 1 is a waveform for a particular printhead (Dimatix DMP 2831) of FIG. 1 and a material jet head blasting mode;

FIG. 1b shows the blast-free mode of the material printer head;

FIG. 2 an example of a printed CuO layer by material printing (Dimatix DMP 2831);

FIG. 3 shows an example of each printed 50 µm CuO droplet (Dimatix DMP 2831). Examples of technical solution

Examples of a particular embodiment of an inorganic nanoparticle ink, in particular for material printing, serve to clarify the nature of the invention.

-2 GB 26391 U1

Example 1

Inorganic material printing ink containing 3.40 wt. CuO, 28.80 wt. % of dispersant mixtures (3: 1 ratio) as opposed to ink No. 4 (1: 3 dispersant ratio) in the same total amount and 67.80 wt. The viscosity and surface tension of the resulting ink are shown in Table 1 below.

Table 1: Ink viscosity and surface tension

Ink # 1 Viscosity (Pa.s) Surface tension (Nm ' ¹ ) (4.66 ± 0.04) x10 ^-3 (22.13 ± 0.09) x10 ^-3

The resulting had a viscosity close to the optimum values falling within the ideal printing range, which are in the region of (6-12) x10 ³ Pa.s, and an optimum surface tension of less than 30x10 ³ Nm ^-1 . The ink thus prepared was already usable for filling the inkjet cartridge and for subsequent printing.

FIG. 1 shows a waveform for inorganic inks according to the invention (for all examples). The specific design is captured as a printscreen in the Dimatix DMP 2831 printer software. Fig. 1a shows the blasting mode and Fig. 1b shows the blast-free mode. Example 2

Inorganic material printing ink containing 4.80 wt. CuO, 28.40 wt. % of a mixture of dispersants and 66.80 wt. Water was prepared in an analogous manner to that described in Example 1. The viscosity and surface tension of the resulting ink are shown in Table 2 below.

Table 2: Ink viscosity and surface tension

Ink # 2 Viscosity (Pa.s) Surface tension (Nm ' ¹ ) (7.13 ± 0.02) x10 ^-3 (21.98 ± 0.04) x10 ^-3

The values shown in Table 2 show that the resulting ink had an optimum viscosity falling within the ideal printing range, i.e. in the range (6-12) x10 ^-3 Pa.s, and an optimum surface tension less than 30x10 ³ Nm ^-1 . The ink thus prepared has already been prepared for filling the injection cartridge and for subsequent printing.

Example 3

Inorganic material printing ink containing 6.60 wt. CuO, 27.80 wt. % of a mixture of dispersants and 65.60 wt. Water was prepared in an analogous manner to that described in Example 1. The viscosity and surface tension of the resulting ink are shown in Table 3 below.

Table 3: Ink viscosity and surface tension

Ink # 3 Viscosity (Pa.s) Surface tension (Nm ' ¹ ) (6.53 ± 0.01) x10 ^-3 (21.73 ± 0.08) x10 ^-3

Table 3 shows that the resulting ink had a viscosity optimum falling within the ideal printing screen, an area (6-12) XLO ^'3 Pa.s, and the optimal surface tension of less than 3OxlO' ³ Nm ^_1. The ink thus prepared has already been prepared for filling the inkjet cartridge and for subsequent printing.

Example 4

Inorganic material printing ink containing 3.40 wt. CuO, 28.80 wt. % of a mixture of dispersants (1: 3 ratio) as opposed to ink No. 1 (3: 1 dispersant ratio) in the same total amount and 67.80 wt. The water viscosity and surface tension of the resulting ink are shown in Table 4 below.

-3EN 26391 Ul

Table 4: Surface tension and ink viscosity

Ink 4 Viscosity (Pa.s) Surface tension (Nm ¹ ) (6.59 ± 0.02) x10 ³ (21.42 ± 0.08) x10 ³

As can be seen from Table 4, this ink had an optimum viscosity falling within the ideal printing range of (6-12) x10 ³ Pa.s and an optimum surface tension of less than 30x10 ³ Nm ^1. for refilling the inkjet cartridge and for subsequent printing.

FIG. 2 shows a printed layer of ink prepared in this way. It can be seen that the layer is compact without any inhomogeneities or artifacts. The experiment was performed on a Dimatix DMP 2831, layered as a printscreen.

Fig. 3 shows the printing of individual ink droplets according to the invention. The experiment was performed on a Dimatix DMP 2831, layered as a printscreen.

Example 5

Inorganic material printing ink containing 7.20 wt. CuO, 32.20 wt. % of a mixture of dispersants and 60.60 wt. The water viscosity and surface tension are shown in Table 5 below.

Table 5: Ink viscosity and surface tension

Ink 5 Viscosity (Pa.s) Surface tension (Nm ¹ ) (10.54 ± 0.01) x10 ^-3 (21.52 ± 0.05) x 10 ³

The table shows that the resulting ink had an optimum viscosity falling within the ideal printing range, i.e. in the range of (6-12) x10 ^-3 Pa.s, and an optimum surface tension of less than 30x10 ^-3 Nm ^1. filling the inkjet cartridge and printing.

Industrial applicability

Possibilities of using inorganic ink based on CuO nanoparticles for material printing are in the area of sensors for detection of gases, electrodes, analytical and diagnostic aids, strips, resp. kits; in the packaging technology to ensure control over the condition of the packaged item, safety of the packaging, indication of opening or breaking the packaging.

Claims (3)

, indication of opening or breaking of the packaging. PROTECTION REQUIREMENTS An inorganic nanoparticle based ink, in particular for material printing, characterized in that it is composed of a dispersion of copper oxide nanoparticles having a concentration of 3 to 10% by weight. % in a mixture of polymer dispersants in an amount of 27 to 35 wt. and an additional amount of water up to 100 wt. Inorganic material printing ink according to claim 1, characterized in that the copper oxide nanoparticles have a size of less than 50 nm. 3 drawings