CZ26729U1 - Polymeric ink for material printing - Google Patents

Description

The technical solution relates to the composition of polymer ink 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. Partial methods (screen printing, inkjet printing, flexographic printing, droplet printing) can be included in this technology. Of these, screen printing and inkjet printing are the most important. This is mainly related to the quality of the deposited layer, as well as the 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.

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 in printing 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 of 6-12x10 ³ Waist and a surface tension between 30x10 ' ³ Nm ^-1 depending on the type of printing

U1 heads (below 3x10 ' ³ Waist for 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 achieved parameters and lower print quality, especially in functionally sensitive surface electronic structures or large format applications.

The essence of the technical solution

Said drawbacks and disadvantages with respect to the surface tension of the ink and the associated adhesion to the substrate, largely removes the polymeric inkjet printing material of the present invention. The essence of the invention consists in that the polymeric printing material ink consists of a conductive polymer - poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene-vinylene] at a concentration of 0.2 to 0.4% by weight. % in a mixture of organic solvents and a polyethylene glycol-p- (1,1,3,3-tetramethylbutyl) -phenyl ether surfactant in an amount of 3 to 4 wt.

The polymeric printing ink material of the present invention preferably has a conductive polymer having a molecular weight Mn in the range of 40,000 to 70,000 and a Mw / Mn ratio of 6.

The advantage of the polymeric material printing material according to the invention is the fact that it achieves a rapid improvement of the blasting of droplets from the print head and an increase of the adhesion to the substrate itself, which results in the printing of precise homogeneous and quality layers. more important.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of jet blasting and setting of process parameters on a waveform printhead nozzle for polymeric inkjet printing material according to the invention are shown in the accompanying drawings, where:

Giant. 1 - blasting of drops from the nozzle head for a specific printhead (Dimatix DMP 2831)

Giant. 2-waveform (ie print head operation mode parameters), 2a blasting, 2b no ink blasting for a particular printhead (Dimatix DMP 2831)

Examples of technical solution

Example 1

Mixture composition - Table 1:

Mixture of solvents MEH-PPV surfactant 96.3353 wt. 0.2398 wt. 3.4249 wt.

Polymeric printing ink material was prepared by first dissolving the conductive MEH-PPV-based polymer (= poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene-vinylene)) in a solvent mixture such that The weight ratio of both components resulting from Table 1 was maintained. After thorough dissolution, polyethylene glycol p- (1,3,3,3-tetramethylbutyl) -phenyl ether surfactant was added to the solution in an amount corresponding to the weight% given in the table. The resulting ink had an optimum viscosity falling within the ideal printing range of 6-12x10 ³ Pas and an optimum surface tension of less than 30x10 ³ Nm ^-1 .

-2EN 26729 Ul

The ink thus prepared has already been prepared for filling the inkjet cartridge and for subsequent printing.

Fig. 1 shows the blasting process - the vertical direction of the droplet paths from the individual nozzles of the treated ink (corresponding to Example 1). It is evident that thanks to the surface tension adjustment according to the technical solution, the blasting process is uniform with high accuracy given by the constant droplet volume and constant blasting speed. The experiment was carried out on the Dimatix DMP 2831, the single droplet blasting paths captured as a printscreen.

Fig. 2 shows the waveform (print head operating mode) for polymeric inks according to the invention (for all examples). The specific design is captured as a printscreen in the Dimatix DMP 2831 printer software.

Example 2

Mixture composition - Table 2:

Mixture of solvents MEH-PPV surfactant 96.2583 wt. 0.3195 wt. 3.4222 wt.

The polymeric polymeric printing ink was prepared in an analogous manner to that described in Example 1, maintaining the actual weight ratios of the components resulting from Table 2. The resulting ink had an optimum viscosity falling within the ideal printing range, i.e. in the 6-12x10 ³ Pas range. , and an optimum surface tension of less than 30x10 ³ Nm ^-1 .

The ink thus prepared has already been prepared for filling the inkjet cartridge and for subsequent printing. Example 3

Mixture composition - Table 3:

Mixture of solvents MEH-PPV surfactant 96.1815 wt. 0.3991 wt. 3.4194 wt.

The polymeric polymeric printing ink was prepared in an analogous manner to that described in Example 1, maintaining the actual weight ratios of the components resulting from Table 3. The resulting ink had an optimum viscosity within the ideal printing range, i.e. in the 6-12x10 ³ Pas range. , and an optimum surface tension of less than 30x10 ³ Nm ^-1 .

The ink thus prepared has already been prepared for filling the inkjet cartridge and for subsequent printing. Industrial applicability

Polymeric material printing ink according to the invention enables the preparation of an active electroluminescent layer in electronic and electrical devices by means of inkjet material printing, which finds application in polymer electronics, especially flexible light sources for lighting and flexible displays. Other possibilities of using polymer ink for material printing are in the area of sensors, electrodes, analytical and diagnostic aids, strips, or. baptism; in packaging to ensure control of the condition of the packaged item, safety of the packaging, indication of opening or breaking the packaging

Claims (2)

PROTECTION REQUIREMENTS Polymeric printing material ink, characterized in that it consists of a conductive polymer - poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene-vinylene] in a concentration of 0.2 to 0.4% by weight. % in a mixture of organic solvents and a surfactant polyethylene glycol-β- (1,1,3,3-tetramethylbutyl) -phenyl ether in an amount of 3 to 4 wt. -3EN 26729 Ul 2. The polymer printing ink composition of claim 1, wherein the conductive polymer has a molecular weight Mn in the range of 40,000 to 70,000 and a Mw / Mn ratio of 6.