Rare earth complex printing ink with scattering particles doped with pyrazoloboron Ce (III) complex, and preparation and application thereof

Abstract

The invention relates to a rare earth complex ink with scattering particles doped with a pyrazoloboron Ce (III) complex, and preparation and application thereof, and belongs to the field of light-emitting display. The scattering particles are introduced into the rare earth complex ink, so that the scattering of light can be effectively increased, the propagation path of light can be prolonged, the opportunity of absorbing light by the rare earth complex can be increased, the luminous efficiency can be enhanced, exciting light can be uniformly distributed, brightness spots and dark areas in printed patterns can be reduced, and the consistency of visual effects can be ensured; the light rays scattered in multiple directions can broaden the light-emitting angle, so that the pattern can keep a good light-emitting effect at different observation angles. In addition, by changing the propagation path of the light, the scattering particles reduce the retention time of the light in the rare earth complex, the self-absorption effect is reduced, and the luminous efficiency is further improved.

Description

Technical Field

[0001] The invention belongs to the field of luminescent display, and more specifically, relates to a rare earth complex ink in which scattering particles are doped with a pyrazole boron Ce (III) complex, and its preparation and application. Background Art

[0002] Rare earth complexes have important applications in the field of luminescence, especially in fluorescence, phosphorescent materials, LEDs, display technology and laser materials. The spectral lines produced by the ff transition of rare earth elements are very narrow, which enables them to produce high-purity red, green and blue primary colors. In addition, the f electron orbits of rare earth elements are less affected by the shielding of outer electrons, so rare earth complexes usually have a longer excited state lifetime. Due to their unique optical properties, they occupy an important position in the field of luminescent materials and continue to promote the development of new generation optoelectronic devices and display technologies.

[0003] Rare earth complexes can effectively improve their solubility and stability by combining with appropriate organic ligands, making them suitable for ink systems, especially the requirements of inkjet printing technology. The inkjet printing application of this type of material has great flexibility and can be used to print high-resolution luminous patterns on a variety of substrates. However, rare earth complexes themselves may face some challenges during the inkjet printing process, such as uneven distribution of rare earth complex particles in the ink, or poor control of ink droplets during printing, uneven brightness or color of the pattern, which restricts their application in the preparation of display devices. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a rare earth complex ink in which scattering particles are doped with a pyrazole boron Ce (III) complex and its application, which is characterized by being able to significantly improve luminous efficiency, improve the uniformity and stability of printed patterns, and simultaneously enhance the mechanical properties and optical properties of the ink. This solves the technical problem in the prior art that the rare earth complex particles in the ink may be unevenly distributed during the inkjet printing process, or the ink droplets are poorly controlled during the printing process, resulting in uneven brightness or color of the pattern.

[0005] According to the first aspect of the present invention, there is provided a rare earth complex ink, comprising a pyrazole boron Ce (III) complex and scattering particles; for

[0006] The structural formula of the pyrazole boron Ce (III) complex is:

[0007] Wherein, R1, R2, R3, and R4 are each independently selected from an alkyl group, an aryl group, a phenyl group, a halogen group, or an alkyl group substituted with a halogen group.

[0008] Preferably, the alkyl group is selected from C1-C 18 of alkyl.

[0009] Preferably, R1 is -CH3; R2 is selected from C1-C 18 alkyl or halogen; R3 is -CH3; R4 is selected from C1-C 18 alkyl or halogen.

[0010] Preferably, the pyrazole boron Ce(III) complex is CeTp3, Ce(Tp 4Me )3. Ce(Tp 4Br )3、Ce(PzTp)3、Ce( i PrTp)3、Ce( n At least one of BuTp)3 and Ce(PhTp)3;

[0011] The structure of CeTp3 is as follows:

[0012] The Ce(Tp 4Me )3 The structure is as follows:

[0013] The Ce(Tp 4Br )3 The structure is as follows:

[0014]

[0015] The Ce(PzTp)3 structure is as follows:

[0016]

[0017] The Ce( i The structure of PrTp)3 is as follows:

[0018]

[0019] The Ce( n The structure of BuTp)3 is as follows:

[0020] The Ce(PhTp)3 structure is as follows:

[0021]

[0022] Preferably, the scattering particles are titanium oxide TiO2, zinc oxide ZnO, silicon oxide SiO2, barium sulfate BaSO4 or sulphur oxide ZrO 2。

[0023] Preferably, the particle size of the scattering particles is in the range of 0.1-1 micrometer.

[0024] According to another aspect of the present invention, a method for preparing a rare earth complex ink is provided, comprising the following steps:

[0025] (1) dissolving the pyrazole boron Ce(III) complex in a solvent containing a benzene ring and a chlorine element;

[0026] (2) Adding a polymer and scattering particles to the solution obtained in step (1); the polymer comprises one or more of polystyrene, polymethyl methacrylate, polycarbonate or polyimide.

[0027] Preferably, the solvent is o-dichlorobenzene, or a mixed solvent of o-dichlorobenzene and dichlorobenzene; preferably, in the mixture, the volume proportion of dichlorobenzene is less than or equal to 30%.

[0028] Preferably, in step (1), the concentration of the pyrazole boron Ce (III) complex in the solvent is 1 mg / ml to 10 mg / ml; in step (2), the concentration of the polymer in the solution is 30 mg / ml to 250 mg / ml, and the mass fraction of the scattering particles is 1 mg / ml-10 mg / ml.

[0029] According to another aspect of the present invention, there is provided a use of a rare earth complex ink for printing a photoluminescent material;

[0030] Preferably, the photoluminescent material is used to prepare a photoluminescent display device;

[0031] Preferably, the photoluminescent material is used as an anti-counterfeiting material or as a color conversion material.

[0032] The above technical solution conceived by the present invention has the following advantages compared with the prior art:

[0033] (1) The introduction of scattering particles of the present invention can increase the scattering of light, extend the propagation path of light in the ink, thereby increasing the chance of rare earth complexes absorbing light energy and improving luminous efficiency. This enhancement effect is particularly critical in applications that require high brightness and high luminous efficiency.

[0034] (2) The presence of the scattering particles of the present invention can evenly scatter the excitation light, reduce brightness spots or dark areas in the printed pattern, and ensure that the visual effect of the pattern is more consistent; it can also scatter light in multiple directions to widen the luminous angle, so that the pattern still maintains a good luminous effect at different observation angles.

[0035] (3) The present invention reduces the residence time of light in the rare earth complex by changing the propagation path of light, thereby alleviating the self-absorption effect and improving the luminous efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is Ce(Tp in Example 2 4Me )3 Schematic diagram of electro-inkjet printing control of complex solution.

[0037] Figure 2 Ce(Tp 4Me )3 Low-magnification fluorescence microscopy pattern printed by inkjet printing of complex solution.

[0038] Figure 3 Ce(Tp 4Me )3 Inkjet printing of high magnification fluorescence microscopy patterns by complex solution.

[0039] Figure 4 It is a bar graph showing the model color conversion rate simulated in Example 3 as a function of the mass fraction of scattering particles.

[0040] Figure 5 The light intensity distribution diagram of the model simulated in Example 3 as the mass fraction of scattering particles changes. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The rare earth complex ink of the present invention is used for printing photoluminescent materials, and the specific printing parameters are: the basic voltage of inkjet printing is 800-1200V, the pulse voltage is 800-1500V, the frequency is 20-50Hz, the duty cycle is 50%-90%, the delay time is 30-60ms, and the substrate moving speed is 10-20mm / min.

[0043] The following are specific embodiments

[0044] Example 1

[0045] The preparation method of the pyrazole boron Ce (III) complex ink in this embodiment has the following specific preparation steps:

[0046] The whole process must be carried out in an environment that is isolated from water and oxygen and at a temperature of 20-30°C. 4Br)3 The complex (solute A) is dissolved in o-dichlorobenzene or a mixed solvent of o-dichlorobenzene and dichlorobenzene (solvent A) to form a mixed solution (solution A). The volume ratio of dichlorobenzene in the mixed solvent is less than or equal to 30%, and the mass / volume ratio of the solute to the solvent is 1-10 mg / ml. Solution A is mixed with a mixer for 2-3 hours at a speed of 2000-3000 rpm until the solute is dissolved. Solution A is filtered with a 0.22 micron nylon filter to obtain solution B. Add polystyrene polymer (weight average molecular weight Mw = 30000-80000) and titanium oxide scattering particles (particle size range between 0.1-1 micron) to solution B, the mass fraction of polystyrene polymer is 30-250 mg / ml, the mass fraction of titanium oxide scattering particles is 1-10 mg / ml, mix with a mixer for 72-96 hours at a speed of 2000-3000 rpm until the polymer is dissolved and the titanium oxide scattering particles are evenly dispersed, and then filter with a 50-micron nylon filter to obtain solution C. Let solution C stand for more than 120 hours to eliminate bubbles for use.

[0047] Example 2

[0048] The inkjet printing application method in this embodiment has an inkjet printing process as follows: Figure 1 As shown, the specific application steps are as follows:

[0049] a) The whole process of inkjet printing is carried out in an air environment. The substrate is made of quartz glass. The substrate is cleaned with deionized water for 5 to 20 minutes, with acetone for 15 to 20 minutes, with isopropyl alcohol for 15 to 20 minutes, with deionized water for 15 to 20 minutes, and then blown dry with a nitrogen gun.

[0050] b) Place the cleaned quartz glass in the designated position of the inkjet printing device, and slowly add solution C along the tube wall into the needle of the electro-fluidic printing device. Set the base voltage to 800-1200V, the pulse voltage to 800-1500V, the frequency to 20-50Hz, the duty cycle to 50%-90%, the delay time to 30-60ms, and the printing speed to 10-20mm / s. The final printing result is as follows: Figure 2 and Figure 3 As shown, it can be seen that the printed rose pattern is relatively complete and clear as a whole. After enlarging it, the pixel diameter is generally around 75μm.

[0051] Example 3

[0052] In this embodiment, an optical simulation is performed on the film generated after rare earth inkjet printing, and a simulation model is constructed. The model includes four parts: a backlight source, a quartz glass substrate, an inkjet-printed film, and a receiving surface. The peak position of the light emitted by the backlight source is 340nm, and the light distribution is a Lambertian distribution. The backlight source and the film cross-section are circular with a radius of 30 microns, and the film thickness is 2 microns. Two receiving surfaces are established on the upper and lower surfaces of the film to measure the number of incident ultraviolet light rays, the number of outgoing ultraviolet light rays, and the number of outgoing blue light rays. By changing the weight percentage of TiO2 scattering particles in the film, the color conversion rate and light intensity distribution of the film under different conditions are obtained. The color conversion rate calculation formula is the number of outgoing blue light rays / (the number of incident ultraviolet light rays-the number of outgoing ultraviolet light rays). From Figure 4 It can be seen that after adding 5% scattering particles, the color conversion rate of the film increases from 13.73% to 17.90%. Then, as the weight percentage of scattering particles increases, the color conversion rate continues to increase, and the increasing trend slows down after 10%. Figure 5 It can be seen that as more scattering particles are added, the light intensity distribution becomes more uniform.

[0053] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rare earth complex ink, characterized in that: Contains pyrazole boron Ce (III) complex and scattering particles; note the structural formula for The structural formula of the pyrazole boron Ce (III) complex is: Wherein, R1, R2, R3, and R4 are each independently selected from alkyl, aryl, phenyl, halogen, or halogen-substituted alkyl.

2. The rare earth complex ink according to claim 1, characterized in that: The alkyl group is selected from C1-C 18 of alkyl.

3. The rare earth complex ink according to claim 1, characterized in that: R1 is -CH3; R2 is selected from C1-C 18 alkyl or halogen; R3 is -CH3; R4 is selected from C1-C 18 alkyl or halogen.

4. The rare earth complex ink according to claim 1, characterized in that: The pyrazole boron Ce (III) complex is CeTp3, Ce (Tp 4Me )3. Ce(Tp 4Br )3、Ce(PzTp)3、Ce( i PrTp)3、Ce( n At least one of BuTp)3 and Ce(PhTp)3; The structure of CeTp3 is as follows: The Ce(Tp 4Me )3 The structure is as follows: The Ce(Tp 4Br )3 The structure is as follows: The Ce(PzTp)3 structure is as follows: The Ce( i The structure of PrTp)3 is as follows: The Ce( n The structure of BuTp)3 is as follows: The Ce(PhTp)3 structure is as follows:

5. The rare earth complex ink according to claim 1, characterized in that: The scattering particles are titanium oxide TiO2, zinc oxide ZnO, silicon oxide SiO2, barium sulfate BaSO4 or zirconium oxide ZrO 2。 6. The rare earth complex ink according to claim 5, characterized in that: The particle size of the scattering particles ranges from 0.1 to 1 micron.

7. The method for preparing a rare earth complex ink according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) dissolving the pyrazole boron Ce(III) complex in a solvent containing a benzene ring and a chlorine element; (2) Adding a polymer and scattering particles to the solution obtained in step (1); the polymer comprises one or more of polystyrene, polymethyl methacrylate, polycarbonate or polyimide.

8. The preparation method according to claim 7, characterized in that: The solvent is o-dichlorobenzene, or a mixed solvent of o-dichlorobenzene and dichlorobenzene; preferably, in the mixture, the volume proportion of dichlorobenzene is less than or equal to 30%.

9. The preparation method according to claim 7, characterized in that: In step (1), the concentration of the pyrazole boron Ce (III) complex in the solvent is 1 mg / ml to 10 mg / ml; in step (2), the concentration of the polymer in the solution is 30 mg / ml to 250 mg / ml, and the mass fraction of the scattering particles is 1 mg / ml-10 mg / ml.

10. Use of the rare earth complex ink according to any one of claims 1 to 6 for printing photoluminescent materials; Preferably, the photoluminescent material is used to prepare a photoluminescent display device; Preferably, the photoluminescent material is used as an anti-counterfeiting material or as a color conversion material.

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