Rare earth complex printing ink with heat conduction material doped with pyrazolo boron Ce (III) complex, preparation and application

Abstract

The invention relates to rare earth complex printing ink formed by doping a heat conduction material into a pyrazolo boron Ce (III) complex, preparation and application, belongs to the field of light-emitting display, and more specifically, heat can be effectively and rapidly conducted out by doping the heat conduction material into the printing ink, non-radiation loss caused by overheating of a rare earth complex is avoided, and therefore the light-emitting efficiency is improved. In the ink-jet printing process, the temperature rise of a printing head may cause aggregation of rare earth complex particles in printing ink, and then the printing uniformity and the pattern quality are affected. The addition of the heat conducting material is beneficial to stabilizing the temperature of the ink, reducing the thermal motion of particles, preventing agglomeration and precipitation, improving the stability and reliability of printing, and ensuring the long-term work of the printing head.

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 a thermal conductive material is doped with a pyrazole boron Ce (III) complex, and the preparation and application thereof. Background Art

[0002] Rare earth elements have unique narrow-bandwidth luminescence characteristics and can produce precise luminescence wavelengths through electronic transitions. As luminescent materials, rare earth complexes have high luminescence efficiency, especially in the red, green and blue light regions, which provide efficient luminescent materials for display technology and light source development. The luminescence of rare earth complexes usually has a long luminescence lifetime, and its luminescence process is less affected by the external environment, and has good thermal stability and photostability. This feature enables rare earth complexes to maintain efficient and stable luminescence performance even in long-term work and harsh environments. With the advancement of rare earth complex synthesis technology and the continuous emergence of new luminescent materials, innovations in display technology, lighting technology, anti-counterfeiting technology, optical sensing and catalysis are being promoted.

[0003] Inkjet printing technology of inks prepared with rare earth complexes is gradually becoming an important method in modern material manufacturing due to its precision, flexibility and high efficiency, especially in anti-counterfeiting technology, display manufacturing and optical devices. Since rare earth complexes usually exist in the ink in the form of particles or nanoparticles, the increase in temperature will cause the particles to agglomerate and precipitate, and even affect the optical properties of the rare earth complexes. Therefore, thermal management of inks has become a key issue in the application of inkjet printing of rare earth complexes. In addition, in practical applications, the luminescence process of rare earth complexes is highly sensitive to temperature, especially in devices with high-power excitation or long-term operation, where thermal effects can lead to problems such as reduced luminescence efficiency and increased light attenuation. 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 a thermal conductive material is doped with a pyrazole boron Ce (III) complex and its application, which is characterized in that the thermal management problem in the inkjet printing process is effectively solved to ensure the luminous efficiency of the rare earth complex, the accuracy of the printed pattern and the stability of the ink. The thermal conductive material optimizes the heat conduction path to avoid local overheating, reduce the decrease in the photoluminescent efficiency of the rare earth complex and the agglomeration of particles.

[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 a thermal conductive material; for

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

[0007]

[0008] Wherein, R1, R2, R3, and R4 are each independently selected from alkyl, aryl, phenyl, halogen, or halogen-substituted alkyl.

[0009] Preferably, the alkyl group is selected from C1-C 18 of alkyl.

[0010] 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.

[0011] 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;

[0012] The structure of CeTp3 is as follows:

[0013]

[0014] The Ce(Tp 4Me )3 The structure is as follows:

[0015] The Ce(Tp 4Br )3 The structure is as follows:

[0016]

[0017] The Ce(PzTp)3 structure is as follows:

[0018]

[0019] The Ce( i The structure of PrTp)3 is as follows:

[0020]

[0021] The Ce( n The structure of BuTp)3 is as follows:

[0022] The Ce(PhTp)3 structure is as follows:

[0023]

[0024] Preferably, the thermal conductivity of the thermally conductive material is greater than 40 W / (m·K);

[0025] Preferably, the particle size of the thermally conductive material is in the range of 0.1-1 micrometer.

[0026] Preferably, the thermally conductive material is boron nitride nanosheets or aluminum oxide nanoparticles.

[0027] According to another aspect of the present invention, a method for preparing a rare earth complex ink is provided, comprising the following steps:

[0028] (1) dissolving the pyrazole boron Ce(III) complex in a solvent containing a benzene ring and a chlorine element;

[0029] (2) Adding a polymer and a thermally conductive material to the solution obtained in step (1); the polymer comprises one or more of polystyrene, polymethyl methacrylate, polycarbonate or polyimide.

[0030] 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%.

[0031] 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 concentration of the thermal conductive material is 1 mg / ml to 10 mg / ml.

[0032] According to another aspect of the present invention, there is provided a use of a rare earth complex ink for printing a photoluminescent material;

[0033] Preferably, the photoluminescent material is used to prepare a photoluminescent display device;

[0034] Preferably, the photoluminescent material is used as an anti-counterfeiting material or as a color conversion material.

[0035] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0036] (1) The present invention can effectively and quickly transfer heat by adding thermal conductive materials to the ink, thereby avoiding non-radiative loss of rare earth complexes due to overheating, thereby improving luminous efficiency. This thermal management is particularly important for high-intensity excitation applications. In scenarios such as high-power LEDs and OLED displays, thermal management of rare earth luminescent materials is a key factor in determining their luminous efficiency and lifespan.

[0037] (2) During the inkjet printing process, the temperature increase of the print head may cause the rare earth complex particles in the ink to agglomerate, which in turn affects the printing uniformity and pattern quality. The agglomerated particles not only affect the fluidity of the inkjet process, but may also clog the printing nozzle, resulting in printing failure. The introduction of thermal conductive materials can help stabilize the temperature of the ink, reduce the thermal motion of the rare earth complex particles, and prevent their agglomeration and precipitation. At the same time, the presence of thermal conductive materials can also increase the stability of the ink and ensure the long-term reliability of the print head. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is Ce(Tp in Example 2 4Me )3 Schematic diagram of electro-inkjet printing control of complex solution.

[0039] Figure 2 Ce(Tp 4Me )3 Low-magnification fluorescence microscopy pattern printed by inkjet printing of complex solution.

[0040] Figure 3 Ce(Tp 4Me )3 Inkjet printing of high magnification fluorescence microscopy patterns by complex solution.

[0041] Figure 4 The results are as follows: undoped alumina nanoparticles, doped with 3%, 6% and 9% Ce (Tp 4Me )3 The temperature change curve of the film spin-coated with the complex ink when it is heated from room temperature to steady state on a 100℃ hot plate.

[0042] Figure 5 The results are as follows: undoped alumina nanoparticles, doped with 3%, 6% and 9% Ce (Tp 4Me )3 The temperature change curve of the film spin-coated with the complex ink when it is heated from room temperature to steady state on a 125℃ hot stage.

[0043] Figure 6 The results are as follows: undoped alumina nanoparticles, doped with 3%, 6% and 9% Ce (Tp 4Me )3 The temperature change curve of the film spin-coated with the complex ink when it is heated from room temperature to steady state on a 145℃ hot stage. DETAILED DESCRIPTION

[0044] 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.

[0045] 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.

[0046] The following are specific embodiments

[0047] Example 1

[0048] The preparation method of the pyrazole boron Ce (III) complex ink in this embodiment has the following specific preparation steps:

[0049] 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 alumina nanoparticles (particle size range between 0.1-10 microns) to solution B, the mass fraction of polystyrene polymer is 30-250 mg / ml, the mass fraction of alumina nanoparticles 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 alumina nanoparticles 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.

[0050] Example 2

[0051] 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:

[0052] 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.

[0053] 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 Great Wall pattern is relatively complete and clear as a whole, and the pixel diameter is about 90μm after magnification.

[0054] Example 3

[0055] The pyrazole boron Ce (III) complex ink doped with different mass fractions of aluminum oxide nanoparticles was spin-coated on quartz glass, and different temperatures were set to test the heat dissipation performance of the pyrazole boron Ce (III) complex film with different mass fractions. Figure 4 , Figure 5 and Figure 6 The results show that after the film is doped with aluminum oxide nanoparticles, the steady-state temperature of the film drops by more than 7°C compared to the film without aluminum oxide nanoparticles, indicating that the aluminum oxide nanoparticles build a thermal conductive system in the film to make the temperature diffuse to the surface faster. However, as the proportion of aluminum oxide nanoparticles increases, the downward trend of the steady-state temperature gradually becomes flat.

[0056] 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 thermal conductive material; remember 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 thermal conductivity of the thermally conductive material is greater than 40 W / (m·K); Preferably, the particle size of the thermally conductive material is in the range of 0.1-1 micrometer.

6. The rare earth complex ink according to claim 5, characterized in that: The thermal conductive material is boron nitride nanosheets or aluminum oxide nanoparticles.

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 a thermally conductive material 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 concentration of the thermal conductive material is 1 mg / ml to 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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