Diffusion plate printing quantum dot ink and preparation method thereof

Abstract

The invention relates to the field of quantum dot ink, and discloses diffusion plate printing quantum dot ink and a preparation method thereof.The diffusion plate printing quantum dot ink comprises acrylic resin, hyperbranched polyester resin, a quantum dot material, modified boron nitride, a reactive diluent, a photoinitiator, a wetting agent and a defoaming agent; the hyperbranched polyester resin is prepared by reacting hyperbranched polyester acrylate and a sulfydryl-terminated silicon-containing reaction monomer, wherein the hyperbranched polyester acrylate is prepared by reacting pentaerythritol with 2, 2-dimethylolpropionic acid and then carrying out esterification reaction with acrylic acid; the sulfydryl-terminated silicon-containing reaction monomer is prepared by reacting eugenol with 1, 1, 3, 3-tetramethyldisiloxane and then carrying out esterification reaction with 3-mercaptopropionic acid; the modified boron nitride is prepared by modifying a cationic polymer which is prepared by carrying out a Mannich reaction on triethylene tetramine, formaldehyde and acetone and then carrying out a condensation polymerization reaction with formaldehyde. After the ink prepared by the invention is cured, a coating film is high in hardness, adhesive force and heat conductivity coefficient, and good in flexibility, heat resistance and migration barrier property.

Description

Technical Field

[0001] The invention belongs to the technical field of quantum dot inks, and in particular relates to a diffusion plate printed quantum dot ink and a preparation method thereof. Background Art

[0002] Quantum dot ink is a special ink whose pigment component is quantum dots, which are nano-scale semiconductor materials. Quantum dots have unique optical properties, such as quantum confinement effect, which enables quantum dots to emit light of a specific color, and the color of the light is related to the size of the quantum dots. By adjusting the size of quantum dots, the color of the light emitted by quantum dots can be precisely controlled, thereby achieving a display effect with high color purity and wide color gamut.

[0003] In the display field, quantum dot materials are used to manufacture high-resolution displays such as OLED, QLED, and liquid crystal, but the traditional extrusion process of quantum dot film production will cause high temperatures, which will seriously affect the efficiency and life of quantum dots, thereby increasing the cost of using quantum dot products and reducing material utilization. At present, quantum dot ink materials have become a favorable solution to the above problems. The quantum dot ink materials are layered and coated on the surface of the diffuser by printing, which can avoid the high temperature of the traditional process and achieve the best use effect of quantum dot products.

[0004] The diffusion plate is a type of low surface energy, and its printing adaptability is poor, resulting in poor ink adhesion and easy falling off. It also has some defects in migration resistance, uniformity and flexibility. Acrylic resin has a high glass transition temperature and good film-forming properties, but as an amorphous thermoplastic resin, it is still difficult to completely prevent the small molecular components in the ink from penetrating the coating film in a high temperature environment. Therefore, it is impossible to achieve the highest level of ink migration barrier effect, thereby reducing the printing quality. Summary of the invention

[0005] In order to solve the deficiencies mentioned in the above-mentioned background technology, the purpose of the present invention is to provide a diffusion plate printed quantum dot ink and a preparation method thereof, with hyperbranched polyester resin and acrylic resin as matrix resins and modified boron nitride as filler. The prepared ink has high hardness, adhesion and thermal conductivity after curing, and good flexibility, heat resistance and migration barrier properties.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A diffusion plate printing quantum dot ink, comprising the following raw materials in parts by weight: 40-55 parts of acrylic resin, 10-20 parts of hyperbranched polyester resin, 3-6 parts of quantum dot material, 1-4 parts of modified boron nitride, 4-7 parts of active diluent, 3-8 parts of photoinitiator, 1-2 parts of wetting agent, and 1-2 parts of defoaming agent;

[0008] The hyperbranched polyester resin is prepared by a thiol-ene click reaction between a hyperbranched polyester acrylate and a mercapto-terminated silicon-containing reactive monomer; wherein the hyperbranched polyester acrylate is prepared by an esterification reaction between pentaerythritol and 2,2-dimethylolpropionic acid and then an esterification reaction with acrylic acid; and the mercapto-terminated silicon-containing reactive monomer is prepared by an esterification reaction between eugenol and 1,1,3,3-tetramethyldisiloxane and then an esterification reaction with 3-mercaptopropionic acid;

[0009] The modified boron nitride is prepared by using a cationic polymer to modify boron nitride; wherein the cationic polymer is prepared by using triethylenetetramine, formaldehyde and acetone to undergo a Mannich reaction and then further adding formaldehyde to undergo a polycondensation reaction.

[0010] Preferably, the quantum dot material is one of perovskite quantum dots or silicon quantum dots.

[0011] Preferably, the active diluent is one or more combinations of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, tetrahydrofurfuryl acrylate, and hydroxyethyl methacrylate.

[0012] Preferably, the photoinitiator is one or more combinations of photoinitiator TPO, photoinitiator 819, photoinitiator 184, and photoinitiator BMS; the wetting agent is BYK-333; and the defoamer is a silicone defoamer.

[0013] Preferably, the preparation method of the hyperbranched polyester resin comprises the following steps:

[0014] A. Put pentaerythritol, 2,2-dimethylolpropionic acid and p-toluenesulfonic acid in a reactor, heat to 140-150° C., stir and react for 2-4 hours, cool to 65-75° C. after the reaction is completed, add acetone, stir and dissolve, then place in petroleum ether for precipitation and stand, and vacuum dry the precipitated product to constant weight to prepare a hydroxyl-terminated hyperbranched polyester;

[0015] B. Put the hydroxyl-terminated hyperbranched polyester and acrylic acid in a reactor, stir and dissolve at 100-115° C., then add p-toluenesulfonic acid catalyst, stir and react for 4-6 hours, wait for the temperature to drop to 55-70° C. after the reaction is completed, add anhydrous ethanol to dissolve, drop into deionized water for precipitation and washing, add anhydrous ethanol to wash the precipitated product until it is neutral and dry, to prepare a hyperbranched polyester acrylate;

[0016] C. Take eugenol and Custer catalyst in a reactor, add toluene solvent, raise the temperature to 60-70° C., add 1,1,3,3-tetramethyldisiloxane, stir and react for 42-48 hours, and after the reaction is completed, remove the unreacted product by rotary evaporation to prepare a silicon-containing reaction monomer;

[0017] D. Put the silicon-containing reaction monomer, 3-mercaptopropionic acid and p-toluenesulfonic acid in a reactor, stir and react at 110-125° C. for 6-8 hours, and vacuum dehydrate to prepare a mercapto-terminated silicon-containing reaction monomer;

[0018] E. Take hyperbranched polyester acrylate, tetrahydrofuran and triethylamine in a reactor, add mercapto-terminated silicon-containing reaction monomer, place it at 40-60° C. and stir to react for 20-24 hours. After the reaction is completed, remove the unreacted materials by rotary evaporation to prepare a hyperbranched polyester resin.

[0019] Preferably, in step A, the molar ratio of pentaerythritol to 2,2-dimethylolpropionic acid is 1:4-4.2; and in step B, the molar ratio of terminal hydroxyl hyperbranched polyester to acrylic acid is 1:8-8.1.

[0020] Preferably, in step C, the molar ratio of eugenol to 1,1,3,3-tetramethyldisiloxane is 2-2.3:1; and in step D, the molar ratio of the silicon-containing reaction monomer to 3-mercaptopropionic acid is 1:2-2.2.

[0021] Preferably, the preparation method of the modified boron nitride comprises the following steps:

[0022] (1) triethylenetetramine is placed in a reactor, the pH value is adjusted to 2-3 with hydrochloric acid, formaldehyde and acetone are added, and the reaction is stirred at 18-22° C. for 50-70 minutes, and then the pH value is adjusted to 8-9 with sodium hydroxide solution, a second batch of formaldehyde is added, and the reaction is stirred at 50-65° C. for 35-50 minutes to prepare a cationic polymer solution;

[0023] (2) Boron nitride is ultrasonically dispersed in a cationic polymer solution, and then stirred at 60-75°C for reaction for 0.5-1h. After the reaction is completed, the product is filtered, washed, and dried. The product is placed in a dryer containing glutaraldehyde and cross-linked at 40-60°C for 10-12h. Finally, the product is taken out and dried to prepare modified boron nitride.

[0024] Preferably, in step (1), the volume ratio of triethylenetetramine, formaldehyde, acetone and the second batch of formaldehyde is 1:1.2-1.5:1.1-1.3:1.1-1.3.

[0025] A method for preparing a diffusion plate printing quantum dot ink comprises the following steps: weighing each raw material by weight, taking an acrylic resin, a hyperbranched polyester resin and an active diluent and stirring and mixing them evenly, then adding a quantum dot material, a modified boron nitride, a photoinitiator, a wetting agent and a defoaming agent and stirring and mixing them, so as to prepare a diffusion plate printing quantum dot ink.

[0026] Beneficial effects of the present invention:

[0027] The invention firstly uses pentaerythritol as a core and 2,2-dimethylol propionic acid as a branching unit, and esterifies the hydroxyl group in pentaerythritol and the carboxyl group in 2,2-dimethylol propionic acid to prepare a terminal hydroxyl hyperbranched polyester, and then uses the carboxyl group in acrylic acid to react with the terminal hydroxyl group on the terminal hydroxyl hyperbranched polyester to prepare a hyperbranched polyester acrylate containing multiple double bond functional groups. At the same time, the invention uses the hydrosilylation reaction between eugenol and 1,1,3,3-tetramethyldisiloxane to prepare a silicon-containing reaction monomer containing an organic silicon segment, and then uses 3-mercaptopropionic acid and the silicon-containing reaction monomer to carry out an esterification reaction to prepare a mercapto-terminated silicon-containing reaction monomer, and carries out a thiol-ene click reaction between part of the double bonds in the hyperbranched polyester acrylate and the mercapto-terminated silicon-containing reaction monomer to prepare a hyperbranched polyester resin. The organic silicon segments introduced into the hyperbranched polyester resin structure prepared by the present invention can significantly reduce surface tension, better wet the attached substrate, and enhance the adhesion of the ink to the substrate. In addition, the unreacted double bond groups in the hyperbranched polyester resin structure have reactive photocuring activity, which helps to construct a highly cross-linked reaction and become a part of the ink cross-linked network, thereby improving the hardness of the coating film. The hyperbranched structure has a toughening effect, thereby maintaining the flexibility of the coating film while improving the hardness of the coating film.

[0028] The present invention utilizes triethylenetetramine, formaldehyde and acetone to generate a Mannich reaction, and then formaldehyde is continuously added to perform a polycondensation reaction. The amine groups on the prepared cationic polymer can be protonated and positively charged in a weakly alkaline solution, while the surface of boron nitride is negatively charged in an alkaline solution. In the modification process, the cationic polymer molecules are firstly adsorbed on the surface of the boron nitride through electrostatic action, and then the hydroxyl and amine groups are cross-linked by glutaraldehyde to achieve firm attachment and surface modification of the boron nitride. The introduction of polar groups such as hydroxyl and amine groups is beneficial to enhancing the interaction between the sheet-like boron nitride and the acrylic resin, and is beneficial to the uniform dispersion of the boron nitride in the coating film, so as to promote the sheet structure of the boron nitride to achieve better barrier performance and achieve complete blocking of ink migration. Meanwhile, the boron nitride has significant advantages such as low cost, strippability, high thermal stability, good electrical insulation, unique size effect, etc., and can be added to the ink cross-linked network structure as an insulating thermal conductive material to improve the heat dissipation capacity of the coating film, and avoid the problems of aging deformation and reduced service life of the device caused by excessive heat accumulation. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1 A method for preparing a hyperbranched polyester resin comprises the following steps:

[0031] A. 1.36 g of pentaerythritol, 5.36 g of 2,2-dimethylolpropionic acid and 0.03 g of p-toluenesulfonic acid were placed in a reactor, heated to 145° C., stirred and reacted for 3 h, cooled to 70° C. after the reaction was completed, 20 mL of acetone was added, stirred and dissolved, and then placed in 70 mL of petroleum ether for precipitation and allowed to stand. The precipitated product was vacuum dried to constant weight to prepare a hydroxyl-terminated hyperbranched polyester;

[0032] B. 4 g of hydroxyl-terminated hyperbranched polyester and 3.9 g of acrylic acid were placed in a reactor, stirred and dissolved at 110 ° C, and then 0.03 g of p-toluenesulfonic acid catalyst was added, and the reaction was stirred for 5 h. After the reaction was completed, the temperature dropped to 60 ° C, 20 mL of anhydrous ethanol was added to dissolve, and deionized water was added dropwise to precipitate and wash. The precipitated product was washed with anhydrous ethanol until neutral and dried to prepare a hyperbranched polyester acrylate;

[0033] C. 16.4 g of eugenol and 0.39 g of Custer catalyst (Pt 2 wt%, xylene as solvent) were placed in a reactor, 20 mL of toluene solvent was added, the temperature was raised to 65° C., 6.7 g of 1,1,3,3-tetramethyldisiloxane was added, and the reaction was stirred for 48 h. After the reaction was completed, the unreacted product was removed by rotary evaporation to prepare a silicon-containing reaction monomer;

[0034] D. 1.6 g of silicon-containing reaction monomer (Mr=462.7), 0.8 g of 3-mercaptopropionic acid and 0.02 g of p-toluenesulfonic acid were placed in a reactor, stirred and reacted at 120° C. for 8 h, and vacuum-dehydrated to prepare a mercapto-terminated silicon-containing reaction monomer;

[0035] E. Take 5.2 g of hyperbranched polyester acrylate, 100 mL of tetrahydrofuran and 0.3 g of triethylamine in a reactor, add 6.4 g of mercapto-terminated silicon-containing reaction monomer (Mr=638.9), stir and react at 55°C for 24 hours, and after the reaction is completed, remove the unreacted materials by rotary evaporation to prepare a hyperbranched polyester resin.

[0036] Embodiment 2 A method for preparing modified boron nitride comprises the following steps:

[0037] (1) 16 mL of triethylenetetramine was placed in a reactor, the pH value was adjusted to 3 with 1 mol / L hydrochloric acid, 20 mL of formaldehyde and 18 mL of acetone were added, the mixture was stirred at 20° C. for 60 min, then the pH value was adjusted to 8 with 1 mol / L sodium hydroxide solution, 18 mL of the second batch of formaldehyde was added, the mixture was stirred at 60° C. for 40 min, and a cationic polymer solution was prepared;

[0038] (2) 2 g of boron nitride was ultrasonically dispersed in 50 mL of cationic polymer solution, and then stirred at 70° C. for 1 h. After the reaction was completed, the product was filtered, washed, and dried. The product was placed in a dryer containing glutaraldehyde and cross-linked at 50° C. for 12 h to promote the cross-linking of the cationic polymer on the surface of the boron nitride with glutaraldehyde vapor. Finally, the product was taken out and dried to prepare modified boron nitride.

[0039] Example 3 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 41 parts of acrylic resin, 10 parts of hyperbranched polyester resin prepared in Example 1, 3 parts of quantum dot material CsPbBr3, 1.5 parts of modified boron nitride prepared in Example 2, 4 parts of active diluent 1,6-hexanediol diacrylate, 3 parts of photoinitiator TPO, 31 parts of wetting agent BYK-33, and 41 parts of defoaming agent BYK-02.

[0040] The preparation method of the above-mentioned diffusion plate printing quantum dot ink includes the following steps: weighing each raw material by weight, taking acrylic resin, hyperbranched polyester resin and active diluent and stirring and mixing them evenly, and then adding quantum dot material, modified boron nitride, photoinitiator, wetting agent and defoaming agent and stirring and mixing to prepare the diffusion plate printing quantum dot ink.

[0041] Example 4 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 47 parts of acrylic resin, 14 parts of hyperbranched polyester resin prepared in Example 1, 35 parts of quantum dot material CsPbBr, 3 parts of modified boron nitride prepared in Example 2, 5 parts of active diluent tripropylene glycol diacrylate, 8195 parts of photoinitiator, 1.5 parts of wetting agent BYK-333, and 1.5 parts of defoaming agent BYK-024.

[0042] The preparation method of the above-mentioned diffusion plate printed quantum dot ink is the same as that in Example 3.

[0043] Example 5 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 52 parts of acrylic resin, 17 parts of hyperbranched polyester resin prepared in Example 1, 35 parts of quantum dot material CsPbBr, 4 parts of modified boron nitride prepared in Example 2, 7 parts of active diluent tetrahydrofurfuryl acrylate, 6.5 parts of photoinitiator BMS, 32 parts of wetting agent BYK-33, and 42 parts of defoaming agent BYK-02.

[0044] The preparation method of the above-mentioned diffusion plate printed quantum dot ink is the same as that in Example 3.

[0045] Comparative Example 1 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 52 parts of acrylic resin, 17 parts of hyperbranched polyester acrylate prepared in Example 1, 35 parts of quantum dot material CsPbBr, 4 parts of modified boron nitride prepared in Example 2, 7 parts of active diluent tetrahydrofurfuryl acrylate, 6.5 parts of photoinitiator BMS, 32 parts of wetting agent BYK-33, and 42 parts of defoaming agent BYK-02.

[0046] The preparation method of the above-mentioned diffusion plate printed quantum dot ink is the same as that in Example 3.

[0047] Comparative Example 2 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 52 parts of acrylic resin, 35 parts of quantum dot material CsPbBr, 4 parts of modified boron nitride prepared in Example 2, 7 parts of active diluent tetrahydrofurfuryl acrylate, 6.5 parts of photoinitiator BMS, 32 parts of wetting agent BYK-33, and 42 parts of defoaming agent BYK-02.

[0048] The preparation method of the above-mentioned diffusion plate printed quantum dot ink is the same as that in Example 3.

[0049] Comparative Example 3 A diffusion plate printing quantum dot ink comprises the following raw materials in parts by weight: 52 parts of acrylic resin, 17 parts of hyperbranched polyester resin prepared in Example 1, 35 parts of quantum dot material CsPbBr, 4 parts of boron nitride, 7 parts of active diluent tetrahydrofurfuryl acrylate, 6.5 parts of photoinitiator BMS, 32 parts of wetting agent BYK-33, and 42 parts of defoaming agent BYK-02.

[0050] The preparation method of the above-mentioned diffusion plate printed quantum dot ink is the same as that in Example 3.

[0051] Performance Testing

[0052] The diffuser plate printed quantum dot ink prepared in Examples 3-5 and Comparative Examples 1-3 was applied to one end of the diffuser plate using a 10 μm wire rod coater and slowly applied to the other end to obtain a diffuser plate ink coating with a thickness of about 10 μm. The coating was photocured using an LED-UV curing machine for 20 seconds, and then placed in an oven and baked at 150° C. for 1 hour to perform performance testing:

[0053] (1) Coating pencil hardness test: Refer to GB / T 6739-1996 and use QHQ pencil hardness tester to test. Fix the diffusion plate for testing on the pencil hardness tester. Grind the pencil on sandpaper in circles until the surface is smooth and the edge is sharp. Then fix it on the instrument. The pencil is at 45° to the coating surface. Put a heavy object on it and shake the hand wheel at a constant speed so that the pencil passes over the coating surface at a speed of about 0.5 mm / s. The data results are shown in Table 1.

[0054] (2) Coating adhesion test: Referring to GB / T 1720-88, the adhesion test method for coating film was used to measure the adhesion using a QFD electric coating film adhesion tester. The adhesion of the coating film to the substrate was evaluated according to 7 levels. The higher the level, the lower the adhesion. The data results are shown in Table 1.

[0055] (3) Coating flexibility test: Refer to GB / T 1731-2020 and use QTX paint film flexibility tester for test. Place the coating on the diffuser upwards and place the diffuser on the shaft for 2-3 seconds according to the shaft diameter from large to small. Bend the diffuser around the shaft at a uniform speed to observe whether the coating falls off or cracks. Repeat the experiment twice for each shaft diameter. The minimum shaft diameter that does not cause the coating to fall off or crack is the coating flexibility, expressed as shaft diameter (mm). The data results are shown in Table 1.

[0056] (4) Heat resistance test of coating: The diffusion plate was placed in an oven and baked at 250°C for 0.5 h. The plate was taken out and cooled directly to observe whether the coating had any peeling, bubbles, cracks, etc. The data results are shown in Table 1.

[0057] (5) Thermal conductivity test: The thermal conductivity of the coating was tested using the laser flash method, and the data results are shown in Table 1.

[0058] (6) Migration barrier performance test: A sample of about 10 cm × 10 cm was cut from the bamboo-printed soft PVC film. The ink was applied to the surface of the film using a wire rod applicator, and then light-cured and dried. Subsequently, a 10 cm × 10 cm white soft PVC film was cut, and the bamboo-printed PVC film coated with ink was stacked on the white film. The two were then placed on a flat glass plate, pressed on top by a thick glass plate weighing 500 g, and placed in an oven at 70°C for 24 h. The double-layer film was then taken out and the bamboo-printed film and the white film were separated. After cooling to room temperature, the ink contamination degree was evaluated according to the European standard EN 20105-A03. Grade 5 indicates the best barrier effect and no ink migration; Grade 1 indicates the worst barrier effect and severe ink migration. The data results are shown in Table 1.

[0059] Table 1 Test results of sample performance

[0060]

[0061]

[0062] From the data in Table 1, it can be seen that the ink coating prepared in Examples 3-5 of the present invention has high hardness, adhesion and thermal conductivity, and good flexibility, heat resistance and migration barrier properties. In Comparative Example 1, the hyperbranched polyester resin is replaced by hyperbranched polyester acrylate in equal amounts, and the hardness and adhesion measured are lower than those of Examples 3-5, because no organosilicon segment is introduced. In Comparative Example 2, no hyperbranched polyester resin is added, and the hardness, adhesion and flexibility measured are significantly lower than those of Examples 3-5, indicating that the addition of hyperbranched polyester resin improves the adhesion of the coating, and can maintain the flexibility of the coating while improving the hardness of the coating. In Comparative Example 3, boron nitride is not modified, and the coating is slightly warped, and the thermal conductivity and ink contamination are lower than those of Examples 3-5, because the modification of boron nitride is conducive to the uniform dispersion of boron nitride in the coating, thereby better exerting its thermal insulation barrier properties.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A diffusion plate printing quantum dot ink, characterized in that: The invention comprises the following raw materials in parts by weight: 40 to 55 parts of acrylic resin, 10 to 20 parts of hyperbranched polyester resin, 3 to 6 parts of quantum dot material, 1 to 4 parts of modified boron nitride, 4 to 7 parts of active diluent, 3 to 8 parts of photoinitiator, 1 to 2 parts of wetting agent and 1 to 2 parts of defoaming agent; The hyperbranched polyester resin is prepared by a thiol-ene click reaction between a hyperbranched polyester acrylate and a mercapto-terminated silicon-containing reactive monomer; wherein the hyperbranched polyester acrylate is prepared by an esterification reaction between pentaerythritol and 2,2-dimethylolpropionic acid and then an esterification reaction with acrylic acid; and the mercapto-terminated silicon-containing reactive monomer is prepared by an esterification reaction between eugenol and 1,1,3,3-tetramethyldisiloxane and then an esterification reaction with 3-mercaptopropionic acid; The modified boron nitride is prepared by using a cationic polymer to modify boron nitride; wherein the cationic polymer is prepared by using triethylenetetramine, formaldehyde and acetone to undergo a Mannich reaction and then further adding formaldehyde to undergo a polycondensation reaction.

2. The diffuser plate printed quantum dot ink according to claim 1, characterized in that: The quantum dot material is one of perovskite quantum dots or silicon quantum dots.

3. The diffuser plate printed quantum dot ink according to claim 1, characterized in that: The active diluent is one or more combinations of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, tetrahydrofurfuryl acrylate, and hydroxyethyl methacrylate.

4. The diffuser plate printed quantum dot ink according to claim 1, characterized in that: The photoinitiator is one or more combinations of photoinitiator TPO, photoinitiator 819, photoinitiator 184, and photoinitiator BMS; the wetting agent is BYK-333; and the defoamer is a silicone defoamer.

5. The diffusion plate printing quantum dot ink according to claim 1, characterized in that: The preparation method of the hyperbranched polyester resin comprises the following steps: A. Put pentaerythritol, 2,2-dimethylolpropionic acid and p-toluenesulfonic acid in a reactor, heat to 140-150° C., stir and react for 2-4 hours, cool to 65-75° C. after the reaction is completed, add acetone, stir and dissolve, then place in petroleum ether for precipitation and stand, and vacuum dry the precipitated product to constant weight to prepare a hydroxyl-terminated hyperbranched polyester; B. Put the hydroxyl-terminated hyperbranched polyester and acrylic acid in a reactor, stir and dissolve at 100-115° C., then add p-toluenesulfonic acid catalyst, stir and react for 4-6 hours, wait for the temperature to drop to 55-70° C. after the reaction is completed, add anhydrous ethanol to dissolve, drop into deionized water for precipitation and washing, add anhydrous ethanol to wash the precipitated product until it is neutral and dry, to prepare a hyperbranched polyester acrylate; C. Take eugenol and Custer catalyst in a reactor, add toluene solvent, raise the temperature to 60-70° C., add 1,1,3,3-tetramethyldisiloxane, stir and react for 42-48 hours, and after the reaction is completed, remove the unreacted product by rotary evaporation to prepare a silicon-containing reaction monomer; D. Put the silicon-containing reaction monomer, 3-mercaptopropionic acid and p-toluenesulfonic acid in a reactor, stir and react at 110-125° C. for 6-8 hours, and vacuum dehydrate to prepare a mercapto-terminated silicon-containing reaction monomer; E. Take hyperbranched polyester acrylate, tetrahydrofuran and triethylamine in a reactor, add mercapto-terminated silicon-containing reaction monomer, place it at 40-60° C. and stir to react for 20-24 hours. After the reaction is completed, remove the unreacted materials by rotary evaporation to prepare a hyperbranched polyester resin.

6. The diffuser plate printed quantum dot ink according to claim 5, characterized in that: The molar ratio of pentaerythritol to 2,2-dihydroxymethylpropionic acid in step A is 1:4-4.2; the molar ratio of terminal hydroxyl hyperbranched polyester to acrylic acid in step B is 1:8-8.

1.

7. The diffuser plate printed quantum dot ink according to claim 5, characterized in that: In the step C, the molar ratio of eugenol to 1,1,3,3-tetramethyldisiloxane is 2-2.3:1; and in the step D, the molar ratio of the silicon-containing reaction monomer to 3-mercaptopropionic acid is 1:2-2.

2.

8. The diffuser plate printed quantum dot ink according to claim 1, characterized in that: The preparation method of the modified boron nitride comprises the following steps: (1) triethylenetetramine is placed in a reactor, the pH value is adjusted to 2-3 with hydrochloric acid, formaldehyde and acetone are added, and the reaction is stirred at 18-22° C. for 50-70 minutes, and then the pH value is adjusted to 8-9 with sodium hydroxide solution, a second batch of formaldehyde is added, and the reaction is stirred at 50-65° C. for 35-50 minutes to prepare a cationic polymer solution; (2) Boron nitride is ultrasonically dispersed in a cationic polymer solution, and then stirred at 60-75°C for reaction for 0.5-1h. After the reaction is completed, the product is filtered, washed, and dried. The product is placed in a dryer containing glutaraldehyde and cross-linked at 40-60°C for 10-12h. Finally, the product is taken out and dried to prepare modified boron nitride.

9. The diffusion plate printing quantum dot ink according to claim 8, characterized in that: In the step (1), the volume ratio of triethylenetetramine, formaldehyde, acetone and the second batch of formaldehyde is 1:1.2-1.5:1.1-1.3:1.1-1.

3.

10. The method for preparing a diffusion plate printing quantum dot ink according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: weighing each raw material by weight, taking acrylic resin, hyperbranched polyester resin and active diluent and stirring and mixing them evenly, then adding quantum dot material, modified boron nitride, photoinitiator, wetting agent and defoaming agent and stirring and mixing them, so as to prepare diffusion plate printing quantum dot ink.

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