A low temperature curing high refractive index ink, its preparation method and application

Abstract

The application provides a low-temperature curing high-refractive-index ink as well as a preparation method and application thereof. The ink comprises an epoxy monomer, an amine compound, a high-refractive-index dispersion liquid and a solvent, can be cured at low temperature, has a suitable viscosity in the case of high refractive index, and can be controlled to a film thickness of 5 mu m relatively easily. In particular, the ink added with a polyester acrylate oligomer and a photoinitiator is double-cured to form a film, the film material is lighter and thinner, can be designed in a pattern according to the requirements of panel design, is an excellent ink for display devices, and has a wide application prospect in OLED, Mini LED, Micro LED, LCD and other displays.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic materials application technology, specifically relating to a low-temperature curing high refractive index ink, its preparation method, and its application. Background Technology

[0002] AMOLED display technology, with its advantages of thinness, low power consumption, and foldability, is known as the "dream display technology." It has gradually replaced LCD in mobile display products (such as mobile phones and watches), becoming the mainstream display technology, and is increasingly penetrating into fields such as laptops and televisions. With the upgrading of consumer demand, advanced manufacturing processes related to AMOLED displays are also constantly being upgraded, giving rise to a series of innovative new technologies, such as Y-OCTA, LTPO, Eco2-OLED, and MLP launched by Samsung Display in the AMOLED display industry. These advanced AMOLED manufacturing technologies, because the core electroluminescent units (EL) in AMOLED displays use small organic molecules, generally have a low glass transition temperature (Tg < 100℃). Unlike traditional liquid crystal display (LCD) technology, which uses negative photoresist BM / CF / OC in the preparation of the black matrix (BM), color filter (CF), and planarization layer (OC), AMOLED cannot withstand high-temperature baking (230℃ for 0.5–1 hour) after exposure and development to deeply cure the photoresist film. Therefore, the exposure and development processes of these photoresists in AMOLED displays all rely on low-temperature curing photoresist.

[0003] Furthermore, Microlens Array (MLP) technology utilizes a combination of low-refractive-index and high-refractive-index materials to create a microlens array above AMOLED displays. This can improve the efficiency of OLED light-emitting devices by 10-20%, significantly reducing the power consumption of OLED displays and extending the battery life of watches / phones. It has become one of the key technologies for enhancing the user experience of AMOLED display products. The core of MLP technology is high-refractive-index materials. The current mainstream manufacturing process involves inkjet printing, applying high-refractive-index ink onto a substrate, and then curing it with ultraviolet light. However, this method currently has the following disadvantages: Because ink leveling is required to ensure the optical effect of the display, the ink thickness cannot be very thin; current mass-produced processes achieve a thickness of approximately 30μm. To increase the refractive index of the material, high-refractive-index inks often require the addition of a large number of inorganic nanoparticles, drastically increasing the ink viscosity. Therefore, there is an incompatible contradiction between ink viscosity and refractive index. While direct UV curing is simple, it cannot be modeled to meet the specific needs of panel manufacturers, hindering its integration with other technologies.

[0004] Therefore, in order to address the shortcomings of photoresist and microlens array technology in AMOLED display technology, it is necessary to develop photocurable inks that are thin, have no viscosity-refractive index limitations, and can be patterned according to the needs of panel design, so as to meet the customized and integrated needs of panel manufacturers, thereby reducing display power consumption, minimizing damage to OLED displays, and improving production yield. Summary of the Invention

[0005] To achieve the above objectives, the main objective of this invention is to provide a low-temperature curing high-refractive-index ink, its preparation method, and its application. The technical solution is as follows:

[0006] A low-temperature curing high-refractive-index ink, comprising the following components:

[0007] Epoxy monomers,

[0008] Amine compounds,

[0009] High refractive index dispersions

[0010] Solvent;

[0011] Wherein, the epoxy monomer is a compound represented by the following general formula (I), and the amine compound is a compound represented by the following general formula (II):

[0012]

[0013] Ar1 and Ar2 are each independently selected from: alkane groups with 1-6 carbon atoms, cycloalkyl groups with 6-25 carbon atoms containing 1-3 aliphatic rings, aromatic groups with 6-25 carbon atoms containing 1-3 aromatic rings, or combinations thereof;

[0014] R1, R2, R3, and R4 are each independently selected from: -CH2-, -O-CH2-, -S-CH2-, and -N(-CH2-)2 (each methylene group is attached to a corresponding epoxy group);

[0015] R5 and R6 are independently selected from: hydrogen, alkane group with 1-6 carbon atoms, cycloalkyl group with 6-15 carbon atoms containing 1-2 aliphatic rings, and aromatic group with 6-15 carbon atoms containing 1-2 aromatic rings.

[0016] a, b, c, x, and y are each independently selected from: 1 and 2.

[0017] Furthermore, Ar1 and Ar2 are independently selected from: cycloalkyl, bicycloalkylalkyl, unsubstituted or substituted phenyl with 1-6 carbon atoms, unsubstituted or substituted diphenylalkyl with 1-6 carbon atoms, and unsubstituted or substituted diphenoxy with 1-6 carbon atoms.

[0018] Furthermore, each alkane group with 1-6 carbon atoms is independently selected from: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl.

[0019] Preferably, the epoxy monomer represented by general formula (I) is one of the following compounds:

[0020]

[0021] Preferably, the amine compound represented by general formula (II) is one of the following compounds:

[0022]

[0023] According to the above scheme, the high refractive index dispersion contains inorganic nanoparticles with a particle size of 1-50 nm and a dispersion, wherein the inorganic nanoparticles are metal oxides or metal sulfides composed of one or two metal elements selected from zirconium, titanium, germanium, niobium, zinc, hafnium, tantalum, bismuth, molybdenum, tin, indium, antimony, cerium, neodymium, hafnium, and tantalum.

[0024] Furthermore, the inorganic nanoparticles are selected from: ZrO2, TiO2, Ti2O3, GeO2, Nb2O5, ZnO, ZnS, Bi4Ti3O2, MoO3, SnO2, In2O3-SnO2(ITO), Sb2O3, Sb2O5, CeO2, Nd2O5, HfO2, and Ta2O5.

[0025] Preferably, the particle size of the high refractive index inorganic nanoparticles is 5-20 nm.

[0026] According to the above scheme, the mass fraction of inorganic nanoparticles in the high refractive index dispersion is 40% to 60%.

[0027] According to the above scheme, the mass fraction ratio of epoxy monomer, amine compound, high refractive index dispersion and solvent in the low-temperature curing high refractive index ink is (2-5):(1-4):(15-30):(50-70).

[0028] According to the above scheme, the preparation method of the low-temperature curing high refractive index ink includes the following steps:

[0029] Add 2-5 parts by weight of epoxy monomer and 1-4 parts by weight of amine compound to the equipment, then add 50-70 parts by weight of solvent, stir evenly at room temperature, then add 15-30 parts by weight of high refractive index dispersion, continue stirring until a transparent and homogeneous solution is formed, and the low-temperature curing high refractive index ink can be prepared.

[0030] According to the above scheme, the low-temperature curing high-refractive-index ink also contains polyester acrylate oligomers and photoinitiators.

[0031] Preferably, the polyester acrylate oligomer is a compound represented by general formula (III):

[0032]

[0033] R7 is selected from: alkane groups with 1-10 carbon atoms, cycloalkyl groups with 6-25 carbon atoms containing 1-3 aliphatic rings, aromatic groups with 6-25 carbon atoms containing 1-3 aromatic rings, or combinations thereof.

[0034] Furthermore, R7 is selected from: unsubstituted or substituted phenyl groups with 1-6 carbon atoms, unsubstituted or substituted biphenyl groups with 1-6 carbon atoms, unsubstituted or substituted diphenylalkyl groups with 1-6 carbon atoms, and unsubstituted or substituted diphenoxy groups with 1-6 carbon atoms.

[0035] Furthermore, in R7, each alkane group with 1-6 carbon atoms is independently selected from: methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, and tert-butylene.

[0036] Preferably, the polyester acrylate oligomer is selected from compounds represented by the following structural formulas:

[0037]

[0038] According to the above scheme, the photoinitiator is an oxime ester photoinitiator.

[0039] Preferably, the photoinitiator is selected from compounds represented by the following structural formulas:

[0040]

[0041] According to the above scheme, the solvent and dispersion are each independently selected from one or a mixture of two or more of esters, ethers, and ketones.

[0042] Furthermore, the solvent and dispersion can be the same or different, and examples include: ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, propylene glycol butyl ether acetate, propylene glycol diacetate, diethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, ethylene glycol diacetate, dimethyl succinate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, etc. Ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol methyl ether, propylene glycol monoethyl ether, propylene glycol n-butyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, acetone, cyclohexanone, methyl isopropyl ketone, methyl isobutyl ketone, etc.

[0043] According to the above scheme, the mass fraction ratio of epoxy monomer, amine compound, high refractive index dispersion, solvent, polyester acrylate oligomer and photoinitiator in the low-temperature curing high refractive index ink is (2-5): (1-4): (15-30): (50-70): (3-6): (2-8).

[0044] According to the above scheme, the preparation method of the low-temperature curing high refractive index ink includes the following steps:

[0045] Add 2-5 parts by weight of epoxy monomer and 1-4 parts by weight of amine compound to the equipment, then add 50-70 parts by weight of solvent, stir evenly at room temperature, then add 3-6 parts by weight of polyester acrylate oligomer, 15-30 parts by weight of high refractive index dispersion and 2-8 parts by weight of photoinitiator, and continue stirring until a transparent and homogeneous solution is formed, thus preparing the low-temperature curing high refractive index ink.

[0046] According to the above scheme, the low-temperature curing high-refractive-index ink also contains functional additives, including one or more of crosslinking agents, adhesion promoters, and surfactants.

[0047] Furthermore, the crosslinking agent is a compound with 2-6 acrylate functional groups at the end.

[0048] Preferably, the crosslinking agent is one of the following compounds:

[0049]

[0050]

[0051] Furthermore, the adhesion promoter is a siloxane compound. Preferably, the adhesion promoter is one of the following compounds:

[0052]

[0053] According to the above scheme, the surfactant is a fluorinated surfactant or an organosilicon surfactant, such as BYK300, BYK301, BYK302, BYK333, BYK352, BYK358N, etc., which are commercially available products from BYK in Germany.

[0054] According to the above scheme, in the low-temperature curing high refractive index ink, the epoxy monomer, amine compound, polyester acrylate oligomer, high refractive index dispersion, photoinitiator, solvent, crosslinking agent, adhesion promoter and surfactant are relatively independent, and the mass fraction ratio is (2~5):(1~4):(3~6):(15~30):(2~8):(50~70) and (1~5):(0.1~0.5):(0.1~0.5).

[0055] According to the above scheme, the preparation method of the low-temperature curing high refractive index ink includes the following steps:

[0056] Add 2-5 parts by weight of epoxy monomer and 1-4 parts by weight of amine compound to the equipment, then add 50-70 parts by weight of solvent. Stir evenly at room temperature, then add 3-6 parts by weight of polyester acrylate oligomer, 15-30 parts by weight of high refractive index dispersion, 2-8 parts by weight of photoinitiator, 1-5 parts by weight of crosslinking agent, 0.1-0.5 parts by weight of adhesion promoter, and 0.1-0.5 parts by weight of surfactant. Continue stirring until a transparent and homogeneous solution is formed to prepare the low-temperature curing high refractive index ink.

[0057] Furthermore, this invention also provides an application of the aforementioned low-temperature curing high-refractive-index ink, which can be prepared by coating, spraying, spin coating, doctor blade coating (wire bar), nanoimprinting, inkjet printing, screen printing, or pad printing. It can be used as a light extraction layer in OLED, Mini LED, Micro LED, and LCD displays. Alternatively, it can be coated, baked, and then exposed and developed using a photomask, serving as a patterned microlens array film material in OLED, Mini LED, Micro LED, and LCD displays. Furthermore, it can be selectively used with or without pigments as a photoresist, prepared as a low-temperature curing planarization layer (LTOC), low-temperature color filter (LTCF), or low-temperature black matrix (LTBM) through processes such as coating, pre-baking, alignment exposure, and development, and applied in OLED, Mini LED, Micro LED, and LCD displays.

[0058] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0059] This invention provides a low-temperature curable high-refractive-index ink. The amine compounds in the ink can adjust the electrophilic / nucleophilic activity of the epoxy resin component, thereby achieving low-temperature curing of the ink. The high solvent ratio of 50%–70% in the ink minimizes the impact of the high-refractive-index dispersion on the ink's viscosity, effectively overcoming the incompatibility between viscosity and refractive index caused by adding large amounts of high-refractive-index dispersion to increase the ink's refractive index. Simultaneously, the epoxy resin in the ink can be thermally cured at low temperatures (temperature ≤90℃, time ≤1h). Without damaging the functional properties of the organic small molecules in the electroluminescent unit, the solvent in the system evaporates more completely compared to other film-forming methods. Therefore, the film thickness can be easily controlled to 5μm. Compared to the current 30μm process thickness required for panel mass production lines to ensure ink leveling and display optical effects, the low-temperature curable high-refractive-index ink of this invention is thinner and has better dispersibility. Furthermore, inks containing polyester acrylate oligomers and photoinitiators, in particular, combine the low-temperature thermal curing of epoxy resin with the photocuring of polyester acrylate oligomers, employing a dual-curing film-forming technology. This results in virtually no solvent residue. The multi-layered cross-linking of active functional groups within the film ensures ink leveling and optimal optical performance for the display, allowing for thinner and lighter film materials. Simultaneously, the specific polyester acrylate oligomers, photoinitiators, epoxy monomers, and amine compounds used in this application can meet the process requirements of photoresist baking, photolithography, exposure, and development. As a flat panel display film material, it can be patterned according to the panel design requirements, facilitating integration with other material layers and display technologies. This meets the customization and integration needs of panel manufacturers, making it an excellent ink for display devices with broad application prospects in OLED, Mini LED, Micro LED, and LCD displays. Attached Figure Description

[0060] Figure 1 Using Fourier transform infrared spectroscopy (FTIR) to examine the infrared spectra of the low-temperature curing high-refractive-index ink prepared in Example 2 before and after heat curing at 90°C for 1 hour, it is possible to determine whether a chemical reaction has occurred between the epoxy monomer and the amine. Figure 2 The image shows the effect of curing the low-temperature curing high-refractive-index ink prepared in Example 2 after curing at 90°C for 1 hour. Detailed Implementation

[0061] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0062] Example 1

[0063] Add 100g of epoxy monomer EP-2 and 40g of amine compound AM-1 to the equipment, then add 1500g of propylene glycol methyl ether acetate. Stir evenly at room temperature, then add 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0064] Example 2

[0065] Add 100g of epoxy monomer EP-1 and 57g of amine compound AM-4 to the equipment, then add 1250g of cyclohexanone. Stir evenly at room temperature, then add 500g of propylene glycol methyl ether acetate dispersion containing 40% Ta2O5. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0066] Example 3

[0067] Add 100g of epoxy monomer EP-3 and 20g of amine compound AM-6 to the equipment, then add 1200g of triethylene glycol monomethyl ether. Stir evenly at room temperature, then add 400g of propylene glycol methyl ether acetate dispersion containing 40% TiO2. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0068] Example 4

[0069] Add 100g of epoxy monomer EP-1 and 38g of amine compound AM-3 to the equipment, then add 1400g of propylene glycol methyl ether. Stir evenly at room temperature, then add 60g of polyester acrylate oligomer PA-1, 600g of propylene glycol methyl ether acetate dispersion containing 60% TiO2, and 60g of photoinitiator OXE-01. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0070] Example 5

[0071] Add 100g of epoxy monomer EP-2 and 40g of amine compound AM-1 to the equipment, then add 1500g of propylene glycol methyl ether acetate. Stir evenly at room temperature, then add 100g of polyester acrylate oligomer PA-3, 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2, and 50g of photoinitiator OXE-02. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0072] Example 6

[0073] Add 100g of epoxy monomer EP-3 and 17g of amine compound AM-2 to the equipment, then add 2500g of dimethyl succinate. Stir evenly at room temperature, then add 250g of polyester acrylate oligomer PA-4, 750g of propylene glycol methyl ether acetate dispersion containing 40% Nb2O5, and 200g of photoinitiator FL-N30. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0074] Example 7

[0075] Add 100g of epoxy monomer EP-1 and 57g of amine compound AM-4 to the equipment, then add 1250g of cyclohexanone. Stir evenly at room temperature, then add 150g of polyester acrylate oligomer PA-5, 500g of propylene glycol methyl ether acetate dispersion containing 40% Ta2O5, and 50g of photoinitiator SBP-31B. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0076] Example 8

[0077] Add 100g of epoxy monomer EP-2 and 56g of amine compound AM-5 to the equipment, then add 2000g of diethylene glycol ethyl methyl ether. Stir evenly at room temperature, then add 200g of polyester acrylate oligomer PA-6, 800g of propylene glycol methyl ether acetate dispersion containing 40% HfO2, and 100g of photoinitiator IB-261. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0078] Example 9

[0079] Add 100g of epoxy monomer EP-3 and 20g of amine compound AM-6 to the equipment, then add 1200g of triethylene glycol monomethyl ether. Stir evenly at room temperature, then add 75g of polyester acrylate oligomer PA-1, 400g of propylene glycol methyl ether acetate dispersion containing 40% TiO2, and 50g of photoinitiator SPTO-41B. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0080] Example 10

[0081] Add 100g of epoxy monomer EP-2 and 40g of amine compound AM-1 to the equipment, then add 1500g of propylene glycol methyl ether acetate. Stir evenly at room temperature, then add 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2, 50g of crosslinking agent CL-3, 5g of adhesion promoter AC-1, and 5g of surfactant BYK300. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0082] Example 11

[0083] Add 100g of epoxy monomer EP-3 and 20g of amine compound AM-6 to the equipment, then add 1200g of triethylene glycol monomethyl ether. Stir evenly at room temperature, then add 400g of propylene glycol methyl ether acetate dispersion containing 40% TiO2, 20g of crosslinking agent CL-9, 12.5g of adhesion promoter AC-9, and 2.5g of surfactant BYK358N. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0084] Example 12

[0085] Add 100g of epoxy monomer EP-2 and 40g of amine compound AM-1 to the equipment, then add 1500g of propylene glycol methyl ether acetate. Stir evenly at room temperature, then add 100g of polyester acrylate oligomer PA-3, 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2, 50g of photoinitiator OXE-02, 50g of crosslinking agent CL-3, 5g of adhesion promoter AC-1, and 5g of surfactant BYK300. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0086] Example 13

[0087] Add 100g of epoxy monomer EP-1 and 57g of amine compound AM-4 to the equipment, then add 1250g of cyclohexanone. Stir evenly at room temperature, then add 150g of polyester acrylate oligomer PA-5, 500g of propylene glycol methyl ether acetate dispersion containing 40% Ta2O5, 50g of photoinitiator SBP-31B, 25g of crosslinking agent CL-8, 2.5g of adhesion promoter AC-4, and 12.5g of surfactant BYK333. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0088] Example 14

[0089] Add 100g of epoxy monomer EP-3 and 20g of amine compound AM-6 to the equipment, then add 1200g of triethylene glycol monomethyl ether. Stir evenly at room temperature, then add 75g of polyester acrylate oligomer PA-4, 400g of propylene glycol methyl ether acetate dispersion containing 40% TiO2, 50g of photoinitiator AN-31A, 20g of crosslinking agent CL-12, 12.5g of adhesion promoter AC-6, and 2.5g of surfactant BYK358N. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0090] Comparative Example 1

[0091] Add 100g of epoxy monomer EP-2 to the equipment, then add 1500g of propylene glycol methyl ether acetate. Stir evenly at room temperature, then add 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2. Continue stirring until a transparent and homogeneous solution is formed to prepare the ink.

[0092] Comparative Example 2

[0093] Add 1500g of propylene glycol methyl ether acetate, 100g of polyester acrylate oligomer PA-3, 500g of propylene glycol methyl ether acetate dispersion containing 40% ZrO2, and 50g of photoinitiator OXE-02 to the equipment, stir at room temperature until a transparent and homogeneous solution is formed, and the ink can be prepared.

[0094] The viscosity of the inks used in Examples 1 to 14 and Comparative Examples 1 and 2 was measured using a viscometer, and the refractive index of the film was measured using an Abbe refractometer. The inks were spin-coated onto a glass substrate (50mm × 50mm) at a rotation speed of 500 rpm for 60 seconds, and then baked in a 90°C oven for 1 hour to cure the film. The curing hardness of the optical material was measured using a hardness tester. Furthermore, the inks used in Examples 1 to 16 and Comparative Examples 1 and 2 were applied as microlens array film materials to OLED devices, and their light extraction efficiency was evaluated. Specifically, the inks used in Examples 4 to 9 and Examples 12 to 14 were spin-coated onto the light-emitting layer of the OLED device, baked in a 90°C oven for 1 hour, and then cured using approximately 100 mJ / cm². 2Intensity UV light was applied through a mask for deep curing. Unexposed areas were treated with a developer and then baked in a 90°C oven for 1 hour to form a 5μm patterned microlens array film in the light-emitting direction of the OLED device. Devices 4 to 9 and 12 to 14 were fabricated. Inks from Examples 1 to 3, 10, 11, Comparative Examples 1 and 2 were spin-coated onto the light-emitting layer of the OLED device and baked in a 90°C oven for 2 hours to form a 5μm planarized microlens array film. Devices 1 to 3, 10, 11, 15, and 16 were fabricated. The OLED devices fabricated above and those without a microlens array film were measured using a Keithley 2400 at 10 mA / cm². 2 The light intensity was used to calculate the light extraction efficiency enhancement rate of the aforementioned low-temperature curing high-refractive-index ink. Specific test results are shown in Table 1 below:

[0095] Table 1

[0096]

[0097]

[0098] As can be seen from the table above, the refractive index of the inks of the present invention is all above 1.65, exhibiting high refractive index, and the viscosity is between 6 and 15 cps. This effectively overcomes the contradiction between viscosity and refractive index caused by adding a large amount of high refractive index dispersion to increase the refractive index of the ink. After adjusting the activity of the epoxy monomers with amine compounds, the inks prepared in Examples 1 to 14, compared with Comparative Examples 1 and 2 which do not contain amine components, can be film-formed using a low-temperature thermosetting process (T≤90℃, t≤1h). Furthermore, the devices prepared using the inks of Examples 1 to 14... The microlens array film materials of devices 1 to 14 can be easily controlled to a thickness of 5μm, and the light extraction efficiency improvement is maintained at more than 10%. In particular, the devices prepared by dual resin components in Examples 4 to 9 and Examples 12 to 14 have dual curing technology of low-temperature thermal curing and photocuring, resulting in higher film hardness. After baking, photolithography, exposure, and development processes, the microlens array film material with patterned design is thinner, lighter, has better light transmittance, and a greater improvement in light extraction efficiency. It is more conducive to the specialization and integration of panels and is an excellent ink for display devices.

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A low temperature curing high refractive index ink characterized in that, Comprise the following components: Epoxy monomer, Amines compound, High refractive index dispersion liquid, Solvent; Among them, the epoxy monomer is a compound represented by the following general formula (I), and the amines compound is a compound represented by the following general formula (II): Ar1, Ar2 are independently selected from: alkyl group of carbon atom number 1-6, cycloalkyl group of carbon atom number 6-25 containing 1-3 aliphatic ring, aromatic hydrocarbon group of carbon atom number 6-25 containing 1-3 aromatic ring, or their combination; R1, R2, R3, R4 are independently selected from: -CH2-, -O-CH2-, -S-CH2-, -N(-CH2-)2; R5, R6 are independently selected from: hydrogen, alkyl group of carbon atom number 1-6, cycloalkyl group of carbon atom number 6-15 containing 1-2 aliphatic ring, aromatic hydrocarbon group of carbon atom number 6-15 containing 1-2 aromatic ring; a, b, c, x, y are independently selected from: 1, 2; The low temperature curing high refractive index ink further comprises polyester acrylate oligomer and photoinitiator; The polyester acrylate oligomer is a compound represented by the following general formula (III): Wherein, R7 is selected from: alkylene group of carbon atom number 1-10, cycloalkylene group of carbon atom number 6-25 containing 1-3 aliphatic ring, aralkylene group of carbon atom number 6-25 containing 1-3 aromatic ring, or their combination; The photoinitiator is oxime ester photoinitiator; The amines compound represented by general formula (I) is one of the following compounds: 、 、 、 、 、 ； The epoxy monomer represented by general formula (II) is one of the following compounds: 、 、 ； The solvent is independently selected from one or more than two mixtures of ester, ether, ketone.

2. The cryogenic-cured high refractive index ink of claim 1, wherein, The high refractive index dispersion liquid comprises high refractive index inorganic nanoparticles with particle size of 1-50nm and dispersion liquid, wherein the inorganic nanoparticles are metal oxide or metal sulfide composed of one or two metal elements of zirconium, titanium, germanium, niobium, zinc, hafnium, tantalum, bismuth, molybdenum, tin, indium, antimony, cerium, neodymium, hafnium, tantalum; the dispersion liquid is independently selected from one or more than two mixtures of ester, ether, ketone.

3. The cryogenic-cured high refractive index ink of claim 1, wherein, The photoinitiator is a compound represented by the following structural formula: 。 4. The cryogenic-cured high refractive index ink of claim 1, wherein, It also contains functional additives, which are one or more of crosslinking agent, adhesion promoter, surfactant; The crosslinking agent is a compound containing 2-6 acrylate functional groups at the end; The adhesion promoter is a siloxane compound.

5. The cryogenic-cured high refractive index ink of claim 4, wherein, In the low temperature curing high refractive index ink, the components of epoxy monomer, amines compound, polyester acrylate oligomer, high refractive index dispersion liquid, photoinitiator, solvent, crosslinking agent, adhesion promoter and surfactant are relatively independent, and the mass fraction ratio is (2~5):(1~4):(3~6):(15~30):(2~8):(50~70),(1~5):(0.1~0.5):(0.1~0.5).

6. A method of preparing a cryogenically solidified high refractive index ink according to claim 1, characterized in that, The method comprises the following steps: The low-temperature curing high-refractive ink is prepared by putting 2-5 parts by weight of an epoxy monomer, 1-4 parts by weight of an amine compound, then adding 50-70 parts by weight of a solvent, stirring uniformly at room temperature, then adding 3-6 parts by weight of a polyester acrylate oligomer, 15-30 parts by weight of a high-refractive dispersion, 2-8 parts by weight of a photoinitiator, and continuing to stir until a transparent and uniform solution is formed.

7. Use of a low temperature-cured high refractive index ink according to any one of claims 1 to 6, characterized in that, It is applied in OLED, Mini LED, Micro LED or LCD display as a photoresist or a microlens array film material.

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