A particle composition for improving large viewing angle color shift and a quantum dot film

Abstract

A particle composition for back coating the surface of a quantum dot film, the particle composition comprising a thermosetting resin, organic or inorganic particles, and a curing agent. Quantum dot films with the particle coating composition can effectively improve color shift at large viewing angles and exhibit better brightness in displays.

Description

Technical Field

[0001] This patent relates to the field of optical thin film technology, and in particular to a particle coating and a quantum dot film that can improve large-view chromatic aberration. Background Technology

[0002] Currently, backlight sources in the display industry can be categorized into edge-lit and direct-lit types based on their installation location. Current display technologies demand both wide viewing angles and improvements in color shift at large viewing angles. There are many reasons for large viewing angle color shift, including light leakage from adjacent pixels, and varying optical path lengths at different locations.

[0003] Quantum dot display technology places the quantum dot film above a diffuser plate or direct light source. It uses blue light to excite the quantum dots, generating red and green light, which is then combined with the blue light to form white light on the light-emitting surface. This enhances the performance of liquid crystal displays; therefore, the appearance of color shift at large viewing angles is largely related to the quantum dot film.

[0004] CN107024812A discloses an array substrate with a color filter layer, which can effectively improve the large viewing angle color shift problem caused by light leakage from adjacent pixels, but does not involve optical thin film technology.

[0005] CN107863084A discloses a driving method and driving device for a display device, which mainly focuses on the improvement of the backlight module and does not involve optical thin film technology.

[0006] CN111554728A discloses a display panel and a display device. By changing the opening corresponding to the first color light-emitting unit, the brightness attenuation of the color light-emitting source in the display panel as the viewing angle increases satisfies the target brightness attenuation law. This technology mainly involves improvements on the panel and does not involve optical thin films.

[0007] CN201711308354.2 discloses a quantum dot film with internally extended optical path, comprising two polymer films. Each polymer film includes a polymer base film, one surface of which has a diffusion particle coating or a microstructure optical diffusion layer, and the other surface of which has a barrier layer with a microprism lattice layer. The microprism lattice layers of the two polymer films are bonded face-to-face by a third polymer adhesive through polymerization and curing. This technology primarily improves the brightness of the quantum dot film through microstructure, but combining a prism film with a quantum dot film involves significant modifications, making it a composite film rather than a conventional quantum dot film.

[0008] CN202110604631.4 discloses a quantum dot module, a patterning method for quantum dot films, and a display device. The quantum dot module includes a first quantum dot film, within which cross-linked first quantum dots and second quantum dots are distributed. The first quantum dots are modified with a first ligand, and the second quantum dots are modified with a second ligand. The first and second ligands are cross-linked through a bridging structure. The bridging structure is obtained by an insertion reaction of a bridging structure precursor, which is obtained by activating a bridging agent, including a bis(azide) compound. After activation, the bridging agent denitrates the azide group to generate an active intermediate, a nitrogen carbene, which then undergoes an insertion reaction to connect the first and second ligands. This technology primarily modifies quantum dot nanoparticle ligands without using adhesive as a carrier, employing a patterned approach. Compared to existing mature sandwich structures, this design differs, and its mass production feasibility is considered low.

[0009] The problem of large viewpoint bias has not been solved in existing technologies. Summary of the Invention

[0010] The purpose of this invention is to solve the problem of large viewing angle color deviation by coating a layer of particle composition on a quantum dot film, so that the backlight source can be uniformly absorbed and uniformly diffused by the quantum dots.

[0011] This patent provides a back coating particle composition for the surface of a quantum dot film, comprising a thermosetting resin, organic particles, inorganic particles, and a curing agent.

[0012] The thermosetting resins include acrylic resins, epoxy resins, urethane resins, and alkyd resins.

[0013] The organic particles include polymethyl methacrylate, polybutyl methacrylate, and polystyrene;

[0014] The inorganic particles include titanium dioxide particles, silicon dioxide particles, aluminum oxide, barium sulfate, and calcium carbonate.

[0015] The curing agent includes hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), and dimethylene diisocyanate (XTI);

[0016] The thermosetting resin comprises 20-40 parts by weight, the organic particles comprise 10-30 parts by weight, the inorganic particles comprise 1-5 parts by weight, and the curing agent comprises 1-5 parts by weight.

[0017] Furthermore, the thermosetting resin includes an acrylic resin with an OH content of 10-30 mg KOH / g, or an acrylic resin with an OH content of 10 mg KOH / g or 20 mg KOH / g.

[0018] Acrylic resin primarily provides the particle carrier and adhesion to the surface of the quantum dot film substrate.

[0019] Furthermore, the organic particles include one or a combination of polymethyl methacrylate, polybutyl methacrylate, and polystyrene; preferably polymethyl methacrylate particles.

[0020] Furthermore, the particle size of polymethyl methacrylate is 0.1-1.0 μm, or 0.20 μm, 0.35 μm, 0.50 μm, or 0.70 μm, and the D90 is 0.45-0.92 μm, or 0.55 μm or 0.70 μm.

[0021] Furthermore, the inorganic particles include one or more combinations of silicon dioxide, titanium dioxide, and aluminum oxide; preferably rutile titanium dioxide particles.

[0022] Furthermore, the preferred rutile titanium dioxide particles have a particle size of 0.1-1.0 μm, or 1.65 μm, 0.20 μm, 0.35 μm, 0.50 μm, or 0.70 μm, and a D90 of 4-6 μm, or 5 μm.

[0023] The particles primarily alter the path of light, enabling the quantum dot film to uniformly absorb the backlight and uniformly convert it into white light.

[0024] Furthermore, the curing agent comprises one or more combinations of hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI), with hexamethylene diisocyanate (HDI) being preferred.

[0025] The curing agent is mainly used to harden the acrylic resin.

[0026] Furthermore, the particle composition includes a diluent, said diluent being one, two, or a combination of more of the following: ethyl acetate, butyl acetate, toluene, xylene, isobutyl acetate, diacetone alcohol, ethylene glycol ethyl ether, ethylene glycol butyl ether, cyclohexanone, butanone, acetone, methyl isobutyl ketone, isoflurane, etc.

[0027] Furthermore, the diluent is most preferably one or a combination of at least two of ethyl acetate, butyl acetate, and methyl isobutyl ketone.

[0028] The diluent plays a role in dissolving the resin, improving the appearance of the coating, simplifying the coating process, increasing the wettability of the substrate, and improving adhesion.

[0029] Furthermore, the thermosetting resin in the particle coating composition is 20-40 parts by weight, or 25-35 parts by weight, or 28 parts by weight, 31 parts by weight, or 34 parts by weight.

[0030] Furthermore, the organic particles in the particle coating composition are 10-30 parts by weight, or 15-25 parts by weight, or 18 parts by weight, 21 parts by weight, or 24 parts by weight.

[0031] Furthermore, the inorganic particles in the particle coating composition are 1-5 parts by weight, or 2-3 parts by weight, or 2.3 parts by weight, 2.6 parts by weight, or 2.9 parts by weight.

[0032] Furthermore, the diluent in the particle coating composition is 20-40 parts by weight, or 25-35 parts by weight, or 28 parts by weight, 31 parts by weight, or 34 parts by weight.

[0033] Furthermore, the curing agent in the particle coating composition is 1-5 parts by weight, or 2-4 parts by weight, or 2.5 parts by weight, 3 parts by weight, or 3.5 parts by weight.

[0034] The particle coating composition of this patent is mainly used for back coating of quantum dot films to improve the color shift phenomenon of quantum dot films at large viewing angles.

[0035] This patent also provides a method for preparing a particle coating composition, comprising:

[0036] Step (1): Add the raw materials into the material cylinder in sequence according to the stated ratio;

[0037] Step (2): Use mechanical stirring to disperse at a speed of not less than 1500 rpm;

[0038] Step (3) is to obtain a particle coating composition after filtration.

[0039] This patent also provides a quantum dot film, including the structure of the quantum dot film, a barrier film and a back coating on its surface, wherein the back coating is prepared by curing the particle coating composition.

[0040] Furthermore, the preparation process includes: step (1), coating the particle coating composition onto the surface of the upper and lower barrier films, and baking and curing to obtain the back coating;

[0041] Step (2) involves coating QD adhesive between two barrier films, followed by slit coating and UV curing to obtain a sandwich-like structure, thereby preparing a quantum dot film.

[0042] In step (1), the particle coating composition is uniformly mixed and then coated on the upper and lower surfaces of the barrier film. After drying and curing, a back coating is obtained.

[0043] In step (1), curing is thermal curing, i.e., NCO reaction.

[0044] In step (2), two steel rollers, one above the other, are used.

[0045] In step (3), curing is performed by UV light radiation curing.

[0046] In step (1), the baking temperature is 55-85℃, or 60-80℃, 70℃, or 80℃; in step (3), the UV energy is 200-600mj / cm, or 250-550mj / cm, 300mj / cm, 350mj / cm, 400mj / cm, 450mj / cm, or 50mj / cm.

[0047] The barrier film is made of a polymer material, including polyethylene phthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polylactic acid (PLA), or polyester polyurethane (PU). Preferred is polyethylene phthalate (PET).

[0048] The substrate layer is made of a transparent material and has a thickness of 12μm-200μm, or 50μm, 75μm, 100μm, 150μm, or 200μm.

[0049] The back coating is prepared by micro-recessed coating.

[0050] The thickness of the back coating is 2-10 μm, or 3 μm, 5 μm, 7 μm, or 8 μm.

[0051] The quantum dot adhesive layer contains quantum dots, specifically red and green quantum dots.

[0052] The wavelengths of the red quantum dots are 620-634nm, or 624nm, 628nm, and 630nm.

[0053] The wavelengths of green quantum dots are 528-539nm, or 532nm, 536nm, and 538nm.

[0054] The present invention further provides the application of the back coating particle composition in improving the large apparent color deviation phenomenon of quantum dot films, wherein the back coating particle composition is coated on the quantum dot film.

[0055] Titanium dioxide particles generally have a diameter smaller than or close to the wavelength of visible light (380-780 nm), thus they can both scatter and diffract light, and their light scattering behavior conforms to Rayleigh scattering law. Furthermore, the size of the titanium dioxide particles is not directly related to the intensity of light absorption; titanium dioxide particles can reflect all wavelengths of visible light with equal and strong intensity.

[0056] Polymethyl methacrylate (PMMA) particles are white powder particles formed by suspension polymerization of MMA (methyl methacrylate) monomers. Due to their unique properties such as large specific surface area, strong adsorption, strong coagulation, and strong surface reactivity, PMMA particles can form micron-sized uneven surfaces on the particle composition surface. These uneven surfaces can refract incident light, thus playing a role in light diffusion and forming a uniform surface light source.

[0057] Compared with existing technologies, the product provided by this patent has the following advantages or functions:

[0058] The particle coating composition provided by this patent exhibits excellent adhesion and masking properties on the surface of quantum dot films; it significantly improves the color shift phenomenon of quantum dot films at wide viewing angles without affecting the original performance. This enhances quality and avoids the need for changes to other components. Attached Figure Description

[0059] Figure 1 The structural diagram of the quantum dot film provided for this patent;

[0060] Figure 2 This is a diagram of the particle structure of polymethyl methacrylate (PMMA).

[0061] Figure 3 Here is a structural diagram of titanium dioxide;

[0062] Figure 4 This is a surface diagram of the particle composition in Example 3. Detailed Implementation

[0063] To better understand the structure of this patent and its functional features and advantages, the preferred embodiments of this patent are described in detail below with reference to the drawings:

[0064] In this patented technical solution, the particle composition consists of polymethyl methacrylate particles. The titanium dioxide can be purchased from the market, for example, R706 titanium dioxide produced by DuPont, MRN-5HN produced by Zongyan Chemical, and the products of the manufacturers mentioned in this patent can also be obtained from other manufacturers.

[0065] The preparation method of the coating composition provided in this patent is as follows: the raw materials are added to the barrel in sequence according to the specified ratio; mechanical stirring is used to disperse the material at a high speed of not less than 1500 rpm; and the particle coating composition is obtained after filtration.

[0066] The solid content of the particle coating composition was measured using a solid content analyzer.

[0067] The particle coating composition provided in this patent is uniformly coated on the surface of the barrier film using a micro-concave roller coating method, and then cured by baking in an oven to evaporate the solvent, resulting in a cured back coating.

[0068] like Figure 1 As shown, the quantum dot film provided by this patent includes an upper and lower particle composition 1101, a barrier film 1102, and a quantum dot adhesive layer 1101.

[0069] The particle composition coated on a quantum dot film provided in this patent is subjected to performance testing according to the following method:

[0070] Adhesion test: Adhesion was tested according to GB / T 9286-2021 standard.

[0071] Brightness test: CS2000 spectrophotometer

[0072] Wide viewing angle test: The quantum dot film was assembled into the backlight module and then fixed on the test stage. The ELDIMEZ Contrast optical viewing angle meter was used for testing, dividing the test into three areas: Area A+: horizontal angle (-10°) - (+10°), vertical angle +8° - (-4°); Area A: horizontal angle (-40°) - (+40°), vertical angle +20° - (-4°); Area B: horizontal angle (-50°) - (+50°), vertical angle +20° - (-10°). The improvement effect was measured using the value of Δu'v'; the smaller the Δu'v', the more significant the improvement.

[0073] The test results are shown in Table 1.

[0074] Example 1

[0075] The composition comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 22 parts by weight of organic particles, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0076] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0077] Example 2

[0078] The composition comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 22 parts by weight of organic particles, 3 parts by weight of inorganic particles, 40 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0079] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0080] Example 3

[0081] The composition comprises 6 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 26 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 24 parts by weight of organic particles, 4 parts by weight of inorganic particles, 38 parts by weight of diluent, and 2 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0082] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0083] Example 4

[0084] The composition comprises 30 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 22 parts by weight of organic particles, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm; the inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm; the diluent is ethyl acetate; and the curing agent is HDI.

[0085] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0086] Example 5

[0087] The composition comprises 30 parts by weight of epoxy resin, 22 parts by weight of organic particles, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm; the inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm; the diluent is ethyl acetate; and the curing agent is HDI.

[0088] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0089] Comparative Example 1

[0090] Compared to Example 1, rutile titanium dioxide particles were replaced with acrylic resin with an OH content of 10 mg KOH / g.

[0091] The composition comprises 7 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 22 parts by weight of organic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0092] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0093] Comparative Example 2

[0094] The mixture comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 24 parts by weight of organic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0095] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0096] Comparative Example 3

[0097] Compared to Example 1, the polymethyl methacrylate particles were replaced with acrylic resin with an OH content of 10 mg KOH / g.

[0098] The mixture comprises 27 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0099] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0100] Comparative Example 4

[0101] The composition comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 24 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The inorganic particles are rutile titanium dioxide with a particle size of 1.65 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0102] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0103] Comparative Example 5

[0104] Compared to Example 1, rutile titanium dioxide particles were replaced with silicon dioxide.

[0105] The composition comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 22 parts by weight of organic particles, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the inorganic particles are silica with a particle size of 0.8 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0106] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0107] Comparative Example 6

[0108] Compared to Example 1, rutile titanium dioxide particles were replaced with aluminum oxide.

[0109] The composition comprises 5 parts by weight of acrylic resin with an OH content of 10 mg KOH / g, 25 parts by weight of acrylic resin with an OH content of 20 mg KOH / g, 22 parts by weight of organic particles, 2 parts by weight of inorganic particles, 43 parts by weight of diluent, and 3 parts by weight of curing agent. The organic particles are polymethyl methacrylate particles with a particle size of 0.35 μm, the inorganic particles are alumina with a particle size of 0.1 μm, the diluent is ethyl acetate, and the curing agent is HDI.

[0110] The particle coating composition is mixed evenly in proportion and then evenly coated on the surface of the barrier film using a micro-grooved roller coating method. It is then baked at 85°C for 2-3 minutes to obtain a coating with high adhesion and a coating thickness of 4μm.

[0111] Table 1 Examples

[0112]

[0113] The test results of the above embodiments and comparative examples show that the particle coating composition provided by this patent can improve the color shift phenomenon of the quantum dot film at a large viewing angle (a small Δu'v' value indicates that the color shift phenomenon is not obvious) while ensuring adhesion to the substrate of 5B, and also maintains good brightness. In Examples 1, 2, and 3, the content of rutile titanium dioxide particles gradually increased, and the Δu'v' value gradually decreased when the viewing angle range of region B was the largest, indicating that the improvement effect was obvious. In Examples 4 and 5, only the acrylic resin component was replaced with epoxy resin, and the color shift value did not change significantly. Comparative Examples 1 and 2 contained only polymethyl methacrylate particles, and Comparative Examples 3 and 4 contained only rutile titanium dioxide particles. Comparative Example 4 had the highest content of rutile titanium dioxide particles and the smallest Δu'v' value when the viewing angle range of region B was the largest. In Comparative Examples 5 and 6, the Δu'v' value did not decrease when the viewing angle range of region B was the largest.

[0114] The above description is merely a preferred embodiment of this patent and is not intended to limit the scope of protection of this patent. All equivalent changes and modifications made based on the content of this patent are covered within the scope of this patent.

Claims

1. A back coating particle composition for a quantum dot film surface, comprising a thermosetting resin, organic particles, inorganic particles, and a curing agent; The thermosetting resin includes one of acrylic resin, epoxy resin, and alkyd resin; The organic particles are polymethyl methacrylate; The inorganic particles are rutile titanium dioxide particles with a particle size of 1.65 μm; The curing agent includes one of hexamethylene diisocyanate and toluene diisocyanate; The thermosetting resin comprises 20-40 parts by weight, the organic particles comprise 10-30 parts by weight, the inorganic particles comprise 1-5 parts by weight, and the curing agent comprises 1-5 parts by weight. in, The acrylic resin has an OH content of 10-30 mg KOH / g acrylic resin, the polymethyl methacrylate has a particle size of 0.1-0.35 μm, and the back coating particle composition has a micron-level uneven surface.

2. The back-coating particle composition according to claim 1, characterized in that, The acrylic resin mentioned therein is an acrylic resin with an OH content of 10 mg KOH / g or 20 mg KOH / g.

3. The back-coating particle composition according to any one of claims 1-2, characterized in that, The polymethyl methacrylate has a particle size of 0.20 μm.

4. The back-coating particle composition according to any one of claims 1-2, characterized in that, The back coating particle composition includes a diluent, which is one or more of ethyl acetate, butyl acetate, toluene, xylene, isobutyl ester, diacetone alcohol, ethylene glycol ethyl ether, ethylene glycol butyl ether, cyclohexanone, butanone, acetone, methyl isobutyl ketone, and isoflurane.

5. A method for preparing a back-coated particle composition, comprising: Step (1): Add the back coating particle composition according to the raw material ratio of any one of claims 1-4 into the material barrel; Step (2): Use mechanical stirring for high-speed dispersion at a speed of not less than 1500 rpm; Step (3) After filtration, a back-coated particle composition is obtained, the surface of which has micron-level unevenness.

6. A quantum dot film comprising a quantum dot film, a barrier film, and a back coating layer thereof, wherein the back coating layer is prepared by curing the back coating particle composition according to any one of claims 1-4.

7. A method for preparing a quantum dot film, comprising a brightening structural layer, a substrate layer, and a back coating layer, wherein the back coating layer is prepared by curing the back coating particle composition according to any one of claims 1-4, comprising: Step (1): The back coating particle composition is coated on the surface of the upper and lower barrier films and baked to cure to obtain the back coating. Step (2) involves coating QD adhesive between two barrier films, followed by slit coating and UV curing to obtain a sandwich-like structure, thereby preparing a quantum dot film.

8. The preparation method according to claim 7, characterized in that, Step (1): The back coating particle composition is uniformly mixed and then coated on the surface of the upper and lower barrier films. After drying, it is cured to obtain the particle back coating.

9. The preparation method according to claim 7, characterized in that, Step (2) uses two steel rollers, one above the other.

10. The preparation method according to claim 7, characterized in that, The baking temperature for step (1) is 55-85℃; the UV energy for step (2) is 200-600mJ / cm. 2 .

11. The use of the back coating particle composition according to any one of claims 1-4 in improving the large apparent color deviation phenomenon of quantum dot films, wherein the back coating particle composition is coated on the quantum dot film.

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