A light conversion film for backlight display with integrated barrier structure and preparation method thereof

Abstract

The present invention belongs to the field of liquid crystal display backlight technology and provides a light conversion film for backlight display with an integrated barrier structure and a preparation method thereof. The light conversion film includes: a first adhesive layer, a first polymer base film provided on both sides of the first adhesive layer, a hybrid coating provided on the free surface of the first polymer base film, a second adhesive layer provided on the free surface of the hybrid coating, a red photosensitive conversion layer and a green photosensitive conversion layer provided on the free surface of the second adhesive layer, a third adhesive layer provided on the free surfaces of the red photosensitive conversion layer and the green photosensitive conversion layer respectively, and a second polymer base film provided on the free surface of the third adhesive layer; the hybrid coating includes an inorganic coating and an inorganic film layer; the inorganic coating surface is composed of uniformly dispersed inorganic particles, and the inorganic film layer has a dense structure so that the inorganic particles are embedded therein; the particle size of the inorganic particles is 2nm to 5nm, and the thickness of the inorganic film layer is 3nm to 10nm. The present invention improves the lighting effect of liquid crystal display.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal display backlight technology, and in particular to a light conversion film for backlight display integrated with a barrier structure and a preparation method thereof. Background Art

[0002] With the development of display technology, the backlight of current liquid crystal display devices has been transformed from LED blue light source combined with phosphor to mix white light to Mini / Micro blue light source combined with quantum dots to mix white light, thereby greatly improving the display color gamut of liquid crystal display devices and meeting people's current display needs for display devices.

[0003] Specifically, the quantum dot-based backlight assembly features a "sandwich" structure, with a light conversion layer containing a mixture of green and red quantum dots placed between two layers of water and oxygen barrier films. When excited by a high-intensity mini / micro blue light source, the light conversion layer emits both green and red light, which mixes with the blue light transmitted by the blue light source to produce white light output. The water and oxygen barrier films block moisture and oxygen from the environment, preventing quenching of the quantum dots and extending their lifetime.

[0004] However, in actual use, this type of "sandwich" structure backlight light conversion film still has the following defects in terms of light output effect: First, the water and oxygen barrier film is generally made of a thicker PET base film and a thinner PET base film, and its water and oxygen barrier property is only provided by a layer of inorganic coating introduced between them, which leads to limited water and oxygen barrier performance; and then leads to the quenching of some quantum dots and the overall reduction of light output brightness. Secondly, the light conversion layer is mostly made by a coating process, and due to the precision limitation of the coating equipment itself, there are inevitable thickness fluctuations between different positions of the same light conversion layer, resulting in uneven yellow and white in the final light output. Furthermore, since the density of the lamp beads of the Mini / Micro blue light source is extremely high, it is easy to directly pass through the light conversion film, and there are lamp bead spots in the final light output, affecting the uniformity of the picture. Summary of the Invention

[0005] The purpose of the present invention is to provide a light conversion film for backlight display with an integrated barrier structure and a preparation method thereof, so as to improve the technical problems of the existing light conversion film, such as limited water and oxygen barrier effect, uneven yellow and white, and lamp bead spots when used with Mini / Micro blue light sources.

[0006] To achieve the above objectives, the present invention proposes the following technical solutions:

[0007] A light conversion film for backlight display integrated with a barrier structure, comprising: a first adhesive layer, a first polymer base film respectively disposed on both sides of the first adhesive layer, a hybrid coating respectively disposed on the free surface of each of the first polymer base films, a second adhesive layer respectively disposed on the free surface of each of the hybrid coatings, a red photosensitive conversion layer and a green photosensitive conversion layer respectively disposed on the free surface of each of the second adhesive layers, a third adhesive layer respectively disposed on the free surfaces of the red photosensitive conversion layer and the green photosensitive conversion layer, and a second polymer base film respectively disposed on the free surface of each of the third adhesive layers;

[0008] The hybrid coating includes an inorganic coating and an inorganic film layer; the inorganic coating is coated on the spare surface of the first polymer base film and is composed of uniformly dispersed inorganic particles; the inorganic film layer has a dense structure so that the inorganic particles are embedded therein; the particle size of the inorganic particles is 2nm~5nm, and the thickness of the inorganic film layer is 3nm~10nm.

[0009] Furthermore, the hybrid coating is a heterogeneous structure, the inorganic particles include one or more of ZnO and TiO2, and the inorganic film layer includes one or more of Al2O3, SiO2, and Si3N4.

[0010] Furthermore, the first adhesive layer is an OCA adhesive layer, the light transmittance of which is greater than 95% and the refractive index is greater than 1.55.

[0011] Furthermore, the second adhesive layer and the third adhesive layer both include light-cured polyurethane acrylate, and both have a thickness of 2 μm to 3 μm.

[0012] Furthermore, the first polymer base film and the second polymer base film are made of the same material, the thickness of the first polymer base film is 10 μm to 50 μm, and the thickness of the second polymer base film is 50 μm to 100 μm.

[0013] Furthermore, the red photosensitive conversion layer includes a cured photosensitive resin and red quantum dots uniformly dispersed in the photosensitive resin; the green photosensitive conversion layer includes a cured photosensitive resin and green quantum dots uniformly dispersed in the photosensitive resin; the thickness of the red photosensitive conversion layer and the green photosensitive conversion layer are both 2μm to 8μm.

[0014] Furthermore, it includes a protective layer, which is respectively provided on the remaining surface of each of the second polymer base films;

[0015] The protective layer includes thermally cured acrylate and anti-scratch particles uniformly dispersed in the acrylate; the thickness of the protective layer is 5 μm to 8 μm, and the particle size of the anti-scratch particles is 2 μm to 3 μm.

[0016] A method for preparing a light conversion film for backlight display integrated with a barrier structure, comprising:

[0017] Dispersing red quantum dots in a photosensitive resin and stirring uniformly to obtain a red photosensitive solution, dispersing green quantum dots in a photosensitive resin and stirring uniformly to obtain a green photosensitive solution; dispersing inorganic particles in a low-boiling-point solvent and stirring uniformly to obtain an inorganic dispersed solution; wherein the solid content of the red quantum dots in the red photosensitive solution is 0.01% to 0.3%, the solid content of the green quantum dots in the green photosensitive solution is 0.01% to 0.3%, and the low-boiling-point solvent comprises one or more of n-butanol, isobutanol, tert-butanol, and n-hexanol;

[0018] Obtain two second polymer base films, and apply a layer of polyurethane acrylate on one side of each of the two films; and then perform photocuring to obtain third adhesive layers corresponding to the second polymer base films;

[0019] Obtain two first polymer base films, apply the inorganic dispersion solution on one side of each of the two films, and dry them at 80°C to 120°C to obtain an inorganic coating layer corresponding to each of the first polymer base films; then, prepare an inorganic film layer on each of the two films by chemical vapor deposition, magnetron sputtering, or evaporation to embed the inorganic coating layer therein; thereby, forming a hybrid coating layer;

[0020] Coating a layer of polyurethane acrylate on the remaining surface of the hybrid coating corresponding to each of the first polymer base films; and then performing photocuring to obtain a second adhesive layer corresponding to each of the first polymer base films;

[0021] A layer of red photosensitive solution is applied on the free surface of one of the third adhesive layers, and a layer of green photosensitive solution is applied on the free surface of another of the third adhesive layers; then, the free surface of a second adhesive layer is brought close to the applied red photosensitive solution to perform surface lamination, and after photocuring, a first prefabricated film is formed; and the free surface of another second adhesive layer is brought close to the applied green photosensitive solution to perform surface lamination, and after photocuring, a second prefabricated film is formed;

[0022] A layer of OCA glue is coated on the spare surface of the first polymer base film in the first prefabricated film, and then the spare surface of the first polymer base film in the second prefabricated film is brought close to the coated OCA glue for surface bonding and a first bonding layer is formed after photocuring, thereby forming a light conversion film for backlight display with an integrated barrier structure.

[0023] Further, including:

[0024] Mixing a monofunctional acrylate and a multifunctional acrylate to form a matrix solution, and uniformly dispersing anti-scratch particles in the matrix solution to obtain a protective solution; wherein the solid content of the anti-scratch particles is 0.5% to 2%;

[0025] A layer of the protective solution is coated on the free surfaces of the two second polymer base films respectively, and a protective layer is formed on each of the two films after thermal curing.

[0026] Furthermore, the hybrid coating is a ZnO / Al2O3 coating, a ZnO / SiO2 coating, a ZnO / Si3N4 coating, a TiO2 / Al2O3 coating, a TiO2 / SiO2 coating or a TiO2 / Si3N4 coating.

[0027] Beneficial effects:

[0028] It can be seen from the above technical solutions that the technical solution of the present invention provides a light conversion film for backlight display integrated with a barrier structure to improve various defects of existing light conversion films in actual use.

[0029] Considering the limitations of barrier film's structural defects on its barrier effect, the inventors intended to improve existing barrier films. Furthermore, considering that the uneven light output defects of existing light conversion films, caused by inherent defects in the coating equipment and the structural characteristics of mini / micro backlights, cannot be effectively avoided from a manufacturing perspective, the inventors also intended to improve these light output defects through corresponding structural improvements.

[0030] Based on this, the inventors designed a light conversion film comprising the following structure: a first adhesive layer, a first polymer base film disposed on both sides of the first adhesive layer, a hybrid coating disposed on the free surface of each of the first polymer base films, a second adhesive layer disposed on the free surface of each of the hybrid coating layers, a red photosensitive conversion layer and a green photosensitive conversion layer disposed on the free surface of each of the second adhesive layers, a third adhesive layer disposed on the free surface of the red photosensitive conversion layer and the green photosensitive conversion layer, and a second polymer base film disposed on the free surface of each of the third adhesive layers. The hybrid coating comprises an inorganic coating layer and an inorganic film layer in sequence. The inorganic coating layer is coated on the free surface of the first polymer base film and is composed of uniformly dispersed inorganic particles. The inorganic film layer has a dense structure in which the inorganic particles are embedded. The particle size of the inorganic particles is 2nm to 5nm, and the thickness of the inorganic film layer is 3nm to 10nm.

[0031] Unlike existing structures that incorporate only one photosensitive conversion layer containing both red and green quantum dots, this solution incorporates a red photosensitive conversion layer containing only red quantum dots and a green photosensitive conversion layer containing only green quantum dots. Furthermore, the water and oxygen barrier structure provided on both sides of the red and green photosensitive conversion layers includes a first polymer base film, a second polymer base film, and a hybrid coating. Because the hybrid coating comprises inorganic particles and a dense inorganic film layer embedded with these particles, it effectively enhances the water and oxygen barrier effect. Since the hybrid coating is located on the side of the red or green photosensitive conversion layer, regardless of whether the Mini / Micro backlight source is located near the red or green photosensitive conversion layer, the hybrid coating is located on the side of the red or green photosensitive conversion layer away from the backlight source. Therefore, the cyan light (composite light of blue light and excited green light) or yellow light (composite light of blue light and excited red light) formed by the blue backlight source after being excited is scattered twice before exciting the red or green quantum dots to form mixed white light. This fully mixes the three primary colors of light, thereby compensating for the uneven light mixing caused by the thickness fluctuation of the photoconversion layer in the preparation process and avoiding the uneven yellow-white color of the emitted light. Multiple scattering also reduces the transmission probability of the light emitted by a single lamp bead in the Mini / Micro backlight source, avoids the lamp bead spot on the light conversion film's exit surface, and improves the uniformity of the light output.

[0032] In particular, while conventional light conversion films typically have a thickness of 300-350μm, this technology allows the final thickness of the film to be maintained between 100-200μm. This reduction in thickness is crucial, ultimately enabling thinner and lighter display devices, making them more suitable for small and medium-sized applications such as monitors, laptops, and tablets.

[0033] This demonstrates that, through improvements to the barrier structure and photosensitive conversion layer, this technical solution not only enhances the barrier effect of the light conversion film but also avoids the defects of uneven color and brightness, thereby improving the overall light output. Furthermore, this solution is more in line with the trend toward thinner and lighter displays and is suitable for small-sized displays.

[0034] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, to the extent such concepts are not mutually inconsistent, can be considered to be part of the inventive subject matter of this disclosure.

[0035] The foregoing and other aspects, embodiments, and features of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as features and / or beneficial effects of the exemplary embodiments, will become apparent from the following description or through practice of specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0037] Figure 1 This is a schematic structural diagram of the light conversion film for backlight display with integrated barrier structure described in Example 1;

[0038] Figure 2 This is a comparison chart of the light output brightness of the light conversion film described in Example 1 and the existing light conversion film under the same Mini / Micro blue light backlight;

[0039] Figure 3 This is a light output effect diagram of the light conversion film described in Example 1 under a Mini / Micro blue light backlight;

[0040] Figure 4 This is a flow chart of the method for preparing a light conversion film for backlight display with an integrated barrier structure as described in Example 2;

[0041] Figure 5 exist Figure 4 Flowchart of the preparation of protective layer on the process shown. DETAILED DESCRIPTION

[0042] To further clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only a portion of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments derived by persons of ordinary skill in the art without requiring creative effort are within the scope of protection of the present invention. Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meanings understood by persons of ordinary skill in the field to which the present invention pertains.

[0043] The words "first", "second" and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "a", "an" or "the" and similar terms do not indicate a quantitative limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" include the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0044] The existing light conversion films used for liquid crystal backlight are mostly of a "sandwich" structure, that is, they are composed of a photosensitive conversion layer including red quantum dots and green quantum dots, and a barrier film provided on both sides of the photosensitive conversion layer. Since the water and oxygen barrier effect of the barrier film is only achieved by the introduced inorganic coating, the water and oxygen barrier effect is limited. At the same time, due to the inevitable fluctuations in the film thickness caused by the errors of the preparation equipment itself during the preparation of the photosensitive conversion layer, there is a yellow-white uneven phenomenon when the white light is emitted. Furthermore, the current light conversion film is mostly used in combination with Mini / Micro backlight sources, which also causes the light conversion film to produce new defects in actual use, namely, uneven picture defects caused by lamp bead spots. Therefore, the present embodiment aims to provide a light conversion film for backlight display integrated with a barrier structure to improve the above-mentioned defects at the same time.

[0045] Example 1

[0046] The light conversion film for backlight display integrated with a barrier structure disclosed in this embodiment will be described in detail below with reference to the accompanying drawings.

[0047] like Figure 1 As shown, the light conversion film includes: a first adhesive layer 1, a first polymer base film 2 respectively arranged on both side surfaces of the first adhesive layer 1, a hybrid coating 3 respectively arranged on the spare surface of each of the first polymer base films 2, a second adhesive layer 4 respectively arranged on the spare surface of each of the hybrid coatings 3, a red photosensitive conversion layer 5 and a green photosensitive conversion layer 6 respectively arranged on the spare surface of each of the second adhesive layers 4, a third adhesive layer 7 respectively arranged on the spare surfaces of the red photosensitive conversion layer 5 and the green photosensitive conversion layer 6, and a second polymer base film 8 respectively arranged on the spare surface of each of the third adhesive layers 7.

[0048] The hybrid coating 3 includes an inorganic coating and an inorganic film layer. The inorganic coating is applied to the remaining surface of the first polymer base film 2 and is composed of uniformly dispersed inorganic particles. The inorganic film layer has a dense structure that embeds the inorganic particles. The inorganic particles have a particle size of 2nm to 5nm, and the thickness of the inorganic film layer is 3nm to 10nm.

[0049] In a specific implementation, a red photosensitive conversion layer 5 containing only red quantum dots and a green photosensitive conversion layer 6 containing only green quantum dots are provided. Furthermore, the water and oxygen barrier structures provided on both sides of the red and green photosensitive conversion layers 5 and 6 include a first polymer base film 2, a second polymer base film 8, and a hybrid coating 3. Because the hybrid coating 3 comprises inorganic particles and a dense inorganic film layer nested with the inorganic particles, and the relationship between the particle size of the inorganic particles and the thickness of the inorganic film layer indicates that the inorganic particles do not disrupt the dense structure of the inorganic film layer, effectively enhancing the water and oxygen barrier effect.

[0050] Since the hybrid coating 3 is located on the side of the red photosensitive conversion layer 5 or the green photosensitive conversion layer 6, regardless of whether the Mini / Micro backlight source is located near the red photosensitive conversion layer 5 or the green photosensitive conversion layer 6, away from the backlight source, the cyan light (composite light of blue light and excited green light) or yellow light (composite light of blue light and excited red light) formed by the blue light backlight source is scattered twice before exciting the red quantum dots or green quantum dots to form mixed white light. This fully mixes the three primary colors of light, thereby compensating for the uneven light mixing caused by the thickness fluctuation of the light conversion layer in the preparation process; avoiding the uneven yellow-white color of the emitted light. The multiple scattering also reduces the transmission probability of the light emitted by a single lamp bead in the Mini / Micro backlight source, avoids the lamp bead spot on the light conversion film output surface, and improves the uniformity of the light output.

[0051] As an optional implementation, the light conversion film has a symmetrical structure symmetrical to the first adhesive layer 1 .

[0052] To further enhance water and oxygen barrier properties, the hybrid coating 3 in this embodiment has a heterogeneous structure. The inorganic particles include one or more of ZnO and TiO2, and the inorganic film layer includes one or more of Al2O3, SiO2, and Si3N4. The resulting hybrid coating 3 can be a ZnO / Al2O3 coating, a ZnO / SiO2 coating, a ZnO / Si3N4 coating, a TiO2 / Al2O3 coating, a TiO2 / SiO2 coating, or a TiO2 / Si3N4 coating.

[0053] In this embodiment, the first adhesive layer 1 is an OCA adhesive layer. In order to prevent it from affecting the brightness of the light, the light transmittance of the first adhesive layer 1 needs to be greater than 95%, and the refractive index needs to be greater than 1.55.

[0054] The second adhesive layer 4 and the third adhesive layer 7 both comprise light-cured polyurethane acrylate, and each has a thickness of 2 μm to 3 μm. Specifically, the polyurethane acrylate can be aromatic polyether polyurethane diacrylate, aliphatic polyether polyurethane diacrylate, aliphatic polyurethane diacrylate, aliphatic polyurethane diacrylate, aromatic polyether polyurethane triacrylate, aromatic polyurethane triacrylate, aromatic polyurethane hexaacrylate, etc.

[0055] The red photosensitive conversion layer 5 comprises a cured photosensitive resin and red quantum dots uniformly dispersed within the photosensitive resin; the green photosensitive conversion layer 6 comprises a cured photosensitive resin and green quantum dots uniformly dispersed within the photosensitive resin. Specifically, the fluorescence emission wavelength of the red quantum dots is required to be between 600-640 nm, with a particle size less than 10 nm; the fluorescence emission wavelength of the green quantum dots is required to be between 510-540 nm, with a particle size less than 10 nm. The photosensitive resin can be broadly selected from monofunctional acrylates, difunctional acrylates, trifunctional acrylates, and trifunctional acrylates. Specifically, it can be methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate, tetrahydrofuran acrylate, diallyl phthalate, 2-hydroxyethyl methacrylate, trimethylolpropane propoxylate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, or mixed solutions of the above acrylates.

[0056] In a specific implementation, the thickness of the red photosensitive conversion layer 5 and the green photosensitive conversion layer 6 are both 2 μm to 8 μm.

[0057] The first polymer base film 2 and the second polymer base film 8 are made of the same material. Specifically, the material may be polyethylene terephthalate, polyvinylidene fluoride, polyvinyl chloride, polyamide, polyester, polyethylene naphthalate, etc.

[0058] Because the second polymer base film 8 is close to the external environment, its thickness can be appropriately increased to extend the service life of the light conversion film. In this embodiment, the second polymer base film 8 is preferably thicker than the first polymer base film 2. Specifically, the thickness of the first polymer base film is set to 10μm to 50μm, and the thickness of the second polymer base film is set to 50μm to 100μm.

[0059] To further enhance the lifespan and light extraction efficiency of the light conversion film, a protective layer 9 is provided. Structurally, the protective layer 9 is applied to the unused surface of each second polymer base film 8 and comprises a heat-cured acrylate and anti-scratch particles uniformly dispersed within the acrylate. The protective layer 9 has a thickness of 5 to 8 μm, and the anti-scratch particles have a particle size of 2 to 3 μm.

[0060] In a specific implementation, the acrylate includes monofunctional acrylate and multifunctional acrylate. The monofunctional acrylate can be selected from one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate, isooctyl acrylate, isobutyl acrylate, tert-butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, isooctyl acrylate, lauryl acrylate and hexadecyl acrylate. The multifunctional acrylate can be selected from one or more of dipentaerythritol hexaacrylate, polyester acrylate, ethoxylated (N=3,9,15,21) trimethylolpropane triacrylate, propoxylated (N=3,4,5,9) trimethylolpropane triacrylate, propoxylated (3) propylene glycol triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, di-trimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, ethoxylated (N=4,5) pentaerythritol tetraacrylate, ethoxylated (N=5) pentaerythritol tetraacrylate, propoxylated (N=5) pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate. The anti-scratch particles include one or more of polymethyl methacrylate microspheres, polycarbonate microspheres and polyvinyl chloride microspheres.

[0061] Furthermore, the final thickness of the light conversion film described in this embodiment can be maintained between 100-200 μm, while the thickness of existing light conversion films is 300-350 μm. In practical applications, this thickness reduction is very important, as it will make display devices thinner and lighter, making them more suitable for small and medium-sized devices such as monitors, laptops, and tablets.

[0062] like Figure 2As shown, the light conversion film described in this embodiment and the existing "sandwich" structure light conversion film both use red and green CdSe system quantum dots, and the comparison chart of the light output brightness under the same Mini / Micro blue light backlight. Among them, curve a is the light output brightness curve of the light conversion film described in this embodiment, and curve b is the light output brightness curve of the existing light conversion film. Specifically, the brightness of the existing light conversion film is 4800, and the brightness of the light conversion film described in this embodiment is 5100, an increase of 7.3%. The intensity of blue light is reduced by about 50%; the intensity of red light is increased by about 36.5%. This shows that the use of this embodiment can effectively reduce the penetration intensity of blue light, and the penetration intensity of red and green light is significantly improved, thereby avoiding color unevenness. At the same time, it can be seen that the brightness of the LCD display is also effectively improved.

[0063] like Figure 3 The figure shows the light output effect of the light conversion film of this embodiment under a Mini / Micro blue light backlight. It can be seen that the light conversion film of this embodiment no longer has lamp bead spots, thereby improving the uniformity of the image.

[0064] Example 2

[0065] This embodiment also discloses a method for preparing the light conversion film for backlight display with integrated barrier structure described in Example 1. A detailed description of the method is given below with reference to the accompanying drawings.

[0066] like Figure 4 As shown, the method includes:

[0067] Step S102: dispersing red quantum dots in a photosensitive resin and stirring evenly to obtain a red photosensitive solution; dispersing green quantum dots in a photosensitive resin and stirring evenly to obtain a green photosensitive solution; dispersing inorganic particles in a low boiling point solvent and stirring evenly to obtain an inorganic dispersed solution.

[0068] In this embodiment, the solid content of the red quantum dots in the red photosensitive solution is 0.01% to 0.3%, and the solid content of the green quantum dots in the green photosensitive solution is 0.01% to 0.3%, and the low boiling point solvent includes one or more of n-butanol, isobutanol, tert-butanol, and n-hexanol. Specifically, the red quantum dots and the green quantum dots can be CdTe, CdS, CdSe, InP, CuInS, CuInSe quantum dots, or CdSe / ZnS, CdSe / CdS, InP / ZnS, CuInS / ZnS, (Zn)CuInS / ZnS, (Mn)CuInS / ZnS, AgInS / ZnS, (Zn)AgInS / ZnS, CuInSe / ZnS, CuInSeS / ZnS quantum dots, all-inorganic CsPbI3 perovskite quantum dots, etc., or red-emitting carbon quantum dots, silicon quantum dots, etc.

[0069] Step S104 , obtaining two second polymer base films, and coating a layer of polyurethane acrylate on one side of each of the two films; and then performing photocuring to obtain third adhesive layers corresponding to the second polymer base films.

[0070] In this embodiment, the coating process is specifically a micro-concave coating process or a doctor blade coating process, and the coating speed is 4 to 20 m / min; the power of the ultraviolet light during light curing is 1 to 3.6 kW.

[0071] Step S106: Obtain two first polymer base films, apply the inorganic dispersion solution on one side of each of them, and dry them to obtain an inorganic coating corresponding to the first polymer base film; then prepare an inorganic film layer on each of the inorganic coatings by chemical vapor deposition, magnetron sputtering or evaporation so that the inorganic coating is embedded therein; and then form a hybrid coating respectively.

[0072] In this embodiment, the drying temperature is 80-120° C. corresponding to the boiling point of the low-boiling-point solvent.

[0073] As an optional implementation method, in order to further avoid the damage of the inorganic film layer caused by the addition of inorganic particles, thereby causing water and oxygen intrusion, the inorganic particles can be self-assembled. Specifically, the steps include:

[0074] Step S106.2′, charging the inorganic particles;

[0075] Step S106.4′: applying opposite polarity to the first polymer base film, wherein the polarity of the first polymer base film away from the surface to be deposited is the same as the polarity of the inorganic particles;

[0076] Step S106.6': spraying the inorganic particles on the surface of the first polymer base film.

[0077] At this time, the inorganic particles will automatically arrange themselves under the action of electricity, thereby making the inorganic particles arranged regularly, thereby avoiding possible damage to the inorganic film layer.

[0078] Step S108 : coating a layer of polyurethane acrylate on the remaining surfaces of the hybrid coating corresponding to each of the first polymer base films; and then performing photocuring to obtain a second adhesive layer corresponding to each of the first polymer base films.

[0079] Step S110: Apply a layer of red photosensitive solution on the free surface of one of the third adhesive layers, and apply a layer of green photosensitive solution on the free surface of the other third adhesive layer; then, place the free surface of a second adhesive layer close to the applied red photosensitive solution for surface bonding and form a first prefabricated film after photocuring, and place the free surface of another second adhesive layer close to the applied green photosensitive solution for surface bonding and form a second prefabricated film after photocuring.

[0080] In this step, a high-precision roll-to-roll process can be used for surface bonding, or laser alignment can be introduced for direct bonding.

[0081] Step S112: Apply a layer of OCA glue on the spare surface of the first polymer base film in the first prefabricated film, and then place the spare surface of the first polymer base film in the second prefabricated film close to the coated OCA glue for surface bonding and form a first bonding layer after photocuring, thereby forming a light conversion film for backlight display with an integrated barrier structure.

[0082] Similarly, in this step, a high-precision roll-to-roll process can be used for surface bonding, or laser alignment can be introduced for direct bonding.

[0083] like Figure 5 As shown, as an optional embodiment, in order to improve the service life and light output effect of the light conversion film, it also includes:

[0084] Step S202 : Mixing monofunctional acrylate and multifunctional acrylate to form a matrix solution, and uniformly dispersing anti-scratch particles in the matrix solution to obtain a protective solution.

[0085] Wherein, the solid content of the anti-scratch particles is 0.5% to 2%.

[0086] Step S204 , coating a layer of the protective solution on the vacant surfaces of the two second polymer base films, and forming a protective layer on each of the two films after thermal curing.

[0087] At this time, based on steps S202 to S204 , a protective layer is respectively formed on the remaining surface of the second polymer base film, so as to prevent the second polymer base film from being scratched during use.

[0088] At this time, after the light conversion film is prepared, adding a Mini / Micro blue light backlight source to one side of the empty surface of any of the protective layers can achieve colorless and spotless mixed white light output, and the water and oxygen barrier effect of the light conversion film is better.

[0089] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A light conversion film for backlight display integrated with a barrier structure, characterized in that: The thickness range is: 100-200μm, comprising: a first adhesive layer, a first polymer base film respectively provided on both sides of the first adhesive layer, a hybrid coating respectively provided on the free surface of each of the first polymer base films, a second adhesive layer respectively provided on the free surface of each of the hybrid coatings, a red photosensitive conversion layer and a green photosensitive conversion layer respectively provided on the free surface of each of the second adhesive layers, a third adhesive layer respectively provided on the free surface of the red photosensitive conversion layer and the green photosensitive conversion layer, and a second polymer base film respectively provided on the free surface of each of the third adhesive layers; The hybrid coating includes an inorganic coating and an inorganic film layer; the inorganic coating is coated on the spare surface of the first polymer base film and is composed of dispersed inorganic particles; the inorganic film layer has a dense structure so that the inorganic particles are embedded therein; the particle size of the inorganic particles is 2nm~5nm, and the thickness of the inorganic film layer is 3nm~10nm; wherein, the first polymer base film, the second polymer base film and the hybrid coating are used for water and oxygen barrier; wherein, the hybrid coating is always located on the side of the red photosensitive conversion layer or the green photosensitive conversion layer away from the backlight source.

2. The light conversion film for backlight display integrated with a barrier structure according to claim 1, characterized in that: The hybrid coating is a heterogeneous structure, the inorganic particles include one or more of ZnO and TiO2, and the inorganic film layer includes one or more of Al2O3, SiO2, and Si3N4.

3. The light conversion film for backlight display integrated with a barrier structure according to claim 1, characterized in that: The first adhesive layer is an OCA adhesive layer, the light transmittance of which is greater than 95% and the refractive index of which is greater than 1.

55.

4. The light conversion film for backlight display integrated with a barrier structure according to claim 1, wherein: The second adhesive layer and the third adhesive layer both include light-cured polyurethane acrylate, and both have a thickness of 2 μm to 3 μm.

5. The light conversion film for backlight display integrated with a barrier structure according to claim 1, characterized in that: The first polymer base film and the second polymer base film are made of the same material. The thickness of the first polymer base film is 10 μm to 50 μm, and the thickness of the second polymer base film is 50 μm to 100 μm.

6. The light conversion film for backlight display integrated with a barrier structure according to claim 1, wherein: The red photosensitive conversion layer includes a cured photosensitive resin and red quantum dots uniformly dispersed in the photosensitive resin; the green photosensitive conversion layer includes a cured photosensitive resin and green quantum dots uniformly dispersed in the photosensitive resin; the thickness of the red photosensitive conversion layer and the green photosensitive conversion layer are both 2μm to 8μm.

7. The light conversion film for backlight display integrated with a barrier structure according to claim 1, wherein: comprising a protective layer, wherein the protective layer is respectively provided on the free surface of each of the second polymer base films; The protective layer includes thermally cured acrylate and anti-scratch particles uniformly dispersed in the acrylate; the thickness of the protective layer is 5 μm to 8 μm, and the particle size of the anti-scratch particles is 2 μm to 3 μm.

8. A method for preparing a light conversion film for backlight display integrated with a barrier structure, characterized in that: include: Dispersing red quantum dots in a photosensitive resin and stirring evenly to obtain a red photosensitive solution, and dispersing green quantum dots in a photosensitive resin and stirring evenly to obtain a green photosensitive solution; Dispersing inorganic particles in a low-boiling-point solvent and stirring uniformly to obtain an inorganic dispersed solution; wherein the solid content of red quantum dots in the red photosensitizing solution is 0.01% to 0.3%, and the solid content of green quantum dots in the green photosensitizing solution is 0.01% to 0.3%, and the low-boiling-point solvent comprises one or more of n-butanol, isobutanol, tert-butanol, and n-hexanol; Obtain two second polymer base films, and apply a layer of polyurethane acrylate on one side of each of the two films; then perform photocuring to obtain a third adhesive layer corresponding to each of the second polymer base films; Obtain two first polymer base films, apply the inorganic dispersion solution on one side of each of the two films, and dry them at 80°C to 120°C to obtain an inorganic coating layer corresponding to each of the first polymer base films; then, prepare an inorganic film layer on each of the two films by chemical vapor deposition, magnetron sputtering, or evaporation to embed the inorganic coating layer therein; thereby, forming a hybrid coating layer; Coating a layer of polyurethane acrylate on the remaining surface of the hybrid coating corresponding to each of the first polymer base films; and then performing photocuring to obtain a second adhesive layer corresponding to each of the first polymer base films; A layer of red photosensitive solution is applied on the free surface of one of the third adhesive layers, and a layer of green photosensitive solution is applied on the free surface of another of the third adhesive layers; then, the free surface of a second adhesive layer is brought close to the applied red photosensitive solution to perform surface lamination, and after photocuring, a first prefabricated film is formed; and the free surface of another second adhesive layer is brought close to the applied green photosensitive solution to perform surface lamination, and after photocuring, a second prefabricated film is formed; A layer of OCA glue is coated on the spare surface of the first polymer base film in the first prefabricated film, and then the spare surface of the first polymer base film in the second prefabricated film is brought close to the coated OCA glue for surface bonding and a first bonding layer is formed after photocuring, thereby forming a light conversion film for backlight display with an integrated barrier structure.

9. The method for preparing a light conversion film for backlight display integrated with a barrier structure according to claim 8, characterized in that: include: Mixing a monofunctional acrylate and a multifunctional acrylate to form a matrix solution, and uniformly dispersing anti-scratch particles in the matrix solution to obtain a protective solution; wherein the solid content of the anti-scratch particles is 0.5% to 2%; A layer of the protective solution is coated on the free surfaces of the two second polymer base films respectively, and a protective layer is formed on each of the two films after thermal curing.

10. The method for preparing a light conversion film for backlight display integrated with a barrier structure according to claim 8, wherein: The hybrid coating is a ZnO / Al2O3 coating, a ZnO / SiO2 coating, a ZnO / Si3N4 coating, a TiO2 / Al2O3 coating, a TiO2 / SiO2 coating or a TiO2 / Si3N4 coating.

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