Structural quantum dot film applied to direct type backlight module and preparation method of structural quantum dot film

Abstract

The invention provides a structural quantum dot film applied to a direct type backlight module and a preparation method of the structural quantum dot film, and relates to the technical field of optical thin films. The structural quantum dot film comprises a quantum dot adhesive layer, a composite barrier layer and a structural layer, wherein the quantum dot adhesive layer is a middle layer, the composite barrier layers are arranged on the two surfaces of the quantum dot adhesive layer, and the structural layers are arranged on the other surfaces, opposite to the quantum dot adhesive layer, of the composite barrier layers; the surface of the structural layer is provided with an optical gain structure, and the optical gain structure comprises at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle and a concave triangular pyramid structure with an R angle. The quantum dot film adopts an integrated structure, the thickness of the module is reduced, and meanwhile, the optical gain structure on the surface of the structural layer has good shielding performance and high brightness on a light source.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and in particular to a structured quantum dot film applied to a direct-type backlight module and a preparation method thereof. Background Art

[0002] Quantum dots are an important low-dimensional semiconductor material. Their sizes in three dimensions are no more than twice the exciton Bohr radius of the corresponding semiconductor material, and they are generally spherical or quasi-spherical, with a diameter usually between 1 and 10 nanometers. Common quantum dots are composed of IV, II-VI, IV-VI or III-V elements, such as silicon quantum dots, germanium quantum dots, cadmium sulfide quantum dots, cadmium selenide quantum dots and indium phosphide quantum dots. Quantum dots have a separated quantized energy spectrum, and the corresponding wave function is located in the quantum dot in space, but extends over several lattice periods. A quantum dot has a small number (1 to 100) of integer electrons, holes or hole-electron pairs, that is, the charge it carries is an integer multiple of the elementary charge. When a quantum dot is excited by external energy (light, electricity), it will emit light of a specific frequency, and the frequency of the emitted light will change with the change of the size of the semiconductor.

[0003] Therefore, by adjusting the size of the nano-semiconductor, the color of the light it emits can be controlled. The color range covers the entire visible region from blue light to red light, and it has the characteristics of high color purity, long life and good stability.

[0004] As an advanced edge lighting technology, direct backlighting is widely used to improve the viewing experience and display quality. In direct backlighting technology, LED lights are evenly distributed behind the entire LCD screen to form a direct lighting array. When the backlight is activated, the LED lights will evenly illuminate the entire screen, making the image projected on the screen brighter and clearer. However, the light emitted by the LED will form a small and bright spot directly above the panel, and the illumination distribution difference between the center of the bright spot and the middle of the two bright spots is large, resulting in the problem of lamp shadow or uneven light emission.

[0005] At present, the most common way to improve the light shadow is to add a diffusion plate and a diffusion film. However, the refraction, scattering and reflection of the particles only play a role in the disordered diffusion of light. This method has a relatively poor effect on the homogenization of light. The thickness of the backlight module will become thicker and the final light output brightness will be reduced. For example: Patent CN105572970A discloses a brightening barrier film and a quantum dot film and a backlight module having the brightening barrier film. By setting an inorganic coating layer and a polymer layer on the upper surface of the substrate layer, and setting a brightening layer with a triangular prism structure on the lower surface of the substrate layer, the ability to improve the brightness is achieved, but the triangular prism structure is easily worn during use, resulting in a shortened service life. Patent CN109459888A discloses a quantum dot film and a backlight module, which uses a special structure and luminescent material to construct a new type of quantum dot film, thereby reducing the use of green quantum dots, reducing costs and being green and environmentally friendly. Under the premise of achieving high color gamut and high water and oxygen blocking capabilities, but this method sacrifices the optical properties of the quantum dot film and the thickness of the module.

[0006] Therefore, it is necessary and urgent to research and develop a structured quantum dot film that can disperse and gather light (shield lamp shadows) and emit light in a directional manner (increase brightness) for use in direct-type backlight modules.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The first object of the present invention is to provide a structured quantum dot film applied to a direct-type backlight module, wherein the structured quantum dot film adopts an integrated structure, effectively reducing the thickness of the module, and having good shielding and high brightness for the light source.

[0009] The second object of the present invention is to provide a method for preparing a structured quantum dot film for use in a direct-lit backlight module.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0011] The present invention provides a structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprising: a quantum dot glue layer, a composite barrier layer and a structure layer;

[0012] The quantum dot glue layer is an intermediate layer, and composite barrier layers are arranged on both sides of the quantum dot glue layer, and a structural layer is arranged on the other side of the composite barrier layer relative to the quantum dot glue layer;

[0013] The surface of the structural layer has an optical gain structure, and the optical gain structure includes at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle, and a concave triangular pyramid structure with an R angle.

[0014] Furthermore, the optical gain structure is a concave pyramid structure, and the angle of the concave pyramid structure is 30 to 150°;

[0015] More preferably, the angle of the concave pyramid structure is 60 to 120°.

[0016] Further, the structural layer is mainly obtained by photocuring micro-replication or thermoforming of a transparent polymer resin;

[0017] Preferably, the transparent polymer resin is one of AR (Acrylic resin, acrylic resin or modified acrylic resin), PMMA or PC;

[0018] Preferably, the refractive index of the transparent polymer resin is 1.4-1.65.

[0019] Furthermore, the thickness of the structural layer is 10-100 um, preferably 20-50 um.

[0020] Further, the structured quantum dot film includes, in order along the direction of entry of the point light source: an optional lower structural layer, a lower composite barrier layer, a quantum dot glue layer, an upper composite barrier layer and an upper structural layer;

[0021] Preferably, the total thickness of the structured quantum dot film is 300-330 um.

[0022] Furthermore, the composite barrier layer is obtained by compounding a substrate layer, a laminating layer, a base barrier layer and a top coating layer in sequence;

[0023] The quantum dot glue layer is cured on the top coating layer side of the composite barrier layer by UV, and the structural layer is arranged on the substrate layer side of the composite barrier layer by photocuring micro-replication or thermoforming;

[0024] Alternatively, a back coating layer is provided on the other side of the substrate layer relative to the laminating layer.

[0025] Furthermore, the thickness of the back coating in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0026] And / or, the thickness of the substrate layer in the composite barrier layer is 25 to 200 um, preferably 50 to 100 um;

[0027] And / or, the thickness of the laminating layer in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0028] And / or, the thickness of the base barrier layer in the composite barrier layer is 2 to 20 um, preferably 4 to 12 um;

[0029] and / or, the thickness of the top coating in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0030] Preferably, the water barrier rate of the composite barrier layer is less than 0.1 g / (㎡*24h).

[0031] Furthermore, the quantum dot adhesive layer is composed of adhesive resin, scattering particles, antioxidant and quantum dots;

[0032] The antioxidant, scattering particles and quantum dots can be uniformly and stably dispersed in the adhesive resin.

[0033] Furthermore, the thickness of the quantum dot glue layer is 50 to 200 um, preferably 70 to 140 um.

[0034] The present invention provides a method for preparing the quantum dot film having the above structure, the method comprising:

[0035] (A) providing upper and lower composite barrier layers, coating the structural layer glue on the outer surface of the substrate layer of the upper and lower composite barrier layers through a copper roller with an engraved pattern, demolding after UV pre-curing, and then performing secondary curing on the structure attached to the substrate layer to obtain the upper and lower composite barrier layers with structural layers;

[0036] Or, providing an upper composite barrier layer, coating the structural layer glue onto the outer surface of the substrate layer of the upper composite barrier layer through a copper roller with an engraved pattern, demoulding after UV pre-curing, and then performing secondary curing on the structure attached to the substrate layer to obtain an upper composite barrier layer with a structural layer;

[0037] Providing a lower composite barrier layer, coating the back coating glue on the lower composite barrier layer and curing it to obtain the lower composite barrier layer with the back coating;

[0038] (B) The quantum dot glue is mixed and stirred under the protection of an inert gas, and the mixed quantum dot glue is evenly coated on the surface of the top coating of the upper and lower composite barrier layers. The upper and lower composite barrier layers are then laminated and UV cured to obtain a structural quantum dot film.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention provides a structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprising: a quantum dot glue layer, a composite barrier layer and a structural layer; wherein the quantum dot glue layer is an intermediate layer, the two sides of the quantum dot glue layer are provided with a composite barrier layer, and the other side of the composite barrier layer relative to the quantum dot glue layer is provided with a structural layer; the surface of the structural layer has an optical gain structure, and the optical gain structure includes at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle, and a concave triangular pyramid structure with an R angle. The structured quantum dot film of the present application adopts an integrated structure, which effectively reduces the thickness of the module, and at the same time, the optical gain structure on the surface of the structural layer has good shielding and high brightness to the light source. Therefore, the structured quantum dot film made by the present application has a certain improvement in optical performance, and there is no significant difference in the surface structure of the structured quantum dot film before and after the wear resistance test, showing good optical performance and long-term use ability.

[0041] The present invention provides a method for preparing a structured quantum dot film, wherein: firstly, a copper roller with an engraved pattern is applied to the outer surface of a substrate layer of an upper and lower composite barrier layer, and the upper and lower composite barrier layers are cured to obtain an upper and lower composite barrier layer having a structured layer; then, quantum dot glue is evenly applied to the surface of the top coating layer of the upper and lower composite barrier layers, and the upper and lower composite barrier layers are bonded, and the structured quantum dot film is obtained after curing. The above-mentioned preparation method has the technical advantages of simple processing technology and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A schematic diagram of the structure of a quantum dot film applied to a direct-type backlight module provided in Example 1 of the present invention;

[0044] Figure 2 A schematic diagram of the structure of a quantum dot film applied to a direct-type backlight module provided in Example 4 of the present invention;

[0045] Figure 3 It is a spectrum comparison diagram of Example 4 of the present invention and Comparative Example 1.

[0046] Icon: 100-quantum dot glue layer; 101-lower composite barrier layer; 102-upper composite barrier layer; 103-lower structural layer; 104-upper structural layer; 105-back coating layer; 1051-back coating particles; 1001-red quantum dots; 1002-green quantum dots; 1003-scattering particles. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] According to one aspect of the present invention, a structured quantum dot film applied to a direct-lit backlight module comprises: a quantum dot glue layer 100, a composite barrier layer and a structure layer;

[0049] The quantum dot glue layer 100 is an intermediate layer, and composite barrier layers are arranged on both sides of the quantum dot glue layer 100, and a structural layer is arranged on the other side of the composite barrier layer relative to the quantum dot glue layer 100;

[0050] The surface of the structural layer has an optical gain structure, and the optical gain structure includes at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle, and a concave triangular pyramid structure with an R angle.

[0051] It should be noted that the shadow shielding of direct-type backlights mainly focuses on adding a uniform light film to the module. Changing the surface structure of the uniform light film is a common method. However, if the uniform light film is directly added to the backlight module, the loss of light efficiency will increase, which will have a greater impact on the final light output brightness. On the other hand, the overall thickness of the module will become thicker, which cannot meet the needs of terminal devices that pursue ultra-thin requirements.

[0052] Therefore, the present invention provides a structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprising: a quantum dot glue layer 100, a composite barrier layer and a structural layer; wherein the quantum dot glue layer 100 is an intermediate layer, the two sides of the quantum dot glue layer 100 are provided with a composite barrier layer, and the other side of the composite barrier layer relative to the quantum dot glue layer 100 is provided with a structural layer; the surface of the structural layer has an optical gain structure, and the optical gain structure includes at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle, and a concave triangular pyramid structure with an R angle. The structured quantum dot film of the present application adopts an integrated structure, which effectively reduces the thickness of the module, and at the same time, the optical gain structure on the surface of the structure layer has good shielding and high brightness to the light source. Therefore, the structured quantum dot film made by the present application has a certain improvement in optical performance, and there is no significant difference in the surface structure before and after the wear resistance test, showing good optical performance and long-term use ability.

[0053] In a preferred embodiment of the present invention, the optical gain structure is a concave pyramid structure, and the angle of the concave pyramid structure is 30 to 150°;

[0054] More preferably, the angle of the concave pyramid structure is 60 to 120°.

[0055] As a preferred embodiment, the angle of the concave pyramid structure is less than 60-120°, and the instability of the structure seriously affects the long-term use of the structured quantum dot film, and the production cost and difficulty are too high; and when the angle is greater than this range, the optical gain effect is minimal.

[0056] In a preferred embodiment of the present invention, the structural layer is mainly obtained by photocuring micro-replication or thermoforming of a transparent polymer resin;

[0057] Preferably, the transparent polymer resin is one of AR (Acrylic resin, acrylic resin or modified acrylic resin), PMMA or PC;

[0058] Preferably, the refractive index of the transparent polymer resin is 1.4-1.65.

[0059] In a preferred embodiment of the present invention, the thickness of the structural layer is 10 to 100 um, preferably 20 to 50 um.

[0060] In a preferred embodiment of the present invention, the structured quantum dot film comprises, in order along the direction of entry of the point light source: an optional lower structure layer 103, a lower composite barrier layer 101, a quantum dot glue layer 100, an upper composite barrier layer 102 and an upper structure layer 104;

[0061] As a preferred embodiment, the lower structure layer 103 can differentiate and diffuse the point light source of the direct-type backlight, thereby weakening the influence of the lamp shadow, and then improve the color gamut and brightness through the quantum dot layer. Finally, the light is gathered through the upper structure layer 104 to improve the brightness of the light output, thereby achieving the effect of high shielding and high brightness.

[0062] Preferably, the total thickness of the structured quantum dot film is 300-330 um.

[0063] In a preferred embodiment of the present invention, the composite barrier layer is obtained by sequentially compounding a substrate layer, a laminating layer, a base barrier layer and a top coating layer; the quantum dot glue layer 100 is UV-cured on the top coating layer side of the composite barrier layer, and the structural layer is disposed on the substrate layer side of the composite barrier layer by photocuring micro-replication or thermoforming;

[0064] Alternatively, a back coating layer 105 is provided on the other side of the substrate layer relative to the laminating layer.

[0065] Preferably, the back coating layer 105 includes a carrier and back coating particles 1051, wherein the carrier is one or more of epoxy resin, acrylate resin, silicone resin and polyurethane resin; the material of the back coating particles 1051 is selected from one or more of SiO2, Al2O3, ZrO2 and TiO2.

[0066] Preferably, the substrate layer is a transparent polymer, and the material is one of polyethylene terephthalate (PET), methyl methacrylate (PMMA), polycarbonate (PC), triacetyl cellulose (TAC), and cycloolefin polymer (COP).

[0067] Preferably, the bonding layer is a polymer binder, a crosslinking agent and a chelating agent. The polymer binder is one or more of polyester, polyurethane or polyacrylate, the polymer binder is at least one of hydroxyl, carboxyl and amino groups, the chelating agent forms a chemical bond crosslink with the polyvinyl alcohol; the crosslinking agent is one or more of polycarbodiimide, aziridine and methylated hexamethylolmelamine; the chelating agent is one or more of boric acid, sodium borate, sodium acrylate and titanate.

[0068] Preferably, the basic barrier layer includes polyvinyl alcohol and an inorganic oxide layer, etc.

[0069] Preferably, the topcoat layer comprises one or more of ethylene vinyl acetate (EVA), butyl acrylate (ABA) and butadiene styrene (SBS).

[0070] In a preferred embodiment of the present invention, the thickness of the back coating layer 105 in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0071] And / or, the thickness of the substrate layer in the composite barrier layer is 25 to 200 um, preferably 50 to 100 um;

[0072] And / or, the thickness of the laminating layer in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0073] And / or, the thickness of the base barrier layer in the composite barrier layer is 2 to 20 um, preferably 4 to 12 um;

[0074] and / or, the thickness of the top coating in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um;

[0075] Preferably, the water barrier rate of the composite barrier layer is less than 0.1 g / (㎡*24h).

[0076] In a preferred embodiment of the present invention, the quantum dot adhesive layer 100 is composed of adhesive resin, scattering particles 1003, antioxidant and quantum dots;

[0077] The antioxidant, scattering particles 1003 and quantum dots can be uniformly and stably dispersed in the adhesive resin.

[0078] In the above preferred embodiment, the adhesive resin system is acrylic resin, which is a general term for polymers of acrylic acid, methacrylic acid and their derivatives.

[0079] The acrylic resin has excellent fullness, gloss, hardness, solvent resistance, weather resistance and the like, and can be used as a UV curing resin.

[0080] The acrylic resin can react with functional groups in amino resins, polyurethanes, etc. to form an insoluble dense network structure during curing.

[0081] In the above preferred embodiment, the antioxidant is mainly used to inhibit the oxidation reaction in the glue, thereby extending the service life of the quantum dot film and maintaining its stable performance.

[0082] Preferably, the antioxidant is one or two of amine, phenol, phosphite and sulfur-containing antioxidants.

[0083] More preferably, the phenolic antioxidants include phenolic antioxidants, asymmetric hindered phenolic antioxidants, monophenolic hindered phenolic antioxidants, bisphenolic hindered phenolic antioxidants and polyphenolic hindered phenolic antioxidants, etc. The amine antioxidants are diaryl secondary amines, p-phenylenediamine, ketone amines, aldehydes, etc., and the common amine antioxidant is 44PD. The common phosphite antioxidants are antioxidant 168 and antioxidant 626. The common sulfur-containing antioxidants are antioxidant 412S and antioxidant DLTP.

[0084] In the above preferred embodiment, the scattering particles 1003 are one or a mixture of two of TiO2, SiO2 and silicone.

[0085] Preferably, the particle size of the scattering particles 1003 is 0.2 to 10 microns, and the shape of the scattering particles 1003 is round. The scattering particles 1003 can scatter light from one direction to another through scattering, thereby increasing the utilization rate of light and improving the brightness of the quantum dot film. In addition, the presence of the scattering particles 1003 can enhance optical performance and improve color uniformity.

[0086] In the above preferred embodiment, the quantum dots include red quantum dots 1001 and green quantum dots 1002, and the red quantum dots 1001 and green quantum dots 1002 are quantum dots with cadmium selenide or indium phosphide as the core.

[0087] Preferably, the wavelength of the red quantum dots 1001 is 615-645 nm.

[0088] Preferably, the wavelength of the green quantum dots 1002 is 530-555 nm.

[0089] Preferably, the particle size of the red quantum dots 1001 is 5 to 10 nm.

[0090] Preferably, the particle size of the green quantum dots 1002 is 2 to 5 nm.

[0091] Preferably, the red and green quantum dots 1002 can emit red light when illuminated by blue light, and the red quantum dots 1001 can emit red light, while the green quantum dots 1002 can emit green light.

[0092] More preferably, the mass ratio of the red quantum dots 1001 and the green quantum dots 1002 in the glue system is 1:1 to 1:5, preferably, the mass ratio is 1:1.5 to 1:3. The amount of red and green quantum dots 1002 added can be different wavelengths and different proportions according to specific color point, color range and other requirements.

[0093] In a preferred embodiment of the present invention, the thickness of the quantum dot glue layer 100 is 50-200 um, preferably 70-140 um.

[0094] According to one aspect of the present invention, a method for preparing the above-mentioned structured quantum dot film comprises:

[0095] (A) providing an upper and lower composite barrier layer 101, coating the structural layer glue onto the outer surface of the substrate layer of the upper and lower composite barrier layer 101 through a copper roller with an engraved pattern, demolding after UV pre-curing, and then performing secondary curing on the structure attached to the substrate layer to obtain an upper and lower composite barrier layer 101 having a structural layer;

[0096] Alternatively, an upper composite barrier layer 102 is provided, and the structural layer glue is coated onto the outer surface of the substrate layer of the upper composite barrier layer 102 by a copper roller having an engraved pattern, and demoulding is performed after UV pre-curing, and then the structure attached to the substrate layer is subjected to secondary curing to obtain the upper composite barrier layer 102 having the structural layer;

[0097] Providing a lower composite barrier layer 101, coating the back coating layer 105 glue on the lower composite barrier layer 101 and curing it to obtain the lower composite barrier layer 101 having the back coating layer 105;

[0098] (B) The quantum dot glue is mixed and stirred under the protection of an inert gas, and the mixed quantum dot glue is evenly coated on the surface of the top coating of the upper and lower composite barrier layers 101, and then the upper and lower composite barrier layers 101 are laminated and UV cured to obtain a structural quantum dot film.

[0099] The present invention provides a method for preparing a structured quantum dot film, wherein: firstly, a copper roller with an engraved pattern is applied to the outer surface of the substrate layer of the upper and lower composite barrier layers 101, and the upper and lower composite barrier layers 101 with a structured layer are obtained after curing; then, quantum dot glue is evenly applied to the surface of the top coating of the upper and lower composite barrier layers 101, and the upper and lower composite barrier layers 101 are bonded together, and after curing, the structured quantum dot film is obtained. The above-mentioned preparation method has the technical advantages of simple processing technology and easy operation.

[0100] The technical solution of the present invention will be further described below in conjunction with embodiments.

[0101] Example 1

[0102] Figure 1 This is a schematic diagram of the structure of the quantum dot film applied to the direct-type backlight module provided in this embodiment.

[0103] like Figure 1 As shown, a structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprises, in sequence along the direction of entry of a point light source: a back coating layer 105, a lower composite barrier layer 101, a quantum dot glue layer 100, an upper composite barrier layer 102 and an upper structural layer 104;

[0104] An optical gain structure is disposed on the upper structure layer 104 , and the optical gain structure is a concave pyramid upper structure layer 104 with an angle of 120° and a pitch of 72 um.

[0105] The method for preparing the structured quantum dot film applied to the direct-type backlight module comprises:

[0106] (1) Applying the pre-mixed structural glue to the outer surface of the substrate layer of the upper composite barrier layer 102 through an engraved copper roller, and performing UV pre-curing and demoulding during coating, and performing a secondary curing process on the structure attached to the substrate layer;

[0107] The structural adhesive is AR (Acrylic resin, acrylic resin or modified acrylic resin)

[0108] (2) Evenly mix the glue and particles required for back coating, and apply the back coating glue on the outer surface of the substrate layer not used as the structural layer to obtain the back coating layer 105. The back coating glue and back coating particles 1051 are epoxy resin and SiO2;

[0109] The back coating particles 1051 are evenly distributed in the back coating layer 105 .

[0110] (3) applying a protective film to one side of the structural layer of the material in step (1) to protect the integrity of the structural layer in subsequent steps;

[0111] (4) Apply the pre-mixed bonding adhesive to the inner surface of the substrate layer of the upper and lower composite barrier layers 101, and bond them to the base barrier film; the base barrier film is an inorganic oxide layer.

[0112] (5) The glue required for the top coating is uniformly mixed, and the mixed top coating glue is applied on the barrier film layer to form a top coating layer; the glue required for the top coating is butyl acrylate.

[0113] (6) The quantum dot glue is mixed and stirred under the protection of an inert gas, and the mixed quantum dot glue is evenly coated on the inner surfaces of the upper and lower barrier layers using a composite film preparation process. The coated composite film is UV cured to obtain a finished structural quantum dot film.

[0114] The product model of the quantum dot film is EQ300, and the manufacturer is Jizhi.

[0115] The thickness of the adhesive layer of the prepared structured quantum dot film is 90 um, and the total thickness of the structured quantum dot film is 300 um.

[0116] Example 2

[0117] This embodiment is the same as the first embodiment except that the optical gain structure on the upper structure layer 104 is a "90°, 50um pitch concave pyramid upper structure layer 104".

[0118] Example 3

[0119] This embodiment is the same as the first embodiment except that the optical gain structure on the upper structure layer 104 is a "60°, 24 um pitch concave pyramid upper structure layer 104".

[0120] Example 4

[0121] Figure 2 This is a schematic diagram of the structure of a quantum dot film applied to a direct-type backlight module provided in Example 4 of the present invention.

[0122] like Figure 2 As shown, a structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprises, in sequence along the direction of entry of a point light source: a lower structure layer 103, a lower composite barrier layer 101, a quantum dot glue layer 100, an upper composite barrier layer 102 and an upper structure layer 104;

[0123] Optical gain structures are disposed on the lower structure layer 103 and the upper structure layer 104;

[0124] The optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 120° and a pitch of 72 um.

[0125] The optical gain structure of the lower structure layer 103 is: a concave pyramid upper structure layer 104 with an angle of 120° and a pitch of 72 um.

[0126] The method for preparing the structured quantum dot film applied to the direct-type backlight module comprises:

[0127] (1) The pre-mixed structural glue is applied to the outer surface of the substrate layer of the upper and lower composite barrier layers 101 through an engraved copper roller, and demolded after UV pre-curing during coating, and the structure attached to the substrate layer is subjected to a secondary curing process; the structural glue is the same as that in Example 1.

[0128] (2) applying a protective film to one side of the structural layer of the material in step (1) to protect the integrity of the structural layer in subsequent steps;

[0129] (3) Apply the pre-mixed bonding adhesive to the inner surface of the substrate layer of the upper and lower composite barrier layers 101, and bond them to the base barrier film; the base barrier film is the same as that in Example 1.

[0130] (4) The glue required for the top coating is uniformly mixed, and the mixed top coating glue is applied on the barrier film layer to form a top coating layer; the glue required for the top coating is the same as that in Example 1.

[0131] (5) The quantum dot glue is mixed and stirred under the protection of an inert gas, and the mixed quantum dot glue is evenly coated on the inner surfaces of the upper and lower barrier layers using a composite film preparation process. The coated composite film is UV cured to obtain a finished structural quantum dot film.

[0132] The quantum dot film is the same as in Example 1.

[0133] The thickness of the adhesive layer of the prepared structured quantum dot film is 90 um, and the total thickness of the structured quantum dot film is 330 um.

[0134] Example 5

[0135] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0136] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 90° and a pitch of 50 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 90° and a pitch of 50 um.

[0137] Example 6

[0138] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0139] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 60° and a pitch of 24 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 60° and a pitch of 24 um.

[0140] Example 7

[0141] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0142] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 90° and a pitch of 50 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with a pitch of 120° and 72 um.

[0143] Example 8

[0144] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0145] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 60° and a pitch of 24 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 120° and a pitch of 72 um.

[0146] Example 9

[0147] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0148] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 60° and a pitch of 24 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 90° and a pitch of 50 um.

[0149] Example 10

[0150] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0151] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 30° and a pitch of 12 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 30° and a pitch of 12 um.

[0152] Embodiment 11

[0153] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0154] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 150° and a pitch of 150 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 150° and a pitch of 150 um.

[0155] Example 12

[0156] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0157] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 20° and a pitch of 8 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 20° and a pitch of 8 um.

[0158] Example 13

[0159] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0160] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave pyramid upper structure layer 104 with an angle of 160° and a pitch of 225 um; the optical gain structure of the lower structure layer 103 is: a concave pyramid lower structure layer 103 with an angle of 160° and a pitch of 225 um.

[0161] Embodiment 14

[0162] This embodiment is the same as Embodiment 4 except that the optical gain structures of the upper structure layer 104 and the lower structure layer 103 are different from those of Embodiment 4;

[0163] In this embodiment, the optical gain structure of the upper structure layer 104 is: a concave triangular pyramid structure upper structure layer 104 with an angle of 90° and a pitch of 50 um; the optical gain structure of the lower structure layer 103 is: a concave triangular pyramid structure lower structure layer 103 with an angle of 90° and a pitch of 50 um.

[0164] Comparative Example 1

[0165] A structured quantum dot film applied to a direct-type backlight module, the structured quantum dot film comprising, in order along the direction of entry of a point light source: a back coating layer 105, a lower composite barrier layer 101, a quantum dot glue layer 100, an upper composite barrier layer 102 and a back coating layer 105;

[0166] The method for preparing the structured quantum dot film applied to the direct-type backlight module comprises:

[0167] (1) The glue and particles required for back coating are uniformly mixed, and the back coating glue is applied on the outer surface of the substrate layer of the upper composite barrier layer 102 and the lower composite barrier layer 101 to obtain a back coating layer 105.

[0168] The back coating layer 105 is the same as that in Example 1.

[0169] (2) Apply the pre-mixed bonding adhesive to the inner surface of the substrate layer of the upper and lower composite barrier layers 101, and bond them to the base barrier film; the base barrier film is the same as that in Example 1.

[0170] (3) The glue required for the top coating is uniformly mixed, and the mixed top coating glue is applied on the barrier film layer to form a top coating layer; the top coating layer is the same as that in Example 1.

[0171] (4) The quantum dot glue is mixed and stirred under the protection of inert gas, and the mixed quantum dot glue is evenly coated on the inner surfaces of the upper and lower barrier layers using a composite film preparation process, and the coated composite film is UV cured to obtain a finished structure quantum dot film. The quantum dot film is the same as in Example 1.

[0172] The thickness of the adhesive layer of the prepared structured quantum dot film is 90 um, and the total thickness of the structured quantum dot film is 270 um.

[0173] The difference between this comparative example and Example 1 is that it does not include a structural layer.

[0174] Test Example 1

[0175] The optical properties and shielding ability of the structured quantum dot films prepared in the above-mentioned Examples 1 to 14 and Comparative Example 1 are tested. The performance testing method of the structured quantum dot films is as follows:

[0176] (1) Test of color coordinates (Wx, Wy) and brightness (Lv / nits) of structured quantum dot film: Cut the film into A4 size and place it in the middle of a 32-inch blue backlight. Cover the quantum dot film with two vertically angled brightness enhancement films as the module structure. Use the CS2000 optical testing instrument to test the optical performance and obtain the white field color coordinates and brightness values ​​of the quantum dot film.

[0177] (2) Test of wavelength (peak / nm) and half-peak width (FWHM / nm) of structured quantum dot film: Cut the film into A4 size and place it in the middle of a 32-inch blue backlight. Cover the quantum dot film with two vertically angled brightness enhancement films as a module structure. Use a CS2000 optical testing instrument to test the optical performance and obtain a spectral data table of the quantum dot film. Use origin to process and calculate the spectral data table to obtain the peak wavelength and half-peak width data of the red quantum dot 1001 of the quantum dot film, and the peak wavelength and half-peak width data of the green quantum dot 1002 of the quantum dot film.

[0178] (3) Test of shielding performance of structured quantum dot film: Cut the film into A4 size and place it in the middle of a 32-inch blue LED light board. Wear anti-blue light glasses to observe the film. If the LED light shadow can be clearly observed, the shielding ability is severe light shadow; if the LED light shadow can be vaguely observed, the shielding ability is slight light shadow; if the LED light shadow cannot be observed, the shielding ability is no light shadow.

[0179] (4) Wear resistance test of structured quantum dot film: The film was placed on a friction tester and rubbed for different times, and the changes in white field color coordinates and brightness values ​​before and after friction were observed.

[0180] The specific test results are shown in Table 1 and Table 2.

[0181] Table 1 Comparison of optical performance and shielding ability data:

[0182]

[0183]

[0184]

[0185] As shown in Table 1, there is no significant difference in the wavelength (peak) and half-peak width (FWHM) of the quantum dots between the embodiment and the control example, indicating that the addition of the structural layer has no significant effect on the performance of the quantum dots themselves. In addition, the shielding performance of the embodiment is significantly better than that of the control example.

[0186] Table 2 Changes in optical properties:

[0187] project △Lv △x △y Example 1 3.44％ 0.0082 0.0175 Example 2 3.77％ 0.0077 0.0174 Example 3 4.35％ 0.0068 0.0179 Example 4 3.79％ 0.006 0.0169 Example 5 5.44％ 0.0081 0.0199 Example 6 6.14％ 0.0097 0.021 Example 7 4.52％ 0.0072 0.0184 Example 8 4.70％ 0.007 0.0193 Example 9 5.63％ 0.0087 0.0204 Example 10 8.23％ 0.0105 0.0222 Embodiment 11 3.53％ 0.0084 0.0174 Example 12 8.54％ 0.0112 0.0229 Example 13 3.27％ 0.0072 0.0166 Embodiment 14 5.25％ 0.0079 0.0178 Comparative Example 1 0.00％ 0 0

[0188] It can be seen from Table 2 that the changes in the optical properties (brightness and white light color point) of the embodiment compared to the control example film are that the brightness is improved by 3.8%-6.1%, the color point x is improved by 0.0060-0.0097, and the color point y is improved by 0.0169-0.0210, indicating that the structural layer can effectively improve the optical properties of the quantum dot film.

[0189] Figure 3 It is a spectrum comparison diagram of Example 4 of the present invention and Comparative Example 1.

[0190] Depend on Figure 3 It can be seen that adding a structural layer has no effect on the spectrum of the quantum dot film.

[0191] Table 3 shows the optical data changes of Example 4 after different times of friction tests:

[0192]

[0193] As shown in Table 3, there is no significant change in the optical properties before and after friction, indicating that the upper and lower structural layers 103 have strong wear resistance and stability, thereby ensuring the long-term use capability of the structural quantum dot film.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A structured quantum dot film applied to a direct-type backlight module, characterized in that: The structured quantum dot film comprises: a quantum dot glue layer, a composite barrier layer and a structural layer; The quantum dot glue layer is an intermediate layer, and composite barrier layers are arranged on both sides of the quantum dot glue layer, and a structural layer is arranged on the other side of the composite barrier layer relative to the quantum dot glue layer; The surface of the structural layer has an optical gain structure, and the optical gain structure includes at least one of a concave pyramid structure, a concave triangular pyramid structure, a concave pyramid structure with an R angle, and a concave triangular pyramid structure with an R angle.

2. The structured quantum dot film according to claim 1, characterized in that: The optical gain structure is a concave pyramid structure, and the angle of the concave pyramid structure is 30 to 150 degrees; More preferably, the angle of the concave pyramid structure is 60 to 120°.

3. The structured quantum dot film according to claim 1, characterized in that: The structural layer is mainly obtained by photocuring micro-replication or thermoforming of transparent polymer resin; Preferably, the transparent polymer resin is one of acrylic resin or modified acrylic resin, PMMA or PC; Preferably, the refractive index of the transparent polymer resin is 1.4-1.

65.

4. The structured quantum dot film according to claim 1, characterized in that: The thickness of the structural layer is 10-100 um, preferably 20-50 um.

5. The structured quantum dot film according to claim 1, characterized in that: The structured quantum dot film includes, in order along the direction of entry of the point light source: an optional lower structural layer, a lower composite barrier layer, a quantum dot glue layer, an upper composite barrier layer and an upper structural layer; Preferably, the total thickness of the structured quantum dot film is 300-330 um.

6. The structured quantum dot film according to claim 1, characterized in that: The composite barrier layer is obtained by compounding a substrate layer, a laminating layer, a base barrier layer and a top coating layer in sequence; The quantum dot glue layer is cured on the top coating layer side of the composite barrier layer by UV, and the structural layer is arranged on the substrate layer side of the composite barrier layer by photocuring micro-replication or thermoforming; Alternatively, a back coating layer is provided on the other side of the substrate layer relative to the laminating layer.

7. The structured quantum dot film according to claim 6, characterized in that: The thickness of the back coating in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um; And / or, the thickness of the substrate layer in the composite barrier layer is 25 to 200 um, preferably 50 to 100 um; And / or, the thickness of the laminating layer in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um; And / or, the thickness of the base barrier layer in the composite barrier layer is 2 to 20 um, preferably 4 to 12 um; and / or, the thickness of the top coating in the composite barrier layer is 1 to 10 um, preferably 2 to 5 um; Preferably, the water barrier rate of the composite barrier layer is less than 0.1 g / (㎡*24h).

8. The structured quantum dot film according to claim 1, characterized in that: The quantum dot adhesive layer is composed of adhesive resin, scattering particles, antioxidant and quantum dots; The antioxidant, scattering particles and quantum dots can be uniformly and stably dispersed in the adhesive resin.

9. The structured quantum dot film according to claim 8, characterized in that: The thickness of the quantum dot glue layer is 50 to 200 um, preferably 70 to 140 um.

10. A method for preparing a structured quantum dot film according to any one of claims 1 to 9, characterized in that: The preparation method comprises: (A) providing upper and lower composite barrier layers, coating the structural layer glue on the outer surface of the substrate layer of the upper and lower composite barrier layers through a copper roller with an engraved pattern, demolding after UV pre-curing, and then performing secondary curing on the structure attached to the substrate layer to obtain the upper and lower composite barrier layers with structural layers; Or, providing an upper composite barrier layer, coating the structural layer glue onto the outer surface of the substrate layer of the upper composite barrier layer through a copper roller with an engraved pattern, demoulding after UV pre-curing, and then performing secondary curing on the structure attached to the substrate layer to obtain an upper composite barrier layer with a structural layer; Providing a lower composite barrier layer, coating the back coating glue on the lower composite barrier layer and curing it to obtain the lower composite barrier layer with the back coating; (B) The quantum dot glue is mixed and stirred under the protection of an inert gas, and the mixed quantum dot glue is evenly coated on the surface of the top coating of the upper and lower composite barrier layers. The upper and lower composite barrier layers are then laminated and UV cured to obtain a structural quantum dot film.

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