A high-haze, high-brightness diffusion film, its preparation method and backlight module

Abstract

The present invention provides a high-haze, high-brightness diffusion film, comprising a substrate, a light diffusion layer, an anti-adhesion layer, and a transmittance adjustment layer. The transmittance adjustment layer uses flake-shaped fumed silica polymer particles with a convex lens structure to adjust the transmittance of the diffusion film; the flake-shaped fumed silica polymer particles have a particle size of 0.2 to 1.7 μm and a refractive index of 1.84. The present invention uses flake-shaped fumed silica polymer particles with a convex lens structure in the transmittance adjustment layer. The special convex lens shape of the particles can achieve the principle of focusing light, increasing the transmittance of all light. This allows the transmittance adjustment layer to effectively enhance and control the transmittance of the optical diffusion film without affecting its haze and covering properties, significantly improving the brightness of the backlight film assembly while maintaining good covering properties. The present invention also provides a method for preparing a high-haze, high-brightness diffusion film and a backlight module.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid crystal displays, and in particular relates to a high-haze, high-brightness diffusion film, a preparation method thereof, and a backlight module. Background Art

[0002] Optical diffusion films are widely used in liquid crystal backlight unit displays, advertising background lighting, light box advertising, and other fields. In liquid crystal backlight unit displays, diffusion films are a key component that uniformly transforms linear light sources into a uniform surface light source. This is especially true in mobile phone backlight units, where the performance requirements are high and therefore the requirements for diffusion films are even more stringent.

[0003] A backlight unit (BLU) typically consists of a reflector, a light guide plate (LGP), and optical films (diffusers, brightness enhancement films, etc.). Currently, the most commonly used LGP in the market is polymethyl methacrylate (acrylic), which has a high surface pencil hardness and good shape, but is expensive, has poor flexibility, and is difficult to process. To reduce BLU costs, the material of the LGP has gradually shifted to polyacrylate organic-inorganic nanocomposites (MS). These materials offer excellent flexibility and ease of processing, but their surface pencil hardness decreases, leading to reduced scratch resistance. The LGP used in mobile phone BLUs is polycarbonate (PC), which has a lower surface pencil hardness and often exhibits white spots (self-damage) during vibration, compression, and drop tests. Furthermore, the higher brightness of mobile phone BLUs makes LGP defects more easily visible, necessitating the use of high-haze (haze above 93%) diffusers to conceal these defects. However, increasing the haze of the diffuser film significantly reduces its light transmittance, significantly reducing the overall BLU brightness.

[0004] A typical optical diffusion film consists of a substrate, a front light diffusion layer, and a back anti-blocking layer. Both the diffusion layer and the anti-blocking layer typically contain a resin film-forming material, spherical light diffusion particles (such as PMMA, PBMA, PA, PU, ​​PS, etc.), and additives.

[0005] In order to cover defects, general optical diffusion films require high haze requirements, so many spherical light diffusion particles are added inside the light diffusion layer. This will significantly increase the cost of the diffusion film. At the same time, the brightness of the backlight module will also be greatly reduced due to the high haze requirement. In this way, more lamp beads are needed to increase the brightness of the light source, which also significantly increases the production cost of the backlight module. Summary of the Invention

[0006] The purpose of the present invention is to provide a high haze, high brightness diffusion film, a preparation method thereof and a backlight module. The diffusion film of the present invention has both high haze and high brightness, and has a simple structure, is easy to manufacture and has low cost.

[0007] The present invention provides a high-haze, high-brightness diffusion film, comprising a substrate, a light diffusion layer disposed on one side of the substrate, an anti-adhesion layer disposed on the other side of the substrate, and a light transmittance adjustment layer disposed between the light diffusion layer and the substrate. The light transmittance of the diffusion film is adjusted using flake-shaped fumed silica polymer particles having a convex lens structure in the light transmittance adjustment layer.

[0008] The particle size of the flaky fumed silica polymer particles is 0.2 to 1.7 μm, and the refractive index is 1.84.

[0009] Preferably, the light diffusion layer comprises, by weight, 16 to 18 parts of the resin film-forming material 1, 21.7 to 23.5 parts of the spherical light diffusion particles 1 and 0.5 to 1 part of the auxiliary agent 1;

[0010] The resin film-forming material 1 is one or more of acrylic resin, polyurethane resin, propylene polyol resin, and epoxy resin;

[0011] The spherical light diffusion particles 1 are one or more of polymethyl methacrylate, polybutyl methacrylate, polypropylene, polyethylene, polyamide, polystyrene and titanium dioxide;

[0012] The auxiliary agent 1 is one or more of a dispersant, a leveling agent, a photopolymerization agent, a light stabilizer, a defoaming agent, a curing agent, a lubricant and an antistatic agent.

[0013] Preferably, the thickness of the light diffusion layer is 4 to 10 μm; the refractive index of the resin film-forming material 1 is 1.4 to 1.6; and the particle size of the spherical light diffusion particles 1 is 3 to 10 μm.

[0014] Preferably, the anti-adhesion layer comprises 13 to 14 parts of a resin film-forming material 2, 0.5 to 0.7 parts of flexible spherical light-diffusing particles 2 and 0.8 to 0.9 parts of an auxiliary agent 2, in parts by weight;

[0015] The resin film-forming material 2 is one or more of acrylic resin, polyurethane resin, propylene polyol resin, and epoxy resin;

[0016] The flexible spherical light diffusion particles 2 are one or more of polybutyl methacrylate, polypropylene, polyethylene, polyamide and polystyrene;

[0017] The auxiliary agent 2 is one or more of a dispersant, a leveling agent, a photopolymerization agent, a light stabilizer, a defoaming agent, a curing agent, a lubricant and an antistatic agent.

[0018] Preferably, the thickness of the anti-adhesion layer is 4 to 8 μm, the refractive index of the resin film-forming material 2 is 1.4 to 1.6; and the particle size of the flexible spherical light-diffusing particles 2 is 3 to 8 μm.

[0019] Preferably, the transmittance adjusting layer comprises, by weight, 12 to 13 parts of a resin film-forming material 3, 1.2 to 3.6 parts of a flaky fumed silica polymer, and 0.8 to 1.0 parts of an auxiliary agent 3;

[0020] The resin film-forming material 3 is acrylic resin and / or polyurethane resin;

[0021] The auxiliary agent 3 is one or more of a dispersant, a leveling agent, a curing agent, a slip agent, an antistatic agent and a defoaming agent.

[0022] Preferably, the thickness of the transmittance adjusting layer is 1-2 μm; and the refractive index of the resin film-forming material 3 is 1.67.

[0023] The present invention provides a method for preparing the high haze and high brightness diffusion film as described above, comprising the following steps:

[0024] Applying the transmittance adjusting layer coating liquid on one surface of the substrate and drying and curing the coating liquid to obtain the transmittance adjusting layer;

[0025] Applying the light diffusion layer coating liquid on the surface of the transmittance adjustment layer and drying and curing it to obtain a light diffusion layer;

[0026] The anti-blocking layer coating liquid is coated on the other surface of the substrate and dried and solidified to obtain an anti-blocking layer.

[0027] The present invention provides a backlight module, comprising the above-mentioned high-haze, high-brightness diffusion film.

[0028] The present invention provides a high-haze, high-brightness diffusion film, comprising a substrate, a light diffusion layer, an anti-adhesion layer, and a transmittance adjustment layer. The transmittance adjustment layer uses flaky fumed silica polymer particles having a convex lens structure to adjust the transmittance of the diffusion film; the flaky fumed silica polymer particles have a particle size of 0.2 to 1.7 μm and a refractive index of 1.84. The present invention provides a transmittance adjustment layer structure and uses flaky fumed silica polymer particles having a convex lens structure in the transmittance adjustment layer. The special morphology of the convex lenses can achieve the principle of focusing light, thereby increasing the transmittance of all light. The transmittance adjustment layer can effectively improve and control the transmittance of the optical diffuser film without affecting the haze and covering properties of the optical diffuser film, thereby significantly improving the brightness of the backlight film assembly while maintaining good covering properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 Schematic diagram of the structure of the high haze and high brightness diffusion film in the present invention,

[0031] 1 is a substrate, 2 is a transmittance regulating layer, 3 is a light diffusion layer, 4 is an anti-adhesion layer, 5 is a resin film-forming material in the light diffusion layer and the anti-adhesion layer, 6 is a light diffusion particle, 6 is a transmittance regulating material, 7 is an auxiliary agent, 8 is an auxiliary agent, and 9 is a resin film-forming material in the transmittance regulating layer. DETAILED DESCRIPTION

[0032] The present invention provides a high-haze, high-brightness diffusion film, characterized in that it includes a substrate, a light diffusion layer arranged on one side of the substrate, an anti-adhesion layer arranged on the other side of the substrate, and a light transmittance adjustment layer arranged between the light diffusion layer and the substrate, and the light transmittance of the diffusion film is adjusted using flaky fumed silica polymer particles having a convex lens structure in the light transmittance adjustment layer;

[0033] The particle size of the flaky fumed silica polymer particles is 0.2 to 1.7 μm, and the refractive index is 1.84.

[0034] In the present invention, the diffusion film has Figure 1 The structure shown includes a light diffusion layer, a light transmittance adjustment layer, a substrate and an anti-adhesion layer that are in contact with each other in sequence.

[0035] In the present invention, the light diffusion layer comprises 16 to 18 parts of a resin film-forming material 1, 21.7 to 23.5 parts of spherical light diffusion particles 1 and 0.5 to 1 part of an auxiliary agent 1, in parts by weight. The thickness of the light diffusion layer is preferably 4 to 10 μm, more preferably 5 to 8 μm.

[0036] In the present invention, the resin film-forming material 1 is preferably one or more of acrylic resin, polyurethane resin, propylene polyol resin, and epoxy resin; in the light diffusion layer, the weight proportion of the resin film-forming material 1 is preferably 16 to 18 parts, more preferably 16.5 to 17.5 parts, such as 16 parts, 16.5 parts, 17 parts, 17.5 parts, and 18 parts, preferably a range value with any of the above values ​​as the upper or lower limit; the refractive index of the resin film-forming material 1 is preferably 1.4 to 1.6.

[0037] The spherical light diffusion particles 1 are one or more of polymethyl methacrylate (PMMA), polybutyl methacrylate (PBMA), polypropylene (PP), polyethylene (PE), polyamide (PA), polystyrene (PS) and titanium dioxide; in the light diffusion layer, the weight proportion of the spherical light diffusion particles 1 is preferably 21.7 to 23.5 parts, more preferably 22 to 23 parts, such as 21.7 parts, 22 parts, 22.5 parts, 23 parts, 23.5 parts, preferably a range value with any of the above values ​​as the upper or lower limit; the particle size of the spherical light diffusion particles 1 is preferably 3 to 10 μm, more preferably 5 to 8 μm.

[0038] The auxiliary agent 1 is preferably one or more of a dispersant, a leveling agent, a photopolymerizer, a light stabilizer, a defoamer, a curing agent, a lubricant and an antistatic agent; the types of the dispersant, leveling agent, photopolymerizer, light stabilizer, defoamer, curing agent, lubricant and antistatic agent can all be the types of dispersants, leveling agents, photopolymerizers, light stabilizers, defoamers, curing agents, lubricants and antistatic agents commonly used in the art. Specifically, in an embodiment of the present invention, the dispersant can be a salt solution of unsaturated polyamine amide and acidic polyester; the leveling agent can be polyether-modified dimethyl polysiloxane; the photopolymerizer can be 2-hydroxy-2-methyl-1-phenyl-1-propanone; the light stabilizer can be bis-2,2,6,6-tetramethylpiperidinol sebacate; the defoamer can be a modified polysiloxane; the curing agent can be trimer HDI; the lubricant can be stearamide; and the antistatic agent can be a sulfonate. In the light diffusion layer, the weight portion of the auxiliary agent 1 is preferably 0.5 to 1 part, more preferably 0.6 to 0.8 parts, such as 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, preferably a range value with any of the above values ​​as the upper or lower limit.

[0039] In the present invention, the transmittance adjusting layer comprises 12-13 parts of a resin film-forming material 3, 1.2-3.6 parts of a flaky fumed silica polymer and 0.8-1.0 parts of an auxiliary agent 3, and the thickness of the transmittance adjusting layer is 1-2 μm.

[0040] The resin film-forming material 3 is an acrylic resin and / or a polyurethane resin; in the transmittance adjusting layer, the mass fraction of the resin film-forming material 3 is preferably 12 to 13 parts, more preferably 12.5 to 12.8 parts, such as 12 parts, 12.1 parts, 12.2 parts, 12.3 parts, 12.4 parts, 12.5 parts, 12.6 parts, 12.7 parts, 12.8 parts, 12.9 parts, 13 parts, preferably a range value with any of the above values ​​as the upper or lower limit; the refractive index of the resin film-forming material 3 is preferably 1.67.

[0041] The flaky fumed silica polymer is a transmittance regulator having a convex lens structure. The flaky fumed silica polymer is a polymer of SiO2 and inorganic minerals (Ca, Al inorganic salts). Specifically, in an embodiment of the present invention, the LMX-A fumed silica polymer provided by SEKISUI PLASTICS can be used. The particle size of the flaky fumed silica polymer is preferably 0.2 to 1.7 μm, more preferably 0.5 to 1.2 μm, such as 0.5 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2.0 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.7 μm, 2.8 μm, 2.9 μm, 3.0 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9 μm, 4. μm, preferably a range value with any of the above values ​​as the upper or lower limit; the refractive index of the flaky fumed silica polymer is preferably 1.84; in the transmittance adjusting layer, the weight proportion of the flaky fumed silica is preferably 1.2 to 3.6 parts, more preferably 1.5 to 3 parts, such as 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.3 parts, 2.5 parts, 2.8 parts, 3 parts, 3.5 parts, 3.6 parts, preferably a range value with any of the above values ​​as the upper or lower limit.

[0042] The auxiliary agent 3 is one or more of a dispersant, a leveling agent, a curing agent, a lubricant, an antistatic agent and a defoaming agent; the dispersant, leveling agent, curing agent, lubricant, antistatic agent and defoaming agent can all be the dispersants, leveling agents, curing agents, lubricants, antistatic agents and defoaming agents commonly used in the art. Specifically, in an embodiment of the present invention, the dispersant can be a salt solution of unsaturated polyamine amide and acidic polyester, the leveling agent can be polyether-modified dimethyl polysiloxane, the curing agent can be trimer HDI, the lubricant can be stearamide, the antistatic agent can be a sulfonate, and the defoaming agent can be a modified polysiloxane; in the transmittance adjusting layer, the weight portion of the auxiliary agent 3 is preferably 0.8 to 1.0 parts, and more preferably 0.9 parts.

[0043] In the present invention, the substrate is preferably one or more of polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polyamide, polyimide and polystyrene; the thickness of the substrate is preferably 25 to 250 μm, more preferably 50 to 200 μm, such as 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, preferably a range value with any of the above values ​​as the upper or lower limit.

[0044] In the present invention, the anti-adhesion layer comprises 13 to 14 parts of a resin film-forming material 2, 0.5 to 0.7 parts of flexible spherical light-diffusing particles 2 and 0.8 to 0.9 parts of an auxiliary agent 2, in parts by weight; the thickness of the anti-adhesion layer is preferably 4 to 8 μm, more preferably 5 to 6 μm.

[0045] The resin film-forming material 2 is one or more of acrylic resin, polyurethane resin, propylene polyol resin, and epoxy resin; in the anti-adhesion layer, the weight proportion of the resin film-forming material 2 is preferably 13 to 14 parts, such as 13 parts, 13.1 parts, 13.2 parts, 13.3 parts, 13.4 parts, 13.5 parts, 13.6 parts, 13.7 parts, 13.8 parts, 13.9 parts, and 14 parts, preferably a range value with any of the above values ​​as the upper or lower limit, and the refractive index of the resin film-forming material 2 is preferably 1.4 to 1.6.

[0046] The flexible spherical light-diffusing particles 2 are preferably one or more of polybutyl methacrylate (PBMA), polypropylene (PP), polyethylene (PE), polyamide (PA) and polystyrene (PS); in the anti-adhesion layer, the weight proportion of the flexible spherical light-diffusing particles 2 is preferably 0.5 to 0.7 parts, such as 0.5 to 0.6 parts; the particle size of the flexible spherical light-diffusing particles 2 is 3 to 8 μm, preferably 5 to 6 μm.

[0047] In the present invention, the auxiliary agent 2 is preferably one or more of a dispersant, a leveling agent, a photopolymerizer, a light stabilizer, a defoamer, a curing agent, a slip agent and an antistatic agent. The dispersant, the leveling agent, the photopolymerizer, the light stabilizer, the defoamer, the curing agent, the slip agent and the antistatic agent are all commonly used dispersants, leveling agents, photopolymerizers, light stabilizers, defoamers, curing agents, slip agents and antistatic agents in the art. Specifically, in an embodiment of the present invention, the dispersant can be an unsaturated polyamine acyl A salt solution of amine and acidic polyester, the leveling agent can be polyether modified dimethyl polysiloxane, the photopolymerizer can be 2-hydroxy-2-methyl-1-phenyl-1-propanone, the light stabilizer can be bis-2,2,6,6-tetramethylpiperidinol sebacate, the defoamer can be modified polysiloxane, the curing agent can be trimer HDI, the slip agent can be stearamide, and the antistatic agent can be sulfonate; in the anti-blocking layer, the weight portion of the auxiliary agent 2 is preferably 0.8 to 0.9 parts.

[0048] The present invention also provides a method for preparing a high-haze, high-brightness diffusion film, comprising the following steps:

[0049] Applying the transmittance adjusting layer coating liquid on one surface of the substrate and drying and curing the coating liquid to obtain the transmittance adjusting layer;

[0050] Applying the light diffusion layer coating liquid on the surface of the transmittance adjustment layer and drying and curing it to obtain a light diffusion layer;

[0051] The anti-blocking layer coating liquid is coated on the other surface of the substrate and dried and solidified to obtain an anti-blocking layer.

[0052] In the present invention, the light diffusion layer coating liquid is prepared by mixing 16 to 18 parts of the resin film-forming material 1, 21.7 to 23.5 parts of the spherical light diffusion particles 1, and 0.5 to 1 part of the auxiliary agent 1 with a solvent. The solvent in the light diffusion layer coating liquid is preferably a mixed solution of butyl acetate and butanone; the weight ratio of the solvent is preferably 59 to 61 parts, and more preferably 59.5 to 60.1 parts.

[0053] In the present invention, the coating process is a conventional process in the art, such as a rod coating method, a micro-concave coating method, a doctor blade coating method, a spray coating method, etc. The light diffusion layer is preferably dried and cured at a temperature of 90 to 110°C, more preferably 95 to 105°C, such as 90°C, 95°C, 100°C, 105°C, 110°C, preferably with any of the above values ​​as the upper or lower limit; the drying and curing time is preferably 8 to 12 minutes, more preferably 10 to 11 minutes.

[0054] In the present invention, the anti-adhesion layer coating liquid is prepared by mixing 13 to 14 parts of the resin film-forming material 2, 0.5 to 0.7 parts of the flexible spherical light-diffusing particles 2 and 0.8 to 0.9 parts of the auxiliary agent 2 described above with a solvent. The solvent in the light-diffusing layer coating liquid is preferably a mixed solution of ethyl acetate, butyl acetate and butanone; the weight proportion of the solvent is preferably 75 to 85 parts, more preferably 80 to 84.8 parts.

[0055] In the present invention, the coating process is a conventional process in the field, such as rod coating, micro-concave coating, doctor blade coating, spray coating and other coating methods. The temperature for drying and curing the anti-adhesion layer is preferably 85-95°C, more preferably 90°C; the drying and curing time is preferably 20-35 minutes, more preferably 25-30 minutes.

[0056] In the present invention, the transmittance adjusting layer coating liquid is prepared by mixing 12 to 13 parts of the resin film-forming material 3, 1.2 to 3.6 parts of the flaky fumed silica polymer, 0.8 to 1.0 parts of the auxiliary agent 3, and a solvent. The solvent in the transmittance adjusting layer coating liquid is preferably a mixed solution of ethyl acetate, butyl acetate, and butanone; the weight proportion of the solvent is preferably 75 to 85 parts, more preferably 80 to 84.1 parts.

[0057] In the present invention, the coating process is a conventional process in the field, such as rod coating, micro-concave coating, doctor blade coating, spray coating and other coating methods. The temperature for drying and curing the anti-adhesion layer is preferably 110-125°C, more preferably 115-120°C; the drying and curing time is preferably 8-12 minutes, more preferably 9-10 minutes.

[0058] In the present invention, the coating order of the light diffusion layer, the anti-adhesion layer and the transmittance adjustment layer is not particularly limited. Figure 1 The structure shown is sufficient.

[0059] The present invention also provides a backlight module, comprising the high-haze, high-brightness diffusion film described above.

[0060] The present invention provides a high-haze, high-brightness diffusion film, comprising a substrate, a light diffusion layer, an anti-adhesion layer, and a transmittance adjustment layer. The transmittance adjustment layer uses flaky fumed silica polymer particles having a convex lens structure to adjust the transmittance of the diffusion film; the flaky fumed silica polymer particles have a particle size of 0.2 to 1.7 μm and a refractive index of 1.84. The present invention provides a transmittance adjustment layer structure and uses flaky fumed silica polymer particles having a convex lens structure in the transmittance adjustment layer. The special morphology of the convex lenses can achieve the principle of focusing light, thereby increasing the transmittance of all light. The transmittance adjustment layer can effectively improve and control the transmittance of the optical diffuser film without affecting the haze and covering properties of the optical diffuser film, thereby significantly improving the brightness of the backlight film assembly while maintaining good covering properties.

[0061] To further illustrate the present invention, a high-haze, high-brightness diffusion film, a preparation method thereof, and a backlight module provided by the present invention are described in detail below in conjunction with embodiments, but this should not be construed as limiting the scope of protection of the present invention.

[0062] Example 1

[0063] Table 1 Composition of the transmittance adjustment layer coating solution of Example 1

[0064]

[0065]

[0066] Table 2 Composition of the light diffusion layer coating solution of Example 1

[0067]

[0068] Table 3 Composition of the anti-adhesion coating solution of Example 1

[0069]

[0070] According to the material list in Table 1, a transmittance regulating layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance regulating layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0071] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0072] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0073] Example 2

[0074] Table 4 Composition of the transmittance adjustment layer coating solution of Example 2

[0075]

[0076] According to the material list in Table 4, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0077] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0078] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0079] Example 3

[0080] Table 5 Composition of the transmittance adjustment layer in Example 3

[0081]

[0082] According to the material list in Table 5, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0083] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0084] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0085] Example 4

[0086] Table 6 Composition of the transmittance adjustment layer of Example 4

[0087]

[0088] According to the material list in Table 6, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0089] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0090] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0091] Example 5

[0092] Table 7 Composition of the transmittance adjustment layer of Example 5

[0093]

[0094] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0095] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0096] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0097] Example 6

[0098] Table 8 Composition of the transmittance adjustment layer of Example 6

[0099]

[0100] According to the material list in Table 8, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 2 μm was obtained. This material was set aside.

[0101] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0102] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0103] Example 7

[0104] Table 9 Composition of the transmittance adjustment layer of Example 7

[0105]

[0106]

[0107] According to the material list in Table 9, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 2 μm was obtained. This material was set aside.

[0108] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0109] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0110] Example 8

[0111] Table 10 Composition of the transmittance adjustment layer of Example 8

[0112]

[0113] According to the material list in Table 10, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 2 μm was obtained. This material was set aside.

[0114] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0115] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0116] Example 9

[0117] Table 11 Composition of the transmittance adjustment layer of Example 9

[0118]

[0119] According to the material list in Table 11, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 2 μm was obtained. This material was set aside.

[0120] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0121] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0122] Example 10

[0123] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 25 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0124] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0125] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 25 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0126] Example 11

[0127] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 75 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0128] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0129] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 75 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of its light transmittance, haze, and brightness are shown in Table 17.

[0130] Example 12

[0131] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 250 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0132] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 9 μm light diffusion layer.

[0133] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 250 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0134] Example 13

[0135] Table 12 Composition of the light diffusion layer coating solution of Example 13

[0136]

[0137] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0138] According to the material list in Table 12, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 4 μm light diffusion layer.

[0139] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0140] Example 14

[0141] Table 13 Composition of the light diffusion layer coating solution of Example 14

[0142]

[0143] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0144] According to the material list in Table 13, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a 10 μm light diffusion layer.

[0145] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0146] Example 15

[0147] Table 14 Composition of the anti-blocking layer coating solution of Example 15

[0148]

[0149]

[0150] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0151] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0152] According to the material list in Table 14, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 3 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0153] Example 16

[0154] Table 15 Composition of the anti-blocking layer coating solution of Example 16

[0155]

[0156] According to the material list in Table 7, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0157] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0158] According to the material list in Table 15, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 8 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0159] Comparative Example 1

[0160] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 38 μm PET, and heated and cured to obtain an 8 μm light diffusion layer.

[0161] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0162] Comparative Example 2

[0163] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 25 μm PET, and heated and cured to obtain a 9 μm light diffusion layer.

[0164] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 25 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0165] Comparative Example 3

[0166] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 75 μm PET, and heated and cured to obtain an 8 μm light diffusion layer.

[0167] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 75 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0168] Comparative Example 4

[0169] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 250 μm PET, and heated and cured to obtain a 9 μm light diffusion layer.

[0170] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 250 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0171] Comparative Example 5

[0172] According to the material list in Table 12, a light diffusion layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of a 38 μm transparent PET film and heated to cure to obtain a light diffusion layer with a thickness of 4 μm;

[0173] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of a 38 μm thick transparent PET film and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0174] Comparative Example 6

[0175] According to the material list in Table 13, a light diffusion layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of a 38 μm transparent PET film and heated to cure to obtain a light diffusion layer with a thickness of 10 μm;

[0176] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of a 38 μm thick transparent PET film and heated to cure to obtain an anti-blocking layer with a thickness of 6 μm. The test results of its light transmittance, haze, and brightness are shown in Table 17.

[0177] Comparative Example 7

[0178] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 38 μm PET, and heated and cured to obtain an 8 μm light diffusion layer.

[0179] According to the material list in Table 14, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 3 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0180] Comparative Example 8

[0181] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of 38 μm PET, and heated and cured to obtain a 9 μm light diffusion layer.

[0182] According to the material list in Table 15, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 8 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0183] Comparative Example 9

[0184] Table 16 Composition of the transmittance adjustment layer in Comparative Example 9

[0185]

[0186]

[0187] According to the material list in Table 16, a transmittance adjusting layer coating liquid was obtained by stirring, and the coating liquid was applied to the upper surface of 38 μm PET. After heating and curing, a transmittance adjusting layer with a coating thickness of 1 μm was obtained. This material was set aside.

[0188] According to the material list in Table 2, a light diffusion layer coating liquid was obtained by stirring, and the light diffusion layer coating liquid was applied to the upper surface of the transmittance adjustment layer, and heated and cured to obtain a light diffusion layer of 8 μm.

[0189] According to the material list in Table 3, an anti-blocking coating liquid was obtained by stirring. The anti-blocking coating liquid was applied to the lower surface of 38 μm thick PET and heated to cure to obtain an anti-blocking layer with a thickness of 5 μm. The test results of light transmittance, haze, and brightness are shown in Table 17.

[0190] Five samples of each of Examples 1 to 16 and Comparative Examples 1 to 9 were prepared, and their transmittance and haze were tested using a transmittance and haze instrument. The brightness of the backlight module was tested using a BM-7 brightness tester (15.6-inch backlight, the module composition was reflective film + LGP + diffusion film (sample) + brightness enhancement film + brightness enhancement film, and the brightness was tested at 9 points. The test equipment was BM-7. The test standard complied with the international information display measurement standard)). The average value was taken, and the results are shown in Table 17.

[0191] Table 17 Performance of the diffusion membranes in the examples and comparative examples

[0192]

[0193]

[0194] Note: “Brightness increase” refers to the increase in the module brightness of the diffusion film in other embodiments or comparative examples relative to the module brightness of the diffusion film in comparative example 1, based on the module brightness of the diffusion film in comparative example 1.

[0195] As can be seen from Table 17, (1) the addition of the transmittance regulating layer can effectively control the transmittance of the finished diffusion film without changing the haze of the finished diffusion film; (2) as the content of the transmittance regulating substance in the transmittance regulating layer continues to increase, the transmittance of the finished diffusion film first increases and then decreases. When the amount of the transmittance regulating substance added is 2.4%, the transmittance of the diffusion film reaches a peak. As the content increases, the transmittance of the finished product decreases and seriously affects the brightness of the module. (3) When the content of the transmittance regulating substance in the transmittance regulating layer is 2.4%, the overall brightness of the backlight module can be increased by 15.13%. (4) The brightness of the light-transmitting film with the addition of convex lens-shaped vapor-phase silica (Example 5) is 20.3% higher than that of the light-transmitting film with the addition of ordinary flake vapor-phase silica (Comparative Example 9). The brightness of the light-transmitting film with the addition of ordinary flake vapor-phase silica (Comparative Example 9) is 4.3% lower than that of the ordinary diffusion film without the transmittance regulating layer (Comparative Example 1).

[0196] The present invention can effectively adjust the transmittance of the diffusion film without changing the haze of the finished diffusion film by adding a transmittance adjustment layer. With a suitable addition amount, the overall brightness of the backlight module can be improved, the utilization rate of the light source can be improved, and the use of lamp beads in the backlight module can be reduced, thereby achieving the effect of energy saving and carbon reduction.

[0197] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A high haze, high brightness diffusion film, characterized in that: The light-transmitting film comprises a substrate, a light-diffusing layer disposed on one side of the substrate, an anti-adhesion layer disposed on the other side of the substrate, and a light-transmittance adjusting layer disposed between the light-diffusing layer and the substrate, wherein the light-transmittance adjusting layer uses flake-shaped fumed silica polymer particles having a convex lens structure to adjust the light transmittance of the diffusion film; The light diffusion layer comprises, by weight, 16 to 18 parts of a resin film-forming material, 21.7 to 23.5 parts of spherical light diffusion particles, and 0.5 to 1 part of an additive; the thickness of the light diffusion layer is 4 to 10 μm; the refractive index of the resin film-forming material is 1.4 to 1.6; and the particle size of the spherical light diffusion particles is 3 to 10 μm. In parts by weight, the transmittance adjusting layer includes 12 to 13 parts of a resin film-forming material, 1.2 to 3.6 parts of a flaky fumed silica polymer, and 0.8 to 1.0 parts of an auxiliary agent; the thickness of the transmittance adjusting layer is 1 to 2 μm; the refractive index of the resin film-forming material is 1.67, and the particle size of the flaky fumed silica polymer particles is 0.2 to 1.7 μm, and the refractive index is 1.

84.

2. The diffusion film according to claim 1, characterized in that The resin film-forming material is one or more of acrylic resin, polyurethane resin, propylene polyol resin and epoxy resin; The spherical light diffusion particles are one or more of polymethyl methacrylate, polybutyl methacrylate, polypropylene, polyethylene, polyamide, polystyrene and titanium dioxide; The auxiliary agent is one or more of a dispersant, a leveling agent, a photopolymerization agent, a light stabilizer, a defoaming agent, a curing agent, a lubricant and an antistatic agent.

3. The diffusion film according to claim 1, characterized in that In parts by weight, the anti-adhesion layer comprises 13 to 14 parts of a resin film-forming material, 0.5 to 0.7 parts of flexible spherical light-diffusing particles, and 0.8 to 0.9 parts of an auxiliary agent; The resin film-forming material is one or more of acrylic resin, polyurethane resin, propylene polyol resin and epoxy resin; The flexible spherical light diffusion particles are one or more of polybutyl methacrylate, polypropylene, polyethylene, polyamide and polystyrene; The auxiliary agent is one or more of a dispersant, a leveling agent, a photopolymerization agent, a light stabilizer, a defoaming agent, a curing agent, a lubricant and an antistatic agent.

4. The diffusion film according to claim 3, characterized in that The thickness of the anti-adhesion layer is 4 to 8 μm, the refractive index of the resin film-forming material is 1.4 to 1.6; and the particle size of the flexible spherical light diffusion particles is 3 to 8 μm.

5. The diffusion film according to claim 1, characterized in that The resin film-forming material is acrylic resin and / or polyurethane resin; The auxiliary agent is one or more of a dispersant, a leveling agent, a curing agent, a slip agent, an antistatic agent and a defoaming agent.

6. The method for preparing a high-haze, high-brightness diffusion film according to any one of claims 1 to 5, comprising the following steps: Applying the transmittance adjusting layer coating liquid on one surface of the substrate and drying and curing the coating liquid to obtain the transmittance adjusting layer; Applying the light diffusion layer coating liquid on the surface of the transmittance adjustment layer and drying and curing it to obtain a light diffusion layer; The anti-blocking layer coating liquid is coated on the other surface of the substrate and dried and solidified to obtain an anti-blocking layer.

7. A backlight module comprising the high-haze, high-brightness diffusion film according to any one of claims 1 to 5.

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