Lightweight integrated diaphragm plate with open pore structure as well as preparation method and application of lightweight integrated diaphragm plate

Abstract

The invention provides a lightweight integrated diaphragm plate with an open pore structure as well as a preparation method and application of the lightweight integrated diaphragm plate, and relates to the technical field of optical display. According to the light-weight integrated diaphragm plate with the open pore structure, an integrated structure formed by sequentially stacking the upper composite optical film layer, the middle attaching glue layer and the lower open pore foaming layer from top to bottom is constructed, and multi-layer integration is achieved through the attaching technology. According to the integrated diaphragm plate, the complex process of step-by-step mounting of the optical film and the diffusion plate in a traditional backlight module is effectively simplified; meanwhile, the lower open-cell foaming layer is a composite system comprising a supporting layer, an upper foaming layer, a transition layer, a lower foaming layer and an atomization layer, the upper foaming layer and the lower foaming layer jointly form a double-layer gradient open-cell structure, the Airgap-like optical effect is achieved, absorption and scattering loss of light in the transmission process is greatly reduced, and the transmission efficiency is improved. Therefore, the problem of brightness reduction caused by integrated attachment is effectively relieved. In addition, due to the high porosity of the open-cell foaming layer, the weight of the plate is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical display technology, in particular to a light-weighted integrated film plate with a perforated structure and a preparation method and application thereof. BACKGROUND

[0002] In the field of optical display, optical film and optical diffusion plate are both core components of the backlight module of liquid crystal display, and they work together. Among them: the optical film is mainly responsible for improving light efficiency and controlling light path, and through the regulation of light reflection, transmission, polarization and other characteristics, the brightness, energy efficiency and visual effect of the display are improved; the optical diffusion plate is focused on converting point or line light source into uniform surface light source to ensure display brightness consistency and visual softness, and the light-weighted advantage of foamed light diffusion plate is particularly prominent compared with ordinary diffusion plate. Therefore, the optical film and light diffusion plate together ensure the display brightness, uniformity and visual comfort.

[0003] In the existing backlight module of liquid crystal display, the optical film and the optical diffusion plate are two independent core components, which usually need to be produced separately and then assembled. However, compared with the pre-assembled structure, the post-assembled structure of the split type will reduce the brightness of the film plate to different degrees, and the highest loss of brightness can reach nearly 50%.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The first object of the present application is to provide a light-weighted integrated film plate with a perforated structure, which realizes functional gradient distribution while ensuring structural strength, and enhances the overall mechanical stability and optical uniformity.

[0006] The second object of the present application is to provide a preparation method of a light-weighted integrated film plate with a perforated structure.

[0007] The third object of the present application is to provide an application of a light-weighted integrated film plate with a perforated structure.

[0008] In order to achieve the above objects of the present application, the following technical solutions are adopted: The light-weighted integrated film plate with a perforated structure provided by the present application comprises an upper composite optical film layer, a middle adhesive layer and a lower perforated foamed layer which are sequentially stacked from top to bottom. The upper composite optical film layer, the middle adhesive layer and the lower perforated foamed layer are integrally formed by co-extrusion and online bonding process, wherein: The lower perforated foamed layer comprises a support layer, an upper foamed layer, a transition layer, a lower foamed layer and an atomization layer which are sequentially arranged from top to bottom. The upper foamed layer is a perforated structure with a perforation rate not less than 80%; and the lower foamed layer is a perforated or closed structure.

[0009] Further, the upper composite optical film layer is a composite structure. Preferably, the upper composite optical film layer comprises a diffusion-prism composite film, a prism-prism composite film, a microlens-prism composite film, a prism-microlens composite film, and a reflective polarizing brightness enhancement film. And / or, the middle adhesive layer is mainly formed by UV curing adhesive. Preferably, the refractive index of the UV curing adhesive is 1.45-1.65, and the viscosity is 100-500 pcs. And / or, the thickness of the upper composite optical film layer is 100-500 μm, the thickness of the middle adhesive layer is 0.5-20 μm, and the total thickness of the lower open-cell foam layer is 0.8-3.0 mm. And / or, the thickness of the support layer in the lower open-cell foam layer is 0.1-0.3 mm, the thickness of the upper foam layer is 0.2-0.5 mm, the thickness of the transition layer is 0.1-0.4 mm, the thickness of the lower foam layer is 0.4-0.7 mm, and the thickness of the atomization layer is 0.2-1.2 mm.

[0010] And / or, the structure of the support layer in the lower open-cell foam layer is a structure of a solid of revolution, a pyramid structure, a pyramid structure, a prism structure, and other polyhedral geometric structures. The distance between adjacent microstructures is between 10-1000 μm.

[0011] Further, the base resin used in the support layer, the transition layer, the atomization layer, the upper foam layer, and the lower foam layer in the lower open-cell foam layer is selected from any one of polystyrene, polymethyl methacrylate, or polycarbonate.

[0012] Further, the raw materials of the support layer include, by weight: base resin 80.0-90.0 parts, toughening agent 1.0-5.0 parts, antioxidant 1.0-3.0 parts, ultraviolet absorber 1.0-2.0 parts, and compatibilizer 3.0-8.0 parts. And / or, the raw materials of the atomization layer include, by weight: base resin 80.0-90.0 parts, light diffuser 0.5-2.0 parts, antioxidant 1.0-3.0 parts, ultraviolet absorber 1.0-2.0 parts, and toughening agent 1.0-5.0 parts.

[0013] Further, the raw materials of the upper foam layer include, by weight: Base resin 60.0~80.0 parts, dispersed phase 10.0~40.0 parts, physical foaming agent 5.0~15.0 parts, penetration modifier 0.05~1.5 parts, physical foaming agent affinity additive 1.0~5.0 parts, toughening agent 1.0~5.0 parts, antioxidant 1.0~3.0 parts, ultraviolet absorber 1.0~2.0 parts, compatibilizer 1.0~5.0 parts; Preferably, the dispersed phase includes at least one of PPO (polyphenylene oxide), POE (polyolefin elastomer), PP (polypropylene), PPG (polypropylene glycol), and PET (polyethylene terephthalate).

[0014] Further, the raw material of the lower foaming layer includes, by weight parts: Base resin 60.0~80.0 parts, dispersed phase 10.0~40.0 parts, foaming agent: 1.0~10.0 parts, toughening agent: 1.0~5.0 parts, antioxidant: 1.0~3.0 parts, ultraviolet absorber: 1.0~2.0 parts, compatibilizer: 1.0~5.0 parts, penetration modifier: 0.05~1.5 parts, physical foaming agent affinity additive: 1.0~5.0 parts.

[0015] The application provides a preparation method of the light-weight integrated film plate, which comprises the following steps: (a) high-speed mixing raw materials of a support layer, an upper foaming layer, a transition layer, a lower foaming layer, and an atomization layer to obtain pre-mixed materials of the layers; (b) performing co-extrusion foaming molding of the pre-mixed materials of the layers under a set temperature and pressure condition through a multi-layer co-extrusion device to obtain an open-cell foaming plate with a five-layer structure; (c) coating a UV curing adhesive on an upper surface of the open-cell foaming plate and introducing an upper composite optical film layer in real time for compression bonding and attachment; (d) cutting to obtain an integrated film plate finished product after UV light irradiation and curing.

[0016] Further, process parameters in the co-extrusion process of the step (b) are as follows: The temperature of the feeding section is 150~180℃, the temperature of the plasticizing section is 180~200℃, the temperature of the melting section is 200~220℃, and the temperature of the die head area is 210~240℃; The screw rotation speed is 20~45 r / min, the die head pressure is 20~30 MPa, the supercritical fluid injection pressure is 10~25 MPa, and the flow rate is 10~15 ml / min.

[0017] Further, the coating thickness of the UV curing adhesive in the step (d) is controlled to be 0.5~20μm, and the UV curing energy is 300~600 MJ / m².

[0018] The application provides application of the light-weight integrated film plate in preparation of a liquid crystal display, a Mini LED backlight module or a vehicle-mounted display device.

[0019] Compared with the prior art, the application has the following beneficial effects: The light-weight integrated film plate with the open hole structure provided by the application effectively simplifies the complex process of step-by-step mounting of optical films and diffusion plates in a traditional backlight module, significantly improves production efficiency, and reduces assembly errors and manufacturing costs. The lower open hole foaming layer is a composite system including a support layer, an upper foaming layer, a transition layer, a lower foaming layer and an atomization layer, which realizes functional gradient distribution while ensuring structural strength, and enhances overall mechanical stability and optical uniformity.

[0020] It should be particularly noted that the upper foaming layer and the lower foaming layer together constitute a double-layer gradient open hole structure, wherein: the upper foaming layer is an open hole structure (the open hole rate is not less than 80%), the lower foaming layer is an open hole or closed hole structure, the open hole rate of the upper foaming layer is higher than that of the lower foaming layer, and the upper foaming layer is used for forming an air channel network from top to bottom to realize an Airgap-like optical effect, greatly reducing the absorption and scattering loss of light in the transmission process, thereby effectively alleviating the problem of brightness reduction caused by integrated mounting, and the actual measured brightness is significantly better than that of a conventional mounting structure; at the same time, the high porosity of the lower open hole foaming layer greatly reduces the weight of the plate material, so that the overall density can be as low as 0.4~0.7g / cm³ order of magnitude, and the light-weight and high-transparency advantages are combined.

[0021] The preparation method of the light-weight integrated film plate provided by the application combines multi-layer co-extrusion foaming molding and UV mounting process organically, realizes integrated manufacturing of the light-weight integrated film plate, simplifies the complex process of step-by-step production and mounting of traditional optical films and diffusion plates, reduces production cost and assembly error, and improves product consistency and large-scale production capacity.

[0022] The light-weight integrated film plate provided by the application can be widely applied to the preparation process of a liquid crystal display, a Mini LED backlight module or a vehicle-mounted display device. DETAILED DESCRIPTION

[0023] The technical solutions of the application will be described clearly and completely in combination with the embodiments. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0024] According to one aspect of the present application, a lightweight integrated film plate of an open-cell structure comprises an upper composite optical film layer, a middle adhesive glue layer and a lower open-cell foaming layer stacked in sequence from top to bottom. The upper composite optical film layer, the middle adhesive glue layer and the lower open-cell foaming layer are integrally formed by a co-extrusion and in-line bonding process, wherein: the lower open-cell foaming layer comprises a support layer, an upper foaming layer, a transition layer, a lower foaming layer and an atomization layer stacked in sequence from top to bottom; the upper foaming layer is of an open-cell structure with an open-cell rate not less than 80%; and the lower foaming layer is of an open-cell or closed-cell structure.

[0025] The lightweight integrated film plate of an open-cell structure provided by the present application effectively simplifies the complex process of step-by-step bonding of optical films and diffusion plates in a conventional backlight module, significantly improves production efficiency, and reduces assembly errors and manufacturing costs by constructing an integrated structure of an upper composite optical film layer, a middle adhesive glue layer and a lower open-cell foaming layer stacked in sequence from top to bottom, and using a bonding process to realize multi-layer integration. The lower open-cell foaming layer is a composite system comprising a support layer, an upper foaming layer, a transition layer, a lower foaming layer and an atomization layer, which realizes functional gradient distribution while ensuring structural strength, and enhances overall mechanical stability and optical uniformity.

[0026] It is particularly noted that the upper foaming layer and the lower foaming layer of the present application together constitute a double-layer gradient open-cell structure, wherein: the upper foaming layer is of an open-cell structure (with an open-cell rate not less than 80%), and the lower foaming layer is of an open-cell or closed-cell structure, the open-cell rate of the upper foaming layer being higher than that of the lower foaming layer, for forming an air channel network from top to bottom and realizing an Airgap-like optical effect, which greatly reduces the absorption and scattering loss of light in the transmission process, thereby effectively alleviating the problem of brightness reduction caused by integrated bonding, and the actual brightness is significantly better than that of a conventional bonding structure; at the same time, the high porosity of the lower open-cell foaming layer greatly reduces the weight of the plate, so that the overall density can be as low as 0.4~0.7g / cm³ order of magnitude, combining the advantages of lightweight and high light transmission.

[0027] It is noted that when the lower foaming layer is of an open-cell structure, the open-cell rate is not less than 40%, and the open-cell rate of the upper foaming layer is higher than that of the lower foaming layer.

[0028] In a preferred embodiment of the present application, the upper composite optical film layer is of a composite structure. Preferably, the upper composite optical film layer comprises a diffusion-prism composite film, a prism-prism composite film, a microlens-prism composite film, a prism-microlens composite film and a reflective polarized brightness enhancement film. In a preferred embodiment of the present application, the middle adhesive glue layer is mainly formed of UV curing glue. As an optional embodiment, the refractive index of the UV curing adhesive is 1.45-1.65, for example, it can be 1.45, 1.53, 1.58, 1.63, 1.65, or any value between 1.45 and 1.65; the viscosity is 100-500 pcs, for example, it can be 100 pcs, 200 pcs, 300 pcs, 400 pcs, 500 pcs, or any value between 100 and 500 pcs.

[0029] In a preferred embodiment of the present application, the thickness of the upper composite optical film layer is 100-500 μm, the thickness of the middle adhesive layer is 0.5-20 μm, and the total thickness of the lower open-cell foam layer is 0.8-3.0 mm.

[0030] As an optional embodiment, the thickness of the upper composite optical film layer is 100-500 μm, for example, it can be 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or any value between 100 and 500 μm; the thickness of the middle adhesive layer is 0.5-20 μm, for example, it can be 0.5 μm, 5 μm, 10 μm, 15 μm, 20 μm, or any value between 0.5 and 20 μm; the total thickness of the lower open-cell foam layer is 1.0-3.0 mm, for example, it can be 0.8 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, or any value between 1.0 and 3.0 mm.

[0031] In a preferred embodiment of the present application, the thickness of the support layer in the lower open-cell foam layer is 0.1-0.3 mm, the thickness of the upper foam layer is 0.2-0.5 mm, the thickness of the transition layer is 0.1-0.4 mm, the thickness of the lower foam layer is 0.4-0.7 mm, and the thickness of the atomization layer is 0.2-1.2 mm.

[0032] In a preferred embodiment of the present application, the structure of the support layer in the lower open-cell foam layer is a structure of a solid of revolution, a pyramid structure, a pyramid structure, a prism structure, and other polyhedral geometric structures. The distance between adjacent microstructures is between 10 and 1000 μm.

[0033] In a preferred embodiment of the present application, the base resin used in the support layer, the transition layer, the atomization layer, the upper foam layer, and the lower foam layer of the lower open-cell foam layer is selected from any one of polystyrene, polymethyl methacrylate, or polycarbonate.

[0034] As a preferred embodiment, the average molecular weight of the base resin of the support layer, the transition layer, and the atomization layer of the open-cell foam layer is controlled to be 2 x 105 5x10 6 g / mol, and a polydispersity of 1-3; the matrix resin of the upper and lower foaming layers is controlled to have a mass average molecular weight of 2x10 4 1x10 5 g / mol, and a polydispersity of 1-5; and the difference in melt flow rate of the two is greater than 5 g / 10 min.

[0035] It should be noted that the support layer, transition layer and atomization layer described above use a resin with a high molecular weight (2x10 5 5x10 6 g / mol), a narrow distribution (PDI = 1-3), which gives it high melt strength, effectively inhibiting the excessive rupture and collapse of the cells during foaming, and ensuring the integrity of the surface layer structure and the ability to resist warping; while the upper and lower foaming layers are selected to have a lower molecular weight (2x10 4 1x10 5 g / mol), a wider distribution (PDI = 1-5), which is conducive to reducing the melt viscosity, promoting cell nucleation and expansion, and forming a uniform cell structure with high open porosity; at the same time, the difference in melt flow rate of the two is greater than 5 g / 10 min, forming a moderate rheological mismatch at the co-extrusion interface, which helps to induce micro-phase separation and optimize stress transfer, further promoting the formation and stability of the open cell structure, thereby significantly improving the light transmittance and lightweight level while ensuring the mechanical strength.

[0036] In a preferred embodiment of the present application, the raw material of the support layer includes, by weight: 80.0-90.0 parts of a matrix resin, 1.0-5.0 parts of a toughening agent, 1.0-3.0 parts of an antioxidant, 1.0-2.0 parts of an ultraviolet absorber, and 3.0-8.0 parts of a compatibilizer. As an optional embodiment, the raw material of the support layer comprises, by weight parts: 80.0-90.0 parts of base resin, for example, it can be 80.0, 81.0, 82.0, 83.0, 84.0, 85.0, 86.0, 87.0, 88.0, 89.0, 90.0, or any value between 80.0 and 90.0; 1.0-5.0 parts of toughening agent, for example, it can be 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, or any value between 1.0 and 5.0; 1.0-3.0 parts of antioxidant, for example, it can be 1.0, 1.5, 2.0, 2.5, 3.0, or any value between 1.0 and 3.0; 1.0-2.0 parts of ultraviolet absorber, for example, it can be 1.0, 1.2, 1.5, 1.8, 2.0, or any value between 1.0 and 2.0; 3.0-8.0 parts of compatibilizer, for example, it can be 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, or any value between 3.0 and 8.0.

[0037] In a preferred embodiment of the present application, the transition layer is composed of a mixture of base resin and toughening agent. Preferably, the transition layer is composed of base resin and toughening agent in a weight ratio of 95:5-85:15, preferably, the content of toughening agent is 5.0-15.0 parts, and the rest is the same as the support layer or the upper foaming layer.

[0038] In a preferred embodiment of the present application, the raw material of the atomization layer comprises, by weight parts: 80.0-90.0 parts of base resin, 0.5-2.0 parts of light diffusing agent, 1.0-3.0 parts of antioxidant, 1.0-2.0 parts of ultraviolet absorber, and 1.0-5.0 parts of toughening agent.

[0039] As an optional embodiment, the raw material of the atomized layer includes, in parts by weight: 80.0-90.0 parts of base resin, for example, 80.0, 81.0, 82.0, 83.0, 84.0, 85.0, 86.0, 87.0, 88.0, 89.0, 90.0 parts, or any value between 80.0 and 90.0; 0.5-2.0 parts of light diffuser, for example, 0.5, 0.6, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0 parts, or any value between 0.5 and 2.0; 1.0-3.0 parts of antioxidant, for example, 1.0, 1.5, 2.0, 2.5, 3.0 parts, or any value between 1.0 and 3.0; 1.0-2.0 parts of ultraviolet absorber, for example, 1.0, 1.2, 1.5, 1.8, 2.0 parts, or any value between 1.0 and 2.0; 1.0-5.0 parts of toughening agent, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0.

[0040] In a preferred embodiment of the present application, the raw material of the upper foaming layer includes, in parts by weight: 60.0-80.0 parts of base resin, 10.0-40.0 parts of dispersed phase, 5.0-15.0 parts of physical foaming agent, 0.05-1.5 parts of permeability modifier, 1.0-5.0 parts of physical foaming agent affinity additive, 1.0-5.0 parts of toughening agent, 1.0-3.0 parts of antioxidant, 1.0-2.0 parts of ultraviolet absorber, 1.0-5.0 parts of compatibility agent; As an optional embodiment, the raw material of the upper foaming layer includes, in parts by weight, 60.0-80.0 parts of base resin, for example, 60.0, 62.0, 65.0, 68.0, 70.0, 72.0, 75.0, 78.0, 80.0 parts, or any value between 60.0 and 80.0; 10.0-40.0 parts of dispersed phase, for example, 10.0, 15.0, 20.0, 25.0, 30.0, 35.0, 40.0 parts, or any value between 10.0 and 40.0; 5.0-15.0 parts of physical foaming agent, for example, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0 parts, or any value between 5.0 and 15.0; 0.05-1.5 parts of penetration modifier, for example, 0.05, 0.1, 0.2, 0.5, 0.8, 1.0, 1.2, 1.5 parts, or any value between 0.05 and 1.5; 1.0-5.0 parts of physical foaming agent affinity additive, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0; 1.0-5.0 parts of toughening agent, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0; 1.0-3.0 parts of antioxidant, for example, 1.0, 1.5, 2.0, 2.5, 3.0 parts, or any value between 1.0 and 3.0; 1.0-2.0 parts of ultraviolet absorber, for example, 1.0, 1.2, 1.5, 1.8, 2.0 parts, or any value between 1.0 and 2.0; and 1.0-5.0 parts of compatibilizer, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0.

[0041] In the above preferred embodiment, the dispersed phase includes at least one of polyphenylene oxide (PPO), polyolefin elastomer (POE), polypropylene (PP), polypropylene glycol (PPG), and polyethylene terephthalate (PET).

[0042] In the above preferred embodiment, the physical foaming agent is at least one of supercritical carbon dioxide, supercritical nitrogen, water, or ethanol. Preferably, when supercritical carbon dioxide is used, the added amount is 5.0-15.0 parts; when supercritical nitrogen is used, the added amount is 1.0-5.0 parts. In the preferred embodiment described above, the penetration modifier is at least one of isopropyl myristate IPM, isopropyl palmitate IPP, dimethyl phthalate DMP, oleic acid or a short-chain alcohol; In the preferred embodiment described above, the physical foaming agent affinity additive is at least one of polytetrafluoroethylene PTFE, polydimethylsiloxane PDMS or azodicarbonamide AC.

[0043] In a preferred embodiment of the present application, the raw material of the lower foaming layer comprises, by weight fraction: base resin 60.0-80.0 parts, dispersed phase 10.0-40.0 parts, foaming agent 1.0-10.0 parts, toughening agent 1.0-5.0 parts, antioxidant 1.0-3.0 parts, ultraviolet absorber 1.0-2.0 parts, compatibility agent 1.0-5.0 parts, penetration modifier 0.05-1.5 parts, and physical foaming agent affinity additive 1.0-5.0 parts.

[0044] As an optional embodiment, the raw material of the lower foaming layer comprises, by weight fraction: 60.0-80.0 parts of base resin, for example, 60.0, 62.0, 65.0, 68.0, 70.0, 72.0, 75.0, 78.0, 80.0 parts, or any value between 60.0 and 80.0; 10.0-40.0 parts of dispersed phase, for example, 10.0, 15.0, 20.0, 25.0, 30.0, 35.0, 40.0 parts, or any value between 10.0 and 40.0; 1.0-10.0 parts of foaming agent, for example, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 parts, or any value between 1.0 and 10.0; 1.0-5.0 parts of toughening agent, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0; 1.0-3.0 parts of antioxidant, for example, 1.0, 1.5, 2.0, 2.5, 3.0 parts, or any value between 1.0 and 3.0; 1.0-2.0 parts of ultraviolet absorber, for example, 1.0, 1.2, 1.5, 1.8, 2.0 parts, or any value between 1.0 and 2.0; 1.0-5.0 parts of compatibilizer, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0; 0.05-1.5 parts of permeation modifier, for example, 0.05, 0.1, 0.2, 0.5, 0.8, 1.0, 1.2, 1.5 parts, or any value between 0.05 and 1.5; 1.0-5.0 parts of physical foaming agent affinity additive, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts, or any value between 1.0 and 5.0.

[0045] In the above preferred embodiment, the foaming agent of the lower foaming layer is at least one of a physical foaming agent or a chemical foaming agent; Preferably, the chemical foaming agent is at least one of an endothermic type or an exothermic type, wherein: the endothermic type comprises at least one of citric acid, sodium bicarbonate, sodium carbonate; the exothermic type comprises at least one of azodicarbonamide, p-toluene sulfonyl urea, benzene sulfonyl hydrazide, foaming agent H.

[0046] According to an aspect of the present application, a method for preparing the above-mentioned lightweight integrated film plate, comprising the following steps: (a) high-speed mixing the raw materials of the support layer, the upper foaming layer, the transition layer, the lower foaming layer, and the atomization layer respectively to obtain the pre-mixed materials of each layer; (b) the each layer of the premix is co-extruded and foamed by a multi-layer co-extrusion equipment under the condition of set temperature and pressure to obtain an open-cell foamed plate with five layers of structure; (c) a UV curing adhesive is coated on the upper surface of the open-cell foamed plate, and an upper composite optical film layer is introduced in real time for compression bonding; (d) after UV light curing, the integrated film plate product is cut.

[0047] The preparation method of the light-weight integrated film plate provided by the application realizes the integrated manufacturing of the light-weight integrated film plate by combining the multi-layer co-extrusion foaming and the UV bonding process, simplifies the complex process of the traditional optical film and the diffusion plate produced in steps and then bonded, reduces the production cost and assembly error, and improves the product consistency and large-scale production capacity.

[0048] In a preferred embodiment of the application, the process parameters in the co-extrusion process of step (b) are as follows: the feeding section temperature is 150-180℃, the plasticizing section temperature is 180-200℃, the melting section temperature is 200-220℃, and the die zone temperature is 210-240℃. As an optional embodiment, the process parameters in the co-extrusion process of step (b) are as follows: the feeding section temperature is 150-180℃, for example, it can be 150℃, 160℃, 170℃, 180℃, or any value between 150-180℃; the plasticizing section temperature is 180-200℃, for example, it can be 180℃, 185℃, 190℃, 195℃, 200℃, or any value between 180-200℃; the melting section temperature is 200-220℃, for example, it can be 200℃, 205℃, 210℃, 215℃, 220℃, or any value between 200-220℃; and the die zone temperature is 210-240℃, for example, it can be 210℃, 220℃, 230℃, 240℃, or any value between 210-240℃.

[0049] In a preferred embodiment of the application, the screw rotation speed is 20-45 r / min, the die pressure is 20-30 MPa, the supercritical fluid injection pressure is 10-25 MPa, and the flow rate is 10-15 ml / min.

[0050] As an optional embodiment, the screw rotation speed is 20-45 r / min, for example, it can be 20 r / min, 25 r / min, 30 r / min, 35 r / min, 40 r / min, 45 r / min, or any value within the range of 20-45 r / min; the die pressure is 20-30 MPa, for example, it can be 20 MPa, 22 MPa, 25 MPa, 28 MPa, 30 MPa, or any value within the range of 20-30 MPa; the supercritical fluid injection pressure is 10-25 MPa, for example, it can be 10 MPa, 12 MPa, 15 MPa, 20 MPa, 25 MPa, or any value within the range of 10-25 MPa; and the flow rate is 10-15 ml / min, for example, it can be 10 ml / min, 11 ml / min, 12 ml / min, 13 ml / min, 14 ml / min, 15 ml / min, or any value within the range of 10-15 ml / min.

[0051] As a preferred embodiment, the present application realizes stable melting transportation and uniform layered flow of the multi-layer material by precisely controlling the temperature, screw rotation speed, die pressure and supercritical fluid injection parameters in the co-extrusion process, and effectively avoids interlayer mixing or interface defects.

[0052] In a preferred embodiment of the present application, the coating thickness of the UV curing adhesive in step (d) is controlled to be 0.5-20 μm, and the UV curing energy is 300-600 MJ / m 2 .

[0053] As a preferred embodiment, the present application controls the coating thickness of the UV curing adhesive in step (d) to be 0.5-20 μm, and cooperates with the curing energy of 300-600 MJ / m2, which not only ensures that the adhesive layer is uniform and complete, effectively fills the interface micro gap, avoids bubble and delamination defects, but also maximizes the absorption and scattering loss of light in the adhesive layer, which helps to maintain high brightness output; the thickness and energy range synergistically act on the adhesive to fully crosslink and cure, form a high-strength, heat-resistant and stable bonding interface, significantly improve the bonding force and long-term reliability between the film and the plate, prevent warping and yellowing, and balance the optical performance, mechanical stability and process repeatability, which provides a key process guarantee for realizing continuous and high-quality production of high-performance lightweight integrated film plates.

[0054] As an optional embodiment, the coating thickness of the UV curing adhesive in step (d) is controlled in the range of 0.5-20 μm, for example, it can be 0.5 μm, 5 μm, 10 μm, 15 μm, 20 μm, or any value in the range of 5-20 μm; the UV curing energy is controlled in the range of 300-600 MJ / m², for example, it can be 300 MJ / m², 400 MJ / m², 500 MJ / m², 600 MJ / m², or any value in the range of 300-600 MJ / m².

[0055] According to one aspect of the present application, the application of the above-mentioned lightweight integrated film plate in the preparation of liquid crystal displays, Mini LED backlight modules or vehicle display devices.

[0056] The lightweight integrated film plate provided by the present application can be widely applied in the preparation process of liquid crystal displays, Mini LED backlight modules or vehicle display devices.

[0057] The technical solutions of the present application will be further described below in combination with examples.

[0058] Example 1 A lightweight integrated film plate with an open-cell structure, and a preparation method thereof, includes the following steps: (1) Raw material preparation and premixing: The raw materials of each layer are weighed according to the following formula and respectively put into a high-speed mixer for sufficient mixing to obtain the premix of each layer: 1. Support layer (weight parts): GPPS 92.5 parts; antioxidant 1010 2.0 parts; antioxidant 168: 1.0 part; ultraviolet inhibitor UV-P 1.0 part; ultraviolet inhibitor UV-499 0.5 part; toughening agent SEBS 3.0 parts; 2. Upper foaming layer (weight parts): GPPS 81.5 parts, PPO (polyphenyl ether) 10.0 parts, supercritical carbon dioxide (physical foaming agent) 10.0 parts, permeability modifier (IPM, isopropyl myristate) 0.5 parts, PDMS (silicone resin, physical foaming agent affinity additive) 3.0 parts.

[0059] Among them, GPPS is a continuous phase matrix resin, the average molecular weight is about 2.5×10 5 g / mol, and the polydispersity index is 2.1; PPO as a dispersed phase component, helps to form a stable "island" structure, promotes the rupture and connection of the cell wall; PDMS and IPM synergistically improve the solubility and diffusion efficiency of supercritical CO2 in the melt, which is beneficial to the formation of open-cell structure.

[0060] 3. Transition layer (weight parts): GPPS 97.0 parts, toughening agent SEBS 3.0 parts.

[0061] 4. Lower foaming layer (parts by weight): GPPS 84.0 parts; PPO 10 parts; supercritical carbon dioxide 5 parts; permeation modifier 1.0 part; Note: The supercritical carbon dioxide as a physical foaming agent is not added in advance in the dry material, but is injected on-line in the extrusion process through a high-pressure metering system.

[0062] 5. Atomized layer (parts by weight): GPPS 94.5 parts; antioxidant 1010 2.0 parts; silicone light diffuser 1.0 part; antioxidant 168 1.0 part; ultraviolet light resistance agent UV-P 1.0 part; ultraviolet light resistance agent UV-499 0.5 part; (2) Co-extrusion foaming molding: The above-mentioned pre-mixed materials of each layer are respectively supplied to the corresponding extrusion units of the five-layer co-extrusion production line, and melt co-extrusion is carried out under the following process conditions and supercritical carbon dioxide is injected for foaming: The temperature of the feeding section is 150-180 °C, the temperature of the plasticizing section is 180-200 °C, the temperature of the melting section is 200-220 °C, the temperature of the die zone is 230-240 °C, the screw rotation speed is 30 r / min, and the die pressure is 15 Mpa. The injection pressure of supercritical carbon dioxide is 20 Mpa, and the flow rate is 2 mL / min In the extrusion process, the material is rapidly depressurized after being extruded through the die, inducing uniform nucleation and bubble growth, forming an open-cell foamed sheet with a five-layer structure. Among them, the upper foaming layer has a highly connected open-cell structure, and the measured open-cell rate is 87.2%, and the average pore size is about 84.3 μm; the lower foaming layer has a partially open-cell structure, and the open-cell rate is 87.5%.

[0063] (3) On-line lamination and UV curing: On the upper surface of the obtained open-cell foamed sheet, a layer of UV curing adhesive (model: 8280, refractive index 1.51, viscosity about 300 mPa·s) is uniformly coated by slit coating, and the coating thickness is controlled to be about 5 μm. Subsequently, a commercialized microlens-prism composite film (MOP type, model: LEF300M-H) is introduced as the upper composite optical film layer in real time, and precise alignment and lamination are achieved by a calender roller.

[0064] Immediately after lamination, it is immediately introduced into a UV curing device, irradiated by a medium-pressure mercury lamp, and the curing energy is set to about 500 MJ / m², so that the adhesive layer is completely cross-linked and cured, forming a firm and stable bonding interface.

[0065] (4) Cutting to obtain finished products: After cooling and setting, the integrated light-weight film plate laminated foamed light diffusion plate is obtained.

[0066] Example 2 The embodiment provides a light-weight integrated film plate, the overall structure and the preparation method of which are basically the same as those of the embodiment 1, except that the amount of supercritical carbon dioxide in the upper foaming layer is increased to 15.0 parts, and the amount of GPPS is correspondingly reduced to keep the total amount balanced.

[0067] Embodiment 3 The embodiment provides a light-weight integrated film plate, the overall structure and the preparation method of which are basically the same as those of the embodiment 1, except that supercritical carbon dioxide is not used as a foaming agent in the lower foaming layer, but a chemical foaming agent is used instead. That is, a chemical foaming agent is introduced into the formula of the lower foaming layer, and the online injection process of supercritical carbon dioxide is cancelled, and specifically, the formula of the lower foaming layer is as follows (parts by weight): The formula of the lower foaming layer is as follows (parts by weight): GPPS 84.0 parts, PPO 10.0 parts, penetration modifier (IPP) 1.0 part, chemical foaming agent (azodicarbonamide, AC) 5.0 parts. The decomposition temperature of the chemical foaming agent is 200 DEG C, and the gas generation amount is about 220 mL / g.

[0068] Embodiment 4 The embodiment provides a light-weight integrated film plate with an open hole structure, the overall structure and the preparation method of which are basically the same as those of the embodiment 1, except that the UV curing glue used in the middle adhesive glue layer is replaced by another type of product (model: Q2, refractive index 1.53, viscosity about 250 mPa·s), and the formula of each layer material, the co-extrusion foaming process and the online bonding condition remain unchanged.

[0069] Embodiment 5 The embodiment provides a light-weight integrated film plate with an open hole structure, the overall structure and the preparation method of which are basically the same as those of the embodiment 1, except that the upper composite optical film layer is replaced by a prism-prism composite film (POP) instead of a microlens-prism composite film (MOP), and the formula of each layer material, the co-extrusion foaming process and the bonding and curing process remain unchanged. The prism-prism composite film (POP) is LEF300 / 400XL-2.

[0070] Embodiment 6 The embodiment provides a light-weight integrated film plate with an open hole structure, the overall structure and the preparation method of which are basically the same as those of the embodiment 1, except that the base resin of the support layer, the transition layer and the atomization layer in the lower open hole foaming layer is replaced by polycarbonate (PC) instead of general-purpose polystyrene (GPPS), so as to improve the heat resistance and the dimensional stability of the material.

[0071] Meanwhile, a compatible agent PC-g-MAH (polycarbonate grafted with maleic anhydride) is introduced into the three-layer formula of the support layer, the transition layer and the atomizing layer in an amount of 5.0 parts (based on 100 parts of PC) to improve the interfacial compatibility between PC and other components (such as the toughening agent SEBS, the light diffusion agent, etc.) and prevent mechanical defects or uneven cells caused by phase separation.

[0072] Example 7 This example provides a lightweight integrated film plate with an open-cell structure, which has basically the same overall structure and preparation method as Example 1, except that the dispersed phase rubber component in the upper foaming layer and the lower foaming layer is replaced from PPO (polyphenylene oxide) to polypropylene glycol (PPG), and PC is replaced for GPPS, and the rest is the same as Example 1.

[0073] Example 8 This example provides a lightweight integrated film plate with an open-cell structure, which has basically the same overall structure and preparation method as Example 1, except that the physical foaming agent used in the upper foaming layer is replaced from supercritical carbon dioxide to supercritical nitrogen.

[0074] Example 9 This example provides a lightweight integrated film plate with an open-cell structure, which has basically the same overall structure and preparation method as Example 1, except that the physical foaming agent used in the upper foaming layer is replaced from supercritical carbon dioxide to supercritical nitrogen. The lower foaming layer does not add any foaming agent, permeability modifier and physical foaming agent affinity additive, and does not undergo foaming treatment to form a solid dense structure; while the upper foaming layer still uses the same formula and process as Example 1, and has the characteristics of open-cell foaming.

[0075] Comparative Example 1 This comparative example provides a lightweight integrated film plate with an open-cell structure, which has basically the same overall structure and preparation method as Example 1, except that the main difference is: 1. No middle UV curing layer; 2. No foaming agent, permeability modifier and affinity additive is added to the upper foaming layer and the lower foaming layer.

[0076] 3. The upper composite brightening layer is directly stacked with the foaming light diffusion plate; The rest is the same as Example 1.

[0077] Comparative Example 2 This comparative example provides a lightweight integrated film plate with an open-cell structure, which has basically the same overall structure and preparation method as Example 1, except that the main difference is: The upper foaming layer does not add any foaming agent, permeability modifier and physical foaming agent affinity additive, and does not undergo foaming treatment to form a solid dense structure; while the lower foaming layer still uses the same formula and process as Example 1, and has the characteristics of open-cell foaming.

[0078] Experimental Example 1 The open-cell structured lightweight integrated film plate prepared in the above Examples 1-9 and Comparative Examples 1 and 2 was inspected, and the specific results are shown in Table 1 and Table 2.

[0079] Table 1:

[0080] Table 2:

[0081] According to the test results in Table 1 and Table 2, the integrated film plate prepared in Examples 1-8 of the present application can achieve significant lightweight while still maintaining excellent optical performance, showing a good balance between high brightness and low density.

[0082] Specifically, the lower open-cell foamed layer in Examples 1-8 of the present application forms a porous structure with high porosity (up to 95.7%) and high open-cell rate (≥80% for the upper foamed layer, up to 92%), and the overall density can be as low as 0.42 g / cm³, which is significantly lower than that of traditional structures, fully embodying its lightweight advantage. The improvement of the above-mentioned performance of the present application is due to the synergistic design of material-structure-process: the present application forms a stable microstructure by melt blending the base resin (such as GPPS or PC) with a specific dispersed phase (such as PPO or PPG) during foaming. This structure is conducive to the uniform distribution of bubble nucleation and promotes the rupture and connection of bubble walls, thereby constructing a penetrating three-dimensional air channel network. Especially, the microstructure of the support layer and the Airgap-like structure formed by the upper and lower foamed layers effectively reduce light loss and significantly alleviate the brightness attenuation problem caused by integrated lamination, with a maximum actual brightness of 2995 cd / m² (Example 5), which is much better than conventional lamination schemes.

[0083] Further analysis of the data of the comparative examples shows that the technical effect of the present application is not a simple superposition of isolated features, but a result of the synergistic effect of multiple necessary technical features: Example 9 (only the upper foamed layer is foamed, and the lower foamed layer is solid) shows that although a certain optical performance (brightness 2616.7 cd / m²) is retained, the overall porosity is low and the density is as high as 0.76 g / cm³ due to the unfoamed lower layer, which seriously weakens the lightweight effect and loses the core advantage of the present application in weight reduction.

[0084] Comparative Example 1 (without UV adhesive layer, without foaming structure) is a conventional separate component structure: it does not undergo integrated lamination, and in theory should avoid the optical loss introduced by the adhesive layer, but because it uses a solid dense structure, the material itself has a very high density (1.05 g / cm³), and lacks effective light management mechanisms, resulting in poor light efficiency per unit weight; more importantly, it completely relies on subsequent manual lamination processes, and has problems such as complex assembly, low yield, and easy to produce interface defects, and cannot meet the requirements of modern display modules for integration and reliability.

[0085] Comparative Example 2 (only the lower foaming layer is foamed, and the upper foaming layer is solid) shows that even if the lower half has a certain open structure (open hole rate 88.1%), if the upper foaming layer does not form a high open hole rate of connected channels, light will still be difficult to efficiently penetrate the entire membrane plate system, and the final brightness is only 2389.6 cd / m², which is significantly lower than Example 1 (2556.5 cd / m²). This shows that the realization of the "Airgap-like" effect is highly dependent on the guiding ability of the upper open structure to the light path.

[0086] In summary, the present application, through the integrated design of "upper composite optical film layer + middle UV adhesive layer + lower five-layer gradient open foaming layer", not only simplifies the production process and improves product consistency, but also realizes the technical breakthrough of "lightweight without sacrificing brightness" through structural innovation. The effect of this multiple functional synergy optimization is beyond the reach of the prior art's single improvement of a certain aspect, and has outstanding substantive features and significant progress.

[0087] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A lightweight integrated membrane panel with an open-pore structure, characterized in that, It includes an upper composite optical film layer, a middle adhesive layer and a lower open-cell foam layer, which are stacked sequentially from top to bottom; The upper composite optical film layer, the middle adhesive layer, and the lower open-cell foam layer are integrally formed through co-extrusion and online bonding processes, wherein: The lower perforated foam layer includes, from top to bottom, a support layer, an upper foam layer, a transition layer, a lower foam layer, and an atomizing layer; The upper foaming layer has an open-cell structure with an open-cell rate of not less than 80%; the lower foaming layer has an open-cell or closed-cell structure.

2. The lightweight integrated membrane plate according to claim 1, characterized in that, The upper composite optical film layer has a composite structure; Preferably, the upper composite optical film layer includes a diffusion-prism composite film, a prism-prism composite film, a microlens-prism composite film, a prism-microlens composite film, and a reflective polarizing brightening film; And / or, the bonding adhesive layer is mainly formed of UV-curable adhesive; Preferably, the UV-curable adhesive has a refractive index of 1.45~1.65 and a viscosity of 100~500pcs; And / or, the thickness of the upper composite optical film layer is 100~500 μm, the thickness of the middle adhesive layer is 0.5~20 μm, and the total thickness of the lower open-cell foam layer is 0.8~3.0 mm; And / or, the thickness of the support layer in the lower open-cell foam layer is 0.1~0.3 mm, the thickness of the upper foam layer is 0.2~0.5 mm, the thickness of the transition layer is 0.1~0.4 mm, the thickness of the lower foam layer is 0.4~0.7 mm, and the thickness of the atomizing layer is 0.2~1.2 mm.

3. The lightweight integrated membrane plate according to claim 1, characterized in that, The matrix resin used in the support layer, transition layer, atomizing layer, upper foaming layer and lower foaming layer of the lower open-cell foaming layer is selected from any one of polystyrene, polymethyl methacrylate or polycarbonate.

4. The lightweight integrated membrane plate according to claim 1, characterized in that, The raw materials of the support layer, by weight, include: 80.0~90.0 parts of matrix resin, 1.0~5.0 parts of toughening agent, 1.0~3.0 parts of antioxidant, 1.0~2.0 parts of ultraviolet absorber, and 3.0~8.0 parts of compatibilizer; And / or, the raw materials of the atomizing layer, by weight, include: 80.0~90.0 parts of matrix resin, 0.5~2.0 parts of light diffusing agent, 1.0~3.0 parts of antioxidant, 1.0~2.0 parts of ultraviolet absorber, and 1.0~5.0 parts of toughening agent.

5. The lightweight integrated membrane plate according to claim 1, characterized in that, The raw materials for the upper foaming layer, by weight, include: The composition includes: 60.0-80.0 parts of matrix resin, 10.0-40.0 parts of dispersed phase, 5.0-15.0 parts of physical foaming agent, 0.05-1.5 parts of penetration modifier, 1.0-5.0 parts of physical foaming agent affinity additive, 1.0-5.0 parts of toughening agent, 1.0-3.0 parts of antioxidant, 1.0-2.0 parts of ultraviolet absorber, and 1.0-5.0 parts of compatibilizer. Preferably, the dispersed phase includes at least one of PPO, POE, PP, PPG and PET.

6. The lightweight integrated membrane plate according to claim 1, characterized in that, The raw materials for the lower foaming layer, by weight, include: The composition includes: 60.0-80.0 parts of matrix resin, 10.0-40.0 parts of dispersed phase, 1.0-10.0 parts of foaming agent, 1.0-5.0 parts of toughening agent, 1.0-3.0 parts of antioxidant, 1.0-2.0 parts of UV absorber, 1.0-5.0 parts of compatibilizer, 0.05-1.5 parts of penetration modifier, and 1.0-5.0 parts of physical foaming agent affinity additive.

7. A method for preparing a lightweight integrated membrane plate according to any one of claims 1 to 6, characterized in that, Includes the following steps: (a) The raw materials of the support layer, upper foaming layer, transition layer, lower foaming layer and atomizing layer are mixed at high speed to obtain the premix of each layer; (b) The premixed materials of each layer are co-extruded and foamed under set temperature and pressure conditions through a multi-layer co-extrusion equipment to obtain an open-cell foam board with a five-layer structure; (c) Apply UV-curable adhesive to the upper surface of the perforated foam board and introduce the upper composite optical film layer in real time for pressing and attachment; (d) After UV curing, the integrated membrane panel is cut to obtain the finished product.

8. The method for preparing the lightweight integrated membrane plate according to claim 7, characterized in that, The process parameters for the co-extrusion process in step (b) are as follows: The temperature of the feeding section is 150~180℃, the plasticizing section is 180~200℃, the melting section is 200~220℃, and the die head area is 210~240℃; The screw speed is 20~45 r / min, the die pressure is 20~30 MPa, the supercritical fluid injection pressure is 10~25 MPa, and the flow rate is 10~15 ml / min.

9. The method for preparing the lightweight integrated membrane plate according to claim 7, characterized in that, In step (d), the coating thickness of the UV-curable adhesive is controlled at 0.5~20μm, and the UV curing energy is 300~600 MJ / m².

10. The application of a lightweight integrated film plate according to any one of claims 1 to 6 in the manufacture of liquid crystal displays, Mini LED backlight modules or automotive display devices.

Images