Polarizer and preparation method thereof, liquid crystal panel and display equipment

Abstract

The invention discloses a polaroid and a preparation method thereof, a liquid crystal panel and display equipment, and relates to the technical field of display, the polaroid comprises a matrix resin layer, the matrix resin layer comprises a plurality of embedded inorganic particles and bubbles wrapping the inorganic particles, and PVA layers combined with a bidirectional material are attached to the inner walls of the bubbles. The PVA material and the matrix resin with multiple bubbles are combined, so that the mechanical supporting capacity of the PVA layer is effectively improved, and the reliability of the PVA layer in a complex environment is remarkably enhanced.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a polarizer, a preparation method thereof, a liquid crystal panel, and a display device. Background Art

[0002] In the field of display technologies, polyvinyl alcohol (PVA) films are widely used as the core functional layer of polarizers due to their excellent orientation and good iodine molecule adsorption ability. However, the PVA material itself has relatively obvious problems of poor weather resistance, which limits its stable application under complex environmental conditions. On the one hand, PVA has strong hydrophilicity and is prone to absorbing moisture in the air in a high-humidity environment, resulting in dimensional expansion, optical fogging, and even performance degradation, seriously affecting the polarization effect. On the other hand, under high-temperature conditions, PVA is prone to softening, deformation, and even thermal degradation, causing a decrease in optical uniformity and a shortening of service life. In addition, the PVA film itself has low mechanical strength and poor flexibility, and is easily damaged by external forces such as scratches and fractures during processing, transportation, and use, thus affecting the product yield and reliability.

[0003] Although in conventional technologies, the PVA layer is usually sandwiched between protective films such as triacetyl cellulose (TAC) to form a composite structure, and environmental isolation is carried out by means of surface moisture-proof and heat-resistant coatings, etc., these methods still have certain limitations in improving the overall reliability of the PVA layer.

[0004] The above content is only used to assist in understanding the technical solution of the present application, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the embodiments of the present application is to provide a polarizer, a preparation method thereof, a liquid crystal panel, and a display device. In the embodiments of the present application, the PVA material is combined with a matrix resin having multiple bubbles, which not only effectively improves the mechanical support ability of the PVA layer, but also significantly enhances its reliability under complex environments.

[0006] To achieve the above purpose, the embodiments of the present application provide a polarizer, which includes:

[0007] A matrix resin layer, wherein the matrix resin layer includes a plurality of embedded inorganic particles and bubbles wrapping the inorganic particles, and a PVA layer combined with a dichroic material is attached to the inner wall of the bubbles.

[0008] In one embodiment, the hardness of the matrix resin is greater than or equal to a first hardness, wherein the first hardness is less than the hardness of an optical film adjacent to the polarizer in a display device, and the pencil hardness difference from the hardness of the optical film is 3.

[0009] In one embodiment, the difference in pencil hardness between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3.

[0010] In one embodiment, the material of the matrix resin is the same as the material of the optical film adjacent to the polarizer in the display device.

[0011] In one embodiment, the material of the matrix resin includes at least one of PET, PS, and PMMA.

[0012] In one embodiment, the inorganic particles include at least one of CaSO4 and BaCO3.

[0013] In one embodiment, the size of the inorganic particles is 5 to 10 nm.

[0014] In addition, to achieve the above object, an embodiment of the present application further provides a method for preparing a polarizer for preparing the polarizer as described above. The method for preparing the polarizer includes the following steps:

[0015] Providing a masterbatch, wherein the masterbatch includes: a first resin layer and a plurality of inorganic particles wrapped by the first resin layer, and a PVA layer is wrapped on the surface of each inorganic particle;

[0016] Mixing the matrix resin and the masterbatch to obtain a mixed material;

[0017] Performing melt extrusion on the mixed material to obtain an extruded resin;

[0018] Stretching the extruded resin in a vapor environment of a dichroic material to form a matrix resin layer and obtain a polarizer.

[0019] In one embodiment, the doping concentration of the inorganic particles in the masterbatch is 5 to 8%;

[0020] The mass ratio of the masterbatch in the mixed material is 8 to 15%.

[0021] In one embodiment, the material of the first resin layer includes at least one of PET, PS, and PMMA.

[0022] In one embodiment, the material of the matrix resin includes at least one of PET, PS, and PMMA.

[0023] In one embodiment, the material of the first resin layer is the same as the material of the matrix resin.

[0024] In one embodiment, the melting temperature is 220 to 250 °C.

[0025] In one embodiment, the thickness of the PVA layer is 5 to 8 μm.

[0026] In one embodiment, the thickness of the first resin layer is 50 - 80 um.

[0027] In one embodiment, the stretching of the extruded resin includes primary stretching and secondary stretching;

[0028] The primary stretching is carried out in a vapor environment of a biaxial material at 70 - 90 °C, and the stretching ratio is 1.5 - 2.5 times;

[0029] The secondary stretching is carried out at 20 - 25 °C, and the stretching ratio is 3 - 5 times.

[0030] In addition, to achieve the above object, an embodiment of the present application further provides a liquid crystal panel, which includes the polarizer as described above, or a polarizer prepared by the polarizer preparation method as described above.

[0031] In addition, to achieve the above object, an embodiment of the present application further provides a display device, which includes the polarizer as described above, or a polarizer prepared by the polarizer preparation method as described above.

[0032] One or more technical solutions proposed in the embodiments of the present application have at least the following technical effects: providing a polarizer, including: a matrix resin layer, wherein a plurality of inorganic particles and bubbles wrapping each inorganic particle are embedded in the matrix resin layer, and a PVA layer combined with a biaxial material is attached to the inner wall of the bubble. In the embodiments of the present application, the matrix resin is used as the structural main body, providing good mechanical strength and flexibility, capable of effectively buffering external forces and preventing the PVA from breaking or being damaged due to external stress; at the same time, the inner wall of the bubble serves as the attachment carrier of the PVA, enabling the PVA to be locally isolated and fixed in a closed space, reducing the possibility of its direct exposure to the external moisture and high-temperature environment, thereby significantly reducing the influence of water vapor penetration and thermal stress on the performance of the PVA and avoiding the problem of optical performance degradation caused by moisture absorption swelling, atomization, or thermal degradation. Through this film layer structure, the PVA material is combined with the matrix resin with multiple bubbles, not only effectively improving the mechanical support ability of the PVA layer, but also significantly enhancing its reliability in complex environments. Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of a conventional polarizer;

[0034] Figure 2 It is a schematic structural diagram of a conventional display device;

[0035] Figure 3 It is a schematic structural diagram of a conventional liquid crystal panel;

[0036] Figure 4Schematic diagram of the structure of the polarizer involved in the embodiments of the present application;

[0037] Figure 5 Schematic diagram of the structure of the masterbatch involved in the embodiments of the present application;

[0038] Figure 6 Cross-sectional scanning electron micrograph of the polarizer involved in the embodiments of the present application;

[0039] Figure 7 Schematic diagram of the PVA molecular chain involved in the embodiments of the present application;

[0040] Figure 8 Schematic diagram of the polarization principle of the polarizer involved in the embodiments of the present application;

[0041] Figure 9 Schematic diagram of the scenario of the polarizer preparation process involved in the embodiments of the present application;

[0042] Figure 10 Schematic diagram of the structure of the liquid crystal panel involved in the embodiments of the present application.

[0043] Description of reference numerals

[0044] 10, Backlight module; 11, Diffusion plate; 12, Optical film;

[0045] 100, Conventional polarizer; 101, Release film; 102, Pressure-sensitive adhesive; 103, First TAC layer;

[0046] 104, First PVA layer; 105, Second TAC layer; 106, Protective film;

[0047] 20, Liquid crystal panel; 21, First glass substrate; 22, Thin-film transistor;

[0048] 23, Liquid crystal layer; 24, Filter film; 25, Second glass substrate;

[0049] 26, First polarizer; 27, Second polarizer; 28, First polarizing sheet; 29, Second polarizing sheet;

[0050] 200, Matrix resin layer; 201, Inorganic particles; 202, Bubbles;

[0051] 203, PVA layer; 204, Matrix resin; 210, Masterbatch.

[0052] The realization, functional features and advantages of the purpose of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase.

[0054] Hereinafter, embodiments of the polarizer, its preparation method, liquid crystal panel, and display device of this application will be specifically disclosed in detail with appropriate reference to the drawings. However, there may be cases where unnecessary details are omitted. For example, there are cases where details of well-known matters are omitted and repeated descriptions of actually identical structures are omitted. This is to prevent the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand this application and are not intended to limit the subject matter recited in the claims.

[0055] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way can include the end values or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, ranges of 60 to 110 and 80 to 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 to 5" have been fully listed herein, and "0 to 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0056] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form new technical solutions.

[0057] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0058] Unless otherwise specified, all steps of this application can be carried out sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out sequentially, or may also include steps (b) and (a) carried out sequentially. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or may also include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0059] Unless otherwise specified, the terms "comprising" and "including" mentioned in this application are open-ended and can also be closed-ended. For example, the terms "comprising" and "including" may mean that other components not listed may also be included or comprised, or may only include or comprise the listed components.

[0060] Unless otherwise specified, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) while B is true (or exists); or both A and B are true (or exist).

[0061] To make the above objects, features, and advantages of this application more obvious and understandable, the technical solutions of this application will be further described below in conjunction with the accompanying drawings and embodiments. However, this application is not limited to the listed embodiments and should also include any other well-known changes within the scope of the rights required by this application.

[0062] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of this application. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0063] To better understand the technical solutions of this application, the following will be described in detail in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0064] In the related art, refer to Figure 1, a conventional polarizer 100 generally includes a release film 101, a pressure-sensitive adhesive 102, a first TAC layer 103, a first PVA layer 104, a second TAC layer 105, and a protective film 106 that are sequentially stacked. The first PVA layer 104 is a carrier for dichroic molecules and is used to achieve the polarization function. The first TAC layer 103 and the second TAC layer 105 are used to protect the first PVA layer 104 from damage by external substances such as water vapor, ensuring the environmental weather resistance of the polarizer 100. The TAC layer is an important part of the polarizer and is expensive, making the cost of the polarizer relatively high. In order to reduce the cost, it is necessary to reduce the surface hardness of the TAC layer so that its surface pencil hardness is reduced from 3HB to below 10B, resulting in a lower hardness of the polarizer. Further, referring to Figure 2 , a conventional display device generally includes a backlight module 10 and a liquid crystal panel 20. Among them, an optical film 12 is provided on the light-emitting side of the backlight module 10, and a diffusion plate 11 may also be provided on the light-incident side of the optical film 12. The conventional liquid crystal panel 20 adjacent to the optical film 12 can be referred to Figure 3 , and includes a first polarizer 26, a first glass substrate 21, thin-film transistors 22, a liquid crystal layer 23, a filter film 24, a second glass substrate 25, and a second polarizer 27 that are sequentially stacked from the light-incident direction to the light-emitting direction. Since the diffusion plate 11 and the optical film 12 of the backlight module 10 usually lack fixing measures, resulting in a large movement space, they are also extremely likely to come into flapping contact with the lower polarizer (i.e., the first polarizer 26) of the liquid crystal panel 20 during transportation. The surface hardness of the optical film 12 is usually 1-2HB, and the hardness of the lower polarizer of the liquid crystal panel 20 is usually 8-10B. The hardness difference between the two is huge. Therefore, the polarizer is extremely likely to be scratched by the optical film 12, resulting in quality accidents.

[0065] In this embodiment, by selecting a substrate resin with a specific hardness as the base material, the polarizer has at least the same hardness level as the optical film adjacent to it in the display device, or has a greater hardness than the optical film, thereby effectively avoiding the situation that the lower polarizer of the liquid crystal panel is scratched by the optical film of the backlight module. Further, the inner wall of the bubble in the substrate resin layer is attached with a PVA layer combined with a dichroic material, so that the film layer can use the selective absorption characteristics of the dichroic material to filter out the light wave vibrations in a specific direction, achieving the polarization effect. Further, since the PVA layer combined with the dichroic material is attached to the inner wall of the bubble in the substrate resin layer, and the bubble is a closed structure, it can better isolate the water vapor erosion and improve the reliability of the polarizer. In addition, the above solution can save the TAC layer in the polarizer, thereby effectively reducing the cost of the polarizer.

[0066] Based on this, in the first aspect of the embodiments of the present application, a polarizer is provided. Referring to Figure 4, the polarizer includes: a substrate resin layer 200, wherein the substrate resin layer 200 includes a plurality of embedded inorganic particles 201 and air bubbles 202 that wrap the inorganic particles 201, and a PVA layer 203 combined with a dichroic material is attached to the inner wall of the air bubbles 202.

[0067] Optionally, a multi-layer and discontinuous air bubble structure is formed in the substrate resin layer.

[0068] Optionally, the gas in the air bubbles includes: air and / or inert gas.

[0069] Optionally, at least one inorganic particle can be wrapped in the air bubbles in the substrate resin layer, and some air bubbles in the substrate resin layer may not wrap inorganic particles. For example, air bubble A in the substrate resin layer wraps 1 inorganic particle, air bubble B wraps 2 inorganic particles, air bubble C wraps 3 inorganic particles, etc., and air bubble D does not wrap inorganic particles.

[0070] Optionally, the substrate resin layer may further include inorganic particles that are not wrapped by air bubbles but are directly embedded in the substrate resin.

[0071] Optionally, the substrate resin layer may further include a PVA layer combined with a dichroic material that is not wrapped by air bubbles.

[0072] Optionally, the material of the substrate resin can be formed by stretching.

[0073] In this embodiment, with the substrate resin as the structural main body, good mechanical strength and flexibility are provided, which can effectively buffer external forces and prevent the PVA from breaking or being damaged due to external stress; at the same time, the inner wall of the air bubble serves as the attachment carrier of the PVA, enabling the PVA to be locally isolated and fixed in a closed space, reducing the possibility of its direct exposure to the external humidity and high-temperature environment, thereby significantly reducing the influence of water vapor penetration and thermal stress on the performance of the PVA and avoiding the optical performance degradation problem caused by moisture absorption expansion, atomization, or thermal degradation. Through this film layer structure, the PVA material is combined with the substrate resin with multiple air bubbles, which not only effectively improves the mechanical support ability of the PVA layer but also significantly enhances its reliability in a complex environment.

[0074] In a feasible implementation manner, the hardness of the substrate resin is greater than or equal to a first hardness, wherein the first hardness is less than the hardness of the optical film adjacent to the polarizer in the display device, and the pencil hardness difference from the hardness of the optical film is 3. Through the limitation of the first hardness, the polarizer can have a hardness equivalent to or higher than that of the optical film, thereby effectively avoiding the occurrence of the situation where the polarizer is scratched by the optical film.

[0075] Exemplarily, when the hardness of the optical film is 5H, the first hardness is 2H, so the hardness of the substrate resin is greater than or equal to 2H.

[0076] In a feasible embodiment, the difference in pencil hardness between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3. By controlling the hardness difference between the matrix resin of the matrix resin layer and the optical film, the adjacent polarizers and polarizing films have substantially equivalent hardness, and the situation where the polarizer and the optical film scratch each other can be avoided simultaneously.

[0077] Exemplarily, when the hardness of the optical film is 5H, the hardness of the matrix resin is 2H - 8H.

[0078] In a feasible embodiment, the material of the matrix resin of the matrix resin layer can be the same as the base material of the optical film adjacent to the polarizer in the display device. By using the same material, the adjacent polarizers and polarizing films have equivalent hardness, and the situation where the polarizer and the optical film scratch each other can be avoided simultaneously.

[0079] Optionally, the PVA layer is a film layer made of polyvinyl alcohol (PolyvinylAlcohol, PVA layer). The PVA layer has high transparency, high ductility, good adsorption effect on dichroic materials, and excellent film-forming properties. The PVA layer combines with the dichroic material and undergoes stretching orientation to make the dichroic material arranged orderly. This structure enables the matrix resin layer to absorb the light vibration component parallel to its arrangement direction and allows the light vibration component in the vertical direction to pass through, thereby achieving a polarization effect close to the theoretical value, with a polarization degree of over 99.9% and a transmittance also maintained at about 42%.

[0080] A dichroic material refers to a material that exhibits selective absorption or reflection characteristics for light or other electromagnetic waves, and its optical properties vary significantly with the direction of incident light, polarization state, or wavelength. The core characteristic of such materials is dichroism, that is, there is a difference in the absorption intensity of light with different polarization directions, so they can be applied to fields such as polarization control and color regulation.

[0081] Optionally, the dichroic material includes at least one of iodine-based materials, azo materials, anthraquinone materials, metal nanomaterials, and quantum materials. In this embodiment, the iodine-based material will be used as an example for illustration.

[0082] Optionally, the polarizer may further include at least one functional film layer provided on at least one side of the matrix resin layer, such as a pressure-sensitive adhesive, a release film, a protective film, etc., and this embodiment does not limit this.

[0083] In this embodiment, by selecting a matrix resin with a specific hardness as the base material, the polarizer has at least a hardness level equivalent to that of the optical film adjacent to it in the display device, or has a greater hardness than the optical film, thereby effectively avoiding the occurrence of the situation where the lower polarizer of the liquid crystal panel is scratched by the optical film of the backlight module. Further, a PVA layer combined with a dichroic material is attached to the inner wall of the bubble in the matrix resin layer, enabling the film layer to filter out light wave vibrations in a specific direction by utilizing the selective absorption characteristics of the dichroic material to achieve the polarization effect. Further, since the PVA layer combined with the dichroic material is attached to the inner wall of the bubble in the matrix resin layer and the bubble is a closed structure, water vapor erosion can be better isolated, improving the reliability of the polarizer. In addition, through the above solution, the TAC layer in the polarizer can be saved, thereby effectively reducing the cost of the polarizer by more than 30%.

[0084] In a feasible embodiment, the material of the matrix resin includes at least one of PET, PS, and PMMA. The above materials are commonly used base materials for optical films, enabling the polarizer to have the same hardness level as the optical film or a greater hardness than the optical film, thereby effectively avoiding the occurrence of the situation where the lower polarizer of the liquid crystal panel is scratched by the optical film of the backlight module.

[0085] PET (Polyethylene terephthalate) has good light transmittance (usually 90 - 95%), ductility, creep resistance, fatigue resistance, abrasion resistance, dimensional stability, tensile strength, and impact strength, and its pencil hardness is approximately between 1HB and 2H.

[0086] PS (Polystyrene), which is a polymer synthesized by the free radical addition polymerization reaction of styrene monomers, has good light transmittance and ductility, is easy to mold and process, and is suitable for various molding technologies, and its pencil hardness is approximately between 1HB and 2H.

[0087] PMMA (Polymethyl Methacrylate) has excellent transparency, outstanding weather resistance, good processability, and relatively high surface hardness, and its pencil hardness is 3 - 4H.

[0088] In a feasible embodiment, the inorganic particles include at least one of CaSO4 and BaCO3.

[0089] In a feasible embodiment, the size of the inorganic particles is 5 to 10 nm. For example, the size of the inorganic particles is 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, etc. If the size of the inorganic particles is relatively large, it may be difficult for the inorganic particles to be uniformly dispersed in the matrix resin, resulting in particle aggregation in local areas, which in turn affects the optical and mechanical properties of the polarizer and may also cause difficulties in processing such as extrusion and stretching, for example, clogging the die orifice or causing defects on the film surface. If the size of the inorganic particles is too small, due to the high surface energy, the inorganic particles are prone to agglomeration, which instead affects the dispersion effect. Therefore, in the embodiments of the present application, the size of the inorganic particles is determined to be 5 to 10 nm.

[0090] In this embodiment, by adding the above-mentioned inorganic particles, the mechanical strength and hardness of the polarizer can be enhanced to a certain extent, which helps to improve its wear resistance and durability. And the above-mentioned inorganic particles also have good thermal stability, so they can improve the dimensional stability and heat resistance of the polarizer in a high-temperature environment. At the same time, appropriately adding inorganic particles can also help reduce light scattering or reflection, thereby optimizing the light transmittance and polarization efficiency. In addition, the inorganic particles belong to inorganic materials, while the matrix resin belongs to organic materials, and there are significant differences in their properties, resulting in low viscosity between the inorganic particles and the matrix resin and the existence of voids. Furthermore, in the preparation process of the polarizer, the thickness of the matrix resin layer can be reduced and the area can be increased by stretching, and then the space occupied by the inorganic particles in the matrix resin can be further enlarged. And the inorganic particles are of moderate hardness, will not deform along with the stretching, and will not break through the matrix resin due to high hardness, so a multi-layer bubble structure in which the inorganic particles are wrapped by bubbles will be formed during the stretching process, and then the matrix resin layer will be formed, thus effectively simplifying the preparation process of the polarizer.

[0091] The second aspect of the embodiments of the present application provides a method for preparing a polarizer for preparing the polarizer as described above. The method for preparing the polarizer includes the following steps:

[0092] Step S10, providing a masterbatch, where the masterbatch includes: a first resin layer and a plurality of inorganic particles wrapped by the first resin layer, and a PVA layer is wrapped on the surface of each inorganic particle;

[0093] In a feasible embodiment, referring to Figure 5 , inorganic particles 201 are provided, and a PVA layer 203 is wrapped on the surface of the inorganic particles 201; then, a plurality of inorganic particles 201 are wrapped by a first resin layer 205 to obtain a masterbatch 210 with a double-wrapped structure similar to "pomegranate".

[0094] Optionally, the inorganic particles include at least one of CaSO4 and BaCO3.

[0095] Optionally, the size of the inorganic particles is 5 to 10 nm.

[0096] In a feasible embodiment, the thickness of the PVA layer is 5 to 8 μm. For example, the thickness of the PVA layer is 5 μm, 5.2 μm, 5.4 μm, 5.6 μm, 5.8 μm, 6 μm, 6.2 μm, 6.4 μm, 6.6 μm, 6.8 μm, 7 μm, 7.2 μm, 7.4 μm, 7.6 μm, 7.8 μm, 8 μm, etc. If the PVA layer is too thin, the PVA content in the polarizer may be small, resulting in a reduction in the polarization effect of the polarizer. Therefore, in the embodiments of the present application, the thickness of the PVA layer is determined to be 5 to 8 μm.

[0097] In a feasible embodiment, the thickness of the first resin layer is 50 to 80 μm. For example, the thickness of the first resin layer is 50 μm, 52 μm, 54 μm, 56 μm, 58 μm, 60 μm, 62 μm, 64 μm, 66 μm, 68 μm, 70 μm, 72 μm, 74 μm, 76 μm, 78 μm, 80 μm, etc. If the first resin layer is too thick, a higher temperature or a longer time is required to completely melt during the mixing process of the masterbatch and the matrix resin, increasing the process cost, and there may be a partially unmelted first resin layer, making it difficult for the target inorganic particles to be uniformly dispersed in the matrix resin. If the first resin layer is too thin, it may be difficult to provide good protection for the inorganic particles and the PVA layer it wraps, resulting in damage to the inorganic particles or the PVA layer during the processing. Therefore, in the embodiments of the present application, the thickness of the first resin layer is determined to be 50 to 80 μm.

[0098] In a feasible embodiment, the doping concentration of the inorganic particles in the masterbatch is 5 to 8%. For example, the doping concentration of the inorganic particles in the masterbatch is 5%, 5.2%, 5.4%, 5.6%, 5.8%, 6%, 6.2%, 6.4%, 6.8%, 7%, 7.2%, 7.4%, 7.6%, 7.8%, 8%, etc. By controlling the doping concentration of the inorganic particles in the masterbatch, the uniform dispersion of the inorganic particles in the matrix resin is promoted, and the situation of particle aggregation in local areas during the later mixing process of the masterbatch and the matrix resin is avoided.

[0099] Step S20: Mix the matrix resin and the masterbatch to obtain a mixed material;

[0100] In a feasible embodiment, the matrix resin and the masterbatch are uniformly mixed and fully dried to obtain a mixed material.

[0101] In a feasible embodiment, the material of the first resin layer includes at least one of PET, PS, and PMMA, and the material of the matrix resin includes at least one of PET, PS, and PMMA. By selecting the first resin layer and the matrix resin with similar properties, the compatibility between the first resin layer and the matrix resin is improved, which is conducive to the uniform dispersion of the masterbatch and the inorganic particles it encapsulates in the matrix resin. At the same time, in the later melt extrusion process, the first resin layer of the masterbatch can fully absorb the environmental heat and protect the inorganic particles encapsulated with the PVA layer inside.

[0102] Optionally, the material of the first resin layer is the same as the material of the matrix resin. By selecting the same material, the compatibility between the first resin layer and the matrix resin is further improved, promoting the uniform dispersion of the masterbatch and the inorganic particles it encapsulates in the matrix resin.

[0103] In a feasible embodiment, the mass ratio of the masterbatch in the mixed material is 8-15%, for example, the mass ratio of the masterbatch in the mixed material is 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, etc. If the addition amount of the masterbatch is too large, the addition amount of the inorganic particles will be too large, making it difficult for the inorganic particles to be uniformly distributed in the resin matrix, which may lead to particle agglomeration and form local stress concentration points; at the same time, the high content of inorganic particles may also pose challenges to the processing processes such as extrusion and stretching, such as clogging the die orifice and increasing the viscosity of the molten resin, resulting in difficult molding. If the addition amount of the masterbatch is too small, the addition amount of the inorganic particles encapsulated with the PVA layer will be too small, resulting in a poor polarization effect of the polarizer. Therefore, the embodiments of the present application determine that the mass ratio of the masterbatch in the mixed material is 8-15%.

[0104] In a feasible embodiment, the hardness of the matrix resin is greater than or equal to the first hardness, where the first hardness is less than the hardness of the optical film adjacent to the polarizer in the display device, and the pencil hardness difference from the hardness of the optical film is 3. By defining the first hardness, the polarizer can have a hardness equivalent to or higher than that of the optical film, effectively avoiding the occurrence of the situation where the polarizer is scratched by the optical film.

[0105] Exemplarily, when the hardness of the optical film is 5H, the first hardness is 2H, so the hardness of the matrix resin is greater than or equal to 2H.

[0106] In a feasible embodiment, the difference in pencil hardness between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3. By controlling the hardness difference between the matrix resin of the matrix resin layer and the optical film, the adjacent polarizers and polarizing films have substantially equivalent hardness, and the situation where the polarizer and the optical film scratch each other can be avoided simultaneously.

[0107] Exemplarily, when the hardness of the optical film is 5H, the hardness of the matrix resin is 2H - 8H.

[0108] In a feasible embodiment, the material of the matrix resin of the matrix resin layer can be the same as the substrate material of the optical film adjacent to the polarizer in the display device. By using the same material, the adjacent polarizers and polarizing films have equivalent hardness, and the situation where the polarizer and the optical film scratch each other can be avoided simultaneously.

[0109] Step S30: Melting and extruding the mixed material to obtain an extruded resin;

[0110] In a feasible embodiment, the mixed material is melted at a temperature of 220 - 250 °C to make it in a flowing state, and then extruded and formed through a mold, so that the inorganic particles wrapped by the PVA layer are evenly distributed in the resin, obtaining an extruded resin.

[0111] Optionally, the melting temperature can be 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, etc. If the melting temperature is too high, the resin may undergo thermal degradation, affecting the mechanical properties of the material, and causing unstable material flow during extrusion, resulting in uneven product thickness or "drooling" phenomenon. If the melting temperature is too low, the resin may not be completely melted, and there may be some unmelted particles, which will form defect points in the final product, affecting the uniformity and mechanical properties of the product. Therefore, the melting temperature is determined to be 220 - 250 °C in the embodiments of the present application.

[0112] Step S40: Stretching the extruded resin in a vapor environment of a dichroic material to form a matrix resin layer, obtaining a polarizer.

[0113] In a feasible implementation, since the inorganic particles encapsulated in the extruded resin are inorganic materials with stable chemical properties, while the matrix resin is an organic material, there is a significant difference in properties between the two. Therefore, the viscosity between the inorganic particles and the matrix resin is low, and there are certain gaps; at the same time, the matrix resin has good ductility. Therefore, by stretching the extruded resin, the thickness of the extruded resin can be reduced and the area can be increased, and then the space occupied by the inorganic particles in the matrix resin can be further stretched. The inorganic particle material is moderately hard and soft, and will not deform along with the stretching, nor will it break through the matrix resin due to its large hardness. Thus, a multi-layer bubble structure in which the bubbles encapsulate the inorganic particles can be formed during the stretching process; and in the vapor environment of the dichroic material (for example, in the iodine vapor environment), the dichroic material can be adsorbed by the PVA in the extruded resin as the extruded resin is stretched, and then as the PVA adheres to the inner wall of the formed bubble structure during the stretching, a structure in which the bubbles encapsulate the inorganic particles and the inner wall of the bubbles is attached with a PVA layer combined with the dichroic material is formed. Since the bubbles are closed structures, in this special structure, the erosion of water vapor on the PVA layer can be better isolated, and the reliability of the polarizer can be improved. In addition, before the film layer is stretched and after the PVA adsorbs the dichroic material, the dichroic molecular chains in the PVA will show a disordered arrangement characteristic. At this time, the matrix resin layer does not have polarization degree; and through stretching, the PVA in the extruded resin will form a parallel arrangement of the molecular chains in the stretching direction from the curly and disordered arrangement, and the dichroic molecular chains in the PVA will also form ordered parallel long chains. This structure enables the matrix resin layer to absorb the light vibration components parallel to its arrangement direction and at the same time allows the light vibration components in the vertical direction to pass through, thus achieving the polarization effect.

[0114] It can be understood that compared with the conventional method of realizing the combination of PVA and the dichroic material by dyeing, the stretching method in the vapor environment of the dichroic material can make the dichroic material more evenly diffuse into the entire material system, shorten the processing time, and avoid the possible solvent residue problem during soaking.

[0115] Exemplarily, referring to Figure 4 and 6 , through the unidirectional stretching process, the space occupied by the inorganic particles 201 is stretched into an ellipsoidal bubble 202, and the bubbles 202 are densely stacked inside the matrix resin and at least partially encapsulate the inorganic particles 201.

[0116] Optionally, during the stretching process, the inner wall of the bubbles formed in the matrix resin will adhere to PVA, and PVA is a linear high molecular polymer obtained by alcoholysis of polyvinyl acetate. Many strongly polar and unstable hydroxyl groups -OH are evenly hung on its molecular long chain. Therefore, it can combine with the vapor of the dichroic material filled into the bubbles; referring to Figure 7, taking iodine vapor (iodine staining) as an example, a long iodine chain complex structure is formed.

[0117] Exemplarily, referring to Figure 8 , taking iodine staining as an example, before stretching, PVA and iodine molecules are arranged randomly and do not have obvious polarization function; while through unidirectional stretching, the long iodine chains can be guided to be parallelly distributed along the stretching direction, and the conduction electrons contained in the iodine molecules can move along the molecular chain direction. When the light beam passes through the long iodine chains, the component parallel to the iodine chains in the incident light wave is strongly absorbed by the electrons, and the component perpendicular to the long iodine chains can pass through completely, thus forming the linearly polarized property manifested macroscopically.

[0118] In a feasible embodiment, the stretching of the extruded resin includes primary stretching and secondary stretching; the primary stretching is carried out in the vapor environment of the dichroic material at 70 - 90 °C, and the stretching ratio is 1.5 - 2.5 times; the secondary stretching is carried out at 20 - 25 °C, and the stretching ratio is 3 - 5 times. Since the primary stretching is mainly to form a bubble structure and combine the dichroic material with PVA, the stretching temperature will be higher than that during the secondary stretching, so that the PVA molecular chain segments are fully activated, the material rigidity is reduced, facilitating preliminary orientation and uniform adsorption of the dye, and at the same time, low-ratio stretching is carried out to avoid excessive disorientation or fracture of the molecular chains at high temperatures, and at the same time reserve space for subsequent high-ratio stretching. At low temperatures during the secondary stretching, the molecular chain mobility decreases, inhibiting disorientation, ensuring the stable extension of the molecular chains under stress, forming a highly oriented structure, and combining high-ratio stretching for forced orientation to enhance the arrangement density of the dichroic molecules and improve the degree of polarization.

[0119] Optionally, the stretching direction can be along the MD (Machine Direction) direction.

[0120] Optionally, referring to Figure 9 , in the case of primary stretching in the vapor environment of the dichroic material, the space occupied by the inorganic particles wrapped by the masterbatch 210 in the matrix resin 204 will form a multi-layer stacked bubble 202 pore structure, and the PVA molecules will also adhere to the inner wall of the bubble 202 pores. Then, the vapor of the dichroic material in the environment (for example, iodine vapor) will fill into the bubble 202 pores and combine with the PVA molecules on the inner wall of the bubble 202 pores. With the progress of the secondary stretching, the randomly arranged PVA molecular chains will form parallel long chains along the stretching direction, making the matrix resin 204 layer have obvious linear polarization. If the polarization direction of the light is perpendicular to the long axis direction of the dichroic molecular chains, the polarized light can pass through completely, otherwise the intensity of the transmitted light will be weakened or blocked accordingly to achieve the polarization effect.

[0121] Optionally, the steam temperature of the bidirectional material during one stretching may be 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, etc. If the stretching temperature is too high, the matrix resin may crystallize quickly, resulting in inability to continue stretching or breaking, and may also destroy the orientation uniformity of the PVA molecular chain and reduce the degree of polarization. If the stretching temperature is too low, it is difficult to achieve the vaporization of the bidirectional material. At the same time, the poor mobility of the PVA chain segments at low temperatures makes it difficult to fully embed the bidirectional material, affecting the polarization effect. Therefore, the embodiment of the present application determines that the steam temperature of the bidirectional material during one stretching can be 70 to 90°C.

[0122] Optionally, the stretching ratio in one stretching can be 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, etc. If the stretching ratio is too high, necking phenomenon is easily induced at high temperature, resulting in local stress concentration and film breakage, and if the stretching ratio is too low, the orientation is insufficient, and subsequent high-multiple stretching is difficult to make up for it, and the final polarization performance is poor. Therefore, the present application embodiment determines that the stretching ratio in one stretching is 1.5 to 2.5 times.

[0123] Optionally, the temperature of the secondary stretching can be 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, etc. If the temperature is too high during the secondary stretching, the molecular chains relax, which may offset the orientation effect of the high-multiple stretching and reduce the polarization degree. If the temperature is too low, the brittleness of the material increases and it is easy to break during high-multiple stretching. Therefore, the embodiment of the present application determines that the temperature during the secondary stretching is 20-25°C.

[0124] Optionally, the stretching ratio during secondary stretching can be 3 times, 3.2 times, 3.4 times, 3.6 times, 3.8 times, 4 times, 4.2 times, 4.4 times, 4.6 times, 4.8 times, 5 times, etc. If the stretching ratio during secondary stretching is too high, it may exceed the material fracture limit and directly cause the film to rupture. If the stretching ratio during secondary stretching is too low, the molecular chain orientation is insufficient, and the transmittance and extinction ratio of the polarizer are not up to standard. Therefore, the present application embodiment determines that the stretching ratio during secondary stretching is 3 to 5 times.

[0125] In this embodiment, a masterbatch composed of a first resin layer wrapping a plurality of inorganic particles is provided, and a PVA layer is further wrapped on the surface of each inorganic particle. Then, the matrix resin and the masterbatch are mixed and melt-extruded to obtain an extruded resin with uniformly distributed inorganic particles. Further, in a vapor environment of a dichroic material, the extruded resin is stretched. Since the inorganic particles wrapped in the extruded resin are inorganic materials, while the matrix resin is an organic material, and there are significant performance differences between the two, during the stretching process, the space occupied by the inorganic particles in the matrix resin will be further pulled and enlarged, thereby forming a multi-layer bubble structure with bubbles wrapping the inorganic particles. And in a vapor environment of a dichroic material (for example, in an iodine vapor environment), the dichroic material can be adsorbed by the PVA in the extruded resin as the extruded resin is stretched, and then as the stretching progresses, the PVA adheres to the inner wall of the formed bubble structure, forming a structure where the bubbles wrap the inorganic particles, and the inner wall of the bubbles is attached with a PVA layer combined with the dichroic material, forming a matrix resin layer to obtain a polarizer. Since the hardness of the matrix resin of the matrix resin layer is equivalent to the hardness level of the optical film adjacent to it in the display device, or has a greater hardness than the optical film, it can effectively avoid the situation that the lower polarizer (i.e., the polarizer) of the liquid crystal panel is scratched by the optical film of the backlight module. Further, since there is no need to worry about the scratching problem, the gap between the optical film and the liquid crystal panel in the display device can be reduced to narrow the overall thickness of the display device, which conforms to the development trend of the ultra-thinning of liquid crystal display products. Further, since the PVA layer combined with the dichroic material adheres to the inner wall of the bubbles in the matrix resin layer, and the bubbles are closed structures, it can better isolate the erosion of water vapor and improve the reliability of the polarizer. In addition, through the above solution, the TAC layer in the polarizer can be saved, thereby effectively reducing the cost of the polarizer.

[0126] In the third aspect of the embodiments of the present application, a liquid crystal panel is provided, and the liquid crystal panel includes the polarizer as described above, or a polarizer prepared by the polarizer preparation method as described above.

[0127] Optionally, referring to Figure 4 , the polarizer includes: a matrix resin layer 200, wherein the matrix resin layer 200 includes a plurality of embedded inorganic particles 201 and bubbles 202 wrapping the inorganic particles 201, and a PVA layer 203 combined with the dichroic material is attached to the inner wall of the bubbles 202.

[0128] Optionally, the hardness of the matrix resin is greater than or equal to a first hardness, wherein the first hardness is less than the hardness of the optical film adjacent to the polarizer in the display device, and the pencil hardness difference from the hardness of the optical film is 3.

[0129] Optionally, the pencil hardness difference between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3.

[0130] Optionally, the material of the matrix resin is the same as that of the optical film adjacent to the polarizer in the display device.

[0131] Optionally, the material of the matrix resin includes at least one of PET, PS, and PMMA.

[0132] Optionally, the inorganic particles include at least one of CaSO4 and BaCO3.

[0133] Optionally, the size of the inorganic particles is 5 to 10 nm.

[0134] Optionally, referring to Figure 10 , the liquid crystal panel includes a first polarizer 28, a first glass substrate 21, a thin-film transistor 22, a liquid crystal layer 23, a filter film 24, a second glass substrate 25, and a second polarizer 29 that are sequentially stacked from the light-incident direction to the light-emitting direction. The first polarizer 28 is the polarizer adjacent to the optical film in the display device. Therefore, the polarizer described in the embodiments of the present application can be used. Among them, the structure of the polarizer refers to Figure 4 , so as to avoid it being scratched by the optical film. Also, since the first polarizer 28 can save the TAC layer, the cost of the polarizer and the liquid crystal panel can be effectively reduced. The second polarizer 29 can also use the polarizer described in the embodiments of the present application, or a conventional polarizer as shown in Figure 1 . The embodiments of the present application do not limit this.

[0135] In the fourth aspect of the embodiments of the present application, a display device is provided. The display device includes: a polarizer as described above, or a polarizer prepared by the polarizer preparation method as described above, or a liquid crystal panel as described above.

[0136] Optionally, referring to Figure 4 , the polarizer includes: a matrix resin layer 200. Among them, the matrix resin layer 200 includes a plurality of embedded inorganic particles 201 and air bubbles 202 that wrap the inorganic particles 201. A PVA layer 203 combined with a dichroic material is attached to the inner wall of the air bubbles 202.

[0137] Optionally, the hardness of the matrix resin is greater than or equal to a first hardness, where the first hardness is less than the hardness of the optical film adjacent to the polarizer in the display device, and the pencil hardness difference from the hardness of the optical film is 3.

[0138] Optionally, the pencil hardness difference between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3.

[0139] Optionally, the material of the base resin is the same as that of the optical film adjacent to the polarizer in the display device.

[0140] Optionally, the material of the base resin includes at least one of PET, PS, and PMMA.

[0141] Optionally, the inorganic particles include at least one of CaSO4 and BaCO3.

[0142] Optionally, the size of the inorganic particles is 5 - 10 nm.

[0143] Optionally, the display device includes a liquid crystal panel and a backlight module; referring to Figure 10 , the liquid crystal panel includes a first polarizer 28, a first glass substrate 21, thin film transistors 22, a liquid crystal layer 23, a filter film 24, a second glass substrate 25, and a second polarizer 29 that are sequentially stacked from the light incident direction to the light exiting direction. The first polarizer 28 is the polarizer adjacent to the optical film in the display device. Therefore, the polarizer described above in the embodiments of the present application can be used. Among them, the structure of the polarizer refers to Figure 4 . In the display device, the first polarizer 28 is adjacent to the optical film on the light exiting side of the backlight module. Since the first polarizer 28 has at least a hardness level equivalent to that of the optical film, or has a greater hardness than the optical film, the situation where the first polarizer 28 is scratched by the optical film is effectively avoided. Furthermore, the gap between the first polarizer 28 and the optical film in the display device can be further reduced to about 3 mm (the conventional gap is 8 - 10 mm), thereby reducing the overall thickness of the machine, achieving a more superior appearance, and conforming to the development trend of the ultra-thinning of liquid crystal display products. At the same time, due to the improvement of the scratching problem, the embodiments of the present application can also omit the lower buffer pad and the front buffer pad that are additionally added in the overall packaging of the display device to avoid scratching in the conventional solution, reduce costs, and reduce the packaging volume of the display device.

[0144] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

Claims

1. A polarizer, characterized in that, The polarizer includes: A matrix resin layer, wherein the matrix resin layer includes a plurality of embedded inorganic particles and air bubbles that enclose the inorganic particles, and a PVA layer combined with a dichroic material is attached to the inner wall of the air bubbles.

2. The polarizer according to claim 1, wherein The hardness of the matrix resin is greater than or equal to a first hardness, wherein the first hardness is less than the hardness of the optical film adjacent to the polarizer in the display device, and the pencil hardness difference from the hardness of the optical film is 3.

3. The polarizer according to claim 1, wherein The pencil hardness difference between the hardness of the matrix resin and the hardness of the optical film adjacent to the polarizer in the display device is less than or equal to 3.

4. The polarizer according to claim 1, wherein, The material of the matrix resin is the same as the material of the optical film adjacent to the polarizer in the display device.

5. The polarizer according to any one of claims 1 to 4, wherein The material of the matrix resin includes at least one of PET, PS, and PMMA.

6. The polarizer according to claim 1, wherein The inorganic particles include at least one of CaSO4 and BaCO3; And / or, the size of the inorganic particles is 5 to 10 nm.

7. A method for preparing a polarizer, characterized in that, The method for preparing the polarizer is applied to prepare the polarizer according to any one of claims 1 to 6, and includes the following steps: Providing a masterbatch, wherein the masterbatch includes a first resin layer and a plurality of inorganic particles wrapped by the first resin layer, and a PVA layer is wrapped on the surface of each inorganic particle; Mixing the matrix resin and the masterbatch to obtain a mixed material; Performing melt extrusion on the mixed material to obtain an extruded resin; Under the vapor environment of the dichroic material, stretching the extruded resin to form a matrix resin layer, thereby obtaining the polarizer.

8. The method for preparing a polarizer according to claim 7, wherein The doping concentration of the inorganic particles in the masterbatch is 5 to 8%, and the mass ratio of the masterbatch in the mixed material is 8 to 15%.

9. A liquid crystal panel, characterized in that, The liquid crystal panel includes the polarizer according to any one of claims 1 to 6, or a polarizer prepared by the method for preparing the polarizer according to claim 7 or 8.

10. A display device, characterized in that, The display device includes the polarizer according to any one of claims 1 to 6, or a polarizer prepared by the method for preparing the polarizer according to claim 7 or 8.

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