Method for preparing polarizing plate, polarizing plate and display device

Abstract

The present invention belongs to the technical field of optical devices, and specifically relates to a method for preparing a polarizing plate, a polarizing plate and a display device, comprising a PVA film, a TAC film, a protective film, a pressure-sensitive adhesive and a release film, wherein a protrusion is arranged at the edge of the release film, and a hygroscopic cotton strip is attached to the surface of the protrusion facing the TAC film; after the polarizing plate is cut, the end faces of the PVA film and the TAC film in the cross section are usually exposed to the external moisture, and water vapor will corrode from the edge to produce white edges, thereby affecting the display effect; therefore, the present invention arranges a protrusion on the release film as a carrier for attaching the hygroscopic cotton strip, and wraps the end face of the edge of the polarizing plate, and then packages and stores the polarizing plate. During the placement of the polarizing plate, when the water vapor contacts the end faces of the PVA film and the TAC film in the cross section of the polarizing plate, it is absorbed by the wrapped hygroscopic cotton strip, thereby preventing the water vapor from corroding the end faces of the PVA film and the TAC film of the polarizing plate to cause white edges.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical devices, and in particular to a method for preparing a polarizing plate, a polarizing plate and a display device. Background Art

[0002] The polarizing plate is the core component of the liquid crystal display. It is attached to the upper and lower sides of the liquid crystal glass and cooperates with the rotation of the liquid crystal to control whether the light passes through the liquid crystal panel to achieve the display effect. The polarizing plate is mainly made of a composite of PVA film, TAC film, protective film, release film and pressure-sensitive adhesive.

[0003] Among them, TAC film is an important material in the production process of liquid crystal displays. It is mainly used to protect polarizing plates. The polarizing plate itself is made of polyvinyl alcohol film that is impregnated with iodide solution and then stretched longitudinally to orient the iodine molecules, thereby forming a polarizing film that has a polarizing effect on light. The thickness of the polarizing film after stretching is about 20μm, and the mechanical strength is very poor. In addition, the oriented iodine molecules are easily affected by external moisture and change their orientation degree, that is, affecting the polarization effect. For this reason, TAC film is pasted on both sides of the PVA polarizing film to improve its physical and mechanical properties and protect it from the influence of external moisture.

[0004] Due to the bottleneck of the physical and chemical properties of iodine molecules, the current temperature and humidity weather resistance level of ordinary iodine-based polarizers is 60℃*90%RH, which can only meet the weather resistance requirements of general consumer and industrial display instruments; and with the expansion of display products in the fields of high-end industrial control, water, electricity and steam instruments and automotive displays, the temperature and humidity weather resistance requirements have risen sharply, reaching a weather resistance level of 80℃*90%RH. Therefore, a protective film based on PET is introduced to cover the surface of the traditional TAC film, which is used to protect the polarizer body from damage on the one hand, and to improve the weather resistance of the polarizer on the other hand.

[0005] After the preparation of the polarizing plate, it needs to be cut. The end faces of the PVA film and TAC film in the cross section of the cut polarizing plate are usually exposed to the outside air. The water vapor in the air will corrode from the edges to produce white edges, which will then affect the display effect. At the same time, the TAC film in the polarizing plate affected by water vapor will also warp, further affecting the performance of the polarizing plate.

[0006] In view of this, in order to solve the problem that the cut end surface of the polarizing plate may be corroded by water vapor, the present invention proposes a method for preparing a polarizing plate, a polarizing plate and a display device. Summary of the invention

[0007] In order to address the deficiencies in the prior art, the present invention provides a method for preparing a polarizing plate, a polarizing plate and a display device; the problem that after the polarizing plate is cut, the end faces of the PVA film and the TAC film in the cross section are usually exposed to the external moisture, and the water vapor will corrode from the edges to produce white edges, which will then affect the display effect. The edges of the polarizing plate are usually sealed with glue and water-proofed after the polarizing plate is pasted to control the shrinkage of the white edges, but in the process of preparing the polarizing plate, it is difficult to effectively and immediately isolate the erosion of water vapor.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A polarizing plate according to the present invention comprises:

[0010] PVA film;

[0011] TAC film, two layers of TAC film are attached to both sides of the PVA film;

[0012] Protective film: the protective film is attached to the TAC film on one side of the PVA film, and the protective film is made of PET film;

[0013] Pressure-sensitive adhesive, which is coated on the TAC film on the other side of the PVA film;

[0014] Release film, the release film is attached to the surface of the pressure-sensitive adhesive;

[0015] The polarizing plate has a structure of protective film-TAC film-PVA film-TAC film-pressure-sensitive adhesive-release film;

[0016] The edge of the release film is provided with a protrusion, and a hygroscopic cotton strip is attached to the surface of the protrusion facing the TAC film. The hygroscopic cotton strip is filled with a polymer of a water-absorbing resin, and the hygroscopic cotton strip is in a strip shape and wrapped around the edge of the polarizing plate.

[0017] Preferably, the polarizing plate is provided with a concave portion at its end face in the thickness direction, and the concave portion is realized by making the size of the PVA film smaller than the TAC films on both sides thereof, and the size of the TAC film smaller than the protective film and release film on its outer side.

[0018] Preferably, the inner recesses are arranged on opposite sides of the polarizing plate.

[0019] Preferably, a flange is further provided on the protruding portion of the release film, the flange faces the TAC film, and a dent is provided on the surface of the hygroscopic cotton strip in contact with the flange.

[0020] Preferably, the top end of the flange is higher than the position of the uppermost TAC film in the polarizing plate.

[0021] Preferably, the end surface of the polarizing plate along the thickness direction is wrapped with a POF film, and the POF film and the flange wrap the hygroscopic cotton strip surrounding the polarizing plate.

[0022] Preferably, the POF film is further coated with a PE strip fixed therein, the PE strip is wound along the POF film and distributed on the end surface of the polarizing plate, and the end of the PE strip is bonded and fixed to the surface of the release film.

[0023] Preferably, the surface of the PE strip is further provided with a blade surface, and the blade surface is parallel to the surface of the POF film.

[0024] The present invention provides a method for preparing a polarizing plate, which is applicable to the above-mentioned polarizing plate, and the steps of the method are as follows:

[0025] S1. Initial process: including pretreatment of TAC film and stretching and compounding of PVA film; wherein the pretreatment of TAC film is carried out by treating TAC film with alkali solution, washing residual alkali solution in a water washing tank, drying and rolling, and the main purpose of the pretreatment process is to reduce the contact angle of TAC film, so as to facilitate the lamination with PVA film; the stretching and compounding of PVA film is carried out by immersing PVA film swollen with pure water into a dyeing tank, absorbing biaxially absorbed iodine molecules, and then stretching and oriented iodine molecules in a stretching tank, and after drying, compounding PVA film with two layers of pretreated TAC film to obtain polarizing film;

[0026] S2, middle process: based on the polarizing film prepared in the first process, the pressure-sensitive adhesive is then coated on the release film, and after the water in the pressure-sensitive adhesive is evaporated in an oven, the release film and the PET film are respectively attached to the two sides of the polarizing film produced in the first process, wherein the area of ​​the release film is 1.1-1.2 times the size of the polarizing film, and the edge of the release film is flanged by a hot press, and then placed in a constant temperature curing room for curing to form a polarizing plate semi-finished product with a protective film-TAC film-PVA film-TAC film-pressure-sensitive adhesive-release film structure;

[0027] S3, post-process: the semi-finished polarizing plate cured in the middle process is cut, edged, cleaned, inspected and packaged according to the required size. When the polarizing plate is packaged, the hygroscopic cotton strip is attached to the flange of the release film on the polarizing plate, and then the POF film is used to wrap along the edge of the polarizing plate to prepare the finished polarizing plate.

[0028] A display device described in the present invention comprises a display panel, and the above-mentioned polarizing plates are attached to both sides of the display panel.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. The polarizing plate described in the present invention uses a protruding portion on a release film as a carrier for attaching a hygroscopic cotton strip, and wraps the end face of the edge of the polarizing plate, and then the polarizing plate is packaged and stored. During the placement of the polarizing plate, when water vapor contacts the end faces of the PVA film and the TAC film in the cross section of the polarizing plate, it is absorbed by the wrapped hygroscopic cotton strip. The water-absorbing resin filled in the hygroscopic cotton strip further enhances the water absorption of the hygroscopic cotton strip, thereby preventing water vapor from eroding into the polarizing plate and causing white edges, and further preventing the TAC film from warping.

[0031] 2. The polarizing plate described in the present invention adopts a polarizing plate in a sealed package, so that the hygroscopic cotton strip wrapped at the end of the polarizing plate plays a protective and buffering role for the stored polarizing plate. When the polarizing plate is attached to the display panel, the hygroscopic cotton strip wrapped around it can be taken away by tearing off the release film, and the edges of the display panel and the polarizing plate are sealed with glue and water-proofed. The space in the inner recess is used to ensure that the ends of the PVA film and the TAC film are coated with sufficient glue for packaging to maintain the sealing performance.

[0032] 3. The polarizing plate described in the present invention forms an inner concave portion on the end face of the thickness dimension of the polarizing plate by arranging the PVA film, TAC film, protective film and release film in the polarizing plate with different sizes, and then the attached hygroscopic cotton strip is surrounded along the inner concave portion of the polarizing plate to maintain the contact state between the hygroscopic cotton strip and the end portions of the PVA film and TAC film in the polarizing plate, thereby reducing the water vapor erosion of the PVA film and TAC film in the polarizing plate.

[0033] 4. A display device described in the present invention reduces water vapor erosion on the PVA film and TAC film end surfaces of the polarizing plate during the process from production to installation on the display panel by installing the above-mentioned polarizing plate in the display panel of the display device and utilizing the hygroscopic cotton strips and POF film used for packaging on the end surfaces of the polarizing plate, thereby reducing the possibility of white edges appearing on the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] Figure 1 is a schematic diagram of the polarizing plate structure of the present invention;

[0036] Figure 2 is a schematic diagram of the structure of the polarizing plate after the hygroscopic tampon is expanded in the present invention;

[0037] Figure 3 is a three-dimensional diagram of the polarizing plate of the present invention;

[0038] Figure 4 is a partial cross-sectional view of the polarizing plate of the present invention;

[0039] Figure 5 yes Figure 4 A partial enlarged view of the middle A;

[0040] In the figure: 1. PVA film; 2. TAC film; 3. Protective film; 4. Pressure-sensitive adhesive; 5. Release film; 51. Protrusion; 52. Flanging; 6. Hygroscopic cotton strip; 61. Water-absorbent resin; 62. Indentation; 7. Concave portion; 8. POF film; 9. PE strip; 91. Blade surface. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical means and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The embodiments of the present invention provide a method for preparing a polarizing plate, a polarizing plate and a display device, which solve the problem that after cutting, the end faces of the PVA film and the TAC film of the cross section of the existing polarizing plate are usually exposed to the external moisture, and the water vapor will corrode from the edge to produce white edges, which will then affect the display effect. The edge of the polarizing plate is usually sealed with glue and water-proofed after the polarizing plate is pasted to control the shrinkage of the generated white edges, but in the process of preparing the polarizing plate, it is difficult to immediately and effectively isolate the erosion of water vapor.

[0043] The technical solution in the embodiment of the present invention is to solve the above technical problems, and the overall idea is as follows: a protrusion is provided on the release film as a carrier for attaching a hygroscopic cotton strip, and the end face of the edge of the polarizing plate is wrapped around and then the polarizing plate is packaged and stored. During the placement of the polarizing plate, when water vapor contacts the end faces of the PVA film and the TAC film of the cross section of the polarizing plate, it is absorbed by the hygroscopic cotton strip wrapped around and around, and the water-absorbing resin filled in the hygroscopic cotton strip further enhances the water absorption of the hygroscopic cotton strip, thereby preventing water vapor from eroding the end faces of the PVA film and the TAC film of the polarizing plate and causing white edges;

[0044] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0045] like Figure 1-4 As shown, a polarizing plate according to the present invention comprises:

[0046] PVA film 1;

[0047] TAC film 2, two layers of TAC film 2 are respectively attached to both sides of the PVA film 1;

[0048] A protective film 3, the protective film 3 is attached to the TAC film 2 on one side of the PVA film 1, and the protective film 3 is made of PET film;

[0049] A pressure-sensitive adhesive 4 is coated on the TAC film 2 on the other side of the PVA film 1;

[0050] A release film 5, the release film 5 is attached to the surface of the pressure-sensitive adhesive 4;

[0051] The polarizing plate has a structure of protective film 3-TAC film 2-PVA film 1-TAC film 2-pressure sensitive adhesive 4-release film 5;

[0052] The edge of the release film 5 is provided with a protrusion 51, and a hygroscopic cotton strip 6 is attached to the surface of the protrusion 51 facing the TAC film 2. The hygroscopic cotton strip 6 is filled with a polymer of a water-absorbing resin 61, and the hygroscopic cotton strip 6 is in a strip shape and wrapped around the edge of the polarizing plate.

[0053] In the process from the preparation of the polarizing plate to the patch, the polarizing plate composed of a multi-layer film structure is mostly about 0.2 mm thick, which makes it difficult to fix the hygroscopic cotton strip 6 directly in the thickness direction of the polarizing plate, and the hygroscopic cotton strip 6 is difficult to stably adhere. The protrusion 51 set on the release film 5 is used as a carrier for attaching the hygroscopic cotton strip 6, and the end face of the edge of the polarizing plate is wrapped around and then the polarizing plate is packaged and stored. During the placement of the polarizing plate, water vapor contacts the PVA film 1 and TAC film of the cross section of the polarizing plate. 2, it is absorbed by the hygroscopic cotton strip 6 wrapped around it, and the water-absorbing resin 61 filled inside the hygroscopic cotton strip 6 further enhances the water absorption of the hygroscopic cotton strip 6 to prevent water vapor from corroding into the polarizing plate and causing white edges. The polarizing plate is sealed and packaged, so that the hygroscopic cotton strip 6 wrapped around the end of the polarizing plate plays a protective and buffering role for the stored polarizing plate. When the polarizing plate is attached to the display panel, the hygroscopic cotton strip 6 wrapped around it can be taken away by tearing off the release film 5, and the edges of the display panel and the polarizing plate are sealed and water-proofed.

[0054] As an embodiment of the present invention, Figure 1 , 4As shown, the polarizing plate is provided with an inner concave portion 7 at the end face in the thickness direction, and the inner concave portion 7 is realized by making the size of the PVA film 1 smaller than the TAC film 2 on both sides thereof, and the size of the TAC film 2 smaller than the protective film 3 and the release film 5 on the outside thereof; the thickness of the polarizing plate itself is about 0.2 mm, and within this size, it is difficult for the attached hygroscopic cotton strip 6 to be stably wrapped on the end face of the polarizing plate, and the gap between the strip-shaped hygroscopic cotton strip 6 and the polarizing plate will be corroded by water vapor; by arranging the PVA film 1, TAC film 2, protective film 3 and release film 5 in the polarizing plate to have non- The same size is used to form an inner concave portion 7 on the end face of the thickness dimension of the composed polarizing plate, and then the attached hygroscopic cotton strip 6 is surrounded along the inner concave portion 7 of the polarizing plate to maintain the contact state between the hygroscopic cotton strip 6 and the ends of the PVA film 1 and the TAC film 2 in the polarizing plate, thereby reducing the water vapor erosion of the PVA film 1 and the TAC film 2 in the polarizing plate; the size of the inner concave portion 7 formed by the edge of the PVA film in the polarizing plate is controlled within 1 mm, and the size of the inner concave portion 7 is integrated into the black border area of ​​1-2 mm of the frame of the display panel assembled by the polarizing plate to avoid interference with the display of the polarizing plate.

[0055] As an embodiment of the present invention, Figure 1 , 4 As shown, the recessed portion 7 is arranged on the opposite sides of the polarizing plate; during the preparation process of the polarizing plate, in order to maintain the shape of the recessed portion 7 formed on the end face in the thickness direction of the polarizing plate, it is necessary to attach PVA films 1 and TAC films 2 of different sizes together, and by setting the width of the TAC film 2 in the rolled state to be greater than that of the PVA film 1, the composite TAC film 2 and the PVA film 1 form the shape of the recessed portion 7 on both sides of the width, and then after the polarizing plate is cut, the recessed portion 7 is formed on the opposite sides, and when the polarizing plate is patched and packaged to the display panel, the space of the recessed portion 7 is used to facilitate the application of sealing glue for water-proofing treatment, and the space of the recessed portion 7 is used to ensure that the ends of the PVA film and the TAC film are coated with sufficient glue for packaging to maintain the sealing performance.

[0056] As an embodiment of the present invention, Figure 1-4As shown, the protruding portion 51 of the release film 5 is also provided with a flange 52, and the flange 52 faces the TAC film 2. The surface of the hygroscopic cotton strip 6 in contact with the flange 52 is provided with a dent 62; the hygroscopic cotton strip 6 surrounding the polarizing plate in the thickness direction maintains its stability through the provided inner concave portion 7, and the hygroscopic cotton strip 6 expands after absorbing a certain amount of water, and the hygroscopic cotton strip 6 surrounds the inner concave portion 7 of the polarizing plate, and then the expanded hygroscopic cotton strip 6 causes the edge of the attached release film 5 to be displaced and detached from the polarizing plate, thereby destroying the protective effect of the release film 5 on the pressure-sensitive adhesive 4; the flange 52 provided on the release film 5 makes the hygroscopic cotton strip 6 The attached surface is on the flange 52 of the release film 5, and the flange 52 on the edge of the release film 5 is used as a margin for bearing the deformation caused by the expansion of the hygroscopic cotton strip 6, thereby reducing the deformation of the contact surface between the release film 5 and the pressure-sensitive adhesive 4, and the deformation of the hygroscopic cotton strip 6 after absorbing moisture only drives the deformation of the flange 52 of the release film 5, and the gap formed between the indentation 62 on the hygroscopic cotton strip 6 and the flange 52 serves as a deformation margin when the hygroscopic cotton strip 6 expands, thereby avoiding squeezing and damage to the inner concave portion 7 of the polarizing plate when the hygroscopic cotton strip 6 expands, thereby maintaining the stability of the main area where the release film 5 is attached to the surface of the pressure-sensitive adhesive, and maintaining the protective effect of the release film 5 on the pressure-sensitive adhesive 4.

[0057] As an embodiment of the present invention, Figure 1-4 As shown, the top of the flange 52 is higher than the position of the uppermost TAC film 2 in the polarizing plate; during the molding process of the TAC film 2 in the polarizing plate, the residual formula components or residual amounts of the inner and outer layers are different, resulting in different hydrophilic degrees, causing the TAC film 2 to extend more than the inner layer after absorbing water and cause warping. By setting the height of the flange 52 on the release film 5 to be greater than the position of the TAC film 2 in the polarizing plate, it is ensured that the absorbent cotton strip attached to the flange 52 completely covers the end surface of the TAC film 2 in the polarizing plate, and the flange 52 of the release film 5 is used to limit the hygroscopic cotton strip 6.

[0058] As an embodiment of the present invention, Figure 1-4 As shown, the end face of the polarizing plate along the thickness direction is wrapped with a POF film 8, and the POF film 8 and the flange 52 wrap the hygroscopic cotton strip 6 surrounding the polarizing plate; due to the strong hygroscopicity of the hygroscopic cotton strip 6 and the environment maintaining a certain amount of moisture, the hygroscopic cotton strip 6 is directly exposed to the environment to prevent the polarizing plate from being corroded by water vapor, but at the same time, the hygroscopic cotton strip 6 will be caused corresponding loss, and the wrapped POF film 8 is provided to cover the surface of the hygroscopic cotton strip 6 exposed in the flange 52 of the release film 5, and the water-proof property of the POF film 8 is utilized to slow down the loss of the hygroscopic cotton strip 6 caused by the environmental water vapor, and the wrapped and attached POF film 8 can reinforce the posture of the hygroscopic cotton strip 6 wrapped around the end face of the polarizing plate.

[0059] As an embodiment of the present invention, Figure 1-5 As shown, the POF film 8 is also coated and fixed with a PE strip 9, which is wound along the POF film 8 and distributed on the end surface of the polarizing plate, and the end of the PE strip 9 is bonded and fixed to the surface of the release film 5; the POF film 8 is used to wrap up the hygroscopic cotton strip 6 and the flange 52 of the release film 5 in the circumferential direction of the polarizing plate to keep the dryness of the polarizing plate, and when the release film 5 is torn off when the polarizing plate is installed, the wound POF film 8 will cause interference, and by coating and fixing the PE strip 9 therein, the tearing trajectory of the POF film 8 is guided by the PE strip 9 when the release film 5 is torn off, so that the release film 5 and the POF film 8 used for packaging can be conveniently removed when the polarizing plate is installed.

[0060] As an embodiment of the present invention, Figure 5 As shown, the surface of the PE strip 9 is also provided with a blade surface 91, and the blade surface 91 is parallel to the surface of the POF film 8; when the POF film 8 is wrapped and packaged on the polarizing plate, the blade surface 91 of the PE strip 9 is parallel to the POF film 8, so as to prevent the polarizing plate from being cut by the blade surface 91 on the PE strip 9 due to external forces during storage and transportation, and when tearing off the release film 5, the PE strip 9 moves along with the release film 5 fixed at its end in a direction perpendicular to the surface of the polarizing plate, so that the blade surface 91 on the PE strip 9 has a cutting effect on the contacted POF film 8, so that the wrapped POF film is separated, and then the film tearing tape is used to stick out the POF film remaining on the polarizing plate for cleaning, so as to maintain the convenient removal effect of the POF film 8.

[0061] The present invention provides a method for preparing a polarizing plate, which is applicable to the above-mentioned polarizing plate, and the steps of the method are as follows:

[0062] S1, the initial process: including the pretreatment of the TAC film 2 and the stretching and compounding of the PVA film 1; wherein the pretreatment of the TAC film 2 is carried out by treating the TAC film 2 with alkali solution, washing the residual alkali solution in a water washing tank, and then drying and rolling it up. The main purpose of the pretreatment process is to reduce the contact angle of the TAC film 2 to facilitate the lamination with the PVA film 1; the stretching and compounding of the PVA film 1 is carried out by immersing the PVA film 1 swollen with pure water into a dyeing tank to adsorb the biaxially absorbed iodine molecules, and then stretching and orienting the iodine molecules in a stretching tank, and after drying, compounding the PVA film 1 with the two layers of the pretreated TAC film 2 to obtain a polarizing film;

[0063] S2, middle process: based on the polarizing film prepared in the first process, the pressure-sensitive adhesive 4 is then coated on the release film 5, and after the water in the pressure-sensitive adhesive 4 is evaporated in an oven, the release film 5 and the PET film are respectively attached to the two sides of the polarizing film produced in the first process, wherein the area of ​​the release film 5 is 1.1-1.2 times the size of the polarizing film, and the edge of the release film 5 is flanged 52 by a hot press, and then placed in a constant temperature curing room for curing to form a polarizing plate semi-finished product with a structure of protective film 3-TAC film 2-PVA film 1-TAC film 2-pressure-sensitive adhesive 4-release film 5;

[0064] S3, post-process: the semi-finished polarizing plate cured in the middle process is cut, edged, cleaned, inspected and packaged according to the required size. When the polarizing plate is packaged, the hygroscopic cotton strip 6 is attached to the flange 52 of the release film 5 on the polarizing plate, and then the POF film 8 is used to wrap along the edge of the polarizing plate to prepare the finished polarizing plate.

[0065] A display device described in the present invention includes a display panel, and the above-mentioned polarizing plates are attached to both sides of the display panel; the above-mentioned polarizing plates are installed in the display panel of the display device, and the hygroscopic cotton strips 6 and POF films 8 used for packaging are used on the end faces of the polarizing plates to reduce the water vapor erosion of the end faces of the PVA film 1 and the TAC film 2 of the polarizing plates during the process from production to installation on the display panel, thereby reducing the possibility of white edges appearing on the display panel.

[0066] The specific workflow is as follows:

[0067] The protrusion 51 provided on the release film 5 is used as a carrier for attaching the hygroscopic cotton strip 6, and wraps the end face of the edge of the polarizing plate, and then the polarizing plate is packaged and stored. During the placement of the polarizing plate, when the water vapor contacts the end faces of the PVA film 1 and the TAC film 2 of the cross section of the polarizing plate, it is absorbed by the hygroscopic cotton strip 6 wrapped around it. The water-absorbing resin 61 filled inside the hygroscopic cotton strip 6 further enhances the water absorption of the hygroscopic cotton strip 6, and prevents the water vapor from corroding into the polarizing plate and causing white edges. The polarizing plate with sealed packaging makes the hygroscopic cotton strip 6 wrapped around the end of the polarizing plate, The stored polarizing plate plays a protective and buffering role. When the polarizing plate is attached to the display panel, the hygroscopic cotton strip 6 wrapped around it can be taken away by tearing off the release film 5, and the edges of the display panel and the polarizing plate are sealed with glue and water-proofed. The PVA film 1, TAC film 2, protective film 3 and release film 5 in the polarizing plate are set to have different sizes, so that the composed polarizing plate forms an inner concave portion 7 on the end face of its thickness dimension, and then the attached hygroscopic cotton strip 6 is surrounded along the inner concave portion 7 of the polarizing plate to maintain the contact state between the hygroscopic cotton strip 6 and the ends of the PVA film 1 and the TAC film 2 in the polarizing plate. , reducing the water vapor erosion of the PVA film 1 and the TAC film 2 in the polarizing plate; the flange 52 set on the release film 5 makes the attached surface of the hygroscopic cotton strip 6 on the flange 52 of the release film 5, and the flange 52 on the edge of the release film 5 is used as a margin to withstand the deformation caused by the expansion of the hygroscopic cotton strip 6, thereby reducing the deformation of the contact surface between the release film 5 and the pressure-sensitive adhesive 4, and the deformation of the hygroscopic cotton strip 6 after absorbing moisture only drives the flange 52 of the release film 5 to deform, and the gap formed between the indentation 62 on the hygroscopic cotton strip 6 and the flange 52 is used as a deformation margin when the hygroscopic cotton strip 6 expands, avoiding When the non-hygroscopic cotton strip 6 expands, it squeezes and damages the inner concave part 7 of the polarizing plate, thereby maintaining the stability of the main area where the release film 5 is attached to the surface of the pressure-sensitive adhesive; when the POF film 8 is wrapped around the polarizing plate, the blade surface 91 of the PE strip 9 is parallel to the POF film 8, and when the release film 5 is torn off, the PE strip 9 moves along with the release film 5 fixed at its end in a direction perpendicular to the surface of the polarizing plate, so that the blade surface 91 on the PE strip 9 has a cutting effect on the contacted POF film 8, so that the wrapped POF film is separated, and then the POF film remaining on the polarizing plate is sticked out with a tearing tape for cleaning.

[0068] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A polarizing plate, characterized in that: include: PVA film (1); TAC film (2), two layers of TAC film (2) are respectively attached to both sides of the PVA film (1); A protective film (3), the protective film (3) is attached to the TAC film (2) on one side of the PVA film (1), and the protective film (3) is a PET film; A pressure-sensitive adhesive (4), the pressure-sensitive adhesive (4) being coated on the TAC film (2) on the other side of the PVA film (1); A release film (5), the release film (5) being attached to the surface of the pressure-sensitive adhesive (4); The polarizing plate has a structure of protective film (3)-TAC film (2)-PVA film (1)-TAC film (2)-pressure-sensitive adhesive (4)-release film (5); The edge of the release film (5) is provided with a protruding portion (51), and a hygroscopic cotton strip (6) is attached to the surface of the protruding portion (51) facing the TAC film (2), and the inside of the hygroscopic cotton strip (6) is filled with a polymer of a water-absorbing resin (61), and the hygroscopic cotton strip (6) is in a strip shape and wrapped around the edge of the polarizing plate; The polarizing plate is provided with inner recesses (7) at two opposite side ends; The inner recess (7) is arranged on opposite sides of the polarizing plate; The protruding portion (51) of the release film (5) is also provided with a flange (52), the flange (52) faces the TAC film (2), and a concave mark (62) is provided on the surface of the hygroscopic cotton strip (6) in contact with the flange (52); The end face of the polarizing plate along its thickness direction is wrapped with a POF film (8), and the POF film (8) and the flange (52) wrap up the hygroscopic cotton strip (6) surrounding the polarizing plate.

2. The polarizing plate according to claim 1, characterized in that: The top end of the flange (52) is higher than the position of the uppermost TAC film (2) in the polarizing plate.

3. The polarizing plate according to claim 1, characterized in that: The POF film (8) is also coated with a PE strip (9) fixed therein. The PE strip (9) is wound along the POF film (8) and distributed on the end surface of the polarizing plate. The end of the PE strip (9) is bonded and fixed to the surface of the release film (5).

4. The polarizing plate according to claim 3, characterized in that: The surface of the PE strip (9) is also provided with a blade surface (91), and the blade surface (91) is parallel to the surface of the POF film (8).

5. A method for preparing a polarizing plate, characterized in that: The method is applicable to the polarizing plate described in any one of claims 1 to 4, and the steps of the method are as follows: S1, the initial process: including the pretreatment of the TAC film (2) and the stretching and compounding of the PVA film (1); wherein the pretreatment of the TAC film (2) is performed by treating the TAC film (2) with alkali solution, washing the residual alkali solution in a water washing tank, and then drying and rolling it up; the stretching and compounding of the PVA film (1) is performed by immersing the PVA film (1) swollen with pure water into a dyeing tank to adsorb the biaxially absorbed iodine molecules, and then stretching and orienting the iodine molecules in a stretching tank, and after drying, compounding the PVA film (1) with the two layers of the pretreated TAC film (2) to obtain a polarizing film; S2, middle process: based on the polarizing film prepared in the first process, the pressure-sensitive adhesive (4) is then coated on the release film (5), and after the water in the pressure-sensitive adhesive (4) is evaporated in an oven, the release film (5) and the PET film are respectively attached to the two sides of the polarizing film produced in the first process, wherein the area of ​​the release film (5) is 1.1-1.2 times the size of the polarizing film, and the edge of the release film (5) is flanged (52) by a hot press, and then placed in a constant temperature curing room for curing, to form a polarizing plate semi-finished product with a structure of protective film (3)-TAC film (2)-PVA film (1)-TAC film (2)-pressure-sensitive adhesive (4)-release film (5); S3, post-process: cutting, edge grinding, cleaning, inspecting and packaging the semi-finished polarizing plate cured in the intermediate process according to the required size. When packaging the polarizing plate, a hygroscopic cotton strip (6) is attached to the flange (52) of the release film (5) on the polarizing plate, and then a POF film (8) is used to wrap around the edge of the polarizing plate to prepare a finished polarizing plate.

6. A display device, characterized in that: The display device is applicable to the polarizing plate described in any one of claims 1 to 4, and comprises a display panel, and the polarizing plates described above are attached to both sides of the display panel.

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