KR102135497B1 - Polarizing plate and liquid crystal display comprising the same - Google Patents

Abstract

This application is a coated polarizing plate; And it is provided on one surface of the coating-type polarizing plate, a laminated polarizing plate comprising a stretched unstained polyvinyl alcohol-based film and a liquid crystal display device including the same.

Description

A polarizing plate and a liquid crystal display device including the same {POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY COMPRISING THE SAME}

The present application relates to a polarizing plate and a liquid crystal display device including the same.

Recently, as interest in information display has been heightened and the demand to use a portable information medium has increased, a lightweight thin-film flat panel display (FPD) that replaces the existing display device, a cathode ray tube (CRT), Korea's research and commercialization are focused. In particular, among these flat panel display devices, a liquid crystal display (LCD) is a device that expresses an image using optical anisotropy of a liquid crystal, and is excellent in resolution, color display, and image quality, and is actively applied to laptops or desktop monitors. have.

The liquid crystal display device is driven by two opposing electrodes and a liquid crystal layer formed therebetween, and drives the liquid crystal molecules of the liquid crystal layer by an electric field generated by applying a voltage to the two electrodes.

Liquid crystal molecules have polarization properties and optical anisotropy, which means that when liquid crystal molecules are placed in an electric field, charges in the liquid crystal molecules are concentrated on both sides of the liquid crystal molecules, and the molecular alignment direction changes according to the electric field. Refers to a change in the path or polarization state of the emitted light depending on the incident direction or polarization state of the incident light due to the elongated structure of the liquid crystal molecules and the aforementioned molecular alignment direction.

Accordingly, the liquid crystal display device has a liquid crystal panel consisting of a pair of transparent insulating substrates each having an electric field generating electrode on a surface facing each other with a liquid crystal layer interposed therebetween, and an electric field change between each electric field generating electrode. Through this, the alignment direction of the liquid crystal molecules is artificially controlled, and various images are displayed using the changed light transmittance.

At this time, the polarizing plates are positioned on the upper and lower portions of the liquid crystal panel, and the polarizing plate transmits light of a polarization component matching the transmission axis to determine the degree of light transmission by the arrangement of the transmission axes of the two polarizing plates and the arrangement characteristics of the liquid crystal. Is done.

Conventional liquid crystal display devices mainly use a PVA stretched polarizing plate that is aligned after stretching iodine ions to water-soluble polyvinyl alcohol (PVA) as a polarizing plate.

Republic of Korea Patent Publication No. 10-2010-0024784

The present application is to prevent the phenomenon that the liquid crystal panel is bent by the shrinking force of the polarizing plate, and to provide a polarizing plate having a stable structure and a liquid crystal display device including the same.

One embodiment of the present application,

Coated polarizers; And

Stretched, unstained polyvinyl alcohol-based film provided on one surface of the coated polarizing plate

It provides a laminated polarizing plate comprising a.

In addition, another embodiment of the present application,

Forming a polarizing layer by coating a composition comprising a host-guest type liquid crystal or LLC (Lyotropic Liquid crystal) on a substrate; And

Bonding the unstained polyvinyl alcohol-based film stretched onto the polarizing layer

It provides a method of manufacturing a laminated polarizing plate comprising a.

In addition, another embodiment of the present application,

Liquid crystal panel; A first polarizing plate provided on one side of the liquid crystal panel; And a second polarizing plate provided on the other surface of the liquid crystal panel,

At least one of the first polarizing plate and the second polarizing plate provides a liquid crystal display device comprising the laminated polarizing plate.

In addition, another embodiment of the present application,

And bonding a first polarizing plate to one side of the liquid crystal panel, and bonding a second polarizing plate to the other side of the liquid crystal panel,

At least one of the first polarizing plate and the second polarizing plate provides a method of manufacturing a liquid crystal display device comprising the laminated polarizing plate.

According to an exemplary embodiment of the present application, the coated polarizing plate; And it is provided on one side of the coating-type polarizing plate, it is possible to provide a laminated polarizing plate comprising a stretched unstained polyvinyl alcohol-based film.

According to an exemplary embodiment of the present application, by at least one polarizing plate of the first polarizing plate and the second polarizing plate of the liquid crystal display device includes the laminated polarizing plate, it is possible to prevent the liquid crystal panel from bending. Accordingly, a liquid crystal display device having a stable structure that prevents distortion of the liquid crystal panel can be provided.

1 and 2 are views schematically showing a structure of a liquid crystal display according to an exemplary embodiment of the present application.
3 is a diagram schematically showing a result of comparison of durability according to a stacked structure of a liquid crystal display according to Example 1 of the present application.
4 is a diagram schematically showing a result of comparison of durability according to a stacked structure of a liquid crystal display according to Example 2 of the present application.
5 is a diagram schematically showing the result of comparison of durability according to the stacked structure of the liquid crystal display according to Comparative Example 1 of the present application.
FIG. 6 is a diagram schematically showing the result of comparison of durability according to the stacked structure of the liquid crystal display according to Comparative Example 2 of the present application.
7 is a view schematically showing a laminated polarizing plate according to an exemplary embodiment of the present application.

Hereinafter, preferred embodiments of the present application will be described. However, the embodiments of the present application may be modified in various other forms, and the scope of the present application is not limited to the embodiments described below. In addition, embodiments of the present application are provided to more fully describe the present application to those skilled in the art.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated.

Consumers are increasingly looking for a display device with a bright and clear screen with high brightness, which is determined by the transmittance of the backlight unit (BLU) and the polarizer. Accordingly, a polarizing plate having high transmittance is required to realize high luminance. However, the conventional stretched/dyed polarizing plate has a limitation in making a high-transmission polarizing plate as the transmittance increases as the polarization degree decreases rapidly. Accordingly, recently, a coated polarizing plate such as a host-guest type liquid crystal or a LLC (Lyotropic Liquid Crystal) is used.

However, there was a limit in the degree of polarization to manufacture the upper/lower polarizer of the liquid crystal display device as a coated polarizer, and accordingly, a method of applying only one of the upper and lower polarizers as a coated polarizer was introduced. However, this structure is an asymmetric laminated structure, and a phenomenon in which the substrate of the liquid crystal panel is bent due to the shrinking force of the stretched polarizing plate. Accordingly, the present application is to provide a liquid crystal display device having a stable structure that can correct the above asymmetric structure and prevent distortion of the liquid crystal panel.

A laminated polarizing plate according to an exemplary embodiment of the present application includes a coated polarizing plate; And a stretched non-stained polyvinyl alcohol-based film provided on one surface of the coated polarizing plate.

In addition, a liquid crystal display device according to an exemplary embodiment of the present application, the liquid crystal panel; A first polarizing plate provided on one side of the liquid crystal panel; And a second polarizing plate provided on the other surface of the liquid crystal panel, and at least one polarizing plate among the first polarizing plate and the second polarizing plate includes the laminated polarizing plate.

Problems such as warping and breakage of a conventional liquid crystal panel are caused by the shrinking force of a polyvinyl alcohol-based polarizing plate to which iodine, etc. are dyed and stretched, and the present inventors of the power of the polarizing plate provided at the upper and lower portions of the liquid crystal panel. I tried to solve this by balancing.

According to an exemplary embodiment of the present application, by applying a stretched unstained polyvinyl alcohol-based film having the same shrinkage force as a polyvinyl alcohol-based polarizing plate to which iodine is dyed and stretched, a structure laminated with a coated polarizing plate as a laminated polarizing plate, It is possible to balance the power of the polarizing plates provided on the upper and lower portions of the liquid crystal panel. The stretched non-stained polyvinyl alcohol-based film does not affect the brightness of the liquid crystal display device and can be used only for balancing power of polarizing plates provided on upper and lower portions of the liquid crystal panel.

In one embodiment of the present application, the coated polarizing plate may include a substrate and a polarizing layer provided on the substrate. In addition, in one embodiment of the present application, an alignment layer may be further included between the substrate and the polarizing layer.

The substrate may be made of a transparent material such as glass or plastic or a transparent film. In addition, the alignment layer may include one or more polyimide-based materials, polyamide-based materials, acrylate-based materials, norbornene-based materials, but is not limited thereto. The alignment layer may be formed on a substrate by a method such as a bar coater, a slot die coater, gravure printing, silk screen printing, or cap porter. As the alignment layer, such as photo-orientation or rubbing, is performed on the alignment layer, a number of micro grooves may be formed along a predetermined direction throughout the alignment layer.

The polarizing layer may include a host-guest type liquid crystal or a Lyotropic Liquid crystal (LLC).

The host material may be mainly a liquid crystal polymer exhibiting liquid crystallinity or a reactive liquid crystal monomer (reactive mesogen). At this time, the reactive liquid crystal monomer is a liquid crystal material containing a polymerizable terminal group, and is a monomer molecule having a liquid crystal phase including a mesogen that expresses liquid crystallinity and a polymerizable terminal. As the polarizing layer is applied or coated on the alignment layer, the host material interacts with the micro grooves formed in the alignment layer and is arranged along the alignment direction.

The guest material may be made of a dichroic dye. The dichroic dye has the property of absorbing one component of the two polarizing components of light and transmitting the other component. As the dichroic dye, iodine-based, anthraquinone-based propyrine azo, viazo, and triazo may be used. The dichroic dye absorbs or transmits light in a specific wavelength range. In the present application, visible light can be polarized by absorbing and transmitting light in a wavelength band corresponding to R, G, and B colors. Further, the dichroic dye may be one or two or more of cyan, magenta, and yellow dyes, not R, G, and B dyes.

The coated polarizing plate can control the transmittance by adjusting the concentration of the dye or by controlling the coating thickness. In addition, the thickness of the conventional PVA polarizing element is 5 to 40㎛, while the thickness of the coating-type polarizing element can perform a polarization function with an ultra-thin film of 0.1 to 2㎛ level.

In order to protect the polarizing layer, the coated polarizing plate may be provided with an acrylate-based hard coating layer on the coating layer, or a protective film such as TAC, acrylic, COP, and PET may be laminated on the coating layer.

A method of manufacturing a laminated polarizing plate according to an exemplary embodiment of the present application comprises forming a polarizing layer by coating a composition comprising a host-guest type liquid crystal or LLC (Lyotropic Liquid crystal) on a substrate ; And bonding the unstained polyvinyl alcohol-based film stretched onto the polarizing layer.

The dye-free polyvinyl alcohol-based film stretched with the coated polarizing plate may be bonded using an aqueous adhesive or a UV curable adhesive, or may be bonded using a PSA adhesive. In addition, the liquid crystal panel and the first polarizing plate or the second polarizing plate may be bonded using a water-based adhesive or a UV curable adhesive, or may be bonded using a PSA adhesive.

In one embodiment of the present application, the substrate of the coated polarizing plate and the stretched unstained polyvinyl alcohol-based film may be bonded to each other, the polarizing layer of the coated polarizing plate and the stretched unstained polyvinyl alcohol-based film The films can be bonded to each other.

In addition, the substrate of the coated polarizing plate and the liquid crystal panel may be bonded to each other, and the polarizing layer of the coated polarizing plate and the liquid crystal panel may be bonded to each other.

In one embodiment of the present application, the laminated polarizing plate may be provided to face the liquid crystal panel. More specifically, the first polarizing plate includes the laminated polarizing plate, and the second polarizing plate may be a polyvinyl alcohol-based polarizing plate to which at least one of iodine and a dichroic dye is attached. A liquid crystal display device having such a structure is schematically illustrated in FIG. 1 below.

In addition, the second polarizing plate includes the laminated polarizing plate, and the first polarizing plate may be a polyvinyl alcohol-based polarizing plate to which at least one of iodine and a dichroic dye is attached. A liquid crystal display device having such a structure is schematically illustrated in FIG. 2 below.

In addition, both the first polarizing plate and the second polarizing plate may include the laminated polarizing plate.

In an exemplary embodiment of the present application, the stretched non-stained polyvinyl alcohol-based film is the same as a conventional polyvinyl alcohol-based film to which iodine or the like is dyed and stretched, except that iodine or the like is not dyed.

More specifically, the stretched non-stained polyvinyl alcohol-based film may be prepared by a method of stretching a polyvinyl alcohol-based film at a stretching ratio of 4 to 10 times by a wet-drying method, a dry-type drying method, or the like, which will be described later. At this time, the stretching is preferably stretched to a stretching temperature of 45 ℃ to 60 ℃.

On the stretched non-stained polyvinyl alcohol-based film, an acrylate-based hard coating layer protecting it may be additionally provided.

A laminated polarizing plate according to an exemplary embodiment of the present application is schematically illustrated in FIG. 7 below.

In an exemplary embodiment of the present application, a polyvinyl alcohol-based polarizing plate to which at least one of the iodine and dichroic dye is dyed can be used as a conventional general polyvinyl alcohol-based polarizing plate.

As an example of a method of manufacturing the polyvinyl alcohol-based polarizing plate, a method comprising preparing a polyvinyl alcohol-based polarizer in which iodine and/or dichroic dye is dyed and laminating a protective film on one side of the polarizer can be used. Can. For example, but not limited to, the step of preparing the polyvinyl alcohol-based polarizer is a dyeing step of dyeing a polyvinyl alcohol-based polymer film with iodine and/or a dichroic dye, and the polyvinyl alcohol It may be carried out through a crosslinking step of crosslinking the system film and a dye and a stretching step of stretching the polyvinyl alcohol-based film.

First, the dyeing step is for dyeing the iodine molecule and/or dichroic dye to the polyvinyl alcohol-based film, and the iodine molecule and/or dichroic dye molecule absorbs light oscillating in the stretching direction of the polarizer, and vertical direction. By passing the light vibrating by, it is possible to obtain polarization having a specific vibration direction. In this case, the dyeing may be performed, for example, by impregnating a polyvinyl alcohol-based film in a treatment bath containing a solution containing an iodine solution and/or a dichroic dye.

At this time, water is generally used as the solvent used in the solution of the dyeing step, but an appropriate amount of an organic solvent having compatibility with water may be added. Meanwhile, iodine and/or dichroic dye may be used in an amount of 0.06 to 0.25 parts by weight based on 100 parts by weight of the solvent. This is because when the dichroic material such as iodine is within the above range, the transmittance of the polarizer prepared after stretching can satisfy a range of 40.0% to 47.0%.

On the other hand, when using iodine as a dichroic material, it is preferable to further contain an auxiliary agent such as an iodide compound to improve the dyeing efficiency, the auxiliary agent in a proportion of 0.3 to 2.5 parts by weight based on 100 parts by weight of the solvent Can be used. At this time, the reason for adding an auxiliary agent such as the iodide compound is to increase the solubility of iodine in water because the solubility in water is low in the case of iodine. Meanwhile, the mixing ratio of the iodine and the iodide compound is preferably 1:5 to 1:10 by weight.

At this time, specific examples of the iodide compound that may be added in the present application include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, or And mixtures thereof, but are not limited thereto.

Meanwhile, the temperature of the treatment bath is preferably maintained at 25°C to 40°C. When the temperature of the treatment bath is lower than 25°C, the dyeing efficiency may be lowered, and at an excessively high temperature exceeding 40°C, iodine sublimation occurs a lot and the amount of iodine used may increase.

At this time, the time for immersing the polyvinyl alcohol-based film in the treatment bath is preferably 30 seconds to 120 seconds. If the immersion time is less than 30 seconds, the polyvinyl alcohol-based film may not be uniformly stained, and if it exceeds 120 seconds, the dyeing is saturated and no further immersion is necessary.

On the other hand, the crosslinking step is to ensure that the iodine and / or dichroic dye is adsorbed on the polyvinyl alcohol polymer matrix, a deposition method performed by depositing a polyvinyl alcohol-based film in a crosslinking bath containing an aqueous solution of boric acid is generally used. However, it is not limited thereto, and may be performed by a coating method or a spraying method of spraying or spraying a solution containing a crosslinking agent on a polyvinyl alcohol-based film.

In this case, water is generally used as the solvent used in the solution of the crosslinking bath, but an appropriate amount of an organic solvent having compatibility with water may be added, and the crosslinking agent is 0.5 parts by weight to 5.0 parts by weight based on 100 parts by weight of the solvent. It can be added in parts by weight. At this time, when the crosslinking agent is contained in less than 0.5 parts by weight, the strength of the polyvinyl alcohol-based film may drop in water due to insufficient crosslinking in the polyvinyl alcohol-based film, and when it exceeds 5.0 parts by weight, excessive crosslinking is formed. This can degrade the stretchability of the polyvinyl alcohol-based film. Further, specific examples of the crosslinking agent include boron compounds such as boric acid and borax, glyoxal, glutaraldehyde, and the like, and these can be used alone or in combination.

On the other hand, the temperature of the crosslinking bath varies depending on the amount of the crosslinking agent and the stretching ratio, but is not limited thereto, and is generally preferably 45°C to 60°C. In general, when the amount of the crosslinking agent is increased, the temperature of the crosslinking bath is controlled under high temperature conditions to improve the mobility of the polyvinyl alcohol-based film chain. Adjust the temperature. However, since the present invention is a process in which stretching is 5 times or more, the temperature of the crosslinking bath should be maintained at 45° C. or higher in order to improve the stretchability of the polyvinyl alcohol-based film. On the other hand, the time for immersing the polyvinyl alcohol-based film in the crosslinking bath is preferably 30 seconds to 120 seconds. The reason is that if the immersion time is less than 30 seconds, crosslinking may not be uniformly made on the polyvinyl alcohol-based film, and when it exceeds 120 seconds, crosslinking is saturated and no further immersion is necessary. .

On the other hand, stretching in the stretching step is intended to orient the polymer chain of the polyvinyl alcohol-based film in a constant direction, and the stretching method can be divided into a wet stretching method and a dry stretching method, and the dry stretching method is again inter-roll stretching. Methods, a heating roll stretching method, a compression stretching method, a tenter stretching method, and the like, and a wet stretching method are classified into a tenter stretching method, a roll-to-roll stretching method, and the like.

At this time, the stretching step is preferably stretched at a stretching ratio of 4 to 10 times the polyvinyl alcohol-based film. Because, in order to impart polarization performance to the polyvinyl alcohol-based film, the polymer chain of the polyvinyl alcohol-based film must be oriented, and the orientation of the chain may not sufficiently occur at a draw ratio of less than 4 times, and poly at a draw ratio of more than 10 times. This is because the vinyl alcohol-based film chain can be cut.

At this time, the stretching is preferably stretched to a stretching temperature of 45 ℃ to 60 ℃. The stretching temperature may vary depending on the content of the crosslinking agent. At a temperature of less than 45° C., the fluidity of the polyvinyl alcohol-based film chain may be reduced, so that the stretching efficiency may be reduced. If it exceeds 60° C., the polyvinyl alcohol-based film This is because the strength can be weakened. Meanwhile, the stretching step may be performed simultaneously or separately with the dyeing step or the crosslinking step.

Meanwhile, the stretching may be performed by a polyvinyl alcohol-based film alone, or may be performed by laminating a base film on a polyvinyl alcohol-based film and then stretching the polyvinyl alcohol-based film and the base film together. The latter method is used to prevent the polyvinyl alcohol-based film from breaking during the stretching process when a thin polyvinyl alcohol-based film (for example, a PVA film of 60 μm or less) is stretched, 10 μm. It can be used to manufacture the following thin PVA polarizer.

At this time, as the base film, polymer films having a maximum draw ratio of 5 times or more under a temperature condition of 20°C to 85°C may be used, for example, high-density polyethylene film, polyurethane film, polypropylene film, polyolefin film, Ester-based films, low-density polyethylene films, high-density polyethylene and low-density polyethylene coextrusion films, high-density polyethylene copolymer resin films containing ethylene vinyl acetate, acrylic films, polyethylene terephthalate films, polyvinyl alcohol-based films, cellulose-based films, etc. Can be used. On the other hand, the maximum draw magnification means the draw magnification just before fracture occurs.

In addition, the method of laminating the base film and the polyvinyl alcohol-based film is not particularly limited. For example, the base film and the polyvinyl alcohol-based film may be laminated through an adhesive or an adhesive, or may be laminated by placing a polyvinyl alcohol-based film on the base film without a separate medium. In addition, it may be performed by a method of coextruding the resin forming the base film and the resin forming the polyvinyl alcohol-based film, or may be performed by a method of coating the polyvinyl alcohol-based resin on the base film. On the other hand, the base film may be removed by removing from the polarizer after the stretching is completed, but without removing, it may proceed to the next step. In this case, the base film may be used as a polarizer protective film to be described later.

Next, when the polyvinyl alcohol-based polarizer is prepared through the above method, a step of laminating a protective film on one surface of the polyvinyl alcohol-based polarizer is performed.

In this case, the protective film is a film for protecting a polarizer having a very thin thickness, and refers to a transparent film attached to one surface of the polarizer, and a film having excellent mechanical strength, thermal stability, moisture shielding property, isotropy, and the like can be used. For example, acetate, polyester, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, cycloolefin, polyurethane, and acrylic, such as TriAcethyl Cellulose (TAC) A resin film or the like may be used, but is not limited thereto.

Further, the protective film may be an isotropic film, an anisotropic film to which an optical compensation function such as a phase difference is provided, or may be composed of one sheet or two or more sheets bonded together. In addition, the protective film may be an unstretched, uniaxial or biaxially stretched film, and the protective film thickness is generally 1 μm to 500 μm, preferably 1 μm to 300 μm.

In this case, the protective film preferably has an adhesive strength to the polyvinyl alcohol-based polarizer of 1N/2cm or more, more preferably 2N/2cm or more. Specifically, the adhesive force refers to an adhesive force measured by a 90 degree peel force using a texture analyzer after attaching a protective film to a polyvinyl alcohol-based polarizer on which at least one of iodine and a dichroic dye is dyed. When the adhesive strength satisfies the above range, the swelling of the protective film and the polyvinyl alcohol-based polarizer is suppressed, and curling and defects during manufacturing can be minimized.

On the other hand, the step of laminating the protective film on one surface of the polyvinyl alcohol-based polarizer is to bond the protective film to the polarizer, it can be bonded using an adhesive. At this time, it may be performed through a lamination method of a film well known in the art, for example, a water-based adhesive such as a polyvinyl alcohol-based adhesive, a thermosetting adhesive such as a urethane-based adhesive, a photo cationic curing adhesive such as an epoxy-based adhesive, etc. , It can be carried out using an adhesive well known in the art, such as photo-radical adhesives such as acrylic adhesives.

The liquid crystal display according to an exemplary embodiment of the present application may further include a backlight unit. The backlight unit serves to supply light to the liquid crystal panel, and a light source of the backlight unit includes a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), a fluorescent lamp of HCFL (hot cold fluorescent lamp), or Any one of LED (light emitting diode) can be applied.

In one embodiment of the present application, the liquid crystal panel is an IPS (In Plane Switching) mode liquid crystal panel, VA (Vertical Alignment) mode liquid crystal panel, FFS (Fringe Field Switching) mode liquid crystal panel or TN (Twisted Nematic) mode liquid crystal panel It may be, but is not limited to this.

In addition, other configurations constituting the liquid crystal display device, for example, types of upper and lower substrates (eg, color filter substrates or array substrates) are also not particularly limited, and configurations known in this field may be employed without limitation. Can.

In addition, a method of manufacturing a liquid crystal display device according to an exemplary embodiment of the present application includes bonding a first polarizing plate to one surface of a liquid crystal panel and bonding a second polarizing plate to the other surface of the liquid crystal panel, wherein the At least one polarizing plate among the first polarizing plate and the second polarizing plate includes the laminated polarizing plate.

In one embodiment of the present application, the laminated polarizing plate may be bonded to face the liquid crystal panel.

Hereinafter, the present invention will be described in more detail through examples. The following examples are intended to aid the understanding of the present invention and are not intended to limit the present invention.

< Example >

< Example 1>

After preparing an LC cell having a 0.2T upper glass substrate, a 0.2T lower glass substrate, and a cell gap of 3 μm, a polarizing plate was adhered to the upper glass substrate and the lower glass substrate using an adhesive. The structure of the manufactured liquid crystal display device is shown in FIG. 3 below. Based on the liquid crystal panel, the upper polarizing plate has the structure of a non-staining PVA / adhesive / polarizing layer / substrate / adhesive / liquid crystal panel, the lower polarizing plate is a liquid crystal panel / adhesive / FUJI TAC / iodine dyed and stretched 30㎛ PVA polarizer (Japan Synthetic Fiber PVA) / FUJI's TAC structure.

The non-stained PVA was prepared by stretching 30 µm PVA of Japanese synthetic yarn, and LG Chemical PSA was used as the adhesive. In addition, MCC Corporation LLC was used for the TAC substrate of FUJI.

< Example 2>

The structure of the liquid crystal display device was performed in the same manner as in Example 1, except that it was manufactured as shown in FIG. 4 below.

< Comparative example 1>

The structure of the liquid crystal display device was performed in the same manner as in Example 1, except that it was manufactured as shown in FIG. 5 below.

< Comparative example 2>

The structure of the liquid crystal display device was performed in the same manner as in Example 1, except that it was manufactured as shown in FIG. 6 below.

< Experimental Example >

The durability of the liquid crystal display elements of Examples and Comparative Examples was evaluated, and the results are shown in Table 1 below.

[Table 1]

Condition 1 in Table 1 was evaluated as a condition for 120°C and 500 hours of standing, and Condition 2 was evaluated as a condition for 60 hours at 90%rh at 60°C. In addition, the size of the evaluated sample was about 13 inches (35 cm × 20 cm), and the height with the ground before and after the durability evaluation was measured at the point in the figure below.

The result of comparison of durability according to the stacked structure of the liquid crystal display device according to the first embodiment is schematically illustrated in FIG. 3, and the result of comparison of durability according to the stacked structure of the liquid crystal display device according to the second embodiment is schematically illustrated in FIG. 4. It is represented by. In addition, the durability comparison result according to the stacked structure of the liquid crystal display device according to Comparative Example 1 is schematically illustrated in FIG. 5, and the durability comparison result according to the stacked structure of the liquid crystal display device according to Comparative Example 2 is shown in FIG. 6. It is shown schematically in.

As described above, according to an exemplary embodiment of the present application, at least one polarizing plate of the first polarizing plate and the second polarizing plate of the liquid crystal display device includes a laminated structure of a coated polarizing plate and a stretched unstained polyvinyl alcohol-based film. , It is possible to prevent the phenomenon that the liquid crystal panel is bent. Accordingly, a liquid crystal display device having a stable structure that prevents distortion of the liquid crystal panel can be provided.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it is possible that various modifications and variations are possible without departing from the technical spirit of the present invention as set forth in the claims. It will be apparent to those of ordinary skill in the field.

10: liquid crystal panel
20: coated polarizing plate
30: stretched dye-free polyvinyl alcohol-based film
40: polyvinyl alcohol-based polarizing plate
50: backlight unit
60: polarizing layer
70: description

Claims (14)

delete delete delete delete delete delete delete Liquid crystal panel; A first polarizing plate provided on one side of the liquid crystal panel; And a second polarizing plate provided on the other surface of the liquid crystal panel,
At least one of the first polarizing plate and the second polarizing plate includes a laminated polarizing plate,
The laminated polarizing plate includes a coated polarizing plate; And a stretched non-stained polyvinyl alcohol-based film provided on one surface of the coated polarizing plate,
The coated polarizing plate includes a substrate and a polarizing layer provided on the substrate,
The polarizing layer comprises a host-guest type (host-guest type) liquid crystal or a liquid crystal display device (Lyotropic Liquid crystal). The liquid crystal display device of claim 8, wherein the coated polarizing plate of the laminated polarizing plate is provided to face the liquid crystal panel. The method according to claim 8, Any one of the first polarizing plate and the second polarizing plate includes the laminated polarizing plate,
Another polarizing plate is a liquid crystal display device which is a polyvinyl alcohol-based polarizing plate to which at least one of iodine and dichroic dye is dyed. The liquid crystal display device of claim 8, wherein the first polarizing plate and the second polarizing plate both include the laminated polarizing plate. The liquid crystal of claim 8, wherein the liquid crystal panel is an IPS (In Plane Switching) mode liquid crystal panel, a VA (Vertical Alignment) mode liquid crystal panel, an FFS (Fringe Field Switching) mode liquid crystal panel, or a TN (Twisted Nematic) mode liquid crystal panel. Display device. And bonding a first polarizing plate to one side of the liquid crystal panel, and bonding a second polarizing plate to the other side of the liquid crystal panel,
At least one of the first polarizing plate and the second polarizing plate includes a laminated polarizing plate,
The laminated polarizing plate includes a coated polarizing plate; And a stretched non-stained polyvinyl alcohol-based film provided on one surface of the coated polarizing plate,
The coated polarizing plate includes a substrate and a polarizing layer provided on the substrate,
The polarizing layer is a method of manufacturing a liquid crystal display device comprising a host-guest type (host-guest type) liquid crystal or LLC (Lyotropic Liquid crystal). The method of manufacturing a liquid crystal display device according to claim 13, wherein the laminated polarizing plate is bonded to face the liquid crystal panel.

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