KR20150139542A - Polarization plate set and liquid crystal display panel integrated with front plate - Google Patents

Abstract

A front plate 10 disposed on the viewing side of the liquid crystal cell and having a Young's modulus of 2 GPa or more and a side far from the liquid crystal cell is bonded to the front side polarizing plate 30 through an ultraviolet curable resin or a pressure- The front polarizing plate 30 is a set of the integral polarizing plate 40 and the rear polarizing plate 50 disposed on the rear side of the liquid crystal cell and the front polarizing plate 30 is set at 85 캜 The rate of dimensional change in the direction of the absorption axis when heated for 100 hours is larger than the rate of dimensional change in the direction of the absorption axis when heated at 85 캜 for 100 hours on the back side polarizing plate 50. A set of the polarizing plate is bonded to a liquid crystal cell to form a front-panel integrated type liquid crystal display panel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display (LCD)

And a front-side polarizing plate in which a rear-side polarizing plate and a front plate are integrated with each other in a high temperature environment, and a front-panel integrated liquid crystal display panel in which these are bonded to a liquid crystal cell.

Background Art [0002] Liquid crystal display devices are conventionally used for desk calculators, electronic timepieces, personal computers, and the like, but their demand is rapidly increasing in recent years. Recently, they are also used for mobile phones and tablet terminals. In such a liquid crystal display device, a pair of polarizing plates are usually disposed on the front and back of the liquid crystal cell to form a liquid crystal display panel.

In recent years, with the spread of mobile devices such as portable telephones and tablet-type terminals with large-sized screens, it is required to make the liquid crystal display panels, which are constituent members thereof, lighter and thinner, . In addition, the front plate tends to be integrated with the liquid crystal display panel by an adhesive or an ultraviolet curable resin in order to improve visibility by eliminating reflection at the interface or light scattering.

In the conventional liquid crystal display panel, since the front plate and the liquid crystal cell are thick, warping due to shrinkage of the polarizing plate is suppressed even under a high temperature environment. However, the thickness of the front plate and the glass used for the liquid crystal cell tend to be thin There is a problem that the liquid crystal display panel is warped due to the shrinkage of the polarizing plate under a high temperature environment, and the case of the final product is not repaired.

In order to suppress such warping of the liquid crystal display panel, a method of suppressing warping of the liquid crystal display panel by changing the thickness of the polarizing plate disposed on the side opposite to the viewer side of the liquid crystal cell and the viewing side of the liquid crystal cell Is being developed. For example, Japanese Patent Laid-Open Publication No. 2012-58429 (Patent Document 1) discloses that the thickness of a polarizing film (polarizer referred to in the present invention) of a polarizing plate disposed on the viewer side of a liquid crystal cell, A method of suppressing warpage of the liquid crystal display panel by making it thinner than a film is disclosed.

However, since the deflection of the liquid crystal display panel in a high temperature environment is caused by the contraction of the polarizer due to the thickness of the polarizer as described above, when the thickness of the polarizer of the polarizer disposed on the viewer side is made thin as in Patent Document 1, In the case of a liquid crystal display panel in which a front plate is integrated with an adhesive or an ultraviolet curable resin for improvement, warpage may occur, so that suppression of warp is not necessarily satisfactory.

Japanese Patent No. 4666430 (Patent Document 2) discloses a liquid crystal display device using a plastic substrate liquid crystal cell (a liquid crystal display panel referred to in the present invention) in which a protective film constituting a polarizing plate on the viewer side and back side of a liquid crystal cell Discloses a liquid crystal display element in which the warp amount of a plastic substrate liquid crystal cell is suppressed by changing the thickness. According to this method, the object of suppressing the warping of the liquid crystal cell is achieved. However, in the case where the front plate is placed in a high-temperature environment in which the front plate is integrated with the polarizing plate for improving the visibility, A warp of the liquid crystal cell due to heat shrinkage of the liquid crystal cell may occur and the case of the final product may not be repaired.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described conventional problems, and its main object is to provide a polarizing plate set in which a warp amount under a high temperature environment is suppressed when a liquid crystal display panel is used, Integrated type liquid crystal display panel.

That is, the present invention provides a liquid crystal display comprising a front plate disposed on the viewer side of a liquid crystal cell and having a Young's modulus of 2 GPa or more and a side far from the liquid crystal cell, Side polarizing plate disposed on the rear side of the liquid crystal cell, the front-side polarizing plate has a dimensional change rate in the direction of the absorption axis when heated at 85 DEG C for 100 hours in a state not bonded to the front plate, Is greater than the rate of dimensional change in the direction of the absorption axis when the back-surface-side polarizer is heated at 85 캜 for 100 hours.

In the set of the polarizing plate, the polarizing plate having the front-side polarizing plate preferably has a dimensional change ratio of 1.2% or more, more preferably 1.3% or more, in the direction of the absorption axis when heated at 85 캜 for 100 hours in a state not bonded to the front plate , And the back surface side polarizing plate is preferably a polarizing plate having a dimensional change ratio in the absorption axis direction of 1.1% or less when heated at 85 캜 for 100 hours.

In the set of the polarizing plate, the front polarizing plate and the back polarizing plate all have a structure in which a transparent protective film is laminated on at least one surface of a polarizer made of a polyvinyl alcohol resin film, and at least one of the polarizing plates has a liquid crystal cell side May be a set of a polarizing plate having an in-plane retardation.

In the set of the polarizing plate, the front polarizer and the back polarizer both have a structure in which a transparent protective film is laminated on both sides of a polarizer made of a polyvinyl alcohol resin film, and a polarizer constituting the front polarizer is a back polarizer Or may be a set of a polarizer plate thicker than the polarizer constituting the polarizer.

It is preferable that another polarizing plate is laminated on the side away from the liquid crystal cell.

It is preferable that the absorption axis of the front side polarizing plate is the short side direction of the liquid crystal cell and the back side polarizing plate has the absorption axis in the long side direction of the liquid crystal cell.

The present invention also relates to a polarizing plate comprising a set of any of the above-mentioned polarizing plates and a liquid crystal cell, a front plate integrated type polarizing plate constituting a set of polarizing plates on the viewing side of the liquid crystal cell is bonded on the polarizing plate side, Side polarizing plate constituting a set of the liquid crystal display panel is a front plate integrated type liquid crystal display panel in which the amount of warping when heated at 85 占 폚 for 240 hours is 0.5 mm or less in absolute value and preferably 0.3 mm or less.

According to the present invention, warpage in a high-temperature environment of a liquid crystal display panel in which a front plate is integrated can be eliminated, and a front-panel integrated liquid crystal display panel can be obtained in which the case of the final product is humidified under a high temperature environment.

1 is a schematic sectional view showing an example of a preferable layer structure in a set of a polarizing plate according to the present invention.
2 is a schematic cross-sectional view showing an example of a preferable layer configuration in the front-panel integrated liquid crystal display panel according to the present invention.

Hereinafter, a set of polarizing plates according to the present invention and a front panel integrated liquid crystal display panel using the same will be described with reference to the drawings, but the present invention is not limited to these embodiments.

First, the set of the polarizing plate of the present invention is composed of the front plate integrated type polarizing plate 40 and the back side polarizing plate 50. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of an example of a preferred layer configuration in a set of polarizing plates according to the present invention. 1, a front plate integrated polarizing plate 40 constituting a set of polarizing plates according to the present invention includes a front plate 10 disposed on the viewer side of a liquid crystal cell and disposed farther from the liquid crystal cell, Is bonded to the polarizing plate (30) through an ultraviolet curing resin or an adhesive (20). The front-side polarizing plate 30 is formed by bonding the transparent protective films 35a and 35b of the front-side polarizing plate to both surfaces of the polarizer 37 of the front-side polarizing plate. The back side polarizing plate 50 is formed by bonding the transparent protective films 55a and 55b of the back side polarizing plate to both surfaces of the polarizer 57 of the back side polarizing plate.

The front plate 10 in the present invention is assumed to have a Young's modulus of 2 GPa or more because of its role of suppressing or protecting the warp of the liquid crystal cell. The front plate 10 may be a single layer or a stacked layer as long as it satisfies the Young's modulus. As described above, since it is disposed on the visual side of the liquid crystal cell, specifically, on the outermost surface in the final product, it is assumed to be used outdoors or outdoors. Therefore, from the viewpoint of durability, it is preferable to be composed of inorganic materials such as glass and tempered glass, organic materials such as polycarbonate resin and acrylic resin, and the like. If the Young's modulus is 2 GPa or more, the front plate may be a tempered glass or a film constituting a touch panel, for example. The touch panel method is not particularly limited, and examples thereof include an electrostatic capacitance method, a surface acoustic wave method, a resistance film method, an electromagnetic induction method, an optical sensor method, and an infrared method. The front plate 10 may have functions such as reflection prevention, dirt prevention, electromagnetic shielding, near infrared ray shielding, color adjustment, or glass scattering prevention. The front plate having such functions may be, for example, at least one film layer having such functions stacked on at least one side of the front plate. Such a multi-layered front plate can be produced by, for example, a method of directly applying an effective agent for imparting the above function to a substrate of an organic material or an inorganic material as described above, or a functional film having the above- good.

It is preferable that the ultraviolet curable resin or adhesive 20 to which the front plate 10 and the front side polarizing plate 30 are bonded is transparent near the front plate 10 with a refractive index. By employing such an ultraviolet curable resin or a pressure sensitive adhesive, reflection and scattering of light at the interface between the front plate and the polarizing plate can be eliminated and the visibility can be improved.

As the ultraviolet ray curable resin, general ultraviolet ray curable liquids such as (meth) acrylic acid esters and epoxy resins can be used. As the pressure-sensitive adhesive, there can be used an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyether, or the like as a base polymer. Among them, it is preferable to use an acrylic pressure-sensitive adhesive having excellent optical transparency and high transparency like an acrylic pressure-sensitive adhesive. Here, the term "(meth) acrylic acid ester" means any one of acrylic acid ester and methacrylic acid ester, and the term "(meth)" when it is also referred to as (meth) acrylate.

In the present invention, the dimensional change rate of the film stretching direction (hereinafter also referred to as the absorption axis direction) when the front-side polarizing plate 30 made of the polarizer 37 is heated at 85 캜 for 100 hours is preferably 1.2 Or more and 3.0% or less, and more preferably 1.3% or more and 2.0% or less. If the upper limit of the rate of dimensional change of the front-side polarizing plate exceeds 3.0%, there is a possibility that the upper limit of the dimensional change rate of the front-side polarizing plate is peeled off from the liquid crystal cell due to contraction of the polarizing plate under high-

The rate of dimensional change in the direction of the absorption axis when heated at 85 DEG C for 100 hours is preferably 0.1% or more and 1.1% or less, more preferably 0.5% or more and 1.1% or less, Do. If the lower limit of the rate of dimensional change of the back-surface-side polarizing plate is lower than 0.1%, the optical characteristics are hindered, and there is a possibility that the contrast is low at the time of liquid crystal display.

In the polarizing plate set of the present invention, the polarizer 37 constituting the front-side polarizing plate is a polarizer 57 (hereinafter referred to as a polarizing plate 57)) is preferable. The thickness of the polarizer 37 constituting the front side polarizing plate is preferably 20 m or more. The thickness of the polarizer 57 of the rear side polarizing plate 50 of the liquid crystal cell is preferably 15 m or less. Arranging the set of polarizing plates satisfying these conditions on both sides of the liquid crystal cell 60 is effective for suppressing the amount of warping of the liquid crystal display panel (FIG. 2) in which the front plate is integrated.

As the polarizer used for the polarizers on the front surface side and the back surface side, any suitable one can be used as long as the conditions for the rate of dimensional change and / or the thickness of the polarizer are satisfied. As the polarizer, a film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film is used. The polyvinyl alcohol resin constituting the polarizer is obtained by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having an ammonium group, and the like. The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may also be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. Specific examples of polyvinyl alcohol-based resins and dichroic dyes include polyvinyl alcohol-based resins and dichroic dyes exemplified in Japanese Patent Laid-Open Publication No. 159778/1989.

Such a polyvinyl alcohol resin film is used as the original film of the polarizer. The method of forming the polyvinyl alcohol resin is not particularly limited, and the film can be formed by a known method such as the method described in Japanese Patent Laid-Open Publication No. 159778/1989. The thickness of the original film made of a polyvinyl alcohol-based resin is not particularly limited, but is, for example, about 1 to 150 mu m. Considering the easiness of stretching, etc., the film thickness is preferably 10 m or more.

The polarizer can be obtained by, for example, stretching a polyvinyl alcohol resin film as described above in a uniaxial stretching step, dyeing the polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye, A step of treating the adsorbed polyvinyl alcohol resin film with a boric acid solution and a step of washing with water after the treatment with the aqueous solution of boric acid and finally drying. The stretching, dyeing, boric acid treatment, washing and drying steps of the polyvinyl alcohol resin film in the production process of the polarizer may be carried out in accordance with the method described in, for example, Japanese Patent Laid-Open Publication No. 2012-159778.

Both the front-side polarizing plate 30 and the back-surface-side polarizing plate 50 defined in the present invention have a structure in which a transparent protective film is laminated on at least one surface of the polarizer produced as described above. As the transparent protective film, those formed of a suitable transparent resin can be used. Specifically, it is preferable to use a polymer which is excellent in transparency, uniform optical characteristics, mechanical strength, thermal stability, and the like. Examples of such a transparent protective film include cellulose-based films such as triacetylcellulose and diacetylcellulose, polyester films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, polymethyl (meth) acrylate and polyethyl (Meth) acrylate, a polycarbonate-based film, a polyether sulfone-based film, a polysulfone-based film, a polyimide-based film, a polyolefin-based film and a polynorbornene-based film. It is not.

The transparent protective films 35a and 35b to be applied to the front side polarizing plate 30 and the transparent protective films 55a and 55b to be applied to the rear side polarizing plate 50 may be the same or independent and different. Further, either or both of the transparent protective films 35b and 55a near the liquid crystal cell may be absent. In the present invention, it is preferable that the transparent protective film formed on the liquid crystal cell side in at least one polarizing plate has in-plane retardation.

The in-plane retardation of the transparent protective film can be imparted by uniaxial stretching or biaxial stretching. The in-plane retardation value may be suitably set in accordance with the type of the liquid crystal cell to be applied, but it is generally preferably 30 nm or more. Although the upper limit of the in-plane phase difference is not particularly limited, for example, about 300 nm is sufficient.

The bonding surface of the transparent protective film may be subjected to an easy bonding treatment such as saponification treatment, corona treatment, primer treatment, and anchor coating treatment before the bonding to the polarizer. The thickness of the transparent protective film is usually in the range of about 5 to 200 mu m, preferably 10 mu m or more, more preferably 80 mu m or less, and further preferably 40 mu m or less.

A surface treatment layer such as a hard coating layer, an antireflection layer, or an antiglare layer may be formed on the surface of the transparent protective film, if necessary. The hard coat layer is a surface treatment layer formed for preventing the surface of the polarizing plate from being damaged. The hard coat layer is suitably selected from a resin such as an ultraviolet ray hardening type resin such as an acrylic type or a silicone type having excellent adhesion with a transparent protective film and hardness, As shown in FIG.

The antireflection layer is a surface treatment layer formed on the surface of the polarizing plate for the purpose of preventing reflection of external light, and can be formed by a known method. The antiglare layer is a surface treatment layer that is formed to prevent the visible light generated on the surface of the polarizing plate from being hindered by the external light. For example, the antiglare layer may be formed by a roughening method such as a sandblast method or an embossing method or by mixing transparent ultrafine particles The surface of the transparent protective film is formed to have a concavo-convex structure.

The transparent protective film is bonded to at least one surface of the polarizer to form a polarizing plate. As the polarizing plate, the transparent protective film may be bonded to both surfaces of the polarizer. The bonding of the polarizer and the transparent protective film is not particularly limited, but an adhesive made of an epoxy-based polymer, a pressure-sensitive adhesive, or the like can be used. Such an adhesive layer or pressure-sensitive adhesive layer is formed as a coating drying layer or the like of an aqueous solution. However, at the time of adjusting the aqueous solution, other additives and catalysts such as an acid can also be incorporated if necessary.

In the present invention, the polarizing plate can be used by laminating one or more layers of optical layers exhibiting different optical functions at the time of use thereof. The optical layer is not particularly limited, and examples thereof include a reflection layer, a semi-transmission type reflection layer, a retardation plate, and a brightness enhancement film. An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on the polarizing plate made of the polarizer and a transparent protective film, a polarizing plate in which one of the polarizing plate made of the polarizing plate and the transparent protecting film is a viewing angle compensating film, Or a polarizing plate in which a brightness enhancement film is further laminated.

A retardation plate is preferably laminated on the protective film to form a? Plate (1/2? Plate or 1/4? Plate) capable of forming a elliptically polarized light or a circularly polarized light composite polarizing plate used for an image display apparatus for mobile use . The elliptically polarized light or the circularly polarized light composite polarizing plate has a function of changing into an elliptically polarized light or a circularly polarized light when the incident polarization direction is linearly polarized and a linearly polarized light when the incident polarization direction is elliptically polarized or circularly polarized light. Particularly, a 1/4? Plate is used as a retardation plate capable of changing elliptically polarized light or circularly polarized light into linearly polarized light and linearly polarized light into elliptically polarized light or circularly polarized light. The 1/2? Plate has a function of changing the direction of linearly polarized light.

Specific examples of the retardation plate include, but are not limited to, polyolefin-based, polyarylate-based, polyamide-based, polyolefin-based, and polynorbornene-based polymers such as polycarbonate, polyvinyl alcohol, polystyrene, polymethylmethacrylate, And a stretched film obtained by stretching a selected polymer. Such a stretched film may be treated by a suitable method such as uniaxial or biaxial stretching. Further, a birefringent film in which the refractive index in the thickness direction of the film is controlled by applying a shrinking force and / or a stretching force under adhesion with the heat-shrinkable film may be used.

The brightness enhancement film is used for the purpose of improving the brightness in a liquid crystal display device or the like. Examples of the brightness enhancement film include a reflection type polarized light separation sheet designed to laminate a plurality of thin film films having different refractive index anisotropy, An orientation film of a steric liquid crystal polymer and a circularly polarized light separation sheet on which the aligned liquid crystal layer is supported on a film base.

In the present invention, it is preferable that the back side polarizing plate (50) is used by laminating one or more layers of optical layers exhibiting the above different optical functions on the side away from the liquid crystal cell.

The various optical layers are integrated with the polarizing plate using a pressure-sensitive adhesive or an adhesive, but the pressure-sensitive adhesive or adhesive used therefor is not particularly limited, and an appropriate one may be selected and used. From the viewpoints of simplicity of the bonding operation and prevention of optical distortion, it is preferable to use a pressure-sensitive adhesive. The pressure-sensitive adhesive is not particularly limited, and for example, an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyether, or the like may be used as the base polymer. Among them, as in the case of an acrylic pressure-sensitive adhesive, there is a problem of exfoliation such as being excellent in optical transparency, maintaining appropriate wettability and cohesive force, exhibiting excellent adhesiveness to a substrate and further having heat resistance and being lifted or peeled off under a high temperature environment It is preferable to select and use it.

The pressure-sensitive adhesive layer may contain fine particles for exhibiting light scattering properties, if necessary. The pressure-sensitive adhesive layer may contain fillers such as glass fibers, glass beads, resin beads, metal powders and other inorganic powders, pigments, colorants, antioxidants, Or the like may be blended. Examples of the ultraviolet absorber include a salicylate ester compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex salt compound.

A pressure-sensitive adhesive layer may be formed on the transparent protective film constituting the polarizing plate or on the optical layer formed on the polarizing plate to adhere to another member such as a liquid crystal cell. The pressure-sensitive adhesive layer can be formed of a pressure-sensitive adhesive suitable for a conventional method such as acrylic. In particular, from the viewpoints of prevention of peeling phenomenon under a high temperature environment, reduction in optical characteristics due to thermal expansion difference, prevention of warping of the front panel integrated type liquid crystal display panel, and formation of a liquid crystal imaging device having high quality and excellent durability, Layer. If necessary, the pressure-sensitive adhesive layer may be formed on a necessary surface. For example, if a transparent protective film of a polarizing plate made of a polarizer and a transparent protective film is mentioned, an adhesive layer may be formed on one side or both sides of the transparent protective film, if necessary. Suitable examples of the pressure-sensitive adhesive layer include acrylic, silicone, polyester, polyurethane, polyether, and rubber.

When the pressure-sensitive adhesive layer formed on the polarizing plate or the optical member is exposed on the surface, it is preferable that the pressure-sensitive adhesive layer is covered with a separator for the purpose of prevention of contamination during actual use. The separator can be formed by a method of forming a peeling coat by an appropriate peeling agent such as a silicon-based, long-chain alkyl-based, fluorine-based molybdenum sulfide or the like, if necessary, on a suitable protective film conforming to the transparent protective film or the like.

In the set of the polarizing plate of the present invention described above, the angle between the short side of the liquid crystal cell and the absorption axis of the front-side polarizing plate 30 is usually within ± 45 degrees, preferably within ± 10 degrees. The angle between the long side of the liquid crystal cell and the absorption axis of the back side polarizing plate is usually within ± 45 degrees, preferably within ± 10 degrees. It is preferable that the absorption axis of the front side polarizing plate 30 is substantially parallel to the short side direction of the liquid crystal cell and that the rear side polarizing plate has its absorption axis approximately parallel to the long side direction of the liquid crystal cell.

Next, a front panel integrated type liquid crystal display panel according to the present invention will be described. The front panel integrated type liquid crystal display panel according to the present invention is obtained by joining the front plate integrated polarizer 40 and the back side polarizer 50 to a liquid crystal cell. FIG. 2 shows a front panel integrated type liquid crystal display panel according to the present invention. An example of a preferable layer configuration is shown in a schematic sectional view. 2, the front-panel integrated liquid crystal display panel 80 of the present invention includes a front-plate integrated polarizer 40 constituting a set of the polarizer of FIG. 1 on the viewer side of the liquid crystal cell 60, (50) are bonded to the rear surface side of the liquid crystal cell (60) through a pressure sensitive adhesive.

As a pressure sensitive adhesive to be used for bonding the liquid crystal cell 60 and a set of polarizing plates, a pressure sensitive adhesive using an acrylic resin having excellent transparency, weather resistance, heat resistance, etc. as a base polymer is preferable.

In the front-panel-integrated liquid crystal display panel 80 of the present invention, the amount of warping when heated at 85 占 폚 for 240 hours is 0.5 mm or less, preferably 0.3 mm or less in absolute value. Therefore, warpage under a high-temperature environment is suppressed, and the front-panel integrated liquid crystal display panel becomes moisture-proof in the case of the final product.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto. In the examples, "%" and "parts" indicating the content or amount are based on weight unless otherwise specified.

[Example 1]

(1) Production of polarizer plate set

The front polarizer (polarizer 1) was produced as follows. First, a polyvinyl alcohol film (average degree of polymerization of about 2,400, degree of saponification of 99.9 mol% or more) having a thickness of 60 탆 was uniaxially stretched by about 5 times by dry drawing and immersed in pure water at 60 캜 for one minute And then immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, the film was washed with pure water at 26 DEG C for 20 seconds, and then dried at 65 DEG C to obtain a polarizer having a thickness of 23 mu m in which iodine was adsorbed and oriented in a polyvinyl alcohol film. Next, 3 parts of a carboxyl group-modified polyvinyl alcohol (trade name "KL-318", available from Kuraray Co., Ltd.) was dissolved in 100 parts of water on one side of the polarizer, and a polyamide Epoxy-based adhesive to which 1.5 parts of an epoxy-based additive (Sumirez Resin 650 (30), an aqueous solution having a solid concentration of 30%) obtained from Daoka Chemical Industry Co., Ltd. was applied, and as a transparent protective film, (Trade name "KC4UY ", manufactured by Konica Minolta Opto Co., Ltd.) of a triacetyl cellulose film was bonded on the opposite side and a film of a norbornene resin and an unstretched film (manufactured by Nippon Zeon Co., Ltd.) Trade name "ZEONOR").

The back side polarizing plate (polarizing plate 2) was produced as follows. First, a polyvinyl alcohol film having a thickness of 30 占 퐉 (average degree of polymerization of about 2,400, degree of saponification of 99.9 mol% or more) was uniaxially stretched by about 5 times by dry stretching and immersed in pure water at 60 占 폚 for one minute And then immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, the film was washed with pure water at 26 DEG C for 20 seconds, and then dried at 65 DEG C to obtain a polarizer having a thickness of 11 mu m in which iodine was adsorbed and oriented on a polyvinyl alcohol film. The polarizer was bonded to the transparent protective film in the same manner as the front polarizer. (Trade name "# L2 ", trade name; manufactured by LINTEC CO., LTD.) Having a thickness of 5 mu m was bonded to the TAC surface side, and a 26 mu m thick brightness enhancement film (" Advanced Polarized Film, Version 3 ").

With regard to the front polarizer and the rear polarizer produced in (1) above, the dimensional change ratio of the polarizer under a high-temperature environment was measured by the following method. First, each of the prepared polarizing plates was cut into a square or rectangular shape having a length of 30 mm to 50 mm and a width of 20 to 50 mm, and left for 100 hours under an environment of 85 캜. Next, the dimension (L ₀ ) in the longitudinal direction (absorption axis direction) at the time of cutting and the dimension (L ₁ ) in the longitudinal direction after standing under a high temperature environment were measured using a two-dimensional measuring instrument "NEXIV VMR- , And the dimensional change rate (%) was obtained from the following equation. The results are shown in the column of " the rate of dimensional change of the polarizing plate "

Dimensional change ratio = [(L ₀ -L ₁ ) / L ₀ ] × 100

(2) Fabrication of front panel integrated type liquid crystal display panel

A set of the polarizing plate produced in (1) was bonded to a liquid crystal cell to produce a front panel integrated type liquid crystal display panel. (Trade name: "P-3132 ", manufactured by LINTEC CORPORATION) having a thickness of 20 m was applied to the surface of the norbornene resin" ZEONOR "side of the polarizing plate prepared in Cut into a size of 5 inches so that the absorption axis of the polarizer was parallel to the short sides of the liquid crystal cell, and the rear-side polarizing plate was cut into a size of 5 inches so that the absorption axis of the polarizer was parallel to the long side of the liquid crystal cell. Subsequently, the cut polarizing plate is bonded to the liquid crystal cell on the side of the pressure-sensitive adhesive, and an ultraviolet curing type optical elastic resin (trade name "Super View Resin", manufactured by Dekkerlyaz Co., Ltd.) is applied to the triacetyl cellulose film side of the front- , And a front plate having a Young's modulus of 70 GPa and a thickness of 0.55 mm (trade name "Gorilla ", manufactured by Corning Incorporated) was laminated thereon. Thereafter, ultraviolet rays were irradiated from the front plate side ("D bulb ", manufactured by Fusion UV System Co., Ltd., cumulative light quantity: 1200 mJ / cm 2) to produce a front panel integrated type liquid crystal cell.

With respect to the front plate integrated type liquid crystal display panel manufactured in (2) above, the amount of warpage under a high temperature environment was measured by the following method. First, the prepared front-panel integrated liquid crystal display panel was placed under the environment of 85 ° C for 240 hours, and then placed on the measurement stand of a two-dimensional measuring instrument "NEXIV VMR-12072" manufactured by Nikon Corporation with the front plate as the upper side. Subsequently, the surface of the measurement table was focused, and on the basis of this, the four corners of the front plate integrated type liquid crystal display panel, the center of each of the four sides and the center of the front plate integrated type liquid crystal display panel were focused, After measuring the distance, the distance from the measurement point was defined as the amount of bending which is the longest distance in absolute value. The measurement results are shown in the column of " amount of warping " in Table 1.

[Example 2]

(1) Production of polarizer plate set

A polyvinyl alcohol aqueous solution was applied on a base film and dried to produce a laminated film to be a disc for polarizer production. Here, a polypropylene film having a thickness of 110 mu m and a melting point of 163 DEG C was used as a substrate film.

Next, an acetoacetyl group-modified polyvinyl alcohol powder (trade name: "Kose Pimer Z-200", manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) having an average degree of polymerization of 1,100 and a degree of saponification of 99.5 mol% was dissolved in hot water at 95 ° C to give 3 % Aqueous solution. To this aqueous solution, a water-soluble polyamide epoxy resin ("Sumirez Resin 650" manufactured by DAOKA CHEMICAL INDUSTRY CO., LTD., Aqueous solution having a solid content concentration of 30%) was mixed as a crosslinking agent at a ratio of 5 parts per 6 parts of solid content of polyvinyl alcohol, To prepare a primer coating solution.

Then, the substrate film made of polypropylene was subjected to corona treatment, the coating solution for the primer was coated on the corona-treated surface with a micro gravure coater and dried at 80 DEG C for 10 minutes to form a primer layer having a thickness of 0.2 mu m .

Next, a polyvinyl alcohol powder having an average degree of polymerization of 2,400 and a degree of saponification of 98.0 to 99.0 mol% ("PVA 124" obtained from Kuraray Co., Ltd.) was dissolved in hot water at 95 ° C and a polyvinyl alcohol aqueous solution of 8% It was prepared. The obtained aqueous solution was coated on the primer layer of the base film using a lip coater at room temperature and dried at 80 DEG C for 20 minutes to produce a laminated film composed of a base film / primer layer / polyvinyl alcohol layer.

The obtained laminated film was subjected to free-end all-axis stretching at a temperature of 160 DEG C at 5.8 times. The total thickness of the laminated stretched film thus obtained was 28.5 占 퐉, and the thickness of the polyvinyl alcohol layer was 5.0 占 퐉.

The resultant laminated stretched film was dyed in an aqueous solution of water / iodine / potassium iodide at a weight ratio of 100 / 0.35 / 10 at 26 DEG C for 90 seconds, dyed and then washed with pure water at 10 DEG C. [ Next, this laminated film was immersed in an aqueous solution of water / boric acid / potassium iodide at a weight ratio of 100 / 9.5 / 5 at 76 DEG C for 300 seconds to crosslink the polyvinyl alcohol. Subsequently, the substrate was washed with pure water at 10 캜 for 10 seconds, and finally dried at 80 캜 for 200 seconds. By the above operation, a polarizing laminated film having a polarizer formed of a polyvinyl alcohol layer in which iodine was adsorbed and oriented was formed on a polypropylene base film.

3 parts (trade name "KL-318 ", available from Kuraray Co., Ltd.) of carboxyl group-modified polyvinyl alcohol with respect to 100 parts of water was applied on the surface (polarizing plane) opposite to the base film of the polarizing laminated film prepared above And 1.5 parts of a polyamide epoxy additive (Sumirez Resin 650 (30), a product of Daoka Chemical Industry Co., Ltd., aqueous solution having a solid concentration of 30%), which is a water-soluble epoxy resin, (TAC) (trade name "KC2UA ", manufactured by Konica Minolta Opto Co., Ltd.) having a thickness of 25 占 퐉 was bonded as a transparent protective film, and only the base film was peeled off to form a TAC / polyvinyl alcohol type Thereby obtaining a polarizing plate composed of a polarizer / primer layer.

Next, an ultraviolet curing type adhesive containing an epoxy compound and a photocationic polymerization initiator was applied to the primer side, and a norbornene resin and an unstretched film (trade name "ZEONOR ", manufactured by Nippon Zeon Co., Ltd.) ("D bulb" manufactured by Fusion UV System Co., Ltd., cumulative light quantity: 1200 mJ / cm 2) was irradiated from the side of the transparent resin to cure the adhesive, whereby a TAC / polyvinyl alcohol polarizer / primer layer / norbornene resin Whereby a polarizing plate 3 was obtained.

(Trade name "# L2 ", manufactured by Lintec Co., Ltd.) was adhered to the TAC side and a 26 탆 thick brightness enhancement film (" Advanced Polarized Film, Version 3 " ).

With respect to the polarizing plate 3 produced above, the polarizing plate was cut into a square or rectangular shape having a length of 30 mm to 50 mm and a width of 20 to 50 mm, and the dimensional change rate (%) was calculated by the same method as in Example 1 I got it.

The pressure-sensitive adhesive on the TAC plane side of the polarizing plate 2 and the luminance improving film were removed from the front polarizing plate. The pressure-sensitive adhesive was applied to the surface of the norbornene resin "ZEONOR" side of the polarizing plate 3 as the back polarizing plate, A front panel integrated type liquid crystal cell was fabricated in the same manner as in Example 1, and the amount of warpage under a high temperature environment was measured. The results are shown in the column of " amount of warping " in Table 1.

[Example 3]

As in the case of Example 1 except that the pressure-sensitive adhesive on the side of the TAC plane and the brightness enhancement film of the back-surface-side polarizing plate (the polarizer having a thickness of 11 탆) used in Example 1 were removed as the front polarizer to be bonded to the liquid crystal cell To produce a front panel integrated type liquid crystal display panel, and the amount of warping under a high temperature environment was measured. The results are shown in the column of " amount of warping " in Table 1.

[Example 4]

(1) Production of polarizer plate set

The front polarizer was produced as follows. First, a polyvinyl alcohol film (average degree of polymerization of about 2,400, degree of saponification of 99.9 mol% or more) having a thickness of 75 占 퐉 was uniaxially stretched by about 5 times by dry stretching and immersed in pure water at 60 占 폚 for one minute And then immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, the film was washed with pure water at 26 占 폚 for 20 seconds and dried at 65 占 폚 to obtain a polarizer having a thickness of 28 占 퐉 in which iodine was adsorbed and oriented in a polyvinyl alcohol film. Next, 3 parts of a carboxyl group-modified polyvinyl alcohol (trade name "KL-318", available from Kuraray Co., Ltd.) was dissolved in 100 parts of water on one side of the polarizer, and a polyamide Epoxy-based adhesive to which 1.5 parts of an epoxy-based additive (Sumirez Resin 650 (30), an aqueous solution having a solid concentration of 30%) obtained from Daoka Chemical Industry Co., Ltd. was applied, and as a transparent protective film, Of a triacetyl cellulose film (trade name "KC4UY ", manufactured by Konica Minolta Opto) was bonded to obtain a polarizing plate made of a TAC / PVA layer.

Then, with respect to the polarizing plate prepared above, the polarizing plate was cut into a square or rectangular shape having a length of 30 mm to 50 mm and a width of 20 to 50 mm, and the dimensional change rate (%) was obtained in the same manner as in Example 1 .

The back side polarizing plate was prepared as follows. First, a polyvinyl alcohol aqueous solution was applied onto a base film and dried to produce a laminated film to be a disc for polarizer production. Here, a polypropylene film having a thickness of 110 mu m and a melting point of 163 DEG C was used as a substrate film.

Next, an acetoacetyl group-modified polyvinyl alcohol powder (trade name: "Kose Pimer Z-200", manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) having an average degree of polymerization of 1,100 and a degree of saponification of 99.5 mol% was dissolved in hot water at 95 ° C to give 3 % Aqueous solution. To this aqueous solution, a water-soluble polyamide epoxy resin (trade name "Sumirez Resin 650" manufactured by Daoka Chemical Industry Co., Ltd., aqueous solution having a solid content concentration of 30%) was mixed as a crosslinking agent at a ratio of 5 parts per 6 parts of solid content of polyvinyl alcohol , And a primer coating solution.

Then, the substrate film made of polypropylene was subjected to corona treatment, and then a coating solution for primer was coated on the corona-treated surface with a micro gravure coater and dried at 80 DEG C for 10 minutes to form a primer layer having a thickness of 0.2 mu m.

Next, a polyvinyl alcohol powder having an average degree of polymerization of 2,400 and a degree of saponification of 98.0 to 99.0 mol% ("PVA 124" obtained from Kuraray Co., Ltd.) was dissolved in hot water at 95 ° C and a polyvinyl alcohol aqueous solution of 8% It was prepared. The obtained aqueous solution was coated on the primer layer of the base film using a lip coater at room temperature and dried at 80 DEG C for 20 minutes to produce a laminated film composed of a base film / primer layer / polyvinyl alcohol layer.

The obtained laminated film was subjected to free-end all-axis stretching at a temperature of 160 DEG C at 5.8 times. The total thickness of the laminated stretched film thus obtained was 28.5 占 퐉, and the thickness of the polyvinyl alcohol layer was 5.0 占 퐉.

The resulting laminated stretched film was dyed in an aqueous solution of water / iodine / potassium iodide at a weight ratio of 100 / 0.35 / 10 at 26 DEG C for 90 seconds, dyed, and then washed with pure water at 10 DEG C. [ Next, this laminated film was immersed in an aqueous solution of water / boric acid / potassium iodide at a weight ratio of 100 / 9.5 / 5 at 76 DEG C for 300 seconds to crosslink the polyvinyl alcohol. Subsequently, the substrate was washed with pure water at 10 캜 for 10 seconds, and finally dried at 80 캜 for 200 seconds. By the above operation, a polarizing laminated film having a polarizer formed of a polyvinyl alcohol layer in which iodine was adsorbed and oriented was formed on a polypropylene base film.

(Trade name "KL-318", available from Kuraray Co., Ltd.) was added to 100 parts of water on the opposite side (polarizing plane) of the base film of the polarizing laminated film prepared above to 3 And 1.5 parts of a polyamide epoxy additive (Sumirez Resin 650 (30), trade name, available from Daoka Chemical Industry Co., Ltd., aqueous solution having a solid content concentration of 30%), which is a water-soluble epoxy resin, was added to the aqueous solution (TAC) (trade name "KC2UA ", manufactured by Konica Minolta Opto Co., Ltd.) having a thickness of 25 占 퐉 was bonded as a transparent protective film, and only the base film was peeled off to obtain TAC / polyvinyl alcohol Polarizer / primer layer was obtained. (Trade name "# L2 ", manufactured by Lintec Co., Ltd.) was adhered to the TAC side and a 26 탆 thick brightness enhancement film (" Advanced Polarized Film, Version 3 " ).

With respect to the polarizing plate prepared above, the polarizing plate was cut into a square or rectangular shape having a length of 30 mm to 50 mm and a width of 20 to 50 mm, and the dimensional change ratio (%) was obtained in the same manner as in Example 1.

Thereafter, a pressure-sensitive adhesive (trade name: "P-3132 ", manufactured by Lintec Co., Ltd.) having a thickness of 20 占 퐉 was directly applied to a polarizing surface without a transparent protective layer, and then a front panel integrated liquid crystal display panel And the amount of warpage under a high-temperature environment was measured. The results are shown in the column of " amount of warping " in Table 1.

[Comparative Example 1]

A front panel integrated type liquid crystal display panel was produced in the same manner as in Example 1 except that the front side polarizing plate (having a polarizer thickness of 23 m) used in Example 1 was used as the back side polarizing plate bonded to the liquid crystal cell, And the amount of warpage under a high-temperature environment was measured. The results are shown in the column of " amount of warping " in Table 1.

[Comparative Example 2]

Side polarizing plate (having a polarizer thickness of 11 占 퐉) used in Example 1 was used as the front polarizing plate to be bonded to the liquid crystal cell, and the pressure-sensitive adhesive on the side of the TAC surface and the luminance improving film were removed, A front panel integrated liquid crystal display panel was manufactured in the same manner as in Example 1 except that the front polarizing plate (the polarizer having a thickness of 23 m) used in Example 1 was used as the polarizing plate, and the amount of warping under a high temperature environment was measured did. The results are shown in the column of " amount of warping " in Table 1.

As apparent from the results of Table 1, in Examples 1 to 4, the front plate integrated type liquid crystal display panel had the dimensional change rate in the absorption axis direction when the polarizing plate on the front side of the liquid crystal cell was heated at 85 DEG C for 100 hours, Side polarizing plate is heated to 85 占 폚 for 100 hours, which is larger than the rate of dimensional change in the absorption axis direction.

In Examples 1 to 4, in the front-panel integrated liquid crystal display panel, the dimensional change ratio in the direction of the absorption axis when the polarizing plate on the front side of the liquid crystal cell was heated at 85 캜 for 100 hours was 1.2% or more and the back- Lt; 0 > C for 100 hours is 1.1% or less. Further, in Examples 1, 2 and 4, the polarizer constituting the front-side polarizing plate is thicker than the polarizing element constituting the rear-side polarizing plate.

In Examples 1 to 4, it can be seen that the amount of warping of the front-panel integrated type liquid crystal display panel after being left in a high-temperature environment for 240 hours is 0.5 mm or less in absolute value.

According to the present invention, warpage in a high-temperature environment of a liquid crystal display panel in which a front plate is integrated can be eliminated, and a front-panel integrated liquid crystal display panel can be obtained in which the case of the final product is humidified under a high temperature environment.

10: front plate,
20: a pressure-sensitive adhesive or an ultraviolet curable resin,
30: front polarizer,
35a, 35b: a transparent protective film of the front polarizer,
37: Polarizer of front polarizer,
40: front plate integrated type polarizing plate,
50: back side polarizing plate,
55a and 55b: a transparent protective film of the rear side polarizing plate,
57: polarizer of the rear side polarizing plate,
60: liquid crystal cell,
80: Front panel integrated type liquid crystal display panel.

Claims (7)

A front plate disposed on the viewing side of the liquid crystal cell and having a Young's modulus of 2 GPa or more and being farther from the liquid crystal cell is bonded to the front polarizer through an ultraviolet curable resin or a pressure sensitive adhesive And a back side polarizing plate disposed on a rear side of the liquid crystal cell,
The front-side polarizing plate is characterized in that the dimensional change ratio in the direction of the absorption axis when heated at 85 캜 for 100 hours in the state that the front-side polarizing plate is not bonded to the front- And the dimensional change rate of the polarizer is larger than that of the polarizer. The polarizing plate according to claim 1, wherein the front-side polarizing plate has a dimensional change ratio of 1.2% or more in an absorption axis direction when heated at 85 캜 for 100 hours in a state not bonded to the front plate,
Wherein the back side polarizing plate has a dimensional change ratio of 1.1% or less in the absorption axis direction when heated at 85 캜 for 100 hours. 3. The polarizing plate according to claim 1 or 2, wherein both the front-side polarizing plate and the back-surface-side polarizing plate have a structure in which a transparent protective film is laminated on at least one surface of a polarizer made of a polyvinyl alcohol- Wherein the polarizer constituting the polarizer is thicker than the polarizer constituting the back-surface-side polarizer. The polarizing plate according to any one of claims 1 to 3, wherein both the front-side polarizing plate and the back-surface-side polarizing plate have a structure in which a transparent protective film is laminated on both surfaces of a polarizer made of a polyvinyl alcohol- The polarizing plate is a set of a polarizing plate in which the transparent protective film formed on the liquid crystal cell side has an in-plane retardation. The set of polarizing plates according to any one of claims 1 to 4, wherein the back surface side polarizing plate has another optical film laminated on the side away from the liquid crystal cell. The polarizing plate according to any one of claims 1 to 5, wherein the absorption axis of the front polarizer is substantially parallel to the short side direction of the liquid crystal cell, and the absorption axis of the rear polarizer is a long side of the liquid crystal cell Lt; RTI ID = 0.0 > direction. ≪ / RTI > A liquid crystal display device comprising a set of the polarizing plate according to any one of claims 1 to 6 and a liquid crystal cell,
A front plate integrated polarizing plate constituting a set of the polarizing plate is adhered to the polarizing plate side and a rear polarizing plate constituting the set of the polarizing plate is adhered to the back side of the liquid crystal cell,
Wherein the amount of warping when heated at 85 占 폚 for 240 hours is 0.5 mm or less in absolute value.

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