KR20150074596A - Polarizing Plate and Liquid Crystal Display Comprising the Same - Google Patents

Abstract

Provided is a liquid crystal display device comprising a polarizing plate manufactured by using an adhesive, wherein the polarizing plate has excellent adhesion between a polarizer and a protective film, can minimize light leakage generated in the liquid crystal display device, and can make brightness distribution for each viewing angle.

Description

[0001] The present invention relates to a polarizing plate and a liquid crystal display device including the polarizing plate.

The present invention relates to a polarizing plate produced by using an adhesive having an excellent adhesive force between a polarizer and a protective film, minimizing a light leakage phenomenon occurring in a liquid crystal display device and uniformizing a luminance distribution by a viewing angle, and a liquid crystal display device including the same will be.

The polarizing plate used for a liquid crystal display device or the like has a structure in which a transparent protective film is laminated on both sides or one side of a polarizer made of a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented.

A polarizer using iodine as a dichroism pigment is called an iodine polarizer, and a polarizer using a dichroic dye is called a dye-based polarizer. The iodine polarizer is widely used because it has high transmittance and high polarization (high contrast) as compared with the dye-based polarizer.

However, the iodine polarizer has better optical characteristics than the dye-based polarizer, but has a lower optical durability. For example, when the iodine polarizer or the polarizing plate including the polarizer is left under dry heat, the transmittance is lowered or discolored.

In recent years, the field of use of liquid crystal display devices has widened and peripheral technologies have been advanced, and the demand for the performance of polarizing plates has become more severe. Specifically, a polarizing plate having high contrast (high transmittance and high polarization degree) as well as excellent optical durability such as heat resistance and heat and humidity resistance is required.

Korean Patent Publication No. 2010-0003715 discloses an epoxy resin composition which exhibits excellent endurance reliability under a severe environment such as high temperature and / or high humidity conditions and is excellent in properties such as cutability, re-release property and workability, Discloses a pressure-sensitive adhesive composition capable of effectively suppressing a light leakage phenomenon occurring in a liquid crystal display device even when applied to a protective film.

However, the patent does not disclose or mention a method capable of suppressing the distortion of the retardation value of the protective film.

Korea Patent Publication No. 2010-0003715

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a liquid crystal display device capable of minimizing light leakage occurring in a liquid crystal display device and uniformizing a luminance distribution by a viewing angle And to provide a polarizing plate produced using an adhesive.

Another object of the present invention is to provide a liquid crystal display device including a polarizing plate.

On the other hand, the present invention provides a polarizing plate comprising a polarizer, a polarizer protective film attached to at least one surface of the polarizer, and an adhesive layer for attaching the polarizer and the polarizer protective film, wherein the adhesive layer satisfies the condition Is satisfied.

[Formula 1]

R _in ? 5 nm

In this formula,

R _in = (n _x -n _y ) x d,

R _in represents the retardation value _in the plane direction,

n _x is the refractive index of the adhesive layer in the direction of the abscissa in the plane direction and is the largest refractive index among the refractive indices in the plane direction,

n _y represents the refractive index in the longitudinal direction in the plane direction of the adhesive layer,

d represents the thickness of the adhesive layer

In one embodiment of the present invention, the thickness (d) of the adhesive layer is 5 占 퐉 or less.

On the other hand, the present invention provides a liquid crystal display device including the polarizer.

The polarizing plate according to the present invention has excellent adhesion between the polarizer and the protective film, suppresses distortion of the retardation value of the protective film, minimizes light leakage occurring in the liquid crystal display device, and uniformizes the luminance distribution by the viewing angle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the results of a light emission simulation test of a liquid crystal display device including a polarizer produced using the adhesive composition obtained in Example 1. FIG.
Fig. 2 is a graph showing the results of a light emission simulation test of a liquid crystal display device including a polarizing plate produced using the adhesive composition obtained in Example 10. Fig.
3 is a graph showing the results of a light emission simulation test of a liquid crystal display device including a polarizing plate produced using the adhesive composition obtained in Comparative Example 5. Fig.

Hereinafter, the present invention will be described in more detail.

An embodiment of the present invention is a polarizing plate comprising a polarizer, a polarizer protective film attached to at least one surface of the polarizer, and an adhesive layer for attaching the polarizer and the polarizer protective film, The present invention relates to a polarizing plate satisfying the conditions.

[Formula 1]

R _in ? 5 nm

In this formula,

R _in = (n _x -n _y ) x d,

R _in represents the retardation value _in the plane direction,

n _x is the refractive index of the adhesive layer in the direction of the abscissa in the plane direction and is the largest refractive index among the refractive indices in the plane direction,

n _y represents the refractive index in the longitudinal direction in the plane direction of the adhesive layer,

and d represents the thickness of the adhesive layer.

In one embodiment of the present invention, the thickness d of the adhesive layer is preferably 5 占 퐉 or less.

When the retardation value (R _in ) _in the plane direction is more than 5 nm or the thickness (d) of the adhesive layer is more than 5 탆, the luminance distribution is different from one another and the adhesion between the polarizer and the protective film is low.

In one embodiment of the present invention, the adhesive composition forming the adhesive layer may comprise a photopolymerizable compound, an epoxy resin and an initiator.

The photopolymerizable compound is not particularly limited and, for example, a monomer having an unsaturated group such as a (meth) acryloyl group, a vinyl group, a styryl group or an allyl group in the molecule can be used as a photocurable functional group. desirable.

Specific examples of the vinyl group-containing monomer include 3-ethyl-3 - ((vinyloxy) methyl) oxetane, 2 - ((4- ((vinyloxy) methyl) cyclohexyl) methoxy) These may be used alone or in combination of two or more.

The photopolymerizable compound is preferably contained in an amount of 5 to 30 parts by weight based on 100 parts by weight of the total adhesive composition.

The epoxy resin preferably has a viscosity of 1 to 50,000 cps, and is preferably contained in an amount of 10 to 90 parts by weight based on 100 parts by weight of the total adhesive composition. If the epoxy resin is contained in an amount of more than 90 parts by weight, the permeability of the composition is lowered. If the epoxy resin is contained in an amount less than 10 parts by weight, the adhesive strength, heat resistance and thermal expansion rate are lowered.

The epoxy resin may be at least one selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD epoxy resin, novolac epoxy resin, naphthalene epoxy resin, trisphenol methane epoxy resin, glycidylamine epoxy resin, Epoxy resins, and the like. Specific examples of the epoxy resin include Epiclon 840, Epicron 840-S, Epicron 850, Epicron 850-S, Epicron 830-CRP, Epicron 850-CRP, Epicron 830, Epicron 830- EP-4080S, EP (available from Dainippon Ink & Chemical Co., Ltd.), Epikron 840, Epikron 835, Epikron N-660, Epikron N-740, Epikron HP- Butene diol diglycidyl ether, 2-ethylhexyl glycidyl ether, and the like can be used as the starting material, for example, EP-A-7088S, EP-4085S, EP-4080, EP-4000S (Adeka), Celloxide- It can be used alone or in combination with two or more.

The epoxy resin may include an acrylic monomer, and the acrylic monomer may be included in an amount of 5 to 40 parts by weight based on 100 parts by weight of the total adhesive composition. Specific examples of the acrylic monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta / hexa (meth) acrylate, isobonol Acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, ethylhexyl (meth) acrylate, glycidyl (Meth) acrylate, cyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentane (meth) acrylate, tetrahydrofuranol (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylate, 4-hydroxybutyl There can be a methacrylate or the like, may be used alone or two or more at the same time.

The initiator may be at least one selected from the group consisting of a radical photopolymerization initiator, a cationic photopolymerization initiator, and a thermal polymerization initiator.

The radical photopolymerization initiator preferably has an absorption wavelength at a wavelength of 340 nm or more, and is preferably included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total adhesive composition. Examples of the radical photopolymerization initiator include benzophenone, benzyldimethylketone, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one , 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2,2-dimethoxy-1,2-diphenylethanone, 4- (2-hydroxyethoxy) Phenyl- (2-hydroxy-2-propyl) ketone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,6- dimethoxybenzoyl) (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like, and they may be used alone or in combination of two or more.

The cationic photopolymerization initiator is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total adhesive composition. As the cationic photopolymerization initiator, an onium salt such as an aromatic diazonium salt, an aromatic halonium salt or an aromatic sulfonium salt can be used. Specific examples include Adeka Optomer SP-150, Adeka Optomer SP-170, Adeka Optomer SP-151, Adeka Optomer SP-171 (Adecasa), Photoinitiator 2074 ), And they can be used alone or in combination of two or more.

The thermal polymerization initiator is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total adhesive composition. Examples of the thermopolymerization initiator include CXC-1612, CXC-1614, CX-7231, TAG-2678, TAG-2700, CDI-4302, CDR-3430 (King Industries), Adeka Optomer CP- And CP-77 (Adeca), which can be used alone or in combination of two or more.

In one embodiment of the present invention, the adhesive composition may further include one or more kinds of photosensitizers, antioxidants, and the like known in the art.

In one embodiment of the present invention, the polarizer is one in which a dichroic dye is adsorbed and oriented on the stretched polyvinyl alcohol-based film.

The polyvinyl alcohol-based resin constituting the polarizer can be obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Other monomers copolymerizable with vinyl acetate include acrylamide monomers having an unsaturated carboxylic acid type, an unsaturated sulfonic acid type, an olefin type, a vinyl ether type, and an ammonium group. The polyvinyl alcohol resin may also be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The degree of polymerization of the polyvinyl alcohol-based resin is usually from 1,000 to 10,000, and preferably from 1,500 to 5,000.

Such a polyvinyl alcohol-based resin film is used as the original film of the polarizer. The method of forming the film of the polyvinyl alcohol-based resin is not particularly limited, and a known method can be used. The thickness of the original film is not particularly limited, and may be, for example, 10 to 150 mu m.

In one embodiment of the present invention, the polarizer is formed by continuously uniaxially stretching a polyvinyl alcohol-based film in an aqueous solution, staining with a dichroic dye and adsorbing it, processing with an aqueous solution of boric acid, and washing and drying .

The uniaxial stretching of the polyvinyl alcohol film may be performed before dyeing, concurrently with dyeing, or may be performed after dyeing. If uniaxial stretching is carried out after dyeing, it may be carried out before the boric acid treatment, or may be carried out during the boric acid treatment. Of course, it is also possible to perform uniaxial stretching in a plurality of such steps. For uniaxial stretching, other rolls or rolls of different circumferences may be used. The uniaxial stretching may be either dry stretching in air or wet stretching in the state of being swollen with a solvent. The stretching ratio is usually 4 to 8 times.

As a step of dyeing a stretched polyvinyl alcohol film with a dichroic dye, for example, a method of immersing a polyvinyl alcohol film in an aqueous solution containing a dichroic dye can be used. As the dichroic dye, iodine or a dichroic dye is used. It is preferable that the polyvinyl alcohol film is pre-immersed in water before dyeing to swell.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol-based film is dipped in an aqueous solution for dyeing usually containing iodine and potassium iodide may be used. Usually, the content of iodine in an aqueous solution for dyeing is 0.01 to 1 part by weight with respect to 100 parts by weight of water (distilled water), and the content of potassium iodide is 0.5 to 20 parts by weight with respect to 100 parts by weight of water. The temperature of the aqueous solution for dyeing is usually 20 to 40 占 폚, and the immersion time (dyeing time) is usually 20 to 1,800 seconds.

When a dichroic dye is used as the dichroic dye, a method in which a polyvinyl alcohol film is dipped in an aqueous solution containing a water-soluble dichroic dye is generally employed. The content of the dichroic dye in this aqueous solution is usually 1 × 10 ^-4 to 10 parts by weight, preferably 1 × 10 ^-3 to 1 part by weight, per 100 parts by weight of water. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The dye aqueous solution used for dyeing usually has a temperature of 20 to 80 캜, and the immersion time for this aqueous solution is usually 10 to 1,800 seconds.

The step of treating the dyed polyvinyl alcohol film with boric acid can be carried out by immersing it in an aqueous solution containing boric acid. Normally, the content of boric acid in an aqueous solution containing boric acid is 2 to 15 parts by weight, preferably 5 to 12 parts by weight, based on 100 parts by weight of water. When iodine is used as the dichroic dye, it is preferable that the aqueous solution containing boric acid contains potassium iodide. The content thereof is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight, based on 100 parts by weight of water. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C. The immersing time is usually 60 to 1,200 seconds, preferably 150 to 600 seconds, 200 to 400 seconds.

After the boric acid treatment, the polyvinyl alcohol film is usually washed with water and dried. The washing treatment can be carried out by immersing the boric acid-treated polyvinyl alcohol-based film in water. The water temperature of the water treatment is usually 5 to 40 占 폚, and the immersion time is usually 1 to 120 seconds. After washing with water, the polarizer can be obtained. The drying treatment can be usually carried out using a hot air dryer or a far infrared ray heater. The drying treatment temperature is usually 30 to 100 占 폚, preferably 50 to 80 占 폚, and the drying time is usually 60 to 600 seconds, preferably 120 to 600 seconds.

The thickness of the polarizer produced as described above is typically 5 to 40 탆.

The polarizer protective film is not particularly limited as long as it is excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc. Specifically, an acrylic type, a cellulose type, a polyolefin type, a cyclic olefin type, a polyester type or a polycarbonate type can be used have.

Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose-based resins such as diacetyl cellulose and triacetyl cellulose; Polyolefin-based resins such as polyethylene, polypropylene, cyclo-based or norbornene-based polyolefin, and ethylene-propylene copolymer; And polycarbonate-based resins.

The thickness of the polarizer protective film is 10 to 200 mu m, preferably 10 to 150 mu m. Further, when the polarizer protective film is laminated on both sides of the polarizer, the same or different thickness can be maintained.

An easy joining process can be performed on the surface of the protective film to be bonded to the polarizer. Examples of the easy-to-bond treatment include a dry treatment such as a primer treatment, a plasma treatment and a corona treatment, a chemical treatment such as an alkali treatment (saponification treatment), and a coating treatment for forming an easy adhesive layer.

The surface of the protective film to be bonded to the polarizer may include a liquid crystal coating layer having a retardation function that is cured by coating a reactive liquid crystal compound. The liquid crystal coating layer may be a retarder for viewing angle compensation, and a film patterned retarder for displaying stereoscopic images.

The method of bonding the polarizer and the polarizer protective film may be a conventional method in the art. For example, a flexible film, a Meyer bar coating method, a gravure coating method, a die coating method, a dip coating method, To apply the adhesive composition to the bonding surfaces of the polarizer or the protective film and then to bond them together. The flexographic method is a method in which the polarizer or protective film is moved in a generally vertical direction, a horizontal direction, or an inclined direction between the two, while applying the adhesive composition to the joint surface. After applying the adhesive composition, a polarizer or a protective film is put on a nip roll or the like and bonded.

After bonding the polarizer and the protective film, a drying treatment can be carried out. The drying treatment is carried out, for example, by spraying hot air. The drying temperature is suitably selected in the range of 40 to 100 占 폚, preferably 60 to 100 占 폚. The drying time may be about 20 to 1,200 seconds. After drying, it is preferable to cure at a room temperature or a slightly higher temperature, for example, at a temperature of 20 to 50 DEG C for about 12 to 600 hours.

A surface treatment layer such as a hard coating layer, an antireflection layer, an antiglare layer, and an antistatic layer may be further laminated on the other side of the polarizer to which the polarizer protective film is bonded on one side. Further, an optical functional film may be further laminated by a pressure-sensitive adhesive layer. Examples of the optically functional film include an optical compensation film in which a liquid crystal compound or a polymer compound thereof is oriented on the surface of a base material, an optical compensation film that transmits polarized light of any kind and reflects polarized light of a property opposite to that, A retardation film including a cyclic polyolefin resin, an antireflection functional film having a concavo-convex shape on its surface, an additional film having a surface antireflection treatment, a reflection film having a reflective function on the surface, And a transflective film having both a reflecting function and a transmitting function.

The polarizing plate according to the present invention can be applied to all liquid crystal display devices. Therefore, one embodiment of the present invention relates to a liquid crystal display device including the polarizing plate.

Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples and Experimental Examples. It should be apparent to those skilled in the art that these examples, comparative examples and experimental examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1-16 and Comparative Example 1-5: Preparation of adhesive composition

An adhesive composition having the retardation and thickness shown in Table 1 below was prepared with the composition shown in Table 1 below.

The retardation (R _in ) was measured by applying the adhesive composition to a cycloolefin resin film and photo-curing, separating only the adhesive layer, taking the size of 30 mm x 30 mm horizontally.

division Photopolymerization
compound Epoxy resin Cation
Photoinitiator (d) Phase difference
(R _in ) thickness
(um) ingredient Weight portion ingredient Weight portion ingredient Weight portion Weight portion Example 1 a-1 20 b-1 76 - - 4 0.2 1.0 Example 2 a-1 20 b-1 60 c-1 16 4 1.2 1.0 Example 3 a-1 20 b-1 58 c-1 18 4 2.3 1.0 Example 4 a-1 20 b-1 56 c-1 20 4 4.1 1.0 Example 5 a-1 20 b-1 54 c-1 22 4 5.0 1.0 Example 6 a-2 20 b-1 60 c-1 16 4 0.23 3.0 Example 8 a-1 20 b-1 60 c-2 16 4 1.5 3.0 Example 9 a-1 15 b-1 65 c-1 16 4 2.0 3.0 Example 10 a-2 20 b-1 58 c-1 18 4 4.3 3.0 Example 11 a-1 15 b-1 63 c-1 18 4 5.0 3.0 Example 12 a-1 15 b-1 61 c-1 20 4 0.16 5.0 Example 13 a-1 15 b-1 59 c-1 22 4 1.3 5.0 Example 14 a-2 20 b-1 56 c-1 20 4 2.4 5.0 Example 15 a-1 10 b-1 70 c-1 16 4 4.2 5.0 Example 16 a-1 10 b-1 68 c-1 18 4 5.0 5.0 Comparative Example 1 a-2 20 b-1 60 c-2 16 4 6.1 5.0 Comparative Example 2 a-3 20 b-1 60 c-2 16 4 6.3 2.0 Comparative Example 3 a-4 20 b-2 60 c-1 16 4 0.4 6.0 Comparative Example 4 a-4 20 b-2 60 c-2 16 4 4.2 6.0 Comparative Example 5 a-4 20 b-2 58 c-2 18 4 6.4 6.0

a-1: 3-Ethyl-3 - ((vinyloxy) methyl) oxetane

a-2: 2 - (((4 - ((Vinyloxy) methyl) cyclohexyl) methoxy) methyl)

a-3: 2 - ((vinyloxy) methyl) oxirane

a-4: OXT-101 (East Asian synthetic resin)

b-1: Celloxide-2021P (Daicel)

b-2: YD-128 (Kukdo Chemical)

c-1: 1,4-butanediol diglycidyl ether

c-2: 2-ethylhexyl glycidyl ether

d: SP-150 (Adeka Optomosa)

EXPERIMENTAL EXAMPLE 1: Light Emission Simulation

The light leakage simulation test of the liquid crystal display device including the polarizer produced using the adhesive composition obtained in Examples 1 and 10 and Comparative Example 5 was carried out, and the results are shown in Figs. 1 to 3 and Table 2 below.

division Slope Luminance Max value (cd / m ² ) Luminance uniformity Example 1 0.2573 O Example 10 0.3161 O Comparative Example 5 0.4623 X

O: uniformity of brightness distribution per viewing angle (Luminance value 0.25 or more, viewing angle distribution range θ = 10 ° or less, φ = 5 ° or less)

X: Unevenness of luminance distribution per viewing angle (Luminance value 0.25 or more, viewing angle distribution range θ = 20 ° or more, φ = 30 ° or more)

As shown in Table 2, the polarizing plate of Comparative Example 5 has a relatively high slope Luminance Max value as compared with the polarizing plates of Examples 1 and 10 of the present invention, .

The luminance uniformity was determined for the uniformity and nonuniformity of the luminance at the slope angle θ (azimuth angle) and φ (azimuth angle) with respect to the slope having the Luminance Max value higher than the value of the slope 1 Luminance Max value. In the case of the comparative example 5, it was found that the values of the slope Luminance Max or more of Example 1 were in the range of? = 20 占 and? = 30 占, and the luminance was uneven.

Experimental Example 2: Adhesion

After applying the adhesive composition obtained in Examples 1 to 16 and Comparative Examples 1 to 5 on both sides of a polyvinyl alcohol polarizer, a corona-treated protective film was bonded to both surfaces using niprol, and then a high-pressure mercury lamp (UVA A total light amount of 500 mJ / cm ² , and an illuminance of 500 mW / cm ² ) to produce a polarizing plate. At this time, the end portion was not coated with the adhesive.

The peeling force was measured by cutting the prepared polarizing plate sample to a width of 25 mm and peeling at a rate of 300 mm / min in a 180 degree peeling direction. Typical adhesion is 3.0 N / 25 mm.

division Peel force (N / 25mm) Example 1 3.8 Example 2 3.5 Example 3 3.5 Example 4 3.2 Example 5 3.1 Example 6 4.3 Example 8 4.1 Example 9 4.0 Example 10 3.7 Example 11 3.2 Example 12 4.9 Example 13 4.85 Example 14 4.7 Example 15 4.2 Example 16 3.5 Comparative Example 1 1.5 Comparative Example 2 0.9 Comparative Example 3 2.1 Comparative Example 4 0.7 Comparative Example 5 0.4

As shown in Table 3, the polarizers prepared using the adhesive compositions obtained in Examples 1 to 16 were excellent in adhesion, whereas the polarizers prepared using the adhesive compositions obtained in Comparative Examples 1 to 5 had poor adhesion .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Do. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the actual scope of the invention is defined by the appended claims and their equivalents.

Claims (5)

A polarizing plate comprising a polarizer, a polarizer protective film attached to at least one side of the polarizer, and an adhesive layer for attaching the polarizer and the polarizer protective film, wherein the adhesive layer satisfies the condition of the following formula 1:
[Formula 1]
R _in ? 5 nm
In this formula,
R _in = (n _x -n _y ) x d,
R _in represents the retardation value _in the plane direction,
n _x is the refractive index of the adhesive layer in the direction of the abscissa in the plane direction and is the largest refractive index among the refractive indices in the plane direction,
n _y represents the refractive index in the longitudinal direction in the plane direction of the adhesive layer,
and d represents the thickness of the adhesive layer. The polarizing plate according to claim 1, wherein the thickness (d) of the adhesive layer is 5 占 퐉 or less. The polarizing plate according to claim 1, wherein the adhesive composition forming the adhesive layer comprises a photopolymerizable compound, an epoxy resin and an initiator. The polarizing plate according to claim 1, wherein the polarizer protective film is an acrylic resin, a cellulose resin, a polyolefin resin, a cyclic olefin resin, a polyester resin or a polycarbonate resin. A liquid crystal display comprising the polarizing plate according to any one of claims 1 to 4.

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