KR20170033084A - Polarizing plate with united prism sheet and image display comprising the same - Google Patents

Abstract

The present invention relates to a polarizing plate integrated with a prism sheet. More particularly, a prism sheet, a diffusion adhesive layer, and a polarizer are successively arranged. The prism sheet includes a pattern layer in which a prism pattern and a lenticular pattern are alternately arranged. Since the height of the prism pattern and the height of the lenticular pattern are different from each other, brightness is excellent, visibility is improved, and adhesion to the diffusion adhesive layer is excellent.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prism sheet integrated type polarizing plate,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prism sheet integral type polarizing plate and an image display apparatus including the same, and more particularly, to a prism sheet integral type polarizing plate having improved brightness and improved visibility, .

Various image display devices such as a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display (PDP), a field emission display (FED) and the like are gradually becoming larger, There is a growing demand for a thinner and lighter display device. As a result, studies have been made on the reduction in thickness and weight of a polarizing plate used in an image display apparatus.

Generally, a liquid crystal display (LCD) includes a liquid crystal panel including a liquid crystal cell containing a liquid crystal and a polarizer laminated on both sides of the liquid crystal cell, and a backlight unit for providing light to the liquid crystal panel.

The backlight unit is intended to make the light of the light source uniform, and to increase the efficiency of utilization of the luminance and light, which is a core part that is indispensable for an LCD which is a non-luminous display that can not emit light by itself.

Specifically, the backlight unit converts the fluorescent light such as a line into a flat light by maintaining the same brightness to every corner of the LCD. Such a backlight unit is divided into a direct type and an edge type according to the manner in which the light emission source is disposed. The backlight unit is divided into a reflection plate, a backlight light source, a light guide plate, a light diffusion member (diffusion plate, diffusion sheet) .

The direct-type backlight unit has a point light source structure in which a light source is disposed so as to face the front of the device directly below the liquid crystal panel, and the light emitted from the light source is reflected and diffused by the reflection plate and the diffusion plate. Such a direct-type backlight unit has advantages such as high luminance and light weight, but has a disadvantage in that it is difficult to form a thin film, and light with a strong directivity enters the user's field of view directly, thereby causing glare and fatigue.

The edge type backlight unit is a planar light source structure in which light emitted from one side or both sides of a liquid crystal panel is incident on the side of the panel and diffused and scattered over the entire area by a reflection plate and a light guide plate. Such an edge type backlight unit is advantageous in that it is lighter in weight than the direct type, but is easy to adjust the luminance and direction of light directing, is advantageous for thinning, and has a long service life.

Specifically, the edge type backlight unit in the LCD enters the light guide plate with light emitted from the light source, and propagates while repeating total reflection on the light exit surface (liquid crystal cell side surface) and the back surface of the light guide plate. A part of the light propagating in the light guide plate is emitted from the light exit surface of the light guide plate by the light scattering body formed on the back surface of the light guide plate or the like. The light emitted from the light exit surface of the light guide plate is diffused and condensed by various optical sheets such as a diffusion sheet, a prism sheet, and a brightness enhancement film, and then enters a liquid crystal display panel having polarizing plates disposed on both sides of the liquid crystal cell. The liquid crystal molecules of the liquid crystal layer of the liquid crystal cell are driven for each pixel, and an image is displayed by controlling transmission and absorption of incident light.

The prism sheet used in the above-described backlight unit is used to compensate for a decrease in luminance of light passing through the diffusion sheet or the diffusion plate. Is generally placed in the case of the apparatus and is formed close to the exit surface of the light guide plate.

In a liquid crystal display device using such a backlight unit, the light guide plate may be rubbed by the prism sheet under installation or in a practical use environment, and scratches may occur in the light guide plate. In order to solve such a problem, a technique of integrating the prism sheet with the light source side polarizing plate has been proposed. However, the liquid crystal display device using the polarizing plate in which such a prism sheet is integrated has a problem that the front luminance is insufficient and dark.

International Publication No. 2009-108003 discloses a technique of appropriately matching an arrangement of optical sheets matched with a liquid crystal panel of a liquid crystal display device such that a part thereof is parallel and a part of the optical sheets are not parallel but the polarization degree and luminance of the liquid crystal display device are There is a problem of deterioration.

International Patent Publication No. 2009-108003

Embodiments of the present invention aim to provide a polarizing plate having excellent brightness.

Embodiments of the present invention also provide a polarizing plate having excellent adhesion between a prism sheet and a diffusion adhesive layer.

Embodiments of the present invention also provide an image display device including the polarizer.

1. A prism sheet comprising a prism sheet, a diffusion adhesive layer and a polarizer,

Wherein the prism sheet includes a pattern layer in which a prism pattern and a lenticular pattern are alternately arranged,

Wherein the height of the prism pattern and the height of the lenticular pattern are different from each other.

2. The prism sheet integral polarizer according to 1 above, wherein the lenticular pattern is represented by the following formula (1) wherein X is 1.2 to 2.5:

[Equation 1]

X = b / a

(Where a is the short axis length of the ellipse formed by the vertical section of the unit lenticular pattern and b is the long axis length of the ellipse formed by the vertical section of the unit lenticular pattern).

3. The prism sheet integral polarizer according to 2 above, wherein X is 1.4 to 2.3.

4. The prism sheet integral polarizer according to 2 above, wherein X is 1.8 to 2.1.

5. The prism sheet-integrated polarizing plate according to item 1, wherein the pattern layer is a prism sheet-integrated polarizing plate in which at least a part of the prism pattern and the lenticular pattern is adhered to the diffusion adhesive layer to form an air gap between the diffusion adhesive layer and the pattern. .

6. The prism sheet integral polarizer according to 5 above, wherein a high-height pattern of the prism pattern and the lenticular pattern is adhered to the diffusion pressure-sensitive adhesive layer.

7. The prism sheet integral polarizer according to item 1, wherein A represented by the following formula (2) is 0.25 or less:

&Quot; (2) "

A = L / P

(Where L is the length of the bonding between the unit prism pattern or the unit lenticular pattern and the diffusion adhesive layer and P is the sum of the base length of the unit prism pattern section and the base length of the unit lenticular pattern section).

8. The prism sheet integral polarizer according to 1 above, wherein the diffusion-sensitive adhesive layer comprises light diffusing particles.

9. The polarizing plate according to 1 above, wherein the polarizer is a protective film bonded on at least one surface.

10. An image display device comprising a prism sheet-integrated polarizing plate according to any one of items 1 to 9 above.

The polarizing plate according to an embodiment of the present invention includes a prism sheet and a diffusion adhesive layer formed by alternately arranging the unit prism pattern and the unit lenticular pattern having different heights of unit prism patterns and heights of unit lenticular patterns, The adhesion between the sheet and the diffusion adhesive layer is excellent and the brightness is remarkably improved.

1 is a schematic cross-sectional view of a polarizer according to an embodiment of the present invention.
2 is a perspective view showing a prism pattern a and a lenticular pattern b constituting a prism sheet according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a prism sheet and a diffusion adhesive layer in a polarizing plate according to an embodiment of the present invention, wherein (a) and (b) show a state before bonding and a state after bonding, respectively.
4 is a view schematically showing definitions of a, b, H and p2 in a cross section of a unit lenticular pattern according to another embodiment of the present invention.
5 is a diagram schematically showing the definition of the junction length L and P when the height H of the unit prism pattern is longer than the height of the unit lenticular pattern in the prism sheet according to an embodiment of the present invention.
6 is a view schematically showing the definition of the bonding length L and P when the height H of the unit lenticular pattern is longer than the height of the unit prism pattern in the prism sheet according to an embodiment of the present invention.

The polarizing plate according to an embodiment of the present invention is arranged in the order of a polarizer, a diffusion adhesive layer, and a prism sheet, and the prism sheet includes a pattern layer in which a prism pattern and a lenticular pattern are alternately arranged. Further, since the height of the prism pattern and the height of the lenticular pattern are different from each other, the adhesion between the prism sheet and the diffusion adhesive layer is improved and the brightness of the polarizing plate is improved.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. And shall not be construed as limited to such matters.

FIG. 1 schematically shows a cross-sectional view of a polarizing plate 100 according to an embodiment of the present invention.

1, a polarizing plate 100 according to an embodiment of the present invention is arranged in the order of a prism sheet 200, a diffusion adhesive layer 300, and a polarizer 600.

Prism sheet

The polarizing plate 100 according to an embodiment of the present invention includes a prism sheet 200.

The prism sheet 200 according to an embodiment of the present invention is formed by alternately arranging prism patterns and lenticular patterns having different heights on one surface of a sheet to change the direction of incident light to maximize the effect of condensation So that the luminance is improved.

3, the surface of the prism sheet 200 according to an embodiment of the present invention may be in contact with the diffusion adhesive layer 300 with the pattern formed thereon. In this case, since the unit prism patterns and the unit lenticular patterns, which have different heights of the unit prism pattern and the unit lenticular pattern, are alternately arranged, the adhesion between the prism sheet 200 and the diffusion adhesive layer 300 Can be improved.

In the present invention, as shown in Fig. 2A, the prism pattern refers to a pattern having a triangular cross-sectional shape. The triangular prism has an asymmetric shape with respect to a straight line orthogonal to the prism sheet surface, (E.g., isosceles triangle) or may be symmetrical with respect to the straight line (for example, an isosceles triangle).

In the prism pattern according to an embodiment of the present invention, the apex angle of the unit prism pattern is not particularly limited, but may be 60 to 120 degrees, and preferably 85 to 95 degrees to improve the light collecting effect of light incident on the prism Lt; / RTI >

5, the height H of the unit prism pattern in the prism pattern according to an embodiment of the present invention can be defined as a straight line distance along the vertical direction between the bottom surface and the vertex angle of the unit prism pattern have. The height H of the unit prism pattern in the prism pattern according to an embodiment of the present invention is not particularly limited. For ease of handling of the prism sheet, may be 10 to 200 mu m, and preferably 15 to 100 mu m.

In the present invention, the lenticular pattern means a pattern in which the cross-sectional shape of the lenticular pattern is semi-circular or semi-circular, as shown in Fig. 2 (b).

The height H of the unit lenticular pattern in the lenticular pattern according to an embodiment of the present invention may be defined as a straight line distance along the vertical direction with respect to the bottom surface of the unit lenticular pattern as shown in FIG. The height (H) of the unit lenticular pattern in the lenticular pattern according to an embodiment of the present invention is not particularly limited. For ease of handling of the prism sheet, may be 1 to 100 mu m, and preferably 1 to 50 mu m.

The lenticular pattern of the prism sheet 200 according to an exemplary embodiment of the present invention may have X of 1.2 to 2.5 expressed by the following equation (1). By satisfying the above range, the luminance and adhesion improving effect can be maximized. Preferably, X may be 1.4 to 2.3, and more preferably X may be 1.8 to 2.1.

[Equation 1]

X = b / a

Where a is the short axis length of the ellipse formed by the vertical section of the unit lenticular pattern and b is the long axis length of the ellipse formed by the vertical section of the unit lenticular pattern.

In the prism sheet 200 according to the embodiment of the present invention, the unit prism pattern and the unit lenticular pattern are alternately arranged. As shown in FIG. 5, The pitch P of the prism sheet 200 according to an exemplary embodiment of the present invention is not particularly limited but may be in the range of 5 to 300 탆 , Preferably 10 to 100 mu m.

The prism sheet 200 according to an exemplary embodiment of the present invention may be formed of various known materials. For example, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cyclic olefin resins such as polyvinyl chloride resins, polycarbonate resins and norbornene resins, poly Butadiene-styrene copolymer, acrylonitrile-styrene copolymer and the like, such as acrylic resin such as urethane resin and methyl methacrylate resin, polystyrene resin, methyl methacrylate-styrene copolymer, acrylonitrile-butadiene- A cellulose-based film such as polyacetyl cellulose, triacetylcellulose, etc. may be used. Among them, polyolefin resins, acrylic resins, polycarbonate resins, polyester resins, polystyrene resins, methyl methacrylate-styrene copolymers, acrylonitrile-butadiene-styrene Based copolymer, an acrylonitrile-based copolymer, and an acrylonitrile-styrene-based copolymer. If necessary, additives such as an ultraviolet absorber, an antioxidant and a plasticizer may be contained.

The prism sheet 200 according to an embodiment of the present invention can be manufactured by using the above-mentioned resin as a base material such as a photopolymer process, a mold extrusion process, a press molding process, an injection molding process, a roll transfer process, a laser abrasion process, And these methods can be used individually or in combination of two or more methods.

The thickness of the prism sheet 200 in the present invention means the shortest distance from the flat surface (the surface opposite to the surface on which the unit prisms are formed) constituting one surface of the prism sheet 101 to the top of the unit prism 101 The thickness of the prism sheet 200 according to an exemplary embodiment of the present invention is not particularly limited, but may be 20 to 200 占 퐉, preferably 30 to 100 占 퐉, for thinning the polarizing plate.

The spreading pressure-

As shown in FIG. 1, the diffusion adhesive layer 300 according to one embodiment of the present invention functions to bond the prism sheet 200 to the side of the polarizer 600, thereby remarkably improving the light diffusibility of the polarizer So that the luminance can be further improved.

Further, due to the light diffusing function of the diffusion adhesive layer 300 according to an embodiment of the present invention, the regularity derived from the surface shape of the prism sheet is relaxed by the diffusion, Interference with the regular shape is greatly alleviated, so that generation of moiré pattern is suppressed and an image with excellent display quality can be obtained.

1, the prism sheet 200 and the diffusion adhesive layer 300 are in contact with each other in the polarizing plate 100 according to an embodiment of the present invention. Preferably, as shown in FIG. 3, A part of at least one of the prism pattern and the lenticular pattern of the pattern layer of the prism sheet 200 may be adhered to the diffusion adhesive layer to form an air gap 210 between the diffusion adhesive layer and the pattern. Also, in one embodiment of the present invention, since the prism pattern and the lenticular pattern have different heights, a pattern having a high height among the prism pattern and the lenticular pattern may be adhered to the diffusion adhesive layer.

In the polarizing plate according to an embodiment of the present invention, A represented by the following formula (2) may be 0.25 or less.

&Quot; (2) "

A = L / P

(Where L is the length of the bonding between the unit prism pattern or the unit lenticular pattern and the diffusion adhesive layer and P is the sum of the base length of the unit prism pattern section and the base length of the unit lenticular pattern section).

5, when the height H of the unit prism pattern is longer than the height of the unit lenticular pattern, the length L of the unit prism pattern and the diffusion adhesive layer (l ₁ + l ₂ ) , And when the height H of the unit lenticular pattern is longer than the height of the unit prism pattern, L is a length (l ₃ ) of the arc that is in contact with the diffusion adhesive layer as shown in Fig.

P is the sum of the base length p1 of the unit prism pattern section and the base length p2 of the unit lenticular pattern section, as described above.

By controlling A to 0.25 or less, the brightness of the polarizing plate can be improved and excellent durability can be exhibited. The value of A is preferably 0.25 or less under the condition of exceeding 0, and therefore the lower limit is not particularly limited, but may be, for example, 0.20, but is not limited thereto.

The haze of the diffusion adhesive layer 300 according to an embodiment of the present invention may be 30 to 99%, and preferably 40 to 97%.

If the haze of the diffusion adhesive layer 300 according to an embodiment of the present invention is less than 30%, the light diffusion may be reduced and a moiré pattern may be generated. If the diffusion adhesive layer is over 99%, the scattering angle may be increased and the luminance may be lowered .

In the present invention, the haze is the degree of fogging when light passes through the sample, wherein the sample means the diffusion-adhesive layer 300. Haze is diffusion transmitted light (Diffuse Transmittance, T _d) to the ratio obtained by dividing the total transmitted light (Total Transmittance, T _t), and spreading the transmitted light (T _d) is the amount of the scattered light of the light transmitted through the sample light and total transmitted light ( T _t ) means the amount of all light transmitted through the sample. On the other hand, the parallel transmitted light (T _p ) can be represented by a value obtained by subtracting the diffused transmitted light (T _d ) from the total transmitted light (T _t ) by the amount of transmitted light without causing scattering among the transmitted light.

The thickness of the diffusion adhesive layer 300 according to an embodiment of the present invention can be adjusted according to the adhesive force, and is not particularly limited. May be 5 to 50 mu m, and preferably 5 to 35 mu m. If the thickness of the diffusion adhesive layer 300 according to an embodiment of the present invention is less than 5 mu m, the adhesive property may be insufficient or it may be difficult to impart the light diffusion performance, and if it exceeds 50 mu m, the appearance of the polarizer may be defective .

The diffusion pressure sensitive adhesive layer 300 according to the present invention is a pressure sensitive adhesive layer in which light diffusion particles capable of scattering and diffusing light are dispersed and can improve brightness by remarkably improving the light diffusing property of the polarizing plate including the light diffusion particles .

The light-diffusing particles according to one embodiment of the present invention are mixed and dispersed in a composition for forming a diffusion-sensitive adhesive layer so as to provide uniform and high light diffusibility.

Various materials such as organic particles and inorganic particles can be used as long as the light-diffusing particles are mixed and dispersed in the pressure-sensitive adhesive resin so as to have a uniform and high light diffusing property, and are not particularly limited in the present invention.

Examples of the light-diffusing particles may be particles composed of a polymer compound such as a polystyrene resin, a polyolefin resin such as polyethylene or polypropylene, or an acrylic resin. Further, it may be a particle composed of a copolymer formed by copolymerizing two or more kinds of monomers selected from ethylene, propylene, styrene, methyl methacrylate, benzoguanamine, formaldehyde, melamine, butadiene and the like. Examples of the inorganic particles include particles of silica, calcium carbonate, aluminum hydroxide, titanium dioxide and the like.

These particles are preferably colorless or white.

In addition, the shape of the particles may be various shapes and is not particularly limited in the present invention. Preferably, spheres are suitable. The average particle diameter of the particles is not particularly limited, but may be 0.1 to 10 mu m, preferably 0.5 to 5 mu m. When the average particle diameter of the particles is less than 0.1 탆, the light diffusion function may not be exhibited. When the average particle diameter of the particles is more than 10 탆, the display quality may be lowered when applied to the liquid crystal display device.

The content of the light diffusing particles according to one embodiment of the present invention is not particularly limited and can be adjusted according to the average particle diameter of the light diffusion particles and the thickness of the diffusion adhesive layer 300. For example, 10 to 100 parts by weight based on 100 parts by weight (based on the solid content) of the pressure-sensitive adhesive resin. If the content of the light-diffusing particles is less than 10 parts by weight, the light diffusing property may be deteriorated. If the amount is more than 100 parts by weight, the whitening of the diffusion pressure-sensitive adhesive layer becomes severe and transparency may be lowered.

The pressure-sensitive adhesive resin that can be included in the composition for forming a diffusion-sensitive adhesive layer according to an embodiment of the present invention can be used without any particular limitation as long as it exhibits adhesive performance, and examples thereof include acrylic copolymers.

If necessary, the composition for forming a diffusion-sensitive adhesive layer according to an embodiment of the present invention may further include a crosslinking agent, a silane coupling agent, and the like in order to exhibit adhesive performance.

In order to improve the dispersion stability of the light-diffusing particles, it is preferable that the light-diffusing particles are completely dispersed in a solvent and then added to the diffusion adhesive composition. The solvent for dispersing the light-scattering particles is not particularly limited For example, ethyl acetate, toluene, xylene, methyl ethyl ketone, etc. may be used as an acetate, benzene or ketone solvent.

Polarizer

(100) of the polarizing plate of the present invention includes a polarizer (600) formed on one side of a diffusion adhesive layer (300).

The polarizer 600 is an optical film that serves to convert incident natural light into a desired single polarization state (linearly polarized light state), and a polyvinyl alcohol based resin film in which a dichroic dye is adsorbed and oriented can be used.

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 polymerization degree of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

The film formed of such a polyvinyl alcohol-based resin can be 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.

The polarizer of the present invention can be produced by continuously uniaxially stretching a polyvinyl alcohol-based film in an aqueous solution, staining with a dichroic dye and adsorbing, treating with an aqueous solution of boric acid, and washing and drying.

The thickness of the polarizer according to the present invention is not particularly limited, but may be, for example, 5 to 40 탆.

If necessary, a protective film may be provided on at least one surface of the polarizer 600 according to the present invention. For example, the first protective film 410 and the second protective film 420 may be provided on both sides of the polarizer 600. The protective films 410 and 420 may be adhered to the polarizer 600 through the adhesive layers 510 and 520.

As the protective film usable in the present invention, a film excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like can be used. Specific examples include polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose-based resins such as diacetylcellulose and triacetylcellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymer; Polyolefin resins such as polyethylene, polypropylene, cyclo- or norbornene-structured polyolefins, ethylene-propylene copolymers; Vinyl chloride resin; Amide resins such as nylon and aromatic polyamide; Imide resin; Polyether sulfone type resin; Sulfone based resin; Polyether ether ketone resin; A sulfided polyphenylene resin; Vinyl alcohol-based resin; Vinylidene chloride resins; Vinyl butyral resin; Allylate series resin; Polyoxymethylene type resin; Epoxy resin, and the like, and a film composed of the blend of the thermoplastic resin may also be used.

Further, a film made of a thermosetting resin such as (meth) acrylic, urethane, acrylic urethane, epoxy, or silicone or a film made of an ultraviolet curable resin may also be used.

The first protective film 410 and the second protective film 420 may be made of the same material or different materials. Cellulose resin such as triacetyl cellulose can be preferably used in consideration of polarization characteristics or durability.

In particular, the first protective film 410 is preferably a polyester film in view of coating properties with a composition for forming a diffusion adhesive, and the second protective film 420 is preferably a cellulose-based film in consideration of polarization characteristics and durability .

The content of the thermoplastic resin in the polarizer protective film is preferably 50 to 100% by weight, preferably 50 to 99% by weight, more preferably 60 to 98% by weight, and most preferably 70 to 97% by weight. When the content is less than 50% by weight, the inherent high transparency of the thermoplastic resin may not be sufficiently exhibited.

Such a protective film may contain one or more suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a colorant.

Further, if necessary, the protective film may be surface-treated. Examples of the surface treatment include a chemical treatment such as an alkaline treatment including a dry treatment such as a plasma treatment, a corona treatment, a primer treatment, and a saponification treatment.

Further, if necessary, at least one of the protective films on both sides of the polarizer may further have optical functionality. For example, an optical compensation film in which a liquid crystal compound or a polymer compound thereof is aligned on the surface of a substrate, a reflection type polarization separation film which transmits a certain kind of polarized light and reflects polarized light of a property opposite to that, An optical compensation film including a cyclic polyolefin resin, a reflecting film having a reflecting function on the surface, a transflective film having both a reflecting function and a transmitting function, and the like. In this respect, Or may be a laminate of two or more layers. The optically functional protective film may preferably be an optical compensation film. When an optical compensation film is adopted, it is preferable that the opposite surface protective film on the side where the surface treatment layer is formed is an optical compensation film. More specifically, for example, the second protective film 420 may be a retardation film serving as a protective film and a retardation film, or a known retardation film laminated on the second protective film 420.

If necessary, a functional surface treatment layer such as a hard coating layer, an antireflection layer, a diffusion or antiglare coating layer, an antiglare layer, and an antistatic layer is further laminated on the other surface of the first protective film 410 that is not bonded to the polarizer Can

The thicknesses of the first protective film 410 and the second protective film 420 may be generally from 1 to 200 탆 in consideration of workability such as strength and handling and thin film properties, 5 to 100 mu m.

In addition, as shown in FIG. 1, the polarizing plate 100 of the present invention may be a polarizing plate in which a pressure sensitive adhesive layer 700 and a release film (not shown) are sequentially laminated on the second protective film 420.

The pressure-sensitive adhesive layer 700 may be a layer composed of a conventional pressure-sensitive adhesive composition including an acrylic copolymer, a crosslinking agent, and a silane coupling agent as a layer for bonding with the liquid crystal cell.

As the acrylic copolymer, the cross-linking agent and the silane coupling agent, those used in a composition for forming a diffusion-sensitive adhesive layer to be described later can be used.

The release film is a film for protecting the pressure-sensitive adhesive layer 700 and is not particularly limited as long as it is a film ordinarily used in the art. Specific examples thereof include polyolefins such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene- Acrylate copolymers, and ethylene-vinyl alcohol copolymers; Polyester films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polyamide-based films such as polyacrylate, polystyrene, nylon 6, and partially aromatic polyamide; Polyvinyl chloride films; Polyvinylidene chloride films; Or a polycarbonate film. These may be appropriately subjected to a releasing treatment with a silicone type releasing agent, a fluorine type releasing agent, a silica powder or the like.

<Image Display Device>

An object of the present invention is to provide an image display device including the polarizing plate and having improved visibility.

The image display device including the polarizer may be a liquid crystal display device, an OLED, a flexible display, or the like, but is not limited thereto, and all image display devices known in the art that can be applied are exemplified.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Synthetic example  One

A four neck jacket reactor (1L) was equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel, and a nitrogen gas introducing tube. The reactor was purged with nitrogen gas, 98 parts by weight of butylacrylate (n-BA), 0.5 part by weight of acrylic acid (AA) and 1.4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) were charged and the external temperature of the reactor was raised to 50.

Then, a solution in which 0.1 part by weight of 2,2'-azobisisobutyronitrile (AIBN) was completely dissolved in 10 parts by weight of ethyl acetate was added dropwise to the reactor. The reaction was continued for an additional 5 hours while keeping the jacket temperature at 50. Then, 90 parts by weight of ethyl acetate was slowly added dropwise for 1 hour using a dropping funnel.

Then, the mixture was further reacted at the same temperature for 5 hours. When the reaction was completed, the reaction solution was diluted with ethyl acetate to obtain an acrylic copolymer solution having a solid content of 20%.

Example  And Comparative Example

Example  One

( 1) a spreading pressure-sensitive adhesive layer  And Diffusion electrodeposited layer  Manufacture of transfer tape

0.8 part by weight of trimethylolpropane-modified tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent, 0.8 part by weight of 3- , 0.15 part by weight of glycidoxypropyltrimethoxysilane (KBM-403) and a dispersion of polymethylmethacrylate particles (average diameter: 5 탆, spherical shape, refractive index: 1.49) dispersed in toluene solvent were added , And diluted with toluene to a concentration of 20% to prepare a composition for forming a diffusion-adhesive layer.

Subsequently, the composition for forming a diffusion pressure-sensitive adhesive layer was coated on one surface of a polyethylene terephthalate film (Toyobo Ester Film E7002, Toyobama Co., Ltd.) with a coater (Barcoater, Daiichi Kagaku Co., Ltd.) And the coating was cured to a thickness of 10 mu m.

Next, the sheet was dried in a forced circulation type hot-air dryer of 100 oven for 3 minutes to prepare a spreading pressure-sensitive adhesive layer sheet, and then a polyethylene terephthalate release film adhered to the silicon release treatment was bonded to produce a diffusion adhesive layer transfer tape.

At this time, the haze value of each of the diffusion adhesive layer transfer tapes having different contents of polymethylmethacrylate particles was measured using a haze meter (HZ-1, manufactured by Suga Test Instrument Co., Ltd.) according to JIS K 7361-1 , And was calculated by the following equation (3). The value was 60%.

&Quot; (3) &quot;

(2) Production of prism sheet integral type polarizing plate

A composition for forming a diffusion-sensitive adhesive layer prepared in (1) above was applied to one side of a TAC protective film on a PVA polarizer having a TAC protective film adhered on both sides thereof. On one side of the PET base film, A prism sheet having a pattern layer in which a pattern and a lenticular pattern were alternately arranged was bonded such that the pattern layer was in contact with the diffusion pressure sensitive adhesive layer.

Then, the prepared polarizing plate was cut to a size of 5 mm X 5 mm to prepare a sample, and a clear cross-sectional shape was obtained through micro-toming. Using a SEM (S-4700; Hitach) (P) of a base length (p1) of a unit prism pattern cross section and a base length (p2) of a unit lenticular pattern section was measured.

Example  2 to 6 and Comparative Example  1 to 10

A prism sheet-integrated polarizing plate was produced in the same manner as in Example 1, except for that shown in Table 1 below.

division pattern prism
Pattern height
(탆) Lenticular
Pattern height
(탆) X = b / a Junction length
(L, 占 퐉) pitch
(P, 占 퐉) Example 1 Prism +
Lenticular 35 10 0.74 25.0 100 Example 2 Prism +
Lenticular 35 13.5 1.48 25.0 100 Example 3 Prism +
Lenticular 35 15 2.0 25.0 100 Example 4 Prism +
Lenticular 35 13.5 2.22 25.0 100 Example 5 Prism +
Lenticular 35 35 2.96 25.0 100 Example 6 Prism +
Lenticular 35 35 2.0 30.0 100 Comparative Example 1 prism 15 - - 7.5 30 Comparative Example 2 prism 35 - - 17.5 70 Comparative Example 3 prism 55 - - 27.5 110 Comparative Example 4 prism 35 - - 21.0 70 Comparative Example 5 Lenticular - 5 0.74 7.5 30 Comparative Example 6 Lenticular - 10 1.48 7.5 30 Comparative Example 7 Lenticular - 13.5 2.0 7.5 30 Comparative Example 8 Lenticular - 15 2.22 7.5 30 Comparative Example 9 Lenticular - 20 2.96 7.5 30 Comparative Example 10 Lenticular - 13.5 2.0 9.0 30

Test Example

The properties of the polarizing plates prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

1. Calculation of A

The L / P value calculated by dividing the bonding length (L) between the pattern and the diffusion adhesive layer by the sum of the base length (p1) of the unit prism pattern section and the base length (p2) of the unit lenticular pattern section Respectively.

2. Measurement of luminance

The polarizers prepared in Examples and Comparative Examples were mounted on and fixed to a backlight unit (BLU) for a 32-inch liquid crystal display panel, and the front luminance (measured angle Phi 0) was measured in a BLU using a measuring device (model name: EZcontrast, ELDIM, France) °, Theta 0 °) were measured.

3. Peel force  Measure

The polarizing plates prepared in the above Examples and Comparative Examples were cut to a size of 200 mm × 25 mm to prepare specimens, and then sodalime glass was pressed under pressure to prepare specimens. At this time, the peeling force measurement is an average peeling force measured in a range of 30 to 180 mm when a length of 200 mm is peeled by 180 DEG at a speed of about 300 mm / min using a UTM machine (EZ-LX; Shimadzu).

division pattern X = b / a A = L / P Brightness (nit) Peel force
(N / 25 mm) Example 1 Prism +
Lenticular 1.19 0.25 1275 1.0 Example 2 Prism +
Lenticular 1.48 0.25 1333 1.0 Example 3 Prism +
Lenticular 2.0 0.25 1392 1.0 Example 4 Prism +
Lenticular 2.22 0.25 1358 1.0 Example 5 Prism +
Lenticular 2.96 0.25 1268 1.0 Example 6 Prism +
Lenticular 2.0 0.30 1110 1.5 Comparative Example 1 prism - 0.25 1242 1.0 Comparative Example 2 prism - 0.25 1248 1.0 Comparative Example 3 prism - 0.25 1243 1.0 Comparative Example 4 prism - 0.30 1004 1.5 Comparative Example 5 Lenticular 0.74 0.25 1036 1.0 Comparative Example 6 Lenticular 1.48 0.25 1159 1.0 Comparative Example 7 Lenticular 2.0 0.25 1210 1.0 Comparative Example 8 Lenticular 2.22 0.25 1181 1.0 Comparative Example 9 Lenticular 2.96 0.25 1077 1.0 Comparative Example 10 Lenticular 2.0 0.30 950 1.5

Referring to Table 2, it was confirmed that the polarizing plate of the example of the present invention had a remarkably improved brightness while maintaining the same level of adhesion as the comparative example.

100: polarizer
200: prism sheet
210: air gap
300: spreading pressure-sensitive adhesive layer
410, 420: protective film
510, 520: adhesive layer
600: Polarizer
700: pressure-sensitive adhesive layer

Claims (10)

A prism sheet, a spreading pressure-sensitive adhesive layer and a polarizer,
Wherein the prism sheet includes a pattern layer in which a prism pattern and a lenticular pattern are alternately arranged,
Wherein the height of the prism pattern and the height of the lenticular pattern are different from each other.
[2] The prism sheet integrated polarizer of claim 1, wherein the lenticular pattern has X of 1.2 to 2.5,
[Equation 1]
X = b / a
(Where a is the short axis length of the ellipse formed by the vertical section of the unit lenticular pattern and b is the long axis length of the ellipse formed by the vertical section of the unit lenticular pattern).
The prism sheet integral polarizer according to claim 2, wherein X is 1.4 to 2.3.
The prism sheet integral polarizer according to claim 2, wherein X is 1.8 to 2.1.
[2] The prism sheet integrated polarizer of claim 1, wherein the pattern layer is formed by attaching at least a part of at least one of a prism pattern and a lenticular pattern to a diffusion adhesive layer to form an air gap between the diffusion adhesive layer and the pattern.
The prism sheet integral polarizer according to claim 5, wherein a high-height pattern of the prism pattern and the lenticular pattern is adhered to the diffusion pressure-sensitive adhesive layer.
The prism sheet-integrated polarizing plate according to claim 1, wherein A represented by the following formula (2) is 0.25 or less:
&Quot; (2) &quot;
A = L / P
(Where L is the length of the bonding between the unit prism pattern or the unit lenticular pattern and the diffusion adhesive layer and P is the sum of the base length of the unit prism pattern section and the base length of the unit lenticular pattern section).
The prism sheet integral polarizer of claim 1, wherein the diffusion-sensitive adhesive layer comprises light diffusing particles.
The prism sheet integral polarizer according to claim 1, wherein the polarizer is formed by bonding a protective film on at least one surface.
An image display apparatus comprising the prism sheet-integrated polarizing plate according to any one of claims 1 to 9.

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