KR20150009893A

KR20150009893A - Polarizing plate and liquid crystal display apparatus comprising the same

Info

Publication number: KR20150009893A
Application number: KR20130084424A
Authority: KR
Inventors: 이상흠
Original assignee: 제일모직주식회사
Priority date: 2013-07-17
Filing date: 2013-07-17
Publication date: 2015-01-27

Abstract

The present invention provides a polarizing film comprising a polarizer, a base film formed on a top surface of the polarizer, and a coating layer formed on an upper surface of the base film, wherein the coating layer comprises a matrix resin and a solid composite preparation dispersed in the matrix resin, Wherein the composite preparation comprises a first preparation having a first size and a second preparation adhered to the first preparation and having a second size, wherein the refractive index of the first preparation is n1, the refractive index of the second preparation is n2, N2 > n3 or n3 > n2 > n1, and a liquid crystal display device including the same, wherein the refractive index of the matrix resin is n3.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate and a liquid crystal display including the polarizing plate.

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

The polarizing plate is used in and out of the liquid crystal cell for the purpose of controlling the direction of light oscillation in order to visualize the display pattern of the liquid crystal display device. Liquid crystal display devices have been used in a wide range from small-sized devices at the beginning of development to notebook computers, liquid crystal monitors, liquid crystal color projectors, liquid crystal televisions, navigation systems for vehicles, personal phones, and measurement devices used indoors and outdoors Respectively.

The polarizer comprises a polarizer, a protective film formed on one side of the polarizer and protecting the polarizer, and typically triacetylcellulose (TAC) film is used, but the TAC film is higher in price than a general polymer protective film. A polyethylene terephthalate (PET) film can be used to replace the TAC film. However, the PET film has a difference in refractive index (nx-ny) between the x-axis direction in the MD direction and the y- (Unevenness) can be generated. There is a method of solving the problem by stretching a PET film by using a PET film having an ultra-high retardation and a thin thickness, but there is a limitation in eliminating the problem.

Korean Patent Laid-Open Publication No. 2011-0097078 discloses a polarizing plate in which a PET film having a moisture permeability of 200 g / m ^2. Day or less and a polarizer are bonded with a thermosetting agent.

It is an object of the present invention to provide a polarizing plate capable of minimizing the visibility of light by interference of light.

Another object of the present invention is to provide a polarizing plate capable of lowering the diffuse reflectance by external light.

A polarizing plate which is one aspect of the present invention comprises a polarizer, a base film formed on the upper surface of the polarizer, and a coating layer formed on the upper surface of the base film, wherein the coating layer includes a matrix resin and a composite preparation dispersed in the matrix resin Wherein the combined preparation comprises a first preparation having a first size and a second preparation adhered to the first preparation and having a second size, wherein the refractive index of the first preparation is n1, the refractive index of the second preparation is n2 > n3 and n3 > n2 > n1, where n2 is the refractive index of the matrix resin, and n3 is the refractive index of the matrix resin.

The liquid crystal display device according to another aspect of the present invention may include the polarizing plate.

According to the present invention, there is provided a polarizing plate capable of minimizing visibility of light caused by interference of light. According to the present invention, there is provided a polarizing plate capable of preventing the coating layer from becoming cloudy by lowering the diffuse reflectance due to external light and increasing the contrast ratio.

1 is a sectional view of a polarizing plate of one embodiment of the present invention.
2 is a cross-sectional view of a coating layer according to one embodiment of the present invention.
3 is a cross-sectional view of a coating layer of another embodiment of the present invention.
4 is a cross-sectional view of a coating layer of another embodiment of the present invention.
5 is a cross-sectional view of a coating layer of another embodiment of the present invention.
6 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
7 is a scanning electron microscopic photograph of the combination preparation of Example 1. Fig.
8 is a scanning electron microscopic photograph of the combination preparation of Example 2. Fig.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

The terms " upper "and" lower "in this specification are defined with reference to the drawings, and the term" lower "

The polarizing plate of the present invention comprises a polarizer, a base film formed on the upper surface of the polarizer, and a coating layer formed on the upper surface of the base film, wherein the coating layer comprises a composite preparation dispersed in a matrix resin or a matrix resin, And a second agent attached to the first agent and having a second size, wherein when the refractive index of the first agent is n1, the refractive index of the second agent is n2, and the refractive index of the resin is n3, n1 > n2 > n3 or n3 > n2 > n1.

1 is a sectional view of a polarizing plate of one embodiment of the present invention. 1, the polarizing plate 100 includes a polarizer 10, a base film 20 formed on the upper surface of the polarizer 10, a coating layer 40 formed on the upper surface of the base film 20, And the optical film 30 formed on the lower surface of the optical film 30.

The base film is a non-TAC (triacetylcellulose) transparent film, for example, a polyester-based, cyclic polyolefin-based film including polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate Of at least one resin selected from the group consisting of a polycarbonate resin, a polyether sulfone resin, a polysulfone resin, a polyamide resin, a polyimide resin, a polyolefin resin, a polyarylate resin, a polyvinyl alcohol resin, a polyvinyl chloride resin, Can be a film. The base film, particularly the polyester film, can interfere with the light emitted from the polarizer and thereby make the moire visible because of the difference (nx-ny) between the refractive indices in the x-axis direction and the y-axis direction in the TD direction. There is a method of including particles on the surface of the substrate film to reduce the degree of Moore's visibility. However, there is a limit in reducing the degree of Moire-visibility and there is a problem that the coating layer is visibly clouded due to the particles.

The present invention relates to a composition comprising a coating layer on a surface of a base film and a coating layer comprising a composite preparation dispersed in a matrix resin or a matrix resin and the composite preparation is attached to a first preparation and a first preparation having a first size, By forming a refractive index gradient between the matrix resin, the first agent and the second agent, by diffusing light by the first agent to relax the muracaine and lowering the surface reflectance by the second agent And reduced low contrast ratio phenomenon in which the coating layer is visibly shaded. According to one embodiment, the coating layer may have a diffuse reflectance of 0.4% or less, for example, 0.01 to 0.4%, for example 0.11 to 0.4%. In the above range, the coating layer can be prevented from becoming cloudy and the contrast ratio can be increased.

N1 > n2 > n3 or n3 > n2 > n1, where n1 is the refractive index of the first agent, n2 is the refractive index of the second agent, and n3 is the refractive index of the matrix resin. If n1 = n2 = n3, the effect of mitigating the mura cience can be deteriorated. If n2> n1> n3 or n2> n3> n1, there is a problem that the diffuse reflectance increases at each surface. According to one embodiment, n1> n2> n3, n1 may be 1.6 to 1.7, n2 may be 1.5 to 1.6, and n3 may be 1.4 to 1.5. According to another embodiment, n3> n2> n1, n1 may be 1.4 to 1.5, n2 may be 1.5 to 1.6, and n3 may be 1.6 to 1.7. In the above range, the muracine can be relaxed and the surface reflectance of the coating layer can be lowered. Preferably, n3 > n2 > n1 may be satisfied in consideration of the supply and demand of the matrix resin, the first agent and the second agent.

The complex preparation is dispersed in the matrix resin, and there is no particular limitation on the form of dispersion. For example, a first type in which the composite preparation is dispersed throughout the matrix resin, a lower portion in which the composite preparation is dispersed in contact with the base film, and a second type in which the lower preparation portion is in contact with the lower portion and the upper portion is not dispersed It can be one.

The combined preparation may be a solid type preparation having a predetermined range of sizes, and may include a first preparation and a second preparation attached to the surface of the first preparation. The size of the combined preparation may be 0.1 to 10 mu m. In the above range, it can be included in the coating layer to reduce the miracian effect and lower the surface reflectance. The size of the combined preparation means the average diameter when the first preparation is spherical, and the maximum length when the first preparation is non-spherical.

As used herein, "adherence" includes not only the case where the outermost part of the second agent is bonded to the surface of the first agent, but also the case where a part of the second particle is embedded in the outer part of the first agent. The composite particles to which the second agent is bonded to the surface of the first agent can be prepared by the hetero-aggregation method. Specifically, the respective dispersions of the first agent and the second agent are mixed, and an acid solution (e.g., HCl) and adjusting the pH. The dispersion of the first and second preparations is adjusted so that the particle zeta potential is at the same potential and allowed to coexist in a dispersed state such that the particles repel each other. At this time, the zeta potential is changed by the pH value of the substance and the solution. In the case of silica, the zeta potential is added at a pH of 2 or higher at a pH of less than 2. The surface of the second preparation is modified with a silane coupling agent, and the zeta potential property of the first preparation is adjusted to be different. As a result, for example, when the pH is 10 or more, both zeta potentials are negative, and when the pH is between 2 and 9, the second formulation having the modified surface can make the first formulation negative. That is, when the pH is initially high and both particles start dispersed and the pH is lowered to the acid, at some point, the first and second agents start to aggregate and thereby form a coated state . Since the second agent adsorbed on the surface is bound by electrostatic attraction, it may be dropped by a strong physical external force. In this case, it is preferable to apply a thin coating of a few nanometers to the synthetic particles. The combined preparation in which the second preparation is embedded on the first preparation surface is prepared by pressing the second preparation onto the surface of the first preparation by a particle hybrid method (e.g., a method described in Korean Application No. 2006-0131389) by physical pressing force or shear force Can also be prepared and follow the methods known to those skilled in the art.

The second agent is attached to the surface of the first agent, which may be attached alone or two or more agents may be aggregated and attached depending on the manufacturing method.

The second formulation is attached to the surface of the first formulation wherein the spacing distance between the second formulations can be from 0 to 1 탆, for example from 0.001 to 1 탆, and the total surface area of the first formulation The ratio of the area can be 0.1 to 0.99. Within this range, there may be an effect of lowering the surface diffuse reflectance of the particles.

The shape of the first preparation is not particularly limited and may be, for example, in the form of a particle or a fiber, for example, a rod shape, a spherical shape, or a combination of a rod shape and a spherical shape (e.g., dumbbell shape) Fiber and layer form. And may be wedge-shaped.

The shape of the second preparation is not particularly limited and may be, for example, a shape of a sphere, a rod, a combination of a rod and a sphere (e.g., a dumbbell shape), a triangle, May be in the form of a square or an n-square (where n is an integer from 3 to 20) prismatic, polyhedron or a combination thereof, or fibers and layers, and the second agent may have more than one curved surface.

In a combined preparation, the size of the first formulation may be greater than the size of the second formulation, and in one embodiment, the ratio of the size of the second formulation to the size of the first formulation is 1/10 ⁴ to 1/10 ¹ , For example, 1/10 ³ to 1/10 ¹ . Within this range, there may be an effect of lowering the diffuse reflectance of the particles.

According to an embodiment, the first agent is a microparticle, the first size is 1 to 10 탆, for example 1 to 5 탆, the second agent is nanoparticles, and the second size is 50 to 200 nm, And the second agent may be attached to the first agent in a plurality of ways, which may be the same or different. Within this range, there may be an effect of lowering the diffuse reflectance.

2 to 5 are sectional views of a coating layer of an embodiment of the present invention.

2, the coating layer 40A is dispersed in a matrix resin 60, a matrix resin 60, and is coated with a spherical first particle 50, a spherical shape (bonded) attached (bonded) to the first particle 50, And may include a second particle 70. 3, the coating layer 40B is dispersed in a matrix resin 60, a matrix resin 60, and a spherical first particle 50, a cross-section (attached) to the first particle 50 And may include a quadrangular hexahedral second particle 80. 4, the coating layer 40C is dispersed in the matrix resin 60, the matrix resin 60, and the spherical first particles 50, the cross-section (attached) to the first particles 50 And may include a second particle 90 of a tetrahedral shape that is triangular. 5, the coating layer 40C is dispersed in the matrix resin 60 and the matrix resin 60, and the spherical first particles 50 and the spherical second particles (Fig. 70).

The first preparation is not limited as long as it is a light-diffusing particle or fiber as a transparent material having the above-mentioned refractive index and size. For example, the first particle may be an organic light-diffusing particle, an inorganic light-diffusing particle, or a mixture thereof. The organic light-diffusing particle may be a silicone, a (meth) (SiO ₂ ), alumina (Al (meth) acrylate), and the like. The inorganic light-diffusing particles may be at least one selected from the group consisting of polyester, polycarbonate, polyurethane, polyamide, ₂ O ₃ ), titania (TiO ₂ ), zirconia (ZrO ₂ ), and zinc oxide (ZnO).

The second preparation is not limited as long as it is a particle or fiber of a transparent material having the above-mentioned refractive index and size. For example, the second preparation may be formed of at least one of polyester-based, polycarbonate-based, polyurethane-based, polyamide-based, and cellulose-based ones including silicone-based and polymethyl (meth) may be, or silica as the inorganic agent (SiO _2), alumina (Al ₂ O _3), titania (TiO _2), zirconia (ZrO _2), zinc oxide can be one or more of the (ZnO), a refractive index gradient The first agent and the second agent are preferably particles of different materials.

The matrix resin is not limited as long as it is a transparent material having the refractive index described above relative to the first agent and the second agent. For example, the matrix resin may be at least one of (meth) acrylic, polycarbonate, polyvinyl, polystyrene, polyester, polyurethane, epoxy, amino and alkyd.

The composite preparation in the coating layer may contain 10 to 50 wt% and the resin may include 50 to 90 wt%. In the above range, there is an effect that the reflectance and the diffuse reflectance can be minimized. For example, the composite preparation in the coating layer may contain 10 to 30 wt% and the resin may include 70 to 90 wt%.

The thickness of the coating layer may be from 1 to 20 mu m, for example, from 1 to 10 mu m, and within this range, there is a mura coating effect and can be used for display. The thickness of the base film may be 9 to 100 탆, for example, 20 to 80 탆, and may be used in the display in the above range. The thickness of the laminate may be 10 to 120 탆, for example, 20 to 90 탆, and may be used in the display in the above range.

The base film can be adhered to the polarizer by a usual adhesive. For example, the adhesive may be an adhesive containing a thermosetting or photo-curable adhesive, for example, a (meth) acrylic resin or the like as an adhesive component.

The laminate of the base film and the coating layer may have a haze of 2 to 50%, for example, 2 to 30%, for example, 2 to 8%. In the above range, there is an effect of solving the problem and the layered product is peeled off, so transparency is poor and screen visibility may be poor.

The laminate of the base film and the coating layer can be produced by a conventional method. For example, the composition for a coating layer may be coated on the surface of a base film and dried / cured (thermosetting or photo-curing), and the composition for a coating layer may include a resin and a composite preparation.

The polarizer is molecularly oriented in a specific direction. When the polarizer is attached to a liquid crystal display device, it transmits only light in a specific direction. The polarizer can be produced by dyeing a polyvinyl alcohol film with iodine or a dichroic dye and stretching it in a certain direction. Specifically, it is produced through a swelling process, a dyeing step, a stretching step and a crosslinking step. Methods of performing each step are commonly known to those skilled in the art.

The polarizer may have a thickness of 20 to 60 占 퐉. In the above range, it can be used for a polarizing plate for a liquid crystal display.

The optical film may be formed on one surface of the liquid crystal display panel and may have a viewing angle compensation function by having a predetermined range of retardation.

The optical film is a transparent optical film, and may be a polyester type, a cyclic polyolefin type, a polytype type, a polyimide type, a polytetrafluoroethylene type, a polytetrafluoroethylene type, a polytetrafluoroethylene type, A polyvinyl alcohol-based, a polyvinylidene chloride-based, a polyvinylidene-based, or a mixture thereof from the group consisting of a carbonate, a polyether sulfone, a polysulfone, a polyamide, a polyimide, a polyolefin, a polyarylate, A film made of a resin to be selected, and preferably a non-polyester film.

The optical film can be adhered to the polarizer by a conventional adhesive. For example, the adhesive may be an adhesive containing a thermosetting or photo-curable adhesive, for example, a (meth) acrylic resin or the like as an adhesive component.

A pressure sensitive adhesive layer is formed on the lower surface of the optical film so that the polarizing plate can be laminated on the liquid crystal display panel. The pressure-sensitive adhesive may be a pressure-sensitive adhesive, but is not limited thereto.

At least one of an adhesive layer and a functional layer may be further formed on the upper surface of the coating layer, and the functional layer may be a hard coating layer, an antiglare layer, or the like.

The thickness of the polarizing plate may be 25 to 500 mu m. Within this range, it can be used as a polarizing plate for an optical display device.

The liquid crystal display device of the present invention may include a module for a liquid crystal display device including the polarizing plate.

6 is a cross-sectional view of a module for a liquid crystal display device according to an embodiment of the present invention. 6, the liquid crystal display module 300 includes a liquid crystal display panel 205, a first polarizer 100 formed on the upper surface of the liquid crystal display panel 205, a lower surface of the liquid crystal display panel 205, And a second polarizing plate 200 formed between the liquid crystal display panel 205 and the light source 220. The first polarizing plate 100 includes a first optical film 30 formed on the upper surface of the liquid crystal display panel 205, A first polarizer 10 formed on the upper surface of the first optical film 30, a base film 20 formed on the upper surface of the first polarizer 10, a coating layer 40 formed on the upper surface of the base film 20, The second polarizing plate 200 includes a first optical film 30 formed on the lower surface of the liquid crystal display panel 205, a second polarizer 30 formed on the lower surface of the second optical film 30, And a base film 55 formed on the lower surface of the first polarizer 30 and the second polarizer 30.

The second polarizing plate 200 may be formed between the liquid crystal display panel 205 and the light source unit 220 including the backlight unit. The backlight unit may be divided into a direct type and a side type depending on the position of the light source. The liquid crystal display of the present invention is not limited thereto, and the light source unit may preferably include an LED light source.

The liquid crystal display panel 205 includes a liquid crystal cell layer sealed between an upper substrate and a lower substrate (not shown), and the upper substrate may be a color filter (CF) substrate and the lower substrate may be a TFT (Thin Film Transistor) have. The upper substrate and the lower substrate may be the same or different, and may be a glass substrate or a plastic substrate. The plastic substrate is made of polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), polyethylene naphthalate (PEN), polyether sulfone (PES), polyarylate (PAR) and cycloolefin copolymer (COC) Or the like, but the present invention is not limited thereto.

The liquid crystal cell layer may be a liquid crystal cell layer including liquid crystal of VA (Vertical Alignment) mode, IPS (In Place Switching) mode, FFS (Fringe Field Switching) mode and TN (Twisted Nematic) mode.

The first polarizing plate and the second polarizing plate may be respectively formed on one surface of the liquid crystal display panel by a pressure-sensitive adhesive layer 50. The pressure-sensitive adhesive layer may be a conventional pressure-sensitive adhesive, for example, a pressure-sensitive adhesive.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Example One

A polyvinyl alcohol film (VF-PS6000, manufactured by Kuraray Co., Ltd., thickness: 60 占 퐉) was stretched three times at 60 占 폚 and adsorbed to iodine and then stretched 2.5 times in an aqueous boric acid solution at 40 占 폚 to prepare a polarizer. (average) of polymethyl methacrylate (PMMA) was added to the first particles (average particle diameter: 2 탆, refractive index: 1.43, shape: spherical) of silicone material using a heterogeneous agglomeration method Particle diameter: 50 nm, refractive index: 1.49, shape: spherical shape). Referring to FIG. 7, it was confirmed that spherical second particles adhere to the spherical first particle surface. A composition prepared by mixing the composite preparation and an acrylic binder (refractive index: 1.61) was applied to a polyethylene terephthalate (PET) film and dried to prepare a laminate of a coating layer and a film. A laminate prepared on the upper surface of the polarizer and a triacetyl cellulose film (KC4DR-1, Japan Fuji Co., thickness: 40 mu m) were adhered to the lower surface of the polarizer with an adhesive so that the polarizer and the PET film were adhered to each other to produce a polarizing plate .

Example 2

A polarizing plate was prepared in the same manner as in Example 1, except that the composite preparation of FIG. 8 prepared using the second particles of PMMA material having an average particle diameter of 100 nm and a refractive index of 1.49 was used. Referring to FIG. 8, it was confirmed that spherical second particles adhere to the spherical first particle surface.

Example 3

A polarizing plate was produced in the same manner as in Example 1, except that an acrylic (ACRYL) film (refractive index: 1.49) was used in place of the polyethylene terephthalate film.

Example 4

A polyvinyl alcohol film (VF-PS6000, manufactured by Kuraray Co., Ltd., thickness: 60 占 퐉) was stretched three times at 60 占 폚 and adsorbed to iodine and then stretched 2.5 times in an aqueous boric acid solution at 40 占 폚 to prepare a polarizer. A second particle (average particle size: 2 m, refractive index: 1.49, shape: spherical) of polymethyl methacrylate (PMMA) Particle diameter: 50 nm, refractive index: 1.43, shape: spherical). A composition prepared by mixing a composite preparation and an acrylic binder (refractive index: 1.40) was applied to a polyethylene terephthalate film and dried to prepare a laminate of a coating layer and a film. A polarizing plate was prepared by adhering a laminate prepared on the upper surface of the polarizer to a lower surface of the polarizer with a triacetylcellulose film (KC4DR-1, Japan Fuji Co., thickness: 40 탆) with an adhesive.

Example 5

A polarizing plate was produced in the same manner as in Example 4, except that an acrylic film (refractive index: 1.49) was used in place of the polyethylene terephthalate film.

Example 6

A polarizing plate was produced in the same manner as in Example 1 except that a second particle made of polymethyl methacrylate (PMMA) (refractive index: 1.49, shape: triangular pyramid having a triangular cross section (width: 100 nm, height: Respectively.

Example 7

A polarizing plate was produced in the same manner as in Example 1, except that a second particle made of polymethyl methacrylate (PMMA) (refractive index: 1.49, shape: square having a square cross section (square diagonal length: 100 nm) .

Example 8

A second particle of polymethylmethacrylate (PMMA) on the surface of a first particle (average particle diameter: 2 m, refractive index: 1.43, shape: spherical) of silicone material by a particle hybrid method by physical pressing force or shearing force (Average particle diameter: 50 nm, refractive index: 1.49, shape: spherical) was embedded in a polarizing plate.

Comparative Example One

In Example 1, a polarizer was produced by the same method, and an acrylic binder (refractive index: 1.61) was applied to a PET film and dried to produce a laminate of a coating layer and a film. Then, a polarizing plate was produced in the same manner as in Example 1.

Comparative Example 2

A polarizer was produced in the same manner as in Example 1 except that the refractive indexes of the first particle, the second particle and the third particle were the same.

Comparative Example 3

Polarizers were produced in the same manner as in Example 1 except that the first particles (average particle diameter: 2 탆, refractive index: 1.43, shape: spherical) of silicone material and polymethylmethacrylate (PMMA) A composition prepared by mixing two particles (average particle diameter: 50 nm, refractive index: 1.49, shape: spherical) and an acrylic binder (refractive index: 1.61) was applied to a polyethylene terephthalate (PET) film and dried to obtain a laminate . Then, a polarizing plate was produced in the same manner as in Example 1.

Comparative Example 4

A polarizer was produced in the same manner as in Example 1 except that the first particles (average particle diameter: 2 탆, refractive index: 1.49, shape: spherical) of polymethylmethacrylate (PMMA) A composition prepared by mixing two particles (average particle diameter: 50 nm, refractive index: 1.43, shape: spherical) and an acrylic binder (refractive index: 1.40) was applied to a polyethylene terephthalate (PET) film and dried to obtain a laminate . Then, a polarizing plate was produced in the same manner as in Example 1.

Comparative Example 5

Polarizers were produced in the same manner as in Example 1 except that the first particles (average particle diameter: 2 탆, refractive index: 1.43, shape: spherical) of silicone material were used as the core and polymethylmethacrylate Shell type particles having a shell of a refractive index (PMMA) material (refractive index: 1.49) were prepared by a conventional method, and the prepared core-shell type particles and an acrylic binder (refractive index: 1.61) were mixed The prepared composition was applied to a polyethylene terephthalate (PET) film and dried to produce a laminate of a coating layer and a film. Then, a polarizing plate was produced in the same manner as in Example 1.

The specifications of the laminate of Examples 1 to 8 and Comparative Examples 1 to 5 are shown in Table 1.

Base film Coating layer Matrix resin Compound preparation Example 1 PET Acrylic binder having a refractive index of 1.61 A first particle having a refractive index of 1.43 and an average particle diameter of 2 m, a refractive index of 1.49, an average particle diameter of 50 nm, Example 2 PET Acrylic binder having a refractive index of 1.61 A first particle having a refractive index of 1.43 and an average particle diameter of 2 占 퐉, a refractive index of 1.49, an average particle diameter of 100 nm, Example 3 ACRYL Acrylic binder having a refractive index of 1.61 A first particle having a refractive index of 1.43 and an average particle diameter of 2 m, a refractive index of 1.49, an average particle diameter of 50 nm, Example 4 PET Acrylic binder with a refractive index of 1.40 A first particle having a refractive index of 1.49 and an average particle diameter of 2 占 퐉, a refractive index of 1.43, an average particle diameter of 50 nm, Example 5 ACRYL Acrylic binder with a refractive index of 1.40 A first particle having a refractive index of 1.49 and an average particle diameter of 2 占 퐉, a refractive index of 1.43, an average particle diameter of 50 nm, Example 6 PET Acrylic binder having a refractive index of 1.61 A refractive index of 1.43, a refractive index of 1.49 to a first particle having an average particle diameter of 2 占 퐉, a particle having a triangular pyramid- Example 7 PET Acrylic binder having a refractive index of 1.61 A first particle having a refractive index of 1.43 and an average particle diameter of 2 占 퐉, a refractive index of 1.49, and a particle having a second- Example 8 PET Acrylic binder having a refractive index of 1.61 A refractive index of 1.49 and a mean particle diameter of 50 nm on the surface of the first particle having an average particle diameter of 2 m, Comparative Example 1 PET Acrylic binder having a refractive index of 1.61 Including compound preparation Comparative Example 2 PET Acrylic binder with a refractive index of 1.43 A first particle having a refractive index of 1.43 and an average particle diameter of 2 m, a refractive index of 1.43, an average particle diameter of 50 nm, Comparative Example 3 PET Acrylic binder having a refractive index of 1.61 A first particle having a refractive index of 1.43 and an average particle diameter of 2 占 퐉 and a second particle having a refractive index of 1.49 and an average particle diameter of 50 nm Comparative Example 4 PET Acrylic binder with a refractive index of 1.40 A first particle having a refractive index of 1.49 and an average particle diameter of 2 탆 and a second particle having a refractive index of 1.43 and an average particle diameter of 50 nm Comparative Example 5 PET Acrylic binder having a refractive index of 1.61 A core-shell type particle including a shell having a refractive index of 1.49 and a refractive index of 1.49 to core particles having an average particle size of 2 탆

Diffuse reflectance (%) of coating layer Whether or not interference is visible Haze (%) Example 1 0.25 × 5.2 Example 2 0.28 × 5.3 Example 3 0.24 × 5.1 Example 4 0.26 × 5.2 Example 5 0.25 × 5.2 Example 6 0.24 × 5.8 Example 7 0.28 × 5.7 Example 8 0.19 × 4.6 Comparative Example 1 0.03 ○ 0.6 Comparative Example 2 0.10 ○ 1.3 Comparative Example 3 0.82 × 9.2 Comparative Example 4 0.89 × 8.9 Comparative Example 5 0.43 × 5.5

(1) Diffuse Reflectance of Coating Layer: A PET film having a coating layer containing particles is adhered to a top of a glass with a black TAPE attached to the bottom thereof by using a weak adhesive film, and then a light source incident on the coating surface is diffused and reflected The amount was measured by integrating sphere (diffuse reflectance at a wavelength of 380 ~ 780nm), and the measured values were averaged and evaluated. However, the PET upper coating layer was further subjected to a planarization coating with a matrix resin in order to minimize the external haze due to the unevenness of the surface particle layer.

(2) Whether or not interference blur is visible: A polarizing plate is disposed between the upper surface of the liquid crystal display panel, the lower surface of the liquid crystal display panel of the VA mode liquid crystal, and the liquid crystal display panel and the backlight. The spectroscopic emission luminance meter (SR-3A, Topcon) was used to observe whether or not the stain due to interference was visually observed. The case where the interference unevenness was not visually observed, the case where the interference unevenness was visually confirmed to be fine, and the case where the interference unevenness was strongly visually evaluated.

(3) Haze of the coating layer and the substrate film laminate: HAZE-GARD2 was used.

As shown in Table 2, the polarizing plate of the present invention minimizes the degree of visibility due to interference unevenness, thereby preventing almost no visible light, and lowering the diffuse reflectance, thereby preventing the coating layer from becoming cloudy and increasing the contrast ratio.

On the other hand, the polarizing plate of Comparative Example 1, which does not include the combination preparation of the present invention, has a problem that interference is visible. In addition, the polarizing plate of Comparative Example 2, which includes a composite preparation not containing a refractive index gradient, has a problem in that interference visibility is increased. In addition, in Comparative Examples 3 to 4 including a simple mixture of first and second particles having a refractive index gradient instead of a complex formulation, and Comparative Example 5 including core-shell type particles, diffusion in the first particle surface It is difficult to lower the reflectance and the contrast of contrast is deteriorated.

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.

Claims

A polarizer, a base film formed on the upper surface of the polarizer, and a coating layer formed on the upper surface of the base film,
Wherein the coating layer comprises a matrix resin and a solid composite preparation dispersed in the matrix resin,
Wherein the combined preparation comprises a first formulation having a first size and a second formulation attached to the first formulation and having a second size,
N2 > n3 or n3 > n2 > n1, where n1 is the refractive index of the first formulation, n2 is the refractive index of the second formulation, and n3 is the refractive index of the matrix resin.

The polarizing plate according to claim 1, wherein the coating layer has a diffuse reflectance of 0.4% or less.

The polarizing plate according to claim 1, wherein a haze of the laminate of the base film and the coating layer is 2 to 50%.

[2] The method according to claim 1, wherein the coating layer comprises a first type in which the composite preparation is dispersed in the matrix resin as a whole, a lower region in contact with the base film and in contact with the lower region and the lower region, And a second region including an upper region.

The polarizer according to claim 1, wherein n1> n2> n3, n1 is 1.6 to 1.7, n2 is 1.5 to 1.6, and n3 is 1.4 to 1.5.

The polarizer according to claim 1, wherein n3> n2> n1, n1 is 1.4 to 1.5, n2 is 1.5 to 1.6, and n3 is 1.6 to 1.7.

The polarizer according to claim 1, wherein the ratio of the second size to the first size is 1/10 ⁴ to 1/10 ¹ .

The polarizing plate according to claim 1, wherein the second agent is bonded to the surface of the first agent or embedded in the outermost portion of the first agent.

The polarizing plate according to claim 1, wherein the first agent has particles of spherical shape, rod shape, or a combination of a rod shape and a spherical shape, or a fibrous shape.

[2] The method according to claim 1, wherein the second preparation comprises a spherical shape, a rod shape, a combination of a rod shape and a spherical shape, a prismatic shape or a polygonal shape having an n-square section (n is an integer of 3 to 20) Particles in a combined form, or a polarizer having a fiber shape.

The method according to claim 1, wherein the base film is at least one selected from the group consisting of polyester, cyclic polyolefin, polycarbonate, polyether sulfone, polysulfone, polyamide, polyimide, polyolefin, polyarylate, A polyvinyl chloride system, a polyvinyl chloride system, and a polyvinylidene chloride system.

The polarizer of claim 1, further comprising an optical film on a lower surface of the polarizer.

A liquid crystal display device comprising the polarizer of any one of claims 1 to 12.