KR101586845B1 - Polarizer protecting film, polarizer plate comprising the same, and method for preparing the polarizer plate - Google Patents

Abstract

The present invention relates to a polarizer protective film, a polarizing plate including the polarizer protective film, and a method of manufacturing the polarizer, and more particularly, to a polarizer protective film exhibiting high hardness and excellent properties, a polarizing plate including the same, and a method of manufacturing the polarizing plate. According to the polarizing plate of the present invention, it exhibits excellent hardness, flexibility, and optical characteristics and can be usefully used in various fields.

Description

[0001] The present invention relates to a polarizer protective film, a polarizer including the polarizer protective film, and a method of manufacturing the polarizer,

The present invention relates to a polarizer protective film, a polarizing plate including the polarizing plate, and a method of manufacturing the polarizing plate. More particularly, the present invention relates to a polarizer protective film exhibiting excellent physical and optical properties, a polarizing plate comprising the same, and a method of manufacturing the polarizing plate.

Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. In general, a liquid crystal display has a structure in which a liquid crystal layer is sealed between a TFT (Thin Film Transistor) array substrate and a color filter substrate. When an electric field is applied to the electrodes existing on the array substrate and the color filter substrate, the arrangement of the liquid crystal molecules in the liquid crystal layer sealed therebetween is changed, and images are displayed using the liquid crystal molecules.

On the other hand, a polarizing plate is provided outside the array substrate and the color filter substrate. The polarizing plate can control the polarization by selectively transmitting light in a specific direction among light incident from the backlight and light passing through the liquid crystal layer.

The polarizer generally has a structure in which a polarizer capable of polarizing light in a specific direction is adhered to a protective film for supporting and protecting the polarizer.

As the protective film, a film made of triacetylcellulose (TAC) is widely used. In addition, a protective film for coating a hard coating layer to achieve a film having properties of hardness and abrasion resistance has been proposed.

On the other hand, in recent years, the use of liquid crystal devices has been widespread and used in various fields of devices, and attention has been paid to the improvement of the hardness and thinness of the polarizing plate.

With respect to this necessity, Japanese Unexamined Patent Application Publication No. 2005-010329 and the like have proposed a polarizing plate in which a TAC film is omitted and a protective layer is formed using a photopolymerizable compound on the surface of a polarizer. However, there is still a demand for a polarizing plate which has sufficient hardness, exhibits a low thickness for thinning and exhibits sufficient flexibility to be suitable for a mass production process.

Disclosure of the Invention In order to solve the above problems, the present invention provides a polarizer protective film which exhibits high hardness and high transparency and can be made thin, at the same time exhibiting excellent flexibility to prevent curling or cracking, a polarizing plate comprising the polarizing plate and a polarizing plate .

In order to solve the above problems, the present invention provides a polarizer protective film comprising a cured resin of a polyfunctional acrylate monomer and an acrylate oligomer having an elongation of 5 to 200%.

The present invention also provides a polarizing element comprising: a polarizer; And a protective film provided on at least one surface of the polarizer, wherein the protective film comprises a curable resin with a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200% .

The present invention also provides a binder comprising: a binder comprising a polyfunctional acrylate-based monomer on a release film and an acrylate-based oligomer having an elongation of 5 to 200%; And applying a resin composition comprising a photoinitiator;

Photocuring the applied resin composition to form a protective film; And

And laminating and bonding the protective film to one surface of the polarizer.

According to the polarizer protective film of the present invention, it exhibits high hardness, scratch resistance and high transparency, and curls or cracks are not generated due to excellent processability, so that it can be applied to various display devices. It can be thinned. In particular, since it does not contain a stretched film, the retardation value is substantially as low as zero, so that it can be used not only for a polarizer protective film but also for various devices requiring such a low retardation value, without limitations in application.

In addition, it exhibits excellent workability and flexibility, and is applicable to a large area or curved surface display.

The polarizer protective film of the present invention comprises a curable resin with a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%.

The polarizer of the present invention comprises: a polarizer; And a protective film provided on at least one side of the polarizer, wherein the protective film comprises a curable resin with a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%.

A method for producing a polarizing plate of the present invention comprises: a binder comprising a polyfunctional acrylate-based monomer on a release film and an acrylate-based oligomer having an elongation of 5 to 200%; And applying a resin composition comprising a photoinitiator; Photocuring the applied resin composition to form a protective film; And laminating and adhering the protective film to one surface of the polarizer.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Hereinafter, the polarizer protective film, the polarizing plate including the same, and the method of producing the polarizing plate of the present invention will be described in detail.

In the specification of the present invention, acrylate eggs mean not only acrylates but also methacrylates, or derivatives having substituents introduced into acrylate or methacrylate.

The polarizer protective film according to an embodiment of the present invention includes a curable resin with a polyfunctional acrylate monomer and an acrylate oligomer having an elongation of 5 to 200%.

The polarizer protective film is used for protecting the polarizer from the outside.

Polarizer protective films generally used include polyester such as polyethylene terephthalate (PET), cyclic olefin copolymer (COC), polyacrylate (PAC), polycarbonate polycarbonate (PC), polyethylene (PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), polyetherimide , Polyimide (PI), triacetylcellulose (TAC), and the like.

Of these materials, triacetylcellulose (TAC) films have been widely used because of their excellent optical properties. However, when the TAC film is used alone, the surface hardness is weak and it is vulnerable to humidity, and it is necessary to add a functional coating layer such as a hard coating. However, when the functional coating layer is further included, the entire thickness of the protective film is increased, which may not meet the recent requirement for thinning, and curl or cracks may occur in the film due to the additional coating.

Accordingly, the present invention provides a protective film having a low thickness so as to be compatible with a sufficient hardness and thinning tendency without replacing a commonly used TAC film and without a separate coating layer. In addition, the protective film of the present invention exhibits excellent optical properties required for a polarizer protective film, and can exhibit excellent flexibility to facilitate production, processing, storage and transportation.

Further, since the stretched film is not included, the retardation value is so low as to be substantially zero that it can be used not only for the polarizer protective film but also for various devices requiring such a low retardation value, without limitations in application.

In addition, it exhibits excellent workability and flexibility, and is applicable to large area or curved surface displays.

The polarizer protective film of the present invention includes a curable resin with a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%.

The polyfunctional acrylate-based monomer includes two or more acrylate-based functional groups and has a molecular weight of less than 1,000 g / mol. More specifically, there may be mentioned, for example, hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol diacrylate (EGDA), trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxy tri Acrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA), or dipentaerythritol hexaacrylate (DPHA). The polyfunctional acrylic But the rate-based monomers are not limited thereto. The polyfunctional acrylate-based monomer is cross-linked with each other or cross-linked with an acrylate-based oligomer to be described later to impart a certain strength and abrasion resistance to the protective film.

The polyfunctional acrylate monomers may be used alone or in combination of two or more.

The acrylate oligomer has an elongation of from about 5 to about 200%, or from about 5 to about 100%, or from about 10 to about 50%, as measured by ASTM D638. Acrylate " means an oligomer having at least two acrylate functional groups. When the elongation of the acrylate oligomer is in the above range, excellent flexibility and elasticity can be exhibited without deteriorating the mechanical properties. The acrylate oligomer satisfying the above elongation ranges is excellent in flexibility and elasticity to form the acrylate-based monomer and the cured resin, and it is possible to impart sufficient flexibility and curling characteristics to the protective film containing the acrylate-based monomer On the basis of which the present invention has been reached.

According to one embodiment of the present invention, the weight average molecular weight of the acrylate oligomer ranges from about 1,000 to about 10,000 g / mol, or from about 1,000 to about 5,000 g / mol, or from about 1,000 to about 3,000 g / mol Lt; / RTI >

According to an embodiment of the present invention, the acrylate oligomer may be an acrylate oligomer modified with at least one of ethylene oxide, propylene oxide, and caprolactone. When the modified acrylate oligomer is used, flexibility is further imparted to the acrylate oligomer due to modification, so that the curling property and flexibility of the protective film can be increased.

The acrylate oligomers may be used alone or in combination of two or more.

The protective film of the present invention includes the above-mentioned polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%, which is cured by ultraviolet rays. In addition, the protective film of the present invention does not contain a triacetyl cellulose (TAC) component.

According to one embodiment of the present invention, the curable resin comprises a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200% of about 2: 8 to about 8: 2, or about 3: 7 to about 7: 3, or from about 4: 6 to about 6: 4. When the cured resin is cured to the above range, the protective film of the present invention can have sufficient flexibility without deteriorating the mechanical properties.

The protective film of the present invention includes a polyfunctional acrylate-based monomer and a cured resin in which an acrylate-based oligomer having an elongation of 5 to 200% is cured, thereby making it possible to achieve high hardness and thinness without deteriorating optical properties. It is also excellent in surface hardness and scratch resistance without a separate functional coating layer such as a hard coating. In addition, excellent flexibility, impact resistance, and flexibility can be secured, and the present invention can be applied to a large area or a curved surface display. Since it contains a cured resin layer that is not a stretched film, the retardation value is substantially as low as zero and can be used for various display devices requiring a low retardation value as well as a polarizer protective film without any limitations in its application.

The protective film according to the present invention includes a cured resin obtained by cross-linking an acrylate oligomer together with the polyfunctional acrylate monomer described above, thereby exhibiting high hardness and flexibility at the same time. Accordingly, the polarizer protective layer can function as a polarizer protective layer without a separate functional coating layer, and at the same time, can function as a hard coating layer and can be applied as a multi-functional polarizer protective film.

According to one embodiment of the present invention, the protective film of the present invention may further comprise inorganic fine particles. The inorganic fine particles may be dispersed in the cured resin.

The inorganic microfine particle may be an inorganic microfine particle having a nanoscale particle size, for example, a particle size of about 100 nm or less, or about 10 to about 100 nm, or about 10 to about 50 nm. The inorganic fine particles may include, for example, silica fine particles, aluminum oxide particles, titanium oxide particles, or zinc oxide particles.

By including the inorganic fine particles, the hardness of the protective film can be further improved.

According to an embodiment of the present invention, when the protective film further comprises inorganic fine particles, the inorganic fine particles may be included in an amount of about 1 to about 100 parts by weight, when the total weight of the curable resin is 100 parts by weight, Or from about 10 to about 50 parts by weight. By including the inorganic fine particles in the above range, it is possible to provide a protective film excellent in both hardness and flexibility.

According to one embodiment of the present invention, the protective film has a thickness of at least about 10 microns, such as from about 10 to about 200 microns, or from about 10 to about 100 microns, or from about 10 to about 50 microns, About 40 占 퐉, or about 10 to about 30 占 퐉. According to the present invention, it is possible to provide a protective film having a thickness as described above, which is thinner than a film including a separate coating layer and has a high hardness without causing curling or cracking.

The polarizer protective film of the present invention as described above can be obtained by curing the resin composition comprising the polyfunctional acrylate monomer, the acrylate oligomer having an elongation of 5 to 200%, the photoinitiator, and optionally the inorganic fine particles and the organic solvent .

Examples of the photoinitiator include 1-hydroxy-cyclohexyl-phenylketone, 2-hydroxy-2-methyl-1-phenyl- 2-benzoyl-2- (dimethylamino) -1- [4- (4-methoxyphenyl) -2-methyl-1-propanone, methylbenzoylformate, -Morpholin yl) phenyl] -1-butanone, 2-methyl-1- [4- (methylcio) , 6-trimethylbenzoyl) -phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like. Products currently on the market include Irgacure 184, Irgacure 500, Irgacure 651, Irgacure 369, Irgacure 907, Darocur 1173, Darocur MBF, Irgacure 819, Darocur TPO, Irgacure 907 and Esacure KIP 100F. These photoinitiators may be used alone or in combination of two or more.

Examples of the organic solvent include alcohol solvents such as methanol, ethanol, isopropyl alcohol and butanol, alkoxy alcohol solvents such as 2-methoxyethanol, 2-ethoxyethanol and 1-methoxy-2-propanol, Ketone solvents such as ethyl ketone, methyl isobutyl ketone, methyl propyl ketone and cyclohexanone, propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, Ether solvents such as diethylene glycol monomethyl ether, diethyl glycol monoethyl ether, diethyl glycol monopropyl ether, diethyl glycol monobutyl ether and diethylene glycol-2-ethylhexyl ether, benzene, toluene, The same aromatic solvent may be used alone or in combination.

On the other hand, the resin composition may contain, in addition to the above-mentioned polyfunctional acrylate monomer, an acrylate oligomer having an elongation of 5 to 200%, an inorganic fine particle, a photoinitiator and an organic solvent, a UV absorber, a surfactant, , An antifouling agent, and the like, which are commonly used in the art to which the present invention belongs. The content thereof is not particularly limited as it can be variously adjusted within a range that does not deteriorate the physical properties of the protective film of the present invention.

According to one embodiment of the present invention, for example, the resin composition may contain a surfactant as an additive, and the surfactant may be a fluorinated acrylate, a fluorinated surfactant or a silicone surfactant having 1 to 2 functionalities. At this time, the surfactant may be dispersed or crosslinked in the cured resin.

Further, the additive may include a yellowing inhibitor, and examples of the yellowing inhibitor include a benzophenone-based compound or a benzotriazole-based compound.

According to another aspect of the present invention, there is provided a polarizer comprising: a polarizer; And a protective film provided on at least one surface of the polarizer, wherein the protective film comprises a curing resin comprising a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200% do.

According to another aspect of the present invention, there is provided a binder comprising: a binder comprising a polyfunctional acrylate-based monomer on a release film and an acrylate-based oligomer having an elongation of 5 to 200%; And applying a resin composition comprising a photoinitiator; Photocuring the applied resin composition to form a protective film; And laminating and bonding the protective film to one surface of the polarizer.

First, a binder comprising a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%; And a photoinitiator are applied on a release film. A detailed description of the components contained in the resin composition is the same as described for the polarizer protective film. The resin composition may further include an organic solvent, an inorganic fine particle, an additive, and the like.

The release film may be used without limitation as long as it is commonly used in the technical field to which the present invention belongs. According to an embodiment of the present invention, the release film may be a polyolefin film such as a polyester film, a polyethylene film, a polyethylene terephthalate film, a polypropylene film, or a Teflon film. Preferably, Resin, melamine resin, urea resin, or the like. The thickness of the release film is not particularly limited, but a release film having a thickness of about 20 to about 200 mu m can be mainly used.

The release film may be peeled off after the protective film is attached to the polarizer after curing the resin composition. Or may be removed after attaching to the polarizer to favor transport and storage.

The method of applying the resin composition is not particularly limited as long as it can be used in the technical field to which the present technology belongs. For example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a micro gravure coating Method, a comma coating method, a slot die coating method, a lip coating method, or a solution casting method.

Next, a protection film can be formed by irradiating the applied resin composition with external light to perform photo-curing reaction. Before applying the ultraviolet rays, the application surface of the resin composition may be planarized and the solvent contained in the composition may be dried to volatilize the resin.

The dose of the ultraviolet rays may be, for example, about 20 to about 600 mJ / cm ² . The light source for ultraviolet irradiation is not particularly limited as long as it can be used in the technical field to which the present technology belongs. For example, a high pressure mercury lamp, a metal halide lamp, a black light fluorescent lamp and the like can be used.

After the resin composition is completely cured, a polarizer protective film formed into a single layer without a base film such as TAC or a separate coating layer can be obtained.

According to the polarizer protective film of the present invention, since the protective film is applied on a separate release film without being formed directly on the polarizer and cured, the film is not affected by shrinkage of the substrate, curls and cracks are not generated, can do. In addition, it exhibits a low retardation value and can provide a polarizer protective film of high hardness without lowering the optical properties required for the polarizer protective film such as light transmittance and haze.

The protective film of the present invention exhibits high hardness, flexibility, scratch resistance and high transparency, and can be used as a single layer film for polarizer protection and can be usefully used in various display devices.

In the present invention, the protective film may be included on only one side of the polarizer or on both sides of the polarizer.

The polarizer vibrates in various directions and exhibits a characteristic of extracting only light vibrating in one direction from the incident light. This property can be achieved by stretching polyvinyl alcohol (PVA) absorbing iodine with a strong tension. For example, more specifically, there is a method comprising swelling a PVA film by swelling in an aqueous solution, dyeing the swollen PVA film with a dichroic material imparting polarizing properties, stretching the dyed PVA film, ) To align the dichroic dye materials in the stretching direction, and a polarizing step for correcting the color of the PVA film after the stretching step. However, the polarizing plate of the present invention is not limited thereto.

The polarizing plate of the present invention includes a protective film provided on at least one surface of the polarizer.

The protective film may have a thickness of at least about 10 microns, such as from about 10 to about 100 microns, or from about 10 to about 50 microns, or from about 10 to about 40 microns, or from about 10 to about 30 microns Lt; / RTI >

Further, the total thickness of the polarizing plate of the present invention may be about 45 탆 or more, for example, about 45 to about 250 탆, or about 50 to about 120 탆, or about 50 to about 100 탆. According to the present invention, it is possible to achieve high hardness without causing curling or cracking while having such a thin thickness.

The protective film may further include a curable resin of a polyfunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5 to 200%, and may further include inorganic fine particles optionally dispersed in the cured resin. A more detailed description thereof and a method for producing the protective film are as described for the polarizer protective film.

According to an embodiment of the present invention, the polarizing plate of the present invention may further include an adhesive layer provided between the polarizer and the protective film.

The adhesive layer may be one comprising an adhesive for a polarizer which has transparency and can maintain the polarization property of the polarizer. Usable adhesives are not particularly limited as long as they are known in the art. For example, there are a one-component or two-component polyvinyl alcohol (PVA) adhesive, an acrylic adhesive, a polyurethane adhesive, an epoxy adhesive, a styrene butadiene rubber adhesive (SBR), or a hot melt adhesive. But it is not limited to examples.

The thickness of the adhesive layer may be about 0.1 to about 10 mu m, or about 0.1 to about 5 mu m, but the present invention is not limited to these examples.

Next, the polarizing plate of the present invention can be obtained by laminating and bonding the formed protective film to a polarizer using an adhesive. The release film may be removed by selectively peeling off the protective film before or after attaching the protective film to the polarizer after curing the resin composition.

According to an embodiment of the present invention, the protective film may be attached to both surfaces of the polarizer.

According to another embodiment of the present invention, the protective film may be attached to only one side of the polarizer and another general film such as TAC may be attached to the other side. At this time, the protective film may be positioned at the outermost face facing the user. As described above, the protective film of the present invention exhibits high hardness, scratch resistance, and optical properties suitable for the outermost layer.

The protective film of the present invention exhibits properties superior enough to replace the TAC film, and thus the polarizing plate comprising it can have excellent pencil hardness, curl characteristic, flexibility and optical characteristics.

For example, according to one embodiment of the present invention, when the polarizing plate of the present invention is placed on a plane after exposure for 24 hours at room temperature, the average value of the distance of each edge or one side of the polarizing plate from the plane is about 3 mm Or less, or about 2 mm or less, or about 1 mm or less.

The polarizing plate of the present invention may have a pencil hardness of not less than 1H, or not less than 2H, or not less than 3H under a load of 500 g.

Further, the polarizing plate of the present invention may have a simple transmittance of 40% or more, or 42% or more.

Further, the polarizing plate of the present invention may not crack when it is wound around a cylindrical umbrella having a diameter of 15 mm, 12 mm, or 5 mm.

The protective film provided on the polarizing plate of the present invention may exhibit a retardation value in the range of 0 to 1 nm, or 0 to 0.6 nm, or 0 to 0.5 nm.

The polarizing plate having the protective film of the present invention can be used in various fields. For example, mobile communication terminals, smart phones, other mobile devices, display devices, electronic blackboards, outdoor electronic signboards, and various displays. According to an embodiment of the present invention, the polarizing plate may be a TN (Twisted Nematic) or STN (Super Twisted Nematic) liquid crystal polarizing plate, and may be an IPS (In-Plane Switching), a Super-IPS, a Fringe Field Switching Or may be a polarizing plate for a vertical alignment mode.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

< Example >

Production of protective film

Example  One

50 g of trimethylolpropane triacrylate (TMPTA), 20 g of DPCA120 (Nippon Kayaku, caprolactone denatured 6-functional group acrylate, 12% elongation measured with ASTM D638, Mw 1,950), PU3400 (MWN, ethylene oxide modified functional group acrylate, , 30 g of an elongation (20% measured by ASTM D638, Mw 2,500), 6 g of a photoinitiator (trade name: Darocur TPO), 3 g of a UV absorbent (Chimassorb 81) and 10 g of MEK were mixed and bar-coated on a PET release film. This was dried at 60 DEG C for 2 minutes, and then black UV was irradiated in a nitrogen atmosphere to obtain a protective film having a thickness of 25 mu m.

Example  2

50 g of trimethylolpropane triacrylate (TMPTA), 20 g of DPCA120, 30 g of TA604AU (Japanese oil, ethylene oxide modified functional group acrylate, 49% elongation measured by ASTM D638, Mw 2,300), 6 g of a photoinitiator (trade name: Darocur TPO) 3 g of an absorbent (trade name: Chimassorb 81) and 10 g of MEK were mixed to prepare a coating solution and bar-coated on a PET release film. This was dried at 60 DEG C for 2 minutes, and then black UV was irradiated in a nitrogen atmosphere to obtain a protective film having a thickness of 25 mu m.

Example  3

C150 (product in which the 20nm SiO ₂ dispersion 50% in TMPTA of _{Nano resin, 25g, SiO 2 25g} ) 50g, PU3400 20g, TA604AU 30g, a photoinitiator (trade name Darocur TPO 6g, UV absorbing agent (product name Chimassorb 81) 3g, MEK 10g To prepare a coating solution, and bar-coated on a PET release film, dried at 60 DEG C for 2 minutes, and then exposed to black UV in a nitrogen atmosphere to obtain a protective film having a thickness of 25 mu m.

Comparative Example  One

50 g of trimethylolpropane triacrylate (TMPTA), 50 g of EB1290 (SK Cytec, 6 functional group urethane acrylate, 0% elongation measured with ASTM D638, Mw 1,000), 6 g of a photoinitiator (trade name Darocur TPO) ) And 10 g of MEK were mixed to prepare a coating solution, which was bar-coated on a TAC film having a thickness of 40 탆. After drying at 60 DEG C for 2 minutes, black UV was irradiated in a nitrogen atmosphere to obtain a protective film having a thickness of 6 mu m on the TAC film.

Production of Polarizer

Example  4

The protective film prepared in Example 1 was laminated and laminated with a PVA film so that the thickness of the adhesive layer was approximately 1 占 퐉 using an acrylic adhesive, and the PET release film was peeled off.

On the other side of the PVA, a polarizing plate was prepared by adhering TAC with a thickness of 40 탆 in the same manner.

Example  5

A polarizing plate was prepared in the same manner as in Example 4, except that a protective film of Example 2 was attached to one surface of the PVA film and a TAC film of 40 m thickness was attached to the other surface of the PVA film.

Example  6

A polarizing plate was prepared in the same manner as in Example 4, except that the protective film of Example 3 was attached to one side of the PVA film and the TAC film was attached to the other side of the PVA film.

Comparative Example  2

A polarizing plate was prepared in the same manner as in Example 4, except that a TAC film having a coating layer of Comparative Example 1 was attached to one side of the PVA film and a TAC film having a thickness of 40 m was attached to the other side thereof.

Comparative Example  3

On both sides of the PVA film, a TAC film having a thickness of 40 占 퐉 was laminated with a PVA film so that the thickness of the adhesive layer was approximately 1 占 퐉, using an acrylic adhesive, and a polarizing plate was produced.

< Experimental Example >

<Measurement method>

1) Thickness

And measured using a digital micrometer.

2) Transmittance

The transmittance and haze were measured using a haze meter (HM 150).

3) Phase difference

The retardation value in the plane direction was measured using a phase difference meter (Axoscan).

4) Pencil Hardness

Using a pencil hardness tester, the surface of the polarizing plate was reciprocated five times under a load of 500 g according to the measurement standard JIS K5400, and the hardness without scratches was confirmed.

5) scratch resistance

The steel wool # 0000 was subjected to a constant load, reciprocated 10 times, and a load without scratches was observed.

6) Curl characteristics

Each polarizing plate was cut into 10 cm x 10 cm, stored for 24 hours, and placed on a plane, and the average value of the distance of one side of each corner from the plane was measured.

7) Cylindrical bending test

Each polarizing plate was sandwiched in a cylindrical ellipse having a diameter of 5 mm, and then the presence or absence of cracks was judged to be OK, the case where no crack occurred was evaluated as OK, and the case where a crack occurred was evaluated as X.

The results of the physical properties measurement are shown in Table 1 below.

Example 4 Example 5 Example 6 Comparative Example 2 Comparative Example 3 Polarizer thickness 91 탆 90 탆 91 탆 111 탆 105 탆 Transmittance 43.0% 43.0% 42.7% 42.6% 42.7% Hayes 0.2 0.3 0.2 0.3 0.2 Phase difference 0.2 nm 0.3 nm 0.3 nm 2.2 nm 2.2 nm Pencil hardness 3H 2H 3H 3H HB My scratch 500g 500g 500g 500g 50g Curl characteristic 0.7mm 0.3mm 0.3mm 28.5 mm 0.1mm Flex Test OK OK OK X OK

As shown in Table 1, the polarizing plate of the example of the present invention showed good properties in all properties. In particular, as compared with the conventional protective film including TAC and the coating layer and Comparative Example 3 including only TAC as in Comparative Example 2, it is required to have a low thickness, high hardness, excellent curl characteristic, flexibility, low phase difference, And the like.

Claims (21)

A polyfunctional acrylate monomer and a curing resin with an acrylate oligomer having an elongation of 5 to 50% as measured by ASTM D638,
Wherein the curable resin has the polyfunctional acrylate monomer and the acrylate oligomer cured at a weight ratio of 2: 8 to 8: 2.
delete The method of claim 1, wherein the polyfunctional acrylate monomer is selected from the group consisting of hexane diol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol diacrylate (EGDA), trimethylolpropane triacrylate ), Trimethylolpropane ethoxy triacrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA), and dipentaerythritol hexaacrylate (DPHA) A polarizer protective film comprising at least one selected.
The method of claim 1, wherein the acrylate oligomer has two or more acrylate functional groups and is modified with at least one selected from the group consisting of ethylene oxide, propylene oxide, and caprolactone Polarizer protective film.
The polarizer protective film according to claim 1, further comprising inorganic fine particles dispersed in the cured resin.
The polarizer protecting film according to claim 5, wherein the inorganic fine particles are contained in an amount of 1 to 100 parts by weight, based on 100 parts by weight of the curable resin.
The polarizer protective film according to claim 5, wherein the inorganic fine particles comprise at least one selected from the group consisting of silica nano-particles, aluminum oxide fine particles, titanium oxide fine particles and zinc oxide fine particles.
A polarizer; And
And a protective film provided on at least one surface of the polarizer, wherein the protective film comprises a polyfunctional acrylate-based monomer and a cured resin with an acrylate-based oligomer having an elongation of 5 to 50% as measured by ASTM D638 Including,
Wherein the curable resin has the polyfunctional acrylate monomer and the acrylate oligomer cured at a weight ratio of 2: 8 to 8: 2.
delete The polyfunctional acrylate monomer as claimed in claim 8, wherein the polyfunctional acrylate monomer is selected from the group consisting of hexane diol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol diacrylate (EGDA), trimethylolpropane triacrylate ), Trimethylolpropane ethoxy triacrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA), and dipentaerythritol hexaacrylate (DPHA) A polarizer comprising at least one selected.
[8] The method of claim 8, wherein the acrylate oligomer has two or more acrylate functional groups and is modified with at least one selected from the group consisting of ethylene oxide, propylene oxide, and caprolactone Polarizing plate.
The polarizing plate according to claim 8, wherein the protective film further comprises inorganic fine particles dispersed in the cured resin.
The polarizer according to claim 8, wherein the protective film is provided on both surfaces of the polarizer.
The polarizer according to claim 8, further comprising an adhesive layer provided between the polarizer and the protective film.
The polarizer according to claim 8, wherein the thickness of the protective film is 10 to 100 탆.
The polarizing plate according to claim 8, wherein the thickness of the polarizing plate is 45 to 250 占 퐉.
The polarizing plate according to claim 8, which shows a pencil hardness of 1 H or more at a load of 500 g.
The polarizing plate according to claim 8, wherein an average value of the distance between each edge of the polarizing plate or one side of the polarizing plate is 3 mm or less when the polarizing plate is placed on a plane after being exposed at room temperature for 24 hours.
The polarizing plate according to claim 8, wherein cracks do not occur when the cylindrical mandrel having a diameter of 15 mm is wound around the cylindrical mandrel.
A binder comprising a polyfunctional acrylate-based monomer on a release film, and an acrylate-based oligomer having an elongation of 5 to 50% as measured by ASTM D638; And applying a resin composition comprising a photoinitiator;
Curing the applied resin composition to form a protective film comprising a cured resin in which the polyfunctional acrylate monomer and the acrylate oligomer are cured at a weight ratio of 2: 8 to 8: 2; And
And laminating and adhering the protective film to one surface of the polarizer.
21. The method of claim 20, further comprising peeling the release film before or after the step of laminating and bonding the protective film to one surface of the polarizer.