KR20140148335A - Polarizer protecting film and method for preparing the same - Google Patents

Abstract

The present invention relates to a polarizer protection film and a manufacturing method thereof. According to the embodiment of the present invention, provided is the polarizer protection film with high physical and optical properties and a high attachment property with a base material. The polarizer protection film according to the embodiment of the present invention includes an attachment enhancement layer which is formed on at least one side of a base material layer and a photocurable layer which is formed on the attachment enhancement layer.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a polarizer protective film,

The present invention relates to a polarizer protective film and a manufacturing method thereof. More particularly, the present invention relates to a polarizer protective film exhibiting excellent physical and optical properties as well as excellent adhesion, and a method for producing the same.

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. The polarizer protective layer is usually formed on a substrate used as a polarizer protective film.

As such a protective film, a film made of triacetyl cellulose (TAC) is widely used. In order to replace this protective film, a polyester film (PET), a cyclic olefin polymer film (COP), a polycarbonate film (PC) A nano film (PNB), an acrylic film, or the like is used. In recent years, in order to develop an optical film having particularly excellent mechanical properties, a film produced by a stretching process is widely used.

In the case of a film produced by the stretching process, the adhesion is reduced due to rearrangement of polymers or the like in the stretching process. Therefore, a separate step (primer adhesion, etc.) is required for securing the adhesion property. In this case, There is a problem in that a separate process is added, and there is a problem that it is difficult to develop a general-purpose primer because physical and chemical properties of each film are different.

Disclosed is a polarizer protective film exhibiting excellent physical and optical properties and excellent adhesion to a substrate, and a process for producing the same.

The present invention relates to a substrate; An adhesion enhancing layer formed on at least one side of the substrate so as to be in direct contact with the substrate to erode the substrate; And a photo-curable layer formed on the adhesion enhancement layer, wherein the adhesion enhancement layer has a thickness of 1 to 10 mu m, and the adhesion enhancement layer includes a curable resin of a photo-curable monofunctional monomer having a hydrogen bondable reactor A polarizer protective film.

The present invention also relates to a method for forming an adhesion promoting layer, comprising: applying a first composition for forming an adhesion promoting layer on at least one side of a substrate; Irradiating the first composition with ultraviolet light to form a first photo-curable composition; Applying a second composition for forming a photocurable layer on the first photocured first composition; And a second photo-curing step of irradiating the applied second composition with ultraviolet light, wherein the first composition comprises a photocurable monofunctional monomer having a hydrogen-bondable reactor and a photopolymerization initiator, wherein the second composition The present invention provides a process for producing a polarizer protective film comprising a photocurable compound and a photopolymerization initiator.

The polarizer protective film of the present invention has high hardness, high transparency and high abrasion resistance, and can be thinned, so that it can be applied to various display devices. Further, the present invention can be applied to substrates such as PET films, COP films, PC films, PNB films and acrylic film substrates as well as substrates such as TAC films without any additional primer treatment, thereby simplifying the manufacturing process.

1 is a sectional view showing the structure of a polarizer protective film according to an embodiment of the present invention.
2 is a SEM image showing a cross section of a polarizer protective film according to an embodiment of the present invention.

The polarizer protective film of the present invention comprises a substrate; An adhesion enhancing layer formed on at least one side of the substrate so as to be in direct contact with the substrate to erode the substrate; And a photo-curable layer formed on the adhesion enhancement layer, wherein the adhesion enhancement layer has a thickness of 1 to 10 mu m, and the adhesion enhancement layer includes a curable resin of a photo-curable monofunctional monomer having a hydrogen bondable reactor do.

The method for producing a polarizer protective film of the present invention includes the steps of: applying a first composition for forming an adhesion promoting layer on at least one side of a substrate; Irradiating the first composition with ultraviolet light to form a first photo-curable composition; Applying a second composition for forming a photocurable layer on the first photocured first composition; And a second photo-curing step of irradiating the applied second composition with ultraviolet light, wherein the first composition comprises a photocurable monofunctional monomer having a hydrogen-bondable reactor and a photopolymerization initiator, wherein the second composition Includes a photocurable compound and a photopolymerization initiator.

In the present invention, the terms first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

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 includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Throughout the present specification, the acrylate egg, acrylate as well as methacrylate, or a derivative having a substituent introduced into acrylate or methacrylate are all included.

Hereinafter, the polarizer protective film and the method for producing the polarizer protective film of the present invention will be described in more detail.

A polarizer protective film according to one aspect of the present invention comprises a substrate; An adhesion enhancing layer formed on at least one side of the substrate so as to be in direct contact with the substrate to erode the substrate; And a photo-curable layer formed on the adhesion promoting layer, wherein the thickness of the adhesion enhancing layer is about 1 to about 10 mu m, and the adhesion enhancing layer is a cured resin of a photo-curable monofunctional monomer having a hydrogen- .

FIG. 1 is a schematic view of a polarizer protective film according to an embodiment of the present invention. Referring to FIG. 1, the polarizer protective film of the present invention comprises a substrate 10; An adhesion promoting layer (20) formed on at least one side of the substrate (10) in a form of being in direct contact with the substrate to erode the substrate; And a photocurable layer 30 formed on the adhesion promoting layer 20.

If the thickness of the adhesion enhancement layer is less than about 1 μm, it may not serve as an adhesion enhancement layer. If the thickness is more than about 10 μm, the adhesion enhancement layer may not meet the requirements for flexibility and thinness. The thickness of the adhesion promoting layer may preferably be about 2 to about 5 mu m.

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

Polarizer protective films generally used include polyester films such as polyethylene terephthalate (PET), cyclic olefin copolymers (COC), polyacrylate (PAC) , Polycarbonate (PC), polyethylene (PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylenenaphthalate (PEN) , Polyetherimide (PEI), polyimide (PI), triacetylcellulose (TAC), and the like.

Of these materials, triacetylcellulose (TAC) films have been widely used because of their excellent optical properties. When the TAC film is used alone, it may be used with a functional coating layer such as a hard coating added thereto since the surface hardness is weak and it is vulnerable to humidity, or a polyester film (PET), a cyclic olefin polymer film (COP) A polycarbonate film (PC), a polynorbornene film (PNB), an acrylic film, or the like is used. In recent years, in order to develop an optical film having particularly excellent mechanical properties, a film produced by a stretching process is widely used.

In the case of a film produced by the stretching process, the adhesion to the polarizer protective layer or the like is reduced due to the rearrangement of polymers or the like in the stretching process. Therefore, a separate step (primer adhesion, etc.) In this case, there is a problem in that a separate process is added in the film production process, and physical and chemical properties are different for each film, so that it is difficult to develop a general purpose primer.

The polarizer protective film according to an embodiment of the present invention has a separate adhesion promoting layer and is provided with a high degree of hardness, high transparency, and high abrasion resistance, and can be thinned, And thus it can be applied without a separate primer treatment even when a stretched film such as a PET film, a COP film, a PC film, a PNB film and an acrylic film is used as a substrate in addition to a cast film such as a TAC film.

The adhesion promoting layer includes a curing resin of a photo-curable monofunctional monomer having a hydrogen-bondable reactor. The photo-curable monofunctional monomer having a hydrogen-bondable reactive group is less volatile than a solvent, and is highly reactive, so that erosion on the substrate is possible irrespective of the properties of the substrate.

Such substrate erosion enables chemical bonding between the substrate layer and the adhesion promoting layer after substrate erosion, so that even when no additional adhesive or crosslinking agent is contained, excellent adhesion can be maintained regardless of the characteristics of the substrate.

It is preferable that about 20 to about 50% of the total thickness of the adhesion promoting layer including the substrate erosion portion is formed in a form such that the substrate is eroded. When the substrate erosion thickness by the adhesion enhancing layer is in the above range, the adhesion enhancing layer can maintain good adhesion, and the polarizer protective film can maintain excellent mechanical properties such as high hardness and high transparency.

2 is a SEM image showing a cross section of a polarizer protective film according to an embodiment of the present invention.

Referring to FIG. 2, a polarizer protective film according to an aspect of the present invention includes a substrate 10; An adhesion promoting layer (20) formed on at least one side of the substrate (10) in a form of being in direct contact with the substrate to erode the substrate; And the photocurable layer 30 formed on the adhesion promoting layer 20. More specifically, the adhesion enhancing layer 20 may be formed on the entire surface of the adhesion enhancing layer 21 including the substrate erosion portion 21, It is confirmed that about 20 to about 50% is formed in a form in which the substrate is eroded.

In the adhesion promoting layer of the present invention, a hydrogen-bondable reactor exists in the cured resin, and after the curing, intermolecular hydrogen bonding becomes possible in the interface between the adhesion promoting layer and the substrate, .

The above-mentioned hydrogen-bondable reactor is not particularly limited as long as it is a reactive group or a residue capable of hydrogen bonding, and examples thereof include -OH group, -NH ₂ group, -NHR group, -COOH group, -CONH ₂ group, -NHOH Or a residue such as -NHCO-bond, -NH-bond, -CONHCO-bond, -NH-NH- bond or the like in the molecule. The hydrogen-bonding site is not particularly limited as long as it is capable of hydrogen bonding with each other even if the sites are contained in different resins. For example, a reactor or a residue containing N or O may be replaced with an -OH group -NH ₂ group or the like, it can be regarded as the hydrogen-bonding site. R may be an aliphatic hydrocarbon, an aromatic hydrocarbon, or a derivative thereof, for example, an aliphatic hydrocarbon having 1 to 16 carbon atoms or a carbon number of 1 to 9, an aromatic hydrocarbon having 5 to 30 carbon atoms or a carbon number of 5 to 16, Or a derivative thereof.

The photo-curable monofunctional monomer having such a hydrogen-bondable reactive group is not particularly limited, and examples thereof include amino group-containing monomers such as N-substituted (meth) acrylate or N, N-substituted (meth) acrylate, (Meth) acryloyloxyacetic acid, 3- (meth) acryloyloxypropyl acid, 4- (meth) acryloyloxypropylacetic acid, Carboxyl group-containing monomers such as acryloyloxybutyl acid, acrylic acid doublet, itaconic acid, maleic acid, or maleic anhydride, heterocyclic compounds such as vinylpyrrolidone or acryloylmorpholine, 2-ureido- A methylene group-containing monomer, or the like. Specific examples thereof include tetrahydrofurfuryl acrylate (THFA), tetrahydrofurfurylmethacrylate THFMA, hydroxyethylacrylate (HEA), hydroxyethylmethacrylate HEMA ), Carboxyethylacrylate, carboxyethylmethacrylate, and the like may be preferably used. However, the present invention is not limited thereto. The photocurable monofunctional monomer having a reactor capable of hydrogen bonding as described above Can be used without any specific limitations.

According to one embodiment of the present invention, the photocurable monofunctional monomer may comprise a monofunctional monomer having a linear structure or a branched structure together with a monofunctional diluent monomer having a cyclic structure, It can be used in combination.

According to an embodiment of the present invention, the adhesion promoting layer may include a curable resin of a photo-curable monofunctional monomer having a hydrogen-bondable reactor and a polyfunctional acrylate-based monomer. As described above, the polyfunctional acrylate-based monomer can be polymerized to form various types of bonds in the photo-curing monofunctional monomer having a hydrogen-bondable reactor, so that the adhesion-promoting layer has superior adhesion and scratch resistance Lt; / RTI >

According to one embodiment of the present invention, the polyfunctional acrylate-based monomer may be selected from the group consisting of hexandiol diacrylate (HDDA), tripropyleneglycoldiacrylate (TPGDA), ethyleneglycoldiacrylate (EGDA ), Trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxylated triacrylate (TMPEOTA), glycerol propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate But are not limited to, pentaerythritol tetraacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and the like. The polyfunctional acrylate monomer generally used in the relevant field is, for example, Can be used without limitation have.

According to one embodiment of the present invention, in the case where the curable resin is a cured resin of a photo-curable monofunctional monomer having a hydrogen-bondable reactor and a polyfunctional acrylate-based monomer, the photocurable monofunctional The polyfunctional acrylate monomer may be cured to about 10 to about 150 parts by weight based on about 100 parts by weight of the entire monomer. When the cured resin is cured in the above range, the polarizer protective film of the present invention can have sufficient flexibility and adhesiveness without deteriorating physical and optical properties.

According to an embodiment of the present invention, the substrate may be a polyethylene terephthalate (PET) film, a cyclic olefin copolymer (COC), a polyacrylate (PAC), a polycarbonate film polycarbonate, PC), polyethylene (PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), polyetherimide film but are not limited to, polyetherimide (PEI), polyimide (PI), triacetylcellulose (TAC), and the like. And can be applied without any specific limitations.

According to one embodiment of the present invention, the photocurable layer may be an antireflection layer, an antiglare layer, or an abrasion-resistant layer. However, the photo-curable layer is not necessarily limited thereto, and a photo-curable layer having various functions may be provided depending on the characteristics of a desired polarizer protective film.

When the photocurable layer is an antireflection layer or an antiglare layer, the antireflection layer or the antiglare layer may be a film for minimizing reflection of light incident from the outside. As a method for minimizing the reflection of light, a method in which a filler such as an inorganic fine particle is dispersed in a resin and is coated on a substrate film to impart irregularities (anti-glare: AG coating); A method of forming a plurality of layers having different refractive indexes on a base film to use interference of light (anti-reflection (AR coating)) or a method of mixing them. In the AG coating, the absolute amount of the reflected light is equivalent to that of a general hard coating, but by using light scattering through the irregularities, the amount of light entering the eye can be reduced to obtain a low reflection effect. As the film using the AR coating, a multi-layer structure in which a hard coating layer (high refractive index layer), a low reflection coating layer, and the like are laminated on a substrate film has been commercialized. The antireflection layer of the present invention can be used without any particular limitation, as the AG coating and / or the AR coating generally used in the art.

For example, the antireflection layer may comprise hollow silica particles. The hollow silica particles have a lower refractive index than hollow particles and thus have excellent antireflection properties. The hollow silica particles may have a number average particle diameter of 20 to 80 nm, preferably 20 to 70 nm, more preferably 30 to 70 nm; The formation of the particles is preferably spherical, but it may be irregular.

Further, the hollow silica particles may be mixed with a surface-treated (coated) fluorochemical compound. That is, when the hollow silica particles are surface-treated with a fluorine-based compound, the surface energy of the particles can be further lowered, thereby being more uniformly distributed in the composition, and more uniform scratch resistance improving effect can be obtained. The method of introducing the fluorine-based compound into the surface of the hollow silica particles can be carried out by a method in which the hollow silica particles and the fluorine-based compound are hydrolyzed and condensed by a sol-gel reaction in the presence of water and a catalyst. However, the present invention is not limited thereto.

The hollow silica particles may be dispersed in an organic solvent. The content of the solid (hollow silica particles) in the dispersion may vary depending on the purpose of the photo-curable layer and the viscosity range suitable for coating the composition. It is not limited thereto.

When the photo-curable layer is an abrasion-resistant layer, the scratch-resistant layer may be composed of a layer for protecting the polarizing plate and the polarizer-protective film from the outside. That is, even when the film is rubbed, the properties such as abrasion resistance and stain resistance can be maintained, the dust removing property and the antistatic property are excellent, and the polarizing plate and the polarizer protective film can be protected, Can be used in the present invention without any particular limitation.

For example, the scratch-resistant layer may be formed by a composition including a binder resin containing a photocurable functional group, a photopolymerization initiator, a nanoparticle, and a conductive inorganic particle. The binder resin containing the photocurable functional group may be a main component capable of imparting abrasion resistance or scratch resistance to the scratch-resistant layer, and for example, an acrylate-based or vinyl-based resin may be used, Containing photocurable functional group-containing compound may be useful for reducing and eliminating contamination by oil components such as fingerprint marks. The nanoparticles may be particles such as silica, alumina, titania, zirconia, and magnesium fluoride, which can impart stain resistance and scratch resistance to the scratch-resistant layer. The size of the particles may be optical transparency The grain size may be limited to ensure that. The conductive inorganic particles are components added for realizing excellent dust removing property and antistatic property in the scratch-resistant layer, and examples thereof include tin-doped indium oxide, antimony-doped tin oxide, antimony- Tin oxide, zinc oxide, and the like, and the particle size may also be limited to ensure the optical transparency of the film.

Also, according to one embodiment of the present invention, the thickness of the photocurable layer may be from about 1 to about 10 microns, and preferably from about 3 to about 5 microns. If the thickness is less than about 1 탆, the photopolymerizable layer may not serve as a photocurable layer for the purpose. If the thickness exceeds about 10 탆, the entire thickness of the polarizer protective film may become thick, which may not meet the needs for flexibility and thinness have.

According to an embodiment of the present invention, the polarizer protective film may further include a hard coating layer between the adhesion promoting layer and the photo-curable layer. The hard coating layer serves to increase the hardness of the polarizer protective film. The hard coating layer generally used in the art can be used without particular limitation.

A method of manufacturing a polarizer protective film according to one aspect of the present invention includes the steps of: applying a first composition for forming an adhesion promoting layer on at least one side of a substrate; Irradiating the first composition with ultraviolet light to form a first photo-curable composition; Applying a second composition for forming a photocurable layer on the first photocured first composition; And a second photo-curing step of irradiating the applied second composition with ultraviolet light, wherein the first composition comprises a photocurable monofunctional monomer having a hydrogen-bondable reactor and a photopolymerization initiator, wherein the second composition Includes a photocurable compound and a photopolymerization initiator.

According to an embodiment of the present invention, the substrate may be a polyethylene terephthalate (PET) film, a cyclic olefin copolymer (COC), a polyacrylate (PAC), a polycarbonate film polycarbonate, PC), polyethylene (PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), polyetherimide film but are not limited to, polyetherimide (PEI), polyimide (PI), triacetylcellulose (TAC), and the like. This is possible.

According to an embodiment of the present invention, the first composition may include a photo-curable monofunctional monomer having a reactive group capable of hydrogen bonding, a polyfunctional acrylate-based monomer, and a photopolymerization initiator, The role of photocurable monofunctional monomers and polyfunctional acrylate monomers is as described above for the polarizer protective film.

According to one embodiment of the present invention, when the first composition contains a photocurable monofunctional monomer having a hydrogen-bondable reactor and a polyfunctional acrylate-based monomer, the photocurable monofunctional monomer having a hydrogen- The polyfunctional acrylate monomer may be contained in an amount of about 10 to about 150 parts by weight based on 100 parts by weight of the total amount. When the first composition contains a photo-curable monofunctional monomer and a polyfunctional acrylate monomer having a hydrogen-bondable reactive group within the above range, the polarizer protective film of the present invention produced therefrom is deteriorated in physical and optical properties Sufficient flexibility and adherence can be achieved without the need for the adhesive.

According to one embodiment of the present invention, the first composition may be applied so that the adhesion promoting layer after curing has a thickness of about 1 to about 10 탆, preferably about 2 to about 5 탆. When the first composition is applied in the above-described range, it can sufficiently serve as a desired adhesion enhancing layer, and a polarizer protective film having sufficient flexibility and adhesion can be produced.

The second composition may also be applied after curing such that the thickness of the photocurable layer is from about 1 to about 10 microns. When applied in the above-mentioned range, a polarizer protective film which can sufficiently serve as a desired photo-curable layer and has sufficient flexibility and adhesion can be produced.

A more detailed description of the photo-curing monofunctional monomer and the polyfunctional acrylate monomer having a hydrogen-bondable reactive group and examples of usable materials are as described above in the polarizer protective film.

The first composition includes a photopolymerization initiator.

Examples of the photopolymerization initiator 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, or bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. However, the present invention is not limited thereto. 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.

The photo-curing compound contained in the second composition is a binder component for securing the minimum scratch resistance and abrasion resistance required for the photo-curable layer, which is a compound that is cured by causing a polymerization reaction when light is irradiated. The photo-curing compound may be a compound commonly used in the art to which the present invention belongs. The photo-curable compound may be, for example, a monomer or oligomer containing a (meth) acrylate functional group, an acryloyl functional group, .

The photopolymerization initiator contained in the second composition may be the same as or different from the photopolymerization initiator contained in the first composition, and specific examples thereof are as described above in the first composition.

In addition, the first and second compositions may further include an organic solvent for controlling the applicability and viscosity.

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.

According to an embodiment of the present invention, the first photo-curing step may include a step of curing the photocurable monofunctional monomer having the hydrogen-bondable reactive group contained in the first composition and / or a part of the polyfunctional acrylate- Lt; / RTI > Partly crosslinked is that the photocurable monofunctional monomer having a hydrogen-bondable reactor in the first composition and the partially crosslinked monomer are partially less than 100% when the crosslinking of the polyfunctional acrylate monomer is 100% It means to be crosslinked. For example, according to an embodiment of the present invention, the first photo-curing step may include a photo-curable monofunctional monomer having a hydrogen-bondable reactor in the first composition and a photo-curable monofunctional monomer having a functional group contained in the polyfunctional acrylate monomer To about 60 mole percent, or from about 40 mole percent to about 50 mole percent of the crosslinking agent may be crosslinked. After the first photo-curing which partially crosslinks, the second composition is applied, and the second photo-curing process can more securely adhere to the substrate and prevent curling or hardening shrinkage that may occur in the photo-curing process .

 The method of applying the first and second compositions is not particularly limited as long as it can be used in the art 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 micro gravure coating method, a comma coating method, a slot die coating method, or a lip coating method.

The amount of ultraviolet irradiation in the curing process 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.

According to one embodiment of the present invention, the method of producing a polarizer protective film of the present invention may further comprise drying the first composition applied on one side of the substrate before the first photo-curing step.

According to another embodiment of the present invention, the method may further comprise drying the second composition applied on the first photocured first composition prior to the second photocuring step.

A polarizer protective film having better physical and optical characteristics can be prepared by flattening the coating surface of the composition through a drying process and evaporating the solvent contained in the composition.

According to an embodiment of the present invention, in the method of manufacturing a polarizer protective film, the photocurable layer may be an antireflection layer, an antiglare layer, or an abrasion-resistant layer, but the present invention is not limited thereto. And a detailed description thereof is the same as the above-described polarizer protective film.

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 >

The adhesion enhancement layer  Resin composition

[Production Example 1]

47.5 wt% of 2-hydroxyethyl acrylate, 2.5 wt% of Irgacure 184 as a photopolymerization initiator, and 50 wt% of methyl ethyl ketone as an organic solvent were mixed to prepare a resin composition.

[Production Example 2]

A resin composition was prepared by mixing 30 wt% of 2-hydroxyethyl acrylate, 17.5 wt% of pentaerythritol tri (tetra) acrylate, 2.5 wt% of Irgacure 184 as a photopolymerization initiator, and 50 wt% of methyl ethyl ketone as an organic solvent.

[Production Example 3]

30 parts by weight of isobornyl acrylate, 17.5% by weight of pentaerythritol tri (tetra) acrylate, 2.5% by weight of Irgacure 184 as a photopolymerization initiator, and 50% by weight of methyl ethyl ketone as an organic solvent were mixed.

[Production Example 4]

47.5 wt% of pentaerythritol tri (tetra) acrylate, 2.5 wt% of Irgacure 184 as a photopolymerization initiator, and 50 wt% of methyl ethyl ketone as an organic solvent were mixed to prepare a resin composition.

Adhesion enhancement layer  &Lt; / RTI &gt; Photocurable layer  Resin composition

[Production Example 5]

47.5 wt% of pentaerythritol tri (tetra) acrylate, 2.5 wt% of Irgacure 184 as a photopolymerization initiator, and 50 wt% of methyl ethyl ketone as an organic solvent were mixed to prepare a resin composition.

Polarizer  Manufacture of protective film

[Example 1]

The resin composition prepared in Preparation Example 1 was coated on an acrylic stretched film having a thickness of 50 탆 by bar coating so as to have a thickness of 4 to 5 탆. The film coated with the composition was dried at 100 ° C for 2 minutes and then semi-cured with a mercury lamp at 50 mJ / cm ² .

The resin composition prepared in Preparation Example 5 was coated on the semi-cured film to a thickness of 4 to 5 μm, dried at 60 ° C. for 2 minutes, and the dried film was cured under a condition of 200 mJ / cm ² using a mercury lamp .

[Example 2]

A polarizer protective film was prepared in the same manner as in Example 1, except that the resin composition prepared in Production Example 2 was used instead of the resin composition prepared in Production Example 1. [

[Comparative Example 1]

A polarizer protective film was prepared in the same manner as in Example 1 except that the resin composition prepared in Production Example 3 was used instead of the resin composition prepared in Production Example 1. [

[Comparative Example 2]

A polarizer protective film was prepared in the same manner as in Example 1, except that the resin composition prepared in Production Example 4 was used instead of the resin composition prepared in Production Example 1.

The compositions for the adhesion promoting layer used in Examples 1, 2, and 1 and Comparative Example 2 are summarized in Table 1 below. The composition for the adhesion enhancement layer is composed of 2.5 wt% of a photopolymerization initiator and 50 wt% of an organic solvent in addition to the components in the following table.

Remarks Photocurable monofunctional monomer
(Content:% by weight) The polyfunctional acrylate-based monomer
(Content:% by weight) Example 1 2-hydroxyethyl acrylate
(47.5) - Example 2 2-hydroxyethyl acrylate
(30) Pentaerythritol tri (tetra) acrylate (17.5) Comparative Example 1 Isobornyl acrylate
(30) Pentaerythritol tri (tetra) acrylate (17.5) Comparative Example 2 - Pentaerythritol tri (tetra) acrylate (47.5)

< Experimental Example >

Adhesion test

The polarizer protective films prepared in Examples 1, 2, Comparative Example 1 and Comparative Example 2 were tested for adhesion by a cross-cut tape test method. The adhesive strength was evaluated according to the area where the film was not removed while the adhesive tape was stuck and then peeled off. In the case where the area where the film is not removed is 5B, the case where the area where the film is not removed is 5B, the case where 95 to 99% is 4B, the case where 85 to 94% is 3B, the case where 65 to 84% The case was rated as 1B, and the case of not more than 34% was evaluated as 0B. The experimental results are summarized in Table 2 below.

Remarks Adhesion Example 1 4B Example 2 5B Comparative Example 1 1B Comparative Example 2 0B

From the results of Table 2, it can be seen that the polarizer protective films of Examples 1 and 2 have better adhesion than the polarizer protective films of Comparative Examples 1 and 2. As described above, it is possible to provide a reactor capable of hydrogen bonding in the adhesion enhancing layer of the polarizer protective film of the present invention, and intermolecular hydrogen bonding becomes possible at the interface between the adhesion promoting layer and the substrate after curing, It can be interpreted that the adhesion between the enhancing layers is excellent.

10: substrate
20: adhesion enhancement layer
21: substrate erosion part
30: Photocurable layer

Claims (15)

materials;
An adhesion enhancing layer formed on at least one side of the substrate in a form of eroding the substrate in direct contact with the substrate; And
And a photo-curable layer formed on the adhesion enhancing layer,
Wherein the adhesion enhancement layer has a thickness of 1 to 10 占 퐉 and the adhesion enhancement layer comprises a curable resin of a photo-curable monofunctional monomer having a hydrogen bondable reactor.
The method according to claim 1,
Wherein the adhesion promoting layer comprises a curable resin of a photo-curing monofunctional monomer having a hydrogen-bondable reactor and a polyfunctional acrylate-based monomer.
The method according to claim 1,
The hydrogen-bondable reactor may be a reactor comprising -OH group, -NH ₂ group, -COOH group, -CONH ₂ group, or -NHOH group; or
A -NH-bond, a -NH-NH- bond, a -NHCO- bond, or a -CONHCO- bond.
3. The method of claim 2,
The polyfunctional acrylate monomer may be selected from the group consisting of hexandiol diacrylate (HDDA), tripropyleneglycoldiacrylate (TPGDA), ethyleneglycoldiacrylate (EGDA), trimethylolpropane triacrylate trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxylated triacrylate (TMPEOTA), glycerol propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA) And dipentaerythritol hexaacrylate (DPHA). &Lt; Desc / Clms Page number 8 &gt;
The method according to claim 1,
The substrate may be a polyethylene terephthalate film (PET), a cyclic olefin copolymer (COC), a polyacrylate (PAC), a polycarbonate (PC), a polyethylene film , PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), polyetherimide (PEI), polyimide film wherein the polarizer protective film comprises at least one selected from the group consisting of polyimide (PI) and triacetylcellulose (TAC).
The method according to claim 1,
Wherein the photocurable layer is an antireflection layer, an antiglare layer, or a scratch-resistant layer.
7. The method according to any one of claims 1 to 6,
And a hard coat layer between the adhesion promoting layer and the photocurable layer.
Applying a first composition for forming an adhesion enhancement layer to at least one side of the substrate;
Irradiating the first composition with ultraviolet light to form a first photo-curable composition;
Applying a second composition for forming a photocurable layer on the first photocured first composition; And
Irradiating the applied second composition with ultraviolet light to form a second photo-curable layer,
Wherein the first composition comprises a photocurable monofunctional monomer having a hydrogen bondable reactor and a photopolymerization initiator, and the second composition comprises a photocurable compound and a photopolymerization initiator.
9. The method of claim 8,
The reactor capable of hydrogen bonding may be a reactor comprising a? H group, a -NH ₂ group, a -COOH group, a -CONH ₂ group, or an -NHOH group; or
A -NH-bond, a -NH-NH- bond, an -NHCO- bond, or a -CONHCO- bond.
9. The method of claim 8,
Wherein the first composition comprises a photocurable monofunctional monomer having a reactive group capable of hydrogen bonding, a polyfunctional acrylate monomer, and a photopolymerization initiator.
11. The method of claim 10,
The polyfunctional acrylate monomer may be selected from the group consisting of hexandiol diacrylate (HDDA), tripropyleneglycoldiacrylate (TPGDA), ethyleneglycoldiacrylate (EGDA), trimethylolpropane triacrylate trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxylated triacrylate (TMPEOTA), glycerol propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA) And dipentaerythritol hexaacrylate (DPHA). &Lt; Desc / Clms Page number 12 &gt;
9. The method of claim 8,
Wherein the first photo-curing step is performed until a part of the photo-curable monofunctional monomer having the hydrogen-bondable reactive group of the first composition is crosslinked.
9. The method of claim 8,
Wherein the adhesion promoting layer has a thickness of 1 to 10 mu m after curing the first composition.
9. The method of claim 8,
Wherein the photocuring layer is an antireflection layer, an antiglare layer, or an abrasion-resistant layer.
9. The method of claim 8,
The substrate may be a polyethylene terephthalate film (PET), a cyclic olefin copolymer (COC), a polyacrylate (PAC), a polycarbonate (PC), a polyethylene film , PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), polyetherimide (PEI), polyimide film wherein the polarizer protective film comprises at least one selected from the group consisting of polyimide (PI) and triacetylcellulose (TAC).

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