WO2016175601A1 - Polarizer protecting film, polarizing plate comprising same, and method for manufacturing polarizing plate - Google Patents

Abstract

Provided are a polarizer protecting film, a polarizing plate comprising the same, and a method for manufacturing a polarizing plate. The polarizer protecting film comprises a (meth)acryl-based resin, and at least one of silica, silicon-based resins, or siloxane-based resins, and has a glass transition temperature of about 50°C to about 115°C.

Description

Polarizer protective film, polarizing plate comprising the same and method for manufacturing polarizing plate

This invention relates to the manufacturing method of a polarizer protective film, a polarizing plate, and a polarizing plate.

In a liquid crystal display or an organic luminescence device, grayscale is obtained for each pixel by optically modulating the transmitted light according to an input video signal or by self-emitting luminance pixels according to the video signal. The layer which modulates such transmitted light and light emission luminance for each pixel is called a modulation function layer. In the liquid crystal display device, the liquid crystal layer corresponds to the modulation function layer, and in the organic light emitting element, the organic EL light emitting layer corresponds to the modulation function layer.

Since the liquid crystal layer is not a light valve that completely blocks light by itself, in the case of a liquid crystal display device, polarizing plates may be disposed on both sides of the liquid crystal layer in the up and down direction of the liquid crystal layer, that is, the backlight side and the viewer's viewing side. have.

On the other hand, since the light emitting layer of the organic light emitting device does not irradiate light when no voltage is applied, it is possible to display completely black and provide a relatively high contrast compared to the liquid crystal display. Therefore, the organic light emitting element does not arrange the polarizing plate for the purpose of shielding light emission. However, in the organic light emitting device, external light may be reflected by the metal wires inside, which causes a decrease in contrast, and thus, a polarizing plate is disposed to prevent this.

The polarizing plate may be composed of a polarizing plate protective film attached to protect the polarizing film and the polarizing film iodine or dichroic dye is dyed, oriented. The polarizing plate protective film prevents iodine or dichroic dyes, etc., which are dyed on the polarizing film from escaping to the outside and prevents penetration of moisture.

Accordingly, the technical problem to be solved by the present invention is to provide a polarizer protective film excellent in the polarizer and the adhesive force and a polarizing plate comprising the same.

Moreover, it is providing the manufacturing method of the polarizing plate which a manufacturing process is easy.

The objects of the present invention are not limited to the above-mentioned technical problem, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

Polarizer protective film according to an embodiment of the present invention for achieving the above object is (meth) acrylic resin; And at least one of silica, silicone-based resin, and siloxane-based resin, wherein the polarizer protective film may have a glass transition temperature of about 50 ° C to about 115 ° C.

The (meth) acrylic resins include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxy ethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexa acrylate, Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyester acrylate, melamine acrylate and silicone acrylate It may include one or more selected from.

The siloxane resin may include polydimethylsiloxane.

At least one or more of the silica, silicone resin, and siloxane resin may be included in an amount of about 0 wt% or more and about 5 wt% or less relative to the entire polarizer protective film.

The polarizer protective film may have a thickness of about 15 μm to about 50 μm.

Polarizer according to an embodiment of the present invention for achieving the above object includes a polarizer, a polarizer protective film disposed on at least one surface of the polarizer, and an adhesive layer interposed between the polarizer and the polarizer protective film, the polarizer The protective film includes (meth) acrylic resin, and at least one or more of silica, silicone resin, and siloxane resin, and the polarizer protective film may have a glass transition temperature of about 50 ° C to about 115 ° C.

The adhesive layer may include an aqueous adhesive.

The polarizer protective film may be directly attached to the polarizer through the adhesive layer.

The glass transition temperature of the polarizer protective film may be about 75 ℃ to about 105 ℃.

The glass transition temperature of the polarizer protective film may be about 85 ℃ to about 100 ℃.

The polarizer protective film includes a functional layer disposed on an opposite side of the surface on which the adhesive layer is formed, and the functional layer includes a hard coating layer, an anti-reflection layer, and an anti-glare layer. Glare layer), or a diffusion layer.

A polarizing plate manufacturing method according to an embodiment of the present invention for achieving the above object includes a (meth) acrylic resin, and at least one or more of silica, silicone resin and siloxane resin, the glass transition temperature is about 50 ℃ to about Preparing a polarizer protective film having a temperature of 115 ° C., treating the surface of the polarizer protective film by corona treatment or plasma treatment, and bonding an adhesive layer between one surface of the polarizer protective film and the polarizer. It may include the step of posting and laminating.

The adhesive layer may include an aqueous adhesive.

The polarizer protective film may directly contact the adhesive layer.

The preparing of the polarizer protective film may include casting a casting film by casting a solution including at least one of a base film, a (meth) acrylic resin, and silica, a silicone resin, and a siloxane resin on at least one surface of the base film. Forming, drying the casting film, and peeling the base film may include the step of obtaining a polarizer protective film.

Specific details of other embodiments are included in the detailed description and the drawings.

According to embodiments of the present invention has at least the following effects.

The polarizer protective film of the present invention is excellent in adhesion with the polarizer, the polarizing plate of the present invention may include the polarizer protective film as described above.

In addition, the manufacturing method of the polarizing plate of the present invention may be easy.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a perspective view of a polarizer protective film according to an embodiment of the present invention.

2 is a perspective view of a polarizer according to an embodiment of the present invention.

3 is a perspective view of a polarizer according to another embodiment of the present invention.

4 is a perspective view of a polarizer according to still another embodiment of the present invention.

5 and 6 are views schematically showing a manufacturing process of the polarizer protective film according to an embodiment of the present invention.

7 is a perspective view schematically showing a surface treatment process of a polarizer protective film according to an embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms. It is provided to fully convey the scope of the invention to those skilled in the art, the invention being defined only by the scope of the claims.

References to elements or layers “on” other elements or layers include both instances in which another layer or other element is placed directly on or in the middle of another element. Like reference numerals refer to like elements throughout.

Although the first, second, etc. are used to describe various components, these components are of course not limited by these terms. These terms are only used to distinguish one component from another. Therefore, of course, the first component mentioned below may be a second component within the technical spirit of the present invention.

In addition, unless the steps constituting the manufacturing method described herein are sequential or sequential, or unless otherwise indicated, one step and another step constituting one manufacturing method in the order described in the specification. It is limited and not interpreted. Therefore, the order of construction steps of the manufacturing method can be changed within a range that can be easily understood by those skilled in the art, in which case the obvious changes to those skilled in the art will be included within the scope of the present invention.

As used herein, "(meth) acryl" refers to acrylic and / or methacryl.

Polarizer  Protective film

1 is a perspective view of a polarizer protective film according to an embodiment of the present invention. 1, the polarizer protective film 10 according to an embodiment of the present invention, (meth) acrylic resin; And at least one of silica, silicone resin, and siloxane resin. That is, the polarizer protective film 10 is a (meth) acrylic resin; And it may be a single layer film formed of at least one of silica, silicone-based resin and siloxane-based resin.

In addition, the glass transition temperature of the polarizer protective film 10 may be about 50 ℃ to about 115 ℃. The glass transition temperature of the polarizer protective film 10 may be, for example, about 75 ° C. to about 105 ° C., or about 85 ° C. or more and about 100 ° C. or less. Inexpensive UV absorbers that can be used at low temperatures in the glass transition temperature range can be used. In addition, molding of the polarizer protective film 10 may be possible even at low temperatures.

The (meth) acrylic resins include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxy ethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexa acrylate, Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyester acrylate, melamine acrylate and silicone acrylate It may include one or more selected from, for example, the (meth) acrylic resin may be included in the polarizing plate protective film 10 in less than about 95% by weight or less than about 100% by weight.

The silica may be included in a silica gel state in the form of a gel in the polarizer protective film. By including the silica and / or silicone-based resin, the polarizer protective film 10 of the present invention can improve the adhesion to the polarizer to be described later, it may be possible to bond with the polarizer with only an adhesive without a separate primer layer. More specifically, while using an aqueous adhesive between the polarizer protective film and the polarizer, the adhesion may be improved by only corona treatment or plasma treatment without the use of a separate primer layer.

The siloxane resin may include polydimethyl siloxane. By including the siloxane-based resin, the polarizer protective film 10 of the present invention can improve the adhesion to the polarizer to be described later, it may be possible to bond with the polarizer with only an adhesive without a separate primer layer. For example, while using an aqueous adhesive between the polarizer protective film and the polarizer, the adhesion may be improved by using only corona treatment or plasma treatment without the use of a separate primer layer.

At least one or more of the silica, silicone resin, and siloxane resin may be included in an amount of about 0 wt% or more and about 5 wt% or less with respect to the entire polarizer protective film 10. When the content exceeds about 5% by weight, the brightness is reduced or the color is degraded due to scattering of light, thereby lowering the overall contrast ratio (CR) of the display device or lowering the viewing angle. The glass transition temperature cannot be reached.

On the other hand, the polarizer protective film 10 may further include a UV absorber, UV blocking agent, for example, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxy-5- With hindered amines such as benzophenones such as sulfobenzophenone, benzotriazoles such as 2- (2'-hydroxy-5-methylphenyl) benzotriazole, phenyl salicylate, and pt-butylphenyl salicylate It may include one or more selected from the group consisting of.

Polarizer

2 is a perspective view of a polarizer according to an embodiment of the present invention. Referring to FIG. 2, a polarizer according to an embodiment of the present invention includes a polarizer 20, a polarizer protective film 10 disposed on at least one surface of the polarizer 20, and the polarizer 20 and the polarizer. It may include an adhesive layer 15 disposed between the protective film 10. In addition, the polarizer protective film 10 is a (meth) acrylic resin; And at least one of silica, silicone resin, and siloxane resin, and may have a glass transition temperature of about 50 ° C to about 115 ° C. Meanwhile, since the components constituting the polarizer protective film 10 and the glass transition temperature thereof have already been described above, overlapping descriptions will be omitted.

The polarizer 20 may include a polyvinyl alcohol-based film in which iodine or dichroic dye is dye-oriented.

As a method of manufacturing the polarizer 20, the polyvinyl alcohol-based film may be subjected to dyeing, crosslinking, and stretching steps. As a result, iodine or dichroic substances may be adsorbed and oriented in the polyvinyl alcohol-based film, and iodine, dye, or pigment molecules absorb light oscillating in the stretching direction of the polarizing film, and light oscillating in the vertical direction is transmitted. By doing so, it is possible to obtain polarized light having a specific vibration direction.

The polarizer 20 may be manufactured by dyeing, crosslinking, or stretching only with the polyvinyl alcohol-based film itself, but may be manufactured through the above process after laminating the polyvinyl alcohol-based film on the base film. When manufacturing a polarizer by laminating with a base film, a thinner polarizer can be manufactured, preventing a polyvinyl alcohol-type film from being judged in the process of extending | stretching etc. On the other hand, as the base film, polycarbonate, polyacrylate, polyethylene terephthalate, polyethylene, triacetyl cellulose, polystyrene, polyimide, polypropylene, cycloolefin, polyurethane It may include a resin, but is not limited thereto.

The dyeing step may be performed by impregnating a polyvinyl alcohol-based film or polyvinyl alcohol-based film on a substrate to form a laminated film by laminating a substrate film and then impregnating a solution of iodine or dichroic material. For example, the case of dyeing using the iodine, the temperature of the iodine solution may be about 20 ℃ to about 50 ℃, the impregnation time may be about 10 seconds to about 300 seconds. When the iodine solution is used as the iodine solution, an aqueous solution containing iodine (I ₂ ) and iodine ions, for example, potassium iodide (KI) used as a dissolution aid, may be used. In an exemplary embodiment, the concentration of iodine (I ₂ ) is from about 0.01% to about 0.5% by weight based on the total weight of the aqueous solution, and the concentration of potassium iodide (KI) is from about 0.01% by weight to the total weight of the aqueous solution About 10% by weight.

In an exemplary embodiment, the swelling step may further be included prior to performing the dyeing step. The swelling step may serve to soften the molecular chain of the polyvinyl alcohol-based film and relax the molecular chain, so that the dichroic material is homogeneously dyed into the inside of the polyvinyl alcohol-based film during the dyeing process, thereby preventing stains. have. In this swelling process, a polyvinyl alcohol-based film may be stretched. In an exemplary embodiment, it may be carried out by a wet method in a swelling bath containing swelling liquid. In addition, the swelling temperature may vary depending on the film thickness and the like, for example, may be about 15 ℃ to about 40 ℃.

In another exemplary embodiment, a crosslinking process may be further included after the dyeing step.

When molecules of iodine or dichroic material are dyed in the polyvinyl alcohol-based film in the dyeing step, the dichroic molecules are adsorbed onto the polymer matrix of the polyvinyl alcohol-based film using boric acid, borate, or the like. Examples of the crosslinking method include a deposition method in which a polyvinyl alcohol-based film is deposited by dipping a boric acid solution or the like, but is not limited thereto, and may be performed by a coating method or a spraying method for applying or spraying a solution to a film. It may be.

On the other hand, the stretching step may use a wet stretching method and / or dry stretching method common to the art polyvinyl alcohol-based film.

Non-limiting examples of the dry stretching method include an inter-roll stretching method, a heating roll stretching method, a compression stretching method, a tenter stretching method, and the like. Non-limiting examples include a tenter stretching method, an inter-roll stretching method, and the like.

In the wet drawing method, the drawing may be performed in alcohol, water or boric acid aqueous solution. For example, a solvent such as methyl alcohol or propyl alcohol may be used, but is not limited thereto.

Stretching temperature and time can be suitably selected and used according to the material of a film, desired elongation rate, a usage method, etc. In addition, the stretching may be uniaxial stretching or biaxial stretching. In order to manufacture a polarizing film adhered to a liquid crystal cell, biaxial stretching may be performed to implement retardation characteristics.

The dyeing and drawing steps need not always be in the same order, and may be appropriately selected according to the process equipment and equipment, and in some cases, the drawing step is performed by the dyeing or crosslinking. It can be done simultaneously with the process. If the stretching step proceeds simultaneously with the dyeing step, the stretching step may be performed in an iodine solution. On the other hand, when the stretching step is performed simultaneously with the crosslinking process, the stretching step may be performed in an aqueous boric acid solution.

In the case of using the base film, the base film may be removed to obtain a polyvinyl alcohol-based film in which iodine or dichroic dye is dye-oriented, and the resulting polyvinyl alcohol-based film may be a polarizer 20. Can be. The base film may be attached to the polyvinyl alcohol-based film with a constant adhesive force, it may be applied a peel force of a certain force or more to remove the base film.

The manufacturing of the polarizer described above is exemplary, and various methods used in the art as a method of manufacturing the polarizer are all applicable, and are not limited thereto.

Meanwhile, the polarizer protective film 10 may be disposed on at least one surface of the polarizer 20. As in the polarizing plate of FIG. 2, when the polarizer protective film 10 is disposed only on one surface of the polarizer 20, a thinner polarizing plate may be manufactured.

The polarizing plate may include an adhesive layer 15 disposed between the polarizer 20 and the polarizer protective film 10, and the adhesive layer 15 may include an aqueous adhesive, but is not limited thereto. And adhesives.

The water-based adhesive may include at least one selected from the group consisting of polyvinyl alcohol-based resins and vinyl acetate-based resins, or may include polyvinyl alcohol-based resins having a hydroxyl group, but is not limited thereto.

In addition, the ultraviolet curing adhesive may include an acrylic compound, for example, may be acrylic, urethane-acrylic, epoxy-based. However, the present invention is not limited thereto.

On the other hand, when the adhesive layer 15 includes an aqueous adhesive, the adhesive layer of the polarizer protective film 10 in order to improve the adhesive strength of the polarizer protective film 10 and the polarizer 20 including a polyvinyl alcohol-based film The surface CA contacted by (15) may be corona treated or plasma treated. Accordingly, the contact surface CA contacted with the adhesive layer 15 may have a lower contact angle than the contact surface NCA with which the adhesive layer 15 of the polarizer protective film 10 is not in contact, whereby the polarizer protective film 10 may be lowered. And the adhesion between the polarizer 20 may be excellent.

In the case of the polarizer protective film 10 according to the present invention, by including at least one or more of silica, silicone resin and siloxane resin, the polarizer protective film by the adhesive layer 15 containing the water-based adhesive without a separate primer layer ( 10) can attach the polarizer 20.

Meanwhile, the polarizer protective film 10 may be directly attached to the polarizer 20 through the adhesive layer 15. That is, as mentioned above, the adhesive layer 15 may be attached to each other with the adhesive layer 15 interposed between the polarizer protective film 10 and the polarizer 20 without a separate primer layer. In other words, the adhesive layer 15 directly contacts the other surface of the polarizer protective film 10, and the adhesive layer 15 directly contacts the surface of the polarizer 20 that faces the polarizer protective film 10. You may be in contact.

However, the present invention is not limited thereto, and the polarizing plate of the present invention may further include a separate primer layer (not shown) between the polarizer protective film 10 and the polarizer 20 in order to improve adhesion. The primer layer may be formed by coating and drying a coating solution including a water dispersible polymer resin, water dispersible fine particles, and water on a protective film using a bar coating method, a gravure coating method, or the like.

3 is a perspective view of a polarizer according to another embodiment of the present invention. Referring to FIG. 3, the polarizer may further include a functional layer 40 disposed on one surface of the polarizer protective film 10. That is, the functional layer 40 may be disposed on the opposite side of the surface on which the adhesive layer 15 of the polarizer protective film 10 is formed.

The functional layer 40 may include a coating layer (Hard-Coating Layer), an anti-reflection layer, an anti-glare layer, or a diffusion layer, but is not limited thereto, and is widely used in the art. It may include various known functional layers. For example, the anti-reflection layer may reduce the reflection by extinguishing light of the light incident from the outside, and the anti-glare layer may prevent the glare by inducing the diffusion and reflection of the light incident from the outside.

Although not separately illustrated, when the polarizer protective film 10 is disposed only on one surface of the polarizer 20 as illustrated in FIGS. 2 and 3, an adhesive layer may be disposed on the other surface of the polarizer 20, which will be described later. It may be attached to the display panel. In addition, a release film may be attached to the other surface of the adhesive layer to facilitate storage and transportation of the manufactured polarizing plate.

4 is a perspective view of a polarizing plate according to another embodiment of the present invention. Referring to FIG. 4, the polarizer may include polarizer protective films 10 and 30 disposed on both sides of the polarizer 20, and in this case, adhesive layers 15 and 25 may be disposed on both sides of the polarizer 20. May be in a state. In addition, the adhesive layers 15 and 25 may directly contact the polarizer 20 or may directly contact the polarizer protective films 10 and 30.

As described above, the polarizing plate of the present invention can implement excellent adhesion between the polarizer and the polarizer protective film even if a separate primer layer is omitted, it may not use an expensive primer layer, it is possible to manufacture a thin polarizing plate. .

Meanwhile, referring back to FIG. 2, the thickness T of the polarizer protective film 10 may be about 15 μm to about 50 μm. If the above range is satisfied, a thinner polarizing plate may be implemented.

Polarizing Plate Manufacturing Method

The present invention provides a polarizing plate manufacturing method, the polarizing plate manufacturing method according to an embodiment of the present invention comprises a (meth) acrylic resin, and at least one or more of silica, silicone resin and siloxane resin, the glass transition temperature is about 50 Preparing a polarizer protective film in the range of ℃ to about 115 ℃, surface treatment by corona treatment or plasma treatment on one surface of the polarizer protective film, and one surface and the polarizer of the polarizer protective film It may include the step of laminating through the adhesive layer therebetween.

The polarizing plate manufacturing method may include preparing a polarizer protective film, and the polarizer protective film may include the polarizer protective film 10 of the present invention described above.

5 and 6 are schematic views illustrating a manufacturing process of the polarizer protective film of the present invention, and referring to FIGS. 5 and 6, the preparing of the polarizer protective film may be performed on at least one surface of the base film 200. The method may include casting a solution including the (meth) acrylic resin and silica, a silicone resin, or a siloxane resin. The casting step may be a non-limiting example, using the casting apparatus 100 as shown in FIG. 5.

Referring to FIG. 5, a solution including at least one of (meth) acrylic resin, silica, silicone resin, and siloxane resin may be discharged through the raw material input unit 110 of the casting apparatus 100. It may be provided as.

The (meth) acrylic resins include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxy ethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexa acrylate, Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyester acrylate, melamine acrylate, silicone acrylate It may include one or more selected from.

Meanwhile, the solution may include a photoinitiator for UV curing, and the photoinitiator may be used alone or in combination with a radical polymerization initiator such as acetophenone-based or an aromatic diazonium salt or aromatic sulfonium salt. However, it is not limited thereto.

In addition, the solution may include a crosslinking agent, the crosslinking agent may include tolylene diisocyanate, hexamethylene diisocyanate or ethylene glycol diglycidyl ether, propylene glycol di glycidyl ether, trimethylhexane diisocyanate It is not limited to this.

In addition, solvents and additives, sunscreens and the like may be further included, which will be well known in the art, specific description thereof will be omitted. In addition, since the silica, silicone resin, and siloxane resin have already been described in the polarizer protective film, overlapping description thereof will be omitted.

In addition, as described above, the solution may include silica, and may include silica gel in the form of a gel. In addition, the solution may include a silicone-based resin.

The siloxane-based resin may include polyether modified polydimethylsiloxane, for example, may include polydimethyl siloxane. That is, the polyether modified siloxane may have a structure in which the polyether chain is substituted with polyethylene oxide or polypropylene oxide.

The siloxane-based resin may be prepared by hydrolyzing a silane compound and then dehydrating condensation polymerization. An acid catalyst such as nitric acid, hydrochloric acid, sulfuric acid, or acetic acid may be used for the hydrolysis and dehydration condensation reaction.

Specifically, as the silane compound, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-part Methoxysilane, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobu Tyltriethoxysilane, Cyclohexyltrimethoxysilane, Phenyltrimethoxysilane, Phenyltriethoxysilane, Vinyltrimethoxysilane, Vinyltriethoxysilane, Allyltrimethoxysilane Allyltriethoxysilane, Dimethyldimethoxy One or two or more compounds selected from silane, dimethyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane may be used, but are not limited thereto.

The siloxane resin may be prepared by hydrolysis and desorption condensation of the silane compound. For example, the weight average molecular weight of the siloxane resin may be in the range of about 1000 to about 100000, or about 5000 to about 20000. have. By implementing the superhydrophilicity while having a low refractive index in the range of about 1000 or more weight average weight, it is possible to improve the adhesion between the polarizer protective film and the polarizer, when exceeding the range of about 100000, the light transmittance problem This can happen.

The solution introduced into the discharge device 120 is discharged onto the base film 200 traveling in a specific direction from the bottom of the casting device 100. The discharging process may be uniformly discharged onto the base film 200 by a discharge unit 130 such as a nozzle having a narrow entrance, thereby casting the solution, whereby the composition described above is formed on the base film 200. The solution containing them can be cast uniformly.

In FIG. 5, the base film 200 proceeds at a uniform speed in a specific direction and includes (meth) acrylic resin and silica, silicone resin, or siloxane resin in the discharge part 130 of the casting apparatus 100 thereon. Although a solution may be added dropwise, the present invention is not limited thereto, and the base film is in a stationary state, and the casting device 100 itself may move at a constant speed and at the same time, may discharge the solution.

As the base film 200, a known plastic film, glass, or the like may be used. For example, a polyethylene terephthalate film, a triacetyl cellulose film, a polyarylate film, a polyimide film, a polyether film, a polycarbonate film, Polysulfone film, polyether sulfone film and the like can be used, but is not limited thereto.

Next, as shown in FIG. 6, the method may include drying a solution including the (meth) acrylic resin and at least one resin of silica, silicone resin, and siloxane resin cast on the base film 200. As a result, the solvent is evaporated, and the polarizer protective film 10 may be manufactured on the base film 200. The drying may be performed by the drying apparatus 300, and the drying may be performed by thermal curing or UV curing. However, the present invention is not limited thereto.

Next, the method may include the step of obtaining the polarizer protective film 10 by peeling the base film 200. As a non-limiting example, as shown in FIG. 6, in a state in which the dried polarizer protective film 10 is laminated on the base film 200 by the drying step, the base film 200 is prevented from rotating the roll 400. By changing the advancing direction, the polarizer protective film 10 can be obtained separated by the downward direction by gravity. However, the present invention is not limited thereto.

The glass transition temperature of the polarizer protective film 10 prepared in the above manner may be about 50 ° C to about 115 ° C, for example, about 75 ° C to about 105 ° C, or about 85 ° C to about 100 ° C Can be.

On the other hand, Figure 7 is a view schematically showing a process of treating the surface of one surface of the polarizer protective film 10 according to an embodiment of the present invention. Referring to FIG. 7, a surface of one surface of the polarizer protective film 10 manufactured by the casting method as described above may be subjected to a corona treatment or plasma treatment.

More specifically, by performing corona treatment or plasma treatment ST on one surface of the polarizer protective film 10, that is, the surface CA on which the adhesive layer is disposed later, the adhesive force with the polarizer can be improved. In addition, one surface CA of the polarizer protective film 10 in which the adhesive layer is disposed has a contact angle lower than that of the other surface NCA by the surface treatment step as described above, so that the adhesive layer may be more easily formed, and as a result, The polarizer protective film can be easily adhered to the polarizer by the adhesive layer.

The corona treatment may be performed once, for example at an intensity of about 800 doses. The dose is a value calculated in the following manner.

dose = (max generator power of corona processor) / (film processing speed x electrode length x number of treatments) (Equation 1)

For example, the method of calculating the dose, if the max generator power of the corona processor is 4000Watt, the film processing speed is 100m / min, the electrode length is 1600mm, the number of treatment is twice, dose = (4000) The calculation of /(100x1.6x2) yields a value of 12.5W min / m ² .

The adhesive layer may include an aqueous adhesive, but is not limited thereto, and may include an ultraviolet curable adhesive layer. As it has been described above, the duplicate description will be omitted.

Display device

Although not separately illustrated, the present invention may provide a display device including the polarizer described above.

The display device may include a display panel and a polarizer disposed on at least one surface of the display panel. That is, the polarizing plate of the present invention may be disposed on one or both surfaces of the display panel. For example, when the display device is a liquid crystal display, the polarizer may be disposed on both sides of the liquid crystal display panel. When the polarizing plate is a polarizing plate including a functional layer, the polarizing plate may be disposed on the viewing side of the display panel. In addition, when the display device is an organic light emitting display device, the polarizer may be disposed only on the viewer side of the display panel, which will be described in detail below.

When the display device is a liquid crystal display device, the display panel constituting the display device may be a liquid crystal cell. In this case, the display device may further include a backlight unit. In the case of a display device including a liquid crystal cell, since there is no separate light source than the OELD panel, a separate backlight unit is required.

The liquid crystal cell may typically include two substrates and a liquid crystal layer interposed between the substrates, one of which is generally formed with a color filter, an opposite electrode, an alignment layer, and the other substrate with liquid crystal driving. An electrode, a wiring pattern, a thin film transistor element, an alignment film, and the like can be formed.

Examples of the operation mode of the liquid crystal cell include a twisted nematic mode or an electrically controlled birefrigence mode. Examples of the electrically controlled birefrigence mode include a vertical alignment method, an OCB (Optically Compensated) method, an IPS (In-Plane Switching) method, and the like.

The backlight unit may generally include a light source, a light guide plate, a reflective film, and the like. According to the configuration of the backlight can be arbitrarily divided into a direct method, a side light method, a planar light source method.

When the display panel is formed of a liquid crystal cell, the polarizer may be formed on both sides of the liquid crystal cell. In this case, the polarizer may transmit only light that vibrates in a specific direction among the light incident from the light source of the backlight unit.

In addition, the polarizer may be included at an opposite position of the backlight unit of the liquid crystal cell. In this case, the display panel may be positioned on the surface of the display panel, but the present invention is not limited thereto and may be a form placed between other components of the display device. That is, when the liquid crystal cell is disposed therebetween, the transmission axis of the upper polarizing film and the lower polarizing film may be orthogonal or parallel.

As a non-limiting example, the display panel may be formed of a flexible material.

The display device may further include a phase difference film disposed between the polarizing plate and the display panel, and the phase difference film compensates for the phase difference of light by a desired value, and serves to improve viewing angle, contrast ratio, color characteristics, and the like. A retardation film having a retardation value required by one of ordinary skill in the art may be applied. In addition, as the retardation film, a film having reverse wavelength dispersion characteristics may be used to improve antireflection characteristics. The retardation film is well known in the art, and a detailed description thereof will be omitted.

Meanwhile, when the display device is an organic light emitting display device, the display panel constituting the display device may include an OLED (Organic Light-Emitting Diode) panel. The OLED panel may include respective pixels, and each of the pixels may include an OLED composed of an organic light emitting layer between an anode and a cathode and a pixel circuit driving the OLED independently. The pixel circuit may mainly include a switching thin film transistor (TFT), a capacitor, and a driving TFT. The switching thin film transistor charges the data voltage to the capacitor in response to the scan pulse, and the driving TFT controls the amount of current supplied to the OLED according to the data voltage charged to the capacitor, thereby adjusting the amount of light emitted from the OLED and displaying an image. I can display it. On the other hand, the OLED panel is well known in the art, more detailed description thereof will be omitted.

The polarizing plate may be disposed on the viewing side of the OLED panel. That is, the polarizer may be attached to the side of the viewer to observe the image displayed from the OLED panel. Therefore, the fall of contrast by reflection of external light can be prevented.

Hereinafter, the present invention will be described through specific experimental data.

Example  One

A protective film including an acrylic resin, polydimethyl siloxane, and 2,2,4-trimethylhexanediisocyanate (2,2,4-trimethyl-hexane-diisocyanate) was prepared, and a polarizer and the prepared protective film were attached. The protective film was attached using a water-based adhesive by corona treatment only without a separate primer layer to prepare a polarizing plate.

Example  2

A protective film including an acrylic resin, silica gel, and 2,2,4-trimethyl-hexane-diisocyanate was prepared, and a polarizer and the prepared protective film were attached. The protective film was attached using a water-based adhesive only by corona treatment without a separate primer layer.

Comparative example  One

A polarizing plate was manufactured in the same manner as in Example 1 except that the corona treatment was not performed.

Comparative example  2

A polarizing plate was manufactured in the same manner as in Example 2 except that the corona treatment was not performed.

Experimental Example  One

The glass transition temperatures of the protective films of Examples 1 and 2 were measured. The glass transition temperature of Example 1 was measured to 90.252 ° C, the glass transition temperature of Example 2 was measured to 102 ° C.

Experimental Example  2

The test of removing the protective film from the polarizing plates of Examples 1 and 2 and Comparative Examples 1 and 2, respectively, was conducted. In Examples 1 and 2, breakage occurred in the process of removing the protective film, and in the case of Comparative Example 1 and Comparative Example 2, peeling was easy. As a result, in Example 1 and Comparative Example 2 according to the present invention, even if the protective film and the polarizer is attached using a water-based adhesive without a separate primer layer, the adhesion between the polarizer and the protective film is very excellent only by corona treatment. You can see that.

The embodiments described above are all exemplary, and different embodiments may be applied in combination.

Claims (15)

1. (Meth) acrylic resins; And

   At least one or more of silica, silicone resin, and siloxane resin,

   A polarizer protective film having a glass transition temperature of about 50 ° C to about 115 ° C.
2. The method of claim 1,

   The (meth) acrylic resins include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxy ethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexa acrylate, Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyester acrylate, melamine acrylate, silicone acrylate A polarizer protective film comprising at least one selected from.
3. The method of claim 1,

   The siloxane resin is a polarizer protective film containing polydimethyl siloxane.
4. The method of claim 1,

   And at least one of the silica, silicone resin, and siloxane resin in an amount of more than about 0 wt% and about 5 wt% or less relative to the entire polarizer protective film.
5. The method of claim 1,

   And a thickness of the polarizer protective film is in the range of about 15 μm to about 50 μm.
6. Polarizer;

   A polarizer protective film disposed on at least one surface of the polarizer; And

   Including; an adhesive layer interposed between the polarizer and the polarizer protective film;

   The polarizer protective film is (meth) acrylic resin; And at least one of silica, silicone resin, and siloxane resin, and having a glass transition temperature of about 50 ° C to about 115 ° C.
7. The method of claim 6,

   The adhesive layer is a polarizing plate containing a water-based adhesive.
8. The method of claim 7, wherein

   The polarizer protective film is a polarizing plate attached directly to the polarizer via the adhesive layer.
9. The method of claim 6,

   The glass transition temperature of the polarizer protective film is about 75 ℃ to about 105 ℃ polarizing plate.
10. The method of claim 6,

    The glass transition temperature of the polarizer protective film is about 85 ℃ to about 100 ℃ polarizing plate.
11. The method of claim 6,

    The polarizer protective film includes a functional layer disposed on the opposite side of the surface on which the adhesive layer is formed,

    The functional layer may include a hard coating layer, a anti-reflection layer, an anti-glare layer, or a diffusion layer.
12. (Meth) acrylic resins; And at least one of silica, silicone resin, and siloxane resin, and preparing a polarizer protective film having a glass transition temperature in a range of about 50 ° C. to about 115 ° C .;

    Surface treatment by corona treatment or plasma treatment on one surface of the polarizer protective film; And

    And laminating an adhesive layer between one surface of the polarizer protective film and a polarizer through an adhesive layer.
13. The method of claim 12,

    The adhesive layer is a polarizing plate manufacturing method comprising an aqueous adhesive.
14. The method of claim 13,

    The polarizer protective film is in direct contact with the adhesive layer manufacturing method.
15. The method of claim 12,

    Preparing the polarizer protective film

    Base film;

    (Meth) acrylic resin on at least one surface of the base film; And casting a solution including at least one of silica, a silicone resin, and a siloxane resin to form a casting film;

    Drying the casting film; And

    Peeling the base film to obtain a polarizer protective film.

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