WO2022220445A1 - Polarization laminate and image display device comprising same - Google Patents

Abstract

The present specification discloses a polarization laminate comprising: a polarizer; a surface treatment layer formed on one surface of the polarizer and having an internal haze value of 20% to 40% and a reflectance of 3.5% or less; a phase delay layer formed on the other surface of the polarizer; and an adhesive layer formed on a surface of the surface treatment layer. Seams of the image display device may be prevented from being visually recognized, and the optical characteristics of the image display device may be improved.

Description

Polarizing laminate and image display device including same

The present invention relates to a polarizing laminate and an image display device including the same. More particularly, it relates to a polarizing laminate including a polarizer and a functional film, and an image display device including the same.

Recently, various image display devices such as a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display (PDP), a field emission display (FED), etc. are commercially available and used. Due to the generalization of the image display apparatus, research for improving the function of the image display apparatus is active. For example, research on a polarizing laminate used for an image display device is in progress.

In general, a polarizing laminate includes an iodine-based polyvinyl alcohol (PVA) polarizer and a protective film for protecting one or both surfaces of the polarizer. As an example of the structure of the polarizing laminate, a protective film may be laminated on one surface of the polarizer, and a protective film, an adhesive layer, and a release film may be sequentially laminated on the other surface of the polarizer.

In addition, the image display device may include a surface treatment layer to improve display quality in addition to the polarizing laminate. The surface treatment layer may further include an anti-glare layer, a low reflection layer, or a hard coating film.

If the thickness of the surface treatment layer is increased to improve hardness, the surface treatment layer may be peeled off from the substrate. In addition, physical properties such as scratch resistance or impact resistance may be insufficient. Moreover, the conventional surface treatment layer provides insufficient optical properties, so that additional research is needed to realize a larger area of the image display device.

For example, Korean Patent Laid-Open Publication No. 10-2013-0074167 discloses a plastic substrate including a hard coating layer. However, due to insufficient optical properties, an alternative to the above-described problems could not be suggested.

One object of the present invention is to provide a polarizing laminate having improved optical properties.

SUMMARY OF THE INVENTION One object of the present invention is to provide an image display device having improved optical properties.

1. Polarizer; a surface treatment layer formed on one surface of the polarizer, an internal haze value of 20% to 40%, and a reflectance of 3.5% or less; a phase delay layer formed on the other surface of the polarizer; and an adhesive layer formed on the surface of the surface treatment layer.

2. The polarizing laminate according to 1 above, further comprising a protective film formed on the surface of the adhesive layer.

3. The polarizing laminate of the above 1, wherein the surface treatment layer comprises a hard coating film.

4. The polarizing laminate of the above 3, wherein the surface treatment layer is formed from a coating composition including a (meth)acrylate compound.

5. The polarizing laminate according to 4 above, wherein the surface treatment layer further comprises inorganic particles.

6. In the above 4, the average particle diameter of the inorganic particles is 100 to 500 nm, the polarizing laminate.

7. The polarizing laminate according to the above 1, wherein the surface treatment layer has a thickness of 1 to 20 μm.

8. Display panel; the polarizing laminate of 1 above disposed on the display panel; and a substrate disposed on the polarizing laminate.

9. The image display device according to 8 above, wherein the polarizing laminate is stacked such that the phase delay layer, the polarizer, the surface treatment layer, and the adhesive layer are sequentially disposed from the display panel.

10. The image display device according to 8 above, wherein the display panel includes a micro light emitting diode (LED) module.

11. The image display device according to 10 above, wherein the micro LED module includes an array in which a plurality of micro LED chips are combined.

According to embodiments of the present invention, a polarizing laminate in which a surface treatment layer having a predetermined haze value is laminated with a polarizer, a retardation layer, and an adhesive layer may be provided. In addition, the optical characteristics of the image display apparatus can be improved through the use of the surface treatment layer having a predetermined haze value.

When the surface treatment layer according to the exemplary embodiments is included, the seam included in the display panel is not recognized, so that luminance is improved and vivid colors can be realized.

In addition, since the polarizing laminate includes the surface treatment layer, the occurrence of color difference due to the seam may be suppressed. Accordingly, the area of the display panel can be easily expanded, and the process cost required to increase the area of the image display device can be reduced.

In the use of an exemplary image display device, the surface of the polarizing laminate may not be exposed to the outside, so that the life of the polarizing laminate may be extended. In addition, through the sealing of the polarizing laminate, optical properties of the polarizing laminate may be constantly maintained independently of use conditions.

1 and 2 are schematic cross-sectional views illustrating a polarizing laminate according to example embodiments.

3 is a schematic cross-sectional view of an image display device including a polarizing laminate according to example embodiments.

Embodiments of the present invention include a polarizer; polarizer; a surface treatment layer formed on one surface of the polarizer, an internal haze value of 20% to 40%, and a reflectance of 3.5% or less; a phase delay layer formed on the other surface of the polarizer; And discloses a polarizing laminate comprising an adhesive layer formed on the surface of the surface treatment layer.

Through the use of the polarizing laminate, visibility of the seam located on the display panel of the image display device can be suppressed and the occurrence of color difference due to the seam can be suppressed. In addition, the clarity of the image display device may be improved by the polarizing laminate. Hereinafter, each configuration will be described in more detail.

In addition, in the description of the present specification, 'arranged' is a term used to encompass terms such as 'formed', 'located', 'stacked', or 'applied'. In addition, 'arranged' is a term used to describe the relative positions of each layer included in the exemplary embodiment and the comparative example, and is not intended to limit a method of manufacturing each layer. Also, although it is described as 'laminated' instead of 'placed', the substrate as described above does not necessarily mean that a particular layer must be in contact with one surface of another layer in the manner of 'lamination'.

Meanwhile, in the description of the present specification, 'one side' and 'the other side' are used as relative concepts. For example, when 'one side' is the upper surface, the lower surface may be referred to as 'the other side'. Conversely, when 'one surface' is the lower surface, the upper surface may be referred to as 'the other surface'.

In addition, in the description of this specification, descriptions of 'top, 'top', 'top', 'viewer side', 'bottom', 'bottom', 'bottom', 'panel side', etc. are based on the orientation of the drawing can be understood as For example, if one surface of a specific layer is disposed toward the upper direction of the drawing, the one surface may be referred to as 'viewing side', 'top surface' or 'top'. Also, the surface opposite to the one surface, that is, the other surface, may be referred to as a 'panel side', a 'lower surface', or a 'lower portion'.

Also, 'top', 'top.' Alternatively, 'upper' may be used to refer to a position from which an observer looks (ie, a viewing side). Accordingly, it may be understood that the observer is generally positioned in the upper surface direction and is looking toward the lower surface direction. As a concept contrasting with the position of the observer, 'lower', 'lower side', or 'lower side' may be used to refer to the position of the display panel (ie, the panel side).

<Surface treatment layer>

An internal haze value of the surface treatment layer according to example embodiments may be 20% to 40%. The haze value is the degree of blur that appears when light passes through the sample, and refers to a ratio obtained by dividing diffuse transmittance (Td) by total transmittance (Tt). The diffusely transmitted light (Td) is the amount of scattered light among the light transmitted through the sample, and the total transmitted light (Tt) is the amount of all the light transmitted through the sample. Meanwhile, the parallel transmitted light Tp is the amount of light transmitted without scattering among the transmitted light, and may be expressed as a value obtained by subtracting the diffusely transmitted light Td from the total transmitted light Tt.

Also, the internal haze value may mean a value obtained by subtracting the external haze value from the haze value. The external haze value may mean a haze value induced by the external unevenness of the surface treatment layer. Accordingly, the internal haze value may mean a haze value induced by the composition of the surface treatment layer.

In exemplary embodiments, an adhesive layer may be formed on the surface of the surface treatment layer. Accordingly, the occurrence of haze due to the surface roughness of the surface treatment layer may be suppressed, and the degree of visibility of the seam included in the display panel may be controlled by adjusting the internal haze value of the surface treatment layer.

When the surface treatment layer satisfies the above-described internal haze value, it is possible to suppress a phenomenon in which a seam between display panels is visually recognized. When the internal haze value of the surface treatment layer is less than 20%, a seam between the display panels may be visually recognized. When the internal haze value of the surface treatment layer exceeds 40%, optical properties of the image display device such as sharpness may be deteriorated due to excessive light diffusion.

Also, preferably, the reflectance of the surface treatment layer may be 3.5% or less. The reflectance of the surface treatment layer may mean internal reflectance. Due to the reduction of the internal reflectance, the sharpness and color reproducibility of the image display device may be improved.

In exemplary embodiments, the surface treatment layer may include a polymer resin with guaranteed transparency. As an example of the polymer resin included in the surface treatment layer, a cycloolefin-based derivative having a unit of a monomer containing a cycloolefin such as norbornene or a polycyclic norbornene-based monomer, cellulose (diacetylcellulose, triacetylcellulose, acetylcellulose butyl rate, isobutyl ester cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose), ethylene vinyl acetate copolymer, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyethersulfone, poly Sulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate , polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, and at least one polymer resin selected from the group consisting of polyepoxy.

In addition, the surface treatment layer may be an unstretched film or may include a uniaxially or biaxially oriented film. In some exemplary embodiments, in order to improve transparency, heat resistance, or optical properties, a uniaxial or biaxial oriented polyester film, a cycloolefin-based derivative film, or a triacetyl cellulose film may be used as the surface treatment layer. have.

In addition, the surface treatment layer may be a hard coating film, an antistatic hard coating film, an antiglare coating layer, an antistatic antiglare coating layer, or a low reflection coating layer. Alternatively, the surface treatment layer may be a composite layer including a hard coating film, an antistatic hard coating film, an anti-glare coating layer, an antistatic anti-glare coating layer, or a low-reflection coating layer.

In some exemplary embodiments, the hard coating film may be obtained from an ultraviolet curable resin composition. In addition, the UV-curable resin composition may include a polyfunctional (meth)acrylate, a photopolymerization initiator, and an organic solvent. (meth)acrylate includes both acrylate and methacrylate.

In addition, in some exemplary embodiments, as examples of polyfunctional (meth)acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (meth) acrylate , ditrimethylolpropane tetra (meth) acrylate, (meth) acrylic ester, trimethylol propane tri (meth) acrylate, glycerol tri (meth) acrylate, tris (2-hydroxyethyl hydroxyethyl) isocyanu Late tri (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1 ,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, iso Octyl (meth)acrylate, isodexyl (meth)acrylate, stearyl (meth)acrylate, tetrafurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, etc. are mentioned.

In addition, in some exemplary embodiments, as examples of the photopolymerization initiator, diphenylketonebenzyldimethylketal, acetphenonedimethylketal, p-dimethylaminebenzoic acid ester, 2-hydroxy-2-methyl-1-phenyl-1 -one, 4-hydroxycyclophenyl ketone, dimethoxy-2-phenylacetophenone, anthraquinone, 2-aminoanthraquinone, fluorene, triphenylamine, carbazole, benzophenone, p-phenylbenzophenone, 3- Methylacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, benzoin, 2-ethylthioxanthone, etc. are mentioned.

In addition, the organic solvent may be compatible with polyfunctional (meth)acrylate. As examples of organic solvents, methanol, ethanol, isopropanol, propanol, butanol, isobutanol, ethyl cellosolve, methyl cellosolve, butyl acetate, dimethylformamide, diacetone alcohol, ethylene glycol isopropyl alcohol, propylene glycol isopropyl alcohol, methyl ethyl ketone, and N-methylpyrrolidone; and the like.

Also, in some exemplary embodiments, the hard coating film may be an anti-glare coating layer to which anti-glare properties are imparted. In order to impart anti-glare properties to the hard coating film, inorganic particles such as silica or polymer particles such as polymethyl methacrylate (PMMA) may be used. In order to improve dispersibility, the polymer particles may be monodisperse particles, polydisperse particles, or a mixture of monodisperse and polydisperse particles having an average particle diameter of 1 to 20 μm.

In addition, the surface treatment layer may further include inorganic particles. The inorganic particles may be silica-based particles. In addition, the silica-based particles may include hollow silica, mesoporous silica, and the like. The inorganic particles including hollow or mesoporous may further increase the internal haze of the surface treatment layer compared to inorganic particles not including hollow or mesoporous.

In some exemplary embodiments, the average particle diameter of the silica-based particles may be a nano size. Nanoparticles refer to particles having an average particle diameter of a nano size. By incorporating the nano-sized inorganic particles, the internal haze of the surface treatment layer may increase. In example embodiments, as the average particle diameter of the nanoparticles increases, the internal haze of the surface treatment layer may increase.

In some exemplary embodiments, in order to adjust the internal haze value of the surface treatment layer to the above-mentioned range, the average particle diameter of the inorganic particles is preferably 100 to 500 nm, more preferably 200 to 400 nm, 250 to 350 nm is most preferred. For example, when the average particle diameter of the inorganic particles is less than 100 nm, the increase in the internal haze value through the addition of the inorganic particles may be insignificant. When the average particle diameter of the inorganic particles exceeds 500 nm, mechanical properties of the surface treatment layer may be deteriorated due to the addition of the inorganic particles, and the interfacial bonding strength with the polarizer may be weakened.

Further, in some exemplary embodiments, the inorganic particles may have any geometric structure. For example, the inorganic particles may be isotropic or anisotropic. The isotropy means that the aspect ratio of the inorganic particles is 1, and the anisotropy means that the aspect ratio of the inorganic particles is not 1. Isotropic inorganic particles are suitable for imparting uniform mechanical and physical properties, and anisotropic inorganic particles are suitable for increasing the internal haze value.

Accordingly, in some exemplary embodiments, in order to improve the mechanical properties and optical properties of the surface treatment layer, only isotropic inorganic particles are included in the surface treatment layer, or only anisotropic inorganic particles are included in the surface treatment layer, or both. All of may be included in the surface treatment layer. In addition, in order to improve the mechanical properties and optical properties of the surface treatment layer, only hollow or mesoporous inorganic particles are included in the surface treatment layer, or only solid inorganic particles are included in the surface treatment layer, or both are included in the surface treatment layer. may be included in the treatment layer.

In addition, as the surface treatment layer includes inorganic particles, the internal haze value can be easily adjusted, and the uniformity of the internal haze value can be improved. For example, even if the composition or thickness of the resin included in the surface treatment layer is changed, the desired internal haze value may be uniform by adjusting the average diameter of the inorganic particles, the presence or absence of hollows, the content, and the like.

Also, in some exemplary embodiments, a binder resin may be used to uniformly disperse the inorganic particles in the surface treatment layer. The binder resin may be a polyvinyl alcohol-based resin, and in this case, the affinity with the surface treatment layer and the inorganic particles may be excellent.

In addition, in some exemplary embodiments, in order to impart antistatic properties to the hard coating film or the anti-glare coating layer, a conductive material may be additionally used. The conductive material may be included in the coating solution composition to impart antistatic properties to the coating layer. Examples of the conductive material include cationic surfactants such as quaternary ammonium salts, phosphonium salts, and sulfonium salts; anionic surfactants such as carboxylic acid, sulfonate, sulfuric acid, phosphate, and phosphite; Cationic surfactants, such as a sulfobetaine type, an alkyl betaine type, and an alkylimidazolium betaine type; Nonionic surfactants, such as a polyhydric alcohol derivative, a sorbitan fatty acid monoester diester, and a polyalkylene oxide derivative, etc. are mentioned.

In addition, as the conductive material, a permanent antistatic agent in which a hydrophilic polymer such as polyethylene methacrylate and an acrylic resin are mixed, a conductive filler such as acetylene black or aluminum oxide, polypyrrole, polythiophene, polyaniline, and the like.

In addition, in some exemplary embodiments, an additive may be used to further improve mechanical properties of the surface treatment layer. A photopolymerization initiation aid may be used to improve photopolymerization efficiency. In addition, fillers, leveling agents, defoamers, ultraviolet absorbers, antioxidants and the like may be added.

In exemplary embodiments, a polarizer may be laminated on one surface of the surface treatment layer. In some exemplary embodiments, an adhesive layer may be laminated on the other surface of the surface treatment layer. Accordingly, in some exemplary embodiments, the adhesive layer, the surface treatment layer, and the polarizer may be sequentially stacked.

Further, in exemplary embodiments, the thickness of the surface treatment layer may be 0.1 to 200 μm, preferably 1 to 50 μm, and more preferably 1 to 20 μm. Within the above numerical range, the mechanical strength of the surface treatment layer may be improved, and it may be easy to increase the area of the surface treatment layer. For example, when the thickness of the surface treatment layer is less than 1 μm, the mechanical strength of the surface treatment layer may be insufficient, and when the thickness of the surface treatment layer exceeds 20 μm, the process cost excessive for increasing the area of the surface treatment layer This may be requested.

<Polarizer>

The polarizer may be one in which the dichroic dye is adsorbed and oriented on the stretchable film. The stretchable film may include a resin capable of being dyed by a dichroic material. For example, the stretchable film may include a hydrophilic polymer such as polyethylene terephthalate resin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, cellulose resin, polyvinyl alcohol-based resin, and partially saponified resins thereof; Alternatively, it may include a polyene orientation resin such as dehydration-treated polyvinyl alcohol-based resin, dehydrochloric acid-treated polyvinyl alcohol-based resin, and the like.

Preferably, a polyvinyl alcohol-based resin may be used in that the uniformity of the degree of polarization in the plane is ensured and the dyeing affinity to the dichroic material is excellent.

For example, the polarizer may include a polyvinyl alcohol-based resin obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and a monomer copolymerizable therewith. Examples of the monomer copolymerizable with vinyl acetate include an unsaturated carboxylic acid-based monomer, an unsaturated sulfonic acid-based monomer, an olefin-based monomer, a vinyl ether-based monomer, and an acrylamide-based monomer having an ammonium group.

In addition, the polyvinyl alcohol-based resin described above may be a modified one. For example, polyvinyl formal or polyvinin acetal modified through the addition of an aldehyde-based compound may be used.

The polarizer may be obtained by processing the polyvinyl alcohol-based resin according to a process including the steps of swelling, dyeing, crosslinking, stretching, washing with water, drying, and the like. The manufacturing method of the polarizer may be subdivided by the stretching method. For example, as the stretching method, a dry stretching method, a wet stretching method, or a hybrid stretching method in which the two types of stretching methods are mixed may be mentioned.

Hereinafter, a manufacturing method of the polarizer will be described on the premise that the polyvinyl alcohol-based resin is processed through a wet stretching method, but the manufacturing method is not limited to the embodiments.

The process such as the swelling step, the dyeing step, the crosslinking step, the stretching step, and the water washing step may be performed in a state in which the film containing the polyvinyl alcohol-based resin is immersed in a constant temperature water bath. The order and the number of repetitions of each process are not particularly limited, and each process may be performed simultaneously or sequentially, and some processes may be omitted if necessary.

The swelling step may be a step for removing impurities such as dust or an anti-blocking agent deposited on the surface of the film, and improving the film's drawing efficiency and dyeing uniformity. The dyeing step is a step of adsorbing the dichroic material to the film. In order to improve the dyeing efficiency, iodide may be used as a dyeing aid. As examples of iodide, potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, etc. can be considered.

The crosslinking step may be performed to chemically fix the dichroic material adsorbed to the film. For example, by immersing a film on which a dichroic material is physically adsorbed in an aqueous solution for crosslinking containing a metal acetate salt, a crosslinking reaction of the dichroic material may be induced. The drying step may be a step for drying the washed film and improving the optical properties of the polarizer by further improving the orientation of the dichroic material.

In example embodiments, the polarizer may be laminated on one surface of the surface treatment layer. In addition, a phase delay layer may be laminated on the other surface of the polarizer. Accordingly, in exemplary embodiments, the surface treatment layer, the polarizer, and the phase delay layer may be sequentially stacked.

<Phase delay layer>

In exemplary embodiments, the retardation layer may be a λ/4 retardation film (1/4 wavelength retardation film). The λ/4 retardation film may be obtained by orienting the polymer film in the uniaxial direction, the biaxial direction, or other suitable method. The λ/4 retardation film can suppress reflected light.

Examples of the polymer compound included in the retardation layer include a polycarbonate-based compound, a polyester-based compound, a polysulfone-based compound, a polyether sulfone-based compound, a polystyrene-based compound, a polyolefin-based compound, a polyvinyl alcohol-based compound, and a cellulose acetate-based compound. compounds, polymethyl methacrylate-based compounds, polyvinyl chloride-based compounds, polyacrylate polyvinyl chloride-based compounds, and polyamide polyvinyl chloride-based compounds. In the selection of the high molecular compound, transparency can be used as an indicator.

Further, in exemplary embodiments, the phase delay layer may include a nematic or smectic liquid crystal material that can be polymerized by in situ polymerization, and preferably includes a nematic liquid crystal material. In addition, in exemplary embodiments, the phase delay layer may provide reverse wavelength separation and may have various phase difference values.

Also, in some exemplary embodiments, the phase delay layer may further include a positive C plate layer. In addition, in order to set the thickness direction retardation (Rth) value of the polarizing laminate to an appropriate range, the retardation value of the positive C plate layer may be adjusted to a predetermined range. In some exemplary embodiments, when the thickness direction retardation value of the λ/4 retardation film is 40 nm to 65 nm, the thickness direction retardation value of the positive C plate layer may be -85 nm to -60 nm. In addition, when the thickness direction retardation value of the λ/4 retardation film is 65 nm to 80 nm, the thickness direction retardation value of the positive C plate layer may be -100 nm to -85 nm. In addition, when the thickness direction retardation value of the λ/4 retardation film is 80 nm to 100 nm, the thickness direction retardation value of the positive C plate layer may be -120 nm to -100 nm. In addition, when the thickness direction retardation value of the λ/4 retardation film is 100 nm to 180 nm, the thickness direction retardation value of the positive C plate layer may be -200 nm to -120 nm.

In exemplary embodiments, a polarizer may be laminated on one surface of the retardation layer, and a protective film may be disposed on the other surface of the retardation layer. For example, a polarizer, a retardation layer, and a protective film may be sequentially disposed.

<Adhesive layer>

In example embodiments, the adhesive layer may be formed using a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA).

For example, the pressure-sensitive adhesive or optically clear adhesive is obtained from a pressure-sensitive adhesive composition comprising an acrylic copolymer and a crosslinking agent, or from a pressure-sensitive adhesive composition comprising a urethane (meth)acrylate resin, (meth)acrylate ester monomer and a photoinitiator can be obtained

In exemplary embodiments, the adhesive layer may be disposed on one surface of the surface treatment layer. Also, in some exemplary embodiments, a release layer may be laminated on the other surface of the adhesive layer. For example, a release layer, an adhesive layer, and a surface treatment layer may be sequentially stacked. In addition, the release layer may be removed prior to lamination of the polarizing laminate.

In addition, since the adhesive layer is laminated on one surface of the surface treatment layer, the occurrence of haze due to the surface irregularities of the surface treatment layer can be suppressed. Accordingly, the haze value of the surface treatment layer may be determined by the internal haze value, and the haze value of the surface treatment layer may be more easily controlled.

<Protection film>

In some exemplary embodiments, the protective film may be laminated on one surface of the retardation layer. Also, the protective film may be oriented toward the display panel.

In some exemplary embodiments, the resin included in the protective film may be selected using the transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc. of the protective film as an index.

As an example of resin contained in a protective film, Polyester-type resin, such as a polyethylene terephthalate, a polyethylene isophthalate, and a polybutylene terephthalate; Cellulose resins, such as a diacetyl cellulose and a triacetyl cellulose; polycarbonate-based resin; acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; styrenic resins such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based resins such as polyethylene, polypropylene, polyolefin having a cyclo-based or norbornene structure, and an ethylene-propylene copolymer; vinyl chloride-based resin; polyamide-based resins such as nylon and aromatic polyamide; imide-based resin; polyether sulfone-based resin; sulfone-based resins; Polyether ketone-based resin: sulfide polyphenylene-based resin; vinyl alcohol-based resin; vinylidene chloride-based resin; vinyl butyral-based resin; allylate-based resin; polyoxymethylene-based resins; and a thermoplastic resin such as an epoxy resin.

In addition, a film formed of a thermosetting resin such as (meth)acrylic, urethane, epoxy, silicone, or the like, or ultraviolet curable resin can be used as the protective film. In some exemplary embodiments, a cellulose-based film having a saponified (saponified) surface may be used as the protective film in that it is easy to improve polarization characteristics and durability.

<Release layer>

In some exemplary embodiments, the release layer may be laminated on one surface of the adhesive layer. In addition, the release layer may be oriented toward the substrate and may be removed prior to lamination of the polarizing laminate.

Also, in some exemplary embodiments, the release layer may be formed of a resin commonly used in a polarizing laminate. For example, the mold release layer may include polyester resins such as polyethylene terephthalate, polybutyrene terephthalate, polyethylene naphthalate, and polybutyrene naphthalate; polyimide resin; acrylic resin; styrene-based resins such as polystyrene and acrylonitrile-styrene; polycarbonate resin; polylactic acid resin; polyurethane resin; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; vinyl resins such as polyvinyl chloride and polyvinylidene chloride; polyamide resin; sulfone-based resins; polyether-etherketone-based resins; allylate-based resin; Or it may be formed of a mixture of the above resins.

<Image display device>

An image display apparatus according to example embodiments includes a display panel; a polarizing laminate disposed on the display panel; and a substrate disposed on the polarizing laminate.

In example embodiments, the polarizing laminate may be stacked such that the phase delay layer, the polarizer, the surface treatment layer, and the adhesive layer are sequentially disposed from the display panel. In addition, under normal use conditions, all surfaces of the polarizing laminate may not be exposed to the outside of the image display device.

In addition, in the image display device according to some exemplary embodiments, when the polarizing laminate additionally includes a protective film, the adhesive layer of the polarizing laminate is laminated on one surface of a substrate, and the display panel is spaced apart from the other surface of the substrate. can be located In this case, the surface of the protective film may be in contact with the air layer inside the image display device.

Board

The substrate may be provided as an insulating substrate, and in this case, the insulating substrate may be made of an insulating material such as glass or resin. In addition, the substrate may be made of a material having flexibility to be bent or folded, and may have a single-layer structure or a multi-layer structure.

The substrate may include a polyester-based resin such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; Cellulose resins, such as a diacetyl cellulose and a triacetyl cellulose; polycarbonate-based resin; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrenic resins such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based resins such as polyethylene, polypropylene, polyolefin having a cyclo-based or norbornene structure, and an ethylene-propylene copolymer; vinyl chloride-based resin; amide-based resins such as nylon and aromatic polyamide; imide-based resin; polyether sulfone-based resin; sulfone-based resins; polyether ether ketone resin; sulfide polyphenylene-based resin; vinyl alcohol-based resin; vinylidene chloride-based resin; vinyl butyral-based resin; allylate-based resin; polyoxymethylene-based resins; A thermoplastic resin such as an epoxy-based resin may be included, and a blend of the thermoplastic resin may be included.

In addition, thermosetting resins such as (meth)acrylic, urethane, acrylic urethane, epoxy, and silicone resins or ultraviolet curable resins may be included. However, materials constituting the substrate may be variously changed, and in some exemplary embodiments, the substrate may be formed of fiber glass reinforced plastic (FRP) or the like.

display panel

In example embodiments, the display panel of the image display device may include a micro light emitting diode (LED) module. In a micro LED module, the term 'micro' may be used to refer to an LED module having a scale of 1 to 100 μm. However, the exemplary embodiments are not necessarily so limited, and in some embodiments, a smaller-scale LED module or a larger-scale LED module may be used.

Further, in exemplary embodiments, the micro LED module may have the form of an LED group or an LED array. The LED group or LED array is a form in which micro LED chips including LED modules are combined in parallel, and a seam may be formed between each LED module.

For example, an array including micro LED modules may have a pitch of 10 μm×10 μm, or a pitch of 5 μm×5 μm. Also, at these densities, a 6 inch substrate can accommodate about 165 million micro LED modules with a 10 μm×10 μm pitch. Alternatively, a 6-inch substrate can accommodate about 660 million micro LED modules having a pitch of 5 μm×5 μm.

In addition, the micro LED module may be composed of a plurality of sub-pixels each including R (Red), G (Green), and B (Blue). Three sub-pixels of R (Red), G (Green), and B (Blue) constitute one pixel PA, and these pixels PA may be sequentially arranged. In addition, the micro LED module may emit blue light, green light, or red light by combining with a wavelength conversion material such as a phosphor, and may emit white light, ultraviolet light, and the like.

Also, in example embodiments, the display panel may be spaced apart from one surface of the polarization stack. As used herein, the term “spaced apart” means that the two are not in direct contact. For example, an air layer may be formed between the display panel and the polarizing laminate, and the display panel and the polarizing laminate may be spaced apart from each other by the air layer.

In addition, a separate support member may be included to form an air layer between the polarizing laminate and the display panel. The support member may appropriately space the display panel and the polarizing laminate so that the air layer maintains a constant thickness. In addition, the outer peripheral surfaces of the polarizing laminate and the display panel may be fixed to form and maintain the air layer. Separate packaging may be performed for fixing the outer circumferential surface.

Also, in exemplary image display devices, the substrate, the polarizing laminate, and the display panel may be sequentially positioned. The substrate, the polarizing laminate, and the display panel may be individually prepared and assembled, or may be prepared simultaneously. In addition, a polarizing laminate may be laminated on one surface of the substrate, and the other surface of the substrate may be oriented toward the viewer side of the image display device.

In addition, as the size of the LED module becomes smaller, the area of the seam included in the display panel may further increase, and the seam may be visually recognized by the user. Since the image display device according to the exemplary embodiments includes the above-described polarizing laminate, visibility of the seam accompanying the use of the micro LED module can be suppressed. Therefore, visibility of a seam is suppressed by a polarizing laminated body, and the optical characteristic of an image display apparatus can be improved.

Hereinafter, with reference to the drawings, embodiments of the present invention will be described in more detail. However, the following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the present invention, so the present invention is described in such drawings It should not be construed as being limited only to the matters.

1 and 2 are schematic cross-sectional views illustrating a polarizing laminate 100 according to example embodiments.

Referring to FIG. 1 , it can be seen that the polarizing laminate 100 includes an adhesive layer 110 , a surface treatment layer 120 , a polarizer 130 , and a phase delay layer 140 . In addition, in exemplary embodiments, the adhesive layer 110 , the surface treatment layer 120 , the polarizer 130 , and the phase delay layer 140 may be sequentially stacked to form the polarization laminate 100 . have. In addition, the upper surface of the adhesive layer 110 may be exposed to the outside, and the lower surface of the phase delay layer 140 may be exposed to the outside.

Referring to FIG. 2 , the polarizing laminate 100 may further include a protective film 150 . In addition, the adhesive layer 110 , the surface treatment layer 120 , the polarizer 130 , the phase delay layer 140 , and the protective film 150 may be sequentially stacked to form the polarizing laminate 100 . In addition, a lower surface of the protective film 150 may be exposed to the outside, and an upper surface of the adhesive layer 110 may be exposed to the outside.

3 is a schematic cross-sectional view of an image display device 1 including a polarizing laminate 100 according to example embodiments.

In example embodiments, the image display apparatus 1 may include a polarizing laminate 100 , a substrate 200 , and a display panel 300 . Also, the substrate 200 , the polarizing laminate 100 , and the display panel 300 may be sequentially disposed to form the image display device 1 . In addition, the display panel 300 may be disposed under the polarization laminate 100 , and an air layer 400 is formed between the polarization laminate 100 and the display panel 300 to form the display panel 300 and the polarized light. The stacked body 100 may be spaced apart.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but these examples are merely illustrative of the present invention and do not limit the appended claims, and are within the scope and spirit of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible, and it is natural that such variations and modifications fall within the scope of the appended claims.

Examples and Comparative Examples

Example 1

A nanoparticle solution (methyl ethyl ketone (MEK) solvent) containing silica nanoparticles (SAT NANO ^® ) with an average particle diameter of 300 nm was applied to a triacetyl cellulose film (thickness 40 μm, TAC) with a moisture film thickness of 5 μm. After application with a Meyer bar as much as possible, the surface of the triacetyl cellulose film was induced to be impregnated by hot air drying at 40° C. for 1 minute. Thereafter, a hard coating solution (DN-0081, manufactured by JSR) was applied with a Meyer bar so that the thickness of the dry coating film was 5 μm, and dried and cured with hot air at 70° C. for 1 minute to obtain a surface treatment layer. . The internal haze value of the obtained surface treatment layer was 30%.

In addition, a transparent unstretched polyvinyl alcohol film (VF-PE 60㎛, Kuraressa) having a saponification degree of 99.9% or more was immersed in water (deionized water) at 30°C for 2 minutes to swell, followed by iodine 3.5mmol/L and iodide. The dye was immersed in an aqueous solution for dyeing at 30° C. containing 2% by weight of potassium for 4 minutes. At this time, the polyvinyl alcohol film was stretched 1.3 times and 1.4 times, respectively, in the swelling and dyeing steps. Then, the first aqueous solution for crosslinking at 50°C containing 10% by weight of potassium iodide and 3.5% by weight of boric acid and the second aqueous solution for crosslinking at 50°C containing 1.0% by weight of citric acid (citric acid) and 1.0% by weight of zinc acetate, respectively Crosslinked by immersion for 2 minutes and 1 minute. At this time, the crosslinking step was such that the total cumulative draw ratio was 6.4 times.

After the crosslinking was completed, the polyvinyl alcohol film was dried in an oven at 70° C. for 4 minutes to prepare a polarizer. The prepared surface treatment layer was laminated on the upper surface of the polarizer, and a λ/4 phase delay layer (manufactured by ZD12 Zeon) having a thickness of 47 µm (manufactured by ZD12 Zeon)) was laminated on the lower surface of the polarizer. In addition, a polarizing laminate was prepared by forming an adhesive layer (acrylic adhesive, manufactured by Lintec Co., Ltd.) having a thickness of 20 μm on the upper surface of the surface treatment layer.

Example 2

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 21%.

Example 3

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 26%.

Example 4

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 35%.

Example 5

A polarizing laminate was manufactured in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 40%.

Comparative Example 1

A polarizing laminate was prepared in the same manner as in Example 1, except for the surface treatment layer, to prepare a polarizing laminate.

Comparative Example 2

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 18%.

Comparative Example 3

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 10%.

Comparative Example 4

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 42%.

Comparative Example 5

A polarizing laminate was prepared in the same manner as in Example 1, except that the content of the inorganic particles and the impregnation time of the inorganic particles were varied so that the internal haze value of the surface treatment layer was 50%.

Experimental example

1. Evaluation of haze value and reflectance

The internal haze value was measured using a spectrophotometer (HZ-1, manufactured by Nihon Kagawa Co., Ltd.). The display panel was a 5V 9W halogen bulb, and the light receiving part was a silicon photocell (with a non-visible filter attached), and the measurement was performed according to JIS K-7136.

In addition, to measure the reflectance, UV-2450 (manufactured by Shimatsu, Japan) and an adapter MPC-2200 (manufactured by Shimatsu, Japan) were used. In a wavelength region of 380 to 780 nm, the internal reflectance was measured for an exit angle of 5° at an incident angle of 5°, and an average reflectance of 450 to 650 nm was calculated.

The haze values and reflectances of the surface-treated layers included in the polarizing laminates of Examples and Comparative Examples, measured through the above-described method, are shown in Table 1 below.

division	Measurement result
	Haze value (%)	reflectivity(%)
Example 1	30	One
Example 2	21	2.1
Example 3	26	1.9
Example 4	35	2.3
Example 5	40	2.4
Comparative Example 1	-
Comparative Example 2	18	One
Comparative Example 3	10	One
Comparative Example 4	42	0.1
Comparative Example 5	50	1.5

2. Evaluation of seam visibility and color difference

An air layer at regular intervals was formed on the top of the display panel including the micro LED module and the seam, and a transparent glass substrate was positioned on the air layer. The width of the micro LED module was 50 μm, and the width of the seam was 0.1 μm. In addition, the refractive index of the transparent glass substrate was 1.51, the thickness of the transparent glass substrate was 520 µm, and the width of the air layer was 120 µm. An image display device was prepared by placing the polarizing laminate of Example or Comparative Example on the substrate.

For the image display devices including the polarizing laminates of Examples and Comparative Examples, the visibility of the seam was evaluated with the naked eye, and the color difference value between the light emitting part and the seam of the display panel was measured. The colorimeter used in the experiment was OSP-SP200 (manufactured by OLYMPUS). ΔL ^* a ^* b ^* is the color difference between the light emitting part and the seam in the CIE 1976 (L ^* , a ^* , b ^* ) space color system. The evaluation results for the image display device including the polarizing laminate of Examples and Comparative Examples are shown in Table 2 below.

<Evaluation criteria>

○: seam recognized

X: No seams are recognized

division	Measurement result
	visibility of seams	△L * a * b *
Example 1	X	3.84
Example 2	X	3.23
Example 3	X	3.71
Example 4	X	2.63
Example 5	X	2.16
Comparative Example 1	○	15.41
Comparative Example 2	○	5.10
Comparative Example 3	○	4.87
Comparative Example 4	X	2.12
Comparative Example 5	X	2.39

3. Clarity evaluation

After the black and white pattern was set to be repeated on the display panel, the sharpness of the image was evaluated by visually observing it from the front and at an angle of 45 degrees. The evaluation criteria are as follows, and the evaluation results are shown in Table 3.

<Evaluation criteria>

◎ (Excellent): Clear image without distortion

○ (appropriate): The width of the pattern changes slightly, but the boundary of the pattern can be checked

X (less than): Distorted to the point where the boundary of the pattern cannot be seen.

division	Measurement result
	Haze value (%)	definition
Example 1	30	○
Example 2	21	○
Example 3	26	◎
Example 4	35	◎
Example 5	40	○
Comparative Example 1	-	○
Comparative Example 2	18	○
Comparative Example 3	10	○
Comparative Example 4	42	X
Comparative Example 5	50	X

Referring to Tables 1 and 2, it can be seen that in exemplary embodiments, when the surface treatment layer satisfies a predetermined haze value, visibility of a seam included in the display panel is improved. Accordingly, through the adoption of the polarizing laminate according to the exemplary embodiments, it is possible to suppress the recognition of the seam by an external observer, and it is possible to prevent a decrease in optical characteristics due to the seam recognition included in the image display device.

In addition, referring to Tables 2 and 3, it can be confirmed that, in the exemplary embodiments, since the surface treatment layer satisfies a predetermined haze value, the seam included in the display panel is not recognized and at the same time, more than adequate clarity is secured. have. In addition, the image display device was able to implement a more vivid color. As a result, the polarizing laminate according to the exemplary embodiments may increase the area and improve the clarity of the image display device.

On the other hand, in Comparative Examples 1, 2, and 3, the sharpness was found to be adequate, but the seam was recognized, and in Comparative Examples 4 and 5, the sharpness was found to be insufficient. Therefore, in Comparative Examples 1, 2, and 3, it can be confirmed that light scattering by the surface treatment layer is absent or insufficient, and in Comparative Examples 4 and 5, the sharpness of the image display device is significantly lowered due to excessive light scattering. it can be confirmed that

Claims (11)

1. polarizer;

   a surface treatment layer formed on one surface of the polarizer, an internal haze value of 20% to 40%, and a reflectance of 3.5% or less;

   a phase delay layer formed on the other surface of the polarizer; and

   A polarizing laminate comprising an adhesive layer formed on the surface of the surface treatment layer.
2. The polarizing laminate according to claim 1, further comprising a protective film formed on a surface of the adhesive layer.
3. The polarizing laminate according to claim 1, wherein the surface treatment layer comprises a hard coat film.
4. The polarizing laminate according to claim 3, wherein the surface treatment layer is formed from a coating composition including a (meth)acrylate compound.
5. The polarizing laminate according to claim 4, wherein the surface treatment layer further comprises inorganic particles.
6. The method according to claim 4, The average particle diameter of the inorganic particles is 100 to 500 nm, the polarizing laminate.
7. The polarizing laminate according to claim 1, wherein the surface treatment layer has a thickness of 1 to 20 µm.
8. display panel;

   the polarizing laminate of claim 1 disposed on the display panel; and

   and a substrate disposed on the polarizing laminate.
9. The image display device of claim 8 , wherein the polarizing laminate is stacked such that the phase delay layer, the polarizer, the surface treatment layer, and the adhesive layer are sequentially disposed from the display panel.
10. The image display device of claim 8 , wherein the display panel comprises a micro light emitting diode (LED) module.
11. The image display device of claim 10 , wherein the micro LED module comprises an array in which a plurality of micro LED chips are coupled.

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