KR102428883B1 - Optical laminate, polarizing plate, and display apparatus - Google Patents

Abstract

The present invention includes an optical laminate comprising a polymer substrate and an anti-glare layer, wherein microprotrusions are formed in an amount of 50 pieces/m 2 or less per unit area on the outer surface of the anti-glare layer, a polarizing plate including the optical laminate, and the polarizing plate It relates to a liquid crystal panel and a display device comprising the.

Description

Optical laminate, polarizing plate, and display device {OPTICAL LAMINATE, POLARIZING PLATE, AND DISPLAY APPARATUS}

The present invention relates to an optical laminate, a polarizing plate, and a display device.

In an image display apparatus like an organic electroluminescent element (OELD) or a liquid crystal display element (LCD), it is calculated|required to prevent the fall of the contrast by reflection of external light or the reflection of an image, and the fall of visibility. For this purpose, an optical laminated film such as an antireflection film is formed on the surface of an image display device in order to reduce reflection or reflection of an image using light scattering or optical interference.

For example, in a liquid crystal display element etc., the optical laminated film containing a glare-proof layer has been generally formed from the past. Such an anti-glare layer mainly includes a binder and fine particles contained in the binder, and these fine particles are usually formed with irregularities so that a part protrudes from the surface of the binder. That is, since the anti-glare layer has a surface asperity due to the fine particles protruding from the surface of the binder, it is possible to control light scattering/light reflection and the like to suppress a decrease in visibility of the image display device.

However, in the case of the previously known optical film including an anti-glare layer, organic particles and inorganic nanoparticles were used together to form irregularities on the surface, but inorganic nanoparticles have low dispersibility in binders and solvents. There was a problem that agglomeration occurred.

In particular, the inorganic nanoparticles induce aggregation of organic particles while surrounding the surface of the organic particles. There is a problem in that a lot of irregularities are formed.

In addition, due to such irregularities, the optical properties of the anti-glare layer are rather deteriorated, so that the anti-glare properties that control light scattering/light reflection, etc., are not properly expressed, and the image is distorted in the area, so that the image clarity is lowered or the reflection of light is reduced in the periphery. It is necessary to improve it because it may cause a defect that is amplified and shiny, so-called sparkling.

An object of the present invention is to provide an optical laminate that implements a high contrast ratio and excellent image sharpness and has mechanical properties such as high wear resistance and scratch resistance.

Another object of the present invention is to provide a polarizing plate that implements a high contrast ratio and excellent image sharpness, and has mechanical properties such as high wear resistance and scratch resistance.

Another object of the present invention is to provide a liquid crystal panel and a display device including the optical laminate, respectively.

In the present specification, a polymer substrate comprising a polymer resin and rubber particles having a cross-sectional diameter of 10 to 500 nm dispersed in the polymer resin; and an anti-glare layer comprising a binder resin and organic or inorganic fine particles dispersed on the binder resin, wherein fine protrusions with a diameter of 100 μm or more formed by aggregation of the organic or inorganic fine particles are on the outer surface of the anti-glare layer An optical laminate can be provided in which the ratio present in is 50 pieces/m 2 or less.

In addition, in the present specification, a polarizing plate including the optical laminate is provided.

Also, in the present specification, a display device including the polarizing plate is provided.

Hereinafter, an optical laminate, a polarizing plate, and a display device according to specific embodiments of the present invention will be described in more detail.

In this specification, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

In addition, (meth)acryl [(meth)acryl] is meant to include both acryl (acryl) and methacryl (methacryl).

In addition, the hollow-structured inorganic nanoparticles refer to particles in the form of voids present on the surface and/or inside of the inorganic nanoparticles.

In addition, the (co)polymer is meant to include both a copolymer (co-polymer) and a homo-polymer (homo-polymer).

According to one embodiment of the invention, a polymer substrate comprising a polymer resin and rubber particles having a cross-sectional diameter of 10 to 500 nm dispersed in the polymer resin; and an anti-glare layer comprising a binder resin and organic or inorganic fine particles dispersed on the binder resin, wherein fine protrusions with a diameter of 100 μm or more formed by aggregation of the organic or inorganic fine particles are on the outer surface of the anti-glare layer An optical laminate can be provided in which the ratio present in is 50 pieces/m 2 or less.

According to the ratio of the microprotrusions having a diameter of 100 μm or more, which are formed by aggregation of the organic or inorganic particles, on the outer surface of the anti-glare layer, 50 pieces/m 2 or less, or 1 to 30 pieces/m 2, or substantially absent , the optical laminate of the embodiment can implement a high contrast ratio and uniform and good image sharpness while having a relatively low haze value.

The anti-glare layer/or polarizing plate may have a transmittance of 90% or more and a haze of 10% or less or 8% or less under the A light source. (Measuring device HM-150, measurement standard JIS K 7105)

More specifically, when the fine protrusions formed by the aggregation of the organic or inorganic fine particles have a diameter of 100 μm or more, a sparkling (shining) phenomenon that is visually recognized by the naked eye may appear. As the ratio formed on the external surface is relatively low, it is possible to prevent a sparkling (glitter) phenomenon due to the amplification of reflected light, and the image sharpness is uniform, and thus a high-resolution image can be clearly realized.

In general, the higher the haze value, the greater the diffusion of external light, and the anti-glare effect is excellent. On the other hand, the optical laminate of the embodiment may exhibit a high contrast ratio and excellent image sharpness while having a haze value that is not very high including the above-described anti-glare layer.

The diameter of the fine protrusions formed by the aggregation of the organic or inorganic fine particles may be determined by a cross-sectional width in a direction parallel to the surface of the anti-glare layer, and is 100 μm or more, or 100 μm to 300 μm, or 110 μm to 250 μm, or It may be 120 μm to 200 μm.

As described above, the proportion of fine protrusions having a diameter of 100 μm or more formed by aggregation of the organic or inorganic fine particles on the outer surface of the anti-glare layer may be 50 pieces/m2 or less, or 1 to 30 pieces/m2, In addition, the ratio of the area where the fine protrusions are located on one surface of the anti-glare layer defined by the following general formula 1 is 0.5 area % or less, 0.3 area % or less, or 0.01 to 0.5 area %, or 0.02 to 0.2 area %, or 0.05 to 1 area %.

[General formula 1]

Ratio of the area where the micro-protrusions are located on one surface of the anti-glare layer = (the number of micro-protrusions * the area of a circle with a diameter of 5 mm) / Area of one surface of the anti-glare layer (㎟)

The "circle having a diameter of 5 mm" in Formula 1 is defined as an area in which the microprotrusions are located.

The above-described characteristics of the anti-glare layer are based on specifying the content of solids excluding the solvent in the coating composition for forming the anti-glare layer, or the type of organic solvent used in forming the anti-glare layer.

More specifically, the content of the solids excluding the solvent in the coating composition for forming the anti-glare layer may be 25 to 40% by weight or 30 to 35% by weight. As the solid content of the coating composition for forming the anti-glare layer is adjusted in the above-described range, the organic or inorganic fine particles may flow smoothly when the anti-glare layer is formed, and accordingly, the fine protrusions, which are aggregates thereof, are substantially may not be created.

In addition, the coating composition for forming the anti-glare layer may include a specific mixed solvent. The organic solvent may include an organic solvent of alcohol and non-alcohol, and more specifically, the organic solvent may be a mixed solvent including n-butyl acetate and 2-butanol. In addition, the organic solvent may include n-butyl acetate and 2-butanol in a weight ratio of 1:2 to 1:5.

According to the use of the above-described organic solvent, the flow of the organic or inorganic fine particles may be smooth when the anti-glare layer is formed, and accordingly, fine protrusions, which are hyperaggregates thereof, may not be substantially generated.

On the other hand, in the optical laminate, from the interface between the polymer substrate and the anti-glare layer, within 75% of the thickness of the anti-glare layer, within 50% of the thickness, or within 30% of the rubber particles having a cross-sectional diameter of 10 to 500 nm Accordingly, the optical laminate may have low gloss and reflectivity, excellent optical properties such as haze properties and anti-glare properties of an appropriate level, and at the same time have relatively high scratch resistance and durability.

The rubber particles having a cross-sectional diameter of 10 to 500 nm included in the polymer substrate may penetrate into the anti-glare layer and be exposed to the outer surface of the anti-glare layer during the manufacturing process of the optical laminate. was adjusted to be located within 75 or 50% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer, or only within 30% of the thickness.

In this way, the rubber particles are positioned only within 75 or 50% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer, or only within 30% of the thickness, so that the rubber particles are located on the outer surface of the anti-glare layer. It is exposed to the light or located on the upper surface of the anti-glare layer to prevent the deterioration of the scratch resistance of the optical laminate or increase the reflectance or haze characteristics.

More specifically, when the coating composition for forming the anti-glare layer is applied and a temperature exceeding 60° C. is applied during heat treatment or drying, the rubber particles rise from the polymer substrate to the formed anti-glare layer, and the polymer The rubber particles may be positioned from the interface between the substrate and the anti-glare layer to a range exceeding 75% of the thickness of the anti-glare layer.

Accordingly, the coating composition for forming the anti-glare layer may be applied and a temperature of 60° C. or less may be applied during heat treatment or drying.

Meanwhile, as described above, some of the rubber particles included in the polymer substrate may move to the anti-glare layer during the manufacturing process of the optical laminate. Accordingly, the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer The rubber particles having a cross-sectional diameter of 10 to 500 nm and the rubber particles having a cross-sectional diameter of 10 to 500 nm included in the polymer substrate may be rubber particles of the same component.

The rubber particles may be conventionally known natural rubber or synthetic rubber. For example, the rubber particles may include at least one rubber selected from the group consisting of styrene-based rubber, butadiene-based rubber, styrene-butadiene-based rubber, and acrylic rubber.

The styrene-based monomer used for preparing the styrene-based or styrene-butadiene-based rubber may be an unsubstituted styrene monomer or a substituted styrene monomer.

The substituted styrene monomer may be styrene substituted with a substituent including an aliphatic hydrocarbon or a hetero atom in a benzene ring or a vinyl group. For example, styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2-methyl-4-chlorostyrene, 2,4,6- Trimethylstyrene, cis-β-methylstyrene, trans-β-methylstyrene, 4-methyl-α-methylstyrene, 4-fluoro-α-methylstyrene, 4-chloro-α-methylstyrene, 4-bromo-α -Methylstyrene, 4-t-butylstyrene, 2-fluorostyrene, 3-fluorostyrene, 4-fluorostyrene, 2,4-difluorostyrene, 2,3,4,5,6-pentafluorostyrene , 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 2,4-dichlorostyrene, 2,6-dichlorostyrene, octachlorostyrene, 2-bromostyrene, 3-bromostyrene, 4-bromo It may be at least one selected from the group consisting of styrene, 2,4-dibromostyrene, α-bromostyrene, and β-bromostyrene, but is not limited thereto. More preferably, styrene substituted with C1-4 alkyl or halogen may be used.

The butadiene-based monomer used in the preparation of the butadiene-based and styrene-butadiene-based rubber is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1 One or more selected from the group consisting of ,3-pentadiene and chloroprene may be used, and most preferably 1,3-butadiene may be used in view of good copolymerizability.

One or more selected from the group consisting of methacrylic acid esters, acrylic acid esters, unsaturated carboxylic acids, acid anhydrides, and esters containing a hydroxyl group may be used as the acrylate-based monomer used in the preparation of the acrylic rubber. .

Specific examples of the acrylate-based monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and benzyl methacrylate. methacrylic acid esters including; acrylic acid esters including methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl methacrylate, phenyl methacrylate, and benzyl methacrylate; unsaturated carboxylic acids including acrylic acid and methacrylic acid; acid anhydrides including maleic anhydride; esters containing hydroxyl groups including 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and monoglycerol acrylate; or mixtures thereof; Alternatively, a compound that polymerizes the acrylic monomer in the presence of a polyfunctional monomer may be used.

The rubber particles may be formed in a single layer of particles having such rubber elasticity, or may be a multilayer structure having at least one rubber elastic layer. As the acrylic rubber particles having a multilayer structure, the particles having the rubber elasticity as described above are used as the nucleus, and the periphery is covered with a hard alkyl methacrylate-based polymer, and the hard alkyl methacrylate-based polymer is used as the nucleus, , the periphery of which is covered with the acrylic polymer having the same rubber elasticity as above, and the periphery of the hard core is covered with the rubbery acrylic polymer, and the periphery is covered with the hard alkyl methacrylate polymer, etc. can be heard The rubber particles formed in the elastic layer usually have an average diameter in the range of about 10 to 500 nm.

Meanwhile, the polymer substrate may have a thickness of 10 to 150 μm, 20 to 120 μm, or 30 to 100 μm. If the thickness of the polymer substrate is less than 10 μm, it may be difficult to control the process due to poor flexibility. In addition, when the polymer substrate is excessively thick, the transmittance of the polymer substrate may decrease and optical properties may decrease, and it is difficult to thin an image display device including the same.

The anti-glare layer may have a thickness of 1 to 10 μm. If the thickness of the anti-glare layer is too thin, the hardness of the film may be lowered or scratch resistance may be deteriorated, which may be unsuitable for use as the outermost film of the optical laminate. If the thickness of the anti-glare layer is too thick, warpage occurs in the film, and the film may be easily broken due to poor bending properties, and thus it may be difficult to run the film during the roll process.

Meanwhile, the ratio of the thickness of the anti-glare layer to the thickness of the polymer substrate may be 0.008 to 0.8, or 0.01 to 0.5. If the ratio of the thickness of the anti-glare layer to the thickness of the polymer substrate is too small, the anti-glare layer may not sufficiently protect the surface of the substrate, and thus it may be difficult to secure mechanical properties such as pencil hardness. In addition, when the ratio of the thickness of the anti-glare layer to the thickness of the polymer substrate is too large, the flexibility of the laminate is reduced and crack resistance may be insufficient.

The polymer substrate may include 5 to 50 parts by weight of rubber particles having a cross-sectional diameter of 10 to 500 nm based on 100 parts by weight of the binder resin.

If the content of the rubber particles compared to the binder resin in the polymer substrate is too small, shock absorption from an external force cannot be absorbed, so that the film is easily broken or the film is broken when bent below a certain curvature.

If the content of the rubber particles compared to the binder resin in the polymer substrate is too high, the mechanical strength of the film is weakened, so that the film can be easily deformed, and the crosslinking density of the binder resin is lowered, so that solvent erosion during hard coating increases, thereby increasing the hardness and resistance of the film. The scratch property may deteriorate, and the transmittance may be lowered due to the difference in refractive index between the rubber particles and the polymer base component, thereby deteriorating the optical properties.

Although the specific component of the polymer substrate is not particularly limited, the polymer resin is selected from the group consisting of (meth)acrylate resins, cellulose resins, polyolefin resins and polyester resins in order to secure moisture resistance with a predetermined light transmittance. It may include one or more types.

In the optical laminate, the moisture transmission amount of the polymer substrate measured for 24 hours at 40˚C and 100% humidity conditions is 150 g/m2 or less, 100 g/m2 or less, or 75 g/m2 or less, or 5 to 75 g/m 2 .

More specifically, when the water permeability of the polymer substrate was measured for 24 hours at 40˚C and 100% humidity (measuring instrument lab think Company Water Vapor Permeability Tester), the water permeability was 150 g/m 2 or less, 100 g/m m 2 or less, or 75 g/m 2 or less, or 5 to 75 g/m 2 .

Meanwhile, the anti-glare layer may include 1 to 10 parts by weight of the organic fine particles or the inorganic fine particles, respectively, based on 100 parts by weight of the binder resin.

If the content of the organic fine particles or rubber particles compared to the binder resin in the anti-glare layer is too small, scattering/reflection of external light may not be properly controlled, so that the anti-glare properties may be greatly reduced, and the stability of the particles during drying may be sharply decreased. It is difficult to secure optical properties because protrusions with a size of several hundred μm can be generated. In addition, if the content of the rubber particles compared to the binder resin in the polymer substrate is too high, the image clarity of the optical film may be greatly reduced due to the increase in refraction of transmitted image light, and the number of overlapping particles may increase, or fine protrusions may increase, Cloudiness may occur or the black sharpness of the film may deteriorate.

The binder resin included in the anti-glare layer may include a photocurable resin. The photocurable resin refers to a (co)polymer of a photopolymerizable compound capable of causing a polymerization reaction when irradiated with light such as ultraviolet rays.

Specific examples of the photopolymerizable compound include (co)polymers formed from vinyl-based monomers or oligomers or (meth)acrylate monomers or oligomers.

Examples of the photocurable resin include a group of reactive acrylate oligomers consisting of urethane acrylate oligomers, epoxide acrylate oligomers, polyester acrylates and polyether acrylates; and dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, glycerin propoxylate triacrylate, trimethylpropane ethoxylate triacrylate Polymers or copolymers formed from the group consisting of polyfunctional acrylate monomers consisting of , trimethylpropyl triacylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and ethylene glycol diacrylate; or an epoxy group , an epoxy resin containing an epoxy group containing an alicyclic epoxy group, a glycidyl epoxy group, or an oxetane group.

The binder resin may further include a (co)polymer having a weight average molecular weight of 10,000 g/mol or more (hereinafter referred to as a high molecular weight (co)polymer) together with the above-described photocurable resin. The high molecular weight (co)polymer is, for example, at least one polymer selected from the group consisting of a cellulose-based polymer, an acrylic polymer, a styrene-based polymer, an epoxide-based polymer, a nylon-based polymer, a urethane-based polymer, and a polyolefin-based polymer. may include

The organic or inorganic fine particles are not specifically limited in particle size.

The organic particles included in the anti-glare layer may be on a micron (㎛) scale, and the inorganic particles included in the anti-glare layer may be on a nano (nm) scale. As used herein, the micron (μm) scale refers to having a particle size or particle size of less than 1 mm, that is, less than 1000 μm, and the nano (nm) scale is less than 1 μm, that is, less than 1000 nm. It refers to having a particle size or particle size, and the term sub-micron scale refers to having a particle size or particle size of micron scale or nano scale.

More specifically, the organic fine particles may have a cross-sectional diameter of 1 to 50 μm, or 1 to 10 μm. In addition, the inorganic fine particles may have a cross-sectional diameter of 1 nm to 500 nm, or 1 nm to 300 nm.

Specific examples of the organic or inorganic fine particles included in the hard coating layer are not limited, but for example, the organic or inorganic fine particles are organic fine particles made of an acrylic resin, a styrene-based resin, an epoxide resin, and a nylon resin, or silicon oxide, titanium dioxide , indium oxide, tin oxide, zirconium oxide, and may be an inorganic fine particle consisting of zinc oxide.

Meanwhile, the optical laminate of the embodiment may further include a low-refractive layer formed on one surface of the anti-glare layer and having a refractive index of 1.20 to 1.60 in a wavelength region of 380 nm to 780 nm.

The low refractive index layer having a refractive index of 1.20 to 1.60 in the 380 nm to 780 nm wavelength region may include a binder resin and organic fine particles or organic fine particles dispersed in the binder resin, and optionally a fluorine-containing compound having a photoreactive functional group and / Alternatively, a silicon-based compound having a photoreactive functional group may be further included.

The binder resin includes a (co)polymer including a polyfunctional (meth)acrylate-based repeating unit, and this repeating unit is, for example, trimethylolpropane triacrylate (TMPTA), trimethylolpropaneethoxytri From polyfunctional (meth)acrylate-based compounds such as acrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA), or dipentaerythritol hexaacrylate (DPHA) may be derived from

The photoreactive functional group included in the fluorine-containing compound or silicone-based compound may include at least one functional group selected from the group consisting of a (meth) acrylate group, an epoxide group, a vinyl group (Vinyl) and a thiol group (Thiol). .

The fluorine-containing compound including the photoreactive functional group may include i) an aliphatic compound or an aliphatic ring compound in which one or more photoreactive functional groups are substituted and at least one carbon is substituted with one or more fluorine; ii) a heteroaliphatic compound or a heteroaliphatic ring compound substituted with one or more photoreactive functional groups, wherein at least one hydrogen is substituted with fluorine and one or more carbons are substituted with silicon; iii) a polydialkylsiloxane-based polymer in which at least one photoreactive functional group is substituted and at least one fluorine is substituted in at least one silicone; And iv) a polyether compound substituted with one or more photoreactive functional groups and at least one hydrogen is substituted with fluorine; may be one or more compounds selected from the group consisting of.

The low refractive layer may include hollow inorganic nanoparticles, solid inorganic nanoparticles, and/or porous inorganic nanoparticles.

The hollow inorganic nanoparticles have a maximum diameter of less than 200 nm and refer to particles in a form in which empty spaces exist on the surface and/or inside. The hollow inorganic nanoparticles may include one or more selected from the group consisting of inorganic fine particles having a number average particle diameter of 1 to 200 nm, or 10 to 100 nm. In addition, the hollow inorganic nanoparticles may have a density of 1.50 g/cm 3 to 3.50 g/cm 3 .

The hollow inorganic nanoparticles may contain at least one reactive functional group selected from the group consisting of a (meth)acrylate group, an epoxide group, a vinyl group (Vinyl) and a thiol group (Thiol) on the surface. By containing the above-described reactive functional group on the surface of the hollow inorganic nanoparticles, a higher degree of crosslinking may be obtained.

The solid inorganic nanoparticles may include one or more selected from the group consisting of solid inorganic fine particles having a number average particle diameter of 0.5 to 100 nm.

The porous inorganic nanoparticles may include at least one selected from the group consisting of inorganic fine particles having a number average particle diameter of 0.5 to 100 nm.

The low reflective layer is 10 to 400 parts by weight of the inorganic nanoparticles relative to 100 parts by weight of the (co)polymer; and 20 to 300 parts by weight of a fluorine-containing compound and/or a silicone-based compound including the photoreactive functional group.

Meanwhile, according to another embodiment of the present invention, a polarizing plate including the optical laminate may be provided.

The polarizing plate may include the optical laminate as a polarizer protective film. Accordingly, the polarizer may include a polarizer, the optical laminate formed on one surface of the polarizer, and a second polarizer protective film formed on the other surface of the polarizer to face the optical laminate.

The second polarizer protective film may be a polymer substrate included in the optical laminate, an ester resin film such as PET, a cellulose-based film such as TAC, an acrylic film, a COP film, or the like.

The polarizing plate of the above embodiment includes a polarizer. The polarizer may be a polarizer well known in the art, for example, a film made of polyvinyl alcohol (PVA) containing iodine or a dichroic dye. In this case, the polarizer may be manufactured by dyeing the polyvinyl alcohol film with iodine or a dichroic dye and stretching it, but the manufacturing method thereof is not particularly limited.

On the other hand, when the polarizer is a polyvinyl alcohol film, the polyvinyl alcohol film can be used without any particular limitation as long as it contains a polyvinyl alcohol resin or a derivative thereof. In this case, the derivative of the polyvinyl alcohol resin includes, but is not limited to, polyvinyl formal resin, polyvinyl acetal resin, and the like. Alternatively, as the polyvinyl alcohol film, commercially available polyvinyl alcohol films generally used for manufacturing polarizers in the art, for example, P30, PE30, PE60 by Kuraray, M3000, M6000, etc. by Japan Synthetic Company can be used. have.

Meanwhile, the polyvinyl alcohol film may have, but is not limited to, a polymerization degree of 1000 to 10000 or 1500 to 5000. When the polymerization degree satisfies the above range, molecular movement is free, and it can be flexibly mixed with iodine or a dichroic dye. In addition, the thickness of the polarizer may be 40 µm or less, 30 µm or less, 20 µm or less, 1 to 20 µm, or 1 µm to 10 µm. In this case, the thickness reduction of devices, such as a polarizing plate and an image display apparatus containing the said polarizer, is possible.

The polarizing plate may further include an adhesive layer positioned between the polarizer and the polymer substrate of the optical laminate and having a thickness of 0.1 μm to 5 μm.

As the adhesive for the adhesive layer, various adhesives for polarizing plates used in the art, for example, polyvinyl alcohol-based adhesives, polyurethane-based adhesives, acrylic adhesives, cationic or radical-based adhesives, etc. may be used without limitation.

According to another embodiment of the present invention, a display device including the above-described optical laminate or polarizing plate may be provided.

A specific example of the display device is not limited, and may be, for example, a liquid crystal display device, a plasma display device, or an organic light emitting diode device.

As an example, the display device may include a pair of polarizing plates facing each other; a thin film transistor, a color filter and a liquid crystal cell sequentially stacked between the pair of polarizing plates; And it may be a liquid crystal display device including a backlight unit.

In the display device, the optical laminate or the polarizing plate may be provided on the outermost surface of the viewer side or the backlight side of the display panel.

In another example, the display device may include a display panel; and the polarizing plate positioned on at least one surface of the display panel.

The display device may be a liquid crystal display device including a liquid crystal panel and a light laminate provided on both surfaces of the liquid crystal panel, wherein at least one of the polarizing plates includes the polarizer according to the exemplary embodiment of the present specification. It may be a polarizing plate that

In this case, the type of liquid crystal panel included in the liquid crystal display device is not particularly limited, but for example, a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectic (F) type, or a polymer dispersed (PD) type. such as passive matrix panel; an active matrix type panel such as a two terminal type or a three terminal type; All known panels such as an In Plane Switching (IPS) panel and a Vertical Alignment (VA) panel may be applied.

According to the present invention, an optical laminate that implements high contrast ratio and excellent image sharpness and has mechanical properties such as high abrasion resistance and scratch resistance, a polarizing plate including the optical laminate, and a liquid crystal panel and display including the polarizing plate A device may be provided.

1 is a photograph taken with a laser microscope (Optical Profiler) of microprotrusions of 100 μm or more identified in the optical laminate of Example 1. FIG.
2 shows a cross-sectional TEM photograph of the optical laminate of Example 1.
3 shows a cross-sectional TEM photograph of the optical laminate of Comparative Example 2.

The invention is described in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

[Examples 1 to 3 and Comparative Examples 1 to 3: Preparation of optical laminates]

(1) Preparation of a coating composition for forming an anti-glare layer

A coating composition for forming an anti-glare layer was prepared by mixing the components shown in Table 1 below.

(2) Manufacture of an optical laminate

Each of the prepared coating solution for forming an anti-glare layer on the polymer substrate shown in Table 1 was coated with #12 mayer bar, dried at a temperature of 40° C. for 2 minutes, and UV cured to an anti-glare layer (coating thickness of 4 μm) has formed For UV curing, an H bulb was used for the UV lamp, and the curing reaction was carried out under a nitrogen atmosphere, and the amount of UV light irradiated during curing was 150 mJ/cm2.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 polymer substrate Acrylic film (WOLF, provided by Sumitomo, thickness: 60 μm, including acrylic rubber particles having an average particle diameter of 300 nm) anti-glare layer
coating
composition TMPTA 9.85 7.88 8.77 10.7 8.76 6.93 PETA 6.11 7.88 7.18 4.67 6.81 8.92 UA-306T 6.11 5.32 6.98 4.67 5.26 5.35 G8161 6.9 7.88 5.98 8.76 7.79 7.93 D1173 0.89 0.83 0.83 0.83 0.83 0.89 I184 0.89 0.83 0.83 0.83 0.83 0.89 Tego270 0.04 0.04 0.06 0.04 0.05 0.05 BYK350 0.07 0.07 0.07 0.07 0.07 0.07 organic particulates
XX-103BQ 0.97 1.16 1.32 1.15 1.31 1.53 Inorganic fine particles MA-ST 0.18 0.18 0.18 0.2 0.16 0.21 EtOH 41.84 9.73 0 n-BA 12.81 12.8 13.12 29.2 10.76 2-BuOH 55.18 55.13 54.68 26.24 29.2 56.47 coating thickness
(μm) 4 4 4 4 4 4

TMPTA: Trimethyloylpropyltriacrylate

PETA: pentaerythritol triacrylate

UA-306T: Reaction product of toluene diisocyanate and pentaerythritol triacrylate as urethane acrylate (Kyoeisha product)

G8161: Photocurable acrylate polymer (Mw ~ 200,000, manufactured by San nopco)

IRG-184: Initiator (Irgacure 184, Ciba)

Tego-270: Tego leveling agent

BYK350: BYK company leveling agent

IPA isopropyl alcohol

XX-103BQ (2.0㎛ 1.515): Polystyrene and polymethyl methacrylate copolymer particles (Sekisui Plastics)

XX-113BQ (2.0㎛ 1.555): Copolymer particles of polystyrene and polymethyl methacrylate (Sekisui Plastic)

MA-ST (30% in MeOH): A dispersion in which nano-silica particles with a size of 10 to 15 nm are dispersed in methyl alcohol (product of Nissan Chemical)

EtOH: ethanol

n-BA: n-butyl acetate

2-BuOH: 2-butanol

[Experimental Example: Measurement of physical properties of optical laminates]

1. Haze evaluation of optical laminates

Prepare a 4 cm x 4 cm specimen from the optical laminate obtained in each of the Examples and Comparative Examples, measure it three times with a haze meter (HM-150, light source A, Murakami Corporation) to calculate the average value, and calculate this as the total haze value did. In the measurement, light transmittance and haze were measured simultaneously, light transmittance was measured according to JIS K 7361 standard, and haze was measured according to JIS K 7136 standard.

2. Measurement of image sharpness (%)

For the optical laminates obtained in each of Examples and Comparative Examples, image sharpness was measured using ICM-1T manufactured by Sugar Test Instrument Co., Ltd. Image sharpness is measured at slit widths of 0.125mm, 0.5mm, 1mm, and 2mm and expressed as a total.

3. Confirmation of the proportion of fine particles agglomerated on the surface of the anti-glare layer

A sample cut to 50 cm * 50 cm (width * length) from the optical laminate obtained in each of the above Examples and Comparative Examples was placed on black matte paper under LED illumination of 700 lux. Then, after placing the film so that light is incident at 70 degrees based on the sample film surface, the light was observed from the reflected side to find fine protrusions with stronger brilliance than the surrounding area.

The parts identified as fine protrusions were marked with a circle with a diameter of 5 mm, and the number of protrusions and the protrusion area ratio were calculated according to the following equation. At this time, the number of protrusions is calculated by the following general formula 2, and the area ratio in which fine protrusions having a diameter of 100 μm or more among the aggregates of the organic or inorganic fine particles are formed on the outer surface of the anti-glare layer is defined by the following general formula 1. .

[General formula 1]

Ratio of the area where the micro-protrusions are located on one surface of the anti-glare layer = (the number of micro-protrusions * the area of a circle with a diameter of 5 mm) / Area of one surface of the anti-glare layer (㎟)

The "circle having a diameter of 5 mm" in Formula 1 is defined as an area in which the microprotrusions are located.

[General formula 2]

Number of projections (pieces/㎡): Number measured at 50cm*50cm*4

4. Section measurement

The sample was cut to a width of 0.5 cm to take a cross-section, and a cross-section sample was prepared using a micro tomming technique. After coating the surface and cross section to be observed with platinum (Pt), the thickness of the coating layer, the thickness of the erosion layer, and the position of the rubber particles were observed by SEM. When the erosion layer was not easily seen, the surface of the cross-section sample was etched with a microwave, coated with platinum, and then observed to confirm the thickness of the erosion layer.

5. Scratch resistance measurement

Reflection obtained in Examples and Comparative Examples by applying a load to the steel wool (#0000) using a scratch-resistance measuring device (KPD-301, Gibai ENT) and reciprocating 10 times at a speed of 27rpm in a section of 2.5cm in width and 13cm in length The surface of the preventive film was rubbed. The maximum load at which one scratch of 1 cm or less observed with the naked eye was observed was measured.

Results of Experimental Examples Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Haze (%) 2.1 2.1 2 2.0 2.1 2.3 image sharpness 368 360 343 300 or less 300 or less 300 or less prominence
(ea/m2) 3 16 38 about 1000 about 300 about 100 Protrusion area ratio (%) <0.1 <0.1 <0.1 ~2% 0.5% 0.2% Maximum thickness of the anti-glare layer where rubber particles are observed <25% <25% <50% <25% <90% <50% scratch resistance 700gf 700gf 500gf 500gf 500gf NG 500gf NG

As shown in Table 2, in the optical laminates of the examples, the ratio of the microprotrusions present on the outer surface of the anti-glare layer is 50 pieces/m 2 or less, and the level at which anti-glare properties can be implemented while having high scratch resistance of haze and high image clarity were confirmed. In contrast, it was confirmed that the optical laminates of Comparative Examples had a ratio of microprotrusions present on the outer surface of the anti-glare layer of 100 pieces/m 2 or more, and exhibited a low level of scratch resistance or relatively low image sharpness.

And, as shown in FIG. 2, in the optical laminate of Example 2, rubber particles having a cross-sectional diameter of 10 to 500 nm exist within 25% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer. Confirmed. In contrast, in the optical laminate of Comparative Example 2, as shown in FIG. 3, from the interface between the polymer substrate and the anti-glare layer to 90% of the thickness of the anti-glare layer, rubber particles having a cross-sectional diameter of 10 to 500 nm was confirmed to exist.

1 Polymer substrate
2 anti-glare layer
3 rubber particles
4 Interface between polymer substrate and anti-glare layer
5 Surface of the anti-glare layer
6 The maximum range in which rubber particles exist from the interface between the polymer substrate and the anti-glare layer

Claims (17)

A polymer substrate comprising a polymer resin and rubber particles having a cross-sectional diameter of 10 to 500 nm dispersed in the polymer resin; and
and an anti-glare layer comprising a binder resin and organic particles and inorganic particles dispersed on the binder resin;
The organic fine particles included in the anti-glare layer have a cross-sectional diameter of 1 to 50 μm,
The inorganic fine particles included in the anti-glare layer have a cross-sectional diameter of 1 nm to 500 nm,
The organic fine particles and the inorganic fine particles are formed by aggregation and the ratio of fine protrusions having a diameter of 100 μm to 300 μm present on the outer surface of the anti-glare layer is 50 pieces/m 2 or less,
The ratio of the area where the fine protrusions are located on one surface of the anti-glare layer defined by the following general formula 1 is 0.5 area% or less,
Rubber particles having a cross-sectional diameter of 10 to 500 nm are present within 75% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer,
Haze according to the measurement standard JIS K 7105 is 8% or less,
Optical Laminate:
[General formula 1]
Ratio of the area where the micro-protrusions are located on one surface of the anti-glare layer = (the number of micro-protrusions * the area of a circle with a diameter of 5 mm) / Area of one surface of the anti-glare layer (㎟)
The “circle having a diameter of 5 mm” in Formula 1 is defined as an area in which the microprotrusions are located.
delete delete delete According to claim 1,
The polymer resin comprises at least one selected from the group consisting of (meth)acrylate resins, cellulose resins, polyolefin resins, and polyester resins, an optical laminate.
According to claim 1,
Rubber particles having a cross-sectional diameter of 10 to 500 nm present within 75% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer;
The rubber particles having a cross-sectional diameter of 10 to 500 nm contained in the polymer substrate are rubber particles of the same component, the optical laminate.
According to claim 1,
The rubber particles include at least one rubber selected from the group consisting of styrene-based rubber, butadiene-based rubber, styrene-butadiene-based rubber, and acrylic rubber.
According to claim 1,
The polymer substrate has a thickness of 10 to 150㎛,
The anti-glare layer has a thickness of 1 to 10 μm, an optical laminate.
9. The method of claim 1 or 8,
The ratio of the thickness of the anti-glare layer to the thickness of the polymer substrate is 0.008 to 0.8, the optical laminate.
According to claim 1,
The polymer substrate is an optical laminate comprising 5 to 50 parts by weight of rubber particles having a cross-sectional diameter of 10 to 500 nm based on 100 parts by weight of the polymer resin.
According to claim 1,
The anti-glare layer comprises 1 to 10 parts by weight of each of the organic fine particles or the inorganic fine particles relative to 100 parts by weight of the binder resin, the optical laminate.
According to claim 1,
The binder resin included in the anti-glare layer is an optical laminate comprising a (co)polymer formed from a vinyl-based monomer or oligomer or (meth)acrylate monomer or oligomer.
delete According to claim 1,
An optical laminate having a moisture transmission amount of 150 g/m 2 or less of the polymer substrate measured for 24 hours at 40˚C and 100% humidity.
A polarizing plate comprising the optical laminate of claim 1 .
16. The method of claim 15,
A polarizing plate comprising the optical laminate as a polarizer protective film.
A display device comprising the polarizing plate of claim 15 .

Images