KR20200056769A - Optical laminate, polarizing plate, and display apparatus - Google Patents

Abstract

The present invention relates to an optical laminate including a polymer substrate and an anti-glare layer and having a rubber particle having a cross-sectional diameter of 10 to 500 nm existing within 50% of the thickness of the anti-glare layer from an interface of the polymer substrate and the anti-glare layer, to a polarizing plate including the optical laminate, and to a liquid crystal panel and a display device including the polarizing plate.

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.

The liquid crystal display has various advantages such as power saving, light weight, and thinness, and is used at the highest rate among various display devices. In such a liquid crystal display device, a polarizer is arranged on the image display surface side of the liquid crystal cell. Therefore, in order to prevent the polarizer from being damaged when handling / using the liquid crystal display device, it is generally known to apply a polarizer protective film including a hard coating layer having a hardness of a certain level or more on the polarizer.

The optical film for polarizer protection is generally in the form of a hard coating layer formed on a light-transmitting base film, and as the light-transmitting base film, a cellulose ester-based film represented by triacetyl cellulose (TAC) is most widely used. Such a cellulose ester-based film has advantages such as excellent transparency and optical isotropy, exhibiting little retardation in the surface, not generating interference fringes, and having little adverse effect on the display quality of the display device.

However, the cellulose ester-based film is not only a material having disadvantages in terms of cost, but also has a disadvantage of high moisture permeability and poor water resistance. Due to such high moisture permeability / inferior water resistance, a considerable amount of water permeation continuously occurs during use, and thus a floating phenomenon may occur from the polarizer, which may cause light leakage.

Accordingly, development of a base film of a polarizer protective optical film capable of securing a higher water resistance to prevent light leakage and having better mechanical properties has been made.

The present invention is to provide an optical laminate having high contrast ratio and excellent image clarity and having mechanical properties such as high wear resistance and scratch resistance.

In addition, the present invention is to provide a polarizing plate that realizes high contrast ratio and excellent image clarity and has mechanical properties such as high wear resistance and scratch resistance.

In addition, the present invention is to provide a liquid crystal panel and a display device each including the optical laminate.

In the present specification, a polymer substrate including 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 fine particles or inorganic fine particles dispersed on the binder, a cross section of 10 to 500 nm within 50% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer. An optical laminate in which rubber particles having a diameter are present can be provided.

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

In addition, in this 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 the present specification, terms such as first and second are used to describe various components, and the terms are used only to distinguish one component from another component.

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

In addition, the inorganic nanoparticles having a hollow structure mean particles having an empty space on the surface and / or inside of the inorganic nanoparticles.

In addition, (co) polymer is meant to include both a copolymer (co-polymer) and a homopolymer (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 fine particles or inorganic fine particles dispersed on the binder, a cross section of 10 to 500 nm within 50% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer. An optical laminate can be provided, in which rubber particles having a diameter are present.

In the optical laminate, there are rubber particles having a cross-sectional diameter of 10 to 500 nm within 50% of the thickness of the anti-glare layer, or within 30% of the thickness, or within 10% from the interface between the polymer substrate and the anti-glare layer. , Accordingly, the optical laminate may exhibit excellent optical and anti-glare properties, such as low gloss and reflectivity, and an appropriate level of haze property, while also having relatively high scratch resistance and durability.

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 in the manufacturing process of the optical layered body. Was adjusted to be located within the range of 50% of the thickness of the anti-glare layer, or within 30% of the thickness, or within 10% of the thickness from the interface between the polymer substrate and the anti-glare layer.

In this way, the rubber particles are located only within a range of 50% of the thickness of the anti-glare layer, or within 30% of the thickness, or within 10% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer. It was exposed to the outer surface or located on the top surface of the anti-glare layer to reduce the scratch resistance of the optical laminate, thereby increasing the reflectance and preventing appearance unevenness.

More specifically, when applying a coating composition for forming the anti-glare layer and applying a temperature exceeding 60 ° C. 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 located from the interface between the substrate and the anti-glare layer to a range exceeding 50% of the thickness of the anti-glare layer.

Accordingly, a coating composition for forming the anti-glare layer may be applied and a temperature of 70 ° C. or less may be applied when heat treatment or drying.

On the other hand, the characteristics of the anti-glare layer may be according to 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 when forming the anti-glare layer.

More specifically, the content of 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.

In addition, the coating composition for forming the anti-glare layer may include a specific organic solvent. The organic solvent may be one or two or more alcohols, or a mixed solvent including an alcohol and a non-alcohol organic solvent. More specifically, the organic solvent is an organic solvent containing ethanol and 2-butanol in a weight ratio of 0.5: 1 to 2: 1, or n-butyl acetate and 2-butanol in a weight ratio of 1: 2 to 1: 5. It may be an organic solvent.

In general, the higher the haze value, the greater the degree of diffusion of external light, the better the anti-glare effect, while the contrast ratio is lowered due to distortion of the image due to scattering of the surface and whitening due to internal scattering. On the other hand, the optical layered body of the embodiment may exhibit a high contrast ratio and excellent image clarity while having a haze value that is not very high, including the above-described anti-glare layer.

The anti-glare layer or optical layered body may have a total haze of 0.1% or more and 10% or less measured using a haze meter (HM-150, A light source, manufactured by Murakami Co.) according to JIS K7105 standard. The total haze is the sum of the outer haze and the inner haze.

The entire haze can be obtained by measuring haze with respect to the optical laminate itself, and the inner haze is formed by attaching a zero-tack adhesive to the surface to form a flattening layer, or by coating a flattening layer on an alkali-treated surface. It can be measured, and the external haze value can be defined as the total haze and internal haze values are defined.

The outer haze of the anti-glare layer or the optical laminate may be 0.2% or more and 9% or less. When the outer haze of the anti-glare layer or the optical laminate is too low, it may not exhibit a sufficient anti-glare function. In addition, when the outer haze of the anti-glare layer or the optical laminate is too high, the transmission image is not clear, and the light transmittance is lowered, which is unsuitable for the use of a protective film provided on a display.

In addition, the anti-glare layer or the polarizing plate may have a phase sharpness of 200 or more and 450 or less measured by using ICM-1T manufactured by Sugar Test Instrument Co., Ltd. The image clarity is measured in slit widths of 0.125 mm, 0.5 mm, 1 mm, and 2 mm and displayed as a total. The anti-glare layer / or polarizing plate may simultaneously exhibit excellent anti-glare function and image clarity.

On the other hand, as described above, in the process of manufacturing the optical laminate, a part of the rubber particles contained in the polymer substrate may move to the anti-glare layer, and accordingly, the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer Rubber particles having a cross-sectional diameter of 10 to 500 nm and rubber particles having a cross-sectional diameter of 10 to 500 nm included in the polymer substrate may be rubber particles having the same component.

The rubber particles may be conventionally known natural rubber or synthetic rubber. For example, the specific type of the rubber particles is not particularly limited, but may include one or more rubbers selected from the group consisting of styrene-butadiene rubber and acrylic rubber.

The styrene-based monomer used in the production of the 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 containing an aliphatic hydrocarbon or a hetero atom in a benzene ring or 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-fluor-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 one or more 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 can be used.

The butadiene-based monomer is one selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and chloroprene. The above can be used, and most preferably, 1,3-butadiene can be used from the viewpoint of good copolymerization.

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; 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 hydroxy groups including 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and monoglycerol acrylate; Or mixtures of these can be used.

The acrylonitrile-based monomer may use one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile. Among these, acrylonitrile and methacrylonitrile are preferable, and acrylonitrile is most preferred from the viewpoint of good polymerizability and easy availability of raw materials.

The rubber particles may be formed of a single layer of particles having rubber elasticity, or may be a multilayer structure having at least one layer of a rubber elastic layer. As the acrylic rubber particles having a multi-layer structure, the particles having the rubber elasticity as described above are used as nuclei, and their surroundings are covered with a rigid alkyl methacrylate polymer, and the rigid alkyl methacrylate polymer is used as a nucleus. , Covering the periphery with an acrylic polymer having rubber elasticity as described above, covering the periphery of the hard core with a rubber elastic acrylic polymer, and covering the periphery with a hard alkyl methacrylate polymer. Can be lifted. The rubber particles formed in the elastic layer usually have an average diameter of about 10 to 500 nm.

On the other hand, the polymer substrate may have a thickness of 10 to 150㎛, 20 to 120㎛, or 30 to 100㎛. If the thickness of the polymer substrate is less than 10㎛, 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 substrate of the polymer substrate may decrease, thereby deteriorating optical properties, and there is a problem that it is difficult to thin an image display device including the same.

The anti-glare layer may have a thickness of 1 to 10 ㎛. If the thickness of the anti-glare layer is too thin, organic particles or inorganic particles may be aggregated, and there may be peaks irregularly distributed while having a high height on the surface of the anti-glare layer. If the thickness of the hard coating layer is 10 μm or more, the coating layer is thick and coated. There is a disadvantage that cracks are likely to occur when handling the film. By adjusting the thickness of the anti-glare layer in the above-described range, it is possible to implement haze and image clarity in a specific range, thereby increasing the sharpness of the image while maintaining the anti-glare function.

Meanwhile, a 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, if 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 may be reduced, resulting in insufficient crack resistance.

The polymer substrate may include 5 to 50 parts by weight of rubber particles having a cross-sectional diameter of 10 to 500 nm relative to 100 parts by weight of the binder resin. When the content of the rubber particles is too small compared to the binder resin in the polymer substrate, there is a disadvantage in that the mechanical strength of the film is insufficient and cracks are likely to occur when the film is handled. If the content of the rubber particles is too high compared to the binder resin in the polymer substrate, there is a problem in that agglomeration between particles occurs and the transmittance decreases.

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

In the optical laminate, the moisture permeation amount of the polymer substrate measured for 24 hours at 40 ° C and 100% humidity may be 150 g / m 2, or 75 g / m 2 or less, or 5 to 75 g / m 2.

Meanwhile, the anti-glare layer may include 2 to 10 parts by weight of organic fine particles relative to 100 parts by weight of the binder resin, and the inorganic fine particles relative to 100 parts by weight of the organic fine particles may include 0 to 20 parts by weight.

If the content of the organic fine particles in the anti-glare layer is too small compared to the binder, scattering / reflection of external light may not be properly controlled, and thus the anti-glare property may be greatly deteriorated, and the thickness of the anti-glare layer is 1 μm or less to obtain appropriate haze. When adjusted to, mechanical properties of the film may deteriorate, which is technically disadvantageous. If the content of the organic fine particles is too high compared to the binder resin in the anti-glare layer, unevenness due to partial agglomeration of the organic fine particles may occur, which is disadvantageous.

If the content of the inorganic fine particles compared to the organic fine particles is too large, inducing overaggregation of the organic fine particles may result in an excessively low image clarity and deterioration of the clarity of the transmitted image.

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

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 oligomer, epoxide acrylate oligomer, polyester acrylate and polyether acrylate; And dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, glycerin propoxylate triacrylate, trimethylpropane ethoxylate triacrylate , Polymethyl acrylate triacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and ethylene glycol diacrylate group consisting of polyfunctional acrylate monomers; polymers or copolymers formed from; or epoxy groups , An epoxy resin including an alicyclic epoxy group, a glycidyl group epoxy group, or an epoxy group containing an oxetane group.

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

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

The organic fine particles included in the anti-glare layer may be micron (µm) scale, and the inorganic fine particles included in the anti-glare layer may be nano (nm) scale. In the present specification, 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. Refers to having a particle size or particle size, and a sub-micron (sub-µm) scale refers to having a particle size or particle size of a micron scale or a nano scale.

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

The specific examples of the organic or inorganic fine particles contained in the hard coating layer are not limited. For example, the organic or inorganic fine particles are organic fine particles made of acrylic resin, styrene resin, epoxide resin, and nylon resin, or silicon oxide and titanium dioxide. , Inorganic fine particles consisting of indium oxide, tin oxide, zirconium oxide, and zinc oxide.

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

The low refractive index layer having a refractive index of 1.20 to 1.60 in the wavelength region of 380 nm to 780 nm 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 / or Or it may further include a silicon-based compound having a photoreactive functional group.

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

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

The fluorine-containing compound containing the photoreactive functional group is i) at least one photoreactive functional group is substituted, and at least one carbon is substituted with at least one fluorine aliphatic compound or aliphatic ring compound; ii) a heteroaliphatic compound or heteroaliphatic ring compound substituted with one or more photoreactive functional groups, at least one hydrogen substituted with fluorine, and one or more carbons substituted with silicon; iii) a polydialkylsiloxane-based polymer in which one or more photoreactive functional groups are substituted and one or more 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 substituted with fluorine; and 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 mean particles having a maximum diameter of less than 200 nm and having an empty space 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 one or more reactive functional groups selected from the group consisting of (meth) acrylate groups, epoxide groups, vinyl groups (Vinyl) and thiol groups (Thiol) on the surface. As the above-mentioned reactive functional groups are contained on the surface of the hollow inorganic nanoparticle, a higher degree of crosslinking can 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 one or more selected from the group consisting of inorganic fine particles having a number average particle diameter of 0.5 to 100 nm.

The low reflection layer is 10 to 400 parts by weight of the inorganic nanoparticles compared to 100 parts by weight of the (co) polymer; And 20 to 300 parts by weight of a fluorine-containing compound and / or a silicon-based compound containing 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 polarizing plate may include a polarizer and a second polarizer protective film formed on the other surface of the polarizer so as to face the optical laminate and the optical laminate formed on one surface of the polarizer.

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

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 dichroic dye. At this time, the polarizer may be prepared by dyeing and stretching an iodine or dichroic dye on a polyvinyl alcohol film, 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 particular limitation as long as it includes a polyvinyl alcohol resin or a derivative thereof. At this time, the derivative of the polyvinyl alcohol resin is not limited thereto, and examples thereof include polyvinyl formal resin, polyvinyl acetal resin, and the like. Alternatively, the polyvinyl alcohol film may be a commercially available polyvinyl alcohol film commonly used in the manufacture of polarizers in the art, for example, P30, PE30, PE60 from Gurayre, M3000, M6000 from Japan Synthetic, etc. have.

Meanwhile, the polyvinyl alcohol film is not limited thereto, and may have a polymerization degree of 1000 to 10000 or 1500 to 5000. When the degree of polymerization satisfies the above range, the molecular movement is free and can be flexibly mixed with iodine or 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, it is possible to reduce the thickness of a device such as a polarizing plate or an image display device including the polarizer.

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 layer, various adhesives for polarizing plates used in the art, for example, polyvinyl alcohol-based adhesives, polyurethane-based adhesives, acrylic-based adhesives, cationic or radical-based adhesives, etc. may be used as the adhesive.

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

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

As one example, the display device includes 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 polarizers; And it may be a liquid crystal display device including a backlight unit.

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

Further, as 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 wide laminate on both sides of the liquid crystal panel, wherein at least one of the polarizers includes a polarizer according to one embodiment of the present specification described above. It may be a polarizing plate.

At this time, the type of the liquid crystal panel included in the liquid crystal display is not particularly limited, for example, TN (twisted nematic) type, STN (super twisted nematic) type, F (ferroelectic) type or PD (polymer dispersed) type A passive matrix panel; An active matrix type panel such as a two-terminal type or a three-terminal type; All well-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 having high contrast ratio and excellent image clarity and having mechanical properties such as high wear resistance and scratch resistance, a polarizing plate comprising the optical laminate, and a liquid crystal panel and display comprising the polarizing plate The device can be provided.

1 is a cross-sectional TEM photograph of the optical laminate of Example 1.
Figure 2 shows a cross-sectional TEM photograph of the optical laminate of Example 2.
Figure 3 shows a cross-sectional TEM photograph of the optical laminate of Comparative Example 1.
Figure 4 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 are only illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

[Production Examples 1 and 2: Preparation of coating composition for forming anti-glare layer]

Preparation Example 1

25% by weight of pentaerythritol tri (tetra) acrylate, UA-306T (reactant of toluene diisocyanate and pentaerythritol triacrylate as urethane acrylate, Kyoeisha) 22.4% by weight, Irgacure184 2.5% by weight as photopolymerization initiator, ethanol 24.5 Weight%, 2-butanol 24.5% by weight, XX-113BQ (average diameter: 2.0 μm, refractive index: 1.555, copolymerized particles of polystyrene and polymethylmethacrylate, manufactured by Sekisui Plastic) 1% by weight, MA-ST (15 nm in diameter) Silica particles, Nissan chemical products) 0.1%?% Was mixed to prepare a coating composition for forming an anti-glare layer.

Preparation Example 2

25% by weight of pentaerythritol tri (tetra) acrylate, 22.4% by weight of 2-hydroxy ethyl acrylate, 2.5% by weight of Irgacure184 as a photopolymerization initiator, 24.5% by weight of methyl ethyl ketone, 24.5% by weight of 2-butanol , XX-113BQ (average diameter: 2.0㎛, refractive index: 1.555, copolymerized particles of polystyrene and polymethylmethacrylate, Sekisui Plastic products) 1% by weight, MA-ST (silica particles with a diameter of 15 nm, Nissan chemical products) 0.1 %? Was mixed to prepare a coating composition for forming an anti-glare layer.

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

Example 1

After drying the coating composition for forming the anti-glare layer of Preparation Example 1 on an acrylic film (provided by WOLF, Sumitomo, thickness: 60 µm) containing rubber particles having an average diameter of 60 um, bar coating so that the thickness becomes about 5 um It was applied in a manner.

Then, the film coated with the composition was dried at 40 ° C for 2 minutes, and then cured under a condition of 50 mJ / cm 2 with a mercury lamp.

Example 2

Acrylic film containing rubber particles having an average diameter of 60 um for the coating composition for forming the anti-glare layer of Preparation Example 1 (provided by WOLF, Sumitomo, Thickness: 60 μm) and then dried and applied with a bar coating method to a thickness of about 5 μm.

Then, the film coated with the composition was dried at 70 ° C. for 2 minutes, and then cured under a condition of 50 mJ / cm 2 with a mercury lamp.

Comparative Example 1

After drying the coating composition for forming the anti-glare layer of Preparation Example 1 on an acrylic film (provided by WOLF, Sumitomo, thickness: 60 µm) containing rubber particles having an average diameter of 60 um, bar coating so that the thickness becomes about 5 um It was applied in a manner.

Then, the film coated with the composition was dried at 90 ° C. for 2 minutes, and then cured under a condition of 50 mJ / cm 2 with a mercury lamp.

Comparative Example 2

After drying the coating composition for forming the anti-glare layer of Preparation Example 2 on an acrylic film (provided by WOLF, Sumitomo, thickness: 60 μm) containing rubber particles having an average diameter of 60 um, bar coating so that the thickness becomes about 5 μm It was applied in a manner.

Then, the film coated with the composition was dried at 40 ° C for 2 minutes, and then cured under a condition of 50 mJ / cm 2 with a mercury lamp.

[Experimental Example: Measurement of Physical Properties of Optical Laminate]

1. Haze evaluation of optical laminate

The internal haze and the external haze of the optical laminates of the prepared examples and comparative examples were obtained, and the total haze value was obtained.

Specifically, using a haze measuring device (HM-150, A light source, manufactured by Murakami Co., Ltd.), the transmittance was measured three times according to the JIS K 7361 standard, and the haze was measured three times according to the JIS K 7105 standard. The average value was calculated to obtain the total haze. In addition, in order to make the surface of the coated layer flat, an adhesive having a haze of 0 is adhered to the surface so that external irregularities are buried in the adhesive, and after measuring the haze 3 times with the haze meter, the average value is calculated to calculate the internal haze. Did. Thereafter, the outer haze was obtained by subtracting the inner haze value from the obtained total haze value.

2. Measurement of image clarity (%)

The optical clarity obtained in each of the above Examples and Comparative Examples was measured for image clarity using ICM-1T manufactured by Suga Test Instrument Co., LTD. The image clarity is measured in slit widths of 0.125 mm, 0.5 mm, 1 mm, and 2 mm and is expressed as a total.

3. Section measurement

By using an electron transmission microscope (TEM), the regions in which the rubber particles exist inside the antiglare layer in each of the optical laminates of Examples and Comparative Examples were specifically identified, and the results are shown in FIGS. 1 to 4.

4. Measurement of scratch resistance

A load was applied to the steel wool (# 0000) and reciprocated 10 times at a speed of 27 rpm to rub the surface of the antireflection film obtained in Examples and Comparative Examples. The maximum load of 1 mm or more and 1 or less scratches observed with the naked eye was measured.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Haze (%) 3.0 2.7 1.8 1.9 External haze (%) 0.5 0.4 0.0 0.1 Internal haze (%) 2.5 2.3 1.8 1.8 Merchant 305 310 340 335 The maximum thickness at which rubber particles are observed 0% 29% 100% 62% Scratch resistance 500gf 500gf Less than 100 gf Less than 100 gf

In addition, as shown in FIG. 1, in the optical laminate of Example 1, rubber particles are not present in the anti-glare layer beyond the interface of the polymer substrate and the anti-glare layer, and in the optical laminate of Example 2, the polymer substrate and the It was confirmed from the interface of the anti-glare layer that rubber particles having a cross-sectional diameter of 10 to 500 nm were present within 29% of the thickness of the anti-glare layer.

On the other hand, in the optical laminate of Comparative Example 1, it was confirmed that the rubber particles present in the polymer substrate were also present in the entire region of the anti-glare layer, and in the optical laminate of Comparative Example 2, the anti-glare from the interface between the polymer substrate and the anti-glare layer. It was confirmed that rubber particles having a cross-sectional diameter of 10 to 500 nm existed up to a range of 62% of the layer thickness.

On the other hand, as shown in Table 1, it is confirmed that the optical laminates of Examples 1 and 2 have high scratch resistance and high levels of haze and high image clarity, which can be implemented with anti-glare properties. It was confirmed that the optical laminates of Examples 1 and 2 had a low level of scratch resistance, and it was confirmed that they had an external haze value that was difficult to have anti-glare properties.

1 Polymer substrate
2 Anti-glare
3 rubber particles
4 Interface between polymer substrate and anti-glare layer
5 Surface of the anti-glare layer
6 Maximum range of rubber particles from the interface between the polymer substrate and the anti-glare layer

Claims (14)

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
It includes; an anti-glare layer comprising organic fine particles or inorganic fine particles dispersed on the binder resin and the binder;
Rubber particles having a cross-sectional diameter of 10 to 500 nm are present within 50% of the thickness of the anti-glare layer from the interface between the polymer substrate and the anti-glare layer,
Optical laminate.
According to claim 1,
From the interface between the polymer substrate and the anti-glare layer, rubber laminate having a cross-sectional diameter of 10 to 500 nm is present within 30% of the thickness of the anti-glare layer.
According to claim 1,
The polymer resin includes (meth) acrylate resin, cellulose resin, polyolefin resin and at least one selected from the group consisting of polyester resin, an optical laminate.
According to claim 1,
Rubber particles having a cross-sectional diameter of 10 to 500 nm present within 50% 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 included in the polymer substrate are rubber particles of the same component, an optical laminate.
The method of claim 1 or 4,
The rubber particles include styrene-butadiene-based rubber and at least one rubber selected from the group consisting of acrylic rubber, optical laminate.
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 ㎛, optical laminate.
The method of claim 1 or 6,
The ratio of the thickness of the anti-glare layer to the thickness of the polymer substrate is 0.008 to 0.8, an optical laminate.
According to claim 1,
The polymer substrate comprises 5 to 50 parts by weight of rubber particles having a cross-sectional diameter of 10 to 500 nm compared to 100 parts by weight of the binder resin.
According to claim 1,
The binder resin included in the anti-glare layer includes a (co) polymer formed from a vinyl-based monomer or oligomer or a (meth) acrylate monomer or oligomer, an optical laminate.
According to claim 1,
The organic fine particles contained in the anti-glare layer has a cross-sectional diameter of 1 to 50㎛,
The inorganic fine particles contained in the anti-glare layer have a cross-sectional diameter of 1 nm to 500 nm, an optical laminate.
According to claim 1,
An optical laminate having a moisture permeation amount of the polymer substrate measured at 40˚C and 100% humidity for 24 hours, which is 150 g / m 2 or less.
A polarizing plate comprising the optical laminate of claim 1.
The method of claim 12,
A polarizing plate comprising the optical laminate as a polarizer protective film.
A display device comprising the polarizing plate of claim 12.

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