Hard coating film and image display device including the same

Abstract

The present invention relates to a hard coating film and an image display device including the same, which includes a hard coating layer; and a low refractive layer formed on the hard coating layer, wherein the low refractive layer is formed from a composition for forming a low refractive layer, the composition for forming a low refractive layer including a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles, the low refractive layer has a thickness of 50 to 200 nm, and the value of Equation 1 is 90 to 150%.

Description

[Technical Field]

[0001] The present invention relates to a hard coating film and an image display device including the same. [Background technology]

[0002] Recently, image display devices such as liquid crystal display (LCD) devices and organic light emitting display (OLED) devices have been becoming thinner and more flexible, and the image display devices have been widely applied to various smart devices characterized by portability, including smartphones, tablet PCs, and various wearable devices.

[0003] Such image display devices may include additional functional layers on one or both sides of a substrate such as glass or resin to provide transparency and durability such as hardness, mechanical properties such as bending properties and / or anti-fouling properties, and optical properties.

[0004] Korean Patent Publication No. 10-2444443 provides a flexible window cover film that includes a hard coating layer to improve physical properties such as flex resistance, pencil hardness, and elastic recovery rate, making it suitable for flexible properties. However, there is a problem in that improving durability may actually decrease optical properties such as refractive index or reflectance.

[0005] Therefore, there is a need to develop a hard coating film that is capable of controlling the refractive index and reflectance to obtain excellent optical properties and has excellent durability, and a display device including the same. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Registration No. 10-2444443 Summary of the Invention [Problem to be solved by the invention]

[0007] In order to solve the above-mentioned problems, the present invention aims to provide a hard coating film having improved optical properties by controlling the reflectance of the hard coating film to 2% or more and less than 3%, and an image display device including the same.

[0008] Another object of the present invention is to provide a hard coating film that controls the reflectance within the above range and has excellent mechanical properties, and an image display device including the same.

[0009] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0010] The present invention relates to a hard coating film comprising a hard coating layer; and a low refractive layer formed on the hard coating layer, wherein the low refractive layer is formed from a composition for forming a low refractive layer, the composition for forming a low refractive layer comprising a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles, the low refractive layer has a thickness of 50 to 200 nm, and the value of the following formula 1 is 90 to 150%:

[0011] [Formula 1] (B / A)*100(%) (In the above formula 1, A is the average particle size of the hollow silica particles contained in the composition for forming a low refractive index layer, and B is the average particle size of the nanosilica particles contained in the composition for forming a low refractive index layer.)

[0012] In the present invention, the fluorine-based UV-curable functional group-containing compound may have 1 to 6 UV-curable functional groups in the molecule.

[0013] The present invention may be characterized in that the reflectance of the hard coating film is 2% or more and less than 3%.

[0014] In the present invention, the hard coating layer and the low refractive index layer may be formed on one or more substrates selected from polyester-based resins, polyimide-based resins, acrylic-based resins, styrene-based resins, polycarbonate-based resins, polylactic acid resins, polyurethane-based resins, polyolefin-based resins, vinyl-based resins, polyamide-based resins, sulfone-based resins, polyether-ether ketone-based resins, arylate-based resins, cellulose-based resins, and release films formed from mixtures of the above resins.

[0015] In the present invention, the composition for forming a low refractive index layer may further contain one or more selected from the group consisting of a light-transmitting resin, an initiator, and a solvent.

[0016] The present invention may be characterized in that the refractive index of the hollow silica particles is 1.17 to 1.40.

[0017] The present invention may be characterized in that the hollow silica particles are contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the total composition for forming a low refractive index layer.

[0018] The present invention may be characterized in that the nanosilica particles have an average particle size of 80 to 130 nm.

[0019] In the present invention, the composition for forming a low refractive index layer may contain, as an additive, one or more selected from the group consisting of a leveling agent, an ultraviolet stabilizer, and a heat stabilizer.

[0020] The present invention may also relate to an image display device including the hard coating film. [Effects of the Invention]

[0021] The hard coating film according to the present invention can control the reflectance to 2% or more and less than 3%.

[0022] Furthermore, the hard coating film according to the present invention has the characteristics of a high initial water contact angle, haze prevention, scratch resistance, and abrasion resistance, and thus it is possible to provide a hard coating film having excellent physical and / or optical properties, and an image display device including the same. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing a laminate structure of a substrate layer including a hard coating film and a substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a hard coating film including a hard coating layer formed on a substrate and a low refractive index layer formed on the hard coating layer, and an image display device including the hard coating film. The hard coating film may be characterized in that the reflectance can be controlled to 2% or more and less than 3%, and excellent mechanical properties are maintained.

[0025] More specifically, the low refractive layer may be formed of a composition for forming a low refractive layer, and the composition for forming a low refractive layer may include a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles. The low refractive layer may have a thickness of 50 to 200 nm and a value of the following Equation 1 may be 90 to 150%. At least one of the compositions for forming the hard coating layer and the low refractive layer may include a fluorine-based UV-curable functional group-containing compound.

[0026] [Formula 1] (B / A)*100(%) In the above formula 1, A is the average particle size of the hollow silica particles contained in the composition for forming a low refractive index layer, and B is the average particle size of the nanosilica particles contained in the composition for forming a low refractive index layer.

[0027] According to one embodiment of the present invention, the hard coating film has a reflectance of 2% or more but less than 3% and maintains excellent mechanical properties. This is an advantage achieved by the low refractive index layer containing a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles at an average particle size ratio of 90 to 150%. When the hard coating film of the present invention is included, it is possible to provide a hard coating film with excellent physical properties such as a high initial water contact angle, haze prevention, scratch resistance, and abrasion resistance, and / or an image display device including the same with excellent optical properties.

[0028] Hereinafter, the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and to facilitate a better understanding of the technical concept of the present invention together with the above-described content of the invention, and therefore the present invention should not be interpreted as being limited solely to the details shown in such drawings.

[0029] The terms used herein are for the purpose of describing embodiments and are not intended to limit the present invention. In this specification, the singular includes the plural unless otherwise specified in the stationery. For example, the term "hard coating layer" used herein may refer to at least one hard coating layer selected from a hard coating layer and a low refractive index layer.

[0030] As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations and / or elements other than the stated components, steps, operations and / or elements. Like reference numerals refer to like elements throughout the specification.

[0031] As used herein, "substantially" can be interpreted to mean not only being completely identical or identical physically, but also being within the error range of measurement or manufacturing process, for example, an error range of 0.1% or less. Furthermore, in the present invention, "transparent" means that the transmittance of visible light is 70% or more or 80% or more.

[0032] <Hard coating film> Referring to FIG. 1 , according to one embodiment of the present invention, a hard coating film 120 may include a hard coating layer 121 and a low refractive index layer 122 formed on the hard coating layer. More specifically, the hard coating film 120 of the present invention is formed on a substrate 110. The low refractive index layer is formed from a composition for forming a low refractive index layer, the composition including a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles. The low refractive index layer has a thickness of 50 to 200 nm, and the value of Equation 1 below is 90 to 150%. This allows the reflectance of a display device including the hard coating film to be controlled to 2 to 3%, thereby providing a display device with improved optical properties and excellent mechanical properties. More specifically, sequentially laminating the hard coating layer and low refractive index layer according to the present invention on a substrate reduces the reflectance of the film and increases its transmittance, thereby increasing brightness and lowering the specific power consumption of the battery. In the case of hollow silica, as the content relative to nanosilica particles increases, the refractive index decreases, which can result in a lower reflectance, but there is a drawback in that mechanical properties deteriorate. However, in the hard coating film according to one embodiment of the present invention, the composition for forming a low refractive index layer contains both a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles, which reduces the reflectance and increases the hardness, thereby improving the mechanical properties.

[0033] In addition, the hard coating film according to the present invention does not require a separate substrate layer for bonding the hard coating layer, and is formed in direct contact with the substrate, which simplifies the manufacturing process compared to conventional laminates.

[0034] [Formula 1] (B / A)*100(%) In the above formula 1, A is the average particle size of the hollow silica particles contained in the composition for forming a low refractive index layer, and B is the average particle size of the nanosilica particles contained in the composition for forming a low refractive index layer.

[0035] Hard Coating Layer 121 The hard coating layer 121 may be prepared using a composition for forming a hard coating layer. Specifically, the composition for forming a hard coating layer may include at least one selected from the group consisting of a translucent resin, an initiator, and a solvent, and may further include an additive. The additive may include at least one selected from the group consisting of a leveling agent, a UV stabilizer, and a thermal stabilizer. Furthermore, the composition may further include other components known in the art for use in hard coating layer compositions, without limitation, as long as they do not affect the objectives and effects of the present invention.

[0036] The hard coating layer 121 is formed on the substrate 110, which will be described later, and can be manufactured by applying a composition for forming a hard coating layer to the substrate 110 and then curing the composition with light or heat. The composition for forming a hard coating layer of the present invention may be a composition for forming a hard coating layer that has excellent adhesion to the substrate 110 and can improve mechanical properties such as hardness, scratch resistance, antifouling properties, abrasion resistance, chemical resistance, and flex resistance.

[0037] Translucent resin The light-transmitting resin used to form the hard coating layer of the present invention contains a photopolymerizable functional group and may be a photopolymerizable monomer, a photopolymerizable oligomer, or the like, for example, a photoradical polymerizable compound.

[0038] The photopolymerizable monomer may be any monomer used in the art having an unsaturated group in the molecule, such as a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group, which is a commonly used photocurable functional group, and more specifically, may have, for example, a monofunctional and / or polyfunctional (meth)acrylate. These may be used alone or in combination of two or more.

[0039] In the present invention, "(meth)acryl-" refers to "methacryl-", "acryl-", or both.

[0040] Specific examples of the (meth)acrylate monomer include (meth)acrylic acid esters such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol (meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Acrylates, 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, poly(meth)acrylates of the above (meth)acrylic acid esters to which ethylene oxide or propylene oxide has been added; Examples of the acrylic acid ester include oligoester (meth)acrylates, oligoether (meth)acrylates, oligourethane (meth)acrylates, and oligoepoxy (meth)acrylates having an acryloyl group; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and products of adding ethylene oxide or propylene oxide to the above (meth)acrylates; and mono(meth)acrylic acid esters, such as isooctyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and phenoxyethyl (meth)acrylate, which are trifunctional or less (meth)acryloyl group-containing monomers, as well as dipentaerythritol hexa(meth)acrylate, dipentaerythritol hydroxypenta(meth)acrylate, pentaerythritol tetra(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate. These may be used alone or in combination of two or more.

[0041] The photopolymerizable oligomer may be at least one selected from the group consisting of epoxy (meth)acrylate, urethane (meth)acrylate, and polyester (meth)acrylate. Specifically, a mixture of urethane (meth)acrylate and polyester (meth)acrylate or a mixture of two polyester (meth)acrylates may be used. To improve the scratch resistance and hardness of the cured product and increase the elastic modulus of the hard coating layer, it is preferable to include a urethane (meth)acrylate oligomer.

[0042] The urethane (meth)acrylate can be prepared by reacting a polyfunctional (meth)acrylate having a hydroxy group in the molecule with a compound having an isocyanate group in the presence of a catalyst by a method known in the art.

[0043] Specific examples of the polyfunctional (meth)acrylate having a hydroxy group in the molecule may be one or more selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxyisopropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, caprolactone ring-opened hydroxyacrylate, pentaerythritol tri / tetra(meth)acrylate mixture, and dipentaerythritol penta / hexa(meth)acrylate mixture.

[0044] Specific examples of the compound having an isocyanate group include 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatododecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, toluene- The isocyanate may be one or more selected from the group consisting of 2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate), 4,4'-oxybis(phenylisocyanate), trifunctional isocyanates derived from hexamethylene diisocyanate, and trimethanepropanol adduct toluene diisocyanate.

[0045] More specifically, the urethane (meth)acrylate oligomer may be a compound containing, in the molecule, two or more substituents represented by the following chemical formula 1 and two or more (meth)acryloyl groups.

[0046] [Chemical formula 1] *-OC(=O)NH-* The urethane (meth)acrylate oligomer may be produced by reacting 1 mol of a diisocyanate represented by the following chemical formula 2 with 2 mol of an active hydrogen-containing polymerizable unsaturated compound.

[0047] [Chemical formula 2] R1-OC(=O)NH-R3-NHC(=O)O-R2 In the formula, R1 and R2 are each independently a substituent containing a (meth)acryloyl group derived from an active hydrogen-containing polymerizable unsaturated compound, and R3 is a divalent substituent derived from a diisocyanate.

[0048] Specific examples of the urethane (meth)acrylate oligomer may be a product of a reaction between 2-hydroxyethyl (meth)acrylate and 2,4-tolylene diisocyanate, a reaction between 2-hydroxyethyl (meth)acrylate and isophorone diisocyanate, a reaction between 2-hydroxybutyl (meth)acrylate and 2,4-tolylene diisocyanate, a reaction between 2-hydroxybutyl (meth)acrylate and isophorone diisocyanate, a reaction between pentaerythritol tri(meth)acrylate and 2,4-toluene diisocyanate, a reaction between pentaerythritol tri(meth)acrylate and isophorone diisocyanate, a reaction between pentaerythritol tri(meth)acrylate and dicyclohexylmethane diisocyanate, a reaction between dipentaerythritol penta(meth)acrylate and isophorone diisocyanate, or a reaction between dipentaerythritol penta(meth)acrylate and dicyclohexylmethane diisocyanate.

[0049] The polyester (meth)acrylate can be produced by reacting a polyester polyol with acrylic acid by a method known in the art.

[0050] The polyester (meth)acrylate may be, for example, one or more selected from the group consisting of polyester acrylate, polyester diacrylate, polyester tetraacrylate, polyester hexaacrylate, polyester pentaerythritol triacrylate, polyester pentaerythritol tetraacrylate, and polyester pentaerythritol hexaacrylate, but is not limited thereto.

[0051] The photopolymerizable monomer and the photopolymerizable oligomer can be used alone or in combination. When the photopolymerizable monomer and the photopolymerizable oligomer are used in combination, the workability and compatibility of the hard coating composition can be improved.

[0052] The content ratio of the photopolymerizable monomer to the photopolymerizable oligomer is not particularly limited and may be appropriately selected in consideration of the storage modulus, contraction force, workability, etc. of the hard coating layer, and may be, for example, a ratio of the polymerizable monomer to the polymerizable oligomer of (1:10) to (10:1). If the content ratio of the polymerizable oligomer to the polymerizable monomer is outside the above range, the storage modulus of the hard coating layer may decrease or the contraction force may increase, resulting in a decrease in hardness and flexibility, which may cause curling.

[0053] The content of the light-transmitting resin is not particularly limited, and may be, for example, 1 to 80 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the total hard coating composition. If the content of the light-transmitting resin is less than 1 part by weight, the elastic modulus of the hard coating layer may decrease, making it easier for cracks to occur in the hard coating layer when bent. If the content of the light-transmitting resin is more than 80 parts by weight, the viscosity may increase, reducing coatability and causing insufficient surface leveling, which may result in problems with the appearance properties.

[0054] The translucent resin may contain an inorganic nanofiller to improve hardness and scratch resistance. The inorganic nanofiller generally has a size of less than 100 nm, preferably 10 to 100 nm, and more preferably 10 to 50 nm. Typical inorganic nanofillers include silica, aluminum oxide particles, titanium oxide particles, and zinc oxide particles, with silica being preferred. The silica may or may not have a photocurable group on its surface that can participate in a photoreaction.

[0055] The inorganic nanofiller can be added by appropriately adjusting the content within a range that does not impair the effects of the present invention.

[0056] initiator The initiator may be any initiator commonly used in the art, and may include, for example, one or more initiators selected from the group consisting of hydroxyketones, aminoketones, hydrogen-removal type photoinitiators, and combinations thereof.

[0057] Specifically, the photoinitiator may be at least one selected from the group consisting of 2-methyl-1-[4-(methylthio)phenyl]2-morpholinepropanone-1, diphenyl ketone, benzil dimethyl ketal, 2-hydroxy-2-methyl-1-phenyl-1-one, 4-hydroxycyclophenyl ketone, 2,2-dimethoxy-2-phenyl-acetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-chloroacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, 1-hydroxycyclohexylphenyl ketone, benzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and combinations thereof.

[0058] The photoinitiator is used in an amount of 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the total hard coating composition. If the content is less than this range, the curing rate of the composition will be slow, and uncured portions will occur, resulting in reduced mechanical properties. Conversely, if the content exceeds this range, over-curing may occur, resulting in cracks in the coating film.

[0059] solvent The solvent can dissolve or disperse the above-mentioned composition, and can be any solvent known in the art as a solvent for compositions for forming a coating layer.

[0060] Usable solvents include alcohols (methanol, ethanol, isopropanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), acetates (ethyl acetate, propyl acetate, normal butyl acetate, tertiary butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol Preferred examples of solvents that can be used include hexanes (hexane, heptane, octane, etc.), benzenes (benzene, toluene, xylene, etc.), and ethers (diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, etc.). The solvents exemplified above can be used alone or in combination of two or more.

[0061] The solvent may be used in an amount of 10 to 95 parts by weight based on 100 parts by weight of the total hard coating composition, or may be included as the remaining amount excluding other components in the composition. If the content of the solvent is less than the above range, the viscosity becomes high, reducing workability and preventing sufficient swelling of the substrate film. Conversely, if the content exceeds the above range, the drying process takes a long time, reducing economic efficiency. Therefore, the solvent should be used appropriately within the above range.

[0062] additives In addition, the composition for forming a hard coating layer according to the present invention may further include one or more additives selected from the group consisting of a leveling agent, an ultraviolet stabilizer, and a heat stabilizer, in addition to the above-mentioned components, and may further include additives commonly used in the technical field to which the present invention pertains. The content of the additives is not particularly limited, as it can be adjusted in various ways within a range that does not deteriorate the physical properties of the composition for forming a hard coating layer according to the present invention.

[0063] The leveling agent is a component that imparts smoothness and coatability to the coating film. The leveling agent may be any leveling agent commonly used in the art, such as a silicone-based leveling agent, a fluorine-based leveling agent, or an acrylic polymer-based leveling agent. These may be used alone or in combination, but are not limited to these. In one embodiment of the present invention, the hard coating layer preferably further contains a silicone-based or acrylic polymer-based additive instead of the fluorine-based UV-curable functional group-containing compound contained in the low refractive index layer described below, in order to reduce the contact angle and facilitate coating of the low refractive index layer on the hard coating layer.

[0064] The leveling agent may be included in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the hard coating composition, but is not limited thereto.

[0065] UV stabilizers are components that block or absorb UV rays, preventing decomposition, discoloration, and cracking of the cured hard coating layer due to UV exposure. UV stabilizers can be classified according to their mechanism of action, such as absorbers, quenchers, and hindered amine light stabilizers (HALS); or according to their chemical structure, such as phenyl salicylates (absorbers), benzophenones (absorbers), benzotriazoles (absorbers), nickel derivatives (quenchers), and radical scavengers. These stabilizers can be used alone or in combination. There are no particular restrictions on the type of UV stabilizer, as long as they do not significantly change the initial color of the hard coating layer.

[0066] Examples of heat stabilizers that can be used include commercially available polyphenol-based primary heat stabilizers, phosphate-based and lactone-based secondary heat stabilizers, and the like, which can be used alone or in combination. These can be used alone or in combination.

[0067] The UV stabilizer and heat stabilizer may be used by appropriately adjusting the content thereof to a level that does not affect UV curing properties. Specifically, the content of the UV stabilizer and heat stabilizer is preferably 0.1 to 3 parts by weight based on 100 parts by weight of the total hard coating composition of the present invention.

[0068] The additives can be added by appropriately adjusting the content within a range that does not impair the effects of the present invention.

[0069] Low refractive index layer 122 The low refractive layer 122 may be formed by applying a composition for forming a low refractive layer onto the hard coating layer 121 and then curing the composition with light or heat, and has low reflectivity and excellent mechanical properties and abrasion resistance. In one embodiment of the present invention, the composition for forming a low refractive layer may include a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles, the low refractive layer may have a thickness of 50 to 200 nm, and the value of the following Equation 1, which calculates the ratio of the average particle diameters of the hollow silica particles and the nanosilica particles, may be 90 to 150%.

[0070] [Formula 1] (B / A)*100(%) In the above formula 1, A may be the average particle size of the hollow silica particles contained in the composition for forming a low refractive index layer, and B may be the average particle size of the nanosilica particles contained in the composition for forming a low refractive index layer.

[0071] In addition, the low refractive index layer 122 according to the present invention may be manufactured using a composition for forming a second hard coating layer, and the composition may include the fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles, and may further include one or more selected from the group consisting of a light-transmitting resin, an initiator, and a solvent, and / or an additive. The light-transmitting resin, initiator, solvent, and additive described in the description of the hard coating layer 121 can be applied as is, so the description thereof will be omitted.

[0072] Fluorine-based UV-curable functional group-containing compound The fluorine-based UV-curable functional group-containing compound is a component that adjusts the refractive index to impart antifouling properties and abrasion resistance. It must contain fluorine and a UV-curable functional group. The fluorine-based UV-curable functional group-containing compound, when incorporated into a hard coating film formed on a polymer material, can increase the initial water contact angle and decrease the refractive index, thereby adjusting the reflectance and transmittance of an image display device (described below). According to one embodiment of the present invention, the inclusion of a fluorine-based UV-curable functional group-containing compound in a composition that forms a low refractive index layer formed on a hard coating layer can improve the initial water contact angle and abrasion resistance.

[0073] Specifically, the fluorine-based UV-curable functional group-containing compound may be a perfluoro group-containing acrylate, methacrylate, vinyl, etc. In this case, the fluorine-based UV-curable functional group-containing compound preferably has 1 to 6 UV-curable functional groups, but the scope of the present invention is not limited thereto and may be any substance that has a UV-curable functional group and also contains a fluorine group.

[0074] According to one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is preferably included in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the total composition for forming a hard coating layer. If the amount is less than 0.01 part by weight, the initial contact angle may be small, which may result in reduced abrasion resistance. If the amount is more than 30 parts by weight, the mechanical properties such as film hardness may be reduced, which may result in reduced abrasion resistance.

[0075] Hollow Silica Particles According to one embodiment of the present invention, the low refractive index layer 122 may include hollow silica particles, and the refractive index of the hollow silica particles may be characterized as being between 1.17 and 1.40.

[0076] The hollow silica particles are silicon-based fine particles with a low refractive index, which allows them to reduce the reflectance of image display devices (described later) and are characterized by their optical transparency. In the present invention, the hollow silica particles have an advantageous refractive index of 1.17 to 1.40 in terms of reducing reflectance. Furthermore, the inclusion of the hollow silica particles can be used to provide oil storage properties in addition to optical functions.

[0077] The hollow silica particles preferably have an average particle size of 20 to 80 nm, more preferably 20 to 70 nm, from the viewpoint of composition processability and coating properties, and the particle shape is preferably spherical, but is not limited thereto.

[0078] The hollow silica particles are preferably included in an amount of 0.1 to 20 parts by weight, and more preferably 1 to 15 parts by weight, based on 100 parts by weight of the total composition for forming a low refractive index layer, in terms of reducing reflectance and imparting excellent mechanical properties.

[0079] Nanosilica Particles According to one embodiment of the present invention, the low refractive index layer 122 may include nanosilica particles. The nanosilica particles, like the hollow silica particles, are silicon-based fine particles having an average particle size of 70 nm or more, preferably 80 to 130 nm, and more preferably 100 to 130 nm. When the particle size satisfies the above range, it is possible to improve strength and reduce light transmission haze. Compared to the hollow silica particles, the nanosilica particles do not have cavities on the surface and / or inside. When included in a composition for forming a low refractive index layer, they can impart durability, such as scratch resistance and abrasion resistance, to the surface.

[0080] When the nanosilica particles are included in the composition in the form of a dispersion in a solvent, they have the advantage of improved dispersibility and easy redispersion. The solvent included in the nanosilica particle dispersion can be any solvent known in the art, and the description of the solvent in the <Hard Coating Layer 110> section above applies, so the description will be omitted. The nanosilica particles may be included in an amount of 0.1 to 50 parts by weight per 100 parts by weight of the total nanosilica particle dispersion, but is not limited thereto, in consideration of ease of processing.

[0081] The nanosilica particles are preferably contained in an amount of 0.1 to 20 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of the total composition for forming a low refractive index layer, in terms of compatibility and light transmittance haze characteristics.

[0082] The hard coating layer may be manufactured by a method known in the art. The thickness of the hard coating layer is not particularly limited and may be, for example, 5 to 30 μm, and the thickness of the low refractive index layer may be 50 to 200 nm, preferably 80 to 120 nm. When the thickness is within this range, it is easy to control the reflectance of the substrate layer including the hard coating film to 2 to 3%, and haze can be prevented, which may affect the optical properties of the image display device described below. On the other hand, if the thickness of the low refractive index layer exceeds this range, there is a disadvantage that the reflectance may increase.

[0083] The hard coating film according to the embodiment of the present invention may be formed by coating a composition for forming a hard coating layer on a substrate, followed by drying and UV curing steps to form a hard coating layer 121, or may be formed by coating a composition for forming a low refractive index layer on the hard coating layer 122, followed by drying and UV curing steps similar to the hard coating layer, to form the low refractive index layer 122.

[0084] The step of drying the hard coating film may be carried out by a heating means such as a hot plate, a hot air circulating oven, or an infrared oven, and may be carried out at a temperature of 50 to 150°C or 50 to 100°C.

[0085] The step of curing the hard coating film may be performed at a temperature of 50 to 1000 mJ / cm 2 , preferably 200 to 800 mJ / cm 2 In particular, the step of forming the hard coating layer 121 is performed by irradiating the substrate with actinic rays such as UV rays at a dose of 50 to 600 mJ / cm. 2 The step of forming the low refractive layer 122 by performing the primary curing weakly at a level of 300 to 800 mJ / cm 2 By irradiating UV with a strong light intensity, the adhesion between the low refractive index layer and the hard coating layer can be further strengthened, and the hard coating layer and low refractive index layer are cured at 300 to 600 mJ / cm. 2 When irradiating with UV light of the same intensity at the same level, the process can be simplified. The light source used for irradiation can be a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, or in some cases, X-rays or electron beams.

[0086] <Image display device> 1 is a diagram showing a laminated structure of a substrate layer according to an embodiment of the present invention. Referring to FIG. 1, the embodiment of the present invention provides a substrate layer 100 including the above-described hard coating film 120 and an image display device including the same.

[0087] For example, the hard coating film 120 may be formed by sequentially laminating the above-mentioned hard coating layer 121 and low refractive index layer 122 on the substrate 110. In this case, the substrate layer 100 including the substrate 110 and the hard coating film 120 may be formed on the outermost surface according to the needs of the image display device, or may be inserted inside the image display device.

[0088] Base material 110 The substrate 110 functions to absorb impact and / or damage such as scratches on the entire surface of the substrate layer, thereby preventing breakage of the internal substrate. Preferably, the substrate 110 is made of a material with a high tolerance for deformation energy, such as polyester-based resins (e.g., polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate); polyimide-based resins; acrylic-based resins; styrene-based resins (e.g., polystyrene and acrylonitrile-styrene); polycarbonate-based resins; polylactic acid resins; polyurethane-based resins; polyolefin-based resins (e.g., polyethylene, polypropylene, and ethylene-propylene copolymer); vinyl-based resins (e.g., polyvinyl chloride and polyvinylidene chloride); polyamide-based resins; sulfone-based resins; polyether-ether ketone-based resins; arylate-based resins; cellulose-based resins (e.g., triacetyl cellulose), or release films formed from mixtures of these resins. In one embodiment of the present invention, polyimide-based resins are most preferred because they are optically transparent, have excellent resistance to friction, heat, and / or chemical damage, and have excellent bending properties.

[0089] The thickness of the substrate using the polyimide resin is not limited, but the thicker the substrate, the lower the holding performance. Therefore, a thickness of 30 to 100 μm is preferred from the viewpoints of holding performance, transparency, and durability.

[0090] The image display device may be, but is not limited to, a flexible display device having flexibility and bending properties, including various image display devices such as a liquid crystal display device, an electroluminescent display device, a plasma display device, a field emission display device, etc. In this case, the substrate layer 100 according to an embodiment of the present invention, i.e., the hard coating laminate, reduces reflectance and improves mechanical properties through the above-described configuration, thereby preventing haze and controlling reflectance to 2 to 3%, thereby realizing an image display device having excellent optical properties, a high initial water contact angle, and excellent durability such as scratch resistance and abrasion resistance. [Example]

[0091] [Mode for carrying out the invention] The present invention will be described in more detail below based on examples. However, the embodiments of the present invention described below are merely illustrative, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the claims and includes all modifications equivalent to the claims and within the scope of the claims. In the following examples and comparative examples, "%" and "parts" indicating the content are by weight unless otherwise specified.

[0092] Preparation Example 1: Preparation of composition for forming hard coating layer 52 parts by weight of 9-functional urethane acrylate (MIWON Specialty Chemicals, Miramer MU9800), 45 parts by weight of butyl acetate, 2.7 parts by weight of 1-hydroxycyclohexyl phenyl ketone, and 0.3 parts by weight of a silicone leveling agent (BYK, BYK-UV3530) were mixed using a mixer and filtered using a PP filter to prepare a composition for forming a hard coating layer.

[0093] Preparation Examples 2 to 9: Preparation of compositions for forming low refractive index layers Manufacturing Example 2 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-H), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of methyl ethyl ketone-dispersed nanoparticle silica sol with an average particle size of 85 nm (MEK-AC-5140Z, Nissan Chemical) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0094] Manufacturing Example 3 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of ethanol and ethylhexanol-dispersed nanoparticle silica sol with an average particle size of 85 nm (VPSKE80, Evonik) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0095] Production Example 4 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), 3 parts by weight of hollow silica with an average particle size of 50 nm, and 2 parts by weight of propylene glycol monomethyl ether-dispersed nanoparticle silica sol with an average particle size of 45 nm (PGM-AC-4130, Nissan Chemical) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0096] Manufacturing Example 5 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of methyl ethyl ketone-dispersed nanoparticle silica sol with an average particle size of 12 nm (MEK-ST-40, Nissan Chemical) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0097] Manufacturing Example 6 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of propylene glycol monomethyl ether-dispersed nanoparticle silica sol with an average particle size of 45 nm (PGM-AC-4130Y, Nissan Chemical) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0098] Manufacturing Example 7 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), and 3 parts by weight of hollow silical with an average particle size of 60 nm were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0099] Manufacturing Example 8 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (DAIKIN, DAC-HP), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of nanoparticle silica sol (SS-SOL100, S-Chemtech) with an average particle size of 100 nm were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0100] Manufacturing Example 9 1.4 parts by weight of pentafunctional urethane acrylate (Kyoeisha, UA-306I), 93 parts by weight of methyl ethyl ketone, 0.1 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a silicon-based leveling agent (BYK-307, BYK), 3 parts by weight of hollow silica with an average particle size of 60 nm, and 2 parts by weight of methyl ethyl ketone-dispersed nanoparticle silica sol with an average particle size of 80 nm (MEK-AC-5140Z, Nissan Chemical) were mixed using a mixer and filtered using a PP filter to produce a composition for forming a low refractive index layer.

[0101] Examples 1 to 5 and Comparative Examples 1 to 4: Preparation of hard coating film and substrate layer including the same Example 1 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 2, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the UV integrated light dose was 500 mJ / cm in a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0102] Example 2 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 3, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the UV integrated light dose was 500 mJ / cm in a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0103] Example 3 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 4, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the UV integrated light dose was 500 mJ / cm in a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0104] Comparative Example 1 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 5, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the UV integrated light dose was 500 mJ / cm in a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0105] Comparative Example 2 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 6, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the coating was irradiated with UV light at an integrated dose of 500 mJ / cm under a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0106] Comparative Example 3 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 7, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the coating was irradiated with UV light at an integrated dose of 500 mJ / cm under a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0107] Comparative Example 4 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 8, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the coating was irradiated with UV light at an integrated dose of 500 mJ / cm under a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0108] Comparative Example 5 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 2, the composition was coated thereon to a thickness of 300 nm after curing, and the solvent was dried and the UV integrated light dose was 500 mJ / cm in a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0109] Comparative Example 6 The composition for forming a hard coating layer prepared in Preparation Example 1 was coated on a polyimide film (PI, 50 μm) to a thickness of 10 μm after curing, and the solvent was dried and the UV integrated dose was 500 mJ / cm. 2 After forming a hard coating layer by irradiating the composition for forming a low refractive index layer of Preparation Example 9, the composition was coated thereon to a thickness of 100 nm after curing, and the solvent was dried and the coating was irradiated with UV light at an integrated dose of 500 mJ / cm under a nitrogen atmosphere. 2 The substrate layer is formed by irradiating the substrate with a hard coating film.

[0110] The preparation examples, coating thicknesses, particle sizes of hollow silica particles and nanosilica particles contained in the low refractive layer, and values ​​calculated by applying the same to Equation 1, which are applied to Examples 1 to 3 and Comparative Examples 1 to 6, respectively, are as shown in Table 1 below.

[0111] [Table 1]

[0112] Experimental Example The physical properties of the substrate layers prepared in Examples 1 to 3 and Comparative Examples 1 to 6 were measured by the following methods. The results are shown in Table 2.

[0113] (1) Measurement of water contact angle The water contact angle was measured at room temperature using a contact angle measuring instrument DSA100 manufactured by KRUSS, with a droplet volume of 3 μl.

[0114] (2) Haze measurement The haze of the substrate layer of each of the examples and comparative examples was measured using a haze meter (HM-2, Murakami Co., Ltd.).

[0115] (3) Reflectance measurement The substrate layers prepared in the examples and comparative examples were bonded to a black acrylic plate to remove rear reflection, and then the reflectance was measured using an integrating sphere reflectance (CM-3700A, Konica Minolta).

[0116] (4) Scratch resistance After fixing the substrate layer to the glass with the hard coating surface facing upward, apply 250 g / cm of steel wool (#0000) to the glass. 2 After rubbing the film back and forth 10 times under a load of 1000 kJ / min, the film surface was checked for the presence or absence of scratches. The results are shown in Table 2 according to the following evaluation criteria.

[0117] <Evaluation criteria> ○: No scratches occurred △: 20 or fewer scratches occurred (hard to distinguish visually) X: Many occurrences of over 20 scratches (5) Abrasion resistance Measurements were carried out using an abrasion resistance tester manufactured by Daesung Precision Co., Ltd. The coating surface was rubbed 1,000 times with an abrasion-resistant Tetos eraser and a 500g weight, and the contact angle was measured. The results are shown in Table 2 according to the following evaluation criteria.

[0118] <Evaluation criteria> ○: Contact angle is 100° or more X: Contact angle less than 100°

[0119] [Table 2]

[0120] According to the experimental data in Table 2, the physical properties of the substrate layers prepared in Examples 1 to 3 according to the present invention were evaluated. As a result, the initial water contact angle was large, the haze value was low, and the reflectance was 2% or more but less than 3%, and the scratch resistance and abrasion resistance were all excellent.

[0121] In contrast, in Comparative Example 3, which used a composition for forming a low refractive index layer that did not contain nanosilica particles, Comparative Examples 1, 2, and 4, in which the value of Equation 1 was less than 90% or more than 150%, and Comparative Example 5, in which the thickness of the low refractive index layer exceeded 200 nm, the initial water contact angle, haze, reflectance, and abrasion resistance evaluation results were poorer than those of the Examples of the present invention, and Comparative Example 6, in which the composition for forming a low refractive index layer did not contain a fluorine-based UV-curable functional group-containing compound, had a particularly low initial water contact angle. Furthermore, in Comparative Examples 1 to 6, which do not follow an Example of the present invention, numerous scratches were observed, unlike the Examples of the present invention.

[0122] Therefore, a hard coating film according to one embodiment of the present invention includes a low refractive index layer formed on a hard coating layer, and the composition forming the low refractive index layer includes a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles. When the thickness of the low refractive index layer is 50 to 200 nm and the ratio of the average particle size of the hollow silica particles to the average particle size of the nanosilica particles is 90 to 150%, the low refractive index layer can achieve a reflectance of 2% or more and less than 3% while maintaining excellent mechanical properties. [Industrial Applicability]

[0123] The hard coating film according to the present invention can control the reflectance to 2% or more and less than 3%. [Explanation of symbols]

[0124] 110: Base material 120: Hard coating film 121: Hard coating layer 122: Low refractive index layer

Claims

1. a hard coating layer; and a low refractive index layer formed on the hard coating layer, the low refractive index layer is formed from a composition for forming a low refractive index layer, the composition for forming a low refractive index layer includes a fluorine-based UV-curable functional group-containing compound, hollow silica particles, and nanosilica particles; The low refractive index layer has a thickness of 50 to 200 nm; A hard coating film characterized in that the value of the following formula 1 is 90 to 150%: [Formula 1] (B / A)*100(%) (In the above formula 1, A is the average particle size of the hollow silica particles contained in the composition for forming a low refractive index layer, B is the average particle size of the nanosilica particles contained in the composition for forming the low refractive index layer.

2. The hard coating film according to claim 1 , wherein the fluorine-based UV-curable functional group-containing compound contains 1 to 6 UV-curable functional groups in a molecule.

3. The hard coating film according to claim 1, wherein the hard coating film has a reflectance of 2% or more but less than 3%.

4. 2. The hard coating film according to claim 1, wherein the hard coating layer and the low refractive index layer are formed on one or more substrates selected from polyester-based resins, polyimide-based resins, acrylic-based resins, styrene-based resins, polycarbonate-based resins, polylactic acid resins, polyurethane-based resins, polyolefin-based resins, vinyl-based resins, polyamide-based resins, sulfone-based resins, polyether-ether ketone-based resins, arylate-based resins, cellulose-based resins, and release films formed from mixtures of the resins.

5. The hard coating film according to claim 1 , wherein the composition for forming the low refractive index layer further comprises at least one selected from the group consisting of a light-transmitting resin, an initiator, and a solvent.

6. The hard coating film according to claim 1, wherein the hollow silica particles have a refractive index of 1.17 to 1.

40.

7. The hard coating film according to claim 6, wherein the hollow silica particles are contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the total composition for forming the low refractive index layer.

8. 2. The hard coating film according to claim 1, wherein the nanosilica particles have an average particle size of 80 to 130 nm.

9. The hard coating film according to claim 1 , wherein the composition for forming the low refractive index layer further comprises, as an additive, at least one selected from the group consisting of a leveling agent, an ultraviolet stabilizer, and a heat stabilizer.

10. An image display device comprising the hard coating film according to any one of claims 1 to 9.

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