Hard coat film, window and image display device to which this is applied

Abstract

The present invention is for being formed on display glass, includes a silane or siloxane compound, and has a Vickers hardness of 20 kgf / mm 2 The following first hard coat layer and a second hard coat layer formed on the first hard coat layer, containing a fluorine-based UV curable functional group-containing compound and having a thickness of 3 to 15 μm, and is characterized by having a pencil hardness of 3H or more, and excellent scratch resistance, antifouling property, abrasion resistance, chemical resistance, pressure resistance, splash prevention property, adhesion and flexibility. The present invention relates to a hard coat film and a window and an image display device to which the same is applied.

Description

Technical Field

[0001] The present invention relates to a hard coat film, a window to which the same is applied, and an image display device.

Background Art

[0002] Recently, thinning and flexibility of image display devices such as liquid crystal display (LCD) devices or organic light emitting display (OLED) devices have been continuing. The image display devices are widely applied to various smart devices characterized by portability, ranging from smart phones and tablet PCs to various wearable devices. Such flexible displays require a glass substrate layer having physical properties such as high transparency, hardness, and warp characteristics.

[0003] On the other hand, in the case of a flexible display, when it is frequently folded or when an impact exceeding the limit is applied, the problem of cracking of the cover glass may frequently occur. In this case, a large amount of small pieces of glass may scatter, which may cause problems such as quality degradation such as foreign matters on the surface of the display and the device, and may lead to safety accidents at the same time. In order to prevent this and ensure stability against glass fragments at the time of breakage, a scattering prevention film or the like may be included in the window layer.

[0004] Korean Registered Patent Publication No. 10-1408511 provides a transparent substrate excellent in bending properties and flexibility by reinforcing thin plate glass by providing a resin layer having specific shrinkage stress on one or both sides of the thin plate glass, and significantly preventing the progress and breakage of cracks in the thin plate glass.

[0005] However, in order to form the resin layer, when it is disposed on the surface of one or both sides of the thin plate glass via an adhesive layer, there is a disadvantage that the manufacturing process of the substrate becomes complicated.

[0006] Therefore, there is a need to develop a hard coat film that directly forms a substrate layer for preventing scattering on glass, simplifies the process, has excellent adhesion, and has durability suitable for realizing flexible characteristics at present.

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a hard coat film of excellent quality that prevents the scattering of fragments at the time of breakage in order to solve the above-described problems.

[0008] Specifically, when applying the hard coat film, another object is to provide a window and an image display device that are excellent in scratch resistance, antifouling property, abrasion resistance, chemical resistance, pressure resistance, scattering prevention, adhesion, and flexibility while having high hardness.

[0009] However, the problems to be solved by the present invention are not limited to the problems 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 Problems

[0010] In order to achieve the above technical problems, the present invention is for forming on display glass, includes a silane or siloxane compound, and has a Vickers hardness of 20 kgf / mm 2 The following first hard coat layer and a second hard coat layer formed on the first hard coat layer, containing a fluorine-based UV curable functional group-containing compound and having a thickness of 3 to 15 μm, characterized in that it provides a hard coat film.

[0011] In the present invention, the display glass may be UTG (Ultra Thin Glass).

[0012] The present invention may be such that the glass for display, the first hard coat layer, and the second hard coat layer do not include another layer and are formed in direct contact with each other, respectively.

[0013] The present invention may be such that the fluorine-based UV curable functional group-containing compound has 1 to 6 UV curable functional groups.

[0014] The present invention may be such that either one of the first hard coat layer and the second hard coat layer is produced from a composition containing at least one selected from the group consisting of a photopolymerizable compound, an initiator, and a solvent.

[0015] The present invention may be such that the photopolymerizable compound further contains an inorganic nanofiller.

[0016] The present invention may be such that either one of the first hard coat layer and the second hard coat layer further contains an additive.

[0017] The present invention may be such that the additive contains at least one selected from the group consisting of a leveling agent, an ultraviolet stabilizer, and a heat stabilizer.

[0018] The present invention may be applied to a flexible display.

[0019] Further, the present invention relates to a window including glass for display and the hard coat film formed on the glass for display.

[0020] Further, the present invention relates to an image display device including the window.

Advantages of the Invention

[0021] The hard coat film according to the present invention, as well as the window and the image display device to which the same is applied, have a pencil hardness of 3H or higher, and are excellent in scratch resistance, antifouling property, abrasion resistance, chemical resistance, pressure resistance, splash prevention property, adhesion and flexibility, and have improved device reliability when applied to a flexible display.

[0022] Further, the hard coat film according to the present invention does not include another base material between the glass and the hard coat layer, is formed in direct contact, and can omit the process for joining each base material layer, and the manufacturing process can be simplified compared to the conventional one.

Brief Description of Drawings

[0023]

Figure 1

Embodiments for Carrying Out the Invention

[0024] The present invention is for being formed on the display glass, contains a silane or siloxane compound, and has a Vickers hardness of 20 kgf / mm 2 It includes the following first hard coat layer and a second hard coat layer formed on the first hard coat layer, containing a fluorine-based UV curable functional group-containing compound and having a thickness of 3 to 15 μm, and relates to a hard coat film suitable for use in a flexible display, as well as a window and an image display device using the same.

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail. However, these examples are merely presented as examples for more specifically explaining the present invention, and it will be obvious to those having ordinary knowledge in the art that the scope of the present invention is not limited by these examples.

[0026] The terms used in this specification are for the purpose of describing embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specifically mentioned in the text. For example, the "hard coat layer" used in this specification may mean at least one hard coat layer of the first hard coat layer and the second hard coat layer.

[0027] As used in this specification, "comprises" and / or "comprising" are used in the sense of not excluding the presence or addition of one or more other components, steps, operations and / or elements other than the recited components, steps, operations and / or elements. The same reference numerals throughout the specification refer to the same components.

[0028] As used herein, "substantially" can be interpreted to include not only those that are physically completely identical or coincident, but also those within the error range in the measurement or manufacturing process. For example, it may be interpreted as having an error range of 0.1% or less.

[0029] FIG. 1 is a diagram showing a laminated structure of display glass laminated with a hard coat film according to an embodiment of the present invention. As shown in FIG. 1, the laminate 100 of the present invention may have a structure in which display glass 110, a first hard coat layer 120a formed on the display glass 110, and a second hard coat layer 120b are formed on the first hard coat layer, that is, at the outermost corner.

[0030] The hard coat film of the present invention can simultaneously have hardness and flexibility for application to a window for a flexible display.

[0031] <Display glass 110> The glass for display is for replacing the existing glass substrate and supporting the hard coat layer 120 and other base materials or panels described later, and may be composed of either thin glass or curved glass for the display of electronic devices. The thin glass can include flat glass and flexible glass.

[0032] According to an embodiment of the present invention, UTG (ultra thin glass) can be applied to the display glass 110. UTG (ultra thin glass) is a component of an ultra-thin toughened glass material used for a display cover window, has high transparency, is as thin as about 10 to 100 μm, and has the property of being foldable flexibly.

[0033] In the present invention, the term "transparent" means that the transmittance of visible light is 70% or more or 80% or more, but is not limited thereto.

[0034] The display glass 110 can include additional base material layers such as the hard coat layer 120 described later in order to ensure durability. Generally, an adhesive layer or an adhesive layer is included to form or bond the base material layer. However, according to the hard coat film of the present invention, it is characterized in that it does not include another base material layer for bonding the hard coat layer and is formed by direct contact, and the manufacturing process can be simplified compared to the conventional laminate.

[0035] <Hard coat film> The hard coat film of the present invention includes a hard coat layer, and preferably can include a first hard coat layer and a second hard coat layer. More specifically, the hard coat film of the present invention is for being formed on the display glass, contains a silane or siloxane compound, and has a Vickers hardness of 20 kgf / mm 2 It can include the following first hard coat layer and a second hard coat layer formed on the first hard coat layer, containing a fluorine-based UV curable functional group-containing compound and having a thickness of 3 to 15 μm.

[0036] Hard coat layer 120 As shown in FIG. 1, the hard coat layer of the present invention can include a first hard coat layer 120a and a second hard coat layer 120b.

[0037] According to an embodiment of the present invention, the first hard coat layer 120a contains a silane or siloxane compound and has a Vickers hardness of 20 kgf / mm 2 The following, and by satisfying the Vickers hardness within the above range, it plays a role in preventing the scattering of fragments when the window breaks. Further, the second hard coat layer 120b is exposed on the surface to impart antifouling properties and a function of protecting the film. The second hard coat layer 120b contains a fluorine-based UV-curable functional group-containing compound and is characterized by having a thickness of 3 to 15 μm.

[0038] Referring to FIG. 1, the first hard coat layer 120a is formed on the display glass 110, and the second hard coat layer 120b may be formed on the first hard coat layer 120a, that is, at the outermost corner of the hard coat film. The first hard coat layer 120a can ensure the adhesion between substrates and impart impact resistance without a layer such as an adhesive layer or another substrate layer.

[0039] According to an embodiment of the present invention, the display glass 110 can apply UTG (ultra thin glass) as described above, and the display glass 110, the first hard coat layer 120a, and the second hard coat layer 120b may be formed by directly contacting each other without including another layer.

[0040] Further, the first hard coat layer 120a and the second hard coat layer 120b can each be independently produced from a hard coat composition containing one or more selected from the group consisting of a photopolymerizable compound, a solvent, and an initiator. The composition can further contain, as an additive, one or more selected from the group consisting of a leveling agent, an ultraviolet stabilizer, a heat stabilizer, etc., as necessary. As an example, the first hard coat layer can be produced from a hard coat composition containing a silane or siloxane compound, a photopolymerizable compound, an initiator, and a solvent.

[0041] Further, the second hard coat layer can be produced from a hard coat composition containing a fluorine-based UV-curable functional group-containing compound, a photopolymerizable compound, an initiator, and a solvent.

[0042] Silane or siloxane compound The siloxane compound contained in the first hard coat layer 120a of the present invention includes a compound having an Si-O-Si bond. In the present invention, the Si-O bond strength of the siloxane compound is stronger than the C-C bond, not only has excellent impact resistance characteristics, but also can impart excellent adhesion characteristics to other adjacent base materials. Also, the bond length of Si-O is longer than C-C, the bond angle of Si-O-Si is 143°, which is larger than the bond angle of 110° of C-C-C bond, and has excellent flexibility against deformation. Thus, the silane or siloxane compound of the present invention has an excellent elastic recovery rate compared to carbon materials. The siloxane compound may be in the form of -(R2SiO)- in which two organic groups are bonded to a silicon element, or -(RSiO 1.5 )- form with one bond. Examples of the -(R2SiO)- type include polydimethylsiloxane (PDMS), etc. Examples of the -(RSiO 1.5 )- type include cage-type silsesquioxane, partial cage-type silsesquioxane, ladder-type silsesquioxane, random-type silsesquioxane, etc. The organic group can have a photocurable (meth)acrylic group functional group or an epoxy group functional group.

[0043] The silane compound includes, but is not limited to, a compound having an X-Si-(OR)3 bond. As an example, examples of the X-Si-(OR)3 type include silane coupling agents. X of the silane compound is a reactive group that chemically bonds to an organic material and can have a photocurable (meth)acrylic group functional group or an epoxy group functional group. R of the silane or siloxane compound refers to any organic group and includes, without limitation, the organic groups of known silane or siloxane compounds.

[0044] According to an embodiment of the present invention, the silane or siloxane compound may be included in an amount of 1 to 10 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the hard coat composition. By including the silane or siloxane compound within the above range, the hard coat layer formed of the hard coat composition has good adhesion between the substrates, can impart flexibility to the film substrate layer, and can prevent fragments from scattering when damaged by frequent folding or external impact.

[0045] Fluorine-based UV curable functional group-containing compound The fluorine-based UV curable functional group-containing compound contained in the second hard coat layer 120b of the present invention is a component that imparts antifouling properties and abrasion resistance, must contain fluorine, and is not particularly limited as long as it has a UV curable functional group.

[0046] Specifically, acrylates, methacrylates, vinyls, etc. containing a perfluoro group can be used. At this time, the fluorine-based UV curable functional group-containing compound preferably has 1 to 6 UV curable functional groups. However, the scope of the present invention is not limited only to these, and any substance having a UV curable functional group and containing a fluorine group is applicable.

[0047] It is preferably contained in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the entire hard coat composition. If it is 0.01 part by weight or less, it is difficult to sufficiently evaluate the abrasion resistance and antifouling property, and if it exceeds 30 parts by weight, the film hardness and rather the abrasion resistance may decrease.

[0048] Photopolymerizable compound The photopolymerizable compound used for forming the hard coat layer of the present invention contains a photopolymerizable functional group and may be a photopolymerizable monomer, a photopolymerizable oligomer, etc., and may be, for example, a photoradical polymerizable compound.

[0049] The photopolymerizable monomer is a commonly used photocurable functional group, and for example, monomers having an unsaturated group such as a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group in the molecule can be used without limitation in the art. More specifically, for example, monofunctional and / or polyfunctional (meth)acrylates can be mentioned. These can be used alone or in admixture of two or more.

[0050] In the present invention, “(meth)acryl-” refers to “methacryl-”, “acryl-”, or both of them.

[0051] Specific examples of the (meth)acrylate monomer include, as (meth)acrylic acid esters, 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, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, and poly(meth)acrylate obtained by adding ethylene oxide or propylene oxide to the (meth)acrylic acid ester; oligoester (meth)acrylate, oligoether (meth)acrylate, oligourethane (meth)acrylate, and oligoepoxy (meth)acrylate having 1 to 3 (meth)acryloyl groups in the molecule; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and products obtained by adding ethylene oxide or propylene oxide to the (meth)acrylic acid ester; and mono(meth)acrylate esters, such as monomers having a trifunctional or less (meth)acryloyl group, such as isooctyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, and dipentaerythritol hexa(meth)acrylate, dipentaerythritol hydroxypenta(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, etc. These can be used alone or in combination of two or more kinds.

[0052] The photocurable oligomer can be one or more selected from the group consisting of, for example, epoxy (meth)acrylate, urethane (meth)acrylate, and polyester (meth)acrylate. Specifically, urethane (meth)acrylate and polyester (meth)acrylate can be mixed and used, or two types of polyester (meth)acrylate can be mixed and used. In order to improve the scratch resistance and hardness of the cured product and increase the elastic modulus of the hard coat layer, it is preferable to contain a urethane (meth)acrylate oligomer.

[0053] The urethane (meth)acrylate can be produced by reacting a polyfunctional (meth)acrylate having a hydroxy group in the molecule and a compound having an isocyanate group by a method known in the art in the presence of a catalyst.

[0054] 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-opening hydroxyacrylate, pentaerythritol tri / tetra (meth)acrylate mixture, and dipentaerythritol penta / hex (meth)acrylate mixture.

[0055] Specific examples of the compound having an isocyanate group may be one or more selected from the group consisting of 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 - 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 - dimethylphenyl isocyanate), 4,4'-oxybis(phenyl isocyanate), a trifunctional isocyanate derived from hexamethylene diisocyanate, and trimethanepropanol adduct toluene diisocyanate.

[0056] More specifically, the urethane (meth)acrylate oligomer may be a compound containing two or more substituents represented by the following chemical formula 1 and (meth)acryloyl groups in the molecule. [Chemical formula]

[0057] 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. [Chemical formula] 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.

[0058] Specific examples of urethane (meth)acrylate oligomers include the reaction of 2-hydroxyethyl (meth)acrylate and 2,4-tolylene diisocyanate, the reaction of 2-hydroxyethyl (meth)acrylate and isophorone diisocyanate, the reaction of 2-hydroxybutyl (meth)acrylate and 2,4-tolylene diisocyanate, the reaction of 2-hydroxybutyl (meth)acrylate and isophorone diisocyanate, the reaction of pentaerythritol tri(meth)acrylate and 2,4-toluene diisocyanate, the reaction of pentaerythritol tri(meth)acrylate and isophorone diisocyanate, the reaction of pentaerythritol tri(meth)acrylate and dicyclohexylmethane diisocyanate, the reaction of dipentaerythritol penta(meth)acrylate and isophorone diisocyanate, and the reaction of dipentaerythritol penta(meth)acrylate and dicyclohexylmethane diisocyanate. The product may also be a reaction product thereof.

[0059] Polyester (meth)acrylate can be produced by reacting a polyester polyol and acrylic acid by a method known in the art.

[0060] Polyester (meth)acrylate can be selected from, for example, 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.

[0061] 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 coat composition can be improved.

[0062] The content ratio of the photopolymerizable monomer and the photopolymerizable oligomer is not particularly limited and can be appropriately selected in consideration of the storage elastic modulus, shrinkage force, workability, etc. of the hard coat layer. For example, the content ratio of the photopolymerizable oligomer to the photopolymerizable monomer may be included at a ratio of (1:10) to (10:1). When the content ratio of the photopolymerizable oligomer to the photopolymerizable monomer exceeds the above range, the storage elastic modulus of the hard coat layer may decrease or the shrinkage force may increase, resulting in a decrease in hardness and flexibility, and thus curl may occur.

[0063] The content of the photopolymerizable compound is not particularly limited. For example, it may be contained in an amount of 1 to 80 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the entire hard coat composition. When the content of the polymerizable compound is less than 1 part by weight, the elastic modulus of the hard coat layer decreases, and cracks are likely to occur in the hard coat layer during bending. When it exceeds 80 parts by weight, the viscosity increases, the coatability decreases, and insufficient surface leveling may cause problems in appearance characteristics.

[0064] In order to improve the hardness and scratch resistance, the photopolymerizable compound can be used together with an inorganic nanofiller. Generally, the inorganic nanofiller can be a nanofiller having a size of less than 100 nm, preferably 10 to 100 nm, and more preferably 10 to 50 nm. As typical inorganic nanofillers, for example, silica, aluminum oxide particles, titanium oxide particles, or zinc oxide particles can be used, and preferably silica can be used. The silica may or may not have a photocurable group capable of participating in the photoreaction on its surface.

[0065] The content of the inorganic nanofiller can be appropriately adjusted and added within a range that does not inhibit the effects of the present invention.

[0066] Solvent The solvent can dissolve or disperse the composition as described above, and can be used without limitation as long as it is known as a solvent for a composition for forming a coat layer in the present technical field.

[0067] Solvents that can be used include alcohol-based ones (such as methanol, ethanol, isopropanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ketone-based ones (such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), acetate-based ones (such as ethyl acetate, propyl acetate, normal butyl acetate, tertiary butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate, methoxypentyl acetate, etc.), hexane-based ones (such as hexane, heptane, octane, etc.), benzene-based ones (such as benzene, toluene, xylene, etc.), ether-based ones (such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, etc.), etc., and these can preferably be used. The exemplified solvents can be used alone or in combination of two or more thereof.

[0068] Such solvents are used in an amount of 10 to 95 parts by weight based on 100 parts by weight of the whole hard coat composition. If the content of the solvent is less than the said content, not only will the viscosity be high and the workability be reduced, but also the swelling of the base film cannot proceed sufficiently. On the contrary, if it exceeds the said range, there is a problem that it takes a lot of time in the drying process and the economy is reduced, so it is used appropriately within the said range.

[0069] Initiator The initiator can be used without limitation as long as it is used in the relevant technical field. For example, one or more selected from the group consisting of hydroxyketones, aminoketones, hydrogen abstraction type photoinitiators, and combinations thereof can be used.

[0070] Specifically, as the photoinitiator, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, diphenyl ketone, benzyl 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-hydroxycyclohexyl phenyl ketone, benzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and one or more selected from the group consisting of combinations thereof can be used.

[0071] Such a photoinitiator is used in the range of 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the entire hard coat composition. If the content is less than the above range, the curing rate of the composition is slow, uncured occurs and the mechanical properties deteriorate. On the contrary, if it exceeds the above range, cracks may occur in the coating film due to overcuring.

[0072] Additive In addition, the hard coat composition used for forming the hard coat layer according to the present invention can further contain additives such as a leveling agent, an ultraviolet stabilizer and / or a heat stabilizer.

[0073] The leveling agent is a component that imparts smoothness and coatability to the coating film. The above leveling agent can be applied with leveling agents commonly used in the industry. For example, silicone-based leveling agents, fluorine-based leveling agents, acrylic polymer-based leveling agents, and the like can be mentioned. These can be used alone or in combination of two or more, but are not necessarily limited thereto.

[0074] The leveling agent may be contained in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the hard coat composition, but is not limited thereto.

[0075] An ultraviolet stabilizer is a component that blocks or absorbs ultraviolet rays to prevent decomposition, discoloration, and cracking of the cured hard coat layer due to ultraviolet exposure. The ultraviolet stabilizer can be classified by its mechanism of action into absorbers, quenchers, hindered amine light stabilizers (HALS), etc.; or classified by its chemical structure into phenyl salicylates (absorbers), benzophenone (absorber), benzotriazole (absorber), nickel derivatives (quenchers), radical scavengers, etc. These can be used alone or in combination of two or more, and the type is not particularly limited as long as it is an ultraviolet stabilizer that does not significantly change the initial color of the hard coat layer.

[0076] For heat stabilizers, for example, as commercially applicable products, polyphenol-based primary heat stabilizers, phosphate-based and lactone-based secondary heat stabilizers can be used alone or in combination respectively. These can be used alone or in combination of two or more.

[0077] The ultraviolet stabilizer and the heat stabilizer can be used by appropriately adjusting the content within a level that does not affect the ultraviolet curability. Specifically, it is preferably contained in an amount of 0.1 to 3 parts by weight based on 100 parts by weight of the entire hard coat composition of the present invention.

[0078] The additive can be added by appropriately adjusting the content within a range that does not inhibit the effects of the present invention.

[0079] The hard coat layer may be manufactured by a method known in the art. The thickness of the first hard coat layer is not particularly limited and may be, for example, 5 to 100 μm, and the thickness of the second hard coat layer may be 3 to 15 μm, preferably 5 to 10 μm. When the thickness is within the above range, better hardness and flexibility can be exhibited.

[0080] The hard coat film according to an embodiment of the present invention may be formed by coating a first hard coat composition on the display glass 110, and forming a first hard coat layer 120a through drying and UV curing steps. Thereafter, after coating a second hard coat composition on the first hard coat layer 120a, a second hard coat layer 120b may be formed through drying and UV curing steps, similar to the first hard coat layer.

[0081] The step of drying the hard coat film can be carried out by heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, etc., and can be performed at a temperature of 50 to 150 °C or 50 to 100 °C.

[0082] The step of curing the hard coat film irradiates actinic rays such as UV rays of 50 to 1000 mJ / cm 2 , preferably 200 to 800 mJ / cm 2 . In particular, the step of forming the first hard coat layer 120a performs weak primary curing at a level of 50 to 600 mJ / cm 2 , and the step of forming the second hard coat layer 120b irradiates UV with a strong light amount at 300 to 800 mJ / cm 2 to further strengthen the adhesion between the second hard coat layer and the first hard coat layer. As the light source used for irradiation, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, etc. can be used, and in some cases, X-rays, electron beams, etc. can also be utilized.

[0083] <Window and Image Display Device> Embodiments of the present invention provide a window and an image display device including the above-described display glass and hard coat film.

[0084] For example, the above-mentioned hard coat film or a laminate including the same is applicable to a window or a window laminate. At this time, at least one of a polarizing layer or a touch sensor layer may be laminated on one surface of the window on which the hard coat film is formed. Such a window or window laminate is applicable to a window film formed on the outermost surface of an image display device. Further, the hard coat film may be inserted inside, for example, an image display device.

[0085] The image display device includes various image display devices such as a liquid crystal display device, an electroluminescent display device, a plasma display device, and a field emission display device, and may be a flexible display device having flexibility and bending characteristics.

[0086] In this case, the hard coat laminate according to an embodiment of the present invention can be effectively applied to the window or window laminate of the flexible display device. Due to the interaction between the base material layer and the easy adhesion layer included in the hard coat film according to an embodiment of the present invention, both the flexibility and durability of the window are improved, and antistatic performance can be realized. As a result, for example, the impact resistance and abrasion resistance of the flexible display device are improved, and at the same time, damage such as cracks and peeling can be prevented even during bending.

Examples

[0087] Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the embodiments disclosed below, and can be realized in various different forms. The embodiments are merely provided to make the disclosure of the present invention complete and to fully inform those with ordinary knowledge in the technical field to which the present invention belongs of the scope of the invention. The present invention is defined only by the scope of the claims. “%” and “parts” are mass % and parts by mass, respectively, unless otherwise specified.

[0088] Production Example: Production of Hard Coat Composition Production Example 1 5 parts by weight of 1,4-functional acrylate (Osaka Organic Chemical Industry Co., Ltd., VISCOAT #1000), 43 parts by weight of 6-functional urethane acrylate (Shin-Nakamura Chemical Co., Ltd., U-6LPA), 1 part by weight of 1-hydroxycyclohexyl phenyl ketone, 1 part by weight of a fluorine-based UV-curable functional group-containing compound (Shin-Etsu Chemical Co., Ltd., KY-1203), and 50 parts by weight of methyl ethyl ketone were blended using a stirrer and filtered using a PP material filter to produce a second hard coat composition.

[0089] Production Example 2 5 parts by weight of 1,4-functional acrylate (Osaka Organic Chemical Industry Co., Ltd., VISCOAT #1000), 43 parts by weight of 6-functional urethane acrylate (Shin-Nakamura Chemical Co., Ltd., U-6LPA), 1 part by weight of 1-hydroxycyclohexyl phenyl ketone, 1 part by weight of a fluorine-based UV-curable functional group-containing compound (Fluorotechnology Co., Ltd., FS-7026), and 50 parts by weight of methyl ethyl ketone were blended using a stirrer and filtered using a PP material filter to produce a second hard coat composition.

[0090] Production Example 3 44 parts by weight of 2-functional acrylate (Miwon Specialty Chemical Co., Ltd., UA5216), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a silicone-based additive (BYK Co., Ltd., BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone Co., Ltd., KR-513) were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0091] Production Example 4 40 parts by weight of a difunctional acrylate (Miwon Specialty Chemical, UA5216), 4 parts by weight of a tetradecafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a silicone-based additive (BYK, BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone, KBM-5803) were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0092] Production Example 5 33 parts by weight of a difunctional acrylate (Miwon Specialty Chemical, UA5216), 11 parts by weight of a tetradecafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a silicone-based additive (BYK, BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone, KBM-503) were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0093] Production Example 6 22 parts by weight of a difunctional acrylate (Miwon Specialty Chemical, UA5216), 22 parts by weight of a tetradecafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a silicone-based additive (BYK, BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone, KBM-5803) were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0094] Production Example 7 11 parts by weight of a bifunctional acrylate (Miwon Specialty Chemical Co., Ltd., UA5216), 33 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry Co., Ltd., VISCOAT #1000), 0.5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a silicone-based additive (BYK Co., Ltd., BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone Co., Ltd., KBM-503) were blended using a stirrer and filtered using a filter made of PP material to produce a first hard coat composition.

[0095] Production Example 8 44 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry Co., Ltd., VISCOAT #1000), 0.5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a silicone-based additive (BYK Co., Ltd., BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic silane compound (Shin-Etsu Silicone Co., Ltd., KR-513) were blended using a stirrer and filtered using a filter made of PP material to produce a first hard coat composition.

[0096] Production Example 9 21.75 parts by weight of a bifunctional acrylate (Miwon Specialty Chemical Co., Ltd., UA5216), 21.75 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry Co., Ltd., VISCOAT #1000), 0.5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 parts by weight of a cationic initiator (IGM Co., Ltd., Omnirad-250), 0.5 parts by weight of a silicone-based additive (BYK Co., Ltd., BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an acrylic siloxane compound (Sooyang Chemtec Co., Ltd., ASO-101) were blended using a stirrer and filtered using a filter made of PP material to produce a first hard coat composition.

[0097] Production Example 10 21.75 parts by weight of a difunctional acrylate (Miwon Specialty Chemical, UA5216), 21.75 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a cationic initiator (IGM, Omnirad-250), 0.5 part by weight of a silicone-based additive (BYK, BYK-UV3530), 50 parts by weight of methyl ethyl ketone, and 5 parts by weight of an epoxy-based silane compound (Shin-Etsu Silicone, KR-517) were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0098] Production Example 11 5 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 43 parts by weight of a hexafunctional urethane acrylate (Shin-Nakamura Chemical, U-6LPA), 1 part by weight of 1-hydroxycyclohexyl phenyl ketone, 1 part by weight of a silicone-based additive (BYK, BYK-307), and 50 parts by weight of methyl ethyl ketone were blended using a stirrer and filtered using a PP material filter to produce a second hard coat composition.

[0099] Production Example 12 24.5 parts by weight of a difunctional acrylate (Miwon Specialty Chemical, UA5216), 24.5 parts by weight of a tetrafunctional acrylate (Osaka Organic Chemical Industry, VISCOAT #1000), 0.5 part by weight of 1-hydroxycyclohexyl phenyl ketone, 0.5 part by weight of a silicone-based additive (BYK, BYK-UV3530), and 50 parts by weight of methyl ethyl ketone were blended using a stirrer and filtered using a PP material filter to produce a first hard coat composition.

[0100] Examples and Comparative Examples: Production of Hard Coat Films The hard coat compositions of Production Examples 1 to 12 were laminated in the order shown in Tables 1 and 2 below to produce hard coat films.

[0101] Specifically, in order to form the first hard coat layer on a 50-μm thin glass, the composition of each production example was applied using a No. 40 bar coater, and then the solvent was dried at 90°C for 2 minutes. The dried coating film was irradiated with UV at a light quantity of 600 mJ / cm 2 to form a 25-μm first hard coat layer (HC1). The composition of the production example corresponding to each example was applied onto the formed first hard coat layer to form a second hard coat layer (HC2). After applying the composition of each example as the second hard coat composition using a No. 12 bar coater, the solvent was dried at 90°C for 2 minutes. Nitrogen was purged into the dried coating film, and under nitrogen conditions, it was irradiated with UV at a light quantity of 600 mJ / cm 2 to form a 7-μm second hard coat layer, thereby manufacturing the final laminated hard coat film.

[0102] In the case of Comparative Example 6, after applying the composition of Production Example 1 of the second hard coat layer as the second hard coat composition using a No. 3 bar coater, the solvent was dried at 90°C for 2 minutes. Nitrogen was purged into the dried coating film, and under nitrogen conditions, it was irradiated with UV at a light quantity of 600 mJ / cm 2 to form a 1-μm second hard coat layer, thereby manufacturing the final laminated hard coat film.

[0103] In the case of Comparative Example 7, after applying the composition of Production Example 1 of the second hard coat layer as the second hard coat composition using a No. 25 bar coater, the solvent was dried at 90°C for 2 minutes. Nitrogen was purged into the dried coating film, and under nitrogen conditions, it was irradiated with UV at a light quantity of 600 mJ / cm 2 to form a 20-μm second hard coat layer, thereby manufacturing the final laminated hard coat film.

[0104] [Table 1]

[0105] [Table 2]

[0106] Experimental Example The physical properties of the hard coat films produced in Examples 1 to 9 and Comparative Examples 1 to 7 were measured by the following methods, and the results are shown in Tables 1 and 2.

[0107] (1) Transmittance evaluation The transmittance of the coated film was measured using a haze meter HM-150N manufactured by Murakami Corporation.

[0108] (2) Scratch resistance evaluation After bonding the base film to the glass using a transparent adhesive so that the hard coat surface faced upward, scratch resistance was measured by reciprocating friction 10 times with a load of 500 g / cm 2 using steel wool (#0000). <Evaluation criteria> ○: When observing by transmitting and reflecting the measurement part on a three-wavelength lamp, no scratches are visually recognized, or 10 or fewer scratches are visually recognized. Χ: When observing by transmitting and reflecting the measurement part on a three-wavelength lamp, more than 10 scratches are visually recognized.

[0109] (3) Pencil hardness evaluation After fixing the base film to the glass so that the hard coat surface faced upward, the pencil hardness was measured under a load of 1 kg. Five tests were carried out with a pencil of the same hardness for a length of 1 cm, and the hardness with 4 or more OK was expressed as the pencil hardness.

[0110] (4) Antifouling property evaluation The contact angle of water was measured using a contact angle measuring instrument DSA100 manufactured by KRUSS. The liquid drop volume was 3 μl at room temperature. When the contact angle of water was 110° or more, it was selected as the pass criterion for the contact angle.

[0111] (5) Abrasion resistance evaluation It was measured by an abrasion resistance measuring device manufactured by DAESUNG PRECISION. After rubbing the coat surface 3000 times using an eraser for abrasion test and a 500 g weight, the contact angle was measured. At this time, when the contact angle of water was 95° or more, it was selected as the pass criterion for abrasion resistance.

[0112] (6) Chemical resistance evaluation It was measured by the wear-resistant measuring device of DAESUNG PRECISION. After rubbing the coat surface 3,000 times with a rubber eraser for wear test and a 500 g weight, the contact angle was measured. Ethanol (purity 99.8%) was applied onto the sample to be rubbed every 50 times. At this time, the case where the contact angle of water was 95° or more was selected as the pass criterion for wear resistance.

[0113] (7) POGO pressure resistance evaluation After fixing the manufactured hard coat glass with an adhesive (25 μm), the surface pressing performance was evaluated using a POGO pressing device. After pressing the hard coat surface with 4 kg using a 5 mm POGO chip, the film was left in an environmental condition of 25°C and 50%, and after 24 hours, the presence or absence of visual confirmation of the pressed part was checked. <Evaluation criteria> ○: Not visible at 4 kg Χ: Visible at 4 kg

[0114] (8) Anti-scattering property evaluation The opposite side of the manufactured hard coat glass was bent in a state joined with an adhesive (25 μm), and compression was applied using a UTM (Universal Testing Machine) device until it cracked. Check the state of the hard coat surface of the cracked sample. If the cracked glass fragments are the hard coat, check whether there are peeled or separated pieces outside. <Evaluation criteria> ○: No glass fragments confirmed Χ: Glass fragments confirmed

[0115] (9) Adhesion evaluation After joining the base film to the glass using a transparent adhesive so that the hard coat surface goes upward, after making incisions on the hard coat surface in 100 square shapes vertically and horizontally at 1 mm intervals with a cutter knife, an adhesion test was carried out 3 times using Nichiban tape. The result was expressed as "the number of OK squares after the adhesion test / 100". <Evaluation Criteria> ○: 100 / 100 Χ: 0 - 99 / 100

[0116] (10) Vickers Hardness Measurement The sample was placed so that the first hard coat layer was on top, and the Vickers hardness of the first hard coat layer against compression was measured with a nanoindenter (Fischer) at a micro load of 5 mN.

[0117] (11) Flexibility Evaluation The manufactured hard coat film was folded so that the second hard coat layers faced each other, and a folding test was performed 200,000 times so that the radius of curvature of the folded part was 5 mm. <Evaluation Criteria> ○: No cracks or breakage Χ: Cracks or breakage occurred

[0118] Referring to the experimental data in Table 1 and Table 2, in the cases of Examples 1 - 9 to which the laminate according to the examples of the present invention was applied, the pencil hardness was 3H or more, and all showed excellent results in the evaluation of scratch resistance, antifouling property, wear resistance, chemical resistance, pressure resistance, splash prevention, adhesion, and flexibility. On the other hand, in Comparative Examples 1 - 7 where the hard coat layer exceeded the examples of the present invention, one or more of the evaluation criteria of scratch resistance, antifouling property, wear resistance, chemical resistance, pressure resistance, splash prevention, adhesion, and flexibility did not reach the level of the present invention, and they could not show physical properties suitable for a hard coat film for a flexible display. In particular, in the case of Comparative Example 1 where the Vickers hardness of the first hard coat layer exceeded 20 kgf / mm 2 exceeded, a pressing phenomenon was visually observed in the pressure resistance evaluation, and glass fragments were confirmed in the splash prevention evaluation. Also, in the case of Comparative Example 6 where the thickness of the second hard coat layer was less than 3 μm, the contact angle of water was measured to be less than 95° in the wear resistance and chemical resistance evaluations, and in the case of Comparative Example 7 where the thickness of the second hard coat layer exceeded 15 μm, cracks or breakage occurred in the flexibility evaluation.

[0119] Therefore, it can be confirmed that the hard coat film according to the present invention, the window and the image display device to which this is applied have excellent physical properties in terms of durability during repeated folding, and particularly have an anti-scattering effect at the time of breakage.

Industrial Applicability

[0120] The hard coat film according to the present invention, the window and the image display device to which this is applied have a pencil hardness of 3H or more, and are excellent in scratch resistance, antifouling property, wear resistance, chemical resistance, pressure resistance, anti-scattering property, adhesion and flexibility, and the device reliability is improved when applied to a flexible display.

Explanation of Reference Numerals

[0121] 100: Laminate 110: Display glass 120a: First hard coat layer 120b: Second hard coat layer

Claims

1. For being formed on display glass, A silane or siloxane compound is included, and the Vickers hardness is 20 kgf / mm ２ The following first hard coat layer, and A hard coat film, characterized by comprising a second hard coat layer formed on the first hard coat layer, containing a fluorine-based UV curable functional group-containing compound, and having a thickness of 3 to 15 μm.

2. The hard coat film according to claim 1, wherein the display glass is UTG (Ultra Thin Glass).

3. The hard coat film according to claim 1, wherein the display glass, the first hard coat layer, and the second hard coat layer do not include other layers and are formed in direct contact with each other.

4. The hard coat film according to claim 1, wherein the fluorine-based UV curable functional group-containing compound has 1 to 6 UV curable functional groups.

5. The hard coat film according to claim 1, wherein either one of the first hard coat layer and the second hard coat layer is manufactured from a composition containing one or more selected from the group consisting of a photopolymerizable compound, an initiator, and a solvent.

6. The hard coat film according to claim 5, wherein the photopolymerizable compound further contains an inorganic nanofiller.

7. The hard coat film according to claim 1, wherein either one of the first hard coat layer and the second hard coat layer further contains an additive.

8. The hard coat film according to claim 7, wherein the additive contains one or more selected from the group consisting of a leveling agent, an ultraviolet stabilizer, and a heat stabilizer.

9. The hard coat film according to claim 1, which is applied to a flexible display.

10. A window including display glass and A hard coat film formed on the display glass, wherein the hard coat film includes the hard coat film according to any one of claims 1 to 9.

11. An image display device including the window according to claim 10. ​

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