Flexible window film and display device

Abstract

Provided are a flexible window film and a display device, the flexible window film comprising: a base layer; and a hard coating layer laminated on the upper surface of the base layer, wherein the hard coating layer comprises a cured product of a composition containing a photocurable compound, a reactive fluorine-based compound, an antistatic agent, and a photo-initiator, the antistatic agent contains a conductive polymer, and the conductive polymer is contained in an amount of 0.1 to 0.3 parts by weight relative to 100 parts by weight of the photocurable compound.

Description

Flexible window films and display devices

[0001] According to one embodiment, the present invention relates to a flexible window film and a display device including the same.

[0002] Interest in flexible display devices is growing. In response to this growing interest, window films mounted on flexible display devices are also required to be flexible. Since window films serve to protect internal optical elements within the display device, it may be desirable for them to have a hard coating layer. In one example, the window film includes a substrate layer and a hard coating layer formed on the substrate layer.

[0003] Flexible display devices are films that can be folded and restored hundreds of thousands of times in both the substrate and hard coating layers. For example, the substrate layer may be a polyimide film. Window films should preferably exhibit excellent bending reliability and impact resistance at low and high temperatures and high humidity.

[0004] The background technology of the present invention is disclosed in Japanese Patent Publication No. 2008-037101, etc.

[0005] According to one embodiment, a window film is provided that is excellent in antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance.

[0006] According to one embodiment, a flexible window film is provided.

[0007] 1. The flexible window film includes a substrate layer and a hard coating layer laminated on an upper surface of the substrate layer, and the hard coating layer includes a cured product of a composition including a photocurable compound, a reactive fluorine-based compound, an antistatic agent, and a photoinitiator, and the antistatic agent includes a conductive polymer, and the conductive polymer is included in an amount of 0.1 to 0.3 parts by weight based on 100 parts by weight of the photocurable compound.

[0008] In 2.1, the photocurable compound may include a mixture of a urethane-based (meth)acrylate and a thiol-based monomer.

[0009] In 3.1-2, the mixture of the urethane-based (meth)acrylate and the thiol-based monomer may be included in an amount of 95 wt% or more of the photocurable compound.

[0010] In 4.1-3, among 100 parts by weight of the photocurable compound, the urethane (meth)acrylate may be included in an amount of 80 to 99 parts by weight, and the thiol monomer may be included in an amount of 1 to 20 parts by weight.

[0011] In 5.1-4, the conductive polymer may be a thiophene-based polymer.

[0012] In 6.1-5, the thiol monomer may be at least one of tetra(3-mercaptopropionic acid)pentaerythritol ester, trimethylolpropanetri(3-mercaptopropionic acid ester), or bis(3-mercaptopropionic acid)ethylene glycol.

[0013] In 7.1-6, the reactive fluorine compound may be included in an amount of 0.01 to 1 part by weight, and the conductive polymer may be included in an amount of 0.1 to 0.3 parts by weight, relative to 100 parts by weight of the photocurable compound.

[0014] In 8.1-7, the conductive polymer may be included in an amount of 95 wt% or more of the antistatic agent.

[0015] In 9.1-8, the conductive polymer may be included in an amount of 30 to 150 parts by weight per 100 parts by weight of the reactive fluorine-based compound.

[0016] According to one embodiment, an optical display device is provided.

[0017] The above optical display device includes the flexible window film.

[0018] According to one embodiment, a window film having excellent antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance was provided.

[0019] Figure 1 is a cross-sectional view of a window film according to one embodiment.

[0020] With reference to the attached drawings, the present invention is described in detail with respect to embodiments thereof so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0021] In order to clearly explain the present invention in the drawings, parts irrelevant to the description have been omitted, and the same or similar components have been designated with the same drawing reference numerals throughout the specification. The length, thickness, etc. of each component in the drawings are illustrated to explain the present invention, and the present invention is not limited to the length, thickness, etc. described in the drawings.

[0022] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0023] As used herein, “combination thereof” means a mixture, laminate, composite, copolymer, alloy, blend, reaction product, etc. of the components.

[0024] It should be understood that the terms “include,” “comprising,” or “having” used in this specification are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0025] In this specification, "upper" and "lower" are defined based on the drawing, and depending on the perspective, "upper" may be changed to "lower" and "lower" may be changed to "upper". Also, "on" or "on" may include not only directly on but also cases where there is another structure intervening. On the other hand, "directly on" or "directly on" means that there is no other structure intervening.

[0026] In this specification, “(meth)acrylic” may mean acrylic and / or methacrylic.

[0027] When a numerical range is described in this specification, ‘X to Y’ means ‘X or more and Y or less (X≤ and ≤Y)’.

[0028] According to one embodiment, the present invention provides a window film having excellent antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance. The window film comprises a substrate layer and a hard coating layer laminated on one surface of the substrate layer, wherein the hard coating layer can provide excellent antistatic properties, excellent optical transparency, excellent fingerprint resistance, excellent abrasion resistance, excellent bending reliability, and excellent crack resistance.

[0029] According to one embodiment, a flexible window film includes a substrate layer and a hard coating layer laminated on an upper surface of the substrate layer, wherein the hard coating layer includes a cured product of a composition including a photocurable compound, a reactive fluorine-based compound, an antistatic agent, and a photoinitiator, wherein the antistatic agent includes a conductive polymer, and the conductive polymer is included in an amount of 0.1 to 0.3 parts by weight based on 100 parts by weight of the photocurable compound.

[0030] Substrate layer

[0031] The substrate layer can support the window film and increase the mechanical strength of the window film.

[0032] The substrate layer can be formed of an optically transparent and flexible resin. According to one embodiment, the resin is selected from the group consisting of polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulose resins such as diacetyl cellulose and triacetyl cellulose; polycarbonate resins; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrene resins such as polystyrene and acrylonitrile-styrene copolymers; polyolefin resins such as polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, and ethylene-propylene copolymers; vinyl chloride resins; amide resins such as nylon and aromatic polyamides; polyimide resins; sulfone resins; polyethersulfone resins; polyetheretherketone resins; sulfated polyphenylene resins; vinyl alcohol resins; Examples of films made of thermoplastic resins include vinylidene chloride resins; vinyl butyral resins; allylate resins; polyoxymethylene resins; and epoxy resins. Films made of blends of the above thermoplastic resins can also be used. In addition, films made of thermosetting resins such as (meth)acrylic, urethane, acrylic urethane, epoxy, and silicone resins, or ultraviolet-curable resins can also be used.

[0033] According to one embodiment, the substrate layer may be a film comprising a polyester resin, for example, polyethylene terephthalate.

[0034] The substrate layer may be a single-layer film. However, the present invention may also include a case where the substrate layer is a laminate in which two or more identical or different resin films are laminated to each other via an adhesive layer, an adhesive layer, or a pressure-sensitive adhesive layer.

[0035] The substrate layer may additionally include a primer layer or a coating layer for providing additional functions on one or both sides. According to one embodiment, the substrate layer may be a single-layer film formed of the above-described resin without a primer layer or an adhesive layer on one or both sides.

[0036] The thickness of the substrate layer may be 20 to 100 μm, for example, 30 to 80 μm. When the thickness of the substrate layer is within the above range, the strength of the window film including the substrate layer may be improved, thereby improving processability, preventing a decrease in transparency, and enabling a reduction in the weight of the film.

[0037] hard coating layer

[0038] The hard coating layer comprises a cured product of a composition comprising a photocurable compound, a reactive fluorine-based compound, a conductive polymer, and a photoinitiator, wherein the conductive polymer is contained in an amount of 0.1 to 0.3 parts by weight based on 100 parts by weight of the photocurable compound.

[0039] Hereinafter, each component of the composition for the hard coating layer will be described in detail.

[0040] photocurable compounds

[0041] The photocurable compound comprises a mixture of a urethane-based (meth)acrylate and a thiol-based monomer.

[0042] According to one embodiment, the mixture of a urethane-based (meth)acrylate and a thiol-based monomer may be included in the photocurable compound in an amount of 95 wt% or more, preferably 99 to 100 wt%, or 100 wt%. In the above range, when the reactive fluorine-based compound and the conductive polymer described below are included, it may be easy to improve the bending resistance of the window film.

[0043] In one specific example, the window film may have a crack strain of 10% or more, for example, 10 to 20%. Within this range, the window film has excellent flexibility, so that even when applied to the outermost surface of a flexible display device, the window film may not break or otherwise fail.

[0044] The above urethane-based (meth)acrylate is cured by a photoinitiator to form a matrix of a hard coating layer. The urethane-based (meth)acrylate may be advantageous in increasing the flexibility of the window film compared to a hard coating layer formed with a composition containing a non-urethane-based (meth)acrylate without a urethane functional group.

[0045] The above urethane-based (meth)acrylate can be produced by reacting a compound having an isocyanate group with a polyol having multiple hydroxyl groups in the molecule in the presence of a catalyst to form a urethane, and then reacting the (meth)acrylate having a hydroxyl group in the molecule.

[0046] The above polyol may include at least one of an ether-based polyol and an ester-based polyol.

[0047] Specific examples of compounds having the above 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-cyclohexenediisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), isophoronediisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, At least one may be selected from the group consisting of 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate), 4,4'-oxybis(phenylisocyanate), a trifunctional isocyanate derived from hexamethylene diisocyanate, and trimethanepropanol adduct toluene diisocyanate.

[0048] Specific examples of (meth)acrylates having a hydroxy group in the molecule include at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxyisopropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, caprolactone ring-opening hydroxy acrylate, pentaerythritol tri / tetra(meth)acrylate mixture, and dipentaerythritol penta / hexa(meth)acrylate mixture.

[0049] In the reaction for producing the above urethane-based (meth)acrylate, in the process of reacting a (meth)acrylate having a hydroxyl group in the molecule, a monomer having multiple (meth)acrylate groups may be further used.

[0050] Specific examples of the monomer having the above (meth)acrylate group include neopentyl glycol acrylate, 1,6-hexanediol (meth)acrylate, propylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1,2,4-cyclohexane tetra(meth)acrylate, pentaglycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate. At least one may be selected from the group consisting of dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol tri(meth)acrylate, tripentaerythritol hexatri(meth)acrylate, bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, isooctyl(meth)acrylate, iso-dexyl(meth)acrylate, stearyl(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, phenoxyethyl(meth)acrylate, and isoborneol(meth)acrylate.

[0051] According to one embodiment, the urethane-based (meth)acrylate may be a urethane-based (meth)acrylate having two or more, preferably five or more, more preferably ten or more, and most preferably 10 to 20 (meth)acrylate groups. In the above range, when including a reactive fluorine-based compound and a conductive polymer described below, it may be advantageous in increasing flexibility, hardness, etc.

[0052] According to one embodiment, among 100 parts by weight of the photocurable compound, the urethane (meth)acrylate may be included in an amount of 80 to 99 parts by weight, for example, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 parts by weight, 85 to 99 parts by weight, or 85 to 95 parts by weight. In the above range, it may be advantageous to increase the flexibility of the window film.

[0053] The above thiol monomer may be a compound having two or more thiol groups (-SH), preferably two to five. Within the above range, when including the reactive fluorine-based compound and conductive polymer described below, wear resistance, hardness, etc. may be excellent.

[0054] According to one embodiment, the thiol monomer may be at least one of tetra(3-mercaptopropionic acid)pentaerythritol ester, trimethylolpropane tris(3-mercaptopropionic acid ester), or bis(3-mercaptopropionic acid) ethylene glycol.

[0055] According to one embodiment, the thiol monomer may be included in an amount of 1 to 20 parts by weight, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 parts by weight, 1 to 15 parts by weight, or 5 to 15 parts by weight, per 100 parts by weight of the photocurable compound. In the above range, it may be advantageous to increase the flexibility of the window film.

[0056] The composition includes a reactive fluorine compound to improve the fingerprint resistance, abrasion resistance, crack resistance, and bending resistance of the window film. The reactive fluorine compound is one of several materials known in the art to improve fingerprint resistance, abrasion resistance, crack resistance, and bending resistance, and is effective in improving the fingerprint resistance, abrasion resistance, and crack resistance of a hard coating layer formed with a composition containing the photocurable compound.

[0057] In this regard, the window film may have a water contact angle of 110 to 120° measured on the hard coating layer at, for example, 25°C. In this range, the window film may provide excellent fingerprint resistance.

[0058] In this regard, the window film may have an abrasion resistance of 5,000 or more cycles as measured by the measurement method below. Within this range, the window film may provide excellent abrasion resistance.

[0059] In this regard, the window film may have the above-described crack strain.

[0060] In this regard, the window film may have an indentation hardness of 35 hv or more, for example, 35 to 45 hv. Within this range, the window film may provide excellent crack resistance.

[0061] reactive fluorine compounds

[0062] The reactive fluorine-based compound may be a (meth)acrylate containing a perfluoroalkyl group, a (meth)acrylate containing a perfluoropolyether group, a (meth)acrylate containing a perfluoroalicyclic group, or a (meth)acrylate containing a perfluoroaromatic group, and these may be used alone or in combination of two or more, but are not limited thereto.

[0063] According to one embodiment, the reactive fluorine-based compound may be included in an amount of 0.01 to 1 part by weight, for example, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 part by weight, 0.1 to 0.5 part by weight, or 0.2 to 0.4 part by weight, based on 100 parts by weight of the photocurable compound. In the above range, the flexibility of the window film is improved and the water contact angle is reached, thereby improving the anti-fingerprint property of the window film.

[0064] antistatic agent

[0065] A window film comprising a hard coating layer comprising a cured product of a composition for a hard coating layer comprising the photocurable compound and the reactive fluorine compound can provide a window film having excellent hardness and flexibility. However, the window film may have limitations in providing excellent antistatic properties.

[0066] The above antistatic agent includes a conductive polymer.

[0067] The conductive polymer can be included in a composition including the photocurable compound and the reactive fluorine compound to improve the antistatic properties of the window film.

[0068] According to one embodiment, the conductive polymer may be included in an amount of 95 wt% or more, for example, 95 to 100 wt%, or 100 wt%, of the antistatic agent. Within this range, excellent antistatic properties can be provided without affecting the optical transparency, fingerprint resistance, abrasion resistance, and bending reliability of the above-described window film.

[0069] The conductive polymer is included in an amount of 0.1 to 0.3 parts by weight per 100 parts by weight of the photocurable compound.

[0070] If the conductive polymer is included in an amount of less than 0.1 part by weight relative to 100 parts by weight of the photocurable compound, the effect of improving antistatic properties may be minimal. In this regard, the window film may have a surface resistance of 1 x 10 11 Ω / □ or less, for example, 5 x 10 9 Ω / □ to 1 x 10 11 It can be Ω / □.

[0071] If the conductive polymer is included in an amount exceeding 0.3 parts by weight relative to 100 parts by weight of the photocurable compound, the optical transparency of the window film may become poor, and the fingerprint resistance, abrasion resistance, and bending reliability may become poor.

[0072] In this regard, the window film may have a light transmittance (e.g., total optical transmittance) of 91% or more and a haze of 1.0% or less. Within the above range, the window film may be used in an optical display device.

[0073] The conductive polymer may be included in an amount of 0.1, 0.15, 0.2, 0.25, or 0.3 parts by weight per 100 parts by weight of the photocurable compound.

[0074] The above conductive polymers include polymers containing repeating units derived from thiophene-based, carbazole-based, phenylene-based, vinylene-based, acetylene-based, aniline-based, phenylenediamine-based, and pyrrole-based monomers, viologen derivatives, phenothiazine-based, tetrathiafulvalene-based, etc., and these may be used singly or in combination of two or more.

[0075] Preferably, the conductive polymer is a thiophene-based polymer, such as polyethylenedioxythiophene (polystyrene sulfonate).

[0076] The conductive polymer must be included in an appropriate amount with respect to the reactive fluorine compound to provide a window film having excellent antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance.

[0077] According to one embodiment, the conductive polymer may be included in an amount of 30 to 150 parts by weight, for example, 30 to 120 parts by weight, or 30 to 100 parts by weight, based on 100 parts by weight of the reactive fluorine-based compound. Within this range, the window film may exhibit excellent antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance.

[0078] photoinitiator

[0079] The photoinitiator can cure a photocurable compound including a urethane (meth)acrylate and a thiol monomer.

[0080] The photoinitiator may be a radical photoinitiator. Any photoinitiator capable of curing the above-described resin, etc., during a curing process such as light irradiation may be used without limitation. For example, the photoinitiator may be a benzoin-based, acetophenone-based, hydroxy ketone-based, amino ketone-based, or phosphine oxide-based photoinitiator. Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylamino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4nonsidiethylaminobenzophenone, dichlorobenzophenone, Examples thereof include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and 1-hydroxy-cyclohexyl-phenyl ketone. Preferably, a hydroxy ketone-based initiator can be used.

[0081] The photoinitiator may be included in an amount of 0.5 to 10 parts by weight, for example, 1 to 5 parts by weight, relative to 100 parts by weight of the photocurable compound. Within the above range, the composition for the hard coating layer is sufficiently cured, and a phenomenon in which a residual amount of initiator remains and the transparency of the window film deteriorates can be prevented.

[0082] The hard coating layer may have a thickness of 1 to 50 μm, specifically 3 to 30 μm, or 4 to 20 μm. Within the above range, it may be used in a flexible window film.

[0083] The composition for the hard coating layer may further include an additive. The additive may provide additional functions to the window film. The additive may include additives commonly added to the window film. Specifically, the additive may include one or more of a leveling agent, a UV absorber, a reaction inhibitor, an adhesion promoter, a thixotropic agent, a conductivity agent, a color regulator, a stabilizer, an antistatic agent, and an antioxidant, but is not limited thereto. The additive may be included in an amount of 0.01 to 5 parts by weight, specifically 0.1 to 3 parts by weight, based on 100 parts by weight of the photocurable compound. Within the above range, the hardness and flexibility of the window film may be improved and the additive effect may be realized.

[0084] The composition for a hard coating layer may further include a solvent to facilitate coating, coating, or processability. The solvent may include, but is not limited to, one or more of methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, and N,N-dimethylacetamide. The solvent may be included as the remainder of the composition for a hard coating layer.

[0085] The hard coating layer can be formed by coating and curing the composition for the hard coating layer on one surface of the substrate layer. The method for coating the composition for the hard coating layer on the substrate layer is not particularly limited. For example, it can be bar coating, spin coating, dip coating, roll coating, flow coating, die coating, etc. Curing can include one or more of photocuring and thermal curing. Photocuring can be performed at a wavelength of 400 nm or less and at a temperature of 10 mJ / cm. 2 1,000mJ / cm 2It may include irradiating with a light amount of . The thermal curing may include applying the composition for the hard coating layer to a predetermined thickness and drying at 80° C. to 150° C. for 5 to 30 minutes.

[0086] The window film may have a thickness of 30 to 200 μm, for example, 30 to 80 μm. It may be used as a flexible window film within the above range.

[0087] Hereinafter, a window film according to one embodiment of the present invention will be described with reference to FIG. 1.

[0088] Referring to FIG. 1, the window film includes a substrate layer (110) and a hard coating layer (120) formed on one surface of the substrate layer (110).

[0089] Below, a method for manufacturing window film is described.

[0090] The window film can form a hard coating layer on the substrate layer by coating a composition for a hard coating layer on the upper surface of the substrate layer and curing the composition.

[0091] The coating method is a conventional method known to those skilled in the art. For example, the coating method may include, but is not limited to, spray coating, die coating, or spin coating. Curing may include one or more of photocuring and thermal curing. The curing conditions for photocuring and thermal curing may be adjusted depending on the thickness of each layer, the material of each layer, etc. Curing may be performed in conjunction with drying, etc., to reduce the surface roughness of each layer or shorten the curing time.

[0092] Hereinafter, the display device of the present invention will be described.

[0093] The display device of the present invention includes the flexible window film of the present invention described above. The display device may be a flexible display device or a non-flexible display device. For example, the display device may be a light-emitting display device, such as an organic light-emitting display device, a liquid crystal display device, or the like, but is not limited thereto.

[0094] Hereinafter, the present invention will be described in more detail through examples; however, these examples are for the purpose of explanation only and should not be construed as limiting the present invention.

[0095]

[0096] Below, the specific specifications of the components used in the examples and comparative examples are as follows.

[0097] a. Urethane acrylate: LP-9000 (Kellon, 15-functional acrylate)

[0098] b. Thiol monomer: ST-032AC (ShinATNC, trifunctional thiol monomer)

[0099]

[0100] c. Reactive fluorine compound: D-100 (Daikin)

[0101] d. Conductive polymer: PEDOT:PSS (SB14, Heraeus)

[0102] e. Photoinitiator: Omnirad-184

[0103]

[0104] Example 1

[0105] A composition for a hard coating layer was prepared by mixing 0.3 parts by weight of a reactive fluorine compound, 0.2 parts by weight of a conductive polymer, and 3 parts by weight of a photoinitiator based on 100 parts by weight of a mixture of 90 parts by weight of urethane acrylate and 10 parts by weight of a thiol monomer, and mixing methyl propylene glycol (PGME) as a solvent.

[0106] Polyethylene terephthalate film (thickness: 50㎛) was used as the substrate layer.

[0107] The composition for the hard coating layer prepared above is coated on the upper surface of the substrate layer to a predetermined thickness, dried at 80°C for 2 minutes, and UV is applied at 300 mJ / cm 2 By investigating the century, the composition for the hard coating layer was photocured, and a window film having a hard coating layer with a thickness of 5 ㎛ formed on the upper surface of the base layer was manufactured.

[0108]

[0109] Examples 2 and 3

[0110] A window film was manufactured in the same manner as in Example 1, except that the content of each component in the composition for the hard coating layer in Example 1 was changed as shown in Table 1 below.

[0111]

[0112] Comparative Examples 1 to 6

[0113] A window film was manufactured in the same manner as in Example 1, except that the content of each component was changed as shown in Table 1 below.

[0114] In Table 1 below, '-' means that the content of the corresponding ingredient is 0 parts by weight.

[0115]

[0116] The following physical properties were evaluated for the window films manufactured in the examples and comparative examples, and the results are shown in Table 1 below.

[0117] physical properties

[0118] (1) Surface resistance (unit: Ω / □): The surface resistance of the hard coating layer of the window film was measured using a surface resistance meter (HT-450, Mitsubishi Chemical Co.) at 25°C for 10 seconds at a voltage of 10 V, and the displayed surface resistance value was recorded.

[0119] (2) Light transmittance and haze (unit: %): For window films, haze was measured using a Hazemeter (NDH2000, Nippon Denshoku), and for window films, light transmittance was measured using a CM-3600A (Konica Minolta).

[0120] (3) Water contact angle (unit: °): Measured at 25℃ using a water contact angle measuring device Phoenic 300 (SEO) on the hard coating layer surface of the window film.

[0121] (4) Abrasion resistance (unit: times): A window film was cut into a size of length x width (100 mm x 10 mm) to produce a specimen, the specimen was mounted on an abrasion resistance evaluation device, a load of 1 kg was applied to the eraser, the eraser was pressed against the hard coating layer, and then repeatedly moved a distance of 2 cm. Then, the water contact angle was measured on the surface of the hard coating layer using the same method as (2) above.

[0122] (5) Indentation hardness (unit: hv): Indentation hardness was measured using Vickers hardness. The window film was mounted on a nanoindenter (HM2000, FIsherscope) and the hard coating layer was pressed using a Vickers tip to measure the hardness.

[0123] (6) Crack strain (unit: %): The window film was cut into a size of length x width (100 mm x 10 mm) to manufacture a specimen, and the manufactured specimen was mounted on a crack strain device. When the specimen was stretched in the longitudinal direction, the value at which no cracks occurred in the hard coating layer was measured. A higher crack strain value means better flexibility of the window film.

[0124] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Urethane acrylate 909090100100100909090 Thiol monomer 101010---101010 Photoinitiator 33333333 Reactive fluorine compound 0.30.30.3-0.30.30.30.3 Conductive polymer 0.20.10.3--0.2-0.050.5 Surface resistance 1x10 10 5x10 10 5x10 9 OVEROVER2x10 10 OVER1x10 12 1x10 9 Light transmittance91.591.79193.593.69193.49288 Haze0.40.40.40.40.30.40.20.30.5 Water contact angle11111211082114110114112105 Abrasion resistance100001000010000NG100001000010000100001000 Indentation hardness363735454545353636 Crack strain10101034210109

[0125]

[0126] *In Table 1 above, 'OVER' means that the surface resistance value is too high to be measured.

[0127]

[0128] As shown in Table 1 above, the window film of the example was excellent in antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance.

[0129] However, the window film of the comparative example did not simultaneously provide excellent antistatic properties, optical transparency, fingerprint resistance, abrasion resistance, bending reliability, and crack resistance compared to the example.

[0130]

[0131] Simple modifications or changes of the present invention can be easily implemented by a person having ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims

1. Includes a base layer and a hard coating layer laminated on the upper surface of the base layer, The hard coating layer comprises a cured product of a composition comprising a photocurable compound, a reactive fluorine compound, an antistatic agent, and a photoinitiator, The above antistatic agent comprises a conductive polymer, A flexible window film, wherein the conductive polymer is included in an amount of 0.1 to 0.3 parts by weight based on 100 parts by weight of the photocurable compound.

2. A flexible window film according to claim 1, wherein the photocurable compound comprises a mixture of a urethane-based (meth)acrylate and a thiol-based monomer.

3. A flexible window film in the second paragraph, wherein the mixture of the urethane-based (meth)acrylate and the thiol-based monomer is included in an amount of 95 wt% or more of the photocurable compound.

4. A flexible window film in the second paragraph, wherein among 100 parts by weight of the photocurable compound, the urethane (meth)acrylate is contained in an amount of 80 to 99 parts by weight, and the thiol-based monomer is contained in an amount of 1 to 20 parts by weight.

5. A flexible window film according to claim 1, wherein the conductive polymer is a thiophene-based polymer.

6. A flexible window film according to claim 1, wherein the thiol monomer is at least one of tetra(3-mercaptopropionic acid)pentaerythritol ester, trimethylolpropanetri(3-mercaptopropionic acid ester), or bis(3-mercaptopropionic acid)ethylene glycol.

7. In paragraph 1, for 100 parts by weight of the photocurable compound, The above reactive fluorine compound is 0.01 to 1 part by weight, A flexible window film, wherein the conductive polymer is included in an amount of 0.1 to 0.3 parts by weight.

8. A flexible window film according to claim 1, wherein the conductive polymer comprises at least 95 wt% of the antistatic agent.

9. A flexible window film according to claim 1, wherein the conductive polymer is included in an amount of 30 to 150 parts by weight based on 100 parts by weight of the reactive fluorine-based compound.

10. A display device comprising a flexible window film according to any one of claims 1 to 9.

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