KR20240048357A - Hard coating composition, hard coating film and flexible display window - Google Patents

Abstract

The hard coating composition of embodiments of the present invention may include a compound represented by Formula 1. As a result, a hard coating film with improved mechanical and bending properties can be manufactured.
[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₁₀ hydrocarbon group or a C ₂ -C ₁₀ ether group, and m and n are each independently an integer of 1 to 10.

Description

Hard coating composition, hard coating film and flexible display window {HARD COATING COMPOSITION, HARD COATING FILM AND FLEXIBLE DISPLAY WINDOW}

The present invention relates to hard coating compositions, hard coating films, and flexible display windows. More specifically, it relates to a hard coating composition containing a film base resin and additives, a hard coating film formed therefrom, and a flexible display window containing the hard coating film.

Recently, image display devices, such as liquid crystal display (LCD) devices or organic light emitting display (OLED) devices, have continued to become thinner and more flexible. Accordingly, the image display device is widely applied to various smart devices characterized by portability, including smart phones and tablet PCs, as well as various wearable devices. there is.

To protect the image display device from external environments such as scratches, drop impacts, external moisture, oil, etc., a window film made of, for example, tempered glass may be formed on the display panel.

Recently, the development of hard coating films with improved flexibility to realize flexible properties while realizing impact resistance equivalent to tempered glass is in progress.

For example, Korean Patent Publication No. 10-2016-0100121 discloses a hard coating composition containing a (meth)acrylate-based monomer mixture and a hard coating composition using the same.

Korean Patent Publication No. 10-2016-0100121

One object of the present invention is to provide a composition for producing a hard coating film with improved flexibility and durability.

One object of the present invention is to provide a hard coating film containing the hard coating film composition.

One object of the present invention is to provide a flexible display window including the hard coating film.

The hard coating composition according to an exemplary embodiment may include a compound represented by Formula 1.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₁₀ hydrocarbon group or a C ₂ -C ₁₀ ether group, and m and n are each independently an integer of 1 to 10.

In one embodiment, R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₈ hydrocarbon group or a C ₂ -C ₈ ether group, and m and n are each independently an integer of 1 to 8. .

In one embodiment, R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₆ hydrocarbon group or a C ₂ -C ₆ ether group, and m and n are each independently an integer of 1 to 5. .

In one embodiment, R ₁ and R ₂ may each independently be a single bond or methylene, and m and n may each independently be an integer of 1 to 3.

In one embodiment, Formula 1 may include at least one of the compounds represented by Formulas 1-1 to 1-4.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

In one embodiment, the hard coating composition may further include a photoinitiator and a solvent.

In one embodiment, the hard coating composition may include 20 to 60 parts by weight of the compound represented by Formula 1, 0.1 to 10 parts by weight of the photoinitiator, and an excess of the solvent, based on a total of 100 parts by weight of the hard coating composition.

In one embodiment, the hard coating composition may further include inorganic nanoparticles.

In one embodiment, the inorganic nanoparticles may include 5 to 40 parts by weight based on a total of 100 parts by weight of the hard coating composition.

The hard coating film according to an exemplary embodiment includes a base layer; And it is formed on the base layer and may include a hard coating layer formed from the hard coating composition.

A flexible display window according to an exemplary embodiment may include the hard coating film.

The hard coating composition according to exemplary embodiments of the present invention may include a compound represented by Chemical Formula 1 to produce a hard coating film.

The hard coating film has improved scratch resistance and impact resistance, and improved flexibility. Therefore, it can be used as a protective film or cover window for flexible displays.

1 is a schematic cross-sectional view showing a hard coating film according to example embodiments.
2 is a schematic cross-sectional view showing a window laminate according to example embodiments.

Embodiments of the present invention provide a hard coating composition containing a compound represented by Chemical Formula 1, which will be described later. Additionally, embodiments of the present invention provide a hard coating film and a window for a flexible display manufactured using the hard coating composition.

The present invention will be described in more detail with reference to the drawings and examples below. However, the following drawings and examples attached and described in this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention along with the contents of the above-described invention, and thus the present invention should not be construed as limited to the matters described in such drawings and examples.

<Hard coating composition>

The hard coating composition according to exemplary embodiments may include a compound represented by Formula 1.

The hard coating composition may include a compound represented by Chemical Formula 1. When a hard coating film manufactured including the compound represented by Formula 1 is applied to a flexible display, mechanical properties can be improved, excellent flexibility can be provided, and reliability is excellent.

[Formula 1]

In Formula 1, each of R ₁ and R ₂ may be independently the same or different from each other. For example, R ₁ and R ₂ may each be a substituted or unsubstituted C ₁ -C ₁₀ hydrocarbon group. For example, R ₁ and R ₂ may each be a substituted or unsubstituted C ₂ -C ₁₀ ether group. For example, R ₁ and R ₂ may each be a single bond.

For example, R ₁ and R ₂ are an unsubstituted C ₁ -C ₁₀ hydrocarbon group, an unsubstituted C ₁ -C ₈ hydrocarbon group, an unsubstituted C ₁ -C ₆ hydrocarbon group, and an unsubstituted C It may be a ₁ -C ₅ hydrocarbon group. For another example, R ₁ and R ₂ may be an unsubstituted C ₂ -C ₁₀ ether group, an unsubstituted C ₂ -C ₈ ether group, or an unsubstituted C ₂ -C ₆ ether group. For another example, R ₁ and R ₂ may be a single bond, methylene.

In Formula 1, m and n may each independently be integers from 1 to 10. For example, m and n can each independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. For another example, m and n may each independently be an integer of 1 to 8, an integer of 1 to 5, or an integer of 1 to 3.

In one embodiment, Formula 1 may include at least one compound represented by Formula 1-1 to Formula 1-4. A hard coating film manufactured using a hard coating composition containing the above compound can suppress defects such as delamination, cracking, and tearing even during repeated operations such as bending and folding. Additionally, it has excellent mechanical properties to ensure durability.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

In one embodiment, the content of the compound represented by Formula 1 may be about 20 to 60 parts by weight based on 100 parts by weight of the hard coating composition. If the content is less than about 20 parts by weight, it may be difficult to secure sufficient hardness of the hard coating layer. If the content exceeds about 60 parts by weight, curling may occur in the hard coating layer and the flexible properties may be impaired.

In some embodiments, the hard coating composition may further include a polymerizable compound. For example, the polymerizable compound may be a component that is photocured to provide the matrix of the hard coating layer. For example, the polymerizable compound may include a (meth)acrylate-based compound. In this application, “(meth)acrylate” is used as a term encompassing acrylate and methacrylate.

Non-limiting examples of (meth)acrylate-based compounds 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, dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol tri(meth)acrylate, tripentaerythritol hexatri(meth)acrylate Latex, 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, isoborneol (meth)acrylate etc. can be mentioned. These may be used alone or in combination of two or more.

In some examples, the (meth)acrylate-based compound may include polyfunctional (meth)acrylate. Accordingly, the hardness of the hard coating layer can be increased to provide improved scratch resistance and impact resistance.

In some embodiments, the polymerizable compound or (meth)acrylate-based compound may further include a urethane (meth)acrylate-based compound. Accordingly, the elasticity and bending properties of the hard coating layer can be improved.

The hard coating composition according to one embodiment may include a photoinitiator capable of forming radicals by light irradiation. A polymer structure can be formed through polymerization of the compound represented by Formula 1 using the photoinitiator.

Examples of photoinitiators include Type 1 initiators, which generate radicals by decomposition of molecules due to differences in chemical structure or molecular bond energy, and Type 2 initiators, which coexist with tertiary amines to induce hydrogen recapture.

For example, Type 1 initiators include 4-phenoxydichloroacetphenone, 4-t-butyldichloroacetphenone, 4-t-butyltrichloroacetphenone, diethoxyacetphenone, 2-hydroxy-2-methyl- l-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-l-one, 1-(4-dodecylphenyl)-2-hydroxy-2- Acetphenones such as methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenylketone; Benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzyl dimethyl ketal; It may include phosphine oxides, titanocene compounds, etc.

For example, Type 2 initiators include benzophenone, benzoylbenzoic acid, benzoylbenzoic acid methyl ether, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzole-4'-methyldiphenyl sulfide, 3,3'- Benzophenones such as methyl-4-methoxybenzophenone, thioxane such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, and isopropylthioxanthone Tone-based compounds, etc. can be mentioned.

The photoinitiator described above may be used alone or in combination of two or more types. Additionally, the Type 1 and Type 2 initiators may be used alone or in combination.

For example, the content of the photoinitiator may be about 0.1 to 10 parts by weight, preferably about 0.1 to 5 parts by weight, based on 100 parts by weight of the hard coating composition. If the content of the photoinitiator is less than about 0.1 part by weight, sufficient curing may not proceed and the mechanical properties and adhesion of the hard coating film or hard coating layer may not be secured. If the content of the photoinitiator exceeds about 10 parts by weight, poor adhesion, cracks, and curling may occur due to curing shrinkage in the (meth)acrylate group.

The hard coating composition according to one embodiment may further include inorganic nanoparticles. As the inorganic nanoparticles are included, mechanical properties such as wear resistance, scratch resistance, and pencil hardness of the hard coating film or hard coating layer can be further improved.

The type of inorganic nanoparticles is not particularly limited, but for example, Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , indium-tin-oxide ( It may be a metal oxide series including ITO), indium-zinc-oxide (IZO), antimony-tin-oxide (ATO), ZnO-Al, Nb ₂ O ₃ , SnO, MgO, or a combination thereof. In one embodiment, Al ₂ O ₃ , SiO ₂ and/or ZrO ₂ may be used as the inorganic nanoparticles.

In one embodiment, the content of the inorganic nanoparticles may be about 5 to 40 parts by weight based on a total of 100 parts by weight of the hard coating composition. If the content of the inorganic nanoparticles is less than about 5 parts by weight, sufficient mechanical properties such as wear resistance, scratch resistance, and pencil hardness may not be realized. If the content of the inorganic nanoparticles exceeds about 40 parts by weight, the polymerization or curing of the photocurable compound may be hindered, thereby weakening the mechanical properties.

For example, the inorganic nanoparticles may be used in the form of silica sol dispersed in an organic solvent at a concentration of about 10 to 80% by weight.

In some embodiments, the hard coating composition may further include additives such as anti-fingerprint agents, anti-static agents, leveling agents, etc.

As the anti-fingerprint agent, a silicone-based anti-fingerprint agent, a fluorine-based anti-fingerprint agent, or a silicon-containing fluorine-based anti-fingerprint agent may be used.

The leveling agent may include agents such as silicone-based, fluorine-based, and acrylic polymer-based agents. Examples of commercially available leveling agents include BYK-307, BYK-323, BYK-331, BYK-333, BYK-337, BYK-373, BYK-375, BYK-377, BYK-378, BYK-UV3570 from BYK; TEGO's TEGO Glide 410, TEGO Glide 411, TEGO Glide 415, TEGO Glide 420, TEGO Glide 432, TEGO Glide 435, TEGO Glide 440, TEGO Glide 450, TEGO Glide 455, TEGO Rad 2100, TEGO Rad 2200N, TEGO Rad 2250, TEGO Rad 2300, TEGO Rad 2500; Examples include 3M's FC-4430 and FC-4432.

Non-limiting examples of antistatic agents include ionic liquids, conductive polymers, lithium salts, quaternary ammonium salts, and metal oxide particles.

In some embodiments, the hard coating composition may further include an ultraviolet ray stabilizer and/or a heat stabilizer as the additive. The UV stabilizer may be added to prevent the surface of the coating film formed from the composition from discoloring or crumbling due to exposure to UV rays by blocking or absorbing UV rays.

UV stabilizers can be classified into absorbers, quenchers, and Hindered Amine Light Stabilizers (HALS) depending on their mechanism of action, for example, phenyl salicylates (absorbers), benzoate. Benzophenone (absorbent), benzotriazole (absorbent), nickel derivative (quencher), radical scavenger, etc. can be used. As the heat stabilizer, polyphenol-based, phosphite-based, and lactone-based heat stabilizers can be used.

The additives may be appropriately mixed and used at a level that does not impair the UV curing process and the hardness and optical properties of the hard coating layer. For example, the additive may be included in an amount of about 0.1 to 5 parts by weight based on a total of 100 parts by weight of the hard coating composition.

In the hard coating composition according to embodiments of the present invention, solvents commonly used in the art can be used without particular limitation.

For example, alcohols (methanol, ethanol, isopropanol, butanol, methyl cellusov, ethyl solusov, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, Cyclohexanone, etc.), acetate series (ethyl acetate, propyl acetate, n-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.), hydrocarbon type (hexane, heptane, octane, etc.), benzene type (benzene, toluene, xylene, etc.), ether type (diethylene glycol dimethyl ether) , diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, etc.) can be used. These may be used alone or in combination of two or more types.

The content of the solvent is not particularly limited as long as it can dissolve the components of the composition described above, and may be included in the remaining amount excluding the components described above or the additives described below. For example, the solvent may be included in an amount of about 20 to 70 parts by weight based on a total of 100 parts by weight of the hard coating composition.

If the content of the solvent is less than about 20 parts by weight, the viscosity of the composition may increase excessively, resulting in reduced applicability and workability. If the content of the solvent exceeds about 70 parts by weight, it is difficult to form a hard coating film or hard coating layer of uniform thickness, and staining may occur when drying, which may damage optical properties.

<Hard coating film, optical filter>

1 is a schematic cross-sectional view showing a hard coating film according to example embodiments.

Referring to FIG. 1, the hard coating film may include a base layer 100 and a hard coating layer 110 formed on one side of the base layer 100.

The base layer 100 may be a transparent polymer film so that it can be applied to a flexible display. For example, the base layer 100 is made of triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, poly Etherimide, polyacrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone. , may include polymer films such as polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polycarbonate. The base layer 100 may include one or two or more of these.

In a preferred embodiment, the base layer 100 may include polyimide-based resin to ensure high elasticity applicable to flexible displays.

The hard coating layer 110 may be formed by applying the hard coating composition according to the above-described exemplary embodiments on the base layer 100 and then performing a curing process such as an ultraviolet curing process.

For example, the hard coating composition may be applied to a slit coating method, a knife coating method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, To be applied through a printing or coating process such as dip coating, spray coating, screen printing, gravure printing, flexo printing, offset printing, inkjet coating, dispenser printing, nozzle coating, capillary coating, etc. You can.

The hard coating layer 110 provides an exposed surface that is visible or in contact with the user, and may include the polymerizable compound of the hard coating composition described above. Accordingly, improved scratch resistance and flexibility can be achieved.

In some embodiments, the hard coating layer 110 further includes the above-described anti-fingerprint agent, anti-static agent, etc., and may be provided as an anti-fingerprint film.

In some embodiments, a protective film may be laminated on the hard coating layer 110. The protective film is provided as a release film, for example, and can be combined with the hard coating layer 110 through, for example, an adhesive layer. When the protective film is removed, static electricity generation can be effectively reduced through the antistatic agent.

As described above, the hard coating film can be provided to an optical filter with improved anti-fingerprint properties and anti-scratch properties. The optical filter is placed on the front or outermost surface of the flexible display device to serve as a cover window of the display, and can function as a color correction film for the flexible display device.

In some embodiments, the optical filter is composed of the hard coating film and may not include a polarizer or other optical layer such as a polarizer. Accordingly, flexibility can be improved by omitting the polarizer or polarizer. Accordingly, a thin optical filter capable of both flexibility and anti-reflection properties can be provided.

<Image display device and flexible display window>

According to exemplary embodiments, a flexible display window or window laminate including the above-described hard coating film may be provided. 2 is a schematic cross-sectional view showing a window laminate according to example embodiments.

Referring to FIG. 2 , the window laminate according to example embodiments may further include a polarizing layer 60 and/or a touch sensor layer 50 below the base layer 100.

The polarizing layer 60 may include a polyvinyl alcohol-based polarizer or a polarizing plate including a protective film attached to at least one surface of the polarizer. In contrast, the polarizing layer 60 includes a liquid crystal layer containing a liquid crystal compound, and may also include an alignment layer to provide orientation to the liquid crystal layer. At least one retardation film may be formed on the polarizing layer.

The touch sensor layer 50 may include a base film and a plurality of electrode patterns that are formed on at least one side of the base film and sense a touch point through electrostatic capacitance sensing. The touch sensor layer 50 may further include an insulating layer to insulate the electrode patterns.

In one embodiment, the polarizing layer 50 may be disposed directly on the touch sensor layer 60 or with the retardation film interposed therebetween.

As shown in FIG. 2, the window laminate may include a sequential stacking structure of a touch sensor layer 50, a polarizing layer 60, and a hard coating film. Alternatively, the window laminate may have a sequential stacking structure of a polarizing layer 60, a touch sensor layer 50, and a hard coating film.

Some embodiments provide an image display device including the hard coating film described above. The image display device may include a display panel (eg, a thin film transistor (TFT) array panel) and the hard coating film or flexible display window disposed on the display panel.

In exemplary embodiments, the hard coating film may be combined with the display panel in the form of a window laminate described with reference to FIG. 2.

For example, the hard coating film or flexible display window has excellent hardness, wear resistance, and flexibility, and can be applied as a window film formed on the outermost surface of an image display device. In this case, the hard coating layer 110 may be disposed toward the user's viewing side.

The image display device includes various image display devices such as a liquid crystal display device, an electroluminescence display device, a plasma display device, and a field emission display device, and may be a flexible display device having flexibility and bending characteristics. Preferably, the image display device may be a flexible organic light emitting diode (OLED) device.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid understanding of the present invention, but this is only illustrative of the present invention and does not limit the scope of the appended claims, and does not limit the scope and technical idea of the present invention. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

<Synthesis example>

Synthesis Example 1 (Synthesis of Formula 1-1)

29.8 g (0.1 mol) of Chemical Formula 2-1 and 35.2 g (0.1 mol) of Chemical Formula 2-2 were dissolved in 62.0 g (about 0.85 mol) of tetrahydrofuran (THF), and 0.01 mol of triethylamine (TEA) was added. The reaction mixture was heated and stirred at 50°C for 24 hours, then distilled under reduced pressure to remove THF and TEA, and Chemical Formula 1-1 was prepared.

Synthesis Example 2 (Synthesis of Formula 1-2)

Formula 1-2 was prepared in the same manner as in Synthesis Example 1, except that 57.8 g (0.1 mol) of Formula 2-3 was used instead of 35.2 g (0.1 mol) of Formula 2-2.

Synthesis Example 3 (Synthesis of Formula 1-3)

Formula 1-3 was prepared in the same manner as in Synthesis Example 2, except that 52.4 g (0.1 mol) of Formula 2-4 was used instead of 29.8 g (0.1 mol) of Formula 2-1.

Synthesis Example 4 (Synthesis of Formula 1-4)

Formula 1-4 was prepared in the same manner as in Synthesis Example 2, except that 20.0 g (0.1 mol) of Formula 2-5 was used instead of 29.8 g (0.1 mol) of Formula 2-1.

Example 1

40 parts by weight of the compound represented by Chemical Formula 1-1 of Synthesis Example 1, 2 parts by weight of 4-phenoxydichloroacetphenone, 57 parts by weight of methyl ethyl ketone (MEK), 0.3 parts by weight of silicone additive (BYK-UV3570), and nanosilica 30 parts by weight of sol (ELCOM V-8802) was mixed using a stirrer and filtered using a polypropylene (PP) filter to prepare a hard coating composition.

After applying the hard coating composition on a polyimide base film (50㎛) (manufactured by Sumitomo Chemical), a hard coating layer (10㎛) was formed by irradiating UV accumulated light of 1000 J/cm ² under a solvent drying and nitrogen purging atmosphere. A film was prepared.

Example 2

A hard coating film was prepared in the same manner as Example 1, except that the compound represented by Chemical Formula 1-2 of Synthesis Example 2 was included.

Example 3

A hard coating film was prepared in the same manner as Example 1, except that the compound represented by Chemical Formula 1-3 of Synthesis Example 3 was included.

Example 4

A hard coating film was prepared in the same manner as Example 1, except that the compound represented by Chemical Formula 1-4 of Synthesis Example 4 was included.

Comparative Example 1

The hard coating composition contains 20 parts by weight of pentaerythritol triacrylate, 20 parts by weight of multifunctional acrylate, 2 parts by weight of 4-phenoxydichloroacetphenone, 57 parts by weight of methyl ethyl ketone (MEK), and 0.3 parts by weight of silicone additive (BYK-UV3570). A hard coating film was prepared in the same manner as in Example 1, except that it included 30 parts by weight of nanosilica sol (ELCOM V-8802).

Experiment example

The physical properties of the hard coating films of Examples and Comparative Examples were evaluated as follows.

(1) Scratch resistance evaluation

After bonding the hard coating film to the glass so that the surface of the hard coating layer was facing upward, the surface of the hard coating layer was rubbed back and forth 10 times with a load of 500 g/cm ² using steel wool (#0000). Scratch resistance was evaluated according to the criteria below.

○: Less than 10 scratches occur

△: 10 to 20 scratches occur

×: More than 20 scratches

(2) Bending resistance evaluation

After a test of folding and unfolding 100,000 times under high temperature and high humidity (60 degrees, 90%) conditions with a radius of curvature of 1 mm so that both end surfaces of the hard coating layer were in contact with each other, fracture of the film was observed.

○: Less than 10 scratches occur

△: 10 to 20 scratches occur

×: More than 20 scratches

The evaluation results are shown in Table 1 below.

Scratch resistant bending resistance Example 1 ○ △ Example 2 ○ △ Example 3 ○ △ Example 4 ○ △ Comparative Example 1 × ×

Referring to Table 1, the hard coating layer of the Examples containing at least one of the compounds of Formulas 1-1 to 1-4 had improved scratch resistance and did not fracture even after repeated folding.

On the other hand, the hard coating layer of the comparative example that did not contain at least one of the compounds of Formulas 1-1 to 1-4 resulted in fracture of the base layer and did not ensure sufficient surface scratch resistance.

100: Base layer 110: Hard coating layer
50: touch sensor layer 60: polarizing layer

Claims (11)

A hard coating composition comprising a compound represented by Formula 1:
[Formula 1]

(In Formula 1, R ₁ and R ₂ are each independently a single bond, a hydrocarbon group of C ₁ -C ₁₀ or an ether group of C ₂ -C ₁₀ , and m and n are each independently an integer of 1 to 10).
The method of claim 1, wherein R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₈ hydrocarbon group or a C ₂ -C ₈ ether group, and m and n are each independently an integer of 1 to 8, hard coating. Composition.
The method of claim 1, wherein R ₁ and R ₂ are each independently a single bond, a C ₁ -C ₆ hydrocarbon group or a C ₂ -C ₆ ether group, and m and n are each independently an integer of 1 to 5, hard coating. Composition.
The hard coating composition according to claim 1, wherein R ₁ and R ₂ are each independently a single bond or methylene, and m and n are each independently an integer of 1 to 3.
The hard coating composition of claim 1, wherein Formula 1 includes at least one of the compounds represented by Formulas 1-1 to 1-4:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

The hard coating composition of claim 1, wherein the hard coating composition further comprises a photoinitiator and a solvent.
The hard coating composition of claim 6, comprising 20 to 60 parts by weight of the compound represented by Formula 1, 0.1 to 10 parts by weight of a photoinitiator, and an excess of the solvent, based on a total of 100 parts by weight of the composition.
The hard coating composition of claim 1, wherein the hard coating composition further includes inorganic nanoparticles.
The hard coating composition of claim 8, wherein the inorganic nanoparticles include 5 to 40 parts by weight based on a total of 100 parts by weight of the composition.
Base layer; and
A hard coating film formed on the base layer and comprising a hard coating layer formed from the hard coating composition of claim 1.
A flexible display window comprising the hard coating film of claim 10.