KR20170088062A - Hard Coating Composition and Hard Coating Film Using the Same - Google Patents

Abstract

Provided are a hard coating composition, a hard coating film formed by using the same and an image display device having the hard coating film. The hard coating composition comprises: polyrotaxane having a hydroxy terminal; an alkoxysilane compound having an epoxy group or a polysiloxane resin produced by a sol-gel reaction of the alkoxysilane compound; a photopolymerization initiator; and a solvent. The hard coating film according to the present invention has excellent hardness, has flexibility and has excellent scratch resistance, adhesion and curl properties.

Description

[0001] The present invention relates to a hard coating composition and a hard coating film using the same,

The present invention relates to a hard coating composition and a hard coating film using the hard coating composition. More particularly, the present invention relates to a hard coating composition having excellent hardness and flexibility and a hard coating film formed using the hard coating composition, .

The hard coating film is used for surface protection for image display devices such as a liquid crystal display device, an electroluminescence (EL) display device, a plasma display (PD), and a field emission display (FED).

In recent years, a flexible display device capable of maintaining the display performance even if bent like paper by using a flexible material such as plastic instead of a conventional glass substrate has rapidly emerged as a next-generation display device, and hardness High hardness, scratch resistance, and curl of the edge of the film do not occur during the production process or use, and a hard coating film which does not generate cracks with appropriate flexibility is being studied.

Korean Patent No. 10-1295325 discloses a cyclic compound having a lactone-based compound bonded at its terminal with a (meth) acrylate-based compound introduced in an amount of 40 mol% to 70 mol%; Linear molecules passing through the cyclic compound; And a hard coat layer comprising a crosslinking agent between a polyrotassine compound (a) and a binder resin (b), the blocking layer being disposed at both ends of the linear molecule to prevent release of the cyclic compound. And the hard coating film can realize self-healing ability with excellent mechanical properties such as high scratch resistance, chemical resistance and abrasion resistance, curl of the film can be minimized while having high strength .

However, the hard coating film has a problem in that it is difficult to ensure sufficient hardness and flexibility to be applicable to a flexible display device.

Korean Patent No. 10-1295325

It is an object of the present invention to provide a hard coating composition which can be used in the production of a hard coating film having excellent hardness and excellent flexibility.

It is another object of the present invention to provide a hardcoat film formed using the hardcoat composition.

It is still another object of the present invention to provide an image display device provided with the hard coating film.

On the other hand, the present invention relates to a hardcoat composition comprising a polyrotasane having a hydroxy end group, an alkoxysilane compound having an epoxy group, or a polysiloxane resin prepared by a sol-gel reaction of the alkoxysilane compound, a photopolymerization initiator and a solvent .

In one embodiment of the present invention, the polyrotaxane having the hydroxy end group has a cyclic molecule, a linear molecule penetrating the cyclic molecule, and a cyclic molecule which is bonded to both ends of the linear molecule to separate the cyclic molecule from the linear molecule , Wherein at least one lactone compound is bonded to the cyclic molecule, and a hydroxy group is present at the end of the residue of the lactone compound.

In one embodiment of the present invention, the alkoxysilane compound having an epoxy group may include a compound represented by the following formula (2): < EMI ID =

(2)

R ¹ _n Si (OR ² ) _4-n

Wherein R ¹ is an epoxy group, R ² is an alkyl group having 1 to 20 carbon atoms, and n is an integer of 1 to 3.

In one embodiment of the present invention, the alkoxysilane compound having an epoxy group of Formula 2 is at least one compound selected from the group consisting of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane. ≪ / RTI >

In one embodiment of the present invention, the polysiloxane resin may be prepared by subjecting an alkoxysilane compound having an epoxy group of Formula 2 to a sol-gel reaction in the presence of a catalyst.

The hard coating composition according to one embodiment of the present invention may further comprise inorganic nanoparticles.

On the other hand, the present invention provides a hard coating film formed using the hard coating composition.

On the other hand, the present invention provides an image display device provided with the hard coating film.

The hard coating film formed using the hard coating composition according to the present invention has excellent hardness and flexibility as well as excellent scratch resistance, adhesiveness and curling property, and can be effectively used for a window of a flexible display device.

Hereinafter, the present invention will be described in more detail.

One embodiment of the present invention relates to a coating composition comprising a polyrotasane having a hydroxy end group, an alkoxysilane compound having an epoxy group, or a hard coating comprising a polysiloxane resin prepared by the sol-gel reaction of the alkoxysilane compound, a photopolymerization initiator and a solvent ≪ / RTI >

In one embodiment of the present invention, the polyrotaxane having a hydroxy end group comprises a cyclic molecule and a linear molecule penetrating the cyclic molecule and a cyclic molecule which is bonded to both ends of the linear molecule to form the cyclic molecule Wherein the blocker for preventing escape is configured to form a dumbbell-shaped structure, at least one lactone compound is bonded to the cyclic molecule, and a hydroxy group is present at the end of the residue of the lactone compound.

The polyrotaxane having such a structural characteristic has a self-healing ability and a hydroxy group present at the terminal is involved in cationic photopolymerization, so that a hard hard coating layer having less shrinkage, curling and flexibility can be obtained after curing.

In one embodiment of the present invention, the polyrotaxane comprises a cyclic molecule, a linear molecule penetrating the cyclic molecule, and a blocking group bonded to both ends of the linear molecule to prevent the separation of the cyclic molecule from the linear molecule And one or more lactone compounds may be bonded to the cyclic molecule.

The cyclic molecule may be a cyclodextrin.

The linear molecule may be selected from the group consisting of polyethylene glycol, polyisoprene, polyisobutylene, polybutadiene, polypropylene glycol, polytetrahydrofuran, polydimethylsiloxane, polyethylene and polypropylene, , A cyclodextrin group, an adamantane group, a trityl group, a fluororesin group, and a pyrene group

The blocking group may be bonded directly to both ends of the linear molecule or via a urethane group, an ether group, a thioester group or an ester group.

The lactone compound may be bonded directly to the cyclic molecule or through a straight or branched oxyalkylene group having 1 to 10 carbon atoms.

The residue of the lactone compound may include a functional group represented by the following formula (1).

[Chemical Formula 1]

Wherein p is an integer from 2 to 11 and q is an integer from 1 to 20.

The polyrotasane having a hydroxy end group has a molecular weight of 100,000 to 1,000,000 and is commercially available or can be prepared according to methods known in the art.

The polyrotaxane having the hydroxy end group may be contained in an amount of 2 to 35% by weight, preferably 3 to 30% by weight based on 100% by weight of the total amount of the hard coat composition. If it is less than 2% by weight, it is difficult to secure sufficient flexibility of the hard coating film. If it is more than 35% by weight, it may be difficult to secure the hardness of the hard coating film.

In one embodiment of the present invention, the alkoxysilane compound having an epoxy group may include a compound represented by the following formula (2): < EMI ID =

(2)

R ¹ _n Si (OR ² ) _4-n

Wherein R ¹ is an epoxy group, R ² is an alkyl group having 1 to 20 carbon atoms, particularly an alkyl group having 1 to 6 carbon atoms, and n is an integer of 1 to 3.

As used herein, an alkyl group having 1 to 20 carbon atoms or an alkyl group having 1 to 6 carbon atoms means a linear or branched hydrocarbon having 1 to 20 carbon atoms or 1 to 6 carbon atoms, and includes, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, n-hexyl and the like.

The alkoxysilane compound having an epoxy group undergoes a cationic photopolymerization reaction with an epoxy group. The cationic photopolymerization reaction has a relatively low shrinkage ratio, and since there is no oxygen inhibition reaction on the surface, stable curing is possible, and the curing rate is excellent. In addition, the polysiloxane resin produced by the sol-gel reaction of the alkoxysilane compound has high cationic photopolymerization and excellent curing rate due to the presence of a siloxane network. Such an alkoxysilane compound having an epoxy group and a polysiloxane resin not only provide an excellent hardness to the hard coating composition, but also provide excellent flexibility at the same time.

The alkoxysilane compound having an epoxy group of the above-mentioned formula (2) is preferably at least one selected from the group consisting of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, Propyl trimethoxysilane, and 3-glycidoxypropyl triethoxysilane.

The polysiloxane resin may be prepared by a hydrolysis-gel reaction of the alkoxysilane compound.

Specifically, the alkoxy group of the alkoxysilane as a starting material is hydrolyzed together with water to form a hydroxyl group, and a siloxane bond is formed by a condensation reaction with an alkoxy group or a hydroxyl group of another alkoxysilane compound to form a polysiloxane.

Catalysts may be preferably introduced to facilitate the hydro-sol-gel reaction. Usable catalysts include acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, chlorosulfonic acid, para-toluic acid, trichloroacetic acid, polyphosphoric acid, pyrophosphoric acid, iodic acid, tartaric acid, perchloric acid or ammonia, sodium hydroxide, Base catalysts such as butylamine, di-n-butylamine, tri-n-butylamine, imidazole, ammonium perchlorate, potassium hydroxide and barium hydroxide, ion exchange resins such as Amberite IPA- ). The amount of the catalyst to be used is not particularly limited, and 0.0001 to 10 parts by weight may be added to 100 parts by weight of the alkoxysilane.

The hydrosol-gel reaction can be carried out by stirring at room temperature for 6 to 144 hours, and may be carried out at 60 to 80 ° C for 12 to 36 hours for accelerating the reaction rate and proceeding the complete condensation reaction.

The alkoxysilane compound or polysiloxane resin may be contained in an amount of 20 to 70% by weight, preferably 25 to 65% by weight based on 100% by weight of the hard coat composition. When the content is less than 20% by weight, it is difficult to secure hardness. When the content is more than 70% by weight, the coating film is broken and it may be difficult to impart bending properties.

In one embodiment of the present invention, the photopolymerization initiator is used for photocuring the hard coating composition, and any initiator that can be used in the art can be used without limitation.

As the photopolymerization initiator, a cationic photopolymerization initiator capable of generating a cationic species or a Lewis acid by irradiation of active energy rays such as visible light, ultraviolet light, X-ray, or electron beam to initiate polymerization reaction of cationic photo- have.

Since the cationic photopolymerization initiator acts catalytically by light, it is excellent in storage stability and workability even when mixed with a cationic photocurable component. Examples of the compound capable of generating a cationic species or a Lewis acid by irradiation with an active energy ray include an onium salt such as an aromatic diazonium salt, an aromatic iodonium salt or an aromatic sulfonium salt; Iron-allene complex and the like. Among them, the aromatic sulfonium salt is preferable because it has ultraviolet ray absorption property even in the wavelength range near 300 nm, and is excellent in curability and can give excellent coating film characteristics. The cationic photopolymerization initiator may be used alone or in combination of two or more.

The photopolymerization initiator may be contained in an amount of 0.1 to 10% by weight based on the total 100% by weight of the hard coating composition. When the content of the photopolymerization initiator is less than 0.1% by weight, the curing rate is slow. When the content of the photopolymerization initiator is more than 10% by weight, excessive cracking may occur in the hard coating layer.

In one embodiment of the present invention, the solvent can be used without limitation as long as it is used in the technical field. Specifically, alcohol-based solvents such as methanol, ethanol, isopropanol, butanol, and propylene glycol methoxy alcohol; Ketones such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone and dipropyl ketone; Acetate-based solvents such as methyl acetate, ethyl acetate, butyl acetate and propylene glycol methoxyacetate; Cellosolves such as methyl cellosolve, ethyl cellosolve and propyl cellosolve; And hydrocarbons such as normal hexane, normal heptane, benzene, toluene and xylene. These solvents may be used alone or in combination of two or more.

The solvent may be included in an amount of 5 to 90% by weight, preferably 20 to 70% by weight, based on 100% by weight of the hard coat composition. When the amount is less than 5% by weight, the viscosity is high and workability is poor. When the amount is more than 90% by weight, it is difficult to adjust the thickness of the coating film and drying unevenness may occur.

The hard coating composition according to one embodiment of the present invention may further comprise inorganic nanoparticles to further improve the mechanical properties.

The inorganic nanoparticles may have an average particle diameter of 1 to 100 nm, preferably 5 to 50 nm. These inorganic nanoparticles are uniformly formed in the coating film, and can improve mechanical properties such as abrasion resistance, scratch resistance and pencil hardness. If the particle size is less than the above range, agglomeration occurs in the composition and a uniform coating film can not be formed. As a result, the above effect can not be expected. On the other hand, if the particle size exceeds the above range, The mechanical properties may be deteriorated.

The inorganic nanoparticles may be a metal oxide and may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , ITO, IZO, ATO, ZnO- Nb ₂ O ₃ , SnO ₂ , MgO, and combinations thereof. In particular, Al ₂ O ₃ , SiO ₂ , ZrO ₂ and the like can be used.

The inorganic nanoparticles can be manufactured directly or commercially available. In the case of commercially available products, those dispersed in an organic solvent at a concentration of 10 to 80 parts by weight may be used.

The inorganic nanoparticles may be included in an amount of 5 to 50% by weight based on the total 100% by weight of the hard coating composition. If it is less than 5% by weight, mechanical properties such as abrasion resistance, scratch resistance and pencil hardness may not be sufficient. If it exceeds 50% by weight, mechanical properties may be deteriorated and appearance may be deteriorated.

In addition to the above-mentioned components, the hard coating composition according to an embodiment of the present invention may further include components commonly used in the art, for example, leveling agents, ultraviolet stabilizers, heat stabilizers, and the like.

The leveling agent can be used to impart smoothness and coatability of a coating film when the composition is coated. Examples of the leveling agent include BYK-323, BYK-331, BYK-333, and BYK-333 manufactured by BYK Corporation, TEGO Glide 411, TEGO Glide 415, TEGO Glide 420, TEGO Glide 432, TEGO Glide 435, TEGO Glide 440, TEGO Glide 440, TEGO Glide 412, BYK- Glide 450, TEGO Glide 455, TEGO Rad 2100, TEGO Rad 2200N, TEGO Rad 2250, TEGO Rad 2300, TEGO Rad 2500, 3M FC-4430 and FC-4432. The leveling agent may be used in an amount of 0.1 to 3% by weight based on 100% by weight of the hard coat composition.

The ultraviolet stabilizer may be added for the purpose of protecting the coating film by blocking or absorbing ultraviolet rays, since the surface of the cured coating film is decomposed by continuous ultraviolet ray exposure to be discolored and crumbled. The ultraviolet stabilizer is classified into an absorbent, a quencher, and a hindered amine light stabilizer (HALS) according to the action mechanism. Depending on the chemical structure, it can be divided into Phenyl Salicylates, Benzophenone, Benzotriazole, Nickel Derivatives and Radical Scavenger. . In the present invention, there is no particular limitation as long as it is an ultraviolet stabilizer that does not significantly change the initial color of the coating film.

The heat stabilizer is a commercially applicable product, and it can be used either alone or in combination with a polyphenol as a primary heat stabilizer, a phosphite as a secondary heat stabilizer, and a lactone system.

The ultraviolet stabilizer and the heat stabilizer can be appropriately used at a level at which the ultraviolet curing property is not affected.

One embodiment of the present invention is directed to a hardcoat film formed using the hardcoat composition described above. The hard coating film according to an embodiment of the present invention is characterized in that a coating layer containing a cured product of the hard coating composition described above is formed on one side or both sides of the transparent substrate.

As the transparent substrate, any transparent polymer film can be used. The polymer film can be produced by a film-forming method or an extrusion method according to the molecular weight and the film production method, and can be used regardless of the commercially available transparent polymer film. Examples thereof include triacetyl cellulose, acetyl cellulose butyrate, ethylene- But are not limited to, vinyl acetate copolymer, propionyl cellulolose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyether imide, polyacryl, polyimide, polyether sulfone, polysulfone, Polyolefins such as polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyethersulfone, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, Polyethylene naphthalate, poly And various transparent polymeric substrates such as polycarbonate and polycarbonate.

The thickness of the transparent substrate is not particularly limited, but may be 10 to 1000 탆, specifically 20 to 150 탆. If the thickness of the transparent base material is less than 10 탆, the strength of the film is lowered and the workability is deteriorated. If the thickness is more than 1000 탆, the transparency is decreased or the weight of the hard coating film is increased.

The hard coating film according to one embodiment of the present invention can be produced by applying the hard coating composition of the present invention to one side or both sides of a transparent substrate and curing to form a coating layer.

The hard coating composition according to an embodiment of the present invention may be coated on a transparent substrate by appropriately using a known method such as die coater, air knife, reverse roll, spray, blade, casting, gravure, microgravure, ) Is possible.

After the hard coating composition is applied to the transparent substrate, volatiles are evaporated at a temperature of 30 to 150 ° C for 10 seconds to 1 hour, more specifically for 30 seconds to 30 minutes, And cured. The irradiation amount of the UV light may be about 0.01 to 10 J / cm 2, and more specifically, about 0.1 to 2 J / cm 2.

At this time, the thickness of the formed coating layer may be specifically 2 to 70 탆, more specifically 3 to 50 탆. When the thickness of the coating layer is within the above range, an excellent hardness effect can be obtained.

One embodiment of the present invention relates to an image display apparatus provided with the above-mentioned hard coating film. For example, the hard coating film of the present invention can be attached to an image display device, particularly a window of a flexible display device. Further, the hard coating film of the present invention may be used by being attached to a polarizing plate, a touch sensor, or the like.

The hard coating film according to one embodiment of the present invention can be used in reflective, transmissive, semi-transmissive LCD or various driving LCDs such as TN type, STN type, OCB type, HAN type, VA type and IPS type. The hard coating film according to one embodiment of the present invention can also be used in various image display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and an electronic paper.

Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples and Experimental Examples. It should be apparent to those skilled in the art that these examples, comparative examples and experimental examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example  1 to 7 and Comparative Example  One: Hard coating  Preparation of composition

Hard coating compositions were prepared by mixing the components in the compositions shown in Table 1 below (unit: wt%).

Polyrotasein Alkoxysilane Polysiloxane resin weapon
Nanoparticle Photopolymerization initiator additive solvent A-1 A-2 Example 1 10 0 - 50 10 2 0.3 27.7 Example 2 0 10 - 50 10 2 0.3 27.7 Example 3 5 5 - 50 10 2 0.3 27.7 Example 4 7.5 2.5 - 50 10 2 0.3 27.7 Example 5 2.5 7.5 - 50 10 2 0.3 27.7 Example 6 20 0 - 40 10 2 0.3 27.7 Example 7 0 20 - 40 10 2 0.3 27.7 Example 8 10 0 50 - 10 2 0.3 27.7 Comparative Example 1 - - 30 30 10 2 0.3 27.7

Compound of A-1: SeRM Super Polymer SH2400P (PEG20K type) (ASMI)

Compound of A-2: SeRM Super Polymer SH2400P (PEG11K type) (ASMI)

Alkoxysilane compound: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (KBM-303) (Shin-Etsu)

Polysiloxane resin: SP-3T (Shin-A & T)

Inorganic nanoparticles: IPA-ST (Nissan Chemical)

Photopolymerization initiator: Irgacure 250 (BASF)

Additive: BYK310 (BYK)

Solvent: methyl ethyl ketone

Experimental Example  One:

The hard coating compositions prepared in Examples and Comparative Examples were coated on one side of an optical polyimide film (Mitsubishi Gas Chemical Co., Ltd., 100 占 퐉, L-3430) so as to have a thickness of 45 占 퐉, Dried and cured at a dose of 1.5 J / cm 2 in a metal halide lamp to prepare a hardcoat film.

The physical properties of the prepared hard coating film were measured by the following method, and the results are shown in Table 2 below.

(1) Pencil Hardness

Pencil hardness was measured by applying a load of 1 kg using a pencil hardness tester (PHT, Kobo Scientific Co., Ltd.). The pencil was made five times per pencil hardness using Mitsubishi products. In case of 2 or more gypsum, it was judged to be defective and recorded as the maximum hardness determined as OK.

(2) Abrasion resistance

And scratch resistance was tested by reciprocating ten times under 1 kg / (2 cm x 2 cm) using a steel wool tester (WT-LCM100, Korea Protec Co.). Steel wool used # 0000.

<Evaluation Criteria>

S: 0 scratches

A: 1 to 10 scratches

B: 11-20 scratches

C: 21 ~ 30 scratches

D: More than 31 scratches

(3) Adhesion

11 straight lines were drawn on the coated surface of the film at intervals of 1 mm to form 100 squares, and then peel test was performed three times using a tape (CT-24, Nichii Co., Ltd.). Three 100 squares were tested and the average was recorded. The adhesion was recorded as follows.

Adhesion = n / 100

n: the number of rectangles that are not to be peeled out of the entire rectangle

100: total number of squares

Therefore, when none of them were peeled off, 100/100 was recorded.

(4) Curl

A sample cut into a square shape of A4 size (29.7 x 21.0 cm) was placed on a flat glass plate with the coated side of the film facing up, and the distance from the four-sided glass plate was measured at 25 DEG C and 50% As a measurement value.

(5) Mandrell

In order to evaluate the flexibility and the cracking property of the coating film, a coated film sample cut into a size of 1 cm × 10 cm was placed on a steel bar of each diameter (2φ~20φ), and the coating layer was turned upwards, The smallest diameter is indicated.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Pencil hardness 6H 6H 6H 6H 6H 6H 6H 5H F Abrasion resistance S S S S S S S S B Adhesiveness 100/100 100/100 100/100 100/100 100/100 100/100 100/100 95/100 70/100 curl 5mm 5mm 5mm 5mm 5mm 3mm 3mm 6mm 14mm Mandrell 4φ 4φ 4φ 4φ 4φ 3φ 3φ 5φ 16φ

As shown in Table 2, the hard coating films prepared using the hard coating compositions of Examples 1 to 8 according to the present invention were excellent in hardness, scratch resistance, adhesion, curl properties as well as crack resistance. On the other hand, the hard coat film prepared using the hard coat composition of Comparative Example 1 was found to be inferior in hardness, scratch resistance, adhesion, curl characteristic, or crack resistance.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Do. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the actual scope of the invention is defined by the appended claims and their equivalents.

Claims (18)

A hard coat composition comprising a polyrotasane having a hydroxy end group, an alkoxysilane compound having an epoxy group, or a polysiloxane resin prepared by a sol-gel reaction of the alkoxysilane compound, a photopolymerization initiator and a solvent. The polyrotaxane as claimed in claim 1, wherein the polyrotaxane having a hydroxy end group is selected from the group consisting of a cyclic molecule, a linear molecule penetrating the cyclic molecule, and a cyclic moiety bonded to both ends of the linear molecule to prevent the cyclic molecule from leaving the linear molecule Wherein at least one lactone compound is bonded to the cyclic molecule and a hydroxy group is present at the end of the residue of the lactone compound. 3. The hard coating composition of claim 2, wherein the cyclic molecule is a cyclodextrin. The composition of claim 2, wherein the linear molecule is selected from the group consisting of polyethylene glycol, polyisoprene, polyisobutylene, polybutadiene, polypropylene glycol, polytetrahydrofuran, polydimethylsiloxane, polyethylene and polypropylene . The hard-coating composition of claim 2, wherein the blocking group is selected from the group consisting of a dinitrophenyl group, a cyclodextrin group, an adamantane group, a trityl group, a fluororesin group, and a pyrene group. 3. The hard-coating composition of claim 2, wherein the blocker is bonded directly to either end of the linear molecule or through a urethane, ether, thioester, or ester group. 3. The hard-coating composition of claim 2, wherein the lactone compound is bonded directly to the cyclic molecule or via a linear or branched oxyalkylene group having 1 to 10 carbon atoms. 3. The hard coating composition of claim 2, wherein the moiety of the lactone compound comprises a functional group of the formula:
[Chemical Formula 1]

Wherein p is an integer from 2 to 11 and q is an integer from 1 to 20. The hard coating composition according to claim 1, wherein the alkoxysilane compound having an epoxy group comprises a compound represented by the following formula (2):
(2)
R ¹ _n Si (OR ² ) _4-n
Wherein R ¹ is an epoxy group, R ² is an alkyl group having 1 to 20 carbon atoms, and n is an integer of 1 to 3. The hard coat composition according to claim 9, wherein R ² is an alkyl group having 1 to 6 carbon atoms. The alkoxysilane compound according to claim 9, wherein the alkoxysilane compound having an epoxy group of Formula 2 is at least one selected from the group consisting of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane , 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane. The hard-coating composition according to claim 1, wherein the polysiloxane resin is prepared by subjecting the alkoxysilane compound to a sol-gel reaction in the presence of a catalyst. The hard coating composition of claim 1, further comprising inorganic nanoparticles. A hardcoat film formed using the hard coating composition of any one of claims 1 to 13. An image display device comprising the hard coating film according to claim 14. A window of a flexible display device comprising the hard coating film according to claim 14. A polarizing plate comprising the hard coating film according to claim 14. A touch sensor comprising the hard coating film according to claim 14.