TWI726152B - Hard coating composition and hard coating film using the same - Google Patents

Abstract

The present invention provides a hard coating composition comprising a dendrimer compound having a terminal (meth)acrylate group, a polyhedral oligomeric silsesquioxane compound, a photoinitiator and a solvent; a hard coating film formed using the same; and an image display device having the hard coating film. The hard coating film according to the present invention can minimize the occurrence of curling while having excellent hardness, scratch resistance and bending resistance.

Description

Hard coating composition and 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. The present invention particularly relates to a hard coating composition that can minimize the occurrence of curling and at the same time have excellent hardness, scratch resistance and bending resistance, a hard coating film formed by using it and An image display device with the hard coating film.

Hard coat films have been used to protect the surface of various image displays, including a liquid crystal display device (LCD), an electroluminescence display device (EL), a plasma display (PD), a field emission display (FED) and the like The surface of the object.

Recently, by using a flexible material, such as plastic, instead of a traditional inflexible glass substrate, even if a flexible display device is bent like paper, the flexible display device can still maintain the display performance. It is attracting attention as a next-generation display device. In this regard, there is a need for a hard coat film that not only has high hardness and good scratch resistance, but also has suitable flexibility so that cracks do not occur, and no curling occurs at the edge of the film during production or use.

Korean Patent Application Publication No. 10-2013-0135151 discloses a high-hardness hard coating composition, including a binder containing tri-functional to hexa-functional acrylate monomers, and inorganic fine particles ( inorganic fine particles), a photoinitiator and an organic solvent.

However, the problem with this high-hardness hard coating composition is that the bending resistance after curing is reduced and curling occurs.

The object of the present invention is to provide a hard coating composition which can be used in the production of a hard coating film, which can inhibit curling and has excellent hardness, scratch resistance, and bending resistance.

Another object of the present invention is to provide a hard coating film formed using the hard coating composition.

Another object of the present invention is to provide an image display device with the hard coating film.

【Technical solutions】

According to one aspect of the present invention, there is provided a hard coating composition, comprising: a dendrimer compound having a terminal (meth)acrylate group, and a polyhedron Polyhedral oligomeric silsesquioxane compound, a photoinitiator and a solvent.

In an embodiment of the present invention, the dendrimer compound having a terminal (meth)acrylate group may include a compound represented by the following chemical formula 1.

[Chemical formula 1][R ₁ ] _4-n -C-[R ₂ -OR ₃ ] _n

，且至少一個R₃是

，R₄是一(甲基)丙烯醯基或

，且至少一個R₄是

R₅是一(甲基)丙烯醯基或

，R₆是一(甲基)丙烯醯基，n是2至4的一整數，且m、x和y是2或3的一整數。 Wherein, R ₁ is a C ₁ -C ₆ alkyl group, R ₂ is a C ₁ -C ₆ alkylene group, and R ₃ is a (meth)acryloyl group or

, And at least one R ₃ is

, R ₄ is a (meth)acryloyl group or

, And at least one R ₄ is

R ₅ is a (meth)acryloyl group or

, R ₆ is a (meth)acrylic acid group, n is an integer of 2 to 4, and m, x, and y are an integer of 2 or 3.

In one embodiment of the present invention, the polyhedral silicone oligomer compound can be A compound represented by the following chemical formula 2 is included.

Wherein, each R is independently hydrogen, or a linear, branched or cyclic hydrocarbon group with 1 to 20 carbon atoms substituted by a (meth)acrylate group, and at least among them One R is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms substituted by a (meth)acrylate group.

In an embodiment of the present invention, the hard coating composition may further include a polyfunctional urethane (meth)acrylate with a cyclohexyl group and a ethylene glycol group (polyfunctional urethane (meth)acrylate). At least one of the polyfunctional (meth)acrylates of ethylene glycol group).

In an embodiment of the present invention, the hard coating composition may further include inorganic particles.

In an embodiment of the present invention, the hard coating composition may further include a fluorine-based leveling agent.

In another aspect, the present invention provides a hard coating film formed using the hard coating composition.

In another aspect, the present invention provides a hard coat film, comprising: a dendrimer compound having a terminal (meth)acrylate group and a polyhedral silicone oligomer Compound, wherein when the hard coat film is folded in half so that the distance between the film surfaces at room temperature is 6 millimeters (mm), the film will spread again and the folded portion can be observed by naked eyes, without Cracks are generated or no cracks with a length of 5 millimeters (mm) or less are generated; and when the hard coating film is folded in half so that the distance between the film surfaces is 6 millimeters (mm), the film can be made to be at 85°C and When placed under 85% relative humidity for 24 hours, the film will unfold again and the folded part can be observed by naked eyes. No cracks or cracks with a length of 5 millimeters (mm) or less are produced.

According to another aspect of the present invention, an image display device having the hard coating film is provided.

【Excellent effect】

The hard coat film formed by using the hard coat composition according to the present invention can minimize the occurrence of curling while having excellent hardness, scratch resistance and bending resistance. This hard coat film can be effectively used in a A window of the flexible display device.

[Best embodiment]

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

An embodiment of the present invention relates to a hard coating composition, comprising: a dendrimer compound having a terminal (meth)acrylate group, a polyhedral silicone oligomer compound, and a photoinitiator With a solvent.

In an embodiment of the present invention, the dendrimer compound with a terminal (meth)acrylate group can be cured by ultraviolet rays by substituting a (meth)acrylate group at the end of the branch structure. This dendritic polymer compound with a terminal (meth)acrylate group has the structural characteristics of a completely aliphatic center, and is composed of three Grade ester bond formation. Therefore, compared with general multifunctional acrylate monomers, this dendrimer compound with a terminal (meth)acrylate group has a structural characteristic. The higher the molecular weight in production, the more functional groups it has. . Since this functional group is distributed at the end, the core part can help to improve the bending property during curing. Therefore, a hard coating film with high hardness and improved bending characteristics and flexibility can be obtained.

In an embodiment of the present invention, the dendrimer compound with terminal (meth)acrylate groups can be represented by the following chemical formula 1: [Chemical formula 1] [R ₁ ] _4-n -C-[R ₂ -OR ₃ ] _n

，且至少一個R₃是

，R₄是一(甲基)丙烯醯基或

，且至少一個R₄是

R₅是一(甲基)丙烯醯基或

，R₆是一(甲基)丙烯醯基，n是2至4的一整數，且m、x、y是2或3的一整數。 Among them, R ₁ is a C ₁ -C ₆ alkyl group, R ₂ is a C ₁ -C ₆ alkylene group, and R ₃ is a (meth)acryloyl group or

, And at least one R ₃ is

, R ₄ is a (meth)acryloyl group or

, And at least one R ₄ is

R ₅ is a (meth)acryloyl group or

, R ₆ is a (meth)acryloyl group, n is an integer of 2 to 4, and m, x, and y are an integer of 2 or 3.

The C ₁ -C ₆ alkyl group used herein refers to a linear or branched monovalent hydrocarbon group having 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n Butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl and the like, but not limited thereto.

The C ₁ -C ₆ alkylene group used herein refers to a straight or branched divalent hydrocarbon group having 1 to 6 carbon atoms, and examples thereof include methylene, ethylene, propylene, butene and the like, but Not limited to this.

In an embodiment of the present invention, the dendrimer compound having a terminal (meth)acrylate group may generally have a structure represented by the following chemical formula 3.

[Chemical formula 3]

The dendrimer compound with terminal (meth)acrylate groups can be purchased from the market or can be prepared according to methods known in the art. For example, to obtain a highly branched dendrimer compound substituted with a plurality of (meth)acrylate groups at the end can be achieved by combining the central skeleton of a specific polyol with dimethylolpropane Acid (dimethylol propionic acid) undergoes a condensation reaction to form a first-generation dendritic structure, and dimethylol propionic acid is repeatedly condensed into a branched structure to grow into a second-generation or more Generation dendritic structure, and condensation reaction of acrylic acid at the end.

Based on 100% of the total weight of the hard coating composition, the dendritic polymer compound may be contained by 10 to 60% by weight, preferably 30 to 45% by weight. When the dendrimer compound is less than 10% by weight, it will be difficult to exhibit bending properties. When the dendrimer compound is more than 60% by weight, unreacted functional groups are generated due to steric hindrance effect. , It will be difficult to give the coating hardness characteristics (hardness characteristic).

In an embodiment of the present invention, the polyhedral siloxane oligomer compound (POSS) is a compound represented by the following chemical formula 2 and has a size of 1 to 5 nanometers (nm) represented _{by the molecular formula (RSiO 1.5} ) _n Silica cage structure. The silicon dioxide cage structure is regarded as an organic/inorganic intermediate compound or hybrid compound with the characteristics of _{silicon dioxide (SiO 2} , an inorganic material) and polysilicon oxide (R _{2 SiO, an organic material).}

In the polyhedral siloxane oligomer compound, the number of Si in the structure is not particularly limited. For example, it can be 6-12.

In Chemical Formula 2, each R is independently hydrogen or has a linear, branched or cyclic hydrocarbon group of 1 to 20 carbon atoms substituted by one (meth)acrylate group, and at least one of R may be A linear, branched or cyclic hydrocarbon group of 1 to 20 carbon atoms substituted with a (meth)acrylate group.

Specifically, R may be an alkyl group having 1 to 6 carbon atoms substituted by a (meth)acrylate group, and in particular may be propyl methacrylate.

Unlike general inorganic particles, even when polyhedral oligomer silsesquioxane compounds are used in a hard coating composition in large quantities, the polyhedral oligomer silsesquioxane compounds can still be synthesized uniformly. Polyhedral silicone oligomer compounds can improve hardness and mechanical properties, and can improve bending properties due to structural stability. In addition, since the polyhedral silicone oligomer compound has terminal (meth)acrylate groups, the polyhedral silicone oligomer compound can be used for photocuring to improve mechanical properties.

Based on 100% of the total weight of the hard coating composition, the polyhedral silicone oligomer compound may contain 3 to 20% by weight, preferably 5 to 15% by weight. When the weight of the polyhedral siloxane oligomer compound is less than 3%, it will be difficult to obtain hardness. When the weight of the polyhedral siloxane oligomer compound is more than 20%, the coating film will be broken, making it difficult to impart bending properties. .

In an embodiment of the present invention, as long as it is a commonly used initiator in the technical field, a photoinitiator can be used without particular limitation. Photoinitiators can be classified as Type I photoinitiators, in which free radicals are generated by the decomposition of molecules due to differences in chemical structure or molecular binding energy. Photoinitiators can be classified as Type II (hydrogen abstraction type) photoinitiators, in which tertiary amines are combined as a co-initiator. Specific examples of Type I photoinitiators may include acetophenone, such as 4-phenoxydichloroacetophenone (4-phenoxydichloroacetophenone), 4-t-butyldichloroacetophenone (4-t-butyldichloroacetophenone) , 4-t-butyltrichloroacetophenone (4-t-butyltrichloroacetophenone), diethoxyacetophenone (diethoxyacetophenone), 2-hydroxy-2-methyl-1-phenyl-1-acetone (2-hydroxy-2-methyl-1-phenylpropan-1-one), 1-(4-isopropylphenyl)-2-hydroxy-2-methyl-1-propanone (1-(4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one), 1-(4-dodecylphenyl)-2-hydroxy-2-methyl-1-propanone (1-(4-dodecylphenyl)-2- hydroxy-2-methylpropan-1-one), 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone (4-(2-hydroxyethoxy)-phenyl(2-hydroxy- 2-propyl)ketone), 1-hydroxycyclohexyl phenyl ketone or similar, benzoins, such as benzoin, benzoin methyl ether, benzoin Benzoin ethyl ether, benzyl dimethyl ketal or the like, acylphosphine oxides and titanocene compounds. Specific examples of type II photoinitiators may include benzophenones, such as benzophenone, benzoyl benzoic acid, and benzoyl benzoic acid methyl ether. , 4-phenylbenzophenone (4-phenylbenzophenone), hydroxybenzophenone (hydroxybenzophenone), 4-benzoyl-4'-methyldiphenylsulfide (4-benzoyl-4'-methyldiphenylsulfide), 3,3'-dimethyl-4-methoxybenzophenone (3,3'-dimethyl-4-methoxybenzophenone) or the like; and thioxanthones, such as thioxanthone ), 2-chlorothioxanthone (2-chlorothioxanthone), 2-methylthioxanthone (2-methylthioxanthone), 2,4-dimethylthioxanthone (2,4-dimethylthioxanthone), isopropylthioxanthone Ketone (isopropylthioxanthone) or similar. These photoinitiators can be used alone or in combination of two or more of them. In addition, a Type I photoinitiator and a Type II photoinitiator can be used together.

Based on 100% of the total weight of the hard coating composition, the photoinitiator may contain 0.1 to 5% by weight, preferably 1 to 3% by weight. If the weight of the photoinitiator is less than 0.1%, the curing may not proceed sufficiently, and therefore the mechanical properties or adhesive force of the finally obtained hard coating film may decrease. If the weight of the photoinitiator is greater than 5%, cracks or curls may occur during curing shrinkage.

In an embodiment of the present invention, as long as it is a solvent commonly used in the technical field, a solvent can be used without particular limitation. Specific examples of solvents may include alcohols (methanol, ethanol, isopropanol, butanol, propylene glycol methyl ether, etc.), ketones (e.g., methyl ethyl ketone, methyl butyl ketone, methyl Isobutyl ketone, diethyl ketone, dipropyl ketone, etc.), acetate (methyl acetate, ethyl acetate, butyl acetate, propylene glycol methoxy acetate, etc.), cellosolve Cellosolves (methyl cellosolve, ethyl cellosolve, propyl cellosolve, etc.), hydrocarbons (n-hexane, n-heptane, benzene, toluene) , Xylene, etc.) and the like. These solvents can be used alone or in combination of two or more of them.

Based on 100% of the total weight of the hard coating composition, the solvent may contain 5 to 90% by weight, preferably 7 to 85% by weight. If the weight of the solvent is less than 5%, the viscosity may increase and the workability may deteriorate. If the weight of the solvent is greater than 90%, it will be difficult to adjust the thickness of the coating film, and drying unevenness may occur, resulting in appearance defects.

The hard coat composition according to an embodiment of the present invention may further include a multifunctional urethane (meth)acrylate having a cyclohexyl group and a ethylene glycol group At least one of a multifunctional (meth)acrylate.

In an embodiment of the present invention, the multifunctional urethane (meth)acrylate with a cyclohexyl group is a component used to improve the mechanical properties (especially hardness) of the film to be coated. The polyfunctional urethane (meth)acrylate having a cyclohexyl group can be produced by a condensation reaction of a monodiisocyanate having a cyclohexyl group and a polyfunctional (meth)acrylate having a hydroxyl group.

Specific examples of diisocyanates having a cyclohexyl group may include 1,4-cyclohexyl diisocyanate (1,4-cyclohexyl diisocyanate), isophorone diisocyanate (isophorone diisocyanate), 4,4-dicyclohexylmethane diisocyanate (4,4-dicyclohexylmethane diisocyanate) and the like, but not limited thereto.

Specific examples of the polyfunctional (meth)acrylate having a monohydroxyl group may include trimethylolpropane di(meth)acrylate (trimethylolpropane di(meth)acrylate), pentaerythritol tri(meth)acrylate (pentaerythritol tri(meth)acrylate meth)acrylate, dipentaerythritol penta(meth)acrylate and the like, but not limited thereto.

In an embodiment of the present invention, the multifunctional urethane (meth)acrylate with a cyclohexyl group may include at least one selected from the group consisting of compounds represented by the following chemical formulas 4 and 5.

Based on 100% of the total weight of the hard coating composition, the polyfunctional urethane (meth)acrylate having a cyclohexyl group may be contained in 3 to 10% by weight, preferably 5 to 8% by weight. When the weight of the multifunctional urethane (meth)acrylate is less than 3%, the mechanical properties (especially hardness) may decrease. When the weight of the multifunctional urethane (meth)acrylate is greater than 10%, the shrinking force will become larger, and therefore curls, cracks, cracks, etc. will occur on the film.

In an embodiment of the present invention, the polyfunctional (meth)acrylate having a glycol group is a component used to impart flexibility to the film to be coated. A polyfunctional alcohol with a glycol group can be obtained by the addition reaction of ethylene oxide and a polyhydric alcohol, and then the (meth)acrylic acid and the polyfunctional alcohol are subjected to a condensation reaction. Prepare this multifunctional acrylate with a glycol group.

The polyol may particularly be glycerol, trimethylol propane, pentaerythritol, dipentaerythritol, and the like, but is not limited thereto.

Specific examples of multifunctional (meth)acrylates having a monoethylene glycol group include trimethylol propane (ethylene oxide) ₃ trimethylol propane (EO) ₃ tri(meth)acrylate ), trimethylol propane (ethylene oxide) ₆ tris (meth) acrylate (trimethylol propane (EO) ₆ tri(meth)acrylate), trimethylol propane (ethylene oxide) ₉ tris (meth)acrylate yl) acrylate _{(trimethylol propane (EO) 9 tri} (meth) acrylate), glycerin (ethylene oxide) ₃ tri (meth) acrylate _{(glycerin (EO) 3 tri (} meth) acrylate), glycerol Alcohol (ethylene oxide) ₆ tri(meth)acrylate (glycerin(EO) ₆ tri(meth)acrylate), glycerin (ethylene oxide) ₉ tri(meth)acrylate (glycerin(EO)) ₉ tri(meth)acrylate), pentaerythritol (ethylene oxide) ₄ pentaerythritol (EO) ₄ tetra(meth)acrylate, pentaerythritol (ethylene oxide) ₈ tetra(meth)acrylic acid Ester (pentaerythritol(EO) ₈ tetra(meth)acrylate), pentaerythritol (ethylene oxide) ₁₂ tetra(meth)acrylate (pentaerythritol(EO) ₁₂ tetra(meth)acrylate), dipentaerythritol (ethylene oxide) ₆ hexa (meth) acrylate _{(dipentaerythritol (EO) 6 hexa (} meth) acrylate), dipentaerythritol (ethylene oxide) ₁₂ hexa (meth) acrylate _{(dipentaerythritol (EO) 12 hexa (} meth) acrylate), dipentaerythritol (ethylene oxide) ₁₈ hexa (meth) acrylate _{(dipentaerythritol (EO) 18 hexa (} meth) acrylate) , and the like.

In an embodiment of the present invention, the multifunctional acrylate with a glycol group may include at least one selected from the group consisting of compounds represented by the following chemical formulas 6 to 7.

Based on 100% of the total weight of the hard coating composition, the polyfunctional (meth)acrylate having a monoethylene glycol group may contain 3 to 10% by weight, preferably 5 to 8% by weight. When the weight of the polyfunctional (meth)acrylate is less than 3%, the flexibility may be insufficient, so cracks or cracks may occur on the coating film. When the weight of the multifunctional (meth)acrylate is higher than 10%, the mechanical properties may deteriorate, so scratches may be generated on the surface or the pencil hardness may decrease.

The hard coating composition according to an embodiment of the present invention may further include inorganic particles to further improve the mechanical properties.

The inorganic particles may have an average particle diameter of 1 to 100 nanometers (nm), preferably 5 to 50 nanometers (nm). These inorganic particles 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 smaller than the above range, agglomeration will occur in the composition, so a uniform coating film cannot be formed and the above-mentioned expected effect cannot be achieved. On the other hand, if the particle size exceeds the above range, not only the optical properties of the finally obtained coating film may be deteriorated, but also the mechanical properties may be deteriorated.

These inorganic particles can be metal oxides, one of which can be selected from aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), zinc oxide (ZnO), zirconium dioxide (ZrO ₂ ), barium titanate ( BaTiO ₃ ), titanium dioxide (TiO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), titanium pentoxide (Ti ₃ O ₅ ), indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide ( ATO), zinc aluminum oxide (ZnO-Al), niobium trioxide (Nb ₂ O ₃ ), stannous oxide (SnO) and magnesium oxide (MgO). In particular, aluminum oxide (Al ₂ O ₃ ), silicon _{dioxide (SiO 2} ), zirconium dioxide (ZrO ₂ ), and the like can be used.

In an embodiment of the present invention, the inorganic particles may be reactive inorganic particles. The active inorganic particle may be an organic compound having at least one polymerizable unsaturated group in the molecule of the active inorganic particle, and the organic compound forms a chemical bond with inorganic metal oxide particles. Examples of polymerizable unsaturated groups include acryloyl group, methacryloyl group, vinyl, propenyl group, butadienyl group, and styryl group. group), cinnamoyl group and the like.

In the active inorganic particles, the polymerizable unsaturated group can participate in photocuring to improve abrasion resistance, and at the same time, the curing shrinkage of the hard coating composition can be reduced to suppress warpage of the hard coating film.

The inorganic particles can be produced directly or obtained from the market. For commercial products, inorganic particles with a weight concentration of 10 to 80% can be dispersed in an organic solvent.

Based on 100% of the total weight of the hard coating composition, the inorganic particles may be contained at 5 to 40% by weight. When the weight of the inorganic particles is less than 5%, the mechanical properties of the coating film such as abrasion resistance, scratch resistance, and pencil hardness may be insufficient. When the weight of the inorganic particles exceeds 40%, the curing ability will be disturbed and the mechanical properties will be deteriorated, and there will be appearance defects.

The hard coat composition according to an embodiment of the present invention may further include a leveling agent to provide smoothness and coating properties of the coating film during the coating of the composition.

As for the leveling agent, commercially available silicon-type, fluorine-type and acrylic polymer-type leveling agents can be selected and used. For example, BYK-323, BYK-331, BYK-333, BYK-337, BYK-373, BYK-375, BYK-377, BYK-378 (BYK Chemie, BYK Chemie, Germany), TEGO Glide can be used 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 (Degussa, Degussa), FC-4430, FC-4432 (3M), KY-1203 (Shin-Etsu, Shin-Etsu Chemical Industry) or the like.

In one embodiment of the present invention, considering the improvement of water resistance, the leveling agent may be a fluorine-based leveling agent. Specifically, a fluorine-based leveling agent having at least one polymerizable unsaturated group in the molecule can be used. Examples of polymerizable unsaturated groups include acryloyl groups, methacryloyl groups, vinyl groups, and the like.

Based on 100% of the weight of the hard coating composition, the leveling agent may be contained at 0.01 to 0.05% by weight.

In addition to the above-mentioned ingredients, the hard coat composition according to an embodiment of the present invention may further include commonly used ingredients in the field, such as ultraviolet stabilizers, heat stabilizers and the like.

Because the surface of the cured coating film is decomposed and broken by the continuous exposure of ultraviolet rays, the surface of the cured coating film will be discolored and cracked. An ultraviolet light stabilizer can be added to protect the coating film by blocking or narrowing the ultraviolet rays. According to the mechanism of action, ultraviolet stabilizers can be classified into absorbers, quenchers, and hindered amine light stabilizers (HALS). Similarly, UV stabilizers can be classified as phenyl salicylate according to their chemical structure (Phenyl salicylate) (absorbent), benzophenone (absorbent), benzotriazole (absorbent), nickel derivative (matting agent) and free radical scavenger. As long as the initial color of the coating film is not significantly changed, the ultraviolet light stabilizer is not particularly limited.

Heat stabilizer is a product that can be applied to commerce, and polyphenol type (first-level heat stabilizer), phosphite type (second-level heat stabilizer), lactone type ( The lactone type) can be used alone or in combination.

The ultraviolet stabilizer and heat stabilizer can be used by appropriately adjusting the content to a level that does not affect the ultraviolet curability (ultraviolet curability).

An embodiment of the present invention relates to using the above-mentioned hard coating composition to form a hard coating film. A hard coating film according to an embodiment of the present invention is characterized in that a coating of a cured product containing the hard coating composition is formed on one surface or both surfaces of a transparent substrate.

For a transparent substrate, any polymer film with transparency can be used. According to the molecular weight of the film and the production method, the polymer film can be produced by a film-forming method or an extrusion method. As long as it is a commercially available transparent polymer film, there are no restrictions on its use.

Examples include various transparent polymer substrates, such as triacetyl cellulose, acetyl cellulose butyrate, and ethylene-vinyl acetate copolymer. , Propionyl cellulose, propionyl cellulose (butyryl cellulose), acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyether imide, polyacryl, polyimide, Polyether sulfone, polyether, polyethylene, polypropylene, polymethyl pentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone ( polyether ketone, polyether ether ketone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Polyethylene naphthalate, polycarbonate and the like.

The thickness of the transparent substrate is not particularly limited, but may be 10 to 1000 micrometers (μm), specifically 20 to 150 micrometers (μm). When the thickness of the transparent substrate is less than 10 micrometers (μm), the strength of the film will decrease, and therefore the processability will also decrease. When the thickness of the transparent substrate is greater than 1000 micrometers (μm), the transparency may decrease or the weight of the hard coating film may increase.

The hard coating composition of the present invention can be applied on one surface or both surfaces of a transparent substrate to produce a hard coating film according to an embodiment of the present invention, and then cured to form a coating.

A conventional coating process (coating process), such as die coater, air knife, reverse roller, spray, knife, casting, gravure, microgravure coating, spin coating, can be appropriately used. Etc., coating the hard coat composition according to an embodiment of the present invention onto a transparent substrate.

After coating the hard coat composition on the transparent substrate, a drying process can be performed by evaporating the volatile substances at a temperature of 30 to 150°C for 10 seconds to 1 hour, more specifically 30 seconds to 30 minutes, Then UV curing is carried out. UV curing may be by 0.01 to 10J / cm ^2, in particular 0.1 to 2J / cm ² ultraviolet ray irradiation is performed.

At this time, the formation thickness of the coating layer may be specifically 2 to 30 micrometers (μm), more specifically 3 to 20 micrometers (μm). When the thickness of the coating is within the above range, a coating with excellent hardness can be obtained.

An embodiment of the present invention relates to a hard coat film, comprising: a dendritic polymer compound having a terminal (meth)acrylate group and a polyhedral silicone oligomer compound, wherein when the hard coat film is folded in half If the distance between the film surfaces at room temperature is 6 millimeters (mm), the film will be unfolded again and the folded part can be visually observed without cracks or cracks with a length of 5 millimeters (mm) or less. And when the hard coat film is folded in half so that the distance between the film surfaces is 6 millimeters (mm), the film can be placed at 85°C and 85% relative humidity for 24 hours, the film will unfold again and can be observed with the naked eye To the folded part, no cracks or cracks with a length of 5 millimeters (mm) or less are generated.

In an embodiment of the present invention, the dendritic polymer compound having a terminal (meth)acrylate group can be the same as the dendritic polymer compound used in the above-mentioned hard coat composition.

In an embodiment of the present invention, the polyhedral siloxane oligomer compound may be the same as the polyhedral siloxane oligomer compound used in the above-mentioned hard coat composition.

Since the hard coat film according to an embodiment of the present invention includes a dendritic polymer compound having a terminal (meth)acrylate group and a polyhedral silicone oligomer compound, the hard coat film can be at room temperature It has excellent bending resistance with high temperature and high humidity environment.

An embodiment of the present invention relates to an image display having the above-mentioned hard coating film 示装置。 Display device. For example, the hard coat film of the present invention can be used as a window of an image display device, especially a window of a flexible display. Furthermore, the hard coat film of the present invention can be used by attaching to a polarizing plate, a touch sensor or the like.

The hard coat film according to an embodiment of the present invention can be used in various operation modes of liquid crystal devices (LCDs), including reflective, transmissive, transflective, and twisted nematic , TN), super-twisted nematic (STN), optically compensated bend (OCB), hybrid-aligned nematic (HAN), vertical alignment (vertical alignment) , VA)-type and in-plane switching (IPS) liquid crystal devices (LCDs). In addition, the hard coat film according to an embodiment of the present invention can be used in various image display devices, including plasma displays, field emission displays, organic EL displays, and inorganic EL displays. display), electronic paper and the like.

Hereinafter, the present invention will be explained in more detail based on examples, comparative examples, and experimental examples. Those with ordinary knowledge in the technical field should know that these embodiments, comparative examples and experimental examples are for illustrative purposes only, and are not intended to limit the present invention.

Examples 1 to 4 and Comparative Examples 1 to 2: Preparation of hard coat composition

The hard coat composition was prepared by mixing each component and composition as shown in Table 1. (unit weight%)

樹枝狀高分子化合物：SP-1106(Miwon Specialty Chemicals，美源特殊化工株式会社)無機粒子：二氧化矽粒子(silica particles)，粒子直徑10-15奈米(nm)光起始劑：1-羥基環已基苯基甲酮(1-hydroxycyclohexyl phenyl ketone)氟系整平劑：KY-1203(信越化學工業(Shin-Etsu))溶劑：甲基乙基酮POSS：MA0736(塑料混合物(Hybrid plastics))化學式4的化合物：SOU-1700B(勝東實業(Shin-A T&C))化學式7的化合物：DPEA126(日本化藥株式會社(Nippon Kayaku))

Dendrimer compound: SP-1106 (Miwon Specialty Chemicals, Miwon Specialty Chemicals Co., Ltd.) Inorganic particles: silica particles, particle diameter 10-15 nanometers (nm) Photoinitiator: 1- 1-hydroxycyclohexyl phenyl ketone fluorine-based leveling agent: KY-1203 (Shin-Etsu) Solvent: methyl ethyl ketone POSS: MA0736 (Hybrid plastics )) Compound of Chemical Formula 4: SOU-1700B (Shin-A T&C) Compound of Chemical Formula 7: DPEA126 (Nippon Kayaku)

Experimental example 1:

Coating the hard coating composition prepared in the Examples and Comparative Examples onto a surface of a polyimide film (100 micrometers (μm)) to perform 5 in an oven at 80°C After drying for minutes, the hard coating composition was made to have a thickness of 10 microns (μm), and the hard coating composition was exposed to a high pressure mercury lamp with a light of 500 mJ. Cured to prepare a hard coat film.

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

(1) Pencil hardness

The pencil hardness was measured by applying a load of 500 grams (g) using a pencil hardness tester (PHT, Korea Sukbo Science). A pencil manufactured by Mitsubishi Corporation was used, and the pencil hardness of the hard coating film was measured five times. When two or more scratches are found, the hard coating film will be judged as defective, and the maximum hardness judged to pass the test will be recorded.

(2) Scratch resistance

By using a steel wool tester (WT-LCM100, Korea Protec) under a load of 1 kilogram (kg) (2 cm (cm) x 2 cm (cm)) to perform 10 reciprocating motions Test scratch resistance. The steel wool used is #0000.

<Evaluation Criteria>

S: 0 scratches

A: 1 to 10 scratches

B: 11 to 20 scratches

C: 21 to 30 scratches

D: Equal to or greater than 31 scratches

(3) Adhesion

On the coated surface of the film, 11 straight lines with an interval of 1 millimeter (mm) were drawn horizontally and vertically to create 100 regular squares. Then use a tape (CT-24, Nichiban Co., Ltd., Japan) to perform three peels Peeling tests. Carry out three hundred grid tests and record the average value. The adhesion records are as follows.

Adhesion=n/100

n: Among all the squares, the number of squares that have not fallen off

100: total number of squares

Therefore, when no square falls off, it will be recorded as 100/100.

(4) Curl

The hard coat film cut into 10 centimeters (cm) x 10 centimeters (cm) is placed at a temperature of 25°C and a relative humidity of 48% for 24 hours. Then, the curl value is obtained by measuring the average height of the hard coat film from the bottom to the four edges. The explanation of the result is as follows.

<Evaluation Criteria>

◎: The average height of the four edges is equal to or less than 20 millimeters (mm)

○: The average height of the four edges is greater than 20 millimeters (mm) and equal to or less than 50 millimeters (mm)

△: The average height of the four edges is greater than 50 millimeters (mm)

X: The four edges are completely lifted, and the film is curled into a cylindrical shape.

(5) Bending resistance at room temperature

This hard coat film (width x length = 10 millimeters (mm) x 100 millimeters (mm)) is folded in half so that the distance between the film surfaces is 6 millimeters (mm). Then, the film is unfolded again, and it can be visually determined whether the folded part has cracks, so as to evaluate the bending resistance of the film. The results are explained below.

<Evaluation Criteria>

◎: No cracks in the folded part

○-A: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is equal to or less than 5)

○-B: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is greater than 5 and equal to or less than 10)

○-C: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is greater than 10)

△-A: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is equal to or less than 5)

△-B: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is greater than 5 and equal to or less than 10)

△-C: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is greater than 10)

×: The folded part has cracks

(6) Bending resistance under high temperature and high humidity

Fold the hard coat film in half (width x length = 10 millimeters (mm) x 100 millimeters (mm)) so that the distance between the surface of the film is 6 millimeters (mm), and the temperature of the film at 85 ℃ is relative to 85% Leave it in humidity for 24 hours. Then, the film is unfolded again, and it can be visually determined whether there are cracks in the folded part, so as to evaluate the bending resistance of the film.

<Evaluation Criteria>

◎: No cracks in the folded part

○-A: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is equal to or less than 5)

○-B: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is greater than 5 and equal to or less than 10)

○-C: There are cracks in the folded part (the length is equal to or less than 5 millimeters (mm), and the number is greater than 10)

△-A: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is equal to or less than 5)

△-B: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is greater than 5 and equal to or less than 10)

△-C: There are cracks in the folded part (the length is greater than 5 millimeters (mm) and equal to or less than 10 millimeters (mm), and the number is greater than 10)

×: The folded part has cracks

(7) Mandrel

In order to evaluate the bending properties and cracking properties of the coating film, a coated film sample cut into a size of 1 cm (cm) x 10 cm (cm) is placed in a film with each diameter (2 Φ-20 Φ). ) On an iron rod. Make the coated layer face up and fold it by hand, and mark the smallest diameter where no cracks occur on the surface.

As shown in Table 2, the hard coating film prepared according to the hard coating composition used in Examples 1 to 4 of the present invention has excellent hardness, scratch resistance and bending resistance, and is compared with those used in Comparative Examples 1 to 2. The hard coat film prepared by the hard coat composition can suppress the occurrence of curling.

Although the present invention has disclosed the above-mentioned embodiments, those skilled in the art to which the present invention pertains will know that these contents only disclose preferred embodiments, and the scope of protection of the present invention is not limited thereto. Those with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention.

Therefore, the scope of protection of the present invention shall be subject to those defined by the attached patent scope.

Claims (11)

A hard coating composition comprising: a dendrimer compound having a terminal (meth)acrylate group, a polyhedral silicone oligomer compound (polyhedral) oligomeric silsesquioxane compound), a photoinitiator and a solvent, wherein, based on 100% of the weight of the hard coating composition, the dendritic polymer compound having the terminal (meth)acrylate group contains 10 to 60 % By weight, the polyhedral silicone oligomer compound contains 3 to 20% by weight, the photoinitiator contains 0.1 to 5% by weight, and the solvent contains 5 to 90% by weight, wherein, The dendrimer compound having the terminal (meth)acrylate group includes a compound represented by the following Chemical Formula 1: [Chemical Formula 1] [R ₁ ] _4-n -C-[R ₂ -OR ₃ ] _n where , R ₁ is a C ₁ -C ₆ alkyl group, R ₂ is a C ₁ -C ₆ alkylene group, R ₃ is a (meth)acryloyl group or

, And at least one R ₃ is

， R ₄ is the (meth)acryloyl group or

, And at least one R ₄ is

, R ₅ is the (meth)acryloyl group or

, R ₆ is the (meth)acryloyl group, n is an integer of 2 to 4, and m, x, and y are an integer of 2 or 3. The hard coating composition according to the first item of the patent application, wherein the polyhedral silicone oligomer compound includes a compound represented by the following chemical formula 2:

Wherein, each R is independently hydrogen, or a linear, branched or cyclic hydrocarbon group with 1 to 20 carbon atoms substituted by a (meth)acrylate group, and at least in which One R is the linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms substituted by the (meth)acrylate group. The hard coating composition as described in item 1 of the scope of patent application further includes a polyfunctional urethane (meth)acrylate with a cyclohexyl group and a ethylene glycol group with a polyfunctional urethane (meth)acrylate. At least one of the polyfunctional (meth)acrylates of the ethylene glycol group. The hard coating composition as described in item 1 of the scope of the patent application further includes inorganic particles. The hard coating composition as described in item 1 of the scope of patent application further includes a fluorine-based leveling agent. A hard coating film formed by using the hard coating composition described in any one of items 1 to 5 in the scope of the patent application. A hard coating film, comprising: a dendrimer compound having a terminal (meth)acrylate group and a polyhedral silicone oligomer compound, wherein when the hard coating film is folded in half, the distance between the surface of the film When it is 6 millimeters (mm) at room temperature, spread the film again and observe the folded portion with the naked eye without cracks or cracks with a length of 5 millimeters (mm) or less; and Wherein, when the hard coat film is folded in half so that the distance between the film surfaces is 6 millimeters (mm), the film is placed at a temperature of 85°C and a relative humidity of 85% for 24 hours, and the film is unfolded again and observed with the naked eye The folded part does not produce cracks or produce cracks having a length of 5 millimeters (mm) or less, wherein the dendrimer compound having the terminal (meth)acrylate group includes a compound represented by the following chemical formula 1 : [Chemical formula 1] [R ₁ ] _4-n -C-[R ₂ -OR ₃ ] _n where R ₁ is a C ₁ -C ₆ alkyl group, R ₂ is a C ₁ -C ₆ alkylene group, R ₃ is a (meth)acryloyl group ((meth)acryloyl group) or

, And at least one R ₃ is

, R ₄ is the (meth)acryloyl group or

, And at least one R ₄ is

, R ₅ is the (meth)acryloyl group or

, R ₆ is the (meth)acryloyl group, n is an integer of 2 to 4, and m, x, and y are an integer of 2 or 3. An image display device having a hard coat film as described in item 7 of the scope of patent application. A window of a flexible display device has a hard coating film as described in item 7 of the scope of patent application. A polarizing plate having a hard coating film as described in item 7 of the scope of patent application. A touch sensor having a hard coating film as described in item 7 of the scope of patent application.