KR102336271B1 - Composition for forming hard coating and optical film using the same - Google Patents

Abstract

The present invention relates to a composition for forming a hard coating, and more particularly, to a thiophene compound (A) substituted with a (meth)acryloyloxy group; and a polymerizable compound (B) comprising a urethane-based (meth)acrylate resin and (meth)acrylate having an oxyethylene group; thereby exhibiting high hardness and excellent antistatic effect at the same time, preferred for forming a hard coating layer for flexible displays can be applied

Description

A composition for forming a hard coating and an optical film using the same

The present invention relates to a composition for forming a hard coating and an optical film using the same.

An image display device is composed of a liquid crystal cell containing liquid crystal and a polarizing plate, which is mainly bonded by forming an adhesive layer on one surface of the polarizing plate. In addition, in order to improve the function of the image display device, a surface protection film such as a retardation plate, a wide viewing angle compensation plate, and a brightness enhancement film is additionally attached to the polarizing plate through an adhesive and used.

Since optical members such as surface protection films and polarizing plates are made of plastic materials, static electricity is generated during friction and peeling. This can happen. Therefore, in order to prevent such a defect, various antistatic treatments are being carried out.

For example, there is a method of adding one or more surfactants to an adhesive and transferring the surfactant to an adherend to perform an antistatic function, but in this case, the surfactant is easy to bleed on the adhesive surface, and when applied to a protective film, There was a problem of concern about contamination of the adherend.

In addition, there is a method of adding an antistatic agent consisting of polyether polyol and an alkali metal salt to the acrylic adhesive, but even in this case, bleeding of the antistatic agent occurred, and the durability of the adhesive was significantly reduced after curing, and when applied to a protective film, Bleeding out easily occurred under high temperature conditions, and there was a problem in that the adherend was contaminated.

Korean Patent Laid-Open No. 2011-0112263 discloses a method of introducing a functional group having excellent compatibility with an antistatic agent into a monomer of an adhesive composition in order to suppress the bleeding of the antistatic agent, but the durability is reduced under conditions of high temperature and high humidity could not be resolved.

Korean Patent Publication No. 2011-0112263

An object of the present invention is to provide a composition for forming a hard coating capable of simultaneously implementing high hardness and excellent antistatic effect and producing a hard coating film with suppressed curl.

In addition, an object of the present invention is to provide an optical film having a hard coat layer formed of the composition for forming a hard coat.

Moreover, an object of this invention is to provide the image display apparatus provided with the said optical film.

1. a thiophene compound (A) substituted with a (meth)acryloyloxy group; and a polymerizable compound (B) comprising (meth)acrylate having a urethane-based (meth)acrylate resin and an oxyethylene group; comprising, a composition for forming a hard coating.

2. The composition for forming a hard coating according to the above 1, wherein the thiophene compound substituted with an acryloyloxy group is a thiophene compound represented by the following Chemical Formula 1:

[Formula 1]

(Wherein, R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, at least one of which is further substituted with an acryloyloxy group).

3. In the above 1, 0.1 to 20 parts by weight of the thiophene compound (A) substituted with the (meth)acryloyloxy group based on 100 parts by weight of the total weight of the polymerizable component (mixed weight of (A) and (B)) A composition for forming a hard coating comprising part.

4. In 1 above, 20 to 70 parts by weight of a urethane-based (meth)acrylate, (meth)acrylate containing an oxyethylene group based on 100 parts by weight of the polymerizable component (total weight of (A) and (B)) A composition for forming a hard coating, comprising 10 to 50 parts by weight.

5. The composition for forming a hard coating according to the above 1, wherein the urethane-based (meth)acrylate includes a cyclohexyl group.

6. The composition for forming a hard coating according to the above 1, further comprising at least one photopolymerization initiator (C) selected from the group consisting of an acetophenone-based photoinitiator and an aminoketone-based photoinitiator.

7. The composition for forming a hard coating according to the above 1, further comprising inorganic nanoparticles.

8. An optical film having a coating layer formed of the composition for forming a hard coating according to any one of claims 1 to 7 on at least one surface of the base film.

9. The optical film according to 8 above, wherein the optical film is a window film.

10. An image display device comprising the optical film of 8 above.

The composition for forming a hard coat of the present invention can form a hard coat layer having high hardness and excellent antistatic effect.

In addition, the composition for forming a hard coat of the present invention can form a hard coat layer having excellent curl properties and flexibility.

Accordingly, the composition for forming a hard coating of the present invention exhibits high hardness and excellent antistatic effect at the same time, and can be preferably applied to the formation of a hard coating layer for a flexible display.

One embodiment of the present invention is a (meth) acryloyloxy group substituted thiophene compound (A); and a polymerizable compound (B) comprising a urethane-based (meth)acrylate resin and (meth)acrylate having an oxyethylene group; thereby exhibiting high hardness and excellent antistatic effect at the same time, preferred for forming a hard coating layer for flexible displays It relates to a composition for forming a hard coating that can be applied to

Hereinafter, specific embodiments of the present invention will be described. However, this is merely an example, and the present invention is not limited thereto.

In the present invention, when there is an isomer of the compound or resin represented by the formula, the compound or resin represented by the formula means a representative formula including the isomer.

In the present invention, "(meth)acryl-" refers to 'acryl-', 'methacryl-', or both.

< hard coating Forming composition>

The composition for forming a hard coating of the present invention comprises a thiophene compound (A) substituted with a (meth)acryloyloxy group; and a polymerizable compound (B) comprising (meth)acrylate having a urethane-based (meth)acrylate resin and an oxyethylene group.

(Meta) a thiophene compound substituted with an acryloyloxy group (A)

The thiophene compound (A) substituted with a (meth)acryloyloxy group according to the present invention serves to significantly improve the antistatic effect and hardness of the hard coating layer.

Specifically, when the thiophene structure exhibits an antistatic effect, the acryloyloxy group reacts with other polymerizable compounds to form a cured product. Therefore, the thiophene compound substituted with an acryloyloxy group according to the present invention can improve the hardness of the hard coating layer and obtain an excellent antistatic effect.

The thiophene compound substituted with an acryloyloxy group according to the present invention may be a thiophene compound represented by the following Chemical Formula 1:

[Formula 1]

(Wherein, R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, at least one of which is further substituted with an acryloyloxy group).

The content of the thiophene compound (A) substituted with the (meth)acryloyloxy group according to the present invention is not particularly limited, and for example, the polymerizable component (total weight of (A) and (B)) in 100 parts by weight It may be included in an amount of 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight. If it is less than 0.1 parts by weight, antistatic properties may be insufficient, and if it is more than 20 parts by weight, hardness may be excessively increased and flexibility may be reduced.

photopolymerization Compound (B)

The photopolymerizable compound (B) according to the present invention is a component for improving the mechanical properties (particularly, hardness) of the hard coating layer.

The composition for forming a hard coating of the present invention includes a urethane-based (meth)acrylate in terms of improving hardness as a photopolymerizable compound (B), and (meth)acrylate including an oxyethylene group in terms of improving flexibility.

In the present invention, the urethane-based acrylate may be prepared by condensation reaction of a diisocyanate compound and a polyfunctional (meth)acrylate compound having a hydroxyl group.

The type of the diisocyanate compound is not particularly limited, but may preferably be a compound substituted with a cyclohexyl group, and accordingly, the urethane acrylate may have a substituent of a cyclohexyl group. In this case, it is preferable in that hardness and flexibility can be secured at the same time due to the structural stability of the cyclohexyl group.

Specific examples of the diisocyanate compound substituted with a cyclohexyl group include, but are not limited to, 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, 4,4-disylchlorohexylmethane diisocyanate, and the like. Specifically, compounds represented by the following Chemical Formulas 3 and 4, etc. may be mentioned.

[Formula 3]

[Formula 4]

Specific examples of the polyfunctional acrylate having a hydroxyl group include, but are not limited to, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc. no.

In the present invention, the acrylate containing an oxyethylene group is prepared by adding ethylene oxide to a polyhydric alcohol to obtain a polyfunctional alcohol containing an oxyethylene group, and then condensing (meth)acrylic acid with the polyfunctional alcohol. Specific examples of the polyhydric alcohol include, but are not limited to, glycerol, trimethylpropane, pentaerythritol, dipentaerythritol, and the like.

Specific examples of the acrylate containing the oxyethylene group include trimethylolpropane (EO) ₃ tri (meth) acrylate, trimethylol propane (EO) ₆ tri (meth) acrylate, trimethylol propane (EO) ₉ tri ( Meth) acrylate, glycerin (EO) ₃ tri (meth) acrylate, glycerin (EO) ₆ tri (meth) acrylate, glycerin (EO) ₉ tri (meth) acrylate, pentaerythritol (EO) ₄ tetra (meth) ) acrylate, pentaerythritol (EO) ₈ tetra (meth) acrylate, pentaerythritol (EO) ₁₂ tetra (meth) acrylate, dipentaerythritol (EO) ₆ hexa (meth) acrylate, dipentaerythritol (EO) ₁₂ hexa (meth) acrylate, dipentaerythritol (EO) ₁₈ hexa (meth) acrylate and the like may be mentioned, but are not limited thereto, and specifically, compounds represented by the following Chemical Formulas 5 and 6, etc. may be mentioned. .

[Formula 5]

[Formula 6]

The content of the urethane-based acrylate is not particularly limited, but, for example, may be included in an amount of 20 to 70 parts by weight, preferably 30 to 100 parts by weight, based on a total of 100 parts by weight of the polymerizable component (the total weight of (A) and (B)). It may be included in an amount of from 40 parts by weight. When the above range is satisfied, excellent mechanical properties can be secured. If it is less than 20 parts by weight, the hardness may decrease, and if it exceeds 70 parts by weight, the shrinkage force may be excessively increased and curl, breakage, cracks, etc. of the coating layer may occur.

In addition, the content of the (meth)acrylate containing the oxyethylene group is not particularly limited, but for example, 10 to 50 parts by weight of the polymerizable components (total weight of (A) and (B)) based on 100 parts by weight in total. It may be included in parts by weight, preferably 30 to 40 parts by weight. When the above range is satisfied, excellent mechanical properties can be secured and flexibility can be realized at the same time. If it is less than 10 parts by weight, mechanical properties may be deteriorated due to a decrease in the curing density, and if it exceeds 50 parts by weight, it may be difficult to secure flexibility due to an increase in the curing density.

If necessary, the composition for forming a hard coating of the present invention may further include a photopolymerizable compound known in the art in addition to the urethane-based acrylate and (meth)acrylate including an oxyethylene group. For example

As a monomer comprising at least one (meth)acrylate functional group as a polymerizable functional group, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (meth) acrylate , ditrimethylolpropane tetra (meth) acrylate, (meth) acrylate containing an oxyethylene group, ester (meth) acrylate, ether (meth) acrylate, and epoxy (meth) acrylate, melamine (meth) acrylic it is rate

A compound having a (meth)acryloyl group or a vinyl group as the polymerizable unsaturated group is preferable, and specific examples thereof include (meth)acrylic acid esters, N-vinyl compounds, vinyl-substituted aromatic compounds, vinyl ethers and vinyl esters. have.

As (meth)acrylic acid ester, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth) ) acrylate, ethylene glycol di(meth)acrylate, propylene glycol (meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexane Diol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, bis( 2-hydroxyethyl) isocyanurate di(meth)acrylate, poly(meth)acrylate in which ethylene oxide or propylene oxide is added to the (meth)acrylic acid ester; oligoester (meth)acrylate, oligoether (meth)acrylic acid ester, oligourethane (meth)acrylic acid ester, oligoepoxy (meth)acrylic acid ester having 1 to 3 (meth)acryloyl groups in the molecule; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and ethylene oxide or propylene oxide addition products to the (meth)acrylic acid ester; Mono (meth) acrylic acid ester, iso-octyl (meth) acrylate, iso-decyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylic Rates may be provided. Further, as the N-vinyl compound, N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl phthalimide, N-vinyl succinimido and the like may be provided. As the vinyl substituted aromatic compound, styrene, divinylbenzene, chloromethylstyrene, hydroxystyrene, alpha-methylstyrene, bromomethylstyrene, tribromomethylstyrene, and the like may be provided. As the vinyl ether, diethylene glycol monomethyl vinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether and the like can be provided. As the vinyl ester, vinyl acetate, vinyl propionate, vinyl benzoate and the like can be provided.

The photopolymerizable compound that may be additionally included may be included, for example, in an amount of 25 parts by weight or less based on 100 parts by weight of the polymerizable component (total weight of (A) and (B)), but is not limited thereto.

Photoinitiator (C)

The photoinitiator (C) according to the present invention is not particularly limited as long as it can form radicals by irradiation with light.

The photopolymerization initiator (C) includes a Type 1 initiator in which radicals are generated by decomposition of molecules due to a difference in chemical structure or molecular binding energy, and a Type 2 initiator of a hydrogen recovery type by coexisting with a tertiary amine.

Specific examples of the Type 1 initiator include 4-phenoxydichloroacetphenone, 4-t-butyldichloroacetphenone, 4-t-butyltrichloroacetphenone, diethoxyacetphenone, 2-hydroxy-2-methyl-1 -Phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methyl Acetphenones such as propan-1-one, 4-(2-hydroxyethoxy)-phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenyl ketone, benzoin, benzoinmethyl Benzoins, such as ether, benzoin ethyl ether, and benzyl dimethyl ketal, acyl phosifine oxides, a titanocene compound, etc. are mentioned.

Specific examples of the Type 2 initiator include benzophenone, benzoylbenzoic acid, benzoylbenzoic acid methyl ether, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzol-4'-methyldiphenylsulfide, 3,3' - Benzophenones such as methyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, and thioxanthone such as isopropylthioxanthone Oxanthone, etc. are mentioned.

A photoinitiator may use 1 type, and may use 2 or more types in parallel. In addition, Type 1 and Type 2 may be used alone or in combination.

Commercially available photopolymerization initiators include Igacure 184 (manufactured by BASF) and the like.

In the present invention, the content of the photopolymerization initiator (C) is not particularly limited, but, for example, may be included in an amount of 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the total composition. . When the above range is satisfied, excellent mechanical properties and adhesion can be realized. If it is less than 0.1 parts by weight, curing may not proceed sufficiently, so that mechanical properties or adhesion of the final coating film may be reduced. If it exceeds 10 parts by weight, cracks and curls may occur due to curing shrinkage.

Solvent (D)

The solvent (D) according to the present invention may be used without particular limitation as long as it can dissolve or disperse the above-mentioned components.

Specific examples include alcohols (methanol, ethanol, isopropanol, butanol, propylene glycol methoxy alcohol, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, etc.); Acetate type (methyl acetate, ethyl acetate, butyl acetate, propylene glycol methoxy acetate, etc.), cellosolve type (methyl cellosolve, ethyl cellosolve, propyl cellosolve, etc.), hydrocarbon type (normal hexane, normal heptane, benzene, toluene) , xylene, etc.), and these may be used alone or in combination of two or more.

In the present invention, the content of the solvent (D) is not particularly limited, but, for example, may be included in an amount of 5 to 90 parts by weight, preferably 20 to 70 parts by weight, based on 100 parts by weight of the total composition. When included in the above content range, it is preferable to implement appropriate applicability. On the other hand, when it is less than 5 parts by weight, the viscosity is high and the applicability is lowered, and when it exceeds 90 parts by weight, it is difficult to adjust the thickness of the coating film, and drying unevenness may occur, resulting in poor appearance.

Inorganic nanoparticles (E)

The composition for forming a hard coating according to the present invention may further include inorganic nanoparticles (E) in order to secure the mechanical properties of the hard coating layer.

The inorganic nanoparticles (E) may be uniformly formed in the coating film to improve mechanical properties such as abrasion resistance, scratch resistance, and pencil hardness.

The average particle diameter of the inorganic nanoparticles (D) according to the present invention is not particularly limited, but may be, for example, 1 to 100 nm, preferably 5 to 50 nm. Excellent mechanical properties can be implemented within the above range. On the other hand, when the average particle diameter is less than 1 nm, particle agglomeration occurs and a uniform coating film cannot be formed.

The type of the inorganic nanoparticles (D) is not particularly limited, but may be, for example, a metal oxide, 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-Al, Nb ₂ O ₃ , SnO, MgO, and one selected from the group consisting of MgO and combinations thereof may be used, preferably Al ₂ O ₃ , SiO ₂ , ZrO ₂ can be used.

In the present invention, the content of the inorganic nanoparticles (D) is not particularly limited, but, for example, may be included in an amount of 10 to 50 parts by weight based on 100 parts by weight of the total composition. When included in the above content range, mechanical properties such as abrasion resistance, scratch resistance, and pencil hardness are excellent. On the other hand, when it exceeds 50 parts by weight, the curability may be disturbed, and mechanical properties may be deteriorated, and the appearance may be deteriorated.

The inorganic nanoparticles may be used by diluting in an organic solvent to a concentration of 10 to 80% by weight.

Additive (F)

The composition for forming a hard coating according to the present invention may further include an additive (F) if necessary in addition to the above-described components, for example, a leveling agent, a UV stabilizer, a heat stabilizer, and the like.

The leveling agent is added to improve the smoothness and applicability of the coating film when the composition is applied, and a silicone leveling agent, a fluorine-based leveling agent, an acrylic-based leveling agent, and the like may be used. Commercial products of the leveling agent include BYK-323, BYK-331, BYK-333, BYK-337, BYK-373, BYK-375, BYK-377, BYK-378 by Chemi, TEGO Glide 410, TEGO Glide by Daegu. 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 3M's FC-4430, FC-4432, etc. can be used.

The sunscreen is added to prevent the surface of the coating film from being discolored or brittle by continuous exposure to ultraviolet rays, and serves to block or absorb ultraviolet rays. The ultraviolet stabilizer may be divided into absorbers, quenchers, and hindered amine light stabilizers (HALS) depending on the mechanism of action, for example, phenyl salicylate (Phenyl Salicylates, absorbents); Benzophenone (absorbent), benzotriazole (absorbent), nickel derivative (quenching agent), radical scavenger (Radical Scavenger), and the like.

As the heat stabilizer, polyphenol-based, phosphite-based and lactone-based heat stabilizers may be used, and the UV stabilizer and heat stabilizer may be mixed in an appropriate amount at a level that does not affect UV curability.

The additive (F) is preferably used in an amount of 0.1 to 3 parts by weight based on 100 parts by weight of the total composition.

<Optical Film>

In addition, the present invention provides an optical film having a hard coat layer formed of the composition for forming the hard coat layer.

The optical film of the present invention includes a base film having a hard coat layer formed of the composition on at least one surface.

The base film may be used without particular limitation as long as it is a transparent polymer film, for example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester , polystyrene, polyamide, polyetherimide, polyacrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, poly The film may be formed of a polymer such as ether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or polycarbonate. These polymers can be used individually or in mixture of 2 or more types.

Among the base films, in the case of crystalline polymer base film, engineering plastic base film, and polymer base film whose surface has changed to hydrophilic due to hydrolysis or saponification, it is difficult to increase adhesion when using a conventional composition for forming a hard coating layer. In some cases, mechanical properties may be deteriorated. However, the composition for forming a hard coat layer of the present invention described above can implement excellent adhesion to these base films without deterioration of mechanical properties.

The base film may have been subjected to surface treatment such as plasma treatment or corona treatment to improve adhesion with the hard coating layer.

The hard coating layer is formed by applying and curing a composition for forming a hard coating layer on a base film, and the application is 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 , roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, gravure printing method, flexographic printing method, offset printing method, inkjet coating method, dispenser printing method, nozzle coating method, capillary coating method A known method such as these can be used.

The thickness of the hard coating layer is not particularly limited, and may be, for example, 5 to 100 μm. When the thickness is within the above range, excellent hardness and flexibility are exhibited, and curling can be prevented.

Since the optical film of the present invention has excellent hardness, flexibility and curl properties, it can be usefully applied to a window film of an image display device.

<Image display device>

In addition, the present invention provides an image display device having the hard coating film.

Since the hard coating film of the present invention has excellent hardness and flexibility, the hard coating film may be used, for example, as an outermost window film of an image display device, and in particular, may be preferably applied to a flexible image display device.

The image display device may be various image display devices such as a conventional liquid crystal display device, an electroluminescence display device, a plasma display device, and a field emission display device.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but these examples are merely illustrative of the present invention and do not limit the appended claims, and are within the scope and spirit of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible, and it is natural that such variations and modifications fall within the scope of the appended claims.

production example One

A thiol-based compound represented by Formula 1-1 was prepared.

[Formula 1-1]

Hydroxymethyl ethylenedioxythiophene and acryloyl chloride were reacted by slowly stirring at low temperature. After raising the temperature to room temperature and stirring for 72 hours, a white solid as a by-product was filtered, washed with HCl solution, and neutralized again. Then, the solvent was removed to obtain a thiophene compound represented by Chemical Formula 1-1.

production example 2

A thiol-based compound represented by Formula 1-2 was prepared.

It was carried out in the same manner as in Preparation Example 1, except that methacryloyl chloride was used instead of acryloyl chloride.

[Formula 1-2]

production example 3

Polymerizable components of the components and contents (parts by weight) shown in Table 1 were prepared.

division Thiophene compound (A) Photopolymerizable compound (B) ingredient content urethane oxyethylene etc content Preparation Example 1 A-1/A-2 5/10 B-1 B'-1 - 50/35 Preparation 2 A-1 15 B-2 B'-1 - 50/35 Preparation 3 A-1/A-2 10/5 B-1 B'-2 - 45/40 Preparation 4 A-1/A-2 10/5 B-2 B'-2 - 45/40 Preparation 5 A-1/A-2 5/10 B-1 B'-2 - 50/35 Preparation 6 A-2 15 B-2 B'-2 - 55/30 Preparation 7 A-1/A-2 5/10 B-1/B-3 B'-2 - 35/30/20 Preparation 8 A-1/A-2 10/5 B-2 B'-2 - 45/40 Preparation 9 A-1/A-2 20/18 B-1 B'-1 - 36/26 Preparation 10 A-1/A-2 5/10 - B'-1 - 85 Preparation 11 A-1/A-2 5/10 B-1 - - 85 Preparation 12 - - B-3 B'-1 - 45/55 Preparation 13 - - - B'-1 B"-1 55/45 Preparation 14 - - B-2 B'-2 - 55/45 Preparation 15 - - - B'-1/B'-2 - 55/45

A-2:

B-1: 신아 T&C SOU-1700B

B-2: 신아 T&C SOU-1290

B-3: UA-306H (공영사)

B’-1: M4004 (미원스페샬리티 케미칼)

B'-2: DPEA126(일본화약)

B"-1: M-340(미원스페샬리티 케미칼)

A-1:

A-2:

B-1: Shin-A T&C SOU-1700B

B-2: Shina T&C SOU-1290

B-3: UA-306H (public corporation)

B'-1: M4004 (Miwon Specialty Chemical)

B'-2: DPEA126 (Japanese gunpowder)

B"-1: M-340 (Miwon Specialty Chemicals)

Example and comparative example

Based on 30 parts by weight of a mixture of polymerizable components according to the components and contents of Table 1, Nanopol 784 (Evonik, PGEMA 50% diluted 20 nm silica sol) 30 parts by weight, photoinitiator igacure 184 (BASF) 5 parts by weight, leveling By adding 3 parts by weight of No. BYK-333, 30 parts by weight of methyl ethyl ketone, and 10 parts by weight of toluene, Examples 1 to 9 (using Preparation Examples 1 to 9), Comparative Examples 1 to 6 (using Preparation Examples 10 to 15) A composition for forming a hard coating was prepared.

Experimental example

The compositions for forming hard coatings of Examples and Comparative Examples were coated on an 80 μm optical polyimide film (Mitsubishi Gas Chemical, 100 μm, L-3430) using a bar coater and dried to a thickness of 20 μm. After drying in an oven at ℃ for 2 minutes, using a high-pressure mercury lamp ^{irradiated at 350mJ/cm 2} to prepare a hard coating film.

1. Pencil hardness

Using a pencil hardness tester (PHT, Seokbo Science Co., Korea), a load of 500 g was applied and the pencil hardness was measured. For the pencil, a Mitsubishi product was used, and the experiment was performed 5 times per pencil hardness.

2. scratch resistance

Abrasion resistance was tested by reciprocating 10 times under 1kg/(2cm×2cm) using a steel wool tester (WT-LCM100, Protec, Korea).

Steel wool #0000 was used.

<Evaluation criteria>

S: 0 scratches

A: 1 to 10 scratches

B: 11-20 scratches

C: 21 to 30 scratches

D: 31 or more scratches

3. Adhesion

After making 100 squares by drawing 11 straight lines horizontally and vertically at 1 mm intervals on the coated side of the film, a peel test was performed three times using a tape (CT-24, Nichiban, Japan). Three 100 squares were tested and the average was recorded.

Adhesion was recorded as follows.

Adhesion = n/100

n: the number of non-exfoliated rectangles among all rectangles

100: the total number of squares

Therefore, when no peeling occurred, it was recorded as 100/100.

4. curl

A sample cut into a square shape of A4 size (29.7 × 21.0 cm) is placed on a flat glass plate, with the film coated side facing up, and the distance from the square glass plate is measured at 25°C and 50%RH, and the average value is obtained It was set as the measured value.

5. mandorel

In order to evaluate the flexibility and cracking properties of the coating film, a coated film sample cut to a size of 1 cm x 10 cm is placed on an iron rod of each diameter (2 φ to 10 φ), and the surface is cracked by folding the coating layer upward by hand. The smallest diameter that does not occur is indicated.

6. Antistatic properties ( surface resistivity )

Using a surface resistance measuring instrument (MCP-HT450, Mitsubishi chemical, Probe: URS, UR100, Probe checker: for URS, for UR100), measure the three points of the coating layer 10 times each, then calculate the average value and follow the criteria below. based on the evaluation.

<Evaluation criteria>

○: Surface resistivity ≤ 5.0×10 ¹⁰ Ω/□

△: 5.0×10 ¹⁰ Ω/□ < Surface resistivity ≤ 9.9×10 ¹⁰ Ω/□

×: 9.9×10 ¹⁰ Ω/□ < surface resistivity

7. Antistatic over time

The antistatic property was evaluated after heat-treating the sample for which the antistatic property was measured in a heat-resistant oven at 60 degrees for 24 hours.

<Evaluation criteria>

○: Change in surface resistivity ≤ 3.0×10 ¹⁰ Ω/□

△: 3.0×10 ¹⁰ Ω/□ < Surface resistivity change ≤ 5.0×10 ¹⁰ Ω/□

×: 5.0×10 ¹⁰ Ω/□ < change in surface resistivity

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 pencil hardness 5H 6H 6H 5H 5H 5H 5H 5H 3H scratch resistance S S S S S S S S A adhesion 100/100 100/100 100/100 100/100 100/100 100/100 100/100 100/100 95/100 curl 2mm 2mm 2mm 2mm 5mm 5mm 3mm 4mm 5mm mandorel 3φ 3φ 3φ 3φ 3φ 3φ 3φ 3φ 5φ antistatic ○ ○ ○ △ ○ ○ ○ △ ○ Antistatic over time ○ ○ ○ ○ ○ ○ ○ ○ △

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 pencil hardness F F H H HB HB scratch resistance B B B B B B adhesion 80/100 80/100 90/100 80/100 75/100 75/100 curl 8mm 7mm 6mm 8mm 8mm 8mm mandorel 7φ 9φ 7φ 9φ 9φ 9φ antistatic ○ ○ × × × × Antistatic over time ○ ○ × × × ×

Referring to Tables 2 and 3, it was confirmed that the optical films formed of the composition for forming a hard coating according to the present invention were implemented within excellent ranges of pencil hardness, flexibility, and (chronic) antistatic properties.

However, it was confirmed that the comparative examples were not suitable for a window substrate of a flexible display and the like, since they did not simultaneously secure hardness, flexibility, and (chronic) antistatic properties.

Claims (10)

(meth) a thiophene compound (A) substituted with an acryloyloxy group; and a polymerizable compound (B) comprising (meth)acrylate having a urethane-based (meth)acrylate resin and an oxyethylene group; comprising, a composition for forming a hard coating.
The composition for forming a hard coating according to claim 1, wherein the (meth)acryloyloxy group-substituted thiophene compound is a thiophene compound represented by the following Chemical Formula 1:
[Formula 1]

(Wherein, R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, at least one of which is further substituted with a (meth)acryloyloxy group).
The method according to claim 1, containing 0.1 to 20 parts by weight of the thiophene compound (A) substituted with the (meth)acryloyloxy group based on 100 parts by weight of the total weight of the polymerizable component (mixed weight of (A) and (B)) A composition for forming a hard coating.
The method according to claim 1, 20 to 70 parts by weight of a urethane-based (meth)acrylate, 10 to (meth)acrylate containing an oxyethylene group based on 100 parts by weight of the total weight of the polymerizable component (the total weight of (A) and (B)) A composition for forming a hard coating, comprising 50 parts by weight.
The composition for forming a hard coating according to claim 1, wherein the urethane-based (meth)acrylate comprises a cyclohexyl group.
The composition for forming a hard coating according to claim 1, further comprising at least one photopolymerization initiator (C) selected from the group consisting of acetophenone-based photoinitiators and aminoketone-based photoinitiators.
The composition for forming a hard coating according to claim 1, further comprising inorganic nanoparticles.
An optical film comprising a coating layer formed of the composition for forming a hard coating according to any one of claims 1 to 7 on at least one surface of the base film.
The optical film of claim 8 , wherein the optical film is a window film.
The image display apparatus provided with the optical film of Claim 8.