KR102341198B1 - Hard coating film and image display device using the same - Google Patents

Abstract

The present invention provides a base layer, a first hard coating layer formed on at least one surface of the base layer and comprising a fluorine-based UV-curable functional group-containing compound, and a first hard coating layer formed between the base layer and the first hard coating layer and comprising inorganic particles By including the 2 hard coating layer, it relates to a hard coating film capable of providing excellent durability, elastic recovery rate and abrasion resistance, and an image display device including the same.

Description

Hard coating film and image display device including same {HARD COATING FILM AND IMAGE DISPLAY DEVICE USING THE SAME}

The present invention relates to a hard coating film and an image display device including the same.

Recently, thinness and flexibility of image display devices, such as liquid crystal display (LCD) devices or organic light emitting display (OLED) devices, have continued. Accordingly, the image display device is widely applied to various smart devices characterized by portability, ranging from smart phones and tablet PCs to various wearable devices, and have.

A window film or protective film made of tempered glass may be formed on or in the display panel to protect the image display device from external environments such as scratches, drop impact, external moisture, and oil. However, the window film is disadvantageous in reducing the weight of a display panel or an image display device due to the characteristics of tempered glass, and is easily broken by an external impact. In addition, there is a limit to the implementation of the flexible (flexible) characteristic through the bendable (bendable) or foldable (foldable) function.

Therefore, recently, research on an optical plastic cover that can secure flexibility and impact resistance and can replace the window film made of the tempered glass material is being conducted.

However, the optical plastic cover has low enough hardness and scratch resistance compared to the window film made of the tempered glass material, and thus the impact resistance against external impact in the image display device or the display panel may be reduced.

In addition, in recent years, flexible displays that can maintain display performance even when bent like paper by using flexible materials such as plastics instead of the existing inflexible glass substrates are rapidly emerging as next-generation display devices, and hardness is reduced. There is a need for development of a hard coating film having high abrasion resistance and excellent flexibility.

In this regard, in Korean Patent Application Laid-Open No. 10-20007-0087003, a hard coating layer and a reflective semi-layer are sequentially laminated on at least one side of a transparent plastic film substrate, and the hard coat layer has a (meth) acrylate group. And an antireflection hard coat film containing a reactive silicone having a (meth)acrylate group in a specific content range is disclosed.

In addition, Korean Patent Application Laid-Open No. 10-2019-0038590 discloses that a hard coating layer laminated on at least one major side of the base film is provided, and the difference between the refractive index of the base film and the refractive index of the hard coating layer is less than or equal to a specific value, where the hard A hard coat film in which the thickness of the coating layer has a specific range is disclosed.

However, the above patents have limitations in forming a hard coating film having improved durability, elastic recovery rate, and abrasion resistance together.

Korean Patent Publication No. 10-20007-0087003 Republic of Korea Patent Publication No. 10-2019-0038590

An object of the present invention is to provide a hard coating film excellent in durability, elastic recovery rate and abrasion resistance in order to solve the above problems.

In addition, an object of the present invention is to provide an image display device including the hard coating film.

The present invention, the substrate layer; a first hard coating layer formed on at least one surface of the base layer and including a fluorine-based UV-curable functional group-containing compound; and a second hard coating layer formed between the base layer and the first hard coating layer and comprising inorganic particles, it provides a hard coating film.

In addition, the present invention provides an image display device comprising the above-described hard coating film.

The hard coating film according to the present invention exhibits improved antifouling performance to exhibit excellent abrasion resistance, and has excellent elastic recovery rate and thus excellent pen pressing characteristics, as well as scratch resistance, chemical resistance, bending resistance, etc. It has the effect of securing durability. Therefore, the image display device including the hard coating film of the present invention can provide improved mechanical reliability and flexibility.

1 is a schematic cross-sectional view for explaining a hard coating film according to an embodiment of the present invention.

The present invention is a substrate layer; a first hard coating layer formed on at least one surface of the base layer and including a fluorine-based UV-curable functional group-containing compound; and a second hard coating layer formed between the base layer and the first hard coating layer and including inorganic particles, thereby providing excellent durability, elastic recovery rate and abrasion resistance, and an image display device including the same is about

For example, the hard coating film of the present invention can provide excellent abrasion resistance by rubbing the surface of the first hard coating layer with an abrasion-resistant eraser 3000 times under a weight of 500 g, and then the water contact angle is 95 degrees or more. In addition, after rubbing the surface of the first hard coating layer with an abrasion-resistant eraser to the site where ethanol was dropped under a weight of 500 g under a weight of 500 g, the water contact angle was 95 degrees or more. Furthermore, the hard coating film of the present invention has an elastic recovery rate of 56% or more, as measured by a load of 5 mN, and has excellent elastic recovery rate. In addition to this, when the surface of the first hard coating layer is pressed with the electronic pen, the occurrence of pressurization is prevented, thereby exhibiting improved properties in pen pressability.

Hereinafter, the present invention will be described in detail.

<Hard coating film>

1 is a schematic cross-sectional view for explaining a hard coating film according to an embodiment of the present invention.

Referring to FIG. 1 , the hard coating film includes a base layer 100 , a first hard coat layer 110 and a second hard coat layer 120 , and a second hard coat layer from the base layer 100 . (120) and the first hard coating layer 110 includes a sequentially stacked structure.

The hard coating film of the present invention exhibits improved antifouling performance, exhibits excellent abrasion resistance, and has excellent elastic recovery rate, so that it is excellent in pen pressing characteristics, and also has excellent durability such as scratch resistance, chemical resistance, and bending resistance. It can also provide an excellent effect.

In addition, as the hard coat film of the present invention is laminated in the order of the base layer 100, the second hard coat layer 120, and the first hard coat layer 110, the components and the base material used to form the first hard coat layer It is possible to prevent the components constituting the layer from mixing, it is possible to further improve the abrasion resistance in the first hard coating layer.

base layer

The base layer 100 is to support the first hard coat layer and the second hard coat layer to be described later, and the hard coat layers formed on the base layer 100 are coated with a hard coating composition on at least one surface of the base layer and cured. It is formed by sequentially stacking the second hard coat layer and the first hard coat layer.

In the present invention, the base layer 100 is a transparent film, and any transparent film may be used as long as the transparent film is a transparent polymer film.

For example, the base layer 100 may include triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, poly Etherimide, polyacrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone , polyether sulfone, polymethyl methacrylate, polybutylene terephthalate, polyethylene naphthalate, may be a film formed of a polymer such as polycarbonate. These polymers can be used individually or in mixture of 2 or more types.

first hard coat layer

The first hard coat layer 110 is formed on at least one surface of the base layer 100 , and more specifically, is formed on the second hard coat layer 120 laminated on the base layer 100 .

For example, the first hard coating layer 110 is a first hard coating composition comprising the fluorine-based UV-curable functional group-containing compound, a light-transmitting resin, a solvent, and a photoinitiator on the second hard coating layer 120. After applying the ultraviolet rays It can be formed by photocuring by irradiation.

The fluorine-based UV-curable functional group-containing compound is a component that imparts antifouling properties, abrasion resistance, and chemical resistance, and must contain a fluorine component, along with a UV-curable functional group, which is chemically bonded to the monomer and oligomer layers that form the hard coat layer It is not particularly limited as long as it can be done.

In the present invention, the first hard coating layer 110 may exhibit more improved wear resistance by including the fluorine-based UV-curable functional group-containing compound.

For example, in the present invention, the UV-curable functional group may mean a fluorine-containing aliphatic hydrocarbon group or a fluorine-containing aromatic hydrocarbon group.

Specifically, the fluorine-based UV-curable functional group-containing compound may be a compound containing at least one fluoro group, and (meth)acrylate containing at least one fluoro group may be used. Preferably, (meth)acrylate containing a perfluoro aliphatic group, (meth)acrylate containing a perfluoro aromatic group, etc. may be used. In this case, it is more preferable that the fluorine-based UV-curable functional group-containing compound has 1 to 6 UV-curable functional groups.

For example, 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2-perfluorobutylethyl acrylate, 3-perfluorobutyl-2 -Hydroxypropyl acrylate, 2-perfluorohexylethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctylethyl acrylate, 3-perfluorooctyl-2 -Hydroxypropyl acrylate, 2-perfluorodecylethyl acrylate, 2-perfluoro-3-methylbutylethyl acrylate, 3-perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate , 2-perfluoro-5-methylhexylethyl acrylate, 3-perfluoro-5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl Acrylate, tetrafluoropropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl acrylate, hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl Methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2-perfluorobutylethyl methacrylate, 3-perfluorobutyl-2-hydroxypropyl methacrylate, 2 -Perfluorooctylethyl methacrylate, 3-perfluorooctyl-2-hydroxypropyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluoro-3-methylbutylethyl methacrylate Late, 3-perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-perfluoro-5-methylhexylethyl methacrylate, 3-perfluoro-5-methylhexyl-2- Hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-6-methyloctyl methacrylate, tetrafluoropropyl methacrylate, octafluoropentyl methacrylate Late, octafluoropentyl methacrylate, dodecafluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyltrifluoroethyl methacrylate, hexafluorobutyl methacrylate, triacryloyl-heptadecafluorononenyl-pentaerythritol etc. are mentioned.

Commercial examples of the fluorine-based UV-curable functional group-containing compound that can be used in the present invention include KY-1203 (Shin-Etsu Silicone), OPTOOL DAC-HP (Daikin), UVAS-2003 (Suyang Chemtech), and the like, and these products can be used for preparing the first hard coating composition of the present invention.

In one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is preferably included in an amount of greater than 0.01 to 10 parts by weight based on 100 parts by weight of the total first hard coating composition. When the fluorine-based UV-curable functional group-containing compound is included in the first hard coating composition in an amount of 0.01 parts by weight or less, it is difficult to sufficiently promote abrasion resistance and antifouling properties, and when it is included in excess of 10 parts by weight, the film hardness and scratch resistance will be reduced. may be

The light-transmitting resin may be a photocurable resin, and the photocurable resin may include a photocurable (meth)acrylate oligomer or monomer.

As the photocurable (meth)acrylate oligomer, epoxy (meth)acrylate, urethane (meth)acrylate, etc. are commonly used, and urethane (meth)acrylate is more preferable. Urethane (meth)acrylate can be prepared in the presence of a catalyst in the presence of a compound having a polyfunctional (meth)acrylate and an isocyanate group having a hydroxyl group in the molecule. Specific examples of the (meth)acrylate having a hydroxyl group in the molecule include 2-hydroxyethyl (meth)acrylate, 2-hydroxyisopropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, capro At least one selected from the group consisting of lactone ring-opened hydroxyacrylate, a pentaerythritol tri/tetra (meth) acrylate mixture, and a dipentaerythritol penta/hexa (meth) acrylate mixture may be selected.

In addition, specific examples of the compound having an isocyanate group include 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatododecane, 1, 5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4 '-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1, 3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis(2,6-dimethylphenylisocyanate), 4,4'-oxybis(phenylisocyanate), hexamethylenediisocyanate At least one selected from the group consisting of trifunctional isocyanate derived from, and trimethanol adduct toluene diisocyanate.

The monomer is a commonly used photocurable functional group having an unsaturated group such as a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group in a molecule, and among them, a (meth)acryloyl group is more preferable.

The monomer having the (meth) acryloyl group is specifically exemplified by neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1 , 2,4-cyclohexanetetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate , dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tri (meth) acrylate, tripentaerythritol hexatri (meth) acrylic Rate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, iso-dexyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, isoborneol (meth) acrylate One or more may be selected from the group consisting of.

The photocurable (meth)acrylate oligomer and monomer, which are the light-transmitting resins exemplified above, may be used alone or in combination of two or more.

The light-transmitting resin is not particularly limited, but is preferably included in an amount of 1 to 80 parts by weight based on 100 parts by weight of the total first hard coating composition. When the light-transmitting resin is included in an amount of less than 1 part by weight, it is difficult to achieve sufficient hardness improvement, and when it is included in an amount exceeding 80 parts by weight, a problem of severe curling may occur.

The description of the light-transmitting resin may be equally applied to the second hard coating composition.

In the present invention, each light-transmitting resin included in the first hard coating composition and the second hard coating composition may be the same as or different from each other.

The solvent may be used without limitation, as long as it is known as a solvent for a composition for forming a coating layer in the art that can dissolve or disperse the above-mentioned composition.

Usable solvents include alcohol-based solvents such as methanol, ethanol, isopropanol, butanol, methyl cellulose and ethyl cellulose; ketones such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone and cyclohexanone; Ethyl acetate, propyl acetate, normal butyl acetate, tert-butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxy acetates such as butyl acetate and methoxypentyl acetate; hexanes, such as hexane, heptane, and octane; benzene systems, such as benzene, toluene, and xylene; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and propylene glycol monomethyl ether; and the like can be preferably used. Each of the solvents exemplified above may be used alone or in combination of two or more.

For example, when the transparent film used as the base layer is a polyimide film, good solvents therefor include acetone, methyl ethyl ketone, cyclopentanone, ethyl acetate, and the like. When the transparent film is a polyimide film, examples of the poor solvent therefor include alcohols such as isopropyl alcohol, butanol and ethanol, and ethers such as butyl acetate and propylene glycol methyl ether.

Preferably, a good solvent alone or a mixed solvent in which a good solvent and a poor solvent are mixed is used as the solvent. A good solvent and a poor solvent can be appropriately selected according to the material of the transparent film used as the base layer.

This solvent is used in an amount of 10 to 95% by weight within 100% by weight of the total of the first hard coating composition. If the content of the solvent is less than the content, the viscosity is high and workability is deteriorated, and the swelling of the transparent film used as the base layer cannot be sufficiently progressed, and thus adhesion may be impaired. Conversely, when it exceeds the above range, there is a problem in that the drying process takes a lot of time and economical efficiency is lowered, and the swelling of the transparent base film is severe and haze may occur. Therefore, a solvent is used suitably within the said range.

The description of the solvent may be equally applied to the second hard coating composition to be described later.

In the present invention, each solvent included in the first hard coating composition and the second hard coating composition may be the same or different from each other.

The photoinitiator may be used without limitation as long as it is used in the art. For example, at least one selected from the group consisting of hydroxy ketones, amino ketones, hydrogen recycle type photoinitiators, and combinations thereof may be used.

Specifically, the photoinitiator is 2-methyl-1-[4-(methylthio)phenyl]2-morpholinepropanone-1, diphenylketone, benzyldimethylketal, 2-hydroxy-2-methyl-1- Phenyl-1-one, 4-hydroxycyclophenyl ketone, 2,2-dimethoxy-2-phenyl-acetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-k Noloacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, 1-hydroxycyclohexylphenyl ketone, benzophenone, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide and One or more selected from the group consisting of combinations thereof may be used.

This photoinitiator may be used in an amount of 0.1 to 10% by weight, preferably 1 to 5% by weight within 100% by weight of the total first hard coating composition. In the present invention, if the content is less than the above range, the curing rate of the composition is slow and non-curing occurs and mechanical properties are deteriorated. Conversely, if the content exceeds the above range, cracks may occur in the coating film due to overcuring.

The description of the photoinitiator may be equally applied to the second hard coating composition to be described later.

In the present invention, each photoinitiator included in the first hard coating composition and the second hard coating composition may be the same or different from each other.

second hard coat layer

The second hard coating layer may be formed between the base layer 100 and the first hard coating layer 110 .

According to an embodiment of the present invention, the second hard coating layer 120 may be formed on at least one surface of the base layer 100 . The second hard coating layer 120 may be formed from a second hard coating composition including inorganic particles, a light-transmitting resin, a solvent, and a photoinitiator. If necessary, the second hard coating composition may further include an additive.

The inorganic particles may be inorganic nanoparticles, and are added to improve the elastic recovery rate of the hard coating layer.

Specifically, when the inorganic nanoparticles are included in the second hard coating composition, there is an advantage that mechanical properties can be further improved. More specifically, the inorganic nanoparticles are uniformly formed in the coating film to improve mechanical properties such as pen pressurization and pencil hardness.

The inorganic nanoparticles may have an average particle diameter of 1 to 100 nm, specifically 1 to 80 nm, and more specifically 5 to 50 nm. When the average particle diameter of the inorganic nanoparticles satisfies the above range, there is an advantage in that a uniform coating film can be formed by preventing aggregation occurring in the composition. In addition, it is possible to prevent a problem in which the optical properties and mechanical properties of the coating film are deteriorated.

The inorganic nanoparticles are 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 may include one or more of the group consisting of combinations thereof, but is not limited thereto, and may include a metal oxide generally used in the art.

Specifically, the inorganic nanoparticles may be Al ₂ O ₃ , SiO ₂ and/or ZrO ₂ . The inorganic nanoparticles may be prepared directly or purchased commercially, and in the case of commercially available products, those dispersed in an organic solvent at a concentration of 10 to 80% by weight may be used.

In one embodiment of the present invention, the second hard coating composition may further include an additive, and the additive may include one or more selected from the group consisting of inorganic nanoparticles, a leveling agent, and a stabilizer.

As an example, the leveling agent may include a silicone-based agent, an acrylic polymer-based agent, and the like.

The remaining components included in the second hard coating composition, that is, the light-transmitting resin, the solvent, and the photoinitiator are the same as described in the above-described first hard coating composition, and thus descriptions are omitted to avoid overlap.

Since the hard coating film of the present invention has excellent properties such as durability, elastic recovery rate, and abrasion resistance, it can be usefully applied to a flexible display.

<Image display device>

Embodiments of the present invention provide an image display device comprising the above-described hard coating film.

For example, it may be applied to a window or a window laminating agent including the above-described hard coating film, in this case, at least one of a polarizing layer or a touch sensor layer may be laminated on one surface of the window on which the hard coating film is formed. Such a window or a window laminate may be applied as a window film formed on the outermost surface of the image display device. In addition, the hard coating film may be inserted into, for example, an image display device.

The image display device includes various image display devices such as a liquid crystal display device, an electroluminescence display device, a plasma display device, and a field emission display device, and may be a flexible display device having flexibility and bending characteristics.

In this case, the hard coating laminate according to embodiments of the present invention can be more effectively applied to the window or window laminate of the flexible display device. Through the interaction of the first and second hard coating layers 110 and 120 included in the hard coating laminate according to the embodiments of the present invention, the flexibility and durability of the window are improved together, and the antistatic performance is implemented together. can Accordingly, for example, impact resistance and abrasion resistance of the flexible display device may be improved, and damage such as cracks and peeling may be prevented even during bending or bending.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid understanding of the present invention, but these are merely illustrative of the present invention and do not limit the appended claims, the scope and spirit of the present invention It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope, and it is natural that such variations and modifications fall within the scope of the appended claims. In addition, "%" and "part" indicating the content below are based on weight unless otherwise specified.

production example

Preparation Example 1: Preparation of the hard coating composition (A-1)

23 parts by weight of hexafunctional urethane acrylate (Gongyeong, UA-306I), 23 parts by weight of acrylate (Miwon Specialty Chemical, Miramer SP1106), 50 parts by weight of methyl ethyl ketone, 3.5 parts by weight of 1-hydroxycyclohexylphenyl ketone , 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (Shin-Etsu Silicone, KY-1203) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Preparation Example 2: Preparation of Hard Coating Composition (A-2)

23 parts by weight of hexafunctional urethane acrylate (DKS, MF-101), 23 parts by weight of acrylate (Osaka Yuki, VISCOAT 1000), 50 parts by weight of methyl ethyl ketone, 3.5 parts by weight of 1-hydroxycyclohexylphenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (Daikin, OPTOOL DAC-HP) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Preparation Example 3: Preparation of Hard Coating Composition (A-3)

23 parts by weight of hexafunctional urethane acrylate (Gongyeong, UA-306I), 23 parts by weight of acrylate (Miwon Specialty Chemical, Miramer SP1106), 50 parts by weight of methyl ethyl ketone, 3.5 parts by weight of 1-hydroxycyclohexylphenyl ketone, 0.5 parts by weight of a fluorine-based UV-curable functional group-containing compound (Suyang Chemtech, UVAS-2003) was blended using a stirrer and filtered using a PP filter to prepare an abrasion-resistant hard coating composition.

Preparation Example 4: Preparation of Hard Coating Composition (A-4)

24.2 parts by weight hexafunctional urethane acrylate (DKS, MF-101), 50 parts by weight silica particle dispersion compound (Nissan Chemical Chemicals, PGM-AC-2140Y), 24.3 parts by weight methyl ethyl ketone, 3.5 parts by weight 1-hydroxy Cyclohexylphenyl ketone and 0.5 parts by weight of a silicone-based additive (BYK, BYK UV-3530) were blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Preparation Example 5: Preparation of the hard coating composition (A-5)

24.2 parts by weight acrylate (Osaka Yukisa, VISCOAT 1000), 50 parts by weight silica particle dispersion compound (Nissan Chemical Chemicals, PGM-AC-2140Y), 24.3 parts by weight methyl ethyl ketone, 3.5 parts by weight 1-hydroxycyclohexylphenyl Ketone, 0.5 parts by weight of a silicone-based additive (BYK, BYK UV-3530) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

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Examples and Comparative Examples: Preparation of a hard coating film

Example 1

After curing the hard coating composition (A-4) of Preparation Example 4 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-1) of Preparation Example 1 on the second hard coating layer, the coating was made to a thickness of 4 μm, and the first hard coating layer was irradiated with ^{UV accumulated light amount of 600 mJ/cm 2 under solvent drying and nitrogen atmosphere.} formed.

Example 2

After curing the hard coating composition (A-4) of Preparation Example 4 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-2) of Preparation Example 2 on the second hard coating layer, the coating was made to have a thickness of 4 μm, and the UV accumulated light amount of 600 mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere to form the first hard coating layer. formed.

Example 3

After curing the hard coating composition (A-4) of Preparation Example 4 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-3) of Preparation Example 3 on the second hard coating layer, the coating was made to a thickness of 4 μm, and the first hard coating layer was irradiated with ^{UV accumulated light amount of 600 mJ/cm 2 under solvent drying and nitrogen atmosphere.} formed.

Example 4

After curing the hard coating composition (A-5) of Preparation Example 5 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-1) of Preparation Example 1 on the second hard coating layer, the coating was made to a thickness of 4 μm, and the first hard coating layer was irradiated with ^{UV accumulated light amount of 600 mJ/cm 2 under solvent drying and nitrogen atmosphere.} formed.

Example 5

After curing the hard coating composition (A-5) of Preparation Example 5 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-2) of Preparation Example 2 on the second hard coating layer, the coating was made to have a thickness of 4 μm, and the UV accumulated light amount of 600 mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere to form the first hard coating layer. formed.

Example 6

After curing the hard coating composition (A-5) of Preparation Example 5 on a polyimide film (PI, 50um), the coating was coated to a thickness of 1um, and UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. 2 A hard coating layer was formed. After curing the hard coating composition (A-3) of Preparation Example 3 on the second hard coating layer, the coating was made to a thickness of 4 μm, and the first hard coating layer was irradiated with ^{UV accumulated light amount of 600 mJ/cm 2 under solvent drying and nitrogen atmosphere.} formed.

Comparative Example 1

After curing the hard coating composition (A-1) of Preparation Example 1 on a polyimide film (PI, 50um), the coating was coated to a thickness of 5um, and the UV accumulated light amount of 600mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A coating layer was formed.

Comparative Example 2

After curing the hard coating composition (A-2) of Preparation Example 2 on a polyimide film (PI, 50um), the coating was coated to a thickness of 5um, and the UV accumulated light amount of 600mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A coating layer was formed.

Comparative Example 3

After curing the hard coating composition (A-3) of Preparation Example 3 on a polyimide film (PI, 50um), the coating was coated so as to have a thickness of 5um, and UV accumulated light amount of 600mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A coating layer was formed.

Comparative Example 4

After curing the hard coating composition (A-4) of Preparation Example 4 on a polyimide film (PI, 50um), the coating was coated to a thickness of 5um, and UV accumulated light amount of 600mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A coating layer was formed.

Comparative Example 5

After curing the hard coating composition (A-5) of Preparation Example 5 under a polyimide film (PI, 50um), the coating was made to have a thickness of 1um, and the UV accumulated light amount of 150mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A hard coat layer was formed.

After curing the hard coating composition (A-4) of Preparation Example 1 on a polyimide film (PI, 50um), the coating was made to have a thickness of 4um, and UV accumulated light amount of 600mJ/cm ² was irradiated under solvent drying and nitrogen atmosphere. A coating layer was formed.

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Experimental example

The physical properties of the hard coating films prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were measured in the following manner, and the results are shown in Table 1.

(1) transmittance

The transmittance of the coating film was measured using a hazemeter HM-150N manufactured by Murakami Corporation.

(2) scratch resistance

After bonding the base film to the glass using a transparent adhesive so that the hard coating side goes upward, the scratch resistance was measured by reciprocating friction 10 times under a load of ^{500 g/cm 2 using steel wool (#0000).}

<Evaluation criteria>

A: No scratches or less than 10 scratches were observed when the measurement part was transmitted and reflected by a three-wavelength lamp

B: When the measurement part is transmitted and reflected by a three-wavelength lamp and observed, more than 10 to 20 scratches are recognized

C: More than 20 scratches were recognized when the measurement part was transmitted and reflected by the three-wavelength lamp and observed

(3) contact angle

The water contact angle was measured using KRUSS' contact angle measuring instrument DSA100. At room temperature, the amount of droplet was 3 μl. In the present application, when the contact angle is 105 degrees or more, it was determined that the antifouling property was excellent.

(4) wear resistance

Measurements were made using a wear-resistance measuring instrument of Daesung Precision Co., Ltd. Apply the coating surface to the abrasion-resistant test eraser (Minoan Rubber Stick, tensile strength: 11.91 kgf/cm ² , Sample Shape: Solid, strength: 81 (Durometer A type), chemical structure: Rubber) and 500g weight for 3000 times. After rubbing, the water contact angle (°) was measured. At this time, the abrasion resistance was evaluated as showing an excellent effect when the water contact angle was 95 degrees (°) or more.

(5) Chemical resistance

Measurements were made using a wear-resistance measuring instrument of Daesung Precision Co., Ltd. The coated surface was rubbed 3000 times on the area where ethanol was dripped using an abrasion-resistant test eraser (Minoan Rubber Stick, tensile strength: 11.91 kgf/cm ² , Sample Shape: Solid, strength: 81 (Durometer A type) and 500g weight. After measuring the water contact angle, the chemical resistance was evaluated as showing an excellent effect when the water contact angle was 95 degrees (°) or more.

(6) Flexural resistance

The film was inspected for breakage by repeating the film folding and unfolding test by repeating the film 200,000 times with a radius of curvature of 1 mm so that the hard coating surface was folded inward.

<Evaluation criteria>

O: No fracture

X: film break

(7) pencil hardness

After fixing the base film to the glass so that the hard coating side went upward, the pencil hardness was measured under a load of 1 kg. The test was conducted 5 times with a length of 1 cm using a pencil of the same hardness, and the hardness that was OK 4 or more times was expressed as pencil hardness.

(8) PEN compressibility

After fixing the base film to the glass so that the hard coating side went upward, pen press was measured using a pencil hardness meter under a load of 500 g. Using a Galaxy note Pen stylus as an electronic pen, the test was conducted 5 times with a length of 1 cm to observe whether the press was recognized.

<Evaluation criteria>

O: Press not recognized

X: pressed acknowledged

(9) elastic recovery rate

After bonding the base film to the glass using a transparent adhesive so that the hard coating surface goes upward, the elastic recovery rate of the hard coating layer was measured using a nanoindenter (Fischer) with a microload of 5 mN. At this time, it was evaluated that the elastic recovery rate showed an excellent effect in the case of 56% or more.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Hard coat film laminate structure (3)
first hard coating layer Preparation Example 1 Preparation Example 2 Preparation 3 Preparation Example 1 Preparation Example 2 Preparation 3 Preparation Example 1 Preparation Example 2 Preparation 3 Preparation 4 Preparation Example 1 (2) second hard coating layer Preparation 4 Preparation 4 Preparation 4 Production Example 5 Production Example 5 Production Example 5 - - - - transparent substrate (1) base layer transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate transparent substrate Production Example 5 Transmittance (%) 88.9 89 88.7 88.9 88.7 89 89.9 89.6 89.7 88.7 88.9 scratch resistant A A A A A A A A A A A Contact angle (°) 111 110 112 111 110 110 111 110 110 80 110 Wear resistance (°) 105 103 98 103 103 100 85 87 85 56 83 Chemical resistance (°) 105 100 97 99 99 98 78 80 83 58 81 Flexibility O O O O O O O O O O X pencil hardness 3H 3H 3H 3H 3H 3H 3H 3H 3H 3H 3H PEN compressibility O O O O O O X X X O O Elastic recovery rate (%) 62 63 62 61 62 62 54 54 55 61 58

In Table 1, the hard coat films according to Examples 1 to 6 and Comparative Examples 1 to 5 have a stacked structure in the order of (1)-(2)-(3). Referring to Table 1, Example 1 The hard coat film according to to 6 not only had excellent transmittance, but also realized excellent antifouling performance, thereby exhibiting superior abrasion resistance compared to Comparative Example. In addition, as it showed excellent results in terms of elastic recovery rate, excellent results were obtained in pen pressing characteristics and in reliability of scratch resistance, chemical resistance and bending resistance.

In comparison, it can be seen that the hard coat films according to Comparative Examples 1 to 5 were significantly lowered in abrasion resistance and chemical resistance compared to Examples of the present invention. In addition, it was confirmed that the bending resistance, elastic recovery rate, and/or pen pressability showed a lower result compared to the Example of the present invention.

100: base layer
110: first hard coating layer
120: second hard coating layer

Claims (12)

base layer;
a first hard coating layer formed on at least one surface of the base layer and including a fluorine-based UV-curable functional group-containing compound; and
It is formed between the base layer and the first hard coat layer and includes a second hard coat layer comprising inorganic particles and a silicone-based additive,
The inorganic particles are SiO ₂ ,
The elastic recovery rate measured with a load of 5 mN is more than 61%,
After rubbing the surface of the first hard coating layer 3000 times under a weight of 500 g with an abrasion-resistant eraser, the water contact angle is 95 degrees or more, the hard coating film. The method according to claim 1, wherein the fluorine-based UV-curable functional group-containing compound comprises at least one selected from (meth)acrylate containing a perfluoro aliphatic group and (meth)acrylate containing a perfluoro aromatic group, hard coating film. The method according to claim 2, The fluorine-based UV-curable functional group-containing compound will include 1 to 6 UV-curable functional groups, the hard coating film. delete The method according to claim 1, wherein the first hard coating layer is formed from a first hard coating composition comprising the fluorine-based UV-curable functional group-containing compound, a light-transmitting resin, a solvent and a photoinitiator, the hard coating film. The method according to claim 1, The second hard coating layer is formed from a second hard coating composition comprising the inorganic particles, the light-transmitting resin, a solvent and a photoinitiator, the hard coating film. The method according to claim 1, which is applied to a flexible display, the hard coating film. delete The method according to claim 1, After rubbing the surface of the first hard coating layer 3000 times with an abrasion-resistant eraser on the site where ethanol is dropped under a weight of 500 g, the water contact angle is 95 degrees or more, the hard coating film. delete The method according to claim 1, When pressing the surface of the first hard coating layer with an electronic pen, the occurrence of pressing is prevented, the hard coating film. An image display device comprising the hard coating film of claim 1.

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