KR102269846B1 - Optical Laminate, Hard Coating Film and Image Display Device Having the Same - Google Patents

Abstract

The present invention provides an optical laminate and a hard coating film, wherein the atomic percent of element fluorine (F) on the surface of a hard coating layer is controlled to a level of 35 to 55 at% by laminating a surface protection film including an adhesive layer containing an antistatic agent on a hard coating layer made of a hard coating composition containing a fluorine-based UV-curable functional group-containing compound and post-heat treatment. The optical laminate and the hard coating film according to the present invention are excellent in abrasion resistance, chemical resistance and antifouling properties of the surface of the hard coating layer.

Description

Optical laminate, hard coating film, and image display device having the same {Optical Laminate, Hard Coating Film and Image Display Device Having the Same}

The present invention relates to an optical laminate, a hard coating film, and an image display device having the same, and more particularly, to an optical laminate having an excellent abrasion resistance and chemical resistance, and a hard coating layer having excellent antifouling properties, a hard coating film, and an image display It's about the device.

The hard coating film is used for the purpose of surface protection in image display devices such as liquid crystal displays, electroluminescence (EL) displays, plasma displays (PD), and field emission displays (FEDs).

Recently, a flexible display device or foldable device that can maintain display performance even when bent like paper by using a flexible material such as plastic or UTG (ultra thin glass) instead of the existing inflexible glass substrate As the display device is rapidly emerging as a next-generation display device, it has high hardness and good scratch resistance, and does not cause curl at the edge of the film during the manufacturing process or use, and has adequate flexibility to prevent cracking. Research on coating films is being made.

Furthermore, in many cases, the hard coating film is disposed on the outermost part of the display, and mechanical properties such as abrasion resistance and scratch resistance and chemical properties such as chemical resistance, as well as resistance to display by fingerprints, markers, etc. and/or Antifouling properties related to ease of removal are required as the main performance.

Korean Patent Laid-Open No. 10-2005-0010064 relates to an object provided with a composite hard coating layer and a method for forming a composite hard coat layer, and specifically includes a hard coat layer installed on the surface of the object and an antifouling surface layer installed on the surface of the hard coat layer. wherein the hard coat layer is a cured product of a hard coat composition containing an active energy ray-curable compound, and the antifouling surface layer is a polyfunctional (meth)acrylate compound containing fluorine and fluorine. Disclosed is an object provided with a composite hard coat layer, which is a cured product of a surface material containing a monofunctional (meth)acrylate compound containing .

However, in the case of the above technology, since a hard coating layer and an antifouling layer must be introduced into the polymer base film, respectively, the process is complicated, and there is a problem such as a price increase due to a decrease in yield and an increase in process cost.

Republic of Korea Patent Publication No. 10-2005-0010064

One object of the present invention is to provide an optical laminate having an excellent abrasion resistance and chemical resistance, and a hard coating layer having excellent antifouling properties.

Another object of the present invention is to provide a hard coating film having an excellent abrasion resistance and chemical resistance, and a hard coating layer having excellent antifouling properties.

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

On the one hand, the present invention provides a substrate,

A hard coating layer formed on at least one surface of the substrate, and

As an optical laminate comprising a surface protection film laminated on the hard coating layer,

The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,

The surface protection film includes a base film and an adhesive layer containing an antistatic agent formed on the base film, and is laminated on the hard coating layer via the adhesive layer,

When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, an atomic percent of the fluorine (F) element on the surface of the hard coating layer is 35 to 55 at%.

In one embodiment of the present invention, the surface protection film may be laminated on the hard coat layer and heat-treated.

In one embodiment of the present invention, the heat treatment may be performed at 80 to 100 °C.

In one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is (meth)acrylate containing a perfluoroalkyl group, (meth)acrylate containing a perfluoropolyether group, perfluorocyclic aliphatic It may include at least one selected from the group consisting of (meth)acrylates containing a group and (meth)acrylates containing a perfluoroaromatic group.

On the other hand, the present invention provides a substrate, and

As a hard coating film comprising a hard coating layer formed on at least one surface of the substrate,

An antistatic agent is present on the surface of the hard coating layer,

The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,

When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, the atomic percent of the element fluorine (F) on the surface of the hard coating layer provides a hard coating film of 35 to 55 at%.

In one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is (meth)acrylate containing a perfluoroalkyl group, (meth)acrylate containing a perfluoropolyether group, perfluorocyclic aliphatic It may include at least one selected from the group consisting of (meth)acrylates containing a group and (meth)acrylates containing a perfluoroaromatic group.

In one embodiment of the present invention, the hard coating layer may not be scratched on the surface after being rubbed 5000 times or more under a load of 1 kg using an eraser and a weight.

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

On the other hand, the present invention provides a window of a flexible display device provided with the optical laminate or hard coating film.

On the other hand, the present invention provides a polarizing plate provided with the optical laminate or hard coating film.

On the other hand, the present invention provides a touch sensor provided with the optical laminate or hard coating film.

The optical laminate and the hard coating film according to the present invention are excellent in abrasion resistance, chemical resistance and antifouling properties of the surface of the hard coating layer.

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

One embodiment of the present invention is

materials,

A hard coating layer formed on at least one surface of the substrate, and

As an optical laminate comprising a surface protection film laminated on the hard coating layer,

The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,

The surface protection film includes a base film and an adhesive layer containing an antistatic agent formed on the base film, and is laminated on the hard coating layer via the adhesive layer,

When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, the atomic percent of the element fluorine (F) on the surface of the hard coating layer is 35 to 55 at% It relates to an optical laminate.

One embodiment of the present invention is

substrate, and

As a hard coating film comprising a hard coating layer formed on at least one surface of the substrate,

An antistatic agent is present on the surface of the hard coating layer,

The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,

When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, the atomic percent of the element fluorine (F) on the surface of the hard coating layer is 35 to 55 at% It relates to a hard coating film.

The optical laminate and the hard coating film according to an embodiment of the present invention are laminated on a hard coating layer formed from a hard coating composition including a fluorine-based UV-curable functional group-containing compound, a surface protection film comprising an antistatic agent-containing pressure-sensitive adhesive layer. And by post-heat treatment, the antistatic agent in the pressure-sensitive adhesive layer affects the CF bond of the hard coating layer so that the CF bond is aligned on the surface of the hard coating layer, so that the atomic percent of the fluorine (F) element on the surface of the hard coating layer is 35 to By controlling the level of 55 at%, it is possible to improve the abrasion resistance, chemical resistance and antifouling properties of the surface of the hard coating layer.

The optical laminate and the hard coating film according to an embodiment of the present invention have an atomic percentage of fluorine (F) element on the surface of the hard coating layer when measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, 35 to 55 at%, Preferably it is 35-50 at%, More preferably, it is 38-50 at%. If the atomic percentage of the element fluorine (F) on the surface of the hard coating layer is less than 35 at%, the abrasion resistance, chemical resistance and/or antifouling properties may be reduced, and if it exceeds 55 at%, it is restored to its original state when pressure is applied in the vertical direction. The properties, that is, the compression resistance, may be deteriorated.

The atomic percentage of the element fluorine (F) on the surface of the hard coating layer is a value measured according to the method described in Experimental Examples to be described later by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer.

An optical laminate according to an embodiment of the present invention includes a substrate, a hard coating layer formed on at least one surface of the substrate, and a surface protection film laminated on the hard coating layer. On the other hand, the hard coating film according to an embodiment of the present invention includes a substrate, and a hard coating layer formed on at least one surface of the substrate.

In one embodiment of the present invention, the substrate may be used without particular limitation as long as it is a substrate used in the art, and specifically, a film excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc. may be used. More specifically, the substrate may include polyester-based resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; Cellulose resins, such as a diacetyl cellulose and a triacetyl cellulose; polycarbonate-based resin; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrenic resins such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based resins such as polyethylene, polypropylene, polyolefin having a cyclo-based or norbornene structure, and an ethylene-propylene copolymer; vinyl chloride-based resin; amide resins such as nylon and aromatic polyamide; imide-based resin; sulfone-based resins; polyether sulfone-based resin; polyether ether ketone resin; sulfide polyphenylene-based resin; vinyl alcohol-based resin; vinylidene chloride-based resin; vinyl butyral-based resin; allylate-based resin; polyoxymethylene-based resins; and a film composed of a thermoplastic resin such as an epoxy-based resin, and a film composed of a blend of the above-mentioned thermoplastic resins can also be used. In addition, a film made of a thermosetting resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone or ultraviolet curable resin or ultra thin glass (UTG) may be used. According to an embodiment of the present invention, a polyimide-based resin or a polyester-based resin that has excellent durability against repeated bending and can be easily applied to a flexible image display device may be used.

The thickness of the substrate is not particularly limited, but may be 8 to 1000 μm, specifically 20 to 150 μm. If the thickness of the substrate is less than 8 μm, the strength of the film is lowered and workability is deteriorated, and when it exceeds 1000 μm, there is a problem in that transparency is lowered or the weight of the hard coating film is increased.

In one embodiment of the present invention, the hard coating layer may be formed by applying a hard coating composition to at least one surface of the substrate.

Since the hard coating layer exhibits antifouling properties, when it is formed on the opposite side of the viewer side of the substrate, it may be difficult to attach to the lower optical layer or panel. Therefore, the hard coating layer may be preferably formed as a single layer on the viewing side of the substrate.

In one embodiment of the present invention, the hard coating composition includes a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent.

In one embodiment of the present invention, the light-transmitting resin is a photocurable resin, and the photocurable resin may include a photocurable (meth)acrylate oligomer and/or monomer, but is not limited thereto.

As the photocurable (meth)acrylate oligomer, epoxy (meth)acrylate, urethane (meth)acrylate, polyheddal oligomeric silsesquioxane (meth)acrylate, etc. can be used, and urethane (meth)acrylic rate is preferred.

The urethane (meth)acrylate may be prepared by reacting (meth)acrylate having a hydroxyl group in a molecule and a compound having an isocyanate group in the presence of a catalyst. 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, caprolactone ring-opened hydroxyacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like. 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-cyclohexenediisocyanate, 4,4 '-methylenebis(cyclohexylisocyanate), 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 trifunctional isocyanate derived from, trimethylolpropane adduct toluene diisocyanate, and the like.

The monomer may be used without limitation, and a monomer having an unsaturated group such as a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group in the molecule as a photocurable functional group is preferable, and among them, (meth) A monomer having an acryloyl group is preferred.

The monomer having the (meth) acryloyl group is, for example, neopentyl glycol acrylate, 1,6-hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylic Rate, 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, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isooctyl (meth) acrylate, isodexyl (meth) acrylate , stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, and may be at least one selected from the group consisting of isoborneol (meth) acrylate.

The above-exemplified photocurable (meth)acrylate oligomers and monomers may be used alone or in combination of two or more.

The light-transmitting resin may be included in an amount of 1 to 80% by weight based on 100% by weight of the total hard coating composition. When the content of the light-transmitting resin is less than 1% by weight, it is difficult to achieve sufficient hardness improvement, and when it exceeds 80% by weight, there is a problem in that curling becomes severe.

In one embodiment of the present invention, the fluorine-based UV-curable functional group-containing compound is a component that imparts antifouling properties, abrasion resistance and chemical resistance. The fluorine-based UV-curable functional group-containing compound contains fluorine, has a UV-curable functional group, and is not particularly limited as long as it can be chemically bonded to the hydroxyl group-containing light-transmitting resin forming the matrix of the hard coating layer.

The fluorine-based UV-curable functional group-containing compound is (meth)acrylate containing a perfluoroalkyl group, (meth)acrylate containing a perfluoropolyether group, and (meth)acrylate containing a perfluorocyclic aliphatic group And one or more selected from the group consisting of (meth)acrylate containing a perfluoroaromatic group can be used, and in this case, it shows excellent antifouling performance and at the same time forms a chemical bond with the hard coating layer to improve antifouling performance even after repeated use It is preferable because it has the advantage of excellent durability to maintain for a long time.

The fluorine-based UV-curable functional group-containing compound preferably has 1 to 6 UV-curable functional groups.

The fluorine-based UV-curable functional group-containing compound may be included in an amount of 1 to 40 wt%, preferably 2 to 40 wt%, based on 100 wt% of the total hard coating composition. When the fluorine-based UV-curable functional group-containing compound is included within the above range, it is preferable because excellent abrasion resistance and antifouling effect can be imparted. When the content of the fluorine-based UV-curable functional group-containing compound is less than the above range, it may be difficult to sufficiently promote abrasion resistance or antifouling properties, and when it exceeds the above range, hardness and/or scratch resistance may be reduced.

In one embodiment of the present invention, the photoinitiator is included to induce photocuring of the hard coating composition, and may include, for example, a photoradical initiator capable of forming radicals by light irradiation.

Examples of the photoinitiator include a Type 1 initiator that generates radicals by decomposition of molecules due to a difference in chemical structure or molecular binding energy, and a Type 2 type initiator that coexists with tertiary amines to induce hydrogen recovery.

For example, the Type 1 initiator is 4-phenoxydichloroacetphenone, 4-t-butyldichloroacetphenone, 4-t-butyltrichloroacetphenone, diethoxyacetphenone, 2-hydroxy-2-methyl -l-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-l-one, 1-(4-dodecylphenyl)-2-hydroxy-2 acetphenones such as -methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenylketone; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzyl dimethyl ketal; phosphine oxides; titanocene compounds and the like.

For example, Type 2 initiators include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoic acid, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzol-4'-methyldiphenylsulfide, 3,3'- benzophenones such as methyl-4-methoxybenzophenone; and thioxanthone such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone and isopropylthioxanthone.

The above-mentioned photoinitiators may be used alone or in combination of two or more. In addition, the Type 1 and Type 2 initiators may be used alone or in combination.

The photoinitiator may be included in an amount of about 0.1 to 10% by weight, preferably about 1 to 5% by weight based on 100% by weight of the total hard coating composition. When the content of the photoinitiator is less than 0.1% by weight, sufficient curing does not proceed, and mechanical properties and adhesion of the hard coating film or the hard coating layer may not be secured. When the content of the photoinitiator exceeds 10% by weight, adhesion failure due to curing shrinkage, cracks, and curling may occur.

In one embodiment of the present invention, the solvent may be used without limitation as long as it is known in the art as capable of dissolving or dispersing the above-mentioned composition. In addition, in the process of applying the hard coating composition to the substrate and drying the hard coating composition, the solvent serves to provide time for the fluorine-based UV-curable functional group-containing compound to float to the outermost surface of the coating layer due to a difference in surface tension.

The solvents that can be used are alcohol (methanol, ethanol, isopropanol, butanol, methylcellulose, ethyl cellulose, etc.), ketone (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), acetates (ethyl acetate, propyl acetate, n-butyl acetate, t-butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate) , propylene glycol monopropyl ether acetate, methoxybutyl acetate, methoxypentyl acetate, etc.), hexane (hexane, heptane, octane, etc.), benzene (benzene, toluene, xylene, etc.), ether (diethylene glycol dimethyl) ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, etc.) can be preferably used. Each of the solvents exemplified above may be used alone or in combination of two or more.

The solvent may be included in an amount of 10 to 95% by weight based on 100% by weight of the total hard coating composition. If the content of the solvent is less than the above content, the viscosity is high, so workability is deteriorated, and the swelling of the substrate cannot be sufficiently progressed. Conversely, when the content of the solvent is exceeded, it takes a lot of time in the drying process and the economical efficiency is lowered. Therefore, it is used appropriately within the above range.

In addition to the above components, the hard coating composition may further include components commonly used in the art, for example, a leveling agent, a UV stabilizer, a heat stabilizer, an antioxidant, a surfactant, a lubricant, an antifouling agent, and the like. .

The hard coating layer may be formed by applying the hard coating composition to one or both surfaces of a substrate and drying, followed by UV curing.

The hard coating composition can be coated on a substrate by appropriately using a known method such as a die coater, air knife, reverse roll, spray, blade, casting, gravure, micro gravure, or spin coating.

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

At this time, the thickness of the formed hard coating layer may be specifically 2 to 30㎛, more specifically 3 to 20㎛. When the thickness of the hard coating layer is included in the above range, excellent hardness and bending resistance can be obtained.

In one embodiment of the present invention, the hard coating layer has an atomic percentage of element fluorine (F) on the surface of which is controlled to 35 to 55 at%, so that using an eraser and a weight, 5000 times or more under a load of 1 kg, for example, 5000 to After rubbing 10000 times, preferably 7000 times or more, more preferably 8000 times or more, the surface scratch may not occur.

In one embodiment of the present invention, the surface protection film includes a base film and a pressure-sensitive adhesive layer containing an antistatic agent formed on the base film, and is laminated on the hard coating layer via the pressure-sensitive adhesive layer.

In one embodiment of the present invention, the base film includes a polyolefin-based film, a polyester-based film, an acrylic film, a styrene-based film, an amide-based film, a polyvinyl chloride film, a polyvinylidene chloride film, a polycarbonate film, and the like. and, preferably, a polyester-based film may be used.

The thickness of the base film is preferably 30 to 80㎛. When the thickness is less than 30 μm, the base film is vulnerable to engraving defects, and when it exceeds 80 μm, handling properties may be deteriorated.

In one embodiment of the present invention, the pressure-sensitive adhesive layer containing the antistatic agent may be formed from a pressure-sensitive adhesive composition comprising an acrylic copolymer, a crosslinking agent and an antistatic agent.

The acrylic copolymer may include a (meth)acrylate monomer having an alkyl group having 1 to 14 carbon atoms and a polymerizable monomer having a crosslinkable functional group.

The (meth)acrylate means acrylate and methacrylate.

Specific examples of the (meth)acrylate monomer having an alkyl group having 1 to 14 carbon atoms include n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethyl Hexyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, pentyl (meth) acrylate, n-octyl (meth) ) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, and among these, n-butyl acrylate, methyl acrylate or mixtures thereof are preferred. These can be used individually or in mixture of 2 or more types.

The polymerizable monomer having a crosslinkable functional group is a component for imparting durability and cutability by reinforcing cohesive force or adhesive strength of the pressure-sensitive adhesive composition by chemical bonding with the following crosslinking agent, for example, a monomer having a hydroxyl group, a carboxyl group A monomer, a monomer having an amide group, a monomer having a tertiary amine group, etc. are mentioned, and these can be used individually or in mixture of 2 or more types.

As a monomer having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxypropylene glycol (meth) acrylate, hydroxyalkylene glycol having 2-4 carbon atoms in the alkylene group ( Meth) acrylate, 4-hydroxybutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, 7-hydroxyheptyl vinyl ether, 8-hydroxyoctyl vinyl ether, 9-hydroxynonyl Vinyl ether, 10-hydroxydecyl vinyl ether, etc. are mentioned, Of these, 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl vinyl ether is preferable.

Examples of the monomer having a carboxyl group include monoacids such as (meth)acrylic acid and crotonic acid; diacids such as maleic acid, itaconic acid and fumaric acid and monoalkyl esters thereof; 3-(meth)acryloylpropionic acid; A ring-opening adduct of succinic anhydride of 2-hydroxyalkyl (meth)acrylate having an alkyl group having 2-3 carbon atoms, and a ring-opening adduct of succinic anhydride of hydroxyalkylene glycol (meth)acrylate having an alkylene group having 2-4 carbon atoms. and a compound obtained by ring-opening addition of succinic anhydride to the caprolactone adduct of 2-hydroxyalkyl (meth)acrylate having 2-3 carbon atoms in the alkyl group, among which (meth)acrylic acid is preferable.

Examples of the monomer having an amide group include (meth)acrylamide, N-isopropyl acrylamide, N-tert-butyl acrylamide, 3-hydroxypropyl (meth)acrylamide, 4-hydroxybutyl (meth)acrylamide, 6 -Hydroxyhexyl (meth)acrylamide, 8-hydroxyoctyl (meth)acrylamide, 2-hydroxyethylhexyl (meth)acrylamide, etc. are mentioned, Among these, (meth)acrylamide is preferable.

Examples of the monomer having a tertiary amine group include N,N-(dimethylamino)ethyl(meth)acrylate, N,N-(diethylamino)ethyl(meth)acrylate, N,N-(dimethylamino)propyl(meth)acrylate ) acrylates and the like.

The polymerizable monomer having a crosslinkable functional group is preferably included in an amount of 0.05 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, based on 100 parts by weight of a (meth)acrylate monomer having an alkyl group having 1 to 14 carbon atoms. If the content is less than 0.05 parts by weight, the cohesive force of the pressure-sensitive adhesive may be reduced and durability may be reduced, and if the content is more than 10 parts by weight, the adhesive force may decrease due to a high gel fraction and cause problems in durability.

The acrylic copolymer may further contain other polymerizable monomers in addition to the monomers in a range that does not reduce adhesive strength, for example, 10% by weight or less based on the total amount.

The method for preparing the acrylic copolymer is not particularly limited, and it can be prepared using methods such as bulk polymerization, solution polymerization, emulsion polymerization or suspension polymerization commonly used in the art, and solution polymerization is preferable. In addition, a solvent, a polymerization initiator, a chain transfer agent for controlling molecular weight, etc. which are commonly used during polymerization may be used.

The acrylic copolymer usually has a weight average molecular weight (in terms of polystyrene) of 500,000 to 1,700,000, preferably 800,000 to 1,500,000, measured by gel permeation chromatography (GPC).

The crosslinking agent is a component for strengthening the cohesive force of the pressure-sensitive adhesive by appropriately crosslinking the copolymer, and the type thereof is not particularly limited. For example, an isocyanate-based compound, an epoxy-based compound, etc. may be mentioned, and these may be used alone or in combination of two or more.

As the isocyanate-based compound, tolylene diisocyanate, xylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate compounds such as diisocyanate; An adduct obtained by reacting 3 moles of a diisocyanate compound with 1 mole of a polyhydric alcohol compound such as trimethylolpropane, an isocyanurate product obtained by self-condensing 3 moles of a diisocyanate compound, and a diisocyanate obtained from 2 moles of 3 moles of a diisocyanate compound The polyfunctional isocyanate compound etc. which contain three functional groups, such as the biuret body which the remaining 1 mol diisocyanate condensed to urea, triphenylmethane triisocyanate, and methylene bistriisocyanate, etc. are mentioned.

Epoxy compounds include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polytetramethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, Diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, resorcinol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylol propane triglycidyl ether, pentaerythritol Polyglycidyl ether, sorbitol polyglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, tris(glycidyl)isocyanurate, tris(glycidoxyethyl)isocyanurate , 1,3-bis(N,N-glycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, etc. are mentioned.

In addition, a melamine-based compound or an aziridine-based compound together with an isocyanate-based compound or an epoxy-based compound may be used alone or in combination of two or more.

Examples of the melamine-based compound include hexamethylolmelamine, hexamethoxymethylmelamine, and hexabutoxymethylmelamine.

Examples of the aziridine-based compound include N,N'-toluene-2,4-bis(1-aziridinecarboxide), N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxide). ), bisisoprotaloyl-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, and the like.

The crosslinking agent is preferably included in an amount of 0.1 to 15 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer. When the content is less than 0.1 parts by weight, the cohesive force becomes small due to the insufficient degree of crosslinking, which causes a decrease in durability such as lifting and may impair cutability. If the content is more than 15 parts by weight, there may be a problem in relieving residual stress due to excessive crosslinking reaction. have.

The antistatic agent may be a compound formed by an ionic combination of a cation and an anion.

For example, as the cation, an organic cation such as ammonium, phosphonium, or sulfonium or an alkali metal cation may be used. Specific examples of the organic cation include quaternary ammonium salts substituted with 4 alkyl groups such as tetrabutylammonium, 1-ethylpyridinium, 1-butylpyridinium, 1-hexylpyridinium, 1-butyl-3-methylpyridinium , 1-Butyl-4-methylpyridinium, 1-hexyl-3-methylpyridinium, 1-hexyl-4-methylpyridinium, 1-butyl-3,4-dimethylpyridinium, 1-octyl-4-methyl A pyridinium salt in which an alkyl group is substituted for N of pyridine, such as pyridinium, an alkyl group at the 1,3-position of imidazole, such as 1-methyl-3-butylimidazolium and 1-methyl-3-hexylimidazolium cations such as substituted imidazolium salts, quaternary phosphonium salts having four alkyl groups such as tetrabutyl phosphonium, and tertiary sulfonium salts having three alkyl groups such as tributyl sulfonium. The alkali metal may be lithium, sodium, potassium or cesium, preferably lithium, sodium or potassium. These can be used individually or in combination of 2 or more types.

In addition, negative ions as OTf ^- (methanesulfonate trifluoroacetate), OTs ^- (toluene-4-sulfonate), OMs ^{- (methanesulfonate), Cl -, Br -,} I -, AlCl 4 -, Al 2 Cl ₇ ^- , BF ₄ ^- , PF ₆ ^- , ClO ₄ ^- , NO ₃ ^- , CH ₃ COO ^- , CF ₃ COO ^- , CH ₃ SO ₃ ^- , CF ₃ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (CF ₃ SO ₂ ) ₃ C ^- , AsF ₆ ^- , SbF ₆ ^- , NbF ₆ ^- , TaF ₆ ^- , F(HF) _n ^- , (CN) ₂ N ^- , C ₄ F ₉ SO ₃ ^- , ( C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ )(CF ₃ CO)N ⁻ and the like.

The content of the antistatic agent is not particularly limited as long as it functions within the range, but may be included, for example, in an amount of 0.1 to 1.0 parts by weight relative to 100 parts by weight of the acrylic copolymer. When the above range is satisfied, it is possible to control the atomic percentage of the element fluorine (F) on the surface of the hard coating layer within the above range while exhibiting excellent antistatic properties.

The pressure-sensitive adhesive composition includes, in addition to the above components, a plasticizer, a silane coupling agent, a tackifying resin, an antioxidant, a corrosion inhibitor, a leveling agent, in order to control the adhesive force, cohesive force, viscosity, elastic modulus, glass transition temperature, etc. required according to the use , surface lubricants, dyes, pigments, antifoaming agents, fillers, may further include additives such as light stabilizers.

The surface protection film is a flow casting method, bar coater (bar coater), air knife (air knife), gravure (gravure), reverse roll (reverse roll), kiss roll (kiss roll), spray the pressure-sensitive adhesive composition on the base film (spray) or a blade (blade) method using a coating method such as direct coating in an appropriate development method can be produced by drying.

The thickness of the pressure-sensitive adhesive layer may be adjusted according to its adhesive strength, and is preferably 3 to 100 μm, and more preferably 10 to 100 μm.

A surface protection film is laminated on the hard coat layer in a laminated structure in which the pressure-sensitive adhesive layer of the surface protection film is in contact with the above-described hard coat layer.

The surface protection film may be heat-treated after being laminated on the hard coating layer.

By the heat treatment, the antistatic agent derived from the pressure-sensitive adhesive layer of the surface protection film affects the CF bond of the hard coat layer so that the CF bond is aligned on the surface of the hard coat layer, so that the atomic percentage of the element fluorine (F) on the surface of the hard coat layer is 35 to It can be controlled at the level of 55 at%.

The heat treatment may be performed at 80 to 100°C. If the heat treatment temperature is less than 80 ℃, it is difficult to control the atomic percentage of the element fluorine (F) on the surface of the hard coating layer in the above range, and abrasion resistance, chemical resistance and / or antifouling properties may be lowered, and if it is more than 100 ℃ of the hard coating film Deformation may occur.

One embodiment of the present invention relates to an image display device provided with the above-described optical laminate or hard coating film. For example, the optical laminate or hard coating film of the present invention may be used as a window of an image display device, particularly a flexible display device or a foldable display device. In addition, the optical laminate or hard coating film of the present invention may be used by attaching it to a polarizing plate, a touch sensor, or the like.

The optical laminate or hard coating film according to an embodiment of the present invention can be used in various driving types of LCD such as reflective, transmissive, transflective LCD or TN type, STN type, OCB type, HAN type, VA type, IPS type, etc. can In addition, the optical laminate or the hard coating film according to an embodiment of the present invention may be used in various image display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper.

Hereinafter, the present invention will be described in more detail by way of Examples, Comparative Examples and Experimental Examples. These Examples, Comparative Examples, and Experimental Examples are only for illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited thereto.

Preparation Example 1: Preparation of a hard coating composition

23 parts by weight of hexafunctional urethane acrylate (DKS, MF-101), 23 parts by weight of acrylate (Yuki Osaka, 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.

Example 1: Preparation of an optical laminate

After curing the hard coating composition of Preparation Example 1 on a polyethylene terephthalate (PET, 50 μm) film, the coating was coated to a thickness of 5 μm, the solvent was dried, and the UV accumulated light amount of 500 mJ/cm 2 was irradiated to form a hard coating layer. did it AY-501 from Fujimori Industries was attached as a surface protection film on the hard coating layer and heat-treated at 80° C. for 1 minute to prepare an optical laminate.

Example 2: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 1, except that AY-310 manufactured by Fujimori Industrial Co., Ltd. was used as the surface protection film.

Example 3: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 1, except that PF-02AT manufactured by Ohsung Advanced Materials was used as the surface protection film.

Example 4: Preparation of an optical laminate

An optical laminate was manufactured in the same manner as in Example 1, except that the heat treatment was performed at 90° C. for 1 minute.

Example 5: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 2, except that the heat treatment was performed at 90° C. for 1 minute.

Example 6: Preparation of an optical laminate

An optical laminate was manufactured in the same manner as in Example 3, except that the heat treatment was performed at 90° C. for 1 minute.

Comparative Example 1: Preparation of an optical laminate

After forming the hard coating in the same manner as in Example 1, SUN-A's SAT-4038 was attached as a surface protection film on the hard coating layer and left at room temperature to prepare an optical laminate.

Comparative Example 2: Preparation of an optical laminate

An optical laminate was manufactured in the same manner as in Comparative Example 1, except that heat treatment was performed at 80° C. for 1 minute instead of standing at room temperature.

Comparative Example 3: Preparation of an optical laminate

After forming a hard coating in the same manner as in Example 1, AY-638 manufactured by Fujimori Industries was attached as a surface protection film on the hard coating layer and left at room temperature to prepare an optical laminate.

Comparative Example 4: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Comparative Example 3, except that heat treatment was performed at 80° C. for 1 minute instead of standing at room temperature.

Comparative Example 5: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 1, except that it was left at room temperature instead of heat treatment at 80° C. for 1 minute.

Comparative Example 6: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 2, except that it was left at room temperature instead of heat treatment at 80° C. for 1 minute.

Comparative Example 7: Preparation of an optical laminate

An optical laminate was prepared in the same manner as in Example 3, except that it was left at room temperature instead of heat treatment at 80° C. for 1 minute.

Experimental Example 1: Physical properties of surface protection film

The sheet resistance values of the surface protection films used in Examples and Comparative Examples were measured according to the following method, and are shown in Table 1 below. The sheet resistance value was measured on the pressure-sensitive adhesive layer of the surface protection film. In addition, the presence or absence of an antistatic agent (manufactured by AS) in the pressure-sensitive adhesive layer of each surface protection film is described in Table 1 below.

(1) sheet resistance

A sheet resistance measuring instrument (Mitsubishi's MCP-HT450) consists of a main body and a measuring circular electrode. A circular electrode was placed on the surface of the measurement sample (minimum area of 2 cm × 2 cm), and the sheet resistance value according to the applied voltage was obtained. The sheet resistance value was calculated by Equation 1 below.

[Equation 1]

Sheet resistance (Rs) = ρ / (1cm×1cm×t)

ρ: resistivity (Ω×cm), t: thickness (cm)

SUN-A company SAT-4038 Fujimori Kogyo AY-638 Fujimori Kogyo AY-501 Fujimori Kogyo AY-310 Ohsung Advanced Materials PF-02AT AS agent or not × × ○ ○ ○ Sheet resistance (Ω/sheet) E+14 or higher (OVER) E+14 or higher
(OVER) 1.8E+12 2.0E+11 2.0E+10

Experimental Example 2: Physical properties of the optical laminate

The physical properties of the optical laminates prepared in Examples and Comparative Examples were measured by the method described below, and the results are shown in Table 2 below.

(One) AS agent content on the surface of the hard coating layer

Using BI3+ Gun with TOF-SIMS 5 (ION-TOF) equipment, surface element analysis was performed on an area of 200㎛ × 200㎛ in positive mode and negative mode, and AS agent content on the surface of the hard coating layer was measured.

(2) surface fluorine (F) element content

The surface elemental fluorine (F) content was measured using a Quantera II (Ulvac-PHI) XPS instrument. After preparing the sample to be 2 cm × 2 cm, it was attached to the XPS exclusive plate using a carbon tape. At this time, the measurement surface was directed upward. The sample was placed in an Intro ^{and maintained at a vacuum degree of 1×10 -4} Pa for at least 1 hour. After that, it was moved to the main chamber by using an arm, and then the vacuum degree ^{was maintained at 1×10 -7} Pa for 1 hour or more. After maintaining the high vacuum for more than 1 hour, the surface data was acquired by measuring an arbitrary position on the sample surface three times under the conditions of X-ray (measurement area 200micron / 25W / 15kV).

(3) wear resistance

The measurement was carried out using the wear-resistance measuring equipment of Daesung Precision. After rubbing the coated surface with a load of 1 kg using an abrasion-resistant eraser and a weight, the appearance change was observed to see if scratches or discoloration occurred on the surface. If there was no change in appearance, OK was processed. Abrasion resistance was evaluated by counting the maximum number of rubs to be OK processing.

(4) chemical resistance

The measurement was carried out using the wear-resistance measuring equipment of Daesung Precision. After applying a small amount of ethanol to the coating surface, it was rubbed under a load of 1 kg using an abrasion-resistant eraser and a weight, and then the appearance change was observed whether scratches or discoloration occurred on the surface. If there was no change in appearance, OK was processed. Chemical resistance was evaluated by counting the maximum number of rubs to be OK processing.

(5) Antifouling

The antifouling property was evaluated by measuring the water contact angle using a KRUSS contact angle measuring instrument DSA100. At room temperature, the amount of liquid drop was 3 µl.

Example comparative example One 2 3 4 5 6 One 2 3 4 5 6 7 AS agent content on the surface of the hard coating layer
(Counts) 4.1
E+05 5.2
E+05 1.5
E+06 2.1
E+05 1.2
E+05 3.1
E+06 - - - - 1.7
E+05 1.7
E+05 1.5
E+06 Surface fluorine (F) element content
(at%) 48 47 48 47 47 48 33 32 33 33 32 33 33 wear resistance
(time) 7.0K 8.0K 8.0K 7.0K 8.0K 8.0K 4.5K 4.5K 4.5K 4.5K 4.5K 4.5K 4.5K chemical resistance
(time) 3.0K 3.0K 3.0K 3.0K 3.0K 3.0K 2.5K 2.5K 2.5K 2.5K 2.5K 2.5K 2.5K antifouling
(°) 107.2 107.4 107.4 106.6 106.8 107.2 97.4 97.1 97.5 96.8 98.4 98.5 97.9

As shown in Table 2, the optical laminate of Examples 1 to 6 in which the atomic percent of the fluorine (F) element on the surface of the hard coating layer is controlled to a level of 35 to 55 at% according to the present invention, the hard coating layer It was confirmed that the atomic percent of the element fluorine (F) on the surface exhibited better abrasion resistance, chemical resistance and antifouling properties compared to the optical laminates of Comparative Examples 1 to 7 out of the range of 35 to 55 at%.

In the optical laminates of Examples 1 to 6 and Comparative Examples 5 to 7, the antistatic agent is transferred onto the hard coating layer by using a surface protection film including an adhesive layer containing an antistatic agent, and the antistatic agent is applied on the hard coating layer surface. appeared to exist. However, in the optical laminates of Examples 1 to 6 depending on whether the post-heat treatment is performed, the atomic percentage of the element fluorine (F) on the surface of the hard coating layer rises to a level of 35 to 55 at%, but the optical laminates of Comparative Examples 5 to 7 are It was found that there was no effect on the atomic percentage of the element fluorine (F) on the surface of the hard coating layer.

As the specific parts of the present invention have been described in detail above, for those of ordinary skill in the art to which the present invention pertains, it is clear that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereto. Do. Those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (11)

materials,
A hard coating layer consisting of a single layer formed on at least one surface of the substrate, and
As an optical laminate comprising a surface protection film laminated on the hard coating layer,
The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,
The surface protection film includes a base film and an adhesive layer containing an antistatic agent formed on the base film, and is laminated on the hard coating layer via the adhesive layer,
An antistatic agent is present on the surface of the hard coating layer,
When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, the atomic percent of the element fluorine (F) on the surface of the hard coating layer is 35 to 55 at% optical laminate. The optical laminate according to claim 1, wherein the surface protection film is laminated on the hard coating layer and heat-treated. The optical laminate according to claim 2, wherein the heat treatment is performed at 80 to 100°C. According to claim 1, wherein the fluorine-based UV-curable functional group-containing compound is a perfluoro alkyl group-containing (meth) acrylate, perfluoro polyether group-containing (meth) acrylate, perfluoro cyclic aliphatic group-containing An optical laminate comprising at least one selected from the group consisting of (meth)acrylates and (meth)acrylates containing a perfluoroaromatic group. substrate, and
As a hard coating film comprising a hard coating layer consisting of a single layer formed on at least one surface of the substrate,
An antistatic agent is present on the surface of the hard coating layer,
The hard coating layer is formed from a hard coating composition comprising a light-transmitting resin, a fluorine-based UV-curable functional group-containing compound, a photoinitiator and a solvent,
When measured by X-ray photoelectron spectroscopy (XPS) on the surface of the hard coating layer, the atomic percent of the element fluorine (F) on the surface of the hard coating layer is 35 to 55 at% hard coating film. The method of claim 5, wherein the fluorine-based UV-curable functional group-containing compound contains a (meth)acrylate containing a perfluoroalkyl group, (meth)acrylate containing a perfluoropolyether group, and a perfluorocyclic aliphatic group. A hard coating film comprising at least one selected from the group consisting of (meth)acrylates and (meth)acrylates containing a perfluoro aromatic group. The hard coating film of claim 5, wherein the hard coating layer is not scratched on the surface after being rubbed 5000 times or more under a load of 1 kg using an eraser and a weight. An image display device provided with an optical laminate according to any one of claims 1 to 4, or a hard coating film according to any one of claims 5 to 7. The window of a flexible display device provided with the optical laminate according to any one of claims 1 to 4, or the hard coating film according to any one of claims 5 to 7. A polarizing plate provided with an optical laminate according to any one of claims 1 to 4, or a hard coating film according to any one of claims 5 to 7. The optical laminate according to any one of claims 1 to 4, or a touch sensor provided with a hard coating film according to any one of claims 5 to 7.