KR20090049516A - Coating composition for antireflection and antireflection film prepared by using the same - Google Patents

Abstract

The present invention provides an antireflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorbent, an antireflective film prepared using the same, and a method of manufacturing the same. . The antireflection film according to the present invention has an effect of reducing manufacturing cost because it is excellent in wear resistance and antireflection function and can be manufactured by one coating process.

Antireflection, UV Curing, Thermal Curing

Description

Anti-reflective coating composition and anti-reflective film produced using the same {COATING COMPOSITION FOR ANTIREFLECTION AND ANTIREFLECTION FILM PREPARED BY USING THE SAME}

The present invention relates to an antireflective coating composition, an antireflective film prepared therefrom and a method for producing the same. More specifically, an antireflective coating composition capable of imparting an antireflection function to an optical film by forming a layer of a GRIN (gradient refractive index) structure using a difference in degree of curing through a single coating process, and an antireflection prepared therefrom It relates to a film and a method for producing the same.

The purpose of surface treatment of the surface of the display is to improve the image resistance by improving the wear resistance of the display and reducing the reflection of external light sources. The reduction in the amount of reflection of external light can be realized in two ways. The first is to induce diffuse reflection through the surface irregularities, and the second is to induce vanishing interference with the multilayer coating design.

Conventionally, the anti-glare coating having the surface irregularities is mainly applied, but the resolution of the high resolution display has a problem of deterioration of resolution and a problem of deterioration of the image clarity due to diffuse reflection on the surface. In order to solve this problem, Japanese Patent Laid-Open No. 11-138712 manufactured a light diffusion film in which light is diffused inside a film using an organic filler having a difference in refractive index from a binder. However, there is a problem that the brightness and contrast are lowered and still need improvement.

Japanese Laid-Open Patent Publications No. 02-234101 and Japanese Patent Laid-Open Nos. 06-18704 disclose a method of extinction interference of reflected light through a multilayer coating design. This method can have an anti-reflection function without distortion of the image. In this case, in order to extinction and interfere with the reflected light, the light reflected from each layer should have a phase difference from each other, and the amplitudes of the waveforms of the reflected light should be matched with each other so as to minimize the reflectance during the extinction interference. For example, when the incident angle is 0 degrees with respect to the monolayer antireflective coating layer provided on the substrate, the following equation may be obtained.

n _o n _s = n ₁ ²

2n ₁ d ₁ = (m + 1/2) λ (m = 0,1,2,3 ...)

(n _{o :} refractive index of air _, n _{s :} refractive index of substrate _, n _{1 :} refractive index of film _, d _{1 :} film thickness, λ: wavelength of incident light)

In general, the lower the refractive index of the anti-reflective coating layer than the refractive index of the substrate, the greater the anti-reflection effect, but in consideration of the wear resistance of the coating layer, the refractive index of the anti-reflective coating layer preferably has a refractive index of 1.3 to 1.5 times the refractive index of the substrate. In this case, the reflectance is less than 3%. However, when the antireflective coating layer is formed on the plastic film, the wear resistance of the display cannot be satisfied, so a hard coating layer of several microns is required under the antireflective coating layer. That is, in the case of the anti-reflective coating layer using the disappearance interference, the hard coating layer and anti-reflective coating layer for the wear resistance reinforcement is formed 1 to 4 layers thereon. Therefore, the multilayer coating method has an anti-reflection function without distortion of the phase, but the manufacturing cost increases due to the multilayer coating still occurs.

Recently, a method of dissipating and interfering reflected light through a single layer coating design has been proposed. Japanese Unexamined Patent Application Publication No. 07-168006 discloses an ultrafine particle dispersion on a substrate and exposes a fine particle spherical shape to a surface, so that the interface with air is an interface. A method of imparting an antireflection effect by causing a gradual difference in refractive index between particles is disclosed. However, this method is difficult to implement through a general coating process because the shape and size of the ultra-fine particles and the uniform distribution of these particles on the substrate. In addition, since the binder must be contained in a predetermined amount or less to obtain a spherical shape on the surface, there is a disadvantage that is very weak in wear resistance, and the coating thickness also has to be thinner than the diameter of the fine particles, there is a very difficult problem to implement wear resistance.

In order to solve the conventional problems as described above, the present invention provides an anti-reflective coating composition, an anti-reflective film prepared therefrom and a method of manufacturing the same by providing an anti-reflective function by one coating process, thereby reducing the manufacturing cost The purpose is to provide.

In order to achieve the above object, the present invention provides an antireflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2 and an ultraviolet absorber.

In addition, the present invention

Iii) preparing an antireflective coating composition comprising a low refractive UV curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorber;

Ii) applying the coating composition to a substrate to form a coating layer;

Iii) curing the low refractive ultraviolet curable resin by irradiating ultraviolet rays to have a concentration gradient in the thickness direction of the coating layer;

Iii) curing the high refractive thermosetting resin at high temperature;

It provides a method for producing an antireflective film comprising a.

In addition, the present invention includes a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2 and an ultraviolet absorber, wherein the low refractive ultraviolet curable resin has a concentration gradient in the thickness direction of the coating layer. It provides an anti-reflection film comprising a.

In addition, the present invention provides a polarizing plate comprising a) a polarizing film, b) an antireflection film according to the present invention provided on at least one surface of the polarizing film.

In addition, the present invention provides a display device including the anti-reflection film or the polarizing plate.

The present invention can provide an antireflective film comprising an antireflective layer consisting of a single coating layer by using the above-described antireflective coating composition and a method for producing an antireflective film. The antireflective film according to the present invention has not only excellent wear resistance and antireflection function, but also can be manufactured by one coating process, thereby reducing manufacturing costs.

Hereinafter, the present invention will be described in detail.

The present invention first prepares a coating composition comprising a low refractive UV curable resin and a high refractive thermosetting resin having different reaction mechanisms, and coating the substrate on a substrate to form a coating layer, and then the low refractive UV curable resin has a thickness direction of the coating layer After irradiating ultraviolet rays to have a concentration gradient to the high refractive thermosetting resin is characterized in that for curing.

In order for the low refractive ultraviolet curable resin to have a concentration gradient in the thickness direction of the coating layer, ultraviolet rays are irradiated in a direction (hereinafter, referred to as an air surface) in which the coating layer contacts air during primary ultraviolet irradiation. At this time, the coating composition is designed such that the coating composition includes an ultraviolet absorber so that ultraviolet rays do not penetrate to the surface (hereinafter, the substrate surface) in contact with the substrate. Through this, the hardening reaction of the low refractive ultraviolet curable resin occurs from the air surface of the coating layer, and the unreacted low refractive ultraviolet curable resin is widely distributed on the substrate surface. After a certain period of time after the first ultraviolet irradiation, in the coating layer, the unreacted low refractive ultraviolet curable resin diffuses and moves in the air plane direction, and the high refractive thermosetting resin in the substrate plane direction. As such, the ultraviolet irradiation and the leaving process may be performed only once or twice or more. Subsequently, when the ultraviolet rays are finally irradiated from both sides of the coating layer, the curing reaction of the low refractive ultraviolet curable resin terminates with a concentration gradient of higher density in the air plane. After applying heat to cure the high refractive thermosetting resin, the anti-reflection film of the GRIN structure is completed.

In the present invention, by using a coating composition and a method of producing an antireflective film as described above, after forming a coating layer having a thickness of several microns in one coating process, energy such as ultraviolet rays and thermal energy (ultraviolet rays and heat Energy) is irradiated more than two times, preferably three times, so that it is possible to obtain excellent wear resistance and antireflection properties, which are the characteristics of hard coatings, and to improve product yield, shorten manufacturing time, and other processes by one coating process. Cost savings are achieved.

The content of each component in the antireflective coating composition is 5 to 80 parts by weight of the low refractive ultraviolet curable resin, 10 to 90 parts by weight of the high refractive thermosetting resin and 0.05 to 30 parts by weight of the ultraviolet absorbent based on 100 parts by weight of the total coating composition. desirable.

In the present invention, the low refractive ultraviolet curable resin is not particularly limited, acrylic resin may be used, it is preferable to use with a photoinitiator and a solvent.

The content of the acrylate-based resin is preferably 10 to 80 parts by weight based on 100 parts by weight of the total amount of the acrylate-based resin, photoinitiator and solvent. If the content is less than 10 parts by weight, the scratch resistance and abrasion resistance of the coating film is lowered, and when the content is more than 80 parts by weight, the coating composition may have a high viscosity, resulting in poor flatness and coating property of the coating film.

The acrylate resins include acrylate monomers, urethane acrylate oligomers, epoxy acrylate oligomers, ester acrylate oligomers, and the like. Specific examples include dipentaerythritol hexaacrylate, pendaerythritol tri / tetra acrylate, trimethylene propane triacrylate, ethylene glycol diacrylate, and the like, and these may be used alone or in combination of two or more thereof.

In order to lower the refractive index of the ultraviolet curable resin, fluorine-based acrylate may be used. As the fluorine acrylate, one or two or more compounds selected from the group consisting of compounds of Formulas 1 to 5 may be used, and these compounds may further have a C ₁ -C ₆ straight or branched hydrocarbon group as a substituent. have.

In Formula 1, R ₁ is -H or C ₁ -C ₆ linear or branched hydrocarbon group, a is an integer of 0 to 4, b is an integer of 1 to 3. The hydrocarbon group of C ₁ -C ₆ is preferably a methyl group (-CH _3).

In Chemical Formula 2, c is an integer of 1 to 10.

In Chemical Formula 3, d is an integer of 1 to 9.

In Chemical Formula 4, e is an integer of 1 to 5.

In Chemical Formula 5, f is an integer of 4 to 10.

The content of the fluorine-based acrylate is preferably 10 to 80 parts by weight relative to 100 parts by weight of the total amount of the acrylate-based resin, photoinitiator and solvent. When the content is less than 10 parts by weight, it is difficult to obtain a low refractive index of 1.2 to 1.45, and when it exceeds 80 parts by weight, there is a problem such that scratch resistance and abrasion resistance of the coating film are lowered.

It is preferable that the photoinitiator uses a compound decomposed to ultraviolet rays. Examples include 1-hydroxy cyclohexylphenyl ketone, benzyl dimethyl ketal, hydroxydimethylacetophenone, benzoin, benzoin methyl ether, or benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and the like. It is not limited only to these examples.

The photoinitiator is preferably included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total amount of the acrylate-based resin, photoinitiator and a solvent, and when the content is less than 1 part by weight, there is a problem that uncuring occurs, 20 parts by weight If it exceeds, there is a problem that the scratch resistance and wear resistance of the coating film is lowered.

Alcohols, acetates, ketones, cellosolves, imides or aromatic solvents may be used as the solvent. Specifically, methanol, ethanol, isopropyl alcohol, butanol, 2-methoxy ethanol, 2-ethoxy ethanol, 2-butoxy ethanol, 2-isopropoxy ethanol, methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, Methyl isobutyl ketone, cyclohexane, cyclohexanone, toluene, xylene, benzene and the like can be used, but are not limited thereto.

The solvent is preferably included in 10 to 90 parts by weight based on 100 parts by weight of the total amount of the acrylate-based resin, photoinitiator and the solvent. If the content is less than 10 parts by weight, the viscosity of the coating composition is increased, the compatibility with the high refractive thermosetting resin is poor, and the flatness of the coating film is bad, and if it exceeds 90 parts by weight, the scratch resistance of the coating film There is a problem that wear resistance is lowered.

The high refractive index thermosetting resin is a resin having a refractive index of 1.45 to 2, and specifically include alkoxysilane reactants, urethane reactor compounds, urea reactor compounds, and esterification reactants capable of sol-gel reaction.

The alkoxysilane reactant refers to a reactive oligomer prepared by subjecting the alkoxysilane or the high refractive alkoxysilane to a silane-based organic substituent, etc., if necessary, by hydrolysis and condensation reaction by sol-gel reaction under water and catalytic conditions. In this case, the average molecular weight of the reactive oligomer is preferably from 1,000 to 200,000 when the polystyrene is measured by GPC as a standard material. The alkoxysilane reactant thus prepared is subjected to a condensation reaction under a temperature condition of room temperature or more after coating to form a crosslinked network.

The alkoxysilane may provide a certain level of strength to the outermost coated thin film. As the alkoxysilane, a tetraalkoxysilane system or a trialkoxysilane system can be used, and tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, glycidoxy Preference is given to using one or more substances selected from the group consisting of propyl trimethoxysilane, glycidoxypropyl triethoxysilane and the like.

The content of the alkoxysilane which is a basic monomer in the alkoxysilane reactant is preferably 20 to 90 parts by weight based on 100 parts by weight of the alkoxysilane reactant. If the content is less than 20 parts by weight of the wear resistance is not good, if more than 90 parts by weight it is difficult to implement high refractive index of the alkoxysilane reactant.

In order to obtain a high refractive index in the alkoxysilane reactant, an alkoxy silane may contain substituents such as sulfur, chlorine, and metal, or aromatics such as phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, and diphenyldimethoxysilane. Preference is given to using one or more high refractive alkoxy silanes selected from the group containing.

The content of the high refractive alkoxysilane is preferably used in 10 to 80 parts by weight relative to 100 parts by weight of the alkoxysilane reactant. If it is less than 10 parts by weight, it is difficult to achieve high refractive index, and when it exceeds 80 parts by weight, it is difficult to secure wear resistance.

The silane-based organic substituent may be chemically bonded to the alkoxysilane, may react with the low refractive ultraviolet curable resin to form a double bond, and may impart compatibility between the low refractive ultraviolet curable resin and the high refractive thermosetting resin. Any compound can be used without limitation. Examples of the silane-based organic substituent include vinyl trimethoxy silane, vinyl tri (beta-methoxyethoxy) silane, vinyl triethoxy silane, vinyl tri-n-propoxy silane, vinyl tri-n-pentoxy silane, and vinyl. Methyl dimethoxy silane, diphenyl ethoxy vinylsilane, vinyl triisopropoxy silane, divinyl di (beta-methoxyethoxy) silane, divinyl dimethoxy silane, divinyl diethoxy silane, divinyl di-n- Propoxy silane, divinyl di (isopropoxy) silane, divinyl di-n-pentoxy silane, 3-acryloxypropyl trimethoxy silane, 3-methacryloxypropyl trimethoxy silane, gamma-methacryloxy Preference is given to using one or more substances selected from the group consisting of propyl methyl diethoxy silane, gamma-methacryloxypropyl methyl diethoxysilane and the like.

In order to maintain compatibility and stability in the coating solution state of the alkoxysilane reactant, the content of the silane-based organic substituent is preferably used in an amount of 10 to 80 parts by weight based on 100 parts by weight of the alkoxysilane reactant. When the content is less than 10 parts by weight, it is difficult to provide sufficient compatibility with the low refractive UV curable resin, and when the content is more than 80 parts by weight, it is difficult to realize film strength and scratch resistance.

The alkoxysilane reactant is preferably prepared through a sol-gel reaction. The sol-gel reaction may use a method commonly used in the art. The sol-gel reaction may be performed by, for example, reacting a composition including an alkoxysilane, a silane-based organic substituent, a catalyst, water, and an organic solvent at a reaction temperature of 0 to 150 ° C. for 1 to 100 hours.

The catalyst used in the sol-gel reaction is a component necessary for controlling the sol-gel reaction time. The catalyst is preferably an acid such as nitric acid, hydrochloric acid, sulfuric acid and acetic acid, and more preferably in the form of hydrochloride, nitrate, sulfate, and acetate along with salts such as zirconium and indium. In this case, the content of the catalyst is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the alkoxysilane reactant.

Water used for the sol-gel reaction is a component necessary for the hydrolysis reaction and the condensation reaction. The amount of water is preferably 5 to 50 parts by weight based on 100 parts by weight of the alkoxysilane reactant.

The organic solvent used for the sol-gel reaction is a component for appropriately adjusting the molecular weight of the hydrolyzed condensate. The organic solvent is preferably alcohols, cellosolves, ketones or two or more mixed solvents selected from these. At this time, the content of the organic solvent is preferably 0.1 to 80 parts by weight based on 100 parts by weight of the alkoxysilane reactant.

Meanwhile, the urethane reactor compound may be prepared by reacting an alcohol and an isocyanate compound under a metal catalyst. A composition comprising a polyfunctional alcohol, a polyfunctional isocyanate and a metal catalyst comprising two or more functional groups at a temperature above normal temperature can form a network structure having a urethane reactor.

Alcohol components used in the preparation of the urethane reactor compounds include low molecular weight polyols (eg, polyols having a weight average molecular weight of less than 400, specifically aliphatic diols such as C ₂ -C ₁₀ aliphatic diols, triols and polyhydric alcohols), Polyester polyols, polyether polyols, amide-containing polyols, polyacrylic polyols, epoxy polyols, polyhydric polyvinyl alcohols, urethane polyols and mixtures of such polyols.

As the isocyanate component used in the preparation of the urethane reactor compound, aliphatic isocyanates, alicyclic isocyanates, aromatic isocyanates, heterocyclic isocyanates are preferable. Specifically, diisocyanate such as hexamethylene diisocyanate, 1,3,3-trimethyl hexamethylene diisocyanate, isophorone diisocyanate, toluene-2,6-diisocyanate, 4,4'-dicyclohexane diisocyanate, or 3 It is preferable to use functional or more isocyanate, such as DIC company DN950, DN980 etc. as a brand name.

A catalyst may be used in the preparation of the urethane reactor compound, and Lewis acid or Lewis base may be used as the catalyst. Specific examples of the catalyst include buty octylate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin dimaleate, dimethyltin hydroxide and triethylamine. It is not limited.

The content of the isocyanate and the polyfunctional alcohol used in the preparation of the urethane reactor compound is preferably such that the molar ratio (NCO / OH) of the NCO group and the OH group as functional groups is 0.5 to 2, and more preferably 0.75 to 1.1. Do. This may cause a problem that when the molar ratio of the functional group is less than 0.5 or more than 2, the unreacted functional group is increased to decrease the strength of the membrane.

The urea reactor compound may be prepared by the reaction of amines and isocyanates. Isocyanates may be used in the same components as the components used in the preparation of the urethane reactor compound, and amines may be used in bifunctional or higher functional groups. In the present invention, a catalyst may be used as necessary, and a Lewis acid or a Lewis base may be used as the catalyst. Specific examples of the catalyst include buty octylate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin dimaleate, dimethyltin hydroxide and triethylamine. It is not limited.

The esterification reactant may be obtained by dehydration and condensation of an acid and an alcohol. The esterification reactant can also form a crosslinked structure when formulated in the coating solution. As the acid, a bifunctional or higher acid may be used. Examples of the bifunctional or higher acid include succinic acid, glutaric acid, adipic acid, suberic acid, and azela. Azelaic acid, sebacic acid, and lauric acid. The alcohol may be a polyfunctional alcohol, specifically 1,4-butanediol, 1,2-butanediol, 1,5-pentanediol, 2,4-pentanediol, 1,4-cyclohexanediol, 1 , 6-hexanediol, 2,5-hexanediol, 2,4-heptanediol, pentaerythritol, and trimetholpropane. In the esterification reaction, an acid catalyst such as sulfuric acid or an alkoxy titanium such as tetrabutoxy titanium may be used. However, it is not necessarily limited to these.

As described above, the curable resins having different reaction mechanisms preferably have a refractive index difference of 0.01 or more after drying and curing. In this case, it is advantageous to form a GRIN structure composed of two or more layers, and a low reflection effect can be obtained.

The antireflective coating composition is a UV absorber is added so that the ultraviolet ray is not transmitted to the substrate surface when irradiated with ultraviolet rays from the air surface of the coating layer, the ultraviolet absorber is benzophenone-based, benzotriazole-based, salicylate-based, cyanoacrylic Ultraviolet absorbers, such as a late type and an oxanilide type, can be used, A light stabilizer can further be used here.

The amount of the ultraviolet absorber is preferably in the range of 0.05 to 30 parts by weight based on 100 parts by weight of the antireflective coating composition. When the content of the ultraviolet absorber is less than 0.05 parts by weight, ultraviolet rays are transmitted to the base surface of the coating layer during the first UV irradiation, so that the GRIN effect is difficult to be obtained. When the content of the ultraviolet absorber exceeds 30 parts by weight, the coating film is not sufficiently cured. This can be caused by falling degrees.

The antireflective coating composition may further comprise a surfactant for coatability. As the surfactant, a leveling agent or a wetting agent may be used, and in particular, it is preferable to use a fluorine-based or polysiloxane-based compound.

The amount of the surfactant is preferably included in an amount of up to 20 parts by weight based on 100 parts by weight of the antireflective coating composition, and when the content exceeds 20 parts by weight, adhesion to the substrate, scratch resistance of the coating film, and abrasion resistance There is a problem of deterioration.

The coating composition according to the present invention may further include a fluorine-based or silicone-based or acrylic-based wetting agent, the same leveling agent for smoothing, etc. in order to improve the wettability of the coating solution.

The present invention comprises the steps of: i) preparing an antireflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorber; Ii) applying the coating composition to a substrate to form a coating layer; Iii) curing the low refractive ultraviolet curable resin by irradiating ultraviolet rays to have a concentration gradient in the thickness direction of the coating layer; Iii) it provides a method for producing an anti-reflection film comprising the step of curing the high refractive thermosetting resin at a high temperature.

In the present invention, the substrate for applying the antireflective coating composition may be glass, plastic sheets, films, and the like, and there is no limitation in thickness. Examples of the plastic film include triacetate cellulose film, norbornene-based cycloolefin polymer, polyester film, polymethacrylate film, polycarbonate film and the like. The substrate may be any one of display components.

In the method for producing an antireflective film of the present invention, the above-mentioned antireflective coating composition is mainly coated with a substrate, such as bar coating, 2 roll or 3 roll reverse coating, gravure coating, die coating, microgravure coating, comma coating, or the like. It can be freely selected depending on the type and rheological properties of the coating composition.

Coating thickness of 1 ~ 30㎛ is suitable and it is preferable to go through a drying process for drying the solvent after coating.

Method for producing an anti-reflection film according to an embodiment of the present invention is as follows. Applying the anti-reflective coating composition according to the present invention as described above to a dry thickness of 1 to 30 μm (step 1); Drying the resultant coated display substrate at a temperature of 20 to 150 ° C. for 0.1 to 30 minutes (step 2); Partially curing the low refractive ultraviolet curable resin distributed on the air surface of the coating layer of the coated dried display substrate as a result of the above step on the air side for 1 to 600 seconds with an ultraviolet irradiation amount of 0.01 to 2J / cm 2 (step 3); Dispersing and moving the uncured low refractive UV curable resin to the air surface and the high refractive thermosetting resin to the substrate surface for 0.1 to 60 minutes at a temperature of 20 to 150 ° C. as a result of the coating cured display substrate. (Step 4); Repeating (step 3) and (step 4) two or more times to maximize partial curing, diffusion, and movement (step 5); Irradiating ultraviolet rays from both sides of the display substrate as a result of the step (step 6); It may include a step (step 7) of heat curing the high refractive index thermosetting resin of the resulting UV cured display substrate at a temperature of 20 to 200 ℃ for 30 minutes to 72 hours.

The antireflective film according to the present invention prepared by the aforementioned antireflective coating composition and method for producing an antireflective film comprises a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorber. And, the low refractive UV curable resin includes an antireflection layer that is a single coating layer having a concentration gradient in the thickness direction of the coating layer.

In the antireflection film, the low refractive ultraviolet curable resin contained in a region corresponding to 50% in the thickness direction from the surface in contact with the air of the antireflection layer is preferably 70% or more relative to the total weight of the low refractive ultraviolet curable resin, It is more preferable that it is 85% or more, and it is more preferable that it is 95% or more. The antireflective film according to the present invention has excellent reflectance of less than 3%.

The present invention also provides a polarizing plate comprising the antireflective film according to the present invention described above. Specifically, the polarizing plate according to the present invention includes a) a polarizing film, b) an antireflection film according to the present invention provided on at least one surface of the polarizing film. A protective film may be provided between the polarizing film and the antireflection film. In addition, the protective film may be used as it is a substrate for forming a single coating layer in the production of the anti-reflection film. The polarizing film and the anti-reflection film may be laminated by an adhesive. As the polarizing film, those known in the art may be used.

 The present invention provides a display including the antireflection film or the polarizing plate. The display device may be a liquid crystal display device or a plasma display device. The display device according to the present invention may have a structure known in the art except that the antireflection film according to the present invention is provided. For example, in the display device according to the present invention, the anti-reflection film may be provided on the outermost surface of the viewer side or the backlight side of the display panel. In addition, the display apparatus according to the present invention may include a display panel, a polarizing film provided on at least one surface of the panel, and an antireflection film provided on an opposite side of the panel contacting the panel of the polarizing film.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

Example 1

Composition of Low Refractive UV Curable Material

8 parts by weight of dipentaerythritol hexaacrylate (DPHA) as a polyfunctional acrylate to impart the film strength of the coating film, and 1H, 1H, 6H, 6H-perfluoro-1,6 as a fluorine acrylate to impart low refractive index 30 parts by weight of hexyl acrylate, 2 parts by weight of Darocur 1173 as a photoinitiator, 20 parts by weight of diacetone alcohol (DAA) and 40 parts by weight of methyl ethyl ketone (MEK) were uniformly mixed to form a low refractive UV curable resin solution. . The triacetate cellulose film was coated with a wire bar (No. 5), cured, and the refractive index was measured using a Prism Coupler manufactured by Sairon Technology.

(Composition of Highly Refractive Thermosetting Material for Making Urethane Compound)

12 parts by weight of isocyanate Vestanat 1358 (Degussa), 19.5 parts by weight of difunctional alcohol Terahtane 650 (Aldrich), 0.5 parts by weight of dibutyltin dilaurate as metal catalyst, 28 parts by weight of diacetone alcohol (DAA) as solvent and methanol 40 parts by weight of (MeOH) were uniformly mixed to form a solution of high refractive material. The triacetate cellulose film was coated with a wire bar (No. 5) and cured, and the refractive index was measured using a Prism Coupler manufactured by Sairon Technology, which was 1.51.

Example 2

Composition of Low Refractive UV Curable Material

It is the same as the composition of the low refractive ultraviolet curable material of Example 1 above.

(Composition of Highly Refractive Thermosetting Material for Making Alkoxysilane Reactant)

A mixture of 30 parts by weight of tetraethoxysilane, 15 parts by weight of vinyl trimethoxy silane, 4 parts by weight of water, 1 part by weight of hydrochloric acid, 20 parts by weight of diacetone alcohol (DAA) and 40 parts by weight of methanol (MeOH) as a solvent A sol-gel reaction was performed at room temperature for 12 hours to form a solution of a high refractive thermosetting material. It was 1.52 when the triacetate cellulose film was coated with a wire bar (No. 5) and cured, and the refractive index was measured using a Prism Coupler manufactured by Sairon Technology.

The low refractive ultraviolet curable solution and the high refractive thermosetting solution prepared in Examples 1 and 2 were prepared by the following method for preparing a coating solution.

(Production of Coating Liquid)

20 parts by weight of the low refractive ultraviolet curable solution, 77 parts by weight of the high refractive thermosetting solution, and 3 parts by weight of Cyasorb UV-24 (Cytec) were mixed with a UV absorber to form a compatible mixed solution.

Comparative Example 1

Only the low refractive UV curable coating solution prepared in Example 1 was used.

Comparative Example 2

Only the high refractive index thermosetting coating liquid prepared in Example 1 was used.

Comparative Example 3

Only the high refractive index thermosetting coating liquid prepared in Example 2 was used.

Experimental Example

The coating solution prepared by the above Examples and Comparative Examples were coated with a wire bar (No. 12) on a triacetate cellulose film having a thickness of 80 μm. This was dried for 2 minutes in an oven at 60 ° C., the air surface of the coating layer was cured for 10 seconds with 20 mJ / cm 2 of UV energy, and then left for 30 minutes in an oven at 60 ° C. for 2 minutes, and then both sides of the substrate and the air plane were After re-irradiation for 10 seconds at 1J / ㎠ UV energy at 60 ℃ heat curing in an oven for 60 minutes. The thickness of the film obtained at this time was 5 micrometers.

The optical properties and abrasion resistance of the antireflection film including the single coating antireflection layer prepared by the above were evaluated in the following manner and the results are shown in Table 1 below.

1) Scratch resistance evaluation

After reciprocating 10 times with steel wool (steel wool # 0000) under a 1kg load, the degree of scratching was evaluated.

2) reflectance

After blacking the back side of the coating film, Shimadzu's Solid Spec. The reflectance was measured with a 3700 spectrophotometer to evaluate the low reflection characteristics with the minimum reflectance value.

3) transmittance and haze

The transmittance and haze of the coating film were evaluated using HR-100 of Murakami, Japan.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 reflectivity(%) 1.9 2.1 1.9 4.1 4.3 Transmittance (%) 95.7 95.5 95.8 94.3 94.1 Haze (%) 0.2 0.3 0.2 0.2 0.3 Scratch resistance Good Good Scratch occurrence Good Good

In the above evaluation results, it was found that both the scratch resistance and the reflectance of the film produced by the present invention were obtained.

Claims (24)

An antireflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorber. The method according to claim 1, wherein 5 to 80 parts by weight of the low refractive ultraviolet curable resin, 10 to 90 parts by weight of the high refractive thermosetting resin and 0.05 to 30 parts by weight of the ultraviolet absorber based on 100 parts by weight of the antireflective coating composition Antireflective coating composition. The antireflective coating composition of claim 1, wherein the low refractive ultraviolet curable resin is an acrylate resin. The method of claim 3, wherein the low refractive UV curable resin further comprises a photoinitiator and a solvent, the acrylate-based resin is 10 to 80 parts by weight based on 100 parts by weight of the total amount of the acrylate-based resin, photoinitiator and solvent, the photoinitiator Is 1 to 20 parts by weight and the solvent is 10 to 90 parts by weight of the antireflective coating composition. The antireflection coating composition according to claim 3, wherein the acrylate resin comprises at least one selected from the group consisting of an acrylate monomer, a urethane acrylate oligomer, an epoxy acrylate oligomer, and an ester acrylate oligomer. The antireflection coating composition according to claim 4, wherein the low refractive UV curable resin further comprises 10 to 80 parts by weight of fluorine acrylate based on 100 parts by weight of the total amount of the acrylate resin, the photoinitiator and the solvent. The antireflection of claim 6, wherein the fluorine-based acrylate is represented by the following Chemical Formulas 1 to 5 and includes one or more of compounds which may further have a C ₁ -C ₆ straight or branched hydrocarbon group as a substituent. Coating composition: [Formula 1]

In Chemical Formula 1, R ₁ is -H or a C ₁ -C ₆ hydrocarbon group, a is an integer of 0 to 4, b is an integer of 1 to 3, [Formula 2]

In Chemical Formula 2, c is an integer of 1 to 10, [Formula 3]

In Chemical Formula 3, d is an integer of 1 to 9, [Formula 4]

In Chemical Formula 4, e is an integer of 1 to 5, [Formula 5]

In Chemical Formula 5, f is an integer of 4 to 10. The antireflective coating composition of claim 1, wherein the high refractive index thermosetting resin comprises at least one selected from the group consisting of alkoxysilane reactants, urethane reactor compounds, urea reactor compounds, and esterification reactants capable of sol-gel reaction. The alkoxysilane reactant is based on 100 parts by weight of the alkoxysilane reactant, 20 to 90 parts by weight of alkoxysilane, 10 to 80 parts by weight of the high refractive alkoxysilane, 10 to 80 parts by weight of the silane-based organic substituent, 0.1 to 10 catalyst Reactivity having an average molecular weight of 1,000 to 200,000 prepared by hydrolysis and condensation reaction by sol-gel reaction at 1 to 100 hours at a reaction temperature of 0 to 150 ° C. by weight, 5 to 50 parts by weight of water and 0.1 to 80 parts by weight of organic solvent. Antireflective coating composition that is an oligomer. The antireflective coating composition according to claim 8, wherein the urethane reactor compound is prepared by reacting an alcohol and an isocyanate compound under a metal catalyst such that the molar ratio (NCO / OH) of the NCO group and the OH group, which is each functional group, is 0.5 to 2. . The antireflective coating composition of claim 8, wherein the urea reactor compound is prepared by the reaction of a bifunctional or higher amine with an isocyanate compound. The antireflective coating composition according to claim 8, wherein the esterified compound is prepared by dehydration and condensation reaction of a bifunctional or higher acid with an alcohol. The antireflective coating composition of claim 1, further comprising greater than 0 and 20 parts by weight of surfactant based on 100 parts by weight of the antireflective coating composition. Iii) preparing an antireflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorbent according to any one of claims 1 to 13; Ii) applying the coating composition to a substrate to form a coating layer; Iii) curing the low refractive ultraviolet curable resin by irradiating ultraviolet rays to have a concentration gradient in the thickness direction of the coating layer; Iii) curing the high refractive thermosetting resin at high temperature; Method for producing an anti-reflection film comprising a. The method according to claim 14, wherein the step ii) is to apply a coating layer with a dry thickness of 1 to 30㎛, and then the coating layer is dried for 0.1 to 30 minutes at a temperature of 20 to 150 ℃. 15. The method according to claim 14, wherein step iii) is a step of irradiating ultraviolet rays in a direction in which the coating layer is in contact with the air, iiib) a surface of the unreacted low refractive UV curable resin in contact with the air of the coating layer, a high refractive thermosetting resin Diffusing and moving to a surface in contact with the substrate, and iiic) irradiating ultraviolet rays from both sides of the coating layer. The method of claim 16, wherein the step iiia) is ultraviolet irradiation for 1 to 600 seconds at an ultraviolet irradiation amount of 0.01 to 2J / ㎠. The method of claim 16, wherein the step iiib) is carried out by maintaining the coating layer for 0.1 to 60 minutes at a temperature of 20 to 150 ℃. The method according to claim 14, wherein the step iv) is to heat-cur the high refractive thermosetting resin at a temperature of 20 to 200 ° C. for 30 minutes to 72 hours. A low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2, and an ultraviolet absorber, wherein the low refractive ultraviolet curable resin includes a single coating layer having a concentration gradient in the thickness direction of the coating layer. Antireflection film. The method of claim 20, wherein the anti-reflective film comprises: i) preparing an anti-reflective coating composition comprising a low refractive ultraviolet curable resin having a refractive index of 1.2 to 1.45, a high refractive thermosetting resin having a refractive index of 1.46 to 2 and an ultraviolet absorber; Ii) applying the coating composition to a substrate to form a coating layer; Iii) curing the low refractive ultraviolet curable resin by irradiating ultraviolet rays to have a concentration gradient in the thickness direction of the coating layer; Iii) an antireflection film produced by the method comprising the step of curing the high refractive thermosetting resin at a high temperature. The antireflection film according to claim 20, wherein the low refractive ultraviolet curable resin contained in a region corresponding to 50% in the thickness direction from the surface in contact with air of the single coating layer is 70% or more based on the total weight of the low refractive ultraviolet curable resin. A polarizing plate comprising a) a polarizing film, b) the antireflection film according to claim 20 provided on at least one surface of the polarizing film. A display device comprising the antireflective film of claim 20.