WO2017030391A1

WO2017030391A1 - Low refractive layer and anti-reflection film comprising same

Info

Publication number: WO2017030391A1
Application number: PCT/KR2016/009110
Authority: WO
Inventors: 김부경; 장영래; 장석훈; 변진석
Original assignee: 주식회사 엘지화학
Priority date: 2015-08-18
Filing date: 2016-08-18
Publication date: 2017-02-23

Abstract

The present invention relates to a low refractive layer and an anti-reflection film comprising same. The low refractive layer can exhibit both excellent optical properties, i.e. low reflectance and high light transmittance, and excellent mechanical properties, such as high abrasion resistance and scratch resistance. In particular, the low refractive layer can maintain said excellent physical properties, even after alkali treatment, due to excellent alkali resistance. Accordingly, in the case of being introduced to a display device, the low refractive layer can simplify the production process and is expected to significantly increase the production rate and output.

Description

[Specifications

[Name of invention]

Low refractive layer and antireflection film comprising the same

Technical Field

Cross Citation with Related Application (s)

This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0116259 of August 18, 2015 and Korean Patent Application No. 10-2016-0104408 of August 17, 2016. All content disclosed in the literature is included as part of this specification.

The present invention relates to a low refractive index layer and an antireflection film including the low refractive index layer and a hard coating layer.

Background Art

In general, a flat panel display device such as a PDP or LCD is equipped with an antireflection film for minimizing reflection of light incident from the outside.

As a method for minimizing the reflection of light, a method of dispersing a filler such as inorganic fine particles in a resin is coated on a base film and imparts irregularities (ant i-gl are: AG coating); There exist a method (ant i-reflect ion: AR coating) which uses the interference of light by forming many layers from which refractive index differs on a base film, or the method of using these commonly.

Among them, in the case of the AG coating, the absolute amount of reflected light is equivalent to that of a general hard coating, but a low reflection effect may be obtained by reducing the amount of light entering the eye by scattering light through unevenness. However, since the AG coating has poor screen clarity due to surface irregularities, much research has recently been conducted on AR coatings.

As the film using the AR coating, a multilayer structure in which a hard coating layer (high refractive index layer), a low reflection coating layer, and the like are laminated on a base film is commercialized. However, the method of forming a plurality of layers as described above has a disadvantage that the adhesion between the layers (interface adhesion force) is weak due to the process of forming each layer separately, poor scratch resistance, high production cost.

This reduces the amount of absolute reflection of light incident from the outside, Many studies have been conducted to improve scratch resistance, but the degree of improvement in physical properties is insufficient. In addition, a method of adding an inorganic additive or the like to the polymer film applied to the antireflection film to increase scratch resistance is known. According to this, the alkali resistance of the polymer film is greatly reduced, and thus it is not applicable to the manufacturing process of the polarizing plate. There was a limit to inadequacy.

[Content of invention]

[Problem to solve]

The present invention provides a low refractive index layer that can exhibit excellent optical and mechanical properties.

In addition, the present invention provides an antireflection film including the low refractive layer.

[Measures of problem]

Hereinafter, a low refractive index layer and an antireflection film including the same according to a specific embodiment of the present invention will be described.

According to one embodiment of the invention, there is provided a low refractive layer that satisfies the following formula (1). [Equation 1]

30% ≥ AS = [(S ₀ -S / So] X 100

In Equation 1,

S ₀ is the maximum load that does not cause scratches when the steel of grade # 0000 is loaded and reciprocated 10 times at a speed of 24 rpm and rubbed the surface of the low refractive layer.

¾ represents the low refractive layer in 3 (10 wt> aqueous sodium hydroxide solution heated to rc).

After immersion for 2 minutes, washed with water and wiped the water, and then immersed in 10% by weight aqueous sodium hydroxide solution heated to 55 ^° C for 30 seconds, washed with water and wiped with water to measure S ₀ for the prepared film The maximum load at which no scratches are measured as with the method.

As used herein, the term low refractive layer may mean a layer having a low refractive index, for example, a layer exhibiting a refractive index of about 1.2 to 1.6. In addition, the unit of the load of the formula 1 is g / (2 * 2 cm ² ), which means the weight (g) per area (2 * 2 cm ² ) of 2 cm horizontal, 2 cm vertical.

The low refractive index layer according to the embodiment has excellent mechanical properties such as scratch resistance and optical properties such as reflectance and color for the visible light region. Accordingly, the low refractive index layer can be used in a display device to remarkably improve the glare caused by light incident from the outside of the device without degrading the image quality, and can effectively protect the surface of the device from external impact or stimulus. .

In addition, the low refractive layer has a very small change in physical properties even when exposed to alkali. Due to this high alkali resistance, the low refractive index layer can omit the process of attaching and detaching the protective film which is essentially performed to protect the low refractive layer in the manufacturing process of the display device, and thus the production process of the display device It can simplify and lower the production cost. In particular, the low refractive index layer is also excellent in alkali resistance at high temperature is expected to be able to greatly improve the production speed and productivity without reducing the quality of the device by adjusting the manufacturing conditions of the manufacturing process of the display device to more severe conditions.

More specifically, the low refractive layer may satisfy the above formula (1). In Formula 1, S ₀ is a value capable of evaluating initial scratch resistance of the low refractive index layer, and ¾ is a value capable of evaluating scratch resistance of an alkali treated low refractive index layer. At this time, the low refractive layer is treated with alkali twice, in particular, the second alkali treatment is performed by a high temperature aqueous sodium hydroxide solution. Thereby, alkali resistance in the silver of a low refractive index layer can be evaluated through the change rate of the scratch resistance of the low refractive layer before and behind alkali treatment of the said Formula 1. The alkali treatment conditions are the same as those described in Equation 1, and for the details related to the alkali treatment, reference may be made to the experimental examples described later. In addition, the scratch resistance for the low refractive layer before and after the alkali treatment can also be evaluated as described in Equation 1, and reference to the experimental example described below also relates to the details of the scratch resistance evaluation method.

The low refractive index layer according to an embodiment may have a change rate (AS) of scratch resistance before and after alkali treatment of Formula 1 due to excellent alkali resistance of 30% or less, 25% or less, 20% or less or 15% or less. In addition, since the low refractive index layer may exhibit unchanged scratch resistance even after high temperature alkali treatment, the AS of Equation 1 may be 0%.

On the other hand, as described above, the low refractive layer has excellent mechanical properties such as scratch resistance. For example, the scratch resistance (So value of Formula 1) before the alkali treatment of the low refractive index layer may be about 250 to 800 g / (2 * 2 cm ² ) black about 300 to 800 g / (2 * 2 cm ² ). In addition, the low refractive index layer has excellent alkali resistance Due to this, excellent scratch resistance can be exhibited even after alkali treatment. For example, the scratch resistance (¾ value of Equation 1) after the low refractive insect alkali treatment may be about 200 to 800 g / (2 * 2cm ² ) or about 230 to 800g / (2 * 2cm ² ).

In the existing low refractive index layer, an inorganic filler or the like was added to improve black scratch resistance to exhibit low reflectance in the visible light region. However, these inorganic fillers greatly reduced the alkali resistance of the low refractive index layer, making it difficult to apply the low refractive index layer to the manufacturing process of the display device which essentially involves an alkali treatment process, and color the low refractive layer to image quality of the display device. There was a problem that adversely affects.

However, the low refractive index layer according to the embodiment may exhibit excellent scratch resistance and alkali resistance without changing color or minimizing color change of the polymer resin included in the low refractive layer. In particular, the low refractive index layer according to the embodiment may exhibit a b ^* value of 1 to -8 or 1 to -5 in the L ^* a ^* b ^* color coordinate system defined by the International Illumination Commission (CIE).

In the L ^* a ^* b ^* color coordinate system, a b ^* value represents a color biased to yellow if it is positive, and a color biased to blue if a negative value. Accordingly, the low refractive index layer according to the embodiment may exhibit the color coordinate values as described above, thereby effectively preventing the glare while transmitting the image as it is without changing the quality of the display device image.

In addition, the low refractive index layer according to the embodiment exhibits excellent alkali resistance as described above, and has a characteristic of almost no color change even when exposed to alkali.

More specifically, the low refractive layer according to the embodiment may satisfy the following formula 2.

[Equation 2]

In Equation 2,

b ^* ₀ is the b ^* value of the L ^* a ^* b ^* color coordinate system as determined by the International Lighting Commission of the low refractive index layer,

b is a low refractive index layer in a 10% by weight aqueous sodium hydroxide solution heated to 3C After immersion for 2 minutes, washed with water and wiped dry, then dipped in 10% by weight aqueous sodium hydroxide solution heated to 55 ^° C for 30 seconds, washed with water and wiped to measure b ^* ₀ on the prepared film Measured as in the method, b ^* value of L ^* a'b ^* color coordinate system. In Equation 2, b'o is a value capable of evaluating the initial color of the low refractive layer, and 1Λ is a value capable of evaluating the color of the alkali-treated low refractive layer. The alkali treatment conditions are the same as those of Equation 1, and detailed examples related to the evaluation method of the b ^* value of the L ^* a ^* b ^* color coordinate system can be referred to the experimental example described later.

Low refractive index layer according to an embodiment may have a color change degree (Ab ^* ) of 0.5 or less, 0.45 or less or 0.4 or less before and after alkali treatment of the formula 2 due to the excellent alkali resistance. Since the low refractive index layer may have no color change even after alkali treatment of silver, 2 b ^* of Equation 2 may be ^' 0 ^' .

As described above, the b ^* value (b ^* ₀ value in Equation 2) before the alkali treatment of the low refractive layer may be 1 to -8 or 1 to ᅳ 5. Accordingly, the b ^* value (b value of Formula 2) after the alkali treatment of the low refractive index layer may be 1.5 to 8.5, 1 to -8, 0 to -8, or 1.5 to -5.5.

The low refractive index layer according to the embodiment may exhibit the minimum reflectance in the visible light region together with the excellent optical and mechanical properties described above. More specifically, the low refractive index layer exhibits a minimum reflectance in a wavelength region of about 480 to 680 nm or a wavelength region of about 500 to 580 nm, thereby effectively preventing glare of the display device.

In addition, the low refractive layer according to the embodiment may exhibit a very low reflectance in the visible light region. More specifically, the low refractive index layer may have an average reflectance of 0.9 to 2.5%, 0.9 to 2.2%, 0.9 to 2.0%, 0.9 to 1.5% black and 1 to 1.3% for light in the wavelength range of 380 to 780 nm. Accordingly, when the low refractive index layer is introduced into the display device, glare caused by light incident from the outside may be prevented.

The average reflectance and color coordinate values of the low refractive index layer may be measured using a spectrophotometer. Specifically, at room temperature, the sampling interval 1 nm (preferably 2 nm or less, but can also be adjusted to 5 nm) ， t ime constant 0.1 sec, slit width 20 nm, fixed at medium scanning speed Both sides of the light The opposite side of the surface to be irradiated may be darkened to prevent light from being transmitted, and the reflectance and color coordinate values may be measured by irradiating the other surface with light in a wavelength region of 380 nm to 780 nm. At this time, the low refractive index layer is a base film; Alternatively, if it is formed in the hard coating layer formed on the base film as described below, the surface where the ^' low refractive index layer or the hard coating layer is not formed may be darkened so as not to transmit light. For example, the darkening may be performed by attaching black tape to a corresponding surface.

In addition, when the low refractive layer has a flat surface free from irregularities, the light is irradiated ^at an angle of incidence of 5 ° and the light reflected at a angle of reflection of 5 ° is provided to provide a standard sample material (BaS0 ₄ and 95% A1 mirror, Shimadzu. ), Based on the measured value of), the reflectance according to the wavelength of the low refractive index is measured (measure mode). The average reflectance and color coordinate values may be derived from the reflectance through the UV-240 IPC color analyzer program.

On the other hand, when the low refractive layer has a surface with irregularities, the light is incident perpendicularly to the low refractive layer and scattered in all directions to measure the reflected light to measure the standard sample material (BaS0 ₄ , provided by Shimadzu). Based on this, the reflectance according to the wavelength of the low refractive layer is measured (100% T mode). The average reflectance and color coordinate values may be derived from the reflectance through the UV-2401PC color analys is program. As described above, the low refractive index layer according to the embodiment capable of exhibiting excellent optical and mechanical properties is a photopolymerizable compound, polysilsesquioxane in which one or more reactive functional groups are substituted, — 0-CF ₂ CF ₂ -0— Photocurable coating composition comprising a fluorine-based compound, inorganic particles and a photopolymerization initiator comprising CF ₃ may include a photocured product obtained by photocuring.

In the present specification, a photopolymerizable compound is collectively referred to as a compound that causes polymerization reaction when light is irradiated, for example, visible light or ultraviolet light.

The photocurable coating composition as a photopolymerizable compound

Monomers or oligomers comprising a (meth) acryloyl group or a vinyl group may be included. The monomer or oligomer may include one or more, two or more or three or more (meth) acryloyl groups or vinyl groups. In the present specification, (meth) acryl [(meth) acryl] is meant to include both acryl and methacryl. Specific examples of the monomer or oligomer containing the (meth) acryloyl group include tri (meth) acrylate for pentaerythrone, tetra (meth) acrylate for pentaerythritol and penta (meth) Acrylate, dipentaerythroxy hexa (meth) acrylate, tripentaerythroxy hepta (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethyl propane polyhydroxy tri (meth) acrylate Ethylene Glycol Di (meth) acrylate, Butanediol Di (meth) acrylate, Ethyl Nucleus

(Meth) acrylates, butyl (meth) acrylates or combinations of two or more thereof, or urethane modified acrylate oligomers, epoxide acrylate oligomers, etheracrylate oligomers, dendritic acrylate oligomers or these And two or more kinds of combinations thereof.

And specific examples of the monomer or oligomer containing the vinyl group include divinylbenzene, styrene, paramethyl styrene or oligomers obtained by polymerizing one or more of these. The molecular weight of the oligomer may be adjusted to 1, 000 to 10, 000g / tiK) l.

The content of the photopolymerizable compound in the photocurable coating composition is 20% by weight to 80% by weight, 30% by weight to ¾ to 70% by weight, based on the solid content of the photocurable coating composition in consideration of the mechanical properties of the low refractive layer to be manufactured. Black can be adjusted from 30% to 65% by weight.

Solid content of the photocurable coating composition means only a solid component in which the liquid component of the photocurable coating composition, for example, components such as an organic solvent, which may be optionally included as described below, are excluded.

The photocurable coating composition includes polysilsesquioxane in which one or more semi-functional functional groups are substituted, and can realize low reflectivity and high light transmittance, and improve alkali resistance and at the same time excellent wear resistance or scratch resistance. It is possible to provide a low refractive index layer that can secure the properties.

The polysilsesquioxane substituted with at least one such reactive functional group may be included in an amount of 0.5 to 25 parts by weight, 1 to 20 parts by weight, 1.5 to 19 parts by weight, or 2 to 15 parts by weight with respect to 100 parts by weight of the photopolymerizable compound. In addition, the content of the polysilsesquioxane substituted with at least one semi-functional group in the photocurable coating composition is The solid content of the photocurable coating composition may be adjusted to 1 wt% to 25 wt%, 1 wt% to 20 wt%, 1 wt ¾> to 15 wt% or 1 wt% to 10 wt%.

If the content of the polysilsesquioxane substituted with at least one reactive functional group is less than the above-mentioned range, it is difficult to sufficiently secure alkali resistance or scratch resistance of the coating film or polymer resin formed during photocuring of the photocurable coating composition. Can be. On the other hand, when the content of the polysilsesquioxane substituted with at least one semi-functional functional group exceeds the above-mentioned range, the transparency of the low refractive layer prepared from the photocurable coating composition may be lowered, and the scratch resistance is rather Can be degraded.

The semi-functional groups which may be substituted in the polysilsesquioxane include alcohols, amines, carboxylic acids, epoxides, imides, (meth) acrylates, nitriles, norbornenes, and olefins [al ly, cyclo] Alkenyl (cycloalkenyl) or vinyldimethylsilyl, etc.], polyethyleneglycol, thiol, and a vinyl group may include one or more functional groups selected from the group, and may preferably include an epoxide or (meth) acrylate. .

More specifically, when the semi-functional group is an epoxide, a 2- [3,4-epoxycyclonucleus] ethyl group or a black 3-glycidoxypropyl group may be introduced as the semi-functional group. In the case of (meth) acrylate, a (meth) acryloyloxyalkyl group (in which the alkyl group may have 1 to 6 carbon atoms) may be introduced as a semi-active functional group.

In the present specification, even though the polysilsesquioxane employs the same functional group as the photopolymerizable compound as a semi-functional functional group, the polysilsesquioxane having a siloxane bond (-Si-0-) as a skeleton is not included in the photopolymerizable compound. It is prescribed.

On the other hand, the polysilsesquioxane substituted with one or more of the semi-active functional group is a linear or branched alkyl group of 1 to 30 carbon atoms, a cycloalkyl group of 6 to 30 carbon atoms and an aryl group of 6 to 30 carbon atoms in addition to the above-mentioned semi-functional functional group It may be further substituted with one or more non-banung functional groups selected from the group consisting of. As described above, the surface of the polysilsesquioxane is substituted with a semi-active functional group and a non-cyclic functional group, so that the siloxane bond (-Si-0-) is in the molecule in the polysilsesquioxane in which the semi-functional functional group is substituted with at least one. The photocurable coating is located at and not exposed to the outside The alkali resistance of the coating film and polymeric resin formed at the time of photocuring of a composition can be improved more. In particular, the non-banung functional group introduced into the polysilsesquioxane together with the semi-aromatic functional group is a linear or branched alkyl group having 6 or more carbon atoms; Linear or branched alkyl groups having 6 to 30 carbon atoms; Or in the case of a C6-C30 cycloalkyl group, the alkali resistance of a low refractive layer can be improved more.

The polysilsesquioxane may be represented by (RSiO _L5 ) _n (wherein n is 4 to 30 or 8 to 20, and R is each independently a semi-functional group; or a straight or branched chain having 1 to 30 carbon atoms). Non-reactive functional group selected from the group consisting of an alkyl group, a cycloalkyl group having 6 to 30 carbon atoms, and an aryl group having 6 to 30 carbon atoms), random, ladder type, cage and partial cage Can be.

Among them, in order to further improve the above-described characteristics, a polysilsesquioxane having one or more semi-functional functional groups substituted therein, polyhedral oligomeric silsesquioxane substituted with one or more reactive functional groups and having a cage structure. (Polyhedral 01 igomer ic Si lsesquioxane) can be used.

More specifically, the polyhedral oligomeric silsesquioxane may comprise 8 to 20 silicon in the molecule.

Examples of polyhedral oligomer silsesquioxanes (POSSs) substituted with one or more semi-active functional groups and having a cage structure include TMP Diollsobutyl POSS, Cyclohexanediol Isobutyl POSS, 1,2 POSS with one or more alcohol substitutions, such as Propanediol Isobutyl POSS, 0cta (3-hydroxy-3 methylbutyldimethylsioxy) POSS; Aminopropyl Isobutyl POSS, Am i nopr opy 11 sooc ty 1 POSS, Ami noethyl aminopropyl Isobutyl POSS, N ᅳ Pheny 1 am i no r opy 1 POSS, N-Me t hy 1 am i no r opy 1 Isobutyl POSS, OctaAmmonium POSS, POSS in which at least one amine is substituted, such as Am inophenyl Cyclohexyl POSS and Am inophenyl Isobutyl POSS; POSS in which at least one carboxylic acid is substituted, such as Maleamic Acid-Cyclohexyl POSS, Maleamic Acid-Isobutyl POSS, Octa Maleamic Acid POSS; POSS substituted with at least one epoxide such as EpoxyCyclohexyl Isobutyl POSS, Epoxycyclohexyl POSS, Glycidyl POSS, GlycidylEthyl POSS, Glycidyl Isobutyl POSS, Glycidyl Isooctyl POSS; POSS Maleimide Cyclohexyl, POSS Maleimide POSS in which at least one imide such as isobutyl is substituted; Acrylolsobutyl POSS, (Meth) acryllsobutyl POSS, (Meth) acrylate Cyclohexyl POSS, (Meth) acrylate Isobutyl POSS, (Meth) acrylate Ethyl POSS, (Meth) acrylEthyl POSS, (Meth) acrylate Isooctyl POSS, (Meth) acryl Isooctyl POSS, POSS in which one or more (meth) acrylates are substituted, such as (Meth) acrylPhenyl POSS, (Meth) acryl POSS, and Acrylo POSS; P0SS in which at least one nitrile group such as Cyanopropyl Isobutyl POSS is substituted; POSS in which at least one norbornene group is substituted, such as NorbornenylethylEthyl POSS, Norbornenyl ethyl Isobutyl POSS, Norbornenyl ethyl DiSilanoIsobutyl POSS, and Trisnorbornenyl Isobutyl POSS; POSS substituted with one or more vinyl groups such as Allyl Isobutyl POSS, MonoVinyl Isobutyl POSS, OctaCyclohexenyldimethylsiylyl POSS, OctaVinyldimethylsiyl POSS, OctaVinyl POSS; POSS in which at least one urepin, such as Allyl Isobutyl POSS, MonoVinyl Isobutyl POSS, OctaCyclohexenyldimethylsiylyl POSS, OctaVinyldimethylsiyl POSS and OctaVinyl POSS, is substituted; P0SS substituted with PEG of 5 to 30 carbon atoms; Or P0SS substituted with at least one cyclo group such as Mercaptopropyl Isobutyl POSS or Mercaptopropyl Isooctyl POSS; Etc. can be mentioned.

In addition, reactive polyfunctional groups may be introduced into at least one of the polyhedral oligomeric silsesquioxanes, and at least one or more of the polysulfolimer silsesquioxanes may be substituted.

When a semi-functional functional group is introduced into at least one of the polyhedral oligomeric silsesquioxane silicones, the mechanical properties of the coating film or the polymer resin formed during photocuring of the photocurable coating composition may be greatly improved. In addition, when a non-acyclic functional group is introduced into the remaining silicon, a molecular structural steric hinderance may occur, thereby greatly reducing the possibility of exposing the siloxane bond (-Si-0-) to the outside. Accordingly, the alkali resistance of the coating film or the polymer resin formed during photocuring of the photocurable coating composition can be greatly improved.

More specifically, when the reactive functional group and the non-reflective functional group are substituted together with the polysilsesquioxane, the molar ratio of the reactive functional group to the non-reflective functional group substituted with the polysilsesquioxane (mole number of the semi-functional functional group / non-reactive) Molar number of functional groups) may be 0.20 or more or 0.30 or more, and may also be 0.20 to 6.00, 0.30 to 4.00 or 0.40 to 3.00. When the ratio between the semi- and semi-cyclic functional groups substituted by the polysilsesquioxane is within the above range, steric hindrance in the polysilsesquioxane molecule may be maximized, and thus, siloxane bond (-Si-0-) The risk of exposure to the outside is significantly reduced, thereby greatly improving the mechanical properties or alkali resistance of the coating film or the polymer resin formed during photocuring of the photocurable coating composition. The photocurable coating composition comprises a fluorine-based compound including -0-CF ₂ CF ₂ -0-CF ₃ .

In the present specification, the fluorine-based compound refers to a compound having a weight average molecular weight of 2,000 g / mol or more and substituted with fluorine, and such a compound is not included in the definition of the photopolymerizable compound described above.

In particular, the fluorine-based compound comprises-()-CF ₂ CF ₂ -0-CF ₃ , low refractive index layer made from the photocurable coating composition may have a lower reflectance and improved light transmittance and improved resistance Alkaline and scratch resistance can be exhibited. The fluorine-based compound includes -0- (CF ₂ ) _n -0- (where n is an integer of 1 to 3) and -0-CF ₂ CF ₂ -0-CF ₃ and 0-CF ₂ CF ₂ CF ₃ The physical properties described above can be further improved.

At least one photoreactive functional group is introduced into the fluorine-based compound, and the photoreactive functional group means a functional group capable of participating in a polymerization reaction by irradiation of light, for example, visible light or ultraviolet light. The photoreactive functional group may include various functional groups known to be able to participate in a polymerization reaction by irradiation of light, and specific examples thereof include (meth) acryloyl groups, epoxy groups, vinyl (vinyl) groups, or mercaptos. And the like can be mentioned.

The fluorine-based compound may have a fluorine content of 1 wt% ¾> to 25 wt%. When the content of fluorine in the fluorine-based compound is less than the above range, the fluorine component may not be arranged on the surface of the final resultant obtained from the photocurable coating composition, and thus it may be difficult to sufficiently secure physical properties such as alkali resistance. In addition, when the content of fluorine in the fluorine-based compound exceeds the above range, the surface properties of the final product obtained from the photocurable coating composition may be lowered or the incidence of defective products during the post-stage process to obtain the final product. The fluorine compound is silicon; Or it may further include a side chain or a repeating unit derived from a silicon compound. When the fluorine-based compound contains a side chain or repeating unit derived from silicon or a silicon compound, the content of silicon is relative to the fluorine-based compound.

0.1 weight% to 20 weight%. Silicon contained in the fluorine-based compound may serve to increase transparency by preventing haze from occurring in the low refractive layer obtained from the photocurable coating composition of the embodiment. On the other hand, when the content of silicon in the fluorine-based compound exceeds the above range, the alkali resistance of the low refractive layer obtained from the photocurable coating composition may be lowered.

The fluorine-based compound may have a weight average molecular weight of 2,000 to 200 ᅳ 000 _§ / 111. If the weight average molecular weight of the fluorine-based compound is too small, the low refractive layer obtained from the photocurable coating composition may not have sufficient alkali resistance. In addition, when the weight average molecular weight of the fluorine-based compound is too large, the low refractive layer obtained from the photocurable coating composition may not have sufficient durability or scratch resistance. In the present specification, the weight average molecular weight means a conversion value with respect to standard polystyrene measured by gel permeat ion chromatograph (GPC).

Specifically, the fluorine-based compound is i) an aliphatic compound or an aliphatic ring compound substituted with one or more photoreactive functional groups, at least one hydrogen is substituted with fluorine; ii) silicon-based compounds in which at least one carbon of the aliphatic compound or aliphatic ring compound is substituted with silicon; iii) a siloxane compound in which at least one carbon of the aliphatic compound or aliphatic ring compound is substituted with silicon and at least one -C¾- is substituted with oxygen; iv) a fluoropolyether wherein at least one -CH ₂ -of said aliphatic compound or aliphatic ring compound is substituted with oxygen; Or a mixture of two or more thereof, or a copolymer.

In order for the low refractive layer to exhibit high alkali resistance enough to satisfy Equation 1 above, a sufficient amount of fluorine should be distributed on the surface of the low refractive layer so that the alkaline solution does not penetrate or be absorbed into the low refractive layer. Even if the alkaline solution penetrates or is absorbed into the layer, the crosslinking density must be high to withstand the alkaline solution.

The cured product of the fluorine-based compound is distributed on the surface of the low refractive layer of the present invention, even if the low refractive layer is treated with alkali, the alkaline solution is brought into the low refractive layer. It can be prevented from penetrating or absorbing. However, since the bleso-based compound has a higher molecular weight than the above-described photopolymerizable compound and has a smaller amount of photoreactive functional groups for the same volume or weight, the bleso-based compound has a low content when the content of the photopolymerizable compound decreases and the content of the fluorine-based compound increases. There exists a tendency for the crosslinking density of a refractive layer to fall. Therefore, when an excessive amount of hardened | cured material of the said fluorine-type compound exists from the surface to the inside of a low refractive layer, the crosslinking density of a low refractive layer will fall and it will be hard to show the outstanding alkali resistance.

In order for the low refractive index layer to exhibit high temperature alkali resistance enough to satisfy Equation 1, the cured product of the fluorine-based compound should exist mostly on the surface of the low refractive layer. It is important to control the content of the fluorine-based compound in the photocurable coating composition in order for the cured product of the fluorine-based compound to exist mostly on the surface of the low refractive index layer.

Specifically, the photocurable coating composition may contain 1 to 75 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight or 1 to 15 parts by weight with respect to 100 parts by weight of the photopolymerizable compound. It may include. In addition, the content of the fluorine-based compound in the photocurable coating composition is 0.5% by weight to 50% by weight, 0.5% by weight to 30% by weight, 0.5% by weight to 20% by weight or 1% by weight relative to the solids of the photocurable coating composition. To 15 increments ¾>.

When the fluorine-based compound is added in excess of the photopolymerizable compound, the coating property of the photocurable coating composition is lowered or the crosslinking density of the low refractive layer obtained from the photocurable coating composition is lowered, thereby providing sufficient alkali resistance, durability, and scratch resistance. Or the like. In addition, when the amount of the fluorine-based compound is too small relative to the photopolymerizable compound, sufficient content of fluorine may not be distributed on the surface of the low refractive index layer obtained from the photocurable coating composition, and thus the low refractive index layer may not have the alkaline resistance. .

On the other hand, the photocurable coating composition includes inorganic particles having a diameter in nanometer or micrometer units.

Specifically, the inorganic particles may be hollow silica particles (si li ca hol low part i cl e) having a number average particle diameter of 10 to 100 nm. The hollow silica particles are silica particles derived from silicon compounds or organosilicon compounds, the surface of the particles And / or silica particles having an empty space therein. The hollow silica particles may have a low refractive index compared to the hollow particles, thereby exhibiting excellent antireflection properties.

The inorganic particles may have a number average particle diameter of 10 to 100 nm, 20 to 70 nm, or 30 to 70 nm, and the shape of the particles is preferably spherical, but may be amorphous.

In addition, as the inorganic particles, those whose surfaces are coated with a fluorine-based compound may be used alone, or black may be used in combination with inorganic particles whose surfaces are not coated with the fluorine-based compound. Coating the surface of the inorganic particles with a fluorine-based compound may lower the surface energy, and more uniform distribution of the inorganic particles in the photocurable coating composition. Accordingly, the film obtained from the photocurable coating composition containing such inorganic particles may exhibit more improved durability or scratch resistance.

A particle coating method or a polymerization method commonly known as a method of coating a fluorine-based compound on the surface of the inorganic particles may be used without particular limitation. As a non-limiting example, a method in which the inorganic particles and the fluorine compound are sol-gel reacted in the presence of water and a catalyst to bind the fluorine compound to the surface of the inorganic particle through hydrolysis and condensation reaction may be used.

In addition, the inorganic particles may be included in the composition in the form of a colloid dispersed in a predetermined dispersion medium. The colloidal phase including the inorganic particles may include an organic solvent as a dispersion medium.

The solid content of the inorganic particles in the colloidal phase of the inorganic particles may be determined in consideration of the content range of the inorganic particles in the photocurable coating composition or the viscosity of the photocurable coating composition. For example, the solid content of the inorganic particles in the colloidal phase may be 5% by weight to 60% by weight.

Herein, examples of the organic solvent in the dispersion medium include alcohols such as methanol, isopropyl alcohol, ethylene glycol and butanol; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Aromatic hydrocarbons such as toluene and xylene; Dimethylformamide. Amides such as dimethylacetamide and N-methylpyridone; Esters such as ethyl acetate, butyl acetate and gamma butyrolactone; Such as tetrahydrofuran, 1,4-dioxane Ethers; Or combinations thereof.

The photocurable coating composition may include 10 to 320 parts by weight, 20 to 200 parts by weight black and 30 to 200 parts by weight based on 100 parts by weight of the photopolymerizable compound. In addition, the content of the inorganic particles in the photocurable coating composition may be adjusted to 10% by weight to 80% by weight, 20% by weight to 70% by weight or 20% by weight to 60% by weight relative to the solids of the photocurable coating composition. have. If the inorganic particles are added in an excessive amount, scratch resistance or abrasion resistance of the coating film may decrease due to a decrease in the content of the polymer resin.

The photopolymerization initiator may be used without particular limitation as long as it is a compound known to be used in the photocurable coating composition, and specifically, a benzophenone compound, acetophenone compound, biimidazole compound, triazine compound, oxime compound, or the like. Two or more kinds thereof may be used.

With respect to 100 parts by weight of the photopolymerizable compound, the photopolymerization initiator may be used in an amount of 1 to 50 parts by weight or 1 to 20 parts by weight. In addition, the content of the photopolymerization initiator in the photocurable coating composition is 0.1% by weight to 15% by weight, 1% by weight to 10% by weight with respect to the solid content of the photocurable coating composition 3% by weight to 7% by weight of black Can be adjusted.

If the amount of the photopolymerization initiator is too small, an uncured material remaining in the photocuring step of the photocurable coating composition may occur. If the amount of the photopolymerization initiator is too large, the unreacted initiator may remain as an impurity or have a low crosslinking density, thereby lowering mechanical properties or significantly increasing reflectance of the film.

Meanwhile, the photocurable coating composition may further include an organic solvent. Non-limiting examples of the organic solvents include ketones, alcohols, acetates and ethers, or combinations of two or more thereof. Specific examples of such organic solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetylacetone or isobutyl ketone; Alcohols such as methanol, ethanol, n-propanol, i so-propanol, n-butanol, i so-butanol, or t-butanol; Acetates such as ethyl acetate, i-propyl acetate, or polyethylene glycol monomethyl ether acetate; Such as tetrahydrofuran or propylene glycol monomethyl ether Ethers; Or two or more kinds thereof.

The organic solvent may be included in the photocurable coating composition while being added at the time of mixing each component included in the photocurable coating composition or in the state in which each component is dispersed or mixed in the organic solvent. When the content of the organic solvent in the photocurable coating composition is too small, a defect may occur such that the flowability of the photocurable coating composition is lowered, resulting in streaks in the final film. In addition, when the excessive amount of the organic solvent is added, the solid content is lowered, coating and film formation are not enough, the physical properties and surface properties of the film may be lowered, the volume may occur during the drying and curing process. Accordingly, the photocurable coating composition may include an organic solvent such that the concentration of the total solids of the components included is 1 to 50% by weight, or 2 to 20% by weight.

Such photocurable coating compositions may be applied and photocured according to methods known in the art to provide the above-described low refractive layer.

First, the photocurable coating composition may be applied on a predetermined substrate. At this time, the specific type or thickness of the substrate is not particularly limited, and the substrate known to be used for the manufacture of the low refractive layer may be used without particular limitation.

The photocurable coating composition may be applied using a method and apparatus known in the art, for example, a bar coating method such as Meyer bar, gravure coating method, 2 roll l reverse coating method, vacuum s It can be applied by lot die coating or 2 roll coating.

The low refractive layer may have a thickness of Iran to 300nm or 50nm to 200nm. Accordingly, the thickness of the photocurable coating composition applied on the predetermined substrate may be adjusted to about lnm to 300ηιη, or 50nm to 200nm.

After applying the photocurable coating composition on the substrate as described above, the photocurable coating composition may be photocured by irradiating ultraviolet or visible light in the wavelength range of 200 to 400nm. At this time, the exposure amount of the irradiated light can be adjusted in the range of 100 to 4,000 mJ / cm ² , the exposure time can be appropriately adjusted according to the exposure apparatus, the wavelength of the irradiation light or the exposure amount used.

The photocuring step may be performed under a nitrogen atmosphere. Accordingly, nitrogen purging may be further performed before or during the photocuring step. The low refractive index layer prepared from the photocurable coating composition as described above is a photopolymerizable compound, a polysilsesquioxane substituted with at least one semi-active functional group and a fluorine-based compound comprising -0-CF ₂ CF ₂ -0-CF ₃ It may include a polymer resin comprising a crosslinked polymer and inorganic particles dispersed in the polymer resin.

However, the low refractive index layer of the present invention is not formed only by the above-described components and compositions, and may be formed with various components and compositions with reference to the above contents if the above Equation 1 is satisfied.

On the other hand, according to another embodiment of the invention, the low refractive layer; And a hard coat layer formed on one surface of the low refractive layer. Since the low refractive index layer has been described in detail above, a detailed description thereof will be omitted.

As the hard coating layer, a commonly known hard coating layer may be employed without particular limitation.

For example, the hard coating layer may include a binder resin including a photocurable resin and a (co) polymer (hereinafter, referred to as a high molecular weight (co) polymer) having a weight average molecular weight of 10, 000 g / mol or more; And it may include organic or inorganic fine particles dispersed in the binder resin. As used herein, (co) polymer is meant to include both co-polymers and homo-polymers.

The high molecular weight (co) polymer may include one or more polymers selected from the group consisting of cellulose-based polymers, acrylic polymers, styrene-based polymers, epoxide-based polymers, nylon-based polymers, urethane-based polymers, and polyolefin-based polymers. have.

The photocurable resin included in the hard coating layer is a polymer of a photopolymerizable compound that may cause polymerization reaction when light such as ultraviolet rays is irradiated, and may be one commonly used in the art. Specifically, the photopolymerizable compound may include a semi-aromatic acrylate oligomer group consisting of urethane acrylate oligomer, epoxide acrylate oligomer, polyester acrylate and polyether acrylate; And dipentaerythri nucleacrylate, dipentaerythri pentaacrylate, pentaerythri tetraacrylate, pentaerythri triacrylate, trimethylolpropane triacrylate, Glycerol propoxy triacrylate, ^'trimethylol propane ethoxy triacrylate, 1, 6-nucleotide diacrylate, triethylene multi-functional acrylate monomer selected from the group consisting of polypropylene glycol diacrylate and ethylene glycol diacrylate One or more species may be used.

The organic or inorganic fine particles may have a particle size of 1 to 10.

The organic or inorganic fine particles are organic fine particles selected from the group consisting of acrylic resins, styrene resins, epoxy resins and nylon resins or inorganic particles selected from the group consisting of silicon oxide, titanium dioxide, indium oxide, tin oxide, zirconium oxide and zinc oxide. It may be particulate.

The hard coating layer may be formed from a coating composition comprising organic or inorganic fine particles, a photopolymerizable compound, a photoinitiator, and a high molecular weight (co) polymer. The anti-reflection film including such a hard coating layer is excellent in anti-glare effect.

Meanwhile, another example of the hard coating layer may include a binder resin including a photocurable resin; And an antistatic agent dispersed in the binder resin.

The photocurable resin included in the hard coating layer is a polymer of a photopolymerizable compound that may cause polymerization reaction when the light of ultraviolet rays is irradiated, and may be one commonly used in the art. Specifically, as the photopolymerizable compound, a polyfunctional (meth) acrylate-based monomer or oligomer may be used, wherein the number of (meth) acrylate-based functional groups is adjusted to 2 to 10, 2 to 8 or 2 to 7 It is possible to secure the desired physical properties of the hard coating layer. More specifically, as the photopolymerizable compound, pentaerythri tri (meth) acrylate, pentaerythri tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythroxy nucleus Hepta (meth) acrylate, toluene diisocyanate, xylene diisocyanate, nusamethylene diisocyanate, trimethylolpropane tri (meth) acrylate and trimethyl One or more kinds selected from the group consisting of tri (meth) acrylates can be used. The antistatic agent may be a quaternary ammonium salt compound, a conductive polymer or a mixture thereof. Here, the quaternary ammonium salt compound is at least one in the molecule It may be a compound having a quaternary ammonium base, it can be used without limitation the low molecular type or polymer type. In addition, the conductive polymer may be used as a low molecular type or a polymer type without limitation, the kind may be conventional in the art to which the present invention belongs, and is not particularly limited.

Binder resin of the photocurable resin; And an antistatic agent dispersed in the binder resin may further include one or more compounds selected from the group consisting of alkoxy silane oligomers and metal alkoxide oligomers. The alkoxy silane compound may be conventional in the art, but preferably tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methacryloxypropyl It may be one or more compounds selected from the group consisting of trimethoxysilane, glycidoxypropyl trimethoxysilane, and glycidoxypropyl triethoxysilane.

In addition, the metal alkoxide-based oligomer may be prepared through a sol-gel reaction of a composition comprising a metal alkoxide-based compound and water. The sol-gel reaction can be carried out by a method similar to the method for producing an alkoxy silane oligomer described above. However, the metal alkoxide compound may react rapidly with water, so that the sol-gel reaction may be performed by dipping the metal alkoxide compound in an organic solvent and slowly dropping water. At this time, in consideration of reaction efficiency, the molar ratio of the metal alkoxide compound to water (based on metal ions) is preferably adjusted within the range of 3 to 170.

Here, the metal alkoxide-based compound may be at least one compound selected from the group consisting of titanium tetra-isopropoxide, zirconium isopropoxide and aluminum isopropoxide.

On the other hand, the anti-reflection film may further include a substrate bonded to the other surface of the hard coating layer. The substrate may have a light transmittance of 90% or more and a haze of 1% or less. In addition, the material of the substrate may be triacetyl cellulose, cycloolefin polymer, polyacrylate, polycarbonate, polyethylene terephthalate and the like. In addition, the thickness of the base film may be 10 to 500 in consideration of productivity. However, the present invention is not limited thereto. 【Effects of the Invention】

The low refractive index layer according to the embodiment of the present invention may exhibit excellent optical properties such as low reflectance and high light transmittance and excellent mechanical properties such as high wear resistance and scratch resistance. In particular, the low refractive index layer may exhibit the above-described excellent physical properties even after alkali treatment, due to its excellent alkali resistance. Accordingly, when the low refractive index layer is introduced into the display device, it is expected that the manufacturing process can be simplified and the production speed and the yield will be significantly increased.

[Brief Description of Drawings]

1 is a graph showing reflectance according to the wavelength of the antireflection film prepared in Example 1. FIG.

2 is a graph showing reflectance according to the wavelength of the antireflection film prepared in Example 2. FIG.

3 is a graph showing reflectance according to the wavelength of the antireflection film prepared in Example 3. FIG.

4 is a graph showing reflectance according to the wavelength of the antireflection film prepared in Comparative Example 1. FIG.

5 is a graph showing reflectance according to the wavelength of the antireflection film prepared in Comparative Example 2. FIG.

6 is a graph showing reflectance according to the wavelength of the antireflective film prepared in Comparative Example 3. FIG.

7 is a graph showing reflectance at a wavelength of the antireflective film prepared in Comparative Example 4. FIG.

8 is a wavelength of an antireflection film prepared in Comparative Example 5;

It is a graph showing reflectance.

[Specific contents to carry out invention]

Hereinafter will be described in more detail the operation, effects of the invention through specific embodiments of the invention. However, this is presented as an example of the invention, whereby the scope of the invention is not limited in any sense.

： Manufacture example> Preparation Example 1 Preparation of Hard Coating Film 1 (HD1)

KY0EISHA salt type antistatic hard coating solution (50% solids, product name: LJD-1000) was coated with # 10 mayer bar on triacetylcell film and dried at 90 ^° C for 1 minute, and then 150 mJ / cm ² UV light was irradiated to prepare a hard coat film (HD1) having a thickness of 5 kHz. Preparation Example 2 Preparation of Hard Coating Film 2 (HD2)

After uniformly mixing pentaerythride with 30 g of triacrylate, high molecular weight copolymer (BEAMSET 371, Arakawa, Epoxy Aery late, molecular weight 40,000), 20 g of methyl ethyl ketone and 0.5 g of leveling agent (Tego wet 270) The hard coating composition was prepared by adding 2 g of acryl-styrene co-polymer (volume average particle diameter: 2, manufacturer: Sekisui Plastic) as fine particles having a refractive index of 1.525. The hard coating composition thus obtained was coated on a triacetylcell film with # 10 mayer bar and dried at 90 ^° C. for 1 minute. The dried material was irradiated with ultraviolet light of 150 mJ / cm ² to prepare a hard coating film (HD2) having a thickness of 5. Preparation Example 3 Preparation of Polysilsesquioxane 1

1L reaction system with nitrogen gas introduction tube, condenser and stirrer, isooctyltrimethoxy silane 36.57g (0.156mol), 3-methacyloxypropyl trimethoxysilane 23.34 g (0.094 mol) of tr imethoxysi lane) and 500 mL of methanol (methanol) were added thereto, and the resultant was stirred for 10 minutes at actual weight. Thereafter, 280 g (0.77 mol, 25 wt in methanol) of tetramethylammonium hydroxide was added thereto, and the reaction was performed at 60 ^° C. under a nitrogen atmosphere for 8 hours. 15g of polyhedral oligomeric sisesquioxane (P0SS) substituted with isooctyl and methacryloxypropyl groups was obtained by column termination chromatography, column chromatography and recrystallization. As a result of GP Chromatography, it was confirmed that the molar ratio of the methacryloxypropyl group (moles of methacryloxypropyl group / moles of isococyl group) to the isooctyl group substituted with silicone of polysilsesquioxane was about 0.6 to 1.67. Preparation Example 4 Preparation of Fluorine Compound 2

After thoroughly replacing a 2.0 L stainless steel autoclave with an electronic stirrer with nitrogen gas, 400 g of ethyl acetate, 53.2 g of perfluoro (propyl vinyl ether), 36.1 g of ethyl vinyl ether, 44.0 g of hydroxyethyl vinyl ether, 1.00 g of lauroyl peroxide, azo group-containing polydimethylsiloxane represented by the following formula (VPS1001 (trade name), 6.0 g of Wako Pure Chemical Industries, Ltd.), and a non-aqueous semi-ung emulsifier (NE-30 (trade name), Asahi) call me industries, Ltd. was added to the) 20.0 g, and then in a dry ice methanol nyaenggak to -50 ^° C, was again remove oxygen within the system with nitrogen gas.

Subsequently, 120.0 g of nucleated tetrafluoropropylene were added, and the temperature rising was started. The pressure at the point when the temperature in the autoclave reached 60 ^° C. was 5.3 × 10 ⁵ Pa. After that, the reaction was continued under stirring at 70 ^° C. for 20 hours, and the reaction was stopped by reacting the autoclave at the time when the pressure dropped to 1.7 × 10 ⁵ Pa. After reaching room temperature, the autoclave was opened after the unbanung monomer was discharged to obtain a polymer solution having a solid content concentration of 26.4%. The obtained polymer solution was poured into methanol to precipitate the polymer, washed with methanol and dried in vacuo at 50 ^° C. to obtain 220 g of a hydroxyl-containing fluorine-containing polymer. ^'

Into a 1-liter flask equipped with an electronic stirrer, glass shell and thermometer, 50.0 g of the hydroxyl group-containing fluorine-containing polymer prepared before, 0.01 g of 2,6-di-t-butylmethyl phenol and methyl isobutyl as polymerization inhibitors 370 g of ketone (MIBK) were added and stirred at 20 ^° C. until the hydroxyl-containing fluorine-containing polymer was dissolved in MIBK and the solution became clear.

Subsequently, 13.7 g of 2-acryloyloxyethyl isocyanate was added to the system and stirred until the solution became uniform. Then, 0.1 g of dibutyltin dilaurate was added, and the temperature of the system was 55-65 ^° C. By stirring for 5 hours while maintaining The MIBK solution of the unsaturated group containing fluorine-containing polymer (acrylic modified fluorine-containing polymer) was obtained. 2 g of this solution was weighed and dropped into an aluminum dish, dried on a hot plate at 150 ^° C. for 5 minutes, and then reweighed to calculate the solid content. The solid content was 15.0 wt%.

(1) Preparation of photocurable coating composition for low refractive layer production

The components shown in Table 1 were combined and diluted to 3% by weight of solids in a solvent of MIBK methyl i sobutyl ketone).

Table 1

(Unit: g; Numbers in parentheses refer to the solid content.)

1) Hollow silica dispersion: THRULYA 4320 (catalyzed product) in which hollow silica particles having a number average diameter of 50 nm were dispersed in MIBK at 20% by weight.

2) polysilsesquioxane 1: polysilsesquioxane 1 prepared according to Preparation Example 3

3) polysilsesquioxane 2: T0AG0SEI CO. , Ltd. MAC-SQ-F

4) Fluorine compound 1: MIBK as a fluorine compound containing a photoreactive functional group, -0-CF ₂ CF ₂ -0-CF ₃ , — 0- (CF ₂ ) ₃ -and -0-CF ₂ CF ₂ CF ₃ RS907 DIC diluted to 30% by weight in

5) Fluorine compound 2: Prepared according to Preparation Example 4, the solid content of 15% by weight Fluorine compound 2 dispersed in MIBK

(2) Preparation of low refractive layer and antireflection film (Examples 1 to 3 and Comparative Examples 1 to 5)

On the hard coating layer of the hard coating film described in Table 2 below, the photocurable coating composition obtained in Table 1 was coated with # 3 mayer bar, and dried at 60 ^° C. for 1 minute. In addition, an antireflection film was prepared by irradiating 180 mJ / cm ² ultraviolet rays to the dried material under nitrogen purge to form a low refractive layer having a thickness of llOnm.

Experimental Example: Measurement of Physical Properties of Antireflection Film

The antireflection films obtained in the Examples and Comparative Examples were subjected to the experiments as follows. 1. Alkali pretreatment

Each of the antireflection films obtained in Examples 1 to 3 and Comparative Examples 1 to 5 was immersed in a 30 ^° C. aqueous NaOH solution (diluted with 10 wt% of NaOH in distilled water) for 2 minutes, washed with running water, and then wiped dry. . Subsequently, the anti-reflective film wiped with water was immersed again in an aqueous NaOH solution ^at 55 ^° C. (a solution diluted by 10% by weight of NaOH in distilled water) for 30 seconds, washed with running water, and then wiped dry.

2. Average reflectance and color coordinate value (b ^* ) measurement

The average reflectance and color coordinate values of the antireflection films prepared in Examples and Comparative Examples were measured using Sol idSpec 3700 (SHIMADZU) at the time points before and after the alkali pretreatment.

Specifically, attach a black tape to prevent light transmission on the surface where the hard coating layer of the base film is not formed, and instant conditions at a sampling interval 1 nm, t ime constant 0.1 sec, sl it width 20 nm, medium scanning speed After fixing, the light of 380nm to 780nm wavelength region was irradiated to the low refractive layer of the antireflection film at room temperature. If used as a hard coating film applied to the HD2 100OT mode using ^HE) the hard coat film 1, the reflectance of the 380nm to 780nm wavelength range was measured by applying a Measure mode. Reflectance measurement results for the wavelength range of 380ran to 780nm of the antireflection films prepared in Examples and Comparative Examples are shown in FIGS. 1 to 8. The dotted line (-) of FIGS. 1-8 is a graph which shows the reflectance (y-axis) according to the wavelength (X-axis) of the antireflection film before alkali treatment, and the solid line () is the wavelength (X) of the antireflection film after alkali treatment This graph shows the reflectance (y-axis) along the axis).

The average reflectance and color coordinate values (b ^* ) in the wavelength range of 380 nm to 780 nm were derived from the reflectance through the UV-2401PC color analyzer, and are shown in Table 2.

3. Scratch resistance measurement

At the time point before and after the pretreatment, the steel of # 0000 grade was loaded on the bottom and reciprocated 10 times at a speed of 24 rpm to rub the surface of the antireflective film obtained in Examples and Comparative Examples. The maximum load at which no scratches were observed visually under the LED 50W ceiling light was measured. The load is defined as the weight in grams per square centimeter (2 cm ² ) by 2 cm by ² cm.

Table 2

EXAMPLES Comparative Example Example Comparative Example Comparative Example Example Comparative Example _, Comparative Example Hard Coating

Low refractive insect

Minimum reflectance

Indicating wavelength

Range [nm]

Before average pretreatment

After reflectance pretreatment

Before T pretreatment (b'o)

Value (b ') After pretreatment 0Λ) -0 -1 -1 -0 -1 -0 ᅀ b ^* = b ^* rb ^* ₀

Nask pretreatment

Latchability [Unit:

g / (2 * 2cm ² )]

After pretreatment

[unit:

1 and 8, the antireflective films of Examples 1 and 2 exhibit significantly low reflectance and high scratch resistance in the visible light region (480 to 680 nm). It is confirmed that it is maintained at an excellent level. In contrast, the antireflective films of Comparative Examples 1 to 3 exhibit poor scratch resistance, and in particular, it is confirmed that scratch resistance remarkably decreases after alkali treatment.

On the other hand, the anti-reflection film of Example 3, Comparative Examples 4 and 5 reduced the content of the hollow silica contained in the low refractive index layer to achieve high scratch resistance, but similarly the anti-reflection films of Comparative Examples 4 and 5 after the alkali treatment It is confirmed that scratch resistance is remarkably lowered.

Thereby, it is confirmed that the antireflection film can be provided that exhibits excellent alkali resistance only when the low refractive index layer that satisfies the specific conditions of the present invention and has little change in physical properties before and after alkali treatment. In particular, the low refractive index layer does not significantly decrease the optical properties such as reflectance or transmittance and the mechanical properties such as abrasion resistance or scratch resistance even when exposed to alkali depending on the manufacturing process of the polarizing plate. Application can be omitted, which simplifies the production process and reduces production costs. In addition, the low refractive layer is expected to contribute significantly to the production speed and productivity improvement by maintaining excellent optical and mechanical properties even in the high temperature alkali treatment process. ^'

Claims

Scope of claim The low refractive index layer that satisfies Claim 1 below:

[Equation 1]

30%> AS = [(So-S / So] X 100

In the above formula 1,

S ₀ is the maximum load that does not cause scratch when the steel wool of # 0000 grade is loaded and reciprocated 10 times at the speed of 24rpm and rubbed the surface of the low refractive layer.

¾ immersed the low refractive layer in a 10% by weight aqueous sodium hydroxide solution heated to 30 ^° C for 2 minutes, washed with water and wiped the water, and then 30 in a 10% by weight aqueous sodium hydroxide solution heated to 55 ^° C After immersion for a second, it is the maximum load which does not generate the scratches measured in the same manner as in the method of measuring So for the film prepared by washing with water and wiping off the moisture. [Claim 2]

The low refractive layer according to claim 1, which satisfies Equation 2:

[Equation 2]

In Equation 2,

b ^* ₀ is the b ^* value of the L ^* a ^* b ^* color coordinate system as determined by the International Lighting Commission of the Low Refractive Layer,

1A immersed the low refractive insect in 10% by weight aqueous sodium hydroxide solution heated to 30 ^° C for 2 minutes, washed with water and wiped dry, and then 30 seconds in 10% by weight aqueous sodium hydroxide solution heated to 55 ^° C After immersion, it is b ^* value of L ^* a ^* b ^* color coordinate system measured like the method of measuring b ^* ₀ with respect to the film prepared by washing with water and wiping water.

[Claim 3]

The low refractive index layer according to claim 2, wherein bV ⁵ ¦ 1 to -8 of Equation 2.

[Claim 4] The low refractive index layer according to claim 1, which exhibits a minimum reflectance in the wavelength region of 480 to 680 nm.

[Claim 5]

The method of claim 1, wherein the average reflectance for light in the wavelength range of 380 to 780 nm

Low refractive index layer of 0.9 to 2.5%.

[Claim 6]

The method of claim 1, wherein the photopolymerizable compound, a polysilsesquioxane substituted with one or more reactive functional groups, a fluorine-based compound including -0-CF ₂ CF ₂ -0-CF ₃ , an inorganic particle and a photopolymerization initiator A low refractive index layer comprising a photocuredol obtained by photocuring a chemical conversion coating composition.

[Claim 7]

The low refractive layer of claim 1; And a hard coating layer formed on one surface of the low refractive layer.