KR20180111345A - Visibility improvement film for display panel and display device comprising the same - Google Patents

Abstract

The present invention relates to a visibility enhancing film for a display panel, and a display device including the same. More specifically, the present invention relates to a visibility enhancing film for a display panel which can exhibit excellent physical and optical characteristics, including metal particles having a certain reflectance for light of a specific wavelength range, in particular, visibility to a laser pointer can be increased, and a display device including the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a visibility improving film for a display panel, and a display device including the same. ≪ Desc / Clms Page number 1 >

The present invention relates to a visibility improving film for a display panel and a display device including the same.

More specifically, the present invention relates to a method for improving the visibility of a display panel, which can exhibit excellent optical characteristics such as luminance and contrast ratio, while enhancing visibility of a laser pointer, including metal particles having a high reflectance, And a display device including the visibility improving film for the display panel.

When a presentation is performed in a lecture, a meeting, an announcement, etc., it is general that a presentation is performed by using a display device to reproduce a data image and pointing to a screen or the like using a laser pointer on the data image.

Conventionally, there have been many cases in which a presentation is performed by projecting a beam projector on a screen or a wall. However, in the case of the projector type, there is a disadvantage that the contrast ratio and image quality are poor. In recent years, a large number of large display panels of various driving methods such as LCD, PDP, and OLED have been supplied, and it becomes possible to display images directly on the display itself and to carry out presentations.

However, the display device has a luminescent characteristic and has a disadvantage in that the visibility of the laser pointer is significantly lowered because there is no factor that can scatter the laser light in addition to the specular reflection at a specific angle.

Therefore, there is still a need for a method for improving the visibility of a laser pointer in a display device without undue additional processing.

The present invention provides a display film for a display panel capable of exhibiting excellent physical and optical characteristics while improving visibility of a laser pointer at low cost in a display panel such as an LCD, a PDF, and an OLED, and a display device including the same do.

According to the present invention,

materials; And a resin layer provided on at least one surface of the substrate, the resin layer having metal fine particles dispersed therein;

The transmittance value (Tt) measured by JIS 7136 is 60 to 90%;

Wherein the product of the internal haze value (Hi) and the transmittance value (Tt) measured by JIS 7316 is 200 to 1500,

And a visibility improving film for a display panel.

Further, according to the present invention,

And a visibility improving film for the display panel.

According to the visibility improving film for a display panel of the present invention, the visibility of a laser pointer deteriorated on a display device can be remarkably improved.

Such an effect can be obtained by applying the present invention in the form of a film to the outside of the display panel without changing the display driving method, the color filter inside the panel, the lamination structure, and the like, Can be saved.

The visibility improving film for a display panel of the present invention comprises: a substrate; And a resin layer provided on at least one surface of the substrate, the resin layer having metal fine particles dispersed therein; The transmittance value (Tt) measured by JIS 7136 is 60 to 90%; The product of the internal haze value (Hi) and the transmittance value (Tt) measured by JIS 7316 is 200 to 1500.

In addition, the display device of the present invention includes the display panel and the visibility improving film for the display panel mounted on the display panel.

The term 'upper surface' in this specification means a surface arranged to face the viewer when the film is mounted on the display panel, and 'upper' means a direction toward the viewer. Conversely, 'bottom' or 'bottom' refers to a face or orientation that is oriented toward the viewer's opposite side when the film is mounted on the display panel.

In the present specification, the term " fine metal particles " means small particles composed of elements in the periodic table or in the metalloid region.

In the present specification, simply the haze value or the total haze value means the haze value (Ht) measured for the film itself without performing any other processing on the film. This total haze value Ht is represented by the sum of the haze value resulting from the surface irregularities of the film and the haze value resulting from the particles contained in the film and the like.

In this specification, the term "internal haze value (Hi)" means a haze value attributable to particles contained in the film or the like, as described above. Specifically, such an internal haze value is determined by removing a surface irregularity by attaching a transparent adhesive releasing film to the surface of the film in order to remove a factor attributable to surface irregularities, that is, surface haze, Means a haze value.

In this specification, the surface haze value (Hs) means the haze value resulting from the film surface irregularities as described above. Specifically, this surface haze value can be calculated by subtracting the internal haze value (Hi) from the total haze value (Ht).

Hereinafter, the visibility improvement film for a display panel of the present invention and a display device including the same will be described in more detail.

(film)

According to one embodiment of the present invention, a substrate; And a resin layer provided on at least one surface of the substrate, the resin layer having metal fine particles dispersed therein; The transmittance value (Tt) measured by JIS 7136 is 60 to 90%; There is provided a visibility improving film for a display panel, wherein the product of the internal haze value (Hi) and the transmittance value (Tt) measured by JIS 7316 is 200 to 1500.

The visibility improving film for a display panel formed using the coating composition of the present invention can exhibit characteristic reflection characteristics with respect to light in the visible light region, thereby contributing to enhancement of the visibility of the laser pointer.

At this time, it is preferable that the fine metal particles are fine particles of metal having a number average particle diameter of about 0.01 to about 10 μm and an average reflectance value of about 60% or more at about 530 to about 570 nm.

Examples of commonly used display panel films include glass, polyesters such as polyethylene terephthalate (PET), polyethylene such as ethylene vinyl acetate (EVA), and cyclic olefin polymers cyclic olefin polymer (COP), cyclic olefin copolymer (COC), polyacrylate (PAC), polycarbonate (PC), polyethylene (PE), polymethyl methacrylate polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylenenaphthalate (PEN), polyetherimide (PEI), polyimide (PI), methyl methacrylate (MMA) Triacetylcellulose (TAC), and the like.

Of these materials, triacetylcellulose (TAC) films have been widely used because of their excellent optical properties.

The present invention is intended to maintain the optical characteristics of an existing display device while improving the visibility of the laser pointer at low cost by simply attaching it to the top of the display panel without changing the basic structure of the color filter or display panel.

According to an embodiment of the present invention, the resin layer may include at least one of a photocurable binder resin layer and a tacky binder resin layer. Such a resin layer may be formed on one surface or both surfaces of the substrate. Particularly, when the resin layer is formed so as to observe the upper portion of the substrate, that is, the viewer's direction, the resin layer can also serve as a coating layer, and the resin layer can serve as a lower part of the substrate, It may also serve as an adhesive layer for bonding the substrate and the display panel.

More specifically, for example, when the resin layer is a photo-curable binder resin layer, the photo-curable binder resin layer may be formed on the substrate to serve also as a hard coating layer, and the resin layer may be a tacky binder resin layer The adhesive binder resin layer may be formed on the bottom surface of the substrate and serve also as an adhesive layer of the substrate and the display panel.

(Composition)

According to one embodiment of the present invention, a coating composition may be used to form the resin layer on at least one side of the substrate.

The coating composition for producing the visibility improving film for a display panel of the present invention comprises: a binder for forming the resin layer; Fine particles of metal having a number average particle diameter of 0.01 to 10 탆 and dispersed in the binder and having an average reflectance value of at least 60% at 530 to 570 nm; An initiator or a crosslinking agent for curing the binder component; And a solvent.

( Photocurable  bookbinder)

When the resin layer is formed by a binder containing a photocurable functional group, the binder containing the photocurable functional group is not particularly limited as long as it is a compound containing an unsaturated functional group capable of causing a polymerization reaction by ultraviolet rays, (Meth) acrylate group, an allyl group, an acryloyl group, or a vinyl group. According to an embodiment of the present invention, the binder containing the photocurable functional group may be at least one selected from the group consisting of a polyfunctional acrylate-based monomer, a polyfunctional acrylate-based oligomer, and a polyfunctional acrylate-based elastic polymer have.

In the specification of the present invention, acrylate eggs mean not only acrylates but also methacrylates, or derivatives having substituents introduced into acrylate or methacrylate.

The polyfunctional acrylate-based monomer means that it contains two or more acrylate-based functional groups and has a weight average molecular weight of less than 1,000 g / mol. More specifically, there can be mentioned, for example, hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol diacrylate (EGDA), trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxy tri Acrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tri (tetra) acrylate (PETA), or dipentaerythritol hexaacrylate (DPHA) The coating composition is not limited thereto. The polyfunctional acrylate-based monomer is cross-linked with the polyfunctional acrylate-based oligomer and polyfunctional acrylate-based elastic polymer to impart a constant pencil strength and abrasion resistance to the protective film.

The polyfunctional acrylate monomers may be used alone or in combination of two or more.

The polyfunctional acrylate oligomer is an oligomer having two or more acrylate functional groups and having a weight average molecular weight of about 1,000 to about 10,000 g / mol, or about 1,000 to about 5,000 g / mol, or about 1,000 to about 3,000 g / mol. < / RTI >

According to one embodiment of the present invention, the polyfunctional acrylate oligomer has an elongation of from about 5 to about 200%, or from about 5 to about 100%, or from about 10 to about 50%, as measured by ASTM D638 Lt; / RTI > When the elongation of the acrylate oligomer is in the above range, it is possible to exhibit more flexibility and elasticity without deteriorating the mechanical properties. The polyfunctional acrylate oligomer satisfying the above elongation ranges is excellent in flexibility and elasticity to form the polyfunctional acrylate-based monomer and the polyfunctional acrylate-based elastic polymer to be described later and a protective film Sufficient flexibility, curl characteristics, etc. can be imparted to the substrate.

According to an embodiment of the present invention, the polyfunctional acrylate oligomer may be at least one selected from the group consisting of urethane, ethylene oxide, propylene oxide, and caprolactone, Acrylate oligomer. When the modified polyfunctional acrylate oligomer is used, the flexibility of the polyfunctional acrylate oligomer is further increased by the modification, so that the curling property and flexibility of the protective film can be increased.

The polyfunctional acrylate oligomer may be used alone or in combination of two or more.

The polyfunctional acrylate-based elastic polymer is excellent in flexibility and elasticity, and has a weight average molecular weight of about 100,000 to about 800,000 g / mol, or about 150,000 to about 700,000 g / mol, which is a polymer having two or more acrylate functional groups. , Or from about 180,000 to about 650,000 g / mol.

The protective film formed by using the coating composition comprising the polyfunctional acrylate-based elastic polymer can ensure high elasticity or flexibility while securing mechanical properties and can minimize curling or cracking .

According to one embodiment of the present invention, the polyfunctional acrylate-based elastic polymer has an elongation of from about 5 to about 200%, or from about 5 to about 100%, or from about 10 to about 50%, as measured by ASTM D638 Lt; / RTI > When the elongation of the polyfunctional acrylate-based elastic polymer is in the above range, excellent flexibility and elasticity can be exhibited without deteriorating the mechanical properties.

An example of the polyfunctional acrylate-based elastic polymer is polyrotaxane.

Generally, polyrotaxane refers to a compound in which a dumbbell shaped molecule and a macrocycle are structurally intercalated. The dumbbell-shaped molecule is a linear molecule and a linear molecule of such a linear molecule. Wherein the linear molecule penetrates the interior of the cyclic compound and the cyclic compound can migrate along the linear molecule and is prevented from being released by the sequestering agent.

According to an embodiment of the present invention, the polyrotaxane is a cyclic compound in which a lactone compound having an acrylate compound introduced at its terminal is bonded; Linear molecules passing through the cyclic compound; And a blocking group disposed at both ends of the linear molecule to prevent the elimination of the cyclic compound.

The cyclic compound can be used without any limitations as far as it has a size enough to penetrate or surround the linear molecule. The cyclic compound may be a compound having a hydroxyl group, an amino group, a carboxyl group, a thiol group or an aldehyde group Functional groups. Specific examples of such cyclic compounds include alpha-cyclodextrin, beta-cyclodextrin, gamma-cyclodextrin, and mixtures thereof.

In addition, as the linear molecule, a compound having a straight chain form can be used without any limitation if it has a molecular weight of a certain level or higher, but a polyalkylene compound or a polycaprolactone group can be used. Specifically, a polyoxyalkylene compound containing an oxyalkylene repeating unit having 1 to 8 carbon atoms or a polycaprolactone group having a lactone repeating unit having 3 to 10 carbon atoms can be used.

And, such linear molecules may have a weight average molecular weight of about 1,000 to about 50,000 g / mol. If the weight average molecular weight of the linear molecule is too small, the protective film produced using the linear molecule may have insufficient mechanical properties or self-healing ability. If the weight average molecular weight is too large, The uniformity of properties and materials may be greatly reduced.

On the other hand, the blocking group can be appropriately controlled in accordance with the properties of the polyrotaxane to be produced, and includes, for example, one kind selected from the group consisting of a dinitrophenyl group, a cyclodextrin group, an adamantane group, a trityl group, Two or more species can be used.

Another example of the polyfunctional acrylate-based elastic polymer is a urethane-based acrylate polymer. The urethane-based acrylate polymer has a form in which urethane-based acrylate oligomers are side-linked to the main chain of the acrylic polymer.

(Adhesive binder)

When the resin layer is formed of a tacky binder, a crosslinkable composition component used for bonding a protective film and a polarizing plate or the like in a conventional polarizing plate or the like may be used.

The crosslinkable composition may include a polyalkylene polyol compound. The crosslinkable composition may further comprise, as a crosslinking component, an acrylic adhesive resin and a crosslinking agent for the acrylic adhesive resin. The acrylic pressure-sensitive adhesive resin and the crosslinking agent may be contained in the crosslinkable composition without crosslinking reaction, and may be included in a crosslinked state in the pressure-sensitive adhesive binder resin layer. The cross-linkable composition may be crosslinked by using a cross-linking reaction between the acrylic adhesive resin and the cross-linking agent for the adhesive resin as a main cross-linking reaction to form the adhesive binder resin layer.

As used herein, the term polyalkylene polyol compound means a compound having a polyalkylene oxide unit and further containing three or more hydroxy groups. In the above, the hydroxy group may be present at the end of the polyalkylene polyol compound.

The acrylic adhesive resin contained in the crosslinkable composition is a polymer that contains an acrylic monomer as a main component and can exhibit adhesiveness before or after crosslinking. The acrylic monomer may be acrylic acid or methacrylic acid, or a derivative of acrylic acid or methacrylic acid, for example, acrylic acid ester or methacrylic acid ester. The inclusion of the main component in the present application means that the weight ratio of the component is at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90% it means. The weight ratio of the components contained as the main component may be 100% or less or 100% or less in other examples.

The acrylic adhesive resin may be contained as a main component in the crosslinkable composition. That is, the acrylic adhesive resin may have a weight percentage of at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90%, based on the total solids of the crosslinkable composition. Or more. The resin may also be 100% or less or 100% or less in other examples in weight ratios based on the total solids of the crosslinkable composition.

As the acrylic adhesive resin, for example, an acrylic adhesive resin having a carboxyl group can be used. In addition, such an acrylic adhesive resin can improve the durability of the crosslinkable composition under the conditions of moisture resistance and moist heat resistance, and when the ionic compound to be described later is added, a film having little change in surface resistance with time . In addition, through the use of the acrylic adhesive resin, a good effect can be obtained in an adhesive optical member applied to an LCD of a so-called VA (Vertical Aligned) mode.

In one example, the acrylic adhesive resin may have an acid value of 20 or more. In the above, the acid value means the number of mg of potassium hydroxide required to neutralize the free fatty acid and the hydroxyl acid contained in 1 g of the sample. The acid value of the resin may be about 25 or more or about 30 or more in another example. In addition, the acid value of the resin may be about 50 or less, about 45 or less, about 40 or less, or about 35 or less in other examples. The effect of inclusion of a carboxyl group can be further improved through the application of such an acid value resin.

As the acrylic adhesive resin, for example, a polymer containing a polymerization unit of a (meth) acrylic acid ester monomer and a polymerization unit of an acidic monomer can be used. As used herein, the term " polymerized unit " may mean a state in which a corresponding monomer forms a polymer skeleton by a polymerization reaction.

As the (meth) acrylic acid ester compound, for example, alkyl (meth) acrylate can be used. In consideration of control of cohesion, glass transition temperature and tackiness, alkyl (meth) acrylate having an alkyl group having 2 to 12 carbon atoms ) Acrylate may be used. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (Meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate and lauryl (meth) acrylate. Of these, one kind or more than two kinds may be included in the polymer.

The acrylic pressure-sensitive adhesive resin may also contain, for example, an acidic monomer as a polymerization unit. The term acidic monomer means a copolymerizable monomer having an acidic group, for example, a monomer having a carboxyl group can be used. Examples of the monomer having a carboxyl group as mentioned above include (meth) acrylic acid, 2- (meth) acryloyloxyacetic acid, 3- (meth) acryloyloxypropyl acid, 4- (meth) acryloyloxybutyric acid, Dicarboxylic acid, itaconic acid, maleic acid or maleic anhydride, but the present invention is not limited thereto.

The acrylic adhesive resin may contain at least about 5 parts by weight, at least about 5.5 parts by weight, or at least about 6 parts by weight, based on 100 parts by weight of the (meth) acrylic acid ester compound, of an acidic monomer as a polymerization unit. As used herein, the term " weight portion " may mean a ratio of weight between components, unless otherwise specified. The acidic monomer may be included in a ratio of up to about 20 parts by weight, up to about 15 parts by weight, or up to about 10 parts by weight in another example.

The acrylic pressure-sensitive adhesive resin may contain, if necessary, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate such as 2-hydroxyethyl (meth) acrylate or 2-hydroxypropyl (meth) acrylate, or hydroxyalkyl A hydroxyl group-containing monomer such as an alkylene glycol (meth) acrylate; Containing monomers such as (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-vinylpyrrolidone or N-vinylcaprolactam ; (Meth) acrylic acid esters, alkoxy alkylene glycol (meth) acrylic acid esters, alkoxy alkylene glycol (meth) acrylic acid esters, alkoxy alkylene glycol (Meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol Alkylene oxide group-containing monomers such as polyalkylene glycol (meth) acrylic acid esters and the like; Styrene-based monomers such as styrene or methylstyrene; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; Or vinyl acetate esters such as vinyl acetate. ≪ RTI ID = 0.0 > [0040] < / RTI >

The acrylic pressure-sensitive adhesive resin can be produced through a conventional polymerization method. For example, a monomer mixture prepared by compounding the required monomers according to the desired monomer composition can be prepared by solution polymerization. If necessary in this process, suitable polymerization initiators or molecular weight regulators, chain transfer agents and the like may be used together.

The crosslinkable composition may further comprise a crosslinking agent, specifically, a crosslinking agent capable of crosslinking the acrylic adhesive resin. As the crosslinking agent, for example, a compound having two or more functional groups capable of reacting with a carboxyl group contained in the acrylic adhesive resin may be used. As such a cross-linking agent, those usual in this field can be used, and examples thereof include an epoxy cross-linking agent or an aziridine cross-linking agent. Specific examples include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'-tetraglycidylethylenediamine, glycerin diglycidyl ether, Bis (1-aziridine carboxamide), N, N'-diphenylmethane-4,4'-bis (1-aziridine carboxamide), triethylene melamine, bis (2-methylaziridine) or tri-1-aziridinylphosphine oxide, but the present invention is not limited thereto. The cross-linking agent may be included in the crosslinkable composition in an amount of 0.0001 to 15 parts by weight based on 100 parts by weight of the acrylic adhesive resin, but is not limited thereto. The proportion of cross-linking agent may, in another example, be at least about 0.0005 parts by weight, or at least about 0.001 part by weight. In another example, the proportion of the crosslinking agent is 13 parts by weight or less, 11 parts by weight or less, 9 parts by weight or less, 7 parts by weight or less, 5 parts by weight or less, 3 parts by weight or less, 1 part by weight or less, 0.5 parts by weight or less, 0.05 parts by weight or less, or 0.05 parts by weight or less.

(Metal particles)

Next, the fine metal particles contained in the coating composition for a visibility improving film for a display panel of the present invention have a number average particle diameter of about 0.01 to about 10 탆, preferably about 0.1 to about 2 탆, Characterized in that it is a fine particle of a metal having an average reflectance value for light at a wavelength of 570 nm of not less than about 60%, preferably about 60 to about 99%, or about 75 to about 95%.

Since the metal fine particles satisfying the above-mentioned conditions have a relatively high reflectance with respect to such light, when light of a laser pointer is irradiated, reflected light is generated inside the film.

In general, when a film for a display panel or the like is produced, inorganic fine particles such as organic particles or metal oxides are often used in a coating composition because the particles have a high transmittance.

These transmissive particles mainly cause light scattering by refraction and diffraction, while metal particles reflect light. More specifically, in the case of the transmissive particles, light scattering due to diffraction and refraction occurs continuously along the fine path through which the light travels. As a result, light is scattered and cloudy light appears. In the case of metal particles, Scattering occurs due to reflection without transmitting light, so that scattering does not occur continuously along the path of light, and the spread of light does not occur.

Particularly, when metal oxide based inorganic particles such as titanium dioxide (TiO ₂ ) particles having a large difference in refractive index from the binder are used, a high light scattering effect can be obtained, but a disadvantage that the contrast ratio is greatly lowered due to high transmittance of particles have.

The contrast ratio of the display device is derived from the brightness of the image coming from the display panel and the difference in brightness due to the film. In the case of using the transmission type particles, the brightness of the film is increased by the particles, The contrast ratio is lowered.

Accordingly, the display panel film according to the embodiment of the present invention can improve the visibility of the laser pointer light by using the metal fine particles, and at the same time, can achieve a high contrast ratio.

As a more specific example, the metal satisfying these conditions is at least one metal selected from the group consisting of aluminum, gold, silver, magnesium, platinum, copper, titanium, zirconium, nickel, tin, silicon, and chromium, And the like, but the present invention is not necessarily limited thereto.

According to an embodiment of the present invention, when the total weight of the binder containing the photocurable functional group is 100 parts by weight, the metal fine particles may be used in an amount of about 0.5 to about 15 parts by weight, preferably about 1 to about 15 parts by weight, Or from about 1 to about 10 parts by weight.

If the amount of the metal fine particles is too small, the effect of improving the visibility of the laser pointer may be insufficient because the light reflection effect at the wavelength is insignificant. If too much is included, the color reproducibility and brightness of the display device are lowered, It is preferable that the above-mentioned range is included.

( Initiator )

Examples of the photopolymerization initiator included in the coating composition of the present invention include 1-hydroxy-cyclohexyl-phenylketone, 2-hydroxy-2-methyl- Methylbenzoylformate,?,? - dimethoxy-p-phenylacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2- (2,4,6-trimethylbenzoyl) -phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like, but are not limited thereto. Products currently on the market include Irgacure 184, Irgacure 500, Irgacure 651, Irgacure 369, Irgacure 907, Darocur 1173, Darocur MBF, Irgacure 819, Darocur TPO, Irgacure 907 and Esacure KIP 100F. These photopolymerization initiators may be used alone or in combination of two or more.

According to one embodiment of the present invention, the content of the photopolymerization initiator is not particularly limited. However, in order to achieve effective photopolymerization without impairing the physical properties of the entire coating composition, the total weight of the binder containing the photopolymerizable functional group is preferably 100 wt% The photo polymerization initiator may be included in an amount of about 0.1 to about 10 parts by weight.

(menstruum)

Examples of the organic solvent included in the coating composition of the present invention include alcohol solvents such as methanol, ethanol, isopropyl alcohol and butanol; organic solvents such as 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy- Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone and cyclohexanone, propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, Ethers such as ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethyl glycol monoethyl ether, diethyl glycol monopropyl ether, diethyl glycol monobutyl ether and diethylene glycol-2-ethylhexyl ether , Aromatic solvents such as benzene, toluene and xylene may be used alone or in combination.

According to one embodiment of the present invention, the content of the organic solvent may be variously adjusted within a range that does not impair the physical properties of the coating composition, so that the amount of the organic solvent may be appropriately adjusted to 100 parts by weight of the binder containing the photocurable functional group 50 to about 200 parts by weight, preferably about 100 to about 200 parts by weight. And may have appropriate fluidity and applicability when the organic solvent is in the above range.

(Organic and inorganic fine particles)

According to an embodiment of the present invention, the coating composition may further include an organic or inorganic fine particle to exhibit anti-glare properties. When the coating composition contains organic or inorganic fine particles, the photocurable resin layer cured by using the organic or inorganic fine particles may exhibit anti-glare properties by scattering light.

The particle size of the organic or inorganic fine particles may be about 1 탆 or more in terms of optimizing the scattering effect of light and 10 탆 or less in terms of proper haze and coating thickness, May be particles having a particle size of from about 1 to about 10 microns, preferably from about 1 to about 5 microns, and more preferably from about 1 to about 3 microns. When the particle size of the organic or inorganic fine particles is less than 1 탆, the effect of preventing light scattering due to light scattering may be insufficient. When the particle size exceeds 10 탆, it is necessary to increase the thickness of the coating in order to adjust the haze to an appropriate level. If the thickness is increased, there is a risk of cracking.

The volume average particle diameter of the organic or inorganic fine particles may be about 2 to about 10 占 퐉, preferably about 2 to about 5 占 퐉, and more preferably about 2 to about 3 占 퐉.

The organic or inorganic fine particles can be used without limitation in the constitution as long as they are of a kind used for forming an anti-glare film.

For example, the organic fine particles may be at least one selected from organic fine particles made of an acrylic resin, a styrene resin, an epoxy resin, and a nylon resin.

More specifically, the organic fine particles may be at least one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl Acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, n-octyl (meth) acrylate, Acrylates such as polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl But are not limited to, methylstyrene, m-methylstyrene, p-ethylstyrene, m-ethylstyrene, p-chlorostyrene, m- chlorostyrene, p- chloromethylstyrene, m- chloromethylstyrene, styrenesulfonic acid, m-butoxystyrene, vinyl acetate (Meth) acrylic acid, maleic acid, unsaturated carboxylic acid, alkyl (meth) acrylamide, (meth) acrylonitrile and the like), vinylidene fluoride, (Meth) acrylate, but the present invention is not limited thereto.

The organic fine particles may be selected from the group consisting of polystyrene, polymethyl methacrylate, polymethyl acrylate, polyacrylate, polyacrylate-co-styrene, polymethyl acrylate-co-styrene, polymethyl methacrylate- Polyvinyl chloride resin, polycarbonate resin, polyvinyl chloride resin, polybutylene terephthalate, polyethylene terephthalate, polyamide resin, polyimide resin, polysulfone, polyphenylene oxide, polyacetal, epoxy resin, phenol resin, silicone resin, melamine resin, One or more members selected from the group consisting of amine, polydivinylbenzene, polydivinylbenzene-co-styrene, polydivinylbenzene-co-acrylate, polydiallyl phthalate and triallyl isocyanurate polymer, A copolymer may be used, but the present invention is not limited thereto.

The inorganic fine particles may be at least one selected from the group consisting of inorganic fine particles of silicon oxide, titanium dioxide, indium oxide, tin oxide, zirconium oxide and zinc oxide, but the present invention is not limited thereto.

The total content of the organic and inorganic fine particles is about 1 to about 20 parts by weight, preferably about 5 to about 15 parts by weight, more preferably about 10 to about 20 parts by weight, relative to 100 parts by weight of the photo- 15 parts by weight.

If the total content of the organic and inorganic fine particles is too small, the haze value due to the internal scattering is not sufficiently realized. If the total content of the organic and inorganic fine particles is too large, the viscosity of the coating composition becomes high and the coating property becomes poor and the haze value due to the internal scattering becomes too large The contrast ratio may be lowered.

According to an embodiment of the present invention, the organic or inorganic fine particles may have a refractive index difference of from about 0.005 to about 0.1, preferably from about 0.01 to about 0.07, more preferably from about 0.01 to about 0.07, About 0.015 to about 0.05. If the difference in refractive index is less than 0.005, it may be difficult to obtain an appropriate haze value required for preventing glare. If the refractive index difference exceeds 0.1, the internal scattering increases and the haze value increases, but the contrast ratio may decrease.

(additive)

Meanwhile, the coating composition of the present invention may further include additives commonly used in the art such as surfactants, antioxidants, UV stabilizers, leveling agents, antifouling agents and the like, in addition to the above-mentioned components. The content can be varied within a range that does not deteriorate the physical properties of the coating composition of the present invention. Therefore, it may be included in an amount of about 0.1 to about 10 parts by weight based on 100 parts by weight of the total coating composition, have.

According to one embodiment of the present invention, the photocurable resin layer formed using the coating composition has a thickness of about 1 탆 or more, for example, about 1 to about 20 탆, or about 2 to about 10 탆, Or from about 2 to about 5 micrometers, and may exhibit appropriate optical and physical properties within such thickness ranges.

(coating)

The visibility improving film for a display panel of the present invention as described above is a transparent plastic substrate, a binder containing a photocurable functional group, metal fine particles dispersed in the binder and having a number average particle diameter of 0.01 to 10 占 퐉, Fine particles of a metal having an average reflectance value at 570 nm of 60% or more; A photopolymerization initiator; And a solvent, and applying a coating composition for a visibility improving film for a display panel and photo-curing the coating composition.

Specific descriptions and examples of the above-mentioned coating composition and each component constituting the coating composition are as described above.

The method of applying the coating composition is not particularly limited as long as it can be used in the technical field to which the present technology belongs. For example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, Method, a comma coating method, a slot die coating method, a lip coating method, or a solution casting method.

Next, a protective film can be formed by irradiating the applied coating composition with ultraviolet light to perform a photo-curing reaction. Before applying the ultraviolet ray, the coating surface of the coating composition may be planarized and the solvent contained in the coating composition may be dried to volatilize the coating composition.

The dose of the ultraviolet rays may be, for example, about 20 to about 600 mJ / cm ² . The light source for ultraviolet irradiation is not particularly limited as long as it can be used in the technical field to which the present technology belongs. For example, a high pressure mercury lamp, a metal halide lamp, a black light fluorescent lamp and the like can be used.

(Properties)

As described above, the visibility improving film for a display panel of the present invention includes fine particles of metal having an average reflectance value of 60% or more with respect to light having a wavelength of 530 to 570 nm. Due to the reflectance characteristics described above, It is possible to provide a display device capable of effectively reflecting a laser beam incident thereon and capable of increasing the visibility of the laser pointer and realizing an image of high image quality with high luminance and contrast ratio.

The visibility improving film for a display panel may have a transmittance value (Tt) of 60 to 90% as measured by JIS 7136 and exhibits high light transmittance.

The visibility improving film for a display panel may have a haze value Hi measured by JIS 7316 and a product of the transmittance value Tt of 200 to 1500, preferably about 500 to 1500, Lt; / RTI >

In optical films and the like, the transmittance and the haze characteristics vary depending on the introduced particles contained in the film. In general, the more the light scattering particles having similar optical characteristics are included, the lower the transmittance and the tendency to increase the haze have.

However, depending on the kind of particles used, it may have a characteristic relationship of transmittance and haze. Particularly, when the metal fine particles are included in the resin layer, the haze value can be lower than that of the organic fine particles or the inorganic oxide fine particles generally used while the transmittance to light is lowered by the reflection characteristic as described above, In particular, when compared with the case of using the transmissive light scattering particles, even if they have the same transmittance value, they can have a relatively low internal haze value.

Particularly, the light transmittance value varies depending on the particle content, and when the transmittance is too high, there is a problem that the amount of particles for scattering or reflecting light is absolutely inadequate so that proper visibility can not be realized, When the display is low, visibility is good, but a contrast ratio and a brightness lowering problem occur, and the image quality of the image to be implemented by the display may be deteriorated.

Therefore, the range of the above-described transmittance (Tt), the characteristic internal haze value (Hi) attributable to the use of the metal fine particles, and the range of the product of the transmittance and the internal haze value are limited and excellent visibility And at the same time an excellent contrast ratio can be realized.

According to an embodiment of the present invention, the visibility improving film for a display panel of the present invention may have a relative luminance value measured by the following formula 1 of about 1.5 or more, preferably about 1.6 or more, But can be from about 1.5 to about 2.5, or from about 1.6 to about 2.1.

[Formula 1]

B1 / A1

In Equation (1)

A1 is a luminance value measured when a transparent base material film is attached to a display panel and a 535 nm laser is irradiated in a 45 占 direction of a normal line in a state where a white screen is implemented on the display,

B1 is a luminance value measured when a visible light enhancement film for a display panel is attached to a display panel and a 535 nm laser is irradiated in a 45 ° direction of the normal line in a state where a white screen is implemented on the display.

As described above, the visibility improving film for a display panel of the present invention has a luminance of about 50% or more, preferably about 50% or more, in terms of luminance before irradiation, compared with a general UV curable coating layer, It is possible to realize an effect of increasing by about 60% or more, and thus the visibility of the laser pointer can be remarkably improved.

According to an embodiment of the present invention, the visibility improving film for a display panel of the present invention has a contrast ratio of 0.7 or more, preferably about 0.7 to about 1, or about 0.75 to about 0.95 .

[Formula 2]

(B2 / A2) * 100

In the above formula 2,

A2 is a dark room contrast ratio value measured after attaching the transparent base film to the display panel, (0 lx)

And B2 is a darkroom contrast ratio value measured after attaching the visibility improving film for a display panel to the display panel.

As described above, the visibility improving film for a display panel of the present invention can remarkably improve the visibility of a laser pointer, and at the same time, can achieve an excellent contrast ratio.

In the visibility improving film for a display panel of the present invention, the substrate on which the resin layer is formed may be glass or transparent plastic resin which is usually used for a display panel. More specifically, according to one embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, including a method of manufacturing a semiconductor device, such as a polyester such as polyethylene terephthalate (PET), a polyethylene such as ethylene vinyl acetate (EVA), a cyclic olefin polymer cyclic olefin polymer (COP), cyclic olefin copolymer (COC), polyacrylate (PAC), polycarbonate (PC), polyethylene (PE), polymethyl methacrylate polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylenenaphthalate (PEN), polyetherimide (PEI), polyimide (PI), methyl methacrylate (MMA) Triacetylcellulose (TAC), and the like.

Preferably, the substrate may be a film comprising triacetylcellulose (TAC).

The thickness of the substrate is not particularly limited, but it is possible to use a substrate having a thickness of about 20 to about 100 占 퐉, or about 20 to about 60 占 퐉, so long as it can satisfy the hardness and other physical properties of the film.

The visibility improving film for a display panel of the present invention may have a pencil hardness of not less than HB, or not less than 1H, or not less than 2H at a load of 500 g.

Further, it is possible to exhibit abrasion resistance which does not cause scratches when a steel wool # 0 is mounted on a friction tester and then reciprocated 10 times under a load of 200 g, or 300 g or 400 g.

According to an embodiment of the present invention, the visibility improving film for a display panel comprises: a substrate; A resin layer provided on an upper portion of the substrate; And a functional coating layer formed on the resin layer, the functional coating layer being at least one of an antireflection layer and a light-shielding layer.

In addition to the antireflection effect of the conventional display panel film, the antireflection layer prevents the specular reflection when the laser pointer is used, thereby preventing the laser pointer light from being directly reflected and directly entering the eye of the observer looking at the image have. Such an antireflection layer may be a general antireflection layer used in a conventional film for a display device or an optical film for a polarizing plate or the like, specifically, for example, an antireflection layer using an interference of light by forming a plurality of layers having different refractive indexes, (Anti reflection, AR) can be used without any particular limitation.

In addition, when the laser pointer is used, the light-diffusing layer is irregularly formed on the surface, and the laser pointer light is irregularly reflected, so that it is possible to effectively prevent the regular reflection light from directly entering the eye of the observer looking at the image. The anti-glare layer may be formed by dispersing a filler such as inorganic fine particles in a resin to impart irregularities to the surface (Anti-glare, AG) without any particular limitation.

When the antireflection layer, the antireflection layer, and the like are provided, it is preferable that the functional coating layer is located at the top of the film.

According to another embodiment of the present invention, there is provided a display device including a display panel and the visibility improvement film for the display panel described above.

At this time, the display panel is not particularly limited to a driving method, a structure, and the like. Specifically, the display panel can be applied to an LCD panel, a PDP panel, or an OLED panel.

The visibility improving film for a display panel and the display panel may be laminated by using a separate adhesive or the like. Usable adhesives are not particularly limited as long as they are known in the art. For example, a water-based adhesive, a one-component or two-component polyvinyl alcohol (PVA) adhesive, a polyurethane adhesive, an epoxy adhesive, a styrene butadiene rubber adhesive (SBR adhesive), a hot melt adhesive, The present invention is not limited to these examples.

The resin layer may also serve as a pressure-sensitive adhesive layer, as described above. When the resin layer does not also serve as a pressure-sensitive adhesive layer, it is preferable that the surface of the substrate, on which the resin layer is not formed, And the resin layer is laminated so as to be positioned outward, so that the structure in which the side where the laser pointer is incident faces directly is preferable.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

<Examples>

Preparation of a coating composition for a film and a visibility improving film for a display panel

Example  One

With respect to 100 parts by weight of the total,

16 parts by weight of pentaerythritol tri (tetra) acrylate (PETA);

16 parts by weight of hexafunctional urethane acrylate (trade name: EB-1290);

7.3 parts by weight of an aluminum particle dispersion (solid content 20 wt%, aluminum purity 99.8%, number average particle diameter of particles: 2 mu m, toluene dispersion)

Leveling agent 0.2 part by weight Megaface F-477 (manufacturer: DIC Co., Ltd.);

Irgacure 184 as a photopolymerization initiator, 2.5 parts by weight;

As a solvent, 18 parts by weight of methyl ethyl ketone and 18 parts by weight of 2-butanol;

22 parts by weight of a silica dispersion (manufacturer: Tosoh, SS50B having a number average particle diameter of 1 to 2 占 퐉 and SS50F having a number average particle diameter of 0.5 to 1 占 퐉 mixed at 1: 1, solid content 20%, toluene dispersion)

To prepare a coating composition for a visibility improvement film for a display panel.

The composition was coated on a 60 탆 thick TAC film. This was dried at 90 ° C. for 2 minutes and irradiated with UV light of 200 mj / cm ^{2 using} a mercury lamp to form a photo-curable resin layer having an average dry thickness of 5 μm to produce a visibility improving film for a display panel. (Aluminum reflectance: 0.91 when measured at 550 nm)

Example  2

With respect to 100 parts by weight of the total,

16 parts by weight of pentaerythritol tri (tetra) acrylate (PETA);

Hexafunctional urethane acrylate 16 parts by weight;

10.3 parts by weight of the aluminum particle dispersion;

0.2 part by weight as leveling agent;

2.5 parts by weight of a photopolymerization initiator;

As a solvent, 16 parts by weight of methyl ethyl ketone and 16 parts by weight of 2-butanol;

And 23 parts by weight of a silica dispersion were mixed to prepare a coating composition for a visibility improving film for a display panel.

The composition was coated on a 60 탆 thick TAC film. This was dried at 90 ° C. for 2 minutes and irradiated with UV light of 200 mj / cm ^{2 using} a mercury lamp to form a photo-curable resin layer having an average dry thickness of 5 μm to produce a visibility improving film for a display panel.

Comparative Example  One

A visibility improving film for a display panel was produced in the same manner as in Example 1 except that the silica dispersion and the aluminum particle dispersion were not used.

Comparative Example  2

With respect to 100 parts by weight of the total,

17.5 parts by weight of pentaerythritol tri (tetra) acrylate (PETA);

Hexafunctional urethane acrylate 17.3 parts by weight;

2.5 parts by weight of a titanium dioxide particle dispersion (solid content: 25 wt%, median particle diameter: 0.39 mu m, butyl cellosolve dispersion);

0.2 part by weight as leveling agent;

2.5 parts by weight of a photopolymerization initiator;

As a solvent, 20 parts by weight of methyl ethyl ketone and 15 parts by weight of 2-butanol;

And 25 parts by weight of a silica dispersion were mixed to prepare a coating composition for a visibility improving film for a display panel.

The composition was coated on a 60 탆 thick TAC film. This was dried at 90 ° C. for 2 minutes and irradiated with UV light of 200 mj / cm ^{2 using} a mercury lamp to form a photo-curable resin layer having an average dry thickness of 5 μm to produce a visibility improving film for a display panel.

The above compositions are summarized in Table 1 below.

Composition component
(Unit: parts by weight) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Photocurable binder 32 32 32 34.8 Aluminum dispersion
(Solid content: 20 wt%) 7.3 10.3 - 2.5 Leveling agent 0.2 0.2 0.2 0.2 Photopolymerization initiator 2.5 2.5 2.5 2.5 menstruum 36 32 36 35 Silica dispersion
(Solid content: 20 wt%) 22 23 - 25 total 100 parts by weight 100 parts by weight 70.7 parts by weight 100 parts by weight

Measurement of permeability value

Using the HM-150 haze meter of Murakami Co., the transmittance values of the visibility improving films for display panels prepared in the above Examples and Comparative Examples were measured by JIS 7136 method.

Hayes  Measure value

Haze values of the visibility improving films for display panels prepared in the above Examples and Comparative Examples were measured by the JIS 7136 method using an HM-150 haze meter manufactured by Murakami.

The total haze (Ht) values were measured by directly using the visibility improving films for display panels prepared in the above Examples and Comparative Examples.

The internal haze values were obtained by laminating a release film (LG Chemical Co., Ltd., S7) on the upper surface of the visibility improving film for display panel prepared in Examples and Comparative Examples to eliminate the value due to surface unevenness, The protective film was peeled off and measured without any irregularities on the surface of the film.

The surface haze (Hs) value was calculated by subtracting the internal haze value (Ht-Hi) from the total haze value.

Specular reflection prevention:

The laser pointer (3M, LP-7000) incident on the film at an angle of 45 degrees was visually judged by the degree of spread of the image due to the regular reflection of light. If the focus of the laser pointer is not visible, the laser pointer is very good. If the focus is blurred, the focus is clearly visible. If there is a peripheral spread, the focus is usually poor.

Whitishness :

After bonding the black panel to the back side of the film, the whiteness of the film was visually evaluated.

Improved Visibility of Laser Pointer Improved visibility of the film even when visually checking the film before black panel bonding Improved visibility of laser pointer Improved visibility of the laser pointer when the film looks transparent after visual observation in front of the black panel, When the film is observed with the naked eye before the black panel bonding, it looks transparent and the black feeling is excellent even after the bonding. However, when the light scattering particles are not added and when the white turbidity is compared, when the difference is good, Respectively.

Laser Pointer Visibility Evaluation:

Improved visibility of the laser pointer Visibility of the laser pointer visually when viewed from a distance of 5 m from the front of the panel for a laser pointer (3M, LP-7000) incident at an angle of 75 degrees at a distance of 5 m from the display- .

If you can not locate the laser pointer on a panel with a white background, you can see the location of the bad, fixed light, but if it is difficult to follow the moving light, you can usually see the location of the fixed light, The results were evaluated as excellent.

Contrast level evaluation

In order to measure the luminance of the black pixel and the white pixel, the luminance of the central part of the panel was measured at a distance of 50 cm from the state of being lit for 40 to 60 minutes in order to stabilize the display panel in the dark room of 25, Values were calculated.

(CR) = Surface Luminance with all white pixels / Surface Luminance with all Black pixels)

[Formula 2]

B2 / A2

In the above formula 2,

A2 is a dark room contrast ratio value for a transparent base film,

B2 is a dark room contrast ratio value for the visibility improving film for a display panel according to Examples and Comparative Examples.

The measurement and evaluation results are summarized in Table 2 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Permeability (%) 84.8 82.8 93.0 84.4 Haze (%) 17.8 25.7 0.3 34 Surface haze (%) 6.1 11.7 - 10.7 Internal Haze (%) 11.7 14 - 23.3 Contrast level (%) 0.83 0.75 One 0.49 Anti-specular Great Great Poor Great Whitishness Very good Great Very good Poor Visibility Great Great Poor Great

Referring to Table 2, in the case of the comparative example, there is no surface irregularity, and the specular reflection preventing function is inferior, and there is no light scattering particles in the inside, so that visibility of the laser pointer is very bad.

Especially, in the case of the viewer located at the square of the square, it is confirmed that the light reflected by the laser pointer is directly incident on the eye and can experience unpleasant glare.

Also, as in Comparative Example 2, when the titania as the transparent particle was introduced, the visibility of the laser pointer itself could be improved, but it was clearly confirmed that the scattered film was floated and the whitishness was greatly lowered. And the contrast ratio was very low. However, it has been confirmed that the incorporation of the inorganic microparticles improves the visibility of the laser pointer, but contributes to the formation of the surface irregularities, thereby reducing the glare caused by the regular reflection of the laser pointer.

However, according to the embodiment of the present invention, it has been found that optical properties required in conventional display panels, such as anti-reflection and anti-whitening, are also excellent, while exhibiting excellent transparency values and excellent visibility to laser pointers.

Also, it was confirmed that the contrast ratio level was improved by about 50% or more when compared with the case of using particles other than metal at the same transmittance.

Particularly, the relationship between the transmittance and the haze of the comparative example and the example is out of the range of the transmittance defined in the present invention in the case of the comparative example 1. In the case of the comparative example 2, the transmittance is satisfactory but the product of the transmittance and the internal haze is 1967, It can clearly be seen that the upper limit set by the present invention is deviated.

Claims (11)

materials; And a resin layer provided on at least one surface of the substrate, the resin layer having metal fine particles dispersed therein;
The transmittance value (Tt) measured by JIS 7136 is 60 to 90%;
Wherein the product of the internal haze value (Hi) and the transmittance value (Tt) measured by JIS 7316 is 200 to 1500,
Visibility improvement film for display panel.
The method according to claim 1,
Wherein the resin layer comprises at least one of a photocurable binder resin layer and a tacky binder resin layer.
3. The method of claim 2,
Wherein the metal fine particles are fine particles of a metal having a number average particle diameter of 0.01 to 10 占 퐉 and an average reflectance value at 530 to 570 nm of 60% or more.
3. The method of claim 2,
Wherein the metal comprises at least one selected from the group consisting of aluminum, gold, silver, magnesium, platinum, copper, titanium, zirconium, nickel, tin, silicon and chromium.
The method according to claim 1,
Wherein the resin layer further comprises at least one of organic fine particles and inorganic oxide fine particles having a number average particle diameter of 2 to 10 占 퐉.
The method according to claim 1,
materials; A resin layer provided on an upper portion of the substrate; And a functional coating layer formed on the resin layer, the functional coating layer being at least one of an antireflection layer and a light-shielding layer.
The method according to claim 1,
A visibility improvement film for a display panel, wherein the pencil hardness is higher than HB at a load of 500 g.
The method according to claim 1,
A visibility improvement film for a display panel in which scratches do not occur when a steel wool # 0 is mounted on a friction tester and then reciprocated 10 times by a load of 200 g.
The method according to claim 1,
The substrate may be made of glass, polyethylene terephthalate (PET), ethylene vinyl acetate (EVA), cyclic olefin polymer (COP), cyclic olefin copolymer (COC) (PAC), polycarbonate (PC), polyethylene (PE), polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyethylenenaphthalate (PEN), polyetherimide (PEI), polyimide (PI), methyl methacrylate (MMA), fluorocarbon resin, and triacetylcellulose (TAC) A visibility improving film for a display panel.
The method according to claim 1,
A visibility improving film for a display panel having a contrast ratio measured by the following formula 2 of 0.7 or more:
[Formula 2]
B2 / A2
In the above formula 2,
A2 is a dark room contrast ratio value for a transparent base film,
B2 is a darkroom contrast ratio value for the display panel visibility improving film.
A display device comprising: a display panel; and a visibility improving film for a display panel according to claim 1.