KR20150079052A - Anti-glare film having surface characteristics of organic particles - Google Patents

Abstract

The antiglare film having improved antiglare property by controlling the surface characteristics of the organic particles according to the present invention is an antiglare film formed by laminating an antiglare layer on a transparent substrate, wherein the antiglare layer is formed by laminating the light- transmitting coating layer and the first and second organic Wherein the first and second organic particles have the same diameter and refractive index and have a carbon content in the range of 82 to 88%.

Description

ANTI-GLARE FILM HAVING SURFACE CHARACTERISTICS OF ORGANIC PARTICLES "

The present invention relates to an antiglare film having surface characteristics of organic particles and more specifically to an antiglare film having an organic particle having a different particle size by changing the degree of hydrophobicity of organic particles having the same diameter and refractive index in a hard coat layer To an antiglare film having surface characteristics of organic particles.

2. Description of the Related Art In recent years, the use of display devices typified by LCD (Liquid Crystal Display), PDP (Plasma Display Panel), CRT (Cathode Ray Tube) or ELD (Electro Luminance Display) When such a display device is used under outdoor and bright illumination, there is a problem that external light such as sunlight and fluorescent light is reflected on the surface of the display, resulting in deterioration of the performance of the device. have.

Accordingly, various antireflection films and antiglare films have been used in display devices. Among them, the anti-glare film is roughened in such a manner that the surface thereof is roughened. The anti-glare treatment of such an anti-glare film is generally performed by (1) physical methods at the time of curing to form a hard coat layer (2) a method of mixing inorganic and organic particles with an antiglare agent in a hard coat agent for forming a hard coat layer (JP-A-2003-347218 and 2003-408023).

However, the film produced by such a method has many restrictions on the raw materials, and in particular, it is difficult to adjust the anti-glare properties.

JP Patent No. 5,088,945 (filed by NIPPON KAYAKU CO LTD) discloses that the surface of the hard coat layer of the optical film is subjected to hydrophobic treatment to uniformize the cluster type of the particles, but it is limited to only the optical film , And inorganic particles that are not organic particles are used.

US Patent Application No. 2012-0114518 (filed by FUSO CHEMICAL CO LTD) is also similar to the above-mentioned technique in that the surface is subjected to hydrophobic treatment using an inorganic particle structure to uniformize the shape of the cluster.

However, the technique of adjusting the surface characteristics of the organic particles and adjusting the dispersion state in the hard coating layer to facilitate the adjustment of the dispersibility by changing the type of cluster between particles having the same diameter and refractive index is not mentioned in the prior art not.

The present invention provides an antiglare film having surface characteristics of organic particles which can control the dispersibility by controlling the dispersion state of the organic particles in the hard coat layer by changing the type of cluster between particles having the same diameter and refractive index The purpose.

According to a preferred embodiment of the present invention, there is provided an organic EL device comprising a transparent substrate, and an antiglare layer laminated on the transparent substrate and comprising a light-transmitting coating layer, wherein the light-transmitting coating layer comprises first and second organic particles, Wherein the diameter and the refractive index of the second organic particles are the same and the carbon content of the first and second organic particles is in the range of 82 to 88%.

The antiglare film having the surface characteristics of the organic particles according to the present invention can be easily controlled in the diffusing properties by controlling the type of aggregate between the particles having the same diameter and refractive index to control the dispersion state of the organic particles in the hard coating layer have.

1 is a schematic cross-sectional view of an antiglare film according to the present invention.
FIG. 2 is a schematic view showing a retardation agent included in an antiglare film according to an embodiment of the present invention. FIG.
3 is a cross-sectional view showing a principle showing an antiglare function of an antiglare film according to an embodiment of the present invention.
4 and 5 are scanning electron microscope (SEM) photographs showing the total particle size of the antiglare agent contained in the antiglare film according to one embodiment of the present invention.
6 to 9 are photographs evaluating the antifogging properties of the antiglare film according to Examples 1 to 4 of the present invention, respectively.

The term 'anti-glare film' in the present invention means a film which reflects the surface of the base film and blurs the outline of the external light, and thus, when an image display device such as a liquid crystal display, an organic EL display or a plasma display is used, It is a film that does not care about projection of reflection image.

The term "total solids " as used in the present invention means a coating composition formed by applying a composition including a hard coat agent, a defoaming agent and a solvent onto a transparent substrate, drying and curing the coating agent It means to be based on total solids.

Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the present invention will be described in detail with reference to the accompanying drawings.

(A) Antiglare film

1 is a schematic cross-sectional view of an antiglare film according to an embodiment of the present invention. Referring to FIG. 1, the antiglare film of the present invention has a structure formed by laminating an antiglare layer 20 on a transparent substrate 10.

The material of the transparent substrate 10 is not particularly limited as long as it has transparency, but a polymer material, that is, a plastic film is preferable in terms of processability.

Examples of the material of the transparent substrate 10 include cellulose materials such as acetylcellulose, diacetylcellulose, triacetylcellulose, propionylcellulose, acetylpropionylcellulose, nitrocellulose and the like, polyethylene terephthalate, polybutylene terephthalate Polyesters such as phthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate and cyclohexanedimethylene terephthalate And polyolefins such as polyethylene, polypropylene and polymethylpentane. In addition, polyolefins such as polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polystyrene, polycarbonate, polyamide, polyether sulfone, Polyether ketone, polysulfone, polyimide and the like. It is not limited. Of these, triacetylcellulose (TAC), polyethylene terephthalate (PET), or polycarbonate (PC) is excellent in transparency and is suitable as a transparent substrate of an optical film. Triacetyl cellulose (TAC) and polyethylene terephthalate (PET) can also be used for LCD polarizing films and optical filters for PDPs.

The antiglare layer 20 includes a light-transmitting coating layer 1 and a antiglare agent 30 contained in the light-transmitting coating layer 1. The antiglare agent 30 includes a first organic particle 2 and a second organic particle 2, And the organic particles 3 are superimposed.

FIG. 2 is a schematic view showing the antiglare agent included in the antiglare film according to one embodiment of the present invention. Referring to FIG. 2, the antiglare agent 30 used in the present invention shows that the first organic particles 2 and the second organic particles 3 are superimposed.

At this time, the antiglare agent 30 has the seeds of the first core and the second core bonded to the center, and the first and second cores are grown and polymerized to form the first organic particles and the second organic particles And a part of the first organic particles and the second organic particles overlap each other.

Wherein the first core is selected from the group consisting of styrene particles (refractive index 1.59), polyvinyl chloride particles (refractive index 1.60) and high refractive index acrylic particles (refractive index 1.59), the second core is selected from the group consisting of high- But are not limited to, methacrylate particles (refractive index: 1.51), acryl-styrene copolymer particles (refractive index: 1.55), melamine particles (refractive index: 1.57), and polycarbonate particles (refractive index: 1.57).

Generally, the principle of imparting a scattering property to a coating layer coated on a transparent substrate can be achieved by forming irregularities on the surface of the coating layer coated on the transparent substrate, or by using the internal scattering property generated in the light transmitting polymer particle having a different refractive index from the light- .

Particularly, in the case of the light transmitting polymer particles, two or more kinds of organic particles having different refractive indexes may be used to simultaneously utilize the external and internal anti-scattering properties. Among them, as the organic particles having a small refractive index, there are, for example, highly crosslinked acrylic particles (refractive index: 1.51), high-crosslinked methacrylic particles (refractive index: 1.51), acryl-styrene copolymer particles (refractive index: 1.55), melamine particles (refractive index: 1.57) And styrene particles (refractive index: 1.59), polyvinyl chloride particles (refractive index: 1.60), and high refractive index acrylic particles (refractive index: 1.59) may be used as the organic particles having a high refractive index.

However, in the present invention, the seeds of the first and second cores are combined and grown and polymerized into respective cores so that the first organic particles (2) And the second organic particles (3) are formed. In the final form, by using a dispersant having a shape in which a part of the organic particles are overlapped with each other, the inner antiglare function and the outer antiglare function can be simultaneously adjusted do.

At this time, the thickness of the antiglare layer 20 is preferably 2 to 20 μm, and more preferably 2 to 7 μm. If the thickness of the antiglare layer is too thin, the hardness is not sufficient. If the thickness of the antiglare layer is too thick, curling will easily occur in the film, Characteristics are lowered.

3 is a cross-sectional view showing the principle of the anti-glare function of the antiglare film according to one embodiment of the present invention. Referring to FIG. 3, the antiglare layer according to the present invention comprises a antiglare agent 30 and a light-transmitting coating layer 1 in which first organic particles 2 and second organic particles 3 are superimposed. When external light is applied, in the case of the second organic particles 3, scattering occurs on the surface of the organic particles exposed on the surface of the light-transmitting coating layer 1 to give an external antiglazing effect. In the case of the first organic particles 2, The transmitted light passes through the light-transmitting coating layer 1 and scattering due to the difference in refractive index at the interface with the second organic particles 3 can give an internal antiglare effect.

The first organic particles 2 and the second organic particles 3 have different refractive indexes and the difference in refractive index between the first organic particles 2 and the second organic particles 3 is 0.04 to 0.1. That is, the refractive index of the first organic particles 2 is preferably 1.57 to 1.62, and the refractive index of the second organic particles 3 is preferably 1.49 to 1.55. The use of the second organic particles 3 having a relatively small refractive index contributes to the improvement of the external antiglare properties and the transmittance and the use of the first organic particles 2 having a relatively high refractive index contributes to the improvement of the internal antiglare property and the transmittance do.

On the other hand, the sizes of the first organic particles 2 and the second organic particles 3 can be adjusted according to the internal antiglare and external antiglare properties.

4 and 5 are scanning electron microscope (SEM) photographs showing the total particle size of the antiglare agent contained in the antiglare film according to an embodiment of the present invention.

Here, the term "total particle diameter" of the antiglare agent means a distance between two points where an extension line connecting the centers of the first organic particles and the second organic particles meets each particle.

4, the sum of the diameters of the respective organic particles (2.02 + 3.13 = 5.15 μm) is smaller than the total particle size of the antiglare agent (5.04 μm), whereby the first antiglare agent and the second organic particle It can be confirmed that it is an overlapped form.

The total particle diameter of the antiglare agent in the form of overlapping the first organic particles and the second organic particles is preferably 3 to 7 占 퐉.

The size of the total particle size of the antiglare agent may be related to the thickness of the final antiglare film. When the particle size is less than 3 μm, the thickness of the antiglare layer is consequently lowered to control the outer antiglare property of the first organic particles, If it is too thin, hardness is not enough. Also, if it is larger than 7 탆, the thickness becomes too thick, curling easily occurs in the film, and the external antiglare property is lowered.

In this case, the size of each organic particle constituting the antiglare agent may be adjusted according to the required haze. The refractive index of the antiglare agent included in the antiglare film according to one embodiment of the present invention And the same first organic particles and second organic particles have the same diameter. In some cases, according to another embodiment of the present invention, when the diameter of the second organic particles having a small refractive index is smaller than the diameter of the first organic particles having a large refractive index among the two organic particles having different refractive indexes constituting the antiglare agent , The diameter of the second organic particles having a small refractive index is larger than the diameter of the first organic particles having a large refractive index.

At this time, the light-transmitting coating layer (1) forming the antiglare layer (20) controls the difference in refractive index with the antiglare agent (30) to determine the degree of haze of the antiglare film.

The carbon content of the first organic particles and the second organic particles is preferably 82 to 88%. When the carbon content of the first organic particles and the second organic particles is in the above range, the organic particles may form a uniform cluster to realize the anti-scattering property.

If the carbon content of the organic particles is less than 82%, the dispersibility of the organic particles is increased, and the surface roughness value is lowered, and the dispersibility is lost. When the carbon content exceeds 88% There is a problem that the roughness increases and the film becomes rough.

(B) Method for producing antiglare film

A method for producing an antiglare film according to an embodiment of the present invention includes:

(a) mixing the hard coat agent, the first organic particles and the second organic particles in a superposed state, and a solvent to prepare a mixed solution;

(b) coating the mixed liquid on a transparent substrate to form an antiglare layer such that the antiglare agent is contained in the light-transmitting coating layer and the light-transmitting coating layer; And

(c) drying and curing the antiglare layer.

At this time, the hard coat agent of step (a) forms a light-transmitting coating layer. The hard coat agent may include a heat and radiation curable resin, a photopolymerization initiator, an inorganic fine particle, a leveling agent, an antiglare layer surface modifier, and a silane coupling agent.

The thermally and radiation-curable resin is preferably a compound having two or more functional groups. Examples of such compounds include oligomers, monomers and polymers having cationic polymerizable functional groups such as polymerizable unsaturated bonds or epoxy groups such as methacryloyl groups, methacryloyloxy groups and the like. These compounds may be used alone or in combination of two or more Can be used as a composition. Such a composition should be in a liquid state when not cured, and preferably contains an ethylenic group and an acrylic group in the molecule so that crosslinking can be achieved at the time of curing.

Examples of the monomer include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydroperfryl acrylate, glycidyl methacrylate, acryloylmorpholine, 2-cyanomethacrylyl N, N-dimethylacrylamide, N-vinylpyrrolidone, N-vinyl-caprolactam, phenoxy diethylene glycol methacrylate, pentaerythritol tetramethacrylate, dipentaerythritol trimethacrylate, tri But are not limited to, methylol propane trimethacrylate, trimethylol ethane trimethacrylate, dipentaerythritol tetramethacrylate, erythritol dimethacrylate, pentaerythritol trimethacrylate, 1,2,3-cyclohexane Tetramethacrylate and the like.

Examples of the oligomer include polyester methacrylate obtained by the reaction of polyester polyol and methacrylic acid, bisphenol epoxy resin, methacrylate or organic polyisocyanate, hydroxy methacrylate or polyol, organic polyisocyanate And urethane methacrylate obtained by reaction with a hydroxy methacrylate compound.

The compound having an ethylenically unsaturated group capable of forming a crosslinked product at the time of curing preferably contains an isocyanate group, an epoxy group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group or an active methylene group as the functional group.

In the present invention, the crosslinking group is not limited to the above-mentioned compounds but may be one which shows reactivity as a result of decomposition of the functional group. These compounds having a crosslinking group can cause a crosslinking reaction by applying heat after application.

The photopolymerization initiator included in the hard coat agent of the present invention serves to cure the composition using ultraviolet rays. Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluoroketone, 4,4'-dimethoxybenzophenone, (4-isopropylphenyl) -2-hydroxypropyl-2-methylpropan-1-one, 2-hydroxynaphthoquinone, benzoin ethyl ether, benzyl dimethyl ketal, 1- 2-methyl-1-phenylpropan-1-one, thioxanthone, diethyltioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6- dimethoxybenzoyl) -2,4,4-trimethyl Pentylphosphine oxide, pentylphosphine oxide, and pentylphosphine oxide.

The addition amount of the photopolymerization initiator is preferably in the range of 0.5 to 10 wt%, more preferably 0.5 to 5 wt%. If the addition amount is less than 0.5% by weight, hardness is not sufficient when the curable composition is cured. If the addition amount exceeds 10% by weight, the photopolymerization initiator itself may react with radicals to inhibit polymerization.

The inorganic fine particles contained in the hard coat agent of the present invention serve to adjust the refractive index of the antiglare layer and increase the hardening strength of the film. The inorganic fine particles preferably have an average particle size of 0.5 탆 or less, more preferably 15 nm or less.

As the inorganic fine particles, silicon dioxide, titanium dioxide, aluminum oxide, tin oxide, calcium carbonate, barium sulfate, talc, kaolin and calcium calcium particles may be used. The amount of the inorganic fine particles to be added to the hard coating liquid is preferably 10 to 90% by weight, more preferably 30 to 60% by weight.

At this time, the hard coat agent may contain a fluorine-based or silicone-based hard coat agent to ensure uneven flow, uneven drying, coating streak, point defect, Any leveling agent or any of them may be added and may include a surface modifier and a silane coupling agent for the purpose of improving the dispersibility and bonding strength of the heat and the radiation curable resin to the organic particles

Meanwhile, the solvent of step (a) may be a mixture of a basic solvent and a secondary solvent, and may be different depending on the substrate to be coated.

The secondary solvent is used only when the substrate is TAC, and a solvent having solubility and swelling property is used. Specific examples of soluble and swellable solvents include methyl ethyl ketone, cyclohexanone, acetone, diacetone alcohol, polyhydric alcohol and ethers such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, ester Methylene chloride, tetrachloroethane, nitrogen-containing compounds such as nitromethane, acetonitrile, N-methylpyrrolidone, N, N-dimethylformamide, and the like, as methylene chloride, ethyl acetate, and halogenated hydrocarbons, Dimethyl sulfoxide are preferable, and they may be mixed and used. The basic solvent may be any solvent other than the above-mentioned secondary solvent, but is not limited thereto.

The content of the solvent is preferably about 20 to 100 parts by weight, more preferably 50 to 100 parts by weight, of the curable resin. When the amount of the solvent is less than 10 parts by weight of the curable resin, it is difficult to uniformly coat the resin due to high viscosity. When the amount of the solvent exceeds 100 parts by weight, pinholes are formed after coating and drying.

The method of coating on the base film in the step (b) may be a roll coating method, a die coating method, a gravure coating method, a microgravure coating method, a wire bar coating method, a knife coating method, a slot die coating method, All coating methods can be used.

The drying step in step (c) is performed at 40 to 100 ° C, and the solvent in the composition is dried and removed, and then the coating layer is cured by ultraviolet rays irradiated in an ultraviolet curing machine to form an antiglare layer. The ultraviolet rays are irradiated using an ultraviolet lamp such as a high pressure mercury lamp, a metal halide lamp, a xenon lamp or a microwave type electrodeless lamp. The typical wavelength range required for curing the coating layer is 200 to 400 nm, To 1000 mJ / m < ^{2 &} gt ;.

(C) Display device

According to an embodiment of the present invention, there is provided a display device comprising an antiglare film according to the present invention. At this time, the display device may be a cathode ray tube (CRT), a plasma display (PDP), an electroluminescence display (ELD) or a liquid crystal display (LCD) Is disposed on the outermost surface of the display to reduce reflectance using the principle of optical interference to prevent deterioration, degradation, and deterioration of visibility.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Example 1

≪ Step 1 > Preparation of a flame-retardant coating composition

11.7 parts by weight Urethane acrylate (Chemtun, CHTU-5101), 20.7 parts by weight Urethane acrylate (MI2100, SC2153), 8.6 parts by weight pentaerythritol triacrylate (MI340), 25.6 parts by weight ethyl acetate (BY Chemie, BYK-358N), 0.4 parts by weight Crosslinking agent (SC organic chemistry, TEMPIC), 18.5 parts by weight of n-butyl acetate, 12.1 parts by weight of methyl isobutyl ketone (Refractive index: 1.52, average particle diameter: 2 탆, carbon content: 82%) 0.8 parts by weight of a photoinitiator (trade name: CP-4) and 1.5 parts by weight of a photoinitiator were prepared.

≪ Step 2 > Manufacture of flame retardant film

One on one side of the triacetyl cellulose film having a thickness of 80um coating the room overt coating composition prepared in step 1 to 6um thickness after following one minutes drying at 80 ℃ oven, by radiation-curing of 300mJ / cm ² intensity room overt film .

Examples 2 to 4

Except that organic particles (refractive index: 1.52, average particle size: 2 μm) having carbon contents of 84%, 86% and 88% were used instead of organic particles having a carbon content of 82% (refractive index: 1.52, average particle size: 2um) The same procedure was used to produce a flame retardant film.

Evaluation example 1

The properties of the water-repellent films prepared in Examples 1 to 4 were measured as follows. The results are shown in Table 1 below.

1) Surface roughness (um)

The prepared anti-glare film was bonded to a glass plate, and Ra, Rz and Sm values were measured with a surface roughness meter (Kosaka Laboratory Ltd., ET4000A).

2) Flammability

The fabricated diaphragm film was contacted with a black acrylic plate using OCA so that the coated side was facing the surface, and then the fluorescent lamp was reflected, and the outline of the fluorescent lamp was checked to evaluate the flicker resistance. Evaluation photographs are shown in Figs.

◎: Fluorescent outline can not be found

○: Fluorescent outline is not clear

X: Reflected clearly enough to accurately draw the outline of a fluorescent lamp

Carbon content (%) Ra (um) Rz (um) Sm (um) Cloudiness Example 1 82 0.0061 0.17160 21.8 ◎ Example 2 84 0.01536 0.21574 20.6 x Example 3 86 0.02246 0.52188 17.6 ○ Example 4 88 0.02708 0.74668 17.7 ◎

As shown in Table 1, the anti-reflection properties of the anti-reflection film can be controlled by adjusting the surface characteristics of particles having the same average particle diameter and refractive index.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present invention as defined by the appended claims and their equivalents. .

1: light-transmitting layer coating layer 2: first organic particle
3: Second organic particle 10: Transparent substrate
20: Visible layer 30:

Claims (1)

Transparent substrate; And
An antiglare layer laminated on the transparent substrate and including a light-transmitting coating layer,
Wherein the translucent coating layer comprises first and second organic particles, the diameter of the first and second organic particles is the same as the refractive index, and the carbon content of the first and second organic particles is 82 to 88% Antiglare film with surface characteristics of organic particles characterized.

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