JP2012068415A - Hardcoat coating liquid and antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardcoat coating liquid capable of forming an antireflection film which includes a superior hardcoat layer and antireflection layer, suppresses an occurrence of interference fringe, has a superior smoothness, eliminates an occurrence of moire, and has a superior antistatic property, transparency, and adhesion.SOLUTION: This hardcoat coating liquid includes: ionizing radiation curable resin that contains polyfunctional monomers having two or more (meth)acryloyl groups in one molecule; and one type or more solvents 1 for dissolving or swelling a transparent substrate 11, a solvent 2 stably dispersing a conductive material, and one type or more solvents 3 having a high boiling point that are included in a conductive material containing at least one type or more metal oxide particles of ATO, ITO, SbO, TiO, ZnO, and CeO.

Description

  The present invention comprises a hard coat coating solution for forming a hard coat layer, and an excellent hard coat layer and an antireflection layer, suppresses the generation of interference fringes, does not cause moiré, has antistatic properties, transparency, The present invention relates to an antireflection film having excellent adhesion.

  A general display such as an LCD or a plasma display panel is used in an environment where external light or the like enters regardless of whether the display is used indoors or outdoors. Incident light such as external light is specularly reflected on the display surface and the like, and the reflected image thereby mixes with the display image, thereby degrading the screen display quality. For this reason, it is essential to provide an antireflection function on the display surface or the like, and there is a demand for higher performance of the antireflection function and a combination of functions other than the antireflection function.

  In general, the antireflection function is obtained by forming an antireflection layer having a multilayer structure having a repeating structure of a high refractive index layer and a low refractive index layer made of a transparent material such as a metal oxide on a transparent substrate. These antireflection layers having a multilayer structure can be formed by a dry film formation method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method (see Patent Document 1). In the case of forming an antireflection layer using a dry film formation method, there is an advantage that the film thickness of the low refractive index layer and the high refractive index layer can be precisely controlled, but the film formation is performed in a vacuum. There is a problem that productivity is low and it is not suitable for mass production. On the other hand, as a method for forming an antireflection layer, production of an antireflection film by a wet film forming method using a coating liquid capable of increasing the area, continuously producing, and reducing the cost is attracting attention (Patent Documents 2 and 5). reference).

  In addition, when these antireflection layers are provided on a film transparent substrate, the surface thereof is relatively flexible, so in order to impart surface hardness, a polymer of an acrylic polyfunctional compound is generally used. A method of providing a hard coat layer and forming an antireflection layer thereon is used (see Patent Documents 3, 4, 6, and 7).

JP 2003-39586 A JP 2003-205563 A JP 2006-35493 A JP 2001-233611 A JP 7-133105 A JP 2002-79616 A JP 2006-106714 A

This hard coat layer has high surface hardness, gloss, transparency, and scratch resistance due to the characteristics of acrylic resin, but it is easily charged due to its high insulation properties, and dust on the product surface provided with the hard coat layer. There are problems such as contamination due to adhesion and troubles caused by charging in the display manufacturing process.
In order to improve these problems, various conductive materials have been added. However, the addition of the conductive material causes a difference in refractive index between the base material and the hard coat, resulting in interference fringes. It will be easier.

Several inventions have been made so far. First, in order to reduce the difference in refractive index between the base material and the hard coat layer, in the method of providing an intermediate layer between the base material and the hard coat layer, interference fringes are generated. It only reduces, not completely disappears.
Furthermore, an optical film characterized by forming a hard coat layer by applying a hard coat layer to the substrate using a resin containing a solvent that dissolves or swells the substrate has also been proposed. Solvents to be dissolved or swollen are mainly those that inhibit the dispersion of conductive materials (particularly metal oxide fine particles), and it is difficult to produce a conductive hard coat layer without interference fringes.

As means for solving these problems, a hard coat film characterized by combining a solvent that dissolves or swells a base material and a solvent in which a conductive material is stably dispersed has been proposed.
However, this invention mainly describes the hard coat layer, and the description as an antireflection film is not sufficient.

  As described above, in order to develop the function as an antireflection film, it is necessary to laminate an antireflection layer on the hard coat layer. As a coating method for forming the hard coat layer, There is a wet coating method that is advantageous in reducing the area and cost. However, since it is not easy to keep the solvent drying immediately after coating, it is difficult to maintain coating drying streaks due to poor leveling after coating, drying unevenness due to differences in solvent drying speed, and wind unevenness caused by drying air. Planar unevenness such as unevenness, apparatus-related, vibration unevenness due to substrate conveyance, etc. is likely to occur. Further, when the unevenness due to these unevenness has periodicity, when it is made into a panel, it interferes with the pixel pitch of the display, resulting in a problem that moire occurs.

In order to improve these unevennesses, it is effective to increase the leveling property of the coating liquid. As one of effective means for that purpose, a method of adding a leveling agent can be mentioned.
However, in the case of the wet coating method, uneven surface properties are likely to occur during coating and the drying process, so in order to completely eliminate the periodicity of the coating film and suppress the occurrence of moire, it is only necessary to add a leveling agent. Often insufficient.

Therefore, as a means for expressing more excellent surface smoothness, there is a method of reducing unevenness due to solvent drying and improving leveling by using a high boiling point solvent in the coating solution.
In this way, by adjusting the content ratio of the solvent that dissolves or swells the base material and the high boiling point solvent in the coating liquid, the base material permeability and rheology of the coating liquid are controlled, and the hard coat layer surface is dried. Alternatively, it is possible to prevent the occurrence of interference fringes while suppressing the occurrence of streaks and unevenness due to vibration, and to achieve both adhesion with the antireflection layer.
The present invention pays attention to the above points, and has an excellent hard coat layer and antireflection layer, suppresses the generation of interference fringes, is excellent in smoothness, has no moire, and has antistatic properties and transparency. An object of the present invention is to provide a hard coat coating solution capable of forming an antireflection film having excellent adhesion.

In order to solve the above problems, the invention described in claim 1 of the present invention is a hard coat coating solution for forming a hard coat layer by coating on the surface of a transparent substrate,
An ionizing radiation curable resin containing a polyfunctional monomer having two or more (meth) acryloyl groups in one molecule, ATO, ITO, Sb ₂ O ₅ , TiO ₂ , ZnO ₂ , Ce ₂ O One or more solvents 1 that dissolve or swell the transparent substrate in a conductive material containing at least one of the _three metal oxide particles, a solvent 2 in which the conductive material is stably dispersed, More than one kind of high boiling point solvent 3 is contained.

  Next, in the invention described in claim 2, the ionizing radiation curable resin is composed of at least one of a urethane (meth) acrylate monomer and an oligomer, and the ionizing radiation curable resin is 90 parts by weight or more based on the solid content. The conductive material is contained within a range of 10 parts by weight or less and 1 part by weight or more with respect to the solid content with respect to a range of 99 parts by weight or less.

Next, in the invention described in claim 3, the solvent 1 contains at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, and cyclohexanone,
The solvent 2 contains at least one of methanol, ethanol, isopropyl alcohol, 1-pentanol, ethylene glycol, methyl cellosolve, cellosolve,
The solvent 3 contains at least one of cyclohexanone, acetylacetone, diacetone alcohol, diisobutylketone, butylcellosolve,
The solvent 1 is in the range of 60 to 80 parts by weight, the solvent 2 is in the range of 25 to 15 parts by weight, and the solvent 3 is in the range of 15 to 5 parts by weight. It is characterized by being within.

Next, the invention described in claim 4 is an antireflection film in which a hard coat layer and a low refractive index layer are laminated in this order on at least one side of a transparent substrate,
The hard coat layer is formed by applying the hard coat coating liquid according to any one of claims 1 to 3.
Next, the invention described in claim 5 is that the solid content concentration of the binder matrix forming material of the hard coat layer is 45% or more and 52% or less, and the center line of the film surface in the state where the antireflection layer is laminated. The average roughness Ra (JIS B0601) is 0.01 μm or more and 0.002 μm or less.

Next, in the invention described in claim 6, the low refractive index layer includes at least one (meth) acryloyl group in the molecule, a polyfunctional monomer containing in the molecule, a low refractive index fine particle, And the refractive index of the low refractive index layer is adjusted within the range of 1.3 or more and 1.5 or less.
Next, the invention described in claim 7 is characterized in that the transparent substrate is a cellulosic film.

The conventional hard coat coating liquid imparts coating film smoothness with a leveling agent. However, it is often not enough to suppress the periodicity of surface irregularities due to coating unevenness and drying unevenness caused by the wet coating method, and to prevent the occurrence of moire. In some cases, adhesion to the low reflective layer May decrease.
On the other hand, the hard coat coating liquid according to the present invention uses a high-boiling solvent as a means for improving the coating film smoothness, thereby improving the coating film smoothness and the excellent anti-reflection film with low adhesion. Can provide.
In addition, by using a high-boiling solvent, it is possible to control the evaporation rate of the coating liquid during film coating or in the drying process, so the influence of vibration and drying unevenness on the substrate during coating can be reduced. Smoothness can be improved.

It is a cross-sectional schematic diagram of the antireflection film which concerns on embodiment based on this invention.

Embodiments of the present invention will be described below with reference to the drawings.
(Antireflection film)
First, the antireflection film of this embodiment will be described.
As shown in FIG. 1, the antireflection film 10 of the present embodiment is a laminate in which a hard coat layer 12 and a low refractive index layer 13 are sequentially laminated on at least one surface of a transparent substrate 11. The hard coat layer 12 is mainly composed of an ionizing radiation curable resin mainly composed of a polyfunctional monomer containing 2 or more (meth) acryloyl groups in one molecule and a conductive material. The hard coat layer 12 includes a hard coat coating solution containing one or more kinds of solvents 1 for dissolving or swelling the transparent base material 11, a solvent 2 in which the conductive material is stably dispersed, and one or more kinds of high boiling point solvents 3. It is formed using. FIG. 1 shows an example in which the hard coat layer 12 and the low refractive index layer 13 are laminated only on the upper surface (surface) of the transparent substrate 11.

The low refractive index layer 13 is excellent by being a resin for forming the low refractive index layer 13 mainly composed of a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule. In addition, the anti-reflection film 10 having the hard coat layer 12 and the low refractive index layer 13 can be provided, the generation of interference fringes can be suppressed, and the antistatic property, transparency and adhesion can be improved.
In addition, as the transparent substrate 11, a cellulose film such as a triacetyl cellulose film is used. Less birefringence, excellent optical properties such as transparency, refractive index, dispersion, and other physical properties such as impact resistance, heat resistance, durability, and because it easily dissolves or swells with solvents, In this invention, it is more preferable than another film.

Various stabilizers, ultraviolet absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, and the like may be added to the transparent substrate 11. The thickness of the transparent substrate 11 is not particularly limited, but is preferably 20 μm or more and 200 μm or less. Furthermore, when it is a triacetylcellulose film, 38 micrometers or more and 80 micrometers or less are preferable.
The ionizing radiation curable resin includes an ultraviolet curable resin and an electron beam curable resin, and is a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule. Is the main component.

  Polyfunctional monomers include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol Di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, diethylene glycol bis β- (meth) acryloyloxypropionate, trimethylolethane Tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2-H Roxyethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,3-bis (meth) acryloyloxyethyloxymethyl [2.2.1] heptane, poly 1,2-butadiene di (meth) acrylate 1,2-bis (meth) acryloyloxymethylhexane, nonaethylene glycol di (meth) acrylate, tetradecane ethylene glycol di (meth) acrylate, 10-decanediol (meth) acrylate, 3,8-bis (meth) acryloyl Oxymethyltricyclo [5.2.10] decane, hydrogenated bisphenol A di (meth) acrylate, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 1,4-bis ((meta ) Acryloyloxymethyl E) Cyclohexane, hydroxypivalin sun ester neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, epoxy-modified bisphenol A di (meth) acrylate, and the like. A polyfunctional monomer may be used independently and may use 2 or more types together. Further, if necessary, it can be copolymerized in combination with a monofunctional monomer.

In addition, urethane acrylate is also exemplified as a preferred polyfunctional monomer in the present invention, and it is generally formed easily by reacting an acrylate monomer having a hydroxyl group with a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer. Can be mentioned.
Specific examples include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate urethane prepolymer. Pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer, and the like can be used. Moreover, these monomers can be used 1 type or in mixture of 2 or more types. Further, these may be monomers in the coating liquid, or may be oligomers that are partially polymerized.

Examples of the photopolymerization initiator include 2,2-ethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, p-chlorobenzophenone, p-methoxybenzophenone, Michler ketone, acetophenone, 2 -Chlorothioxanthone and the like. You may use these individually or in combination of 2 or more types.
Examples of the photosensitizer include tertiary amines such as triethylamine, triethanolamine and 2-dimethylaminoethanol, alkylphosphine such as triphenylphosphine, and thioethers such as β-thiodiglycol. These may be used alone or in combination of two or more.

Furthermore, for performance improvement, an anti-foaming agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a polymerization inhibitor and the like can also be contained.
Examples of the conductive material include metal oxide fine particles such as ATO (antimony oxide / tin oxide), ITO (indium oxide / tin oxide), Sb ₂ O ₅ , TiO ₂ , ZnO ₂ , and Ce ₂ O ₃ . Among them, it is desirable to use ATO fine particles having excellent conductivity.
The hard coat layer 12 has a configuration in which the ionizing radiation curable resin is in the range of 90 to 99 parts by weight with respect to the solid content, and the conductive material is 10 parts by weight or less and 1 weight with respect to the solid content. A range of parts or more is preferred.

When the amount of the conductive material in the hard coat layer 12 is less than 1 part by weight, sufficient conductivity is not exhibited. On the other hand, when the amount exceeds 10 parts by weight, coloring by the metal oxide fine particles and optical scattering occur, resulting in an optical lamination. Sufficient function as a body is not expressed.
The hard coat layer 12 is formed by a wet coating method, such as a dip coating method, a spin coating method, a flow coating method, a spray coating method, a roll coating method, a gravure roll coating method, an air doctor coating method, a blade coating method. , Wire doctor coating method, knife coating method, reverse coating method, transfer roll coating method, micro gravure coating method, kiss coating method, cast coating method, slot orifice coating method, calendar coating method, die coating method, etc. It can be formed by applying to at least one side of the material 11. The microgravure coating method is preferably used because it is particularly necessary to form a thin and uniform layer.

In addition, when it becomes necessary to form a thick layer, a die coating method can be used. Both application methods require a high shear rate during coating.
As a curing method for forming the hard coat layer 12, for example, ultraviolet irradiation, heating, or the like can be used. In the case of ultraviolet irradiation, a high-pressure mercury lamp, a halogen lamp, a xenon lamp, or the like can be used. The amount of ultraviolet irradiation is usually 100 mJ / cm ² or more and 800 mJ / cm ² or less.

  Moreover, the film thickness of the hard coat layer 12 is sufficient if it is 3 μm or more, but it is preferably in the range of 5 μm or more and 10 μm or less from the viewpoint of coating accuracy and handling. This is because if it exceeds 10 μm, warping, distortion, and bending of the substrate due to curing shrinkage will occur. Furthermore, it is very preferable for the hard coat layer 12 to have a film thickness in the range of 5 μm to 7 μm.

  Solvent 1 constituting the hard coat coating solution is a solvent that dissolves or swells the surface of the cellulose-based film. Dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane Ethers such as 1,3,5-trioxane, tetrahydrofuran, anisole and phenetole, and ketones such as acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, methylcyclohexanone and methylcyclohexanone, Examples include esters such as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, propion brewed ethyl, n-pentyl acetate, and γ-ptyrolactone. It is. You may use these individually or in combination of 2 or more types. Of these, methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, and cyclohexanone can be suitably used as the solvent 1.

  The solvent 2 constituting the hard coat coating liquid is intended to maintain a stable coating liquid state without causing aggregation or the like of the metal oxide fine particles. Methanol, ethanol, isopropyl alcohol, 1-butanol, 2-butanol Alcohols such as isobutyl alcohol; glycols such as methylene glycol, ethylene glycol and propylene glycol; and cellosolves such as methyl cellosolve, cellosolve and cellosolve acetate. You may use these individually or in combination of 2 or more types. Among these, methanol, ethanol, isopropyl alcohol, 1-pentanol, ethylene glycol, methyl cellosolve, and cellosolve can be suitably used as the solvent 2.

  The solvent 3 constituting the hard coat coating liquid is intended to suppress the drying speed of the coating liquid in the coating process, suppress coating unevenness and drying unevenness, and improve surface smoothness. A solvent having a high boiling point and a low evaporation rate such as acetone alcohol, diisobutyl ketone, butyl cellosolve, xylol and methoxybutyl acetate is suitable. You may use these individually or in combination of 2 or more types. Among these, cyclohexanone, acetylacetone, diacetone alcohol, diisobutyl ketone, and butyl cellosolve can be suitably used as the solvent 3.

The solvent 1, the solvent 2 and the solvent 3 are within the range of 60 to 80 parts by weight of the solvent 1, 15 to 15 parts by weight of the solvent 2 and 15 to 5 parts by weight of the solvent 3. Yes, it is preferable to prepare the solution so as to be 100 parts by weight when the solvent 1, the solvent 2 and the solvent 3 are combined.
If the solvent 1 is less than 60 parts by weight, it is not sufficient to dissolve and swell the cellulose-based film surface, and interference fringes are generated and adhesion of the hard coat layer 12 is reduced. On the other hand, when the solvent 1 exceeds 80 parts by weight, the conductive material becomes unstable in the coating liquid, and problems such as aggregation of fine particles occur.

(Low refractive index layer 13)
The antireflection film 10 of the present invention has a low refractive index layer 13 and is formed on the hard coat layer 12. Thereby, the optical characteristics such as the antireflection function in the antireflection film 10 can be improved.
The low refractive index layer 13 preferably has a lower refractive index than the hard coat layer 12. As a preferable form of the present invention, the refractive index of the hard coat layer 12 is 1.5 or more, the refractive index of the low refractive index layer 13 is less than 1.5, more preferably 1.45 or less, still more preferably. 1.35 or less. If the refractive index is 1.5 or more, the difference in refractive index between the low refractive index layer 13 and the hard coat layer 12 is small, and the reflection becomes high. Therefore, it is desirable that the refractive index is low.

For example, the following method is used to form the low refractive index layer 13. That is, as a resin for forming the low refractive index layer 13, a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule, hollow silica fine particles, and an additive (polymerization initiator) as necessary , An antistatic agent, an antiglare agent, etc.) dissolved or dispersed in a solvent is used as a composition for forming the low refractive index layer 13 to form a coating film with the above composition, and ultraviolet irradiation or heating The low refractive index layer 13 is obtained by curing by, for example. In addition, well-known things can be used for additives, such as a polymerization initiator, an antistatic agent, and an anti-glare agent.
The polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule of the resin for forming the low refractive index layer 13 is an ionizing radiation curable resin used when forming the hard coat layer 12. The described resins and the like can be used.

  The low refractive index layer 13 is usually applied after being diluted in a volatile solvent. In consideration of stability of the composition, wettability to the hard coat layer 12, volatility, etc., alcohols such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, acetone, methyl ethyl ketone , Ketones such as methyl isobutyl, esters such as methyl acetate, ethyl acetate and butyl acetate, ethers such as diisopropyl ether, glycols such as ethylene glycol, propylene glycol and hexylene glycol, ethyl cellosolve, butyl cellosolve, ethyl carbitol , Glycol ethers such as butyl carbitol, aliphatic hydrocarbons such as hexane, heptane, and octane, halogenated hydrocarbons, aromatic hydrocarbons such as benzene, toluene, xylene, N-methylpyrrolidone, Methylformamide, and the like. You may use these individually or in combination of 2 or more types. Of these, methyl isobutyl ketone, methyl ethyl ketone, isopropyl alcohol (IPA), n-butanol, s-butanol, t-butanol, PGME, and PGMEA are preferable. Moreover, the preparation method of a composition should just be able to mix a component uniformly, should just implement according to a well-known method, and can carry out mixing and dispersion | distribution using a well-known apparatus.

The low refractive index layer 13 is applied on the hard coat layer 12 that has been surface-treated by the wet coating method described above, and the solvent in the coating film is volatilized by heating and drying, and then heating, ultraviolet irradiation, and electron beam irradiation are performed. Etc. to cure the coating film. The low refractive index layer 13 is preferably formed using a microgravure method in the same manner as the hard coat layer 12 is formed.
The film thickness (nm) dA when forming the low refractive index layer 13 preferably satisfies the following formula (1).
dA = mλ / (4 nA) (1)
Here, in formula (1), nA represents the refractive index of the low refractive index layer 13, m represents a positive odd number, preferably 1 and λ is a wavelength, preferably in the range of 480 to 580 nm. Value.

Hereinafter, specific examples of the present invention will be described in detail, but the present invention is not limited to the examples.
Example 1
Based on the said embodiment, as shown in FIG. 1, as the 1st transparent base material 11, the 80-micrometer-thick triacetyl cellulose film was prepared.
On the first transparent substrate 11, a coating liquid obtained by stirring and mixing the hard coat layer formulation is applied and dried by the bar coating method so that the film thickness after drying is about 6 μm, and 600 mJ / cm ² by a high-pressure mercury lamp. Were irradiated with ultraviolet rays to form a hard coat layer.

The hard coat layer was formulated according to the following formulation.
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (Irgacure 184 Ciba Japan) 5.0 parts by weight / solvent 1: 70 parts by weight of acetone / solvent 2: 20 parts by weight of ethanol / solvent 3: 10 parts by weight of acetylacetone A coating solution in which a low refractive index layer is formulated on the hard coat layer. Is applied for 60 seconds in a heat oven at a temperature of 50 ° C., the solvent in the coating film is evaporated, and the coating film is cured by irradiating ultraviolet rays so that the integrated light quantity becomes 300 mJ. An antireflection film was prepared by forming a low refractive index layer (at the time of ² g / cm ² drying).

In the low refractive index layer prescription, the following prescription was performed.
<Low refractive index layer prescription>
-Hollow silica fine particles (The solid content of the silica fine particles is a 20 wt% solution; methyl isobutyl ketone, particle diameter 50 nanometers) 70 parts by weight-Pentaerythritol triacrylate (PETA) 30 parts by weight-Photopolymerization initiator (Irgacure 127 Ciba Japan Co., Ltd.) 3.0 parts by weight, 50 parts by weight of methyl isobutyl ketone, 50 parts by weight of propylene glycol monomethyl ether (PGME)

(Example 2)
Similarly to the above (Example 1), a hard coat layer was formed in the following hard coat layer formulation.
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (Irgacure 184 Ciba Japan) 5.0 parts by weight / solvent 1: 65 parts by weight of acetone / solvent 2: 20 parts by weight of ethanol / solvent 3; 15 parts by weight of diacetone alcohol In other formation methods and formation of the low refractive index layer, An optical laminate was produced in the same manner as in Example 1).

(Example 3)
Similarly to the above (Example 1), a hard coat layer was formed in the following hard coat layer formulation.
<Hard coat layer prescription>
-Urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.) 95 parts by weight-Conductive metal oxide (antimony pentoxide, refractive index n = 1.60) 5 parts by weight-Photopolymerization initiator (Irgacure 184 Ciba Japan 3.5 parts by weight / solvent 1: 70 parts by weight of acetone / solvent 2: 20 parts by weight of ethanol / solvent 3: 10 parts by weight of acetylacetone In other formation methods and formation of the low refractive index layer, Examples An optical laminate was produced in the same manner as 1).

Example 4
Similarly to the above (Example 1), a hard coat layer was formed in the following hard coat layer formulation.
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UA306H manufactured by Kyoeisha Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (manufactured by Irgacure 184 Ciba Japan) 3.5 parts by weight / solvent 1: ethyl acetate 70 parts by weight / solvent 2: isobutyl alcohol 20 parts by weight / solvent 3: acetylacetone 10 parts by weight In other formation methods and formation of the low refractive index layer, Example 1 ) To produce an optical laminate.
As comparative examples for comparison with the performance according to the solvent composition of the present invention, (Comparative Example 1), (Comparative Example 2) and (Comparative Example 3) were prepared to compare other performances (Comparative Example 4).

(Comparative Example 1)
Similarly to the above (Example 1), a hard coat layer was formed in the following hard coat layer formulation.
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (Irgacure 184 Ciba Japan) 5.0 parts by weight / solvent 1: 50 parts by weight of acetone / solvent 2: 35 parts by weight of ethanol / solvent 3: 15 parts by weight of acetylacetone In other formation methods and formation of the low refractive index layer, Examples An optical laminate was produced in the same manner as 1).

(Comparative Example 2)
Similarly to the above (Example 1), a hard coat layer was formed in the following hard coat layer formulation. At this time, the drying air was not directly applied to the coated surface, and the wind unevenness was not generated.
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (Irgacure 184 Ciba Japan) 5.0 parts by weight / solvent 1: 85 parts by weight of acetone / solvent 2: 10 parts by weight of ethanol / solvent 3: 5 parts by weight of acetylacetone In other formation methods and formation of the low refractive index layer, Examples An optical laminate was produced in the same manner as 1).

(Comparative Example 3)
<Hard coat layer prescription>
-90 parts by weight of urethane acrylate (UV-1700B, Nippon Synthetic Chemical Co., Ltd.)-10 parts by weight of conductive metal oxide (antimony pentoxide, refractive index n = 1.60)-Photopolymerization initiator (Irgacure 184 Ciba Japan) 5.0 parts by weight, solvent 1: 70 parts by weight of acetone, solvent 2: 30 parts by weight of ethanol, solvent 3: 0 part by weight of acetylacetone. An optical laminate was produced in the same manner as 1).

The performance of each of the antireflection films of (Example 1), (Example 2), (Example 3), (Comparative Example 1), (Comparative Example 2) and (Comparative Example 3) is according to the following method. evaluated. The evaluation results are shown in Table 1.
"Surface roughness (centerline average roughness Ra)
About the obtained anti-reflective film, centerline average roughness Ra of the low refractive index layer surface was calculated | required based on JISB0601.

"Interference fringe observation"
About the obtained anti-reflection film, after applying a matte black paint on the surface of the triacetyl cellulose film which is the transparent substrate 11 where the low refractive index layer is not formed, it is low immediately under the fluorescent lamp (three-wave fluorescent lamp). The interference fringes on the surface of the refractive index layer were visually confirmed.
The evaluation confirmed visually is
○: Color unevenness is not confirmed even in a dark environment.
X: Color unevenness is clearly confirmed even in a dark environment.

"Moire observation"
With the obtained antireflection film attached to both surfaces of the A3 chemical glass, a 46-inch liquid crystal display was displayed in green, and the moire was visually confirmed in a state where the gap between the glass and the display surface was 1 mm.
The evaluation confirmed visually is
○: Moire is not confirmed in a dark environment.
X: Moire is clearly confirmed in a dark environment.

(B) Surface resistance value “surface resistance”
The surface resistance value of the surface of the low-refractive index layer of the obtained antireflection film was measured using a high resistivity meter (manufactured by Dia Instruments Co., Ltd., High Lester MCP-HT260) according to JIS-K6911-1994. did.

(C) Mechanical strength “Abrasion resistance test”
Steel wool (manufactured by Nippon Steel Wool Co., Ltd.) with a load of 250 g / cm ² applied to the surface of the low refractive index layer of the optical laminate using a Gakushin type friction fastness tester (AB-301, manufactured by Tester Sangyo Co., Ltd.) , Bonster # 0000), and the appearance change due to 10 reciprocal rubbing, rubbing traces and scratches was visually evaluated.
The evaluation confirmed visually is
○: Scratches cannot be confirmed.
Δ: Several scratches can be confirmed.
X: Many scratches can be confirmed.

"Adhesion test"
The obtained antireflection film was evaluated by the number of remaining coating films on the surface of the low refractive index layer in accordance with the adhesion test method (cross-cut tape method) of the paint general test method JIS-K5400-1990.
The evaluation confirmed visually is
○: No peeling can be confirmed.
Δ: Peeling of 20 squares or less can be confirmed.
X: Peeling of 20 squares or more can be confirmed.
The performance evaluation results of this film are shown in (Table 1).

As can be seen from Table 1, the antireflection film of the present invention obtained in (Example 1), (Example 2), (Example 3), and (Example 4) has excellent scratch resistance and interference fringes. Is observed, and a hard coat layer and an antireflection layer having excellent coating film smoothness in which moire is not observed are provided.
On the other hand, since the antireflection film of the present invention obtained in (Comparative Example 1) has a low content of solvent 1 having permeability to the base material, the base material cannot be sufficiently dissolved, Interference fringes were generated and the scratch resistance was reduced. Since (Comparative Example 2) does not contain the solvent 2 that keeps the coating liquid state stable, the metal oxide fine particles aggregated, and the coating liquid after preparation was gelled. Since (Comparative Example 3) does not contain the solvent 3 for enhancing the surface smoothness of the coating film by slowing the coating liquid, the unevenness of the coating film surface cannot be suppressed, and moire has occurred. .

DESCRIPTION OF SYMBOLS 10 Antireflection film 11 Transparent base material 12 Hard-coat layer 13 Low refractive index layer

Claims (7)

A hard coat coating solution for forming a hard coat layer by coating on the surface of a transparent substrate,
An ionizing radiation curable resin containing a polyfunctional monomer having two or more (meth) acryloyl groups in one molecule, ATO, ITO, Sb ₂ O ₅ , TiO ₂ , ZnO ₂ , Ce ₂ O One or more solvents 1 that dissolve or swell the transparent substrate in a conductive material containing at least one of the _three metal oxide particles, a solvent 2 in which the conductive material is stably dispersed, A hard coat coating solution containing at least one kind of high boiling point solvent 3.   The ionizing radiation curable resin is composed of at least one of a urethane (meth) acrylate monomer and an oligomer, and the ionizing radiation curable resin has a conductivity within a range of 90 parts by weight or more and 99 parts by weight or less based on the solid content. The hard coat coating solution according to claim 1, wherein the material is contained in a range of 10 parts by weight or less and 1 part by weight or more based on the solid content. The solvent 1 contains at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone, cyclohexanone,
The solvent 2 contains at least one of methanol, ethanol, isopropyl alcohol, 1-pentanol, ethylene glycol, methyl cellosolve, cellosolve,
The solvent 3 contains at least one of cyclohexanone, acetylacetone, diacetone alcohol, diisobutylketone, butylcellosolve,
The solvent 1 is in the range of 60 to 80 parts by weight, the solvent 2 is in the range of 25 to 15 parts by weight, and the solvent 3 is in the range of 15 to 5 parts by weight. The hard coat coating solution according to claim 1, wherein the hard coat coating solution is an inner layer. An antireflection film in which a hard coat layer and a low refractive index layer are laminated in this order on at least one side of a transparent substrate,
The said hard-coat layer was formed by apply | coating the hard-coat coating liquid described in any one of Claims 1-3, The antireflection film characterized by the above-mentioned.   The solid content concentration of the binder matrix forming material of the hard coat layer is 45% or more and 52% or less, and the center line average roughness Ra (JIS B0601) of the film surface in the state where the antireflection layer is laminated is 0.01 μm. The antireflection film according to claim 4, wherein the film has a thickness of 0.002 μm or less.   The low refractive index layer contains a polyfunctional monomer containing two or more (meth) acryloyl groups in one molecule and low refractive index fine particles. 6. The antireflection film according to claim 4, wherein the rate is adjusted within a range of 1.3 or more and 1.5 or less.   The antireflection film according to any one of claims 4 to 6, wherein the transparent substrate is a cellulose-based film.

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