JPH10727A - Reflection preventive film and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly functional and high quality reflection preventive film using an application method which is advantageous in terms of mass production and equipment cost. SOLUTION: This reflection preventive film consists of a transparent base material film 1 and a hard coat layer 2, a layer 3 with high index of reflection and a layer 4 with low index of reflection which overlie this film directly or through another layer. In this case, the layer 4 with lox index of reflection comprises a SiO2 gel layer formed of an SiO2 sol liquid which is prepared by hydrolyzing silicon alkoxide expressed by Rm Si(OR')n (R and R' are a 1-10C alkyl group each; m+n is 4; and m and n are an integer each).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various displays such as word processors, computers, televisions and plasma display panels, surfaces of polarizing plates used in liquid crystal displays, sunglass lenses made of transparent plastics, prescription eyeglass lenses, and cameras. The present invention relates to an antireflection film excellent in antireflection of the surface of an optical lens such as a finder lens, a cover of various instruments, a window glass of an automobile or a train, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, transparent substrates such as glass and plastic have been used for displays such as curve mirrors, rearview mirrors, goggles, window glasses, personal computers, word processors, plasma displays, and various other commercial displays. When observing visual information such as objects, characters, and figures through these transparent substrates, or when observing an image from a reflective layer through a transparent substrate with a mirror, the surface of these transparent substrates is There is a problem that visual information of the person is difficult to see.

[0003] As a method of preventing reflection of such a transparent substrate, a method of applying an antireflection paint to the surface of glass or plastic, or a method of coating a surface of a transparent substrate such as a glass or plastic substrate, if necessary, have been used. There has been a method of forming a thin film of about 0.1 μm in thickness such as MgF ₂ or SiO ₂ through a hard coat layer by a vapor phase method such as vapor deposition, sputtering, or plasma CVD.

[0004]

According to the method for producing a functional thin film by a vapor phase method, a high-performance and high-quality thin film can be obtained, but precise atmosphere control in a high vacuum system is required. In addition, there is a problem that a special heating or ion generation acceleration device is required, and the manufacturing apparatus is complicated and large, so that the manufacturing cost is necessarily increased. Further, there is a problem that it is difficult to increase the area of the thin film or to manufacture a thin film having a complicated shape. On the other hand, among the methods for producing a functional thin film by a coating method, the method by a spray method has problems such as poor use efficiency of a coating liquid and difficulty in controlling film forming conditions. In addition, a method for producing a functional thin film using a coating method such as an immersion method and a screen printing method has a good use efficiency of a film forming material and has an advantage in mass production and equipment cost,
The functional thin film obtained by the coating method has a problem that the function and quality are inferior to the thin film obtained by the gas phase method.

In recent years, as a method for obtaining a thin film of excellent quality by a coating method, there has been proposed a method in which a dispersion liquid in which inorganic or organic ultrafine particles are dispersed in an acidic or alkaline aqueous solution is applied to a substrate and fired. ing. This method is advantageous in terms of mass production and equipment costs, but requires a high-temperature sintering process during the manufacturing process, making it impossible to form a film on a plastic substrate. The uniformity of the film is not sufficient due to the difference in the degree of shrinkage between the film and the coating film, and the performance is still inferior when compared with a thin film obtained by a gas phase method. Or more), resulting in poor productivity. Therefore, an object of the present invention is to provide a high-performance and high-quality antireflection film by a coating method which is advantageous in mass production and equipment cost.

[0006]

The above object is achieved by the present invention described below. That is, the present invention provides an antireflection film comprising a hard coat layer, a high refractive index layer and a low refractive index layer laminated directly or through another layer on a transparent base film, wherein the low refractive index layer is Hydrolyzing a silicon alkoxide represented by R _m Si (OR ′) _n (R and R ′ represent an alkyl group having 1 to 10 carbon atoms, m + n is 4 and m and n are each an integer) An anti-reflection film comprising a SiO ₂ gel layer formed from a SiO ₂ sol solution prepared by the above method, and a method for producing the same.

According to the present invention, a lower silicon alkoxide is hydrolyzed to prepare fine particles of several nanometers by a sol-gel method, and the sol solution in which the ultrafine particles are dispersed is coated on the surface of a transparent substrate film. After coating on the high refractive index layer formed on the hard coat layer, heat treatment is performed at a temperature equal to or lower than the thermal deformation temperature of the transparent base film, or by irradiating active energy rays to form a SiO ₂ gel layer. A low-refractive-index layer having almost the same performance as the low-refractive-index layer obtained by the gas-phase method can be obtained, and even when a substrate having a low heat deformation temperature such as a plastic substrate is used, high performance is obtained. In addition, a high-quality antireflection film can be formed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a diagram schematically showing a cross section of an example of the antireflection film of the present invention. The anti-reflection film of this example is an example in which a hard coat layer 2, a high refractive index layer 3, and a low refractive index layer 4 are laminated on a transparent base film 1, and reference numeral 5 in the drawing denotes a laminate as necessary. Adhesive layer or primer layer to be formed.

In the present invention, the transparent substrate film may be any film as long as it is a transparent film, for example, triacetyl cellulose film, diacetyl cellulose film, acetate butyrate cellulose film, polyether sulfone. Films, polyacrylic resin films, polyurethane resin films, polyester films, polycarbonate films, polysulfone films, polyether films, trimethylpentene films, polyetherketone films, (meth) acrylonitrile films, etc. can be used. Uniaxially or biaxially stretched polyester is preferably used because it is excellent in transparency and heat resistance and has no optical anisotropy. Its thickness is usually 8 μm to 1,
Those having a size of about 000 μm are preferably used.

The hard coat layer and the high refractive index layer formed on the surface of the transparent base film are formed of a thermosetting resin or an ionizing radiation-curable resin. However, since the transparent base film is formed of a thermoplastic resin, It is preferable to use an ionizing radiation curable resin that does not require a high temperature when the coating film is cured. In the present specification, "hard coat layer" or "having a hard property" means a material having a hardness of H or more in a pencil hardness test shown in JIS K5400.
In the present invention, the terms “high refractive index” and “low refractive index” refer to the relative refractive index of adjacent layers.

The ionizing radiation-curable resin suitable for forming the hard coat layer and the high refractive index layer is preferably one having an acrylate-based functional group, for example, a polyester resin or a polyether resin having a relatively low molecular weight. , Acrylic resin, epoxy resin, urethane resin, alkyd resin, spiro acetal resin, polybutadiene resin, polythiol polyene resin, oligomer or prepolymer such as (meth) acrylate of polyfunctional compound such as polyhydric alcohol, and reactive diluent Monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate and hexanediol (meth) acryl Chromatography, tri propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, dipentaerythritol hexa (meth)
Those containing relatively large amounts of acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like can be used. Further, in order to make the above-mentioned ionizing radiation-curable resin an ultraviolet-curable resin, a photopolymerization initiator containing acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide is used. , Thioxanthones, n-butylamine, triethylamine, and tri-n-amine as photosensitizers
Butyl phosphine and the like can be mixed and used.

When the hard coat layer and the high refractive index layer are formed of the above ionizing radiation curable resin alone, if the crosslinking density becomes too high during curing, the flexibility is reduced, and the resulting antireflection film is bent. Occasionally, the hard coat layer or the high refractive index layer may easily crack. In this case, the hard coat layer and the high refractive index layer forming composition,
It is preferred to mix the non-reactive resin in an amount up to about 50% by weight of the total composition. If the amount of the non-reactive resin is too large, the resulting layer may have insufficient hardness. As the non-reactive resin, a thermoplastic resin is mainly used. In particular, when a mixture of polyester acrylate and polyurethane acrylate is used for the ionizing radiation-curable resin, polymethyl methacrylate or polybutyl methacrylate for the thermoplastic resin used can keep the hardness of the coating film high. it can. Moreover, in this case, since the refractive index of the main ionizing radiation-curable resin is close, the transparency of the coating film is not impaired,
This is advantageous in terms of transparency, particularly low haze value, high transmittance, and compatibility.

The refractive index of the hard coat layer and the high refractive index layer composed of the above components is usually about 1.49 to 1.51. In the example shown in FIG. 1, in order to make the hard coat layer and the high refractive index layer have a high refractive index, a metal or a metal oxide having a high refractive index is contained in the resin composition for forming the hard coat layer and the high refractive index layer. It is preferable to improve the refractive index of the formed hard coat layer and high refractive index layer to about 1.50 to 2.30 by adding ultrafine particles of the above. As a material for improving the refractive index of the hard coat layer and the high refractive index layer, for example, ZnO
(Refractive index 1.90), TiO ₂ (refractive index 2.3-2.
7), CeO ₂ (refractive index: 1.95), Sb ₂ O ₅ (refractive index: 1.71), SnO ₂ , ITO (refractive index: 1.95), Y ₂
O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.9)
5), fine powders such as ZrO ₂ (refractive index: 2.05) and Al ₂ O ₃ (refractive index: 1.63). In addition, in order to further improve the refractive index of the hard coat layer and the high refractive index layer, in the resin composition for forming the hard coat layer and the high refractive index layer, a resin containing molecules and atoms of a high refractive index component is used. You may.
As the molecules and atoms of the component for improving the refractive index,
Examples include halogen atoms other than F, atoms of S, N, and P, and aromatic rings.

The hard coat layer and the high refractive index layer comprising the above components are dissolved or dispersed in an appropriate solvent to form a coating solution, and this coating solution is directly applied to the base film. After being cured, or after being applied to a release film and cured, it can be formed by transferring to the transparent substrate film using an appropriate adhesive. The thickness of the hard coat layer is usually preferably about 3 to 10 μm. The hard coat layer and the high refractive index layer can be cured by a usual method of curing an ionizing radiation-curable resin, that is, a method of curing by irradiation with an electron beam or ultraviolet rays. For example, in the case of electron beam curing, 50 to 1000 KeV emitted from various electron beam accelerators such as Cockloft-Walton type, Bande graph type, Resonant transformation type, Insulating core transformer type, Linear type, Dynamitron type, High frequency type, Preferably 10
An electron beam having an energy of 0 to 300 KeV is used. In the case of ultraviolet curing, ultraviolet rays emitted from light beams such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used.

Next, a low refractive index layer made of a SiO ₂ gel film having a refractive index of 1.38 to 1.46 was formed from a SiO ₂ sol solution on the surface of the high refractive index layer, as shown in FIG. The antireflection film of the present invention is obtained. The SiO ₂ sol can be prepared by dissolving a silicon alkoxide in an organic solvent suitable for coating and adding a certain amount of water to carry out hydrolysis. Preferred examples of the silicon alkoxide used for forming the SiO ₂ sol are compounds represented by R _m Si (OR ′) _n , wherein R and R ′ represent an alkyl group having 1 to 10 carbon atoms, and m + n Is 4, and m and n are each an integer. More specifically, tetramethoxysilane,
Tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane , Tetrapenta-n-propoxysilane, tetrapenta-n
-Butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane Dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxysilane, hexyltrimethoxysilane and the like.

The hydrolysis of the silicon alkoxide is performed by dissolving the silicon alkoxide in a suitable solvent. As the solvent used, for example, methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate, alcohols such as ethyl acetate, ketones, esters, halogenated hydrocarbons, toluene, aromatic hydrocarbons such as xylene, Alternatively, a mixture thereof may be mentioned. The alkoxide in the solvent,
The alkoxide is dissolved in an amount of 0.1% by weight or more, preferably 0.1 to 10% by weight in terms of SiO _2, which is generated as a result of 100% hydrolysis and condensation. If the concentration of the SiO ₂ sol is less than 0.1% by weight, the sol film formed cannot exhibit desired properties sufficiently, while if it exceeds 10% by weight, it becomes difficult to form a transparent homogeneous film. In the present invention, if the solid content is within the above range, an organic or inorganic binder can be used in combination.

Water is added to the solution in an amount not less than the amount required for hydrolysis, and the mixture is stirred at a temperature of 15 to 35 ° C., preferably 22 to 28 ° C., for 0.5 to 10 hours, preferably 2 to 5 hours. In the above-mentioned hydrolysis, it is preferable to use a catalyst, and as such a catalyst, an acid such as hydrochloric acid, nitric acid, sulfuric acid or acetic acid is preferable.
It is added as an aqueous solution of 0.0N, preferably about 0.005 to 5.0N, and the water in the aqueous solution can be used as the water for hydrolysis. The SiO ₂ sol obtained as described above is a colorless and transparent liquid, is a stable solution having a pot life of about one month, has good wettability to the high refractive index layer, and has excellent coating suitability. ing.

Various additives can be added to the sol solution. Examples of the additive include curing agents that promote film formation, and examples of these curing agents include organic acid solutions of organic acid metal salts such as sodium acetate and lithium acetate, such as acetic acid and formic acid. The concentration of the organic solvent solution is about 0.5.
The amount of the organic acid salt is preferably in the range of about 0.1 to 1 part by weight based on 100 parts by weight of SiO ₂ present in the sol solution. .

Further, the gel film finally obtained is a low refractive index layer of the antireflection film, but there are cases where the refractive index needs to be adjusted. For example, a fluorine-based organic silicon compound can be added to lower the refractive index, an organic silicon compound can be added to increase the refractive index, and a boron-based organic compound can be added to further increase the refractive index. Specifically, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, tetrabutoxysilane, alkyl trialkoxysilane, Colcoat 40 (manufactured by Colcoat), MS51
Organic silicon compounds such as (Mitsubishi Chemical) and Snowtex (Nissan Chemical); Zafflon FC-110, 220, 250
(Manufactured by Toa Gosei Chemical Co., Ltd.), sexual coat A-402B (manufactured by Central Glass), fluorinated compounds such as heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, trifluoropropyltrimethoxysilane, triethyl borate, trimethyl borate, And boron-based compounds such as tripropyl borate and tributyl borate. These additives may be added during the preparation of the sol, or may be added after the formation of the sol. By using these additives, a more uniform and transparent sol solution is obtained by reacting with the silanol group during or after the hydrolysis of the silicon alkoxide, and the refractive index of the formed gel film is within a certain range. Can be changed.

The method for forming a low refractive index layer using the aforementioned SiO ₂ sol solution, the SiO ₂ sol solution to the surface of the high refractive index layer was applied using a coating method, then coated material By performing an active energy ray irradiation treatment or a heat treatment, a SiO ₂ gel film can be formed,
The adhesion of the gel film to the high refractive index layer is significantly improved. The thickness of the low refractive index layer thus formed is usually preferably in the range of about 50 to 300 nm. Examples of the method of applying the SiO ₂ sol solution to the high refractive index layer include a spin coating method, a dip method, a spray method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, a bead coater method, and the like. .

The heat treatment of the coating layer performed after the application of the sol solution is performed at a temperature equal to or lower than the thermal deformation temperature of the transparent base film. For example, when the transparent base film is polyethylene terephthalate film (PET), about 80 to
The heat treatment may be performed at a temperature of 150 ° C. for about 1 minute to 1 hour to form a silica gel film. Since such heat treatment conditions vary depending on the type and thickness of the transparent base film to be used, it may be determined according to the type of the transparent base film to be used.

The active energy ray used for curing after the application of the sol solution includes an electron beam or ultraviolet ray. In particular, the same electron beam as used for curing the hard coat layer and the high refractive index layer is preferable. The heat treatment and the electron beam irradiation are preferably performed while replacing air with oxygen or in a sufficient oxygen atmosphere. By performing the heat treatment and the electron beam irradiation in an oxygen atmosphere, generation, polymerization and condensation of SiO ₂ are promoted, and the heat treatment and electron beam irradiation are performed more uniformly and A high quality gel layer can be formed.

An example of the formation of the high refractive index layer is as follows.
The index layer is made of a lower metal alkoxide R _mTi (OR ')
_n(R and R ′ represent an alkyl group having 1 to 10 carbon atoms,
m + n is 4 and m and n are each an integer)
Is R _mTa (OR ')_n(R and R ′ each have 1 to 10 carbon atoms.
Represents an alkyl group, m + n is 5, and m and n are
Each of which is an integer)
Can be formed from metal oxide sol prepared by cracking
You.

Examples of the lower metal alkoxide include titanium tetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, titanium tetra-sec-butoxide and titanium tetra-oxide. Examples include tert-butoxide, tantalum pentaethoxide, tantalum penta-i-propoxide, tantalum penta-n-propoxide, tantalum penta-n-butoxide, tantalum penta-sec-butoxide, tantalum penta-tert-butoxide and the like.

The hydrolysis of the metal alkoxide is performed by dissolving the metal alkoxide in a suitable solvent. As the solvent used, for example, methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate, alcohols such as ethyl acetate, ketones, esters, halogenated hydrocarbons, toluene, aromatic hydrocarbons such as xylene, Alternatively, a mixture thereof may be mentioned. The metal alkoxide is dissolved in the solvent in an amount of 0.1% or more, preferably 0.1 to 10% by weight in terms of a metal oxide generated when the metal alkoxide is hydrolyzed and condensed by 100%. If the concentration of the metal oxide sol is less than 0.1% by weight, the functional film formed cannot exhibit desired properties sufficiently, while if it exceeds 10% by weight, it becomes difficult to form a transparent homogeneous film. Further, by changing the metal oxide gel concentration within the above range, the refractive index of the obtained gel film can be adjusted in proportion to the gel concentration. In the present invention,
If the solid content is within the above range, an organic or inorganic binder can be used in combination.

Water is added to the above metal alkoxide solution in an amount not less than the amount required for hydrolysis, and is added at 15 to 35 ° C., preferably 22 to 35 ° C.
At a temperature of ~ 28 ° C for 5-30 hours, preferably 12-1
Stir for 6 hours. In the hydrolysis, it is preferable to use catalysts, and as such catalysts, acids such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, and acetic acid are preferable. It can be added as an aqueous solution of about 0.5 to 7.0 N, and the water in the aqueous solution can be used as the water for hydrolysis. By changing the concentration of the catalyst in the above range during the hydrolysis, the refractive index of the obtained gel film can be adjusted in proportion to the concentration of the catalyst.

The metal oxide sol obtained as described above is a colorless and transparent liquid, is a stable solution having a pot life of about one month, has good wettability to the hard coat layer, and has good wettability. Excellent aptitude. The metal oxide sol is applied to the surface of the hard coat layer using an application method. Examples of the method for applying the metal oxide sol to the hard coat layer include a spin coating method, a dipping method, a spray method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, and a bead coater method.

Thereafter, the coated material is subjected to a heat treatment and / or an active energy ray irradiation treatment to form a metal oxide gel film. The heat treatment of the coating layer performed after the application of the sol solution is performed at a temperature equal to or lower than the thermal deformation temperature of the transparent substrate film, as in the case of the SiO ₂ sol solution. Further, as the active energy ray used for curing the sol solution after application, an electron beam is preferably used as in the case of using the hard coat layer for curing. The electron beam irradiation is preferably performed while replacing air with oxygen or in a sufficient oxygen atmosphere.
By performing the reaction in an oxygen atmosphere, generation, polymerization and condensation of the metal oxide are promoted, and a more uniform and high quality gel layer can be formed. Next, a low-refractive-index layer made of SiO ₂ gel is formed as in the prior art, and the antireflection film of the present invention is obtained.

The antireflection film of the present invention may further include a layer for imparting various functions, in addition to the above-described layers. For example, an adhesive layer or a primer layer may be provided to improve the adhesion between the transparent base film and the hard coat layer, and a plurality of hard coat layers may be provided to improve the hard performance. As described above, the refractive index of the other layer provided between the transparent base film and the hard coat layer is preferably set to an intermediate value between the refractive index of the transparent base film and the refractive index of the hard coat layer.

The other layer may be formed by directly or indirectly applying a desired coating solution on the transparent substrate film as described above, or on the transparent substrate film. When the hard coat layer is formed by transfer, a coating liquid for forming another layer is applied on the hard coat layer formed on the release film in advance, and then formed on the transparent base film. Another layer may be transferred to the transparent base film by laminating the release film with the release film with the coated surface of the release film inside, and then peeling the release film.
Further, an adhesive may be applied to the lower surface of the antireflection film of the present invention, and this antireflection film can be used by attaching it to an object to be antireflection, for example, a polarizing element. The antireflection film of the present invention obtained as described above can be used for various displays such as a word processor, a computer, a television, and a plasma display panel, a surface of a polarizing plate used for a liquid crystal display, a sunglass lens made of transparent plastics, and glasses with a prescription. It is useful for preventing reflection on surfaces of lenses, optical lenses such as viewfinder lenses for cameras, covers for various instruments, and window glasses of automobiles and trains.

[0031]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Example 1 Methyltriethoxysilane (MTEOS) is ideally S
The MTEO is adjusted so that the solid content concentration becomes 3% by weight when it is assumed that the solid content is hydrolyzed and condensed to iO ₂ or MeSiO _1.5.
S was dissolved in methyl ethyl ketone, a solvent, and the solution temperature was 2
The mixture was stirred for 30 minutes until it was stabilized at 5 ° C (Solution A). Hydrochloride having a concentration of 0.005 N as a catalyst was added to Solution A in an equimolar amount to the alkoxide group of MTEOS, and hydrolysis was performed at 25 ° C. for 3 hours (solution B). A mixture of sodium acetate and acetic acid as a curing agent was added to the solution B, and the mixture was stirred at 25 ° C. for 1 hour to obtain a SiO ₂ sol solution.

PET film having a smooth surface (Lumirror T
-60: trade name, manufactured by Diafoil Co., Ltd., thickness 50μ
m), ionizing radiation-curable resin (X-12-240)
0: trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and ultrafine ZrO ₂ particles (No. 926: trade name, manufactured by Sumitomo Osaka Cement, refractive index: 1.9) were mixed at a weight ratio of 15: 1. The coating is performed by slit reverse coating so as to have a thickness of 0.1 μm / dry, and the electron beam is applied at an accelerating voltage of 175 kV for 5 hours.
The coating was cured by Mrad irradiation to form a high refractive index layer. On this high refractive index layer, ionizing radiation curable resin (X-1
2-2400) is applied by gravure reverse coating so as to be 7 μm / dry, and the electron beam is accelerated at an accelerating voltage of 175.
The coating film was cured by irradiating 5 Mrad with KeV to form a hard coat layer. A two-component curable adhesive (LX660, KW75 (curing agent)) was applied on the hard coat layer by gravure reverse coating to form an adhesive layer.

Next, a PET film (A-4300: trade name, manufactured by Toyobo, 100 μm thick) was applied through the adhesive layer.
m) was laminated and aged at 40 ° C. for 4 days, and then the PET film (T-60) was peeled off to form a hard coat layer and a high refractive index layer on the PET film (A-43).
00). The obtained PET film (A-
On the high refractive index layer above 4300), the above-mentioned SiO ₂ sol solution was further applied so as to have a thickness of 0.1 μm / dry, and heat-treated at 120 ° C. for 1 hour to obtain the reflection of the present invention. A prevention film was obtained. The obtained antireflection film had a total light transmittance of 94.5%, a haze value of 0.5, and a minimum reflectance in the visible light wavelength region of 0.2, and was excellent in antireflection properties. The surface pencil hardness was 3H, and the hardness was excellent.

Example 2 (Ti (OC ₄ H ₉ ) ₄ ) (Ti (OC ₄ H ₉ ) ₄ ) (Ti (OC ₄ H ₉ ) ₄ ) was adjusted so that the solid content concentration would be 3% by weight assuming that it was ideally hydrolyzed and condensed to TiO _2. (OC ₄ H ₉ )
₄ ) is dissolved in a solvent, ethyl cellosolve, and the solution temperature is 2
The mixture was stirred for 30 minutes until it was stabilized at 5 ° C (solution C). To the solution C, 3N hydrochloric acid as a catalyst was added in a 2.5-fold molar amount with respect to the alkoxide group of (Ti (OC ₄ H ₉ ) ₄ ), and the mixture was hydrolyzed at 25 ° C. for 3 hours to obtain a TiO ₂ sol solution. I got

As a transparent substrate film, a 50 μm thick P
An ET film (Lumilar T-60) was prepared. on the other hand,
The TiO ₂ sol solution is coated on the PET film by gravure reverse coating so that the film thickness after drying is 0.1 μm / dry, and heat-treated at 120 ° C. for 1 hour to form a high refractive index layer (refractive layer). Rate 1.9). A hard coat resin (PPZ-N-200) is formed on the high refractive index layer.
0: trade name, manufactured by Osaka Kyoei Chemical Co., Ltd.) was applied by gravure reverse coating so as to be 7 μm / dry, and the coating was cured by irradiating an electron beam with 5 Mrad at an acceleration voltage of 175 KeV to form a hard coat layer. .

A two-part curable adhesive (LX660, KW75 (curing agent), trade name, manufactured by Dainippon Ink and Chemicals, Inc.) was applied on the hard coat layer by gravure reverse coating to form an adhesive layer. Next, a PET film (A-4300) was laminated through this adhesive layer,
After aging at 0 ° C. for 4 days, the PET film (T-60) was peeled off, and the hard coat layer and the high refractive index layer were transferred onto the PET film (A-4300).
On the high refractive index layer on the obtained PET film (A-4300), the SiO ₂ sol solution of Example 1 was 0.1 μm thick.
/ Dry to obtain an antireflection film of the present invention. The obtained antireflection film had a total light transmittance of 94.5% and a haze value of 0.4, and was excellent in antireflection properties. The surface pencil hardness was 3H, and the hardness was excellent.

Comparative Example 1 An antireflection film was produced in the same manner as in Example 1 except that an SiOx film was formed as a low refractive index layer by a vacuum evaporation method. The total light transmittance of this antireflection film is 93.
The haze value was 8%, and the anti-reflection property was inferior to that of the example. The surface pencil hardness is 2
H.

Comparative Example 2 An antireflection film was produced in the same manner as in Example 2 except that a SiOx film was formed as a low refractive index layer by a vacuum evaporation method. The total light transmittance of this antireflection film is 94.
The haze value was 0%, and the anti-reflection property was inferior to that of the example. The surface pencil hardness is 2
H.

[0039]

As described above, according to the present invention, the lower silicon alkoxide is hydrolyzed to prepare fine particles of several nanometers by the sol-gel method, and the sol solution in which the ultrafine particles are dispersed is obtained. After applying to the high refractive index layer formed on the hard coat layer on the surface of the transparent substrate film, heat-treat at a temperature lower than the thermal deformation temperature of the transparent substrate film, or irradiate active energy rays to form the SiO ₂ gel layer. By forming a low refractive index layer having substantially the same performance as that of the low refractive index layer obtained by the gas phase method, a substrate having a low heat deformation temperature such as a plastic substrate is used. Even
It is possible to form a high-performance and high-quality antireflection film.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of an example of an antireflection film of the present invention.

[Explanation of symbols]

 1: transparent base film 2: hard coat layer 3: high refractive index layer 4: low refractive index layer 5: adhesive layer

Continued on the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B32B 27/36 B32B 27/36 G02B 1/11 G02B 1/10 A

Claims (7)

[Claims] 1. An antireflection film comprising a hard coat layer, a high refractive index layer, and a low refractive index layer laminated directly or through another layer on a transparent base film, wherein the low refractive index layer is R _m Si (OR ′) _n (R and R ′ each have 1 to 10 carbon atoms)
Represents an alkyl group, m + n is 4, SiO ₂ m and n which are formed a silicon alkoxide represented by each an integer) of SiO ₂ sol solution prepared by hydrolyzing
An anti-reflection film comprising a gel layer. 2. The low refractive index layer has a refractive index of 1.38 to 1.4.
6. The anti-reflection film according to claim 1, wherein 3. The method according to claim 1, wherein the high refractive index layer comprises a lower metal alkoxide R
_mTi (OR ')_n(R and R ′ each have 0 to 1 carbon atoms.
Represents an alkyl group of 0, m + n is 4, and m and n are
Each is an integer) or R _mTa (OR ')_n(R and
R ′ represents an alkyl group having 0 to 10 carbon atoms, and m + n is 5
And m and n are each an integer)
Oxide sol prepared by hydrolyzing genus alkoxide
The reflection according to claim 1, wherein the reflection layer is a metal oxide gel layer composed of:
Prevention film. 4. The high refractive index layer has a refractive index of 1.50 to 2.3.
2. The antireflection film according to claim 1, wherein the value is zero. 5. A method for producing an antireflection film, comprising laminating a hard coat layer, a high refractive index layer, and a low refractive index layer directly or via another layer on a transparent base film, The rate layer is defined as R _m Si (OR ′) _n (R and R
′ Represents an alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer.) A SiO ₂ sol solution prepared by hydrolyzing a silicon alkoxide represented by It was applied directly or via another layer on the surface of the film, forming process for the production of an antireflection film, which comprises forming a coating layer as heat treatment or irradiation of ionizing radiation to Si0 ₂ gel layer. 6. The low refractive index layer has a refractive index of 1.38 to 1.4.
6. The method for producing an antireflection film according to claim 5, wherein 7. The method according to claim 7, wherein the high refractive index layer is formed of a lower metal alkoxide R
_mTi (OR ')_n(R and R ′ each have 0 to 1 carbon atoms.
Represents an alkyl group of 0, m + n is 4, and m and n are
Each is an integer) or R _mTa (OR ')_n(R and
R ′ represents an alkyl group having 0 to 10 carbon atoms, and m + n is 5
And m and n are each an integer)
Oxide sol prepared by hydrolyzing genus alkoxide
6. The metal oxide gel layer according to claim 5,
A method for manufacturing an anti-reflection film.