JPH10728A - Reflection preventive film and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a functional thin film with high function and high quality using an application process 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 5 with moderate index of reflection, a layer 3 with high index of reflection and a layer 4 with low index of reflection which overlie this film in that order directly or through another layer. The layer 4 with low index of refraction is an SiO2 gel layer comprising an SiO2 sol which is prepared by hydrolyzing silicon alkoxide expressed by RnSi(OR')n (R and R' are a 1-10C alkyl group each; m+n is 4; and m an 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 object of the present invention is as follows.
Achieved by That is, the present invention provides a transparent base film
Hard coat layer, directly or through another layer
The order of the refractive index layer, high refractive index layer and low refractive index layer
And the low refractive index layer is formed of R _mSi (OR ')
_n(R and R ′ are each an alkyl group having 1 to 10 carbon atoms.
And m + n is 4, and m and n are each an integer.
Prepared by hydrolyzing silicon alkoxide represented by
SiO_TwoSiO consisting of sol_TwoSpecially for gel layer
An anti-reflection film and a method of manufacturing the same.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a preferred embodiment of the present invention.
A description will be given with reference to FIGS. FIG. 1 shows a basic embodiment of the present invention.
Then, a hard coat layer 2 and a middle
The refractive index layer 5, the high refractive index layer 3, and the low refractive index layer 4 are referred to in this description.
And the low refractive index layer 4 is formed of R _mSi
(OR ')_n(R and R ′ each represent an atom having 1 to 10 carbon atoms.
M + n is 4, m and n are each
Hydrolyze the silicon alkoxide represented by
Prepared SiO_TwoSiO consisting of sol_TwoGel layer
It is characterized by:

The transparent base film used in the present invention includes, for example, an acetate butyrate cellulose film, a polyether sulfone film, a polyacrylic resin film, a polyurethane resin film, a polyester film, a polycarbonate film, a polysulfone film, and a polystyrene film. Ether films, trimethylpentene films, polyetherketone films, (meth) acrylonitrile films, and the like can be used. In particular, uniaxially or biaxially stretched polyester films are preferably used because they are excellent in transparency and have no optical anisotropy. Can be Usually, the thickness of about 8 μm to 1000 μm is suitably used.

[0009] The hard coat layer formed on the surface of the transparent substrate film is a layer showing a hardness of H or more in a pencil hardness test shown in JIS K5400. For the formation of the hard coat layer, it is preferable to use a reaction curable resin, that is, a thermosetting resin and / or an ionizing radiation curable resin. The thermosetting resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin,
Epoxy resins, amino alkyd resins, melamine-urea co-condensation resins, silicon resins, polysiloxane resins, and the like are used, and if necessary, a curing agent such as a cross-linking agent, a polymerization initiator, a polymerization accelerator, or a solvent. , A viscosity modifier and the like.

The ionizing radiation-curable resin preferably has an acrylate-based functional group, for example, a polyester resin or 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 of polyfunctional compound such as polyhydric alcohol such as (meth) acrylate, and ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone as reactive diluent And monofunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene 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.

Particularly preferably, a mixture of a polyester acrylate and a polyurethane acrylate is used. The reason is that polyester acrylate has a very hard coating and is suitable for obtaining a hard coat.However, polyester acrylate alone has low impact strength and is brittle, so that the coating has high impact resistance and flexibility. To give a polyurethane acrylate. The mixing ratio of the polyurethane acrylate to 100 parts by weight of the polyester acrylate is 30 parts by weight or less. If it exceeds this value, the coating film is too soft and loses the hard coat property.

Furthermore, in order to make the above-mentioned ionizing radiation-curable resin composition into an ultraviolet-curable resin composition, acetophenones, benzophenones,
Michler benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones, n-butylamine, triethylamine, tri-n-butylphosphine and the like as a photosensitizer can be used in combination. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

The solvent-drying type resin may be contained in an amount of 10 to 100 parts by weight based on 100 parts by weight of the ionizing radiation-curable resin. As the solvent drying type resin, a thermoplastic resin is mainly used. The type of the solvent-dried thermoplastic resin to be added to the ionizing radiation-curable resin is commonly used, but especially when a mixture of polyester acrylate and polyurethane acrylate is used for the ionizing radiation-curable resin. Polymethyl methacrylate or polybutyl methacrylate can keep the hardness of the coating film high as the solvent-drying type resin. 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.
In particular, it is advantageous in terms of low haze value, high transmittance, and further compatibility.

A medium refractive index layer is formed on the hard coat layer. In the present invention, the terms “high, middle, and low refractive indices” are relative expressions, and mean that the respective layers to be laminated have a high, middle, and low refractive index.
Therefore, the formation method of the middle refractive index layer and the high refractive index layer may be the same method except that the refractive indexes of both layers are adjusted. As a method of forming these medium and high refractive indexes, there are a method of forming using a paint in which fine particles having different refractive indexes are dispersed in a binder resin having a different refractive index, and a method of forming a medium refractive index layer from a metal oxide gel. Then, there is a method of forming the high refractive index layer by sputtering vapor deposition of indium oxide-tin oxide (ITO) having a high electromagnetic wave shielding effect.

As the binder resin used in the former method, as the binder resin having a high refractive index, a resin containing an aromatic ring, a halogen element other than F, for example, Br, I, C
Examples include resins containing l and the like, and resins containing atoms such as S, N, and P. A resin satisfying at least one of these conditions is preferable because it has a high refractive index. Examples of the above resins include:
Styrene resin such as polystyrene, polyethylene terephthalate, polyvinyl carbazole, bisphenol A
And the like. Other examples of the above resins include polyvinyl chloride, polytetrabromobisphenol A glycidyl ether, and polybisphenol S
Glycidyl ether, polyvinyl pyridine and the like can be mentioned.

The high refractive index fine particles dispersed in the binder resin include, for example, ZnO (refractive index: 1.90), T
iO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.
95), Sb ₂ O ₅ (refractive index 1.71), SnO ₂ , IT
O (refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), L
a ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.0
5), Al ₂ O ₃ (refractive index 1.63) and the like. Among these high refractive index fine particles, ZrO ₂ , Z
It is preferable to use nO, TiO ₂ , CeO _2, etc., because the antireflection film of the present invention is further provided with a UV shielding effect.

The coating liquid for the medium refractive index layer and the coating liquid for the medium refractive index layer are adjusted by changing the kind of the binder resin used and the kind and amount of the fine particles dispersed in the binder resin. can do. The coating liquid for the medium refractive index layer has a refractive index of the formed layer of 1.50 to 1.
Preferably, the composition is determined to be 95, while
The coating liquid for a high refractive index layer has a refractive index of 1.
The composition is preferably determined so as to be 65 to 2.50, and the middle and high refractive index layers can be respectively formed by a coating method. The thickness of the medium refractive index layer formed by such a coating method is preferably in the range of about 50 to 300 nm, while the thickness of the high refractive index layer is preferably in the range of about 100 to 250 nm.

When an ionizing radiation-curable resin is used as the binder resin, the resin can be cured by a usual method of curing an ionizing radiation-curable resin, that is, 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 100 to 300
An electron beam or the like having an energy of 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.

The medium refractive index layer is formed from a metal oxide gel.
One example of a method uses a lower metal alkoxide.
Method. In this method, the lower metal alkoxy
De R _mTi (OR ')_n(R and R ′ each have 1 carbon atom
Represents an alkyl group of from 10 to 10, wherein m + n is 4, m and
n is each an integer) or R _mTa (OR ')_n(R
And R ′ each represent an alkyl group having 1 to 10 carbon atoms.
And m + n is 5, and m and n are each integers
Prepared by hydrolyzing a metal alkoxide represented by
Metal oxide gel layer by coating and forming a metal oxide sol
Is formed. With such a coating method
The refractive index of the formed medium refractive index layer is in the same range as described above.
The thickness is preferably in the range of about 50 to 300 nm.

Specific examples of such lower metal alkoxides include titanium tetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, titanium tetra-s
ec-butoxide, titanium tetra-tert-butoxide, tantalum pentaethoxide, tantalum penta-i-
Propoxide, tantalum penta-n-propoxide, tantalum penta-n-butoxide, tantalum penta-se
c-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% by weight 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%. When the concentration of the metal oxide sol is less than 0.1% by weight, the functional film formed cannot exhibit desired characteristics sufficiently.
If it exceeds 0% 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 alkoxide solution in an amount not less than the amount required for hydrolysis, and is added at 15 to 35 ° C., preferably 22 to 2 ° C.
Stirring is performed at a temperature of 8 ° C. for 5 to 30 hours, preferably 12 to 16 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.
An aqueous solution of about 1 to 20.0 N, preferably about 0.5 to 7.0 N is added, and the water in the aqueous solution can be used as 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 a coating substrate, and has excellent coating suitability. I have.

Further, when it is necessary to adjust the refractive index of the gel film forming the finally obtained intermediate refractive index layer, for example,
To lower the refractive index, a fluorine-based organic silicon compound, an organic silicon compound, a boron-based organic compound, or the like can be added. Specifically, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, tetrabutoxysilane, alkyl trialkoxysilane, colcoat 40
Organic silicon compounds such as MS51 (manufactured by Mitsubishi Chemical) and Snowtex (manufactured by Nissan Chemical), Zafflon FC-110, 220, 250 (manufactured by Toa Gosei Chemical), sexual coat A-402B (manufactured by Central Glass) And fluorine compounds such as heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane and trifluoropropyltrimethoxysilane, and boron compounds such as triethyl borate, trimethyl borate, tripropyl borate and tributyl borate. These additives may be added at the time of preparing the metal oxide sol, or may be added after the formation of the metal oxide sol.

In order to increase the refractive index, it is necessary to change the concentration of the catalyst to be added, the amount of water, and the concentration of the solid content. The refractive index tends to be increased by increasing these.
By using these additives, a metal alkoxide is hydrolyzed, or thereafter, reacts with hydroxyl groups of the gel to obtain a more uniform and transparent sol solution, and the refractive index of the formed gel film is within a certain range. Can be changed. Examples of the method for applying the metal oxide sol 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, 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 base film. For example, when the transparent substrate film is a polyethylene terephthalate film, the metal oxide gel film can be formed by performing a heat treatment at a temperature of about 80 to 150 ° C. for about 1 minute to 1 hour. 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 above heat treatment, while replacing the air with oxygen,
Alternatively, the reaction is preferably performed in a sufficient oxygen atmosphere. By performing the reaction in an oxygen atmosphere, generation, polymerization, and condensation of the metal oxide gel are promoted, and a more uniform and high-quality gel layer can be formed.

The active energy beam used after the application of the sol solution includes an electron beam or an ultraviolet ray, and an electron beam is particularly preferable. For example, in the case of electron beam curing, 50 to 1 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, etc. 2,000K
An electron beam having an energy of eV, preferably 100 to 300 KeV is used. In the case of ultraviolet curing, ultraviolet rays emitted from a light source 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 are used. Is done. When the active energy beam is an electron beam, the total irradiation amount of the active energy beam is 0.5.
Mrad or more, preferably in the range of 0.5 to 50 Mrad.

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. When the high refractive index layer is formed using antimony-doped SnO ₂ or ITO,
A conventionally known sputter deposition method or the like can be arbitrarily used. The refractive index of the high refractive index layer thus formed is in the same range as described above, and its thickness is preferably in the range of about 100 to 250 nm. By forming the high refractive index layer using antimony-doped SnO ₂ or ITO as described above, the electrical conductivity of the obtained anti-reflection film is improved, and the anti-reflection film is used to prevent dust from adhering. It is preferable because an electromagnetic wave shielding effect can be obtained when the antireflection film is used for a CRT.

In the present invention, a low refractive index layer is formed on the high refractive index layer. This low refractive index layer is a SiO ₂ gel layer formed by a so-called sol-gel method. The lower silicon alkoxide used for forming the SiO ₂ gel layer is R _m Si
(OR ′) _n is a compound represented by _n
'Represents an alkyl group having 1 to 10 carbon atoms, and m +
n is 4. 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, methyltrimethoxy Silane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxysilane And hexyltrimethoxysilane.

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 functional 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 5 to 30 hours, preferably 12 to 16 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
It is a colorless and transparent liquid, is a stable solution with a pot life of about one month, has good wettability to the transparent substrate film, and is excellent in application suitability. Various additives can be added to the SiO ₂ sol solution. The most important additives 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 0.01 to 0.1% by weight, and the amount of the organic acid salt is about 0.1 to 100 parts by weight of SiO ₂ present in the sol solution. The range is preferably about 1 to 1 part by weight.

Furthermore, the finally obtained SiO ₂ gel film becomes a low refractive index layer of the antireflection film, but it may be necessary to adjust the refractive index in some cases. 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), M
S51 (Mitsubishi Chemical), Snowtex (Nissan Chemical)
Organic silicon compounds such as Zafflon FC-110, 220,
250 (manufactured by Toa Gosei Chemical), sexual coat A-402
B (manufactured by Central Glass), a fluorine compound 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 SiO ₂ sol may be added after the formation of the SiO ₂ 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 SiO ₂ sol is applied to the surface of the high refractive index layer by using a coating method. The method for applying the SiO ₂ sol to the high refractive index layer and the method for curing the same are the same as those for the metal oxide sol.

[0034]

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), a dispersion of ultra-fine particles of ZrO ₂ (No. 926: trade name, manufactured by Sumitomo Osaka Cement, refractive index: 1.9) was placed at 7 μm /
A dry coating was applied by slide coating, and an electron beam was irradiated at an acceleration voltage of 175 KeV at 5 Mrad to cure the coating and form a medium refractive index layer. A hard coat resin (X-12-24) was formed on the middle refractive index layer of the obtained PET film.
00: trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied by gravure reverse coating so as to be 7 μm / dry, and an electron beam was irradiated at an acceleration voltage of 175 KeV for 5 Mrad to cure the coating film to form a hard coat layer.

A two-component curable adhesive (LX660, KW75: trade name, manufactured by Dainippon Ink) is applied on the obtained hard coat layer by gravure reverse coating to form an adhesive layer, and then the adhesive is formed. PET film (A-4300: trade name, manufactured by Toyobo, thickness 100 μm) through the layer
After aging at 40 ° C. for 4 days, the PET film (T-60) was peeled off to form a hard coat layer and a medium refractive index layer on the PET film (A-4300).
Transferred to the top. The obtained PET film (A-430)
0) On the middle refractive index layer, as a high refractive index layer, an indium oxide-tin oxide (ITO) layer having transparency and high electromagnetic wave shielding effect was formed by sputter deposition so as to have a film thickness of 145 nm. .

The PET film obtained (A-4300)
Of on the high refractive index layer (ITO layer) was coated so as to further comprising the SiO ₂ sol solution and film thickness 0.1 [mu] m / dry, 1
Heat treatment was performed at 20 ° C. for 1 hour to obtain an antireflection film of the present invention. The obtained antireflection film of the present invention has a total light transmittance of 94.0%, a haze value of 0.5, and a minimum reflectance in the visible light wavelength region of 0.2, and is excellent in antireflection properties. Was. The surface pencil hardness was 3H, and the hard coat property was excellent.

Example 2 Assuming that tetrabutoxytitanium (Ti (OC ₄ H ₉ ) ₄ ) is ideally hydrolyzed and condensed to TiO ₂ , Ti ( OC ₄ H ₉ ) ₄
Was dissolved in a solvent, ethyl cellosolve, and the solution temperature was 25 ° C.
The mixture was stirred for 30 minutes until it became stable (liquid 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 perform TiO ₂ sol 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 becomes 0.1 μm / dry, and heat-treated at 120 ° C. for 1 hour to form a medium refractive index layer (refractive layer). Rate 1.9). A hard coat resin (PPZ-N-200) is formed on the middle 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-component 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 middle refractive index layer were transferred onto the PET film (A-4300).
Indium oxide-tin oxide (ITO) having a transparent conductivity and a high electromagnetic wave shielding effect as a high refractive index layer on the medium refractive index layer on the obtained PET film (A-4300).
The layer was formed by sputter deposition to a thickness of 145 nm.

Obtained PET film (A-4300)
Of on the high refractive index layer (ITO layer), further SiO ₂ sol solution (C solution) was coated to a thickness of 0.1 [mu] m / dry, heat treatment is performed for 1 hour at 120 ° C., the present invention An anti-reflection film was obtained. The obtained antireflection film of the present invention has a total light transmittance of 94.0%, a haze value of 0.7, and a minimum reflectance in the visible light wavelength region of 0.3, and is excellent in antireflection properties. Was.

[0042] In the antireflection film of Comparative Example 1 Example 1, in the case where the SiO _X film formed between the low refractive index layer by a vacuum deposition method, the total light transmittance of the obtained anti-reflection film 94.
0%, the haze value was 0.6, and the antireflection property was the same as that of each of the above Examples, but the surface pencil hardness was 2H,
Similarly, the values are lower than those of the above embodiments.

Comparative Example 2 In the antireflection film of Example 2, when the SiO _X film formed by the vacuum evaporation method was used as the low refractive index layer, the total light transmittance of the obtained antireflection film was 93.
The haze value was 5%, and the antireflection property was inferior to those of the above examples. The surface pencil hardness is 2H
Similarly, it is lower than that of each of the above embodiments.

[0044]

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 through the hard coat layer and the medium refractive index layer on the surface of the transparent substrate film, heat-treat at a temperature not higher than the thermal deformation temperature of the transparent substrate film or irradiate with ionizing radiation. By forming a SiO ₂ gel layer, it is possible to form an anti-reflection film even on a substrate having a low heat deformation temperature, such as a plastic substrate, and has almost the same performance as a thin film obtained by a gas phase method. A thin film having similar performance is obtained.

[Brief description of the drawings]

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

[Explanation of symbols]

1: transparent base film 2: hard coat layer 3: high refractive index layer 4: SiO ₂ gel layer as a low refractive index layer 5: medium refractive index layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B32B 27/36 B32B 27/36 C23C 14/08 C23C 14/08 N G02B 1/11 G02B 1/10 A

Claims (10)

[Claims] 1. The method according to claim 1, wherein the surface of the transparent substrate film is directly or other
Hard coat layer, middle refractive index layer, high refractive index layer and
Anti-reflection by laminating low refractive index layers in this order
In the film, the low refractive index layer has _mSi (OR
´)_n(R and R ′ each represent an alkyl having 1 to 10 carbon atoms.
M + n is 4, and m and n are each an integer
Hydrolyze the silicon alkoxide represented by
Prepared SiO_TwoSiO consisting of sol_TwoBe a gel layer
An anti-reflection film characterized by the following. 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 middle refractive index layer comprises a lower metal alkoxide R
_mTi (OR ')_n(R and R ′ each have 1 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 1 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. A medium refractive index layer having a refractive index of 1.50 to 1.9.
The antireflection film according to claim 3, wherein 5. The indium oxide-tin oxide (IT) in which the high refractive index layer has a transparent conductivity and has a high electromagnetic wave shielding effect.
2. The antireflection film according to claim 1, which is formed by O) sputter deposition. 6. The high refractive index layer has a refractive index of 1.65 to 2.
2. The anti-reflection film according to claim 1, wherein the number is 50. 7. The method according to claim 7, wherein the transparent substrate film is directly or other
Hard coat layer, middle refractive index layer, high refractive index layer and
And a low-refractive-index layer in the order described.
In the method for producing an antireflection film, the low refractive index layer
And R _mSi (OR ')_n(R and R 'are each carbon atoms
Represents an alkyl group of 1 to 10, wherein m + n is 4,
And n are each an integer)
SiO prepared by hydrolysis of_TwoSol to SiO_Twogel
Of an anti-reflection film characterized by being formed as a layer
Production method. 8. The low refractive index layer has a refractive index of 1.38 to 1.4.
The method for producing an antireflection film according to claim 7, wherein: 9. The method according to claim 9, wherein the lower refractive index layer comprises a lower metal alkoxide R
_mTi (OR ')_n(R and R ′ each have 1 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 1 to 10 carbon atoms;
+ N is 5, m and n are each an integer)
Acid prepared by hydrolysis of the metal alkoxide to be prepared
Sol, heat treatment and / or active energy ray
Irradiation treatment and TiO_TwoOr Ta_TwoO_FiveForm as a gel layer
A method for producing an antireflection film according to claim 7. 10. A medium refractive index layer having a refractive index of 1.50-1.
The method for producing an anti-reflection film according to claim 9, wherein the ratio is 95.