JP2006330742A - Antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film, wherein a low refractive index layer on the outermost layer has excellent adhesion to a hard coat layer. <P>SOLUTION: The antireflection film comprises hard coat layers having a high refractive index and low refractive index layers layered on a transparent base film, wherein the high refractive index layer consists of a gel film having a refractive index of 1.65 or more formed from a sol liquid containing an oxide sol of titanium or tantalum and a reactive organosilicon compound such as methyltrimethoxysilane in a liquid medium. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes various types of displays such as word processors, computers, televisions, plasma display panels, the surfaces of polarizing plates used in liquid crystal display devices, sunglasses lenses made of transparent plastics, prescription eyeglass lenses, optical lenses such as finder lenses for cameras, The present invention relates to an antireflection film excellent in antireflection of the surfaces of various instrument covers, window glass of automobiles, trains and the like.

  Conventionally, transparent substrates such as glass and plastic have been used for displays such as curved mirrors, rearview mirrors, goggles, window glass, personal computers, word processors, plasma displays, and other various commercial displays. When observing visual information such as objects, characters, figures, etc., or when observing an image from a reflective layer through a transparent substrate with a mirror, the surface of these transparent substrates is reflected by external light and the internal visual information is visible. There was a problem that it was difficult.

As a method for preventing reflection of such a transparent substrate, conventionally, a method of applying an antireflection coating on the surface of glass or plastic, a hard coat layer as necessary on the surface of a transparent substrate such as a glass / plastic substrate, etc. There is a method of forming a thin film such as MgF ₂ or SiO _{2 with} a film thickness of about 0.1 μm through a vapor phase method such as vapor deposition, sputtering, or plasma CVD.

However, an ionizing radiation curable resin is applied to the surface of a plastic product such as a plastic lens to form a hard coat layer, and a thin film such as MgF ₂ or SiO ₂ having a thickness of about 0.1 μm is formed on the obtained hard coat layer. In the method of forming the antireflection film by vapor deposition, the adhesion of the deposited thin film such as MgF ₂ or SiO ₂ to the hard coat layer is insufficient, and if the antireflection film is repeatedly bent, these thin films are cracked. There is a problem that the film enters and the thin film peels off.

In recent years, as a method for obtaining an excellent quality thin film by a coating method, a method in which a dispersion liquid in which inorganic or organic ultrafine particles are dispersed in an acidic and / or alkaline aqueous solution is coated on a substrate and baked has been proposed. This manufacturing method is advantageous in terms of mass production and equipment costs, but requires a baking process at a high temperature during the manufacturing process, so that it is 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 with the coating film, etc., and when compared with a thin film obtained by the vapor phase method, the performance is still inferior in adhesion to the substrate, etc. (For example, several tens of minutes or more) is required, and there is a disadvantage that productivity is inferior.
Accordingly, an object of the present invention is to provide an antireflection film having an outermost low refractive index layer having excellent adhesion to a hard coat layer.

  The above object is achieved by the present invention described below. That is, the present invention relates to an antireflection film comprising a transparent base film and a hard coating layer having a high refractive index and a low refractive index layer laminated, wherein the high refractive index layer comprises titanium or tantalum in a liquid medium. Oxide sol and methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane An antireflective film comprising a gel film having a refractive index of 1.65 or more formed from a sol solution containing a reactive organosilicon compound selected from methyldimethoxysilane, methyldiethoxysilane, and hexyltrimethoxysilane It is.

  According to the present invention, a high refractive index hard coat layer of an antireflection film is formed from a sol solution containing a titanium or tantalum oxide sol and a reactive organosilicon compound in a liquid medium, and having a refractive index of 1.65 or more. As a result, it is possible to economically provide an antireflection film in which the low refractive index layer has excellent adhesion to the high refractive hard coat layer without using expensive and complicated equipment.

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 antireflection film of this example is an example in which a hard coat layer 2 having a high refractive index and a low refractive index layer 3 are laminated on a transparent substrate film 1, and reference numeral 4 in the figure is laminated as necessary. An adhesive layer or a primer layer.
The example shown in FIG. 2 is an example in which the hard coat layer 2 having a high refractive index in the example shown in FIG. 1 is functionally separated into a hard coat layer 5 and a high refractive index layer 6 formed thereon.
The example shown in FIG. 3 is an example in which fine irregularities are provided on the surface of the example shown in FIG. 1 and the antireflection film is imparted with an antiglare property.

  In the present invention, the transparent substrate film may be any film as long as it is transparent. For example, a triacetyl cellulose film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyether sulfone film, a poly Acrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, trimethylpentene film, polyetherketone film, (meth) acrylonitrile film, etc. can be used. It is preferably used because it is excellent in transparency and heat resistance and has no optical anisotropy. The thickness is usually about 8 μm to 1000 μm.

In the example of FIG. 1, the hard coat layer having a high refractive index formed on the surface of the transparent base film is a sol solution containing a titanium or tantalum oxide sol and a reactive organosilicon compound in a liquid medium, or It is a gel film having a refractive index of 1.65 or more formed from a mixture of the sol solution and a thermosetting resin capable of forming a hard coat layer or an ionizing radiation curable resin.
The titanium or tantalum metal oxide sol is preferably formed by hydrolyzing the metal alkoxide. The metal alkoxide used here is R _m Ti (OR ′) _n (R represents an alkyl group having 1 to 10 carbon atoms, R ′ represents an alkyl group having 1 to 10 carbon atoms, and m + n is an integer of 4. Or R _m Ta (OR ′) _n (R represents an alkyl group having 1 to 10 carbon atoms, R ′ represents an alkyl group having 1 to 10 carbon atoms, and m + n is an integer of 5). Metal alkoxide. More specifically, titanium tetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, titanium tetra-sec-butoxide, titanium tetra-tert-butoxide, tantalum penta Examples thereof include ethoxide, tantalum penta-i-propoxide, tantalum penta-n-propoxide, tantalum penta-n-butoxide, tantalum penta-sec-butoxide, and tantalum penta-tert-butoxide.

The metal alkoxide is hydrolyzed by dissolving the metal alkoxide in a suitable solvent. Examples of the solvent used include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, esters, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, Or the mixture of these is mentioned.
The alkoxide is dissolved in the solvent so as to be 0.1% by weight or more, preferably 0.1 to 10% by weight in terms of a metal oxide generated when the alkoxide is 100% hydrolyzed and condensed. If the concentration of the metal oxide sol is less than 0.1% by weight, the formed functional film cannot sufficiently exhibit the desired characteristics, while if it exceeds 10% by weight, it becomes difficult to form a transparent homogeneous film.
In addition, by changing the metal oxide gel concentration within the above range, the refractive index of the gel film obtained can be adjusted in proportion to the gel concentration. Moreover, in this invention, if it is less than the above solid content, it is also possible to use an organic substance and an inorganic binder together.

Water above the amount necessary for hydrolysis is added to the alkoxide solution, and stirring is performed at a temperature of 15 to 35 ° C., preferably 22 to 28 ° C., for 0.5 to 10 hours, preferably 1 to 5 hours. In the hydrolysis, it is preferable to use a catalyst. As these catalysts, acids such as hydrochloric acid, nitric acid, sulfuric acid, formic acid and acetic acid are preferable, and these acids are contained in about 0.1 to 20.0 N, preferably 0. It can be added as an aqueous solution of about 0.5 to 7.0 N, and water in the aqueous solution can be used as water for hydrolysis.
By changing the concentration of the catalyst within the above range during hydrolysis, the refractive index of the gel film obtained 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 1 month, has good wettability with respect to the base material, and is excellent in coating suitability. .

  Further, when it is necessary to adjust the refractive index of the finally obtained gel film, for example, a fluorine-based organic silicon compound, an organic silicon compound, a boron-based organic compound, or the like can be added to lower the refractive index. Specifically, tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, tetrabutoxysilane, alkyltrialkoxysilane, Colcoat 40 (manufactured by Colcoat), MS51 (manufactured by Mitsubishi Chemical), Snowtex (manufactured by Nissan Chemical), etc. Organosilicon compounds, ZAFLON FC-110, 220, 250 (manufactured by Toa Gosei Chemical), Sexual Coat A-402B (manufactured by Central Glass), heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, trifluoropropyltrimethoxy Examples thereof include fluorine compounds such as silane, and boron compounds such as triethyl borate, trimethyl borate, 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.

  In order to increase the refractive index, it is necessary to change the concentration of the catalyst to be added, the amount of water, or the solid content concentration. Increasing these factors increases the refractive index. By using these additives, a more uniform and transparent sol solution can be obtained by reacting with the hydroxyl group of the gel during or after the hydrolysis of the metal alkoxide, and the refractive index of the gel film to be formed is within a certain range. Can be changed.

  In the present invention, a reactive organosilicon compound or a partial hydrolyzate thereof is added to the above titanium or tantalum oxide sol. Examples of the reactive organosilicon compound include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert. -Butoxysilane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyl Triethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, di Chill propoxysilane, dimethyl-butoxy silane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane and the like.

More preferable examples of the reactive organosilicon compound include a plurality of groups that are reactively crosslinked by heat or ionizing radiation, for example, an organosilicon compound having a molecular weight of 5000 or less having a polymerizable double bond group. Such reactive organosilicon compounds include one-end vinyl functional polysilane, both-end vinyl functional polysilane, one-end vinyl-functional polysiloxane, both-end vinyl-functional polysiloxane, or vinyl-functional polysilane obtained by reacting these compounds, Or a vinyl functional polysiloxane etc. are mentioned.
Examples of specific compounds are as follows.

その他の化合物しては、３−（メタ）アクリロキシプロピルトリメトキシシラン、３−（メタ）アクリロキシプロピルメチルジメトキシシラン等の（メタ）アクリロキシシラン化合物が挙げられる。
以上の如き反応性有機珪素化合物は、前記チタン又はタンタルの酸化物ゾル（固形分）１００重量部当り約０．１〜５０重量部の割合で使用することが好ましい。 ^{_{CH 2 = CH- (R 1 R}} 2 Si) n -CH = CH 2 (A)

Examples of other compounds include (meth) acryloxysilane compounds such as 3- (meth) acryloxypropyltrimethoxysilane and 3- (meth) acryloxypropylmethyldimethoxysilane.
The reactive organic silicon compound as described above is preferably used at a ratio of about 0.1 to 50 parts by weight per 100 parts by weight of the titanium or tantalum oxide sol (solid content).

A method of forming a high refractive index layer using a titanium or tantalum oxide sol solution containing the above reactive organosilicon compound, the titanium or tantalum oxide sol solution is applied to the surface of the transparent substrate film. A low refractive index layer can be formed on a titanium or tantalum oxide sol film by coating using a coating method and then subjecting the coating to active energy ray irradiation or heat treatment. Adhesion with is significantly improved.
Examples of the method for applying the titanium or tantalum oxide sol solution to the transparent substrate film include spin coating, dipping, spraying, roll coating, meniscus coating, flexographic printing, screen printing, and bead coating. Etc.

  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 (PET), a heat treatment is performed at a temperature of about 80 to 150 ° C. for about 1 minute to 1 hour to form an oxide gel film of titanium or tantalum. it can. Such heat treatment conditions vary depending on the type and thickness of the transparent substrate film to be used, and may be determined according to the type of transparent substrate film to be used.

  Examples of active energy rays used for curing after application of the sol solution include electron beams and ultraviolet rays, and electron beams are particularly preferable. For example, in the case of electron beam curing, 50 to 1 emitted from various electron beam accelerators such as a Cockloft Walton type, a bandegraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type An electron beam having an energy of 1,000,000 KeV, preferably 100 to 300 KeV is used. In the case of ultraviolet curing, ultraviolet rays emitted from a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. Used. When the active energy ray is an electron beam, the total irradiation amount of the active energy ray is 0.5 Mrad or more, preferably 0.5 to 50 Mrad.

The electron beam irradiation is preferably performed while substituting air with oxygen or in a sufficient oxygen atmosphere. By performing the irradiation in an oxygen atmosphere, formation of titanium or tantalum oxide sol, polymerization / condensation is promoted. A homogeneous and high quality gel layer can be formed.
The above heat treatment is preferably performed while substituting air with oxygen or in a sufficient oxygen atmosphere. By performing the heat treatment in an oxygen atmosphere, generation of oxide gel of titanium or tantalum, polymerization / condensation is promoted, and a more homogeneous condition is obtained. And a high quality gel layer can be formed.

  In addition, in the thermosetting resin and ionizing radiation curable resin that can form a high refractive index hard coat layer in combination with the sol solution, the transparent base film is made of a thermoplastic resin. It is preferable to use an ionizing radiation curable resin that is not required. In the present specification, “hard coat layer” or “having a hard property” means a material having a hardness of H or higher in a pencil hardness test shown in JIS K5400. In the present invention, “high refractive index” and “low refractive index” refer to the relative refractive index between adjacent layers.

  The ionizing radiation curable resin suitable for forming the hard coat layer is preferably one having an acrylate functional group, for example, a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane. Resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers such as (meth) acrylates of polyfunctional compounds such as polyhydric alcohols, and ethyl (meth) acrylate, ethylhexyl ( Monofunctional monomers such as (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, and polyfunctional 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) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate Those containing a relatively large amount can be used.

Furthermore, in the present invention, as the curable resin for forming the hard coat layer, the above-mentioned reactive organic silicon compound having a molecular weight of 5000 or less can be used alone or mixed with the above curable resin. By using the organosilicon compound as at least a part of the hard coat forming material, the adhesion between the hard coat layer and the low refractive index layer can be remarkably improved.
Further, in order to convert the ionizing radiation curable resin into an ultraviolet curable resin, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide are used as photopolymerization initiators. In addition, thioxanthones, and n-butylamine, triethylamine, tri-n-butylphosphine, etc. can be mixed and used as a photosensitizer.

When the hard coat layer is formed of the above ionizing radiation curable resin alone, if the crosslink density becomes too high at the time of curing, the flexibility is lowered, and the hard coat layer is cracked when the resulting antireflection film is bent. May be easier to enter.
In this case, it is preferable to mix the non-reactive thermoplastic resin with the hard coat layer forming composition in an amount up to about 50% by weight in the entire composition. If the amount of the non-reactive resin added is too large, the hard coat property may be insufficient.

  A thermoplastic resin is mainly used as the non-reactive resin. In particular, when a mixture of polyester acrylate and polyurethane acrylate is used as the ionizing radiation curable resin, poly (methyl methacrylate) or poly (butyl methacrylate) can keep the coating film high in the thermoplastic resin used. it can. Moreover, in this case, since the refractive index is close to that of the main ionizing radiation curable resin, the transparency of the coating film is not impaired, and it is advantageous in terms of transparency, in particular, low haze value, high transmittance, and compatibility. .

The refractive index of the hard coat layer comprising the above components is usually about 1.49 to 1.51, but in order to further improve the refractive index of the hard coat layer, Ultrafine particles of metal or metal oxide having a refractive index can be added. A preferable refractive index of the hard coat layer is 1.50 to 2.10.
Since the antireflection effect is determined by the refractive index and the film thickness of the light buffer film, the antireflection effect can be enhanced by adjusting both parameters.
Examples of the material having a high refractive index include ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 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 1.95), ZrO ₂ (refractive index 2. 05), fine powders such as Al ₂ O ₃ (refractive index 1.63).

In order to further improve the refractive index of the hard coat layer, a resin containing molecules and atoms of a high refractive index component may be used in the resin composition for forming a hard coat layer. Examples of the molecules and atoms of the component that improves the refractive index include aromatic rings, halogen atoms other than F, S, N, and P atoms.
The hard coat layer composed of the above components is prepared by dissolving or dispersing the above components in an appropriate solvent to form a coating solution, which is directly applied to the substrate film and cured, or released from the release film. It can also be formed by applying and curing to a transparent substrate film using an appropriate adhesive. The thickness of the hard coat layer is usually preferably about 3 to 10 μm.

  For curing the hard coat layer, a normal method of curing an ionizing radiation curable resin, that is, a method of curing by irradiation with an electron beam or ultraviolet rays can be used. For example, in the case of electron beam curing, 50 to 1000 KeV emitted from various electron beam accelerators such as a Cockloft Walton type, a bandegraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type, Preferably, an electron beam or the like having an energy of 100 to 300 KeV is used, and in the case of ultraviolet curing, ultraviolet rays emitted from light rays such as an ultrahigh 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, the antireflective film of the present invention is obtained by forming a low refractive index layer on the surface of the high refractive index hard coat layer.
As the low refractive index layer, a method of forming a thin film such as MgF ₂ or SiO _{2 with} a film thickness of about 0.08 to 0.2 μm by vapor deposition such as vapor deposition, sputtering, plasma CVD, or the above organic silicon compound a method such as to form a refractive index of 1.44 or less of SiO ₂ gel film from the sol solution containing SiO ₂ sol obtained by hydrolyzing the like with the liquid medium, in particular the molecular weight of the above SiO ₂ in the sol By forming the refractive index layer from a sol solution to which a reactive organic silicon compound of 5000 or less is added, the adhesion between the formed low refractive index layer and the hard coat layer is further improved.

  The example shown in FIG. 2 is an example in which the hard coat layer having a high refractive index in the example shown in FIG. 1 is functionally separated into the hard coat layer 5 and the high refractive index layer 6, and the materials and layers used in this example are formed. The method of performing is the same as in the example shown in FIG. The antireflection film shown in FIG. 2 has a lower minimum reflectance in the visible light region and a higher antireflection efficiency than the antireflection film shown in FIG.

  In the example shown in FIG. 3, an anti-glare property is imparted to the anti-reflection film by providing fine irregularities 7 on the surface of the anti-reflection film. The fine uneven shape may be formed by any conventionally known method. For example, as a preferable method, when forming a high refractive index hard coat layer by a transfer method, the fine uneven shape is formed on the surface as a substrate film of a transfer material. A coating film for a high refractive index hard coat layer is applied and cured on the film, and then the hard coat layer is formed on the transparent base film surface via an adhesive or the like, if necessary. And a method of imparting a fine uneven shape to the surface of the high refractive index hard coat layer. As another method, a coating liquid for a high refractive index hard coat layer is applied to the surface of the base film and dried, and in such a state, the mat film as described above is pressure-bonded to the surface of the resin layer, and in this state, the resin is There is a method in which the layer is cured, then the mat film is peeled off, and the fine uneven shape of the mat film is transferred to the surface of the high refractive index hard coat layer. In any case, since the low refractive index layer formed on the surface of the high refractive index layer having such a fine uneven shape is a thin film, the above fine uneven shape 7 appears on the surface of the low refractive index layer.

  The antireflection film of the present invention can be further provided with layers for imparting various functions in addition to the above-described layers. For example, an adhesive layer or a primer layer is provided to improve the adhesion between the transparent substrate film and the high refractive index hard coat layer (high refractive index layer), and the hard coat layer is provided to improve the hard performance. Can be a plurality of layers. 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 applying a desired coating solution directly or indirectly on the transparent base film as described above, or by applying a hard coat on the transparent base film. When the layer is formed by transfer, it is formed by applying a coating solution for forming another layer on the hard coat layer formed in advance on the release film, and then the transparent base film and the release film The other layer may be transferred to the transparent substrate film by laminating the film with the release film coating surface facing inward, 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 being attached to an object to be antireflection, for example, a polarizing element.

  The antireflection film of the present invention obtained as described above is used for various displays such as word processors, computers, televisions, plasma display panels, the surfaces of polarizing plates used in liquid crystal display devices, sunglasses lenses made of transparent plastics, and prescription glasses. It is useful for preventing reflection of surfaces such as lenses, optical lenses such as camera finder lenses, covers of various instruments, window glass of automobiles, trains and the like.

Next, the present invention will be described more specifically with reference to examples and comparative examples.
Example 1
Tetrabutoxytitanium (Ti (OR ₄ )) is dissolved in ethyl cellosolve as a solvent so that the solid content concentration is 3% by weight assuming that it is ideally hydrolyzed and condensed to TiO ₂ The mixture was stirred for 30 minutes until the liquid temperature was stabilized at 25 ° C. (liquid A).
In solution A, hydrochloric acid having a concentration of 3N as a catalyst was added in a 2.5-fold molar amount with respect to the alkoxide group of tetrabutoxytitanium and hydrolyzed at 25 ° C. for 3 hours to obtain a TiO ₂ sol solution (solution B). ).

In the liquid B, a vinyl group-containing silane having a molecular weight of 5000 or less (X-12-2400: trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) at a ratio of 5 parts by weight with respect to 100 parts by weight of liquid B (solid content 3%). This was added to obtain a coating solution for high refractive index layer (refractive index 1.9).
An ionizing radiation curable phosphazene-modified acrylate (PPZ-N-2000: trade name, manufactured by Osaka Kyoeisha Chemical Co., Ltd.) on a PET film (T-60: trade name, manufactured by Diafoil Co., Ltd., thickness 50 μm) having a smooth surface After applying the liquid resin composition blended with the coating solution for the high refractive index layer at a weight ratio of 2: 1 by gravure reverse coating so as to be 7 μm / dry, and irradiating the electron beam for 5 Mrad at an acceleration voltage of 175 kV, A high-refractive-index hard coat layer (refractive index 1.75) was formed by heat treatment at 120 ° C. for 1 hour to cure.

  A two-component curable adhesive (LX660 (main agent), KW75 (hardener): trade name, manufactured by Dainippon Ink & Chemicals, Inc.) is applied by gravure reverse coating on the high refractive index hard coat layer to form an adhesive layer. Formed. Next, a PET film (A-4300: trade name, manufactured by Toyobo Co., Ltd., 100 μm thick) is laminated through this adhesive layer, and after aging at 40 ° C. for 4 days, the PET film (T-60) is peeled off. Then, the high refractive index hard coat layer was transferred onto a PET film (A-4300).

On the high refractive index hard coat layer on the obtained PET film (A-4300), SiOx was further deposited by plasma CVD to form a 100 nm thick SiOx layer (refractive index 1.46). An antireflection film of the present invention was obtained.
The obtained antireflection film had a total light transmittance of 94.0%, a haze value of 0.5, and a minimum reflectance of 0.4 in the visible light wavelength region, and was excellent in antireflection properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 2
MTEOS was dissolved in methyl ethyl ketone as a solvent so that the solid content concentration would be 3% by weight assuming that methyltriethoxysilane (MTEOS) was ideally hydrolyzed and condensed to SiO ₂ or MeSiO _1.5. Stir for 30 minutes until the temperature stabilizes at 25 ° C.
To this solution, 0.005N hydrochloric acid as a catalyst was added in an equimolar amount with the alkoxide group of MTEOS and hydrolyzed at 25 ° C. for 3 hours. To this solution, a mixture of sodium acetate and acetic acid as a curing agent was added and stirred at 25 ° C. for 1 hour to obtain a SiO ₂ sol solution.
A vinyl group-containing silane having a molecular weight of 5000 or less (X-12-2400: trade name) is added to the above solution at a ratio of 10 parts by weight with respect to 100 parts by weight of SiO ₂ sol solution (solid content: 3%). A coating solution for the refractive index layer was obtained.

  An ionizing radiation curable phosphazene-modified acrylate (PPZ-N-2000: trade name) on a mat PET film (Lumirror E-06, trade name, manufactured by Toray, thickness 50 μm) having fine irregularities formed on the surface A liquid resin composition in which the same high refractive index coating solution as in Example 1 was blended at a weight ratio of 2: 1 was applied by gravure reverse coating so as to be 7 μm / dry, and an electron beam was applied at an acceleration voltage of 175 kV for 5 Mrad. After irradiation, it was cured by heat treatment at 120 ° C. for 1 hour to form a high refractive index antiglare hard coat layer (refractive index 1.65). Next, a two-component curable adhesive (LX660 (main agent), KW75 (curing agent): trade name) was applied on the high refractive index hard coat layer by gravure reverse coating to form an adhesive layer. Next, a PET film (A-4300) was laminated through this adhesive layer, and after aging at 40 ° C. for 4 days, the PET film (Lumirror E-06) was peeled off to obtain a high refractive index antiglare hard The coat layer was transferred onto a PET film (A-4300). The surface of the high refractive index antiglare layer has the same fine uneven shape as the surface shape of the PET film (Lumirror E-06).

On the high refractive index hard coat layer on the obtained PET film (A-4300), the above-mentioned coating liquid for low refractive index layer (refractive index 1.42) has a film thickness after drying of 0.1 μm. Then, heat treatment was performed at 120 ° C. for 1 hour to obtain an antiglare and antireflection film of the present invention.
The obtained antireflection film had a total light transmittance of 92.5% and a haze value of 1.0, and was excellent in antireflection properties and antiglare properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 3
A PET film (Lumirror T-60: trade name) having a thickness of 50 μm was prepared as a transparent substrate film. On the other hand, the coating solution for high refractive index layer (refractive index 1.9) and ionizing radiation curable resin of Example 1 and ionizing radiation curable resin 1 weight with respect to 15 parts by weight of titanium oxide sol in the coating solution. So as to be part. This liquid resin composition was applied on the PET film by gravure reverse coating so that the film thickness after drying was 0.1 μm / dry, and heat-treated at 120 ° C. for 1 hour to obtain a high refractive index layer (refractive index 1.9) was formed. On this high refractive index layer, a hard coat resin (PPZ-N-2000: trade name) 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 kV for 5 Mrad to form a coating film. It was cured to form a hard coat layer (refractive index 1.55).

  On this high refractive index hard coat layer, a two-component curable adhesive (LX660 (main agent), KW75 (hardener): trade name) was applied by gravure reverse coating to form an adhesive layer. Next, after laminating a PET film (A-4300: trade name) through this adhesive layer and aging at 40 ° C. for 4 days, the PET film (T-60) was peeled off to obtain a high refractive index antiglare. The conductive hard coat layer was transferred onto a PET film (A-4300).

On the high refractive index hard coat layer on the obtained PET film (A-4300), SiOx is further deposited by plasma CVD method to form a 0.1 μm thick SiOx layer (refractive index 1.46). Thus, the antireflection film of the present invention was obtained.
The obtained antireflection film had a total light transmittance of 94.0% and a haze value of 0.5, and was excellent in antireflection properties and antiglare properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 4
In Example 3, the low refractive index layer coating liquid of Example 2 (refractive index 1.9) was formed on the high refractive index hard coat layer (refractive index 1.9) formed on the PET film (A-4300). A refractive index of 1.42) was applied so that the film thickness after drying was 0.1 μm, and heat treatment was performed at 120 ° C. for 1 hour 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 the minimum reflectance in the visible light wavelength region was 0.2, which was excellent in antireflection properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 5
Liquid obtained by blending the coating liquid for high refractive index layer and the hard coat resin (PPZ-N-2000: trade name) in a weight ratio of 2: 1 on a PET film (A-4300: trade name) having a smooth surface. The resin composition was applied by gravure reverse coating so as to be 7 μm / dry, and the solvent was removed by drying. Next, a mat PET film (Lumirror E-06: trade name, thickness 50 μm) having fine irregularities formed on the surface through this high refractive index hard coat layer is laminated, and an electron beam is irradiated at an acceleration voltage of 175 kV for 5 Mrad. Then, the coating film was cured, and the PET film (Lumirror E-06) was peeled off to form a high refractive index antiglare hard coat layer. The surface of the high refractive index antiglare hard coat layer on the PET film (A-4300) has the same fine uneven shape as the surface shape of the PET film (Lumirror E-06).

On the high refractive index hard coat layer on the obtained PET film (A-4300), SiOx is further deposited by plasma CVD method to form a 0.1 μm thick SiOx layer (refractive index 1.46). Thus, the antireflection film of the present invention was obtained.
The obtained antireflection film had a total light transmittance of 92.5% and a haze value of 1.0, and was excellent in antireflection properties and antiglare properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 6
On the antiglare high refractive index hard coat layer of Example 4, the low refractive index layer coating solution of Example 2 (refractive index 1.42) is applied so that the film thickness after drying is 0.1 μm. The film was heat treated at 120 ° C. for 1 hour to obtain the antireflection film of the present invention.
The obtained antireflection film had a total light transmittance of 93.5% and a haze value of 1.0, and was excellent in antireflection properties and antiglare properties. Moreover, the surface pencil hardness was 3H, and the hard coat performance was also excellent. Further, the adhesion between the high refractive index hard coat layer and the low refractive index layer was 100/100 in the cross-cut tape peeling test, and the adhesion was excellent.

Example 7
When it is assumed that pentaethoxy tantalum (PEOT) is ideally hydrolyzed and condensed to Ta ₂ O ₅ , the solution is dissolved in isopropyl alcohol (IPA) as a solvent so that the solid concentration is 3% by weight. Stir for 30 minutes until the temperature stabilizes at 25 ° C.
In the above solution, 5 mol of water in which hydrochloric acid having a concentration of 1N as a catalyst was dissolved was added to 1 mol of PEOT, followed by hydrolysis at room temperature for 3 hours to obtain a sol solution. A vinyl group-containing silane having a molecular weight of 5000 or less (X-12-2400: trade name) is added to this sol solution at a ratio of 5 parts by weight with respect to 100 parts by weight of the solid content of the sol solution. (Refractive index 1.9) was obtained.
An antireflection film of the present invention was obtained in the same manner as in Example 1 except that this high refractive index layer coating solution was used. This antireflection film has excellent total light transmittance, haze value, antireflection property, surface pencil hardness and adhesion between the high refractive index hard coat layer and the low refractive index layer as in Example 1. It was.

Comparative Example 1
In the antireflection film of Example 1, antireflection was performed in the same manner as in Example 1 except that the refractive index layer was formed using a TiO ₂ sol solution to which no reactive silicon organic compound (X-12-2400) was added. A film was prepared. This antireflection film has a total light transmittance of 94.5% and a haze value of 0.5, and the antireflection property is the same as in Example 1. However, the antireflective film has a high refractive index hard coat layer and a low refractive index layer. The adhesion was 80/100 in a cross-cut tape peel test.

Comparative Example 2
In the antireflection film of Example 1, an antireflection film was produced in the same manner as in Example 1 except that the TiOx film formed by vacuum deposition was changed to a high refractive index layer. This antireflection film has a total light transmittance of 93.7% and a haze value of 0.7, and the antireflection properties are lower than those of the above examples. The surface pencil hardness was 2H, and the adhesion between the high refractive index hard coat layer and the low refractive index layer was 60/100 in a cross-cut tape peel test.

  As described above, according to the present invention, a high refractive index hard coat layer of an antireflection film is formed from a sol solution containing a titanium or tantalum oxide sol and a reactive organosilicon compound in a liquid medium, with a refractive index of 1.65. By forming the gel film as described above, an antireflection film in which the low refractive index layer has excellent adhesion to the high refractive hard coat layer is economically provided without using expensive and complicated equipment. be able to.

The figure explaining the cross section of one example of the antireflection film of this invention. The figure explaining the cross section of the other example of the antireflection film of this invention. The figure explaining the cross section of the other example of the antireflection film of this invention.

Explanation of symbols

1: Transparent base film 2: High refractive index hard coat layer 3: Low refractive index layer 4: Adhesive layer 5: Hard coat layer 6: High refractive index layer 7: Fine uneven shape

Claims (8)

  In the antireflection film formed by laminating a hard coat layer having a high refractive index and a low refractive index layer on a transparent substrate film, the high refractive index layer comprises an oxide sol of titanium or tantalum in a liquid medium, Methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyl An antireflection film comprising a gel film having a refractive index of 1.65 or more formed from a sol liquid containing a reactive organosilicon compound selected from diethoxysilane and hexyltrimethoxysilane.   2. The antireflection film according to claim 1, wherein the sol solution contains 0.1 to 50 parts by weight of a reactive organosilicon compound per 100 parts by weight of titanium or tantalum oxide sol (solid content).   2. The antireflection film according to claim 1, wherein the reactive organosilicon compound is an organosilicon compound having a plurality of functional groups curable by heat and / or ionizing radiation or a partial hydrolyzate thereof.   2. The antireflection film according to claim 1, wherein the hard coat layer having a high refractive index is functionally separated into a hard coat layer and a high refractive index layer.   The antireflection film according to claim 1, wherein fine irregularities are formed on the surface to impart antiglare properties.   2. The antireflective film according to claim 1, wherein the oxide sol of titanium or tantalum is prepared by dissolving in an organic solvent suitable for application of a metal alkoxide and adding a certain amount of water to perform hydrolysis. The antireflective film according to claim 1, wherein the low refractive index layer is a thin film of MgF ₂ or SiO ₂ formed by vapor deposition, sputtering, or plasma CVD. _2. The antireflection film according to claim 1, wherein the low refractive index layer is a SiO ₂ thin film formed from a SiO ₂ sol solution.

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