JP2012128168A - Antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film which is inexpensive, prevents generation of interference fringes, has good adhesiveness between an antireflection layer and a substrate, and has excellent mechanical strength against, for example, cracks in top ends of projections in a fine concavo-convex pattern on the antireflection film, and excellent sticking resistance and stripping property.SOLUTION: An antireflection film includes an easy-adhering layer formed on a light-transmitting substrate formed of a PET resin, and an antireflection layer. The easy-adhering layer has an average refractive index between a refractive index of the light-transmitting substrate and a refractive index of the antireflection layer. The antireflection layer includes a base portion formed on the easy-adhering layer, and fine recesses and projections in a concavo-convex pattern formed on the base portion. The projection in the fine recesses and projections includes a truncated main body rising in a tapered shape on the light-transmitting substrate and a top end portion having a curved structure formed to cover the top face of the main body.

Description

  The present invention relates to an antireflection film used for various display media.

  2. Description of the Related Art In recent years, various studies have been made for the purpose of improving the display quality of images, characters, numbers, and the like on various display media such as paintings, print media, and displays. In particular, the development of anti-reflection technology for the purpose of improving display quality is one of the important technical issues common to various display media.

  Conventionally, as such an antireflection technique, for example, a technique of obtaining an antireflection effect effective for light of a single wavelength by forming a thin film made of a low refractive index material on the surface as a single layer, A technique for obtaining an antireflection effect for light in a wider wavelength range by forming a plurality of layers in which thin films of a low refractive index substance and a high refractive index substance are alternately formed has been used. Among them, the technique using a plurality of layers has been useful in that it can obtain an antireflection effect even for light having a wider wavelength range by increasing the number of layers. It has been put to practical use.

However, there are some problems in such a technique using a plurality of layers. First, in order to form a plurality of layers having an excellent antireflection effect, it is usually necessary to form a film using a vacuum deposition method or the like, and therefore it is necessary to provide a vacuum facility when manufacturing a display device. There was a problem of becoming. Further, in the vacuum evaporation method, since the film formation time is generally long, a problem of manufacturing efficiency has been pointed out. In particular, for displays used in environments with very strong ambient light, a higher antireflection function is required, and the number of layers that make up multiple layers must be increased, resulting in significant manufacturing costs. There was a problem of becoming high.
Second, even from a technical point of view, the antireflection technology using a plurality of layers makes use of the light interference phenomenon, so the antireflection effect greatly affects the incident angle and wavelength of light. There is a problem that it is difficult to obtain the same antireflection effect.

In order to deal with such problems, Patent Documents 1 to 6 disclose techniques for preventing reflection by forming on the surface a fine uneven pattern in which the uneven period is controlled to be equal to or less than the wavelength of visible light. Such a method uses the principle of a so-called moth-eye structure, and continuously changes the refractive index for light incident on the substrate, thereby eliminating the discontinuous interface of the refractive index. This prevents light reflection. Such antireflection technology using a moth-eye structure is useful in that it can prevent reflection of light in a wide wavelength range by a simple method, and its practical application is also being studied in the field of displays. .
In addition, as a fine uneven | corrugated pattern used for the said moth-eye structure, the shape where the front-end | tip is sharp in the shape containing cones and cylinders, such as a cone shape and a quadrangular pyramid shape, is common.

  However, when a fine concavo-convex pattern with a sharp tip such as a cone having a conical shape is used as the moth-eye structure, there is a problem that the fine concavo-convex pattern is liable to break because the tip is thin, In the case of a shape including a shape, there is a problem that the die-cutting property of the fine uneven pattern is not good. Further, in the case of a cylindrical shape, when a liquid having a large surface tension enters the moth-eye structure and evaporates, a phenomenon in which adjacent structures contact or stick to each other (sticking) easily occurs. When sticking occurs in 50% or more of the structure, there arises a problem that haze increases due to a decrease in the antireflection function and an increase in diffused light.

  On the other hand, the moth-eye structure is generally manufactured by using a mold (stamper or mold) having a shape obtained by inverting the fine uneven shape and transferring the uneven shape to an arbitrary resin layer. Is. Therefore, as a method for producing an antireflection film using a moth-eye structure (hereinafter sometimes referred to as “moth-eye type antireflection film”), after forming a resin layer made of a curable resin on a substrate, A method of forming a moth-eye structure on the surface of the resin layer using the mold as described above and further curing the resin layer can be used. Such a production method has an advantage that an antireflection film can be continuously produced by a simple method and high production efficiency. On the other hand, the interface between the substrate and the resin layer is Since it is clear, there are problems that interference fringes are generated due to the difference in refractive index between the substrate and the resin layer, and the adhesion between the substrate and the resin layer is not sufficient.

  On the other hand, interference fringes can be prevented by forming a solvent permeation layer in which the solvent and resin used in forming the resin layer penetrated the substrate at the interface between the resin layer and the substrate, and the resin layer It is known that the adhesion between the substrate and the substrate can be improved. However, the substrate on which such a solvent permeation layer can be formed is limited in the resin used. For example, an inexpensive polyethylene terephthalate (PET) resin is used for the substrate in order to reduce the cost of the antireflection film. In such a case, since the PET resin has high solvent resistance, a solvent permeation layer cannot be formed, and interference fringes cannot be prevented and adhesion between the resin layer and the substrate cannot be improved. .

JP-T-2001-517319 JP 2004-205990 A JP 2004-287238 A JP 2001-272505 A JP 2002-286906 A International Publication No. 2006/059686 Pamphlet

  The present invention has been made in view of the above problems, is inexpensive, can prevent the occurrence of interference fringes, has good adhesion between the antireflection layer and the substrate, and has fine irregularities in the antireflection layer. The main object is to provide an antireflection film excellent in mechanical strength, sticking resistance, and die-cutting property against cracks at the tips of convex portions of a pattern.

In order to achieve the above object, the present inventors have conducted intensive research, and as a result, when a fine concavo-convex pattern having a flat convex tip, such as a truncated cone shape such as a truncated cone, is used as a moth-eye structure, an antireflection layer It was found that the problem such as cracking of the tip of the fine uneven pattern in can be solved, and further, the die-cutting property can be improved, but the antireflection function is lowered when the tip of the convex part is flat. There is a possibility that. Therefore, by adopting a moth-eye structure with a fine concavo-convex pattern having a shape with a curvature at the tip of the convex part, the mechanical strength, sticking resistance and die-cutting properties against cracks etc. of the convex part of the fine concavo-convex pattern in the antireflection layer are improved And the antireflection function is not deteriorated.
In addition, even when an inexpensive PET resin is used for the substrate, the present inventor can improve the adhesion between the resin layer and the substrate by forming an easy adhesion layer between the resin layer and the substrate. Furthermore, it has been found that interference fringes can be prevented by controlling the refractive index of the easy adhesion layer. The present invention has been made based on these findings.

  That is, the present invention provides a light-transmitting substrate made of polyethylene terephthalate (PET) resin, an easy-adhesion layer formed on the light-transmitting substrate, an easy-adhesion layer, and has a visible light region on the surface. An antireflection film having an antireflection layer having a concavo-convex shape formed with a period equal to or shorter than a wavelength, wherein the easy-adhesion layer includes a refractive index of the light transmissive substrate and a refractive index of the antireflection layer. It has an average refractive index, and the antireflection layer has a base portion formed on the easy-adhesion layer, a fine unevenness formed on the base portion and having the uneven shape, and the above The convex part in the fine unevenness is composed of a frustum-shaped main body part that rises in a tapered shape with respect to the light-transmitting substrate, and a tip part having a curved surface structure so as to cover the top surface of the main body part. Reflection characterized by To provide a stop film.

  According to the present invention, the adhesion between the antireflection layer and the light transmissive substrate can be improved by forming the easy adhesion layer between the light transmissive substrate and the antireflection layer, and the easy adhesion layer. By having a predetermined refractive index, generation of interference fringes can be prevented and reflection unevenness can be suppressed. In addition, by using a light-transmitting substrate made of PET resin, an inexpensive antireflection film can be obtained. Further, according to the present invention, the convex portion in the fine unevenness of the antireflection layer has a curved surface structure formed so as to cover the top surface of the frustum-shaped main body portion that rises in a tapered shape with respect to the light-transmitting substrate. Since it has a tip, it has a good anti-reflection function, and it should be an anti-reflection film with excellent mechanical strength, sticking resistance and die-cutting properties against cracks at the tip of the convex part of the fine uneven pattern in the anti-reflection layer. Can do. Furthermore, since the convex part in the said fine unevenness | corrugation has the said frustum-shaped main-body part, it can be set as the antireflection film which is easy to come off from the metal mold | die used when manufacturing an antireflection film.

  In the said invention, it is preferable that the functional layer is formed between the said easily bonding layer and the said reflection preventing layer. It is because a desired function can be provided to the antireflection film of the present invention by forming the functional layer.

  In the said invention, it is preferable that the said functional layer is a hard-coat layer, a primer layer, or an antistatic layer. It is because the hardness of the antireflection film of the present invention can be improved and the antireflection film excellent in durability can be obtained by forming the hard coat layer. In addition, since the primer layer is formed, the adhesion between the easy adhesion layer and the antireflection layer is improved, and the adhesion between the antireflection layer and the light-transmitting substrate is improved through the easy adhesion layer and the primer layer. It is because it can improve more. In addition, since the antistatic layer is formed, generation of static electricity can be suppressed and adhesion of dust and dirt to the antireflection film of the present invention can be prevented.

  In the said invention, it is preferable that the taper angle with respect to the said transparent substrate in the longitudinal cross-section of the said main-body part exists in the range of 50 degrees-87 degrees. This is because it can be more easily removed from the mold used for manufacturing the antireflection film.

  In the said invention, it is preferable that the height of the said main-body part exists in the range of 60 nm-1400 nm. This is because the antireflection layer can have a good antireflection function.

  The antireflection film of the present invention is inexpensive, can prevent the generation of interference fringes, has good adhesion between the antireflection layer and the substrate, cracks at the tips of the convex portions of the fine uneven pattern in the antireflection layer, etc. The mechanical strength, sticking resistance and die-cutting properties are excellent.

It is a schematic sectional drawing which shows an example of the antireflection film of this invention. It is a schematic sectional drawing which shows an example of the antireflection layer in the antireflection film of this invention. It is the schematic explaining the shape of the fine unevenness | corrugation in an antireflection film. It is a schematic sectional drawing which shows an example of the front-end | tip part in the antireflection film of this invention. It is the schematic explaining the parameter which specifies the fine unevenness | corrugation in the antireflection film of this invention. It is a schematic sectional drawing which shows the other example of the antireflection film of this invention. It is a schematic sectional drawing which shows the other example of the antireflection film of this invention. It is a schematic sectional drawing which shows the other example of the antireflection film of this invention. It is a schematic sectional drawing which shows the other example of the antireflection film of this invention. It is a schematic sectional drawing which shows an example of the metal mold | die for antireflection film manufacture used for this invention. It is a schematic sectional drawing which shows the other example of the metal mold | die for antireflection film manufacture used for this invention. It is the schematic explaining the parameter which specifies the fine unevenness | corrugation in the metal mold | die for antireflection film used for this invention. It is process drawing which shows an example of the manufacturing method of the metal mold | die for antireflection film manufacture used for this invention.

  Hereinafter, the antireflection film of the present invention will be described in detail.

  The antireflection film of the present invention includes a light-transmitting substrate made of polyethylene terephthalate (PET) resin, an easy-adhesion layer formed on the light-transmitting substrate, and an easy-adhesion layer formed on the surface and visible light on the surface. An antireflection film having an antireflection layer having a concavo-convex shape formed with a period equal to or less than the wavelength of the region, wherein the easy-adhesion layer includes a refractive index of the light-transmitting substrate and a refractive index of the antireflection layer. The antireflective layer has a base formed on the easy-adhesion layer, and a fine unevenness formed on the base and having the uneven shape, And the convex part in the said fine unevenness | corrugation from the frustum-shaped main-body part which taper-rises with respect to the said transparent substrate, and the front-end | tip part which has a curved-surface structure formed so that the top surface of the said main-body part might be covered. It is composed of Is shall.

  The antireflection film of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the antireflection film of the present invention. 1A shows the entire antireflection film, and FIG. 1B shows an enlarged antireflection layer in the antireflection film shown in FIG. 1A. An antireflection film 10 illustrated in FIG. 1A includes a light-transmitting substrate 1 made of polyethylene terephthalate (PET) resin, an easy-adhesion layer 2 formed on the light-transmitting substrate 1, and an easy-adhesion layer 2 And an antireflection layer 3 having a concavo-convex shape formed on the surface of the visible light region with a period equal to or shorter than the wavelength of the visible light region. The easy adhesion layer 2 has a refractive index that is an average of the refractive index of the light-transmitting substrate 1 and the refractive index of the antireflection layer 3, and the antireflection layer 3 is formed on the easy adhesion layer 2. The base portion 4 and the fine unevenness 5 formed on the base portion 4 and having the uneven shape are provided. Furthermore, as illustrated in FIG. 1B, the convex portions of the fine irregularities 5 cover the frustum-shaped main body portion 5a that rises in a tapered shape with respect to the light-transmitting substrate and the top surface of the main body portion 5a. It is comprised from the front-end | tip part 5b which has the curved surface structure formed in this.

  According to the present invention, the adhesion between the antireflection layer and the light transmissive substrate can be improved by forming the easy adhesion layer between the light transmissive substrate and the antireflection layer, and the easy adhesion layer. By having a predetermined refractive index, generation of interference fringes can be prevented and reflection unevenness can be suppressed. In addition, by using a light-transmitting substrate made of PET resin, an inexpensive antireflection film can be obtained. Further, according to the present invention, the convex portion in the fine unevenness of the antireflection layer has a curved surface structure formed so as to cover the top surface of the frustum-shaped main body portion that rises in a tapered shape with respect to the light-transmitting substrate. Since it has a tip, it has a good anti-reflection function, and it should be an anti-reflection film with excellent mechanical strength, sticking resistance and die-cutting properties against cracks at the tip of the convex part of the fine uneven pattern in the anti-reflection layer. Can do. Furthermore, since the convex part in the said fine unevenness | corrugation has the said frustum-shaped main-body part, it can be set as the antireflection film which is easy to come off from the metal mold | die used when manufacturing an antireflection film.

The antireflection film of the present invention has at least a light-transmitting substrate, an easy-adhesion layer, and an antireflection layer, and may have any other configuration as necessary.
Hereinafter, each structure in the antireflection film of the present invention will be described.

1. Easy-Adhesion Layer First, the easy-adhesion layer in the present invention will be described. The easy adhesion layer in the present invention is formed on a light-transmitting substrate made of polyethylene terephthalate (PET) resin, and is a refractive index that is an average of the refractive index of the light-transmitting substrate and the refractive index of the antireflection layer. Has a rate. In the present invention, the adhesion between the light transmissive substrate and the antireflection layer can be improved by forming an easy-adhesion layer having a predetermined refractive index between the light transmissive substrate and the antireflection layer. And generation | occurrence | production of an interference fringe can be prevented.

The easy-adhesion layer in the present invention is usually made of a resin. Examples of the resin used for the easy adhesion layer include an ultraviolet curable resin, a thermosetting resin (including a two-component curable resin), and a thermoplastic resin.
Although it does not specifically limit as an ultraviolet curable resin, For example, the compound which has an at least 3 or more ethylenically unsaturated double bond is mentioned. Specifically, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) Acrylate, tris (acryloxyethyl) isocyanurate, caprolactone-modified tris (acryloxyethyl) isocyanurate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, alkyl-modified dipentaerythritol Such as tra (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetra (meth) acrylate, polyurethane polyacrylate, polyester polyacrylate, etc. Ester compound of polyhydric alcohol and (meth) acrylic acid; polyurethane poly (meth) acrylate, polyester poly (meth) acrylate, polyether poly (meth) acrylate, polyacryl poly (meth) acrylate, polyalkyd poly (meth) Acrylate, polyepoxy poly (meth) acrylate, polyspiroacetal poly (meth) acrylate, polybutadiene poly (meth) acrylate, polythiol polyempo (Meth) acrylates, (meth) acrylate compound of the polysilicon poly (meth) polyfunctional compounds such acrylate.
Among these compounds having at least three or more ethylenically unsaturated double bonds, polyurethane poly (meth) acrylate and polyepoxy poly (meth) acrylate having at least six functional groups from the viewpoint of coating film strength and adhesion. Poly (meth) acrylates such as polyfunctional acrylates having 4 or more acryloyl groups in the molecule can be suitably used.
The polyurethane poly (meth) acrylate is obtained by reacting, for example, a diisocyanate and a (meth) acrylate having a hydroxyl group, or an isocyanate group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under an excess of isocyanate groups. Some are obtained by reacting polymers with (meth) acrylates having a hydroxyl group. Alternatively, a hydroxyl group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under hydroxyl-excess conditions can be obtained by reacting with a (meth) acrylate having an isocyanate group.
Examples of polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentane glycol, neopentyl glycol, hexanetriol, trimellilol propane, polytetra Examples include methylene glycol and a condensation polymer of adipic acid and ethylene glycol.
Examples of the polyisocyanate include tolylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.
Examples of (meth) acrylates having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and ditrimethylolpropane tetraacrylate. .
Examples of (meth) acrylates having an isocyanate group include 2-methacryloyloxyethyl isocyanate and methacryloyl isocyanate.
Polyepoxy poly (meth) acrylate is an epoxy resin whose ester group is esterified with (meth) acrylic acid and whose functional group is (meth) acryloyl group, and (meth) acrylic acid addition to bisphenol A type epoxy resin Products, (meth) acrylic acid addition products to novolac type epoxy resins, and the like.
Specific examples of the polyfunctional group having four or more acryloyl groups in the molecule include the above-mentioned polyhydric alcohol and acrylic acid ester compounds, and a single compound or a mixture of two or more compounds is preferred.
Furthermore, a (meth) acrylic polymerizable composition described in WO2007 / 040159 can be used.

  Examples of the thermosetting resin or thermoplastic resin include acrylic resin, polyester resin, epoxy resin, polyolefin resin, polyethyleneimine resin, polyether resin, polyether urethane resin, polyester urethane resin, styrene resin, polyamide resin, Polyimide resin, polyamideimide resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polycarbonate resin, melamine resin, urea resin, alkyd resin, phenol resin, cellulose resin, diallyl phthalate resin, silicone resin, polyarylate Resin, Polyacetal resin, Styrene-isoprene rubber, Olefin / maleimide copolymer, Fluorine epoxy, Fluorine acrylate, Fluoro Mention may be made in polyester, a fluorine resin, or the like.

As the transparency of the easy-adhesion layer in the present invention, the light transmittance with respect to the entire wavelength range of visible light is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. preferable.
Here, the light transmittance can be measured by, for example, a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Corporation.

The refractive index of the easy-adhesion layer in the present invention is the average of the refractive index of the light-transmitting substrate and the refractive index of the antireflection layer described later. Here, “becomes the average of the refractive index of the light transmissive substrate and the refractive index of the antireflection layer” means “± 2.5 of the arithmetic average value of the refractive index of the light transmissive substrate and the refractive index of the antireflection layer”. % ”.
In the present invention, by making the refractive index of the anti-reflection layer close to the refractive index of the light-transmitting substrate, the refractive index of the easy-adhesion layer is the same as the refractive index of the light-transmitting substrate and the refractive index of the anti-reflection layer. It is preferable that the value be as close as possible. Thereby, in the antireflection film of the present invention, a discontinuous interface of refractive index is formed at each interface of the antireflection layer, the easy-adhesion layer, and the light-transmitting substrate, and light is reflected at the discontinuous interface. This is because the antireflection function of the antireflection film can be prevented from being impaired. Among these, the refractive index of the easy-adhesion layer is preferably such that the difference between the refractive index of the antireflection layer and the refractive index of the light-transmitting substrate is in the range of 0 to 0.5, and is in the range of 0 to 0.2. It is more preferable that it is in the range of 0 to 0.1.
In the present invention, the refractive index value of the easy-adhesion layer is determined by the refractive index of the light-transmitting substrate and the refractive index of the antireflection layer. It is set within the range of ~ 2.40.

  In addition, the easy adhesion layer in the present invention may be a single layer or a multilayer. When the easy adhesion layer is a multilayer, the average refractive index obtained by averaging the refractive indexes of the layers constituting the easy adhesion layer is the average of the refractive index of the light-transmitting substrate and the refractive index of the antireflection layer. When the easy adhesion layer is a multilayer, it is desirable that the refractive index of the light-transmitting substrate> the refractive index of the easy adhesion layer> the refractive index of the antireflection layer.

  The thickness of the easy-adhesion layer of the present invention is not particularly limited as long as the adhesion between the antireflection layer and the light-transmitting substrate can be improved and interference fringes can be prevented. Although not intended, it is preferably within the range of 0.01 μm to 10.0 μm, more preferably within the range of 0.05 μm to 5.0 μm, and within the range of 0.10 μm to 2.0 μm. More preferably it is. If the thickness of the easy-adhesion layer is larger than the above range, curling may occur in the antireflection film of the present invention. If the thickness of the easy-adhesion layer is smaller than the above range, it is desirable for the easy-adhesion layer. This is because it may be difficult to impart the hardness of.

  The easy-adhesion layer in the present invention may contain any additive as necessary in addition to the above-described resin. Such an additive is not particularly limited as long as a desired function can be imparted to the easy-adhesion layer of the present invention, and examples thereof include an antistatic agent (conductive agent), a refractive index adjusting agent, and a leveling. Agents, antifouling agents, adhesives, ultraviolet and infrared absorbers, hardeners, hardness modifiers, fluidity modifiers, antioxidants, fluororesins, liquid paraffin, paraffin wax, synthetic polyethylene wax and other hydrocarbons Release agents such as metal soaps, fatty acid amides, metal stearates, metal soaps such as calcium stearate / magnesium stearate, lead stearate / zinc stearate, fatty acid esters, silicone oils, acrylic polymers Examples thereof include an internal or external lubricant, a polarization refraction adjusting agent such as strontium carbonate, a hydrophilic agent, a lipophilic agent, and a coloring agent. Specifically, for example, the following substances described in JP 2009-230045 A can be mentioned.

<Antistatic agent (conductive agent)>
By adding an antistatic agent (conductive agent), dust adhesion on the surface of the easy-adhesion layer can be effectively prevented. Specific examples of the antistatic agent (conductive agent) include quaternary ammonium salts, pyridinium salts, various cationic compounds having a cationic group such as first to third amino groups, sulfonate groups, sulfate ester bases, Anionic compounds having an anionic group such as phosphate ester base and phosphonate base, amphoteric compounds such as amino acid series and amino sulfate ester series, nonionic compounds such as amino alcohol series, glycerin series and polyethylene glycol series, tin and titanium And metal chelate compounds such as acetylacetonate salts thereof, and compounds obtained by increasing the molecular weight of the compounds listed above. In addition, a monomer or oligomer having a tertiary amino group, a quaternary ammonium group, or a metal chelate portion and polymerizable by ionizing radiation, or an organometallic compound such as a coupling agent having a functional group, etc. Polymerizable compounds can also be used as antistatic agents.

  Examples of the antistatic agent include conductive polymers, and specific examples thereof include aliphatic conjugated polyacetylene, polyacene, oliazulene, etc .; aromatic conjugated poly (paraphenylene), etc .; heterocyclic conjugated type Examples include polypyrrole, polythiophene, polyisocyannaphthene, etc .; heteroatom-containing polyaniline, polythienylene vinylene, etc .; mixed conjugated poly (phenylene vinylene), etc. In addition to these, a plurality of conjugated chains are included in the molecule. Examples thereof include a double-chain conjugated system that is a conjugated system, a conductive composite that is a polymer obtained by grafting or block-copolymerizing the conjugated polymer chain described above to a saturated polymer, and these conductive polymer derivatives. In particular, it is more preferable to use an organic antistatic agent such as polypyrrole, polythiophene or polyaniline. By using the above-mentioned organic antistatic agent, it is possible to exhibit excellent antistatic performance and at the same time increase the total light transmittance of the easy-adhesive layer and reduce the haze value. An anion such as an organic sulfonic acid or iron chloride can be added as a dopant (electron donor) for the purpose of improving conductivity and improving antistatic performance. In view of the effect of dopant addition, polythiophene is particularly preferable because of its high transparency and antistatic properties. As the polythiophene, oligothiophene can also be preferably used. The derivative is not particularly limited, and examples thereof include polyphenylacetylene, polydiacetylene alkyl group-substituted products, and the like. In addition, conductive carbon nanotubes, boron, and compounds thereof can be used. Metals and fine powders of these metal oxides having a particle diameter of 1 μm or less can also be added. For example, a metal made of titanium, aluminum, cerium, yttrium, zirconium, niobium, antimony, or a metal oxide, or a compound in which these are coated or doped on the surface is used.

  According to a preferred aspect of the present invention, the antistatic agent is 0.01% by weight or more and 50% by weight or less based on the total amount of the resin composition for forming an easy adhesion layer used when forming the easy adhesion layer. Preferably, the lower limit is 0.1% by weight or more and the upper limit is about 30% by weight or less. By adjusting to the above numerical range, it is preferable in that the transparency as the easy-adhesion layer is maintained and the antistatic performance can be imparted without affecting the function of the easy-adhesion layer.

<Refractive index modifier>
By adding a refractive index adjusting agent, it is possible to adjust the optical characteristics of the easy adhesion layer. Examples of the refractive index adjusting agent include a low refractive index agent, a medium refractive index agent, and a high refractive index agent.

1) Low refractive index agent The refractive index of the easy-adhesion layer to which the low refractive index agent is added is less than 1.5, preferably 1.45 or less. Preferable examples of the low refractive index agent include low refractive index inorganic ultrafine particles such as silica and magnesium fluoride (all kinds of fine particles such as porous and hollow), and fluorine-based resins which are low refractive index resins. As the fluororesin, a polymerizable compound containing at least a fluorine atom in the molecule or a polymer thereof can be used. The polymerizable compound is not particularly limited, but for example, those having a curing reactive group such as a functional group that is cured by ionizing radiation and a polar group that is thermally cured are preferable. Moreover, the compound which has these reactive groups simultaneously may be sufficient. In contrast to this polymerizable compound, a polymer has no reactive groups as described above.

  As the polymerizable compound having an ionizing radiation curable group, fluorine-containing monomers having an ethylenically unsaturated bond can be widely used. More specifically, to illustrate fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.) Can do. As having a (meth) acryloyloxy group, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) Ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, α-trifluoromethacryl (Meth) acrylate compounds having fluorine atoms in the molecule, such as methyl acrylate and ethyl α-trifluoromethacrylate; C 1-14 fluoroalkyl groups having at least 3 fluorine atoms in the molecule, fluorocyclo An alkyl group or a fluoroalkylene group and at least two (medium There are also fluorine-containing polyfunctional (meth) acrylic acid ester compounds having an acryloyloxy group.

  Preferable examples of the thermosetting polar group include hydrogen bond forming groups such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. These are excellent not only in adhesion to the coating film but also in affinity with inorganic ultrafine particles such as silica. Examples of the polysynthetic compound having a thermosetting polar group include 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, phenol, polyimide, etc. Fluorine modified products of each resin can be mentioned.

  Polymerizable compounds having both ionizing radiation curable groups and thermosetting polar groups include acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, fully or partially fluorine. Illustrative examples include fluorinated vinyl esters, fully or partially fluorinated vinyl ketones, and the like.

  Specific examples of the fluorine-containing polymer include a polymer of a monomer or a monomer mixture containing at least one fluorine-containing (meth) acrylate compound of the polymerizable compound having the ionizing radiation curable group; the fluorine-containing (meth) At least one kind of acrylate compound and no fluorine atom in the molecule such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate ( Copolymer with (meth) acrylate compound; fluoroethylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3- Trifluoropropylene, hexafluoropropylene Homopolymers or copolymers of fluorine-containing monomer are mentioned, such as.

  Silicone-containing vinylidene fluoride copolymers obtained by adding a silicone component to these copolymers can also be used. The silicone components in this case include (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl-modified (poly) dimethylsiloxane, azo group-containing (poly) dimethylsiloxane, Dimethyl silicone, phenylmethyl silicone, alkyl aralkyl modified silicone, fluorosilicone, polyether modified silicone, fatty acid ester modified silicone, methyl hydrogen silicone, silanol group containing silicone, alkoxy group containing silicone, phenol group containing silicone, methacryl modified silicone, acrylic Modified silicone, amino modified silicone, carboxylic acid modified silicone, carbinol modified silicone, epoxy modified silicone, mercapto modified silicone Over emissions, fluorine-modified silicones, polyether-modified silicone and the like. Among them, those having a dimethylsiloxane structure are preferable.

  Furthermore, non-polymers or polymers composed of the following compounds can also be used as the fluororesin. That is, a fluorine-containing compound having at least one isocyanato group in the molecule is reacted with a compound having at least one functional group in the molecule that reacts with an isocyanato group such as an amino group, a hydroxyl group, or a carboxyl group. Compound obtained: a compound obtained by reacting a fluorine-containing polyol such as fluorine-containing polyether polyol, fluorine-containing alkyl polyol, fluorine-containing polyester polyol, fluorine-containing ε-caprolactone modified polyol with a compound having an isocyanato group Can be used.

  According to a preferred embodiment of the present invention, it is preferable to use “fine particles having voids” as the low refractive index agent. The “fine particles having voids” can reduce the refractive index while maintaining the layer strength of the easily adhesive layer. In the present invention, the term “fine particles having voids” means a structure in which a gas is filled with gas and / or a porous structure containing gas, and the gas in the fine particle is compared with the original refractive index of the fine particle. It means fine particles whose refractive index decreases in inverse proportion to the occupation ratio. The present invention also includes fine particles capable of forming a nanoporous structure inside and / or at least part of the surface depending on the form, structure, aggregation state, and dispersion state of the fine particles inside the coating film. It is.

  As specific examples of the inorganic fine particles having voids, silica fine particles prepared by using the technique disclosed in JP-A-2001-233611 are preferably exemplified. In addition, it may be silica fine particles obtained by the production methods described in JP-A-7-133105, JP-A-2002-79616, JP-A-2006-106714, and the like. Since the silica fine particles having voids are easy to manufacture and have high hardness, when mixed with a binder and added to the easy-adhesion layer, the layer strength is improved and the refractive index is 1.20 to 1.45. It is possible to adjust within a range. In particular, as specific examples of the organic fine particles having voids, hollow polymer fine particles prepared by using the technique disclosed in JP-A-2002-80503 are preferably exemplified.

  The fine particles capable of forming a nanoporous structure inside and / or at least part of the surface of the coating are manufactured for the purpose of increasing the specific surface area in addition to the silica fine particles, and the packing column and the surface porosity Examples include controlled release materials that adsorb various chemical substances in the mass part, porous fine particles used for catalyst fixation, or dispersions and aggregates of hollow fine particles intended to be incorporated into heat insulating materials and low dielectric materials. it can. As such a specific example, as a commercial product, an assembly of porous silica fine particles from the product names Nippil and Nipgel manufactured by Nippon Silica Kogyo Co., Ltd., a structure in which silica fine particles manufactured by Nissan Chemical Industries, Ltd. are linked in a chain form From the colloidal silica UP series (trade name), it is possible to use those within the preferred particle diameter range of the present invention.

  The average particle diameter of the “fine particles having voids” is 5 nm or more and 300 nm or less, preferably the lower limit is 8 nm or more and the upper limit is 100 nm or less, more preferably the lower limit is 10 nm or more and the upper limit is 80 nm or less. When the average particle diameter of the fine particles is within this range, excellent transparency can be imparted to the easy adhesion layer.

2) High refractive index agent / medium refractive index agent The high refractive index agent and the medium refractive index agent are used to further improve the optical properties of the easily adhesive layer. The refractive index of the high refractive index agent and the medium refractive index agent may be set within the range of 1.55 to 2.00, and the refractive index of the medium refractive index agent is within the range of 1.55 to 1.80. The high refractive index agent means one having a refractive index in the range of 1.65 to 2.00.

  Examples of these refractive index agents include fine particles. Specific examples thereof (indicated by the refractive index in parentheses) include zinc oxide (1.90), titania (2.3 to 2.7), and ceria (1.95). ), Tin-doped indium oxide (1.95), antimony-doped tin oxide (1.80), yttria (1.87), and zirconia (2.0).

<Leveling agent>
The leveling agent can impart an effect of slipping property, antifouling property and scratch resistance to the easily adhesive layer. Therefore, the leveling agent functions as an antifouling agent, a water repellent, an oil repellent, and a fingerprint adhesion preventive. Preferable leveling agents include fluorine or silicone.

<Contaminant>
The main purpose of the antifouling agent is to prevent contamination of the easy-adhesion layer, and it is possible to impart scratch resistance to the easy-adhesion layer. As specific examples of the antifouling agent, additives that exhibit water repellency, oil repellency, and fingerprint wiping are effective. Specific examples include fluorine compounds, silicon compounds, or mixed compounds thereof. More specifically, silane coupling agents having a fluoroalkyl group, such as 2-perfluorooctylethyltriaminosilane, and the like can be mentioned, and those having an amino group can be preferably used.

<Ultraviolet / infrared absorber>
Examples of the ultraviolet absorber include benzotriazole compounds, benzophenone compounds, salicylate compounds, and the like. Examples of the infrared absorber include diimonium compounds and phthalocyanine compounds.

<High hardness agent, hardness modifier, and fluidity modifier>
Any of the hardening agent, hardness adjusting agent, and fluidity adjusting agent may be used as long as they are used in a functional layer generally used in an antireflection film.

2. Next, the antireflection layer in the present invention will be described. The antireflection layer in this invention is formed on the said easily bonding layer, and provides the antireflection function to the antireflection film of this invention. Further, the antireflection layer in the present invention has an uneven shape (hereinafter sometimes referred to as “moth eye structure”) formed on the surface with a period equal to or less than the wavelength of the visible light region. It has a base portion formed on the top and fine unevenness formed on the base portion and having the uneven shape.

(1) Fine unevenness The fine unevenness used for this invention consists of uneven | corrugated shape formed with the period below the wavelength of visible light region, and the convex part in the said fine unevenness is a taper with respect to a transparent substrate. A frustum-shaped main body portion that rises like a cone and a tip portion having a curved surface structure formed so as to cover the top surface of the main body portion.

(A) Main body The main body used in the present invention has a frustum shape that rises in a tapered shape with respect to the light-transmitting substrate. In this invention, since it has the said frustum-shaped main-body part, while having a favorable antireflection function, it becomes easy to remove | deviate from the metal mold | die used when manufacturing an antireflection film. When the removal from the mold is bad, the resin for forming the main body part remains in the fine holes of the mold. The surface of the easy-adhesion layer to which the portion corresponding to the remaining portion has been transferred is in a state where there is no concavo-convex shape for exhibiting the antireflection function, which causes the antireflection function to be inhibited. Further, since the main body portion has a tapered shape, the mechanical strength is also improved, and sticking is less likely to occur than when the taper is small.

The taper angle with respect to the light-transmitting substrate in the longitudinal section of the main body is not particularly limited as long as it is an angle capable of forming a truncated cone shape that rises in a tapered shape, but is 50 ° to 87 °. It is preferably within the range, more preferably within the range of 55 ° to 85 °, and even more preferably within the range of 55 ° to 82 °. When the taper angle is larger than the above range, the main body portion is close to a columnar shape that rises vertically, and may not be easily removed from the mold used in manufacturing the antireflection film of the present invention. This is because the antireflection function may not be exhibited. Furthermore, sticking may easily occur. On the other hand, when the taper angle is smaller than the above range, the antireflection function is lowered, the wavelength dependency of the reflectance is easily received, and it may be difficult to form the main body.
The taper angle in the present invention refers to an angle formed by a straight line approximating the side surface and a straight line parallel to the light-transmitting substrate surface when the side surface in the longitudinal section of the main body is linear. , An angle represented by θ ₁ in FIG.
On the other hand, when the side surface in the longitudinal section of the main body is curved, the point on the outer periphery of the top surface of the main body and the point on the outer periphery of the bottom surface of the main body are selected and connected so as to be the shortest distance An angle formed by a straight line parallel to the surface of the light-transmitting substrate, for example, an angle represented by θ ₂ in FIG.
Here, the top surface of the main body portion is a surface including a cross section of a portion where the curvature of the side surface of the convex portion in the fine unevenness greatly changes, and the bottom surface of the main body portion is a surface where the main body portion and the base portion are in contact.
The taper angle in the present invention is the average of the measured values obtained by observing the longitudinal section of the main body portion with an electron microscope and measuring the taper angle for ten pieces. FIG. 2 is a schematic cross-sectional view showing an example of the antireflection layer according to the present invention. Since the reference numerals in FIG. 2 are the same as those in FIG. 1B, description thereof is omitted here.

The height of the main body is not particularly limited as long as it is within a range in which a desired antireflection function can be imparted to the antireflection layer in the present invention, and can be adjusted as appropriate. Here, as the height is higher, the reflectance of the antireflection layer can be lowered. On the other hand, as the height is lower, the reflectance on the long wavelength side tends to increase. For this reason, the height of the main body in the present invention is preferably in the range of 60 nm to 1400 nm, more preferably in the range of 100 nm to 1000 nm, and in the range of 120 nm to 750 nm. More preferably. If the height of the main body portion is higher than the above range, the main body portion is likely to be damaged, and sticking may easily occur. If the height of the main body portion is lower than the above range, the antireflection in the present invention. This is because the antireflection function for light on the long wavelength side of the layer may be insufficient.
The height of the main body in the present invention refers to the distance from the base surface to the top surface of the main body, for example, a distance represented by H in FIG. In addition, let the height of the said main-body part in this invention be the average value determined by the method mentioned above.

  The diameter of the top surface of the main body is not particularly limited as long as it is smaller than the diameter of the bottom of the main body, but is preferably in the range of 1 nm to 100 nm, and in the range of 2 nm to 50 nm. More preferably. This is because if the diameter of the top surface of the main body is too small, the mechanical strength is reduced and the main body is easily damaged. Moreover, if the diameter of the top surface of the main body is too large, the taper becomes small, so that sticking is likely to occur or it is difficult to remove from the mold. In addition, let the diameter of the top surface of the said main-body part in this invention be the average value determined by the method mentioned above.

  The diameter of the bottom surface of the main body is not particularly limited as long as it is larger than the diameter of the top surface of the main body, but is preferably in the range of 25 nm to 500 nm, and in the range of 50 nm to 250 nm. More preferably. When the diameter of the bottom surface of the main body portion is reduced, the space between adjacent structures is opened, and the portion not forming the structure is increased, so that the antireflection function is deteriorated. In addition, let the diameter of the bottom face of the said main-body part in this invention be the average value determined by the method mentioned above.

  The top surface shape and the bottom surface shape of the main body are not particularly limited, and examples thereof include a polygonal shape in addition to a circular shape such as a circle and an ellipse.

  The side surface shape of the main body may be linear or curved in the longitudinal section of the main body. In particular, in the present invention, it is preferable that the main body portion forms a curved side surface that is continuous with a tip portion described later. This is because, as illustrated in FIG. 2, the convex portions of the fine irregularities can be formed into a bell shape, and a good antireflection function can be obtained. Hereinafter, the reason why the antireflection function is good when the convex portion has a bell shape will be specifically described.

The principle that the moth-eye structure prevents reflection is considered as follows. The refractive index N of the space (pseudo layer a) near the apex of the moth eye structure X illustrated in FIG. 3A is 1 for the refractive index of air and the volume occupied by the moth eye structure X in the pseudo layer a. When the ratio is V _m and the refractive index of the resin constituting the moth-eye structure X is N _m , the following formula (1) is established.
N = 1 × (1−V _m ) + N _m × V _m (1)
That is, the refractive index of the pseudo layer a is given as a weighted average considering the respective volumes and refractive indexes of air and resin. The same applies to the pseudo layer b and the subsequent layers. As the substrate Y approaches the pseudo layer a to the pseudo layer k, the refractive index of the pseudo layer increases. However, as illustrated in FIG. 3B, the amount of change in the refractive index of the cone shape changes in a curved manner. In contrast, the amount of change in the refractive index of the bell shape changes almost linearly. This is because the volume ratio occupied by the moth-eye structure X can be regarded as a change in the cross-sectional area from the pseudo layer a to the pseudo layer k. This is because the bell shape changes almost linearly. Therefore, the bell-shaped moth-eye structure X has a feature that the rate of change of the refractive index in the vicinity of the substrate Y is smaller than that of the cone-shaped moth-eye structure X. When the refractive index change rate in the vicinity of the substrate Y is smaller, the refractive index between the air and the resin is reduced in a pseudo manner, and the reflectance can be reduced. Further, when the taper of the main body is small, as shown in FIG. 3B, the amount of change in the refractive index in the pseudo layer k is small, but the amount of change in the refractive index in the portion from the pseudo layer a to c is large. Therefore, the whole tends to be whitish. Therefore, the bell-shaped moth-eye structure X is superior in antireflection function to the cone-shaped moth-eye structure X and the moth-eye structure X having a small taper.
In the present invention, the refractive index distribution of the pseudo layer is optimized by appropriately adjusting the taper angle of the main body part and the radius of curvature of the tip part and defining the bell shape of the convex part in the fine unevenness. Thus, the fine unevenness can be a moth-eye structure having excellent optical characteristics.

(B) Tip portion The tip portion used in the present invention has a curved surface structure formed so as to cover the top surface of the main body portion. In the present invention, since the tip portion has a curved surface structure, there is no problem such as cracking of the leading edge of the convex portion of the fine unevenness pattern in the antireflection layer, and the antireflection film excellent in die-cutting property and can do. The curved surface structure of the tip portion can be controlled by the pressure when forming the antireflection layer, the viscosity of the resin of the antireflection layer, and the like.

  The shape of the tip is not particularly limited as long as it is a curved structure formed so as to cover the top surface of the main body. In the present invention, in particular, it is preferably substantially spherical, and the radius of curvature thereof can be appropriately adjusted according to the application of the antireflection film of the present invention, for example, used in the present invention. The diameter of the top surface of the main body is preferably within a range of 1.0 to 5.0 times, more preferably within a range of 1.0 to 2.0 times. More preferably, it is in the range of 0.0 times to 1.5 times. If the curvature radius of the tip portion is larger than the above range, the tip portion becomes close to a flat shape, so that the reflectance of the antireflection layer increases, and the antireflection function of the antireflection film of the present invention may deteriorate. Because. Further, as illustrated in FIG. 4A, the curved surface structure of the tip 5b is preferably spherical, but as illustrated in FIGS. 4B and 4C, the curved surface of the tip 5b. The structure may have a partially pointed shape and / or undulation. In addition, the tip end portion of the tip portion does not need to be at the center of the top surface of the main body portion, and the antireflection function does not change even if it is deviated from the center. 4A to 4C are schematic cross-sectional views showing an example of the tip portion of the antireflection film of the present invention.

  Further, the height of the tip portion, that is, the distance from the top surface of the main body portion to the most distal portion of the tip portion is appropriately adjusted within a range in which a desired antireflection function can be imparted to the antireflection layer in the present invention. It is something that can be done.

(C) Convex part The convex part used for this invention is comprised from the said front-end | tip part and the said main-body part, and the antireflection function with which the antireflection layer in this invention is provided has the said convex part. Depends on period, height, interval.
The period of the convex portion is formed, a height, and spacing, P _1, Q _1, and as shown by R _1, the top portion of the tip portion from the top of the front end portion of the raised portion adjacent each respectively, in FIG 5 , The distance from the top of the tip of the protrusion to the bottom of the main body, and the shortest distance between the outer peripheries of the bottom of the main body of the adjacent protrusion. Here, FIG. 5 is a schematic diagram for explaining parameters for specifying fine irregularities in the antireflection film of the present invention. Reference numerals not described in FIG. 5 can be the same as those in FIG. Therefore, the description here is omitted.

  The period of the convex portion is not particularly limited as long as it is equal to or shorter than the wavelength of the visible light region, and can be appropriately determined according to the use of the antireflection film of the present invention. Here, the period affects the wavelength dependence of the reflectance of the antireflection layer used in the present invention, and the reflectance for light on the short wavelength side in the visible light region increases as the period becomes longer. There is a tendency. On the other hand, when the period is 200 nm or less, the change in the wavelength dependence of the reflectance due to the fluctuation of the period is small. For this reason, the period of the convex portions in the present invention is preferably in the range of 80 nm to 400 nm, more preferably in the range of 100 nm to 300 nm, and in the range of 120 nm to 250 nm. Is more preferable. This is because if the period of the convex portions is shorter than the above range, the shape of the individual convex portions becomes extremely small, so that it may be difficult to form the convex portions with high accuracy. Further, if the period of the convex portion is longer than the above range, the antireflection function for light on the short wavelength side of the antireflection layer in the present invention may be insufficient. In addition, the period of the said convex part in this invention observes the longitudinal cross-section of a convex part with an electron microscope, measures the period for ten pieces, and makes it the average value of the measured value.

  The height of the convex portion can be appropriately adjusted within a range in which a desired antireflection function can be imparted to the antireflection layer in the invention, and is not particularly limited. Here, as the height is higher, the reflectance of the antireflection layer can be lowered. On the other hand, when the height is lowered, the reflectance on the long wavelength side tends to increase. Therefore, the height of the convex portion in the present invention is preferably in the range of 62 nm to 1402 nm, more preferably in the range of 100 nm to 1002 nm, and in the range of 120 nm to 752 nm. More preferably. If the height of the convex portion is higher than the above range, the individual convex portions may be easily damaged, and if the height of the convex portion is lower than the above range, the antireflection layer of the present invention This is because the antireflection function for light on the long wavelength side may be insufficient. In addition, the height of the said convex part in this invention is taken as the average value determined by the method mentioned above.

  As the interval at which the convex portions are formed increases, the reflectance tends to increase in the entire wavelength region of visible light, and as the interval decreases, the reflectance tends to decrease in the entire wavelength region of visible light. For this reason, the interval at which the convex portions are formed in the present invention can be appropriately adjusted within a range in which a desired antireflection function can be imparted to the antireflection layer in the present invention, and is particularly limited. It is not something. In addition, the space | interval of the said convex part in this invention is taken as the average value determined by the method mentioned above.

  The variation in the height of the protrusions is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 10 nm or less. This is because if the variation in the height of the convex portions is larger than the above range, unevenness may occur in the antireflection function of the antireflection layer in the present invention. Moreover, the mechanical strength of the surface comprised from the vertex of a convex part falls, and it becomes easy to receive a damage. In addition, the variation in the height of the convex portion means a difference between the maximum value and the minimum value of the measured values obtained by observing the vertical section of the convex portion with an electron microscope and measuring the height of ten pieces.

The number of convex portions per unit area can be appropriately adjusted within a range in which a desired antireflection function can be imparted to the antireflection layer in the present invention, and is not particularly limited. 50 / μm ² or more, preferably 60 / μm ² or more, and more preferably 70 / μm ² or more. If the number of the convex portions per unit area is 50 / μm ² or less, glare occurs and the antireflection function deteriorates. Moreover, the mechanical strength of the surface comprised from the vertex of a convex part falls, and it becomes easy to receive a damage.
In the present invention, the antireflection layer may have a structure other than the protrusions, but the ratio of the number of protrusions in the antireflection layer to the total number of structures in the antireflection layer is 50% or more, more preferably 60% or more, and even more preferably 75% or more. This is because if the ratio is too small, the antireflection function, the sticking resistance and the mold release property are lowered.

The regular reflectance at an incident angle of 5 ° in the wavelength region of 360 nm to 760 nm of the convex portion is preferably 0.5% or less, and more preferably in the range of 0.005% to 0.3%. Preferably, it is more preferably in the range of 0.005% to 0.1%.
Moreover, it is preferable that the haze value in the 360 nm-760 nm wavelength range of the said convex part exists in the range of 0.1%-50%.

  The convex portion can reflect all over from a short wavelength region to a long wavelength region.

(2) Base part The base part in the antireflection layer used for this invention is formed on the said easily bonding layer, and supports the said fine unevenness | corrugation.
The thickness of the base is preferably in the range of 0.5 μm to 150 μm, more preferably in the range of 1 μm to 100 μm, and still more preferably in the range of 2 μm to 80 μm. When the thickness of the base portion is within the above range, the degree of shrinkage stress of the antireflection layer can be reduced, and the reflection of the present invention is performed regardless of the kind of the easily adhesive layer and the light-transmitting substrate described later. This is because curling can be prevented from occurring in the prevention film. Moreover, there exists an effect as a cushion layer and it can reinforce the mechanical damage of an antireflection layer. For example, the mechanical strength of the antireflection layer can be increased, scratch resistance can be improved, and scratch resistance can be reduced. Furthermore, the adhesion between the antireflection layer and the easy-adhesion layer can be improved.

(3) Antireflection layer The antireflection layer in the present invention is usually made of a resin. The resin used for the antireflection layer is not particularly limited as long as it can form the fine irregularities described above. Ionizing radiation curable resins such as ultraviolet curable resins and electron beam curable resins, and thermosetting. Examples thereof include resins and thermoplastic resins. Among these, in the present invention, it is preferable to use an ionizing radiation curable resin. This is because by using the ionizing radiation curable resin, fine irregularities can be produced with high accuracy, and a good antireflection function can be imparted to the antireflection layer.

Examples of the ionizing radiation curable resin used in the present invention include acrylic resins. Examples of the acrylic resin include compounds having at least three ethylenically unsaturated double bonds. For example, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, tris (Acryloxyethyl) isocyanurate, caprolactone-modified tris (acryloxyethyl) isocyanurate, trimethylol ethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, alkyl-modified dipentaerythritol tet (Meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetra (meth) acrylate, polyurethane polyacrylate, polyester polyacrylate, etc. Ester compound of monohydric alcohol and (meth) acrylic acid; polyurethane poly (meth) acrylate, polyester poly (meth) acrylate, polyether poly (meth) acrylate, polyacryl poly (meth) acrylate, polyalkyd poly (meth) acrylate , Polyepoxy poly (meth) acrylate, polyspiroacetal poly (meth) acrylate, polybutadiene poly (meth) acrylate, polythiol polyene poly ( Data) acrylate, (meth) acrylate compound of the polysilicon poly (meth) polyfunctional compounds such acrylate.
Among these compounds having at least three or more ethylenically unsaturated double bonds, polyurethane poly (meth) acrylate and polyepoxy poly (meth) acrylate having at least six functional groups from the viewpoint of coating film strength and adhesion. Poly (meth) acrylates such as polyfunctional acrylates having 4 or more acryloyl groups in the molecule can be suitably used.
The polyurethane poly (meth) acrylate is obtained by reacting, for example, a diisocyanate and a (meth) acrylate having a hydroxyl group, or an isocyanate group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under an excess of isocyanate groups. Some are obtained by reacting polymers with (meth) acrylates having a hydroxyl group. Alternatively, a hydroxyl group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under hydroxyl-excess conditions can be obtained by reacting with a (meth) acrylate having an isocyanate group.
Examples of polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentane glycol, neopentyl glycol, hexanetriol, trimellilol propane, polytetra Examples include methylene glycol and a condensation polymer of adipic acid and ethylene glycol.
Examples of the polyisocyanate include tolylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.
Examples of (meth) acrylates having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and ditrimethylolpropane tetraacrylate. .
Examples of (meth) acrylates having an isocyanate group include 2-methacryloyloxyethyl isocyanate and methacryloyl isocyanate.
Polyepoxy poly (meth) acrylate is obtained by esterifying an epoxy group of an epoxy resin with (meth) acrylic acid and converting the functional group to a (meth) acryloyl group, and (meth) acrylic acid to bisphenol A type epoxy resin There are adducts, (meth) acrylic acid adducts to novolac type epoxy resins, and the like.
Specific examples of the polyfunctional group having four or more acryloyl groups in the molecule include the above-described polyhydric alcohol and acrylic acid ester compounds, and a single compound or a mixture of two or more compounds is preferable.
Furthermore, a (meth) acrylic polymerizable composition described in WO2007 / 040159 can be used.
Moreover, it is desirable to add a photopolymerization initiator to the resin as appropriate. Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, and the like. Specifically, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diethoxyacetophenone, gendyl dimethyl ketal, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2 , 4,6-trimethylbenzoin diphenylphosphine oxide, Michler's ketone, isoamyl N, N-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and the like. It can also be used together as appropriate.
In the present invention, it is preferable to appropriately select and use a resin having a refractive index close to the refractive index of a light-transmitting substrate described later from among these ionizing radiation curable resins. This is because the refractive index of the easy adhesion layer can be made close to the refractive index of the antireflection layer and the refractive index of the light-transmitting substrate.

  Examples of the thermosetting resin or thermoplastic resin used in the present invention include acrylic resin, polyester resin, epoxy resin, polyolefin resin, styrene resin, polyamide resin, polyimide resin, polyamideimide resin, polyurethane resin, and polyacetic acid. Vinyl resin, polyvinyl alcohol resin, polyvinyl butyral resin, polycarbonate resin, melamine resin, urea resin, alkyd resin, phenol resin, cellulose resin, diallyl phthalate resin, silicone resin, polyarylate resin, polyacetal resin, styrene-isoprene rubber, olefin Menimide copolymers, fluorinated epoxies, fluorinated acrylates, fluorinated polyesters, fluororesins and the like can be mentioned. Moreover, these elastomers and acid-modified products can be mentioned.

As the transparency of the antireflection layer in the present invention, the light transmittance with respect to the entire wavelength range of visible light is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. preferable.
Here, the light transmittance can be measured by, for example, a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Corporation.

  The antireflection function of the antireflection layer used in the present invention depends on the refractive index of the antireflection layer and the refractive index of the easy-adhesion layer. That is, the smaller the difference between the refractive index of the antireflection layer and the refractive index of the easy-adhesion layer, the more the discontinuity of the refractive index can be corrected. Therefore, the antireflection function of the antireflection layer can be improved. It can be done. From such a viewpoint, in the present invention, the difference between the refractive index of the antireflection layer and the refractive index of the easy-adhesion layer is preferably in the range of 0 to 0.5, and preferably 0 to 0.2. More preferably, it is in the range of 0 to 0.1. Although the specific refractive index value of the antireflection layer is not particularly limited, since it is preferable that the difference from the refractive index of the easy-adhesion layer is small, the refractive index of the light-transmitting substrate described later is used. It is preferable that they are close to each other, and usually within a range of 1.20 to 2.40.

  The antireflection layer used in the present invention may contain any additive as necessary in addition to the above-described resin. As such an additive, the same additive as the additive described in the section of “1. Easy-adhesion layer” can be used, and the description thereof is omitted here.

3. Next, the light transmissive substrate in the present invention will be described. The light-transmitting substrate in the present invention is made of polyethylene terephthalate (PET) resin. The light-transmitting substrate supports the above-mentioned easy adhesion layer and antireflection layer, and in combination with the above easy adhesion layer and antireflection layer, imparts a desired antireflection function to the antireflection film of the present invention. To do.

Further, the light-transmitting substrate in the present invention has transparency to visible light, and in particular, the light transmittance for the entire wavelength range of visible light is preferably 80% or more, and 85% or more. More preferably, it is more preferably 90% or more.
Here, the light transmittance can be measured by, for example, a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Corporation.

  The refractive index of the light-transmitting substrate in the present invention is substantially constant, and is usually about 1.57 to 1.59.

  The light-transmitting substrate in the present invention is made of a PET resin, but may contain any additive as necessary. Examples of such additives include antistatic agents (conductive agents), refractive index adjusters, leveling agents, antifouling agents, adhesives, ultraviolet / infrared absorbers, hardeners, hardness adjusters, and fluidity. Conditioners, antioxidants, fluororesins, hydrocarbons such as liquid paraffin, paraffin wax, synthetic polyethylene wax, fatty acid amides, metal stearate, calcium stearate / magnesium stearate, lead stearate / zinc stearate, etc. Release agents such as metal soaps, fatty acid esters, silicone oils, acrylic polymers, internal or external lubricants, polarization refraction regulators such as strontium carbonate, hydrophilic agents, lipophilic agents, colorants, etc. Can be mentioned.

  The thickness of the light transmissive substrate in the present invention is not particularly limited as long as it can support the above-mentioned easy adhesion layer and antireflection layer, and can be appropriately selected according to the antireflection film of the present invention. However, it is preferably in the range of 1 μm to 1000 μm, and more preferably in the range of 5 μm to 500 μm.

4). Antireflection Film The antireflection film of the present invention may have a structure in which an easy-adhesion layer 2 and an antireflection layer 3 are sequentially formed on a light-transmitting substrate 1 as illustrated in FIG. As illustrated in FIG. 6, a structure in which the easy adhesion layer 2 and the antireflection layer 3 are sequentially formed so as to sandwich the light transmissive substrate 1 may be employed. FIG. 6 is a schematic cross-sectional view showing another example of the antireflection film of the present invention. Reference numerals not described in FIG. 6 can be the same as those in FIG. Is omitted.

Moreover, although the antireflection film of the present invention has at least the antireflection layer, the easy-adhesion layer, and the light transmissive substrate, any configuration may be used as necessary. . The arbitrary structure used for this invention is not specifically limited, According to the use etc. of the antireflection film of this invention, the structure which can provide a desired function can be selected suitably, and can be used. . Among them, as an arbitrary configuration suitably used in the present invention, functions such as a primer layer (adhesion stable layer), a hard coat layer, an antistatic layer and the like formed between the easy adhesion layer and the antireflection layer And a pressure-sensitive adhesive layer formed on the surface of the light-transmitting substrate opposite to the surface on which the easy-adhesion layer and the antireflection layer are formed. The primer layer can also serve as a hard coat layer and / or an antistatic layer. A protective layer formed on the surface of the antireflection layer can also be used.
Here, since the hard coating layer is formed as the functional layer, the hardness of the antireflection film of the present invention can be improved and the antireflection film excellent in durability can be obtained. When the film is used for a display device, there is an advantage that the antireflection film of the present invention can be used as a protective film for the display device. Further, by forming a primer layer as the functional layer, the adhesion between the easy adhesion layer and the antireflection layer is improved, and the antireflection layer and the light-transmitting substrate are interposed via the easy adhesion layer and the primer layer. The anti-static layer is formed as the functional layer, thereby suppressing the generation of static electricity and preventing the adhesion of dust and dirt to the antireflection film of the present invention. Can do.
On the other hand, since the adhesive layer is formed, for example, when the antireflection film of the present invention is used in a display device, there is an advantage that the antireflection film of the present invention can be easily bonded to another member. is there.

  The case where the above-mentioned hard coat layer, primer layer or antistatic layer is used in the antireflection film of the present invention will be described with reference to the drawings. FIG. 7 is a schematic cross-sectional view showing an example in which a hard coat layer, a primer layer or an antistatic layer is used in the antireflection film of the present invention. As illustrated in FIG. 7, in the antireflection film 10 of the present invention, a hard coat layer, a primer layer, or an antistatic layer 6 may be formed between the easy-adhesion layer 2 and the antireflection layer 3. In addition, about the code | symbol which is not demonstrated in FIG. 7, since it can be made the same as that of Fig.1 (a), description here is abbreviate | omitted.

  The hard coat layer, primer layer, or antistatic layer used in the present invention is not particularly limited as long as it has a desired hardness, adhesion to an easily adhesive layer, and antistatic properties. The material constituting such a hard coat layer, primer layer, or antistatic layer is composed of the same resin as that of the above-described antireflection layer and additives that are appropriately used.

  The thickness of the hard coat layer, primer layer or antistatic layer used in the present invention depends on the type of material used for the hard coat layer, primer layer or antistatic layer. The layer is not particularly limited as long as it has a desired hardness, adhesion to an easily adhesive layer, and antistatic properties. Among them, the thickness of the hard coat layer, primer layer or antistatic layer used in the present invention is preferably in the range of 0.05 μm to 50 μm, more preferably in the range of 0.1 μm to 30 μm, More preferably, it is in the range of 1 μm to 20 μm. When the thickness of the hard coat layer, primer layer or antistatic layer is thicker than the above range, the antireflection film of the present invention may be curled depending on the type of material constituting the hard coat layer, primer layer or antistatic layer. This is because it may end up. On the other hand, if the thickness is less than the above range, it may be difficult to make the hardness of the hard coat layer to a desired level depending on the type of material constituting the hard coat layer. In addition, depending on the type of material constituting the primer layer, when adding a function as a primer layer, adhesion may not be achieved and the material may be peeled off. This is because depending on the type, sufficient antistatic performance may not be achieved.

  The hard coat layer, primer layer or antistatic layer may be previously laminated on the easy-adhesion layer, or the hard coat layer, primer layer or antistatic layer and antireflection layer resin laminated simultaneously. It may be used.

  Furthermore, the hard coat layer, primer layer or antistatic layer used in the present invention preferably has a refractive index comparable to the refractive index of the easy adhesion layer and the refractive index of the antireflection layer. Thus, at the boundary between the easy adhesion layer and the hard coat layer, primer layer or antistatic layer in the antireflection film of the present invention, and at the boundary between the hard coat layer, primer layer or antistatic layer and antireflection layer Since it is possible to prevent the formation of a discontinuous interface of refractive index, it is possible to prevent the antireflection function of the antireflection film of the invention from being impaired due to light being reflected at these boundaries. It is. Among them, the difference between the refractive index of the hard coat layer, primer layer or antistatic layer used in the present invention and the refractive index of the easy-adhesion layer and the antireflection layer may be in the range of 0 to 0.5. Preferably, it is in the range of 0-0.2, more preferably in the range of 0-0.1.

  Next, the case where the said adhesion layer is used for the antireflection film of this invention is demonstrated, referring drawings. FIG. 8 is a schematic cross-sectional view showing an example in which an adhesive layer is used in the antireflection film of the present invention. As illustrated in FIG. 8, in the antireflection film 10 of the present invention, the adhesive layer 7 is formed on the surface of the light transmissive substrate 1 opposite to the surface on which the easy adhesion layer 2 and the antireflection layer 3 are formed. It may be what was done. In addition, about the code | symbol which is not demonstrated in FIG. 8, since it can be the same as that of Fig.1 (a), description here is abbreviate | omitted.

  The adhesive layer used for this invention will not be specifically limited if it consists of a desired adhesive according to the use of the antireflection film of this invention. Examples of the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers, so-called gel polymers, and the like.

  The thickness of the pressure-sensitive adhesive layer used in the present invention is preferably in the range of 1 μm to 400 μm, more preferably in the range of 1 μm to 100 μm, and still more preferably in the range of 1 μm to 50 μm. However, it is not particularly limited.

  In addition to the adhesive mentioned above, the adhesive layer used for this invention may contain the additive as needed. As such an additive, the same additive as the additive described in the section of “1. Easy-adhesion layer” can be used, and the description thereof is omitted here.

  Next, the case where the said protective layer is used for the antireflection film of this invention is demonstrated, referring drawings. FIGS. 9A to 9C are schematic cross-sectional views showing an example in which a protective layer is used in the antireflection film of the present invention. As illustrated in FIGS. 9A to 9C, the antireflection film 10 of the present invention may have a protective layer 8 formed on the surface of the antireflection layer 3. As illustrated in FIG. 9A, the protective layer 8 may be formed so that only the top surface of the antireflection layer 3 is in contact with the protective layer 8, and as illustrated in FIG. 9B. The antireflection layer 3 may be formed so as to be slightly recessed into the protective layer 8, and the antireflection layer 3 may be formed so as to enter the protective layer 8 as illustrated in FIG. 9C. . In addition, about the code | symbol which is not demonstrated in Fig.9 (a)-(c), since it can be made the same as that of Fig.1 (a), description here is abbreviate | omitted.

  As a method for forming a protective layer formed on the surface of the antireflection layer used in the present invention, a method of applying a protective film that expresses pressure-sensitive or heat-sensitive adhesive force, a resin having a protective function is coated, UV irradiation, There are a method of forming a film by drying, a method of melting and extruding to the surface of the antireflection layer, and forming by cooling.

The protective layer formed by the pressure-sensitive or heat-sensitive method is not particularly limited as long as it is made of a desired protective layer material according to the use of the antireflection film of the present invention. Examples of the pressure-sensitive protective layer material include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers, so-called gel polymers, and the like. Further, the protective layer comprises an olefin-based thermoplastic resin, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, 1-butene homopolymer and copolymer, styrene-butadiene block copolymer, styrene-butadiene. You may form with the resin layer which mixed the hydrogenated substance of the block copolymer, the tackifier, and said adhesive.
Further, the protective layer comprises an unsaturated carboxylic acid graft-modified α-olefin polymer and α-olefin copolymer, a copolymer of ethylene and acrylic acid or an acrylic acid derivative, ethylene and methacrylic acid or methacrylic acid. It may be formed from a resin layer containing a copolymer with a derivative, a metal ion-crosslinked α-olefin polymer, a copolymer of ethylene and α-olefin, or the like.

  When the protective layer is formed by melt extrusion onto the surface of the antireflection layer and cooling, the protective layer materials include α-olefin polymers, copolymers of ethylene and α-olefins, and copolymers of propylene and α-olefins. The polymer can be used alone or blended. Examples of the resin to be blended include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers, so-called gel polymers, and the like. Also, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, 1-butene homopolymer and copolymer, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, tackifier, Saturated carboxylic acid graft-modified α-olefin polymers and α-olefin copolymers, copolymers of ethylene and acrylic acid or acrylic acid derivatives, copolymers of ethylene and methacrylic acid or methacrylic acid derivatives, metal ions Crosslinked α-olefin polymers or copolymers of ethylene and α-olefins may be mentioned.

  As a method of coating a resin having a protective function and forming a film by UV irradiation or drying, the film is formed by coating the upper surface of the antireflection layer with or without diluting with an organic solvent or an aqueous system. If necessary, drying, cooling, and UV irradiation are performed to improve the film strength. Examples of the resin used include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluororesins and rubber polymers, so-called gel polymers, and the like.

5. Next, a method for producing the antireflection film of the present invention will be described. As a manufacturing method of the antireflection film of the present invention, for example, the manufacturing method of the antireflection film of the present invention is to apply a resin composition for forming an easy adhesion layer on a light transmissive substrate made of polyethylene terephthalate (PET) resin. And then curing the resin composition for forming an easy-adhesion layer after drying, and an easy-adhesion layer forming step for forming an easy-adhesion layer, and coating the resin composition for forming an antireflection layer on the easy-adhesion layer. By using a mold having a shape capable of forming fine irregularities of the antireflection layer in the present invention, and a film forming step of forming a film comprising the resin composition for forming an antireflection layer, By applying a pressure capable of forming fine irregularities, a molding step of shaping the fine irregularities on the film made of the resin composition for forming an antireflection layer, and after releasing the pressure, the reflection By curing the sealing layer forming resin composition can include the anti-reflection layer forming step of forming an antireflection layer, a manufacturing method and a peeling step of peeling the mold from the anti-reflection layer.
Hereinafter, each process in the manufacturing method of the said anti-reflective film is demonstrated.

(1) Easy-adhesion layer forming step The easy-adhesion layer forming step in the method for producing an antireflection film of the present invention involves applying a resin composition for forming an easy-adhesion layer on a light-transmitting substrate made of polyethylene terephthalate (PET) resin. It is a step of forming an easy-adhesion layer by curing and drying the resin composition for forming an easy-adhesion layer after drying.

  Examples of the light transmissive substrate used in the method for producing an antireflection film of the present invention include those described in the above section “3. Light transmissive substrate”.

The resin composition for easily bonding layer formation used for the manufacturing method of the antireflection film of the present invention contains a resin, and the refractive index of the light-transmitting substrate and the refraction of the antireflection layer finally formed. It is possible to obtain an easy adhesion layer having a refractive index that is an average of the refractive index. The average refractive index here is the same as described above. The resin used for the resin composition for forming an easy-adhesion layer is not particularly limited as long as a desired easy-adhesion layer can be formed. For example, the above section “1. Easy-adhesion layer” What was described in (5) can be used suitably.
Moreover, the said resin composition for easily bonding layer formation may contain arbitrary additives other than the said resin as needed. As such an additive, for example, the additive described in the section of “1. Easy-adhesion layer” can be appropriately used.

  In this step, the method for applying the resin composition for forming an easy-adhesion layer is not particularly limited as long as it can be uniformly applied onto a light-transmitting substrate. For example, a spin coating method or a dip method is used. Well-known methods such as a spray method, a slide coat method, a bar coat method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, and a bead coater method can be used.

  In this step, the method for drying the applied resin composition for forming an easy-adhesion layer is not particularly limited, and examples thereof include reduced-pressure drying or heat drying, or a combination of these drying methods. Can be mentioned. Moreover, when drying at a normal pressure, it is preferable to dry at the temperature within the range of 30 to 180 degreeC.

  In this step, the method for curing the resin composition for forming an easy adhesion layer after drying is appropriately selected according to the type of resin contained in the resin composition for forming an easy adhesion layer. For example, when the resin is an ultraviolet curable resin, examples thereof include an ultraviolet curable method, and when the resin is a thermosetting resin, examples thereof include a heat curable method and a room temperature curable method. Moreover, when using a thermoplastic resin for the said resin, it can be hardened | cured by the cooling method which makes a cooling roll etc. contact.

(2) Film formation process The film formation process in the manufacturing method of the antireflection film of the present invention comprises applying the antireflection layer forming resin composition on the easy-adhesion layer, thereby forming the antireflection layer forming resin. This is a step of forming a film made of the composition.

The resin composition for forming an antireflection layer used in the method for producing an antireflection film of the present invention contains a resin. The resin used for the antireflection layer-forming resin composition is not particularly limited as long as it can form fine irregularities of a desired shape. For example, the above-mentioned “2. Antireflection layer” Those described in the item can be preferably used.
Moreover, the said resin composition for anti-reflective layer formation may contain arbitrary additives other than the said resin as needed. As such an additive, for example, the same additives as those described in the section “1. Easy-adhesion layer” can be used as appropriate.

The viscosity of the antireflective layer forming resin composition is not particularly limited as long as the antireflective layer forming resin composition can enter the mold to a desired degree. In the range of 10 mPa · s to 10000 mPa · s, more preferably in the range of 50 mPa · s to 5000 mPa · s, and further in the range of 100 mPa · s to 3000 mPa · s. preferable.
In the case of a melt-type resin, for example, the melt flow index (MFI) at 190 ° C. is preferably 1.0 g / 10 min or more, more preferably 3.0 g / 10 min or more. More preferably, it is 0.0 g / 10 min or more.

  In this step, the method for coating the resin composition for forming an antireflection layer is the same as the coating method described in the section “(1) Easy-adhesion layer forming step”. Is omitted.

(3) Molding process The molding process in the production method of the antireflection film of the present invention uses the mold having a shape capable of forming the fine irregularities of the antireflection layer in the present invention, and forms the fine irregularities. In this step, the fine irregularities are formed on the film made of the resin composition for forming an antireflection layer by applying a pressure capable of being applied. In this process, in the fine unevenness formed by a truncated cone-shaped main body portion that rises in a tapered shape with respect to the light-transmitting substrate, and a tip portion having a curved structure formed so as to cover the top surface of the main body portion. The shape of the convex portion can be formed.

  The mold used in the method for producing an antireflection film of the present invention is not particularly limited as long as fine irregularities having a desired shape can be molded into the antireflection layer-forming resin composition. A mold described in the section of “6. Mold for producing antireflection film” described later can be suitably used. Further, the mold may be a flat plate shape, a roll shape, or a belt shape.

  The pressure in this step is appropriately selected according to the viscosity and the like of the antireflection layer forming resin composition used in the present invention, and the antireflection layer forming resin composition and the mold are used. The degree to which the shape of the mold can be formed in the resin composition for forming an antireflection layer is found by repeating experiments while adjusting the pressure. For example, when the antireflection layer forming resin composition having the above-described viscosity is used, the pressure is preferably in the range of 1.0 N / cm to 50 N / cm, and 2.5 N / cm to 40 N. More preferably within the range of / cm, and even more preferably within the range of 5.0 N / cm to 25 N / cm. If the pressure is too low, the resin composition for forming an antireflection layer does not enter the mold so much that the height of the projections in the fine irregularities may not be sufficient, and the pressure is too high. This is because the anti-reflective layer forming resin composition may enter the mold too much and not come out of the mold.

  In this step, examples of the method of applying the pressure include a method using a roll press, a flat plate press, an injection press, a belt press method, a sleeve touch method, a roll touch method using an elastic metal roll, and the like.

(4) Antireflection layer formation process The antireflection layer formation process in the manufacturing method of the antireflection film of this invention is the antireflection layer by hardening the said resin composition for antireflection layer formation after releasing the said pressure. Is a step of forming.

  In this step, the method for curing the resin composition for forming an antireflection layer is appropriately selected according to the resin contained in the resin composition for forming an antireflection layer. In the case of an ionizing radiation curable resin, an ultraviolet curing method and an electron beam curing method can be exemplified, and when the resin is a thermosetting resin, a heat curing method and a room temperature curing method can be exemplified. Moreover, when using a thermoplastic resin for the said resin, it can be hardened | cured by the cooling method which makes a cooling roll etc. contact.

(5) Peeling process The peeling process in the manufacturing method of the antireflection film of this invention is a process of peeling the said metal mold | die from the said antireflection layer.

  The peeling method in this step is not particularly limited as long as the mold can be peeled without damaging the antireflection layer.

6). Next, the mold for producing an antireflection film used in the present invention will be described. The antireflection film production mold used in the present invention is, for example, an antireflection film production mold comprising a metal substrate and a metal oxide film formed on the surface of the metal substrate and having a plurality of fine holes. In addition, the opening of the fine hole may have a tapered shape whose depth is in the range of 60 nm to 2000 nm.

  Such a mold for producing an antireflection film will be described with reference to the drawings. FIG. 10 is a schematic sectional view showing an example of a mold for producing an antireflection film used in the present invention. An antireflection film manufacturing mold 20 illustrated in FIG. 10 includes a metal base 11 and a metal oxide film 11 ′ formed on the surface of the metal base 11 and having a plurality of micropores. The portion has a tapered shape with a depth D within a predetermined range.

  The metal substrate is the same as that described in the section of “7. Method for producing mold for production of antireflection film” described later, and the description thereof is omitted here. Hereinafter, the other structure in the metal mold | die for antireflection film manufacture used for this invention is demonstrated.

  The metal oxide film in the mold for producing an antireflection film used in the present invention is formed on the surface of a metal substrate and has a plurality of fine holes. The metal oxide film is usually formed by anodizing a metal substrate. The thickness of the metal oxide film is not particularly limited, and can be appropriately selected according to a target mold for producing an antireflection film.

The metal mold for producing an antireflection film used in the present invention is greatly characterized by having a tapered shape having a depth within a predetermined range at the openings of the plurality of fine holes of the metal oxide film. The depth of the tapered shape at the opening of the micropores may be in the range of 60 nm to 2000 nm, but is preferably in the range of 100 nm to 1200 nm, and is preferably in the range of 120 nm to 800 nm. Is more preferable. When the taper-shaped depth is deeper than the above range, in the antireflection film of the present invention, the transfer portion of the micropores may be easily damaged, or sticking may easily occur. This is because it may be difficult to remove from the mold. On the other hand, if the depth of the tapered shape is shallower than the above range, it is difficult to form the tapered shape, and the antireflection function may be deteriorated.
Here, the taper-shaped depth in the opening portion of the microhole refers to the distance from the opening surface of the microhole to the deepest portion of the taper shape, and is a distance represented by D in FIG. Depending on the shape of the fine holes, the depth of the tapered shape may be the same as the depth of the fine holes. In addition, the taper-shaped depth in the mold for manufacturing an antireflection film used in the present invention is measured by observing the longitudinal section of the micropores with an electron microscope and measuring the taper-shaped depth of 10 pieces. The average value.

The taper angle in the longitudinal section of the opening of the fine hole is not particularly limited as long as it is an angle capable of forming a tapered shape, but is preferably in the range of 50 ° to 87 °. More preferably, it is within the range of 55 ° to 85 °, and further preferably within the range of 55 ° to 82 °. When the taper angle in the longitudinal section of the opening of the fine hole is larger than the above range, the opening becomes close to a vertical shape, and it is difficult for the resin layer to enter the fine hole of the mold when manufacturing the antireflection film. Because there is. In addition, it is difficult to remove from the mold. On the other hand, if the taper angle in the longitudinal section of the opening of the microhole is smaller than the above range, it may be difficult to form the opening. In addition, the antireflection function becomes inferior.
Here, the taper angle in the longitudinal section of the opening of the microhole is formed by a straight line approximating the side wall and a straight line parallel to the opening surface when the side wall in the longitudinal section of the microhole is linear. Refers to an angle, for example, the angle represented by θ ₃ in FIG. On the other hand, when the side wall in the vertical cross section of the microhole is curved, the point on the outer periphery of the opening surface of the microhole and the point on the outer periphery of the surface formed by the transverse cross section of the tapered deepest part in the microhole are defined as the shortest distance. An angle formed by a straight line selected and tied in such a way and a straight line parallel to the opening surface is an angle represented by θ ₄ in FIG. In addition, let the said taper angle in the metal mold | die for antireflection film manufacture used for this invention be the average value determined by the method mentioned above. FIG. 11 is a schematic cross-sectional view showing another example of the mold for producing an antireflection film used in the present invention, and the reference numerals in FIG. 11 are the same as those in FIG. To do.

  The micropores in the antireflection film manufacturing mold used in the present invention need only have a tapered shape with a predetermined depth in the opening, and the shape of the tip portion should be narrower than the opening. It is not particularly limited. The shape of the tip of the fine hole may be, for example, a pointed shape, a flat shape, or a curved shape. Especially, in the said metal mold | die for antireflection film manufacture, it is preferable that the shape of the front-end | tip part of the said micropore is a curved surface shape. This is because, in the case of a curved surface shape, the resin is likely to enter uniformly and variation in shape is reduced. On the other hand, in the case of a planar shape, if the resin fills the planar shape, it may not come off.

The shape of the opening surface of the micropore is not particularly limited, and examples thereof include a round shape such as a circle and an ellipse, and a polygonal shape.
The diameter of the opening surface of the micropore, that is, the pore size of the micropore is not particularly limited, but is preferably in the range of 25 nm to 500 nm, and in the range of 50 nm to 250 nm. Is more preferable. When the hole diameter of the fine holes is 25 nm or less, the space between adjacent structures in the antireflection film becomes large, so that the portion where the structures are not formed increases and the antireflection function deteriorates. In addition, let the said hole diameter in the metal mold | die for antireflection film manufacture used for this invention be the average value determined by the method mentioned above.

  The period of the fine holes is not particularly limited, and can be appropriately determined according to the use of the antireflection film of the present invention. Here, the period of the micropores affects the wavelength dependence of the reflectance of the antireflection film of the present invention, and the reflectance for light on the short wavelength side in the visible light region increases as the period becomes longer. It tends to be. On the other hand, when the period is 200 nm or less, the change in the wavelength dependence of the reflectance due to the fluctuation of the period is small. For this reason, the period of the micropores is preferably in the range of 80 nm to 400 nm, and more preferably in the range of 100 nm to 300 nm. In addition, let the said period in the metal mold | die for antireflection film manufacture used for this invention be the average value determined by the method mentioned above.

  The depth of the micropores also affects the wavelength dependency of the reflectance of the antireflection film of the present invention. The deeper the depth, the lower the reflectance. The reflectance on the wavelength side tends to increase. For these reasons, the depth of the micropores is preferably in the range of 60 nm to 2000 nm, and more preferably in the range of 100 nm to 800 nm. In addition, let the said depth in the metal mold | die for antireflection film manufacture used for this invention be the average value determined by the method mentioned above.

  In addition, as the spacing between the micropores increases, the reflectance tends to increase in the entire wavelength region of visible light in the antireflection film of the present invention, and the reflectance decreases in the entire wavelength region of visible light as the spacing decreases. Tend to. For this reason, the interval between the micropores is preferably in the range of 0 nm to 100 nm, and more preferably in the range of 5 nm to 80 nm. In addition, let the said space | interval in the metal mold | die for antireflection film manufacture used for this invention be the average value determined by the method mentioned above.

Here, the period, depth, and interval of the micropores are as shown by P ₂ , Q ₂ , and R ₂ in FIG. 12, respectively, from the top of the tip to the top of the tip in each adjacent microhole. The distance, the distance from the top of the tip of the minute hole to the opening surface, and the shortest distance between the outer peripheries of the opening surfaces of adjacent minute holes. In addition, FIG. 12 is a schematic diagram for explaining parameters for specifying fine irregularities in the mold for manufacturing an antireflection film used in the present invention.

  The variation in the depth of the micropores is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 10 nm or less. This is because if the variation in the depth of the fine holes is larger than the above range, unevenness may occur in the antireflection function of the antireflection film of the present invention. The variation in the depth of the micropores means a difference between the maximum value and the minimum value of the measured values obtained by observing the longitudinal cross section of the micropores with an electron microscope and measuring the depth of 10 pieces.

  In the mold for producing an antireflection film used in the present invention, the step between the opening surfaces of the adjacent micropores (hereinafter referred to as small undulations) is preferably 100 nm or less, and preferably 80 nm or less. Is more preferable, and it is further more preferable that it is 50 nm or less. This is because if the small undulation exceeds 100 nm, the surface can be visually recognized as a scratch, and the antireflection function becomes non-uniform.

In the mold for producing an antireflection film used in the present invention, the step between the opening surfaces of the micropores separated by 500 nm or more (hereinafter referred to as large swell) is preferably 10 μm or less, and 500 nm. More preferably, it is in the range of ˜2 μm. This is because, when the swell is 500 nm or more, if the large swell is 10 μm or less, the antireflection function is not affected, and even if it is visually observed, it is not understood (deceived).
As a method of creating large waviness on the surface of the metal substrate, the surface of the metal substrate or the support of the metal substrate is roughened to form irregularities, the surface of the metal substrate or the support of the metal substrate is roughened, and irregularities are formed. After laminating the metal substrate by sputtering, plating, vapor deposition, roughening the surface of the metal substrate or the support of the metal substrate, forming irregularities, laminating the resin, and smoothing the irregularities , A method of laminating a metal substrate by a sputtering method, a plating method, a vapor deposition method, a method of laminating a resin on the surface of the metal substrate or a support of the metal substrate, forming an unevenness, and then laminating the metal substrate, silica on the surface, Examples include a method of laminating a resin containing metal or metal oxide particles on a metal substrate or a support of the metal substrate, forming irregularities, and then laminating the metal substrate.
As a method for roughening the surface of the metal substrate or the support of the metal substrate, mechanical treatment, electrochemical treatment, anodization, embossing method, polishing method, etching method, wet plating method, dry plating method, thermal spraying method, Examples include a method in which a photolithography method, a surface heat treatment method, a sol-gel method, and the like are appropriately used alone or in combination.
Mechanical treatment methods include sand blast method, shot blast method, grit blast method, blast method such as glass bead blast method, synthetic resin hair made of synthetic resin such as nylon, polypropylene, and vinyl chloride resin, Brush graining method using brush hair (material) such as non-woven fabric, animal hair, steel wire, wire graining method using metal wire, brush polishing method while supplying slurry containing abrasive (brush grain method) And buffing methods such as a ball grain method and a liquid honing method, and a shot peening method.
As an electrochemical treatment method, there is a method using a direct current or an alternating current in an aqueous electrolyte solution containing hydrochloric acid, nitric acid or sulfuric acid and chloride ion or nitrate ion.
Examples of the embossing method include roll embossing or single-wafer press-type embossing that presses a roll mold or a single-wafer press mold having a large waviness shape on the surface and transfers the shape by 50% or more.
As the polishing method, barrel polishing method using a rotary barrel or vibration barrel, buff polishing method, leuter polishing method, abrasive flow polishing method, electrolytic polishing method, chemical polishing method, chemical composite polishing method, electrolytic composite polishing method , Chemical mechanical polishing, CMP polishing and the like.
Examples of the etching method include chemical etching, electrolytic etching, and dry etching using sputtering.
Examples of the wet plating method include an electroplating method, an electroless plating method, a hot dip galvanizing method, a hot dip aluminum plating method, and an insoluble anode method.
Examples of dry plating include physical vapor deposition (PVD) such as vacuum vapor deposition, resistance heating, sputtering, ion plating, and chemical vapor deposition (CVD) such as atmospheric pressure CVD, reduced pressure CVD, and plasma CVD. .
Flame spraying methods using metal, ceramics, plastics, cermets, carbides, and abradables as materials include flame spraying methods such as wire flame spraying, powder flame spraying, welding rod flame spraying, and explosive spraying (D gun). Examples include arc spraying, plasma spraying (low pressure plasma spraying / atmospheric plasma spraying / water plasma spraying), electric spraying methods such as line explosion spraying, high-speed flame spraying, and cold spray spraying.
Surface heat treatment methods include bubbles on the surface, brushing, cratering, cracking, crystal growth treatment, bulking, convection dissipation patterning, sinking dissipation Examples include a method of forming a shape by a method such as patterning, dissipating patterning, agglomeration of particles, or nano buckling.
Further, a plasma ashing method in which undulations are formed on the surface using plasma can also be used.
Methods for laminating a resin on a metal substrate or its support include spraying, electrodeposition, dipping, dip coating, roll coating, T-die coating, cast coating, blade coating, spin coating, bar A known method such as a coating method, a wire bar coating method, a casting method, an LB method, an electrostatic coating method, a powder coating method, or a method of coating a tube or a sleeve can be used. After coating, a drying process or a half curing process by heat, UV or EB can be appropriately performed.
Examples of the resin used include ionizing radiation curable resins such as ultraviolet curable resins and electron beam curable resins, thermosetting resins, thermoplastic resins, and the like, for example, acrylic resins, polyester resins, epoxy resins, polyolefins. Resin, styrene resin, polyamide resin, polyimide resin, polyamideimide resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polycarbonate resin, melamine resin, urea resin, alkyd resin, phenol resin, cellulose resin, diallyl Examples thereof include phthalate resin, silicone resin, polyarylate resin, polyacetal resin, styrene-isoprene rubber, and fluorine resin. Moreover, there are these elastomers and acid-modified products.
The formation of large waviness is the case where the anodizing step, the first etching step, and the subsequent second etching step described later in “7. Method for producing mold for producing antireflection film” are the main treatment steps. You may give as a pre-process of this process process, and you may process after this process process. Or you may carry out before and after this process process. Furthermore, it may be performed after the anodic oxidation step in the present processing step, or may be performed after the first etching step, and further, a combination thereof can be used.

  The transfer rate of the antireflection film production mold used in the present invention is appropriately adjusted according to the viscosity and pressure of the resin used during the production of the antireflection film, but may be 50% or more. That is, the anti-reflection film manufacturing mold used in the present invention has micropores to such an extent that a fine concavo-convex pattern having sufficient physical properties to be used as an anti-reflection film can be obtained even if the transfer rate is not 100%. The shape can be molded into the resin layer. Therefore, at the tip portion of the resin layer that has entered the fine hole of the mold, a bottom surface or a side wall of the fine hole, or a portion that does not contact the bottom surface and the side wall is generated. Here, the transfer rate refers to the ratio of the depth at which the resin layer enters with respect to the depth of the fine holes. Since the penetration depth of the resin layer is the same as the height of the convex portion of the molded product, the transfer rate is the ratio of the height of the convex portion of the molded product to the depth of the fine holes.

  The method for producing the antireflection film production mold used in the present invention is not particularly limited as long as it is a method capable of producing the antireflection film production mold having the above-described configuration. Examples include the method described in the section of “7. Method for producing mold for production of antireflection film”.

7). Next, the manufacturing method of the metal mold | die for antireflection film manufacture used for this invention is demonstrated. As a method for producing a mold for producing an antireflection film used in the present invention, for example, an anodic oxidation step is used in which a metal base is used and a metal oxide film having a plurality of fine holes is formed on the surface of the metal base by an anodic oxidation method. And etching the metal oxide film to form a tapered shape in the opening of the microhole, and etching the metal oxide film at an etching rate higher than the etching rate of the first etching process. Thus, a manufacturing method having a micropore forming step of forming a plurality of micropores on the surface of the metal base by sequentially repeating the second etching step of enlarging the pore diameter of the micropores can be given.

A method for producing such a mold for producing an antireflection film will be described with reference to the drawings. 13 (a) to 13 (e) are process diagrams showing an example of a method for producing a mold for producing an antireflection film used in the present invention. As illustrated in FIGS. 13A to 13E, the metal substrate 11 is used in the manufacturing method of the antireflection film manufacturing mold used in the present invention (FIG. 13A). As shown in FIG. 13 (b) to FIG. 13 (d), an antireflection film manufacturing mold 20 having a configuration in which micropores are formed on the surface of the metal substrate 11 is manufactured. (FIG. 13E).
Here, in the fine hole forming step, the metal substrate 11 is used (FIG. 13A), and an anodic oxidation step of forming a metal oxide film 11 ′ having a plurality of fine holes on the surface of the metal substrate 11 by an anodic oxidation method. (FIG. 13B), a first etching step (FIG. 13C) for forming a tapered shape in the opening of the microhole by etching the metal oxide film 11 ′, and the metal oxide film 11 ′ The second etching step (FIG. 13 (d)) for enlarging the hole diameter of the fine holes by etching at an etching rate higher than the etching rate of the first etching step is sequentially repeated, so that the surface of the metal substrate 11 is finely formed. A hole is formed.

The method for producing a mold for producing an antireflection film used in the present invention includes a micropore forming step having at least an anodizing step, a first etching step, and a second etching step, and other optional ones as necessary. These steps may be used.
Hereinafter, each process in the manufacturing method of the metal mold | die for antireflection film manufacture used for this invention is demonstrated.

(1) Micropore forming step The micropore forming step in the method of manufacturing the antireflection film manufacturing mold used in the present invention uses a metal substrate and has a plurality of micropores on the surface of the metal substrate by an anodic oxidation method. An anodic oxidation step for forming a metal oxide film; a first etching step for forming a tapered shape in the opening of the microhole by etching the metal oxide film; and an etching for the metal oxide film in the first etching step. In this step, a plurality of fine holes are formed in the surface of the metal substrate by sequentially and repeatedly performing a second etching step of expanding the diameter of the fine holes by etching at an etching rate higher than the rate.

(A) Metal substrate The metal substrate used in the method for producing the mold for producing an antireflection film used in the present invention is made of a metal capable of forming an anodized film on its surface, that is, a so-called valve metal. For example, there is no particular limitation. Examples of such a metal substrate include those made of aluminum, magnesium, titanium, silicon, etc. Among them, those made of aluminum can be suitably used. This is because aluminum is easily oxidized and an anodic oxide film is easily formed. The metal substrate used in the above method for producing a mold for producing an antireflection film may be made of aluminum alone, and a layer made of aluminum on an arbitrary base material by sputtering, vapor deposition or plating. You may have the structure formed so that it might become the outermost layer. Examples of the base material used for the metal substrate include those made of rubber, resin, metal and the like.

  Moreover, the form of the metal substrate used in the method for producing the mold for producing an antireflection film is not particularly limited. Therefore, in the manufacturing method of the mold for producing an antireflection film, a metal substrate having any form such as a sheet form, a roll form, a belt form, a three-dimensional form, and a film form can be suitably used. Here, the “three-dimensional metal substrate” refers to a metal substrate that is a three-dimensional object formed by injection molding or the like, and the “film-shaped metal substrate” refers to polyethylene terephthalate having a thickness of 200 μm or less, Polyester resin such as polyarylate, polyethylene naphthalate, and polybutylene terephthalate, polyolefin resin such as polypropylene, polyamide resin such as nylon 66, acrylic resin, acrylic melamine resin, silicone resin, polyimide resin, polyimide amide resin, polycarbonate resin , A metal substrate on which a resin layer such as a fluororesin is laminated, or a metal such as nickel, aluminum, stainless steel, copper, or an alloy thereof, or a surface of these alloys such as chromium, tantalum, Chita Refers copper, silver, gold, metal or inorganic or metal substrate laminated on the metal film such as a metal formed by stacking these compounds, such as silicon, or to a metal substrate made of these composites.

  The thickness of the metal substrate is not particularly limited as long as it can form a metal oxide film having a plurality of fine holes on the surface of the metal substrate and has sufficient strength as a mold. However, it can set within the range of 50 nm-100 mm, for example.

(B) Anodizing step The anodizing step in the method for producing a mold for producing an antireflection film used in the present invention is a step of forming a metal oxide film having a plurality of fine holes on the surface of the metal substrate by an anodizing method. It is.

  The anodic oxidation method used in this step is not particularly limited as long as it is a method capable of forming a metal oxide film having fine holes formed in a desired depth and arrangement on the surface of the metal substrate. Here, the depth and arrangement of the micropores formed by the anodic oxidation method depend on the liquidity of the electrolytic solution used for the anodic oxidation, and the electrolytic solution used in this step is neutral. Even an electrolytic solution or an acidic electrolytic solution can be suitably used. Especially, in this process, it is preferable to use an acidic electrolytic solution as the electrolytic solution. This is because the use of an acidic electrolytic solution makes it possible to form micropores at random positions on the surface of the metal substrate in this step. Examples of the acidic electrolytic solution used in this step include a sulfuric acid aqueous solution, an oxalic acid aqueous solution, and a phosphoric acid aqueous solution.

  The anodic oxidation time in this step is not particularly limited as long as a metal oxide film having a plurality of micropores having a desired shape can be formed on the surface of the metal substrate, and the production of the antireflection film used in the present invention It is appropriately set according to the metal substrate used in the manufacturing method of the metal mold, the electrolytic solution used in this step, and the like.

  The thickness of the metal oxide film formed by this step is not particularly limited as long as it has a plurality of fine holes having a desired shape.

(C) 1st etching process The 1st etching process in the manufacturing method of the metal mold | die for anti-reflective film manufacture used for this invention forms a taper shape in the opening part of the said micropore by etching the said metal oxide film. It is a process.

  In this step, the method for etching the metal oxide film is not particularly limited as long as it can form a desired tapered shape in the opening of the fine hole. Examples of such a method include an alkali etching method, an acidic etching method, and an electrolytic etching method. Although any of these methods can be used in this step, the alkali etching method has a large gloss, surface roughness, etc., and it is difficult to maintain the etching surface in a constant state. It is preferable to use an acidic etching method because it is required to always control the dissolved metal component in the bath in a certain range.

Especially, in the manufacturing method of the metal mold | die for antireflection film used for this invention, this process may be a process performed in the electrolyte solution used at the said anodizing process immediately after the said anodizing process. preferable. This is because it is not necessary to separately prepare an etching solution used in the first etching step, and a tapered shape can be easily formed in the opening portion of the fine hole.
The electrolytic solution used in this step is the one used in the anodizing step. Specifically, an acidic electrolytic solution such as a sulfuric acid aqueous solution, an oxalic acid aqueous solution, a phosphoric acid aqueous solution, or a mixed solution thereof is used. Among them, an oxalic acid aqueous solution is preferable from the viewpoint of handling and management.
In addition, a time during which this step is performed immediately after the anodizing step in the electrolytic solution used in the anodizing step, that is, a metal oxide film having a plurality of micropores is formed on the surface by the anodizing step. The time for leaving the metal substrate as it is in the electrolytic solution used in the anodizing step is not particularly limited as long as a desired tapered shape can be formed in the opening of the micropore, For example, it is preferably 3 seconds or more, more preferably 10 seconds or more, and further preferably 60 seconds or more.
The reason why the tapered shape can be formed in the opening of the fine hole by this step is as follows.
<1> When anodizing is performed, a porous cylindrical hole is formed while forming an oxide film.
<2> When this oxide film is chemically dissolved, the outside (ie, the top surface) is exposed to the etching solution longer than the inside (ie, the bottom surface). This is because the exchange rate of the etchant that has entered the interior is slower than that of the external etchant.
<3> As a result, the amount of etching on the outside increases, resulting in a tapered shape.

  The etching rate in this step is lower than the etching rate in the second etching step described later. In the manufacturing method of the antireflection film manufacturing mold used in the present invention, the reason why the shape formed in the opening of the fine hole is different due to the difference in the etching rate in the first etching step and the second etching step, This is because the second etching has a higher etching rate than the first etching, and thus has the effect of expanding the entire diameter of the hole formed in the tapered shape by the first etching.

(D) Second Etching Step The second etching step in the method of manufacturing the antireflection film manufacturing mold used in the present invention etches the metal oxide film at an etching rate higher than the etching rate of the first etching step. This is a step of enlarging the hole diameter of the fine holes. In the manufacturing method of the antireflection film manufacturing die, a tapered shape is usually not formed in the opening of the fine hole by the second etching step, but a tapered shape formed by the first etching step. Increase the diameter evenly.

  In this step, the method of etching the metal oxide film at an etching rate higher than the etching rate of the first etching step may be a method of expanding the hole diameter of the fine holes formed in the metal oxide film to a desired level. For example, there is no particular limitation. As such a method, an etching method similar to the method described in the first etching step can be given.

  The etching rate in this step is higher than the etching rate in the first etching step and is not particularly limited as long as the diameter of the micropores can be enlarged, but the etching rate in the first etching step is not limited. Thus, it is preferably 1.2 times or more, more preferably 1.5 times or more, and further preferably 2.0 times or more. This is because if the ratio is 1.2 times or less, the effect of sufficiently expanding the hole diameter is reduced.

As an etching solution used in this step, for example, an aqueous sulfuric acid solution, an aqueous oxalic acid solution, an aqueous phosphoric acid solution, an aqueous chromic acid solution, or a mixed solution thereof is used. An alkaline aqueous solution such as sodium hydroxide is used. Among these, an aqueous phosphoric acid solution is preferable from the viewpoint of handling and management.
The concentration of the etchant is appropriately adjusted according to the type of etchant used in this step, the metal substrate used in the method for producing the mold for producing the antireflection film used in the present invention, and the like. However, for example, it is preferably in the range of 0.005M to 2.0M, and more preferably in the range of 0.01M to 1.5M. This is because if the concentration of the etchant used in the second etching step is higher than the above range, the metal oxide film may be completely removed by the second etching step. This is because if the concentration is lower than the above range, the etching rate in the second etching step is lowered, and sufficient pore diameter expansion processing cannot be performed.
The etching time in this step is appropriately adjusted according to the etching solution used in this step, the metal substrate used in the production method of the antireflection film manufacturing mold, and for example, 1 minute to It is preferably within a range of 60 minutes, and more preferably within a range of 2 minutes to 30 minutes. If the etching time of the second etching step is longer than the above range, the metal oxide film is completely removed by the second etching step, the wall between the holes becomes thin, the strength becomes weak, and the resin enters. If the etching time of the second etching step is shorter than the above range, the fine holes cannot be sufficiently enlarged, and a desired shape may not be obtained. Because.

(E) Micropore forming step In this step, the degree of repetition when the anodic oxidation step, the first etching step, and the second etching step are sequentially repeated is as follows. It is repeated a plurality of times until fine pores that are uniform enough to be used as This step may end with the anodizing step or the second etching step.

  In this step, the number of times that the anodic oxidation step, the first etching step, and the second etching step are sequentially repeated can be appropriately determined according to the shape of the target micropore. It is a thing and is not specifically limited. Further, in this step, the number of times that these steps are sequentially repeated is appropriately adjusted together with etching conditions such as an etching solution and an etching time according to the target etching amount.

  The shape of the fine holes formed on the surface of the metal substrate by this step is not particularly limited as long as the opening has a tapered shape. About the shape of the said micropore, since it can be made to be the same as that of what was described in the term of the above-mentioned "6. Antireflection film manufacture metal mold | die", description here is abbreviate | omitted.

(2) Arbitrary process The manufacturing method of the metal mold | die for antireflection film manufacture used for this invention has the said micropore formation process at least, and may have other arbitrary processes as needed. It ’s good. Examples of such a process include a mold release process, a water washing process, and a drying process.

Especially, in the manufacturing method of the metal mold | die for antireflection film manufacture used for this invention, it may have a mold release process process which performs a shaping process to the metal mold | die for antireflection film obtained by the said micropore formation process. preferable. It is because it can provide mold release property to the metal mold | die for antireflection film used for this invention by having a mold release process process. Since the mold for producing an antireflection film has releasability, there is an advantage that when the antireflection film is produced, the antireflection film can be easily taken out from the mold for producing the antireflection film.
The release treatment method is not particularly limited as long as it does not fill the fine holes of the metal oxide film in the antireflection film production mold. For example, a release agent may be used to produce the antireflection film. Examples thereof include a method of applying to a metal mold, a method of laminating a release agent on the metal mold for producing an antireflection film by a sputtering method, and the like. Examples of the release agent include fluorine compounds, silicone compounds, aliphatic amide compounds, paraffin compounds, and the like.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described by giving examples.

[Example 1]
(Production of anti-reflection film mold)
First, after polishing an aluminum cylinder provided with rotating shafts at both ends of an extruded aluminum pipe with a purity of 99.85% so that the surface roughness Rz is 30 nm as a small undulation and the large undulation is 1 μm, 0.02M Anodization was performed for 120 seconds in an electrolytic solution of an acid aqueous solution under conditions of a formation voltage of 40 V and 20 ° C. Next, as a first etching process, an etching process was performed for 60 seconds with the electrolytic solution after anodization. Subsequently, as a second etching process, a pore size expansion process was performed with a 1.0 M aqueous phosphoric acid solution for 150 seconds. Further, the above steps were repeated, and these were added five times in total. As a result, an anodized alumina film having a plurality of fine holes was formed on the aluminum cylinder. Finally, a fluorine mold release agent was applied and the excess mold release agent was washed to obtain a mold for producing an antireflection film.

[Example 1-1]
(Preparation of antireflection film)
A 125 μm thick polyethylene terephthalate film (refractive index of 1.58) prepared as a light-transmitting substrate is dried with a water dispersible thermoplastic urethane resin adjusted to have a refractive index of 1.54 in a dry film state of 1 μm in dry thickness. And then dried at a temperature of 80 ° C. for 30 seconds to form an easy adhesion layer. Furthermore, after applying an ultraviolet curable resin composition (refractive index 1.49, viscosity 500 mPa · s) having a solid content of 100% thereon to a thickness of 20 μm, the antireflection film obtained in Example 1 was applied. The product was pressed onto the production mold with a rubber roller at a load of 10 N / cm. By confirming that the uniform ultraviolet curable resin composition was applied to the entire mold, and irradiating ultraviolet rays with energy of 2000 mJ / cm ² from the film side to photocur the ultraviolet curable resin composition, An antireflection layer was formed. Then, it peeled from the said metal mold | die and obtained the antireflection film.

[Example 1-2]
(Preparation of antireflection film)
An ultraviolet curable resin containing 80 parts by weight of methyl ethyl ketone, adjusted to have a refractive index of 1.52 in a dry film state on a 125 μm-thick polyethylene terephthalate film (refractive index 1.58) prepared as a light-transmitting substrate Was coated to a dry thickness of 5 μm and dried at a temperature of 80 ° C. for 30 seconds to form an easy adhesion layer. Furthermore, after applying an ultraviolet curable resin composition (refractive index 1.49, viscosity 500 mPa · s) having a solid content of 100% thereon to a thickness of 20 μm, the antireflection film obtained in Example 1 was applied. The product was pressed onto the production mold with a rubber roller at a load of 10 N / cm. By confirming that the uniform ultraviolet curable resin composition was applied to the entire mold, and irradiating ultraviolet rays with energy of 2000 mJ / cm ² from the film side to photocur the ultraviolet curable resin composition, An antireflection layer was formed. Then, it peeled from the said metal mold | die and obtained the antireflection film.

[Example 1-3]
(Preparation of antireflection film)
A 125 μm thick polyethylene terephthalate film (refractive index of 1.58) prepared as a light-transmitting substrate was adjusted to a dry thickness of 0.5 μm with a thermoplastic polyurethane resin adjusted to have a dry film refractive index of 1.56. Then, it was coated at a temperature of 80 ° C. for 30 seconds to form a first easy-adhesion layer. Next, an ultraviolet curable resin (refractive index of 1.52) containing 50 parts by weight of toluene is coated thereon to a dry thickness of 4 μm, dried at a temperature of 80 ° C. for 30 seconds, and a second easy-adhesion layer Formed. Furthermore, after applying an ultraviolet curable resin composition (refractive index 1.49, viscosity 500 mPa · s) having a solid content of 100% thereon to a thickness of 20 μm, the antireflection film obtained in Example 1 was applied. The product was pressed onto the production mold with a rubber roller at a load of 10 N / cm. By confirming that the uniform ultraviolet curable resin composition was applied to the entire mold, and irradiating ultraviolet rays with energy of 2000 mJ / cm ² from the film side to photocur the ultraviolet curable resin composition, An antireflection layer was formed. Then, it peeled from the said metal mold | die and obtained the antireflection film.

[Example 2]
(Production of anti-reflection film mold)
First, a chromium plating was formed to a thickness of 80 μm on the surface of a nickel sleeve having a thickness of 150 μm to form a smooth layer. Then, after polishing so that the surface roughness Rz was 80 nm as a small undulation, the smooth layer was blasted to form a large undulation of 2 μm. Next, 500 nm of silicon dioxide was laminated on the smooth layer by sputtering, and 500 nm of tantalum oxide was further laminated thereon to obtain an intermediate layer. Then, after forming an aluminum thin film layer with a thickness of 29.9 μm and a purity of 99.9% on the intermediate layer by sputtering, in an electrolytic solution of 0.05 M aqueous chromic acid phosphate, the conversion voltage is set to 30 V and 20 ° C. For 120 seconds. Next, as a first etching process, an etching process was performed for 120 seconds with the electrolytic solution after anodization. Subsequently, as a second etching process, a pore size expansion process was performed with a 0.5 M aqueous phosphoric acid solution for 150 seconds. Further, the above steps were repeated, and these were added six times in total. As a result, an anodized alumina film having a plurality of fine holes was formed on the aluminum thin film layer. Finally, a fluorine mold release agent was applied and the excess mold release agent was washed to obtain a mold for producing an antireflection film.

[Example 2-1]
(Preparation of antireflection film)
Thermoplastic polyethylene terephthalate resin (refractive index 1.58) as a resin for light-transmitting substrate, thermoplastic polyurethane resin adjusted to a refractive index 1.56 as a resin for easy adhesion layer, and refractive index 1.53 as a resin for antireflection layer A linear rhoden polyethylene having a melt viscosity of 20 g / 10 min was prepared. Simultaneously extrude from a T-die at 250 ° C. so that the light-transmitting substrate resin is 200 μm, the easy-adhesion layer resin is 5 μm, and the anti-reflection layer resin is 20 μm. With a load of 10 N / cm by a rubber roller on the antireflection film manufacturing mold obtained in Example 2 so that the antireflection layer resin is on the mold side of the laminate composed of resin / antireflection layer resin Crimped. After confirming that the resin for the antireflection layer was filled in the entire mold and cooling with air cooling, the laminate was cured to form a light transmissive substrate, an easy adhesion layer, and an antireflection layer. Then, it peeled from the said metal mold | die and obtained the antireflection film.

[Comparative example]
(Preparation of antireflection film)
A UV curable resin composition having a solid content of 100% (refractive index 1.49, viscosity) in a state where there is no easy-adhesion layer on a 125 μm thick polyethylene terephthalate film (refractive index 1.58) prepared as a light transmissive substrate. 500 mPa · s) was applied to a thickness of 20 μm, and then pressure-bonded to the antireflection film-producing mold obtained in Example 1 with a rubber roller under a load of 10 N / cm. After confirming that the uniform ultraviolet curable resin composition was applied to the entire mold, ultraviolet rays were irradiated from the film side with an energy of 2000 mJ / cm ² to photocur the ultraviolet curable resin composition. Then, it peeled from the said metal mold | die and obtained the antireflection film.

[Evaluation 1]
(Observation of cross section of mold for manufacturing antireflection film by scanning electron microscope)
The anti-reflection film manufacturing mold is cut vertically with a focused ion beam, and the cross section of the mold is observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. The hole diameter, period, depth, and shape of the opening were measured.

  In the antireflection film-manufacturing mold obtained in Example 1, it was observed that a micropore having a pore diameter of approximately 0.5 nm was formed in the back of a tapered micropore having a pore diameter of approximately 100 nm. The period was 110 nm, and the depth of the micropores was 220 nm. Further, it was confirmed that a tapered shape was formed in the opening portion of the fine hole, the depth of the tapered shape was 215 nm, and the taper angle was 77 °.

  In the antireflection film production mold obtained in Example 2, it was observed that a micropore having a pore diameter of approximately 0.5 nm was formed in the back of a tapered micropore having a pore diameter of approximately 75 nm. The period was 80 nm, and the depth of the micropores was 90 nm. In addition, it was confirmed that a tapered shape was formed in the opening of the fine hole, the depth of the tapered shape was 87 nm, and the taper angle was 67 °.

[Evaluation 2]
(Observation of surface and cross section of antireflection film by scanning electron microscope)
The surface of the antireflection film was observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. Moreover, a cross section was produced with a glass slice, and the cross section of the film was observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. From the obtained image, the period of the convex portions in the fine irregularities, The height, the shape of the main body and the tip were measured.

(Reflectivity of antireflection film)
Black tape was affixed to the back surface of the antireflection film, and a 5 ° regular reflectance to the film surface was measured using a self-recording spectrophotometer UV-3100 manufactured by Shimadzu Corporation.

(Appearance of antireflection film)
Black tape was affixed to the back surface of the antireflection film and visually confirmed.

(Anti-reflection film sticking)
The antireflection film was immersed in water and taken out, and then air-dried for 24 hours. After confirming that no water droplets remained on the surface, the surface of the film was observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. The presence or absence of sticking was confirmed from the obtained image.

(Wipe cloth for antireflection film)
The antireflection film was rubbed with a load of 50 g / cm ^{2 with} flannel and allowed to stand for 12 hours, and then the surface of the film was observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. From the obtained image, it was confirmed whether or not the structure was damaged.

(Displacement of antireflection film from mold for manufacturing antireflection film)
The surface of the antireflection film was observed using a scanning electron microscope S-4500 manufactured by Hitachi High-Technologies. The damage state of the structure on the film surface was observed from the obtained image.

(Adhesion between the antireflection layer and the light-transmitting substrate)
A cross cut test described in JIS K5400 (a test in which 100 cross cuts were made at 1 mm intervals and peeled off with cellophane tape (manufactured by Nichiban Co., Ltd.)) was performed. Specifically, the surface of the antireflection film on the side of the antireflection layer is provided with 11 cuts at 1 mm intervals in the vertical and horizontal directions to make 100 1 mm square grids, on which cellophane tape is applied, 90 The film was peeled off quickly at 0 °, and the number of grids remaining without peeling off the antireflection layer was counted. As an evaluation method, the cellophane tape was always new, and the peel test was conducted 5 times. When the antireflection layer peeled off at least once in the grid, it was judged that there was no practicality.

(With or without interference fringes)
Using an interference fringe inspection lamp (Na lamp) manufactured by Funatech, the presence or absence of interference fringes in the antireflection film was visually inspected. It was judged that there was no problem if the interference fringes were not visible at all, or if they were faintly seen, and those that were clearly visible were judged as bad.

  The surface structure of the mold was transferred to the surface (transfer surface) of the antireflection film obtained in Example 1-1. The transfer surface has a convex shape with a period of 110 nm, a height of the convex part of 210 nm, and a main body part having a tapered shape with a taper angle of 77 ° and a tip part having a radius of 4 nm. The structure was formed. The removal from the mold was carried out without problems. The 5 ° regular reflectance was 0.6%. The appearance was not white and could withstand practical use. In addition, there was no sticking, damage was suppressed even with cloth wiping, there was no problem with the adhesion between the antireflection layer and the light transmissive substrate, and interference fringes were also suppressed. .

  The surface structure of the mold was transferred to the surface (transfer surface) of the antireflection film obtained in Example 1-2. The transfer surface has a convex shape with a period of 110 nm, a height of the convex part of 210 nm, and a main body part having a tapered shape with a taper angle of 77 ° and a tip part having a radius of 4 nm. The structure was formed. The removal from the mold was carried out without problems. The 5 ° regular reflectance was 0.8%. The appearance was not white and could withstand practical use. In addition, there was no sticking, damage was suppressed even with cloth wiping, there was no problem with the adhesion between the antireflection layer and the light transmissive substrate, and interference fringes were also suppressed. .

  The surface structure of the mold was transferred to the surface (transfer surface) of the antireflection film obtained in Example 1-3. The transfer surface has a convex shape with a period of 110 nm, a height of the convex part of 210 nm, and a main body part having a tapered shape with a taper angle of 77 ° and a tip part having a radius of 4 nm. The structure was formed. The removal from the mold was carried out without problems. The 5 ° regular reflectance was 0.6%. The appearance was not white and could withstand practical use. In addition, there was no sticking, damage was suppressed even with cloth wiping, there was no problem with the adhesion between the antireflection layer and the light transmissive substrate, and interference fringes were also suppressed. .

  The surface structure of the mold was transferred to the surface (transfer surface) of the antireflection film obtained in Example 2-1. The transfer surface has a convex period of 80 nm, a convex part height of 88 nm, a main body part having a taper shape having no curvature, a taper angle of 67 °, and a tip part having a radius of 1 nm. An arc-shaped structure was formed. The removal from the mold was carried out without problems. The 5 ° regular reflectance was 1.0%. The appearance was not white and could withstand practical use. In addition, there was no sticking, damage was suppressed even with cloth wiping, there was no problem with the adhesion between the antireflection layer and the light transmissive substrate, and interference fringes were also suppressed. .

  The surface structure of the mold was transferred to the surface (transfer surface) of the antireflection film obtained in the comparative example. The transfer surface has a convex shape with a period of 110 nm, a height of the convex part of 210 nm, and a main body part having a tapered shape with a taper angle of 77 ° and a tip part having a radius of 4 nm. The structure was formed. The adhesion between the antireflection layer and the light-transmitting substrate was poor, and the ability to remove from the mold was poor. Therefore, the 5 ° regular reflectance could not be measured, the appearance was white, and it could not be put into practical use. In addition, generation of interference fringes was also observed.

DESCRIPTION OF SYMBOLS 1 ... Light-transmitting substrate 2 ... Easy-adhesion layer 3 ... Antireflection layer 4 ... Base part 5 ... Fine unevenness 5a ... Main-body part 5b ... Tip part 6 ... Hard-coat layer, primer layer, or antistatic layer 7 ... Adhesive layer 8 ... Protective layer 10 ... Antireflection film 11 ... Metal substrate 11 '... Metal oxide film 20 ... Mold for manufacturing antireflection film

Claims (5)

A light-transmitting substrate made of polyethylene terephthalate (PET) resin, an easy-adhesion layer formed on the light-transmitting substrate, formed on the easy-adhesion layer, and formed on the surface with a period below the wavelength of the visible light region An antireflection film having an antireflection layer having an uneven shape,
The easy-adhesion layer has a refractive index that is an average of the refractive index of the light-transmitting substrate and the refractive index of the antireflection layer;
The antireflection layer has a base portion formed on the easy-adhesion layer, and fine unevenness formed on the base portion and having the uneven shape, and the convex portion in the fine unevenness is the light An antireflection structure comprising a frustum-shaped main body portion that rises in a tapered shape with respect to a transparent substrate, and a tip portion having a curved surface structure formed so as to cover the top surface of the main body portion. the film.   The antireflection film according to claim 1, wherein a functional layer is formed between the easy adhesion layer and the antireflection layer.   The antireflection film according to claim 2, wherein the functional layer is a hard coat layer, a primer layer, or an antistatic layer.   The antireflection according to any one of claims 1 to 3, wherein a taper angle with respect to the light transmissive substrate in a longitudinal section of the main body portion is in a range of 50 ° to 87 °. the film.   The height of the said main-body part exists in the range of 60 nm-1400 nm, The antireflection film in any one of Claim 1 to 4 characterized by the above-mentioned.

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