JP2009211061A - Antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film which is excellent in productivity and suppressed in interference unevenness, and never impairs contrast and clearness when applied to a display device. <P>SOLUTION: The antireflection film comprises: a transparent film including irregularities formed on one surface of a transparent substrate; and a high refractive index layer having a refractive index higher than that of the transparent substrate and a low refractive index layer having a refractive index lower than that of the high refractive index layer, which are provided in this order on the one surface of the transparent film. The irregularities are formed by deforming the transparent substrate, and the antireflection film satisfies the following expressions [1] and [2]: [1] 0.04≤Ra≤0.25 μm, [2] 0.001≤Ra/Sm≤0.005 (Ra and Sm represent an arithmetic average roughness and an average interval of the irregularities measured respectively based on JIS B0601:1994). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection film. More specifically, the present invention relates to an antireflection film in which color unevenness is suppressed without causing a decrease in contrast and sharpness of a display device.

Conventionally, in a laminated film in which a transparent thin film layer is formed on a transparent substrate, the light reflected on the surface of the transparent substrate interferes with the light reflected on the surface of the laminated film, so that a pattern called interference fringes (interference unevenness) Has been visually recognized, causing display unevenness.
Therefore, various proposals have been made to solve the above problems.

  For example, Patent Document 1 discloses a method of controlling the roughness of a boundary surface between two layers having a difference in refractive index as means for preventing interference fringes when a laminated film is obtained. According to this method, it is described that a laminate having no interference fringes and having a haze of 1% or less can be obtained.

  In Patent Document 2, a hard coat layer and an antireflection layer are provided on a transparent substrate film having an uneven surface, and the refractive index of the hard coat layer is higher than the refractive index of the antireflection layer, and the antireflection film having a small haze. Here, it is described that the surface roughness of the unevenness is in the range of 0.05 to 0.15 μm. And it is described that this antireflection film can suppress interference unevenness (color unevenness) and surface glare of the display device.

  Patent Document 3 discloses an optical film in which the contact interface between the first transparent layer and the second transparent layer is a light scattering interface. Here, the contact interface has an average roughness of 10 points. Is 0.4 μm or more. And this optical film says that generation | occurrence | production of an interference fringe can be suppressed, and providing an antireflection layer as a preferable aspect is described.

JP 2001-080013 A JP 2004-069867 A JP 2005-107005 A

  However, when the laminate described in Patent Document 1 is applied to a display device, interference unevenness is eliminated by controlling the roughness of the boundary surface, but the average roughness is as large as 0.5 μm or more, so that the display image The sharpness deteriorates and is not suitable for high-definition display applications.

Moreover, in the antireflection film described in Patent Document 2 or Patent Document 3, the unevenness is imparted by applying a layer containing fine particles on a support. Therefore, in the methods disclosed in Patent Document 2 and Patent Document 3, it is necessary to separately provide a process for applying and curing a layer for preventing interference fringes on the support, and depending on the properties of the support. The manufacturing process becomes more complicated because it is necessary to apply a means such as a surface treatment for preventing the prevention layer from peeling off, and there is a possibility that the productivity is lowered.
Accordingly, an object of the present invention is to provide an antireflection film that is excellent in productivity, suppresses uneven interference, and does not impair contrast and sharpness when applied to a display device.

  Therefore, as a result of investigations to achieve the above object, the present inventor has controlled the average height of the unevenness in addition to the average height / depth of the unevenness among the indices related to the surface shape, and further, these two indices. By providing the projections and depressions that satisfy a certain relationship to the transparent film by deforming the transparent substrate, and stacking an antireflection layer on the projections and depressions provided on the transparent film, the productivity is excellent and interference is achieved. It has been found that an antireflection film suitable for a display in which unevenness is suppressed and the contrast and sharpness are not impaired when applied to a display device can be obtained, and the present invention has been completed.

Thus, the present invention includes the following.
A high refractive index layer having a refractive index higher than the refractive index of the transparent substrate, and a refractive index of the high refractive index layer on the one surface of the transparent film formed by forming irregularities on one surface of the transparent substrate. An antireflection film comprising a low refractive index layer having a lower refractive index in this order, wherein the irregularities are formed by deforming a transparent substrate, and satisfy the following [1] to [2] .
[1] 0.04 ≦ Ra ≦ 0.25 μm
[2] 0.001 ≦ Ra / Sm ≦ 0.005
(Ra and Sm are the arithmetic average roughness and the average interval of irregularities measured based on JIS B0601: 1994, respectively.)
(2) The contact angle between the surface of the high refractive index layer far from the transparent film and water is higher than the contact angle between the surface of the transparent film and water, and the transparent film of the low refractive index layer. The antireflection film according to (1), wherein a contact angle between the surface far from the surface and water is higher than a contact angle between the surface far from the transparent film of the high refractive index layer and water.
(3) the high refractive index layer is 1.60 or more and 1.70 or less, an arithmetic mean roughness Ra _h of the farther from the transparent film surface of the high refractive index layer is 0.1μm or less The antireflection film according to (1) or (2).
(4) The refractive index of the low refractive index layer is less than 1.40, and the arithmetic average roughness Ra ₁ of the surface of the low refractive index layer on the side far from the transparent film is 0.06 μm or less, (1) Antireflection film in any one of-(3).
(5) The minimum value of the reflectance measured on the surface on which the low refractive index layer measured at an incident angle of 5 degrees at a wavelength of 430 to 700 nm is 1.5% or less, (1) to (4) The antireflection film according to any one of the above.

  ADVANTAGE OF THE INVENTION According to this invention, the antireflection film which is excellent in productivity, the interference nonuniformity is suppressed, and does not impair contrast and clearness when applied to a display device can be obtained.

FIG. 1 is a view showing an antireflection laminate according to the present invention.

The above-described present invention will be described in detail below with reference to the drawings.
FIG. 1 is a configuration diagram of an antireflection film according to the present invention. In the figure, 1 is a transparent film, 2 is a high refractive index layer, 3 is a low refractive index layer, and 4 is uneven.

The antireflection film of the present invention comprises a high refractive index layer having a refractive index higher than the refractive index of the transparent substrate on the one surface of the transparent film formed by forming irregularities on one surface of the transparent substrate. And a low refractive index layer having a refractive index lower than the refractive index of the high refractive index layer in this order, and the irregularities are formed by deforming the transparent substrate, [1] to [ 2] is satisfied.
[1] 0.04 ≦ Ra ≦ 0.25 μm
[2] 0.001 ≦ Ra / Sm ≦ 0.005
(Ra and Sm are the arithmetic average roughness and the average interval of irregularities measured based on JIS B0601: 1994, respectively.)
When the Ra of the surface having the unevenness of the transparent film is not less than the above value, the sharpness of the display image tends to be lowered when the antireflection film is applied to the display device. When Ra of the surface having irregularities of the transparent film is not more than the above value, interference unevenness occurs when a high refractive index layer and a low refractive index layer described later are formed, and the visibility of the display device tends to decrease. .
When Ra / Sm of the surface having irregularities of the transparent film is not less than the above value, the sharpness of the display image tends to be lowered when the antireflection film is applied to the display device. When Ra / Sm of the surface having irregularities of the transparent film is not more than the above value, interference unevenness occurs when a high refractive index layer and a low refractive index layer described later are formed, and the visibility of the display device tends to decrease. There is.

  Ra of the surface having irregularities of the transparent film is preferably 0.05 μm or more and 0.2 μm or less, and Ra / Sm of the surface having irregularities of the transparent film is preferably 0.0012 or more and 0.0045 or less.

The method for obtaining the transparent film having the concavo-convex surface is not particularly limited as long as the concavo-convex that satisfies the above conditions can be obtained by deforming the surface of the transparent substrate. The nip molding method that presses the transparent substrate immediately after extrusion obtained in the melt extrusion molding method to transfer the unevenness, or the transparent substrate is pressed with the release film having the unevenness to form the unevenness of the release film. Examples thereof include a method of peeling the release film after the transfer, and a method of cutting the surface of the transparent substrate by spraying fine particles on the surface of the transparent substrate.
Among them, since a transparent film having uneven transfer unevenness can be obtained in a wide width, a nip forming method using a forming roll having unevenness is preferable, and a transparent substrate is formed using a mirror roll and an forming roll having unevenness. It is preferable to pinch.
Examples of the surface material of each roll include metal, rubber, and resin. Although these are suitably selected so that the target uneven | corrugated shape can be transferred to a transparent base material, it is preferable that the hardness of a shaping roll is more than the hardness of a mirror surface roll. Moreover, in order to satisfy | fill the said conditions, you may make it narrow through a resin film etc. which have the surface property equivalent to a mirror surface roll and are softer than a shaping roll.

  It is preferable that the mirror-shaped roll and the shaping roll having irregularities can be independently adjusted in temperature. The temperature of the mirror roll is preferably 40 ° C. or higher and 160 ° C. or lower, and the temperature of the shaping roll having irregularities is preferably 60 ° C. or higher and 200 ° C. or lower. The temperature of the mirror roll is more preferably 60 ° C. or higher and 130 ° C. or lower, and the temperature of the shaping roll having irregularities is more preferably 80 ° C. or higher and 180 ° C. or lower.

  In the nip formation method, Ra of the transparent film is the transparent substrate and the temperature of each roll at the time of clamping, the roll speed, the pressure when clamping the transparent substrate, and the material of the surface of each roll, which will be described later. Although it can adjust by selecting suitably according to the characteristic of this, mirror surface roll and a shaping roll temperature are (Tg-60)-(Tg + 20) with respect to the glass transition temperature (Tg) of transparent resin mentioned later. ) C. is preferable.

For example, when using an acrylic resin as a transparent base material, a preferable pressure is 5k-13kN / m. If the pressure applied to the film exceeds the above value, the film may break. If the pressure applied to the film is not more than the above value, uneven transfer unevenness tends to occur in the width direction of the film.
The preferable temperature of a mirror surface roll and a shaping roll is 60-130 degreeC. When the temperature of the mirror surface roll or the shaping roll is higher than this, the film may be wound around the roll. If the temperature of the mirror surface roll or the shaping roll is lower than this, uneven transfer unevenness tends to occur in the film surface.
The roll speed is preferably 20 m / min or less. When the roll speed is higher than this, uneven transfer unevenness tends to occur in the film plane.

  The Sm of the transparent film can be adjusted by replacing the shaping roll with a shaping roll having a predetermined uneven period.

  The irregularities may be on both sides of the transparent substrate. Ra and Sm on both sides may be the same or different. From the viewpoint of sharpness, it is preferable that the unevenness is formed only on one surface.

The transparent substrate that can be used to obtain the transparent film of the present invention has a thickness of 1 mm and a total light transmittance of 80% or more. Examples of the material constituting the transparent substrate include transparent resins.
The transparent resin that can be used in the present invention has a thickness of 1 mm and a total light transmittance of 80% or more. For example, resin having alicyclic structure, polyester resin, cellulose resin, polycarbonate resin, polysulfone resin, polyethersulfone resin, polystyrene resin, polyolefin resin, polyvinyl alcohol resin, polyvinyl chloride resin, polymethyl methacrylate resin, etc. It is done.

  The transparent substrate used in the present invention may contain other compounding agents in addition to the transparent resin. The compounding agent is not particularly limited, but inorganic fine particles; antioxidants, heat stabilizers, light stabilizers, weathering stabilizers, UV absorbers, near infrared absorbers and other stabilizers; resins such as lubricants and plasticizers Modifiers; coloring agents such as dyes and pigments; antistatic agents and the like. These compounding agents can be used alone or in combination of two or more, and the compounding amount is appropriately selected within a range not impairing the object of the present invention, and is usually 0 to 100 parts by weight of the transparent resin. 5 parts by weight, preferably 0 to 3 parts by weight.

  The transparent substrate may be a single layer or a laminate comprising a plurality of layers. The total thickness of each layer constituting the transparent substrate is preferably 20 to 300 μm.

The surface of the transparent film having irregularities can be subjected to surface modification treatment. Examples of the surface modification treatment include energy beam irradiation treatment and chemical treatment.
Examples of the energy ray irradiation treatment include corona discharge treatment, plasma treatment, electron beam irradiation treatment, ultraviolet ray irradiation treatment, and the like. From the viewpoint of treatment efficiency, corona discharge treatment and plasma treatment are preferable.
Examples of the chemical treatment include a method of immersing in an aqueous solution of an oxidizing agent such as potassium dichromate solution or concentrated sulfuric acid and then thoroughly washing with water. It is effective to shake in the immersed state, but there is a problem that the surface will dissolve or the transparency will be lowered if treated for a long time. Depending on the reactivity and concentration of the chemical used, the treatment time etc. It needs to be adjusted.

  The haze of the transparent film is preferably 30 to 5%, and more preferably 25 to 10%. When the haze of the transparent film is more than this, the transparency when the antireflection film is obtained is lowered, and when it is less than this, interference unevenness tends to occur when the antireflection film is used.

  The antireflective film in the present invention has a high refractive index layer higher than the refractive index of the layer in which the unevenness of the transparent film is formed on the surface on which the unevenness of the transparent film is formed, and the refractive index of the high refractive index layer. It is obtained by forming a low refractive index layer in this order.

(High refractive index layer)
A high refractive index layer is a layer which has a refractive index higher than the refractive index of the layer in which the unevenness | corrugation of the above-mentioned transparent film was formed. In the present invention, the refractive index of the high refractive index layer is preferably 1.60 to 1.70. When the refractive index of the high refractive index layer is within this range, reflection of external light can be suppressed and reflection can be prevented when a low refractive index layer described later is laminated on the high refractive index layer.
For example, the refractive index is adjusted by forming the high refractive index layer using a material containing metal oxide fine particles.
Examples of the metal oxide fine particles include titanium oxide, zirconium oxide, zinc oxide, cerium oxide, antimony oxide, tin oxide, indium oxide, and tungsten oxide. These metal oxide fine particles can be used singly or in combination of two or more.
The refractive index can be obtained by measuring using a known spectroscopic ellipsometer, for example.

In the present invention, the high refractive index layer may exhibit a hardness of “2H” or more in a pencil hardness test shown in JIS K5600-5-4 (the test is performed with a test sample placed on a glass plate). preferable. When the pencil hardness of the high refractive index layer is within the above range, the high refractive index layer can also serve as a hard coat layer. In this case, it is not necessary to provide a hard coat layer separately, and as a result, the thickness of the entire antireflection film Can be made thinner.
Moreover, the average thickness of a high refractive index layer is 0.3-30 micrometers normally, Preferably it is 0.8-10 micrometers, More preferably, it is 1.0-3 micrometers.

As a material for forming the high refractive index layer, an inorganic material, a synthetic resin, or a mixture thereof can be used, but a resin material is preferable from the viewpoint of excellent productivity.
As said synthetic resin, what has sufficient intensity | strength as a membrane | film | coat after high refractive index layer formation, and also has transparency can be especially used without a restriction | limiting. Examples of the synthetic resin include a thermosetting resin, a thermoplastic resin, and an ionizing radiation curable resin, and a thermosetting resin or an ionizing radiation curable resin is preferable from the viewpoint of the strength and workability of the film.

Thermosetting resins include phenolic resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicone resin, polysiloxane Resin.
Moreover, you may add a solvent, a catalyst, the microparticles | fine-particles mentioned above, etc. to these thermosetting resins as needed.

The ionizing radiation curable resin is a resin in which a prepolymer, oligomer or monomer having a polymerizable unsaturated bond or epoxy group in the molecule is cured by irradiation with ionizing radiation. Ionizing radiation refers to electromagnetic waves or charged particle beams having energy quanta that can polymerize or crosslink molecules, and usually use ultraviolet rays.
There is no restriction | limiting in particular as resin hardened | cured with an ultraviolet-ray or an electron beam, It can select suitably from what is used conventionally and can use it. Examples of the ultraviolet curable resin include a photopolymerizable prepolymer or a photopolymerizable monomer and a photopolymerization initiator or a photosensitizer, and examples of the electron beam curable resin include a photopolymerizable prepolymer or a photopolymer. The thing containing a polymerizable monomer is mentioned.

Examples of the photopolymerizable prepolymer include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate. These photopolymerizable prepolymers may be used alone or in combination of two or more. Examples of the photopolymerizable monomer include polymethylolpropane triacrylate, polymethylolpropane trimethacrylate, hexanediol acrylate, hexanediol methacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, Pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol di Methacrylate etc. It is.
In the present invention, it is preferable to use urethane acrylate as the prepolymer and dipentaerythritol hexaacrylate or dipentaerythritol hexamethacrylate as the monomer.

  Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, tetramethylchuram monosulfide, thioxanthones, and the like. As the photosensitizer, n-butylamine, triethylamine, poly-n-butylphosphine, or the like can be used alone or in combination.

  In the present invention, the high refractive index layer preferably contains conductive fine particles. By including conductive fine particles in the high refractive index layer, not only a function as a high refractive index layer but also a function as an antistatic layer can be imparted.

  The conductive fine particles are not particularly limited as long as they are conductive fine particles, but metal oxide fine particles are preferable because of excellent transparency.

  Examples of the metal oxide constituting the conductive metal oxide fine particles include antimony pentoxide, tin oxide, tin oxide doped with phosphorus (PTO), tin oxide doped with antimony (ATO), and tin doped. Indium oxide (ITO), zinc doped indium oxide (IZO), aluminum doped zinc oxide (AZO), fluorine doped tin oxide (FTO), zinc oxide / aluminum oxide, zinc antimonate Etc. These metal oxide fine particles can be used singly or in combination of two or more. Among these, at least one selected from antimony pentoxide fine particles and tin oxide fine particles doped with phosphorus is preferable because of excellent transparency.

  In the present invention, fine particles imparted with conductivity by coating conductive metal oxide on fine metal oxide particles having no conductivity can also be used as the conductive metal oxide fine particles. . For example, the surface of fine particles of titanium oxide, zirconium oxide, cerium oxide or the like having a high refractive index but no conductivity can be used by coating the conductive metal oxide to impart conductivity.

  Moreover, the metal oxide particle which does not have electroconductivity, and electroconductive metal oxide fine particle can also be used together.

  The number average particle diameter of the conductive fine particles is preferably 200 nm or less, more preferably 50 to 15 nm. The number average particle size is determined by visual observation from a secondary electron emission image photograph obtained by a transmission electron microscope (TEM) or image processing of the image photograph, or a dynamic light scattering method, a static light scattering method, or the like. Can be measured with a particle size distribution meter using

  In the present invention, the content of the conductive fine particles in the high refractive index layer is preferably 30% by volume or more, and more preferably 40 to 60% by volume.

  In the present invention, the high refractive index layer is a surface on which the unevenness of the transparent film is formed by diluting a composition for forming a high refractive index layer containing the material for forming the high refractive index layer with a solvent as necessary. Directly or transparent film is applied on the other surface formed on the uneven surface, and the obtained coating film is formed by irradiating with heat and / or ionizing radiation as necessary. Can do. As a means for applying the composition for forming a high refractive index layer to the transparent film, a known method such as a spin coating method, a dip method, a spray method, a bar coating method, or a gravure method can be used.

  The solid content concentration in the composition for forming a high refractive index layer can be appropriately adjusted within a range not impairing the solution stability. Usually, it is preferably 0.1 to 20% by weight, preferably about 0.5 to 10% by weight. When the solid content concentration is less than this, convection of the coating solution occurs, and the surface unevenness after the formation of the high refractive index layer increases.

  The composition for forming a high refractive index layer may contain a leveling agent or a dispersant for the purpose of improving the uniformity of the layer thickness or improving the adhesion. Examples of the leveling agent include surfactants and compounds that lower the surface tension such as silicone oil, fluorinated polyolefin, and polyacrylate, and examples of the dispersant include silane coupling agents.

  Examples of the silicone oil include unmodified dimethyl silicone oil and modified silicone oil. Examples of the modified silicone oil include long-chain alkyl-modified dimethyl silicone oil, fluorine-modified dimethyl silicone oil, methacryl-modified dimethyl silicone oil, carbinol-modified dimethyl silicone oil, and methylstyryl-modified dimethyl silicone oil.

Examples of the surfactant include a fluorine-based surfactant and a silicone-based surfactant. Fluorosurfactants include non-ionic perfluoroalkylsulfonic acid amide group-containing nonions such as Fluorard FC-431 manufactured by 3M, MegaFac F-171, F-172, F-173, F Perfluoroalkyl group-containing oligomers such as -176PF, F-470, and F-471. Examples of the silicone surfactant include polydimethylsiloxane in which the side chain or the end of the main chain is modified with various substituents such as oligomers such as ethylene glycol and propylene glycol.
The content of the surfactant contained in the composition for forming a high refractive index layer is preferably 0.1 to 2.5% by weight, more preferably 0, based on the solid content of the composition for forming a high refractive index layer. .5 to 2.0% by weight.

In the present invention, it is preferable that the relationship between the arithmetic average roughness (Ra _h ) of the interface on the side far from the transparent film of the high refractive index layer and Ra is Ra _h <Ra. Furthermore, it is preferred that the Ra _h is 0.1μm or less, and more preferably less 0.07 .mu.m. When ra _h is greater than the above values, irregularities after forming the low refractive index layer to be described later is increased, when attached to the display device antireflection film, clearness of the display device tends to decrease.

As a method of setting the arithmetic average roughness of the interface on the side far from the transparent film of the high refractive index layer to the above range, in addition to the method using a solvent having a low evaporation rate, the surface of the composition for forming a high refractive index layer is used. A method for reducing the tension is mentioned.
As a method for reducing the surface tension of the composition for forming a high refractive index layer, a method for adding the above-mentioned leveling agent to the composition for forming a high refractive index layer, or the solid content concentration of the composition for forming a high refractive index layer is used. The method of making it small is mentioned.

  A surface treatment can be applied to the surface of the high refractive index layer. Examples of the surface treatment include the same methods as the surface treatment method for the transparent film described above.

  The contact angle between the surface of the high refractive index layer after formation of the high refractive index layer and water is preferably higher than the contact angle between the surface of the transparent film and water.

[Low refractive index layer]
The antireflection film of the present invention has a low refractive index layer on the high refractive index layer. The low refractive index layer is a layer having a lower refractive index than the above-described high refractive index layer. The refractive index of the low refractive index layer is preferably less than 1.4.
The refractive index of the low refractive index layer can be adjusted, for example, by dispersing holes in the low refractive index layer.
As a method of dispersing pores in the low refractive index layer, a method of dispersing fine particles having a hollow structure in which cavities are formed inside an outer shell, which will be described later, or a foamable substance for the low refractive index layer is used. The method of forming using the material containing is mentioned.
The refractive index of the low refractive index layer having pores is preferably 1.25 to 1.39, more preferably 1.30 to 1.38. By setting the refractive index of the low refractive index layer in the above range, in addition to antireflection properties, scratch resistance can be imparted.

  The average thickness of the low refractive index layer is usually 10 to 1000 nm, preferably 20 to 500 nm.

  The material for forming the low refractive index layer is preferably a material containing a resin that is cured by irradiation with heat or ionizing radiation.

(Thermosetting resin)
As a resin that is cured by heat, a general formula, R _1n Si (OR ₂ ) _m (wherein R ₁ is a monovalent hydrocarbon group that may have a substituent, OR ₂ is a hydrolyzable group). N, m represents an integer, m is 1 to 4, and m + n is 4.) A silicon compound obtained by hydrolyzing all or part of the compound can be used. .
Examples of the monovalent hydrocarbon group R that may have a substituent include an alkyl group, a phenyl group, a cycloalkyl group, an aryl group, a haloalkyl group; an alkenylcarbonyloxyalkyl group; an alkyl group having an epoxy group, and a mercapto group. And an alkyl group having an amino group, a perfluoroalkyl group, and the like. Among these, an alkyl group having 1 to 4 carbon atoms, a phenyl group, and a perfluoroalkyl group are preferable because of easy synthesis.

Specific examples of the hydrolyzable group include alkoxyl groups such as methoxy group, ethoxy group and propoxy group; acyloxy groups such as acetoxy group and propionyloxy group; oxime group (—O—N═C—R ₁ (R ₂ ) ), Enoxy group (—O—C (R ₁ ) = C (R ₂ ) R ₃ ), amino group, aminoxy group (—O—N (R ₁ ) R ₂ ), amide group (—N (R ₁ )) -C (= O) -R ₂₎ like. In these groups, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom or a monovalent hydrocarbon group. Among these, as the OR, an alkoxyl group is preferable because a strong cured product can be obtained.

As a silicon compound represented by R ₁ nSi (OR ₂ ) m, a silicon compound in which n is an integer of 0 to 2 is preferable. Specific examples thereof include alkoxysilanes, acetoxysilanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, amidosilanes and the like. Among these, alkoxysilanes are more preferable from the viewpoint of obtaining a strong cured product.

  Examples of the tetraalkoxysilane in which n is 0 include tetramethoxysilane and tetraethoxysilane. Examples of the organotrialkoxysilane in which n is 1 include methyltrimethoxysilane, methyltriethoxysilane, and methyltriisopropoxysilane. And phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of the diorganodialkoxysilane in which n is 2 include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane.

The silicon compound preferably contains fluorine. Examples of the fluorine-containing silicon compound include perfluoroalkylalkoxysilanes. For example, the general formula CF ₃ (CF ₂ ) nCH ₂ CH ₂ Si (OR ₄ ) ₃ (wherein R ₄ has 1 to 5 carbon atoms) An alkyl group, and n represents an integer of 0 to 12). More specifically, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxy Examples include silane. Among these, the compound wherein n is 2 to 6 is preferable.

  The silicon compounds can be used alone or in admixture of two or more. Also, the order of mixing and hydrolysis of two or more silicon compounds may be sequential or simultaneous.

(Ionizing radiation curable resin)
As the resin that is cured by irradiation with ionizing radiation, a monomer or prepolymer having an acryloyl group or a methacryloyl group can be preferably used.
Monomers include monofunctional acrylates or monofunctional methacrylates such as glycidyl acrylate and glycidyl methacrylate; polyfunctional acrylates such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, and dipentaerythritol hexaacrylate; A polyfunctional methacrylate is mentioned.
Examples of the prepolymer include polyester acrylate, polyurethane acrylate, epoxy acrylate, polyol acrylate and the like.

(Filler)
A filler may be added to the low refractive index layer. The filler is not particularly limited as long as it is fine particles of an inorganic compound. As the inorganic compound, an inorganic oxide is common. Examples of the inorganic oxide include SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₅ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ and WO _3. 1 type or 2 types or more can be mentioned.

(Hollow particles)
The fine particles preferably have a hollow structure in which cavities are formed in the outer shell, and silica-based hollow fine particles are particularly preferable as such a particle. By adding hollow silica fine particles to the low refractive index layer, it is possible to improve the scratch resistance in addition to the low refractive index property.

  As the hollow fine particles, (A) a single layer composed of a single inorganic oxide, (B) a single layer composed of a composite oxide composed of different kinds of inorganic oxides, (C) (A) and (B) above Those containing double layers can be utilized.

  The average particle diameter of the hollow fine particles is not particularly limited, but is preferably 5 to 2000 nm, and more preferably 20 to 100 nm. If it is smaller than 5 nm, the effect of lowering the refractive index due to hollowness is reduced. When it is larger than 2000 nm, the transparency is lowered and scattering due to diffuse reflection is increased. Here, the average particle diameter is a number average particle diameter by observation with a transmission electron microscope.

  Although the compounding quantity of a hollow microparticle is not specifically limited, It is preferable that it is 10 to 30 weight% with respect to the whole low-refractive-index layer. Within this range, both low refractive index properties and scratch resistance can be obtained.

(Other ingredients)
The composition for forming a low refractive index layer may contain other components. Examples of other components include photopolymerization initiators; leveling agents such as surfactants, dispersants such as silane coupling agents, and thickeners. Examples of the leveling agent and dispersant include the same leveling agent and dispersant as those used in the above-described composition for forming a high refractive index layer.

The composition for forming a low refractive index layer preferably contains a surfactant. The content of the surfactant contained in the composition for forming a low refractive index layer is preferably from 0.1 to 2.5% by weight, more preferably 0, based on the solid content of the composition for forming a low refractive index layer. .5 to 2.0% by weight. When the content of the surfactant is less than the above range, convection of the coating solution occurs, and the unevenness on the surface of the low refractive index layer cannot be reduced.
Examples of the surfactant include the same surfactant as that used in the above-described composition for forming a high refractive index layer.

Examples of the photopolymerization initiator include known photopolymerization initiators. Specifically, aryl ketone photopolymerization initiators (for example, acetophenones, benzophenones, alkylaminobenzophenones, benzyls, benzoins, benzoin ethers) , Benzyldimethyl ketals, benzoylbenzoates, α-acyloxime esters, etc.); sulfur-containing photopolymerization initiators (for example, sulfides, thioxanthones, etc.); acylphosphine oxide photopolymerization initiators; There is a polymerization initiator. The photopolymerization initiator can also be used in combination with a photosensitizer such as amines.
Content of a photoinitiator is 0.01-20 weight part with respect to 100 weight part of ionizing radiation hardening resin, Preferably it is 0.1-10 weight part.

  In the present invention, the low refractive index layer was prepared by adjusting a composition for forming a low refractive index layer obtained by diluting the material constituting the low refractive index layer with a solvent as necessary, and applying the composition on the high refractive index layer. Thereafter, a cured film having a low refractive index layer can be formed by drying and curing.

  The coating method is not particularly limited, and examples thereof include ordinary methods such as a doctor blade method, a gravure roll coater method, a dipping method, a spin coating method, a brush coating method, and a flexographic printing method.

Solvents that can be used to prepare the composition for forming a low refractive index layer include alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. Glycols such as toluene; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as n-hexane and n-heptane; esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; And a combination of two or more of these;
Among these, the relative evaporation rate when the evaporation rate of n-butyl acetate measured according to ASTM D3539-87 is set to 1 for the purpose of suppressing the convection of the coating solution and reducing the surface unevenness of the resulting low refractive index layer. It is preferable to use a solvent that is 3 or less, and it is more preferable to use a solvent that is 2 or less. Examples of such an organic solvent include isopropyl alcohol and methyl isobutyl ketone.

  The solid content concentration in the composition for forming a low refractive index layer can be appropriately adjusted within a range not impairing the solution stability. Since it is preferable to form the low refractive index layer with a good thickness accuracy, it is usually preferable to adjust the thickness to about 0.1 to 20% by weight, preferably about 0.5 to 10% by weight.

Curing can be performed by heating and / or irradiating with ionizing radiation according to the composition for forming a low refractive index layer. Curing conditions can be appropriately determined depending on the boiling point of the solvent used, the saturated vapor pressure, the type of the transparent substrate, etc., but when heating to suppress the coloring and decomposition of the transparent substrate, usually 160 ° C. or lower, UV irradiation In that case, it is usually preferably 600 mJ / cm ² or less.

The relationship between the low-refractive index layer transparent film from the arithmetic average roughness on the far side of the surface of the (Ra _l) and Ra _h are _preferably the Ra l <Ra _h. Further, Ra _l is preferably at most 0.06 .mu.m, more preferably at most 0.04 .mu.m. When ra _l is a more, scattering external light due to surface irregularities is large, clearness of the display image tends to decrease.
The ra _l as a method of the above range, other using a solvent having the evaporation rate of the aforementioned range, and a method of reducing the surface tension of the low refractive index layer-forming composition.
Examples of a method for reducing the surface tension of the composition for forming a low refractive index layer include a method for adding the aforementioned surfactant to the composition for forming a low refractive index layer, and a solid content concentration of the composition for forming a low refractive index layer. The method of making small is mentioned.

  The contact angle with water on the surface of the low refractive index layer is preferably higher than the contact angle with water on the surface of the high refractive index layer. By making the contact angle with water on the surface of the low refractive index layer higher than the contact angle with water on the surface of the high refractive index layer, an effect of improving the antifouling property can be obtained.

In the present invention, an antifouling layer may be provided on the low refractive index layer. The antifouling layer is provided for protecting the low refractive index layer and enhancing the antifouling performance.
The material for forming the antifouling layer is not particularly limited as long as the function of the low refractive index layer is not inhibited and the required performance as the antifouling layer is satisfied. Usually, a compound having a hydrophobic group can be preferably used.
As specific examples, a perfluoroalkylsilane compound, a perfluoropolyethersilane compound, or a fluorine-containing silicone compound can be used. As a method for forming the antifouling layer, for example, a physical vapor deposition method such as vapor deposition or sputtering; a chemical vapor deposition (CVD) method; a wet coating method; The thickness of the antifouling layer is not particularly limited, but is usually preferably 20 nm or less, and more preferably 1 to 10 nm.

As for the reflectance of the antireflection film of the present invention, the minimum value measured at an incident angle of 5 degrees at a wavelength of 430 to 700 nm is preferably 1.5% or less. By setting the minimum reflectance to 1.5% or less, the interference unevenness is further suppressed.
Minimum antireflection film reflectivity less than 1 percent, to reduce the Ra _l, and a refractive index n _L of the refractive index n _H and the low refractive index layer of the high refractive index layer, n _H ^1/2 -0. It can be obtained by laminating a high refractive index layer and a low refractive index layer so as to have a relationship of 2 <n _L <n _H ^1/2 +0.2.

The haze of the antireflection film of the present invention is preferably 2% or less, and more preferably 1.5% or less. If the haze is higher than this, the display image tends to be whitish and visibility is lowered.
The antireflection film having a haze of 2% or less can be obtained by forming the high refractive index layer and / or the low refractive index layer using the material containing the leveling agent described above.

  The antireflection film of the present invention includes a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), a cathode tube display (CRT), a field emission display (FED), electronic paper, a touch panel, and the like. It can be used by directly bonding to the display device or by replacing with a surface member incorporated in the display device such as a polarizing plate protective film or a front plate.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Parts and% are based on weight unless otherwise specified.
(Thickness of transparent film)
After embedding the film in an epoxy resin, it was sliced using a microtome (manufactured by Yamato Kogyo Co., Ltd., product name “RUB-2100”), and the cross section was observed and measured using a scanning electron microscope.
(Refractive index of transparent substrate)
A transparent base material is formed into a film with a single layer without unevenness, and a prism coupler (manufactured by Metricon, product name “model2010”) is used, wavelength 633 nm, temperature 20 ° C. ± 2 ° C., humidity 60 ± The measurement was performed under the condition of 5%.
(Refractive index of high refractive index layer and low refractive index layer)
Using high-speed spectroscopic ellipsometry (manufactured by JA Woollam, product name “M-2000U”) under conditions of incident angles of 55, 60, 65 degrees, temperature 20 ° C. ± 2 ° C., humidity 60 ± 5% Calculated from the spectrum in the wavelength region of 400 to 1000 nm when measured by (Abrasion resistance)
In a state where a load of 0.025 MPa was applied to steel wool # 0000, the surface of the low refractive index layer of the antireflection film was reciprocated 10 times, and the surface state after the reciprocation was visually observed.
○: Scratches are not recognized.
Δ: There are 3 or more streak scratches.
X: There are 8 or more streak scratches.
(Haze)
It was measured using a turbidimeter (manufactured by Nippon Denshoku Co., Ltd., product name “NDM 2000”).
(Minimum reflectance)
Using a spectrophotometer (manufactured by JASCO Corporation, product name “V-550”), the reflectance at an incident angle of 5 degrees at a wavelength of 430 to 700 nm is measured (measurement wavelength interval is 1 nm), and the minimum in the above wavelength range The reflectance was calculated.
(Ra, Sm measurement)
Using a surface roughness meter (manufactured by Mitutoyo Corporation, product name “SJ400”), measurement was performed based on JIS B 0601: 1994.
Sm (average interval of irregularities) is a contour curve (roughness curve) obtained by cutting a long wavelength component with a high-pass filter having a cutoff value λc from the measured cross-sectional curve, and the roughness curve The reference length (L) is extracted with respect to the average line, and is the average value of the lengths (Xsi) of adjacent peaks and valleys on the reference length. Ra (arithmetic mean roughness) is the average value of the absolute value of the height (distance from the average line to the measurement curve) at the reference length of the curve obtained by the method as described above. is there.
(Contact angle measurement)
Distilled water was dropped with a contact angle measuring device (product name “DM500” manufactured by Kyowa Interface Science Co., Ltd.), and the contact angle after 2 seconds was measured.
(Interference unevenness)
Black vinyl tape (Nitto Denko, No. 21) is attached to the back of the antireflection film, placed under a three-wavelength light source in the dark, and observed at an azimuth angle of 0 ° from the normal direction of the antireflection film. Visually inspect for unevenness.
○: No interference unevenness ×: Interference unevenness present (clearness)
According to JIS K 7105, measurement was performed with an optical comb having a width of 0.5 mm using a image clarity measuring device (manufactured by Suga Test Instruments Co., Ltd.). Higher values mean higher clarity.
The image clarity is measured through an optical comb that moves the transmitted light from the sample, and the value is obtained by calculation. When the sample is blurred, the slit image formed on the optical comb becomes thick due to the blur. Therefore, both ends of the slit image are applied to the opaque part at the position of the transmission part, and the amount of light is 100%. Decrease. Further, at the position of the opaque portion, light leaks from the opaque portion at both ends of the slit image, and the amount of light of 0% increases.
The sharpness value is defined by the following equation from the maximum value M of the transmitted light of the transparent portion of the optical comb and the minimum value m of the opaque portion.
Clarity value C (%) = [(M−m) / (M + m)] × 100
(contrast)
The antireflection film was removed from the commercially available liquid crystal display device to obtain a test device.
The side of the antireflection film on which the antireflection layer is not formed is brought into intimate contact with the display device through glycerin (refractive index 1.49) to display black and white on the display device. The brightness of the central portion of the antireflection film was measured under the name “BM-5”) and calculated as contrast ratio = brightness during white display / brightness during black display.

(Production Example 1) Production of transparent film 1 Polymethylmethacrylate resin (trade name “Sumipex HT20Y” manufactured by Sumitomo Chemical Co., Ltd.) constituting both surface layers using a two-kind / three-layer multilayer coextrusion apparatus, intermediate layer Highly heat-resistant polymethylmethacrylate resin (trade name “Sumipex MH”, manufactured by Sumitomo Chemical Co., Ltd.) constituting each is discharged from a T-type die at an extrusion rate of 20 kg / hr and 10 kg / hr, respectively, and this is immediately followed by a wire A nip was formed between a forming roll having irregularities with an Sm of 25 μm heated to a surface temperature of 90 ° C. and a mirror roll heated to a surface temperature of 90 ° C. at a pressure of 9 kN / m and a roll speed of 20 m / min, and the irregularities were transferred to a film. Thereafter, cooling was performed to obtain a transparent film 1 having a three-layer structure.
The thickness of each layer constituting the transparent film 1 is such that the thickness of the surface layer (surface layer 1) on which the unevenness is formed is 40 μm, the intermediate layer is 40 μm, and the surface layer on which the unevenness is not formed (surface layer 2). Was 40 μm, and the total thickness of the transparent film 1 was 120 μm.
Ra of the surface of the transparent film 1 on which the unevenness is formed is 0.08 μm, Sm is 25 μm, the refractive index of the surface layer 1 is 1.49, and the contact angle of the surface on which the unevenness of the transparent film S1 is formed is 80 degrees. Met.

Production Example 2 Production of Transparent Film 2 In Production Example 1, the temperature of the mirror roll and the shaping roll was set to 70 ° C., and a shaping roll having irregularities with Sm of 90 μm was used. Thus, a transparent film S2 was obtained. Ra of the surface of the transparent film S2 on which the irregularities were formed was 0.11 μm, Sm was 90 μm, and Ra / Sm was 0.0012.

Production Example 3 Production of Transparent Film 3 A transparent film S3 was obtained in the same manner as in Production Example 2 except that the temperature of the mirror roll and the shaping roll was 90 ° C. in Production Example 2. Ra of the surface of the transparent film S3 on which the irregularities were formed was 0.14 μm, Sm was 90 μm, and Ra / Sm was 0.0016.

(Production Example 4) Production of transparent film 4 In Production Example 2, a transparent film was produced in the same manner as in Production Example 1 except that the linear pressure was 12 kN / m, the roll speed was 10 m / min, and the temperature of the shaping roll was 120 ° C. S4 was obtained. Ra of the surface of the transparent film S4 on which the irregularities were formed was 0.18 μm, Sm was 90 μm, and Ra / Sm was 0.002.

Production Example 5 Production of Transparent Film 5 Production Example 1 was the same as Production Example 1 except that a linear roll having a linear pressure of 13 kN / m, a roll speed of 10 m / min, and an irregular roll with Sm of 165 μm was used. Thus, a transparent film S5 was obtained. Ra of the surface of the transparent film S5 on which the irregularities were formed was 0.18 μm, Sm was 165 μm, and Ra / Sm was 0.0011.

Production Example 6 Production of Transparent Film 6 Production Example 1 was the same as Production Example 1 except that a linear roll having a linear pressure of 14 kN / m, a roll speed of 10 m / min, and an irregular roll with Sm of 180 μm was used. Thus, a transparent film S6 was obtained. Ra of the surface of the transparent film S6 on which the irregularities were formed was 0.3 μm, Sm was 180 μm, and Ra / Sm was 0.0017.

Production Example 7 Production of Transparent Film 7 Production Example 1 was the same as Production Example 1 except that a linear roll having a linear pressure of 7 kN / m, a roll speed of 30 m / min, and an irregular roll having an Sm of 20 μm was used. Thus, a transparent film S7 was obtained. Ra of the surface of the transparent film S7 where the irregularities were formed was 0.03 μm, Sm was 20 μm, and Ra / Sm was 0.0015.

Production Example 8 Production of Transparent Film 8 A transparent film S8 was obtained in the same manner as in Production Example 1 except that the linear pressure was 12 kN / m in Production Example 1. Ra of the surface of the transparent film S8 on which the irregularities were formed was 0.15 μm, Sm was 25 μm, and Ra / Sm was 0.006.

(Production Example 9) Production of transparent film 9 In Production Example 2, a transparent film S9 was obtained in the same manner as in Production Example 1 except that a shaping roll having irregularities with Sm of 120 μm was used. Ra of the surface of the transparent film S9 on which the irregularities were formed was 0.1 μm, Sm was 120 μm, and Ra / Sm was 0.0008.

(Production Example 10) Preparation of High Refractive Index Layer Composition H1 100 parts of an acryloyl group-containing oligomer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name “UV-1700B”) was mixed with Sb ₂ O ₅ particles (catalyst). 200 parts by Kasei Kogyo Co., Ltd. (average particle size 30 nm) and 2 parts by photopolymerization initiator (Ciba Specialty Chemicals, trade name “IRGACURE 184”) are added, and methacryl-modified dimethyl silicone oil (Shin-Etsu Chemical Co., Ltd.) is added. , Trade name “X-22-164A”) was added, and the mixture was stirred with a stirrer at 2000 rpm for 5 minutes to obtain a composition H1 for forming a high refractive index layer.

Production Example 11 Preparation of High Refractive Index Layer Composition H2 Same as Production Example 10 except that in Production Example 10, Sb ₂ O ₅ particles were changed to 50 parts instead of Sb ₂ O ₅ particles 200 parts. Thus, a composition H2 for forming a high refractive index layer was obtained.

(Production Example 12) Preparation of High Refractive Index Layer Composition H3 A high refractive index layer composition H3 was produced in the same manner as in Production Example 10 except that methacryl-modified dimethyl silicone oil was not added. Obtained.

(Production Example 13) Preparation of composition L1 for forming a low refractive index layer By adding 200 parts of ethanol to a four-necked reaction flask equipped with a reflux tube and adding 120 parts of oxalic acid to this ethanol in small amounts. An ethanol solution of oxalic acid was prepared. The solution was then heated to the reflux temperature, and a mixture of 20 parts tetraethoxysilane and 4 parts tridecafluorooctyltrimethoxysilane (GE Toshiba Silicone, trade name “TSL8257”) was added dropwise to the refluxed solution. did. After completion of the dropwise addition, heating was continued for 5 hours under reflux, followed by cooling and dilution with methanol so that the solid content was 1% by weight, thereby preparing Liquid 1.
Next, hollow silica fine particles (number average particle diameter 30 nm, refractive index 1.29) were added so as to be 80% by weight with respect to the solid content of the liquid 1 to prepare a composition L1 for forming a low refractive index layer. .

(Production Example 14) Preparation of composition L2 for forming a low refractive index layer A photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) was added to 100 parts of a monomer containing acryloyl group (Asahi Denka Kogyo Co., Ltd., trade name “Optomer KR566”). Product, trade name “IRGACURE184”) 2 parts, hollow silica fine particles (number average particle diameter 30 nm, refractive index 1.29) 150 parts, methacryl-modified dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-22— 164A ") 10 parts was added, and the mixture was stirred for 5 minutes at 2000 rpm with a stirrer to obtain a composition L2 for forming a low refractive index layer.

(Production Example 15) Preparation of Low Refractive Index Layer-Forming Composition L3 In Production Example 14, instead of 150 parts of hollow silica fine particles, 100 parts of hollow silica fine particles were used. A layer forming composition L3 was obtained.

(Production Example 16) Preparation of composition L4 for forming a low refractive index layer A composition 4 for forming a low bending layer was obtained in the same manner as in Production Example 14 except that methacryl-modified dimethyl silicone oil was not added. It was.

Example 1
After applying the high refractive index layer forming composition H1 obtained in Production Example 4 to the surface of the transparent film S1 obtained in Production Example 1 with a bar coater, the wavelength is measured using an ultraviolet irradiator. Ultraviolet irradiation was performed so that the accumulated light amount was 200 mJ / cm ² in the range of 300 to 390 nm, and the product was cured by forming an item refractive index layer having a thickness of 3 μm, thereby obtaining a laminate of transparent film / high refractive index layer. The refractive index of the high refractive index layer was 1.62, and the contact angle of the surface of the high refractive index layer far from the transparent film was 90 °.
Next, on the high refractive index layer, the low refractive index layer forming composition L1 obtained in Production Example 7 was applied with a bar coater, and the obtained coating film was dried and cured at 60 ° C. for 1 minute, A low refractive index layer having a thickness of 100 nm was formed to obtain the antireflection film 1 of the present invention. The refractive index of the low refractive index layer was 1.37, and the contact angle of the surface of the low refractive index layer far from the transparent film was 110 °.
The evaluation results of the antireflection film 1 are shown in Table 1.

(Example 2)
In Example 1, the antireflection film 2 was obtained in the same manner as in Example 1 except that the transparent film S2 was used instead of the transparent film 1.
The evaluation results of the antireflection film 2 are shown in Table 1.

(Example 3)
In Example 1, the antireflection film 3 was obtained in the same manner as in Example 1 except that the transparent film S3 was used instead of the transparent film 1.
The evaluation results of the antireflection film 3 are shown in Table 1.

Example 4
In Example 1, the antireflection film 4 was obtained in the same manner as in Example 1 except that the transparent film S4 was used instead of the transparent film 1.
The evaluation results of the antireflection film 4 are shown in Table 1.

(Example 5)
In Example 1, the antireflection film 5 was obtained in the same manner as in Example 1 except that the transparent film S5 was used instead of the transparent film 1.
The evaluation results of the antireflection film 5 are shown in Table 1.

(Example 6)
In Example 1, the low refractive index layer forming composition L2 obtained in Production Example 13 was used in place of the low refractive index layer forming composition L1, and the low refractive index layer was formed on the high refractive index layer. Except that the forming composition L2 was applied with a bar coater, the obtained coating film was dried at 60 ° C. for 1 minute, and irradiated with ultraviolet rays so as to obtain an integrated light amount of 100 mJ / cm ² in a wavelength range of 300 to 390 nm. Obtained an antireflection film 6 in the same manner as in Example 1. The refractive index of the low refractive index layer was 1.37, and the contact angle of the surface of the low refractive index layer far from the transparent film was 110 °.
The evaluation results of the antireflection film 6 are shown in Table 1.

(Example 7)
In Example 1, the antireflection film 7 was prepared in the same manner as in Example 1 except that the low refractive index layer forming composition L3 obtained in Production Example 14 was used instead of the low refractive index layer forming composition L1. Got. The refractive index of the low refractive index layer was 1.42, and the contact angle of the surface of the low refractive index layer far from the transparent film was 110 °.
The evaluation results of the antireflection film 7 are shown in Table 1.

(Example 8)
In Example 1, the antireflection film 8 was prepared in the same manner as in Example 1 except that the low refractive index layer forming composition L4 obtained in Production Example 15 was used instead of the low refractive index layer forming composition L1. Got. The refractive index of the low refractive index layer was 1.37, and the contact angle of the surface of the low refractive index layer far from the transparent film was 60 °.
The evaluation results of the antireflection film 8 are shown in Table 1.

Example 9
In Example 6, the antireflection film 9 was prepared in the same manner as in Example 6 except that the high refractive index layer forming composition H2 obtained in Production Example 10 was used instead of the high refractive index layer forming composition H1. Got. The refractive index of the high refractive index layer was 1.55, and the contact angle of the surface far from the transparent film of the high refractive index layer was 90 °.
The evaluation results of the antireflection film 9 are shown in Table 1.

(Example 10)
In Example 6, the antireflective film 10 was prepared in the same manner as in Example 6 except that the high refractive index layer forming composition H3 obtained in Production Example 11 was used instead of the high refractive index layer forming composition H1. Got. The refractive index of the high refractive index layer was 1.62, and the contact angle of the surface of the high refractive index layer far from the transparent film was 60 °.
The evaluation results of the antireflection film 10 are shown in Table 1.

(Comparative Example 1)
In Example 1, the antireflection film 11 was obtained in the same manner as in Example 1 except that the transparent film S6 was used instead of the transparent film S1.
The evaluation results of the antireflection film 11 are shown in Table 1.

(Comparative Example 2)
In Example 1, the antireflection film 12 was obtained in the same manner as in Example 1 except that the transparent film S7 was used instead of the transparent film S1.
The evaluation results of the antireflection film 12 are shown in Table 1.

(Comparative Example 3)
In Example 1, the antireflection film 13 was obtained in the same manner as in Example 1 except that the transparent film S8 was used instead of the transparent film S1.
The evaluation results of the antireflection film 13 are shown in Table 1.

(Comparative Example 4)
In Example 1, the antireflection film 14 was obtained in the same manner as in Example 1 except that the transparent film S9 was used instead of the transparent film S1.
The evaluation results of the antireflection film 14 are shown in Table 1.

  The antireflection laminates of Examples 1 to 10 and Comparative Examples 1 to 4 prepared above were evaluated for scratch resistance, minimum reflectance, and interference unevenness, and the results are shown in Table 1.

From Table 1, the antireflection film obtained using the transparent films S1 to S5 having irregularities defined by the present application has no color unevenness and high sharpness, so that it is difficult to reduce the visibility when used in a display device. I understand that. On the other hand, the antireflection film of Comparative Example 1 obtained using a transparent film having an Ra value exceeding the upper limit of the range specified by the present application, and the Ra / Sm value exceeding the upper limit of the range specified by the present application In Comparative Example 3 obtained using the transparent film having, the interference unevenness was suppressed, but the sharpness was inferior.
On the other hand, the antireflection film of Comparative Example 2 obtained by using a transparent film having a Ra value not more than the lower limit of the range specified by the present application, and a transparent having a Ra / Sm value not more than the lower limit of the range specified by the present application. Although the antireflection film of Comparative Example 4 obtained using the film had high clarity, interference unevenness occurred.

DESCRIPTION OF SYMBOLS 1 Transparent film 2 High refractive index layer 3 Low refractive index layer 4 Concavity and convexity 5 Antireflection film

Claims (5)

A high refractive index layer having a refractive index higher than the refractive index of the transparent substrate, and a refractive index of the high refractive index layer on the one surface of the transparent film formed by forming irregularities on one surface of the transparent substrate. An antireflection film comprising a low refractive index layer having a lower refractive index in this order, wherein the irregularities are formed by deforming the transparent substrate, and satisfy the following [1] to [2] .
[1] 0.04 ≦ Ra ≦ 0.25 μm
[2] 0.001 ≦ Ra / Sm ≦ 0.005
(Ra and Sm are the arithmetic average roughness and the average interval of irregularities measured based on JIS B0601: 1994, respectively.) The contact angle between the surface of the high refractive index layer far from the transparent film and water is higher than the contact angle between the transparent film surface and water, and
The contact angle between the surface of the low refractive index layer far from the transparent film and water is higher than the contact angle between the surface of the high refractive index layer far from the transparent film and water,
The antireflection film according to claim 1. The refractive index of the high refractive index layer is 1.60 or more and 1.70 or less,
Arithmetic average roughness Ra _h of the farther from the transparent film surface of the high refractive index layer is 0.1μm or less,
The antireflection film according to claim 1 or 2. The refractive index of the low refractive index layer is less than 1.40,
The arithmetic average roughness Ra ₁ of the surface of the low refractive index layer far from the transparent film is 0.06 μm or less.
The antireflection film according to any one of claims 1 to 3. The minimum value of the reflectance measured on the surface on which the low refractive index layer measured at an incident angle of 5 degrees at a wavelength of 430 to 700 nm is 1.5% or less,
The antireflection film according to any one of claims 1 to 4.

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