JP6481277B2 - Display device with touch panel and optical film - Google Patents

Description

The present invention relates to a display device with a touch panel and an optical film.

Conventionally, a display device with a touch panel in which a touch panel is arranged on a display panel such as a liquid crystal display is known. In such a display device with a touch panel, information can be directly input by touching the image display surface with a finger or the like.

When fixing a touch panel on a display panel, the display panel and the touch panel are often arranged apart from each other. That is, the display panel and the touch panel are often disposed via an air layer (air gap) (see, for example, Patent Document 1).

The image display surface of the display device with a touch panel may be strongly pressed not only by touching with a finger but also by a finger. When the image display surface is pressed strongly, the touch panel is deformed, so that the distance between the touch panel and the display panel is narrowed (the thickness of the air layer is reduced), and the light reflected from the surface of the touch panel on the display panel side There is a problem in that the light reflected on the surface of the touch panel side of the display panel interferes to generate Newton rings and lowers the visibility of the screen.

In recent years, display devices with a touch panel have been made thinner and larger in area. As the display device with a touch panel becomes thinner, the distance between the touch panel and the display panel becomes narrower, and as the display device with a touch panel becomes larger, the touch panel is easily deformed. For this reason, the problem of Newton rings has become more prominent.
In the following, Newton rings that occur with the deformation of the touch panel are also referred to as watermarks.

To deal with such a watermark problem, for example, in Patent Document 2, a resin layer is filled with a resin material in a gap between a touch panel and a liquid crystal display panel, thereby forming an interface between the touch panel and the liquid crystal display panel. Proposes to eliminate reflections.
However, when a final product is manufactured by filling a resin material, even if a defect is found in the touch panel after the final product is manufactured, it is not possible to replace only the touch panel. In addition, it is difficult to completely fill the gap between the touch panel and the liquid crystal display panel with the resin material, and if the bubbles are included, the display image is defective.

Here, in a display device in which the display panel and the touch panel are spaced apart from each other, a method is known in which an uneven surface is provided on the surface of the display panel and incident light is diffused on the uneven surface to suppress the occurrence of Newton rings. (For example, refer to Patent Document 3).
However, in a display device with a touch panel in which such an uneven surface is provided on the surface of the display panel, image light may be scattered by the uneven surface, and so-called glare may occur.

In order to deal with such a glare problem, for example, a method for suppressing glare by increasing the internal haze of the display panel is known.
Here, in recent years, small mobile phones equipped with touch panels such as smartphones and tablet terminals are rapidly spreading. However, in such small mobile devices, the problem of glare is more conspicuous because of the ultra-high definition of the displayed image. On the other hand, the image display apparatus is required to have higher luminance and light transmittance than ever.
However, a display panel with an increased total haze or internal haze to suppress glare will cause a decrease in luminance and light transmission. Therefore, for an ultra-high-definition image display device, the internal haze of the display panel is reduced. The method to raise could not be adopted.

JP 2010-15154 A JP 2004-077887 A JP 2002-189565 A

The present invention has been made in view of the above-described situation, and an object of the present invention is to provide a display device with a touch panel that can sufficiently suppress the occurrence of watermarks and glare.

The present invention is a display device with a touch panel having a configuration in which an optical film in which an optical layer having a concavo-convex shape is laminated on a light-transmitting substrate and a touch panel are arranged to face each other, and the optical film The touch panel is disposed so that the optical layer and the touch panel face each other with a gap therebetween, and the total haze value of the optical film is 0% or more and 5% or less. An optical comb having an internal haze value of 0% or more and 5% or less and a transmission image definition of the optical film measured using an optical comb having a width of 0.125 mm is C (0.125). when the C (0.25) the transmission image clarity of the optical film as measured using, satisfies the following formula (1) and (2), the optical layer, the binder resin and the fine particles Containing said fine particles are inorganic oxide particles, irregularities of the surface of the optical layer, the inorganic oxide is formed by fine particles, the three-dimensional average slope of the irregularities constituting a surface of the optical film The angle θa _3D is not less than 0.12 ° and not more than 0.5 °, the average peak interval Smp is not less than 0.05 mm and not more than 0.3 mm , and the arithmetic average roughness Ra is not less than 0.01 μm and not more than 0.11 μm, 10-point average roughness Rz is 0.10 μm or more and 0.30 μm or less, and the above θa _3D , Smp, Ra and Rz were obtained by measurement with a contact-type surface roughness meter or a non-contact-type surface roughness meter. The Smp is calculated from a three-dimensional roughness surface, and in order to remove insignificant peaks, the above Smp is 1 / 10,000 or more of the area of a circle having a diameter of Low wavelength and a height of 1 Rtm. / The display device with a touch panel is characterized in that 10 or more peaks are calculated as count targets .
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2)

In the display device with a touch panel of the present invention, preferably it has an average primary particle diameter of the inorganic oxide fine particles is 1nm or more 100nm or less, the inorganic oxide fine particles, inorganic oxide fine particles whose surface is hydrophobized It is preferable that
The total haze value of the optical film is preferably 0% or more and 1% or less, and the internal haze value of the optical film is preferably 0%.
Further, the present invention is an optical film in which an optical layer having a concavo-convex shape on a surface is laminated on a light-transmitting substrate, and is opposed to a touch panel and used for a display device with a touch panel. The haze value is 0% or more and 5% or less, the internal haze value is 0% or more and 5% or less, and the transmitted image sharpness measured using an optical comb having a width of 0.125 mm is C (0.125). , When the transmitted image clarity measured using an optical comb having a width of 0.25 mm is C (0.25), the following formulas (1) and (2) are satisfied, and the optical layer includes a binder resin and The fine particles are inorganic oxide fine particles, and the uneven shape on the surface of the optical layer is formed by the inorganic oxide fine particles, and the three-dimensional unevenness constituting the surface of the optical film. the average angle of inclination θa _3D is 0. And at 0.5 ° or less 2 ° or more, the average peak distance Smp is at 0.05mm or more 0.3mm or less, the arithmetic average roughness Ra is at 0.01μm or 0.11μm or less, ten point average roughness Rz Is from 0.10 μm to 0.30 μm, and the above θa _3D , Smp, Ra, and Rz are obtained from a three-dimensional roughness curved surface obtained by measurement with a contact surface roughness meter or a non-contact surface roughness meter. In order to exclude non-significant peaks, the above Smp is a peak whose area is 1 / 10,000 or more of the area of a circle whose diameter is Low wavelength and whose height is 1/10 or more of Rtm. It is also an optical film characterized by being calculated as a count target .
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2)
The present invention is described in detail below.
In the present specification, “resin” is a concept including monomers, oligomers and the like unless otherwise specified.

As a result of intensive studies, the inventors have determined that the surface on the touch panel side of the optical film having a configuration opposed to the touch panel has a specific uneven shape, thereby providing a gap between the touch panel and the optical film. Further, it has been found that the generation of a watermark can be suppressed to a high degree, and further the generation of glare can be suppressed to a high level regardless of the internal haze of the optical film, and a good display image can be obtained. It came to complete.

FIG. 1 is a cross-sectional view schematically showing a display device with a touch panel according to the present invention.
As shown in FIG. 1, in the display device with a touch panel 10 of the present invention, the optical film 11 and the touch panel 15 are arranged to face each other, and the optical film 11 is formed on one surface of the light transmissive substrate 12. An optical layer 13 having a concavo-convex shape 14 is laminated on the surface.
In the display device with a touch panel 10 of the present invention, the optical film 11 and the touch panel 15 are disposed to face each other so that the optical layer 13 (uneven shape 14) and the touch panel 15 face each other with a gap therebetween.
Here, examples of the touch panel 15 include a resistive touch panel, a capacitive touch panel, and the like. In the display device with a touch panel 10 of the present invention, any method can be used. Suitable for touch panels.

In the display device with a touch panel 10 of the present invention, the total haze value of the optical film 11 is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less.
The total haze value and the internal haze value are values when measured as the entire optical film.
The total haze value and the internal haze value can be measured by a method based on JIS K7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory). Specifically, the total haze value of the optical film is measured according to JIS K7136 using a haze meter. Thereafter, a triacetyl cellulose base material (manufactured by FUJIFILM Corporation, TD60UL) is attached to the surface of the optical film via a transparent optical adhesive layer. Thereby, the uneven shape on the surface of the optical film is crushed, and the surface of the optical film becomes flat. And in this state, an internal haze value is calculated | required by measuring a haze value according to JISK7136 using a haze meter (HM-150, Murakami Color Research Laboratory make). This internal haze does not take into account the uneven shape of the surface of the optical film.

In the display device with a touch panel of the present invention, the total haze value of the optical film 11 is preferably 1% or less, and more preferably 0.3% or more and 0.5% or less. The internal haze value is preferably substantially 0%. Here, “the internal haze value is substantially 0%” is not limited to the case where the internal haze value is completely 0%, even if the internal haze value exceeds 0%. It is within the range of errors, and includes a range in which the internal haze value can be regarded as almost 0% (for example, an internal haze value of 0.3% or less).

When the total haze value of the optical film 11 is 0% to 5% and the internal haze value is 0% to 5%, the surface haze value of the optical film 11 is 0% to 5%. Yes. The surface haze value of the optical film 11 is preferably 0% or more and 1% or less, and more preferably 0% or more and 0.3% or less. The surface haze value is attributed only to the irregular shape of the surface of the optical film 11, and the surface haze value attributable to only the irregular shape of the surface of the optical film 11 is obtained by subtracting the internal haze value from the total haze value. It is done.

In the display device with a touch panel of the present invention, the clarity of the transmitted image of the optical film 11 measured using an optical comb having a width of 0.125 mm is C (0.125), and measurement is performed using an optical comb having a width of 0.25 mm. When the transmitted image definition of the optical film 11 is C (0.25), the following expressions (1) and (2) are satisfied.
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2)

The “transmission image definition” can be measured by a transmission image definition measurement device based on the transmission method of image definition of JIS K7374. As such a measuring apparatus, for example, image clarity measuring instrument ICM-1T manufactured by Suga Test Instruments Co., Ltd. may be mentioned.
As shown in FIG. 2, the transmitted image definition measuring apparatus 100 includes a light source 101, a slit 102, a lens 103, a lens 104, an optical comb 105, and a light receiver 106, emitted from the light source 101, and The light passing through the slit 102 is converted into parallel light by the lens 103, and the parallel light is irradiated to the light transmissive substrate 12 side of the optical film 11, and the light transmitted from the uneven shape 14 of the optical layer 13 of the optical film 11 is transmitted. The light collected by the lens 104 and passed through the optical comb 105 is received by the light receiver 106. Based on the amount of light received by the light receiver 106, the transmitted image definition is obtained by the following equation (3). C is calculated.
C (n) = {(M−m) / (M + m)} × 100 (%) (3)
In Expression (3), C (n) is the transmitted image definition (%) when the optical comb width is n (mm), and M is the maximum light intensity when the optical comb width is n (mm). Yes, m is the minimum light quantity when the width of the optical comb is n (mm).
The optical comb 105 is movable along the longitudinal direction of the optical comb 105 and has a light shielding portion and a transmission portion. The ratio of the width of the light shielding portion and the transmission portion of the optical comb 105 is 1: 1. Here, in JIS K7374, five types of optical combs having a width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are defined as optical combs.

In the present invention, the optical film needs to satisfy the above formulas (1) and (2). This is for the following reason.
That is, first, in the optical film, in order to obtain a watermark prevention property, an uneven shape is formed on the surface of the optical layer, but when the present inventors have studied, it satisfies the requirement of the above formula (2), that is, It was found that the watermark can be effectively prevented by setting the value of C (0.125) to 64% or less.
On the other hand, the irregularities in the irregular shape may collect and diffuse light and act like a lens (lens effect). And when such a lens effect arises, the black matrix which partitions pixels, such as a liquid crystal display, and the transmitted light from a pixel will be emphasized at random, and it will be thought that this produces glare.
Therefore, the present inventors further researched and determined that the diffusion of light by the uneven shape formed on the surface of the optical layer of the optical film is a finer angle diffusion. It has been found that the occurrence of glare can be suppressed by satisfying the requirement of 1), that is, by setting the value of C (0.25) -C (0.125) to 2% or more. This is considered to be due to the following reason.
That is, the transmitted image definition decreases as the optical comb becomes smaller due to the influence of diffusion at a minute angle. Therefore, it can be said that the value at a small optical comb is small, and the larger the value at a large optical comb is, the less wide angle diffusion is. Therefore, by increasing C (0.25), which is the next largest optical comb, by 2% or more with respect to the value of C (0.125) necessary for watermark prevention, diffusion at a minute angle can be achieved. I think it can be done. As described above, it is considered that the lens effect can be made extremely small and glare can be prevented by performing diffusion at a minute angle.
For this reason, the optical film is required to satisfy the above formulas (1) and (2).
In general, those skilled in the art should have a smaller difference between the value of C (0.25) and the value of C (0.125) from the viewpoint of suppressing glare, and if this difference is large, Predicts that glare will worsen. This is supported by, for example, Japanese Patent Application Laid-Open No. 2010-269504. In this publication, from the viewpoint of suppressing glare, the ratio between the transmitted image definition using an optical comb of 0.125 mm and the transmitted image definition using an optical comb of 2.0 mm is set to 0.70 or more. And this ratio is preferably 0.80 or more and 0.93 or less. That is, although this publication does not use an optical comb of 0.25 mm, it is described that the above ratio is preferably 0.80 or more than 0.70 or more, so an optical comb of 0.125 mm is used. The difference between the transmission image definition using the optical fiber and the transmission image definition using the optical comb of 2.0 mm indicates that the smaller the better. On the other hand, contrary to this prediction, in the present invention, in order to suppress glare, the difference between the value of C (0.25) and the value of C (0.125) is set to 2% or more.
Therefore, it can be said that the optical film satisfying the above formulas (1) and (2) exceeds the range that can be predicted in light of the technical level of conventionally known optical films.

In the display device with a touch panel of the present invention, the difference between the value of C (0.25) and the value of C (0.125) is preferably 5% or more, and more preferably 10% or more. The difference between the C (0.25) value and the C (0.125) value is preferably 30% or less. The value of C (0.125) is preferably 60% or less, and more preferably 50% or less. Further, the value of C (0.125) is preferably 5% or more, and more preferably 20% or more.

In the display device with a touch panel of the present invention, the optical film has an optical layer having a concavo-convex shape laminated on a light-transmitting substrate.
The light-transmitting substrate is not particularly limited as long as it has light-transmitting properties. For example, a cellulose acylate substrate, a cycloolefin polymer substrate, a polycarbonate substrate, an acrylate polymer substrate, a polyester substrate, or And glass substrates.

As said cellulose acylate base material, a cellulose triacetate base material, a cellulose diacetate base material, etc. are mentioned, for example.
Moreover, as said cycloolefin polymer base material, the base material etc. which consist of polymers, such as a norbornene-type monomer and a monocyclic cycloolefin monomer, are mentioned, for example.

Examples of the polycarbonate substrate include aromatic polycarbonate substrates based on bisphenols (bisphenol A and the like), aliphatic polycarbonate substrates such as diethylene glycol bisallyl carbonate, and the like.

Examples of the acrylate polymer base material include poly (meth) methyl acrylate base material, poly (meth) ethyl acrylate base material, (meth) methyl acrylate- (meth) butyl acrylate copolymer group. Materials and the like. In this specification, (meth) acrylic acid means acrylic acid or methacrylic acid.

Examples of the polyester base material include base materials containing at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as constituent components.

Examples of the glass substrate include glass substrates such as soda lime silica glass, borosilicate glass, and alkali-free glass.

Among these, a cellulose acylate base material is preferable because of excellent retardation and adhesion with a polarizer, and a triacetyl cellulose base material (TAC base material) is more preferable among cellulose acylate base materials. A triacetyl cellulose base material is a light-transmitting base material capable of setting an average light transmittance to 50% or more in a visible light region of 380 to 780 nm. The average light transmittance of the triacetyl cellulose base material is preferably 70% or more, and more preferably 85% or more.
In addition to the pure triacetyl cellulose, the triacetyl cellulose base material is a combination of components other than acetic acid as a fatty acid forming an ester with cellulose, such as cellulose acetate propionate and cellulose acetate butyrate. Also good. Moreover, various additives, such as other cellulose lower fatty acid ester, such as a diacetyl cellulose, or a plasticizer, a ultraviolet absorber, and a lubricant, may be added to these triacetyl celluloses as needed.

From the viewpoint of excellent retardation and heat resistance, a cycloolefin polymer substrate is preferable, and from the viewpoint of mechanical properties and heat resistance, a polyester substrate is preferable.

The thickness of the light transmissive substrate is not particularly limited, but can be 5 μm or more and 1000 μm or less, and the lower limit of the thickness of the light transmissive substrate is preferably 15 μm or more from the viewpoint of handling properties, 25 μm or more is more preferable. The upper limit of the thickness of the light transmissive substrate is preferably 80 μm or less from the viewpoint of thinning.

The optical film is a mixture of the light transmissive substrate and a resin containing a photopolymerizable monomer having a weight average molecular weight of 1000 or less as a monomer unit in an interface portion with the optical layer of the light transmissive substrate. It is preferable to have a region. By having the mixed region, it is possible to suppress interference fringes caused by interface reflection between the light-transmitting substrate and the optical layer.
The photopolymerizable monomer is the same as the photopolymerizable monomer having a weight average molecular weight of 1000 or less contained as a monomer unit in a binder resin described later of the optical layer.

The thickness of the mixed region is preferably 0.01 μm or more and 1 μm or less. Since the display device with a touch panel of the present invention can sufficiently suppress the generation of interference fringes by the uneven surface described later of the optical layer, the generation of interference fringes is suppressed even when the thickness of the mixed region is thin. it can. In addition, interference fringes are suppressed by forming a mixed region similar to the above mixed region even in a conventionally known antireflection film, but the thickness of the mixed region formed by a conventional known antireflection film Is thicker than 3 μm, and the thickness of the mixed region formed in the present invention can be said to be sufficiently thinner than the mixed region formed of the conventional antireflection film.
Moreover, the adhesiveness of a light-transmitting base material and an optical layer can be improved more by forming the said mixing | blending area | region.
As described above, since the generation of interference fringes can be sufficiently suppressed by the uneven surface of the optical layer, it is not necessary to form such a mixed region in the optical film. Even when the mixed region is not formed in this way, the generation of interference fringes can be suppressed. For example, it is difficult to form a mixed region such as an acrylic substrate, a cycloolefin polymer substrate, or a polyester substrate. Even if it exists, it can be used as a light-transmitting substrate.

As said optical layer, the layer etc. which exhibit functions, such as antireflection property, hard-coat property, anti-glare property, antistatic property, or antifouling property, are mentioned, for example.

In the case where the optical layer is a layer that exhibits hard coat properties in addition to antireflection properties, the optical layer is determined by a pencil hardness test (4.9 N load) defined by JIS K5600-5-4 (1999). It preferably has a hardness of “H” or higher.

The surface of the optical layer is an uneven surface on which an uneven shape is formed as described above. The “surface of the optical layer” means a surface on the side opposite to the surface of the optical layer on the light transmissive substrate side (the back surface of the optical layer).

Also, if the internal haze value is in the range of 0% or more and 5% or less, the internal haze value does not affect the transmitted image definition, so the transmitted image definition affects the uneven shape on the surface of the optical film. Receive. On the other hand, in the present invention, the surface of the optical film is an uneven surface of the optical layer. Therefore, in the present invention, whether the transmitted image definition of the optical film satisfies the above formulas (1) and (2) depends on the concavo-convex shape of the concavo-convex surface of the optical layer. Hereinafter, the uneven surface of the optical layer in which the optical film satisfies the above formulas (1) and (2) is referred to as a “specific uneven surface”.

The unique irregular surface can be formed by appropriately adjusting the number of irregularities, the size of the irregularities, the inclination angle of the irregularities, etc. As a method for adjusting these, for example, a binder resin after curing And a method of forming an uneven surface using a composition for an optical layer containing a photopolymerizable compound and fine particles.

In the method for forming the concavo-convex surface, when the photopolymerizable compound is polymerized (crosslinked) to become a binder resin, the photopolymerizable compound undergoes curing shrinkage in a portion where fine particles are not present. Shrink. On the other hand, in the portion where the fine particles are present, since the fine particles do not cause curing shrinkage, only the photopolymerizable compounds existing above and below the fine particles cause curing shrinkage. As a result, the portion where the fine particles are present has a thicker optical layer than the portion where the fine particles are not present, so that the surface of the optical layer becomes an uneven surface. Therefore, an optical layer having a specific uneven surface can be formed by appropriately selecting the type and particle size of the fine particles and the type of the photopolymerizable compound and adjusting the coating film forming conditions.

The optical layer contains a binder resin and fine particles, and is preferably formed by the method described above.

The binder resin contains a polymerized product (crosslinked product) of a photopolymerizable compound.
The binder resin may contain a solvent-drying resin or a thermosetting resin in addition to a polymer (crosslinked product) of a photopolymerizable compound.
The photopolymerizable compound has at least one photopolymerizable functional group. In the present specification, the “photopolymerizable functional group” is a functional group capable of undergoing a polymerization reaction upon irradiation with light.
Examples of such a photopolymerizable functional group include an ethylenic double bond such as a (meth) acryloyl group, a vinyl group, and an allyl group. The “(meth) acryloyl group” means to include both “acryloyl group” and “methacryloyl group”.
Moreover, examples of the light irradiated when the photopolymerizable compound is polymerized include visible light and ionizing radiation such as ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays.

As said photopolymerizable compound, a photopolymerizable monomer, a photopolymerizable oligomer, or a photopolymerizable polymer is mentioned, for example, These can be suitably adjusted and used.
The photopolymerizable compound is preferably a combination of a photopolymerizable monomer and a photopolymerizable oligomer or photopolymerizable polymer. In addition, when forming the said mixing | blending area | region, a photopolymerizable monomer is included as a photopolymerizable compound at least.

The photopolymerizable monomer preferably has a weight average molecular weight of 1000 or less. When the weight average molecular weight of the photopolymerizable monomer is 1000 or less, the photopolymerizable monomer can be allowed to penetrate into the light transmissive substrate together with the solvent that penetrates into the light transmissive substrate. Thereby, in the vicinity of the interface of the optical layer in the light transmissive substrate, the light transmissive substrate and the photopolymerizable monomer are monomer units for relaxing the refractive index of the light transmissive substrate and the optical layer. As a result, it is possible to form a mixed region in which the resin contained as a mixture is mixed. In addition, you may use not only one type but multiple types of such photopolymerizable monomers.

As the photopolymerizable monomer, a polyfunctional monomer having two (that is, bifunctional) or more photopolymerizable functional groups is preferable.
Examples of the bifunctional or higher monomer include trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate Tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra ( (Meth) acrylate, adamantyl di (meth) acrylate, isoboronyl di (meth) acrylate, dicyclopentane di (meth) acrylate, tricyclodecane di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and these are PO, EO And the like modified.

Among these, from the viewpoint of obtaining an optical layer having high hardness, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate (PETTA), dipentaerythritol pentaacrylate (DPPA) and the like are preferable.

The photopolymerizable oligomer has a weight average molecular weight of more than 1000 and 10,000 or less.
As the photopolymerizable oligomer, a polyfunctional oligomer having two or more functions is preferable, and a polyfunctional oligomer having three (trifunctional) or more photopolymerizable functional groups is preferable.
Examples of the polyfunctional oligomer include polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and isocyanurate. (Meth) acrylate, epoxy (meth) acrylate, etc. are mentioned.

The photopolymerizable polymer has a weight average molecular weight exceeding 10,000, and the weight average molecular weight is preferably more than 10,000 and not more than 80,000, more preferably more than 10,000 and not more than 40,000. When the weight average molecular weight exceeds 80,000, the viscosity is high, so that the coating suitability is lowered, and the appearance of the obtained optical film may be deteriorated.
Examples of the polyfunctional polymer include urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, and epoxy (meth) acrylate.

The solvent-drying resin is a resin that forms a film only by drying a solvent added to adjust the solid content during coating, such as a thermoplastic resin. When the solvent-drying type resin is added, film defects on the coating surface of the coating liquid can be effectively prevented when forming the optical layer. It does not specifically limit as solvent dry type resin, Generally, a thermoplastic resin can be used.

Examples of the thermoplastic resin include styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, and polyamide resins. Resins, cellulose derivatives, silicone resins and rubbers or elastomers can be mentioned.

The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoint of transparency and weather resistance, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) and the like are preferable.

The thermosetting resin is not particularly limited. For example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation Examples thereof include resins, silicon resins, polysiloxane resins, and the like.

The fine particles may be either inorganic fine particles or organic fine particles. Among them, for example, silica (SiO ₂ ) fine particles, alumina fine particles, titania fine particles, tin oxide fine particles, antimony-doped tin oxide (abbreviation: ATO) fine particles. Inorganic oxide fine particles such as zinc oxide fine particles are preferred. The inorganic oxide fine particles can form an aggregate in the optical layer, and a specific uneven surface can be formed by the degree of aggregation of the aggregate.

Examples of the organic fine particles include plastic beads. Specific examples of the plastic beads include polystyrene beads, melamine resin beads, acrylic beads, acrylic-styrene beads, silicone beads, benzoguanamine beads, benzoguanamine / formaldehyde condensation beads, polycarbonate beads, polyethylene beads, and the like.

It is preferable that the organic fine particles have moderately adjusted resistance to curing shrinkage of the fine particles in the curing shrinkage described above. In order to adjust the resistance to shrinkage, a plurality of optical films containing organic fine particles having different hardnesses prepared in advance by changing the degree of three-dimensional crosslinking are prepared, and the transmitted image clarity of the optical film is evaluated. Therefore, it is preferable to select a degree of crosslinking suitable for providing a specific uneven surface.

When inorganic oxide particles are used as the fine particles, the inorganic oxide particles are preferably subjected to surface treatment. By subjecting the inorganic oxide fine particles to surface treatment, the distribution of the fine particles in the optical layer can be suitably controlled, and the chemical resistance and saponification resistance of the fine particles themselves can be improved.

The surface treatment is preferably a hydrophobizing treatment that makes the surface of the fine particles hydrophobic. Such a hydrophobization treatment can be obtained by chemically reacting the surface of the fine particles with a surface treatment agent such as silanes or silazanes. Specific examples of the surface treatment agent include dimethyldichlorosilane, silicone oil, hexamethyldisilazane, octylsilane, hexadecylsilane, aminosilane, methacrylsilane, octamethylcyclotetrasiloxane, and polydimethylsiloxane. When the fine particles are inorganic oxide fine particles, hydroxyl groups are present on the surface of the inorganic oxide fine particles. However, by performing the hydrophobic treatment as described above, the hydroxyl groups present on the surface of the inorganic oxide fine particles are reduced. In addition, the specific surface area of the inorganic oxide fine particles measured by the BET method can be reduced, and the inorganic oxide fine particles can be prevented from excessively agglomerating, so that a functional layer having a specific uneven surface can be formed.

When inorganic oxide particles are used as the fine particles, the inorganic oxide fine particles are preferably amorphous. This is because when the inorganic oxide particles are crystalline, the Lewis acid salt of the inorganic oxide fine particles becomes strong due to lattice defects contained in the crystal structure, and excessive aggregation of the inorganic oxide fine particles can be controlled. It is because there is a risk of disappearing.

The content of fine particles in the optical layer is not particularly limited, but is preferably 0.1% by mass or more and 5.0% by mass or less. Since the content of fine particles is 0.1% by mass or more, a peculiar uneven surface can be formed more reliably, and the content of fine particles is 5.0% by mass or less, so Aggregation does not occur excessively, and it is possible to suppress internal diffusion and / or generation of large irregularities on the surface of the functional layer, thereby suppressing cloudiness. The lower limit of the fine particle content is more preferably 0.2% by mass or more, and the upper limit of the fine particle content is more preferably 3.0% by mass or less.

The fine particles are preferably spherical in shape in a single particle state. Since the single particles of the fine particles are spherical, an image having excellent contrast can be obtained when the optical film is disposed on the image display surface of the image display device. Here, “spherical” means, for example, a true spherical shape, an elliptical spherical shape, etc., but a so-called indeterminate shape is not included.

When organic fine particles are used as the fine particles, the difference in refractive index with the binder resin can be reduced by changing the copolymerization ratio of resins having different refractive indexes, for example, less than 0.01 to suppress light diffusion by the fine particles. It is preferable in that it can be performed. The average primary particle size of the organic fine particles is preferably less than 8.0 μm, and more preferably 5.0 μm or less.

Among the above methods, the optical layer is preferably formed using fine particles that form a gentle aggregate. The “loose aggregate” means an aggregate having a structure including a bent portion formed by continuous primary particles and an inner region sandwiched between the bent portions, rather than agglomerates of fine particles. . Here, in this specification, the “bent portion” is a concept including a curved portion. Examples of the shape having a bent portion include a V shape, a U shape, an arc shape, a C shape, a string shape, and a hook shape. Both ends of the bent portion may be closed, for example, an annular structure having a bent portion.

The bent portion may be formed by agglomerates of a single fine particle that is formed by a series of primary particles and is bent, but a trunk formed by a series of primary particles and a branch from the trunk However, it may be constituted by branch portions formed by continuous primary particles, or may be constituted by two branch portions branched from the trunk portion and connected at the trunk portion. The “stem” is the longest part of the aggregate of fine particles.

The inner region is filled with a binder resin. The bent portion is preferably present so as to sandwich the inner region from the thickness direction of the optical layer.

The aggregate aggregated in a lump shape acts as a single solid upon curing shrinkage (polymerization shrinkage) of the photopolymerizable compound that becomes the binder resin after curing, so that the uneven surface of the optical layer corresponds to the shape of the aggregate. . In contrast, an aggregate in which fine particles are gently aggregated has a bent portion and an inner region sandwiched between the bent portions, and therefore acts as a solid having a buffering action upon curing shrinkage. Therefore, the aggregate in which the fine particles are gradually aggregated is easily and uniformly crushed during the curing shrinkage. Thereby, the shape of the concavo-convex surface is gradual as compared with the case where the fine particles are aggregated in a lump shape, and a large concavo-convex shape is hardly generated in a part.
In the case where the optical layer is formed of aggregates that are gently aggregated, it is possible to adjust the size of the aggregates that are gradually aggregated by adjusting the film thickness. That is, when the film thickness is large, the size of the aggregates that are gradually aggregated tends to be larger. Thereby, the size of the unevenness can be made larger and the interval between the unevennesses can be made wider.

Moreover, as the fine particles forming a gentle aggregate, for example, inorganic oxide fine particles having an average primary particle size of 1 nm or more and 100 nm or less are preferable. Since the average primary particle size of the fine particles is 1 nm or more, an optical layer having a specific uneven surface can be formed more easily, and since the average primary particle size is 100 nm or less, Light diffusion can be suppressed, and excellent darkroom contrast can be obtained. The lower limit of the average primary particle size of the fine particles is more preferably 5 nm or more, and the upper limit of the average primary particle size of the fine particles is more preferably 50 nm or less. The average primary particle size of the fine particles is a value measured using an image processing software from an image of a cross-sectional electron microscope (a transmission type such as TEM or STEM and preferably having a magnification of 50,000 times or more).

When inorganic oxide fine particles are used as the fine particles forming the above-mentioned gentle aggregates, the irregularities on the irregular surface of the optical layer are preferably formed only from the inorganic oxide fine particles. “The irregularities on the irregular surface of the optical layer are formed only by the inorganic oxide fine particles” means that the irregularities on the irregular surface of the optical layer are fine particles other than the inorganic oxide fine particles in addition to the inorganic oxide fine particles. In the case of being formed due to, it means that it is not substantially included. Here, “substantially free” means fine particles that do not form irregularities on the irregular surface of the optical layer, or a slight amount that does not affect the antireflection even if irregularities are formed. If present, it means that the optical layer may contain fine particles other than the inorganic oxide fine particles.

Among the inorganic oxide fine particles, fumed silica is particularly preferable from the viewpoint that a gentle aggregate can be formed and a unique uneven surface can be easily formed.
The fumed silica is amorphous silica having a particle size of 200 nm or less prepared by a dry method, and can be obtained by reacting a volatile compound containing silicon in a gas phase. Specific examples include those produced by hydrolyzing a silicon compound such as silicon tetrachloride (SiCl ₄ ) in a flame of oxygen and hydrogen. Examples of commercially available fumed silica include AEROSIL R805 manufactured by Nippon Aerosil Co., Ltd.

The fumed silica includes a hydrophilic property and a hydrophobic property. Among these, a hydrophobic property is obtained from the viewpoint that the water absorption is reduced and the functional layer composition is easily dispersed. Is preferable.
Hydrophobic fumed silica can be obtained by chemically reacting a surface treatment agent as described above with silanol groups present on the surface of fumed silica. From the viewpoint of easily obtaining the aggregate as described above, the fumed silica is most preferably treated with octylsilane.

The BET specific surface area of the fumed silica is preferably 100 m ² / g or more and 200 m ² / g or less. By setting the BET specific surface area of the fumed silica to 100 m ² / g or more, the fumed silica does not disperse excessively and it becomes easy to form an appropriate aggregate, and the BET specific surface area of the fumed silica is 200 m ² / g. By making it below, it becomes difficult for fumed silica to form excessively large aggregates. The lower limit of the BET specific surface area of fumed silica is more preferably 120 m ² / g, still more preferably 140 m ² / g. The upper limit of the BET specific surface area of fumed silica is more preferably 180 m ² / g, still more preferably 165 m ² / g.

Such an optical layer can be formed, for example, by the following method.
First, the following optical layer composition is applied to the surface of the light transmissive substrate.
Examples of the method for applying the optical layer composition include known coating methods such as spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, and die coating. It is done.

The composition for an optical layer contains at least the photopolymerizable compound and the fine particles. In addition, you may add the said thermoplastic resin, the said thermosetting resin, a solvent, and a polymerization initiator to the composition for optical layers as needed. Further, the optical layer composition includes conventionally known dispersants, surfactants, antistatic agents, silanes depending on purposes such as increasing the hardness of the optical layer, suppressing cure shrinkage, and controlling the refractive index. Coupling agent, thickener, anti-coloring agent, coloring agent (pigment, dye), antifoaming agent, leveling agent, flame retardant, UV absorber, adhesion-imparting agent, polymerization inhibitor, antioxidant, surface modifier Further, an easy lubricant or the like may be added.

The above-mentioned solvent is unique by adjusting the viscosity in order to facilitate the application of the optical layer composition, adjusting the evaporation rate and dispersibility with respect to the fine particles, and adjusting the degree of aggregation of the fine particles during the formation of the optical layer. It can be used for the purpose of easily forming a rough surface.
Examples of such solvents include alcohols (eg, methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol), ketones (acetone, methyl ethyl ketone (MEK). ), Cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone, etc.), ethers (1,4-dioxane, dioxolane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic carbonization Hydrogen (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, Such as ethyl acid), cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., and mixtures thereof. May be.

Further, as described above, when the mixed region is formed near the interface with the optical layer in the light transmissive substrate, the solvent is highly permeable to the light transmissive substrate, and the light transmissive group is used. While using the thing containing the permeable solvent which melt | dissolves or swells a material, the thing containing the photopolymerizable monomer whose weight average molecular weight is 1000 or less is used as a photopolymerizable compound at least.
By using the permeable solvent and the photopolymerizable monomer, not only the permeable solvent but also the photopolymerizable monomer penetrates the light transmissive substrate. A mixed region in which a transparent substrate and a resin containing a photopolymerizable monomer as a monomer unit are mixed can be formed.

Examples of the permeable solvent include ketones (acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone), esters (methyl formate, methyl acetate, ethyl acetate, acetic acid). Propyl, butyl acetate, ethyl lactate, etc.), ethers (1,4-dioxane, dioxolane, tetrahydrofuran, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), Phenols (phenol, orthochlorophenol) and the like can be mentioned. Moreover, these mixtures may be sufficient. In the case of using a triacetyl cellulose base material as the light transmissive base material, among these, examples of the permeable solvent include methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate. At least one selected from the group consisting of the above is preferred, and orthochlorophenol is preferred when a polyester substrate is used as the light-transmitting substrate.

The polymerization initiator is a component that is decomposed by light irradiation to generate radicals to initiate or advance polymerization (crosslinking) of the photopolymerizable compound.
Such a polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by light irradiation, and conventionally known ones can be used. Specific examples include, for example, acetophenones Benzophenones, Michler benzoyl benzoate, α-amyloxime esters, thioxanthones, propiophenones, benzyls, benzoins, acylphosphine oxides. In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

As the polymerization initiator, when the binder resin is a resin system having a radical polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like alone or in combination. .

The content of the polymerization initiator in the optical layer composition is preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound. By setting the content of the polymerization initiator within this range, the hard coat performance can be sufficiently maintained, and curing inhibition can be suppressed.

Although it does not specifically limit as a content rate (solid content) of the raw material in the composition for optical layers, Usually, 5 to 70 mass% is preferable, and it is more preferable to set it as 25 to 60 mass%.

As the leveling agent, for example, silicone oil, fluorine-based surfactant and the like are preferable because the optical layer is prevented from having a Benard cell structure. When a resin composition containing a solvent is applied and dried, a surface tension difference or the like is generated between the coating film surface and the inner surface in the coating film, thereby causing many convections in the coating film. A structure generated by this convection is called a Benard cell structure, which causes problems such as the skin and coating defects in the optical layer to be formed.

In the Benard cell structure, the surface irregularities of the optical layer may become too large. When the leveling agent as described above is used, this convection can be prevented, so that not only an optical layer free from defects and unevenness can be obtained, but also the unevenness of the surface of the optical layer can be easily adjusted.

The method for preparing the optical layer composition is not particularly limited as long as each component can be uniformly mixed. For example, the composition can be performed using a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer.

After coating the optical layer composition on the surface of the light transmissive substrate, the coated optical layer composition is transported to a heated zone for drying, and the optical layer is formed by various known methods. The composition is dried and the solvent is evaporated. Here, by selecting the solvent relative evaporation rate, solid content concentration, coating solution temperature, drying temperature, drying air speed, drying time, solvent atmosphere concentration in the drying zone, etc., the aggregation state and distribution state of the fine particles can be adjusted. .

In particular, a method of adjusting the distribution state of the fine particles by selecting the drying conditions is simple and preferable.
For example, as the above-mentioned drying conditions, the drying temperature is lowered and / or the drying air speed is reduced, so that the drying speed is slowed down so that the fine particles are more easily aggregated. Therefore, the unevenness is large and the unevenness interval is wide. It can be made into a shape easily.
The specific drying temperature is preferably 30 to 120 ° C., and the drying wind speed is preferably 0.2 to 50 m / s. The drying treatment appropriately adjusted within this range is performed once or a plurality of times to thereby form fine particles. The distribution state can be adjusted to a desired state.

Moreover, when the composition for optical layers is dried, the permeable solvent which has permeated the light-transmitting substrate evaporates, but the photopolymerizable compound remains in the light-transmitting substrate.
Then, the composition for optical layer is irradiated with light such as ultraviolet rays, and the photopolymerizable compound is polymerized (crosslinked) to cure the composition for optical layer to form an optical layer. A mixed area is formed.

When ultraviolet rays are used as the light for curing the optical layer composition, ultraviolet rays emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, or the like can be used. Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

In addition, the optical layer which has a specific uneven | corrugated surface can also be formed by using a photopolymerizable compound and solvent dry resin as a material which forms binder resin.
Specifically, for example, using a composition for an optical layer containing a photopolymerizable compound, a solvent-drying resin, and fine particles, the composition for an optical layer is formed on a light-transmitting substrate by the same method as described above. A coating film is formed and the optical layer composition is cured in the same manner as described above.
As a material for forming the binder resin, when a photopolymerizable compound and a solvent-drying resin are used in combination, the viscosity can be increased as compared with the case where only the photopolymerizable compound is used. (Shrinkage) can be reduced, so that the irregular surface of the optical layer is formed without following the shape of the fine particles during drying and curing, and a unique irregular surface can be formed. However, since the concavo-convex shape of the concavo-convex surface of the optical layer is affected by the film thickness of the optical layer, the film thickness of the optical layer is appropriately adjusted even when the optical layer is formed by such a method. Needless to say, there is a need.

In the present invention, the optical layer may have a single-layer structure or a multilayer structure of two or more layers as long as the above formulas (1) and (2) are satisfied. Specifically, the optical layer may have a two-layer structure including a base concavo-convex layer having a concavo-convex surface and a surface adjustment layer formed on the base concavo-convex layer.
The foundation uneven layer may be an optical layer.
The surface adjustment layer fills the fine unevenness present on the surface of the underlying uneven layer to obtain a smooth uneven surface, and / or adjusts the spacing and size of the unevenness present on the surface of the uneven layer. It is a layer to do. The surface adjustment layer has an uneven surface, and the uneven surface of the surface adjustment layer has a unique uneven surface. However, when the optical layer has a multi-layer structure, the manufacturing process is complicated, and the management of the manufacturing process may be difficult compared to the case of a single-layer structure. Therefore, the optical layer preferably has a single-layer structure.

The film thickness of the surface adjustment layer is preferably from 0.5 μm to 20 μm from the viewpoint of adjusting the unevenness. The upper limit of the thickness of the surface adjustment layer is more preferably 12 μm or less, and further preferably 8 μm or less. The lower limit of the thickness of the surface adjustment layer is preferably 3 μm or more.

The optical layer composed of the above-mentioned uneven surface layer and the surface adjustment layer can be formed by the following method using the under-surface uneven layer composition and the surface adjustment layer composition as the optical layer composition.

As the composition for the base uneven layer, the same composition as the optical layer composition described in the column of the optical layer composition can be used. Moreover, as a composition for surface adjustment layers, the composition containing at least the photopolymerizable compound similar to the photopolymerizable compound demonstrated in the column of the said binder resin can be used. In addition to the photopolymerizable compound, the surface adjustment layer composition may contain a leveling agent, a solvent, and the like similar to the leveling agent and solvent described in the column of the optical layer composition.

When forming the optical layer composed of the above-mentioned foundation concavo-convex layer and the surface adjustment layer, first, the composition for the base concavo-convex layer is applied on the transparent substrate, and then the composition for the base concavo-convex layer on the light-transmitting substrate. Form a coating of objects.
Then, after drying this coating film, the coating film is irradiated with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound, thereby curing the foundation uneven layer composition to form a foundation uneven layer. To do.
Then, the composition for surface adjustment layers is apply | coated on a base uneven | corrugated layer, and the coating film of the composition for surface adjustment layers is formed. And after drying this coating film, the coating film is irradiated with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound, thereby curing the composition for the surface adjustment layer to form a surface adjustment layer. To do. Thereby, an optical layer having a specific uneven surface can be formed without using fine particles that form loose aggregates. However, the uneven shape of the uneven surface of the optical layer is also affected by the drying conditions of the coating film, the film thickness of the underlying uneven layer and the surface adjustment layer, and so on when forming the optical layer by such a method. Even if it exists, it cannot be overemphasized that it is necessary to adjust the drying conditions of a coating film, the film thickness of a base uneven | corrugated layer, and a surface adjustment layer suitably.

The optical film preferably has a total light transmittance of 85% or more. When the total light transmittance is 85% or more, color reproducibility and visibility can be further improved when the optical film is mounted on the surface of the image display device. The total light transmittance is more preferably 90% or more. The total light transmittance can be measured by a method based on JIS K7361 using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

In the surface of the optical film, the three-dimensional average inclination angle θa _{3D of} the unevenness constituting the surface is preferably 0.12 ° or more and 0.5 ° or less, and preferably 0.15 ° or more and 0.4 °. More preferably, it is as follows.
On the surface of the optical film, the average peak spacing Smp of the unevenness constituting the surface is preferably 0.05 mm or more and 0.3 mm or less, and preferably 0.10 mm or more and 0.25 mm or less. More preferred.

On the surface of the optical film, the arithmetic average roughness Ra of the unevenness constituting the surface is preferably 0.01 μm or more and 0.11 μm or less, and 0.035 μm or more and 0.08 μm or less. Is more preferable.
On the surface of the optical film, the 10-point average roughness Rz of the unevenness constituting the surface is preferably 0.10 μm or more and 0.30 μm or less, and is 0.12 μm or more and 0.28 μm or less. It is more preferable.

そして（ｉ，ｊ）における傾斜角度は、ｔａｎ^−１（Ｓｔ）で算出される。
上記三次元粗さ曲面は、簡便性から干渉顕微鏡を用いて測定することが好ましい。このような干渉顕微鏡としては、例えば、Ｚｙｇｏ社製の「Ｎｅｗ Ｖｉｅｗ」シリーズ等が挙げられる。
そして、上記三次元平均傾斜角θａ_３Ｄは、各点の傾斜角度の平均値により算出される。
また、本発明における上記凹凸の平均山間隔Ｓｍｐは、次のように求める。
上記３次元粗さ曲面から基準面より高い部分で一つの領域で囲まれた部分を一つの山としたきの山の個数をＰｓとし、測定領域全体（基準面）の面積をＡとすると、Ｓｍｐは下記式で算出される。

また、本発明における上記凹凸の算術平均粗さＲａは、ＪＩＳ Ｂ０６０１：１９９４に記載されている２次元粗さパラメータであるＲａを３次元に拡張したものであり、基準面に直交座標軸Ｘ、Ｙ軸を置き、粗さ曲面をＺ（ｘ，ｙ）、基準面の大きさをＬｘ、Ｌｙとすると下記式で算出される。

Ａ＝Ｌｘ×Ｌｙ
また、上述のＺ_ｉ，ｊを用いると、上記凹凸の算術平均粗さＲａは、下記式で算出される。

Ｎ：全点数 “Θa _3D ”, “Smp”, “Ra” and “Rz” are contact surface roughness meters and non-contact surface roughness meters (for example, interference microscopes, confocal microscopes, atomic force microscopes, etc.) It can be calculated from the three-dimensional roughness curved surface obtained by the measurement. The data of the three-dimensional roughness curved surface is represented by points arranged in a grid pattern at intervals d on the reference plane (the horizontal direction is the x-axis and the vertical direction is the y-axis) and the height at the position of the point. The
That is, if the height at the position of the i-th point in the x-axis direction and the j-th point in the y-axis direction (hereinafter referred to as (i, j)) is Z _{i, j} , at an arbitrary position (i, j) The slope Sx in the x-axis direction with respect to the x-axis and the slope Sy in the y-axis direction with respect to the y-axis are calculated as follows.
Sx = (Z _{i + 1, j} −Z _{i−1, j} ) / 2d
Sy = (Z _{i, j + 1} −Z _{i, j−1} ) / 2d
Further, the slope St with respect to the reference plane at (i, j) is calculated by the following equation.

The tilt angle at (i, j) is calculated by tan ⁻¹ (St).
The three-dimensional roughness curved surface is preferably measured using an interference microscope for simplicity. Examples of such an interference microscope include “New View” series manufactured by Zygo.
The three-dimensional average inclination angle θa _3D is calculated from the average value of the inclination angles at the respective points.
Moreover, the average crest interval Smp of the unevenness in the present invention is obtained as follows.
If the above-mentioned three-dimensional roughness curved surface is a part higher than the reference plane and surrounded by one area is defined as one peak, Ps is the number of peaks, and A is the area of the entire measurement area (reference plane). Smp is calculated by the following formula.

In addition, the arithmetic average roughness Ra of the unevenness in the present invention is obtained by expanding Ra, which is a two-dimensional roughness parameter described in JIS B0601: 1994, into three dimensions, and orthogonal coordinate axes X, Y on the reference plane. If the axis is set, the roughness curved surface is Z (x, y), and the reference surface is Lx, Ly, the following formula is used.

A = Lx × Ly
Further, when the above Z _{i, j} is used, the arithmetic average roughness Ra of the unevenness is calculated by the following formula.

N: All points

The 10-point average roughness Rz in the present invention is obtained by extending Rz, which is a two-dimensional roughness parameter described in JIS B0601: 1994, to three dimensions.
That is, a plurality of straight lines passing through the center of the reference surface on the reference surface are radially arranged so as to cover the entire area, and a cross-section curve obtained by cutting from the three-dimensional roughness curved surface based on each straight line is obtained. The 10-point average roughness (sum of the highest peak height from the highest peak to the fifth highest and the average of the fifth highest valley depth from the lowest deepest to the deepest) is obtained in the curve. It is calculated by averaging the top 50% of the large number of 10-point average roughness thus obtained.

Moreover, since the optical film in the display device with a touch panel of the present invention can more suitably prevent the generation of watermarks, the optical layer has a low refractive index layer laminated on an uneven layer having an uneven shape on the surface. A configuration is preferred.
Examples of the concavo-convex layer include those formed by the same composition and method as those of the optical layer containing the binder resin and fine particles described above.
The low refractive index layer is a layer that plays a role of reducing the reflectance when external light (for example, a fluorescent lamp, natural light, etc.) is reflected on the surface of the optical film. The low refractive index layer is preferably 1) a resin containing low refractive index particles such as silica and magnesium fluoride, 2) a fluorine-based resin which is a low refractive index resin, and 3) fluorine containing silica or magnesium fluoride. 4) a resin, 4) a thin film of a low refractive index material such as silica or magnesium fluoride, or the like. As for the resin other than the fluorine-based resin, a resin similar to the binder resin constituting the optical layer described above can be used.
Moreover, it is preferable that the silica mentioned above is a hollow silica fine particle, and such a hollow silica fine particle can be produced by, for example, a production method described in Examples of JP-A-2005-099778.
These low refractive index layers preferably have a refractive index of 1.45 or less, particularly 1.42 or less.
Further, the thickness of the low refractive index layer is not limited, but it may be set appropriately from the range of about 30 nm to 1 μm.
In addition, although the low refractive index layer is effective as a single layer, it is possible to provide two or more low refractive index layers as appropriate for the purpose of adjusting a lower minimum reflectance or a higher minimum reflectance. . When the two or more low refractive index layers are provided, it is preferable to provide a difference in the refractive index and thickness of each low refractive index layer.

As the fluororesin, a polymerizable compound containing a fluorine atom in at least a molecule or a polymer thereof can be used. Although it does not specifically limit as a polymeric compound, For example, what has hardening reactive groups, such as a functional group hardened | cured by ionizing radiation, and a polar group thermally cured, is 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 a functional group that is cured by ionizing radiation, 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 those 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-trifluoro (Meth) acrylate compounds having a fluorine atom in the molecule, such as methyl methacrylate and α-trifluoroethyl methacrylate; a C 1-14 fluoroalkyl group having at least 3 fluorine atoms in the molecule, fluoro A cycloalkyl 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 polymerizable compound having a thermosetting polar group include 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, phenol, polyimide, and the like. Examples include fluorine-modified products of each resin.
Examples of the polymerizable compound having both a functional group curable by ionizing radiation and a polar group curable by heat include acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, fully Alternatively, partially fluorinated vinyl esters, fully or partially fluorinated vinyl ketones and the like can be exemplified.

Moreover, as a fluorine resin, the following can be mentioned, for example.
Polymer of monomer or monomer mixture containing at least one fluorine-containing (meth) acrylate compound of a polymerizable compound having an ionizing radiation curable group; at least one fluorine-containing (meth) acrylate compound; and methyl (meth) Copolymers with (meth) acrylate compounds that do not contain fluorine atoms in the molecule such as acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; fluoroethylene , Fluorine-containing compounds such as vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene, hexafluoropropylene Monomer homopolymer or Copolymer 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. Of these, those having a dimethylsiloxane structure are preferred.

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.

Moreover, each binder resin as described in the said optical layer can also be mixed and used with the polymeric compound and polymer which have the above-mentioned fluorine atom. Furthermore, various additives and solvents can be used as appropriate in order to improve the curing agent for curing reactive groups and the like, to improve the coating property, and to impart antifouling properties.

In the formation of the low refractive index layer, 0.5 to 5 mPa · s (25 ° C.) at which a preferable coating property is obtained for the viscosity of the composition for a low refractive index layer obtained by adding a low refractive index agent and a resin, It is preferable to set it as the range of 0.7-3 mPa * s (25 degreeC) preferably. An optical layer excellent in visible light can be realized, a uniform thin film with no coating unevenness can be formed, and a low refractive index layer particularly excellent in adhesion can be formed.

The resin curing means may be the same as that described in the optical layer described above. When a heating means is used for the curing treatment, it is preferable to add a thermal polymerization initiator that generates, for example, a radical by heating to start polymerization of the polymerizable compound, to the fluororesin composition.

The layer thickness (nm) d _A of the low refractive index layer is expressed by the following formula (A):
d _A = mλ / (4n _A ) (A)
(In the above formula,
n _A represents the refractive index of the low refractive index layer;
m represents a positive odd number, preferably 1;
λ is a wavelength, preferably a value in the range of 480 to 580 nm)
Those satisfying these conditions are preferred.

In the present invention, the low refractive index layer is represented by the following formula (B):
120 <n _A d _A <145 (B)
It is preferable from the viewpoint of low reflectivity.

According to the present invention, an optical film measured using an optical comb having a width of 0.25 mm, where C (0.125) is the transmitted image definition of the optical film measured using an optical comb having a width of 0.125 mm. When the transmitted image definition of C is C (0.25), the optical film satisfies the above formulas (1) and (2), so that the optical film has a low total haze of 0% to 5%. Even if it has a low internal haze of 0% or more and 5% or less, glare can be suppressed and watermarks can be suppressed for the reasons described above.

When the optical layer is formed using inorganic oxide fine particles (for example, fumed silica) having an average primary particle size of 1 nm to 100 nm as the fine particles, a lower total haze value (for example, 1% or less) An optical film having a total haze value) and a lower internal haze value (eg, substantially 0% internal haze value) can be obtained. That is, the total haze and the internal haze of the optical film are the ratio of the transmitted light that deviates from the incident light by 2.5 ° or more due to forward scattering in the transmitted light transmitted through the optical film. If the ratio of transmitted light deviating by more than 0 ° can be reduced, the total haze value and the internal haze are lowered. On the other hand, since the inorganic oxide fine particles having an average primary particle size of 100 nm or less do not aggregate in the optical layer but form a gentle aggregate, the light transmitted through the optical layer diffuses in the optical layer. Hard to do. Accordingly, when an optical layer is formed using inorganic oxide fine particles having an average primary particle size of 1 nm or more and 100 nm or less, generation of transmitted light deviated by 2.5 ° or more from incident light can be suppressed. Thereby, an optical film with a lower total haze value and internal haze value can be obtained.

When the unevenness on the uneven surface of the optical layer is formed only by the inorganic oxide fine particles, it becomes easy to form an uneven surface having a gentle and uniform unevenness capable of obtaining a watermark property. Therefore, it is possible to obtain an optical film that has a low total haze value and an internal haze value and can further suppress glare.

According to the present invention, the optical film has a total haze value of 0% or more and 5% or less, and an internal haze value of 0% or more and 5% or less. Can be suppressed. In addition, since the diffusion of the image light inside the optical film can be suppressed, a part of the image light does not become stray light, and as a result, the dark room contrast does not decrease and the image may be blurred. Absent. As a result, the optical film is incorporated into an ultra-high-definition small mobile phone or an ultra-high-definition image display device having a horizontal pixel count of 3000 or more such as 4K2K (horizontal pixel count 3840 × vertical pixel count 2160). Can be used.
As the image display device, a liquid crystal display device provided with a known backlight unit is suitable, but a quantum dot LED can also be used as the backlight.

According to the present invention, since the optical film includes an optical layer having a concavo-convex surface, interference between light reflected at the interface between the light-transmitting substrate and the optical layer and light reflected from the concavo-convex surface of the optical layer. Can be suppressed. Thereby, generation | occurrence | production of an interference fringe can be suppressed. In addition, when the mixed region is formed, the reflection at the interface between the light transmissive substrate and the optical layer can be suppressed, so that the generation of interference fringes can be further suppressed.

When the unevenness on the uneven surface of the optical layer is formed only by the inorganic oxide fine particles, it is easy to prevent the inclination angle of the unevenness constituting the uneven surface from increasing. Thereby, since excessive diffusion of external light does not occur, it is possible to suppress a decrease in bright room contrast. Further, since it is possible to prevent the image light from becoming stray light, a good dark room contrast can be obtained. Furthermore, since it has an appropriate specular reflection component, when a moving image is displayed, the brightness and brightness of the image increase, and a dynamic feeling can be obtained. As a result, it is possible to obtain a black feeling having both excellent contrast and dynamic feeling.

It is also possible to provide a method for improving glare and watermark by using an optical film satisfying the above formulas (1) and (2).

The optical film used for the display device with a touch panel of the present invention described above is also one aspect of the present invention.
That is, the optical film of the present invention is an optical film in which an optical layer having a concavo-convex shape on the surface is laminated on a light-transmitting substrate, and is disposed opposite to the touch panel and used for a display device with a touch panel. Yes, the total haze value is 0% or more and 5% or less, the internal haze value is 0% or more and 5% or less, and the transmitted image clarity measured using an optical comb having a width of 0.125 mm is C (0. 125), and the transmitted image sharpness measured using an optical comb having a width of 0.25 mm is C (0.25), the optical system satisfies the following expressions (1) and (2): It is a film.
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2)

Examples of the materials constituting the optical film of the present invention described above include those similar to the optical film described in the above-described display device with a touch panel of the present invention.

Since the display device with a touch panel of the present invention has a specific uneven shape formed on the surface of the optical film facing the touch panel, the occurrence of watermarks and glare can be sufficiently suppressed, and a high-quality display image can be obtained. Can be obtained.

It is sectional drawing which showed typically the display apparatus with a touchscreen of this invention. It is the schematic diagram which showed a mode that the transmission image definition of an optical film was measured with a transmission image definition measuring apparatus.

The contents of the present invention will be described with reference to the following examples, but the contents of the present invention should not be construed as being limited to these embodiments. Unless otherwise specified, “part” and “%” are based on mass.

Example 1
(Production of optical film)
A light-transmitting substrate (cellulose triacetate film, thickness 40 μm, manufactured by Konica Minolta, KC4UAW) was prepared, and the optical layer composition having the composition shown below was applied to one side of the light-transmitting substrate. A film was formed.
Next, 50 ° C. dry air was passed through the formed coating film at a flow rate of 0.2 m / s for 30 seconds, and then 70 ° C. dry air was passed through for 30 seconds at a flow rate of 10 m / s. To evaporate the solvent in the coating film.
Then, using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb), ultraviolet rays are irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light amount becomes 100 mJ / cm ^2. Was cured to form an optical layer having a thickness of 5.0 μm (during curing) to produce an optical film.

(Composition for optical layer)
Silica fine particles (octylsilane-treated fumed silica, average primary particle size 12 nm, manufactured by Nippon Aerosil Co., Ltd.) 0.5 parts by mass Pentaerythritol tetraacrylate (PETTA) (product name “PETA”, manufactured by Daicel-Cytec) 50 parts by mass Acrylate (product name “V-4000BA”, manufactured by DIC) 50 parts by mass polymerization initiator (Irgacure 184, manufactured by BASF Japan) 5 parts by mass polyether-modified silicone (product name “TSF4460”, Momentive Performance Materials) 0.025 parts by mass Toluene 115 parts by mass Isopropyl alcohol 45 parts by mass Cyclohexanone 15 parts by mass

A display device with a touch panel is manufactured by a method including a step of disposing the obtained optical film and the touch panel so that a gap between the optical layer and the touch panel is 0.3 mm.

(Example 2)
The concavo-convex layer was formed in the same manner as the optical layer of Example 1 except that the coating film was cured by irradiating the coating film under the curing conditions such that the cumulative amount of ultraviolet light was 50 mJ / cm ² .
The composition for low refractive index layer shown below was apply | coated to the surface of the formed uneven | corrugated layer, and the coating film was formed.
Next, 40 ° C. dry air was passed through the formed coating film at a flow rate of 0.2 m / s for 15 seconds, and further, 40 ° C. dry air was passed through for 30 seconds at a flow rate of 10 m / s. To evaporate the solvent in the coating film.
Then, using an ultraviolet irradiation device (Fusion UV System Japan, light source H bulb), ultraviolet rays are irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light amount becomes 100 mJ / cm ^2. Was cured to form a low refractive index layer having a thickness of 0.1 μm (when cured), and an optical layer having a structure in which the low refractive index layer was laminated on the concave and convex layer. Thus, an optical film according to Example 2 was produced.

(Composition for low refractive index layer)
Hollow silica fine particles (average particle size 60 nm) 125 parts by mass (converted to 100% solid content)
Pentaerythritol triacrylate (PETA) (Product name: PETIA, manufactured by Daicel-Cytec) 20 parts by mass fluorine-containing polymer (Product name: “OPSTAR JN35”, manufactured by JSR)
80 parts by mass (converted to 100% solid content)
Polymerization initiator (Irgacure 127; manufactured by BASF Japan) 7 parts by mass Modified silicone oil (X22164E; manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts by mass Methyl isobutyl ketone (MIBK) 5300 parts by mass Propylene glycol monomethyl ether acetate (PGMEA) 2200 parts by mass

(Example 3)
The compounding amount of silica fine particles in the optical layer composition is 0.8 parts by mass, and the drying conditions of the coating film are 10 m / s after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 1.0 m / s. An optical film was produced in the same manner as in Example 1 except that 70 ° C. dry air was circulated for 30 seconds at a flow rate of s.

Example 4
An optical film was produced in the same manner as in Example 1 except that the thickness of the optical layer when cured was 4.5 μm.

(Example 5)
The drying conditions of the coating film were such that 70 ° C. dry air was circulated for 15 seconds at a flow rate of 1.0 m / s, and then 70 ° C. dry air was circulated for 30 seconds at a flow rate of 10 m / s. An optical film was produced in the same manner as in Example 3, except that the thickness at curing was 4.5 μm.

(Example 6)
The optical layer composition contains 1.0 part by mass of organic particles (acryl-styrene copolymer particles, average particle size: 2.0 μm, refractive index: 1.55, manufactured by Sekisui Plastics Co., Ltd.) The drying conditions of the membrane were such that 70 ° C. dry air was circulated for 15 seconds at a flow rate of 1.0 m / s, and then 70 ° C. dry air was circulated for 30 seconds at a flow rate of 10 m / s. An optical film was produced in the same manner as in Example 1.

(Comparative Example 1)
The amount of silica fine particles in the optical layer composition is 1.0 part by mass, and organic particles (acryl-styrene copolymer particles, average particle size: 2.0 μm, refractive index: 1.55, Sekisui Plastics) (Made by Kogyo Co., Ltd.) was added, and the drying condition of the coating film was 70 ° C. at a flow rate of 10 m / s after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 0.2 m / s. An optical film was produced in the same manner as in Example 1 except that the dry air was circulated for 30 seconds and the thickness of the optical layer when cured was 4.0 μm.

(Comparative Example 2)
An optical film was produced in the same manner as in Example 1 except that silica fine particles were not blended in the optical layer composition.

<With / without watermark>
The optical films prepared in each of the examples and comparative examples were attached to a black acrylic plate with a concavo-convex surface on the surface via a transparent adhesive.
A tape was attached to both ends of a glass plate having a thickness of 0.7 mm and a size of 10 cm × 10 cm. And the surface which affixed the tape of a glass plate was arrange | positioned so that an optical film might face so that an optical film and a glass plate might space apart. The distance of the air gap between the surface of the optical film and the glass plate was 0.1 mm. And in the state which pressed the glass plate with the finger | toe, light was irradiated from the sodium lamp arrange | positioned on glass, and it was investigated whether a watermark was confirmed. The evaluation criteria were as follows. The results are shown in Table 1.
A: No watermark was confirmed.
○: Some watermark was observed, but there was no problem.
X: The watermark was clearly confirmed.

<Measurement of transmitted image clarity>
About each optical film obtained by the Example and the comparative example, the transmitted image clarity was measured as follows. The results are shown in Table 1.
First, a image clarity measuring device (model number: ICM-1T, manufactured by Suga Test Instruments Co., Ltd.) was prepared.
And each optical film which concerns on an Example and a comparative example is installed so that the triacetyl cellulose resin film side may become the light source side of a image clarity measuring device, and it complies with the measuring method of the image definition by the transmission method of JIS K7374. The transmission image definition was measured. As the optical comb, those having a width of 0.125 mm and a width of 0.25 mm were used. Then, the transmission image definition (C (0.25)) measured using an optical comb having a width of 0.25 mm and the transmission image definition (C (0. 0) measured using an optical comb having a width of 0.125 mm). 125)) (C (0.25) -C (0.125)). For reference, the transmission image definition of each optical film according to the example and the comparative example was measured in the same manner as described above using optical combs of 0.5 mm width, 1.0 mm width, and 2.0 mm width.

<Glare evaluation (1)>
In each optical film obtained in Examples and Comparative Examples, the surface of the optical film where the optical layer is not formed and the glass surface where the matrix of 350 ppi black matrix (glass thickness 0.7 mm) is not formed are adhered. It stuck together with the agent. For the sample thus obtained, a white surface light source (LIGHTBOX manufactured by HAKUBA, average luminance of 1000 cd / m ² ) was installed on the black matrix side, thereby causing pseudo glare. This was photographed from the optical film side with a CCD camera (KP-M1, C mount adapter, close-up ring; PK-11A Nikon, camera lens; 50 mm, F1.4s NIKOR). The distance between the CCD camera and the optical film was 250 mm, and the focus of the CCD camera was adjusted to match the optical film. Images taken with a CCD camera were taken into a personal computer and analyzed by image processing software (ImagePro Plusver. 6.2; manufactured by Media Cybernetics) as follows. First, an evaluation location of 200 × 160 pixels was selected from the captured image, and converted to a 16-bit gray scale at the evaluation location.
Next, the low-pass filter was selected from the enhancement tab of the filter command, and the filter was applied under the conditions of 3 × 3, number of times 3, and strength 10. As a result, components derived from the black matrix pattern were removed.
Next, flattening was selected, and shading correction was performed under the condition of background: dark, object width 10.
Next, contrast enhancement was performed with a contrast enhancement command with a contrast of 96 and a brightness of 48. The obtained image was converted to an 8-bit gray scale, and the variation in the value for each pixel was calculated as a standard deviation value for 150 × 110 pixels in the image, thereby glaring was digitized. It can be said that the smaller the numerical value of the glare value, the less the glare. The results are shown in Table 1.

<Glare evaluation (2)>
In each optical film obtained in Examples and Comparative Examples, glare was evaluated as follows. Luminance 1500 cd / ^{m 2} of the light box (white surface light source), a black matrix glass 350Ppi, in an overlapped state in sequence from the bottom of the optical film, the upper and lower at a distance of about 30 cm, from the left and right different angles, 15 subjects are evaluated visually Went. It was determined whether or not the glare was worrisome and was evaluated according to the following criteria. The results are shown in Table 1.
◎: 13 or more people who answered good ○: 10-12 people who answered good △: 7-9 people who answered good ×: 6 or less people who answered good

<All haze, internal haze, surface haze measurement>
About each optical film obtained by the said Example and comparative example, total haze, internal haze, and surface haze were measured as follows. The results are shown in Table 2.
First, the total haze value of the optical film was measured according to JIS K7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory).
Thereafter, a triacetylcellulose base material (manufactured by Konica Minolta, KC4UAW) was attached to the surface of the optical layer via a transparent optical adhesive layer. Thereby, the uneven shape of the uneven surface in the optical layer was crushed, and the surface of the optical film became flat. In this state, the haze value was measured according to JIS K7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory) to determine the internal haze value. Then, the surface haze value was determined by subtracting the internal haze value from the total haze value.

<Measurement of three-dimensional average inclination angle θa _3D >
On the surface of each optical film obtained in Examples and Comparative Examples, the three-dimensional average inclination angle θa _3D was measured as follows. The results are shown in Table 2.
Using a white interference microscope (New View 7300, manufactured by Zygo) on a surface opposite to the surface on which the unevenness of each optical film is formed, a transparent adhesive is attached to a glass plate as a sample, The surface shape of the optical film was measured and analyzed under the following conditions. In addition, Microscope Application 8.3.2 Microscope Application was used as measurement / analysis software.
(Measurement condition)
Objective lens: 50 × Zoom: 1 × Measurement area: 545 μm × 545 μm
Resolution (interval per point): 0.44 μm
(Analysis conditions)
Removed: Plane
Filter: High Pass
FilterType: GaussSpline
Low wavelength: 250 μm
High wavelength: 3 μm
Remove spikes: on
Spike Height (xRMS): 2.5
Low wavelength corresponds to the cutoff value λc in the roughness parameter.
Next, “Ra” was displayed on the Slope Map Map screen with the above analysis software (MetroPro ver. 8.3.2-Microscope Application), and the numerical value was defined as θa _3D of the optical film.

<Measurement of Smp, Ra, Rz>
“Ra” and “SRz” are displayed on the Surface Map screen using the surface shape data obtained when calculating the above three-dimensional average inclination angle θa _3D and the same analysis conditions, and the respective numerical values are optical films. Ra and Rz.
Next, a “Save Data” button was displayed in the Surface Map screen, and the analyzed three-dimensional curved surface roughness data was saved. Then, the above saved data was read by Advanced Texture Application, and the following analysis conditions were applied.
(Analysis conditions)
High FFT Filter: off
Low FFT Filter: off
Remove: Plane
Next, the Peak / Valleys screen was displayed, and the number of peaks was counted from “Peaks Stats”. However, in order to exclude non-significant peaks, counts are made for peaks with an area that is 1 / 10,000 or more of the area of a circle whose diameter is Low wavelength (125 μm × 125 μm × π), and whose height is 1/10 or more of Rtm. It was. Note that Rtm can be read from the “Roughness / Waviness Map” screen, and represents the average of the maximum height for each section when the entire measurement area is divided into 3 × 3. And Smp was computed by the method mentioned above, ie, based on the following formula. The results are shown in Table 2.

As shown in Table 1 and Table 2, the optical films according to the examples are excellent in evaluation of watermark, glare (1), (2), and each of all haze, internal haze, and surface haze. The value was also low enough.
On the other hand, in the optical film according to Comparative Example 1, the difference between the value of C (0.25) and the value of C (0.125) was small, and the uneven shape on the surface of the optical layer was inferior to evaluation of gentle glare. The optical film according to Comparative Example 2 has a large C (0.125) value, and the difference between the C (0.25) value and the C (0.125) value is small. It was inferior to evaluation.

Since the display device with a touch panel of the present invention has the above-described configuration, generation of watermarks and glare can be sufficiently suppressed, and a high-quality display image can be obtained. Therefore, the display device with a touch panel of the present invention includes a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), electronic paper, and a tablet PC. It can apply suitably to.

DESCRIPTION OF SYMBOLS 10 Display apparatus with a touch panel 11 Optical film 12 Light transmissive base material 13 Optical layer 14 Concave and convex shape 15 Touch panel 100 Transmitted image definition measuring device 101 Light source 102 Slit 103, 104 Lens 105 Optical comb 106 Light receiver

Claims (5)

A display device with a touch panel having a configuration in which an optical film in which an optical layer having a concavo-convex shape is laminated on a light-transmitting substrate and a touch panel are arranged to face each other,
The optical film and the touch panel are arranged to face each other so that the optical layer and the touch panel face each other with a gap between them.
The total haze value of the optical film is 0% or more and 5% or less, and the internal haze value of the optical film is 0% or more and 5% or less,
The transmitted image clarity of the optical film measured using an optical comb having a width of 0.125 mm is defined as C (0.125), and the transmitted image clarity of the optical film measured using an optical comb having a width of 0.25 mm. When the degree is C (0.25), the following formula (1) and formula (2) are satisfied,
The optical layer contains a binder resin and fine particles,
The fine particles are inorganic oxide fine particles,
The uneven shape on the surface of the optical layer is formed by the inorganic oxide fine particles,
The three-dimensional average inclination angle θa _{3D of} the unevenness constituting the surface of the optical film is 0.12 ° or more and 0.5 ° or less, the average peak interval Smp is 0.05 mm or more and 0.3 mm or less , and the arithmetic average roughness Ra is 0.01 μm or more and 0.11 μm or less, 10-point average roughness Rz is 0.10 μm or more and 0.30 μm or less,
The θa _3D , Smp, Ra, and Rz are calculated from a three-dimensional roughness curved surface obtained by measurement with a contact-type surface roughness meter or a non-contact-type surface roughness meter, and the Smp is significant In order to exclude non-mountain mountains, a mountain having an area of 1/10000 or more of a circle having a diameter of low wave length and a height of 1/10 or more of Rtm is calculated as a count target. A display device with a touch panel.
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2) Inorganic oxide having an average primary particle size of the touch panel with the display device according to claim 1, wherein at 1nm or more 100nm or less fine particles. Inorganic oxide fine particles surface with the touch panel display device according to claim 1 or 2 wherein the inorganic oxide fine particles having been hydrophobic-treated. Total haze of the optical film is less than 1% 0% internal haze value is substantially touch with the display device according to claim 1, wherein 0% of the optical film. An optical film in which an optical layer having a concavo-convex shape on the surface is laminated on a light-transmitting substrate,
It is used in a display device with a touch panel that is placed opposite to the touch panel.
The total haze value is 0% or more and 5% or less, the internal haze value is 0% or more and 5% or less,
The transmitted image definition measured using an optical comb having a width of 0.125 mm is C (0.125), and the transmitted image definition measured using an optical comb having a width of 0.25 mm is C (0.25). When satisfying the following formula (1) and formula (2),
The optical layer contains a binder resin and fine particles,
The fine particles are inorganic oxide fine particles,
The uneven shape on the surface of the optical layer is formed by the inorganic oxide fine particles,
The three-dimensional average inclination angle θa _{3D of} the unevenness constituting the surface of the optical film is 0.12 ° or more and 0.5 ° or less, the average peak interval Smp is 0.05 mm or more and 0.3 mm or less , and the arithmetic average roughness Ra is 0.01 μm or more and 0.11 μm or less, 10-point average roughness Rz is 0.10 μm or more and 0.30 μm or less,
The θa _3D , Smp, Ra, and Rz are calculated from a three-dimensional roughness curved surface obtained by measurement with a contact-type surface roughness meter or a non-contact-type surface roughness meter, and the Smp is significant In order to exclude non-mountain mountains, a mountain having an area of 1/10000 or more of a circle having a diameter of low wave length and a height of 1/10 or more of Rtm is calculated as a count target. An optical film.
C (0.25) -C (0.125) ≧ 2% (1)
C (0.125) ≦ 64% (2)

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