JP2018128541A - Antireflection optical film and low refractive index layer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low refractive index layer composition and an antireflection optical film capable of forming a low refractive index layer having extremely good antifouling property and scratch resistance, as well as excellent in antireflection performance.SOLUTION: An antireflection optical film at least includes a hard coat layer and a low refractive index layer laminated on one surface of the hard coat layer. When root-mean-square roughness Rq, ten-point average roughness Rz and maximum height roughness Ry are measured respectively with a cutoff wavelength of 2.5 mm, on a surface opposite to the hard coat layer side of the low refractive index layer, the Rq is 0.010-0.050 μm, the Rz is 0.050-0.250 μm and the Ry is 0.050-0.350 μm.SELECTED DRAWING: None

Description

The present invention relates to an antireflection optical film and a composition for a low refractive index layer.

In a product having a display screen such as a mobile phone, a tablet terminal, a video camera, a digital camera, and an automobile device, the display screen portion is configured by a combination of a liquid crystal panel, an organic EL panel, and the like.
The display screen part of such products is required to have anti-reflection properties in order to make the displayed screen easier to see, and since it is exposed to the outside, it has high anti-stain properties and is easily scratched even when touched directly. High scratch resistance without sticking is required.
In addition, display screens of image display devices in recent years have been increasingly refined, and it has been required to obtain a better design feeling (such as glossy black display).

On the other hand, for example, Patent Document 1 discloses an antireflection molded product including an antireflection layer having an average surface roughness Ra of 2.0 to 150 nm.
Such a conventional antireflection layer is manufactured using a mold having a specific shape, so that the value of the average surface roughness Ra is controlled within a predetermined range.
However, even with an antireflection layer having such an average surface roughness, it is difficult to say that antifouling properties and scratch resistance are sufficient, and antireflection optics having better antifouling properties and scratch resistance. A film was sought.

JP 2002-205317 A

In view of the above situation, the present invention has a composition for a low refractive index layer capable of forming a low refractive index layer having extremely excellent antifouling properties and scratch resistance, and also having excellent antireflection performance, and extremely excellent Another object of the present invention is to provide an antireflection optical film having antifouling properties and scratch resistance and excellent antireflection performance.

The present invention is an antireflection optical film having at least a hard coat layer and a low refractive index layer laminated on one surface of the hard coat layer, the hard coat layer side of the low refractive index layer, On the opposite surface, when the cut-off wavelength is 2.5 mm and the root mean square roughness Rq, the ten-point average roughness Rz, and the maximum height roughness Ry are measured, the Rq is 0.010 μm or more and 0.0. An antireflection optical film having a thickness of 050 μm or less, Rz of 0.050 μm or more and 0.250 μm or less, and Ry of 0.050 μm or more and 0.350 μm or less.

The antireflection optical film of the present invention has a root mean square roughness Rq and a ten-point average roughness on the surface opposite to the hard coat layer side of the low refractive index layer, with cutoff wavelengths of 2.5 mm and 0.25 mm. When the Rz and the maximum height roughness Ry were measured, the ratio of the value at the cutoff wavelength of 2.5 mm to the value at the cutoff wavelength of 0.25 mm (the value at the cutoff wavelength of 2.5 mm). / Value at a cutoff wavelength of 0.25 mm) is preferably 1.00 or more and 2.00 or less.
The hard coat layer preferably contains 10 to 300 parts by mass of inorganic fine particles with respect to 100 parts by mass of the binder component.
Moreover, it is preferable that the transparent optical adhesive film is laminated | stacked on the opposite side to the low refractive index layer side of the said hard-coat layer.
Moreover, it is preferable that the adhesion layer is laminated | stacked through the anchor layer and this anchor layer on the opposite side to the low refractive index layer side of the said hard-coat layer.
In the antireflection optical film of the present invention, the total film thickness of the low refractive index layer and the hard coat layer is preferably 3 μm or more and 15 μm or less. The low refractive index layer, the hard coat layer, and the transparent optical adhesive It is preferable that the total film thickness of the film and the total film thickness of the low refractive index layer, the hard coat layer, the anchor layer, and the adhesive layer are 8 μm or more and 30 μm or less.
In addition, a release film is attached to the side opposite to the hard coat layer side of the low refractive index layer, and the peel force between the low refractive index layer and the release film is 10 mN / 25 mm or more and 500 mN / 25 mm. The following is preferable.

The present invention is also a composition for a low refractive index layer containing hollow particles and a binder resin, and contains 20% by mass or more of an alkylene oxide-modified (meth) acrylate compound in 100% by mass of the binder resin solid content. This is a composition for a low refractive index layer.
In the composition for a low refractive index layer of the present invention, the alkylene oxide-modified (meth) acrylate compound is preferably an ethylene oxide-modified (meth) acrylate compound and / or a propylene oxide-modified (meth) acrylate compound. .
The number of functional groups of the alkylene oxide modified (meth) acrylate compound is preferably 6 or less.
The hollow particles are preferably contained in an amount of 40 to 200 parts by mass with respect to 100 parts by mass of the binder resin, and the hollow particles are preferably hollow silica fine particles.
Hereinafter, the present invention will be described in detail.

As a result of intensive studies, the present antireflection optical film provided with a conventional antireflection layer has a sebum and a sebum when the unevenness on the outermost surface (for example, the low refractive index layer) on the display screen side is touched with a finger. It was found that the antifouling performance was insufficient due to the dust remaining, and the scratch resistance was inferior due to being caught by the irregularities.
That is, the antireflection optical film of the present invention has extremely excellent antifouling properties and scratch resistance because the uneven shape controlled with extremely high precision is formed on the surface of the low refractive index layer. It also has prevention performance.
In addition, the composition for a low refractive index layer of the present invention can suitably form a low refractive index layer having such an uneven shape controlled with extremely high accuracy.

First, the composition for a low refractive index layer of the present invention will be described.
The composition for low refractive index layers of the present invention contains hollow particles and a binder resin.
The said hollow particle means the particle | grains which have an outer shell layer and the inside of the particle | grains enclosed by the said outer shell layer is porous or a cavity, and contain air inside a particle | grain.
The composition for a low refractive index layer of the present invention can reduce the refractive index of the low refractive index layer to be formed by including the hollow fine particles.
The refractive index of the hollow particles is preferably 1.44 or less, particularly preferably 1.40 or less, from the viewpoint of imparting low refractive index properties.

The outer shell layer of the hollow particles may be an inorganic substance or an organic substance, and examples thereof include those made of metal, metal oxide, resin, silica and the like.
The hollow particles are preferably hollow silica particles whose outer shell layer is silica. When the outer shell layer is silica, the silica may be in a crystalline state, a sol state, or a gel state.
The shape of the hollow particles may be any of a spherical shape, a chain shape, a needle shape, a plate shape, a piece shape, a rod shape, a fiber shape, etc. such as a spherical shape, a spheroid shape, and a polyhedral shape that can approximate a sphere. Among these, a true spherical shape and a substantially spherical shape are preferable, and a spheroidal shape or a true spherical shape is particularly preferable.

The particle diameter of the hollow particles is not particularly limited, but the average particle diameter defined as 50% particle diameter (d50 median diameter) when the particle diameter distribution measured by the dynamic light scattering method is represented by a volume cumulative distribution ( Hereinafter, it may be simply referred to as “average particle diameter (d50)”) is preferably 10 nm to 120 nm, more preferably 40 nm to 100 nm, and still more preferably 50 nm to 80 nm.
When the average particle diameter (d50) of the hollow particles is not more than the above upper limit value, the obtained low refractive index layer is excellent in transparency, and when the hollow particle is not less than the above lower limit value, the hollow particles are reduced to the low refractive index layer. It becomes easy to disperse uniformly in it, and it becomes easy to impart low refractive index properties to the low refractive index layer. Moreover, when the average particle diameter (d50) of the hollow particles is within the above range, the uneven shape of the uneven surface of the low refractive index layer can easily have a specific maximum height difference.
The average particle size (d50) is the primary particle size average particle size (d50) if the hollow particles are not agglomerated, and the secondary particle size (d50) is the aggregated particle. The average particle size (d50) is used.
Moreover, the said average particle diameter (d50) can be measured using the Nikkiso Co., Ltd. Microtrac particle size analyzer or Nanotrac particle size analyzer.

The hollow particles are preferably used in combination of two or more kinds having different average particle diameters (d50) from the viewpoint of improving the scratch resistance of the low refractive index layer, and in particular, the average particle diameter (d50). ) Is preferably used in combination with hollow fine particles A having a diameter of 40 to 60 nm and hollow fine particles B having an average particle diameter (d50) larger than the average particle diameter (d50) of the hollow fine particles A and 50 to 80 nm. When two or more kinds of hollow particles having different average particle diameters (d50) are used, it is preferable that each hollow particle has a uniform particle diameter. Specifically, the standard deviation of the particle diameters is the average particle diameter ( It is preferably 20% or less of d50), and more preferably 10% or less. By using a combination of two or more types of hollow particles having a small variation in particle size and different average particle size (d50), the scratch resistance can be further improved.
Further, the ratio (X / Y) of the content (X parts by mass) of the hollow fine particles A in the total solid content of the composition for the low refractive index layer and the content (Y parts by mass) of the hollow fine particles B. Is preferably 0.5-2.

Moreover, the average particle diameter of the hollow particles capable of measuring the low refractive index layer after curing from a TEM photograph or SEM photograph is not particularly limited, but is preferably 10 nm to 120 nm, and preferably 40 nm to 100 nm. Is more preferable, and it is still more preferable that they are 50 nm-80 nm.
The method for measuring the average particle size is, for example, observing particles using a TEM photograph or SEM photograph taken at a magnification of 2 to 2 million times, and using the average value of the particle sizes of 100 observed particles as the average particle size. can do. In addition, when the shape of the hollow particles is a shape including the concept of aspect ratio, such as a spheroid shape having a minor axis and a major axis or a rod shape, the particle diameter of the hollow particles is an average value of the minor axis and the major axis. .
The average particle diameter measured from the TEM photograph or SEM photograph is the average particle diameter of the primary particle diameter if the hollow particles are not agglomerated particles, and the secondary particles if the hollow particles are agglomerated particles. The average particle diameter is taken as the diameter.

Specific examples of the hollow particles include composite oxide sols or hollow silica fine particles disclosed in JP-A-7-133105 and JP-A-2001-233611. Of these, hollow silica particles prepared by using the technique disclosed in JP-A-2001-233611 are preferable. Moreover, as the hollow particles, since the hardness is high, the layer strength of the low refractive index layer is improved, and the refractive index can be adjusted within a range of about 1.20 to 1.44. Fine particles are preferred.

It is preferable that content of the said hollow particle is 40 to 200 mass parts with respect to 100 mass parts of binder resin mentioned later. When the content of the hollow particles is equal to or higher than the lower limit value, it is easy to impart low refractive index properties, and when the content is equal to or lower than the upper limit value, the film strength of the low refractive index layer formed can be improved. The hollow particles are more preferably 100 parts by mass or more and 150 parts by mass or less.

The composition for low refractive index layers of the present invention contains 20% by mass or more of an alkylene oxide-modified (meth) acrylate compound in 100% by mass of the binder resin solid content. When it is less than 20% by mass, when a release film is attached to the surface of the formed low refractive index layer, the peeling force between the release film and the low refractive index layer becomes insufficient.
The content of the alkylene oxide-modified (meth) acrylate compound is preferably 50 parts by mass or more with respect to 100 parts by mass of the binder resin in 100% by mass of the binder resin solid content.
In addition, in this specification, (meth) acrylate represents an acrylate or a methacrylate.

The alkylene oxide-modified (meth) acrylate-based compound is preferably an ethylene oxide (EO) -modified (meth) acrylate-based compound and / or a propylene oxide (PO) -modified (meth) acrylate-based compound. In view of the peel force between the low refractive index layer and the low refractive index layer, a PO-modified (meth) acrylate compound is more preferable.

The number of functional groups of the alkylene oxide modified (meth) acrylate compound is preferably 6 or less.
If the number of functional groups exceeds 6, the peeling force between the release film and the low refractive index layer described above may be insufficient.

Examples of the binder resin other than the alkylene oxide-modified (meth) acrylate compound include pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol (meth) tetraacrylate, and dipentaerythritol penta (meth). And a polymer or copolymer of at least one monomer selected from the group consisting of acrylate, trimethylolpropane tri (meth) acrylate, and dipentaerythritol tetra (meth) acrylate.

In the composition for a low refractive index layer of the present invention, a solvent is usually used in order to improve coatability. The solvent may be appropriately selected from those that do not react with each component in the low refractive index layer composition and can uniformly dissolve or disperse each component. Examples of such a solvent include various ketone solvents such as methyl isobutyl ketone and methyl ethyl ketone.
It is preferable that content of the said solvent is 60-98 mass% with respect to the whole quantity of the composition for low refractive index layers, and it is more preferable that it is 70-97 mass%.
Moreover, the said composition for low refractive index layers may contain the conventionally well-known photoinitiator.

The composition for a low refractive index layer of the present invention having such a composition can suitably form a low refractive index layer having a low refractive index and extremely excellent flatness. The antifouling performance and scratch resistance are extremely excellent, and the optical film provided with the low refractive index layer can be excellent in antireflection performance.

Moreover, since the optical film provided with the low refractive index layer formed using the composition for low refractive index layer of the present invention can be made more excellent in antireflection performance, the high refractive index layer is described above. It is preferably formed so as to be adjacent to the low refractive index layer.
Examples of the high refractive index layer include a layer having a refractive index higher than that of the low refractive index layer.

Further, the refractive index of the high refractive index layer may be higher than the refractive index of the low refractive index layer. Specifically, for example, it is preferably in the range of 1.5 to 1.7. .
When the high refractive index layer is provided between a hard coat layer and a low refractive index layer, which will be described later, the refractive index of the high refractive index layer is higher than the refractive index of the low refractive index layer, and The refractive index of the hard coat layer is preferably higher.

The high refractive index layer is not particularly limited as long as it satisfies the above refractive index range and has transparency. For example, a layer obtained by curing an ionizing radiation curable resin, an ionizing radiation curable resin, and a high refractive index. And those obtained by curing a composition for a high refractive index layer containing refractive index fine particles. Especially, since adjustment of a refractive index is easy, it is preferable to harden the composition for high refractive index layers containing ionizing radiation hardening resin and high refractive index microparticles | fine-particles.

The ionizing radiation curable resin used for the high refractive index layer is not particularly limited as long as it satisfies the above refractive index range and can obtain a transparent high refractive index layer. It is appropriately selected from the viewpoint of film strength and the like.
Examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and among them, an ultraviolet curable resin is preferable.

Specific examples of the ionizing radiation curable resin include ionization used in high refractive index layers described in JP2013-142817A, JP2012-150226A, JP2011-170208A, and the like. Examples include radiation curable resins.

The high refractive index fine particles are not particularly limited as long as the refractive index is higher than that of the ionizing radiation curable resin, and a high refractive index layer satisfying the refractive index range can be obtained. The refractive index of the fine particles is preferably about 1.5 to 2.8.
Examples of such high refractive index fine particles include metal oxide fine particles. Specifically, zirconium oxide, antimony oxide, antimony tin oxide, indium tin oxide, phosphorus tin compound, gallium zinc oxide, β -Al ₂ O ₅ , γ-Al ₂ O ₅ , barium titanate, titanium oxide, cerium oxide, tin oxide, aluminum zinc oxide, gallium zinc oxide, zinc antimonate and the like.

The high refractive index fine particles may be surface-treated. By applying a surface treatment to the high refractive index fine particles, the affinity with ionizing radiation curable resin and solvent is improved, the dispersion of the high refractive index fine particles becomes uniform, and the aggregation of the high refractive index fine particles is less likely to occur. It is possible to suppress a decrease in transparency of the high refractive index layer, a coating property of the composition for high refractive index layer, and a decrease in the coating strength of the composition for high refractive index layer.
Examples of the surface-treated high refractive index fine particles include those described in JP2013-142817A.
The high refractive index fine particles may be reactive fine particles having a photocurable group on the surface thereof.

The average particle diameter of the high refractive index fine particles is not limited as long as a high refractive index layer having a uniform thickness can be formed. For example, it is preferably in the range of 5 nm to 200 nm, more preferably 5 nm. It is in the range of not less than 100 nm and more preferably in the range of not less than 10 nm and not more than 80 nm.
If the average particle diameter of the high refractive index fine particles is within the above range, the transparency of the high refractive index layer is not impaired, and a good dispersion state of the high refractive index fine particles can be obtained. If the average particle size of the high refractive index fine particles is within the above range, the average particle size may be either the primary particle size or the secondary particle size, and the high refractive index fine particles are connected in a chain. May be.
Here, the average particle diameter of the high refractive index fine particles refers to an average value of 20 particles observed by a transmission electron microscope (TEM) photograph of a cross section of the high refractive index layer.
The shape of such a high refractive index fine particle is not particularly limited, and examples thereof include a spherical shape, a chain shape, and a needle shape.

The contents of the ionizing radiation curable resin and the high refractive index fine particles in the high refractive index layer are not particularly limited, and are appropriately set so that the refractive index of the high refractive index layer as a whole satisfies the refractive index range.

When an ultraviolet curable resin is used as the ionizing radiation curable resin, the high refractive index layer may contain a photopolymerization initiator. The high refractive index layer may contain various additives according to desired physical properties. In addition, the same thing as the said photoinitiator and the said low-refractive-index layer is mentioned, As said additive, a dispersion | distribution adjuvant, a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, for example , Infrared absorbers, adhesion improvers, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, antifoaming agents, fillers and the like.

The thickness of the high refractive index layer varies depending on the refractive index, but is preferably in the range of 50 nm to 200 nm, for example.

As a method for forming the high refractive index layer, for example, a composition for a high refractive index layer formed by mixing the above-mentioned ionizing radiation curable resin and high refractive index fine particles, a solvent, a photopolymerization initiator and various additives is applied. And a method of curing the formed coating film by irradiation with ionizing radiation.

The present invention is an antireflection optical film having at least a hard coat layer and a low refractive index layer laminated on one surface of the hard coat layer, the hard coat layer side of the low refractive index layer, When the root mean square roughness Rq, the ten-point average roughness Rz, and the maximum height roughness Ry are measured on the opposite surface (hereinafter also referred to as a surface) with a cutoff wavelength of 2.5 mm, the Rq is 0.010 μm or more and 0.050 μm or less, the Rz is 0.050 μm or more and 0.250 μm or less, and the Ry is 0.050 μm or more and 0.350 μm or less. But there is.

When the low refractive index layer satisfies the requirements of Rq, Rz and Ry, the antireflective optical film of the present invention has a very high surface with a low refractive index layer.
Here, the conventional antireflection optical film provided with the low refractive index layer exhibited antifouling performance by adding a leveling agent to the low refractive index layer and the hard coat layer described later. Since the prevention optical film can exhibit extremely excellent antifouling performance due to the flatness of the surface of the low refractive index layer, it is not necessary to include a leveling agent in the low refractive index layer or the like.

Conventionally, even if the surface of the low refractive index layer appears to be flat visually, there are actually various fine irregularities. In other words, it is flat because it is visually observed, but as described later, the low refractive index layer in a state of being attached to a release film is actually transferred to a transfer medium by a transfer method to form a low refractive index layer. As a result, the antifouling property and scratch resistance sometimes differed depending on the transfer surface of the completed low refractive index layer.
The inventors of the present application have found that this is caused by fine irregularities present on the surface of the low refractive index layer that cannot be visually recognized. And about the uneven | corrugated shape of the surface of the said low-refractive-index layer, especially the parameter regarding the height direction of the surface of a low-refractive-index layer, the root mean square roughness Rq, the ten-point average roughness Rz, and the maximum height roughness Ry Are controlled so as to be within a predetermined range at a cut-off wavelength of 2.5 mm, respectively, thereby exhibiting extremely excellent antifouling performance and scratch resistance due to the flatness of the surface of the low refractive index layer.
In addition, the antireflection optical film of the present invention exhibits excellent antifouling properties without using an additive such as a fluorine material, and the surface of the low refractive index layer is extremely smooth. Can be expressed.

The Rq represents the root mean square roughness. Specifically, as shown in FIG. 1, in the roughness curve f (x) of the cross section of the low refractive index layer, Rq ′ at the sampling length l is shown. The Rq ′ obtained by the equation shown in FIG. 1 and obtained for a plurality of sampling lengths is arithmetically averaged. The Rq can also be determined according to ISO 4287-1984 or ISO 4287-1997, and specifically measured using a surface roughness measuring instrument (SE3400, SE3500, SE4000, manufactured by Kosaka Laboratory). it can.
Rq is a representative value representing the average height of the convex portions on the surface of the low refractive index layer.
In the antireflection optical film of the present invention, the root mean square roughness Rq of the surface of the low refractive index layer is 0.010 μm or more and 0.050 μm or less at a cutoff wavelength of 2.5 mm. Although smoothness is good when it is less than 0.010 μm, and it is preferable for scratch resistance and antifouling properties, it tends to be difficult to peel off from the release film and the folded film actually produced, and when it exceeds 0.050 μm, The smoothness becomes insufficient and the scratch resistance and antifouling properties tend to decrease. The upper limit with said preferable Rq is 0.040 micrometer, and a more preferable upper limit is 0.030 micrometer.

Rz is the ten-point average roughness of JIS B0601-1994, and the lowest to fifth concave portions and the maximum to fifth convex portions that cannot be seen with an average value such as Rq. Since this is the ten-point average roughness value obtained by adding together, it is the average value in the maximal direction existing on the plane, and this makes it possible to express an unexpected roughness that is not visually recognized.
In the antireflection film of the present invention, the ten-point average roughness Rz of JIS B0601-1994 on the surface of the low refractive index layer is 0.050 μm or more and 0.250 μm or less at a cutoff wavelength of 2.5 mm. If it is less than 0.050 μm, the smoothness is good and preferable for antifouling properties, but it tends to be difficult to peel off from the release film or the film actually produced, and if it exceeds 0.250 μm, the smoothness is insufficient. As a result, the scratch resistance and antifouling properties tend to decrease, and it causes optical defects of the antireflection film. The upper limit with said preferable Rz is 0.200 micrometer, and a more preferable upper limit is 0.150 micrometer.

The parameters representing the flatness of the surface of the low refractive index layer on average may be the above Rq and Rz, but in the product using the antireflection optical film of the present invention, it protrudes to the surface of the low refractive index layer. Such irregularities may cause optical defects in the product and thus reduce the scratching properties. Therefore, it is necessary to limit such protruding irregularities. For this reason, in this invention, the range of Ry is controlled as a limit value of the unevenness | corrugation in the surface of the said low refractive index layer.
The Ry is the maximum height roughness of JIS B0601-1994, and is a value obtained by measuring the distance between the peak line of the convex part and the valley line of the concave part in the direction of the vertical magnification of the roughness curve.
In the antireflection film of the present invention, the maximum height roughness Ry of JIS B0601-1994 on the surface of the low refractive index layer is 0.050 μm or more and 0.350 μm or less at a cutoff wavelength of 2.5 mm. When the thickness is less than 0.050 μm, the smoothness is good and preferable for antifouling properties. However, when it is actually manufactured, peeling from the release film tends to be difficult, and when it exceeds 0.350 μm, the reflection of the present invention. This is an optical defect of the prevention optical film and also causes a decrease in scratch resistance. A preferable upper limit of Ry is 0.300 μm, and a more preferable upper limit is 0.250 μm.

In addition, as in the antireflection optical film of the present invention, it is extremely possible to achieve excellent antifouling properties and scratching properties only by controlling the uneven shape on the surface of the low refractive index layer without adding any additive. It should be flat without resistance. That is, in the antireflection optical film of the present invention, it is preferable that the surface of the low refractive index layer has no difference in unevenness between the low frequency component and the high frequency component.
Here, in the measurement of the concavo-convex shape of the surface of the low refractive index layer, when the cut-off wavelength is set to 0.25 mm, a narrow range is measured, so it is considered as a high frequency component of the surface flatness. On the other hand, when the cutoff wavelength is 2.5 mm, a wider range is measured as compared to the case of 0.25 mm, and it is considered that the low frequency component of the surface flatness is observed.
And the said low frequency component is a thing like the basic big waviness which comprises the surface of a low refractive index layer, and the small unevenness | corrugation which exists slightly on it becomes a high frequency component.

The antireflection optical film of the present invention has a root mean square roughness Rq according to ISO 4287-1984 or 1997, with a cutoff wavelength of 2.5 mm and 0.25 mm on the surface of the low refractive index layer, When the ten-point average roughness Rz and the maximum height roughness Ry of JIS B0601-1994 were measured, the values of Rq, Rz and Ry at a cutoff wavelength of 2.5 mm and values at a cutoff wavelength of 0.25 mm The ratio (value at a cutoff wavelength of 2.5 mm / value at a cutoff wavelength of 0.25 mm) (hereinafter also referred to as a cutoff ratio) is preferably 1.00 or more and 2.00 or less. When the cutoff ratios of Rq, Rz and Ry are all 1.00 or more and 2.00 or less, the antireflection optical film of the present invention has extremely excellent antifouling properties and scratch resistance. it can. The cutoff ratio of Rq, Rz, and Ry is more preferably 1.70 or less, and further preferably 1.50 or less.

The low refractive index layer satisfying the relationship of Rq, Rz and Ry can be suitably formed by using the above-described composition for low refractive index layer of the present invention. A specific method for forming the low refractive index layer will be described in detail later.

The hard coat layer preferably contains 10 to 300 parts by mass of inorganic fine particles with respect to 100 parts by mass of the binder component. If it is less than 10 parts by mass, the hard coat performance of the antireflection optical film of the present invention will be insufficient, and if it exceeds 300 parts by mass, the hard coat layer will become rigid and there will be no elongation and cracks will easily occur. There is. The minimum with more preferable content of the said inorganic fine particle is 20 mass parts, and a more preferable upper limit is 150 mass parts.
The inorganic particles are preferably reactive silica fine particles for increasing the hardness, and high refractive index particles for increasing the refractive index. As the high refractive index particles, fine particles made of zirconia, antimony pentoxide, alumina, ATO, ITO, TiO ₂ or the like are used.

In the antireflection optical film of the present invention, a transparent optical adhesive film is preferably laminated on the side surface of the hard coat layer opposite to the low refractive index layer side. By laminating the transparent optical adhesive film, it is possible to produce an antireflection optical film excellent in transferability and adhesion to a transfer product.
Examples of the transparent optical adhesive film include a configuration in which an optical pressure-sensitive adhesive layer is formed on a substrate. Specifically, the optical pressure-sensitive adhesive layer includes, for example, light resistance in terms of optical characteristics. In view of weather resistance, heat resistance and transparency, acrylic resins are used. Examples of the monomer constituting the acrylic resin include alkyl acrylates such as ethyl acrylate, butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and benzyl acrylate, Methacrylic acid alkyl esters such as butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, ethyl methacrylate, and vinyl acetate, vinyl propionate, vinyl ether, styrene, acrylonitrile, methacrylonitrile, etc. A group-containing compound may be copolymerized. Furthermore, in order to improve the adhesion durability performance and suppress the generation of outgas, the optical adhesive main component is an acrylic resin, the weight average molecular weight is 500,000 or more, and the polydispersity is 5 or less. In addition, when an adhesive layer is used for bonding various optical films, if the refractive index difference between the optical film and the adhesive layer is large, light interface reflection occurs at the bonding interface between the optical film and the adhesive layer. A refractive index adjusting agent is added to adjust the refractive index. If necessary, crosslinking agents, catalysts, UV absorbers, antioxidants, color pigments, glass beads, fillers, flame retardants, antibacterial agents, light stabilizers, colorants, fluidity improvers, lubricants, antiblocking agents An agent, an antistatic agent, a crosslinking aid and the like can be blended. These may be used alone or in combination of two or more. Any crosslinking agent can be used without particular limitation as long as it does not interfere with the required properties. For example, polyisocyanate, chelate, epoxy resin, melamine resin, amide resin and the like can be mentioned.

The thickness of the optical pressure-sensitive adhesive layer can be arbitrarily set, but is preferably 3 μm or more and 30 μm or less.
The substrate for providing the optical pressure-sensitive adhesive layer is not particularly limited. For example, polyester resin sheet, olefin resin sheet, polyphenylene sulfide resin sheet, triacetate resin sheet, acrylic resin sheet, polyimide resin sheet, polycarbonate There are resin sheets and norbornene resin sheets. Although there is no restriction | limiting in particular in the thickness of a sheet | seat, less than 500 micrometers is preferable, and also 10 micrometers or more and 50 micrometers or less are more preferable. In order to protect the optical pressure-sensitive adhesive layer, it can be used by being bonded to a release liner or the like, if necessary. The release liner is not particularly limited, and examples thereof include a PET film, an olefin resin film, a PPS resin film, a TAC film, an acrylic resin film, and those obtained by performing a release treatment. Although there is no restriction | limiting in particular in the thickness of a peeling liner, Less than 500 micrometers is preferable, Furthermore, 10 micrometers or more and 50 micrometers or less are more preferable.

In the antireflection optical film of the present invention, it is preferable that an adhesive layer is laminated on the side opposite to the low refractive index layer side of the hard coat layer via the anchor layer.

The anchor layer is a layer provided as desired in order to improve the adhesion between the hard coat layer and the adhesive layer.
The anchor layer is a two-component curable urethane resin, thermosetting urethane resin, melamine resin, cellulose ester resin, chlorine-containing rubber resin, chlorine-containing vinyl resin, acrylic resin, epoxy resin, vinyl copolymer Using a coalesced resin, for example, coating on the hard coat layer formed as described above by a gravure coating method, a roll coating method, a comma coating method, etc., a gravure printing method, a screen printing method, etc. Can be formed. The thickness of the anchor layer is usually about 0.1 μm to 5 μm, preferably about 1 μm to 5 μm.

The said adhesive layer is a layer formed in order to transfer to a resin molding with sufficient adhesiveness. For this adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for the material of the resin molding is appropriately used. For example, when the material of the resin molding is an acrylic resin, it is preferable to use an acrylic resin. If the resin molding is made of polyphenylene oxide / polystyrene resin, polycarbonate resin, or styrene resin, use an acrylic resin, polystyrene resin, polyamide resin, or the like that has an affinity for these resins. Is preferred. Furthermore, when the material of the resin molding is a polypropylene resin, it is preferable to use a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, or a coumarone indene resin.
Examples of the method for forming the adhesive layer include a coating method such as a gravure coating method and a roll coating method, a printing method such as a gravure printing method and a screen printing method.
The thickness of the adhesive layer is usually preferably about 0.1 μm to 5 μm.

The total film thickness of the low refractive index layer and the hard coat layer is preferably 3 μm or more and 15 μm or less. If it is less than 3 μm, the hard coat performance may be insufficient, and if it exceeds 15 μm, it may become rigid and easily crack.

Moreover, it is preferable that the total film thickness of the said low refractive index layer, a hard-coat layer, and a transparent optical adhesive film is 8 micrometers or more and 30 micrometers or less. When the thickness is less than 8 μm, the adhesive strength is weak and transfer described later may not be possible. When the thickness exceeds 30 μm, hardness may not be obtained due to the influence of the transparent optical adhesive film.
The total film thickness of the low refractive index layer, hard coat layer, anchor layer, and adhesive layer is preferably 8 μm or more and 30 μm or less. When the thickness is less than 8 μm, the adhesive strength is weak and transfer described later may not be possible. When the thickness exceeds 30 μm, hardness may not be obtained due to the influence of the transparent optical adhesive film.

In addition, a release film is stuck on the surface of the low refractive index layer, and the peel force between the low refractive index layer and the release film is preferably 10 mN / 25 mm or more and 500 mN / 25 mm or less. .
As the release film, an untreated polyethylene terephthalate (PET) film is preferably exemplified.
As will be described later, the low refractive index layer is suitably transferred to a transfer medium by a transfer method in a state where the release film is adhered, and then the release film is peeled off, but the peeling force is 10 mN / If it is less than 25 mm, the release film may be peeled off during the transfer method, and if it exceeds 500 mN / 25 mm, the release film may not be peeled off by the transfer method.
A more preferable lower limit of the peeling force is 20 mN / 25 mm, and a more preferable upper limit is 300 mN / 25 mm.
In addition, the peeling force between the said low refractive index layer and the said peeling film can be measured based on JISZ0237.

The antireflection optical film of the present invention can be formed by a transfer method.
That is, a coating film is formed on the release film using the composition for low refractive index layer of the present invention, and semi-cured by, for example, ultraviolet irradiation. Next, a coating film is formed using the hard coat layer composition on the semi-cured coating film of the low refractive index layer composition. An antireflection optical film that can be suitably peeled off at the interface with the rate layer can be obtained.
In addition, by forming by the transfer method, the entire film can be reduced in weight, and even if the design of the display device is curved or foldable, cracks are not easily generated, and it is easy to follow Are better.
The release film may be a known resin film such as a polyethylene terephthalate film, or may be a plate such as glass. Further, the surface of the release film on which the low refractive index layer is provided may be subjected to surface treatment, but from the viewpoint of preventing an increase in the reflectance of the low refractive index layer due to the influence of the treatment agent on the surface. The surface of the release film on which the low refractive index layer is provided is preferably not surface-treated.
The release film had a cutoff wavelength of 2.5 mm, and when the root mean square roughness Rq, ten-point average roughness Rz, and maximum height roughness Ry were measured, the Rq was 0.010 μm. It is preferably 0.050 μm or less, more preferably 0.040 μm or less, still more preferably 0.035 μm or less, and Rz is preferably 0.070 μm or more and 0.350 μm or less, more preferably 0.250 μm or less, more preferably 0.200 μm or less, and Ry is preferably 0.100 μm or more and 0.450 μm or less, more preferably 0.350 μm or less, and further preferably 0.250 μm or less. It is.
In addition, Rq, Rz, and Ry on the surface of the release film are the same as those described in the low refractive index layer.

The ultraviolet irradiation dose at the time of semi-curing the coating film of the composition for a low refractive index layer is preferably 20 mJ / cm ² or more 75 mJ / cm ² or less. If it is less than 20 mJ / cm ² , the low refractive index layer may not be formed. If it exceeds 75 mJ / cm ² , peeling may occur at the interface between the hard coat layer and the low refractive index layer described later.
The amount of ultraviolet irradiation for curing the coating of the hard coat layer composition is preferably 20 mJ / cm ² or more 150 mJ / cm ² or less. If it is less than 20 mJ / cm ² , the hard coat layer may not be formed, and if it exceeds 150 mJ / cm ² , it may become rigid and easily crack.
In addition, when the ultraviolet irradiation amount at the time of semi-curing the coating film of the low refractive index layer composition is 20 mJ / cm ² , the ultraviolet irradiation amount at the time of curing the coating film of the hard coat layer composition is It is preferably 20 mJ / cm ² or more.
Moreover, when the ultraviolet irradiation amount at the time of semi-curing the coating film of the low refractive index layer composition is 50 mJ / cm ² , the ultraviolet irradiation amount at the time of curing the coating film of the hard coat layer composition is It is preferably 50 mJ / cm ² or more.
When the ultraviolet irradiation amount at the time of semi-curing the coating film of the low refractive index layer composition is 75 mJ / cm ² , the ultraviolet irradiation amount at the time of curing the coating film of the hard coat layer composition is 100 mJ / It is preferable that it is cm ² or more.
An antireflection optical film that can be suitably peeled off at the interface between the release film and the low refractive index layer can be produced by forming the low refractive index layer and the hard coat layer by irradiating ultraviolet rays under the conditions described above. .
A transparent optical adhesive film may be laminated on the side surface of the hard coat layer opposite to the low refractive index layer side.

As a specific method of transferring to the transfer medium using the above-described antireflection optical film of the present invention, for example, the antireflection optical film of the present invention is transparent on a polarizer (or a layer made of a PVA adhesive). An optical adhesive film is laminated, the antireflection optical film of the present invention is pressed with a roller, the transparent optical adhesive film is bonded to a polarizer (or a layer made of a PVA adhesive), and the release film is peeled off after drying. The method of letting it be mentioned.

The antireflection optical film of the present invention has a hardness of preferably B or more, more preferably 2H or more, in a pencil hardness test (load 4.9 N) according to JIS K5600-5-4 (1999).

Moreover, it is preferable that the antireflection optical film of the present invention does not cause scratches in a scratch resistance test in which friction load is 100 g / cm ² using 10th steel wool (manufactured by Bonstar Co., Ltd.) and rubs 10 times.

The antireflection optical film of the present invention preferably has a reflection Y value of 1.5% or less. When the reflection Y value exceeds 1.5%, the antireflection performance of the antireflection optical film of the present invention may be insufficient. A more preferable upper limit of the reflection Y value is 1.0%.

The antireflection optical film of the present invention is extremely excellent in antifouling properties and scratch resistance, and also has excellent antireflection performance, and is therefore suitable for a display screen of an image display device, the back surface of a camera lens, and the like. Can be used.
Although it does not specifically limit as an image display apparatus using the antireflection optical film of this invention, Especially, display apparatuses, such as a mobile terminal provided with touch sensors, such as a smart phone and a tablet terminal, and an apparatus for motor vehicles, are suitable.
Examples of the camera lens include a camera lens mounted on a smartphone or a tablet terminal, a video camera or a digital camera lens, and the like.
When the antireflection film of the present invention has the above-described anchor layer and adhesive layer, it can be suitably used for in-vehicle use (in-mold molding).

The image display device may be a liquid crystal display device (LCD), PDP, FED, ELD (organic EL, inorganic EL), CRT, or the like.

The LCD includes a transmissive display body and a light source device that irradiates the transmissive display body from the back. When the image display device is an LCD, the antireflection optical film of the present invention is formed on the surface of the transmissive display body.

When the image display device is an LCD, the light source of the light source device is irradiated from the polarizer side. Note that in the STN liquid crystal display device, a phase difference plate may be inserted between the liquid crystal display element and the polarizer. An adhesive layer may be provided between the layers of the liquid crystal display device as necessary.

The PDP includes a front glass substrate and a rear glass substrate disposed with a discharge gas sealed between the front glass substrate and the front glass substrate. When the image display device is a PDP, the surface of the surface glass substrate or the front plate (glass substrate or film substrate) is provided with the antireflection optical film described above.

The image display device is an ELD device that performs display by controlling a voltage applied to the substrate by depositing a light emitting material such as zinc sulfide or a diamine substance that emits light when a voltage is applied thereto, or an electric signal to light. It may be an image display device such as a CRT that converts and generates an image visible to the human eye. In this case, the antireflection optical film described above is provided on the outermost surface of each display device as described above or the surface of the front plate.

In any case, the antireflection optical film of the present invention can be used for display displays such as televisions and computers, and lenses for cameras. In particular, it can be suitably used for high-definition image displays such as liquid crystal panels, PDPs, ELDs, touch panels, and electronic paper, and camera lenses mounted on cholera.

Since the antireflection optical film of the present invention has the above-described configuration, it has an excellent antifouling property and scratch resistance, and can form a low refractive index layer having excellent antireflection performance. It is possible to provide a layer composition and an antireflection optical film having extremely excellent antifouling properties and scratch resistance and excellent antireflection performance. For this reason, the antireflection optical film of the present invention is a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a display such as an electronic paper, a tablet terminal, especially a mobile terminal and a camera mounted thereon. It can be suitably used for a lens.

It is explanatory drawing of Rq.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.
In the text, “part” or “%” is based on mass unless otherwise specified.

(Coating liquid for low refractive index layer)
Propylene oxide-modified pentaerythritol tetraacrylate (product name “ATM-4P”, manufactured by Shin-Nakamura Chemical Co., Ltd.) 72.5 parts by mass Pentaerythritol triacrylate (PET) 25.5 parts by mass hollow silica fine particles (Thruria 4320, solid content 20 %, Manufactured by JGC Catalysts & Chemicals, average particle size 60 nm) 70.0 parts by mass Reactive silica fine particles (MIBK-SD, solid content 30%, manufactured by Nissan Chemical Industries, average particle size 10 nm) 83.3 parts by mass Photopolymerization started Agent (Irgacure 127, manufactured by Ciba Specialty Chemicals) 7.0 parts by mass Methyl isobutyl ketone 7721.9 parts by mass Propylene glycol monomethyl ether acetate 917.8 parts by mass

(Coating solution for hard coat layer)
Acrylic polymer (product name “BL-2002”, solid content 35%, weight average molecular weight 70,000, acrylic equivalent 265, manufactured by Seiko PMC) 228.6 parts by mass reactive silica fine particles (product name “ELCOM V8803”, solid 40% min., Manufactured by JGC Catalysts & Chemicals Co., Ltd.) 50.0 parts by mass fluorine compound (product name “F-554”, manufactured by DIC) 0.20 parts by mass photopolymerization initiator (Irgacure 184, Ciba Specialty Chemicals) Made) 4.0 parts by weight methyl ethyl ketone 238.2 parts by weight

Example 1
First, a polyethylene terephthalate film (product name “Cosmo Shine A4100”, manufactured by Toyobo Co., Ltd.) having a 50 μm-thick single-sided adhesive treatment as a release film is prepared. The coating solution for refractive index layer was applied so that the film thickness after drying (25 ° C. × 1 minute−50 ° C. × 1 minute) was 0.1 μm.
And using the ultraviolet irradiation device (the fusion UV system Japan company make, light source H bulb), it irradiated with ultraviolet irradiation with the irradiation dose of 20 mJ / cm < ² >, it was made to harden | cure, and the low refractive index layer was formed.
Next, the coating liquid for hard coat was applied on the formed low refractive index layer so that the film thickness after drying (100 ° C. × 1 minute) was 5 μm. Then, using a UV irradiation device (Fusion UV System Japan, light source H bulb), UV irradiation is performed at an irradiation dose of 100 mJ / cm ² to cure, thereby forming a hard coat layer, and antireflection optics for transfer. A film was obtained.

(Example 2)
Example 1 except that the blending amount in the coating solution for the low refractive index layer was 50.0 parts by mass of ATM-4P, 70.0 parts by mass of PETA, and 600.0 parts by mass of hollow silica fine particles. In the same manner as above, an antireflection optical film for transfer was obtained.

(Example 3)
Example 1 except that the blending amount in the coating solution for the low refractive index layer was 30.0 parts by mass of ATM-4P, 50.0 parts by mass of PETA, and 600.0 parts by mass of hollow silica fine particles. In the same manner as above, an antireflection optical film for transfer was obtained.

(Comparative Example 1)
Example 1 except that the blending amount in the coating liquid for the low refractive index layer is 15.0 parts by mass of ATM-4P, 85.0 parts by mass of PETA, and 600.0 parts by mass of hollow silica fine particles. In the same manner as above, an antireflection optical film for transfer was obtained.

(Comparative Example 2)
The blending amount in the coating solution for the low refractive index layer is the same as in Example 1 except that ATM-4P is not blended, PETA is 100.0 parts by mass, and hollow silica fine particles are 600.0 parts by mass. Thus, an antireflection optical film for transfer was obtained.

(Comparative Example 3)
The blending amount in the coating solution for the low refractive index layer is 600.0 parts by mass of hollow silica fine particles, and a 50 μm thick polyethylene terephthalate film (product name “Diafoil T100-50S”, Mitsubishi Plastics, Inc.) An antireflection optical film for transfer was obtained in the same manner as in Example 1 except that the product No. was used.

(Transferability)
Prepare a 100 mm x 100 mm x 1 mm thick black acrylic plate in which a transparent optical adhesive film is bonded using a roller in advance, and the hard coat layer surface of the obtained antireflection optical film for transfer is in contact with the transparent optical adhesive film In addition, after laminating using a roller, peeling was performed at a rate of about 300 mm / min, and visually evaluated according to the following criteria.
A: Transferred over the entire surface of the black acrylic plate and easily transferred.
○: Transferred over the entire black acrylic plate.
(Triangle | delta): Although 50% or more of black acrylic board area is transcribe | transferred, there exists a location which is not partially transcribe | transferred.
X: Only less than 50% of the acrylic plate area is transferred.

(Reflection Y value)
From the surface of the low refractive index layer, using a spectral reflectance measuring device “MPC3100” manufactured by Shimadzu Corporation, 5 ° regular reflectance is measured in the wavelength range of 380 to 780 nm, and then the brightness that humans can perceive with eyes. As a reflection Y value, a value indicating luminous reflectance, calculated by software (MPC3100 built-in) for conversion, is calculated.

(Anti-fouling property)
After attaching a fingerprint to the surface of each antireflection film obtained, Kim Paper (registered trademark) made by Nippon Paper Crecia Co., Ltd. was reciprocated 30 times and wiped off. Evaluation based on the criteria.
◎: Can be wiped off completely within 30 round trips (compared to ○, it was easier to wipe off)
○: Can be wiped off completely within 30 round trips ×: Cannot be wiped off after 30 round trips

(Abrasion resistance)
The surface of the low refractive index layer of each antireflection film obtained was subjected to 10 reciprocating frictions with each friction load of 100 and 200 g / cm ² using # 0000 steel wool, and then the coating film was peeled off. The presence or absence was visually observed, and the results were evaluated according to the following criteria.
◎: No scratch at 200 g / cm ² ○: No scratch at 100 g / cm ² ×: Scratch at 100 g / cm ²

(Measurement of uneven shape)
Rz, Rq, and Ry on the surface that was in contact with the hard coat layer of the polyethylene terephthalate film after the polyethylene terephthalate film was peeled off by irradiating the sample obtained from the antireflection optical film according to Examples and Comparative Examples While measuring, Rz, Rq, and Ry on the surface of the protective film in contact with the polyethylene terephthalate film were measured. The definition of Rz and Ry shall be in accordance with JIS B0601-1994, and Rq will follow the formula described in ISO 4287-1984, but it can be similarly measured in ISO 4287-1997. Rz, Rq, and Ry were measured under the following measurement conditions using a surface roughness measuring device (product name “Surfcoder SE3400, manufactured by Kosaka Laboratories”). It was set as the arithmetic average value of the value obtained by measuring 3 times.

Measurement sample:
A sample in which an acrylic plate (manufactured by Kuraray Co., Ltd., product name: Comaglass product number: DFA502K 10 cm × 10 cm, plate thickness 2 mm) is bonded through a transparent adhesive layer (refractive index: 1.55 PDC-S1 50 μm manufactured by Panac Co., Ltd.) Produced.
1) Stylus of surface roughness detector (product name “Surfcoder SE-3400”, manufactured by Kosaka Laboratory, 2 μm standard)
・ Tip radius of curvature 2μm, apex angle 90 degrees, material diamond

Hereinafter, measurement conditions used in Examples and Comparative Examples are described.
When the flatness is excellent, a vertical magnification of 100,000 is suitable. On the other hand, when the flatness is inferior, the waveform amplitude appearing at the time of measurement may protrude from the recording paper, so the vertical magnification is reduced and 10,000 times is used. Since the vertical magnification may affect the measured value, it is preferably 10,000 to 100,000 times when measuring a flat surface, and preferably 100,000 times when measuring a flat surface. As for the lateral magnification, there is no influence on the measured value, but it is sufficient that the waveform is easy to see on the recording paper, and 5 to 50 times is preferable.
In addition, when the feed speed is 0.25 mm, it is 0.1 mm / s because the measurement range is small and it is preferable that the feed speed is slow for stable stylus measurement. On the other hand, in the case of 2.5 mm / s, the lowest speed was 0.5 mm / s in the apparatus setting, and the slowest speed was selected in order to stably measure the stylus.

Measurement condition 1 of surface roughness measuring instrument (used in Examples and Comparative Examples 1 and 2)
Reference length (roughness curve cut-off value λc): 0.25 mm
Evaluation length (reference length (cutoff value λc) × 5): 1.25 mm
・ Feeding speed of stylus: 0.1 mm / s
・ Vertical magnification: 100,000 times ・ Horizontal magnification: 50 times ・ Skid: Not used (no contact with measurement surface)
・ Cutoff filter type: Gaussian ・ JIS mode: JIS1994

Measurement condition 2 of surface roughness measuring instrument (used in Examples and Comparative Examples 1 and 2)
Reference length (roughness curve cut-off value λc): 2.5 mm
Evaluation length (reference length (cutoff value λc) × 5): 12.5 mm
・ Feeding speed of stylus: 0.5mm / s
・ Vertical magnification: 100,000 times ・ Horizontal magnification: 50 times ・ Skid: Not used (no contact with measurement surface)
・ Cutoff filter type: Gaussian ・ JIS mode: JIS1994

Measurement condition 3 of surface roughness measuring instrument (used in Comparative Example 3)
Reference length (roughness curve cut-off value λc): 0.25 mm
Evaluation length (reference length (cutoff value λc) × 5): 1.25 mm
・ Feeding speed of stylus: 0.1 mm / s
・ Vertical magnification: 10000 times ・ Horizontal magnification: 50 times ・ Skid: Not used (no contact with measurement surface)
・ Cutoff filter type: Gaussian ・ JIS mode: JIS1994

Measurement condition 4 of surface roughness measuring instrument (used in Comparative Example 3)
Reference length (roughness curve cut-off value λc): 2.5 mm
Evaluation length (reference length (cutoff value λc) × 5): 12.5 mm
・ Feeding speed of stylus: 0.5mm / s
・ Vertical magnification: 10000 times ・ Horizontal magnification: 50 times ・ Skid: Not used (no contact with measurement surface)
・ Cutoff filter type: Gaussian ・ JIS mode: JIS1994
The results are shown in Tables 1 to 3 below.

The antireflection optical film of the present invention is a display such as a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), an electronic paper, and a tablet terminal, particularly a mobile terminal, a camera lens mounted thereon, and an in-vehicle It can be suitably used for applications (in-mold molding).

Claims (14)

An antireflection optical film having at least a hard coat layer and a low refractive index layer laminated on one surface of the hard coat layer,
On the surface opposite to the hard coat layer side of the low refractive index layer, the root-mean-square roughness Rq, the ten-point average roughness Rz, and the maximum height roughness Ry were measured with a cutoff wavelength of 2.5 mm. When
Rq is 0.010 μm or more and 0.050 μm or less,
Rz is 0.050 μm or more and 0.250 μm or less,
Said Ry is 0.050 micrometer or more and 0.350 micrometer or less, The antireflection optical film characterized by the above-mentioned. On the surface opposite to the hard coat layer side of the low refractive index layer, the cut-off wavelength is 2.5 mm and 0.25 mm, and the root mean square roughness Rq, the ten-point average roughness Rz, and the maximum height roughness Ry are respectively set. When measured, the ratio of the Rq, Rz and Ry values at the cutoff wavelength of 2.5 mm to the values at the cutoff wavelength of 0.25 mm (cutoff wavelength 2.5 mm / cutoff wavelength 0.25 mm) is 2. The antireflection optical film according to claim 1, which is 1.00 or more and 2.00 or less. The antireflection optical film according to claim 1, wherein the hard coat layer contains 10 to 300 parts by mass of inorganic fine particles with respect to 100 parts by mass of the binder component. The antireflection optical film according to claim 1, wherein a transparent optical adhesive film is laminated on a side surface opposite to the low refractive index layer side of the hard coat layer. The antireflection optical film according to claim 1, 2 or 3, wherein an anchor layer and an adhesive layer are laminated on the side surface opposite to the low refractive index layer side of the hard coat layer via the anchor layer. The antireflection optical film according to claim 1, wherein the total film thickness of the low refractive index layer and the hard coat layer is 3 μm or more and 15 μm or less. The antireflection optical film according to claim 4, wherein the total film thickness of the low refractive index layer, the hard coat layer, and the transparent optical adhesive film is from 8 μm to 30 μm. The antireflection optical film according to claim 5, wherein the total film thickness of the low refractive index layer, the hard coat layer, the anchor layer and the adhesive layer is 8 μm or more and 30 μm or less. A release film is attached to the side opposite to the hard coat layer side of the low refractive index layer, and the peel force between the low refractive index layer and the release film is 10 mN / 25 mm or more and 500 mN / 25 mm or less. The antireflection optical film according to claim 1, 2, 3, 4, 5, 6, 7 or 8. A composition for a low refractive index layer containing hollow particles and a binder resin, characterized in that it contains an alkylene oxide-modified (meth) acrylate compound in an amount of 20% by mass or more in 100% by mass of the binder resin solid content. A composition for a low refractive index layer. The composition for a low refractive index layer according to claim 10, wherein the alkylene oxide-modified (meth) acrylate compound is an ethylene oxide-modified (meth) acrylate compound and / or a propylene oxide-modified (meth) acrylate compound. The composition for low refractive index layers according to claim 10 or 11, wherein the number of functional groups of the alkylene oxide-modified (meth) acrylate compound is 6 or less. The composition for a low refractive index layer according to claim 10, 11 or 12, comprising 40 to 200 parts by mass of hollow particles with respect to 100 parts by mass of the binder resin. The composition for a low refractive index layer according to claim 10, 11, 12, or 13, wherein the hollow particles are hollow silica particles.

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