JP2015087763A - Partition member and monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a partition member which is a transparent partition member for partitioning an area, and enables a good view field to be ensured between two sections through the partition member.SOLUTION: Partition members 10 and 50 are provided with transparent bodies 15 and reflection preventive films 20 pasted on one side surfaces 15a of the transparent bodies 15. The reflection preventive film has a rugged structure layer 30 having a rugged surface 31 formed by minute protrusions 32 provided at intervals d which is the shortest wave length or less of a visible ray band. The reflection preventive film is disposed so as to turn the rugged surface to the opposite side to the transparent body. A reflection ratio due to 5° regular reflection on the rugged surface of the reflection preventive film is 0.3% or less. A contact angle to water on the rugged surface of the reflection preventive film is 20° or less.

Description

  The present invention relates to a transparent partition member for partitioning a region, and more particularly to a partition member that makes it possible to ensure a good field of view between two sections through the partition member. The present invention also relates to a monitoring system having such a partition member.

  Conventionally, a transparent partition member for partitioning a region, typically a glass window, has been widely used (for example, Patent Document 1). Such a partition member is required to ensure visibility between two sections while partitioning the region into two sections. As an application example of such a partition member, a glass window of a supervisor room that monitors a person entering or leaving the site can be exemplified. The monitor in the monitor room can monitor the outside from the room through the partition member, thereby eliminating the need to open the glass window forming the partition member or to go out of the room. In this case, the amount of air conditioning used in the supervisor room can be omitted, and energy saving can be realized. Moreover, it is preferable also in the point which can prevent an insect invasion.

  However, if there is a difference in brightness between two areas located on both sides of the partition member, the amount of transmitted light from the dark area side to the bright area side will be larger than the amount of light reflected on the bright area side surface of the partition member. Will be reduced. For this reason, an image on the bright area side is reflected on the surface on the bright area side of the partition member, and this reflection significantly reduces the visibility when a dark area is observed from the bright area side. For example, if a person looks into the room through a partition member from a supervisor room whose lighting equipment is turned on at night, the indoor situation is projected on the partition member, and the outdoor situation cannot be observed sufficiently. In this regard, in Patent Document 1, the inner surface (inner side) of the partition member is formed by a low refractive index layer, and the reflection on the inner surface of the partition member is reduced.

JP 2008-37667 A

  However, in a partition member that divides the interior and exterior of a building represented by a guard room, etc., the difference in brightness between the two sections located on both sides of the partition member is significantly large on a rainy or cloudy day or night. Become. In this case, the antireflective function of the low refractive index layer is inadequate, reflection occurs on the surface of the partition member, and visibility through the partition member is significantly deteriorated.

  Furthermore, as a result of confirmation by the present inventors, it has been found that condensation is likely to occur in the partition member provided with the low refractive index layer. In addition, the dew condensation occurred more conspicuously in the partition member that partitions the interior and the exterior of the building where the difference between the temperature and the temperature is particularly large. When dew condensation occurs on the surface of the partition member, the visibility through the partition member is significantly reduced. A general low refractive index layer contains a silicon-based additive or fluorine-containing material having low hydrophilicity, and the silicon-based additive or fluorine-containing material repels moisture without spreading uniformly on the surface. It is presumed that the formation of water droplets is promoted and as a result, the occurrence of condensation is promoted.

  In addition, the reflectance of the antireflection film formed as a low refractive index layer has a spectral distribution, and the antireflection function strongly affects light of a specific wavelength according to the thickness of the low refractive index layer and the observation direction. It is. As a result, the low refractive index layer is tinted according to the viewing direction, which may be inconvenient depending on the use of the partition member.

  The present invention has been made in consideration of the above points, and is a transparent partition member for partitioning a region, and ensures a good field of view between two sections through the partition member. It is an object of the present invention to provide a partition member that enables the above-mentioned and a monitoring system using the partition member.

The partition member according to the present invention is:
A transparent partition member for partitioning an area,
A transparent body,
An antireflection film affixed to the surface of one side of the transparent body,
The antireflection film has a concavo-convex structure layer having a concavo-convex surface formed by minute protrusions provided at intervals equal to or shorter than the shortest wavelength in the visible light band, and the concavo-convex surface is opposite to the transparent body. Placed to face
The reflectance by 5 ° regular reflection on the uneven surface of the antireflection film is 0.3% or less,
The contact angle with respect to water on the uneven surface of the antireflection film is 20 ° or less.

  The partition member by this invention WHEREIN: The said antireflection film may be affixed on a part of surface of the one side of the said transparent body.

  In the partition member according to the present invention, the fine protrusions of the concavo-convex structure layer may be provided at intervals of 70 nm or more and 180 nm or less, and the height of the fine protrusions may be 100 nm or more and 250 nm or less.

  In the partition member according to the present invention, the reflectance by 50 ° regular reflection on the uneven surface of the antireflection film is more preferably 1.0% or less. In such a partition member according to the present invention, the height of the fine protrusion may be 100 nm or more and 250 nm or less.

  In the partition member according to the present invention, the contact angle of the resin material forming the uneven structure layer with respect to water may be 10 ° or more and 90 ° or less.

  In the partition member according to the present invention, the uneven structure layer may include a compound having an ethylene oxide group.

  The division member by this invention may be attached to the opening part of the wall which divides the inside and the exterior of a building.

The partition member according to the present invention further includes a second antireflection film attached to the other surface of the transparent body so as to face the antireflection film,
The second antireflection film has a concavo-convex structure layer having a concavo-convex surface formed by minute protrusions provided at intervals equal to or shorter than the shortest wavelength in the visible light band, and the concavo-convex surface is opposite to the transparent body. Placed to face
The reflectance by 5 ° regular reflection on the uneven surface of the second antireflection film may be 0.3% or less.
Such a partition member according to the present invention is attached to an opening of a wall surface that partitions the inside and the outside of the building, the antireflection film is located inside the building, and the second antireflection film is outside the building. You may arrange | position so that it may be located.

  The partition member by this invention WHEREIN: The pattern may be provided in the part used as the circumference | surroundings of the said antireflection film of the said antireflection film or the said transparent body.

  In the partition member according to the present invention, the antireflection film may be elongated in the horizontal direction.

  In the partition member according to the present invention, a width along the horizontal direction of the antireflection film may be wider than a width along a direction orthogonal to the horizontal direction of the antireflection film.

  In the partition member according to the present invention, the storage elastic modulus (E1 ′) at 25 ° C. of the resin material forming the uneven structure layer is 300 MPa or less, and the uneven structure layer is formed with respect to the storage elastic modulus (E1 ′). The ratio of loss elastic modulus (E1 ″) at 25 ° C. of the resin material (tan δ (= E1 ″ / E1 ′)) is 0.2 or less, and n-hexadecane on the surface of the resin material forming the concavo-convex structure layer The contact angle may be 30 ° or less, or the contact angle of oleic acid may be 25 ° or less.

In the partition member according to the present invention,
The microprojection includes a plurality of multimodal microprojections having a plurality of vertices, and a single-peak microprojection having one vertex.
The frequency distribution of the height of the microprotrusions is a distribution consisting of one top,
The multimodal microprotrusions may be distributed more in the vicinity of the apex than the base of the distribution.

In the partition member according to the present invention,
The microprojection includes a plurality of multimodal microprojections having a plurality of vertices, and a single-peak microprojection having one vertex.
The average value of the height H in the frequency distribution of the height H of the microprotrusions is m, the standard deviation is σ,
The region where H <m−σ is the low altitude region,
The region of m−σ ≦ H ≦ m + σ is defined as a medium altitude region,
When the region of m + σ <H is a high altitude region,
The ratio between the number Nm of the multi-peaked microprojections in each region and the total number Nt of the microprojections in the entire frequency distribution is as follows:
Nm / Nt in middle altitude region> Nm / Nt in low altitude region,
The relationship of Nm / Nt in the middle altitude region> Nm / Nt in the high altitude region may be satisfied.

In the partition member according to the present invention,
The frequency distribution of the height h of the microprojections is bimodal having two peaks,
With the height hs serving as the boundary between the two peaks, the frequency distribution is composed of two distributions: a distribution of microprojections having a height less than hs and a distribution of microprojections having a height of hs or more.
In the distribution below the height hs, the average value of the heights h of the microprotrusions is m1, and the standard deviation is σ1,
Let h <m1-σ1 be the low-altitude region,
The area of m1−σ1 ≦ h ≦ m1 + σ1 is a middle altitude area,
When the region of m1 + σ1 <h <hs is a high altitude region,
The ratio between the number Nm1 of the multi-modal microprojections in each region in the distribution of less than hs and the total number Nt of the microprojections in the entire frequency distribution is:
Nm1 / Nt in the middle altitude region> Nm1 / Nt in the low altitude region,
Satisfying the relationship of Nm1 / Nt in the middle altitude region> Nm1 / Nt in the high altitude region,
In the distribution of the height hs or more, the average value of the height h of the microprotrusions is m2, the standard deviation is σ2,
The region of hs <h <m2-σ2 is set as a low altitude region,
The region of m2-σ2 ≦ h ≦ m2 + σ2 is defined as a middle altitude region,
When the area of m2 + σ2 <h is a high altitude area,
The ratio between the number Nm2 of the multi-modal microprojections in each region in the distribution of hs or more and the total number Nt of the microprojections in the entire frequency distribution is:
Nm2 / Nt in the middle altitude region> Nm2 / Nt in the low altitude region,
The relationship of Nm2 / Nt in the middle altitude region> Nm2 / Nt in the high altitude region may be satisfied.

The monitoring system according to the present invention includes any one of the partition members according to the present invention described above,
Photographing means for photographing through the partition member.

  In the monitoring system according to the present invention, the imaging unit is relatively rotatable with respect to the partition member about an axial direction, and the antireflection film may extend in a direction non-parallel to the axial direction. Good.

  According to the present invention, the antireflection film attached to the transparent body has a concavo-convex structure layer having a concavo-convex surface formed by microprojections provided at intervals that are equal to or shorter than the shortest wavelength of the visible light band, It arrange | positions so that a surface may face the other side. The reflectance by 5 ° regular reflection on the uneven surface of this antireflection film is 0.3% or less, and an excellent antireflection function is exhibited. Moreover, since the contact angle with respect to the water on the uneven | corrugated surface of an antireflection film is 20 degrees or less, the outstanding anti-fogging function is expressed. From these things, a favorable visual field can be ensured via a partition member.

FIG. 1 is a perspective view showing a partition member for explaining an embodiment of the present invention. FIG. 2 is a cross-sectional view of the partition member taken along line II-II in FIG. FIG. 3 is a cross-sectional view showing the antireflection film of the partition member in a cross section along the normal direction to the film surface of the antireflection film. FIG. 4 is a perspective view showing an uneven structure layer of the antireflection film of FIG. FIG. 5 is a schematic view showing an example of a method for producing an antireflection film. FIG. 6 is a perspective view illustrating an example of a monitoring system including a partition member. 7 is a sectional side view of the monitoring system of FIG. FIG. 8 is a plan photograph showing an example of the uneven surface of the uneven structure layer. FIG. 9 shows the maximum points in the photograph of FIG. FIG. 10 shows a Delaunay diagram in the photograph of FIG. FIG. 11 is a graph showing the distribution of the distance between adjacent protrusions of the minute protrusions. FIG. 12 is a graph showing the distribution of the heights of the microprojections. FIG. 13 is a graph showing the frequency distribution of the heights of the microprojections. FIG. 14 is a flowchart showing a production process of a roll plate. FIG. 15 is a schematic diagram showing fine holes produced by an anodizing process and an etching process in the manufacturing process of the forming mold. FIG. 16 is a diagram for explaining a process in which micro holes with different depths are formed according to control of the height distribution of micro protrusions. FIG. 17 is a diagram illustrating an example of a frequency distribution of the height H of the microprojections of the antireflection film. FIG. 18 is a diagram illustrating another example of the frequency distribution of the height H of the fine protrusions of the antifogging film. FIG. 19 is a diagram for explaining the microprojections. FIG. 20 is a photograph of multimodal microprojections. FIG. 21 is a perspective view showing the shape of the minute protrusions. 22 is a plan view, a front view, and a side view of FIG. FIG. 23 is a conceptual cross-sectional view showing a form in which the envelope surface of the valley bottom of the microprojection exhibits an uneven valley bottom surface (waviness).

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings other than the photographs attached to the present specification, for the sake of illustration and ease of understanding, the scale and the vertical / horizontal dimensional ratio are appropriately changed and exaggerated from those of the actual ones.

  In the present specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in names. For example, “film” is a concept that includes a member that can be called a plate or a sheet. Therefore, an “antireflection film” is only a different name from a member called “antireflection plate” or “antireflection sheet”. Cannot be distinguished.

  In addition, “film surface (plate surface, sheet surface)” means a target film-like member (plate-like) when the target film-like (plate-like, sheet-like) member is viewed as a whole and globally. It refers to a surface that coincides with the planar direction of the member (sheet-like member).

  Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

<<< Division member >>>
The partition member 10 is a transparent member that partitions the region. As a typical example, the partition member 10 is attached to an opening formed in a building and separates the room and the outdoors. In such an application, the partition member 10 partitions the indoor space from the outside while ensuring the visible light transmission between the room and the outside, that is, ensuring the visibility between the room and the outdoors. In particular, the partition member 10 described here is also used when the two sections S1 and S2 where light and dark are generated, or when the section member 10 is used as a member for distinguishing two areas where light and dark may be generated according to time and time zone. This makes it possible to ensure a good field of view between the two areas via the partition member 10.

  Here, the occurrence of light and dark means that there is a difference between the amount of light directed toward the partition member 10 in one area S1 and the amount of light directed toward the partition member 10 in the other area S2. Therefore, by comparing the illuminance measured by the illuminometer arranged in the vicinity of the partition member 10 in each of the one area S1 and the other area S2, it is possible to determine whether or not light and darkness has occurred. it can. As a result of extensive research conducted by the inventor of the present invention, as described later with reference to FIGS. 6 and 7, the window glass plate of a guard (guardian) who monitors entry / exit in a factory or parking lot, etc. In the case of applying a member, even under night conditions where the outdoor brightness is 5% or less of the indoor brightness, sufficient visibility is ensured for the purpose of monitoring when observing the outdoor from inside the room. We were able to.

  Further, in the present specification, “transparent” means that the state beyond can be visually recognized through the member. When the antireflection film of the present invention is pasted on the window glass as a partition member, it can be visually recognized even if the window glass is entirely colored or clouded. Therefore, it is necessary to prevent reflection rather than transmittance. However, generally, the total light transmittance as the antireflection film is 80% or more, preferably 95% or more so as not to impair the transparency of the window glass or the like.

  As shown in FIGS. 1 and 2, the partition member 10 includes a transparent transparent body 15 and a first antireflection film 20 a attached to a surface (first surface) 15 a on one side of the transparent body 15. Have. In particular, in the illustrated example, the partition member 10 is formed on the surface (second surface) 15b on the other side of the transparent body 15 on the antireflection film 20a in order to secure a better field of view through the partition member 10. Oppositely, it has the 2nd antireflection film 20b stuck. As shown in FIG. 2, the first antireflection film 20 a is bonded to the first surface 15 a of the transparent body 15 via the first bonding layer 18 a. The second antireflection film 20b is bonded to the second surface 15b of the transparent body 15 via the second bonding layer 18b.

  In the example shown in FIGS. 1 and 2, the first antireflection film 20 a is disposed only on a part of the first surface 15 a of the transparent body 15. Similarly, the second antireflection film 20 b is disposed only on a part of the second surface 15 b of the transparent body 15. Moreover, in the example shown by FIG.1 and FIG.2, along the normal line direction to the plate | board surface of the plate-shaped transparent body 15, the outer outline of the 1st antireflection film 20a and the outer outline of the 2nd antireflection film 20b And are arranged so as to overlap. That is, two antireflection films 20 a and 20 b formed in the same shape in plan view are arranged at positions facing each other with the transparent body 15 in between.

  Hereinafter, the transparent body, the bonding layer, and the antireflection film, which are components of the partition member 10, will be described in order. The first antireflection film 20a and the second antireflection film 20b can be configured identically. When there is no need to distinguish between the first antireflection film 20a and the second antireflection film 20b, the antireflection film will be described using the reference numeral “20”. Similarly, the first bonding layer 18a and the second bonding layer 18b can be configured identically. When there is no need to distinguish between the first bonding layer 18a and the second bonding layer 18b, the bonding layer will be described using the reference numeral “18”.

<< Transparent body >>
The transparent body 15 is attached and fixed to a building, for example, and forms a main body portion of the partition member 10.

  As the transparent body 15, a known transparent substrate can be appropriately selected and used, and is not particularly limited. Examples of the material used for the transparent body 15 include a transparent inorganic material and a transparent resin. Examples of the transparent inorganic material include glass such as soda glass, potassium glass, and lead glass, ceramics such as PLZT, quartz, and fluorite. On the other hand, examples of the transparent resin include acetyl cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefins such as polyethylene, polypropylene, polymethylpentene, cycloolefin polymer, and cycloolefin copolymer. Resin, polymethyl methacrylate, acrylic resin such as acrylic-styrene copolymer, polyurethane resin, vinyl chloride resin, polystyrene, polyethersulfone and polycarbonate, polysulfone, polyether, polyetherketone, acrylonitrile, methacrylate Ronitrile etc. can be mentioned.

  From the viewpoint of ensuring good visibility through the partition member 10, the visible light transmittance of the transparent body 15 is preferably 70% or more, and more preferably 80% or more. The transparent body 15 is preferably colorless (that is, colorless and transparent). However, depending on the use and required characteristics, the transparent body 15 may be colored chromatic or achromatic within a range that does not hinder the visibility as the partition member 10. May be.

  The transparent body 15 may be formed of a single layer or may be formed of multiple layers. However, when it is formed in multiple layers, the refractive index difference between adjacent layers is preferably 0.03 or less from the viewpoint of suppressing reflection between adjacent layers, and is 0.01 or less. More preferably.

<< Bonding layer >>
The bonding layer 18 is a transparent layer for bonding the antireflection film 20 to the transparent body 15. The bonding layer 18 may be formed as an adhesive layer made of an adhesive, or may be formed as an adhesive layer that has reworkability, that is, can be peeled and re-bonded. The bonding layer 18 can be formed using various known adhesive materials and adhesive materials. However, depending on the installation location of the partition member 10, it is preferable that the joining layer 18 is formed of a material having water resistance. Further, from the viewpoint of ensuring good visibility through the partition member 10, the visible light transmittance of the bonding layer 18 is preferably 80% or more, and more preferably 90% or more. Similarly, from the viewpoint of ensuring good visibility through the partition member 10, it is preferable that no orange peel (coconut skin-like thickness unevenness) occurs in the bonding layer 18. Furthermore, from the viewpoint of suppressing reflection at the interface between the bonding layer 18 and the transparent body 15, the difference in refractive index between the bonding layer 18 and the transparent body 15 is preferably 0.03 or less, and 0.01 or less. More preferably.

<< Antireflection Film >>
As shown in FIGS. 3 and 4, the antireflection film 20 includes an uneven structure layer 30 having an uneven surface 31. The concavo-convex surface 31 of the concavo-convex structure layer 30 is formed by minute protrusions 32 arranged at intervals equal to or shorter than the shortest wavelength in the visible light band. The antireflection film 20 shown in FIGS. 3 and 4 further includes a transparent substrate 25 that supports the concavo-convex structure layer 30. The antireflection film 20 is disposed such that the uneven surface 31 faces the side opposite to the transparent body 15. Therefore, in the region where the first antireflection film 20a is provided, the surface of the partition member 10 is formed by the uneven surface 31 of the first antireflection film 20a. Similarly, in the region where the second antireflection film 20b is provided, the surface of the partition member 10 is formed by the uneven surface 31 of the second antireflection film 20b.

  In this antireflection film 20, the uneven structure layer 30 functions as a so-called moth-eye structure. As a result, the antireflection film 20 can exhibit an extremely excellent antireflection function on the uneven surface 31 of the uneven structure layer 30. In addition, the antireflection film 20 can exhibit an extremely excellent antifogging function when the uneven structure layer 30 is formed of a hydrophilic material. The antifogging function of the antireflection film 20 is manifested due to the uneven surface 31 exhibiting hydrophilicity. More specifically, water droplets attached to the uneven surface 31 due to condensation or the like spread widely on the hydrophilic uneven surface 31, and thereafter, uniform and quick evaporation on the uneven surface 31 is promoted. Anti-fogging is realized. In this way, both the antireflection function and the antifogging function are exhibited on the uneven surface 31 of the antireflection film 20.

  In addition, compared with the hydrophilic property of the material itself used for the concavo-convex structure layer 30, the concavo-convex surface 31 of the concavo-convex structure layer 30 formed using the hydrophilic material exceeds the expectation greatly exceeding the hydrophilicity of the material itself. It becomes hydrophilic.

  That is, in the antireflection film 20 of the present invention, the contact angle with water of the concavo-convex structure layer 30 formed on the surface of the hydrophilic material is 50% or less of the contact angle with water of the hydrophilic material itself. Such hydrophilic expression is referred to as super hydrophilicity in the present specification.

  In addition, the contact angle (that is, the static contact angle in the θ / 2 method) of the specific material itself referred to in this specification is different from the contact angle on the uneven surface 31 of the uneven structure layer 30. The contact angle of the specific material itself is a contact angle measured on the flat surface with the surface of the specific material as a flat surface having no microprojection shape 32. Here, the flat surface is a surface having a 10-point average roughness Rz measured in accordance with JIS B 0601 (1994) of 10 nm or less.

  The hydrophilicity of the specific material itself is hydrophilicity based on the contact angle of water with a flat surface made of the specific material. As a specific method for measuring the contact angle of a specific material with respect to a specific liquid, one of specific liquids (pure water, n-hexadecane, oleic acid, etc.) whose contact angle is to be measured on a flat surface made of the specific material is used. A value measured according to the θ / 2 method of calculating the contact angle from the angle of the straight line connecting the left and right end points and the apex of the dropped liquid droplet with respect to the solid surface 1 second after dropping the liquid droplet of 0.0 μL (static Contact angle) can be the value of the contact angle. As the measuring device, for example, a contact angle meter DM 500 manufactured by Kyowa Interface Science Co., Ltd. can be used. Specifically, when the concavo-convex structure layer 30 is formed using a material having a contact angle with water of 50 ° or more and 90 ° or less, the contact angle with respect to the water of the concavo-convex surface 31 can be reduced to 20 ° or less. It becomes possible. The concavo-convex surface 31 of the concavo-convex structure layer 30 exhibits superhydrophilicity because the hydrophilicity of the material forming the concavo-convex structure layer 30 is a concavo-convex surface 31 having a large specific surface area formed by the microprojections 32 of the concavo-convex structure layer 30. This is considered to be due to the fact that it is greatly enhanced. And, by applying the uneven surface 31 that can express both the antireflection function and the antifogging function at an extremely high level to the surface of the partition member 10, as will be described later, a unique requirement for the transparent partition member 10, In other words, it is possible to achieve an excellent effect that is suitable for the requirement of partitioning the region while securing the field of view.

  Therefore, in view of such a background, the effect obtained by applying the uneven structure layer 30 formed using a hydrophilic material to the partition member 10 is remarkable beyond the range predicted from the technical level. It can be said that. Alternatively, the application of the concavo-convex structure layer 30 formed using a hydrophilic material to the partition member 10 is different or distinctive from the antireflection function of the concavo-convex structure layer 30 as a moth-eye structure. In comparison with the hydrophilicity of the material itself forming the structural layer 30, it can be said that it is possible to achieve outstanding effects.

  In the present specification, “hydrophilic” means that the contact angle with water is less than 90 °. Further, the contact angle referred to in the present specification is a value measured in accordance with JIS R3257 (1999). That is, the contact angle referred to in the specification is as described above, and the contact angle of the material itself with respect to water is 10 μm in thickness using the material in order to eliminate the influence of the surface of the part to be actually measured. A film having a flat surface is formed, and the contact angle of the film with respect to water is a value measured according to JIS R3257 (1999).

  Further, from the viewpoint of ensuring good visibility through the partition member 10, the visible light transmittance of the antireflection film 20 is preferably 70% or more, and more preferably 80% or more.

  Hereinafter, the transparent base material 25 and the uneven structure layer 30 of the antireflection film 20 will be described in order.

<Transparent substrate>
As the transparent substrate 25, a known transparent substrate can be appropriately selected and used, and is not particularly limited. For example, the materials exemplified as the material used for the transparent body 15 can be applied to the transparent substrate 25. However, from the viewpoint of ensuring good visibility through the partition member 10, the visible light transmittance of the transparent substrate 25 is preferably 85% or more, and more preferably 90% or more. In addition, from the viewpoint of suppressing reflection at the interface between the transparent base material 25 and the bonding layer 18, the refractive index difference between the transparent base material 25 and the bonding layer 18 is preferably 0.03 or less. More preferably, it is as follows.

  The thickness of the transparent substrate 25 can be appropriately set according to the use of the antireflection film 20 and is not particularly limited, but is usually 20 to 5000 μm, and the transparent substrate 25 is flexible and in the form of a roll. It may be either supplied, not bent to the extent that it can be wound, but curved by applying a load, or not completely bent. However, when the bonding layer 18 has reworkability, the transparent base material 25 is curved together with the uneven structure layer 30 described later so that the antireflection film 20 can be easily peeled off from the transparent body 15. It is preferable that the thickness is as large as possible.

  The configuration of the transparent substrate 25 is not limited to a configuration composed of a single layer, and may have a configuration in which a plurality of layers are laminated. When it has the structure by which the several layer was laminated | stacked, the layer of the same composition may be laminated | stacked, and the several layer which has a different composition may be laminated | stacked. Moreover, when the transparent base material 25 and the uneven structure layer 30 are formed from different materials, a primer layer may be formed between the transparent substrate 25 and the uneven structure layer 30. This primer layer is provided in order to improve the adhesion and thus improve the wear resistance and / or to reduce the refractive index step between the concavo-convex structure layer 30 and the transparent substrate 25. The primer layer preferably has adhesiveness to both the transparent substrate 25 and the uneven structure layer 30, is transparent, and has an intermediate refractive index between the transparent substrate 25 and the uneven structure layer 30. As a material for the primer layer, an ionizing radiation curable resin, a thermosetting resin, or the like can be used.

<Uneven structure layer>
As shown in FIGS. 3 to 5, the concavo-convex structure layer 30 has a concavo-convex surface 31 formed by minute protrusions 32 arranged at intervals equal to or shorter than the shortest wavelength in the visible light band. In this case, the “microscopic” of the microprotrusions 32 means that the microprotrusions 32 are so small that they are arranged at intervals equal to or shorter than the shortest wavelength in the visible light band. The shortest wavelength in the visible light band indicates the shortest wavelength in the visible light band in an environment where the partition member 10 including the antireflection film 20 is used. Therefore, when only light from a limited light source exists in an environment where the partition member 10 is used, the shortest wavelength of visible light emitted from the light source is the shortest wavelength in the visible light band here. In other cases, 380 nm is adopted as the shortest wavelength in the visible light band here, as the shortest wavelength in the general visible light band.

  The concavo-convex surface 31 of the concavo-convex structure layer 30 exhibits both an anti-reflection function and an anti-fogging function, and is divided from the bright side area S1 to the dark side with respect to the partition member 10 that divides the areas S1 and S2 where the contrast difference occurs. Gives good visibility when observing the area. From this point of view, the reflectivity by 5 ° regular reflection on the uneven surface 31 of the uneven structure layer 30 is preferably 0% or more and 0.3% or less, and is 0.1% or less. Is more preferable. At the same time, the contact angle with water on the concavo-convex surface 31 of the concavo-convex structure layer 30 is preferably greater than 0 ° and 30 ° or less, more preferably 20 ° or less, and 9 ° or less. It is still more preferable, and it is still more preferable that it is 6 degrees or less. Then, if the uneven structure layer 30 is formed as described below, such characteristics can be realized.

  Note that the reflectance of regular reflection referred to in this specification is a value measured according to JIS R3106 using UV-3100 manufactured by Shimadzu Corporation.

  The concavo-convex structure layer 30 can be a layer containing a resin, and can be a layer made of a cured product of the resin composition. The resin composition used for forming the concavo-convex structure layer 30 contains at least a resin and, if necessary, other components such as a polymerization initiator. From the viewpoint of suppressing reflection at the interface between the concavo-convex structure layer 30 and the transparent substrate 25, the refractive index difference between the concavo-convex structure layer 30 and the transparent substrate 25 is preferably 0.03 or less, 0.01 More preferably, it is as follows. As described above, the resin used to form the uneven structure layer 30 is not particularly limited as long as it is a hydrophilic material. For example, ionizing radiation curable resins such as acrylate, epoxy, and polyester, thermosetting resins such as acrylate, urethane, epoxy, and polysiloxane, acrylate, polyester, polycarbonate, polyethylene, and polypropylene Various materials such as a thermoplastic resin such as a thermoplastic resin and various types of curing resins can be used for forming the concavo-convex structure layer 30.

  From the viewpoint of imparting high hydrophilicity to the concavo-convex structure layer 30, a resin having a highly hydrophilic structure, for example, a composition containing a compound having an ethylene oxide group (EO group), a hydroxyl group, a carboxyl group, or the like is used. Thus, it is preferable that the uneven structure layer 30 is formed. The contact angle of the resin material itself forming the concavo-convex structure layer 30 with respect to water is sufficient if it is 90 ° or less, and more preferably 60 ° or less.

  As the resin used for forming the concavo-convex structure layer 30, an ionizing radiation curable resin is preferable from the viewpoint of excellent moldability and mechanical strength of the fine protrusions 32. The ionizing radiation curable resin is a mixture of a monomer having radically polymerizable and / or cationically polymerizable bonds in the molecule, a polymer having a low polymerization degree, and a reactive polymer, depending on the polymerization initiator. It is to be cured. In addition, you may contain a non-reactive polymer. The ionizing radiation means electromagnetic waves or charged particles having energy that can be cured by polymerizing molecules. For example, all ultraviolet rays (UV, UV-B, UV-C), visible rays, gamma rays, X Examples thereof include electromagnetic waves such as rays, charged particle beams such as electron beams and α rays.

  The resin composition further comprises a surfactant, a polymerization initiator, a release agent, a photosensitizer, an antioxidant, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, and a viscosity modifier as necessary. Further, it may contain an adhesion improver and the like. In particular, the resin composition may contain a surfactant containing the above-described hydrophilic group, but when the main hydrophilicity of the resin composition is supported by the surfactant, Since there is a concern about a decrease in anti-fogging performance due to surfactant elution, the resin skeleton itself is more preferably hydrophilic.

Next, the dimension of the uneven structure layer 30 will be described. In the anti-reflection function using the moth-eye structure, the effective refractive index at the interface between the moth-eye structure and the medium adjacent thereto is continuously changed in the thickness direction to prevent reflection. For this reason, the concavo-convex surface 31 of the concavo-convex structure layer 30 is formed by the minute projections 32 arranged along the sheet surface of the concavo-convex structure layer 30 with an interval d equal to or shorter than the shortest wavelength in the visible light band. From the viewpoint of securing an excellent antireflection function, the average value d _ave of the interval d between the adjacent minute protrusions 32 is set to be equal to or shorter than the shortest wavelength in the visible light band. In particular, it is more preferable that the maximum value d _{max of the} distance d is not more than the shortest wavelength in the visible light band. Here, the adjacent microprotrusions 32 related to the distance d are so-called adjacent microprotrusions 32, which are two protrusions that are in contact with the hem portion of the microprotrusion that is the base portion on the transparent substrate 25 side. . In the concavo-convex structure layer 30, the microprojections 32 are arranged in close contact with each other so that when a line segment is created so as to sequentially follow the valleys between the microprojections 32, polygonal regions surrounding the microprojections are obtained in plan view. A mesh-like pattern formed by connecting a large number is produced. The adjacent minute protrusions 32 related to the distance d are protrusions that share a part of the line segments constituting the mesh pattern. Moreover, the space | interval d can be made into the distance between the top parts 33 of the two adjacent microprotrusion 32 along the film surface of the antireflection film 20, as shown in FIG. Hereinafter, the distance d between the adjacent minute protrusions 32 is also referred to as the distance between adjacent protrusions.

  However, from the viewpoint of imparting an excellent antireflection function and antifogging function to the concavo-convex structure layer 30, it is more preferable that the fine protrusions 32 forming the concavo-convex structure layer 30 are formed as follows. First, the fine protrusions 32 of the concavo-convex structure layer 30 are preferably provided at intervals d of 70 nm or more and 300 nm or less, and are provided at intervals d of 70 nm or more and 180 nm or less along the film surface of the antireflection film 20. More preferably. Further, the height H of the fine protrusion 32 along the normal direction nd to the film surface of the antireflection film 20 is preferably 50 nm or more and 300 nm or less, and more preferably 100 nm or more and 250 nm or less. preferable.

  The superhydrophilicity on the uneven surface 31 of the uneven structure layer 30 is obtained by a combination of a hydrophilic material and the uneven surface 31 and is affected by the aspect ratio of the microprojections 32 and the specific surface area of the uneven surface 31. Similarly, the antireflection function on the uneven surface 31 is also affected by the aspect ratio of the microprojections 32. The aspect ratio is the ratio of the height H of the microprojections 32 to the width of the microprojections 32. In the concavo-convex structure layer 30, the width of the microprojections 32 can be replaced with the interval d between the microprojections 32. It is an indicator. From the viewpoint of imparting an excellent antireflection function and antifogging function to the concavo-convex structure layer 30, the aspect ratio of the fine protrusions 32 is preferably 0.17 or more and 4.23 or less, and is 1.8 or more. It is more preferable that it is 3.57 or less. On the other hand, the specific surface area is an effective surface area per unit area. When the specific surface area is increased by the fine protrusion structure, the hydrophilicity of the material forming the uneven structure is more emphasized on the hydrophilic side.

  The various dimensions and shapes of the concavo-convex surface 31 and the microprotrusions 32 of the concavo-convex structure layer 30 are specified using an atomic force microscope (AFM) or a scanning electron microscope (SEM). be able to.

The thickness of the concavo-convex structure layer 30 is not particularly limited, but may be 10 to 300 μm as an example. In this case, the thickness of the concavo-convex structure layer 30 means that the microprojections 32 forming the concavo-convex surface 31 of the concavo-convex structure layer 30 from the interface on the transparent substrate 25 side of the concavo-convex structure layer 30 as shown in FIG. The height t ₁ along the normal direction nd to the film surface of the antireflection film 20 up to the top 33 is meant.

  Further, when the concavo-convex structure layer 30 is observed from a direction inclined with respect to the normal direction nd, the concavo-convex surface 31 of the concavo-convex structure layer 30 may be observed as white and cloudy. Is based on the phenomenon that scattering occurs when the wavelength is close to the lower limit wavelength of visible light. In order to avoid this, the pitch may be reduced. However, it is possible to deliberately widen the pitch for applications where it is difficult to see when viewed from an oblique direction.

  It is surmised that the following factors are responsible for the white turbidity observed. First, by observing the microprotrusions 32 formed small relative to the wavelength of light from an oblique direction, the cross-sectional shape of the microprotrusions 32 along the observation direction changes. Then, when observing from a certain observation direction inclined from the normal direction of the concavo-convex structure layer 30, the distance d between adjacent protrusions or the outer peripheral length in a cross section parallel to the observation direction is generally visible light. May be equal to the wavelength of. As a result, the antireflection effect by the moth-eye structure is reduced. Further, at this time, Mie scattering is caused by the minute protrusions 32, and it is assumed that the observer observes the Mie scattered light as white turbid light. However, the present invention is not limited to this estimation.

  In the concavo-convex structure layer 30 as described above, in consideration of ensuring good visibility through the partition member 10, the visible light transmittance of the concavo-convex structure layer 30 alone is preferably 90% or more, More preferably, it is 95% or more.

  Incidentally, in the concavo-convex structure layer 30 shown in FIG. 5, the microprojections 32 are irregularly arranged, but the arrangement of the microprojections 32 may be irregular or regular. However, from the viewpoint of preventing the occurrence of interference patterns, it is preferable that the arrangement of the microprojections 32 is irregular. Therefore, as shown in FIGS. 1 and 2, when the two antireflection films 20a and 20b are arranged so as to overlap at least partially, a minute amount is formed between the two antireflection films 20a and 20b. It is preferable that the arrangement of the minute projections 32 of at least one antireflection film 20 is irregular so that an interference pattern due to the arrangement of the projections 32 does not occur.

<Method for producing antireflection film>
The antireflection film 20 may be appropriately selected from conventionally known methods for forming the uneven structure layer 30 on the transparent substrate 25. For example, first, a concavo-convex structure layer forming resin composition that forms the concavo-convex structure layer 30 is applied onto the transparent substrate 25, and the concavo-convex structure layer forming micropores complementary to the desired microprojection shape is applied. After forming into a coating film of the resin composition for forming the uneven structure layer using the original plate, the uneven structure layer is formed by curing the resin composition for forming the uneven structure layer, and from the original plate for forming the uneven structure layer Examples include a peeling method. The method of curing the resin composition for forming an uneven structure layer can be appropriately selected according to the type of the resin composition for forming an uneven structure layer.

  The original plate for forming a concavo-convex structure layer is not particularly limited as long as it is not deformed and worn when repeatedly used, and may be made of metal or resin, A metal is preferably used. This is because it is excellent in deformation resistance and wear resistance. The surface having the fine holes of the original for forming an uneven structure layer is not particularly limited, but is preferably made of aluminum from the viewpoint of easy processing by anodic oxidation. Specifically, the original plate for forming the concavo-convex structure layer is, for example, a high-purity aluminum layer by sputtering or the like directly on the surface of a metal base material such as stainless steel, copper, or aluminum, or through various intermediate layers. Is provided, and a fine hole is formed in the aluminum layer. Prior to providing the aluminum layer, the surface of the base material may be made into a super mirror surface by an electrolytic composite polishing method in which electrolytic elution action and abrasion action by abrasive grains are combined.

  Examples of a method for forming fine holes in the original plate for forming a concavo-convex structure layer include, for example, an anodic oxidation step of forming a porous alumina layer having a plurality of fine holes on the surface of an aluminum layer by an anodic oxidation method, and a porous alumina layer Can be formed by sequentially repeating an etching process for forming a tapered shape at the opening of the fine hole and increasing the diameter of the fine hole. When forming a fine concavo-convex shape, a desired shape can be obtained by appropriately adjusting the purity (amount of impurities), crystal grain size, anodizing treatment and / or etching conditions of the aluminum layer. . In anodizing treatment, more specifically, by controlling the liquid temperature, the voltage to be applied, the time to be subjected to anodization, etc., the fine holes are formed into shapes corresponding to the target depth and the shape of the fine protrusions, respectively. Can do.

  In this way, the concavo-convex structure layer forming original plate is densely prepared with a large number of fine holes whose hole diameter gradually decreases in the depth direction. The concavo-convex structure layer 30 manufactured using the concavo-convex structure layer forming original plate has a plurality of microprojections 32 that gradually decrease in diameter as they approach the top corresponding to the fine holes of the concavo-convex structure layer forming original plate. The concavo-convex structure layer 30 that is closely arranged is formed, that is, the material portion that forms the microprojection 32 in the horizontal cross section when it is assumed that the microprojection 32 is cut in a horizontal plane perpendicular to the depth direction of the microprojection 32. A microprojection shape is formed in which the cross-sectional area occupancy increases gradually and gradually as it approaches the deepest portion from the top of the microprojection 32.

  In addition, the shape of the original plate for forming a concavo-convex structure layer is not particularly limited as long as a desired shape can be formed. For example, the shape may be a flat plate or a roll. However, it is preferable to use a roll-shaped mold (hereinafter sometimes referred to as “roll mold”) as the concavo-convex structure layer forming original plate from the viewpoint of improving productivity. As the roll mold, for example, a cylindrical metal material is used as a base material, and the aluminum layer provided directly or via various intermediate layers on the peripheral side surface of the base material, as described above, The thing by which the fine uneven | corrugated shape was produced by repeating an anodizing process and an etching process is mentioned.

  In FIG. 5, when the photocurable resin composition is used as the resin composition for forming the uneven structure layer and the roll mold is used as the original plate for forming the uneven structure layer, the uneven structure layer 30 is formed on the transparent substrate 25. An example of how to do this is shown. In the method shown in FIG. 5, in the resin supply step, an uncured and liquid photocurable resin composition is applied to the transparent base material 25 in the form of a strip by a die 36 to form a receiving layer 35 for microprojections. To do. In addition, about application | coating of a photocurable resin composition, not only the case by the die | dye 36 but various methods are applicable. Subsequently, the transparent base material 25 is pressed and pressed against the peripheral side surface of the roll die 37 which is the first master for forming the concavo-convex structure layer by the pressing roller 38 a, and thereby the receiving layer 35 is brought into close contact with the transparent base material 25. At the same time, the photocurable resin composition constituting the receiving layer 35 is sufficiently filled in the fine uneven holes formed on the peripheral side surface of the roll mold 37. In this state, the photocurable resin composition is cured by irradiation with ultraviolet rays, whereby the concavo-convex structure layer 30 is produced on the surface of the transparent substrate 25. Subsequently, the transparent base material 25 is peeled from the roll die 37 through the peeling roller 38b integrally with the hardened concavo-convex structure layer 30. If necessary, an adhesive layer or the like is formed on the side surface of the transparent substrate 25 opposite to the surface on which the concavo-convex structure layer 31 is formed. Thereby, the antireflection film 20 sequentially molds the microprojection shape 32 produced on the peripheral side surface of the roll mold 37 which is the original plate for forming the concavo-convex structure layer on the long transparent base material 25 made of a roll material, Mass production is efficient.

  In the above-described embodiment, the case where the film-shaped antireflection film 20 is produced by the forming process using the roll die 37 is described. However, the present invention is not limited to this example, and the transparent substrate according to the shape of the antireflection film 20 is described. Depending on the shape of the material 25, for example, when forming the antireflection film 20 by processing of a flat plate or a sheet using a mold for molding with a specific curved surface shape, the process related to the molding process, the formation of the concavo-convex structure layer The original plate can be appropriately changed according to the shape of the transparent substrate 25 related to the shape of the antireflection film 20.

<< Effect of partition member >>
Next, the effect of the partition member 10 as described above will be described. The partition member 10 described above for partitioning a region includes a transparent body 15 and an antireflection film 20 attached to the transparent body 15 as shown in FIG. As shown in FIG. 3, the antireflection film 20 has a concavo-convex structure layer 30 having a concavo-convex surface 31 formed by minute protrusions 32 provided at intervals d that are equal to or shorter than the shortest wavelength in the visible light band. The antireflection film 20 is arranged so that the uneven surface 31 faces the side opposite to the transparent body 15.

  And the reflectance by 5 degree regular reflection on the uneven surface 31 of the antireflection film 20 is 0.3% or less, and the contact angle with respect to the water on the uneven surface 31 of the antireflection film 20 is 20 degrees or less. It has become. That is, the concavo-convex surface 31 of the antireflection film 20 can exhibit an antireflection function that is remarkably superior to an antireflection layer made of a conventional low refractive index layer. At the same time, since the uneven surface 31 of the antireflection film 20 has super hydrophilicity, it is possible to effectively prevent the uneven surface 31 from being clouded with water droplets. Specifically, even if water droplets adhere to the uneven surface 31 due to condensation or the like, the water drops extend thinly on the uneven surface 31. As a result, light scattering by the water droplet particles on the uneven surface 31 is suppressed, and an antifogging function is exhibited. In addition, since a thin water film is formed on the surface, dirt hardly adheres and self-cleaning properties are also exhibited. This anti-fogging performance is not due to imparting hydrophilicity by the addition of a surfactant or the like, but is expressed by a synergistic effect of the hydrophilic resin material and the surface microstructure, so that the anti-fogging performance is unlikely to deteriorate over time. There is also.

  According to such a partition member 10, surface reflection in the region where the antireflection film 20 is provided is extremely effectively prevented. Accordingly, not only observation between the sections S1 and S2 is possible through the partition member 10 with a high visible light transmittance, but also the reflection over the surface of the partition member 10 is prevented while passing through the partition member 10. Observation between the areas S1 and S2 becomes possible. In addition, it is effective that the surface of the partition member 10 is clouded with water droplets even when the humidity is high such as the rainy season or when the environmental conditions are different between the areas S1 and S2 due to air conditioning or the like. Can be prevented. As a result, there is a difference in brightness between the areas S1 and S2, and even when the dark area side is observed from the bright area side, the dark area can be confirmed relatively clearly through the partition member 10. .

  In particular, when the antireflection film 20 is formed on both surfaces of the transparent body 15, the antireflection function and the antifogging function are sufficiently exhibited on both the pair of opposing surfaces of the partition member 10. Therefore, a very good field of view can be secured through the partition member 10.

  Furthermore, since the concavo-convex surface 31 of the concavo-convex structure layer 30 has super hydrophilicity, the dirt on the concavo-convex surface 31 can be sufficiently cleaned using an aqueous cleaner. That is, the cleaner extends along the concavo-convex surface 31 together with moisture and can enter between the minute protrusions 32. As a result, the removal of the foreign matter that has entered between the minute protrusions 32 can be promoted by the cleaner, and the uneven structure layer 30 can continue to sufficiently exhibit the antireflection function and the antifogging function. In this respect, it can be said that the antireflection film 20 and the partition member 10 are excellent in decontamination.

  Furthermore, the reflectance of the antireflection film formed as the low refractive index layer has a spectral distribution. Specifically, the antireflection film composed of the low refractive index layer is superior to the light of a specific wavelength according to the thickness and the observation direction of the low refractive index layer than the light of other wavelength regions. Provides antireflection function. As a result, the low refractive index layer is colored according to the viewing direction, and when applied to the partition member 10, it is expected that inconvenience will occur. On the other hand, unlike the antireflection layer composed of the low refractive index layer, in the partition member 10 that exhibits the antireflection function by the concavo-convex structure layer 30, when the partition member 10 is observed, the color changes according to the observation direction. Will not occur.

  Furthermore, the antireflection film 20 can be produced by forming an uneven structure layer 30 formed by molding an ionizing radiation curable resin on the transparent substrate 25. And the uneven | corrugated structure layer 30 which consists of hardened | cured material of a resin composition is excellent in the surface of stability, and can continue exhibiting the function planned stably for a long period of time. In this regard, the uneven structure layer 30 has a longer life compared to a structure that exhibits a lotus effect (lotus effect) by a chemical method, and can be easily formed at a low cost.

<< Specific application example of partition member >>
6 and 7 show specific application examples of the partition member 50. FIG. In the example shown in FIGS. 6 and 7, for example, a building 90 in which a supervisor (guard) G who monitors entry into a site such as a factory or a parking lot and exit from the site is stationed is divided. A member 50 is applied. As shown in FIG. 7, the building 90 forms an indoor area S <b> 1 that is separated from the outside by a wall 91, a ceiling 92, and a floor 93. The partition member 50 is attached to an opening formed in the building 90 as a so-called window member, and divides the area S1 that is indoors and the area S2 that is outdoor. The guard G faces the partition member 50 and is located in the indoor section S1 and monitors the state from the section S1 to the section S2 through the partition member 50. A lighting fixture 84 is attached to the ceiling 92 in the building 90. By turning on the lighting fixture 84 from the evening to the night, the area S1 in the building 90 becomes brighter than the area S2.

  The partition member 50 shown in FIGS. 6 and 7 includes a first antireflection film 60a attached to a part of the surface of the transparent body 55 on the area S1 side, and a surface of the transparent body 55 on the area S2 side. And a second antireflection film 60b pasted to the first antireflection film 60a. The first antireflection film 60a and the second antireflection film 60 are disposed at positions facing the guard G. The first antireflection film 60a and the second antireflection film 60b are bonded to the transparent body 55 via the bonding layer 18 as in the above-described embodiment. The transparent body 55 can be configured similarly to the transparent body 15 of the above-described embodiment. Moreover, the 1st antireflection film 60a and the 2nd antireflection film 60b may be comprised similarly to the antireflection film 20 of embodiment mentioned above.

  Furthermore, in the example shown in FIG. 6 and FIG. 7, the photographing means 80 is provided in the area S1. The imaging unit 80 forms a monitoring system 40 together with the partition member 50. The photographing unit 80 is attached to the ceiling 92 of the building 90 by a support unit 81. The support unit 81 rotatably supports the photographing unit 80 with respect to the building 90 and the partition member 50. The imaging means 80 is arranged in the vicinity of the partition member 50 and images the state of the area S2 from the area S1 in the building 90 through the partition member 50. In the building 90, display means 82 connected to the photographing means 80 via a connection line 83 is provided. The display means 82 can receive the video imaged by the imaging means 80 via the connection line 83 and display the video image. In the illustrated example, the display means 82 is disposed behind the guard G, and the display surface of the display means 82 faces the partition member 50 side.

  In the example shown in FIGS. 6 and 7, the partition member 50 includes a third antireflection film 60 c attached to a part of the surface of the transparent body 55 which is the area S1 side, and the area S2 side of the transparent body 55. And a fourth antireflection film 60d attached to a part of the surface facing the third antireflection film 60c. The third antireflection film 60c and the fourth antireflection film 60d are elongated in a direction non-parallel to the rotation axis a1 of the photographing unit 80. And the imaging | photography means 80 is image | photographing area S2 through the part to which the 3rd antireflection film 60c and the 4th antireflection film 60d of the division member 50 are bonded. In other words, the third antireflection film 60c and the fourth antireflection film 60d are arranged at a position between the photographing unit 80 and the photographing range by the photographing unit 80.

  In the illustrated example, the rotation axis a1 of the photographing means 80 is parallel to the vertical direction. As a result, the photographing unit 80 can photograph a wide area extending in the horizontal direction. Accordingly, the third antireflection film 60c and the fourth antireflection film 60d are elongated in the horizontal direction. That is, the width along the horizontal direction of the third and fourth antireflection films 60c and 60d is a direction perpendicular to the horizontal direction of the third and fourth antireflection films 60c and 60d (the partition member 50 extends in the vertical direction). If it is, it is wider than the width along the vertical direction).

  In addition, the 3rd antireflection film 60c and the 4th antireflection film 60d are bonded by the transparent body 55 via the joining layer 18 similarly to embodiment mentioned above. The third antireflection film 60c and the fourth antireflection film 60d are disposed at positions shifted from the first antireflection film 60a and the second antireflection film 60b along the plate surface of the partition member 10, respectively. The third antireflection film 60c and the fourth antireflection film 60d can be configured similarly to the antireflection film 20 of the above-described embodiment.

  According to such a partition member 50, the guard G from the section S <b> 1 in the building 90 through the portion of the partition member 50 where the first and second antireflection films 60 a and 60 b are provided. The state of the area S2 outside the building 90 will be observed. The first and second antireflection films 60a and 60b exhibit both an antireflection function and an antifogging function. For this reason, for example, the indoor image of the lighting fixture 84 or the display means 82 is effectively prevented from being reflected on the partition member 50, and at the same time, the partition member 50 is dewed depending on the environmental conditions such as humidity. Clouding is effectively prevented.

As a result, the guard G has the first and second antireflection films 60a and 60b in the partition member 50 even at night when the brightness of the area S1 is brighter than the brightness of the area S2 due to cloudy weather. The state of the area S1 to the area S2 can be clearly confirmed through the portion provided with. That is, as in the prior art, it is necessary to open the partition member 50 made of an openable window material each time, and further to check the state of the area S2 outside the building 90 by exposing the face from the area S1 to the area S2. There is no. Thus, the ability to eliminate the necessity of opening and closing the partition member 50 is preferable for safety, and is particularly useful for the partition member 50 that cannot be opened from the viewpoint of safety. Moreover, it is not necessary to open the partitioning member 50, it is possible to remove the amount of air-conditioning equipment, to achieve energy saving and more can also be reduced in the CO _2. In addition, insects and the like can be prevented from entering the building 90.

  In addition, the width along the horizontal direction of the first and second antireflection films 60a and 60b is perpendicular to the horizontal direction of the first and second antireflection films 60a and 60b (the partition member 50 extends in the vertical direction). The first and second antireflection films 60a and 60b may be elongated in the horizontal direction so as to be wider than the width along the vertical direction in the case of being present. In this case, the guard G can monitor a wider range through the partition member 50 along the horizontal direction while sitting down.

  Similarly, the imaging means 80 that forms the monitoring system 40 passes from the section S1 within the building 90 to the building 90 via the portion of the partition member 50 where the third and fourth antireflection films 60c and 60d are provided. The state of the outside area S2 is photographed. At this time, the third and fourth antireflection films 60c and 60d exhibit both the antireflection function and the antifogging function. For this reason, the photographing unit 80 can photograph the state of the area S2 with high image quality without photographing a room image such as the lighting fixture 84 and the display unit 82 reflected in the partition member 50. In addition, it is possible to avoid a problem that the partition member 50 unintentionally adheres to the partition member 50 due to condensation or the like and later notices that the state of the area S2 has not been photographed. As such photographing means, a TV camera using an imaging tube or a solid-state imaging device, a photographic machine using a silver salt film, or the like can be used. As the shooting mode, a moving image or a still image is appropriately selected according to the use and purpose. As the display means 82, a normal liquid crystal display device (LCD), a plasma display device (PDP), a cathode ray tube (CRT) display device, an electroluminescence (EL) display device, etc. may be appropriately selected.

  The first and second antireflection films 60a and 60b are provided over the entire surface of the transparent body 55, so that the first antireflection film 60a and the third antireflection film 60c can be used together. The second antireflection film 60b and the fourth antireflection film 60d can also be used. Moreover, in the case of such a form, it is possible to ensure favorable visibility over the front surface of the partition member 50. However, in the case of such a configuration, since the presence of the partition member 50 is difficult to detect, there is a possibility that a problem such as a body or an object easily colliding with the partition member 50 may occur. In order to prevent this, in the case of such a form, it is preferable to display for collision prevention on a part of the partition member. As such a collision-preventing display, for example, a predetermined pattern is printed on the interlayer between the transparent body 55 and the antireflection films 60a, 60b (etc.) or on the outer surface of the antireflection films 60a, 60b (etc.). Printing, coating, writing with paint, or colored paper, resin film, metal foil, or the like can be cut out in a predetermined pattern and bonded through an adhesive layer. As the predetermined pattern, for example, a figure such as a circle or a polygon, or a character or sentence such as “with window glass, attention” can be selected as appropriate.

In addition, since the dew condensation of the first and third antireflection films 60a and 60c can be prevented on the area S1 side in the building 90, it is possible to omit the need to dehumidify the inside of the building 90. In this respect as well, it is possible to realize energy saving and further reduce CO ₂ .

  Further, it is possible to clearly check the state of the section S1 from the section S2 through the portion of the partition member 50 where the antireflection films 60a, 60b, 60c, 60d are provided. This instigates the suspicion of suspicious persons who are trying to enter the site, thereby preventing the suspicious person from entering. In particular, in the illustrated example, since the antireflection films 60a, 60b, 60c, and 60d are bonded to a part of the partition member 50, attention or alertness can be evoked more effectively.

  The partition members 10 and 50 and the monitoring system 40 are not limited to the examples shown in FIGS. 6 and 7 and can be applied to various specific applications. As an example, the window member of the moving means can be replaced with a partition member having an antireflection film. In this application, a person (operator, passenger, crew member, and / or crew member) who has traveled on a moving means such as a car, a train, an airplane, or a ship can see the outside of the moving means with good visibility through the partition member. Can be confirmed. Moreover, the recent moving means has a monitoring system such as a drive recorder and a travel recorder, and the monitoring system 40 including the partition members 10 and 50 and the photographing means 80 is used as a drive recorder or a travel recorder as the moving means. Can be applied.

  Moreover, the partition members 10 and 50 mentioned above can be applied to a transparent window or door of a store. Furthermore, as represented by convenience stores, crime prevention photographing means may be provided in the store. It is also possible to apply the monitoring system 40 having the partition members 10 and 50 and the imaging unit 80 described above to such a store.

  Furthermore, the partition members 10 and 50 described above can be applied to the windows of observation vehicles, observation platforms, and observation facilities. Moreover, the partition members 10 and 50 described above can be applied to a windshield of a helmet, particularly a full-face helmet.

<< Resin material forming the concavo-convex structure layer >>
As described above, the uneven structure layer 30 can be formed using a resin material. More specifically, the concavo-convex structure layer 30 can be made of a cured product of the resin composition. Here, the results obtained by the inventors of the present invention will be described regarding the resin material forming the concavo-convex structure layer 30 incorporated in the reflecting member 10.

  As a result of repeated studies by the present inventors, when the uneven structure layer 30 of the antireflection film 20 is made of a resin material, particularly a cured product of the resin composition, the resin material (cured product of the resin composition) The inventors have found that it is preferable to have the following physical properties. First, the storage elastic modulus (E1 ′) at 25 ° C. of the resin material (cured product of the resin composition) itself is preferably 300 MPa or less. Next, the ratio (tan δ (= E1 ″ / E1 ′)) of the loss elastic modulus (E1 ″) to the storage elastic modulus (E1 ′) at 25 ° C. of the resin material (cured product of the resin composition) is 0.2. The following is preferable. Furthermore, the contact angle (static contact angle by the θ / 2 method) of n-hexadecane on the surface of the resin material (cured product of the resin composition) is 30 ° or less, or the resin material (resin composition) The contact angle of oleic acid on the surface of the cured product) (static contact angle by the θ / 2 method) is preferably 25 ° or less. In these cases, it is easy to wipe off dirt by dry wiping, and even if oily dirt such as fingerprint dirt adhered to the surface is not completely wiped off, it spreads thinly on the surface of the fine uneven layer, so that the dirt is It becomes inconspicuous and the visibility after wiping is improved. Therefore, when the antireflection film 20 is laminated on the reflector 15, the visibility of the reflector 15 through the antireflection film 20 can be improved.

  As the conventional moth-eye structure, one having a high hardness of the fine protrusion 32 has been widely used from the viewpoint of scratch resistance. Since the fine protrusions with high hardness hardly deform even when pressure is applied during wiping, it is difficult to wipe off the dirt by dry wiping. On the other hand, the microprotrusions 32 that can be easily deformed by pressure are easily crushed by the pressure, and sticking, which is a phenomenon in which the adjacent microprotrusions are kept in contact with each other, is easily generated. It was easy to leave marks.

On the other hand, when the storage elastic modulus (E1 ′) of the resin material (cured product of the resin composition) forming the concavo-convex structure layer 30 is 300 MPa or less and the loss tangent (tan δ) is 0.2 or less, the resin The microprotrusions 32 of the concavo-convex structure layer 30 made of a material are deformed by a pressure of wiping and have an excellent elastic restoring property. Therefore, when the dirt is wiped by dry wiping, the microprotrusions 32 are deformed by the pressure, and the dirt adhering to the valleys between the microprotrusions 32 is squeezed out to the vicinity of the tops of the microprotrusions and mechanically scraped off. When the pressure is removed, the shape of the original microprojection 32 is restored without causing plastic deformation. For this reason, according to the concavo-convex structure layer 30 having the above-described physical properties, it is possible to wipe off dirt without deteriorating the antireflection performance, even with dry wiping. The size of the pressure when Ri wiping is not particularly limited, usually, is about 2~5kg / cm ² pressure of about.

  Hereinafter, in an example in which the concavo-convex structure layer 30 is formed as a cured product of the resin composition, suitable physical properties of the cured product of the concavo-convex structure layer forming resin composition used for forming the concavo-convex structure layer will be described, and then A suitable composition of the resin composition for forming a concavo-convex structure layer for realizing physical properties will be described.

  As described above, the storage elastic modulus (E1 ′) at 25 ° C. of the cured product of the resin composition for forming an uneven structure layer is preferably 300 MPa or less. By setting E1 ′ to 300 MPa or less, the microprotrusions are deformed by the wiping pressure, and the dirt that has entered the gaps between the microprotrusions can be squeezed out to the vicinity of the tops of the microprotrusions and removed by dry wiping. . In this respect, the storage elastic modulus (E1 ′) is preferably 1 to 250 MPa, and more preferably 1 to 100 MPa.

  Similarly, as described above, the ratio of loss elastic modulus (E1 ″) to storage elastic modulus (E1 ′) at 25 ° C. of the cured product of the resin composition for forming an uneven structure layer (tan δ (= E1 ″ / E1 ′) loss The tangent) is preferably 0.2 or less. By setting the loss tangent to 0.2 or less, the minute protrusions deformed at the time of wiping are elastically restored and easily return to the original shape. As a result, the plastic deformation of the protrusions and the permanent fusion of sticking years, that is, sticking, are suppressed, and the dirt can be wiped off by dry wiping without deteriorating the antireflection performance. Among them, tan δ is preferably 0.18 or less.

  In addition, the storage elastic modulus and loss elastic modulus (simply referred to as the storage elastic modulus and loss elastic modulus of the resin composition) of the resin composition itself referred to in this specification are as follows according to JIS K7244. Measured by the method. First, the resin composition for forming a concavo-convex structure layer is sufficiently cured by irradiating an ultraviolet ray having an energy of 2000 mJ / cm2 for 1 minute or more, and does not have a substrate and microprojection shape, a thickness of 1 mm, a width of 5 mm, A single film with a length of 30 mm is used. Next, under 25 ° C., by applying 25 g of periodic external force at 10 Hz in the length direction of the cured product of the resin composition for forming an uneven structure layer, measuring dynamic viscoelasticity, E ′ at 25 ° C., E ″ is required. As a measuring device, for example, Rhegel E400 manufactured by UBM can be used.

  Further, the cured product of the resin composition for forming an uneven structure layer has a contact angle of n-hexadecane (static contact angle in the θ / 2 method) of 30 ° or less on the surface of the cured product, or The contact angle of oleic acid (static contact angle in the θ / 2 method) is preferably 25 ° or less. When the surface of the cured product of the resin composition for forming the concavo-convex structure layer has lipophilicity as described above, the oily dirt attached to the concavo-convex surface 31 forming the surface of the concavo-convex structure layer 30 could not be completely wiped off. Even so, since it spreads thinly on the concavo-convex surface 31 of the concavo-convex structure layer 30, the dirt becomes inconspicuous, and the visibility after wiping is improved.

  The contact angle of the cured product of the resin composition for forming an uneven structure layer referred to in this specification is not the contact angle on the uneven surface 31 of the uneven structure layer 30 as described above, but an uneven structure on the substrate. It is a contact angle measured on a flat surface having no microprojection shape 32 of a cured product formed by applying and curing the layer-forming resin composition.

  In the antireflection film 20, the elastic modulus of the concave-convex surface 31 of the concave-convex structure layer 30 (different from the elastic modulus of the resin composition itself) is preferably 200 to 500 MPa, and preferably 220 to 400 MPa from the viewpoint of excellent flexibility. It is preferable that The maximum indentation depth of the concavo-convex surface 31 of the concavo-convex structure layer 30 is preferably 1.0 to 2.0 μm, and preferably 1.2 to 1.8 μm from the viewpoint of being easily deformable and excellent in wiping properties. Is more preferable. In addition, the elastic recovery rate of the concavo-convex surface 31 of the concavo-convex structure layer 30 is preferably 80% or more, more preferably 85-98%, from the point that plastic deformation is small and wiping marks are not easily generated. preferable.

The elastic modulus, maximum indentation depth, and elastic recovery rate referred to in this specification are measured as follows. That is, the indentation surface 31 of the uneven structure layer 30 of the antireflection film 20 can be pressed into an indenter under the following specific conditions to measure the elastic modulus, maximum indentation depth, and elastic recovery rate of the film surface. As the measuring apparatus, for example, PICODENER HM-500 manufactured by Fischer Instruments can be used.
<Measurement conditions>
・ Loading speed 1mN / 10 seconds ・ Holding time 10 seconds ・ Load unloading speed 1 mN / 10 seconds ・ Indenter Vickers ・ Measurement temperature 25 ℃

  Next, the composition of the resin composition for forming the uneven structure layer 30 will be described.

  The resin composition for forming a concavo-convex structure layer includes a thermosetting component and / or a photocurable component, and those having the above physical properties after curing are used. Especially, it is preferable that it is a photocurable resin composition containing a photocurable component. As said photocurable component, it is preferable that it is a composition containing the compound which has an ethylenically unsaturated bond, and it is more preferable that it is a composition containing (meth) acrylate. The photocurable resin composition should just contain the said photocurable component at least, and may contain another component as needed. In addition, the resin composition for forming an uneven structure layer may contain a compound having a long-chain alkyl group having 10 or more carbon atoms from the viewpoint that the lipophilicity of the cured product surface is improved and the fine protrusions are excellent in flexibility. preferable. Hereinafter, each component in the composition containing (meth) acrylate which is preferably used as the photocurable component will be described in order.

(1) (Meth) acrylate (meth) acrylate is a monofunctional (meth) acrylate having one (meth) acryloyl group in one molecule, but two or more (meth) acryloyl groups in one molecule It may be a polyfunctional acrylate having a monofunctional (meth) acrylate and a polyfunctional (meth) acrylate. Among these, it is preferable to use a monofunctional (meth) acrylate and a polyfunctional (meth) acrylate in combination from the viewpoint that the cured product satisfies the above physical properties and the microprotrusions have both flexibility and elastic resilience.

  Specific examples of monofunctional (meth) acrylates include, for example, methyl (meth) acrylate, hexyl (meth) acrylate, decyl (meth) acrylate, allyl (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate , Butoxyethylene glycol (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycerol (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, isobornyl (meth) acrylate, isodexyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate Relate, 2-methoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, stearyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, biphenyloxyethyl acrylate, bisphenol A diglycidyl (meth) acrylate, biphenylyloxyethyl (meth) acrylate, ethylene oxide modified biphenylyloxyethyl (meth) acrylate, bisphenol A epoxy (meth) acrylate, and the like. Among these, a monofunctional (meth) acrylate having a long-chain alkyl group having 10 or more carbon atoms is preferable from the viewpoint that the lipophilicity of the cured product surface is improved and the microprotrusions are excellent in flexibility. It is even more preferable that it contains at least one of tridecyl (meth) acrylate and dodecyl (meth) acrylate. These monofunctional (meth) acrylic acid esters can be used alone or in combination of two or more. In addition, when using the monofunctional (meth) acrylate which has a C10 or more long-chain alkyl group, it has the characteristic of the compound which has a C10 or more long-chain alkyl group mentioned later.

  It is preferable that content of monofunctional (meth) acrylate is 5-40 mass% with respect to the total solid of a photocurable resin composition, and it is more preferable that it is 10-30 mass%.

  Specific examples of the polyfunctional acrylate include, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene di (meth) acrylate, hexanediol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. Bisphenol A di (meth) acrylate, tetrabromobisphenol A di (meth) acrylate, bisphenol S di (meth) acrylate, butanediol di (meth) acrylate, di (meth) acrylate phthalate, ethylene oxide modified bisphenol A di ( (Meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tri (Acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane tri (meth) acrylate, ester tri (meth) acrylate, urethane hexa (meth) acrylate, ethylene oxide modified tri Examples include methylolpropane tri (meth) acrylate. Among these, from the viewpoint that the microprotrusions are excellent in flexibility and restorability, it is preferable to use a polyfunctional (meth) acrylate containing an alkylene oxide, more preferably an ethylene oxide modified polyfunctional (meth) acrylate, and an ethylene oxide modified Even more preferably, at least one of bisphenol A di (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, and polyethylene glycol di (meth) acrylate is included.

  It is preferable that content of the said polyfunctional (meth) acrylate is 10-95 mass% with respect to the total solid of a photocurable resin composition, and it is more preferable that it is 15-90 mass%.

(2) Compound having a long-chain alkyl group having 10 or more carbon atoms The resin composition for forming a concavo-convex structure layer has an improved lipophilicity on the surface of the cured product, and the fine protrusions are excellent in flexibility. A compound having a long-chain alkyl group is preferably contained, and a compound having a long-chain alkyl group having 12 or more carbon atoms is more preferably contained. Specific examples of the compound having a long chain alkyl group having 10 or more carbon atoms include compounds having decane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, and the like. Moreover, unless the effect of this invention is impaired, you may have a substituent further. Specific examples of the substituent include halogen atoms such as fluorine, chlorine and bromine, hydroxyl groups, carboxy groups, amino groups and sulfo groups, as well as ethylenically unsaturated double bonds such as vinyl groups and (meth) acryloyl groups. Groups and the like. Especially, it is preferable to have an ethylenically unsaturated double bond from a point provided with photocurability, and it is more preferable to have a (meth) acryloyl group. In addition, when the compound which has a C10 or more long-chain alkyl group has a (meth) acryloyl group, the said compound may correspond also to the said (meth) acrylate.

  When using a compound having a long-chain alkyl group having 10 or more carbon atoms, the content of the compound is preferably 5 to 30% by mass with respect to the total solid content of the photocurable resin composition. More preferably, it is 20 mass%.

  The photocurable resin composition preferably used as the resin composition for forming an uneven structure layer is easy to adjust the storage elastic modulus and loss tangent of the cured product within the above-mentioned ranges and easy to adjust to oleophilicity, and is excellent in dryness. It is particularly preferable that at least a (meth) acrylate having a long-chain alkyl group having 10 or more carbon atoms and an ethylene oxide-modified polyfunctional (meth) acrylate are contained from the viewpoint that wiping properties can be obtained. Especially, it is preferable that the content rate of the (meth) acrylate which has a C10 or more long-chain alkyl group is 5-30 mass parts with respect to 100 mass parts of ethylene oxide modified polyfunctional (meth) acrylate. More preferably, it is -15 mass parts.

(3) Photopolymerization initiator In order to initiate or accelerate the curing reaction of the (meth) acrylate, a photopolymerization initiator may be appropriately selected and used as necessary. Specific examples of the photopolymerization initiator include, for example, bisacylphosphinoxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-dimethoxy-1. , 2-Diphenylethane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-hydroxy-2-methyl-1-phenyl -Propane-1-ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylbis (2,4,6-trimethylbenzene) Benzoyl) - phosphine oxide, phenyl (2,4,6-trimethylbenzoyl) ethyl phosphinic acid and the like. These can be used alone or in combination of two or more.

  When using a photoinitiator, content of the said photoinitiator is 0.8-20 mass% normally with respect to the total solid of a photocurable resin composition, and 0.9-10 mass% It is preferable that

(4) Antistatic agent It is preferable to contain an antistatic agent in the resin composition for forming an uneven structure layer. By containing the antistatic agent, it is possible to prevent dirt from adhering to the uneven surface 31 of the uneven structure layer 30, and the dirt is easily removed during wiping. The antistatic agent can be appropriately selected from conventionally known ones. Specific examples of the antistatic agent include, for example, various cationic compounds having a cationic group such as a quaternary ammonium salt, a pyridinium salt, and a primary to tertiary amino group, a sulfonate group, a sulfate ester base, and a phosphate ester. Bases, anionic compounds having an anionic group such as phosphonic acid bases, amphoteric compounds such as amino acid series and aminosulfate ester series, nonionic compounds such as amino alcohol series, glycerin series and polyethylene glycol series, tin and titanium alkoxides And metal chelate compounds such as acetylacetonate salts thereof. Of these, cationic compounds are preferred, cationic compounds having a tertiary amino group are more preferred, and trialkylamines such as N, N-dioctyl-1-octaneamine are even more preferred.

  When using an antistatic agent, content of the said antistatic agent is 1-20 mass% normally with respect to the total solid of a photocurable resin composition, and it is preferable that it is 2-10 mass%.

(5) Solvent The resin composition for forming a concavo-convex structure layer may use a solvent from the viewpoint of imparting coatability and the like. In the case of using a solvent, the solvent does not react with each component in the composition, and can be appropriately selected from solvents that can dissolve or disperse each component. Specific examples of such solvents include hydrocarbon solvents such as benzene and hexane, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, tetrahydrofuran, 1,2-dimethoxyethane, propylene glycol monoethyl ether ( PGME) ether solvents such as chloroform and dichloromethane, halogenated alkyl solvents such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate and other amide solvents such as N, N-dimethylformamide And sulfoxide solvents such as dimethyl sulfoxide, anone solvents such as cyclohexane, and alcohol solvents such as methanol, ethanol, and propanol, but are not limited thereto. Not to. Moreover, the solvent used for the resin composition for concavo-convex structure layer formation may be used individually by 1 type, and the mixed solvent of 2 or more types of solvents may be sufficient as it.

  The ratio of the solid content relative to the total amount of the resin composition for forming an uneven structure layer is preferably 20 to 70% by mass, and more preferably 30 to 60% by mass. In addition, solid content referred in this specification represents all components other than the solvent in a resin composition.

(6) Other components The resin composition for forming an uneven structure layer used for the antireflection film 20 may further contain other components as long as the effects of the present invention are not impaired. As other components, for example, a surfactant for adjusting wettability, a silane coupling agent for improving adhesion, a stabilizer, an antifoaming agent, an anti-repellent agent, an antioxidant, an aggregation inhibitor, A viscosity modifier, a mold release agent, etc. are mentioned.

  Here, the results of investigation of the fingerprint wiping property and the scratch resistance of the concavo-convex structure layer 30 of the produced antireflection film 20 by the inventors of the present invention will be described.

(Production Example 1-1: Production of anti-reflection film mold 1-1)
A rolled aluminum plate having a purity of 99.50% is polished so that its surface has an irregular shape with a 10-point average roughness Rz of 30 nm and a period of 1 μm, and then formed in an electrolyte solution of 0.02 M oxalic acid aqueous solution. Anodization was performed for 120 seconds under conditions of a voltage of 40 V and 20 ° C. Next, as a first etching process, an etching process was performed for 60 seconds with the electrolytic solution after anodization. Subsequently, as the second etching treatment, a pore size treatment was performed with a 1.0 M phosphoric acid aqueous solution for 150 seconds. Furthermore, the said process was repeated and these were added and implemented 5 times in total. As a result, an anodized aluminum layer having fine irregularities formed on the aluminum substrate was formed. Finally, a fluorine-based mold release agent was applied and the excess mold release agent was washed to obtain an antireflection film mold 1-1. In addition, the fine uneven shape formed in the aluminum layer has an average distance between adjacent micropores of 100 nm, an average depth of 200 nm, and a large number of micropores that are gradually reduced in the depth direction. It was a shape.

(Production Example 1-2: Production of Resin Composition A for Uneven Structure Layer)
The following components were mixed, and a resin composition A for an uneven structure layer having a solid content of 45% by mass was prepared using methyl ethyl ketone and methyl isobutyl ketone as diluent solvents.
<Composition of Resin Composition A>
-Ethylene oxide modified (EO modified) bisphenol A diacrylate 55 parts by mass-EO modified trimethylolpropane triacrylate 35 parts by mass-Tridecyl acrylate 5 parts by mass-Dodecyl acrylate 5 parts by mass-Diphenyl (2,4,6-trimethoxy Benzoyl) phosphine oxide (Lucirin TPO) 1 part by mass

(Production Example 1-3: Production of resin composition B for uneven structure layer)
The following components were mixed, and a resin composition B for an uneven structure layer having a solid content of 45% by mass was prepared using methyl ethyl ketone and methyl isobutyl ketone as diluent solvents.
<Composition of Resin Composition B>
-EO-modified bisphenol A diacrylate 50 parts by mass-EO-modified trimethylolpropane triacrylate 30 parts by mass-tridecyl acrylate 5 parts by mass-dodecyl acrylate 5 parts by mass-methyl methacrylate 5 parts by mass-hexyl methacrylate 5 parts by mass-diphenyl (2 , 4,6-Trimethoxybenzoyl) phosphine oxide (Lucillin TPO) 1 part by mass

(Comparative Production Example 1-4: Production of resin composition C for comparative uneven structure layer)
The following components were mixed, and a resin composition C for comparative uneven structure layer having a solid content of 45% by mass was prepared using methyl ethyl ketone and methyl isobutyl ketone as diluent solvents.
<Composition of Resin Composition C>
-EO-modified bisphenol A diacrylate 30 parts by mass-EO-modified trimethylolpropane triacrylate 20 parts by mass-dodecyl acrylate 50 parts by mass-diphenyl (2,4,6-trimethoxybenzoyl) phosphine oxide (lucillin TPO) 1 part by mass

(Comparative Production Example 1-5: Production of resin composition D for comparative uneven structure layer)
The following components were mixed, and a resin composition D for comparative uneven structure layer having a solid content of 45% by mass was prepared using methyl ethyl ketone and methyl isobutyl ketone as diluent solvents.
<Composition of Resin Composition D>
Pentaerythritol triacrylate 15 parts by mass 2,4,4-trimethylhexamethylene diisocyanate 15 parts by mass Polyethylene glycol diacrylate 70 parts by mass Diphenyl (2,4,6-trimethoxybenzoyl) phosphine oxide (lucillin TPO) 1 Parts by mass

(Production Example 1-6: Production of antireflection film A)
The resin composition A for the concavo-convex structure layer obtained in Production Example 1-2 is covered with the fine concavo-convex surface of the anti-reflection film mold 1-1 obtained in Production Example 1-1, and the concavo-convex structure after curing. After coating and filling so that the thickness of the layer is 20 μm, a triacetyl cellulose film (TAC) (manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm is laminated as a transparent substrate on the layer, and then laminated. The bonded body was pressure-bonded with a rubber roller under a load of 10 N / cm ² . After confirming that the uniform composition was applied to the entire mold, the resin composition A for the concavo-convex structure layer was cured by irradiating ultraviolet rays with an energy of 2000 mJ / cm ² from the transparent substrate side. Then, it peeled from the metal mold | die and the antireflection film A was obtained.

(Production Example 1-7: Production of antireflection film B)
In Production Example 1-6, the same procedure as in Production Example 1-6 was conducted except that resin composition B for an uneven structure layer obtained in Production Example 1-3 was used instead of resin composition A for an uneven structure layer. Thus, an antireflection film B was obtained.

(Comparative Production Example 1-8: Production of Comparative Antireflection Film C)
In Production Example 1-6, instead of Resin Composition A for Uneven Structure Layer, Resin Composition C for Comparative Uneven Structure Layer obtained in Comparative Production Example 1-4 was used, and Production Example 1-6 Similarly, a comparative antireflection film C was obtained.

(Comparative Production Example 1-9: Production of Comparative Antireflection Film D)
In Production Example 1-6, instead of Resin Composition A for uneven structure layer, Resin Composition D for Comparative Convex Structure layer obtained in Comparative Production Example 1-5 was used, and Production Example 1-6 Similarly, a comparative antireflection film D was obtained.

<Physical properties of resin composition for uneven structure layer and antireflection film>
(Measurement of storage elastic modulus (E ′) and tan δ)
The resin compositions A to D for the concavo-convex structure layer obtained in Production Examples 1-2 to 1-5 are sufficiently cured by irradiating ultraviolet rays with energy of 2000 mJ / cm ² for 1 minute, respectively, so that the substrate and the minute Test single films A to D having no protrusions and having a thickness of 1 mm, a width of 5 mm, and a length of 30 mm were obtained. Next, in accordance with JIS K7244, a 25 g periodic external force was applied at 10 Hz in the length direction of the test single membranes A to D at 25 ° C., and the dynamic viscoelasticity was measured to store at 25 ° C. The elastic modulus E ′ and the loss elastic modulus E ″ were obtained. Further, tan δ was calculated from the results of E ′ and E ″. As a measuring device, Rheogel E400 made by UBM was used. The results are shown in Table 1.

(Measurement of contact angle)
The resin compositions A to D for the concavo-convex structure layer were applied on the triacetyl cellulose film and cured to form a coating film having no fine concavo-convex shape. The surface of the coating film side was used as the upper surface, and a droplet of 1.0 μL of water was dropped on the surface adhered to a black acrylic plate with an adhesive layer, and the contact angle of water 5 seconds after the landing was measured. The contact angle of each solvent was measured using n-hexadecane and oleic acid, respectively, instead of water. The results are shown in Table 1. As a measuring device, a contact angle meter DM 500 manufactured by Kyowa Interface Science Co., Ltd. was used.

(Measurement of elastic modulus, maximum indentation depth, elastic recovery rate)
An indenter is pushed into the concavo-convex surface of the anti-reflective films A to B and comparative anti-reflective films C to D obtained in Production Examples 1-6 to 1-9 under the following specific conditions, and The elastic modulus, maximum indentation depth, and elastic recovery rate of the uneven surface were measured. The measuring device used was PICODENER HM-500 manufactured by Fisher Instruments. The results are shown in Table 2.
○ Measurement conditions ・ Loading speed 1mN / 10sec ・ Holding time 10sec ・ Load unloading speed 1mN / 10sec ・ Indenter Vickers ・ Measurement temperature 25 ℃

  A 1.0 μL drop of pure water (distilled water for liquid chromatography (manufactured by Junsei Chemical Co., Ltd.)) was dropped on the uneven surface of the antireflection film, and after 1 second, the contact angle meter made by Kyowa Interface Science Co., Ltd. The contact angle was measured using DM 500. The contact angle was measured using a contact angle meter DM 500 manufactured by Kyowa Interface Science Co., Ltd. The results are shown in Table 2.

<Fingerprint wiping test evaluation>
Fingerprints were attached by pressing a finger against the concavo-convex surfaces of the concavo-convex structure layers of the antireflection films A to B and comparative antireflection films C to D obtained in Production Examples 1-6 to 1-9. Thereafter, the fingerprint was wiped dry with Zavina Minimax (Fuji Chemical). Dry wiping was performed 10 times with a force of about 3 kg / cm ² , and the appearance after wiping was evaluated. The results are shown in Table 3.
(Fingerprint wiping test evaluation criteria)
A: Fingerprint stains are not visible.
B: A slight color change is visually recognized on the fingerprint adhesion mark.
C: Fingerprints are hardly wiped off.

<Abrasion resistance test>
On the concavo-convex surface of the concavo-convex structure layers of the antireflection films A to B and comparative antireflection films C to D obtained in Production Examples 1-6 to 1-9, 3 kg / cm by Zavina Minimax (Fuji Chemical) Rubbing was performed 10 times with a force of about ² . The visibility after 1 minute of rubbing was evaluated according to the following criteria. The results are shown in Table 3.
(Slidability test evaluation criteria)
A: Scratch marks are not visually recognized.
B: The tint has a slight change in color.
C: Scratch marks are clearly cloudy.

  Antireflection having a concavo-convex structure layer formed using a cured product of a resin composition for a concavo-convex structure layer having a storage elastic modulus (E ′) of 300 MPa or less and tan δ of 0.2 or less at 25 ° C. Films A and B were able to wipe fingerprints even with dry wiping, and no wiping trace was confirmed. In the comparative antireflection film C having a tan δ of 0.69, it is presumed that the fine protrusions caused plastic deformation or sticking occurred due to the pressure during wiping. In the comparative antireflection film D having a storage elastic modulus E ′ of 330 MPa, the fine protrusions are not easily deformed, and the fingerprint stain cannot be sufficiently removed by dry wiping.

<< Configuration of microprotrusions >>
The inventors of the present invention have studied to further improve the scratch resistance of the concavo-convex structure layer 30. In addition to the physical properties of the cured product of the resin composition for forming an uneven structure layer and the contact angle characteristics on the uneven surface 31, the inventors of the present invention devised the configuration of the microprojections 32 forming the uneven surface 31. It has been found that the scratch resistance of the concavo-convex structure layer 30 can also be improved by adding.

  That is, as a result of intensive research, the inventors have provided microprojections (called multimodal microprojections) 32 having a plurality of apexes (maximum points of height) at the top with a predetermined distribution. It has been found that the scratch resistance of the concavo-convex structure layer 30 can be improved. In the following, a microprojection having only one apex is referred to as a single-peak microprojection in comparison with a multimodal microprojection. Moreover, each convex part which forms each vertex which concerns on a multimodal microprotrusion and a monomodal microprotrusion is called a peak suitably.

  The “peak” of the multi-peak projection is a region near each local maximum point of the microprojection, and is a minimum region of the height between each local maximum point, that is, the groove g separated from each other by the groove g (see FIG. 19). Also say high altitude area. A feature of the multimodal microprotrusions is that a plurality of peaks are shared by the ridges of the same microprotrusions. Further, as shown in FIG. 19, the wrinkle area cut along the virtual cut surface perpendicular to the height direction gradually decreases in the height direction of the microprotrusions (the + Z direction from the wrinkle to the top) (Mathematical). In other words, a mode in which the ridge area is a monotonously decreasing function in a broad sense having a height Z) is preferable from the viewpoint of reducing the reflectance.

  As a result of repeated studies by the present inventors, the antireflection film 20 having the following constitution (a) exhibited excellent scratch resistance. Further, the antireflection film 20 having the configurations (b1) and (b2), which are more specific to the configuration (a), has excellent scratch resistance more stably.

  Configuration (a): The microprotrusions 32 are composed of multi-peak microprojections having a plurality of vertices and single-peak microprojections having a single vertex, and the frequency distribution of the heights of the microprojections is one or two peaks. (It is the top of the frequency distribution columnar graph or frequency distribution curve, and is also the maximum value of the frequency distribution), and the multi-modal microprotrusions are distributed more in the vicinity of the apex than the base of each distribution. Yes.

  According to the configuration (a), the concavo-convex structure layer 30 has a frequency distribution of the height of microprojections 32 (including both single-peak microprojections and multimodal microprojections when simply called microprojections). Is composed of one or two distributions consisting of one or two apexes, and the multimodal microprotrusions are distributed more in the vicinity of the apex than the skirts of the respective distributions. The anti-reflection function can be broadened by 30 and the viewing angle characteristics can be limited by limiting the optical characteristics from the oblique direction. Unlike the multimodal microprotrusions caused by poor filling of the resin after the molding process, the multimodal microprotrusions having such a shape are produced by a mold for molding process having a corresponding shape. Thus, the height distribution as designed can be set to ensure uniform and high mass productivity. Furthermore, by setting the distance between the protrusions wider than in the case of defective filling, the scratch resistance can be sufficiently improved, and further the optical characteristics can be improved.

  Further, by providing the microprotrusions 32 having excellent mechanical strength as compared with the unimodal microprotrusions, when the impact force is applied, the protuberances are smaller than in the case of only the unimodal microprotrusions. It is possible to prevent damage, thereby reducing local deterioration of the antireflection function, and further reducing appearance defects. Further, even if the microprojection is damaged, the area of the damaged portion can be reduced, and this can also reduce the local deterioration of the antireflection function and further reduce the appearance defect.

  Configuration (b1): The average value of the height H in the frequency distribution of the height H of the microprojections 32 is m, the standard deviation is σ, the region where H <m−σ is the low altitude region, and m−σ ≦ H When the region of ≦ m + σ is a medium altitude region and the region of m + σ <H is a high altitude region, the number Nm of multimodal microprojections in each region and the total number Nt of microprojections 32 in the entire frequency distribution The ratio satisfies the relationship of Nm / Nt in the medium altitude region> Nm / Nt in the low altitude region and Nm / Nt in the medium altitude region> Nm / Nt in the high altitude region.

  According to the configuration (b1), the antireflection film 20 has a ratio (Nm / Nt) of the number of micro-protrusions (Nm) in the medium-altitude region to the total number of micro-protrusions (Nt) in the entire frequency distribution. Is larger than the ratio (Nm / Nt) of the number of microprotrusions in the low altitude region and the high altitude region to the total number of microprotrusions (Nt) in the entire frequency distribution (Nm / Nt). In addition, the viewing angle characteristics can be more specifically limited.

Configuration (b2): The frequency distribution of the height h of the microprotrusions 32 is bimodal having a distribution peak on each of the high side and the low side,
With the height hs serving as the boundary between the two peaks, the frequency distribution is composed of two distributions: a distribution of microprojections having a height less than hs and a distribution of microprojections having a height of hs or more.
The average value of the heights h of the microprotrusions 32 in the distribution less than the height hs is m1, the standard deviation is σ1,
When the region of h <m1−σ1 is a low altitude region, the region of m1−σ1 ≦ h ≦ m1 + σ1 is a medium altitude region, and the region of m1 + σ1 <h <hs is a high altitude region, The ratio between the number Nm1 of multi-peak microprojections in the region and the total number Nt of microprojections in the entire frequency distribution is such that Nm1 / Nt in the middle altitude region> Nm1 / Nt in the low altitude region and Nm1 / Nt in the middle altitude region. Nt> satisfies the relationship with Nm1 / Nt in the high altitude region,
The average value of the heights h of the microprojections 32 in the distribution of the height hs or more is m2, the standard deviation is σ2, the region where hs <h <m2−σ2 is the low altitude region, and m2−σ2 ≦ h ≦ m2 + σ2 Is a medium altitude region and a region of m2 + σ2 <h is a high altitude region, the number Nm2 of multi-peak microprojections in each region in the distribution of hs or more and the total number Nt of microprojections in the entire frequency distribution The ratio of Nm2 / Nt in the middle altitude region> Nm2 / Nt in the low altitude region and Nm2 / Nt in the middle altitude region> Nm2 / Nt in the high altitude region is satisfied.

  According to the configuration (b2), the antireflection film 20 has two peak height distributions, that is, two maximum values of the protrusion height. Then, in each of the two distributions, ie, the distribution of the fine protrusions with the protrusion height less than hs and the distribution of the fine protrusions with the protrusion height hs or more, with the boundary height hs as the boundary, the multi-peak minute in the middle altitude region. The ratio of the number of protrusions to the total number of microprojections in the entire frequency distribution is greater than the ratio of the number of multi-peak microprojections in the low and high altitude areas to the total number of microprojections in the entire frequency distribution. Therefore, the antireflection function can be broadened in band and the viewing angle characteristics can be more specifically restricted. In particular, according to the configuration (b2), it is possible to realize a wide band of the antireflection function.

  The details of the above points will be described below.

  As described above, various dimensions and shapes of the concavo-convex surface 31 and the microprojections 32 of the concavo-convex structure layer 30 are measured using an atomic force microscope (AFM) or a scanning electron microscope (SEM). Can be identified. That is, the distance (adjacent protrusion interval) d between adjacent microprotrusions 32 and the height H of the microprotrusions 32 can be measured using an atomic force microscope or a scanning electron microscope. First, a method for identifying various dimensions and shapes related to the microprojections 32 will be described in detail.

  (1) That is, first, an in-plane arrangement of microprojections 32 using an atomic force microscope (hereinafter referred to as AFM) or a scanning electron microscope (hereinafter referred to as SEM) ( The shape of the projection array in plan view) is detected. 8 to 10 are enlarged photographs actually obtained by an atomic force microscope. Since the AFM data is accompanied by the in-plane distribution data of the height of the microprojections, this photograph can be said to be a photograph showing the in-plane distribution of the height by luminance. 8 to 10, the single-peaked microprojection is indicated by reference numeral 32A, and the multi-peak microprotrusion is indicated by reference numeral 32B.

  (2) Subsequently, the maximum point of the height of each protrusion (hereinafter simply referred to as the maximum point) is detected from the obtained in-plane arrangement. The maximum point means a point where the height is larger (maximum value) than any point around the vicinity. There are various methods for obtaining the maximum point, such as a method of sequentially comparing the planar view shape and the enlarged photograph of the corresponding cross-sectional shape to obtain the maximum point, and a method of obtaining the maximum point by image processing of the plan view enlarged photo. Can be applied. FIG. 9 is a diagram showing the detection result of the maximum point by the processing of the image data related to the enlarged photograph shown in FIG. 8, and the portions indicated by black dots in this figure are the maximum points of the respective protrusions. In this process, image data is processed in advance by a low-pass filter having a Gaussian characteristic of 4.5 × 4.5 pixels, thereby preventing erroneous detection of the maximum point due to noise. Further, a maximum point was obtained in units of 1 nm (= 1 pixel) by sequentially scanning a filter for detecting a maximum value of 8 pixels × 8 pixels.

  (3) Next, a Delaunay diagram with the detected maximum point as a generating point is created. Here, Delaunay diagram is obtained by dividing the Voronoi region adjacent to the Voronoi region when the Voronoi division is performed with each local maximum as the generating point, and connecting the adjacent generating points with line segments. This is a net-like figure made up of triangular aggregates. Each triangle is called a Delaunay triangle, and a side of each triangle (a line segment connecting adjacent generating points) is called a Delaunay line. FIG. 10 is a diagram in which the Delaunay diagram (represented by white line segments) obtained from FIG. 9 is superimposed on the original image of FIG. The Delaunay diagram has a dual relationship with the Voronoi diagram. Voronoi division means that a plane is divided by a net-like figure made up of a closed polygon aggregate defined by perpendicular bisectors of line segments (Droney lines) connecting between adjacent generating points. A network figure obtained by Voronoi division is a Voronoi diagram, and each closed region is a Voronoi region.

  (4) Next, the frequency distribution of the line segment length of each Delaunay line, that is, the frequency distribution of the distance between adjacent maximum points (hereinafter referred to as the distance between adjacent protrusions) is obtained. FIG. 11 is a histogram of the frequency distribution created from the Delaunay diagram of FIG. As shown in FIG. 8 and FIG. 19, when a groove-like recess is present on the top of the protrusion, or the top is split into a plurality of peaks, the distribution of such protrusion is determined from the obtained frequency distribution. A frequency distribution is created by removing data resulting from a fine structure having a concave portion at the top and a fine structure in which the top is split into a plurality of peaks, and selecting only the data of the projection body itself.

  Specifically, in a fine structure in which a concave portion exists at the top of the protrusion, or a fine structure related to a multi-modal micro protrusion in which the top is divided into a plurality of peaks, a single peak that does not have such a fine structure. The distance between adjacent local maximum points is clearly different from the numerical value range in the case of a sexual microprojection. Thus, by removing the corresponding data using this feature, only the data of the projection body itself is selected and the frequency distribution is detected. More specifically, for example, about 5 to 20 adjacent single-peak microprojections are selected from an enlarged photograph of the microprojections (group) as shown in FIG. 8, and the distance between adjacent maximum points is selected. A value that deviates in a direction that is clearly smaller than the numerical range obtained by sampling this value (usually the value is ½ or less of the average distance between adjacent maximum points obtained by sampling) Frequency distribution is detected. In the example of FIG. 11, data having a distance between adjacent maximum points of 56 nm or less (the leftmost small mountain indicated by the arrow A) is excluded. FIG. 11 shows a frequency distribution before such exclusion processing is performed. Incidentally, such exclusion processing may be executed by setting the above-described maximum inspection filter.

(5) The average value d _AVG and the standard deviation σ are obtained from the frequency distribution of the distance d between adjacent protrusions thus obtained. When the frequency distribution obtained in this way is regarded as a normal distribution and the average value d _AVG and the standard deviation σ are obtained, the average value d _AVG = 158 nm and the standard deviation σ = 38 nm are obtained in the example of FIG. Thereby, the maximum value of the distance d between adjacent protrusions can be set to dmax = d _AVG + 2σ, and in this example, dmax = 234 nm.

The same method is applied to define the height of the protrusion. In this case, a relative height difference of each local maximum point position from a specific reference position is acquired from the local maximum point obtained by the above (2), and is histogrammed. FIG. 12 is a diagram showing a histogram of the frequency distribution of the protrusion height H with the protrusion root position thus obtained as a reference (height 0). The average value _HAVG of the protrusion height and the standard deviation σ are obtained from the frequency distribution based on the histogram. Here in the example of FIG. 12, the mean value _H AVG = 178 nm, the standard deviation sigma = 30 nm. Thus in this example, the height of the projections is an average value _H AVG = 178 nm. In the histogram of the projection height H shown in FIG. 12, in the case of a multi-peak microprojection, the plurality of data are mixed for one projection because of having a plurality of vertices. Therefore, in this case, the frequency distribution is obtained by adopting the vertex having the highest height from among the plurality of vertices belonging to the same microprotrusion as the protuberance.

  In addition, the reference position when measuring the height of the protrusion described above is based on the valley bottom (minimum point of height) between the adjacent minute protrusions as a reference of height 0. However, when the height of the valley bottom itself varies depending on the location (for example, as described later with reference to FIG. 23, when the height of the valley bottom has undulation with a period larger than the distance between adjacent projections of the microprojections, etc.) (1) First, the average value of the height of each valley bottom measured from the front surface or the back surface of the base material 2 is calculated within an area sufficient for the average value to converge. (2) Next, a surface having the height of the average value and parallel to the front surface or the back surface of the substrate 2 is considered as a reference surface. (3) Then, the height of each microprotrusion from the reference surface is calculated by setting the reference surface to a height of 0 again.

If the protrusions are irregularly arranged, when this way the maximum value of the adjacent protrusions distance obtained by dmax = d AVG ₊ 2σ, average H _AVG height of projections are arranged regularly It has been found that it is more preferable to satisfy the above conditions. Specifically, the condition of the distance between the microprotrusions that exhibits the antireflection effect is preferably dmax ≦ Λmin. The minimum necessary condition that can exhibit the antireflection effect at the longest wavelength in the visible light band is Λmin = λmax. Therefore, it is preferable that dmax ≦ λmax, and antireflection is performed for all wavelengths in the visible light band. The necessary and sufficient condition that can exert the effect is Λmin = λmin, and therefore dmax ≦ λmin is preferable. A preferable condition that can more reliably exhibit the antireflection effect for all wavelengths in the visible light band is dmax ≦ 300 nm, and a more preferable condition is dmax ≦ 180 nm. However, from the viewpoint of ensuring the antireflection function to a practically sufficient level, the average inter-protrusion distance dave may be set so that dave ≦ λmin.

8 to 12, dmax = 234 nm ≦ λmax = 780 nm, and it can be seen that the antireflection effect can be sufficiently achieved by satisfying the condition of dmax ≦ λmax. In addition, since the shortest wavelength λmin in the visible light band is 380 nm, it can be seen that the sufficient condition dmax ≦ λmin for exhibiting the antireflection effect in all visible light wavelength bands is also satisfied. Since dave ≦ dmax, it can be seen that the condition of dave ≦ λmin is also satisfied. When the average protrusion the height _H AVG = 178 nm Also, the average projection height _{H AVG} ≧ 0.2 × λmax = _156nm becomes (as the longest wavelength .lambda.max = 780 nm in the visible light wavelength band), realizing a sufficient antireflection effect It can be seen that the condition (H _AVG ≧ 0.2 × λmax) related to the height of the protrusion for satisfying the above condition is also satisfied. Note since the standard deviation sigma = 30 _nm, since the relationship between the _{H AVG -σ = 148nm <0.2 ×} λmax = 156nm is satisfied, statistically, more than 50% of the total protrusions, 84% or less It can be seen that the condition of the height of the protrusion (178 nm or more) is satisfied. From the observation results by AFM and SEM, and the analysis result of the height distribution of the microprojections, the multi-peak microprojections tend to occur more frequently with the microprojections with a higher height than the microprojections with a relatively low height. It turned out to be.

  In this way, when the monomodal microprotrusions 32A and the multimodal microprotrusions 32B are mixed, similarly to the case where the monomodal microprotrusions having different aspect ratios are mixed, the low peak is low over a wide wavelength band. The reflectance can be ensured. The aspect ratio is defined as H / W, which is a ratio obtained by dividing the height H of the minute protrusions by the diameter W at the bottom of the valley (also referred to as width or thickness). Here, the diameter at the bottom of the valley coincides with the (bottom) diameter of the cylinder if the shape of the vicinity of the bottom of the microprojection is a cylinder. If the shape of the vicinity of the valley bottom of the microprojection is not a cylinder and the diameter of the bottom surface obtained by the intersection of the virtual plane connecting the valley bottom and the microprojection differs depending on the in-plane direction, the maximum value of the microprojection The diameter of the protrusion. For example, when the bottom shape of the microprojection is an ellipse, the diameter is the major axis. In addition, when the bottom surface shape of the minute protrusion is a polygon, the diameter is the maximum diagonal length. In addition, when the width of the bottom of the valley (region consisting of the minimum point of the height) is smaller than the diameter and 20% or less, the average value (H / W) ave of the aspect ratio H / W of each microprotrusion is In terms of design, it can be regarded as Have / dave.

  The antireflection function of the antireflection film 20 depends not only on the interval between the minute protrusions but also on the aspect ratio. When the aspect ratio is constant, for example, even when a sufficiently low reflectance can be secured in the visible light region, the ultraviolet ray In the region, the reflectance increases as compared with the visible light region, and the antireflection function is insufficient. If the distance between adjacent protrusions is further reduced so that a sufficient antireflection function can be secured in the ultraviolet region, the antireflection function will be lowered in the infrared region.

  However, in a microprojection group including multimodal microprotrusions, the distance between ridges existing near the top of the same microprotrusion is smaller than the distance between adjacent protrusions (usually about 100 to 200 nm) (usually about 10 to 50 nm). By such contribution of the distance between the peaks, it is possible to ensure an antireflection function that reduces the effective spacing between adjacent projections compared to a group of minute projections consisting of only single-peaked microprojections having the same distance between adjacent projections. As a result, a low reflectance can be secured in a wide wavelength band due to the mixture of multimodal microprojections and monomodal microprojections. When securing a sufficiently small reflectance in a wide wavelength band centered on the visible light region, the spacing between adjacent protrusions that contributes to the antireflection performance for light in the wavelength range of 480 to 660 nm in the visible light region, that is, It is desirable to mix multimodal microprojections and monomodal microprojections in microprojections that satisfy d ≦ 400 nm, preferably d ≦ 300 nm.

  As described above, in the case where the microprotrusions 32 of the concavo-convex structure layer 30 have multimodal microprotrusions together with single-peak microprotrusions, the above-described configuration (a ) Or both configurations (a) and (b). FIG. 13 is a diagram showing an example of the frequency distribution of the height H of the fine protrusions formed on the concavo-convex structure layer 30. In this frequency distribution, there is only one peak (maximum value).

  As described above, the antireflection film 20 can be produced by shaping the concavo-convex structure layer 30 on the transparent substrate 25 using the roll plate 37. Further, the roll plate 37 can be formed with fine holes for forming the fine protrusions 32 by anodic oxidation and etching. Next, the manufacturing method of the roll plate 37 for shaping the concavo-convex structure layer 30 having the multimodal microprojections 32B in addition to the single-peak microprojections 32A will be described.

[Anodic oxidation treatment, etching treatment]
FIG. 14 is a diagram illustrating a manufacturing process of the roll plate 37. In this manufacturing process, the peripheral side surface of the base material is made into a super mirror surface by an electrolytic composite polishing method that combines electrolytic elution action and abrasion action by abrasive grains (electrolytic polishing). Subsequently, in this step, in the aluminum layer forming step, aluminum is sputtered on the peripheral side surface of the base material to produce a high-purity aluminum layer. Subsequently, in this step, the base material is processed by alternately repeating the anodic oxidation steps A1,..., AN, etching steps E1,.

  In this manufacturing process, in the anodic oxidation steps A1,..., AN, a fine hole is produced on the peripheral side surface of the base material by an anodic oxidation method, and the produced fine hole is further dug. Here, in the anodic oxidation step, various methods applied to the anodic oxidation of aluminum can be widely applied, for example, when a carbon rod, a stainless steel plate, or the like is used for the negative electrode. Further, as the solution, various neutral and acidic solutions can be used, and more specifically, for example, sulfuric acid aqueous solution, oxalic acid aqueous solution, phosphoric acid aqueous solution and the like can be used. In the manufacturing steps A1,..., AN, the fine holes are formed in shapes corresponding to the target depth and the shape of the fine protrusions, respectively, by managing the liquid temperature, the applied voltage, the time for anodization, and the like.

  In the subsequent etching process E1,..., EN, the mold is immersed in an etching solution, the hole diameter of the fine hole produced and dug in the anodizing process A1,. These fine holes are shaped so that the hole diameter becomes smaller and smoother. As the etching solution, various etching solutions that are applied to this type of treatment can be widely applied. More specifically, for example, a sulfuric acid aqueous solution, an oxalic acid aqueous solution, a phosphoric acid aqueous solution, or the like can be used. Note that the same solution as the solution used for the anodic oxidation treatment may be used without applying a voltage so that the solution can be used also as an etching solution. As a result, in this manufacturing process, the anodizing process and the etching process are alternately performed a plurality of times, so that fine holes for forming are formed on the peripheral side surface of the base material.

[Formation process of minute holes to form minute protrusions]
Next, a description will be given of a method of forming the multi-peak microprotrusions 32B and forming fine holes in which the distribution of the heights H of the microprotrusions 32 is controlled. As described above, the fine hole formed in the shaping mold (roll plate) is formed by alternately repeating the anodizing treatment and the etching treatment, and the applied voltage in the repeated anodizing treatment is varied. Thus, the depth of the fine holes (the height distribution of the fine protrusions) can be controlled. Here, since the applied voltage in the anodizing process and the interval (pitch) between the fine holes to be formed are in a proportional relationship, the applied voltage of the anodizing process can be varied in the repetition of the anodizing process and the etching process. For example, it is possible to mix fine holes having different times for digging in the depth direction and control the ratio.

  Further, in the case where the applied voltage in the anodic oxidation process is varied as described above, a plurality of micro holes are created on the bottom surface of the micro hole having a large thickness (diameter) to relate to the multi-peak micro protrusion 32B. It can be a fine hole. By controlling the height of the fine holes having a large thickness, the height distribution can be controlled also for the multimodal microprotrusions 32B.

  FIG. 15 is a schematic diagram for explaining the control of such a height distribution, and is a diagram showing fine holes produced by an anodizing step and an etching step in the manufacturing process of the shaping mold. As described above, the relationship between the applied voltage in the anodic oxidation process and the pitch of the fine holes is proportional, but in practice, the pitch of the fine holes varies due to the grain boundaries of the aluminum used for the treatment. However, in FIG. 15, the description will be made assuming that the fine holes are formed in a regular arrangement, assuming that this variation does not exist. In FIGS. 15A to 15E, the left drawing shows an enlarged view of the surface of the roll plate 37, and the right drawing shows an aa cross-sectional view in the left drawing.

(First step)
As shown in FIG. 15 (a), first, the voltage V1 is applied to the aluminum layer on the surface of the shaping mold to perform the anodizing step A1, and then the etching step E1 is performed to form the fine hole f1. Form. Here, the anodic oxidation step A1 is to create a trigger for the anodic oxidation treatment that follows the flat surface of aluminum. In this case, the etching process may be omitted as appropriate.

(Second step)
Next, after applying the voltage V2 (V2> V1) higher than the voltage V1 to execute the anodic oxidation step A2, the etching step E2 is executed. As a result, in the anodizing step A2, as shown in FIG. 15B, among the fine holes f1 formed in the previous anodizing step A1, the fine holes f1 having an interval corresponding to the anodizing step A2 are further dug down. . In the illustrated example, a process of digging every two fine holes f1 formed in the previous anodizing process A1 is performed by the anodizing process A2. Therefore, every two wide and deeply drilled fine holes f2 are formed on the surface of the mold for molding, and the surface of the roll plate 37 is in a state where the fine holes f1 and f2 are mixed. Become.

(Third step)
Subsequently, after applying the voltage V3 (V3> V2) higher than the voltage V2 to execute the anodic oxidation step A3, the etching step E3 is executed. In this step, fine holes with different pitches are produced. Specifically, when the voltage to be applied is gradually increased from the voltage V2 to the voltage V3, and the increase in the applied voltage is executed discretely (stepwise), the height distribution of the microprojections 32 (depth of the microholes) Distribution) can be created discretely, and the height distribution of the microprotrusions 32 can be set to a normal distribution by continuously increasing the applied voltage. Therefore, in this embodiment, the application time of the applied voltage in the anodizing step A3 and the processing time of the etching step are set longer than those in the first step and the second step described above, as shown in FIG. As described above, two fine holes f1 formed in the first anodic oxidation step A1 are dug wide and deep so as to be combined into one, and the bottom surface of the fine hole f3 integrated into one is substantially flat. (Flat fine hole forming step). Here, “substantially flat” means not only a state where the bottom surface of the fine hole is flat but also a state where the bottom surface is curved with a large curvature radius.

(Fourth process)
Subsequently, after applying the voltage V4 (V4> V3) higher than the voltage V3 to execute the anodic oxidation step A4, the etching step E4 is executed. In this step, fine holes are created with a pitch based on the desired interprotrusion spacing. Also in this anodizing step A4, the applied voltage is gradually increased from the voltage V3 to the voltage V4. Thereby, a part of the fine hole f3 dug by the third step is further dug, and as a result, as shown in FIG. 15 (d), the fine hole f4 is formed, and the fine hole f4 has a height. High unimodal microprotrusions are formed.

(Fifth step)
Subsequently, after changing the applied voltage to the voltage V1 in the first step and performing the anodic oxidation step A5, the etching step E5 is performed. In this step, the fine hole f3 formed in the anodic oxidation step A3 and not affected by the anodic oxidation step A4 in the fourth step is formed on the bottom surface of the fine hole f3 as shown in FIG. Then, a plurality of fine holes are formed to form a fine hole f5 corresponding to the multi-peak microprotrusions (a multi-hole protrusion micro-hole forming step). Here, by adjusting the magnitude of the voltage V1 to be applied, the number of fine holes formed in the bottom surface of the fine hole f5 can be increased or decreased, and the interval between the fine holes can be adjusted.

  As described above, the fine holes f1, f2, and f4 for forming the minute protrusions having different heights and the minute holes f5 for forming the multimodal minute protrusions are formed on the surface of the shaping mold. Here, in this series of steps, the fine holes f1 and f2 having different depths produced in the first step and the second step are dug in the third step to form a substantially flat fine hole f3 on the bottom surface. In the fourth step, the minute hole f3 is dug to produce the minute hole f4 related to the single-peaked minute protrusion. In the fifth step, the bottom surface of the minute hole f3 is processed. A fine hole f5 related to a multi-peak microprojection is produced. Here, by controlling the application time, the processing time, the processing time of the etching process, etc. of the anodizing process according to the first to fourth processes, the depth of the fine hole produced in each process is controlled. Thus, it is possible to control the height distribution of the microprojections and the height distribution of the multimodal microprojections. In addition, the above-mentioned 1st process-5th process can abbreviate | omit the number as needed, can repeat, or can integrate a process.

  FIG. 16 is a diagram for explaining the process of forming micro holes with different depths related to the control of the height distribution of the microprojections in comparison with FIG. 15.

(First step)
Here, as shown in FIG. 16 (a), in the first step, first, the voltage V1 is applied to the aluminum layer on the surface of the molding die to perform the anodic oxidation step A1, and then the etching step E1. To form a fine hole f1. Here, the anodic oxidation step A1 is to create a trigger for the anodic oxidation treatment that follows the flat surface of aluminum. In this case, the etching process may be omitted as appropriate.

(Second step)
Next, after applying the voltage V2 (V2> V1) higher than the voltage V1 to execute the anodic oxidation step A2, the etching step E2 is executed. As a result, in the anodizing step A2, as shown in FIG. 16B, among the fine holes f1 formed in the previous anodizing step A1, fine holes f1 having an interval corresponding to the anodizing step A2 are formed. Dig further.

  Here, when the applied voltage V2 is set to V2 = 2 × V1, a process of digging every other minute hole f1 formed in the previous anodizing process A1 is performed by the anodizing process A2. Accordingly, every other wide and deeply drilled fine hole f2 is formed on the surface of the molding die, and the minute hole f1 and the minute hole 2 are mixed on the surface of the mold. It becomes a state.

(Third step)
Subsequently, after applying the voltage V3 (V2>V3> V1) between the voltage V1 and the voltage V2 to execute the anodic oxidation step A3, the etching step E3 is executed. In this step, fine holes with different pitches are produced. Specifically, the voltage to be applied is set to the voltage V3, and every other specific minute hole f1 as illustrated between the minute holes f2 arranged in the plane vertically and horizontally is dug wide and deep. Here, when the applied voltage V3 is set to V3 = (V1) ^1/2 , the application time of the applied voltage in the anodizing step A3 and the processing time of the etching step are set longer than those in the first step described above. As shown in FIG. 15C, among the fine holes f1 formed in the first anodic oxidation step A1, the fine hole f1 located at the center of the smallest square surrounded by the four fine holes f2 is selected. Deeply digging deeply. At the same time, among the fine holes f2 formed in the second anodic oxidation step A2, a part of the fine holes f2 having the positional relationship shown in FIG. 16C is further dug down to become fine holes f3.

  As a result, as shown in FIG. 16 (c), fine holes f2 and f3 (medium respectively) deeper than f1 around the fine hole f1 (which corresponds to the minute protrusion having the lowest height). And a mold having a surface structure in which a group of holes surrounded by a small projection having a high height is arranged in a plane.

  In this way, the depth of the micro holes can be greatly varied by changing the micro holes to be drilled by switching the applied voltage in multiple times of anodizing treatment, thereby controlling the height of the micro protrusions by the intended distribution can do.

  Next, an example in which the concavo-convex structure layer 30 is actually produced using the shaping mold produced by the above-described method will be described.

[Example 1]
FIG. 17 is a diagram showing a frequency distribution of the height H of the fine protrusions of the antireflection film 20 of Example 1. The mold for producing the antireflection film 20 of Example 1 is obtained by continuously changing the applied voltage of the anodizing treatment in the second step, the third step, and the fourth step described above. In the fourth step, the voltage is reduced from the applied voltage in the third step. More specifically, in the example of FIG. 17, the applied voltage V2 in the second step is set to V2 = 3 × V1 with respect to the applied voltage V1 in the first step, and the applied voltage V3 in the third step is V3 = 4. This is an example in which × V1 is set and the applied voltage V4 in the fourth step is V4 <V3.

  Moreover, the example of FIG. 17 is a case where the anodizing step and the etching step are repeated five times, and the applied voltage in the first anodizing step is set to V1 (a constant voltage in the range of 15V to 35V). In this case, the applied voltages in the second, third, fourth, and fifth anodic oxidation steps are 2V1, 3.5V1, 5V1, and V1, respectively. The anodizing treatment was performed for 100 seconds using an oxalic acid aqueous solution having a concentration of 0.02M. In the etching step, an etching process was performed for 45 seconds using an aqueous oxalic acid solution having a concentration of 0.02M, and then an etching process was performed for 110 seconds using an aqueous solution of phosphoric acid having a concentration of 1.0M.

  The antireflection film 20 manufactured by this mold for mold shows a normal distribution in which the height distribution of the fine protrusions is a distribution of one top, and the vertical line of the surface on which the fine protrusions are formed is shown. A good antireflection function can be ensured in a relatively narrow range centered. At this time, in such a height distribution, the normal distribution in which the average values of the heights of the multi-peaked microprotrusions (two and three vertices are indicated by two peaks and three peaks, respectively) are substantially the same. As a result, the scratch resistance function and the optical property improving function of the multi-modal microprotrusions can be exhibited efficiently.

  As shown in FIG. 17, the antireflection film 20 of Example 1 manufactured by the above-described method has an average height of minute protrusions of m = 145.7 nm and a standard deviation of σ = 22.1 nm. It is. Here, in the frequency distribution of the height H of the microprotrusions, the low altitude region is H <m−σ = 123.6 nm, and the middle altitude region is m−σ = 13.6 nm ≦ H ≦ m + σ = 167.8 nm. Thus, the high altitude region is H> m + σ = 167.8 nm. The total number Nt of microprojections in the entire frequency distribution is 263. Further, since the number Nm of multi-modal microprotrusions in the middle altitude region is 23, Nm / Nt in the middle altitude region is 0.087. Since the number Nm of multimodal microprotrusions in the low altitude region is two, Nm / Nt in the low altitude region is 0.008. Since the number Nm of multi-modal microprotrusions in the high altitude region is 5, Nm / Nt in the high altitude region is 0.019.

Therefore, the antireflection film 20 of Example 1 has the following relationships (i) and (ii):
(I) Nm / Nt in the middle altitude region = 0.087> Nm / Nt = 0.008 in the low altitude region
(Ii) Nm / Nt = 0.087 in the middle altitude region> Nm / Nt = 0.19 in the high altitude region
Satisfied.

  As described above, the antireflection film 20 of Example 1 has a low ratio (Nm / Nt) between the number of multi-peaked microprojections (Nm) in the middle altitude region and the total number of microprojections (Nt) in the frequency distribution. Since the multimodal microprotrusions are formed so as to be larger than the ratio between the altitude region and the high altitude region, the reflectance with respect to incident light in the visible light region can be reduced, and the reflection of the antireflection film 20 can be reduced. The broadening of the prevention function can be achieved.

  In addition, in this height distribution, the average value of the height is almost the same for the multi-peak microprotrusions (two and three vertices are indicated by two peaks and three peaks, respectively) in such a height distribution. Therefore, the viewing angle characteristic can be limited. In addition, the scratch resistance of the multimodal microprotrusions can be improved efficiently.

  Furthermore, by adopting the above-described configuration, the antireflection film 20 has a small ratio of multi-peak microprojections distributed in microprojections having a high height (180 nm or more) and a large ratio of single-peak microprojections. Therefore, even if other objects come into frictional contact with the microprotrusions, the high unimodal microprotrusions come into contact first, making contact with the multimodal microprotrusions that mainly improve the antireflection function. Can be suppressed.

[Example 2]
FIG. 18 is a diagram illustrating another example of the frequency distribution of the height h of the microprojections 32 of the antireflection film 20 according to the second embodiment. The shaping mold for producing the antireflection film 20 of Example 2 is the third step and the fourth step by increasing the voltage stepwise in the second step among the first to fifth steps described above. In the fourth step, the anodizing process is executed at a voltage higher than the highest voltage in the example of FIG. 17, and the fifth step is further performed corresponding to the fourth step. It has been executed.

More specifically, in the example of FIG. 18, the anodic oxidation process and the etching process were executed with the same number of repetitions, solution, and processing time as in the example of FIG. In the example of FIG. 18, when the applied voltage in the first anodic oxidation step is V1 (a constant voltage in the range of 15V to 35V), the second, third, fourth, In this example, the applied voltage in the second anodic oxidation step is set to 2.5 V1, 4 V1, 6 V1, and V1 ^{1/2 to} V1, respectively. In the second to fourth anodic oxidation steps, the start voltage of the second anodic oxidation treatment and the end voltage of the fourth anodic oxidation treatment are set to 2.5 V1 and 6 V1, respectively, and the applied voltage is gradually increased. Increased.

  In the example of FIG. 18, in the frequency distribution of the protrusion height, the height distribution of the minute protrusion 32 having a distribution peak (peak; maximum value) on the high side and the low side is discrete. That is, a distribution having bimodality is shown, and a multimodal microprojection distribution is formed corresponding to each distribution peak.

  In the antireflection film 20 of Example 2, the frequency distribution of the height is a bimodal distribution, the average value of the heights of the microprojections in the entire frequency distribution is m = 195.7 nm, and the standard deviation is σ = 57.2 nm.

  Here, in the frequency distribution of the height h of the microprojections, the low altitude region is h <m−σ = 138.5 nm, and the middle altitude region is m−σ = 138.5 nm ≦ h ≦ m + σ = 252.9 nm. Thus, the high altitude region is h> m + σ = 252.9 nm. The total number Nt of fine protrusions in the entire frequency distribution is 131. In addition, since the number Nm of multimodal microprotrusions in the middle altitude region is 21, the Nm / Nt in the middle altitude region is 0.160. Since the number Nm of the multimodal microprotrusions in the low altitude region is 3, Nm / Nt in the low altitude region is 0.023. Since the number Nm of multimodal microprojections in the high altitude region is 0, Nm / Nt in the high altitude region is 0.

Therefore, the antireflection article of Example 2 has the following relationships (i) and (ii):
(I) Nm / Nt = 0.160 in the middle altitude region> Nm / Nt = 0.024 in the low altitude region
(Ii) Nm / Nt = 0.160 in the middle altitude region> Nm / Nt = 0 in the high altitude region
Satisfied.

  Further, as described above, the frequency distribution of the height h of the microprojections 32 of the antireflection film 20 of Example 2 is bimodal, that is, there are two distribution peaks. In this case, a low altitude region, a medium altitude region, and a high altitude region are also defined for the peaks of each distribution, and the number of multi-peak microprojections in each region of each peak and the total number Nt of microprojections in the entire frequency distribution, It is necessary to evaluate the size of the ratio.

Specifically, when the height of the boundary between the peaks is hs, the average value of the height h is m1 for the peaks of the distribution less than hs (the peaks of the distribution on the lower side), When the standard deviation is σ1, the region of h <m1−σ1 is the low altitude region, the region of m1−σ1 ≦ h ≦ m1 + σ1 is the medium altitude region, and the region of m1 + σ1 <h <hs is the high altitude region, It is preferable that the ratio between the number Nm1 of multimodal microprotrusions in each region in the distribution peak less than hs and the total number Nt of microprotrusions in the entire frequency distribution satisfy the following relationships (iii) and (iv). .
(Iii) Nm1 / Nt in the middle altitude region> Nm1 / Nt in the low altitude region
(Iv) Nm1 / Nt in the middle altitude region> Nm1 / Nt in the high altitude region

For a distribution higher than hs (distribution on the higher side), the average value of height h is m2, the standard deviation is σ2, the region of hs <h <m2-σ2 is the low altitude region, and m2 When the region of −σ2 ≦ h ≦ m2 + σ2 is a medium altitude region and the region of m2 + σ2 <h is a high altitude region, the number Nm2 of multi-peak microprojections in each region in the distribution of hs or more and the entire frequency distribution It is preferable that the ratio with the total number Nt of microprojections satisfies the following relationships (v) and (vi).
(V) Nm2 / Nt in the middle altitude region> Nm2 / Nt in the low altitude region
(Vi) Nm2 / Nt in the middle altitude region> Nm2 / Nt in the high altitude region

  Here, the average value of the heights h of the fine protrusions in the distribution of less than hs (the lower side) is m1 = 52.9 nm, and the standard deviation is σ1 = 24.8 nm. The height hs that becomes the boundary of each distribution is obtained as follows. First, the data of the height of the frequency distribution is displayed as a columnar graph (histogram) as shown in FIG. 18, and then a curve obtained by smoothing the polygonal line connecting the midpoints at the top of the columnar graph by the least square method (this is the smoothing frequency). (Referred to as a distribution curve), and with respect to the smoothed frequency distribution curve, the height at the minimum point located between the peaks of the two frequency distributions is determined, and this is used to determine the boundary height between the two peaks. Hs. In the example of FIG. 18, hs = 100 nm is obtained by such processing. Therefore, the low altitude region with a distribution of less than hs is h <m1-σ1 = 28.1 nm, the middle altitude region is m1-σ1 = 28.1 nm ≦ h ≦ m1 + σ1 = 77.7 nm, and the high altitude region is m1 + σ1 = 77.7 nm <h <hs = 100 nm. In addition, since the number Nm1 of the multi-modal microprotrusions in the middle altitude region is two, Nm1 / Nt in the middle altitude region is 0.015. Since the number Nm1 of the multi-modal microprojections in the low altitude region is 0, Nm1 / Nt in the low altitude region is 0. Since the number Nm1 of the multimodal microprotrusions in the high altitude region is 0, Nm1 / Nt in the high altitude region is 0.

Therefore, the antireflection article of Example 2 has the relationship of (iii) and (iv) in the distribution of less than hs, that is,
(Iii) Nm1 / Nt = 0.015 in the middle altitude region> Nm1 / Nt = 0 in the low altitude region
(Iv) Nm1 / Nt = 0.015 in the middle altitude region> Nm1 / Nt = 0 in the high altitude region
Satisfy the relationship.

  For the fine protrusions with a distribution of hs or higher (higher side), the average height h is m2 = 209.2 nm, and the standard deviation is σ2 = 39.4 nm. Therefore, the low altitude region having a distribution of hs or higher is hs = 100 nm ≦ h <m2−σ2 = 169.9 nm, and the middle altitude region is m2−σ2 = 169.9 nm ≦ h ≦ m2 + σ2 = 248.7 nm. The altitude region is m + σ = 248.7 nm <h. Further, since the number Nm2 of the multi-modal microprotrusions in the middle altitude region is 19, Nm2 / Nt in the middle altitude region is 0.145. Since the number Nm2 of the multimodal microprojections in the low altitude region is 3, Nm2 / Nt in the low altitude region is 0.023. Since the number Nm2 of multimodal microprojections in the high altitude region is 0, Nm2 / Nt in the high altitude region is 0.

Therefore, the antireflection article of Example 2 has the relationship of (v) and (vi) above, even in the distribution of hs or more, that is,
(V) Nm2 / Nt = 0.145 in the middle altitude region> Nm2 / Nt = 0.024 in the low altitude region
(Vi) Nm2 / Nt = 0.145 in the middle altitude region> Nm2 / Nt = 0 in the high altitude region
Satisfy the relationship.

  As described above, the antireflection film 20 of Example 2 has a low altitude ratio (Nm / Nt) between the number (Nm) of multimodal microprojections in the middle altitude region and the total number (Nt) of microprojections in the frequency distribution. Since the multimodal microprotrusions are formed so as to be larger than the ratio of the region and the high altitude region, the reflectance with respect to the incident light in the visible light region can be reduced, and the antireflection function of the antireflection article can be reduced. Broadband can be achieved.

  Moreover, since the antireflection film 20 of Example 2 has a bimodal frequency distribution and satisfies the above relationships (iii) to (vi), the distribution of the multimodal microprojections in each distribution is changed to each distribution. Can be concentrated in the vicinity of the top. Thereby, the optical characteristic from an oblique direction can be improved and the wide viewing angle characteristic can be improved. In addition, the antireflection function in the ultraviolet region is improved by the multimodal microprotrusions on the lower side distribution, and the antireflection function in the visible light region is improved by the multimodal microprojections present on the higher side distribution. Therefore, the antireflection function having a wider band can be further improved.

  In addition, for the infrared region, it is necessary to form single-peaked microprojections having a wide arrangement interval (pitch) and a high height in order to ensure the antireflection function. No. 20 has a small ratio of multi-modal microprotrusions distributed to microprojections having a high height, and therefore it is possible to prevent a decrease in the antireflection function in the infrared region due to the presence of multi-modal microprotrusions. In addition, with such a configuration, even if another object comes into frictional contact with the microprotrusions, the high single-peak microprotrusions come into contact first, and the contact with the multimodal microprotrusions is suppressed. can do.

  The feature of the multimodal microprotrusions 32B described in connection with the first and second embodiments is that the multimodal microprotrusions produced by the microholes having the corresponding shapes of the molding die This is a characteristic that cannot be obtained by the multimodal microprotrusions caused by the resin filling failure disclosed in Japanese Patent Application Laid-Open No. 2012-037670. That is, the multi-peak microprotrusions due to poor filling of the resin are produced by not sufficiently filling the fine holes that are originally produced as single-peak microprotrusions, so that there is a gap between the vertices. Therefore, it is difficult to sufficiently improve the scratch resistance, and it is also difficult to improve the optical characteristics as described above.

  In addition, in the multi-peak microprojections due to poor filling, there is a disadvantage that the reproducibility is poor, and thus a uniform product cannot be mass-produced, whereas the multi-peak micro-projections according to this embodiment are High reproducibility can be ensured by a so-called mold. In addition, as described in detail with respect to the above-described Example 1 and Example 2, the height distribution of the multimodal microprojections can be controlled, whereas the multimodal microprojections with poor filling are It is difficult to control.

[Improved scratch resistance]
As described above, the concavo-convex structure layer 30 including not only the unimodal microprojections 32A but also the multimodal microprojections 32B is excellent in scratch resistance. The surface shape of the concavo-convex structure layer 30 of the antireflection film 20 with improved scratch resistance is observed with an AFM (Atomic Force Microscope) and an SEM (Scanning Electron Microscope). The multimodal microprotrusions 32B not only have a plurality of vertices, but are divided into a plurality of regions by grooves formed outward from the center when the microprotrusions are viewed in plan from the tip side. Each region of the plurality of regions is formed to be a peak related to each vertex. In addition, the multi-peak microprojections are produced by forming a micro-hole having a corresponding shape, and the micro-holes related to such multi-peak micro-protrusions are repeatedly anodized and etched. In FIG. 5, the micro holes produced in close proximity are produced integrally by etching. As a result, the multi-peak microprotrusions are formed such that the perimeter when the microprotrusions are viewed in plan from the tip side is longer than that of the single-peak microprotrusions. This point can be seen from FIG. 20 described later. The shape of these multimodal microprotrusions is a feature different from the multimodal microprotrusions caused by poor filling of the resin during the molding process disclosed in Japanese Patent Application Laid-Open No. 2012-037670.

The multi-peak microprotrusions 32B having a plurality of vertices are relatively thicker at the skirts than the single-peak microprotrusions 32A. Thereby, it can be said that the multimodal microprotrusions 32B are superior in mechanical strength to the single-peak microprotrusions 32A. Thus, when there are multi-modal microprotrusions 32B having a plurality of vertices, it is considered that the antireflection film 20 has improved scratch resistance as compared with the case of only the single-peak microprotrusions 32A. Further, when an external force is applied to the antireflection film 20 specifically, the external force is distributed and received at more vertices than in the case of only the single-peaked microprojections 32A. Thus, the microprojections 32 can be made less likely to be damaged, whereby local deterioration of the antireflection function can be reduced, and the occurrence of poor appearance can be reduced. Even if the microprojection 32 is damaged, the area of the damaged portion can be reduced. Further, about half of the multi-peak microprotrusions 32B are generated in microprotrusions having the highest peak height (the height of the highest peak belonging to the same microprotrusion) having a protrusion height equal to or higher than the average value _HAVG . The external force is first received by each peak portion and sacrificially damaged, thereby preventing the wear of the main body portion lower than the peak of the microprojection and the microprojection lower than the multi-peak microprojection. This also reduces local deterioration of the antireflection function and further reduces the occurrence of appearance defects. In the frequency distribution shown in FIG. 17 described above, there is one maximum value at 146 nm for the distance d between adjacent protrusions (value on the horizontal axis), and such a wear prevention function can be more effectively exhibited.

  Needless to say, the multi-peak microprotrusions 32B can improve the scratch resistance due to their presence, but if they do not exist sufficiently, the effect of improving the scratch resistance cannot be fully exhibited. From such a viewpoint, the ratio of the number of multimodal microprojections in all the microprojections is preferably 10% or more. In particular, in order to sufficiently exhibit the effect of improving the scratch resistance by the multimodal microprotrusions 32B, the ratio of the multimodal microprotrusions is 30% or more, preferably 50% or more. Further, since the difficulty of managing the manufacturing process increases as the ratio of the multimodal microprotrusions is increased, the ratio is preferably 90% or less, more preferably 80% or less.

  Further, the antireflection film 20 having the microprotrusion group including the multimodal microprotrusions 32B is formed with the microprotrusions 32 whose heights are controlled as described above, and microprojections having different heights. 32 are distributed. Here, as described above, the height H of each microprotrusion 32 refers to the peak (highest peak) having the highest height at the top of a specific microprotrusion that shares the ridge (root) portion. Say the height of the apex. In the case of a single-peak microprotrusion such as the microprotrusion 32A in FIG. 19A, the height (maximum point) of the only peak at the top is the protrusion height H of the microprotrusion. Further, in the case of a multi-peak microprotrusion such as the microprotrusion 32B of FIG. 19A, the height of the microprotrusion is determined with the height of the highest peak among a plurality of peaks sharing the ridge at the top. (When all the peaks sharing the buttock have the same height, the height of the same apex is used as the height of the minute protrusion). As described above, when the height H of the microprojections 32 is variously different, for example, even when the shape of the microprojections having a high height is damaged by contact with an object, the shape is maintained in the microprojections having a low height. Will be. Also by this, in the concavo-convex structure layer 30 of the antireflection film 20, it is possible to reduce the local deterioration of the antireflection function, and further reduce the occurrence of appearance defects, and as a result, the scratch resistance can be improved. it can.

  Further, when dust adheres between the minute projection group of the concavo-convex structure layer 30 of the antireflection film 20 and the object, the dust is used as an abrasive when the article slides relative to the concavo-convex structure layer 30. It functions to promote wear and damage of the microprojections (groups). In this case, if there is a difference in height between the microprojections constituting the microprojection group, the dust strongly contacts the microprojections having a high height and is damaged. On the other hand, the contact with the low-height microprotrusions is weakened, and damage to the low-height microprotrusions is reduced, and the antireflection performance is maintained by the low-height microprotrusions that remain intact or light.

  In addition to this, the microprotrusion group with distribution (height difference) in the height of each microprotrusion has a broad antireflection performance and has light with multiple wavelengths such as white light or a broadband spectrum. For light, it is advantageous to realize a low reflectance in the entire spectral band. This is because the wavelength band in which good antireflection performance can be exhibited by such a microprojection group depends on the projection height H in addition to the distance d between adjacent projections.

  Further, in this case, only the high microprojections 32 among the many microprojections are in contact with the surfaces of various members arranged to face the uneven structure layer 30 of the antireflection film 20, for example. Become. Thereby, compared with the case where it is only by the microprotrusion with the same height, a slip can be improved markedly and handling of the antireflection film 20 in a manufacturing process etc. can be made easy. From the viewpoint of improving the slip as described above, the variation needs to be 10 nm or more when defined by the standard deviation. However, when the variation is larger than 50 nm, the surface becomes rough. Therefore, the height variation is preferably 10 nm or more and 50 nm or less.

  In addition, in the case where the multi-peak microprotrusions 32B coexist in this way, the antireflection performance can be improved as compared with the case of using only the single-peak microprotrusions. That is, the multi-peak microprotrusions 32B as shown in FIGS. 8, 19 and 20, etc., even if the distance between adjacent protrusions is the same or the height of the protrusions is the same. Compared with the ridge-shaped microprotrusions, the light reflectance is further reduced. The reason is that the multimodal microprotrusions 32B have a smaller effective refractive index change rate in the height direction in the vicinity of the apex than the monomodal microprotrusions having the same shape below the top (the middle and the heel). Because of that.

That is, in FIG. 19, when Z = 0 is set as height H = 0, it is assumed that the microprojection 32B is cut at a virtual cutting plane Z = z orthogonal to the height direction (Z-axis direction). The effective refractive index n _ef obtained as the average value of the refractive indexes of the microprotrusions and the surrounding medium (usually air) at z is the refractive index of the surrounding medium (here, air) at the cutting plane Z = z. _A = 1, the refractive index of the constituent material of the minute protrusion 32B is n _M > 1, the total value of the sectional area of the peripheral medium (air) is S _A (z), and the total value of the sectional area of the minute protrusion 32B is S _{When M} (z)
n _ef (z) = 1 × S _A (z) / (S _A (z) + S _M (z)) + n _A × S _M (z) / (S _A (z) + S _M (z)) (Formula 1 )
It is represented by This is because the refractive index n _A of the peripheral medium and the refractive index n _M of the constituent material of the microprojections are respectively set to the total sectional area S _A (z) of the peripheral medium and the total value S _M (z) of the total sectional area of the microprojections. The value is proportionally distributed by ratio.

Here, when considered on the basis of the single-peak microprotrusions 32, the multi-peak microprotrusions 32B are divided into a plurality of peaks near the top. Therefore, in the virtual cutting plane Z = z that cuts the vicinity of the top, the multimodal microprotrusion 32B has a total cross-sectional area S of the peripheral medium that has a relatively low refractive index compared to the single-peak microprotrusion 32A. The ratio of _A (z) is further increased as compared with the ratio of the total cross-sectional area S _M (z) of the microprojections having a relatively high refractive index.

As a result, the effective refractive index n _ef (z) at the virtual cut surface Z = z is higher in the refractive index n _{A of the} peripheral medium in the multimodal microprojection 32B than in the single-peak microprojection 32A. Close to. The difference between the refractive index of the effective refractive index and the surrounding medium multimodal microprotrusions in the plane _{Z = z | n ef (z} ) -n A (z) | multi, the effective refractive index of the unimodal microprojection the difference between the refractive index of the surrounding medium and _{| n ef (z) -n a} (z) | When _mono,
| N _ef (z) −n _A (z) | _multi <| n _ef (z) −n _A (z) | _mono (Expression 2)
It becomes. Here, if n _A (z) = 1,
| N _ef (z) -1 | _multi <| n _ef (z) -1 | _mono (Formula 2A)
It becomes.

  As a result, in the vicinity of the top portion, the microprojection group including the multimodal microprojections 32B (including the peripheral medium between the microprojections) is more effective than the projection group including only the single-peak microprojections 32A. The difference between the refractive index and the refractive index of the surrounding medium (air), more specifically, the rate of change of the refractive index per unit distance in the height direction of the microprojections is further reduced, in other words, the refractive index. It can be seen that the continuity of the change in the height direction can be further increased.

In general, when light is incident on an interface between an adjacent medium having a refractive index n _{0 and} a medium having a refractive index n ₁ , the reflectance R of the light at the interface is set as an incident angle = 0.
R = (n ₁ −n ₀ ) ² / (n ₁ + n ₀ ) ² (Formula 3)
It becomes. From this equation, the smaller the refractive index difference n ₁ -n ₀ between the media on both sides of the interface, the lower the light reflectivity R at the interface, and as (n ₁ -n ₀ ) approaches 0, R also approaches 0. It will be.

  From (Equation 2), (Equation 2A), and (Equation 3), for the microprojection group including the multi-peak microprojections 32B (including the peripheral medium between the microprojections), only the single-peak microprojections 32A The light reflectance is reduced as compared with the projection group consisting of

  Even when a microprojection group consisting of only single-peak microprojections 32A is used, by setting the maximum value dmax of the distance between adjacent projections to a sufficiently small value not more than the shortest wavelength λmin of the wavelength band of electromagnetic waves for preventing reflection, It is possible to exhibit a sufficient antireflection effect. However, in this case, since the distance between adjacent peaks and the distance between adjacent minute protrusions are the same, a phenomenon (so-called sticking) in which adjacent minute protrusions are brought into contact with each other and integrated together is likely to occur. When sticking occurs, the substantial distance d between adjacent protrusions increases by the number of minute protrusions integrated together.

  For example, when four microprojections with d = 200 nm are stuck, the size of the stuck and integrated projection is substantially d = 4 × 200 nm = 800 nm> the longest wavelength in the visible light band (780 nm). The antireflection effect is locally impaired.

On the other hand, in the case of the microprotrusion group composed of the multimodal microprotrusions 32B, the distance between adjacent protrusions d ^PEAK between the peaks near the top is larger than the distance between adjacent protrusions d _BASE of the microprotrusion main body from the heel to the middle. It becomes smaller (d ^PEAK <d _BASE ) and is usually about d ^PEAK = d _BASE / 4 to d _BASE / 2. Therefore, sufficient antireflection performance can be obtained by setting the distance d ^PEAK << λmin between adjacent protrusions between the peaks. However, the ratio of the height of the ridge to the width of the ridge is small in each ridge of the multimodal microprotrusion 32B, and the ratio of the height of the apex to the width of the ridge of the single-peak microprojection 32A is small. It is about 1/2 to 1/10. Therefore, for the same external force, the peak of the multimodal microprotrusions is less likely to deform than the single-peak microprotrusions. In addition, the main body itself of the multimodal microprotrusions has a greater distance between adjacent protrusions and a greater strength than the ridges. Therefore, after all, the microprojection group composed of multimodal microprotrusions can easily achieve both stickiness and low reflectivity compared to the projection group composed of monomodal microprotrusions.

  In addition, even if it is other uses for antireflection of visible light, or under a visible light environment, the antireflection material depends on the assumed antireflection wavelength depending on the environmental conditions where the antireflection material is installed and used. By forming a moth-eye structure and having a height distribution, as described above, even when using materials that are more resistant to abrasion than conventional products and have low hardness due to process requirements, etc., prevent sticking to each other In addition, it is possible to produce an antireflection material having both optically required performance. For example, when it is desired to obtain antireflection performance in the ultraviolet region around 380 nm, the height of the moth eye can be about 50 nm. Similarly, in the infrared region around 700 nm, about 150 nm to 400 nm in consideration of practical use. Is possible. As described above, it is possible to find manufacturing conditions that saturate the height of the arrangement pitch of the moth-eye, and to effectively control the reflectance of the moth-eye. In addition, the top structure of the moth-eye can be improved from the conventional single peak to achieve both height and reflectivity, and it is difficult to cause physical sticking and can effectively reduce reflectivity. Yes.

  FIG. 20 is a photograph showing a plurality of minute protrusions at the apex, and FIG. 20A is an example of a minute protrusion different from that of the present embodiment, but is based on AFM, and FIG. (C) is an example of a microprotrusion according to the present embodiment, which is based on SEM. In FIG. 20 (a), a groove g and a microprojection having three vertices and a groove g and a microprojection having two vertices can be seen, and in FIG. 20 (b), the groove g and four vertices are present. A microprotrusion and a microprotrusion having a groove g and two vertices can be seen, and in FIG. 20C, a microprotrusion having a groove g and three vertices, a microprotrusion having a groove g and two vertices can be seen. be able to. 20 (b) and 20 (c) are obtained by applying an oxalic acid aqueous solution having a water temperature of 20 ° C. and a concentration of 0.02M in the first step and performing an anodic oxidation treatment for 120 seconds with an applied voltage of 40V. In the etching process, an anodic oxidation solution was applied to the first step, and an aqueous phosphoric acid solution having a water temperature of 20 ° C. and a concentration of 1.0 M was applied to the second step. In the anodizing process, as described above, the applied voltage is gradually increased from the first step to the fourth step, and the fifth step is performed again with the same applied voltage as in the first step. is there. The number of times of anodizing treatment and etching treatment is 5 times.

  FIGS. 21 and 22 are perspective views showing the shapes of the minute protrusions 32 of the antireflection film 20 actually manufactured using the roll plate 37 manufactured by the manufacturing method described with reference to FIGS. 14 to 16. FIG. 21 is a plan view (FIG. 22A), a front view (FIG. 22B), and a side view (FIG. 22C). These FIG. 21 and FIG. 22 are contour maps. As described above, by switching the applied voltage in a plurality of anodic oxidation treatments, in the microprojections according to FIGS. 21 and 22, three peaks having greatly different heights are combined to form one microprojection. It can be seen that microprojections are produced by dividing the region into three peak areas by three radial grooves (swelled local minimum portions) formed outward from the center. FIG. 21 and FIG. 22 show data in detail by partially selecting data based on measurement results by AFM. The unit of the numbers in FIGS. 21 and 22 is [nm]. The X coordinate and the Y coordinate are coordinate values from a predetermined reference position.

[Evaluation of scratch resistance]
Table 4 shows the evaluation results of the scratch resistance. This is because the antireflection film 20 according to the example of FIG. 17 is compared with an antireflection film having a similar protrusion height distribution using only unimodal microprotrusions. In addition, the antireflection film having only the single-peaked microprojections 32A was produced by using the same constant voltage as that in the first step even when the applied voltage of the repeated anodizing treatment was not higher than that in the second step.

  In Table 4, the column of steel wool is the result of visually confirming the change in the surface after the steel wool was pressed and reciprocated with a pressing force of 100 g and 200 g. The double circle mark was evaluated to be visually free of scratches and turbidity, and the x mark was visually observed for 6 or more scratches. The evaluation range is a rectangular area with a side of 5 cm. It can be seen that the scratch resistance is sufficiently improved by the multimodal microprotrusions.

  Further, the column of dry wiping shows 5 ° regular reflectance ΔY (%) when fingerprints are attached and then wiping in a dry state not containing a solvent is reciprocated 50 times using a nonwoven fabric. With the fingerprint attached, the 5 ° regular reflectance was set to 4%. As the nonwoven fabric, Savina Minimax (registered trademark) 150 mm □ manufactured by KB Seiren Co., Ltd. was used. In addition, the initial value of the 5 ° regular reflectance in a state where no dirt due to fingerprints was attached was 0.5%. According to the results of this study, it was found that the dirt attached by the multimodal microprotrusions was easily wiped off, and the antireflection performance was restored to a state close to that before the fingerprint attachment. In the case where it is provided, it is considered that the dirt does not penetrate deeply into the base side of the minute protrusion.

  According to the above configuration, by combining a multi-peak microprojection having a plurality of vertices and a single-peak microprojection having a single vertex, the scratch resistance can be improved as compared with the conventional case. . In addition, the stain resistance (easy wiping property) against fingerprints is also improved.

  Furthermore, the slipperiness can be improved by giving a distribution to the heights of the microprotrusions.

  By the way, in the above description, as shown in FIG. 19A, the surface connecting the valley bottoms (minimum points of height) between adjacent minute protrusions is a flat surface having a constant height. Not limited to this, as shown in FIG. 23, the envelope surface connecting valleys between the microprotrusions may be undulated with a period D (that is, D> λmax) equal to or longer than the longest wavelength λmax of the visible light band. Further, the periodic undulation is only in one direction (for example, the X direction) in the XY plane (see FIGS. 19 and 23) parallel to the front and back surfaces of the transparent base material 25, and in a direction (for example, the Y direction) orthogonal thereto. The height may be constant, or the two directions (X direction and Y direction) on the XY plane may have undulations. The concave and convex valley bottom surface 33 that undulates with a period D satisfying D> λmax is superimposed on a microprojection group made up of a large number of microprojections, thereby scattering the reflected light remaining without being completely antireflected by the microprojections group, It is further difficult to visually recognize the Shiodome reflected light, in particular, the specular reflected light, thereby further improving the antireflection effect.

When the period D of the concave and convex valley bottom surface 33 has a distribution that is not constant over the entire surface, the frequency distribution of the distance between the convex portions is obtained for the concave and convex valley bottom surface 33, and the average value is D _AVG and the standard deviation. Where Σ is Σ
D _MIN = D _AVG -2Σ
Designed as an alternative to period D with a minimum inter-protrusion distance defined as That is, conditions that can sufficiently exhibit the scattering effect of the reflected light of the microprojections are as follows:
D _MIN > λmax
Also, the Rz value (10-point average roughness) defined in JIS B0601 (1994) corresponding to the height difference of the unevenness is
Rz ≧ λmin
It is. Usually, D or D _MIN is 1 to 600 μm, preferably 10 to 3100 μm. Usually, Rz is set to 0.4 to 5 μm. An example of a specific manufacturing method for forming a concavo-convex microprojection group having an uneven valley bottom surface 33 in which the envelope shape connecting the valley bottoms of each microprojection is D (or D _MIN )> λmax is as follows. It is. That is, in the manufacturing process of the roll plate 37, a concave-convex shape corresponding to the concave-convex shape of the concave-convex valley bottom surface 33 is formed on the surface of a cylindrical (or columnar) base material by sandblasting or mat (matte) plating. Next, an appropriate intermediate layer is formed directly or if necessary on the uneven surface, and then an aluminum layer is laminated. Thereafter, an anodizing process and an etching process are performed on the aluminum layer shaped to have a surface shape corresponding to the uneven surface to form a microprojection group including microprojections 32 in the same manner as in the above-described embodiment.

<< Addition, modification, other >>
Various additions and changes can be made to the above-described example. Hereinafter, an example of modification will be described.

  In the example described above, the antireflection film is formed to include two layers of the transparent base material 25 and the concavo-convex structure layer 30. Such an antireflection film can be produced by forming an uneven structure layer 30 formed by molding an ionizing radiation curable resin on the transparent substrate 25. On the other hand, the antireflection film may be a three-layer laminated structure or a single-layer product. The antireflection film 20 can also be produced by extruding a thermoplastic resin.

  In the example described above, the antireflection film is disposed only on a part of the first surface 15a of the transparent body 15. However, the present invention is not limited to this, and the entire surface of the first surface 15a of the transparent body 15 is antireflection. The film may be covered. In the above-described example, the antireflection film is disposed only on a part of the second surface 15b of the transparent body 15. However, the present invention is not limited to this, and the entire surface of the second surface 15b of the transparent body 15 is antireflection. The film may be covered.

  Furthermore, in the above-described example, the outer contour of one antireflection film on the first surface 15a of the transparent body 15 and the second surface 15b along the direction normal to the plate surface of the plate-like transparent body 15 Although an example in which the outer contour of the other antireflection film 20b on the top is arranged so as to overlap is shown, the present invention is not limited to this, and one antireflection film on the first surface 15a of the transparent body 15 and the other These antireflection films may be arranged so as to overlap at least partially along the normal direction of the transparent body 15.

  Moreover, in the example mentioned above, although the one antireflection film on the 1st surface 15a of the transparent body 15 and the other antireflection film on the 2nd surface 15b were shown, the example was shown, but it does not restrict to this. I can't. For example, between one antireflection film on the first surface 15a of the transparent body 15 and the other antireflection film on the second surface 15b, the reflectance and unevenness due to 5 ° regular reflection on the uneven surface 31 You may make it the at least one characteristic of the contact angle with respect to the water on the surface 31 mutually differ.

  In the first place, one antireflection film on the first surface 15a of the transparent body 15 and the other antireflection film on the second surface 15b can each exhibit an antireflection function and an antifogging function. One of the two antireflection films may be omitted together with the corresponding bonding layer, or one of the two antireflection films facing each other may be a simple moth-eye structure formed of a hydrophobic material. For example, an antireflection film having both an antireflection function and an antifogging function is positioned on the inner side of the building 90, and a simple moth-eye structure having no antifogging function is positioned on the outside of the building 90. Also good.

  Furthermore, the uneven surface 31 of the uneven structure layer 30 of one of the two antireflection films facing each other may be formed as a hard coat layer for improving the scratch resistance. This hard coat layer may be formed as a thin film. Alternatively, from the viewpoint of improving the scratch resistance, the concavo-convex structure layer 30 may contain a slip agent. Furthermore, from the viewpoint of preventing deterioration due to ultraviolet rays, any part of the partition member or the partition member may contain an ultraviolet absorbent such as a benzotriazole-based compound.

  Furthermore, since the antireflection film exhibits an excellent antireflection function and an antifogging function, a portion of the partition member on which the antireflection film is provided is visually recognized as being open. For this reason, some patterns may be formed on the antireflection film or on the periphery of the antireflection film of the transparent body 15. Here, the pattern is a recording object of various modes that can be recorded or printed on the antireflection film or the transparent body 15, and is not particularly limited, and is not limited to a figure, a character, a pattern, a pattern, a symbol, a pattern, a mark. Including widely etc. For example, characters such as “Don't Touch”, a pattern bordering the antireflection film, a net pattern formed in the region of the antireflection film, and the like can be exemplified. Moreover, about these patterns, you may form in the shape which cut out the antireflection film itself, or the remainder (area | region which does not have an antireflection function).

  In addition, although the some modification with respect to the example mentioned above was demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

10 partition member 15 transparent body 18 bonding layer 18a first bonding layer 18b second bonding layer 20 antireflection film 20a first antireflection film 20b second antireflection film 25 transparent substrate 30 concavo-convex structure layer 31 concavo-convex surface 32 minute protrusion 33 Top 40 Monitoring system 50 Partition member 55 Transparent body 60a First antireflection film 60b Second antireflection film 60c Third antireflection film 60d Fourth antireflection film 80 Imaging means 81 Support means 82 Display means 83 Connection line 84 Lighting fixture 90 Building 91 Wall 92 Ceiling 93 Floor

Claims (16)

A transparent partition member for partitioning an area,
A transparent body,
An antireflection film affixed to the surface of one side of the transparent body,
The antireflection film has a concavo-convex structure layer having a concavo-convex surface formed by minute protrusions provided at intervals equal to or shorter than the shortest wavelength in the visible light band, and the concavo-convex surface is opposite to the transparent body. Placed to face
The reflectance by 5 ° regular reflection on the uneven surface of the antireflection film is 0.3% or less,
The partition member whose contact angle with respect to the water on the said uneven surface of the said antireflection film is 20 degrees or less.   The partition member according to claim 1, wherein the antireflection film is affixed on a part of a surface on one side of the transparent body. The fine protrusions of the concavo-convex structure layer are provided at intervals of 70 nm or more and 180 nm or less,
The partition member according to claim 1 or 2, wherein a height of the minute protrusion is 100 nm or more and 250 nm or less.   The partition member as described in any one of Claims 1-3 whose reflectance by the 50 degree regular reflection on the said uneven surface of the said antireflection film is 1.0% or less.   The partition member according to claim 1, wherein a contact angle with respect to water of the resin material forming the uneven structure layer is 10 ° or more and 90 ° or less.   The division member as described in any one of Claims 1-5 attached to the opening part of the wall which divides the inside and the exterior of a building. A second antireflection film affixed to the other surface of the transparent body so as to face the antireflection film;
The second antireflection film has a concavo-convex structure layer having a concavo-convex surface formed by minute protrusions provided at intervals equal to or shorter than the shortest wavelength in the visible light band, and the concavo-convex surface is opposite to the transparent body. Placed to face
The partition member according to claim 1, wherein a reflectance by 5 ° regular reflection on the uneven surface of the second antireflection film is 0.3% or less. It is attached to the opening of the wall that separates the inside and outside of the building,
The partition member of Claim 7 arrange | positioned so that the said antireflection film may be located in the inside of a building, and the said 2nd antireflection film may be located in the exterior of the said building.   The partition member as described in any one of Claims 1-8 by which the pattern is provided in the part used as the circumference | surroundings of the said antireflection film of the said transparent body or the said antireflection film.   The partition member according to any one of claims 1 to 9, wherein the antireflection film is elongated in a horizontal direction.   The storage elastic modulus (E1 ′) at 25 ° C. of the resin material forming the uneven structure layer is 300 MPa or less, and the loss at 25 ° C. of the resin material forming the uneven structure layer with respect to the storage elastic modulus (E1 ′). The ratio of elastic modulus (E1 ″) (tan δ (= E1 ″ / E1 ′)) is 0.2 or less, and the contact angle of n-hexadecane on the surface of the resin material forming the concavo-convex structure layer is 30 °. The partition member according to claim 1, wherein the contact angle of oleic acid is 25 ° or less. The microprojection includes a plurality of multimodal microprojections having a plurality of vertices, and a single-peak microprojection having one vertex.
The frequency distribution of the height of the microprotrusions is a distribution consisting of one top,
The partition member according to any one of claims 1 to 11, wherein the multimodal microprotrusions are distributed more in the vicinity of the apex than the base of the distribution. The microprojection includes a plurality of multimodal microprojections having a plurality of vertices, and a single-peak microprojection having one vertex.
The average value of the height H in the frequency distribution of the height H of the microprotrusions is m, the standard deviation is σ,
The region where H <m−σ is the low altitude region,
The region of m−σ ≦ H ≦ m + σ is defined as a medium altitude region,
When the region of m + σ <H is a high altitude region,
The ratio between the number Nm of the multi-peaked microprojections in each region and the total number Nt of the microprojections in the entire frequency distribution is as follows:
Nm / Nt in middle altitude region> Nm / Nt in low altitude region,
The partition member as described in any one of Claims 1-12 satisfy | filling the relationship of Nm / Nt of a middle altitude area | region> Nm / Nt of a high altitude area | region. The frequency distribution of the height h of the microprojections is bimodal having two peaks,
With the height hs serving as the boundary between the two peaks, the frequency distribution is composed of two distributions: a distribution of microprojections having a height less than hs and a distribution of microprojections having a height of hs or more.
In the distribution below the height hs, the average value of the heights h of the microprotrusions is m1, and the standard deviation is σ1,
Let h <m1-σ1 be the low-altitude region,
The area of m1−σ1 ≦ h ≦ m1 + σ1 is a middle altitude area,
When the region of m1 + σ1 <h <hs is a high altitude region,
The ratio between the number Nm1 of the multi-modal microprojections in each region in the distribution of less than hs and the total number Nt of the microprojections in the entire frequency distribution is:
Nm1 / Nt in the middle altitude region> Nm1 / Nt in the low altitude region,
Satisfying the relationship of Nm1 / Nt in the middle altitude region> Nm1 / Nt in the high altitude region,
In the distribution of the height hs or more, the average value of the height h of the microprotrusions is m2, the standard deviation is σ2,
The region of hs <h <m2-σ2 is set as a low altitude region,
The region of m2-σ2 ≦ h ≦ m2 + σ2 is defined as a middle altitude region,
When the area of m2 + σ2 <h is a high altitude area,
The ratio between the number Nm2 of the multi-modal microprojections in each region in the distribution of hs or more and the total number Nt of the microprojections in the entire frequency distribution is:
Nm2 / Nt in the middle altitude region> Nm2 / Nt in the low altitude region,
Satisfying the relationship of Nm2 / Nt in the middle altitude region> Nm2 / Nt in the high altitude region,
The partition member according to claim 8. The partition member described in any one of Claims 1-14,
And a photographing means for photographing through the partition member. The photographing means is relatively rotatable around a certain axial direction with respect to the partition member,
The monitoring system according to claim 15, wherein the antireflection film extends in a direction non-parallel to the axial direction.