JP2014123077A - Anti-reflection body and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously enhance optical performance and mechanical strength of an anti-reflection body, which have been considered to be in a trade-off relationship.SOLUTION: An anti-reflection body (10) includes; a base material (11); a first concavo-convex structure (S) which is provided on a main surface of the base material (11) and has a first average pitch (PS); and a second concavo-convex structure (L) having a second average pitch (PL) greater than the first average pitch (PS). A shortest distance between an average protrusion apex position of the first concavo-convex structure (S) and an average protrusion apex position of the second concavo-convex structure (L) is more than 0 nm and 100 μm or less. The average protrusion apex position of the second concavo-convex structure (L) is located further out in an out-of-plane direction of the base material (11) compared with the average protrusion apex position of the first concavo-convex structure (S).

Description

  The present invention relates to an antireflection body and a method for manufacturing the same.

  It is known that low reflectance can be realized by a nanoscale uneven structure (for example, Non-Patent Document 1 or Patent Document 1). Microstructures having such a nanoscale concavo-convex structure are attracting attention because of their low reflectance, and are widely expected to be applied to optical applications such as LCDs and lenses.

  In the fine structure, the reflectance of incident light is reduced based on the principle of optical effective field quality approximation, so the shape of the fine structure is a plane perpendicular to the incident direction of light in its cross-sectional shape. It is important not to have a (smooth surface). This is because, when a plane perpendicular to the incident direction of light is provided, the change in the effective medium refractive index becomes steep. Therefore, in the fine structure, it is important to increase the filling rate of the fine structure to be applied to the surface and minimize the vertical plane so that the effective medium refractive index changes gently.

International Publication No. 2011/0665429 Pamphlet

"Optical Technology Contact" 43 (11), 630 (2005)

  By the way, when using an anti-reflective body that has an anti-reflective function due to a nanoscale uneven structure, it is necessary to allow the target light to enter from the uneven structure surface side in order to maximize the anti-reflective function. There is. However, in order to develop an antireflection function depending on the structure, it is necessary to make an effective medium approximation function in which light does not substantially recognize the concavo-convex structure function. Such a concavo-convex structure that exhibits an effective medium approximating action is a fine concavo-convex structure, which is problematic in that it is damaged when mounted on a device or used. For example, when dirt such as dust or fingerprints attached to the surface is wiped off, or when the concavo-convex structure is touched when mounted on a device, the fine structure is destroyed, the surface becomes cloudy, and low reflectance cannot be maintained. . In particular, there is a problem that the more the effective medium approximating action is expressed, the finer the concavo-convex structure becomes, and thus the strength thereof decreases.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an antireflection body that can simultaneously solve the optical performance and strength improvement of the antireflection bodies that have been traded off each other, and a method for manufacturing the same. And

  As a result of intensive studies to solve the above problems, the present inventors have found that the uneven structure of the antireflection body is composed of two types of uneven structures with different average pitches. By providing the other concavo-convex structure having an average pitch larger than the average pitch of the one concavo-convex structure on at least a part of the surface of the concavo-convex structure, simultaneously solving the antireflection performance and strength that have been traded off each other Based on this finding, the present invention has been made. That is, the present invention is as follows.

  The antireflection body of the present invention includes a base material, a first concavo-convex structure (S) provided on the main surface of the base material and having a first average pitch (PS), and the first average pitch. A second concavo-convex structure (L) having a second average pitch (PL) that is larger than the average concavo-convex top position of the first concavo-convex structure (S) and the second concavo-convex structure (L). ) Of the second convexo-concave structure (L) is equal to the average convex part of the first concave-convex structure (S). It is characterized by being located in the out-of-plane direction of the base material with respect to the top position.

  With this configuration, it is possible to separate and develop the function of the anti-reflective body by the concavo-convex structure surface composed of the first concavo-convex structure (S) and the second concavo-convex structure (L). That is, the antireflection performance is improved by the first uneven structure (S) having the first average pitch (PS), and the strength is improved by the second uneven structure (L) having the average pitch (PL). it can. Furthermore, the average convex portion top position of the second concave-convex structure (L) is positioned more in the out-of-plane direction of the base material than the average convex portion top position of the first concave-convex structure (S), and the first concave-convex structure Since the shortest distance between the average convex top position of (S) and the average convex top position of the second concavo-convex structure (L) satisfies a predetermined range, it is possible to maintain antireflection performance and improve strength. It becomes.

  In the antireflection body of the present invention, the first concavo-convex structure (S) is composed of a plurality of protrusions spaced apart from each other, and the diameter of the protrusions is from the bottom of the protrusions to the protrusions. It is preferable to become smaller toward the top.

  According to this configuration, when light is incident from the concavo-convex structure surface side, the refractive index of the first concavo-convex structure (S) viewed from the light changes gently due to the effective medium approximation action. For this reason, it becomes possible to reduce a reflectance effectively.

  In the antireflection body of the present invention, the first average pitch (PS) is preferably 50 nm or more and 350 nm or less.

  According to this structure, the wavelength band which can exhibit the performance of an antireflection object spreads. That is, it is possible to exhibit antireflection performance regardless of the application.

  In the antireflection body of the present invention, the refractive index nS of the substance constituting the first concavo-convex structure (S) and the refractive index nL of the substance constituting the second concavo-convex structure (L) are 0 ≦ It is preferable to satisfy | nL−nS | ≦ 0.2.

  According to this configuration, since reflection of light at the interface between the first uneven structure (S) and the second uneven structure (L) can be suppressed, the antireflection performance can be improved.

  Moreover, it is preferable that the antireflective body of this invention is a film form.

  According to this configuration, since the antireflection body has flexibility, it is possible to suppress damage such as cracks in the antireflection body. Furthermore, since it is a film form, the mounting application location to a device can be expanded. Moreover, the controllability of the concavo-convex structure during manufacturing is improved.

  The antireflection roll of the present invention is produced by winding the antireflection body described above.

  According to this structure, it becomes possible to use an antireflection body in a place suitable for use of an antireflection body.

  The cylindrical master of the present invention is a cylindrical master for producing the above-described antireflective body by a transfer method, and the cylindrical master has a fine pattern on the surface of the first concave-convex structure (S). And a fine pattern having an inverted shape of the second concavo-convex structure (L).

  According to this configuration, when peeling off the antireflection body from the cylindrical master, the external force applied to the first uneven structure (S) of the antireflection body is weakened and the stress applied to the first uneven structure (S) is reduced. Since it can disperse | distribute, destruction of the uneven structure which arises at the time of manufacture of an antireflection body can be suppressed.

  The method for producing an antireflective body according to the present invention is the method for producing an antireflective body described above, wherein the surface of the cylindrical master having the fine pattern and the surface of the substrate are pasted via a transfer material. A step of combining, and a step of separating the cylindrical master and the base material.

  According to this configuration, it is possible to continuously manufacture an antireflection body having an uneven structure surface capable of achieving both antireflection performance and strength with high accuracy.

  Moreover, the manufacturing method of the anti-reflective body of this invention is a manufacturing method of the above-mentioned anti-reflective body, Comprising: The fine which made the reverse shape of the said 1st uneven structure (S) provided in the surface of the cylindrical master A step of bonding a pattern and a base material via a transfer material, a step of separating the cylindrical master and the base material to obtain a base material having the first concavo-convex structure (S), And a step of producing the second concavo-convex structure (L) on the first concavo-convex structure (S) of the base material.

  According to this configuration, the material constituting the first concavo-convex structure (S) and the material constituting the second concavo-convex structure (L) can be arbitrarily selected, and therefore the first concavo-convex structure (S ) And the strength of the second concavo-convex structure (L) can be improved satisfactorily.

  ADVANTAGE OF THE INVENTION According to this invention, the antireflection performance and intensity | strength of the fine grooving | roughness structure surface of the antireflection body which were made a trade-off mutually can be solved simultaneously.

It is a cross-sectional schematic diagram which shows the reflection preventing body which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the reflection preventing body which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows an example of the reflection preventing body which concerns on this Embodiment. It is explanatory drawing and the enlarged schematic diagram which show the anti-reflection roll which concerns on this Embodiment. It is the top view which looked at the reflection preventing body concerning this Embodiment from the uneven structure surface side. It is a top view in case the uneven structure which comprises the uneven structure surface of the antireflection body concerning this Embodiment is a dot structure. It is a cross-sectional schematic diagram of the concavo-convex structure at the line segment position corresponding to the pitch p shown in FIG. It is a top view in case the uneven structure which comprises the uneven structure surface of the antireflection body concerning this Embodiment is a hole structure. It is a cross-sectional schematic diagram of the concavo-convex structure at a line segment position corresponding to the pitch p shown in FIG. It is explanatory drawing which shows the upper surface image at the time of observing the antireflection body concerning this Embodiment from the uneven structure surface side.

  First, an outline of the present invention will be described. The antireflection function by the concavo-convex structure is achieved by an optical effective medium approximating action. The effective medium approximation action is that when there is a concavo-convex structure that is sufficiently smaller than its wavelength when viewed from light, the light does not recognize the concavo-convex structure, and the optical behavior of the concavo-convex structure and the medium surrounding the volume average refractive index of the thin film Is a phenomenon observed. More specifically, when light enters the concavo-convex structure, the volume of the refractive index of the material constituting the concavo-convex structure and the refractive index of the medium surrounding the concavo-convex structure from the light incident surface side to the light exit surface side of the concavo-convex structure. This is a phenomenon in which the optical behavior is observed so that the average refractive index gradually changes.

  Incidentally, the reflection of light is a phenomenon that occurs when light reaches different medium interfaces. Here, the medium viewed from light is defined by the refractive index.

  In other words, as described above, when the refractive index gradually changes, the refractive index interface disappears from the viewpoint of light, so that the optical reflection phenomenon is suppressed.

  Such a concavo-convex structure capable of exhibiting an effective medium approximating action is a concavo-convex structure that is sufficiently small in view of the wavelength of light. Here, the physical strength of the concavo-convex structure decreases as the concavo-convex structure becomes minute. That is, when emphasis is placed on the strength of the concavo-convex structure, the effective medium approximation function becomes difficult to function, and the reflectance increases. On the other hand, when the reflection performance is regarded as important, the concavo-convex structure becomes a finer structure, so that the physical strength decreases.

  Therefore, we paid attention to the difference in antireflection performance and strength principle that are in a trade-off relationship.

  When antireflection is expressed by the concavo-convex structure, it is necessary to effectively express the effective medium approximation as described above. In order to exhibit an effective medium approximating action and greatly reduce the reflectance, it is necessary to make the change in the effective medium approximate refractive index more gentle.

  On the other hand, in order to improve the physical strength of the concavo-convex structure, it is necessary to improve resistance to the external force of the concavo-convex structure. Resistance to external force can be determined by the absolute value of the physical fracture strength and the stress distribution that relaxes the stress concentration.

  From the above, in order to improve the antireflection performance and strength of the antireflection body at the same time, providing one concavo-convex structure that can improve antireflection performance and the other concavo-convex structure that can improve physical strength, The present inventors have found that an arrangement in which the structure does not hinder each function is important and completed the present invention.

  In the present invention, one concavo-convex structure for improving antireflection performance and the other concavo-convex structure for improving physical strength are determined by the difference in average pitch (pav) of the concavo-convex structure. That is, the concavo-convex structure of the antireflection body of the present invention includes the concavo-convex structure (S) having the first average pitch (PS) and the second concavo-convex structure (L) having the second average pitch (PL). The first average pitch (PS) is smaller than the second average pitch (PL). Here, antireflection performance is expressed by the first uneven structure (S) having the first average pitch (PS), and physical strength is expressed by the uneven structure (L) having the second average pitch (PL). Further, in order to synergize the functions of the respective concavo-convex structures and complement each other, in other words, the first concavo-convex structure (S) that improves the antireflection performance can improve the physical strength without decreasing the physical strength. Since the anti-reflection performance does not deteriorate due to the concave / convex structure (L), the convex portion top average position of the second concave / convex structure (L) is higher than the convex top average position of the first concave / convex structure (S). The first concavo-convex structure (S) and the second concavo-convex structure (L) are arranged so as to be positioned in the out-of-plane direction of the base material constituting the antireflection body.

  Further, the present invention includes an antireflection roll in which the antireflection body of the present invention is wound up.

  The present invention also includes a cylindrical master characterized in that it is used for producing the above-described antireflection body of the present invention.

  Moreover, the manufacturing method of the antireflection body and the antireflection roll of the present invention described above is included in the present invention.

  Next, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  Hereinafter, the antireflection body will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an antireflection body according to the present embodiment. 1A shows a case where the base material 11 and the uneven structure surface 20 constituting the antireflection body 10 are the same substance, and FIG. 1B shows a case where the base material 11 and the uneven structure surface 20 are different substances. Each is shown. That is, even if the antireflection body 10 is manufactured by directly processing the base material 11 to produce the concavo-convex structure surface 20 on the surface, the layer 12 having the concavo-convex structure surface 20 is separately provided on the base material 11. May be manufactured. In FIG. 1A and FIG. 1B, the concavo-convex structure surface 20 is illustrated as a simple repetition of convex portions, but the concavo-convex structure surface 20 has a larger average than the first concavo-convex structure S having the average pitch PS and the average pitch PS. It is comprised by the 2nd uneven structure L which has the pitch PL. And the uneven structure S and the uneven structure L are arrange | positioned so that the convex-part top average position of the uneven structure L may be located in the out-of-plane direction of the base material 11 rather than the convex-part top average position of the uneven structure S. .

  FIG. 2 is a schematic cross-sectional view showing the antireflective body according to the present embodiment. In FIG. 2, the case where the uneven | corrugated structure surface 20 is provided in both surfaces of the base material 11 is shown. As described with reference to FIG. 1A and FIG. 1B, the uneven structure surfaces 20 provided on both surfaces of the substrate 11 may be the same as or different from those of the substrate 11. Further, when the concavo-convex structure surfaces 20 are provided on both surfaces of the base material 11, at least one of the concavo-convex structure surfaces 20 may be configured by the concavo-convex structure S and the concavo-convex structure L. And if the uneven structure S and the uneven structure L are arrange | positioned so that the convex-part top average position of the uneven | corrugated structure L may be located in the out-of-plane direction of the base material 11 rather than the convex-part top average position of the uneven structure S. Good.

  FIG. 3 is a schematic cross-sectional view showing the antireflection body according to the present embodiment. As shown in FIG. 3, the concavo-convex structure S having the average pitch PS is provided on the surface of the antireflection body 10, and the concavo-convex structure L having the average pitch PL is provided on at least a part of the surface of the concavo-convex structure S.

  More specifically, a concavo-convex structure S composed of a plurality of convex portions 1 and concavo-convex portions 2 is formed on the main surface of the base material 11, and the concavo-convex structure S is separated from each other so that a part of the surface of the concavo-convex structure S is exposed. A plurality of convex portions 3 are formed to constitute the concavo-convex structure L.

  By adopting such a configuration, the antireflection performance can be improved by the exposed uneven structure S, and the strength by the uneven structure L can be improved.

  The antireflection body according to the present embodiment is preferably a film. Here, the film form is a state in which the antireflection body has flexibility, and in particular, a state in which the form of an antireflection roll described below can be taken. For example, when a plastic film typified by a PET film, a TAC film, and a PEN film is selected as the base material and the concavo-convex structure surface is made of a resin, the antireflection body has flexibility. By using such a film-shaped antireflection body, handling properties when mounting on a device are improved, and the number of mounting locations on an applicable device can be increased.

  Next, the antireflection roll according to the present embodiment will be described. FIG. 4A is an explanatory view showing the antireflection roll according to the present embodiment, and FIG. 4B is an enlarged schematic view in which a part of the side surface of the antireflection roll shown in FIG. 4A is enlarged. The antireflection roll 30 shown in FIG. 4A is obtained by winding the film-like antireflection body 10 on the peripheral surface of the roll core portion 31. In the antireflective body 10 according to the present embodiment, the strength can be improved by the concavo-convex structure L, and therefore, the breakage of the concavo-convex structure surface 20 can be suppressed even when wound. By making it the form of such a rolled-up roll, it becomes possible to use the antireflection body 10 in a place suitable for use. As shown in FIG. 4B, the concavo-convex structure surface 20 is in contact with the base material 11 of the antireflection body 10 wound inside, but the cover film is put on the concavo-convex structure surface 20, and the state You may wind up with. In this case, contamination of the concavo-convex structure S by the cover film can be suppressed by the concavo-convex structure L.

  By using the antireflection body 10 according to the present embodiment, the antireflection performance and the strength are simultaneously improved. The reason is as follows.

  As described above, the antireflection performance is mainly expressed by the concavo-convex structure S. The average pitch PS of the concavo-convex structure S is smaller than the average pitch PL of the concavo-convex structure L. For this reason, the uneven structure S is a minute uneven structure. For this reason, it becomes possible to effectively express the effective medium approximating action, and the reflectance is lowered.

  However, when the effective medium approximating function is effectively functioned and the effective medium approximate refractive index is gently changed, the physical strength is reduced only by the uneven structure S alone, and the uneven structure S is destroyed. When the uneven structure S is destroyed, the reflectance increases greatly. This is a phenomenon that occurs even when one uneven portion is missing when the uneven structure S is composed of a plurality of convex portions. For example, when there are a plurality of convex portions arranged in a regular hexagon, the distances between adjacent convex portions are all constant. Here, when one convex part is missing, a site where the adjacent distance between the convex parts is doubled occurs. In such a part, the effect of approximating the effective medium as seen from the wavelength of light is less likely to occur, so that the reflectance increases. The degree of increase in reflectivity increases according to the proportion of the concavo-convex structure S that is destroyed.

  Here, the convex portion top average position of the concave-convex structure L having an average pitch PL larger than the average pitch PS is larger than the convex top portion average position of the concave-convex structure S having the average pitch PS. By disposing the concavo-convex structure S and the concavo-convex structure L so as to be located in the outer direction, the concavo-convex structure L can suppress stress concentration on the concavo-convex structure S, and thus physical strength is improved. Furthermore, since the average convex part top position of the concavo-convex structure L and the average convex part top position of the concavo-convex structure S satisfy a predetermined range, it is considered that the deterioration of the antireflection performance due to the provision of the concavo-convex structure L is suppressed. It is done. That is, it is considered that the uneven structure S can improve the antireflection performance, and the uneven structure L can improve the strength while maintaining the antireflection performance.

  Next, the concavo-convex structure surface 20 of the antireflection body 10 according to the present embodiment will be described.

  The concavo-convex structure surface 20 is composed of two concavo-convex structures having different average pitches (pav). Here, the two uneven structures are referred to as an uneven structure S and an uneven structure L, respectively. The average pitch of the concavo-convex structure S is PS, and the average pitch of the concavo-convex structure L is PL. The average pitch PL is larger than the average pitch PS.

  Note that the concavo-convex structure L and the concavo-convex structure S may be optically continuous or have an optical interface. This is because even when the optical interface, that is, when the difference in refractive index is provided between the concavo-convex structure L and the concavo-convex structure S, the concavo-convex structure S is disposed at the interface, so that the effective medium approximating action is achieved. This is because the function can be suppressed and reflection at the interface can be suppressed. In other words, the refractive index nS of the substance constituting the concavo-convex structure S and the refractive index nL of the substance constituting the concavo-convex structure L may be different or the same. In particular, satisfying | nL−nS | ≦ 0.2 is preferable because reflection at the interface between the uneven structure L and the uneven structure S described above can be effectively suppressed.

  As long as the concavo-convex structure surface 20 has a convex part and a concave part, the shape and arrangement thereof are not limited. As described above, the positional relationship between the concavo-convex structure L and the concavo-convex structure S and the average pitch PL of the concavo-convex structure L. Is larger than the average pitch PS of the concavo-convex structure S, the strength can be increased while maintaining the antireflection performance. For this reason, for example, a line and space structure in which a plurality of fence-like bodies are arranged, a lattice structure in which a plurality of fence-like bodies intersect, a dot structure in which a plurality of dot (convex, protrusion) -like structures are arranged, and a plurality of A hole structure in which hole (concave) -like structures are arranged can be employed. Examples of the dot structure and hole structure include a cone, a cylinder, a quadrangular pyramid, a quadrangular prism, a hexagonal pyramid, a hexagonal pyramid, a polygonal pyramid, a double ring shape, and a multiple ring shape. These shapes include a shape in which the outer diameter of the bottom surface is distorted and a shape in which the side surface is curved.

  Regardless of which shape is employed, in the concavo-convex structure S, from the viewpoint of improving the antireflection performance, it is preferable that the diameter of the convex portion decreases as it goes from the bottom portion to the top portion of the convex portion. This is for smoothing the change in the effective medium approximate refractive index. Furthermore, it is preferable that the convex top part and the convex side surface part are continuously and smoothly connected. In particular, it is preferable that the width of the top of the convex portion is asymptotic to 0 because the effective medium approximate refractive index at the convex portion top position of the concavo-convex structure S becomes gentle.

  The dot structure is a structure in which a plurality of convex portions are arranged independently of each other. That is, each convex part is separated by a continuous concave part. In addition, each convex part may be smoothly connected by the continuous recessed part. On the other hand, the hole structure is a structure in which a plurality of recesses are arranged independently of each other. That is, each recessed part is separated by the continuous convex part. In addition, each recessed part may be smoothly connected by the continuous convex part. Among these, from the viewpoint of improving the antireflection performance, the concavo-convex structure surface 20 is preferably a dot-like structure. In particular, in order to improve the antireflection performance, the concavo-convex structure S is preferably a structure having no flat surface at the top of the convex portion among the dot-like structures. Furthermore, it is more preferable that the concave bottom portion of the concavo-convex structure S does not have a flat surface. Further, in the concavo-convex structure L, from the viewpoint of improving the strength and maintaining the antireflection performance, the concavo-convex structure L is preferably a dot-like structure and a structure in which the convex top part and the convex side surface part are smoothly connected. .

  Subsequently, definitions used for explaining the concavo-convex structure surface 20 will be described. In the following description, the concavo-convex structure surface 20 is constituted by the concavo-convex structure S and the concavo-convex structure L, and unless otherwise specified, both the concavo-convex structure L and the concavo-convex structure S are simply referred to as “concavo-convex structure”. .

<Average pitch (pav)>
FIG. 5 is a top view of the antireflection body according to the present embodiment as viewed from the concave-convex structure surface side. As shown in FIG. 5, when the concavo-convex structure surface 20 has a dot structure in which a plurality of convex portions 1 are arranged, the center of a certain convex portion A1 and the convex portions B1-1 to convex portions adjacent to the convex portion A1. the distance _{p A1B1-1} ~ distance _{p A1B1-6} between the center of B1-6, defined as the pitch p. However, as shown in FIG. 5, when the pitch p varies depending on the adjacent convex portions, the average pitch (pav) is determined according to the following procedure. (1) A plurality of arbitrary convex portions A1, A2,... AN are selected. (2) convex portions adjacent to the convex portion AM and the convex portion AM (1 ≦ M ≦ N) and (BM-1~BM-k), to measure the pitch _{p AMBM-1 ~p AMBM-k} of. (3) For the convex portions A1 to AN, the pitch p is measured as in (2). (4) An arithmetic average value of the pitches p _{A1B1-1 to} p _{ANBN -k} is defined as an average pitch (pav). However, N is 5 or more and 10 or less, and k is 4 or more and 6 or less. In the case of the hole structure, the average pitch (pav) can be defined by replacing the convex portion described in the dot structure with a concave opening. The average pitch (pav) measured for the concavo-convex structure S is the average pitch PS, and the average pitch (pav) measured for the concavo-convex structure L is the average pitch PL.

<Height H>
The height of the concavo-convex structure constituting the concavo-convex structure surface 20 is defined as the shortest distance between the average position of the concave bottom of the concavo-convex structure and the average position of the convex top of the concavo-convex structure. The number of sample points for calculating the average position is preferably 10 or more. In addition, the height of the uneven structure L is measured with respect to the uneven structure L, and the height of the uneven structure S is measured with respect to the uneven structure S.

<Convex top width lcvt, concave opening width lcct, convex bottom width lcvb, concave bottom width lcc>
FIG. 6 is a top view when the concavo-convex structure constituting the concavo-convex structure surface of the antireflection body according to the present embodiment is a dot structure. A line segment indicated by a broken line in FIG. 6 is the distance between the center of a certain convex portion 1 and the center of the convex portion 1 closest to the convex portion 1, and means the pitch p described above. FIGS. 7A and 7B show schematic cross-sectional views of the concavo-convex structure at the line segment position corresponding to the pitch p shown in FIG.

  As shown in FIG. 7A, the convex portion top width lcvt is defined as the width of the convex portion top surface, and the concave portion opening width lcct is defined as a difference value (p−lcvt) between the pitch p and the convex portion top width lcvt. The

  As shown in FIG. 7B, the convex bottom width lcvb is defined as the width of the convex bottom, and the concave bottom width lccb is defined as a difference value (p−lcvb) between the pitch p and the convex bottom width lcvb. .

  FIG. 8 shows a top view when the concavo-convex structure surface 20 has a hole structure. A line segment indicated by a broken line in FIG. 8 is the distance between the center of a certain recess 2 and the center of the recess closest to the recess 2, and means the pitch p described above. FIGS. 9A and 9B show schematic cross-sectional views of the concavo-convex structure surface 20 at the position of the line segment corresponding to the pitch p shown in FIG.

  As shown in FIG. 9A, the recess opening width lcct is defined as the opening diameter of the recess 2, and the protrusion top width lcvt is defined as a difference value (p−lcct) between the pitch p and the recess opening width lcct.

  As shown in FIG. 9B, the convex bottom width lcvb is defined as the width of the convex bottom, and the concave bottom width lccb is defined as a difference value (p−lcvb) between the pitch p and the convex bottom width lcvb. .

  The convex top width lcvt, concave opening width lcct, convex bottom width lcvb, and concave bottom width lccb of the concave-convex structure L are measured with respect to the concave-convex structure L, and the convex top width lcvt, concave opening width of the concave-convex structure S is measured. It is assumed that lcct, convex bottom width lcvb, and concave bottom width lcc are measured with respect to the concavo-convex structure S.

<Filling rate>
The filling rate of the concavo-convex structure is defined as the ratio of the area of the bottom of the convex part included in the unit area when the concavo-convex structure is dot-like. For example, when the outer shape of the bottom of the convex portion is circular, it can be defined as follows using the convex portion bottom width lcvb described above.
Filling rate (%) = (lcvb / 2) × (lcvb / 2) × π × N ÷ S
However, S is a unit area. N is the number of convex portions included in the unit area.

  For example, if one convex part that completely fits within the unit area and six convex parts that fit only in the area of 1/3 of the convex bottom area, N = 1 + (1/3) × 6 = 3. . In addition, when a convex part is adjacently arranged through a smooth recessed part, according to the said definition, a filling rate will be 100%.

On the other hand, when the concavo-convex structure is a hole shape, the filling rate is defined as a ratio of the area of the concave opening included in the unit area. For example, when the outer shape of the recess opening is circular, it can be defined as follows using the recess opening width lcct described above.
Filling rate (%) = (lcct / 2) × (lcct / 2) × π × N ÷ S
However, S is a unit area. N is the number of recesses included in the unit area.

  For example, if one recess that completely fits within the unit area and six recesses that fit only in the region of 1/3 of the recess opening area are included, N = 1 + (1/3) × 6 = 3. In addition, when a recessed part is adjacently arranged through a smooth convex part, according to the said definition, a filling rate will be 100%.

<Duty>
It is represented by the ratio (lcvb / p) between the convex bottom width lcvb and the pitch p. The duty of the concavo-convex structure L is measured for the concavo-convex structure L, and the duty of the concavo-convex structure S is measured for the concavo-convex structure S.

<Aspect ratio>
When the uneven structure is a dot structure, the aspect ratio is defined as the height of the uneven structure / lcvb using the above-described lcvb. On the other hand, when the concavo-convex structure is a hole structure, the aspect ratio is defined as the depth of the concavo-convex structure / lcct using the above-described lcct. The aspect ratio of the concavo-convex structure L is measured with respect to the concavo-convex structure L, and the aspect ratio of the concavo-convex structure S is measured with respect to the concavo-convex structure S.

<Convex bottom circumscribed circle diameter φout, convex bottom inscribed circle diameter φin>
10A to 10E show top images when the antireflection body 10 is observed from the concave-convex structure surface side. The convex part of the concavo-convex structure of the antireflection body 10 according to the present embodiment may have a bent shape. An outline when the antireflection body 10 is observed from the concavo-convex structure surface side (hereinafter referred to as a convex bottom outline) is indicated by “A” in FIGS. 10A to 10E. Here, when the convex bottom contour A is not a perfect circle, the inscribed circle and circumscribed circle with respect to the convex bottom contour A do not match. 10A to 10E, the inscribed circle is indicated by “B”, and the circumscribed circle is indicated by “C”.

  The diameter of the inscribed circle B with respect to the convex bottom contour A is defined as the convex bottom inscribed circle diameter φin. Note that φin is the diameter of the inscribed circle B when the size of the inscribed circle B is maximized. The inscribed circle B is a circle arranged inside the convex bottom contour A, is a circle that touches a part of the convex bottom contour A and does not protrude outside the convex bottom contour A. .

  On the other hand, the diameter of the circumscribed circle C with respect to the convex bottom contour A is defined as the convex bottom circumscribed circle diameter φout. Φout is the diameter of the circumscribed circle C when the size of the circumscribed circle C is minimized. The circumscribed circle C is a circle arranged outside the convex bottom contour A, is in contact with a part of the convex bottom contour A, and does not enter inside the convex bottom contour A. is there.

  The convex bottom circumscribed circle diameter φout and the convex bottom inscribed circle diameter φin of the concavo-convex structure L are measured with respect to the concavo-convex structure L, and the convex bottom circumscribed circle diameter φout of the concavo-convex structure S and the convex bottom inscribed circle. The diameter φin is measured with respect to the concavo-convex structure S.

  When the concavo-convex structure is composed of a plurality of recesses, the term “convex bottom” can be read as “concave opening”.

<Convex side inclination angle Θ>
The inclination angle Θ of the convex side surface is determined by the shape parameter of the concavo-convex structure described above. The concave side surface inclination angle Θ is determined in the same manner. The convex side surface inclination angle Θ of the concave-convex structure L is measured with respect to the concave-convex structure L, and the convex side surface inclination angle Θ of the concave-convex structure S is measured with respect to the concave-convex structure S.

<Disturbance of uneven structure>
The concavo-convex structure surface 20 can include disturbances described below. It is estimated that the antireflection performance can be improved by including the disturbance. More specifically, when a low reflectance is realized by the concavo-convex structure surface 20 in a range where the wavelength λ is A or more and B or less, the reflectance of light having a wavelength λ of C (<A) is increased. Here, in order to effectively exhibit the effective medium approximating action, the arrangement of the concavo-convex structure S is preferably regular. From this point of view, light having a wavelength λ of C causes light diffraction because the effective medium approximation action is weakened. For example, when A is set to 550 nm with high visibility and the antireflective body 10 is designed only from the concavo-convex structure S having a regular hexagonal arrangement, the reflectivity with respect to 550 nm is effectively reduced due to the effective medium approximation action, and thus transparent. The antireflection body 10 could be produced. However, ultraviolet light is diffracted. For this reason, a slight bluish color could be observed. By including disturbance in the concavo-convex structure surface 20, the light diffraction can be disturbed, so that the diffraction color can be weakened. From the viewpoint of weakening the diffracted color, it is preferable that the irregularity of the concavo-convex structure surface 20 is provided in at least one of the concavo-convex structure S or the concavo-convex structure L. In particular, it is preferable to add disturbance to the concavo-convex structure L because the effect of weakening the diffracted color is further improved.

  The elements of the concavo-convex structure having disorder are not particularly limited, but the elements that cause the disorder of the concavo-convex structure include, for example, pitch p, duty, aspect ratio, convex top width lcvt, convex bottom width lcvb, and concave opening width. lcct, concave bottom width lccb, convex side slope angle, number of convex side slope angles, convex bottom inscribed circle diameter φin, convex bottom circumscribed circle diameter φout, convex height, convex top height Examples of the information include the area, the number of minute projections (density) on the surface of the convex portion, the ratio thereof, and information that can be inferred from the arrangement of the concave and convex structure (for example, the shape of the concave portion).

  Among these elements, the pitch p means disorder of the arrangement of the concavo-convex structure, and elements other than the pitch mean disorder of the shape of the concavo-convex structure. These disturbances may be a disturbance of only one type of element or a complex disturbance. In particular, from the viewpoint of weakening the diffracted color described above, it is preferable that a plurality of elements simultaneously satisfy the disturbance shown in Expression (1) described below. In particular, when pitch p, duty, height H, aspect, convex portion bottom circumscribed circle diameter φout or ratio (φout / φin) is disturbed, it is considered that the effect of disturbing light diffraction and weakening the diffraction color is increased. . Among these, by including two or more disturbances at the same time, the effect of disturbing the light diffraction described above becomes more remarkable. Among these, it is more preferable that any one of the pitch p, the height H, the convex portion bottom circumscribed circle diameter φout and the convex portion bottom circumscribed circle diameter φout / the convex portion bottom circumscribed circle diameter φin satisfies (1) described below. When the disturbance has regularity, the antireflection performance can be improved by the concavo-convex structure S, and a predetermined wavelength can be extracted by the regular disturbance.

The disturbance of the element that causes the disturbance of the concavo-convex structure has (standard deviation / arithmetic mean) shown in the following formula (1), that is, a variation coefficient. In the formula (1), the (standard deviation / arithmetic mean) of the concavo-convex structure is a value for an element constituting the concavo-convex structure. For example, when the concavo-convex structure is composed of three elements A, B, and C, it is defined as the standard deviation for the same element and the ratio to the arithmetic average, such as standard deviation for element A / arithmetic average for element A. To do.
0.025 ≦ (standard deviation / arithmetic mean) ≦ 0.8 (1)

(Arithmetic mean)
When N measured values of a distribution of an element (variable) are x1, x2,..., Xn, the arithmetic mean value is defined by the following equation.

(standard deviation)
When N measured values of the distribution of elements (variables) are x1, x2,..., Xn, the arithmetic mean value defined above is used and is defined by the following equation.

  The number N of sample points when calculating the arithmetic mean is defined as 10 or more. The number of sample points when calculating the standard deviation is the same as the number N of sample points when calculating the arithmetic mean.

  Further, (standard deviation / arithmetic mean) is defined not as a value in the surface of the concavo-convex structure surface 20 of the antireflection body 10 but as a value for a local part of the antireflection body 10. That is, instead of calculating N points (standard deviation / arithmetic mean) over the surface of the concavo-convex structure surface 20, local observation of the antireflective body 10 is performed, and within the observation range (standard Deviation / arithmetic mean). Here, the local range used for observation is defined as a range of about 5 to 50 times the average pitch (pav) of the concavo-convex structure. For example, if the average pitch (pav) is 300 nm, the observation is performed within the observation range of 1500 nm to 15000 nm. Therefore, for example, a field-of-view image of 2500 nm is picked up, and the standard deviation and arithmetic mean are obtained using the picked-up image, and (standard deviation / arithmetic mean) is calculated. Note that the average pitch PL is used for disturbance of the concavo-convex structure L, and the average pitch PS is used for disturbance of the concavo-convex structure S.

  The (standard deviation / arithmetic mean) has an optimum value for each element constituting the concavo-convex structure, but satisfying the formula (1) regardless of the element that causes the disturbance of the concavo-convex structure, In the state where the intensity is maintained, the above-described light diffraction can be disturbed and the diffraction color can be weakened. From the viewpoint of expressing the effect of disturbing the optical diffraction described above, the lower limit value is more preferably 0.03 or more. On the other hand, the upper limit value is preferably 0.5 or less, preferably 0.35 or less, more preferably 0.25 or less, from the viewpoint of maintaining both antireflection performance and strength. Most preferably, it is 15 or less.

Subsequently, the concavo-convex structure L and the concavo-convex structure S constituting the concavo-convex structure surface 20 will be described.
As described above, the main function of the uneven structure S is to improve the antireflection performance. On the other hand, the main function of the uneven structure L is to improve strength. From the viewpoint of achieving both strength and antireflection performance, the refractive index (nS) of the substance constituting the concavo-convex structure S, the refractive index (nL) of the substance constituting the concavo-convex structure L, and the refractive index of the substance constituting the substrate 11 ( nB) preferably satisfies the following relationship. | NL-nS | and | nS-nB | are preferably 0.2 or less because reflection at each interface can be suppressed. From the viewpoint of more exerting this effect, | nL-nS | and | nS-nB | are more preferably 0.15 or less, and most preferably 0.1 or less.

  Further, nL ≦ nS is preferable because the antireflection performance can be further improved.

  The material constituting the concavo-convex structure S, the concavo-convex structure L, and the substrate 11 is not particularly limited as long as the refractive index relationship is satisfied.

  In particular, a low refractive index material can be selected as the substance constituting the concavo-convex structure L. Here, the low refractive index material is defined as a substance having a refractive index of 1.45 or less. When the refractive index nL is 1.45 or less, the deterioration of the antireflection performance due to the concavo-convex structure L can be further suppressed. From this viewpoint, the refractive index nL is preferably 1.4 or less, and most preferably 1.35 or less.

  The shortest distance between the average protrusion top position of the uneven structure S and the average protrusion top position of the uneven structure L satisfies 0 nm to 100 μm. In particular, the strength is improved by satisfying more than 0 nm, and the antireflection performance can be maintained by satisfying 100 μm or less. From the same viewpoint, the shortest distance is more preferably 10 nm or more, more preferably 100 nm or more, and most preferably 1000 μm or more. On the other hand, the upper limit value preferably satisfies 80 μm or less, more preferably satisfies 50 μm or less, and most preferably satisfies 10 μm or less from the same effect.

Next, the uneven structure L and the uneven structure S will be described in detail.
<Uneven structure L>
The main function of the uneven structure L is to improve strength. As the arrangement, a hexagonal arrangement, a quasi-hexagonal arrangement, a quasi-tetragonal arrangement, a tetragonal arrangement, a combination of these arrangements, an arrangement with low regularity, or the like can be adopted. In particular, it is preferable that the arrangement regularity of the concavo-convex structure L is higher as the effect of reducing the external force becomes larger. Furthermore, it is preferable that the concavo-convex structure L be a point-symmetric arrangement because a stress dispersion effect is enhanced. From these viewpoints, a hexagonal arrangement or a tetragonal arrangement is preferable, and a hexagonal arrangement is most preferable.

  The filling rate of the concavo-convex structure L is preferably 0.0003% or more and 25% or less. By being 0.0003% or more, the strength can be improved. From the same viewpoint, it is preferably 0.04% or more, more preferably 0.06% or more, and most preferably 0.1% or more. On the other hand, when the upper limit value is 25% or less, the antireflection performance can be improved. From the same viewpoint, the upper limit value is preferably 15% or less, more preferably 10% or less, and most preferably 6% or less.

  The average pitch PL is preferably 800 nm or more and 100 μm or less in a range larger than the average pitch PS. In particular, when the average pitch PL is 800 nm or more, the strength can be improved. From the same effect, the thickness is preferably 1000 nm or more, more preferably 5000 nm or more, and most preferably 10,000 nm or more. On the other hand, when the upper limit satisfies the range of 100 μm or less, the antireflection performance can be improved. From the same viewpoint, it is preferably 75 μm or less, more preferably 50 μm or less, and most preferably 45 μm or less.

  Further, by adding the above-described disturbance to the pitch p of the concavo-convex structure L, diffracted light generated by the concavo-convex structure L can be weakened. The (standard deviation / arithmetic mean) with respect to the pitch p of the concavo-convex structure L is preferably 0.03 or more and 0.4 or less in the widest range (0.025 or more and 0.8 or less). In particular, when it is 0.03 or more, the effect of disturbing light diffraction becomes large, and when it is 0.4 or less, the antireflection performance can be improved. From the same viewpoint, 0.035 or more is preferable, and 0.04 or more is more preferable. Moreover, 0.35 or less is preferable, 0.25 or less is more preferable, and 0.15 or less is the most preferable.

  Note that the disturbance of the pitch p of the concavo-convex structure L may have high regularity or low regularity. For example, in the case of a concavo-convex structure including a hexagonal array, a quasi-hexagonal array, a quasi-tetragonal array, and a singular structure irregularly including a tetragonal array, the regularity of the irregularity of the pitch p of the concavo-convex structure L is reduced, so that light diffraction is performed. The weakening effect is increased. On the other hand, in the case of a concavo-convex structure including a peculiar structure in which the increase / decrease of the pitch p occurs periodically in a regular hexagonal arrangement, the irregularity of the pitch p has high regularity. Can be extracted and light of a predetermined wavelength can be extracted. In addition, for example, when a non-hexagonal sequence (for example, a tetragonal sequence) site that is a specific structure is locally arranged in a regular hexagonal sequence that is a basic structure, if the specific structure is scattered irregularly, Since the regularity of the disturbance of the pitch p of the concavo-convex structure L is lowered, the effect of weakening light diffraction is increased. On the other hand, when a non-hexagonal arrangement (for example, a tetragonal arrangement) portion that is a specific structure is locally arranged in a regular hexagon arrangement that is a basic structure and the specific structure is regularly provided, the pitch of the concavo-convex structure L Since the disorder of p has high regularity, the concave-convex structure S exhibits antireflection performance and can extract light having a predetermined wavelength.

  The ratio (lcvt / lcct) between the convex top width lcvt and the concave opening width lcct of the concave-convex structure L is preferably as small as possible, and is most preferably substantially zero. Note that “lcvt / lcct = 0” means a case where there is no flat surface at the top of the convex portion of the concavo-convex structure L. In other words, lcvt / lcct = 0 when the top of the convex portion of the concavo-convex structure L has an acute angle or when the top of the convex portion is rounded. In particular, from the viewpoint of improving strength and maintaining antireflection performance, it is preferable that the top of the convex portion of the concavo-convex structure L has a rounded shape. A ratio (lcvt / lcct) of 3 or less is preferable because the effect of maintaining the antireflection performance is increased. Furthermore, it is preferable because (lcvt / lcct) is 1 or less because reflection at the top of the convex portion can be suppressed, and when it is 0.4 or less, it is preferable because the top of the convex portion and the side surface of the convex portion can be smoothly connected. . From the viewpoint of exhibiting the above effects and simultaneously improving the antireflection performance and strength, 0.2 or less is more preferable, and 0.15 or less is still more preferable.

  Furthermore, when the convex top width lcvt is smaller than the convex bottom width lcvb, it becomes easy to satisfy the above-described ratio (lcvt / lcct). Improvement of antireflection performance can be realized at the same time.

  The duty represented by the ratio (lcvb / p) between the convex bottom width lcvb and the pitch p is preferably 0.03 or more and 0.5 or less. By being 0.03 or more, the effect of improving the strength is increased. From the same effect, the ratio (lcvb / p) is more preferably 0.05 or more, and most preferably 0.10 or more. On the other hand, when it is 0.83 or less, the effect of maintaining antireflection performance is improved. From the same effect, the ratio (lcvb / p) is more preferably 0.4 or less, and most preferably 0.4 or less.

  The convex bottom circumscribed circle diameter φout and the convex bottom circumscribed circle diameter φout / convex bottom inscribed circle diameter φin described below satisfy the above formula (1), thereby increasing the effect of weakening the diffracted light. preferable. The fact that the convex portion bottom circumscribed circle diameter φout is disturbed means that the duty is disturbed.

  When the aspect ratio is 0.1 or more, an effect of suppressing breakage of the concavo-convex structure S can be obtained. From the same viewpoint, 0.3 or more is preferable, 0.5 or more is more preferable, and 0.8 or more is most preferable. On the other hand, when the aspect ratio is 5 or less, breakage of the concavo-convex structure L can be suppressed. From the same effect, 2 or less is preferable, 1.5 or less is more preferable, and 1.0 or less is most preferable.

  In addition, when the height H demonstrated below has disorder which satisfy | fills said Formula (1), since the effect which suppresses optical diffraction becomes large, it is preferable. In this case, the aspect ratio is also disturbed at the same time. The irregularity of the height H of the concavo-convex structure L may have high regularity or low regularity. That is, the disorder of the aspect ratio may have high regularity or low regularity. For example, in the case of the concavo-convex structure L including the concavo-convex structure L having the center height H0, the minimum height H1, and the maximum height H2, and the height H is a regular structure with low regularity within the above range, the concavo-convex structure The regularity of the disturbance of the height H of L is lowered, and the effect of suppressing light diffraction is exhibited. On the other hand, in the case of a concavo-convex structure including a peculiar structure in which the increase and decrease of the height H occur periodically, the disturbance of the height H has a high regularity, and the anti-reflection performance is exhibited by the concavo-convex structure S. Wavelength light can be extracted. In addition, for example, in the case where specific portions with height H2 are locally arranged in the basic structure that is a set of heights H1, if the specific portions are scattered irregularly, the height H of the concavo-convex structure L The regularity of the disturbance is reduced, and the effect of suppressing light diffraction is exhibited. On the other hand, when a specific part having a height H2 is locally arranged in a basic structure that is a set of heights H1, and the specific part is regularly provided, the disturbance of the height H has high regularity. Thus, the uneven structure S can exhibit antireflection performance and can extract light having a predetermined wavelength.

  The ratio (φout / φin) between the convex portion bottom circumscribed circle diameter φout and the convex portion bottom inscribed circle diameter φin is a measure representing the distortion of the convex portion bottom contour A. The ratio (φout / φin) is preferably 1 or more and 3 or less. When the ratio (φout / φin) is 1, the convex portion bottom contour A is a perfect circle. In this case, when designing the concavo-convex structure L, an optical simulation can be suitably applied, and the strength of the convex portion of the concavo-convex structure L is improved. On the other hand, when the ratio (φout / φin) is 3 or less, the effect of suppressing the breakage of the concavo-convex structure S is increased. From the same effect, 2 or less is more preferable, and 1.5 or less is most preferable.

  Further, from the viewpoint of suppressing light diffraction due to the disturbance of the convex portion bottom circumscribed circle diameter φout, (standard deviation / arithmetic mean) with respect to the convex bottom circumscribed circle diameter φout of the concavo-convex structure L that is a factor of disturbance is In the widest range (0.025 to 0.8), it is preferably 0.03 or more and 0.4 or less. Particularly, 0.03 or more is preferable because disturbance of light diffraction increases. By being 0.4 or less, the effect of maintaining strength and antireflection performance is increased. From the same viewpoint, 0.04 or more is preferable, 0.05 or more is more preferable, and 0.06 or more is most preferable. Moreover, 0.35 or less is preferable, 0.25 or less is more preferable, and 0.15 or less is the most preferable.

  Further, from the viewpoint of suppressing optical diffraction due to disturbance of the ratio (φout / φin), (standard deviation / arithmetic mean) with respect to the ratio (φout / φin) of the concavo-convex structure that is a factor of disturbance is the widest range described above. Among (0.025 to 0.8), it is preferably 0.03 or more and 0.35 or less. In particular, the effect of disturbing light diffraction becomes large when the ratio is 0.03 or more. By being 0.35 or less, the effect of maintaining strength and antireflection performance is increased. From the same viewpoint, 0.04 or more is preferable, 0.05 or more is more preferable, and 0.06 or more is most preferable. Moreover, 0.25 or less is preferable, 0.15 or less is more preferable, and 0.10 or less is the most preferable.

  When the convex bottom circumscribed circle diameter φout and the convex bottom circumscribed circle diameter φout / convex bottom inscribed circle diameter φin satisfy the above ranges, it is preferable because the effect of suppressing light diffraction based on disturbance of the concavo-convex structure is increased. .

  Further, when the convex portion bottom circumscribed circle diameter φout and the above-described height H satisfy the range of the above formula (1), the volume change of the portion corresponding to the disturbance becomes large, so that the optical diffraction is suppressed. Even better. From the same effect, it is preferable that the convex bottom circumscribed circle diameter φout, the height H and the pitch p satisfy the above formula (1), and the convex bottom circumscribed circle diameter φout, the height H, the pitch p and the convex bottom circumscribed circle More preferably, the diameter φout / the bottom inscribed circle diameter φin of the convex portion satisfies the above formula (1).

  Further, from the viewpoint of suppressing light diffraction due to the disturbance of the height H, the (standard deviation / arithmetic mean) with respect to the height H of the concavo-convex structure L, which is the cause of the disturbance, is the widest range (0.025 to 25). 0.8) is preferably 0.03 or more and 0.40 or less. In particular, when it is 0.03 or more, the effect of suppressing light diffraction is increased. By being 0.40 or less, the effect of maintaining strength and antireflection performance is increased. From the same viewpoint, 0.04 or more is preferable, 0.05 or more is more preferable, and 0.12 or more is most preferable. Moreover, 0.35 or less is preferable, 0.3 or less is more preferable, and 0.25 or less is the most preferable.

  When the height H satisfies the above range, it is preferable because the effect of suppressing light diffraction based on the disturbance of the concavo-convex structure L is increased. From the same principle, it is more preferable that the height H, pitch p, and convex bottom circumscribed circle diameter φout satisfy the above formula (1), and the height H, pitch p, convex bottom circumscribed circle diameter φout, and convex bottom It is more preferable that the circumscribed circle diameter φout / convex bottom inscribed circle diameter φin satisfies the above formula (1).

  The disturbance of the height H may have high regularity or low regularity. For example, in the case of the concavo-convex structure L including the concavo-convex structure L having the center height H0, the minimum height H1, and the maximum height H2, and the height H is a regular structure with low regularity within the above range, the concavo-convex structure The regularity of the disturbance at the height H of L is lowered, and the effect of disturbing the light diffraction is increased. On the other hand, in the case of the concavo-convex structure L including a specific structure in which the height H increases and decreases periodically, the disturbance of the height H has high regularity, and the concavo-convex structure S exhibits antireflection performance and is specified. Can be extracted. In addition, for example, in the case where specific portions with height H2 are locally arranged in the basic structure that is a set of heights H1, if the specific portions are scattered irregularly, the height H of the concavo-convex structure L The regularity of the disturbance is reduced, and the effect of disturbing the light diffraction is increased. On the other hand, when a specific part having a height H2 is locally arranged in a basic structure that is a set of heights H1, and the specific part is regularly provided, the disturbance of the height H has high regularity. Thus, the uneven structure S exhibits antireflection performance and can extract light of a specific wavelength.

<Uneven structure S>
The main function of the concavo-convex structure S is to improve the antireflection performance, that is, to realize a low reflectance.

  The filling rate of the concavo-convex structure S is preferably 65% or more from the viewpoint of effectively working the effective medium approximation and reducing the reflectance. In particular, it is preferable that the ratio is 70% or more because a sharp change in the effective medium approximate refractive index can be suppressed. From the same effect, it is preferably 80% or more, more preferably 85% or more, and most preferably 90% or more. A filling rate of 100% is preferable because adjacent convex portions are connected through smooth concave portions, and the effect of suppressing reflection is particularly great.

  The average pitch PS of the concavo-convex structure S is preferably 50 nm or more and 800 nm or less from the viewpoint of increasing the wavelength band of light capable of exhibiting antireflection performance. In particular, in order to realize a low reflectance in the visible light region, it is preferable to satisfy 50 nm to 400 nm, more preferably 50 nm to 300 nm, and most preferably 50 nm to 250 nm.

  Further, by adding the above-described disturbance to the pitch p of the concavo-convex structure S, light diffraction by the concavo-convex structure S can be suppressed. The (standard deviation / arithmetic mean) with respect to the pitch p of the concavo-convex structure S is preferably 0.03 or more and 0.5 or less in the widest range (0.025 or more and 0.8 or less). In particular, when it is 0.03 or more, the effect of disturbing light diffraction is increased. On the other hand, a low reflectance can be maintained by being 0.4 or less. From the same viewpoint, 0.035 or more is preferable, and 0.04 or more is more preferable. Moreover, 0.35 or less is preferable, 0.25 or less is more preferable, and 0.15 or less is the most preferable.

  Note that the disturbance of the pitch p of the concavo-convex structure S may have high regularity or low regularity, similar to the disturbance of the pitch p of the concavo-convex structure L described above.

  As the arrangement of the concavo-convex structure S, from the viewpoint of realizing a low reflectance, a hexagonal arrangement, a quasi-hexagonal arrangement, a quasi-tetragonal arrangement, a tetragonal arrangement, a combination thereof, or an arrangement with low regularity can be adopted. In particular, in order to improve the filling rate of the concavo-convex structure S, a hexagonal arrangement is preferable.

  The convex part top width lcvt of the concavo-convex structure S is preferably as small as possible. This is to suppress a steep change in the effective medium approximate refractive index. The ratio (lcvt / lcct) between the convex top width lcvt and the concave opening width lcct of the concave-convex structure S is preferably as small as possible, and is most preferably substantially zero. Here, “lcvt / lcct = 0” means that lcvt = 0 nm. However, for example, even when lcvt is measured by a scanning electron microscope, 0 nm cannot be measured accurately. Therefore, lcvt here includes all cases where the resolution is less than the measurement resolution. It is preferable that the ratio (lcvt / lcct) is 3 or less because the top area of the convex portion decreases and the effective medium approximate refractive index changes gently. Furthermore, since (lcvt / lcct) is 1 or less, the volume change of the convex portion can be reduced, so that the reflectance can be reduced. From the viewpoint of more exerting the above-described effects, (lcvt / lcct) is preferably 0.4 or less, more preferably 0.2 or less, and still more preferably 0.15 or less.

  Further, when the convex top width lcvt is smaller than the convex bottom width lcvb, a sharp change in the effective medium approximate refractive index can be effectively suppressed, so that the antireflection performance can be improved.

  Further, when the concavo-convex structure S is a dot structure, the control of the convex top width lcvt and the convex bottom width lcvb is facilitated, and the ratio (lcvt / lcct) can be easily satisfied. The antireflection performance is improved.

  When the aspect ratio is 0.5 or more, the antireflection performance by the concavo-convex structure S is exhibited. On the other hand, from the viewpoint of suppressing the breakage of the concavo-convex structure S, the aspect ratio is preferably 5 or less. From the viewpoint of making the effective medium approximate refractive index change more gentle, 1.0 or more is preferable, 1.2 or more is more preferable, and 1.5 or more is most preferable. On the other hand, the aspect ratio is preferably 4 or less, more preferably 3 or less, and most preferably 2 or less from the viewpoint of reducing moment energy applied to the concavo-convex structure S and suppressing breakage.

  In addition, when the height H demonstrated below has disorder which satisfy | fills said Formula (1), light diffraction can be suppressed similarly to having demonstrated in the said uneven structure L. FIG. In this case, the aspect ratio is also disturbed at the same time. The irregularity of the height H of the concavo-convex structure S may have high regularity or low regularity. That is, the disorder of the aspect ratio may have high regularity or low regularity. For example, in the case of the concavo-convex structure S having the center height H0, the minimum height H1, and the maximum height H2, and the concavo-convex structure S including the singular structure with the height H being regular and low in the above range, the concavo-convex structure The regularity of the disturbance of the height H of S decreases, and light diffraction can be effectively disturbed. On the other hand, in the case of a concavo-convex structure including a peculiar structure where the increase and decrease of the height H occur periodically, the disturbance of the height H has high regularity, and extracts predetermined light while exhibiting antireflection performance. It becomes possible. In addition, for example, in the case where specific portions with height H2 are locally arranged in the basic structure that is a set of heights H1, if the specific portions are scattered irregularly, the height H of the concavo-convex structure S The regularity of the disturbance is reduced, and the effect of disturbing the light diffraction is increased. On the other hand, when a specific part having a height H2 is locally arranged in a basic structure that is a set of heights H1, and the specific part is regularly provided, the disturbance of the height H has high regularity. In other words, it is possible to extract the predetermined light while exhibiting the antireflection performance.

  The ratio (φout / φin) between the convex portion bottom circumscribed circle diameter φout and the convex portion bottom inscribed circle diameter φin is a measure representing the distortion of the convex portion bottom contour A. The ratio (φout / φin) is preferably 1 or more and 5 or less. When the ratio (φout / φin) is 1, the convex portion bottom contour A is a perfect circle. In this case, when designing the concavo-convex structure S, an optical simulation can be suitably applied, and the antireflection performance is improved because the filling rate is improved. On the other hand, when the ratio (φout / φin) is 5 or less, the antireflection performance is maintained and the strength is improved. In particular, from the viewpoint of further improving the strength, the ratio (φout / φin) is preferably 3 or less, more preferably 2 or less, and most preferably 1.5 or less.

  Further, from the viewpoint of suppressing optical diffraction due to the disturbance of the convex portion bottom circumscribed circle diameter φout, the (standard deviation / arithmetic mean) with respect to the ratio (φout / φin) satisfies the range described in the concavo-convex structure L. it can.

  When the convex bottom circumscribed circle diameter φout and the convex bottom bottom circumscribed circle diameter φout / convex bottom inscribed circle diameter φin satisfy the above ranges, the light diffraction can be effectively suppressed by the disturbance of the concavo-convex structure. In addition, when the convex portion bottom circumscribed circle diameter φout and the above-described height H satisfy the range of the above formula (1), the volume change of the concavo-convex structure at the disordered portion is increased, and the effect of suppressing light diffraction is obtained. growing. From the same effect, it is preferable that the convex bottom circumscribed circle diameter φout, the height H and the pitch p satisfy the above formula (1), and the convex bottom circumscribed circle diameter φout, the height H, the pitch p and the convex bottom circumscribed circle More preferably, the diameter φout / the bottom inscribed circle diameter φin of the convex portion satisfies the above formula (1).

  When the height H of the convex portion of the concavo-convex structure S is 3 times or less of the average pitch (pav), the strength of the concavo-convex structure S is improved. From the viewpoint of achieving both strength and antireflection performance, it is more preferably 2 times or less, and most preferably 1.5 times or less.

  Further, from the viewpoint of suppressing light diffraction due to the disturbance of the height H, the (standard deviation / arithmetic mean) with respect to the height H of the concavo-convex structure S that is the cause of the disturbance is the range described in the concavo-convex structure L. Can be met.

  When the height H satisfies the above range, light diffraction can be suppressed due to disturbance of the concavo-convex structure S. From the same principle, it is more preferable that the height H, pitch p, and convex bottom circumscribed circle diameter φout satisfy the above formula (1), and the height H, pitch p, convex bottom circumscribed circle diameter φout, and convex bottom It is more preferable that the circumscribed circle diameter φout / convex bottom inscribed circle diameter φin satisfies the above formula (1).

  The disturbance of the height H may have high regularity or low regularity. For example, in the case of the concavo-convex structure S having the center height H0, the minimum height H1, and the maximum height H2, and the concavo-convex structure S including the singular structure with the height H being regular and low in the above range, the concavo-convex structure The regularity of the disturbance of the height H of S decreases, and light diffraction can be suppressed. On the other hand, in the case of the concavo-convex structure S including a peculiar structure in which the increase and decrease of the height H occur periodically, the disturbance of the height H has high regularity, exhibits antireflection performance, and emits light of a predetermined wavelength. Can be extracted. In addition, for example, in the case where specific portions with height H2 are locally arranged in the basic structure that is a set of heights H1, if the specific portions are scattered irregularly, the height H of the concavo-convex structure S The regularity of the disturbance is reduced, and light diffraction can be suppressed. On the other hand, when a specific part having a height H2 is locally arranged in a basic structure that is a set of heights H1, and the specific part is regularly provided, the disturbance of the height H has high regularity. As a result, it is possible to extract light having a predetermined wavelength while exhibiting antireflection performance.

  Next, the material constituting the concavo-convex structure S, the concavo-convex structure L, and the substrate 11 will be described. The material constituting the concavo-convex structure S, the concavo-convex structure L, and the base material 11 is not limited as long as the above-described refractive index relationship is satisfied. Cured resin, thermoplastic resin, cured inorganic precursor, cured curable organic / inorganic mixture, cured cured curable organic / inorganic hybrid resin, insulating inorganic material, conductive inorganic material, semiconductor, etc. can be used. .

  Among these, from the viewpoint of using the emitted light transmitted at a high transmittance by preventing reflection, it is preferable that the material constituting the concavo-convex structure S, the concavo-convex structure L, and the substrate 11 is an optically transparent material. Here, optically transparent means that the extinction coefficient (k) is zero. When k = 0, the absorption coefficient can be set to zero. For this reason, it can suppress that light is absorbed and attenuate | damped inside an antireflection body. Here, the case where the absorption coefficient k is 0 is defined as a range satisfying k ≦ 0.01. Since the said effect is acquired by satisfy | filling this range, it is preferable. In particular, k ≦ 0.001 is more preferable from the viewpoint of suppressing multiple reflection. In addition, k is so preferable that it is small.

Next, a method for manufacturing the antireflection body 10 according to the present embodiment will be described.
The manufacturing method of the antireflection body 10 according to the present embodiment is not particularly limited as long as the concavo-convex structure surface that satisfies the above-described conditions can be formed on the surface of the substrate.

  The concavo-convex structure surface 20 can be produced by a transfer method or injection molding using a mold having a fine pattern that is a reverse shape of the concavo-convex structure surface 20.

  Alternatively, the concavo-convex structure surface 20 can also be produced by producing the concavo-convex structure S and subsequently producing the concavo-convex structure L. The production method of the concavo-convex structure S can be classified into two.

(1) When the base material is directly processed to provide the concavo-convex structure S As a method for processing the base material 11 directly to provide the concavo-convex structure S, a transfer method, a photolithography method, a thermal lithography method, an electron beam drawing method, an interference exposure method. And a lithography method using nanoparticles as a mask, and a lithography method using a self-organized structure as a mask. When the substrate 11 is an inorganic material, a photolithography method and an interference exposure method are useful. Further, when the substrate 11 is an organic material, a transfer method is effective. The transfer method will be described later.

(2) When the uneven structure S is separately provided on the substrate As a method of separately providing the uneven structure S on the substrate 11, a transfer method, a method of forming a thin film containing particles on the substrate 11, nanoparticles A part of the resist formed on the substrate 11 is removed, and the removed part is filled with the material constituting the concavo-convex structure S (for example, vapor deposition, sputtering, electroforming), and finally A method of removing the resist, a method of forming a film of the concavo-convex structure S on the substrate 11, a method of directly processing the formed material of the concavo-convex structure S, a method using self-organization of a block copolymer, an electrospinning method , Chemical vapor deposition method, chemical solution deposition method (Liquid Phase Deposition method), alternating adsorption method (Layre by Layer Adsorption method) and the like. Among them, it is preferable to employ a transfer method because the concavo-convex structure can be manufactured with high accuracy and high productivity. The transfer method will be described later.

  The concavo-convex structure surface 20 can be produced by producing the concavo-convex structure S by the above-described method and subsequently producing the concavo-convex structure L.

  As a method of providing the concavo-convex structure L on the concavo-convex structure S, a transfer method, an ink jet method, an ink jet method in which a strong electric field is applied to a nozzle, a casting method, an electrospinning method, a method of arranging microparticles, a photolithography method, a thermal lithography method And electron beam lithography, interference exposure, lithography using nanoparticles as a mask, lithography using a self-organized structure as a mask, and the like. It is preferable to employ a transfer method, an ink jet method, or a casting method. The transfer method will be described later.

(Transfer method)
The transfer method is defined as a method including a step of transferring a fine pattern to an object to be processed in a mold having a fine pattern on the surface. That is, it is a method including at least a step of bonding the fine pattern of the mold and the object to be processed through a transfer material and a step of peeling the mold. When the substrate 11 and the concavo-convex structure surface 20 are made of the same material, the transfer material has the same meaning as the object to be processed. More specifically, the transfer method can be classified into two.

  First, the base material 11 is directly deformed. In this case, the mold fine pattern can be pressed against the object to be processed at a temperature equal to or higher than the deformable temperature of the object to be processed (base material 11), and the mold can be peeled off after cooling. For example, glass or a thermoplastic resin can be employed as the base material.

  Second, it is a case where an uneven structure is separately provided on the substrate 11. This is a method including a step (1) of pressing a fine pattern of a mold onto a workpiece through a transfer material, a step (2) of curing the transfer material, and a step (3) of removing the fine pattern. When the transfer material is an energy ray curable resin, in the step (2), the transfer material is cured by irradiating energy rays. When the transfer material is a thermosetting resin, in step (2), the transfer material is cured by heating.

  In particular, when the transfer method is employed, the roll-to-roll method can be employed, so that the accuracy and productivity of the concavo-convex structure can be improved. In this case, the mold is a cylindrical mold, that is, a cylindrical master, and a fine pattern is provided on the cylindrical surface.

  That is, the cylindrical master according to the present embodiment is a mold used for the transfer method, and includes a fine pattern having a reverse shape of the concavo-convex structure surface 20 described above on the surface of the cylinder. The material of the cylindrical surface is not particularly limited, and glass, quartz, aluminum, aluminum oxide, chromium, chromium oxide, or the like can be used. Further, it is preferable to carry a methyl group or a group containing fluorine on the surface of the fine pattern of the cylindrical master because the accuracy of the transfer method is improved.

  Since the fine pattern of the cylindrical master is the inverted shape of the concavo-convex structure described above, the external force applied to the concavo-convex structure S applied when the antireflection body 10 is peeled from the cylindrical master is weakened, and the concavo-convex structure S Therefore, the accuracy of the concavo-convex structure surface of the antireflection body 10 can be improved.

Examples performed to confirm the effects of the present invention will be described below.
The symbols used in the following description have the following meanings.
・ DACHP: Fluorine-containing urethane (meth) acrylate (OPTOOL DAC HP (manufactured by Daikin Industries))
M350: trimethylolpropane (EO-modified) triacrylate (M350, manufactured by Toagosei Co., Ltd.)
・ I. 184 ... 1-hydroxycyclohexyl phenyl ketone (Irgacure (registered trademark) 184, manufactured by BASF)
・ I. 369 ... 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Irgacure (registered trademark) 369, manufactured by BASF)
-TTB: Titanium (IV) tetrabutoxide monomer (Wako Pure Chemical Industries, Ltd.)
SH710: Phenyl-modified silicone (Toray Dow Corning)
・ 3APTMS ... 3-acryloxypropyltrimethoxysilane (KBM5103 (manufactured by Shin-Etsu Silicone))
DIBK: diisobutyl ketone MEK: methyl ethyl ketone MIBK: methyl isobutyl ketone DR833: tricyclodecane dimethanol diacrylate (SR833 (manufactured by SARTOMER))
SR368 ... Tris (2-hydroxyethyl) isocyanurate triacrylate (SR833 (manufactured by SARTOMER)

(Examples 1 and 2)
An antireflection body having a concavo-convex structure surface on the surface was prepared, and the strength and reflectance of the antireflection body were compared.

Example 1
In the following examination, in order to produce the antireflection body which has a concavo-convex structure surface on the surface, the concavo-convex structure S was produced, and subsequently, the concavo-convex structure L was produced on the surface of the concavo-convex structure S.

-Production of concavo-convex structure S The concavo-convex structure S was produced by producing a cylindrical master molding having a fine pattern on its surface, and then continuously copying the fine pattern of the cylindrical master mold onto a film by a transfer method. .

(1) Production of Cylindrical Master Mold An inverted shape of the concavo-convex structure S was formed on the surface of cylindrical quartz glass by a direct drawing lithography method using a semiconductor laser. First, a resist layer was formed on the surface of the cylindrical quartz glass by a sputtering method. The sputtering method was carried out using φ3 inch CuO (containing 8 atm% Si) as a target (resist layer) with a power of RF 100 W to form a 20 nm resist layer. Subsequently, the entire resist layer was exposed using a semiconductor laser having a wavelength of 405 nm while rotating the cylindrical quartz glass. Subsequently, the exposed resist layer was subjected to pulse exposure using a semiconductor laser having a wavelength of 405 nm. The pulse interval was 200 nm in the circumferential direction and 173 nm in the axial direction. The pulse arrangement was a hexagonal arrangement. After the pulse exposure, the resist layer was developed. Development was carried out for 240 seconds using a 0.03 wt% glycine aqueous solution. Next, using the developed resist layer as a mask, the etching layer (quartz glass) was etched by dry etching. Dry etching was performed using SF ₆ as an etching gas under the conditions of a processing gas pressure of 1 Pa, a processing power of 300 W, and a processing time of 5 minutes. Finally, only the resist layer residue was peeled off from the cylindrical quartz glass having a fine pattern on its surface using hydrochloric acid having a pH of 1. The peeling time was 6 minutes.

  Durasurf HD-1101Z (made by Daikin Chemical Industries, Ltd.), which is a fluorine-based mold release agent, is applied to the fine pattern of the obtained cylindrical quartz glass, heated at 60 ° C. for 1 hour, and then allowed to stand at room temperature for 24 hours. And fixed. Then, it wash | cleaned 3 times by Durasurf HD-ZV (made by Daikin Chemical Industries), and the cylindrical master mold was obtained.

(2) Manufacture of a reel provided with the concavo-convex structure S The concavo-convex structure S was continuously prepared on the surface of the reel by using the produced cylindrical master mold as a mold and applying an optical nanoimprint method.

The protective film is peeled off from a TAC (triacetylcellulose) film having a width of 300 mm and a length of 200 m, and the coated film thickness is 3 μm by microgravure coating (manufactured by Yurai Seiki Co., Ltd.) on the surface where the protective film is combined. The transfer material shown below was applied to Next, the TAC film coated with the material 1 is pressed against the cylindrical master mold with a nip roll so that the integrated exposure amount under the center of the lamp is 1500 mJ / cm ^{2 in} the air at a temperature of 25 ° C. and a humidity of 60%. In addition, a UV-irradiation apparatus (H bulb) manufactured by Fusion UV Systems Japan Co., Ltd. was used to irradiate ultraviolet rays to continuously carry out photocuring, and a reel having a concavo-convex structure S transferred onto the surface (length: 200 m, width) 300 mm). A photocurable acrylate resin was used as the transfer material. A photocurable acrylate having a refractive index after curing of 1.53 (550 nm) was used.

When the concavo-convex structure S on the obtained reel surface was observed using a scanning electron microscope, the arrangement and shape of the concavo-convex structure S were as follows.
Array: It was a hexagonal array. The pitch in the longitudinal direction of the film was 200 nm. The average pitch PS was 200 nm.
Shape: Convex height H was 250 nm. The diameter of the convex bottom is 190 nm. The diameter of the convex part became thin as it went from the convex part bottom part to the convex part top part. Moreover, there was no flat surface in the convex part top part.

-Production of concavo-convex structure surface By producing the concavo-convex structure L on the concavo-convex structure S surface of the reel having the concavo-convex structure S obtained as described above, the concavo-convex structure surface constituted by the concavo-convex structure S and the concavo-convex structure L A reel-shaped antireflection body comprising

  On the surface of the concavo-convex structure S, the same raw material as that of the concavo-convex structure S was dropped by an ink jet method. Subsequently, light was irradiated with a high-pressure mercury lamp in an environment where the oxygen concentration was reduced by nitrogen purge, and the droplets dropped by the ink jet were cured.

When the concavo-convex structure surface of the obtained reel-shaped antireflection body was observed using a scanning electron microscope, it was found that the shape of the concavo-convex structure S did not change. Moreover, the arrangement | sequence and shape of the uneven structure L were as follows.
Array: It was a hexagonal array. The average pitch was 200 μm.
Shape: The average diameter of the bottom of the convex portion was 5 μm or 10 μm. The shape of the bottom of the convex part included from a shape close to a perfect circle to a distorted contour. Moreover, the convex part top part and the convex part side surface were connected smoothly smoothly.

  Moreover, the distance of the average convex part top position of the uneven structure S and the average convex part top position of the uneven structure L was 0.5 micrometer-5 micrometers.

  Table 1 shows the sample Nos. Obtained in Example 1. 1 and no. 2, the arrangement of the concavo-convex structure S and the concavo-convex structure L, the average pitch pav, the convex bottom diameter lcvb and the filling rate, and the average convex top position of the concavo-convex structure S and the average of the concavo-convex structure L The distance from the top position of the convex portion (in Table 1, simply referred to as “distance”) is described. In Table 1, “Hex” means a hexagonal arrangement.

(Example 2)
In Example 2, a flat master having a fine pattern composed of inverted shapes of the concavo-convex structure L and the concavo-convex structure S is manufactured, and the fine pattern of the flat master is copied onto the reel surface by a transfer method. Then, an antireflection body having an uneven structure surface composed of the uneven structure S and the uneven structure L was produced.

(1) Production of flat master mold An inverted shape of the concavo-convex structure S was formed on the surface of flat quartz glass by a direct drawing lithography method using a semiconductor laser. First, a resist layer was formed on the surface of the flat quartz glass by sputtering. The sputtering method was carried out using φ3 inch CuO (containing 8 atm% Si) as a target (resist layer) with a power of RF 100 W to form a 20 nm resist layer. Subsequently, the entire surface of the resist layer was exposed using a semiconductor laser having a wavelength of 405 nm while rotating the flat quartz glass. Subsequently, the exposed resist layer was subjected to pulse exposure using a semiconductor laser having a wavelength of 405 nm. The pulse interval was 200 nm in the circumferential direction and 173 nm in the axial direction. The pulse arrangement was a hexagonal arrangement. After the pulse exposure, the resist layer was developed. Development was carried out for 240 seconds using a 0.03 wt% glycine aqueous solution. Next, using the developed resist layer as a mask, the etching layer (quartz glass) was etched by dry etching. Dry etching was performed using SF ₆ as an etching gas under the conditions of a processing gas pressure of 1 Pa, a processing power of 300 W, and a processing time of 5 minutes. Finally, only the resist layer residue was peeled off from the cylindrical quartz glass provided with a fine pattern corresponding to the concavo-convex structure S on the surface using hydrochloric acid having a pH of 1. The peeling time was 6 minutes.

  Subsequently, a fine pattern corresponding to the concavo-convex structure L was produced by photolithography from the fine pattern surface side of the plate-like quartz glass having the inverted shape of the concavo-convex structure S. Thus, the fine pattern comprised by the inverted shape of the uneven structure S and the uneven structure L was formed in the surface of flat quartz glass.

  Durasurf HD-1101Z (made by Daikin Chemical Industries), which is a fluorine-based mold release agent, is applied to the fine pattern of the obtained flat-plate quartz glass, heated at 60 ° C. for 1 hour, and then allowed to stand at room temperature for 24 hours. And fixed. Then, it wash | cleaned 3 times with Durasurf HD-ZV (made by Daikin Chemical Industry Co., Ltd.), and the flat master mold was obtained.

(2) Production of antireflection body Using the produced flat master mold as a mold, an optical nanoimprint method was applied to produce an antireflection film.

The protective film was peeled from a TAC (triacetylcellulose) film having a width of 150 mm and a length of 200 mm, and a transfer material was applied to the surface on which the protective film was combined using a bar coater. The coating film thickness was 5 μm. Subsequently, the transfer material surface was laminated to the fine pattern surface of the flat master, and light irradiation was performed from the flat master surface side using a high-pressure mercury lamp so that the integrated light amount was 1500 mJ / cm ² . Finally, the TAC film was peeled off to obtain a film-shaped antireflection body. As the transfer material, the same photocurable acrylate resin as in Example 1 was used.

  When the concavo-convex structure surface of the obtained antireflective body was observed using a scanning electron microscope, the arrangement and shape of the concavo-convex structure surface were as follows.

・ Uneven structure S
Array: It was a hexagonal array. The pitch was 200 nm. The average pitch PS was 200 nm.
Shape: Convex height H was 250 nm. The diameter of the convex bottom is 190 nm. The diameter of the convex part became thin as it went from the convex part bottom part to the convex part top part. Moreover, there was no flat surface in the convex part top part.

・ Uneven structure L
Array: It was a hexagonal array. The average pitch was 50 μm.
Shape: The average diameter of the bottom of the convex portion was 1 μm, 5 μm, or 10 μm. The shape of the bottom of the convex part included from a shape close to a perfect circle to a distorted contour. Moreover, the convex part top part and the convex part side surface were connected smoothly smoothly.

  Moreover, the distance of the average convex part top position of the uneven structure S and the average convex part top position of the uneven structure L was 0.2 micrometer-1 micrometer.

  Table 1 shows the sample Nos. Obtained in Example 2. 3-No. For the antireflection film of 5, the arrangement of the concavo-convex structure S and the concavo-convex structure L, the average pitch pav, the convex portion bottom diameter lcvb and the filling rate, and the average convex portion top position of the concavo-convex structure S and the average convex portion of the concavo-convex structure L The distance to the top position (in Table 1, simply referred to as “distance”) is described. In Table 1, “Hex” means a hexagonal arrangement.

(Comparative example)
As comparative examples, the following three samples were produced.
A, B: TAC film having only a concavo-convex structure L made of a cured product of the transfer material C ... TAC film having only a concavo-convex structure S made of a cured product of the transfer material

  In Table 1, for the antireflection films of Samples A to C obtained in Comparative Examples, the arrangement of the concavo-convex structure S and the concavo-convex structure L, the average pitch pav, the convex bottom diameter lcvb and the filling rate, and the concavo-convex structure S The distance between the average convex portion top position and the average convex portion top position of the concavo-convex structure L (in Table 1, simply referred to as “distance”) is described. In Table 1, “Hex” means a hexagonal arrangement.

(Evaluation)
As described above, the following two studies were performed on the antireflection bodies manufactured in Examples 1 and 2 and the comparative example.

Test 1: Strength The concavo-convex structure surface side of the antireflection body prepared in Examples 1 and 2 and the comparative example was wiped up 50 times (reciprocating) with a dry cloth. After wiping up, it observed visually. The case where scratches and turbidity (haze) were observed was indicated as x, and the case where there was no change before and after wiping was indicated as ◯.

Test 2: Optical performance The antireflective bodies prepared in Examples 1 and 2 and the comparative example were bonded onto the liquid crystal screen of the mobile phone via an optical adhesive.

  2-1: A mobile phone equipped with an anti-reflective body was used for one week, and the number of times the user felt uncomfortable, such as lack of clarity on the liquid crystal screen, compared to a mobile phone without an anti-reflective body, was statistically processed. The case where the sharpness was increased as compared with the case where no antireflective body was provided was marked with 、, the case where the sharpness was the same as ◯, the case where the sharpness was slightly lacked as Δ, and the case where the image was difficult to see as x.

  2-2: The number N of times when it was recognized that the visibility of the liquid crystal screen was lowered due to external light (sunlight) reflection was recorded. Finally, N / T was calculated by dividing the number N by the total time T during which the mobile phone was operated under sunlight.

  The results of the above tests 1 and 2 and comprehensive evaluation are shown in Table 1.

  As can be seen from Table 1, the strength is improved by providing the concavo-convex structure S and the concavo-convex structure L in a predetermined positional relationship. This is presumably because the stress applied to the concavo-convex structure S can be suppressed by the concavo-convex structure L. On the other hand, in the samples A and B of the comparative example having only the concavo-convex structure L, the strength is strong, but it can be seen that the sense of incongruity when mounted on a mobile phone is large. This is because the concavo-convex structure S is not provided, and the scattering property by the concavo-convex structure L is strongly expressed. In the case of the sample C of the comparative example having only the concavo-convex structure S, the uncomfortable feeling was reduced and the image became clearer by being mounted on the mobile phone. This is because the antireflection function by the uneven structure S is exhibited. However, the strength is weak. In addition, the number of visibility decreases due to external light is also large. This is because, in the case of the concavo-convex structure S, a critical angle exists in order to realize antireflection by an effective medium approximating action. The effective medium approximation function is most effective when the mobile phone screen and the line of sight are perpendicular to each other, but the line of sight is at a large angle with respect to the screen, and total reflection occurs when the angle exceeds the specified angle. is there. Sample No. 1 prepared in Examples 1 and 2 were used. 1-No. It was found that by providing the concavo-convex structure L as in 5, the visibility to external light is also improved. This is presumed to be due to the manifestation of scattering by the concavo-convex structure L.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited.

  The present invention can be applied to an antireflection body, for example, preferably applied to an antireflection film provided on a display surface of a smartphone, a mobile phone, or a TV, or an antireflection film provided on a window glass of a building or a house. Is possible.

DESCRIPTION OF SYMBOLS 1, 3 Convex part 2 Concave part 10 Antireflection body 11 Substrate 20 Uneven structure surface 30 Antireflection roll

Claims (9)

A substrate;
A first concavo-convex structure (S) provided on a main surface of the substrate and having a first average pitch (PS);
A second concavo-convex structure (L) having a second average pitch (PL) larger than the first average pitch (PS),
The shortest distance between the average convex portion top position of the first concave-convex structure (S) and the average convex portion top position of the second concave-convex structure (L) is more than 0 nm and not more than 100 μm,
The average convex portion top position of the second concave-convex structure (L) is located more in the out-of-plane direction of the base material than the average convex portion top position of the first concave-convex structure (S). Antireflective body.   The first concavo-convex structure (S) includes a plurality of protrusions spaced apart from each other, and the diameter of the protrusion decreases from the bottom of the protrusion toward the apex of the protrusion. The antireflection body according to claim 1.   The antireflection body according to claim 2, wherein the first average pitch PS is not less than 50 nm and not more than 350 nm.   The refractive index nS of the substance constituting the first concavo-convex structure (S) and the refractive index nL of the substance constituting the second concavo-convex structure (L) satisfy 0 ≦ | nL−nS | ≦ 0.2. The antireflection body according to claim 3, wherein the antireflection body is satisfied.   The antireflection body according to claim 4, wherein the antireflection body is in the form of a film.   An antireflection roll produced by winding up the antireflection body according to any one of claims 1 to 5.   A cylindrical master for producing the antireflection body according to any one of claims 1 to 5 by a transfer method, wherein the cylindrical master has the first uneven structure (S) and the surface on the surface thereof. A cylindrical master comprising a fine pattern having an inverted shape of the second concavo-convex structure (L).   It is a manufacturing method of the reflection preventing object in any one of Claims 1-5, Comprising: The surface which has the said fine pattern of the cylindrical master of Claim 7, and the surface of a base material through a transfer material The manufacturing method of the antireflective body characterized by including the process of bonding, The process of isolate | separating the said cylindrical master and the said base material.   6. A method of manufacturing an antireflective body according to claim 1, wherein a fine pattern and a base having an inverted shape of the first concavo-convex structure (S) provided on a surface of a cylindrical master are provided. A step of bonding a material via a transfer material, a step of separating the cylindrical master and the base material to obtain a base material having the first concavo-convex structure (S), and the base material And a step of producing the second concavo-convex structure (L) on the first concavo-convex structure (S).

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