JP2014032250A - Antireflection article, plate material for display, and showcase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection article which is capable of more sufficiently preventing reflection compared with the conventional art, has sufficient rework performance, and is hardly peeled from an object to which the antireflection article is attached.SOLUTION: It is constituted so that fine projections 7 are arranged in close contact with each other and the interval between the adjacent fine projections 7 is the shortest wavelength of a wavelength band for preventing reflection or less. The fine projections 7 are provided on one surface of a base material 5 and a strong adhesive layer 8 and a weak adhesive layer whose adhesive power is weak relative to that of the strong adhesive layer 8 are provided on the other surface of the base material 5 in order.

Description

  The present invention relates to an antireflection article for preventing reflection by closely arranging a large number of minute projections at intervals of not more than the shortest wavelength of a wavelength band for preventing reflection.

  In recent years, regarding an antireflection film, which is a film-shaped antireflection article, there has been proposed a method for preventing reflection by arranging a large number of microprotrusions closely on the surface of a transparent substrate (transparent film) (patent) References 1-3). This method utilizes the principle of a so-called moth-eye structure, and the refractive index for incident light is continuously changed in the thickness direction of the substrate, whereby a discontinuous interface of refractive index is obtained. Is eliminated to prevent reflection.

  In the antireflection article according to this moth-eye structure, the microprojections are closely arranged so that the distance d between adjacent microprojections is equal to or less than the shortest wavelength λmin (d ≦ λmin) of the wavelength band for preventing reflection. Moreover, each microprotrusion is produced so that a cross-sectional area may become small gradually toward the front end side from a transparent base material so that it may be planted on a transparent base material. Patent Document 4 describes that an antireflection film having a moth-eye structure is applied to a product display case.

  By the way, in the exhibition of arts and the like, the exhibits are protected by storing the exhibits in a showcase. Furthermore, in this type of exhibition, various devices have been devised for illumination so that the exhibit can be appreciated in detail. For this reason, showcases have traditionally been made of an anti-reflection film that uses thin film multilayer processing, etc., so that such illumination does not interfere with appreciation, and so that outdoor scenery does not interfere with appreciation. Is pasted.

  However, conventional antireflection films applied to showcases still have insufficient problems in practice. In other words, thin-film multi-layer processing cannot sufficiently prevent reflection in the state of high-illuminance illumination that illuminates the exhibit, or in the state where multi-color illumination is properly used depending on the exhibit, and this prevents the reflection. However, there are still insufficient problems. In addition, in order to ensure sufficient performance, it is necessary to increase the number of layers related to multilayering. If the number of layers is increased in this way, there is a problem that the transparency is lowered and the productivity is remarkably lowered. is there. In addition, when applied to such showcases, etc., it is necessary to replace them due to stains, etc., and for this purpose, they must be easily peeled off from glass or the like (reworkability), but are difficult to remove except during replacement. Is required. Incidentally, the antireflection film by the thin film multilayer treatment also has a problem that a defect such as a crack or a microcrack is generated on the surface when the film is attached at the time of replacement.

Japanese Patent Laid-Open No. 50-70040 Special Table 2003-531962 Japanese Patent No. 4632589 Japanese Patent No. 4197100

  The present invention has been made in view of such a situation, and an antireflection article that can prevent reflection as compared with the prior art, has sufficient rework performance, and is difficult to peel off from an object to be attached. The purpose is to propose.

  The present inventor has conducted extensive research to solve the above-mentioned problems, and has come up with the idea that the anti-reflection method using the moth-eye structure is applied to adjust the adhesive force between layers by adopting a multilayer structure. The present invention has been completed.

    Specifically, the present invention provides the following.

(1) In an antireflection article in which microprotrusions are closely arranged, and the interval between adjacent microprotrusions is equal to or shorter than the shortest wavelength of a wavelength band to prevent reflection,
The microprotrusions are provided on one surface side of the substrate,
On the other surface side of the substrate, a strong pressure-sensitive adhesive layer and a weak pressure-sensitive adhesive layer having a relatively weak adhesive strength with respect to the strong pressure-sensitive adhesive layer are provided.

  According to (1), reflection can be prevented with a simple structure by preventing reflection with the moth-eye structure. Further, by adjusting the adhesive force, it is possible to hold the object to be pasted with sufficient strength while ensuring sufficient reworkability.

(2) In (1),
The strong adhesive layer is
The peel force to the glass plate by the 180 degree peel test specified in JIS K6854-2 is 10N / 25mm width, 20N / 25mm width,
The weak adhesive layer is
The peel force to the glass plate according to the 180 degree peel test specified in JIS K6854-2 is 0.01N / 25mm width, 10N / 25mm width.

  According to (2), it can hold | maintain to a sticking object by sufficient intensity | strength, fully ensuring rework property by more specific structure.

(3) In (1) or (2),
A transparent core material is provided between the strong pressure-sensitive adhesive layer and the weak pressure-sensitive adhesive layer.

  According to (3), handling of the antireflection article can be facilitated by applying the core material, and the degree of freedom in material selection can be increased.

(4) In (1), (2), or (3),
Affixed and held on the desired transparent member by the weak adhesive layer,
The difference in refractive index between the weak pressure-sensitive adhesive layer and the transparent member and the difference in refractive index at each interface of the constituent members are 0.12 or less.

  In (4), the reflection can be sufficiently suppressed even at the interface between the constituent members and the interface between the components.

(5) In (1), (2), (3), or (4),
A part of the microprotrusions is
It is a minute projection having a plurality of vertices.

  According to (5), the scratch resistance can be improved.

  (6) In the display board, the antireflection article of (1), (2), (3), (4), or (5) is attached to both surfaces of the transparent board.

  According to (6), it is possible to significantly prevent reflection with respect to a transparent member such as a glass plate constituting the showcase.

(7) In a showcase that stores exhibits and provides them for display,
The display board according to (6) is provided.

  According to (7), it is possible to significantly prevent reflection with respect to the showcase.

  It is possible to provide an antireflective article that can prevent reflection as compared with the prior art, has sufficient rework performance, and is difficult to peel off from an object to be attached.

It is a figure which shows the showcase which concerns on 1st Embodiment of this invention with the structure which concerns. It is a figure where it uses for description of an adjacent protrusion. It is a figure which shows the manufacturing process of the antireflection article | item of FIG. It is a figure which shows the roll plate which concerns on the reflection preventing article of FIG. It is a figure which shows the preparation processes of the roll plate of FIG. It is a figure which shows the antireflection film which concerns on 2nd Embodiment of this invention. It is a chart with which it uses for description of the antireflection film of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1A is a perspective view showing a showcase according to the first embodiment of the present invention, and FIG. 1B is a sectional view partially showing the showcase as indicated by an arrow A. FIG. FIG. 1C is a cross-sectional view showing an antireflection film applied to this showcase. The showcase 1 is a case for storing exhibits made of precious items such as jewelry and artworks and presenting the exhibits. This showcase 1 is composed of an exhibition board material 1A for display of exhibits on the outer peripheral surface and the ceiling surface so that the exhibits placed inside can be viewed from above and around. . Further, in this embodiment, as shown in FIG. 1B, the display board 1A has an antireflection film 3 that is a film-shaped antireflection article attached to both surfaces of a glass plate 2 that is a transparent board. Formed. Here, the antireflection film 3 is an antireflection film having a moth-eye structure. As a result, the showcase 1 can sufficiently prevent the reflection of lighting and the reflection of outdoor scenery, etc., so that the exhibit can be viewed with a much higher sense of reality than before.

  As shown in FIG. 1, the showcase is not limited to the case where the display plate 1A is provided on the five surfaces of the outer peripheral surface and the ceiling surface. For example, there are various cases such as the case where the display plate 1A is provided on the four surfaces except the back surface. The configuration of can be widely applied. Moreover, you may make it arrange | position only about one side about a specific transparent board | plate material, such as when arrange | positioning an anti-reflective film only on the single side | surface, only the transparent plate material of a back side. It should be noted that the anti-reflection film with the moth-eye structure can ensure extremely high transparency compared to the anti-reflection film with the thin-film multilayer structure, so that there is no plate material such as glass for protecting the exhibit. Such an illusion may be given to the viewer. Therefore, instead of disposing the antireflection film 3 on the entire surface of the crow plate 2, the attachment of the antireflection film 3 to both surfaces is partially stopped, or the position of attachment between the front and back surfaces of the glass plate 2 is shifted. Alternatively, the areas to be attached may be different between the front surface and the back surface of the glass plate 2. In addition, a decorative effect may be imparted by shifting the position to be pasted in this way, changing the region, or partially pasting.

  In this embodiment, the antireflection film 3 that is an antireflection article is formed by a flat film shape, as shown by its name, but is not limited to this, and is a flat sheet shape or flat plate shape. (In the order of relatively small thickness, it can be referred to as a film, sheet, and plate), and instead of a flat shape, a curved shape, a three-dimensional film shape, a sheet shape, and a plate shape are used. You can also.

  The antireflection film 3 (FIGS. 1 (b) and (c)) is produced by closely arranging a large number of microprojections 7 on one surface of a substrate 5 made of a transparent film. A plurality of closely arranged microprotrusions 7 are collectively referred to as a microprotrusion group. Here, the base material 5 is, for example, a cellulose resin such as TAC (Triacetylcellulose), an acrylic resin such as PMMA (polymethyl methacrylate), a polyester resin such as PET (Polyethylene terephthalate), or PP (polypropylene). Polyolefin resins such as PVC, vinyl resins such as PVC (polyvinyl chloride), and various transparent resin films such as PC (polycarbonate) can be applied. As described above, the shape of the antireflection article is not limited to the film shape, and various shapes can be adopted. Various transparent inorganic materials such as glass such as soda glass, potash glass, lead glass, ceramics such as PLZT, quartz, and meteorite can be applied.

  The antireflection film 3 is formed by forming an uncured resin layer (hereinafter referred to as a receiving layer as appropriate) 6 to be a fine uneven receiving layer 6 made of a group of minute protrusions on a base material 5, and then receiving the receiving layer. The layer 6 is subjected to a molding treatment and cured, whereby the microprojections 7 are placed in close contact with the surface of the substrate 5. In this embodiment, an ultraviolet curable resin, which is one of the molding resins used for the molding process, is applied to the receiving layer 6, and the ultraviolet curable resin layer 6 is formed on the substrate 5. The antireflection film 3 is manufactured so that the refractive index gradually changes in the thickness direction due to the uneven shape by the minute protrusions 7, and reduces the reflection of incident light in a wide wavelength range by the principle of the moth-eye structure. As the ultraviolet curable resin, for example, an acrylate resin can be applied.

  In this way, the microprotrusions produced on the antireflection film 3 are closely arranged so that the distance d between the adjacent microprotrusions 7 is equal to or less than the shortest wavelength λmin (d ≦ λmin) of the wavelength band for preventing reflection. . In this embodiment, the shortest wavelength is set to the shortest wavelength (380 nm) in the visible light region in consideration of individual differences and illumination conditions, and the interval d is set to 100 to 100 in consideration of variation. It is set to 300 nm. The adjacent minute protrusions related to the distance d are so-called adjacent minute protrusions, which are in contact with the hem portions of the minute protrusions, which are the base portions on the substrate 5 side. In the antireflection film 3, the minute protrusions are closely arranged so that when a line segment is created so as to sequentially follow the valleys between the minute protrusions, a large number of polygonal regions surrounding the minute protrusions are connected in plan view. Thus, a mesh-like pattern is produced. The adjacent minute protrusions related to the distance d are protrusions that share a part of the line segments constituting the mesh pattern.

  The minute protrusions are defined in more detail as follows. That is, with respect to the interval between the protrusions 7, when the minute protrusions are regularly arranged at a constant period as disclosed in, for example, Japanese Patent Laid-Open No. 50-70040, Japanese Patent No. 4632589, etc., the distance d between adjacent minute protrusions 7 is d. Is the period P (d = P) of the protrusion arrangement. As a result, when the longest wavelength in the visible light band is λmax and the shortest wavelength is λmin, the minimum necessary condition that can exhibit an antireflection effect at the longest wavelength is P ≦ λmax. Necessary and sufficient conditions capable of exhibiting the antireflection effect with respect to the wavelength are P ≦ λmin.

  The wavelengths λmax and λmin may have some width depending on observation conditions, light intensity (luminance), individual differences, and the like, but are typically λmax = 780 nm and λmin = 380 nm. A preferable condition that can more reliably exhibit an antireflection effect for all wavelengths in the visible light band is d ≦ 300 nm, and a more preferable condition is d ≦ 200 nm. Note that the lower limit value of the period d is usually d ≧ 50 nm, preferably d ≧ 100 nm, for reasons such as the expression of the antireflection effect and the securing of the isotropic (low angle dependency) of the reflectance. On the other hand, the height H of the protrusion is set to H ≧ 0.2 × λmax = 156 nm (assuming λmax = 780 nm) from the viewpoint of exhibiting a sufficient antireflection effect.

  However, when the minute protrusions 7 are irregularly arranged, the distance d between adjacent minute protrusions varies. More specifically, as shown in FIG. 2, when the microprotrusions 7 are not regularly arranged with a constant period when viewed in a plan view from the normal direction of the front surface or the back surface of the substrate, the repetition period of the protrusions Depending on P, the distance d between adjacent protrusions cannot be defined, and even the concept of adjacent protrusions causes doubt. Therefore, in such a case, an in-plane arrangement of projections (planar shape of projection arrangement) is detected using an atomic force microscope (AFM) or a scanning electron microscope (SEM). By detecting the coordinates of each projection vertex from the detection result and statistically processing the detected coordinates, the interval d between adjacent minute projections is detected.

  In the case of an irregular arrangement as shown in FIG. 2, although the distance between adjacent protrusions to be detected varies, the distance between adjacent protrusions dmax defined by the average value + 2σ (σ = standard deviation) is It is necessary to satisfy the above-mentioned conditions for the longest wavelength λmax and the shortest wavelength λmin.

  As shown in FIG. 2, in the microprojections, a projection having a plurality of vertices (hereinafter referred to as a multi-modal microprojection) and a projection having only one vertex (hereinafter referred to as a single-peak microprojection). Can be mixed. Specifically, it can be seen that the protrusion indicated by reference numeral 7A has two vertices, and that the protrusion indicated by reference numeral 7B has three vertices. Such multi-peak microprotrusions 7A and 7B have a cross-sectional area on the base side larger than that of the single-peak microprotrusions 7, so that they are lateral (see FIG. 2 has strength against stress in the in-plane direction). In addition, it can be said that the abrasion is stronger than the unimodal microprotrusions. Thus, by mixing the multi-peak microprotrusions and the single-peak microprotrusions in this way, the scratch resistance can be improved.

  Needless to say, the multi-peak microprotrusions can improve the scratch resistance due to their presence, but if they do not exist sufficiently, the effect of improving the scratch resistance cannot be fully exhibited. From such a point of view, the multimodal microprotrusions are provided at 10% or more with respect to the total number of microprotrusions present on the surface. In order to sufficiently exhibit the effect of improving the scratch resistance by the multimodal microprojections, the ratio of the multimodal microprojections is 30% or more, preferably 50% or more.

  In addition, the microprotrusion group (7, 7A, 7B,...) Including the multimodal microprotrusions 7A and 7B is set such that the height varies from 10 nm to 50 nm when defined by the standard deviation. . As a result, for example, even when the shape of the microprojections with a high height is lost due to contact with an object, the shape of the microprojections with a low height is maintained, and local deterioration of the antireflection function is reduced. In addition, the occurrence of defective appearance can be reduced, and as a result, the scratch resistance can be improved.

  The antireflection film 3 is disposed on the glass plate 2 via two adhesive layers 8 and 9 provided on the other surface of the substrate 5. Here, the two pressure-sensitive adhesive layers 8 and 9 are a strong pressure-sensitive adhesive layer 8 having a relatively strong adhesive force and a weak pressure-sensitive adhesive layer 9 having a relatively weak adhesive force. The pressure-sensitive adhesive layer 9 on the glass plate 2 side is sufficiently peelable to the extent that reworkability can be ensured with respect to the glass plate 2 to be attached, and is sufficiently reflective except at the time of replacement. Adhesive strength (so-called weak adhesive strength) that can hold the prevention film 3 on the glass plate 3 is provided. Specifically, in the 180 degree peel test specified in JIS K6854-2, an adhesive having a peel force of 0.01 N / 25 mm width or 10 N / 25 mm width is applied to the glass plate to be attached. The On the other hand, the subsequent pressure-sensitive adhesive layer 8 has a sufficiently strong adhesive force (so-called strong adhesion) between the base material 5 and the pressure-sensitive adhesive layer 9. Specifically, in the 180 degree peel test defined in JIS K6854-2, a pressure sensitive adhesive having a peel strength of 10 N or more / 25 mm width and 20 N or less / 25 mm width is applied. Thus, by laminating the weak pressure-sensitive adhesive layer 9 and the strong pressure-sensitive adhesive layer 8, in this embodiment, while ensuring reworkability, it is difficult to peel off except at the time of replacement so as to prevent reflection on the glass plate 2. Hold film 3.

  Here, for the pressure-sensitive adhesive layers 8 and 9, various materials applicable to this kind of film material can be applied. However, in this embodiment, a combination of materials in which the difference in refractive index is 0.12 or less is applied at each interface in the antireflection film 3 and at the interface between the antireflection film 3 and the glass plate 3. Reflection is effectively prevented, and the antireflection effect by attaching an antireflection film having a moth-eye structure is further improved.

  Specifically, in the antireflection film 3, the difference in refractive index between the ultraviolet curable resin layer 6 and the substrate 5, the difference in refractive index between the substrate 5 and the adhesive layer 8, the adhesive layer 8 and the adhesive. The materials are selected and adjusted so that the difference in refractive index with the layer 9 and the difference in refractive index between the pressure-sensitive adhesive layer 9 and the glass plate 2 are 0.12 or less, respectively. For this adjustment, a method of mixing different resin materials or a method of mixing transparent fine particles having different refractive indexes into the resin material can be applied. Incidentally, for example, by applying the same type of resin to the ultraviolet curable resin layer 6, the base material 5, and the pressure-sensitive adhesive layers 8 and 9, more specifically, for example, by applying an acrylic resin to them, Can satisfy various conditions.

  The antireflection film 3 (FIG. 1 (c)) is held with the separator film 10 attached to the adhesive layer 9, and the adhesive film 9 is peeled off when the separator film 10 is attached to the glass plate 2. Is exposed and pressed against the glass plate 2. In addition, the antireflection film 3 is provided with a protective film F that protects the fine protrusions 7, and after being attached to the glass plate 2, the protective film F is removed.

〔Manufacturing process〕
FIG. 3 is a diagram showing a manufacturing process of the antireflection film 3. In the manufacturing process 11, in the resin supplying process, an uncured and liquid ultraviolet curable resin that forms a microprojection-shaped receiving layer is applied to the substrate 5 in the form of a belt-shaped film by the die 12. In addition, about application | coating of an ultraviolet curable resin, not only the case by the die | dye 12 but various methods are applicable. Subsequently, the manufacturing process 11 presses and presses the base material 5 against the peripheral side surface of the roll plate 13 which is a mold for shaping the antireflection article by the pressing roller 14, thereby causing the base material 5 to be in an uncured state. The system ultraviolet curable resin is brought into close contact, and the fine concavo-convex recesses formed on the peripheral side surface of the roll plate 13 are sufficiently filled with the ultraviolet curable resin. In this state, in this manufacturing process, the ultraviolet curable resin is cured by irradiation with ultraviolet rays, and thereby a microprojection group is formed on the surface of the substrate 5. In this manufacturing process, the substrate 5 is peeled off from the roll plate 13 through the peeling roller 15 together with the cured ultraviolet curable resin. In the manufacturing process 11, the adhesive layers 8 and 9 and the separator film 10 are sequentially provided on the base material 5, and then cut into a desired size to produce the antireflection film 3. Thereby, the antireflection film 3 is mass-produced efficiently by sequentially molding the fine shape produced on the peripheral side surface of the roll plate 13 which is a mold for molding on the long base material 5 made of a roll material. The

  FIG. 4 is a perspective view showing the configuration of the roll plate 13. The roll plate 13 has a fine concavo-convex shape formed on the peripheral side surface of the base material, which is a cylindrical metal material, by repeating anodizing treatment and etching treatment, and the fine concavo-convex shape is formed on the substrate 5 as described above. It is shaped. For this reason, a columnar or cylindrical member in which a high-purity aluminum layer is provided at least on the peripheral side surface is used as the base material. More specifically, in this embodiment, a hollow stainless steel pipe is applied to the base material, and a high-purity aluminum layer is provided directly or via various intermediate layers. In addition, it may replace with a stainless steel pipe and may apply pipe materials, such as copper and aluminum. In the roll plate 13, fine holes are densely formed on the peripheral side surface of the base material by repeating the anodizing treatment and the etching treatment, and the fine holes are dug, and the diameter of the roll plate 13 increases as it approaches the opening. The concavo-convex shape is produced by gradually increasing the diameter of the fine holes. As a result, the roll plate 13 is densely formed with fine holes whose hole diameter gradually decreases in the depth direction, and the antireflection film 3 has a diameter that gradually decreases as it approaches the top corresponding to the fine holes. A fine concavo-convex shape is produced by a large number of fine protrusions.

  FIG. 5 is a diagram illustrating a manufacturing process of the roll plate 13. In this manufacturing process, the peripheral side surface of the base material is made into a super mirror surface by an electrolytic composite polishing method that combines electrolytic elution action and abrasion action by abrasive grains (electrolytic polishing). Subsequently, in this step, aluminum is sputtered on the peripheral side surface of the base material to produce a high-purity aluminum layer. Subsequently, in this process, the base material is processed by alternately repeating the anodic oxidation processes A1,..., AN, and the etching processes E1,.

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

  In the subsequent etching process E1,..., EN, the mold is immersed in an etching solution, the hole diameter of the fine hole produced and dug in the anodizing process A1,. These fine holes are shaped so that the hole diameter becomes smaller and smoother. As the etching solution, various etching solutions that are applied to this type of treatment can be widely applied. More specifically, for example, a sulfuric acid aqueous solution, an oxalic acid aqueous solution, a phosphoric acid aqueous solution, or the like can be used. As a result, in this manufacturing process, the anodizing process and the etching process are alternately performed a plurality of times, so that fine holes for forming are formed on the peripheral side surface of the base material.

  In this embodiment, in the alternating repetition of the anodizing step and the etching process, by controlling the power source used for anodization, monomodal microprojections and multimodal microprojections are mixed, and the height of the projections is further increased. Scatter. More specifically, the applied voltage used for anodic oxidation is varied, thereby mixing single-peaked microprojections and multi-peaked microprojections.

  According to the above configuration, an antireflection article is created with a moth-eye structure, and by holding it on the object to be pasted with a laminated structure of a strong adhesive layer and a weak adhesive layer, reflection is sufficiently prevented. Thus, it can be held on the object to be pasted with sufficient strength while ensuring reworkability. Thereby, the application field of the anti-reflective article by this moth-eye structure can be expanded further.

  In addition, by setting the difference in refractive index between members at a certain value or less at each interface, reflection at each interface can be sufficiently reduced, and the optical characteristics of the antireflection article with the moth-eye structure can be fully exhibited. it can.

  In addition, the scratch resistance can be improved by mixing the single protrusion and the multimodal protrusion in the protrusion.

[Second Embodiment]
FIG. 6 is a diagram showing an antireflection film according to the second embodiment of the present invention in comparison with FIG. In this embodiment, it replaces with the antireflection film 3, and is comprised similarly to 1st Embodiment except the point to which this antireflection film 23 is applied. The antireflection film 23 is configured in the same manner as the antireflection film 3 except that a core material 24 made of a transparent film is provided between the pressure-sensitive adhesive layers 8 and 9.

  By providing the core member 24 in this manner, in this embodiment, the thickness of the antireflection film 23 can be increased, and the handling when the antireflection film 23 is replaced can be simplified.

  Furthermore, in this embodiment, the conditions are set so as to satisfy the condition that the refractive index difference is set to 0.12 or less at each interface and the above-described peel strength condition. The range of member selection that satisfies the above can be expanded. More specifically, for example, in this case as well, more specifically, by applying the same type of resin to, for example, the ultraviolet curable resin layer 6, the base material 5, the pressure-sensitive adhesive layers 8 and 9, and the core material 24. Such conditions can be satisfied by applying, for example, an acrylic resin.

  FIG. 7 is a view showing an evaluation result of the antireflection film according to this embodiment together with a comparative example. In FIG. 8, strong adhesive 1 is an acrylic adhesive (PDS1 (manufactured by Panac)), and strong adhesive 2 is an acrylic strong adhesive manufactured by Nichiei Kako. Further, the weak adhesive 1 is gel poly (Panac adhesive), and the weak adhesive 2 is an acrylic adhesive (h120 (manufactured by Nichiei Kako)). Comparative Examples 1 to 3 are cases in which only one pressure-sensitive adhesive layer is provided instead of the pressure-sensitive adhesive layer 8, the core material 24, and the pressure-sensitive adhesive layer 9 in the configuration shown in FIG. This is a case where strong adhesive 1, weak adhesive 1, and weak adhesive 2 are applied to the adhesive layer.

  In Comparative Examples 4 and 5, Examples 1 and 2, the pressure-sensitive adhesive layer 8, the core material 24, and the pressure-sensitive adhesive layer 9 are provided. In Comparative Example 4, the pressure-sensitive adhesive layer 8, the core material 24, This is a case where strong adhesive 1, PET resin, and weak adhesive 1 are applied to the adhesive layer 9, respectively. Example 1 is a case where strong adhesive 1, acrylic resin, and weak adhesive 1 are applied to the adhesive layer 8, the core material 24, and the adhesive layer 9, respectively, and Comparative Example 5 is the adhesive layer 8, the core material 24. In this case, strong adhesive 2, PET resin, and weak adhesive 2 are applied to the adhesive layer 9, respectively. In Example 2, strong adhesive 2, acrylic resin, and weak adhesive 2 are applied to the adhesive layer 8, the core material 24, and the adhesive layer 9, respectively.

  In FIG. 7, the transmittance is indicated by “◯” when a certain criterion value is satisfied, and “X” when the criterion is not satisfied. This criterion value is a criterion value for determining whether or not a sufficiently high transmittance can be secured in a wide incident angle range as an antireflection article having a moth-eye structure. The reworkability was marked with “◯” when the peel strength measured between the respective glass plates to be attached satisfies the above range, and marked with “X” when not satisfied. In addition, the adhesion to the substrate was marked with ◯ when the peel strength between the base material and the pressure-sensitive adhesive layer satisfied the above range, and marked with x when not satisfied.

  According to this test result, as shown in Comparative Examples 1 to 3, when the pressure-sensitive adhesive layer is composed of one layer, depending on the selection of the materials according to these Comparative Examples, sufficient reworkability is ensured while sufficient. It was found that it was difficult to hold on the object to be pasted due to strength. Further, in the case where the pressure-sensitive adhesive layer 8, the core material 24, and the pressure-sensitive adhesive layer 9 are provided, although sufficient reworkability can be secured, it can be held on the object to be adhered with sufficient strength (Comparative Example 4, 5, Examples 1 and 2) and Comparative Examples 4 and 5 showed that the transmittance deteriorated depending on the selection of the material.

  According to this embodiment, even if a core material is provided between the pressure-sensitive adhesive layers 8 and 9, the same effect as that of the first embodiment can be obtained. Moreover, in this embodiment, the range of material selection can be expanded, and the handling at the time of re-covering can be simplified.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention can be variously modified from the configuration of the above-described embodiment without departing from the spirit of the present invention, and further the conventional configuration. Combinations or other various configurations can be added.

  That is, in the above-described embodiment, the case where the ultraviolet curable resin layer is directly provided on the surface of the base material has been described. However, the present invention is not limited to this, and can be widely applied when various intermediate layers are interposed. . Such an intermediate layer is, for example, a hard coat layer or a cushion layer. Alternatively, the fine protrusions may be formed by directly shaping the substrate.

  In the above-described embodiment, the case where the anodizing process and the etching process are repeated a plurality of times has been described. However, the present invention is not limited to this, and can be widely applied to the case where the last process is an anodizing process. it can.

  In the above-described embodiment, the case where the display board is applied to the showcase has been described. However, the present invention is not limited to this, and the show window can be applied to a case where various items of clothes are displayed at a store, for example. The display board can be widely applied to various exhibitions, for example, when it is constituted by the display board.

  In the above-described embodiment, the case where an acrylate-based ultraviolet curable resin is applied to the shaping resin has been described. However, the present invention is not limited thereto, and various ultraviolet curable resins such as epoxy-based and polyester-based resins, or Also when using various materials such as acrylate-based, epoxy-based, polyester-based electron beam curable resins, urethane-based, epoxy-based, polysiloxane-based thermosetting resins, and various types of curing resins The present invention can be widely applied. Further, for example, the present invention can be widely applied to the case of shaping by pressing a heated thermoplastic resin.

  Moreover, although the above-mentioned embodiment described the case where the anti-reflective article by a film shape was produced by the shaping process using a roll plate, this invention is not limited to this, The transparent base material which concerns on the shape of an anti-reflective article Depending on the shape, for example, when creating an antireflection article by processing a sheet using a shaping mold with a specific curved shape, such as a flat plate, the process related to the shaping process, the mold is the antireflection article It can change suitably according to the shape of the transparent base material which concerns on a shape.

  In the above-described embodiment, the case where an antireflection film is pasted on both sides of a transparent plate made of a glass plate to form a display plate is described, but the present invention is not limited thereto, and various transparent plates such as an acrylic plate are used. You may make it comprise the board | plate material for exhibition by applying.

  Moreover, although the case where an antireflection film was directly affixed on the transparent plate material by a glass plate was described in the above-mentioned embodiment, this invention is not limited to this, For example, it affixes via other film materials, such as a scattering prevention film. You may do it.

DESCRIPTION OF SYMBOLS 1 Showcase 1A Display board | plate material 2,23 Glass plate 3 Antireflection film 5 Base material 6 Ultraviolet curable resin layer, receiving layer 7, 7A, 7B Microprotrusion 8, 9 Adhesive layer 10 Separator film 11 Manufacturing process 12 Die 13 Roll plate 14, 15 Roller 24 Core material

Claims (7)

In the antireflection article in which the microprotrusions are closely arranged and the interval between the adjacent microprotrusions is equal to or less than the shortest wavelength of the wavelength band to prevent reflection,
The microprotrusions are provided on one surface side of the substrate,
An antireflection article provided with a strong pressure-sensitive adhesive layer and a weak pressure-sensitive adhesive layer having a relatively weak adhesive strength with respect to the strong pressure-sensitive adhesive layer on the other surface side of the substrate. The strong adhesive layer is
The peel force to the glass plate by the 180 degree peel test specified in JIS K6854-2 is 10N / 25mm width, 20N / 25mm width,
The weak adhesive layer is
The antireflection article according to claim 1, wherein a peeling force to a glass plate by a 180-degree peeling test specified in JIS K6854-2 is 0.01 N or more / 25 mm width, 10 N or less / 25 mm width. The antireflection article according to claim 1, wherein a transparent core material is provided between the strong pressure-sensitive adhesive layer and the weak pressure-sensitive adhesive layer. Affixed and held on the desired transparent member by the weak adhesive layer,
The difference in refractive index between the weak pressure-sensitive adhesive layer and the transparent member and the difference in refractive index at each interface between the constituent members are 0.12 or less. Anti-reflective article. A part of the microprotrusions is
The antireflection article according to claim 1, wherein the antireflection article is a microprojection having a plurality of apexes. An exhibition board material, wherein the antireflection article according to claim 1, claim 2, claim 3, claim 4, or claim 5 is attached to both surfaces of a transparent board material. In a showcase that houses exhibits and serves for the exhibition,
A showcase provided with the display board according to claim 6.