JP6923293B2 - Fine concavo-convex structure and joint - Google Patents

Description

The present invention relates to a fine concavo-convex structure having a fine concavo-convex structure on its surface, and a bonded body in which a fine concavo-convex structure and another member are joined via an adhesive.

It is known that a fine concavo-convex structure having a fine concavo-convex structure on its surface exhibits antireflection performance by a continuous change in the refractive index. It is also known that the fine concavo-convex structure exhibits superhydrophobicity due to the Lotus effect.

However, in the fine concavo-convex structure, a liquid substance (fingerprint oil, adhesive, etc.) easily adheres to the surface having the fine concavo-convex structure, and the antireflection performance and the like are greatly impaired at the portion where the liquid substance adheres.
For example, when the fine concavo-convex structure is handled with bare hands, fingerprint oils and fats adhere to the surface having the fine concavo-convex structure.
Further, as an image display device, an image display device with a touch panel in which an image display panel and a touch panel having a fine concavo-convex structure on the surface are joined via an adhesive has been proposed (see, for example, Patent Document 1). When the image display panel and the touch panel are joined via an adhesive, the adhesive adheres to the surface of the touch panel having a fine concavo-convex structure.

In the image display device, a light-shielding portion (bezel or the like) for concealing the wiring or the like of each panel is formed on the peripheral edge of the image display portion. When handling the touch panel at the time of manufacturing the image display device, the portion corresponding to the light-shielding portion is gripped so that the oil and fat of the fingerprint does not adhere to the portion corresponding to the image display portion. Further, when the image display panel and the touch panel are joined via the adhesive, the adhesive is provided in the portion corresponding to the light-shielding portion so that the adhesive does not adhere to the portion corresponding to the image display portion. Become.

Japanese Unexamined Patent Publication No. 2013-125317

However, in the fine concavo-convex structure, the low molecular weight component contained in the liquid substance adhering to the surface having the fine concavo-convex structure wets and spreads over the fine concavo-convex structure over several minutes to several days, and the portion where the liquid substance first adheres. It was newly found that the antireflection performance and the like are significantly impaired in a wider range than that.
Therefore, low molecular weight components contained in fingerprint oils and fats and adhesives adhering to the surface of the touch panel having a fine concavo-convex structure during manufacturing of the image display device wet and spread from the light-shielding portion to the image display portion, and are reflected in the image display portion. The prevention performance is greatly impaired.

The present invention provides a fine concavo-convex structure and a bonded body in which a liquid substance adhering to a surface having a fine concavo-convex structure does not easily get wet and spread outside a predetermined region.

The present invention has the following aspects.
<1> From a plurality of convex portions whose average height is equal to or less than the wavelength of visible light and whose average distance between adjacent convex portions is equal to or less than the wavelength of visible light, and from concave portions formed between the plurality of convex portions. A fine concavo-convex structure having a fine concavo-convex structure on at least one surface, further having a dam portion on the surface having a height higher than the convex portion and dividing the surface into a plurality of regions. Structure.
<2> The fine concavo-convex structure according to <1>, wherein the weir portion is a coating film formed on the fine concavo-convex structure.
<3> The fine concavo-convex structure according to <1> or <2>, wherein the weir portion contains a resin, and the higher of the melting point or the glass transition temperature of the resin is 50 ° C. or higher.
<4> The fine concavo-convex structure according to <3>, wherein the weir portion further contains a dye or a pigment.
<5> The fine concavo-convex structure according to any one of <1> to <4>, wherein the width of the weir portion is 10 mm or less.
<6> From a plurality of convex portions whose average height is equal to or less than the wavelength of visible light and whose average distance between adjacent convex portions is equal to or less than the wavelength of visible light, and from concave portions formed between the plurality of convex portions. A fine concavo-convex structure having a fine concavo-convex structure on at least one surface, wherein a groove having a width of 0.1 mm or more is formed on the surface to divide the surface into a plurality of regions. body.
<7> The fine concavo-convex structure according to <6>, wherein the bottom of the groove is at the same depth as the bottom of the recess, or is deeper than the bottom of the recess.
<8> The fine concavo-convex structure according to <6> or <7>, wherein the convex portion does not exist in the groove portion.
<9> The fine concavo-convex structure according to any one of <6> to <8>, wherein the width of the groove is 10 mm or less.
<10> The adhesive having the fine concavo-convex structure according to any one of <1> to <9>, another member, and an adhesive for joining the fine concavo-convex structure and the other member. Is provided in a part of the plurality of regions on the surface of the fine concavo-convex structure.
<11> The fine concavo-convex structure according to any one of <1> to <9>, another member, and an adhesive provided on the other member, and the adhesive is the fine concavo-convex structure. A bonded body in contact with a part of the plurality of regions on the surface of the structure.
<12> The joint body is an image display device having an image display panel, a protective plate, and an adhesive for joining the image display panel and the protective plate, and the image display panel is the other member. The joint body of <10>, wherein the protective plate is the fine concavo-convex structure.
<13> The joint body is an image display device having an image display panel, a touch panel, and an adhesive for joining the image display panel and the touch panel, and the image display panel is the other member. The joint body of <10>, wherein the touch panel is the fine concavo-convex structure.

In the fine concavo-convex structure of the present invention, the liquid substance adhering to the surface having the fine concavo-convex structure is unlikely to wet and spread outside the predetermined region.
In the bonded body of the present invention, the adhesive that joins the fine concavo-convex structure and other members is unlikely to get wet and spread outside a predetermined region.

It is sectional drawing which shows an example of the fine concavo-convex structure of the 1st aspect of this invention. It is a top view which shows the appearance that the liquid substance adhered to the surface which has the fine concavo-convex structure of the fine concavo-convex structure of the 1st aspect. FIG. 2 is a sectional view taken along line III-III of FIG. It is a top view which shows the state in which the liquid substance attached to the surface which has the fine concavo-convex structure of the fine concavo-convex structure of the first aspect wets and spreads. It is a VV cross-sectional view of FIG. It is sectional drawing which shows an example of the fine concavo-convex structure of the 2nd aspect of this invention. It is sectional drawing which shows the other example of the fine concavo-convex structure of the 2nd aspect of this invention. It is sectional drawing which shows the other example of the fine concavo-convex structure of the 2nd aspect of this invention. It is a top view which shows the appearance that the liquid substance adhered to the surface which has the fine concavo-convex structure of the fine concavo-convex structure of the 2nd aspect. It is a top view which shows the appearance that the liquid substance attached to the surface which has the fine concavo-convex structure of the fine concavo-convex structure of the 2nd aspect wets and spreads. It is sectional drawing which shows an example of the junction of this invention. It is sectional drawing which shows the process of manufacturing a mold.

The definitions of the following terms apply throughout the specification and claims.
The "liquid substance" means a substance that is in a liquid state at room temperature (25 ° C.), and is a component that is slowly released from a composition or the like (for example, oleic acid in a human fingerprint, a low molecular weight in a pressure-sensitive adhesive). It also includes substances contained in the composition such as (ingredients, etc.).
The "melting point" is the melting peak temperature determined by differential scanning calorimetry (DSC) according to JIS K 7121: 1987.
The “glass transition temperature” is the intermediate point glass transition temperature determined by DSC according to JIS K 7121: 1987.
"(Meta) acrylate" is a general term for acrylate and methacrylate.
"(Meta) acryloyl group" is a general term for acryloyl group and methacryloyl group.
The "active energy ray" means visible light, ultraviolet light, electron beam, plasma, heat ray (infrared ray, etc.) and the like.
The dimensional ratios in FIGS. 1 to 12 are different from the actual ones for convenience of explanation. Further, in FIGS. 2 to 11, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

<Fine uneven structure>
(First aspect)
The fine concavo-convex structure according to the first aspect of the present invention has a fine concavo-convex structure composed of a plurality of convex portions and recesses formed between the plurality of convex portions on at least one surface, and the surface is divided into a plurality of regions. It has a weir portion extending along the surface so as to be divided.

FIG. 1 is a cross-sectional view showing an example of a fine concavo-convex structure according to the first aspect of the present invention.
The fine concavo-convex structure 10 includes a base material 12; a fine concavo-convex structure 18 formed on the surface of the base material 12 and composed of a plurality of convex portions 14 and a concave portion 16 formed between the plurality of convex portions 14. The cured resin layer 20 on the surface; along the surface of the cured resin layer 20 so as to divide the surface of the cured resin layer 20 formed on the fine concavo-convex structure 18 of the cured resin layer 20 into regions I and II. It has a weir portion 22 extending through the pipe.

(Base material)
As the material of the base material, acrylic resin (methyl methacrylate (co) polymer, etc.), polypropylene, styrene resin (styrene (co) polymer, methyl methacrylate-styrene copolymer, etc.), cellulose resin (cellulose di) Acetate, cellulose triacetate, cellulose acetate butyrate, etc.), polyester, polyamide, polyimide, polyether sulfone, polysulphon, polyolefin (polypropylene, polymethylpentene, etc.), alicyclic polyolefin, vinyl chloride resin (polyvinyl chloride, etc.) , Polyvinyl acetal, polyether ketone, polyurethane, glass and the like.
As the material of the base material, a material that transmits light is preferable from the viewpoint of the use of the fine concavo-convex structure.

Examples of the form of the base material include films, sheets, plates, molded products having an arbitrary shape, and the like, and films or sheets are preferable from the viewpoint of productivity and handleability of the fine concavo-convex structure.
The base material can be produced by a known production method such as an injection molding method, an extrusion molding method, or a cast molding method.
The surface of the base material may be coated, corona-treated, or the like for the purpose of improving properties such as adhesion, antistatic property, scratch resistance, and weather resistance.

(Curing resin layer)
The cured resin layer is a film made of a cured product of an active energy ray-curable composition described later, and has a fine concavo-convex structure having a plurality of convex portions and concave portions formed between the plurality of convex portions on the surface.
It is known that a fine concavo-convex structure in which a plurality of convex portions are lined up (so-called moth-eye structure) can be an effective antireflection means by continuously increasing the refractive index from the refractive index of air to the refractive index of the material. Has been done.

As the fine concavo-convex structure of the cured resin layer, there are a plurality of fine anodic oxide porous aluminas because the antireflection performance of the fine concavo-convex structure is further excellent and it is easy to manufacture a large-area fine concavo-convex structure at low cost. A fine concavo-convex structure composed of a plurality of convex portions formed by transferring the holes is preferable.

The average spacing between adjacent protrusions is equal to or less than the wavelength of visible light, that is, 400 nm or less, preferably 380 nm or less. When the average distance between adjacent convex portions is equal to or less than the wavelength of visible light, good antireflection performance is exhibited. When the average spacing between adjacent convex portions is 380 nm or less, scattering of visible light can be sufficiently suppressed.
When a plurality of pores of anodized porous alumina are transferred to form a convex portion, it is necessary to increase the voltage in order to increase the pore spacing, which makes it difficult to industrially produce anodized porous alumina. The average spacing between adjacent protrusions is particularly preferably 200 nm or less.
The average spacing between the adjacent convex portions is preferably 20 nm or more, more preferably 80 nm or more, from the viewpoint that the convex portions are easily formed.
For the average distance between adjacent convex parts, the distance P between adjacent convex parts (distance from the center of the convex part to the center of the adjacent convex part) was randomly measured at 10 points by electron microscope observation, and these were measured. It is the average of the values.

The average height of the convex portion is equal to or less than the wavelength of visible light, that is, 400 nm or less, and preferably 350 nm or less. When the average height of the convex portion is equal to or less than the wavelength of visible light, the scratch resistance of the convex portion becomes good. In addition, it is easy to form a convex portion.
The average height of the convex portion is preferably 60 nm or more, more preferably 90 nm or more. When the average height of the convex portion is 60 nm or more, it is possible to suppress an increase in the minimum reflectance and the reflectance at a specific wavelength, and sufficient antireflection performance can be obtained.
For the average height of the convex portion, the vertical distance H between the top of the convex portion and the bottom of the concave portion adjacent thereto was randomly measured at 10 points by electron microscope observation, and these values were averaged. It is a thing.

The aspect ratio of the convex portion (average height of the convex portion / average distance between the convex portions) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Is even more preferable. When the aspect ratio of the convex portion is 0.8 or more, the antireflection performance of the fine concavo-convex structure is further excellent. When the aspect ratio of the convex portion is 5.0 or less, the scratch resistance of the convex portion is good. In addition, it is easy to form a convex portion.

Examples of the shape of the convex portion include a conical shape, a pyramid shape, a bell shape, a cylindrical shape, and the like. Conical shape, pyramid shape, bell shape in order to continuously increase the refractive index from the air to the surface of the material forming the fine concavo-convex structure to develop antireflection performance that achieves both low reflectance and low wavelength dependence. A shape in which the cross-sectional area of the convex portion in the direction orthogonal to the height direction continuously increases from the top in the depth direction is preferable.
The convex portion may be one in which a plurality of fine convex portions are united to form one convex portion.

(Method of forming fine uneven structure)
The fine concavo-convex structure can be formed by, for example, the following method or the like.
(Method 1) A method of forming a fine concavo-convex structure directly on the surface of a base material by performing injection molding or press molding using a mold having an inverted structure of the fine concavo-convex structure on the surface.
(Method 2) The active energy ray-curable composition is cured while the active energy ray-curable composition is sandwiched between a mold having an inverted structure having a fine concavo-convex structure and a base material to form a cured resin layer. A method of separating the cured resin layer and the mold after forming.
(Method 3) The active energy ray-curable composition is sandwiched between a mold having an inverted structure of a fine concavo-convex structure and a substrate, and the fine concavo-convex structure of the mold is transferred to the active energy ray-curable composition. A method of forming a cured resin layer by curing an active energy ray-curable composition after separating the mold.
As a method for forming the fine concavo-convex structure, the method 2 or the method 3 is preferable, and the method 2 is particularly preferable, from the viewpoint of the transferability of the fine concavo-convex structure and the degree of freedom of the surface composition.

Examples of the mold include the following molds and the like.
-A mold in which an inverted structure with a fine uneven structure is provided on the surface by a lithography method.
-A mold with an inverted structure of fine uneven structure on the surface by laser processing.
-A mold in which anodized porous alumina having multiple pores is formed on the surface.
-A replica mold that is duplicated by electroforming from a mother mold that has a fine uneven structure.

Examples of the lithography method include an electron beam lithography method and a laser interference lithography method. Examples of the method for manufacturing the mold by the lithography method include the following methods.
A method of obtaining a mold having a fine concavo-convex structure composed of a resist pattern by applying a photoresist film on the surface of a substrate, exposing it with an ultraviolet laser, an electron beam, an X-ray, or the like and developing it.
A method of selectively etching a substrate through the resist pattern by dry etching or the like to remove the resist pattern to obtain a mold in which a fine concavo-convex structure is directly formed on the surface of the substrate.

Examples of the method for producing a mold in which porous alumina on the surface is anodized include a method in which aluminum is anodized at a predetermined voltage using oxalic acid, sulfuric acid, phosphoric acid or the like as an electrolytic solution. According to this method, high-purity aluminum is anodized at a constant voltage for a long time, and then all or part of the oxide film is once removed and then anodized again, so that very highly regular pores are self-structured. Passivationally formed porous alumina can be formed. Further, by combining the anodic oxidation treatment and the pore diameter expansion treatment in the second anodic oxidation step, it is possible to form pores having a triangular or bell-shaped cross section instead of a rectangular cross section. It is also possible to sharpen the angle of the innermost part of the pores by appropriately adjusting the time, number of times, conditions and the like of the anodic oxidation treatment and the pore diameter expansion treatment.

As the mold, a mold in which anodized porous alumina is formed on the surface is preferable because it is easy to manufacture a mold having a large area at low cost.
For example, Patent Document 1 and the like describe a specific method for producing a mold in which anodized porous alumina is formed on the surface.

Examples of the shape of the mold include a flat plate shape, a belt shape, a roll shape, and the like. As the shape of the mold, a belt shape or a roll shape is preferable from the viewpoint that the fine concavo-convex structure can be continuously transferred and the productivity can be further improved.

The active energy ray-curable composition is a composition in which the polymerization reaction proceeds by irradiating with active energy rays and the composition is cured.
The active energy ray-curable composition contains a polymerizable compound, a polymerization initiator, and optionally other additives.

Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having either or both of radically polymerizable bonds and cationically polymerizable bonds in the molecule.
Examples of the monomer having a radically polymerizable bond include a monofunctional monomer having a (meth) acryloyl group, a vinyl group and the like, and a polyfunctional monomer. Specific examples thereof include (meth) acrylate and its derivatives.
Examples of the monomer having a cationically polymerizable bond include a monomer having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group and the like.
Examples of oligomers or reactive polymers include unsaturated polyesters such as condensates of unsaturated dicarboxylic acids and polyhydric alcohols; polyester (meth) acrylates, polyether (meth) acrylates, polyol (meth) acrylates, and epoxies (meth). Examples thereof include acrylates, urethane (meth) acrylates, cationically polymerizable epoxy compounds, and single or copolymerized polymers of the above-mentioned monomers having a radically polymerizable bond in the side chain.

Examples of the polymerization initiator include known photopolymerization initiators, electron beam polymerization initiators, thermal polymerization initiators and the like.
The active energy ray-curable composition may optionally contain a non-reactive polymer.
Active energy ray-curable compositions include antioxidants, mold release agents, lubricants, plasticizers, antioxidants, light stabilizers, flame retardants, flame retardants, polymerization inhibitors, UV absorbers, as needed. It may contain other additives such as fillers, silane coupling agents, colorants, strengtheners, inorganic fillers, impact modifiers and the like.

When water repellency (specifically, the contact angle of water is 90 ° or more) is required on the surface of the fine concavo-convex structure, as an active energy ray-curable composition capable of forming a hydrophobic material, It is preferable to use a composition containing a fluorine-containing compound or a silicone-based compound.
When hydrophilicity (specifically, the contact angle of water is 25 ° or less) is required on the surface of the fine concavo-convex structure, as an active energy ray-curable composition capable of forming a hydrophilic material, as an active energy ray-curable composition. It is preferable to use a composition containing a polyfunctional (meth) acrylate having four or more functionalities, a hydrophilic (meth) acrylate having two or more functionalities, and, if necessary, a monofunctional monomer.
The specific composition and the like of the active energy ray-curable composition are described in, for example, Patent Document 1 and the like.

The active energy ray-curable composition preferably has a small difference in refractive index from the substrate when cured. Specifically, the cured product of the active energy ray-curable composition, that is, the difference in refractive index between the cured resin layer and the base material is preferably 0.3 or less, and more preferably 0.1 or less. The smaller the difference in refractive index, the smaller the reflection of light at the interface between the cured resin layer and the base material, and a fine uneven structure having further excellent antireflection performance can be obtained.

As a method of sandwiching the active energy ray-curable composition between the mold and the base material, the mold and the base material are pressed with the active energy ray-curable composition placed between the mold and the base material. As a result, a method of injecting the active energy ray-curable composition into the fine concavo-convex structure of the mold can be mentioned.
For example, Patent Document 1 and the like describe an apparatus provided with a mold having anodized porous alumina formed on the surface, and a specific method for forming a fine concavo-convex structure using the apparatus and an active energy ray-curable composition. Has been done.

(Weir)
The weir portion extends along the surface so as to divide at least one surface of the fine concavo-convex structure into a plurality of regions.
Regions I and II of the illustrated example divided by the weir are, for example, a low reflection region and a pollution tolerance region, respectively.

The contamination-tolerant area is an area to which the pressure-sensitive adhesive is applied, or an area that must be touched by hand during the production of the bonded body. The contamination tolerance area is an area that cannot be seen by the product user in the state of the final product. Specifically, it is a portion covered by a light-shielding portion (bezel) on the periphery of the image display portion of the image display device.
The low reflection area is an area that can be visually recognized by the product user in the state of the final product. Specifically, it is an image display unit or the like of an image display device. If the liquid substance from the contamination tolerance area gets wet and spreads in the low reflection area, the antireflection performance is impaired and the appearance of the final product is impaired.

The weir portion may be provided so as to block the invasion route of the liquid substance that is about to get wet and spread from the predetermined region (contamination allowable region) to the region adjacent thereto (low reflection region). That is, it may be provided at least a part of the boundary between the pollution tolerance region and the low reflection region, and it is not necessary to completely surround the low reflection region.
Further, the boundary of the region (position of the weir portion) may be arbitrarily set according to the form of the final product. For example, in the case of an image display device, the boundary between the contamination tolerance region and the low reflection region is set to a portion covered by a light-shielding portion (bezel or the like) on the periphery of the image display portion of the image display device.

The height of the weir is higher than the height of the convex part as a whole. If the height of the weir portion is higher than the height of the convex portion, it is possible to block the spread of the liquid substance that tends to get wet and spread outside the predetermined region. The height of the weir portion is preferably 0.1 μm or more, more preferably 0.5 μm or more.
The height of the weir portion is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 25 μm or less, from the viewpoint of easily forming the weir portion.
The height of the weir portion is the vertical distance h between the topmost portion of the weir portion and the bottommost portion of the recess of the portion where the weir portion is formed.

The width of the weir portion is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. If the width of the weir is 10 mm or less, the weir itself does not get in the way. In addition, it is easy to form a weir.
The width of the weir portion is preferably 0.1 mm or more from the viewpoint that it can sufficiently block the spread of the liquid substance that is about to get wet and spread outside the predetermined region and that the weir portion is easily formed. 0.5 mm or more is more preferable.

The weir portion preferably contains a resin from the viewpoint that the weir portion can be easily formed and the shape of the weir portion can be easily maintained. As the resin, acrylic resin (methyl methacrylate (co) polymer, etc.), polycarbonate, styrene resin (styrene (co) polymer, methyl methacrylate-styrene copolymer, etc.), cellulose resin (cellulose diacetate, cellulose, etc.) Triacetate, cellulose acetate butyrate, etc.), polyester, polyamide, polyimide, polyether sulphon, polysulphon, polyolefin (polypropylene, polymethylpentene, etc.), alicyclic polyolefin, vinyl chloride resin (polyvinyl chloride, etc.), polyvinyl acetal , Polyether ketone, polyurethane and the like. As the resin, one type may be used alone, or two or more types may be used in combination.

The melting point of the resin contained in the weir portion is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. When the melting point of the resin contained in the weir portion is 50 ° C. or higher, it is possible to prevent the resin itself from getting wet and spreading from the weir portion. When the weir portion is constructed by using an amorphous polymer material, such a material does not have a clear melting point. In this case, the glass transition temperature of the resin contained in the weir portion is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. When the glass transition temperature of the resin contained in the weir portion is 50 ° C. or higher, it is possible to prevent the resin itself from getting wet and spreading from the weir portion. When the dam is made of a material having both a glass transition temperature and a melting point, the higher of the melting point and the glass transition temperature is preferably 50 ° C. or higher, and more preferably 60 ° C. or higher. It is preferably 70 ° C. or higher, and more preferably 70 ° C. or higher.

The weir portion preferably further contains a dye or pigment from the viewpoint that the boundary of the region becomes easily visible due to the coloring of the weir portion. Examples of the dye include natural dyes, synthetic dyes, fluorescent dyes and the like, and specific examples thereof include anionic azo dyes and azo metal complex salts. Examples of the pigment include inorganic pigments and organic pigments, and specific examples thereof include titanium oxide, azo pigments, phthalocyanine pigments and carbon black.

All the components contained in the weir portion preferably have a melting point or a glass transition temperature of 50 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. When all the components contained in the weir portion have a melting point or a glass transition temperature of 50 ° C. or higher, the shape of the weir portion can be easily maintained and the components can be prevented from spreading from the weir portion.

The weir portion may be separately formed on the fine concavo-convex structure of the cured resin layer as shown in (α) illustrated example; (β) the shape of the weir portion is a part of the cured resin layer or the base material. It may be molded into.
As for the weir part, in the case of the weir part of (β), a special mold is required to form the weir part, the pattern of the weir part is difficult to change, the versatility is low, and the weir of (α) In the case of a portion, the weir portion of (α) is preferable from the viewpoint that a weir portion having an arbitrary pattern can be easily formed and has high versatility.

As the weir portion of (α), a coating film formed on a fine concavo-convex structure is preferable because a weir portion having an arbitrary pattern can be easily formed.
For the weir portion made of the coating film, for example, an arbitrary pattern composed of the weir portion forming composition is formed on the fine concavo-convex structure of the cured resin layer by using a known drawing means, and the weir portion forming composition is solidified or cured. It is formed by doing. At this time, in the weir portion made of the coating film, the solidified or cured product of the weir portion forming composition is filled in the concave portion of the fine concavo-convex structure of the cured resin layer, and is raised higher than the convex portion of the fine concavo-convex structure. , It is formed on the surface of the fine concavo-convex structure of the cured resin layer without gaps and higher than the convex portion.

The weir portion forming composition is obtained by dissolving or dispersing a resin, a dye or pigment as needed, and other additives or the like as needed in a solvent. The weir portion forming composition may contain a material that vaporizes and evaporates after forming an arbitrary pattern. Examples of the weir portion forming composition include commercially available oil-based inks for oil-based pens, commercially available inks for printers, known ultraviolet curable inks, and known electron beam curable inks.
Examples of the drawing means include an oil-based pen, a stamper, and a printer.

(Use)
Applications of the fine concavo-convex structure of the present invention include transparent protective members (covers for instruments, front plates for lighting, front plates for picture frames), transparent cases (cases for works of art, showcases for products), and optical members (glasses). , Mirrors, optical lenses, etc.), windows of transportation equipment (automobiles, trains, ships, etc.), building materials (windows, walls, roofs, etc.), image display devices (liquid crystal displays, plasma displays, electroluminescence displays, cathode tube displays, etc.) Examples include members (image display panel, touch panel, etc.) constituting the device (device, etc.).

(Other forms)
The fine concavo-convex structure according to the first aspect of the present invention includes a specific fine concavo-convex structure composed of a plurality of convex portions and recesses formed between the plurality of convex portions on at least one outermost surface, and a plurality of the above-mentioned surfaces. It suffices as long as it has a specific weir portion extending along the surface so as to be divided into the regions of the above, and is not limited to the illustrated example.

For example, the fine concavo-convex structure of the first aspect may be composed of only a cured resin layer, or the fine concavo-convex structure may be directly formed on the surface of the base material. However, from the viewpoint that the fine concavo-convex structure can be efficiently formed, it is preferable that the fine concavo-convex structure is formed on the cured resin layer as shown in the illustrated example.
The fine concavo-convex structure of the first aspect may have a layer other than the base material and the cured resin layer between the base material and the cured resin layer; on the back surface side of the base material, the base material. And may have other layers and other members other than the cured resin layer.

(Mechanism of action)
The fine concavo-convex structure according to the first aspect of the present invention described above has a weir portion extending along the surface so as to divide the surface having a specific fine concavo-convex structure into a plurality of regions, and has a weir portion. Since the weir portion is made higher than the convex portion as a whole, it is difficult for the liquid substance adhering to the surface having the fine concavo-convex structure to wet and spread outside the predetermined region. The reason for this is as follows.
The fine concavo-convex structure 10 of the first aspect of the present invention shown in FIG. 1 has a plurality of microconcavo-convex structures 10 having an average height equal to or less than the wavelength of visible light and an average interval between adjacent convex portions 14 being equal to or less than the wavelength of visible light. It has a fine concavo-convex structure 18 including a convex portion 14 and a concave portion 16 formed between the plurality of convex portions 14. In the fine concavo-convex structure 18, the low molecular weight component 32 contained in the liquid substance 30 adhering to the surface region II having the fine concavo-convex structure 18 as shown in FIGS. 2 and 3 is shown in FIGS. 4 and 5. As described above, it is easy to get wet and spread along the fine uneven structure 18. In the fine concavo-convex structure 10 of the first aspect of the present invention, the liquid substance 30 that is about to spread by the dam portion 22 higher than the convex portion 14 provided at the boundary between the region I and the region II. Since the low molecular weight component 32 of the above is blocked, the low molecular weight component 32 of the liquid substance 30 adhering to the surface having the fine concavo-convex structure 18 is unlikely to wet and spread outside the region II.
Here, as the liquid substance, fats and oils contained in fingerprints and the like (free fatty acids such as oleic acid, myristic acid, squalene and cholesterol), low molecular weight components contained in adhesives and silicone oils (low molecular weight siloxanes and the like) and the like. Can be mentioned.

(Second aspect)
The fine concavo-convex structure according to the second aspect of the present invention has a fine concavo-convex structure composed of a plurality of convex portions and recesses formed between the plurality of convex portions on at least one surface, and the surface is covered with the fine concavo-convex structure. The groove portion that divides the surface into a plurality of regions is formed so as to extend in the surface direction.

FIG. 6 is a cross-sectional view showing an example of a fine concavo-convex structure according to a second aspect of the present invention.
The fine concavo-convex structure 10 includes a base material 12; a fine concavo-convex structure 18 formed on the surface of the base material 12 and composed of a plurality of convex portions 14 and a concave portion 16 formed between the plurality of convex portions 14. It has a cured resin layer 20 on the surface.
On the surface of the fine concavo-convex structure 10 on the side of the fine concavo-convex structure 18, a groove 24 is formed which divides the cured resin layer 20 so as to divide the surface of the cured resin layer 20 into regions I and II.
The fine concavo-convex structure of the second aspect of FIG. 6 has the same configuration as the fine concavo-convex structure of the first aspect of FIG. 1 except that the weir portion 22 is replaced with the groove portion 24.
Hereinafter, those having the same configuration as that of the first aspect are designated by the same reference numerals and detailed description thereof will be omitted.

(Groove)
The groove extends in the plane direction so as to divide at least one surface of the fine concavo-convex structure into a plurality of regions.
Regions I and II of the illustrated example divided by the groove are, for example, a low reflection region and a contamination tolerance region, respectively. The low reflection area and the pollution tolerance area are the same as the low reflection area and the pollution tolerance area in the first aspect.

The groove may be provided so as to block the invasion path of the liquid substance that is about to get wet and spread from the predetermined region (contamination allowable region) to the region adjacent to the groove (contamination allowable region). That is, it may be provided at least a part of the boundary between the pollution tolerance region and the low reflection region, and it is not necessary to completely surround the low reflection region.
Further, the boundary of the region (position of the groove) may be arbitrarily set according to the form of the final product. For example, in the case of an image display device, the boundary between the contamination tolerance region and the low reflection region is set to a portion covered by a light-shielding portion (bezel or the like) on the periphery of the image display portion of the image display device.

It is preferable that the bottom of the groove is at the same depth as the bottom of the recess having a fine concavo-convex structure, or deeper than the bottom of the recess. Therefore, as shown in FIG. 6, the groove portion 24 may be formed by removing the cured resin layer 20, and as shown in FIG. 7, a part of the cured resin layer 20 and the base material 12 may be formed. It may be formed by removing it, or as shown in FIG. 8, it may be formed by removing only the convex portion 14. If the bottom of the groove is at the same depth as the bottom of the recess, or deeper than the bottom of the recess, it can sufficiently block the spread of the liquid substance that is trying to get wet and spread outside the predetermined area. can.
The depth of the groove is preferably 0 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more.
The depth of the groove is the vertical distance h between the bottom of the groove and the bottom of the recess in the vicinity where the groove is formed.

If a plurality of convex portions having an average distance between adjacent convex portions equal to or less than the wavelength of visible light are formed in the groove portion, a liquid substance may be spread and spread along the convex portions in the groove portion. .. Therefore, it is preferable that the groove portion does not have a convex portion.

The width of the groove is 0.1 mm or more, preferably 0.3 mm or more. The width of the groove is preferably 1 mm or less, more preferably 0.8 mm or less, still more preferably 0.5 mm or less.
When the width of the groove portion is 0.1 mm or more, it is possible to block the spread of the liquid substance that tends to get wet and spread outside the predetermined region. In addition, it is easy to form a groove. If the width of the groove is 1 mm or less, the groove itself does not get in the way. In addition, it is easy to form a groove.

The groove can be formed by manufacturing a fine concavo-convex structure without a groove and then scraping off the cured resin layer at an arbitrary position, compressing the cured resin layer, or heating the cured resin layer. From the viewpoint of ease of forming the groove, a method of scraping off the cured resin layer with a cutter or the like is preferable. As the cutter for forming the groove, a general stationery cutter or a work cutter can be used. The types of cutters include, for example, P-cutter S type (manufactured by Orfa, blade thickness: 0.55 mm), P-cutter L-type (manufactured by Orfa, blade thickness: 0.6 mm), work design knife (NT cutter). Manufactured, blade thickness: 0.3 mm) and the like.

(Use)
Examples of the use of the fine concavo-convex structure according to the second aspect of the present invention include the same uses as the fine concavo-convex structure according to the first aspect of the present invention.

(Other forms)
The fine concavo-convex structure according to the second aspect of the present invention has a specific fine concavo-convex structure composed of a plurality of convex portions and recesses formed between the plurality of convex portions on at least one outermost surface, and the surface thereof. In addition, the surface may be divided into a plurality of regions as long as a groove having a width of 0.1 mm or more is formed, and the present invention is not limited to the illustrated example.

For example, the fine concavo-convex structure of the second aspect may be composed of only a cured resin layer, or the fine concavo-convex structure may be directly formed on the surface of the base material. However, from the viewpoint that the fine concavo-convex structure can be efficiently formed, it is preferable that the fine concavo-convex structure is formed on the cured resin layer as shown in the illustrated example.
The fine concavo-convex structure of the second aspect may have a layer other than the base material and the cured resin layer between the base material and the cured resin layer; on the back surface side of the base material, the base material. And may have other layers and other members other than the cured resin layer.

(Mechanism of action)
In the fine concavo-convex structure of the second aspect of the present invention described above, the width extending along the surface direction so as to divide the surface having a specific fine concavo-convex structure into a plurality of regions is 0.1 mm or more. Since the groove is formed, it is difficult for the liquid substance adhering to the surface having the fine concavo-convex structure to wet and spread outside the predetermined region. The reason for this is as follows.
In the fine concavo-convex structure 10 of the second aspect of the present invention shown in FIGS. 6 to 8, the average height is equal to or less than the wavelength of visible light, and the average distance between adjacent convex portions 14 is equal to or less than the wavelength of visible light. It has a fine concavo-convex structure 18 including a plurality of convex portions 14 and concave portions 16 formed between the plurality of convex portions 14. In the fine concavo-convex structure 18, the low molecular weight component 32 contained in the liquid substance 30 adhering to the surface region II having the fine concavo-convex structure 18 as shown in FIG. 9 is the fine concavo-convex structure 18 as shown in FIG. It is easy to get wet and spread along. In the fine concavo-convex structure 10 of the second aspect of the present invention, the liquid substance 30 that is about to get wet and spread by the groove 24 having a width of 0.1 mm or more formed at the boundary between the region I and the region II. Since the low molecular weight component 32 of the above is blocked, the low molecular weight component 32 of the liquid substance 30 adhering to the surface having the fine concavo-convex structure 18 is unlikely to wet and spread outside the region II.
Here, examples of the liquid substance include the same substances as those exemplified in the first aspect.

<Joined body>
The bonded body of the present invention has the fine concavo-convex structure of the present invention, another member, and an adhesive for joining the fine concavo-convex structure and the other member.

(Fine uneven structure)
When the joint is an image display device, examples of the fine concavo-convex structure include a protective plate, a touch panel, an image display panel, and the like, and the light (image) from the protective plate or the liquid crystal display panel at the interface between the touch panel and air. A protective plate or a touch panel is preferable from the viewpoint of preventing reflection and improving the visibility of the image display device.

(Other members)
The other member may be a member having no fine concavo-convex structure on the surface, or may be a fine concavo-convex structure having a fine concavo-convex structure on the surface. In the case of a fine concavo-convex structure, it is preferable that the fine concavo-convex structure of the present invention has the weir portion or the groove portion is formed.

When the joint body is an image display device and the other member is a member having no fine uneven structure on the surface, examples of the other member include a protective plate, a touch panel, an image display panel, and the like, and the liquid crystal display panel. An image display panel is preferable because the reflection of light at the interface with air does not significantly affect the visibility of the image display device.

(Adhesive)
The pressure-sensitive adhesive is provided in a part of a plurality of regions on the surface of the fine concavo-convex structure of the present invention, and is not provided in the other regions.
Examples of the region where the pressure-sensitive adhesive is provided include the above-mentioned region II (contamination-tolerant region), and examples of the region where the pressure-sensitive adhesive is not provided include the above-mentioned region I (low reflection region).

Examples of the pressure-sensitive adhesive include commercially available pressure-sensitive adhesives.
As the adhesive, silicone adhesive, silylated urethane resin adhesive, urethane resin adhesive, epoxy adhesive, polyolefin adhesive, chlorinated polyolefin adhesive, acrylic adhesive, cyanoacrylate adhesive Examples thereof include agents, rubber-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyimide-based pressure-sensitive adhesives, and phenol-based pressure-sensitive adhesives.
As the pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive containing organopolysiloxane is preferable, and a silicone-based pressure-sensitive adhesive containing dimethylpolysiloxane is more preferable, from the viewpoints of electrical insulation, heat resistance, and cold resistance.
The form of the pressure-sensitive adhesive is not limited to liquid, and may be a hot-melt pressure-sensitive adhesive, double-sided pressure-sensitive adhesive tape, or the like.

(Example of Embodiment of Joined Body)
FIG. 11 is a cross-sectional view showing an example of an image display device which is a joined body of the present invention.
The image display device 1 is a touch panel 11 (fine concavo-convex structure) arranged to face the liquid crystal display panel 40 (other members) as the main body of the image display device; on the side where the image of the liquid crystal display panel 40 is displayed with a gap. ) And; a joining member 34 (adhesive) for joining the liquid crystal display panel 40 and the touch panel 11, and a backlight 80 of the liquid crystal display panel 40 arranged on the side opposite to the side on which the touch panel 11 is arranged. ..

The liquid crystal display panel 40 and the touch panel 11 are joined so that the low-reflection film 70 of the touch panel 11 faces the liquid crystal display panel 40 through a gap.
By providing the low-reflection film 70 on the surface of the touch panel 11 facing the liquid crystal display panel 40, reflection of light (image) from the liquid crystal display panel 40 at the interface between the touch panel 11 and air is prevented, and the image display device 1 Improve visibility.

(Liquid crystal display panel)
The liquid crystal display panel 40 includes a first glass substrate 41 on which a color filter (not shown), a transparent electrode (not shown), an alignment film (not shown), and the like are formed; a transparent electrode (not shown), an alignment film (not shown). The second glass substrate 42 on which (omitted) and the like are formed; the liquid crystal layer 43 sandwiched between the first glass substrate 41 and the second glass substrate 42; the first glass on the opposite side of the liquid crystal layer 43. A first polarizing film 44 bonded to the surface of the substrate 41 via an adhesive layer (not shown); an adhesive layer (not shown) on the surface of a second glass substrate 42 opposite to the liquid crystal layer 43. It has a second polarizing film 45 bonded via the glass.
Examples of the adhesive for the adhesive layer include known transparent adhesives and transparent adhesives used for optical applications.

(Touch panel)
The touch panel 11 is a capacitance type touch panel that detects the position of a conductor (finger, metal, etc.) approaching or in contact with the input surface S as a change in capacitance.
The touch panel 11 has a cover glass 50 having an input surface S; an electrode substrate 60 bonded to the opposite side of the input surface S with the cover glass 50 sandwiched therein via an adhesive layer 54; and a transparent electrode of the electrode substrate 60. With a detection unit (not shown) that is electrically connected and detects a change in capacitance when a conductor approaches or comes into contact with the input surface S; it is bonded to the surface of the electrode substrate 60 via an adhesive layer 56. It has a low-reflection film 70 and the like.

Electrode substrate:
The electrode substrate 60 includes a substrate main body 62; a striped first transparent electrode 64 formed on one surface of the substrate main body 62 and composed of a plurality of electrode patterns extending in the first direction; and the other of the substrate main body 62. It has a striped second transparent electrode 66 formed on the surface of the surface and composed of a plurality of electrode patterns extending in a second direction intersecting the first direction.

The substrate body 62 is made of a transparent plate, film, sheet or the like. Examples of the material of the substrate body 62 include glass, acrylic resin, polycarbonate, styrene resin, polyester, cellulose resin, polyolefin, alicyclic polyolefin and the like.

The first transparent electrode 64 and the second transparent electrode 66 are thin films capable of transmitting light and having conductivity.
Examples of the first transparent electrode 64 and the second transparent electrode 66 include a conductive metal oxide thin film and the like. Examples of the conductive metal oxide include tin-doped indium oxide (hereinafter referred to as ITO) and the like.

Detection unit:
The detection unit detects, for example, a change in capacitance between the conductor and the electrode when the conductor approaches or comes into contact with the input surface while applying a predetermined voltage to the transparent electrode, and at any location. It detects whether the conductors are approaching or in contact with each other.

Low reflection film:
The low-reflection film 70 has a surface of a fine concavo-convex structure 18 composed of a base material 12; a plurality of convex portions 14 formed on the surface of the base material 12 and a concave portion 16 formed between the plurality of convex portions 14. Along the surface of the cured resin layer 20 so as to divide the surface of the cured resin layer 20 formed on the fine concavo-convex structure 18 of the cured resin layer 20 into regions I and II. It has a weir portion 22 extending in a frame shape.

The area I is a low reflection area, that is, an image display unit of the image display device 1.
Region II is a contamination-tolerant region, that is, a portion covered by a light-shielding portion (bezel) (not shown) on the periphery of the image display portion of the image display device 1.
The weir portion 22 is provided in a portion covered by the light-shielding portion of the image display device 1.

Adhesive layer:
Examples of the adhesive of the adhesive layer 54 and the adhesive layer 56 include known transparent adhesives and transparent adhesives used for optical applications.

(Joining member)
The joining member 34 joins the first polarizing film 44 side of the liquid crystal display panel 40 and the low reflection film 70 side of the touch panel 11.
The joining member 34 is provided in a frame shape in a region II (contamination allowable region) of a plurality of regions on the surface of the touch panel 11 having a fine concavo-convex structure 18, and is provided in a region I (low reflection region). Not.
The bonding member 34 may be made of only an adhesive, or may be a double-sided adhesive tape in which the adhesive is arranged on both sides of the tape base material.

(Other forms)
The bonded body of the present invention has the fine concavo-convex structure of the present invention, another member, and an adhesive for joining the fine concavo-convex structure and the other member, and the adhesive is the surface of the fine concavo-convex structure. It suffices as long as it is provided in a part of a plurality of regions of the above, and is not limited to the illustrated example.

For example, the image display device may be provided with a protective plate instead of the touch panel.
The image display panel is not limited to the liquid crystal display panel, and may be a plasma display panel, an organic EL display panel, a CRT, or the like.
The touch panel is not limited to the capacitance type touch panel, and may be a resistive touch panel or the like.
The fine concavo-convex structure is not limited to being formed only on the surface of the touch panel, and may be formed on the surface of the image display panel, or may be formed on both the surface of the touch panel and the surface of the image display panel.
Further, the joint is not limited to the image display device, but is an instrument, a lighting, a frame, various cases, eyeglasses, a mirror, an optical device, a window, a building member, etc. provided with the fine concavo-convex structure of the present invention. May be good.
Further, the bonded body of the present invention is not limited to the one in which the fine concavo-convex structure and other members are directly bonded by an adhesive. For example, even when the fine concavo-convex structure is in contact with an adhesive that adheres and fixes other members to each other or an adhesive provided to protect a part of the surface of the other member, the adhesive. Some of the components contained in the above may wet and spread on the surface of the fine concavo-convex structure. Even in such a case, by providing a weir portion or a groove portion so as to divide the portion in contact with the adhesive and the other portion, some components contained in the adhesive are wetted and spread outside the predetermined region. Can be suppressed.

(Mechanism of action)
In the bonded body of the present invention described above, a weir portion extending along the surface or a groove portion is formed on the surface of the fine concavo-convex structure so as to divide the surface having the fine concavo-convex structure into a plurality of regions. And since the adhesive is provided in a part of the plurality of regions, the adhesive for joining the fine concavo-convex structure and the other member is unlikely to get wet and spread outside the predetermined region.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

(Average spacing and average depth of mold pores)
Platinum was deposited on a part of the longitudinal section of the mold made of anodized porous alumina for 1 minute, observed with a field emission scanning electron microscope (JSM-7400F, manufactured by JEOL Ltd.) at an acceleration voltage of 3.00 kV, and adjacent to each other. The spacing between the pores and the depth of the pores were measured. 10 points were measured for each, and the average value was used as the measured value.

(Average spacing and average height of convex parts of fine concavo-convex structure)
Platinum was deposited on the vertical cross section of the fine concavo-convex structure for 10 minutes, and the distance between adjacent convex portions and the height of the convex portions were measured under the same equipment and conditions as in the case of molding. 10 points were measured for each, and the average value was used as the measured value.

(Spreading of oleic acid outside Region II)
One drop of oleic acid was added dropwise to region II of the surface of the fine concavo-convex structure having the fine concavo-convex structure. After 2 hours, the observation was carried out under a fluorescent lamp (1000 lux), and the presence or absence of the spread of oleic acid from the region II to the region I was visually confirmed.

(Making a mold)
According to the process shown in FIG. 12, a mold was prepared as follows.
First, an aluminum plate 100 having a purity of 99.99% was polished with a feather cloth, and then electropolished in a perchloric acid / ethanol mixed solution (1/4 volume ratio) to make a mirror surface.

Step (a):
The mirrored aluminum plate 100 was anodized in a 0.3 M oxalic acid aqueous solution under the conditions of a direct current of 40 V and a temperature of 16 ° C. for 30 minutes to form an oxide film 102 having pores 101.

Step (b):
The aluminum plate 100 on which the oxide film 102 is formed is immersed in a 6 mass% phosphoric acid / 1.8 mass% chromic acid mixed aqueous solution for 6 hours to remove the oxide film 102, and periodic depressions corresponding to the pores 101 are formed. 103 was exposed.

Step (c):
The aluminum plate 100 with the recess 103 exposed was anodized for 30 seconds in a 0.3 M aqueous oxalic acid solution under the conditions of a direct current of 40 V and a temperature of 16 ° C. to form an oxide film 104 having pores 105.

Step (d):
The aluminum plate 100 on which the oxide film 104 was formed was immersed in 5% by mass phosphoric acid at 32 ° C. for 8 minutes to expand the diameter of the pores 105.

Step (e):
The diameter-enlarged aluminum plate 100 is anodized for 30 seconds in a 0.3 M oxalic acid aqueous solution under the conditions of a direct current of 40 V and a temperature of 16 ° C., and an oxide film 104 in which small-diameter pores extend below the pores 105. Was formed.

Step (f):
Step (d) and step (e) were repeated a total of four times, and finally step (d) was performed to obtain anodized porous alumina having substantially conical pores 105 with an average interval of 100 nm and an average depth of 180 nm. .. The obtained anodized porous alumina was washed with deionized water, the water on the surface was removed by air blow, and the surface antifouling coating agent (Optool (registered trademark) DSX manufactured by Daikin Industries, Ltd.) was added with a solid content of 0.1 mass. The mixture was immersed in a solution diluted with a diluent (HD-ZV, manufactured by Harves) for 10 minutes and air-dried for 20 hours to obtain a mold 106.

(Preparation of active energy ray-curable composition)
20 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, 19 parts by mass of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate, 40 parts by mass of polyethylene glycol diacrylate, and 20 parts by dimethylacrylamide. By mixing parts by mass, 1 part by mass of the first photopolymerization initiator (BASF, Irgacure (registered trademark) 184), the second photopolymerization initiator (BASF, Irgacure (registered trademark) 819). 0.5 part by mass and 0.1 part by mass of an internal mold initiator (TDP-2, manufactured by Nikko Chemicals Co., Ltd.) were added and mixed to prepare an active energy ray-curable composition.

(Example 1)
The active energy ray-curable composition was poured into the surface on which the pores of the mold were formed, and a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., A4300) having a thickness of 75 μm was spread and coated on the active energy ray-curable composition. The active energy ray-curable composition was cured by irradiating ultraviolet rays ^{from the film side with an energy of 1000 mJ / cm 2} using a fusion UV irradiation device. The mold was peeled off from the film to obtain a fine concavo-convex structure.
The pores of the mold are transferred to the surface of the fine concavo-convex structure, and as shown in FIG. 1, a substantially conical shape in which the average spacing of adjacent convex portions is 100 nm and the average height of the convex portions is 180 nm. A fine concavo-convex structure composed of a plurality of convex portions and concave portions between the convex portions was formed.
Acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., Acrypet (registered trademark), glass transition temperature: 100 ° C.) was dissolved in acetone so as to have a glass transition temperature of 10% by mass to obtain a weir portion forming composition.
A straight line is drawn on the surface of the fine concavo-convex structure having a fine concavo-convex structure using the weir portion forming composition to form a weir portion composed of a coating film (thickness: about 15 μm) of the weir portion forming composition. Was divided into a region I and a region II by a weir. The spread of oleic acid outside Region II was evaluated. The results are shown in Table 1.

(Comparative Example 1)
A fine concavo-convex structure was obtained in the same manner as in Example 1.
One drop of oleic acid was added dropwise to the region corresponding to region II without forming a weir. After 2 hours, it was visually confirmed whether or not the oleic acid was spread from the region corresponding to the region II to the region corresponding to the region I. The results are shown in Table 1.

(Comparative Example 2)
A fine concavo-convex structure was obtained in the same manner as in Example 1.
Polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., PEG-600, melting point: 20 ° C.) was dissolved in acetone so as to have a melting point of 10% by mass to obtain a weir forming composition.
A straight line was drawn using the weir portion forming composition on the surface of the fine concavo-convex structure having the fine concavo-convex structure to form a weir portion composed of a coating film of the weir portion forming composition. However, the weir could not be formed, and the weir itself got wet and spread. One drop of oleic acid was added dropwise to the region corresponding to region II. After 2 hours, it was visually confirmed whether or not the oleic acid was spread from the region corresponding to the region II to the region corresponding to the region I. The results are shown in Table 1.

(Example 2)
A fine concavo-convex structure was obtained in the same manner as in Example 1.
A groove was formed on the surface of the fine concavo-convex structure having a fine concavo-convex structure using a P cutter (manufactured by OLFA, blade thickness: 0.6 mm), and the surface was divided into a region I and a region II by the groove. The width of the formed groove was 0.145 mm. Further, the vertical distance between the top of the convex portion adjacent to the groove and the bottom of the groove was 0.12 mm, which was sufficiently deeper than the average height of the convex portion of 180 nm (that is, the depth of the groove was high). , 0.102 mm from the bottom of the recess). One drop of oleic acid was added dropwise to the region corresponding to region II. After 2 hours, it was visually confirmed whether or not the oleic acid was spread from the region corresponding to the region II to the region corresponding to the region I. The results are shown in Table 2.

The fine concavo-convex structure of the present invention is useful as a transparent protective member, a transparent case, an optical member, a window of a transportation device, a building member, a member constituting an image display device, and the like.

1 Image display device 10 Fine concavo-convex structure 11 Touch panel 12 Base material 14 Convex part 16 Concave 18 Fine concavo-convex structure 20 Hardened resin layer 22 Weir part 24 Groove part 30 Liquid substance 32 Low molecular weight component 34 Joining member 40 Liquid crystal display panel 41 1 glass substrate 42 second glass substrate 43 liquid crystal layer 44 first polarizing film 45 second polarizing film 50 cover glass 54 adhesive layer 56 adhesive layer 60 electrode substrate 62 substrate body 64 first transparent electrode 66th 2 Transparent electrode 70 Low reflection film 80 Backlight 100 Aluminum plate 101 Pore 102 Oxidized film 103 Depression 104 Oxidized film 105 Pore 106 Mold

Claims (12)

At least one fine concavo-convex structure including a plurality of convex portions having an average height of 400 nm or less and an average spacing between adjacent convex portions of 400 nm or less and a concave portion formed between the plurality of convex portions. A fine concavo-convex structure for an image display device on the surface.
The surface is further provided with a weir portion that is higher than the convex portion and divides the surface into a plurality of regions, and one of the regions divided by the weir portion is a contamination tolerance region.
A fine concavo-convex structure in which the weir portion, which is the boundary of the contamination tolerance region, is covered with a light-shielding portion on the periphery of the image display portion of the image display device. The fine concavo-convex structure according to claim 1, wherein the weir portion is a coating film formed on the fine concavo-convex structure. The weir portion contains resin and
The fine concavo-convex structure according to claim 1 or 2, wherein the higher of the melting point and the glass transition temperature of the resin is 50 ° C. or higher. The fine concavo-convex structure according to claim 3, wherein the weir portion further contains a dye or a pigment. The fine concavo-convex structure according to any one of claims 1 to 4, wherein the width of the weir portion is 10 mm or less. At least one fine concavo-convex structure including a plurality of convex portions having an average height of 400 nm or less and an average spacing between adjacent convex portions of 400 nm or less and a concave portion formed between the plurality of convex portions. A fine concavo-convex structure for an image display device on the surface.
A groove having a width of 0.1 mm or more and 10 mm or less is formed on the surface, and one of the regions divided by the groove is a contamination tolerance region.
A fine concavo-convex structure in which the groove portion, which is the boundary of the contamination tolerance region, is covered with a light-shielding portion on the periphery of the image display portion of the image display device. The fine concavo-convex structure according to claim 6, wherein the bottom of the groove is at the same depth as the bottom of the recess, or is deeper than the bottom of the recess. The fine concavo-convex structure according to claim 6 or 7, wherein the convex portion does not exist in the groove portion. The fine concavo-convex structure according to any one of claims 1 to 8.
With other members
It has an adhesive for joining the fine concavo-convex structure and the other member.
A bonded body in which the pressure-sensitive adhesive is provided in a part of the plurality of regions on the surface of the fine concavo-convex structure. The fine concavo-convex structure according to any one of claims 1 to 8.
With other members
It has an adhesive provided on the other member and has.
A bonded body in which the pressure-sensitive adhesive is in contact with a part of the plurality of regions on the surface of the fine concavo-convex structure. The joint is an image display device having an image display panel, a protective plate, and an adhesive for joining the image display panel and the protective plate.
The image display panel is the other member.
The joint according to claim 9 , wherein the protective plate is the fine concavo-convex structure. The joint is an image display device having an image display panel, a touch panel, and an adhesive for joining the image display panel and the touch panel.
The image display panel is the other member.
The joint according to claim 9 , wherein the touch panel is the fine concavo-convex structure.

Images