JP2011167924A - Material with low reflection conductive surface and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material with a low reflection conductive surface which can be easily formed to a desired surface shape, the conductive surface being given desired reflection restraining characteristics and also, being typical as a low reflection conductive surface allowing light transmission, as well as a method for manufacturing the material. <P>SOLUTION: This material with a low reflection conductive surface is characterized in that a transparent conductive thin film composed of a transparent conductive material is formed on the surface with an uneven pattern, having reflection restraining characteristics, which is formed using a mold. Also, the method for manufacturing this material is provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a material having a low reflective conductive surface having antireflection properties and surface conductivity, and a method for producing the same.

  Various anti-reflection coatings with anti-reflective function provided by the fine concavo-convex structure on the surface are known. For example, anodized porous alumina is used to form a fine concavo-convex pattern corresponding to the shape of the pores on the surface of the polymer material. A method for manufacturing an antireflection film is known (Patent Document 1). Anodized porous alumina can be controlled with precision and high regularity, with a fine uneven structure formed on the surface, by appropriately setting the conditions in a simple process. Taking advantage of this, various developments are being made.

  On the other hand, the conductive surface having an antireflection function can be expected to be applied to various fields including substrate materials for organic solar cells. In particular, light-transmissive plates and sheets coated with conductive layers that function as transparent conductive films such as ITO, zinc oxide, tin oxide, and other oxide semiconductors, organic conductive polymers, and metal thin films are used for liquid crystal displays, solar It is used in various fields such as batteries and touch panels. Since the substrate provided with these conductive films is used as a transparent electrode, the light transmission characteristics as well as the conductivity are important. Currently, transparent electrodes used for various applications are manufactured by forming an oxide semiconductor on the surface of a smooth substrate by various methods such as sputtering, vacuum deposition, and sol-gel.

  Since an oxide semiconductor that functions as a transparent conductive film generally exhibits a high refractive index, surface reflection increases in the substrate on which these thin films are formed, resulting in a decrease in light transmittance. Also, in applications such as a touch panel, when the surface reflection of the transparent electrode to be used is large, difficulty in viewing due to reflection on the panel surface outdoors or under illumination is also a problem. In order to improve these problems, an antireflection structure using a multilayer film has been studied. However, in forming a multilayer film, in addition to the process becoming complicated, it is necessary to control the thickness of the transparent conductive film layer in order to obtain an antireflection effect using optical interference. There is a problem that the thickness that can be formed is limited because the film cannot be obtained. In addition, the antireflection film based on the multilayer film has an effect of suppressing the reflection of light of a specific wavelength, but has a problem that it is difficult to prevent reflection in a wide wavelength region.

  As a technique related to the present invention, a photoelectric conversion element in which a moth-eye structure is formed on the surface of a flexible transparent substrate and a transparent electrode and a semiconductor tank are laminated thereon is known (Patent Document 2). The structure is formed by applying a resist on a substrate, forming a concavo-convex pattern with an electron beam or ultraviolet light, laminating Ni on the concavo-convex pattern by electroforming, producing a master, and on the concavo-convex formation surface of the master In addition, a method for forming a moth-eye structure by pouring an ultraviolet curable resin and irradiating and removing ultraviolet rays is used. In addition to the many processes, the process is extremely complicated. There is a problem that it is not easy compared with the case of anodized porous alumina.

JP 2007-86283 A Japanese Patent Laid-Open No. 2008-34687

  Accordingly, an object of the present invention is to solve the above-mentioned problems in the prior art, easily form a desired surface form, have a desired antireflection characteristic, and further have a low reflection conductivity capable of transmitting light. The object is to provide a technique relating to a material having a surface and a method for producing the material.

  In order to solve the above problems, a material having a low reflective conductive surface according to the present invention is formed from a transparent conductive material on a surface having a concavo-convex pattern having an antireflection characteristic, formed using a mold. A transparent conductive thin film is formed (for example, coated). As a material for forming this thin film, for example, a transparent conductive film or a conductive polymer can be used. Various materials such as a resin material and a glass material can be used as the surface forming material having the uneven pattern, and for example, any of polyethylene terephthalate, polyethylene naphthalate, acrylic resin, and polycarbonate can be selected.

  That is, according to the present invention, a fine concavo-convex pattern formed by a simple process of transferring a concavo-convex structure of a mold having a predetermined concavo-convex structure to the surface of a material is controlled easily, accurately and with high regularity. Utilizing the advantage of being possible, the first attempt was made to combine the antireflection characteristics of this fine concavo-convex pattern with the transparent conductive thin film formed on the surface having the concavo-convex pattern, and it was completed. That is, in the material according to the present invention, a desired antireflection function is imparted by the concavo-convex pattern on the surface of the substrate mainly formed by transferring the concavo-convex structure of the mold, and the transparent formed on the surface The conductive thin film provides a surface conductive function while maintaining the antireflective function, and realizes a material having a low reflective conductive surface having both surface conductivity and antireflective characteristics by a simple manufacturing process. .

  In the material having a low reflective conductive surface according to the present invention, the transparent conductive thin film can be provided alone on the surface having the concavo-convex pattern or can be provided together with other thin films. For example, the transparent conductive thin film can be directly formed on the uneven pattern formed on the surface. In this case, if the entire material having a low reflective conductive surface is configured to transmit light, light can be taken from the transparent conductive thin film side to the substrate side having a concavo-convex pattern on the surface, Light can be taken out from the side of the substrate having a concavo-convex pattern to the side of the transparent conductive thin film, and the structure is effective as a conductive material having high light transmission (that is, excellent transparency). That is, a material having a conductive surface that is advantageous for taking in light from the outside of the material and taking out light from the inside of the material, such as a conductive substrate having a high light transmittance, can be manufactured. As the light transmittance, for example, the light transmittance at a wavelength of 550 nm is preferably 80% or more.

  In addition, an opaque thin film made of an opaque material may be formed on the uneven pattern formed on the surface, and the transparent conductive thin film may be formed as the outermost layer on the opaque thin film. In such a form, the concavo-convex pattern on the base, that is, the surface of the base material is formed as an concavo-convex pattern having a structure with antireflection characteristics, so the thin film structure laminated on the upper surface side also has antireflection characteristics as it is The transparent conductive thin film formed as the outermost layer also has a structure having antireflection characteristics. Therefore, when light is incident from the outside of the material, the incident light is efficiently taken into the layers up to the opaque thin film through the transparent conductive thin film. Such a structure is an effective structure for solar cells, for example. The opaque thin film can be composed of a layer made of a conductive material, for example, a metal electrode layer.

  Furthermore, the transparent conductive thin film is formed on the uneven pattern formed on the surface, and an opaque thin film made of an opaque material is formed as the outermost layer of the layer on the transparent conductive thin film. obtain. In such a form, when taking in light from the back side of the base material which has an uneven | corrugated pattern on the surface, light can be taken in efficiently to the said opaque thin film through a transparent conductive thin film. The opaque thin film can be composed of a layer made of a conductive material, for example, a metal electrode layer.

  In the configuration having the opaque thin film as described above, a configuration in which at least one light transmission layer is interposed between the transparent conductive thin film and the opaque thin film can be adopted. It can be applied as an assumed structure. For example, if a P-type semiconductor layer, an N-type semiconductor layer, or the like is interposed between a metal electrode layer as an opaque thin film and a transparent conductive thin film, a structure suitable for a solar cell or the like can be realized. Light can be efficiently taken in from the transparent conductive thin film to the metal electrode layer.

  The desired concavo-convex pattern on the material surface can be easily formed by an imprint process in which the mold is pressed against the surface of the material. In particular, when the concavo-convex pattern on the surface is formed using an anodized porous alumina or a negative mold made using the same as a mold, by appropriately setting the conditions in the anodized porous alumina production process, The advantage that the fine uneven structure formed on the surface of alumina can be controlled with high accuracy and high regularity can be utilized, and this can be transferred to the surface of the material to obtain a desired fine uneven pattern. It is possible to form more reliably, and a desired antireflection function is imparted by the concavo-convex pattern on the surface of the substrate formed by utilizing the surface fine concavo-convex structure of the anodized porous alumina, and the conductive material formed on the surface The surface conductive function is imparted by the conductive thin film while maintaining the antireflection function, and it combines the target surface conductivity and antireflection characteristics. Material having a low reflective conductive surface had example can be realized with a relatively simple fabrication process.

  In order to ensure good antireflection characteristics, it is possible to employ a structure in which the concavo-convex pattern is a tapered protrusion array or a tapered hole array. Such a concavo-convex pattern can be produced by general-purpose microfabrication technology using electron beam lithography and dry etching, but in particular, a mold produced using the surface fine concavo-convex structure of anodized porous alumina is used. By using the nanoimprint process, it can be formed efficiently. In this imprint process, a thermal imprint method in which a mold is pressed against a thermoplastic resin under a heating condition to transfer a fine pattern, a photoimprint method using a photocurable resin, or the like can be used. The formation of the concavo-convex pattern by the imprint process can be applied to the resin layer formed on the substrate, or can be directly processed on the resin plate. Moreover, the method of imprinting on the precursor of metal oxides including silica and titanium oxide can also be used.

  Various methods such as sputtering, vapor deposition, CVD, and casting can be used to form the transparent conductive thin film on the concavo-convex pattern. Among them, the transparent conductive thin film is formed by sputtering or vacuum vapor deposition. Preferably it is formed.

  In addition, for example, by patterning the transparent conductive thin film in a lattice pattern on the concavo-convex pattern, it is possible to produce a touch panel substrate having excellent light transmission characteristics. As a method for patterning, a method of forming a transparent conductive thin film on the entire surface and then removing it partially, or a method of coating a concavo-convex substrate using a mask can be used.

  The thickness of the transparent conductive thin film is preferably 10 nm or more and 1 μm or less, more preferably 30 nm or more and 500 nm or less, further preferably 50 nm or more and 500 nm or less, and more preferably 50 nm or more. 200 nm or less. When the transparent conductive thin film has a thickness of less than 10 nm, it is difficult to ensure sufficient conductivity, and when the conductive layer is deposited thickly exceeding 1 μm, the shape of the concavo-convex pattern changes and sufficient antireflection properties are obtained. It becomes difficult to obtain.

  It is also possible to form a laminated structure of a plurality of thin film layers by laminating several materials on the surface of the concavo-convex pattern. In this case, at least the material of the thin film forming the outermost layer has conductivity, so that a low reflection conductive surface suitable for various applications can be formed. Taking a solar cell as an example, after depositing a metal thin film that functions as an electrode on a concavo-convex substrate, various electrolyte layers are laminated on it, and a transparent conductive film is deposited on the outermost surface. A solar cell with high light capturing efficiency can be manufactured.

  Such a material having a low reflective conductive surface according to the present invention can be applied to, for example, a touch panel and a solar cell as described above. For example, when applied to a touch panel, it is possible to employ a configuration in which the two sheet-like materials having the low reflective conductive surface are arranged with their transparent conductive thin films facing each other. It is preferable that the transparent conductive thin film is formed in a predetermined form, for example, in a lattice pattern.

  A method for producing a material having a low reflective conductive surface according to the present invention includes forming a concavo-convex pattern having antireflection characteristics on the surface of a material using a mold, and forming a transparent conductive material on the formed concavo-convex pattern. And forming a transparent conductive thin film. Also in this method, as a material for forming the thin film, for example, a transparent conductive film or a conductive polymer can be used. Moreover, various materials, such as a resin material and a glass material, can be used for the surface formation base material which has an uneven | corrugated pattern.

  In the method for producing a material having a low reflective conductive surface according to the present invention, as described above, the concavo-convex pattern is formed on the surface of a transparent substrate, and the transparent directly on the formed concavo-convex pattern. A conductive thin film can be formed. Further, the uneven pattern is formed on the surface of the substrate, an opaque thin film made of an opaque material is formed on the formed uneven pattern, and the transparent conductive thin film is formed as the outermost layer on the opaque thin film. You can also. Furthermore, the said uneven | corrugated pattern is formed in the surface of a base material, the said transparent conductive thin film is formed on the formed uneven | corrugated pattern, and the opaque thin film which consists of an opaque material as an outermost layer of the layer on this transparent conductive thin film It can also be formed. As an opaque thin film, it can comprise from the layer (for example, metal electrode layer) which consists of an electroconductive material, for example.

  The uneven pattern on the surface can be formed by an imprint process. Furthermore, in order to enable continuous imprinting, a roll-shaped mold can be used as a mold for continuous imprinting.

  Further, in the method for producing a material having a low reflective conductive surface according to the present invention, the uneven pattern on the surface can be formed using an anodized porous alumina or a negative mold produced using the same. For example, when using a roll-shaped mold as the above-mentioned continuous imprint mold, if an aluminum round bar is anodized, a roll-shaped nanoimprint mold having a regular hole array pattern formed on the surface can be produced. If imprinting is performed while rotating this, a nanopillar array pattern can be formed with higher throughput. By continuously forming a transparent conductive thin film on the nanopattern obtained in this way, it is possible to form a low reflective transparent conductive thin film with higher throughput.

  The anodized porous alumina as described above is obtained by anodizing aluminum in an acidic bath. In the present invention, a nanoimprint method using this as a mold can be used. Anodized porous alumina can make pores highly regular by setting appropriate conditions, and the pore shape is tapered by the method of repeated anodization and wet etching during its production. Since it is controllable, if a nanoimprint is performed using this as a mold, a tapered pillar array made of resin or metal oxide can be produced. In addition, if a negative mold is made by transferring the structure to metal or resin using anodized porous alumina as a mold, and imprint processing is performed using this, a tapered hole array pattern made of resin or metal oxide can be obtained. Obtainable.

  As anodized porous alumina, for example, sulfuric acid is used as an electrolyte, anodized porous alumina in which pores are regularly arranged at an formation voltage of 10 V to 120 V, or oxalic acid is used as an electrolyte, and an formation voltage of 30 V to Anodized porous alumina with pores regularly arranged at 130V, and anodized porous alumina with pores regularly arranged at a chemical conversion voltage of 180V to 220V using phosphoric acid as an electrolyte can be used. . By using such anodization, it becomes possible to produce porous alumina in which pores of uniform size are regularly arranged. By adopting these porous alumina as a mold for nanoimprinting, size and shape can be obtained. It is possible to fabricate a fine pattern in which pillars or holes with a high degree of control are regularly arranged. By using a base material having an irregular pattern with such regularity, it is possible to obtain a material having a low reflective conductive surface that exhibits uniform antireflection characteristics over the entire surface without unevenness in location.

  Also, after anodizing under constant voltage conditions, the oxide film is once dissolved and removed, and then anodized again (for example, by anodizing again under the same conditions), the pores are regular. Anodized porous alumina can be obtained, and the anodized porous alumina can also be used.

  Prior to anodic oxidation, anodized porous alumina prepared by forming a fine depression on the surface of aluminum and using this as a starting point for pore generation during anodic oxidation can also be used. By using alumina, it is also possible to obtain a material having a low reflection conductive surface that exhibits uniform antireflection characteristics over the entire surface without unevenness in place.

  According to the material having a low reflective conductive surface and a method for producing the same according to the present invention, a liquid crystal having both good antireflection characteristics and surface conductivity, and also having good light transmittance. An excellent material that can satisfy the required characteristics in various fields such as a display, a solar cell, and a touch panel can be provided at a high level, and the excellent material can be manufactured by a relatively simple process.

It is a schematic diagram of the manufacturing method of the material which has the low reflective electroconductive surface which concerns on one embodiment of this invention. It is a schematic diagram which shows one example of the material which has the low reflective electroconductive surface based on this invention. It is a schematic diagram which shows an example in the case of comprising a touch panel using the material which has the low reflective electroconductive surface shown in FIG. It is a schematic diagram which shows another form example of the material which has the low reflective electroconductive surface based on this invention. It is a schematic diagram which shows another form example of the material which has the low reflective electroconductive surface based on this invention. It is a schematic diagram of the manufacturing method of the material which has the low reflective electroconductive surface which concerns on another embodiment of this invention. It is a schematic diagram of the manufacturing method of the material which has the low reflective electroconductive surface which concerns on another embodiment of this invention. It is a schematic diagram of the manufacturing method of the material which has the low reflective electroconductive surface which concerns on another embodiment of this invention. It is a schematic diagram which shows an example of the manufacturing method of the material which has the low reflective electroconductive surface which uses an anodized porous alumina as a casting_mold | template in this invention. It is a schematic diagram which shows an example of the manufacturing method of the material which has a low reflective conductive surface using the negative mold produced using the anodized porous alumina as a casting_mold | template in this invention.

Hereinafter, with reference to drawings, the material which has the low reflective conductive surface concerning each embodiment of the present invention, and its manufacturing method are explained in detail.
FIG. 1 schematically shows a method for producing a material having a low reflective conductive surface obtained by forming a transparent conductive thin film on the surface of a concavo-convex pattern. In FIG. 1, 1 has a concavo-convex pattern 2 having antireflection properties formed on the surface, for example, using an anodized porous alumina as described later or a negative mold prepared using the same as a mold. Material is shown. On the surface having the concavo-convex pattern 2, a thin film layer 3 (transparent conductive thin film layer) made of a conductive transparent material is formed by coating or the like to produce a material 4 having a low reflective conductive surface. .

  More specifically, the material having such a basic structure and having a low reflective conductive surface according to the present invention can take a form as shown in FIGS. 2, 4, and 5. FIG. 2 shows a form in which the transparent conductive thin film layer 3 is provided alone directly on the surface of the concavo-convex pattern 2 formed on the concavo-convex pattern forming layer 5a of the substrate 5 made of a light transmissive material. Show. In this case, as shown in FIG. 2 (A), light can pass from the transparent conductive thin film layer 3 side to the substrate 5 side, and as shown in FIG. 2 (B), the substrate 5 Light can be passed from the side to the transparent conductive thin film layer 3 side, and an excellent structure as a conductive substrate having low reflection characteristics and high light transmission can be realized.

  By using the two sheet-like materials 4 provided with the transparent conductive thin film layer 3 as shown in FIG. 2, for example, a structure suitable as a touch panel can be configured as shown in FIG. That is, as shown in FIG. 3, two sheet-like materials 4 having a low-reflection conductive surface having a transparent conductive thin film layer 3 on the surface are arranged so that the transparent conductive thin film layers 3 face each other. By doing so, the touch panel 10 excellent in transparency can be realized. The transparent conductive thin film layer 3 is coated on the surface of the concavo-convex pattern 2 by being patterned in a lattice pattern. In such a touch panel 10, when the opposing sheet 4 is pressed with a finger, the position of that portion can be detected in order to contact the opposite sheet 4. Such a position detection can be performed by patterning the transparent conductive thin film layer 3 in a lattice pattern.

  FIG. 4 shows that a metal electrode layer 7 as an opaque thin film made of an opaque material is formed on the surface of the concavo-convex pattern 2 formed on the concavo-convex pattern forming layer 6 a of the substrate 6. The form in which the transparent conductive thin film layer 3 is formed as the outermost layer on the layer 7 is shown. Between the metal electrode layer 7 and the transparent conductive thin film layer 3, a layer 8 made of another transparent material (for example, a P-type semiconductor layer or an N-type semiconductor layer as described above) may be interposed. In such a form, as described above, the transparent conductive thin film layer 3 is also transferred to the transparent conductive thin film layer 3 formed as the outermost layer by the anti-reflection structure 2 on the surface of the substrate 6 as the outermost layer. It becomes the structure with. The light (arrow) incident from the outside of the material is efficiently taken into the metal electrode layer 7 as the opaque thin film through the transparent conductive thin film layer 3, and the surface conductivity is maintained while maintaining the antireflection characteristic. Will be secured.

  Furthermore, FIG. 5 shows the transparent conductive material directly on the surface of the concavo-convex pattern 2 formed on the concavo-convex pattern forming layer 5a of the base material 5 made of a light transmissive material, or through a layer made of another transparent material. 1 shows a mode in which a conductive thin film layer 3 is formed and a metal electrode layer 7 as an opaque thin film made of an opaque material is formed as an outermost layer on the transparent conductive thin film layer 3. Reference numeral 9 in the illustrated example indicates a layer made of another transparent material (for example, a P-type semiconductor layer, an N-type semiconductor layer as described above). In such a form, as described above, when light (arrow) is captured from the back side of the substrate 5, light can be efficiently captured through the transparent conductive thin film layer 3 to the metal electrode layer 7 as the opaque thin film. . The structure shown in FIGS. 4 and 5 is a structure suitable for a solar cell, for example.

  FIG. 6 schematically shows a method for producing a material having a low reflective conductive surface based on an imprint process. In FIG. 6, an imprint mold 13 having a predetermined concavo-convex pattern is pressed against the concavo-convex forming layer 12 provided on the base material 11 for forming the concavo-convex surface, and the surface of the concavo-convex forming layer 12 is pressed. The uneven pattern of the imprint mold 13 is transferred. After the transfer, the imprint mold 13 is removed, and a material 14 having a concavo-convex pattern having antireflection characteristics on the surface is formed on the substrate 11. A thin film layer 15 (transparent conductive thin film layer) made of a transparent material having conductivity is formed on the surface of the material 14 having the concavo-convex pattern, thereby producing a material 16 having a low reflective conductive surface.

  FIG. 7 schematically shows a method for producing a low-reflection transparent conductive material based on an imprint process. In FIG. 7, the imprint mold 23 having a predetermined concavo-convex pattern is pressed against the concavo-convex forming layer 22 made of a transparent material for forming surface concavo-convex provided on the transparent base material 21 to form the concavo-convex. The uneven pattern of the imprint mold 23 is transferred to the surface of the layer 22. After the transfer, the imprint mold 23 is removed, and a transparent material 24 having an uneven pattern with antireflection characteristics on the surface is formed on the transparent substrate 21. A thin film layer 25 (transparent conductive thin film layer) made of a transparent material having conductivity is formed on the surface of the material 24 having the concavo-convex pattern, and a transparent material 26 having a low reflective conductive surface is manufactured. .

  FIG. 8 schematically shows a method for producing a material having a low reflective conductive surface formed by laminating several substance layers on a surface having an uneven pattern. In FIG. 8, reference numeral 31 denotes a material having a concavo-convex pattern 32 having antireflection characteristics on the surface. A plurality of thin film layers 33 are laminated on the surface having the concavo-convex pattern 32, and a thin film layer 34 (transparent conductive thin film layer) made of a transparent material having conductivity is laminated as an outermost layer to deposit a multilayer film. A material 36 having a low reflective conductive surface is produced in which layer 35 is formed.

  FIG. 9 schematically shows a method for producing a material having a low reflective conductive surface based on a nanoimprint process using anodized porous alumina itself as a mold. In FIG. 9, reference numeral 41 denotes an anodized porous alumina mold having a predetermined uneven pattern (for example, a regular predetermined pore arrangement). The uneven pattern of the anodized porous alumina mold 41 is an uneven forming layer. A material 44 having a concavo-convex pattern 43 having antireflection characteristics on the surface is formed by being transferred to the surface of 42 by an imprint process. A thin film layer 45 (transparent conductive thin film layer) made of a transparent material having conductivity is formed on the surface uneven pattern 43 by coating or the like, and a material 46 having a low reflective conductive surface is manufactured.

  FIG. 10 schematically shows a method of forming a concavo-convex pattern by a nano-imprint process using a negative mold produced using anodized porous alumina as a mold, and using this to manufacture a material having a low reflective conductive surface. is there. In FIG. 10, reference numeral 51 denotes anodized porous alumina having a predetermined uneven pattern (for example, a regular predetermined pore arrangement). The surface of the anodized porous alumina 51 is filled with a filling material 52. The concavo-convex pattern of the anodized porous alumina 51 is transferred to the surface of the filling material 52. By removing the anodized porous alumina 51 after the transfer, a negative mold 53 having the concavo-convex pattern transferred thereon is obtained. The concavo-convex pattern of the negative mold 53 is transferred to the surface of the concavo-convex forming layer by an imprint process to form a material 55 having the concavo-convex pattern 54 having antireflection characteristics on the surface. A thin film layer 56 (transparent conductive thin film layer) made of a conductive transparent material is formed on the uneven surface pattern 54 by coating or the like, and a material 57 having a low reflective conductive surface is manufactured.

Example 1 (ITO film formation on protrusion-shaped polymer pillar array with projection height of 200 nm and pitch of 100 nm)
After anodizing for 3 hours under the condition of 0.3M oxalic acid bath, bath temperature 17 ° C, formation voltage 40V on the surface of 99.99% pure aluminum plate, the sample is immersed in chromic acid phosphoric acid mixed solution and only oxide film is selected Anodized porous alumina having tapered pores is obtained by repeating the operation of dissolving and removing the sample and performing anodic oxidation again for 25 seconds under the same conditions and then performing etching for 7 minutes in a 5 wt% phosphoric acid aqueous solution five times. Formed. The surface of the produced porous alumina was immersed in a fluoroalkylsilane solution, and the surface was subjected to mold release treatment to obtain an imprint mold. A taper-shaped polymer pillar array having a diameter of 70 nm and a protrusion height of 200 nm was formed by imprinting a photocurable resin on a polyethylene naphthalate (PEN) sheet using the obtained mold. ITO was deposited on the surface of the fabricated nanopattern as a conductive thin film by 80 nm sputtering. The resistivity of the obtained sample was 1.2 kΩ □, and the transmittance was 86% at a wavelength of 550 nm. At this time, when ITO was sputtered to 80 nm on a flat PEN substrate, the transmittance was 70% at a wavelength of 550 nm, and it was confirmed that the transmittance was improved by depositing ITO on the surface of the fine pattern.

Example 2 (ITO film formation on protrusion-shaped 150 nm, pitch 100 nm tapered polymer pillar array)
After anodizing for 3 hours under the condition of 0.3M oxalic acid bath, bath temperature 17 ° C, formation voltage 40V on the surface of 99.99% pure aluminum plate, the sample is immersed in chromic acid phosphoric acid mixed solution and only oxide film is selected The porous alumina having tapered pores was formed by repeating the operation of dissolving and removing for 20 seconds under the same conditions and then performing the etching for 7 minutes in a 5 wt% phosphoric acid aqueous solution 5 times. . The surface of the produced porous alumina was immersed in a fluoroalkylsilane solution, and the surface was subjected to mold release treatment to obtain an imprint mold. A taper-shaped polymer pillar array having a diameter of 70 nm and a protrusion height of 150 nm was formed by imprinting a photocurable resin on a polyethylene naphthalate (PEN) sheet using the obtained mold. ITO was deposited on the surface of the fabricated nanopattern by sputtering at 80 nm. The resistivity of the obtained sample was 550Ω □, and the transmittance was 86% at a wavelength of 550 nm. At this time, when ITO was sputtered to 80 nm on a flat PEN substrate, the transmittance was 70% at a wavelength of 550 nm, and it was confirmed that the transmittance was improved by depositing ITO on the surface of the fine pattern.

Example 3 [Production of ITO on Tapered Polymer Pillar Array with Projection Height of 250 nm and Pitch of 200 nm]
The surface of the aluminum plate having a purity of 99.99% was subjected to texturing using a mold having a protrusion pattern regularly arranged at a pitch of 200 nm, thereby forming a recess pattern. Tapered pores are obtained by repeating the anodizing process for 2 seconds under conditions of 0.05M oxalic acid bath, bath temperature of 17 ° C and formation voltage of 80V, followed by etching for 5 minutes in 5wt% phosphoric acid aqueous solution 5 times. A porous alumina having was formed. The surface of the produced porous alumina was immersed in a fluoroalkylsilane solution, and the surface was subjected to mold release treatment to obtain an imprint mold. A taper-shaped polymer pillar array having a diameter of 70 nm and a protrusion height of 150 nm was formed by imprinting a photocurable resin on a polyethylene naphthalate (PEN) sheet using the obtained mold. ITO was deposited on the surface of the fabricated nanopattern by sputtering at 80 nm. The resistivity of the obtained sample was 550Ω □, and the transmittance was 86% at a wavelength of 550 nm. At this time, when ITO was sputtered to 80 nm on a flat PEN substrate, the transmittance was 70% at a wavelength of 550 nm, and it was confirmed that the transmittance was improved by depositing ITO on the surface of the fine pattern.

  The material having a low reflective conductive surface according to the present invention can be applied to all fields where both antireflection characteristics and conductivity of the surface are required, and is also suitable in fields where light transmittance is required. It is a thing.

1, 14, 24, 31, 44, 55 Material having an uneven pattern as a mold 2, 32, 43, 54 Uneven pattern 3, 15, 25, 34, 45, 56 Transparent conductive thin film layers 4, 16, 26, 36, 46, 57 Material 5, 6, 11 having a low reflective conductive surface Substrate 5 a, 6 a Uneven pattern forming layer 7 Metal electrode layer 8, 9 as opaque thin film 10 Layer made of other transparent material 10 Touch panel 12 Uneven formation Layers 13 and 23 Imprint mold 21 Transparent substrate 22 Concavity and convexity formation layer 33 made of transparent material Thin film layer 35 Multilayer film deposition layer 41 Anodized porous alumina mold 42 Concavity and convexity formation layer 51 Anodized porous alumina 52 Filling material 53 Negative mold

Claims (35)

  A low-reflective conductive surface characterized in that a transparent conductive thin film made of a transparent conductive material is formed on a surface having a concavo-convex pattern having antireflection characteristics, formed using a mold. material.   2. The material having a low reflective conductive surface according to claim 1, wherein a material of the surface-formed material having the concavo-convex pattern is one of polyethylene terephthalate, polyethylene naphthalate, acrylic resin, and polycarbonate.   The material having a low reflective conductive surface according to claim 1 or 2, wherein the transparent conductive thin film is formed directly on the concavo-convex pattern formed on the surface.   The material having a low reflective conductive surface according to any one of claims 1 to 3, wherein the material is light transmissive.   5. The material having a low reflective conductive surface according to claim 4, wherein the transmittance of light having a wavelength of 550 nm is 80% or more.   An opaque thin film made of an opaque material is formed on the concavo-convex pattern formed on the surface, and the transparent conductive thin film is formed as an outermost layer of the layer on the opaque thin film. Item 5. A material having a low reflective conductive surface according to Item 1.   The transparent conductive thin film is formed on the concavo-convex pattern formed on the surface, and an opaque thin film made of an opaque material is formed as the outermost layer of the layer on the transparent conductive thin film. A material having a low reflective conductive surface according to claim 1.   The material having a low reflective conductive surface according to claim 6 or 7, wherein the opaque thin film is made of a conductive material.   9. The material having a low reflective conductive surface according to claim 8, wherein the opaque thin film comprises a metal electrode layer.   10. The material having a low reflective conductive surface according to claim 6, wherein at least one light transmission layer is interposed between the transparent conductive thin film and the opaque thin film. .   The material having a low reflective conductive surface according to claim 1, wherein the uneven pattern on the surface is formed by an imprint process.   The low reflective conductive surface according to any one of claims 1 to 11, wherein the uneven pattern on the surface is formed by using anodized porous alumina or a negative mold made by using the same as a mold. Having material.   The material having a low reflective conductive surface according to any one of claims 1 to 12, wherein the concavo-convex pattern comprises a tapered protrusion array or a tapered hole array.   The low-reflection conductive surface according to claim 1, wherein the transparent conductive thin film is formed on the surface having the concavo-convex pattern by a sputtering method or a vacuum deposition method. material.   The material having a low reflective conductive surface according to claim 1, wherein the transparent conductive thin film has a thickness of 10 nm or more and 1 μm or less.   The material having a low reflective conductive surface according to claim 15, wherein the thickness of the conductive thin film is 30 nm or more and 500 nm or less.   The material having a low reflective conductive surface according to claim 16, wherein the thickness of the conductive thin film is 50 nm or more and 500 nm or less.   The material having a low reflective conductive surface according to claim 17, wherein the thickness of the conductive thin film is 50 nm or more and 200 nm or less.   The low-thickness according to any one of claims 1 to 18, wherein a plurality of thin film layers are laminated on the surface having the concavo-convex pattern, and at least the material of the thin film forming the outermost layer has conductivity. A material having a reflective conductive surface.   Two sheet-like materials having a low reflective conductive surface according to any one of claims 1 to 5, 11 to 19, wherein the transparent conductive thin films are arranged to face each other. Touch panel.   The touch panel as set forth in claim 20, wherein the transparent conductive thin film is formed by patterning into a predetermined form.   Low reflection, characterized by forming a concavo-convex pattern with antireflection characteristics on the surface of the material using a mold, and forming a transparent conductive thin film made of a transparent conductive material on the formed concavo-convex pattern A method for producing a material having a conductive surface.   The low-reflective conductive surface according to claim 22, wherein the concave-convex pattern is formed on a surface of a transparent substrate, and the transparent conductive thin film is formed directly on the formed concave-convex pattern. Material manufacturing method.   Forming the concavo-convex pattern on the surface of the substrate, forming an opaque thin film made of an opaque material on the formed concavo-convex pattern, and forming the transparent conductive thin film as the outermost layer of the layer on the opaque thin film. 23. A method for producing a material having a low reflective conductive surface according to claim 22 characterized in that   The uneven pattern is formed on the surface of the substrate, the transparent conductive thin film is formed on the formed uneven pattern, and an opaque thin film made of an opaque material is formed as the outermost layer of the layer on the transparent conductive thin film 23. A method of manufacturing a material having a low reflective conductive surface as claimed in claim 22.   26. The method of manufacturing a material having a low reflective conductive surface according to claim 24 or 25, wherein the opaque thin film is formed of a conductive material.   27. The method of manufacturing a material having a low reflective conductive surface according to claim 26, wherein the opaque thin film is composed of a metal electrode layer.   The method for producing a material having a low reflective conductive surface according to any one of claims 22 to 27, wherein the uneven pattern on the surface is formed by an imprint process.   The method for producing a material having a low reflective conductive surface according to claim 28, wherein a roll-shaped mold is used as the continuous imprint mold.   The material having a low reflective conductive surface according to any one of claims 22 to 29, wherein the uneven pattern on the surface is formed by using anodized porous alumina or a negative mold prepared by using the same as a mold. Manufacturing method.   The material having a low reflective conductive surface according to claim 30, characterized in that sulfuric acid is used as an electrolytic solution and anodized porous alumina having pores regularly arranged at a conversion voltage of 10V to 120V is used. Production method.   31. The material having a low reflective conductive surface according to claim 30, wherein anodized porous alumina having pores regularly arranged using oxalic acid as an electrolytic solution and formed at a conversion voltage of 30 V to 130 V is used. Manufacturing method.   31. The material having a low reflective conductive surface according to claim 30, wherein phosphoric acid is used as an electrolytic solution, and anodized porous alumina having pores regularly arranged at a conversion voltage of 180 V to 220 V is used. Manufacturing method.   31. Anodized porous alumina in which pores prepared by dissolving and removing the oxide film once after anodizing at a constant voltage and then anodizing again is regularly used. A method for producing a material having a low reflective conductive surface according to any one of .about.33.   Prior to anodizing, anodized porous alumina prepared by forming a fine depression on the surface of aluminum and using this as a starting point for pore generation during anodization is used. A method for producing a material having a low reflective conductive surface according to claim 1.

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