JP2011029099A - Substrate with transparent conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate with a transparent conductive film which includes the transparent conductive film having the conductivity increased while ensuring light remittance without need of increasing the content of metal nanowires. <P>SOLUTION: The substrate with the transparent conductive film includes the transparent conductive film 2 formed on the surface of a transparent substrate 1 by including the metal nanowires 3 in a matrix resin 5. The matrix resin 5 of the transparent conductive film 2 contains translucent particles 4 each of which has a refractive index difference of &plusmn;0.03 with respect to the matrix resin 5 and has a particle size greater than the thickness of the transparent conductive film 2 by 0.5 to 1.2 times. The existence region of the metal nanowires 3 in the matrix region 5 is limited by the translucent particles 4 and the contact probability between the metal nanowires 3 is enhanced to ensure a large number of contacts between the metal nanowires 3. As a result, without the need of increasing the content of the metal nanowires 3, the conductivity of the transparent conductive film 2 is enhanced. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a substrate with a transparent conductive film provided with a transparent conductive film on the surface.

  Transparent conductive films are widely used as transparent electrodes in fields such as liquid crystal displays, PDPs, touch panels, organic ELs, and solar cells. In forming such a transparent conductive film that exhibits conductivity, in addition to a method of forming a film using a transparent and conductive material, a film containing a conductive substance in a transparent resin is used. There is a method of forming a transparent conductive film that exhibits conductivity while securing transparency by the shape and orientation of the conductive substance although it is colored by forming the film.

  Here, since a conductive substance generally has a large number of free electrons that exhibit conductive characteristics, it is often colored by plasma resonance vibration absorption generated particularly from the visible light wavelength region. For this reason, for example, when a particulate conductive material is contained, transparency is ensured in the visible range by reducing the particle size to the nano order. However, when the particle size is reduced, the surface area is increased, so that aggregation between particles of the conductive material is likely to occur. In order to prevent this, it is necessary to modify the surface of the particles with a dispersant, but this dispersant hinders the conductivity of the transparent conductive film. In this case, it is possible to increase the conductivity by increasing the addition amount of the conductive substance, but conversely, the transparency is lowered, and therefore it is difficult to achieve both transparency and conductivity.

  One way to solve this trade-off between transparency and conductivity is to change the shape of the conductive material from particle to fiber, increase the contact probability of the conductive material, and mix the conductive material. There are ways to reduce the amount.

  Particularly in recent years, a method for forming a transparent conductive film using a material such as carbon nanofiber or carbon nanotube has been reported. For example, as shown in Patent Document 1, a transparent conductive film is formed using vapor grown carbon fiber. There is an example of forming. However, since the carbon-based material has a specific resistance of about 50 S / cm, it is currently difficult to apply it to a transparent electrode that requires high conductivity.

On the other hand, Patent Document 2 proposes forming a transparent conductive film using metal nanowires. The conductivity of the metal nanowire is derived from the metal. For example, in the case of silver, it has a very excellent conductivity of 10 ⁻⁷ Ω · cm, so that it can be applied to a transparent electrode.

  Here, as one method of forming the transparent conductive film 2 containing the metal nanowire 3, there is a method of forming a film by applying a resin solution in which the metal nanowire 3 is dispersed on the surface of the transparent substrate 1, FIG. As shown in FIG. 2, the transparent conductive film 2 is formed as a material in which a metal nanowire 3 is contained in a matrix resin 5 that forms a film. And the electroconductivity is provided to the transparent conductive film 2 by the metal nanowires 3 being in contact with each other.

  Thus, in the transparent conductive film 2 formed by including the metal nanowire 3 in the matrix resin 5, it is necessary to increase the content of the metal nanowire 3 in order to increase the conductivity of the transparent conductive film 2. However, when the content of the metal nanowire 3 is increased, the haze of the transparent conductive film 2 is increased, the light transmittance is decreased, and the quality as the transparent conductive film 2 may be impaired. .

JP 2002-266170 A Special table 2009-505358

  This invention is made | formed in view of said point, The base material with a transparent conductive film provided with the transparent conductive film which improved the electroconductivity, ensuring the light transmittance, without having to increase content of metal nanowire Is intended to provide.

  The substrate with a transparent conductive film according to the present invention is a substrate with a transparent conductive film provided on the surface of the transparent substrate with a transparent conductive film formed by containing metal nanowires in a matrix resin, the transparent conductive film In the matrix resin, translucent particles having a refractive index difference of ± 0.03 or less and 0.5 to 1.2 times the film thickness of the transparent conductive film are included in the matrix resin. It is characterized by comprising.

  Thus, by containing translucent particles in the matrix resin, the presence region of the metal nanowires in the matrix resin can be limited by the translucent particles, and the contact probability of the metal nanowires is increased. A large number of contact points between the metal nanowires can be secured, and the conductivity of the transparent conductive film can be increased without increasing the content of the metal nanowires. Therefore, the haze of the transparent conductive film is not increased and the transmittance is not decreased as in the case where the content of the metal nanowire is increased. In addition, since the translucent particles have a refractive index difference within ± 0.03 with the matrix resin, the translucent particles contained in the matrix resin do not increase the haze of the transparent conductive film. It does not reduce the permeability of the membrane.

  The present invention is also characterized in that the ratio of the particle diameter (D) of the translucent particles to the length (L) of the metal nanowires is 0.005 ≦ D / L <1.

  By setting the ratio of the particle diameter (D) of the translucent particles to the length (L) of the metal nanowires within this range, the region where the metal nanowires are present in the matrix resin is limited by the translucent particles. The effect of increasing the contact probability of the nanowire can be obtained satisfactorily.

  The present invention is also characterized in that the volume ratio of the matrix resin and the translucent particles in the transparent conductive film is matrix resin / translucent particles ≦ 5.

  By setting the volume ratio of the matrix resin and the translucent particles within this range, the presence region of the metal nanowires in the matrix resin is limited by the translucent particles, and the effect of increasing the contact probability of the metal nanowires is obtained favorably. It is something that can be done.

  According to the present invention, translucent particles having a particle diameter of 0.5 to 1.2 times the film thickness of the transparent conductive film are contained in the matrix resin, so that the presence of metal nanowires in the matrix resin is present. The region can be limited by translucent particles, the contact probability of metal nanowires is increased, and many contact points between metal nanowires can be secured, and transparency is increased by increasing the content of metal nanowires. The conductivity of the transparent conductive film can be increased without lowering the thickness. In addition, since the translucent particles have a refractive index difference with the matrix resin of 0.03 or less, the translucent particles contained in the matrix resin do not increase the haze of the transparent electroconductive film. This does not decrease the transmittance.

It is the schematic which shows an example of embodiment of this invention. It is the schematic which shows a prior art example.

  Embodiments of the present invention will be described below.

  In the present invention, any metal nanowire can be used, and the means for producing the metal nanowire is not particularly limited. For example, a known means such as a liquid phase method or a gas phase method can be used. it can. There is no restriction | limiting in particular also in a specific manufacturing method, A well-known manufacturing method can be used. For example, as a method for producing Ag nanowires, Adv. Mater. 2002, 14, P833-837, Chem. Mater. 2002, 14, P4736-4745, the above-mentioned Patent Document 2 and the like, as a method for producing Au nanowires, JP 2006-233252A and the like, as a method for producing Cu nanowires, JP 2002-266007 A and the like, As a method for producing Co nanowires, JP-A No. 2004-148771 can be cited. In particular, the above Adv. Mater. And Chem. Mater. The method for producing Ag nanowires reported in 1) can produce Ag nanowires easily and in large quantities in an aqueous system, and since the conductivity of silver is the largest among metals, production of metal nanowires used in the present invention It can be preferably applied as a method.

  In the present invention, the average diameter of the metal nanowires is preferably 200 nm or less from the viewpoint of transparency, and preferably 10 nm or more from the viewpoint of conductivity. It is preferable that the average diameter is 200 nm or less because a decrease in light transmittance can be suppressed. On the other hand, if the average diameter is 10 nm or more, the function as a conductor can be expressed significantly, and a larger average diameter is preferable because conductivity is improved. Therefore, the average diameter is more preferably 20 to 150 nm, and further preferably 40 to 150 nm. The average length of the metal nanowires is preferably 1 μm or more from the viewpoint of conductivity, and preferably 100 μm or less from the viewpoint of the effect on the transparency due to aggregation. More preferably, it is 1-50 micrometers, and it is still more preferable that it is 3-50 micrometers. The average diameter and the average length of the metal nanowires can be obtained from an arithmetic average of measured values of individual metal nanowire images by taking an electron micrograph of a sufficient number of nanowires using SEM or TEM. The length of the metal nanowire should be obtained in a state where it has been stretched in a straight line, but in reality it is often bent, so the projection diameter and projection of the metal nanowire using an image analyzer from an electron micrograph The area is calculated and calculated assuming a cylindrical body (length = projected area / projected diameter). The number of metal nanowires to be measured is preferably at least 100 or more, and more preferably 300 or more metal nanowires.

  The metal nanowire is used by being dispersed in a resin solution. As described later, this resin solution is applied to the surface of a transparent substrate to form a transparent conductive film. In the resin solution, as a matrix resin for forming a film of the transparent conductive film, one that is polymerized by a polymerization reaction of monomers or oligomers is used.

  When a resin that undergoes a photopolymerization reaction or a thermal polymerization reaction is used as such a matrix resin, a polymerization reaction is generated directly or by the action of an initiator by irradiation with ionizing radiation such as ultraviolet light or electron beam. Monomers or oligomers can be used, and monomers or oligomers having an acrylic group or a methacryl group are preferred. Among them, a polyfunctional binder component is preferable in order to increase the scratch resistance and hardness by crosslinking.

  As one having one functional group in one molecule, specifically, for example, isoamyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxy-diethylene glycol (meta ) Acrylate, methoxy-triethylene glycol (meth) acrylate, methoxy-polyethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate phenoxyethyl (meth) acrylate, phenoxy-polyethylene glycol (meth) ) Acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, -Hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethyl-succinic acid, 2- (meth) acryloyloxyethyl phthalate Acid, isooctyl (meth) acrylate, isomyristyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, Examples include cyclohexyl methacrylate, benzyl (meth) acrylate, (meth) acryloylmorpholine, and the like.

  As those having two or more functional groups, specifically, for example, polyethylene glycol diacrylate, glycerin triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, diester Examples thereof include pentaerythritol hexaacrylate, alkyl-modified dipentaerythritol hexaacrylate, and the compounds having a benzene ring include ethylene oxide-modified bisphenol A diacrylate, modified bisphenol A diacrylate, ethylene glycol diacrylate, and ethylene oxide propylene oxide-modified bisphenol. A diacrylate, propylene oxide tetramethylene oxide Modified bisphenol A diacrylate, bisphenol A- diepoxy - acrylic acid adduct, ethylene oxide-modified bisphenol F diacrylate, and polyfunctional acrylates or methacrylates such as polyester acrylates.

  1,2-bis (meth) acryloylthioethane, 1,3-bis (meth) acryloylthiopropane, 1,4-bis (meth) acryloylthiobutane, 1,2-bis (meth) acryloylmethylthiobenzene, The use of sulfur-containing (meth) acrylates such as 1,3-bis (meth) acryloylmethylthiobenzene is also effective for increasing the refractive index.

  Further, a light or thermal polymerization initiator may be blended in order to promote curing by ultraviolet rays or heat.

  Although what is generally marketed may be used as a photoinitiator, when it illustrates especially, benzophenone, 2, 2- dimethoxy- 1, 2- diphenyl ethane- 1-one (Ciba Specialty Chemicals Co., Ltd. product " Irgacure 651 "), 1-hydroxy-cyclohexyl-phenyl-ketone (" Irgacure 184 "manufactured by Ciba Specialty Chemicals), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Ciba Specialty Chemicals' “Darocur 1173”, Lamberti's “Esacure KL200”), Oligo (2-hydroxy-2-methyl-1-phenyl-propan-1-one) (Lamberti's “Esacure KIP150” "), 2-hydroxyethyl-phenyl-2-hydride Xyl-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Specialty Chemicals Co., Ltd.), 2-methyl-1 (4- (methylthio) phenyl) -2-morpholinopropane-1 -ON ("Irgacure 907" manufactured by Ciba Specialty Chemicals Co., Ltd.), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Ciba Specialty Chemicals Co., Ltd. " Irgacure 369 "), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (" Irgacure 819 "manufactured by Ciba Specialty Chemicals Co., Ltd.), bis (2,6-dimethoxybenzoyl) -2,4 , 4-Trimethyl-pentylphosphine oxide (Ciba Specialty Chemical) ("CGI403" manufactured by Co., Ltd.), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (= TMDPO) ("Lucirin TPO" manufactured by BASF AG, "Darocur TPO" manufactured by Ciba Specialty Chemicals Co., Ltd.) Thioxanthone or a derivative thereof, and the like can be used, and one or a mixture of two or more of these can be used.

  Further, a tertiary amine such as triethanolamine, ethyl-4-dimethylaminobenzoate, isopentylmethylaminobenzoate or the like may be added for the purpose of photosensitization.

  As a polymerization initiator by heat, a peroxide such as benzoyl peroxide (= BPO) or an azo compound such as azobisisobutylnitrile (= AIBN) is mainly used.

  The blending amount of the photopolymerization initiator and the thermal polymerization initiator is usually preferably about 0.1 to 10 parts by mass with respect to 100 parts by mass of the composition (resin + metal nanowire).

  Moreover, you may use the monomer or oligomer which has cationic polymerizable functional groups, such as an epoxy group, a thioepoxy group, and an oxetanyl group. Further, if necessary, a photocationic initiator or the like can be used in combination. These are likewise preferably polyfunctional.

  Moreover, about resin to thermally polymerize, a sol-gel type material is mentioned generally, Sol-gel type materials, such as alkoxy silane and alkoxy titanium, are preferable. Of these, alkoxysilane is preferred. The sol-gel material forms a polysiloxane structure. Specific examples of the alkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, and methyl. Tributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3- Glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylto Trialkoxysilanes such as ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, Examples include diethyldimethoxysilane and diethyldiethoxysilane. These alkoxysilanes can be used as a partial condensate thereof. Among these, tetraalkoxysilanes or partial condensates thereof are preferable. In particular, tetramethoxysilane, tetraethoxysilane or a partial condensate thereof is preferable.

  Furthermore, a conductive polymer can also be used as a matrix resin for the resin solution. Examples of the conductive polymer include polyaniline, polypyrrole, polythiophene, polytriphenylamine and the like.

  Further, as the matrix resin of the resin solution, two or more kinds selected from the above-mentioned photopolymerizable resin, thermopolymerizable resin, and conductive polymer may be used in combination.

  In the present invention, translucent particles are dispersed in a resin solution in addition to metal nanowires. The translucent particles have translucency such as transparency, and the difference in refractive index from the matrix resin is within ± 0.03, that is, the difference in refractive index between the matrix resin and the translucent particles is +0. There is no particular limitation as long as it is within the range of 03 to -0.03. For example, silica, alumina, magnesium fluoride, calcium fluoride, cerium fluoride, aluminum fluoride, acrylic particles, styrene Particles, urethane particles, styrene acrylic particles and crosslinked particles thereof, melamine-formalin condensate particles, PTFE (polytetrafluoroethylene) particles, PFA (perfluoroalkoxy resin) particles, FEP (tetrafluoroethylene-hexafluoropropylene) Copolymer) particles, PVDF (polyfluorovinylidene) particles, ETFE (ethylene-tet) Fluoropolymer particles of fluoroethylene copolymer) and the like, silicone resin particles include glass beads. These may be used alone or in combination of two or more. The translucent particles may be solid particles, or may be hollow particles having a structure in which one outer shell covers a single cavity, or porous particles. Furthermore, the shape of the translucent particles may be spherical or irregular.

  Moreover, the translucent particle | grains which have a particle diameter of 0.5-1.2 times the film thickness of a transparent conductive film 50 to 120%, ie, the film thickness of a transparent conductive film, for the reason mentioned later are used. Is. Further, the particle diameter of the translucent particles is determined by assuming that the particle diameter of the translucent particles is D and the length (average length) of the metal nanowires is L for the reasons described later. The ratio of the length L of the nanowires is preferably set so that 0.005 ≦ D / L <1. In the present invention, the particle diameter of the translucent particles means an average particle diameter, and the average particle diameter is a value measured by a laser diffraction / scattering method.

  The compounding amount of the metal nanowires in the resin solution is adjusted and set so that 0.01 to 90% by mass of the metal nanowires are contained in the transparent conductive film when the transparent conductive film is formed as described later. Is preferred. As for content of metal nanowire, 0.1-30 mass% is more preferable, More preferably, it is 0.5-10 mass%.

  In addition, the amount of translucent particles added to the resin solution is that the volume ratio of the matrix resin to the translucent particles in the transparent conductive film is the matrix resin when the transparent conductive film is formed as described later for the reason described later. / It is preferable to set so that translucent particles ≦ 5.

  Here, it is essential that the resin solution contains a solvent for dissolving or dispersing solid components such as resin solids, metal nanowires, and translucent particles, but the type of solvent is particularly limited. is not. For example, alcohols such as methanol, ethanol and isopropyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene Or mixtures thereof can be used. Among these, it is preferable to use a ketone-based organic solvent. When a resin solution is prepared using a ketone-based solvent, it can be easily and uniformly applied to the surface of the transparent substrate, and the solvent after coating. Since the evaporation rate is moderate and hardly causes uneven drying, a transparent conductive film having a uniform thickness and a large area can be easily obtained. In addition to the above organic solvent, water may be used as the solvent, or an organic solvent and water may be used in combination. The amount of the solvent can uniformly dissolve and disperse each of the above solid components so that the concentration does not cause aggregation during storage after preparing the resin solution and is not too dilute during coating. Adjust as appropriate. Prepare a high-concentration resin solution by reducing the amount of solvent used within the range that satisfies this condition, store it in a state that does not take up the volume, take out the necessary amount at the time of use, and adjust the solvent to a concentration suitable for coating work. It is preferable to dilute with. When the total amount of the solid content and the solvent is 100 parts by mass, the amount of the solvent is preferably set to 50 to 99.9 parts by mass with respect to 0.1 to 50 parts by mass of the total solids, and more preferably By using 70 to 99.5 parts by mass of the solvent with respect to 0.5 to 30 parts by weight of the total solid content, a resin solution that is particularly excellent in dispersion stability and suitable for long-term storage can be obtained. . The combination of the resin and the solvent to be used is not particularly defined, but it is preferable to use a solvent in which the compounded resin is easily dissolved. Further, depending on the transparent substrate to be coated, dissolution may occur depending on the solvent used. Therefore, it is desirable to design an appropriate solvent composition after confirming the solubility in the transparent substrate in advance.

  On the other hand, the shape, structure, size and the like of the transparent substrate used in the present invention are not particularly limited and can be appropriately selected according to the purpose. Examples of the shape of the transparent substrate include a flat plate shape, a sheet shape, and a film shape, and the structure may be, for example, a single layer structure or a laminated structure, and may be appropriately selected. Can do. There is no restriction | limiting in particular also about the material of a transparent base material, Any of an inorganic material and an organic material can be used suitably. Examples of the inorganic material forming the transparent substrate include glass, quartz, and silicon. Examples of organic materials include acetate resins such as triacetyl cellulose (TAC); polyester resins such as polyethylene terephthalate (PET); polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, and polyimides. Resin, polyolefin resin, acrylic resin, polynorbornene resin, cellulose resin, polyarylate resin, polystyrene resin, polyvinyl alcohol resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyacrylic resin Etc. These may be used individually by 1 type and may use 2 or more types together.

  Further, in the present invention, the transparent substrate may be a single substrate as described above, but may be one in which one or a plurality of hard coat layers are formed on the surface of the substrate. Thus, when a transparent base material is provided with a hard-coat layer, a transparent conductive film is formed on a hard-coat layer.

  In this invention, it is a contact interface part with a transparent conductive film among transparent substrates that a refractive index becomes a problem between a transparent conductive film and a transparent base material. Therefore, in the present invention, the refractive index of the transparent substrate means the refractive index of the transparent substrate itself if the transparent substrate is a single substrate, and the transparent substrate has a hard coat layer on the surface. If it is, it means the refractive index of the hard coat layer.

  The hard coat layer can be formed using, for example, a reactive curable resin, that is, a hard coat coating material containing at least one of a thermosetting resin and an ionizing radiation curable resin.

  As the thermosetting resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, silicon resin, polysiloxane resin, etc. can be used. A crosslinking agent, a polymerization initiator, a curing agent, a curing accelerator, and a solvent can be added to these thermosetting resins as necessary.

  The ionizing radiation curable resin preferably has an acrylate functional group, for example, a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiro resin. Acetal resin, polybutadiene resin, polythiol polyene resin, oligomers such as (meth) acrylates of polyfunctional compounds such as polyhydric alcohol, prepolymers, and reactive diluents such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, Monofunctional monomers such as methylstyrene and N-vinylpyrrolidone, as well as polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate , Diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Can be used. Furthermore, in order to make the ionizing radiation curable resin into an ultraviolet curable resin, it is preferable to incorporate a photopolymerization initiator therein. Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, thioxanthones, and the like. In addition to the photopolymerization initiator, a photosensitizer may be used. Examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone.

In addition, by adding high refractive index particles, that is, ultrafine particles of high refractive index metal or metal oxide, to the hard coat coating material, the refractive index is adjusted by adding high refractive index particles to the hard coat layer. Also good. The high refractive index particles preferably have a refractive index of 1.6 or more and a particle size of 0.5 to 200 nm. The compounding quantity of high refractive index particle | grains is adjusted so that it may become the range of 5-70 volume% with respect to a hard-coat layer. Examples of the ultrafine particles of the high refractive index metal or metal oxide include one or more oxide particles selected from titanium, aluminum, cerium, yttrium, zirconium, niobium, and antimony. Are, for example, ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1.71), SnO. ₂ , ITO (refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ ( Examples thereof include fine powder having a refractive index of 1.63).

  After applying such a hard coat coating material on the base material and drying it as necessary, in the case of a hard coat coating material containing a thermosetting resin, it is heated and a hard coat coating containing an ionizing ray curable resin is applied. In the case of a material, a hard coat layer is formed by forming a cured film by irradiating ionizing rays such as ultraviolet rays. The coating method is not particularly limited, and various methods such as spin coating method, dip method, spray method, slide coating method, bar coating method, roll coater method, meniscus coater method, flexographic printing method, screen printing method, and bead coater method are available. Adopted.

  The refractive index of this hard coat layer is preferably in the range of 1.54 to 1.90. If this refractive index is less than 1.54, there is a risk that a sufficient antireflection effect may not be obtained particularly in an optical member for antireflection use. If this refractive index is greater than 1.90, the high refractive index of the hard coat layer may be lost. For this reason, a large amount of high refractive index particles is added to reduce the practicality such as wear resistance.

  And the transparent conductive film 2 is formed like FIG. 1 by apply | coating the resin solution which mix | blended said metal nanowire 3 and the translucent particle | grains 4 on the surface of the transparent base material 1, and making it dry and harden | cure. It is something that can be done. In the transparent conductive film 2 formed in this way, as shown in FIG. 1, the metal nanowires 3 and the translucent particles 4 are contained in a transparent matrix resin 5 in a substantially uniformly dispersed state. Examples of the resin solution coating method include spin coating, casting, roll coating, flow coating, printing, dip coating, casting film formation, bar coating, and gravure printing.

  The transparent conductive film 2 formed in this way exhibits conductivity when the metal nanowires 3 contained in the matrix resin 5 of the film come into contact with each other. Here, the translucent particles 4 are contained in the matrix resin 5 of the transparent conductive film 2. Therefore, for example, when forming the transparent conductive film 2 with the same thickness, if the translucent particles 4 are contained in the matrix resin 5, the volume of the translucent particles 4 in the transparent conductive film 2, the matrix resin The volume of 5 is reduced (see the contrast between FIG. 1 and FIG. 2). Thus, when the volume of the matrix resin 5 decreases, the region where the metal nanowires 3 can exist in the matrix resin 5 is limited, that is, the metal nanowires 3 are concentrated and exist in a high density. The probability that the metal nanowires 3 come into contact with each other is increased, and many contacts between the metal nanowires 3 can be secured. Therefore, it is possible to increase the conductivity of the transparent conductive film 2 by securing the contact of the metal nanowire 3 without increasing the content of the metal nanowire 3. Thus, since it is not necessary to increase the content of the metal nanowire 3 in order to increase the conductivity of the transparent conductive film 2, the haze of the transparent conductive film 2 is increased as in the case where the content of the metal nanowire 3 is increased. The transmittance of the transparent conductive film 2 can be kept high without increasing.

  Here, the particle diameter of the translucent particles 4 is 0.5 to 1.2 times the film thickness of the transparent conductive film 2 as described above. When the particle diameter of the translucent particles 4 is less than 0.5 times the film thickness of the transparent conductive film 2, the conductivity is improved by including the translucent particles 4 in the matrix resin 5 of the transparent conductive film 2. The effect cannot be obtained sufficiently. Moreover, when the particle diameter of the translucent particle 4 exceeds 1.2 times the film thickness of the transparent conductive film 2, the translucent particle 4 greatly protrudes from the surface of the transparent conductive film 2, and the surface of the transparent conductive film 2 is exposed. The smoothness will be impaired, and if the particle diameter is too large with respect to the film thickness, the contact between the metal nanowires cannot be secured, and the conductivity may be lowered.

  Further, as described above, the particle diameter of the translucent particles 4 is as follows. When the particle diameter of the translucent particles 4 is D and the length (average length) of the metal nanowires is L, the particle diameter D of the translucent particles 4 is as follows. And the ratio of the length L of the metal nanowire 3 is 0.005 ≦ D / L <1. That is, as the translucent particle 4, a particle having a particle size smaller than the length of the metal nanowire 3 and a particle size larger than 1/200 of the length of the metal nanowire 3 is used. In both cases where the particle size of the translucent particle 4 is larger or smaller than this range, the function of limiting the region where the metal nanowire 3 exists in the matrix resin 5 by the translucent particle 4 becomes insufficient. The effect of increasing the conductivity of the transparent conductive film 2 cannot be sufficiently obtained.

  In addition, as described above, the content of the translucent particles 4 in the transparent conductive film 2 is such that the volume ratio of the matrix resin 5 and the translucent particles 4 in the transparent conductive film 2 is matrix resin / translucent particles ≦ It is set to be 5. That is, the translucent particles 4 are set to have a volume ratio of 1/5 or more of the matrix resin 5. If the content of the translucent particles 4 is less than this, the function of limiting the region where the metal nanowires 3 are present in the matrix resin 5 by the translucent particles 4 becomes insufficient, and the conductivity of the transparent conductive film 2 is reduced. The effect of enhancing cannot be obtained sufficiently. The upper limit of the content of the transparent resin 4 is not particularly set, but is practically matrix resin / translucent particle ≧ 0.1. Therefore, the volume ratio between the matrix resin 5 and the translucent particles 4 is preferably in the range of 0.1 ≦ matrix resin / translucent particles ≦ 5.

  When the translucent particles 4 are contained in the matrix resin 5 of the transparent conductive film 2 to increase the conductivity of the transparent conductive film 2 as described above, the refractive index of the matrix resin 5 as the translucent particles 4 is increased. Therefore, the transparent conductive film 2 does not increase in haze due to the light-transmitting particles 4 contained in the matrix resin 5, and the transmittance of the transparent conductive film 2 is increased. Is not reduced by the translucent particles 4. When the difference in refractive index between the translucent particles 4 and the matrix resin 5 exceeds ± 0.03, light is easily scattered at the interface between the matrix resin 5 and the translucent particles 4, and the haze of the transparent conductive film 2 is increased. There is a risk that the transmittance will be lowered.

  In addition, you may form a surface smooth layer in the range which does not increase the surface resistance of the transparent conductive film 2 on the surface of the transparent conductive film 2.

  The use of the substrate with a transparent conductive film according to the present invention obtained as described above is not particularly limited, but is applicable to organic EL elements, transparent wiring, photoelectric conversion elements, electromagnetic wave shields, touch panels, electronic papers, and the like. Is something that can be done.

  Next, the present invention will be specifically described with reference to examples.

Example 1
10.00 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 300 nm, refractive index) 1.49) A mixture A was prepared by mixing 4.55 parts by mass with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and dissolving the photocurable acrylic resin. Silver nanowires were used as metal nanowires. This silver nanowire was prepared according to a known paper “Materials Chemistry and Physics vol. 114 p333-338“ Preparation of Ag nanorods with high yield by polyol process ””, and has an average diameter of 150 nm and an average length of 5 μm. This metal nanowire was dispersed in methyl ethyl ketone in an amount of 3.0% by mass to prepare a mixture B. After adding 15.0 parts by mass of mixture B to mixture A and mixing well, 0.72 parts by mass of photoinitiator 1-hydroxy-cyclohexyl-phenyl-ketone (“Irgacure 184” manufactured by Ciba Geigy) was added thereto. The mixture was further mixed and stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to obtain a coating material composition comprising a resin solution containing metal nanowires and translucent particles.

  Then, using a transparent PET film (thickness 125 μm, refractive index 1.665) as a transparent substrate, the above-mentioned coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 4, and 2 at room temperature (23 ° C.). The substrate with a transparent conductive film in which a transparent conductive film having a thickness of 0.5 μm is formed by drying by heating at 120 ° C. for 3 minutes and then drying by irradiating ultraviolet rays with an intensity of 500 mJ / cm for curing. Was obtained (see FIG. 1). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

(Example 2)
10.00 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 350 nm, refractive index) 1.49) A mixture A was prepared by mixing 4.55 parts by mass with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and dissolving the photocurable acrylic resin. 15.0 parts by mass of the mixture B prepared in Example 1 was added to the mixture A and mixed well. Then, a photopolymerization initiator 1-hydroxy-cyclohexyl-phenyl-ketone (“Irgacure 184” manufactured by Ciba Geigy) was added. 72 parts by mass was added and mixed well, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour. Further, 35.00 parts by mass of methyl ethyl ketone and 35.00 parts by mass of methyl isobutyl ketone were added and diluted to obtain a coating material composition comprising a resin solution containing metal nanowires and translucent particles.

  Then, in the same manner as in Example 1, this coating material composition was coated, dried and cured on the surface of a transparent substrate made of a transparent PET film to form a transparent conductive film having a thickness of 0.3 μm. An attached substrate was obtained (see FIG. 1). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

(Example 3)
10.00 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 3 μm, refractive index) 1.49) A mixture A was prepared by mixing 4.55 parts by mass with a mixed solvent of 9.87 parts by mass of methyl ethyl ketone and 9.86 parts by mass of methyl isobutyl ketone, and dissolving the photocurable acrylic resin. A coating material composition comprising a resin solution containing metal nanowires and translucent particles was obtained in the same manner as in Example 1 except that this mixture A was used.

  Then, using a transparent PET film (thickness 125 μm, refractive index 1.665) as a transparent substrate, the above-mentioned coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 20, and 2 at room temperature (23 ° C.). The substrate with a transparent conductive film in which a transparent conductive film having a thickness of 5.0 μm is formed by drying for 3 minutes, heating at 120 ° C. for 3 minutes, drying, and further irradiating and curing ultraviolet rays at an intensity of 500 mJ / cm. Was obtained (see FIG. 1). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

Example 4
Silicone resin ("MS51" manufactured by Mitsubishi Chemical Co., Ltd .: 51% by mass in terms of oxide, refractive index 1.51) 19.60 parts by mass, silica particles as translucent particles (CAI Kasei Co., Ltd .: isopropyl alcohol dispersed solid) The mixture A was prepared by mixing 22.75 parts by mass of 20% by mass, particle size 120 nm, refractive index 1.50) with 34.87 parts by mass of isopropyl alcohol and dissolving the silicone resin. Moreover, the same silver nanowire as Example 1 was used as a metal nanowire, and this metal nanowire was disperse | distributed to the amount of 3.0 mass% in isopropyl alcohol, and the mixture B was prepared. Add 15.0 parts by weight of mixture B to mixture A and mix well, then add 2.65 parts by weight of 0.1N nitric acid and mix well, and stir and mix in a constant temperature atmosphere at 25 ° C. for 1 hour. Thus, a coating material composition comprising a resin solution containing metal nanowires and translucent particles was obtained.

  Then, using a transparent PET film (thickness 125 μm, refractive index 1.665) as a transparent substrate, the above-mentioned coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 2, and 2 at room temperature (23 ° C.). The substrate with a transparent conductive film in which a transparent conductive film having a thickness of 0.2 μm is formed by drying for 3 minutes, heating at 120 ° C. for 3 minutes, drying, and further irradiating and curing ultraviolet rays at an intensity of 500 mJ / cm. Was obtained (see FIG. 1). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

(Example 5)
4.55 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 300 nm, refractive index) 1.49) 10.00 parts by mass was mixed with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and the photocurable acrylic resin was dissolved to prepare a mixture A. A coating material composition comprising a resin solution containing metal nanowires and translucent particles was obtained in the same manner as in Example 1 except that this mixture A was used.

  Then, in the same manner as in Example 1, this coating material composition was applied, dried, and cured on the surface of a transparent substrate made of a transparent PET film, thereby forming a transparent conductive film having a thickness of 0.5 μm. An attached substrate was obtained (see FIG. 1). In the transparent conductive film, the matrix resin / translucent particle volume ratio was about 0.45, and the content of metal nanowires in the transparent conductive film was about 3.0 mass%.

(Comparative Example 1)
Photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) 14.55
Part A was mixed with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and the acrylic resin was dissolved to prepare a mixture A. Moreover, the same silver nanowire as Example 1 was used as a metal nanowire, and this metal nanowire was disperse | distributed to methyl ethyl ketone in the quantity of 3.0 mass%, and the mixture B was prepared. After adding 15.0 parts by mass of mixture B to mixture A and mixing well, 0.72 parts by mass of photoinitiator 1-hydroxy-cyclohexyl-phenyl-ketone (“Irgacure 184” manufactured by Ciba Geigy) was added thereto. Then, the mixture was stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to obtain a coating material composition comprising a resin solution containing metal nanowires.

  A transparent conductive film in which a transparent conductive film having a thickness of 0.5 μm was formed by applying, drying, and curing the coating material composition on the surface of a transparent substrate made of a transparent PET film in the same manner as in Example 1. An attached substrate was obtained (see FIG. 2). In addition, content of the metal nanowire in a transparent conductive film was about 3.0 mass%.

(Comparative Example 2)
10.00 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 300 nm, refractive index) 1.49) A mixture A was prepared by mixing 4.55 parts by mass with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and dissolving the photocurable acrylic resin. A coating material composition comprising a resin solution containing metal nanowires and translucent particles was obtained in the same manner as in Example 1 except that this mixture A was used.

  Then, using a transparent PET film (thickness: 125 μm) as a transparent substrate, the above coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 10, dried at room temperature (23 ° C.) for 2 minutes, and then 120 A substrate with a transparent conductive film on which a transparent conductive film having a thickness of 1.2 μm was formed was obtained by heating and drying at 3 ° C. for 3 minutes, and further irradiating and curing ultraviolet rays at an intensity of 500 mJ / cm (FIG. 1). reference). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

(Comparative Example 3)
10.00 parts by mass of a photocurable acrylic resin (“A-DPH” manufactured by Shin-Nakamura Chemical Co., Ltd .: refractive index 1.49) and acrylic resin particles (manufactured by Soken Chemical Co., Ltd .: particle size 2 μm, refractive index) 1.49) A mixture A was prepared by mixing 4.55 parts by mass with a mixed solvent of 34.87 parts by mass of methyl ethyl ketone and 34.86 parts by mass of methyl isobutyl ketone, and dissolving the photocurable acrylic resin. A coating material composition comprising a resin solution containing metal nanowires and translucent particles was obtained in the same manner as in Example 1 except that this mixture A was used.

  Then, using a transparent PET film (thickness 125 μm, refractive index 1.665) as a transparent substrate, the above-mentioned coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 10, and 2 at room temperature (23 ° C.). The substrate with a transparent conductive film in which a transparent conductive film having a film thickness of 1.2 μm is formed by drying for 3 minutes, heating at 120 ° C. for 3 minutes, drying, and further irradiating and curing ultraviolet rays at an intensity of 500 mJ / cm. Was obtained (see FIG. 1). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

  Then, using a transparent PET film (thickness 125 μm) as a transparent substrate, the above coating material composition was applied to the surface of the transparent substrate with a wire bar coater # 4, dried at room temperature (23 ° C.) for 2 minutes, and then 120 A substrate with a transparent conductive film in which a transparent conductive film having a thickness of 0.5 μm was formed was obtained by heating and drying at 3 ° C. for 3 minutes, and further irradiating and curing ultraviolet rays at an intensity of 500 mJ / cm (FIG. 1). reference). In the transparent conductive film, the volume ratio of matrix resin / translucent particles was about 2, and the content of metal nanowires in the transparent conductive film was about 3.0% by mass.

  About the base material with a transparent conductive film of said Examples 1-5 and Comparative Examples 1-3, the surface resistance of the transparent conductive film and the transmittance | permeability of the transparent conductive film were measured.

  Here, the surface resistance of the transparent conductive film was measured using a surface resistance meter (“Hiresta IP (MCP-HT260)” manufactured by Mitsubishi Chemical Corporation). The transmittance of the transparent conductive film was measured using a spectrophotometer (“U-4100” manufactured by Hitachi High-Tech). The results are shown in Table 1.

  As can be seen in Table 1, it was confirmed that the transparent conductive film of each Example had a small surface resistance, improved conductivity, and high transmittance.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Transparent electrically conductive film 3 Metal nanowire 4 Translucent particle | grains 5 Matrix resin

Claims (3)

  A substrate with a transparent conductive film provided with a transparent conductive film formed on the surface of the transparent base material containing a metal nanowire in the matrix resin, and the matrix resin of the transparent conductive film has a refraction with the matrix resin. A transparent conductive film comprising translucent particles having a difference in rate of within ± 0.03 and having a particle diameter of 0.5 to 1.2 times the film thickness of the transparent conductive film With base material.   2. The transparent conductive film-attached group according to claim 1, wherein the ratio of the particle diameter (D) of the translucent particles to the length (L) of the metal nanowires is 0.005 ≦ D / L <1. Wood.   3. The substrate with a transparent conductive film according to claim 1 or 2, wherein the volume ratio of the matrix resin and the translucent particles in the transparent conductive film is matrix resin / translucent particles ≦ 5.

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