JP5949238B2 - Method for producing transparent conductive substrate - Google Patents

Description

  The present invention relates to a method for producing a transparent conductive substrate.

  In recent years, flat displays have been used in many fields and places, and their importance has been increasing with the progress of computerization.

  Currently, liquid crystal displays (LCD) can be said to be at the center of flat displays, but organic EL, inorganic EL, and plasma display panels (PDP) can be used as flat displays based on a different display principle from liquid crystal displays (LCD). Development of a light emitting diode display device (LED), a fluorescent display tube display device (VFD), a field emission display (FED), and the like is also actively conducted.

  A transparent conductive substrate is used in almost all of the various flat displays including a liquid crystal display (LCD).

Conventionally, a transparent conductive substrate has been composed of a transparent base material and a transparent conductive layer located on the base material and obtained by vapor-depositing a transparent conductive metal oxide. However, in recent years, with the increase in the size of flat displays, in order to solve the problem that a voltage drop occurs only with a transparent conductive layer, not only a transparent conductive layer but also a conductive metal oxide is formed on a transparent substrate. Forming the pattern conductive layer containing by application | coating is performed. By forming the patterned conductive layer in this way, the patterned conductive layer becomes a current path, and it is possible to prevent the occurrence of a voltage drop due to an increase in the size of the flat display.
In addition, the following patent document 1 is mentioned as a prior art considered to be related to this invention.

JP 2006-107996 A

  However, as described above, when two types of layers, a transparent conductive layer and a patterned conductive layer, are formed on a substrate, these layers are formed in different ways, that is, the transparent conductive layer is formed by a vapor deposition method. Since the pattern conductive layer is formed by application of a coating solution, the adhesion strength between these layers and the base material is different, which may cause a problem that the degree of completion as a final product is lowered. The reason why the adhesion strength between the patterned conductive layer formed by coating and the transparent conductive layer formed by vapor deposition is not necessarily clear, but when formed by coating, it was coated on the substrate. At the stage, it is not yet a “layer”, but gradually becomes a layer by drying after that, whereas when formed by vapor deposition, it is formed as a “layer” directly on the base material. It can be considered that the adhesion strength varies depending on changes and the magnitude of damage to the substrate. It can also be considered that the compatibility with the functional group present on the substrate surface and the wettability of the substrate surface influence the adhesion. In other words, even when the functional group present on the substrate surface and the solid content in the coating liquid for forming the pattern conductivity are good, the substance constituting the transparent conductive layer formed by vapor deposition When the compatibility is poor, it can be assumed that good adhesion cannot be obtained. Furthermore, a layer formed by vapor deposition generally has a higher residual stress than a layer formed by coating, and it is considered that the residual stress of the transparent electrode layer is higher than that of the pattern conductive layer. It can also be considered that this difference in residual stress affects the adhesion.

  In order to solve the problem, the transparent conductive layer and the patterned conductive layer may be formed by the same forming method, that is, for example, each layer may be formed by vapor deposition, or each layer may be formed by application of a coating solution. In such a case, the material and the like of each layer is restricted by the forming method, and the performance of each layer is lowered and the cost is increased, which is not preferable.

  The present invention has been made under such circumstances, and relates to a method for producing a transparent conductive substrate in which a patterned conductive layer is formed in addition to the transparent conductive layer in order to prevent the occurrence of a voltage drop. A new transparent conductive substrate in which the adhesion strength between each layer and the base material is not lowered even if the pattern conductive layer and the pattern conductive layer are formed by different forming methods such as vapor deposition and coating liquid coating, respectively. It is a main subject to provide a manufacturing method.

The invention for solving the above problems is a method for producing a transparent conductive substrate, wherein a primer layer obtained by curing a curable resin containing a silane coupling agent is formed on a transparent substrate. , A step of preparing a transparent substrate, and a step of forming a patterned conductive layer by applying a coating solution for forming a patterned conductive layer containing a conductive metal or a conductive metal compound on the primer layer and then drying And forming a transparent conductive layer by vapor-depositing a transparent conductive metal oxide on the primer layer, the amount of the silane coupling agent contained in the primer layer is the mass of the primer layer It is characterized by being 10 mass% or more and 25 mass% .

  In the above invention, a gas barrier layer containing a silicon compound or an aluminum compound may be present on the surface of the transparent substrate on which the primer layer is formed.

  According to the method for producing a transparent conductive substrate of the present invention, first, since a pattern conductive layer is formed on a transparent base material in addition to the transparent conductive layer, a flat display can be produced without causing a voltage drop. It can meet the demand for larger size. Second, the patterned conductive layer is formed by applying a coating liquid, while the transparent conductive layer is formed by a vapor deposition method, that is, a forming method according to each layer is adopted. There are no restrictions and no cost increases. Third, since a primer layer obtained by curing a curable resin containing a silane coupling agent is formed on a transparent substrate, the function of the silane coupling agent in the primer layer allows Even if the transparent conductive layer and the patterned conductive layer are formed by different forming methods such as vapor deposition and coating liquid, respectively, it is possible to prevent the adhesion strength between these layers and the substrate from being lowered. .

It is a schematic sectional drawing of the base material prepared in the process of preparing a transparent substrate. It is a schematic sectional drawing at the time of forming a pattern conductive layer on the transparent substrate shown to Fig.1 (a). It is a schematic sectional drawing at the time of forming a transparent conductive layer on the transparent substrate after the pattern conductive layer shown in FIG. 2 was formed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the form demonstrated below, In the range which does not deviate from a technical thought, it can implement in various deformation | transformation. In the accompanying drawings, the vertical and horizontal scales may be exaggerated for the sake of explanation, and the actual scales may differ.

  The manufacturing method of the transparent conductive substrate of this invention prepares the transparent substrate by which the primer layer obtained by hardening the curable resin containing a silane coupling agent was formed on the transparent base material (1). And (2) applying a pattern conductive layer forming coating solution containing a conductive metal or a conductive metal compound on the primer layer, followed by drying to form a patterned conductive layer; 3) forming a transparent conductive layer by vapor-depositing a transparent conductive metal oxide on the primer layer. Hereinafter, each step will be described.

(1) Process for Preparing Transparent Substrate FIG. 1 is a schematic cross-sectional view of a base material prepared in this process.

  As shown in FIG. 1 (a), the transparent substrate 10 prepared in this step is obtained by curing a transparent base material 11 and a curable resin containing a silane coupling agent on the base material 11. And a primer layer 12 to be formed. Thus, the presence of the primer layer 12 containing the silane coupling agent can strengthen the adhesion between the patterned conductive layer formed by coating and the transparent conductive layer formed by the vapor deposition method. it can.

  Here, the material of the base material 11 constituting the transparent substrate 10 is not particularly limited, and a material having a desired transparency and used in a conventional transparent conductive substrate is appropriately selected. Can be used. Specifically, for example, a rigid material such as quartz glass, Pyrex (registered trademark) glass, synthetic quartz, or a transparent flexible material having flexibility such as a transparent resin film or an optical resin plate can be used. .

  Moreover, it does not specifically limit about the thickness of the base material 11, What is necessary is just to be about 50-300 micrometers like the past, for example.

  FIG. 1B shows another aspect of the base material 11 constituting the transparent substrate 10. The substrate 11 shown in FIG. 1 (a) has a single-layer structure, but is not limited to the single-layer structure, and may have a laminated structure as shown in FIG. 1 (b). . FIG. 1B shows a two-layer structure.

  In the case where the base material 11 has a laminated structure, the material and thickness of each layer constituting the base material 11 are not particularly limited, and various materials that can be selected as the base material 11 have desired performance. What is necessary is just to laminate | stack suitably so that it may exhibit.

  More specifically, for example, as shown in FIG. 1B, when the substrate 11 has a two-layer structure, a rigid material such as quartz glass, Pyrex (registered trademark) glass, synthetic quartz, or the like, A layer 11a made of a transparent flexible material having flexibility, such as a transparent resin film or an optical resin plate, and a gas barrier layer 11b containing a silicon compound or an aluminum compound are stacked, and the structure is described later on the gas barrier layer 11b. The primer layer 12 to be formed may be formed.

  Thus, by providing the gas barrier layer 11b at the portion located at the interface between the base material 11 and the primer layer 12 described later, when outgassing from the layer 11a constituting the base material 11 occurs, This can prevent the primer layer 12 from being adversely affected.

  The gas barrier layer 11b is not particularly limited as long as it includes a silicon compound or an aluminum compound and exhibits a desired gas barrier property. For example, the gas barrier layer 11b is formed by a conventionally known sputtering method or vacuum deposition method. A silicon oxide layer, an aluminum oxide layer, or the like can be used.

  A curable resin containing a silane coupling agent on the surface of such a substrate 11, more specifically, on the surface on which either or both of the patterned conductive layer and the transparent conductive layer are formed in the subsequent step. A primer layer 12 obtained by curing is formed.

  The curable resin constituting the primer layer may be appropriately selected from general thermosetting resins, ultraviolet curable resins, and further electron beam curable resins, and is not particularly limited. However, in view of industrial productivity, it is preferable to use an ultraviolet curable resin. This is because when a thermosetting resin or an electron beam curable resin is used, the base material 11 may be damaged by heat or an electron beam.

  Among the ultraviolet curable resins, it is preferable to use a resin having an acrylic monomer as a main component. Specifically, those having an acrylate functional group, for example, a relatively low molecular weight polyester resin, a polyether resin, an acrylic resin, Examples include epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers such as (meth) acrylates of polyfunctional compounds such as polyhydric alcohols, and reactive diluents. Of these, polyester acrylate is preferably used in consideration of industrial production and the like. More specifically, monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, and polyfunctional monomers such as polymethylolpropane tri (meth) acrylate, hexanediol (Meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol (meth) acrylate, Neopentyl glycol di (meth) acrylate, nonylphenol EO modified acrylate, bisphenol AEO modified diacrylate, polypropylene glycol diacrylate, dipentaery Lithol pentaacrylate, trimethylolpropane triacrylate, trimethylolpropane EO-modified triacrylate, ditrimethylolpropane tetraacrylate, urethane acrylate, 2-hydroxy-3-phenoxypropyl acrylate and the like. In the present specification, “(meth) acrylate” means acrylate or methacrylate.

  The silane coupling agent contained in the resin and constituting the primer layer 12 is not particularly limited, and a conventionally known silane coupling agent can be appropriately selected and used. Among them, when the polyester acrylate mentioned above as a preferable example is used as a curable resin, it is preferable to use a silane coupling agent having an ethylenically unsaturated double bond, specifically, a vinyl silane. It is preferably at least one selected from a coupling agent, a methacryloxy silane coupling agent, and an acryloxy silane coupling agent. This is because these are silane coupling agents that are industrially easily obtained, and methacryloxy-based silane coupling agents are particularly preferable in consideration of safety.

  Examples of the vinyl silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, and vinyltriethoxysilane. Examples of the methacryloxy silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane. Can do. Examples of the acryloxy silane coupling agent include 3-acryloxypropyltrimethoxysilane. Among these, 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldiethoxysilane (KBE-502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyl Triethoxysilane (KBE-503, manufactured by Shin-Etsu Chemical Co., Ltd.) is preferable in terms of safety and industrial use.

  The content of the silane coupling agent as described above is preferably 10% by mass or more and 25% by mass or less with respect to the mass of the primer layer 12. That is, when the mass of the primer layer 12 is 100% by mass, the content of the silane coupling agent is preferably controlled to be 10% by mass or more and 25% by mass or less. By setting the content of the silane coupling agent to 10% by mass or more, the group having silicon formed by the silane coupling agent has the primer layer 12 and the patterned conductive layer and the transparent conductive layer formed thereon. It is easy to obtain the effect of maintaining adhesion over time. On the other hand, content of the silane coupling agent which does not contribute to the said adhesiveness can be controlled by setting it as 25 mass% or less.

  The presence of a silicon-containing group at the interface between the primer layer 12 and the patterned conductive layer and transparent conductive layer formed thereon, and the adhesion between the primer layer, the patterned conductive layer, and the transparent conductive layer. Although the relationship is not necessarily clear, according to the study of the present inventor, there is some relationship between them, and it is considered preferable that a group containing silicon is present on the surface of the primer layer 12. The amount of the silicon-containing group present on the surface of the primer layer 12 is not particularly limited, but it is preferably, for example, 0.1 to 0.25%. This amount can be obtained by ESCA (X-ray photoelectron spectroscopy) analysis of the surface of the primer layer 12 to determine the amount of silicon (atomic%).

  The method for forming the primer layer 12 is not particularly limited, and a known method can be appropriately selected and used. For example, it may be formed by applying and curing a primer layer forming coating solution.

  The primer layer forming coating solution may contain a polymerization initiator and a photosensitizer in addition to the above-described curable resin and silane coupling agent, and may contain various solvents from the viewpoint of viscosity adjustment. . In addition, it contains various additives such as heat stabilizers, radical scavengers, plasticizers, surfactants, antistatic agents, antioxidants, ultraviolet absorbers, infrared absorbers, dyes, extender pigments, light diffusing agents, etc. May be.

  The primer layer 12 does not necessarily have to be formed. If there is a transparent substrate 10 on which the primer layer 12 is formed in advance, it may be purchased.

  The thickness of the primer layer 12 is not particularly limited, and may be, for example, 0.1 μm or more and 20 μm or less, and particularly preferably 0.5 μm or more and 10 μm or less.

(2) Pattern conductive layer formation process FIG. 2: is a schematic sectional drawing at the time of forming the pattern conductive layer 20 on the transparent substrate 10 shown to Fig.1 (a).

  As shown in FIG. 2, in the manufacturing method of the transparent conductive substrate of this invention, the coating liquid for pattern conductive layer formation containing a conductive metal or a conductive metal compound in the primer layer 12 in the prepared transparent substrate 10 is shown. The process of forming the pattern conductive layer 20 is performed by apply | coating and drying after that.

  As a conductive metal or a conductive metal compound contained in the pattern conductive layer forming coating solution used in the step, a conventionally known one may be appropriately selected and used without any particular limitation. Examples thereof include metals such as Cu, Ag, Au, Pt, Al, Cr, and Co, alloys thereof, and oxide grains and nitrides of the metals. In addition, a multilayer metal film represented by MAM (molybdenum / aluminum / neodymium alloy / molybdenum) can be given.

  Furthermore, in the coating liquid for pattern conductive layer formation, a dispersing agent etc. can be contained other than an organic compound and a solvent.

  The method for applying such a pattern conductive layer forming coating solution is not particularly limited, and various printing methods such as an ink jet printing method may be appropriately selected and used.

(3) Pattern conductive layer formation process FIG. 3: is a schematic sectional drawing at the time of forming a transparent conductive layer on the transparent substrate after the pattern conductive layer shown in FIG. 2 was formed.

  As shown in FIG. 3, in the manufacturing method of the transparent conductive substrate of this invention, the transparent conductive layer 30 is formed by vapor-depositing a transparent conductive metal oxide on the primer layer 12 in the prepared transparent substrate 10. A forming step is performed.

  As the transparent conductive metal oxide deposited in the process, those that are already commonly used may be appropriately selected and used. For example, indium tin oxide (ITO), indium oxide, zinc oxide, or oxide A stannic etc. can be mentioned.

  Also, a specific vapor deposition method is not particularly limited, and a conventionally known vapor deposition method may be used.

  Although the transparent conductive layer 30 shown in FIG. 3 is formed not only on the primer layer 12 but also on the patterned conductive layer 20, the transparent conductive layer 30 is not limited to this aspect and is formed on at least the primer layer 12. It only has to be.

  In the above description, the case of manufacturing in the order of (1), (2), and (3) has been described. However, (2) and (3), that is, (2) pattern conductive layer forming step, and (3) transparent The conductive layer forming step is not necessarily performed in this order, and (2) the patterned conductive layer forming step may be performed after the (3) transparent conductive layer forming step.

Example 1
As a transparent base material constituting the transparent substrate, a PEN substrate (Q65-FA, Teijin DuPont, 300 mm width, 300 m, 125 umt) was prepared, and this was washed with water and dried to clean the surface of the base material. .

  Next, a primer layer-forming coating solution shown below was prepared, applied to the surface of the cleaned substrate by a slot die coating method, and dried to form a primer layer having a thickness of 1 μm. In addition, when the centerline average roughness (Ra) of the surface of a primer layer was measured, it was confirmed that it was Ra = 2nm and was a very flat surface.

(Primer layer forming coating solution)
-Methacryloxy silane coupling agent (3-methacryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-503): 8 parts by mass-Polyester acrylate (polymerizable compound, manufactured by Toagosei Co., Ltd., product) Name: M-8030): 15 parts by mass fluorene acrylate (polymerizable compound, manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: NK ester A-BPEF): 15 parts by mass, methyl ethyl ketone: 30 parts by mass, toluene: 30 parts by mass Part / oligo [2-hydroxy-2-methyl- [1- (methylvinyl) phenyl] propanone] (photopolymerization initiator, manufactured by Lamberti, trade name: ESACURE ONE): 2 parts by mass

  Next, a silver nanocolloid solution (Halima Kasei, NPS-J) is prepared as a coating liquid for pattern conductive layer formation, and is printed in a pattern on the primer layer by inkjet printing (coating). The patterned conductive layer was formed by drying at 120 ° C. for 15 minutes in the air. The thickness of the patterned conductive layer after drying was 200 nm.

  Subsequently, the transparent conductive substrate by the manufacturing method of Example 1 of this invention was obtained by forming the transparent conductive layer which consists of ITO by sputtering method (vapor deposition method). The thickness of the transparent conductive layer was 100 nm.

(Evaluation of Example 1)
An organic solar cell was manufactured using the transparent conductive substrate by the manufacturing method of Example 1 above. That is, PEDOT-PSS (Clevious, AI-4083) as a hole transport layer and a P3HT / PCBM layer as a photoelectric conversion layer are formed on a transparent conductive substrate by a gravure printing method, and Ca is opposed to an electron transport layer. Al was vapor-deposited as an electrode to produce an organic thin-film solar cell element. In the organic thin film solar cell formation process, a heating step of 150 ° C. for 15 minutes in the PEDOT-PSS drying step and a heating step of 150 ° C. for 15 minutes in the drying step of the photoelectric conversion layer were performed. The state of was good.

  Moreover, the organic thin-film solar cell manufactured above is cut into a predetermined size to obtain a strip-shaped single cell having a width of 250 mm and 20 mm, which is irradiated with pseudo-sunlight of AM1.5G, and the solar cell characteristics are evaluated. As a result, a solar cell characteristic of conversion efficiency: 4% was obtained.

(Comparative Example 1)
The same transparent substrate as in Example 1 was prepared and washed in the same manner as in Example 1. The surface of the substrate after washing is subjected to an easy adhesion treatment, and the pattern conductive layer is applied to the easy adhesion treatment surface under the same conditions as in Example 1 using the same pattern conductive layer forming coating solution as in Example 1. A layer was formed.

  Subsequently, the transparent conductive substrate by the manufacturing method of the comparative example 1 was obtained by forming the transparent conductive layer which consists of ITO on the same conditions as Example 1. FIG. That is, in Comparative Example 1, the primer layer is not provided.

(Evaluation of Comparative Example 1)
When the same evaluation as in Example 1 was performed using the transparent conductive substrate according to the manufacturing method of Comparative Example 1, the transparent conductive layer was peeled off from the transparent base material, and cracks were generated in the transparent conductive layer. . It was unsuitable as an organic thin film solar cell.

(Comparative Example 2)
The same transparent substrate as in Example 1 was prepared and washed in the same manner as in Example 1. A patterned conductive layer was formed on the surface of the substrate after washing using the same pattern conductive layer forming coating solution as in Example 1 under the same conditions as in Example 1. That is, in Comparative Example 2, the primer layer is not provided and the easy adhesion treatment is not performed.

(Evaluation of Comparative Example 2)
When the surface was observed after forming a pattern conductive layer, it turned out that the pattern conductive layer has peeled from the transparent base material in several places. Therefore, it is not necessary to form a transparent conductive layer, and it is unsuitable as a transparent conductive substrate, and an organic thin film solar cell could not be produced.

DESCRIPTION OF SYMBOLS 10 ... Transparent substrate 11 ... Transparent base material 12 ... Primer layer 20 ... Pattern conductive layer 30 ... Transparent conductive layer

Claims (2)

A step of preparing a transparent substrate on which a primer layer obtained by curing a curable resin containing a silane coupling agent is formed on a transparent substrate;
On the primer layer, a pattern conductive layer forming coating solution containing a conductive metal or a conductive metal compound is applied and then dried to form a pattern conductive layer; and
Forming a transparent conductive layer by depositing a transparent conductive metal oxide on the primer layer; and
Including
The method for producing a transparent conductive substrate, wherein the amount of the silane coupling agent contained in the primer layer is 10% by mass to 25% by mass with respect to the mass of the primer layer .   The method for producing a transparent conductive substrate according to claim 1, wherein a gas barrier layer containing a silicon compound or an aluminum compound is present on a surface of the transparent base material on which the primer layer is formed.

Images