JP5691334B2 - Method for producing transparent conductive laminate - Google Patents

Description

  The present invention relates to a method for producing a transparent conductive laminate used for electronic recording, for example.

  In recent years, some electronic devices have a transparent touch panel attached as an input device on a display. As a touch panel system, a resistance film type, a capacitance type, and the like are known.

  Among these, for the capacitive touch panel, a transparent conductive laminate formed by forming a transparent conductive film having a pattern is used, and it is necessary to bond transparent conductive laminates having different patterns.

  As a method for forming a pattern on the transparent conductive layer, for example, a method by photolithography in which a pattern is formed using a resist is known (Patent Documents 1 to 3). As another method, pattern exposure is performed using an indium compound having a functional group or site that reacts with light and a tin compound having a similar functional group or site as a composition for forming a conductive film (reference document). 4) A method of forming a pattern with laser light (Cited document 5) is known.

  By the way, since these transparent conductive laminates are liquid crystal displays, plasma displays, and touch panels as optical components, the transparent conductive film is required to have low electrical resistance, high transmittance for visible light, high durability, and the like. Therefore, a means for crystallizing the transparent conductive film by heating the film is taken. The transparent conductive film thus formed has high conductivity (low electrical resistivity), high light transmission in the visible light region, and mechanical strength.

  In order to crystallize the transparent conductive film, there is a method (Cited Document 6) in which a transparent conductive film is formed and then subjected to heat treatment for crystallization.

JP-A-1-197911 JP-A-2-109205 JP-A-2-309510 Japanese Patent Laid-Open No. 9-142848 JP 2008-140130 A Japanese Patent Laid-Open No. 2-194943

  However, in the crystallization method described in Patent Document 6, since the electrode laminate is a polymer film, the heat treatment temperature is limited, and a relatively long heat treatment is required at a relatively low temperature of 150 ° C. As a result, the productivity and the cost are inferior.

  In addition, when laminating transparent conductive laminates with different patterns, in order to accurately read the two-dimensional position information, a pattern as fine as possible was formed and provided on both sides of the transparent substrate layer. It is necessary to accurately align the pattern. However, since the transparent conductive laminate is a polymer film, the film shrinks due to heat treatment, causing deformation of the film such as curl, making it difficult to align the pattern with high precision during bonding, and its production is very Has the problem of being troublesome.

  The present invention has been made in view of the problems of the related art, and the transparent conductive layer formed on both surfaces of the laminated body after bonding is crystallized at the same time by heat treatment after bonding the transparent conductive laminated body. To provide a method for producing a transparent conductive laminate that can easily perform pattern alignment by shortening necessary steps and time and performing bonding before film deformation after heat treatment. With the goal.

The invention according to claim 1 includes a step of forming at least a transparent conductive layer on one side of the first transparent substrate layer, a step of forming at least a transparent conductive layer on one side of the second transparent substrate layer, and the transparent conductive layer. A step of bonding the first transparent substrate layer and the second transparent substrate layer with an adhesive, with the layer facing outside, the transparent conductive layer of the first transparent substrate layer, and the second transparent substrate layer A conductive pattern region and a non-conductive pattern region on the transparent conductive layer of the first transparent substrate layer and the transparent conductive layer of the second transparent substrate layer subjected to the heat treatment of the transparent conductive layer; Holders of Bei and forming, and wherein the processing der Rukoto for the heat treatment to crystallize the transparent conductive layer of the transparent conductive layer and said second transparent substrate layer of the first transparent substrate layer This is a method for producing a transparent conductive laminate.

The invention according to claim 2 is the method for producing the transparent conductive laminate according to claim 1 , wherein the heat treatment is performed in the atmosphere, and the heating temperature is 130 ° C. or higher and 150 ° C. or lower. And heating time is 30 minutes or more and 90 minutes or less.

The invention according to claim 3 is a method in which the heat treatment is performed in vacuum (atmospheric pressure to 0.01 Pa) in the method for producing a transparent conductive laminate according to claim 1 , and the heating temperature Is 80 ° C. or higher and 150 ° C. or lower, and the heating time is 1 minute or longer and 90 minutes or shorter.

The invention according to claim 4 is the method for producing a transparent conductive laminate according to any one of claims 1 to 3 , wherein the heat treatment is performed by a roll-to-roll method. .

  According to the present invention, the transparent conductive layer formed on both sides of the laminated body is crystallized at the same time by heat treatment after the transparent conductive laminated body is bonded, thereby shortening necessary steps and time. A method for producing a transparent conductive laminate can be provided.

It is sectional drawing which showed the transparent conductive laminated body produced by the manufacturing method of the transparent conductive laminated body which concerns on embodiment of this invention. It is sectional drawing shown in order to demonstrate the preparation procedure of FIG. It is sectional drawing shown in order to demonstrate the structure of the transparent conductive laminated body which concerns on other embodiment of this invention. It is sectional drawing shown in order to demonstrate the structure of the transparent conductive laminated body which concerns on other embodiment of this invention. It is sectional drawing shown in order to demonstrate the structure of the transparent conductive laminated body which concerns on other embodiment of this invention. It is sectional drawing shown in order to demonstrate the process of forming a conductive pattern area | region and a nonelectroconductive pattern in the 1st transparent conductive layer and 2nd transparent conductive layer of FIG. 5, respectively. It is sectional drawing shown in order to demonstrate the process of heat-processing to the transparent conductive layer of FIG.

  Hereinafter, the manufacturing method of the transparent conductive laminated body concerning embodiment of this invention is demonstrated in detail with reference to drawings. The present invention is not limited to the embodiments described below, and modifications such as design changes can be made based on the knowledge of those skilled in the art, and such modifications have been added. Embodiments are also included in the scope of the present invention.

  FIG. 1 shows a transparent conductive laminate 8 according to the method for producing a transparent conductive laminate of the present invention. For example, first and second transparent substrate layers 1a and 1b are bonded together with an adhesive layer interposed therebetween. Is done. As shown in FIG. 2, transparent conductive layers 3a and 3b are respectively laminated on the first and second transparent substrate layers 1a and 1b, and an optical adjustment layer is formed on the transparent conductive layers 3a and 3b. 2a and 2b are laminated respectively. The first and second transparent substrate layers 1a and 1b are stacked with the adhesive layers interposed between the transparent conductive layers 3a and 3b and subjected to heat treatment or the like as described later. Thus, the transparent conductive laminate 8 is formed.

  Here, the first and second transparent substrate layers 1a and 1b are, for example, surfaces on which the transparent conductive layer 3b of the first transparent substrate layer 1a and the transparent conductive layer 3b of the second transparent substrate layer 1b are not formed. May be configured to be bonded together by the adhesive layer 6. Also, both the optical adjustment layers 2a and 2b and the resin layers 5a and 5b are arranged on only one of the first and second transparent substrate layers 1a and 1b, or the optical adjustment layers 2a and 2b are provided on one side and the other is provided on the other side. The resin layers 5a and 5b may be provided.

  In addition, as the transparent conductive laminate 8, for example, as shown in FIG. 3, the transparent conductive layer 8 is directly transparent on one side of the first and second transparent substrate layers 1 a and 1 b bonded together via the adhesive layer 6. The layers 3a and 3b are disposed, or only the optical adjustment layers 2a and 2b are interposed between the first and second transparent substrate layers 1a and 1b and the transparent conductive layers 3a and 3b as shown in FIG. Alternatively, as shown in FIG. 5, only the resin layers 5a and 5b are arranged between the first and second transparent substrate layers 1a and 1b and the transparent conductive layers 3a and 3b, and the other surface side is arranged. You may make it comprise by bonding using the adhesion layer 6. FIG.

  Furthermore, the first and second transparent substrate layers 1a and 1b are arranged with optical adjustment layers 2a and 2b stacked only between the transparent conductive layers 3a and 3b, as shown in FIG. Alternatively, as shown in FIG. 5, the resin layers 5 a and 5 b may be stacked and bonded together via the adhesive layer 6.

  That is, at least transparent conductive layers 3a and 3b are laminated on one side of the first and second transparent substrate layers 1a and 1b, and the optical adjustment layer 2a is interposed between the transparent conductive layers 3a and 3b. 2b and resin layers 5a and 5b are selectively stacked.

  Further, as shown in FIG. 6, the transparent conductive layer 3a of the first transparent substrate layer 1a and the transparent conductive layer 3b of the second transparent substrate layer 1b of the transparent conductive laminate 8 have conductive pattern regions 4a and The non-conductive pattern region 4b is selectively patterned. Here, the conductive pattern region 4a refers to a conductive portion of the transparent conductive layers 3a and 3b, and the non-conductive pattern region 4b refers to a conductive portion of the transparent conductive layers 3a and 3b. This refers to a portion that does not have electrical conductivity except for a portion that has.

  The first and second transparent substrate layers 1a and 1b are made of a plastic film made of resin in addition to glass. The plastic film is not particularly limited as long as it has sufficient strength in the film-forming process and the post-process and has good surface smoothness. For example, polyethylene terephthalate film, polybutylene terephthalate film, polyethylene naphthalate film, polycarbonate Examples include films, polyethersulfone films, polysulfone films, polyarylate films, cyclic polyolefin films, polyimide films, and the like. The thickness is about 10 μm or more and 200 μm or less in consideration of the thinning of the member and the flexibility of the laminate.

  As materials contained in the first and second transparent substrate layers 1a and 1b, various known additives and stabilizers such as antistatic agents, plasticizers, lubricants, and easy-adhesive agents may be used. . In order to improve adhesion with each layer, corona treatment, low temperature plasma treatment, ion bombardment treatment, chemical treatment, etc. may be performed as pretreatment.

  The resin layers 5a and 5b are provided to give the transparent conductive laminate 8 mechanical strength. Although it does not specifically limit as resin used, Resin which has transparency, moderate hardness, and mechanical strength is preferable. Specifically, a photocurable resin such as a monomer or a crosslinkable oligomer mainly composed of a trifunctional or higher functional acrylate that can be expected to be three-dimensionally crosslinked is preferable.

  Trifunctional or higher acrylate monomers include trimethylolpropane triacrylate, isocyanuric acid EO-modified triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate Ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, polyester acrylate and the like are preferable. Particularly preferred are isocyanuric acid EO-modified triacrylates and polyester acrylates. These may be used alone or in combination of two or more. In addition to these tri- or higher functional acrylates, so-called acrylic resins such as epoxy acrylate, urethane acrylate, and polyol acrylate can be used in combination.

  As the crosslinkable oligomer, acrylic oligomers such as polyester (meth) acrylate, polyether (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate, and silicone (meth) acrylate are preferable. Specific examples include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenol A type epoxy acrylate, polyurethane diacrylate, and cresol novolac type epoxy (meth) acrylate.

  In addition, the resin layers 5a and 5b may further contain additives such as particles and a photopolymerization initiator. Examples of the particles to be added include organic or inorganic particles, but it is preferable to use organic particles in consideration of transparency. Examples of the organic particles include particles made of acrylic resin, polystyrene resin, polyester resin, polyolefin resin, polyamide resin, polycarbonate resin, polyurethane resin, silicone resin, and fluorine resin.

  The average particle diameter of the particles varies depending on the thickness of the resin layers 5a and 5b, but for reasons of appearance such as haze, the lower limit is 2 μm or more, more preferably 5 μm or more, and the upper limit is 30 μm or less, preferably 15 μm or less. Is used. Further, for the same reason, the particle content is preferably 0.5% by weight or more and 5% by weight or less based on the resin.

  When a photopolymerization initiator is added, radical generating photopolymerization initiators include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl methyl ketal, acetophenone, 2, 2 , -Dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, and other acetophenones, methylanthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone and other anthraquinones, thioxanthone, 2,4-diethylthioxanthone, 2, 4 -Thioxanthones such as diisopropylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenone, 4,4-bismeth Le benzophenones such aminobenzophenone and azo compounds, and the like. These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine, benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate, etc. It can be used in combination with a photoinitiator aid or the like.

  The addition amount of the photopolymerization initiator is 0.1% by weight or more and 5% by weight or less, preferably 0.5% by weight or more and 3% by weight or less with respect to the main component resin. Less than the lower limit is not preferable because the hard coat layer is insufficiently cured. Moreover, when exceeding an upper limit, since yellowing of a hard-coat layer will be produced or a weather resistance will fall, it is unpreferable. The light used for curing the photocurable resin is ultraviolet rays, electron beams, or gamma rays, and in the case of electron beams or gamma rays, it is not always necessary to contain a photopolymerization initiator or a photoinitiating aid. As these radiation sources, high pressure mercury lamps, xenon lamps, metal halide lamps, accelerated electrons, and the like can be used.

  The thickness of the resin layers 5a and 5b is not particularly limited, but is preferably in the range of 0.5 μm or more and 15 μm or less. Moreover, it is more preferable that the refractive index is the same or close to that of the first and second transparent substrate layers 1a and 1b, and it is preferably about 1.45 or more and 1.75 or less.

  The resin layers 5a and 5b are formed by dissolving a resin as a main component in a solvent, a die coater, a curtain flow coater, a roll coater, a reverse roll coater, a gravure coater, a knife coater, a bar coater, a spin coater, and a micro gravure. It is formed by a known coating method such as a coater.

  The solvent is not particularly limited as long as it dissolves the main component resin and the like. Specifically, as a solvent, ethanol, isopropyl alcohol, isobutyl alcohol, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, methyl cellosolve, ethyl cellosolve, Examples include butyl cellosolve, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate. These solvents may be used alone or in combination of two or more.

  The adhesive layer 6 is a layer for bonding the first transparent substrate layer 1a and the second transparent substrate layer 1b. Examples of the resin used for the adhesive layer 6 include acrylic resins, silicone resins, and rubber resins, and it is preferable to use a resin excellent in cushioning properties and transparency.

Unnecessary light can be absorbed in a wide wavelength region.

  The optical adjustment layers 2a and 2b have a function of making the pattern formed on the transparent conductive layer 2a and the transparent conductive layer 2b inconspicuous and improve visibility. When an inorganic compound is used as the optical adjustment layers 2a and 2b, materials such as oxides, sulfides, fluorides, and nitrides can be used. The thin film made of the inorganic compound has a different refractive index depending on the material, and the optical characteristics can be adjusted by forming a thin film having a different refractive index with a specific film thickness. The number of optical functional layers may be a plurality of layers depending on the target optical characteristics.

  Materials having a low refractive index include magnesium oxide (1.6), silicon dioxide (1.5), magnesium fluoride (1.4), calcium fluoride (1.3 to 1.4), cerium fluoride ( 1.6), aluminum fluoride (1.3), and the like. Moreover, as a material with a high refractive index, titanium oxide (2.4), zirconium oxide (2.4), zinc sulfide (2.3), tantalum oxide (2.1), zinc oxide (2.1), Examples include indium oxide (2.0), niobium oxide (2.3), and tantalum oxide (2.2). However, the numerical value in the parenthesis represents the refractive index.

  Examples of the transparent conductive layers 3a and 3b include indium oxide, zinc oxide, and tin oxide, or two or three kinds of mixed oxides thereof, and those added with other additives. However, various materials can be used depending on the purpose and application, and are not particularly limited. At present, the most reliable and proven material is indium tin oxide (ITO).

  When indium tin oxide (ITO), which is the most common transparent conductive film, is used as the transparent conductive layers 3a and 3b, the content ratio of tin oxide doped in indium oxide is an arbitrary ratio depending on the specifications required for the device. Select. For example, when the transparent substrate is a plastic film, the sputtering target material used for crystallizing the thin film for the purpose of increasing the mechanical strength preferably has a tin oxide content of less than 10% by weight. In order to impart the properties, the content ratio of tin oxide is preferably 10% by weight or more. Moreover, when low resistance is calculated | required by a thin film, the content rate of a tin oxide has the preferable range of 3 to 20 weight%.

  As a method for manufacturing the optical adjustment layers 2a and 2b and the transparent conductive layers 3a and 3b, any film forming method may be used as long as the film thickness can be controlled, and a thin film forming dry method is particularly preferable. For this, a vacuum vapor deposition method, a physical vapor deposition method such as sputtering, or a chemical vapor deposition method such as a CVD method can be used. In particular, in order to form a thin film having a uniform film quality over a large area, a sputtering method in which the process is stable and the thin film becomes dense is preferable.

  In the heat treatment step of the transparent conductive laminate 8, for example, as shown in FIG. 7, a heat source 7a for heat-treating the transparent conductive layer 3a of the first transparent substrate layer 1a and a transparent conductive material of the second transparent substrate layer 1b. This is performed using a heating mechanism having a heat source 7b for heat-treating the layer 3b. And heat processing is performed from both surfaces of the transparent conductive laminated body 8 using this heat source 7a, 7b.

  In this heat treatment, if the transparent conductive layer 3a of the first transparent substrate layer 1a and the transparent conductive layer 3b of the second transparent substrate layer 1b can be crystallized, the heating conditions are adjusted, You may comprise so that it may carry out from the single side | surface of the property laminated body 8. FIG.

  The heat treatment step is a treatment performed in the air, and the heating temperature is preferably 130 ° C. or higher and 150 ° C. or lower, and the heating time is preferably 30 minutes or longer and 90 minutes or shorter. According to the above conditions, the transparent conductive layers 3a and 3b can be sufficiently crystallized.

  The heat treatment step may be performed in a vacuum. In the case of the treatment performed in this vacuum, the heating temperature is preferably 80 ° C. or higher and 150 ° C. or lower, and the heating time is preferably 1 minute or longer and 90 minutes or shorter. According to the above conditions, the transparent conductive layers 3a and 3b can be sufficiently crystallized in a shorter time than in the atmosphere.

  The heat source used for the heat treatment performed in the air or in the vacuum is not particularly limited as long as it is a heating means capable of performing the heat treatment in the air or in vacuum, but for example, an IR heater can be used. .

  Moreover, since the heat treatment process of the said transparent conductive laminated body 8 can heat-process simultaneously the transparent conductive layers 3a and 3b of the 1st and 2nd transparent substrate layers 1a and 1b, the transparent conductive after bonding The necessary steps and time for simultaneously crystallizing the transparent conductive layers 3a and 3b formed on both surfaces of the laminate 8 are reduced, and bonding is performed before the deformation of the film that occurs after the heat treatment. The manufacturing method of the transparent conductive laminated body which can match | combine easily can be provided.

  As a pattern forming method for the transparent conductive layers 3a and 3b, first, a resist is applied on the transparent conductive layers 3a and 3b, a pattern is formed by exposure and development, and then the transparent conductive layer is chemically dissolved. And a method of vaporizing by a chemical reaction in a vacuum, a method of sublimating a transparent conductive layer with a laser, and the like. The pattern forming method can be appropriately selected depending on the shape and accuracy of the pattern, but it is preferable to use a photolithography method in order to simultaneously form different patterns for the transparent conductive layers 3a and 3b.

  The transparent conductive laminate 8 is roll-to-roll from the step of forming the transparent conductive layers 3a and 3b on the first and second transparent substrate layers 1a and 1b to the step of heat-treating the transparent conductive layers 3a and 3b. It is preferable to carry out by a roll method. Thereby, manufacturing time can be reduced significantly.

  Next, examples and comparative examples will be described.

<Example>
PET (188 μm) was used as a transparent substrate, and two transparent conductive laminates were formed on one surface by sputtering, with silicon oxide and titanium oxide as the optical adjustment layer and ITO as the transparent conductive layer. After the two transparent conductive laminates are bonded together by the adhesive layer, the transparent conductive film layers on both sides are simultaneously heat-treated in the atmosphere at 150 ° C. for 60 minutes in an oven capable of heat treatment, and then photolithography The transparent conductive film layers on both sides were patterned using the method described above. Moreover, the surface resistance value was measured about the transparent conductive film layer patterned on both surfaces.

<Comparative example>
PET (188 μm) was used as a transparent substrate, and two transparent conductive laminates were formed on one surface by sputtering, with silicon oxide and titanium oxide as the optical adjustment layer and ITO as the transparent conductive layer. The two transparent conductive layers were subjected to heat treatment in the atmosphere at 150 ° C. for 60 minutes in an oven capable of heat treatment, respectively, and then the two transparent conductive layers were patterned. Then, two transparent conductive laminated bodies were bonded together by the adhesion layer. Moreover, the surface resistance value was measured about the transparent conductive film layer patterned on both surfaces.

  The evaluation result about this Example and a comparative example is described.

  When the surface resistance value of the transparent electroconductive laminate produced in the example was measured, one surface was 210Ω / □ and the other surface was 230Ω / □. On the other hand, the surface resistance of the transparent conductive laminate produced in the comparative example was 210Ω / □ on one side and 215Ω / □ on the other side. In the transparent conductive laminates obtained in Examples and Comparative Examples, it was confirmed that both transparent conductive layers were crystallized and the resistance was reduced.

  However, while the position of the pattern of the transparent conductive layers on both sides produced in the example could be controlled with high precision, the position of the pattern of the transparent conductive layer on both sides produced in the comparative example was different from that of the transparent conductive layers on both sides. By heat-treating the film layers separately, the dimensions of the two transparent conductive laminates were different and could not be controlled with high precision.

  In addition, it was confirmed that the manufacturing method of the example greatly shortened the necessary steps and time as compared with the manufacturing method of the comparative example.

  The present invention is used for a transparent touch panel attached as an input device on a display of an electronic device. In particular, it is used for mobile devices capable of multi-touch.

DESCRIPTION OF SYMBOLS 1a ... 1st transparent substrate layer 1b ... 2nd transparent substrate layer 2a, 2b ... Optical adjustment layer 3a, 3b ... Transparent conductive layer 4a ... Conductive pattern area | region 4b ... Nonelectroconductive pattern area | region 5a, 5b ... Resin layer 6 ... Adhesive layers 7a, 7b ... Heat source 8 ... Transparent conductive laminate

Claims (4)

Forming at least a transparent conductive layer on one side of the first transparent substrate layer;
Forming at least a transparent conductive layer on one side of the second transparent substrate layer;
The step of bonding the first transparent substrate layer and the second transparent substrate layer with an adhesive, with the transparent conductive layer on the outside,
Heat-treating the transparent conductive layer of the first transparent substrate layer and the transparent conductive layer of the second transparent substrate layer;
Forming a conductive pattern region and a non-conductive pattern region in the heat-treated transparent conductive layer of the first transparent substrate layer and the transparent conductive layer of the second transparent substrate layer;
Equipped with,
The method for producing a transparent conductive laminate, wherein the heat treatment is a treatment for crystallizing the transparent conductive layer of the first transparent substrate layer and the transparent conductive layer of the second transparent substrate layer . 2. The transparent conductive material according to claim 1, wherein the heat treatment is performed in the air, the heating temperature is 130 ° C. or more and 150 ° C. or less, and the heating time is 30 minutes or more and 90 minutes or less. A manufacturing method of a layered product. 2. The transparent conductive material according to claim 1, wherein the heat treatment is performed in vacuum, the heating temperature is 80 ° C. or more and 150 ° C. or less, and the heating time is 1 minute or more and 90 minutes or less. A manufacturing method of a layered product. The said heat processing are performed by a roll toe roll system, The manufacturing method of the transparent conductive laminated body as described in any one of Claim 1 to 3 characterized by the above-mentioned.

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