JP2015128070A - Method for producing transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in appearance due to visual recognition of a pattern boundary of a patterned transparent conductive layer in a transparent conductive film, even when a thickness of a base material of the transparent conductive film is reduced down to 80 μm or less.SOLUTION: A production method of the present invention includes: a laminate preparation step of preparing a laminate including an un-patterned transparent conductive layer formed on a flexible transparent base material; a patterning step of removing a part of the transparent conductive layer to pattern a pattern formation part having the transparent conductive layer on the flexible transparent base material and a pattern opening part having no transparent conductive layer on the flexible transparent base material; and a heat treatment step of heating the laminate after the transparent conductive layer has been patterned. An absolute value of a difference H-Hbetween a dimensional change rate Hat the pattern formation part and a dimensional change rate Hat the pattern opening part during the heat treatment step is preferably less than 0.03%.

Description

  The present invention relates to a method for producing a transparent conductive film having a transparent conductor layer on one surface of a flexible transparent substrate.

  2. Description of the Related Art Conventionally, a transparent conductive film used for a touch panel or the like is known in which a transparent conductive layer made of a conductive metal oxide such as ITO is laminated on a flexible transparent substrate such as a transparent film. In recent years, projected capacitive touch panels capable of multi-point input (multi-touch) and matrix resistive touch panels have attracted attention. In these touch panels, transparent conductors of transparent conductive films The layer is patterned in a predetermined shape (for example, a stripe shape). Such a transparent conductive film includes a pattern forming portion having a transparent conductor layer on a flexible transparent substrate, and a pattern opening having no transparent conductor layer on the flexible transparent substrate. Have.

  If the transparent conductor layer is patterned, the difference in reflectance between the portion where the transparent conductor layer is formed (pattern forming portion) and the portion where the transparent conductor layer is not formed (pattern opening) As a result, the pattern is visually recognized, and the appearance as a display element may be deteriorated. From the viewpoint of suppressing the difference in visibility due to the presence or absence of such a transparent conductor layer, a plurality of optical interference layers are provided as an undercoat layer between the film substrate and the transparent conductor layer, and the refractive index of the optical interference layer Etc. have been proposed (for example, Patent Documents 1 to 4).

JP 2010-15861 A JP 2008-98169 A Patent No. 4,364,938 JP 2009-76432 A

  As described above, when the transparent conductor layer is patterned, it is required that the boundary is difficult to be visually recognized. In addition to this, from the viewpoint of reducing the weight and thickness of the display device, the touch panel and the like are used. Thinning of the transparent conductive film used is required. In order to reduce the thickness of the transparent conductive film, it is necessary to reduce the thickness of the film substrate that occupies most of the thickness. However, when the present inventors examined, when the thickness of a film base material was made small, even if the optical interference layer was provided between the base material and the transparent conductor layer, the transparent conductive film was incorporated in the touch panel. At this time, it has been found that the pattern boundary of the transparent conductor layer is easy to be visually recognized and the appearance may be deteriorated.

  In view of the above, an object of the present invention is to provide a transparent conductive film in which the pattern of the transparent conductor layer is hardly visible when incorporated in a touch panel even when the thickness of the substrate is as small as 80 μm or less. .

  As a result of the study by the present inventors in view of the above problems, in the heat treatment step performed after patterning the transparent conductor layer of the transparent conductive film, the difference in the dimensional change rate between the pattern forming portion and the pattern opening is reduced. As a result, it was found that the pattern of the transparent conductor layer is difficult to be visually recognized, and the present invention has been achieved.

  The present invention relates to a method for producing a transparent conductive film having a transparent conductor layer patterned on a flexible transparent substrate having a thickness of 80 μm or less. A transparent conductive film has a pattern formation part which has a transparent conductor layer on a flexible transparent base material, and a pattern opening part which does not have a transparent conductor layer on a flexible transparent base material. The production method of the present invention includes a laminate preparation step of preparing a laminate in which a transparent conductor layer that is not patterned is formed on a flexible transparent substrate having a transparent film substrate, one of the transparent conductor layers Patterning to be patterned into a pattern forming portion having a transparent conductor layer on a flexible transparent substrate and a pattern opening having no transparent conductor layer on the flexible transparent substrate And a heat treatment step of heating the laminated body after the transparent conductor layer is patterned.

In the present invention, it is preferable absolute value of the difference H ₁ -H ₂ the dimensional change rate of H ₂ dimensional change H ₁ and the pattern opening of the pattern forming portion in the heat treatment step is small. Specifically, H ₁ -H ₂ is preferably less than 0.03%, more preferably 0.025% or less, further preferably 0.02% or less, and particularly preferably 0.015% or less. .

  In one Embodiment, it is preferable that the temperature in the heat treatment process which heats the said laminated body after a transparent conductor layer is patterned is less than 100 degreeC.

  In one embodiment of the present invention, the removal of a part of the transparent conductor layer can be suitably performed by wet etching using an etchant. In this case, it is preferable to heat dry the laminate in the heat treatment step.

  In one embodiment of the present invention, the flexible transparent base material is one in which an undercoat layer is formed on the transparent conductor layer forming surface side of the transparent film base material. Moreover, it is preferable that a transparent conductor layer consists of tin dope indium oxide, and it is preferable that a flexible transparent base material uses a polyethylene terephthalate film as a transparent film base material.

  According to the present invention, in the transparent conductive film after patterning the transparent conductor layer, the difference in the dimensional change rate during heating of the pattern forming portion and the pattern opening is within a predetermined range. Therefore, even after heating, the stress generated at the interface between the transparent conductor layer and the flexible transparent substrate is small, and the film is unlikely to swell. In the case where the transparent conductive film thus obtained is bonded to a rigid substrate such as a glass plate to form a touch panel or the like, the step at the pattern boundary is reduced and the appearance of the pattern boundary is visually recognized. Decline is suppressed.

It is typical sectional drawing of the transparent conductive film in which the transparent conductor layer was patterned. It is sectional drawing which shows one form of the transparent conductive film with an adhesive layer. It is typical sectional drawing which shows the form which bonded the transparent conductive film with the other base | substrate. It is a typical top view showing one form of a transparent conductive film in which a transparent conductor layer was patterned. It is a figure showing an example of the measurement result of the surface shape (step difference) in a pattern boundary. It is a figure for demonstrating notionally that a level | step difference arises in a pattern boundary when a transparent conductive film is bonded together with a base | substrate. In Examples and Comparative Examples, it is obtained by plotting the relationship between the difference in level value and the pattern boundary (H 1 _{-H 2).}

  FIG. 1 is a schematic cross-sectional view showing one embodiment of a transparent conductive film having a patterned transparent conductor layer. A transparent conductive film 100 shown in FIG. 1 has a patterned transparent conductor layer 2 on one surface of a flexible transparent substrate 1. As for the flexible transparent base material, the undercoat layer 12 grade | etc., Is formed in the surface of the transparent film base material 11 as needed. The transparent conductive film 100 includes a pattern forming portion P in which the transparent conductor layer 2 is formed and a pattern opening O in which the transparent conductor layer is not formed. FIG. 2 is a schematic cross-sectional view showing an embodiment of a transparent conductive film with an adhesive layer having an adhesive layer 3 on the surface of the flexible transparent substrate 1 where the transparent conductor layer 2 is not formed. is there. FIG. 3 is a schematic cross-sectional view showing the transparent conductive film 110 with the pressure-sensitive adhesive layer in which the transparent conductive film is bonded to a rigid substrate 50 such as glass via the pressure-sensitive adhesive layer 3.

  First, in the transparent conductive film having the above-described configuration, when the thickness of the flexible transparent substrate 1 was reduced, the cause of the pattern boundary of the transparent conductor layer 2 being easily visible was examined. A transparent conductive film 100 in which a patterned transparent conductor layer 2 made of ITO is formed on a flexible transparent substrate 1 made of a PET film substrate having a thickness of 23 μm is formed on a glass plate 50 through an adhesive layer 3. FIG. 5 shows an example of the surface shape profile on the transparent conductor layer side when bonded together. In FIG. 5, an elevation difference (step) of 150 nm or more occurs at the boundary between the pattern forming portion P where the transparent conductor layer is formed and the pattern opening O where the transparent conductor layer is not formed. . In this example, the difference in height at the pattern boundary is much larger than the thickness of the transparent conductor layer (22 nm), and this step was considered to be a factor that makes the pattern boundary easy to see.

  Thus, when the cause which a big level | step difference arises in the pattern boundary of the transparent conductive film bonded together to the glass plate was further examined, in the transparent conductive film before bonding to a glass plate, a concept is shown to Fig.6 (a). As shown specifically, the wavy undulation was generated with the transparent conductive layer 2 forming surface side of the pattern forming portion P being convex. When a film with undulations is bonded to a flat glass plate via an adhesive layer, the undulation of the film is almost eliminated because the glass plate is more rigid than the film. It becomes flat. On the other hand, when the undulation of the transparent conductive film is eliminated and the film becomes flat, the strain concentrates on the boundary portion of the pattern forming portion P that has been curved in a convex shape. It is estimated that the transparent conductor layer swells in the vicinity of the boundary at the end as shown in FIG. In FIG. 3 and FIG. 6 (b), a form in which the flexible transparent substrate 1 side of the transparent conductive film 100 is bonded to a rigid base via the adhesive layer 3 is illustrated. Even when the transparent conductor layer 2 side is bonded to another substrate (for example, a touch panel window layer), a step is generated at the pattern boundary due to the waviness of the film, and the pattern boundary is easily visible. It is done.

  In order to eliminate the step and make it difficult to visually recognize the pattern boundary, it was considered important to eliminate the undulation of the transparent conductive film before being bonded to a rigid substrate such as glass. Furthermore, when the cause which a wave | undulation produces in a transparent conductive film was considered, when the film was heated after patterning a transparent conductor layer by an etching etc., it turned out that a wave | undulation tends to arise. In general, after the transparent conductor layer is patterned by wet etching, the etchant is washed with water and then dried by heating. In addition, when the transparent conductor layer is amorphous, the transparent conductor layer is crystallized by heating in the presence of oxygen for the purpose of improving the heating reliability and transparency of the transparent conductor layer, reducing resistance, etc. There is a case. Furthermore, heating is also performed when forming a pattern wiring for electrically connecting a control means such as an IC and the transparent conductor layer on the transparent conductive film or when assembling the touch panel.

The present invention reduces the level difference when a transparent conductive film is bonded to a rigid substrate such as a glass plate by suppressing the occurrence of waviness in the heat treatment step after patterning the transparent conductor layer. This is based on the estimation principle that it is difficult to visually recognize the boundary. Then, further studies results, in the heating process after patterning the transparent conductor layer, if substantially equal to the dimensional change rate of H ₂ dimensional change H ₁ and the pattern opening of the pattern forming portion, undulation of occurrence It has been found that even when bonded to glass or the like, the pattern boundary is hardly visible.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment. In FIG. 1, a transparent conductive film 100 in which a transparent conductor layer 2 is formed on a flexible transparent substrate 1 is illustrated. In FIG. 1, a flexible transparent substrate 1 in which an undercoat layer 12 is formed on a film substrate 11 is illustrated, but the flexible transparent substrate 1 has an undercoat layer. Not necessary. Moreover, functional layers (not shown), such as a hard-coat layer, an antiblocking layer, and an antireflection layer, may be formed on the surface of the film base 11 on which the transparent conductor layer 2 is not formed.

<Flexible transparent substrate>
(Film substrate)
Although it does not restrict | limit especially as the transparent film base material 11 which comprises the flexible transparent base material 1, The various plastic film which has transparency is used. For example, the materials include polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, polyvinyl chloride resins, poly Examples thereof include vinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. Of these, polyester resins, polycarbonate resins, and polyolefin resins are particularly preferable. In addition, for example, in FIG. 1, when the member (namely, flexible transparent base material) shown with the code | symbol "1" is comprised only with the transparent film base material 11, the said member is called a flexible transparent base material.

  From the viewpoint of making it difficult to produce undulations or steps in the transparent conductive film, it is preferable to increase the thickness of the base film and increase the rigidity, but from the viewpoint of thinning, the thickness of the base film in the present invention is 80 μm. It is as follows. As will be described later, when an undercoat layer 12 such as an optical interference layer or a hard coat layer is formed on the film substrate 11, the thickness as a flexible transparent substrate including these is 80 μm or less. Preferably there is.

  From the viewpoint of thinning, it is preferable that the thickness of the film substrate is small. However, if the thickness is excessively small, problems such as inferior handling properties occur. . The present invention is also suitable in the case where the thickness of the film substrate is 10 to 60 μm, and even 10 to 30 μm. In addition, if the film base is made thin as in the above range, the total thickness of the transparent conductive film becomes thin. For example, when the transparent conductor layer is formed by sputtering or the like, from the inside of the film base. The amount of generated volatile components is reduced, and as a result, a transparent conductor layer with few defects can be formed.

  The film base material preferably has high dimensional stability during heating. In general, plastic films are likely to undergo dimensional changes due to expansion and contraction during heating. On the other hand, a transparent conductor layer made of a metal oxide is less likely to cause a dimensional change. Therefore, if a dimensional change occurs in the base film during heating, the interface between the flexible transparent base material and the transparent conductive layer is distorted. This causes swell. Therefore, it is preferable that the base film has a high heat distortion temperature.

  The transparent film base material may be subjected to etching treatment or undercoating treatment such as sputtering, corona discharge, flame, ultraviolet ray irradiation, electron beam irradiation, chemical conversion, oxidation, etc. on the surface in advance. Thereby, the adhesiveness with respect to base materials, such as a transparent conductor layer and an undercoat layer provided on this, can be improved. Moreover, before providing a transparent conductor layer, an undercoat layer, etc., you may remove and clean the film base-material surface by solvent washing | cleaning, ultrasonic washing, etc. as needed.

  Although the transparent film substrate can be used as the flexible transparent substrate 1 as it is, as shown in FIG. 1, a hard coat layer and an anti-blocking layer are formed on the transparent conductor layer 2 forming surface side of the transparent film substrate 11. Alternatively, an undercoat layer 12 such as an optical interference layer may be provided.

(Undercoat layer)
Generally, the hard coat layer is provided for the purpose of imparting hardness to the film to prevent scratches, and the anti-blocking layer is provided for forming unevenness on the film surface to impart slipperiness and blocking resistance. . The optical interference layer is provided in order to reduce the difference in reflectance between the transparent conductor layer when the transparent conductor layer is patterned into the pattern forming portion and the pattern opening portion, and to prevent the pattern from being visually recognized.

  Examples of the resin for forming the hard coat layer include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins. Among these, curing by ultraviolet irradiation is possible. An ultraviolet curable resin capable of efficiently forming a hard coat layer by a simple processing operation is preferable. Examples of the ultraviolet curable resin include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based resins, and include ultraviolet curable monomers, oligomers, polymers, and the like. Examples of the ultraviolet curable resin preferably used include those having an ultraviolet polymerizable functional group, particularly those containing an acrylic monomer or oligomer component having 2 or more, particularly 3 to 6 functional groups. Further, an ultraviolet polymerization initiator is blended in the ultraviolet curable resin.

  The formation method in particular of a hard-coat layer is not restrict | limited, A suitable system can be employ | adopted. For example, a method of applying a resin composition that forms a hard coat layer on the transparent film 11, drying, and curing is employed. The resin composition is applied by an appropriate method such as phantom, die coater, casting, spin coating, phanten metalling, and gravure. In the application, the resin composition is preferably diluted with a common solvent such as toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol, ethyl alcohol, and the like to prepare a solution.

  As described above, the hard coat layer is provided for the purpose of preventing the scratches by imparting hardness to the film, but in the present invention, it contributes to the suppression of the heating dimensional change of the flexible transparent substrate. It can also be made. That is, since the hard coat layer generally has a cross-linked structure, a dimensional change is less likely to occur compared to a polymer film substrate, and a flexible transparent substrate having a hard coat layer formed on a film substrate is The heating dimensional change is small compared to the case of the film base material alone. Therefore, by providing a hard coat layer as the undercoat layer 12 on the transparent film substrate 11, the dimensional change of the flexible transparent substrate is suppressed, and the transparent conductive film in which the transparent conductor layer 2 is patterned is heated. This can also contribute to the reduction of swells.

  1-7 micrometers is preferable and, as for the thickness of a hard-coat layer, 2 micrometers-5 micrometers are more preferable. If the thickness of the hard coat layer is small, the hardness may be insufficient or the effect of suppressing the dimensional change as described above may not be sufficiently exhibited. On the other hand, if the thickness is excessively large, problems such as curling of the flexible transparent substrate and the transparent conductive film and occurrence of cracks in the hard coat layer may occur.

  The hard coat layer as described above may have a function as an antiblocking layer. When the hard coat layer has a function as a blocking layer, the arithmetic average roughness Ra of the surface is preferably 50 nm or more. By setting the arithmetic average roughness within the above range, good slipperiness and blocking resistance are imparted to the transparent conductive film.

  Examples of such an anti-blocking layer include those containing fine particles in a curable resin layer, those using a coating composition containing two or more components that are phase-separated as a curable resin composition, or these By using together, those having irregularities formed on the surface are preferably used. As the components of the curable resin layer, those described above as the components of the hard coat layer are preferably used. Moreover, as a coating composition containing 2 or more types of components which phase-separate, the composition as described in international publication WO2005 / 073763 pamphlet, for example can be used conveniently.

  The optical interference layer reduces the reflectance difference between the two by adjusting the optical thickness difference between the pattern forming portion where the transparent conductor layer is formed and the pattern opening where the transparent conductor layer is removed, It is provided for the purpose of making the pattern difficult to be visually recognized.

The optical interference layer can be formed of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material. For example, NaF (1.3), Na ₃ AlF ₆ (1.35), LiF (1.36), MgF ₂ (1.38), CaF ₂ (1.4), BaF ₂ (1. 3), inorganic substances such as SiO ₂ (1.46), LaF ₃ (1.55), CeF ₃ (1.63), Al ₂ O ₃ (1.63) It is a rate]. Of these, SiO ₂ , MgF ₂ , Al ₂ O _{3 and the} like are preferably used. In particular, SiO ₂ is suitable. In addition to the above, a composite oxide containing about 10 to 40 parts by weight of cerium oxide and about 0 to 20 parts by weight of tin oxide with respect to indium oxide can be used.

  Examples of the organic substance include acrylic resin, urethane resin, melamine resin, alkyd resin, siloxane polymer, and organic silane condensate. At least one of these organic substances is used. In particular, as the organic substance, it is desirable to use a thermosetting resin made of a mixture of a melamine resin, an alkyd resin, and an organosilane condensate.

An optical interference layer can be provided between the transparent film base material 11 and the transparent conductor layer 2, and does not have a function as a conductive layer. That is, the optical interference layer is provided as a dielectric layer that insulates between the patterned transparent conductor layers 2. Therefore, the optical interference layer usually has a surface resistance of 1 × 10 ⁶ Ω / □ or more, preferably 1 × 10 ⁷ Ω / □ or more, and more preferably 1 × 10 ⁸ Ω / □ or more. There is no particular limitation on the upper limit of the surface resistance of the optical interference layer. In general, the upper limit of the surface resistance of the optical interference layer is about 1 × 10 ¹³ Ω / □, which is the measurement limit, but may exceed 1 × 10 ¹³ Ω / □.

  The difference between the refractive index of the optical interference layer and the refractive index of the transparent conductor layer is preferably 0.1 or more. The difference between the refractive index of the transparent conductor layer and the refractive index of the optical interference layer is preferably 0.1 or more and 0.9 or less, and more preferably 0.1 or more and 0.6 or less. In addition, it is preferable that the refractive index of an optical interference layer is 1.3-2.5 normally, Furthermore, 1.38-2.3, Furthermore, it is preferable that it is 1.4-2.3. By controlling the refractive index of the optical interference layer in this way, the difference in reflectance between the pattern forming portion and the pattern opening can be reduced.

  The optical interference layer closest to the transparent film substrate 11 is preferably formed of an organic material when patterning the transparent conductor layer by etching. Therefore, when the optical interference layer is composed of one layer, the optical interference layer is preferably formed of an organic material.

  When the optical interference layer is composed of two or more layers, at least the optical interference layer farthest from the transparent film base material is formed of an inorganic material. preferable. When the optical interference layer is composed of three or more layers, the optical interference layer above the second layer from the film substrate is preferably formed of an inorganic material.

The optical interference layer formed of an inorganic material can be formed by a dry process such as a vacuum deposition method, a sputtering method, or an ion plating method, or a wet method (coating method). As described above, SiO ₂ is preferable as the inorganic substance forming the optical interference layer. In the wet method, a SiO ₂ film can be formed by applying silica sol or the like.

  From the above, when the optical interference layer is provided, it is preferable that the first optical interference layer is formed of an organic material and the second optical interference layer is formed of an inorganic material.

  The thickness of the optical interference layer is not particularly limited, but is usually about 1 to 300 nm, preferably 5 to 300 nm, from the viewpoint of optical design and the effect of preventing oligomer generation from the transparent film substrate. . In addition, when an optical interference layer consists of two or more layers, it is preferable that the thickness of each layer is about 5-250 nm, and it is more preferable that it is 10-250 nm.

  Such an optical interference layer may be provided directly on the base film, or may be provided on the hard coat layer or the anti-blocking layer as described above. The optical interference layer can also contribute to the suppression of the heating dimensional change of the flexible transparent substrate in the same manner as the hard coat layer. However, since the optical interference layer is generally smaller in thickness than the hard coat layer, the hard coat layer is superior in the effect of suppressing changes in heating dimensions. Therefore, a hard coat layer is provided on the transparent film substrate, and an optical interference layer is provided thereon, thereby suppressing the dimensional change of the flexible transparent substrate and between the pattern forming portion and the pattern opening portion. It is also possible to suppress the difference in reflectance.

<Transparent conductor layer>
The transparent conductor layer 2 is formed of a conductive metal oxide. The conductive metal oxide constituting the transparent conductor layer is not particularly limited, and is a group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, tungsten. A conductive metal oxide of at least one metal selected from the above is used. The metal oxide may further contain a metal atom shown in the above group, if necessary. For example, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), or the like is preferably used. Of these, ITO is most preferable. Further, when the optical interference layer is formed on the surface of the flexible transparent substrate on the transparent conductor layer 2 side, the transparent conductor layer has a refractive index difference of 0.1 or more with respect to the optical interference layer. It is preferable.

The thickness of the transparent conductor layer is not particularly limited, but is preferably 10 nm or more, more preferably 15 to 40 nm, and still more preferably 20 to 30 nm. When the thickness of the transparent conductor layer is 15 nm or more, a good continuous film having a surface resistance of, for example, 1 × 10 ³ Ω / □ or less is easily obtained. Moreover, it can be set as a layer with higher transparency as the thickness of the transparent conductor layer 2 is 40 nm or less.

  The formation method of a transparent conductor layer is not specifically limited, A conventionally well-known method is employable. Specific examples include vacuum deposition, sputtering, and ion plating. In addition, an appropriate method can be adopted depending on the required film thickness. The transparent conductor layer may be amorphous or crystalline. As a method for forming a crystalline transparent conductor layer, a crystalline film can be formed as it is by forming a film on the flexible transparent substrate 1 at a high temperature. However, considering the heat resistance of the substrate, etc., the crystalline transparent conductor layer is formed by once forming an amorphous film on the substrate and then heating and crystallizing the amorphous film together with the flexible transparent substrate. It is preferable to form by.

  Crystallization of the transparent conductor layer can be performed either before or after patterning the transparent conductor layer. In addition, when patterning a transparent conductor layer by wet etching, if the transparent conductor layer is crystallized before etching, etching may be difficult. Therefore, the crystallization of the transparent conductor layer is preferably performed after patterning the transparent conductor layer. When crystallization is performed after patterning of the transparent conductor layer, it is preferable to set the heating conditions so that the dimensional change rate of the pattern forming portion and the dimensional change rate of the pattern opening portion are small, as will be described in detail later. .

<Patterning of transparent conductor layer>
The laminate in which the transparent conductor layer is formed on the flexible transparent substrate as described above is patterned by removing a part of the transparent conductor layer. The transparent conductive film in which the transparent conductor layer is patterned includes a pattern forming portion P having the transparent conductor layer 2 on the flexible transparent substrate 1 and a transparent conductor layer on the flexible transparent substrate 1. Pattern opening O not having. Various shapes can be formed as the pattern according to the application to which the transparent conductive film is applied. Examples of the shape of the pattern forming portion P include a square shape in addition to the stripe shape shown in FIG. In FIG. 4, the width of the pattern forming portion P is shown larger than the width of the pattern opening O, but the present invention is not limited to this form.

  The patterning of the transparent conductor layer 2 is preferably performed by wet etching. When patterning is performed by removing a portion of the transparent conductor layer 2 by wet etching, a portion of the transparent conductor layer 2 (pattern forming portion) is covered with a mask for forming a pattern, and the transparent conductor layer The portion not covered with the mask (pattern opening) is removed by exposure to an etchant. As described above, since the transparent conductive layer 2 is made of a conductive metal oxide such as ITO or ATO, an acid is preferably used as the etchant. Examples of the acid include inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid and phosphoric acid, organic acids such as acetic acid, and mixtures thereof, and aqueous solutions thereof.

<Heat treatment>
The transparent conductive film after the transparent conductor layer is patterned as described above is subjected to a heat treatment step. As the heat treatment, the etchant used for patterning was cleaned with a cleaning liquid such as water, and then the heating was performed for drying the cleaning liquid, the heating for crystallizing the amorphous transparent conductor layer, and the patterning. Heating for drying silver paste or the like at the time of forming a pattern wiring for electrically connecting the transparent conductor layer to a control means such as an IC, heating at the time of assembling the touch panel, and the like can be mentioned.

In the present invention, in the heat treatment step, the absolute value of the difference H ₁ -H ₂ the dimensional change rate of H ₂ dimensional change H ₁ and the pattern opening portion O of the pattern forming portion P is less than 0.03% Is preferred. Generation | occurrence | production of the wave | undulation in a transparent conductive film is suppressed by making the difference of the dimensional change rate of the pattern formation part and pattern opening part in a heat treatment process small. Therefore, when a transparent conductive film is incorporated in a touch panel or the like, a decrease in appearance due to a large step occurring at the pattern boundary is suppressed. From the viewpoint of suppressing the occurrence of waviness and reducing the level difference generated at the pattern boundary, the absolute value of H ₁ -H ₂ is more preferably 0.025% or less, and 0.02% or less. More preferably, it is particularly preferably 0.015% or less.

The dimensional change rate (%) is defined as 100 × (L−L ₀ ) / L ₀ using the distance L ₀ between the two points before the heat treatment and the distance L between the two points after the heat treatment. If the rate sign is positive, it indicates expansion, and if it is negative, it indicates contraction. Therefore, when H ₁ -H ₂ is negative, the pattern opening from which the transparent conductor layer is removed has a dimension after the heat treatment as compared with the pattern formation portion where the transparent conductor layer is formed. It means that it becomes small (it is easy to heat shrink). When the dimensional change rate (thermal shrinkage rate) of the transparent conductive film in the heat treatment step varies depending on the direction, the difference in the dimensional change rate in any one direction is preferably within the above range. In addition, as shown in FIG. 4, when the transparent conductor layer is patterned in a stripe shape, it is preferable that the difference in the dimensional change rate in the patterning direction (direction in which the patterns are arranged) is in the above range. .

  An estimation principle for suppressing the swell when the difference in the dimensional change rate between the pattern forming portion and the pattern opening in the heat treatment step is small will be described below.

In the pattern opening from which the transparent conductor layer has been removed, when the flexible transparent substrate 1 is heated to a high temperature, a dimensional change is likely to occur due to thermal expansion and contraction of the substrate film. For example, when a biaxially stretched polyethylene terephthalate film is used as the transparent film substrate, when the transparent conductive film is heated to about 120 ° C., the substrate of the pattern opening undergoes thermal shrinkage, and the dimensional change rate H ₂ is generally a negative value. On the other hand, the transparent conductor layer 2 made of a metal oxide has a hardness higher than that of the base film and hardly causes a dimensional change due to heating. Therefore, in the pattern formation part in which the transparent conductor layer 2 is formed on the flexible transparent substrate 1, the dimensional change of the flexible transparent substrate is suppressed by the transparent conductor layer, and the dimensional change of the pattern formation part P The absolute value of the rate H ₁ tends to be smaller than the absolute value of the dimensional change rate H ₂ of the pattern opening O from which the transparent conductor layer has been removed.

Although the absolute value of the dimensional change H ₁ in the pattern forming portion P is smaller than the H _2, for dimensional changes of the base material is suppressed by the transparent conductor layer, the flexible transparent substrate 1 and transparent Stress is generated at the interface with the conductor layer 2. On the other hand, in the pattern opening where the transparent conductor layer is not formed, such stress at the interface does not occur. Therefore, the transparent conductive film in which the transparent conductor layer is patterned is a film in which a wavy undulation occurs in the film with the pattern forming portion P projecting on the transparent conductor layer 2 side as conceptually shown in FIG. it is conceivable that. FIG. 7 shows the case where the flexible transparent base material contracts by heating. However, if the flexible transparent base material expands by heating, the transparent conductor layer 2 of the pattern forming portion is formed. It is thought that the undulation occurs with the side that is not made convex.

That the difference between the dimensional change rate of the pattern forming portion and the pattern opening is small, it means that the stress generated at the interface between the flexible transparent substrate and the transparent conductor layer, such as described above is small, H ₁ as the absolute value of -H ₂ is small, it is considered that the generation of waviness can be suppressed. If the waviness of the transparent conductive film is small, the step at the pattern boundary when bonded to a rigid substrate such as glass is reduced, and the pattern boundary is considered to be difficult to visually recognize.

  Hereinafter, specific examples of the heat treatment step will be described. A typical example of the heat treatment after patterning the transparent conductive film is heating for drying the cleaning liquid after cleaning the etchant used for patterning with a cleaning liquid such as water. In general, since a liquid containing water as a main component is used as a cleaning liquid, heating for drying the cleaning liquid is often performed at a high temperature of 100 ° C. or higher. On the other hand, when the transparent conductive film after patterning the transparent conductor layer is exposed to heat treatment at such a high temperature, the flexible transparent substrate undergoes a dimensional change, and the pattern forming portion and the pattern opening portion There is a tendency that the dimensional change rate difference of becomes large. Therefore, the cleaning liquid is preferably dried at a low temperature of less than 100 ° C. The heating temperature during drying is preferably 90 ° C. or lower, more preferably 80 ° C. or lower.

In addition, when a flexible transparent substrate with suppressed heating dimensional change is used, such as a film substrate surface with an undercoat layer such as a hard coat layer, it is heated at a temperature higher than the above range. Even if the absolute value of H ₁ -H ₂ is less than 0.03%, the occurrence of swell may be suppressed. In such a case, the heating temperature in the heat treatment step can be appropriately set within a range where the absolute value of H ₁ -H ₂ does not become 0.03% or more.

Other heat treatments include heating to crystallize the amorphous transparent conductor layer, and silver paste at the time of pattern wiring formation for electrically connecting the patterned transparent conductor layer to a control means such as an IC. The heating for drying etc., the heating at the time of assembly processing of a touch panel, etc. are mentioned. Even when these heat treatments are performed, the absolute value of H ₁ -H ₂ can be made less than 0.03% by adjusting the heating temperature in the same manner as the drying of the cleaning liquid.

  The transparent conductive film in which the transparent conductor layer 2 is patterned as described above is suitably used for touch panels and the like. In particular, since the transparent conductor layer is patterned and has a plurality of transparent electrodes, it is suitably used for a projection capacitive touch panel and a matrix resistive touch panel. In application to a touch panel or the like, as shown in FIG. 2, the transparent conductive material with the adhesive layer having the adhesive layer 3 on the surface of the flexible transparent substrate 1 on which the transparent conductor layer 2 is not formed. A film may be formed. The transparent conductive film with the pressure-sensitive adhesive layer can be used by being bonded to the substrate 50 through the pressure-sensitive adhesive layer 3, for example, as shown in FIG. At this time, even if a rigid substrate such as a glass plate is used as the substrate 50, if the swell of the transparent conductive film is suppressed, the generation of a step at the pattern boundary is suppressed, and a touch panel with excellent visibility is formed. can do. In addition, even when a pressure-sensitive adhesive layer is provided on the side where the transparent conductor layer 2 is provided and bonded to another substrate such as a touch panel window layer, the step at the pattern boundary is similarly suppressed. A touch panel with excellent visibility can be formed.

  The pressure-sensitive adhesive layer 3 can be used without particular limitation as long as it has transparency. Specifically, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy systems, fluorine systems, natural rubbers, rubbers such as synthetic rubbers, etc. Those having the above polymer as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint that it is excellent in optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is excellent in weather resistance and heat resistance.

  Depending on the type of the pressure-sensitive adhesive that is a constituent material of the pressure-sensitive adhesive layer 3, there is one that can improve the anchoring force with the base material by using an appropriate pressure-sensitive adhesive primer. Therefore, when such an adhesive is used, it is preferable to use an adhesive primer for the flexible transparent substrate 1.

  The pressure-sensitive adhesive layer can contain a crosslinking agent according to the base polymer. In addition, the pressure-sensitive adhesive layer may include, for example, natural and synthetic resins, glass fibers and glass beads, fillers made of metal powder and other inorganic powders, pigments, colorants, antioxidants and the like. Appropriate additives can also be blended. Moreover, it can also be set as the adhesive layer 3 which contained the transparent fine particle and was provided with the light diffusibility.

  The pressure-sensitive adhesive layer is usually used as a pressure-sensitive adhesive solution having a solid content concentration of about 10 to 50% by weight in which a base polymer or a composition thereof is dissolved or dispersed in a solvent. As the solvent, an organic solvent such as toluene or ethyl acetate or an adhesive such as water can be appropriately selected and used.

This adhesive layer is, for example, a transparent conductor layer 2 provided on one surface of the substrate 1 due to its cushioning effect after bonding to a rigid substrate such as glass or another plastic film substrate. It can have a function of improving the scratch resistance and the dot characteristics for touch panels, so-called pen input durability and surface pressure durability. Therefore, it is preferable to give a cushioning effect to the pressure-sensitive adhesive layer, particularly when used in a matrix-type resistive film type touch panel. Specifically, it is desirable to set the elastic modulus of the pressure-sensitive adhesive layer 3 in the range of 1 to 100 N / cm ² and the thickness in the range of 1 μm or more, usually 5 to 100 μm. When the thickness of the pressure-sensitive adhesive layer is in the above range, the cushion effect can be sufficiently exhibited, and the adhesive force by the pressure-sensitive adhesive layer can be sufficient. If the thickness of the pressure-sensitive adhesive layer is thinner than the above range, the durability and adhesion cannot be ensured sufficiently, and if it is thicker than the above range, defects such as transparency may occur. In addition, when a transparent conductive film is used for a capacitive touch panel, the cushioning effect by the pressure-sensitive adhesive layer as described above is not necessarily required, but the adhesion to various substrates and the pressure-sensitive adhesive layer From the viewpoint of facilitating handling of the attached transparent conductive film, the pressure-sensitive adhesive layer 3 preferably has the same thickness and elastic modulus as described above.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded. In the following examples, those having a thickness of 1 μm or more were measured with a Mitutoyo micro gauge thickness gauge. The thickness of the undercoat layer and the ITO film was calculated based on the waveform of the interference spectrum using an instantaneous multi-photometry system model number “MCPD2000” manufactured by Otsuka Electronics.

[Example 1]
(Flexible transparent substrate)
As a transparent film substrate, a biaxially stretched polyethylene terephthalate (PET) film (trade name “Diafoil”, refractive index 1.65 manufactured by Mitsubishi Plastics) having a thickness of 23 μm was directly used as a flexible transparent substrate.

(Deposition of ITO film)
A sintered body containing indium oxide and tin oxide at a weight ratio of 97: 3 as a target material was attached to a DC magnetron sputtering apparatus. After carrying out dehydration and degassing while conveying the flexible transparent substrate, the heating temperature of the substrate was set to 100 ° C., argon gas and oxygen gas were introduced, and DC was discharged at a discharge output of 6.35 mW / cm ² . A film was formed by a sputtering method to form an ITO film having a thickness of 22 nm on the substrate.

(Patterning of ITO film)
A 7 cm square rectangular test piece was cut out from the laminate in which the ITO film was formed as a transparent conductor layer on the flexible transparent substrate thus obtained, and a polyimide tape having a width of 2 mm was formed on the surface of the ITO film. A plurality of layers were bonded at intervals of 2 mm. At this time, the tape was bonded in a direction orthogonal to the MD direction (hereinafter referred to as “TD direction”) so that the transport direction (hereinafter referred to as “MD direction”) during sputtering film formation becomes the patterning direction. This test piece was immersed in a 5 wt% hydrochloric acid aqueous solution heated to 50 ° C. for 10 minutes, and the transparent conductor layer in the non-masking portion (portion where the polyimide tape was not bonded) was etched. The sample after removing the transparent conductor layer was washed with water by immersing it in a sufficient amount of pure water, and then the polyimide tape was slowly peeled off.

(Heat treatment)
The patterned transparent conductive film was dried in a 70 ° C. oven for 5 minutes.

(Evaluation of level difference)
The transparent conductive film patterned with the ITO film thus obtained was placed on a glass plate through an acrylic adhesive layer having a thickness of 22 μm using a hand roller with the ITO film surface facing upward. Pasted together. Using a fine shape measuring machine (model number “ET4000”) manufactured by Kosaka Laboratory Ltd., the sample surface on the ITO film forming side is scanned at a cut-off value of 0.8 mm and a speed of 0.2 mm / second to obtain a transparent conductor layer The level difference was measured at the boundary between the pattern forming portion on which the pattern was formed and the pattern opening from which the transparent conductor layer was removed. Further, it was evaluated whether or not the pattern forming portion and the pattern opening portion can be visually discriminated. The viewing distance was 20 cm, and the viewing angle was 40 degrees from the sample surface.

(Measurement of dimensional change rate during heat treatment)
As described below, the laminated body on which the transparent conductor layer was formed was regarded as a pattern forming portion, and the transparent conductor layer removed by etching was regarded as a pattern opening portion, and heating similar to the above heat treatment was performed. Each dimensional change rate was measured.
(1) Dimensional change rate of pattern formation part A 7 cm square rectangular test piece was cut out from a laminate in which an ITO film was formed as a transparent conductor layer on a flexible transparent substrate, and 10% in 50 ° C. pure water. Immerse for a minute. Two mark points (scratches) are formed on the flexible transparent substrate at intervals of about 50 mm in the patterning direction (MD direction), and then heated at 70 ° C. for 5 minutes in the same manner as the above heat treatment. The distance L ₀ between the gauge points before heating and the distance L between the gauge points after heating are measured by a surface coordinate measuring machine (model number “CP600S”) manufactured by TOPCON, and the dimensional change rate H ₁ of the pattern forming portion is measured. = 100 × (L−L ₀ ) / L ₀ (%) was determined.
(2) Dimensional change rate of pattern opening A rectangular test piece of 7 cm square is cut out from a laminate in which an ITO film is formed as a transparent conductor layer on a flexible transparent substrate, and the above ITO film is patterned. Similarly to the above, the ITO film was removed by immersing in a 5 wt% hydrochloric acid aqueous solution heated to 50 ° C. for 10 minutes. Thereafter, a heat treatment in the same manner as described above with respect to the pattern forming unit, the dimensional change was measured of H ₂ before and after heating.

[Example 2]
A thermosetting resin composition containing a melamine resin: alkyd resin: organosilane condensate in a weight ratio of 2: 2: 1 in terms of solid content was diluted with methyl ethyl ketone so that the solid content concentration was 8% by weight. This solution was applied to one surface of a 23 μm thick PET film similar to that used in Example 1 and cured by heating at 150 ° C. for 2 minutes to form a 33 nm thick optical interference layer (refractive index: 1.54). (This optical interference layer is referred to as “undercoat layer A”). Using the PET film with the undercoat layer A formed as a flexible transparent substrate, the transparent conductive film of the transparent conductive film was formed in the same manner as in Example 1 except that an ITO film was formed on the undercoat layer forming surface side. Fabrication and evaluation were performed.

[Example 3]
From one surface of a PET film having a thickness of 23 μm similar to that used in Example 1, by dry process, SiOx having a thickness of 50 nm and a refractive index of 1.6 to 1.9 (x is 1.5 or more and less than 2). An optical interference layer was formed (this optical interference layer is referred to as “undercoat layer B”). The PET film on which this undercoat layer B was formed was used as a flexible transparent substrate, an ITO film was formed on the undercoat layer forming surface side, and the temperature in the heat treatment step was 120 ° C., and the heating time was 5 minutes. A transparent conductive film was produced and evaluated in the same manner as in Example 1 except that.

[Example 4]
5 parts by weight of hydroxycyclohexyl phenyl ketone (trade name “Irgacure 184” manufactured by Ciba Geigy) is added as a photopolymerization initiator to 100 parts by weight of acrylic / urethane resin (trade name “Unidic 17-806” manufactured by DIC). A hard coat coating solution was prepared by diluting with toluene to a solid content of 30% by weight. This solution was applied to one surface of a PET film having a thickness of 23 μm similar to that used in Example 1, dried by heating at 100 ° C. for 3 minutes, and then an ozone type high-pressure mercury lamp (energy density 80 W / cm ² , 15 cm). (Condensing type) Two lamps were irradiated with ultraviolet rays (integrated light quantity 300 mJ / cm ² ) to form a hard coat layer having a thickness of 2 μm (this hard coat layer is referred to as “undercoat layer C”). Using the PET film on which this undercoat layer C was formed as a flexible transparent substrate, an ITO film was formed on the undercoat layer forming surface side, and the temperature in the heat treatment step was 160 ° C., and the heating time was 5 minutes. A transparent conductive film was produced and evaluated in the same manner as in Example 1 except that.

[Example 5]
An undercoat layer A was formed in the same manner as in Example 2 on one surface of a biaxially stretched polyethylene terephthalate film (trade name “Diafoil”, refractive index 1.65, manufactured by Mitsubishi Plastics) having a thickness of 50 μm. Except that this PET film was used as a flexible transparent substrate, an ITO film was formed on the undercoat layer forming surface side, and the temperature in the heat treatment step was 160 ° C. and the heating time was 5 minutes. In the same manner as in No. 1, a transparent conductive film was produced and evaluated.

[Example 6]
In the same manner as in Example 1, after preparing a laminate in which an ITO film was formed on a flexible transparent substrate, in the patterning of the ITO film, the direction in which the polyimide tape was applied was changed to be patterned in the TD direction. Went. The dimensional change rate was performed in the TD direction. Other than that was carried out similarly to Example 1, and produced and evaluated the transparent conductive film.

[Comparative Example 1]
A transparent conductive film was produced and evaluated in the same manner as in Example 1 except that the temperature in the heat treatment step was 120 ° C. and the heating time was 5 minutes.

[Comparative Example 2]
A transparent conductive film was prepared and evaluated in the same manner as in Example 1 except that the temperature in the heat treatment step was 160 ° C. and the heating time was 5 minutes.

[Comparative Example 3]
A transparent conductive film was prepared and evaluated in the same manner as in Example 2 except that the temperature in the heat treatment step was 120 ° C. and the heating time was 5 minutes.

[Comparative Example 4]
A transparent conductive film was produced and evaluated in the same manner as in Example 2 except that the temperature in the heat treatment step was 160 ° C. and the heating time was 5 minutes.

[Comparative Example 5]
A transparent conductive film was produced and evaluated in the same manner as in Example 3 except that the temperature in the heat treatment step was 160 ° C. and the heating time was 5 minutes.

[Comparative Example 6]
A transparent conductive film was produced and evaluated in the same manner as in Example 6 except that the temperature in the heat treatment step was 160 ° C. and the heating time was 5 minutes.

Table 1 shows the production conditions and evaluation results of the transparent conductive films of the above Examples and Comparative Examples. In addition, visual evaluation of the pattern has shown the result evaluated in the following three steps.
○: It is difficult to distinguish between the pattern forming portion and the pattern opening.
(Triangle | delta): A pattern formation part and a pattern opening part can be discriminate | determined slightly.
X: A pattern formation part and a pattern opening part can be distinguished clearly.

As can be seen from Table 1, when the absolute value of H ₁ -H ₂ is less than 0.03%, the step at the pattern boundary becomes small and the pattern boundary is difficult to be visually recognized. Further, from the comparison between Example 1, Comparative Example 1 and Comparative Example 2, the comparison between Example 2, Comparative Example 3 and Comparative Example 4, and the comparison between Example 3 and Comparative Example 5, the base materials were the same. if, as the absolute value of H ₁ -H ₂ is small in the heat treatment step, it can be seen that a step is suppressed.

Further, as is apparent from Table 2, when the heating temperature in the heat treatment step is less than 100 ° C., the absolute value of H ₁ -H ₂ is suppressed to less than 0.03%, and the step at the pattern boundary is reduced. It can be seen that the pattern boundary is hardly visible. Further, from the comparison between Example 1, Comparative Example 1 and Comparative Example 2, the comparison between Example 2, Comparative Example 3 and Comparative Example 4, and the comparison between Example 6 and Comparative Example 6, the base materials were the same. If it exists, it turns out that a level | step difference is suppressed, so that the heating temperature in a heat treatment process is low.

FIG. 7 is a plot of pattern boundary steps against H ₁ -H _{2 of} each example and comparative example. According to FIG. 7, step becomes larger as the absolute value of H ₁ -H ₂ increases, regardless of the patterned direction of the base material of the type of thickness and the undercoat layer, and a transparent conductor layer, H ₁ It can be seen that the value of −H _{2 and} the level difference show a high correlation. Therefore, it can be seen that by setting H ₁ -H ₂ within a predetermined range, the step is reduced and the pattern boundary is hardly visually recognized.

DESCRIPTION OF SYMBOLS 1 Flexible transparent base material 11 Transparent film base material 12 Undercoat layer 2 Transparent conductor layer 3 Adhesive layer 50 Base body 100 Transparent conductive film

Claims (7)

A method for producing a transparent conductive film having a transparent conductor layer patterned on one surface of a flexible transparent substrate having a transparent film substrate, wherein the transparent conductive film is flexible and transparent It has a pattern forming part having a transparent conductor layer on the substrate, and a pattern opening having no transparent conductor layer on the flexible transparent substrate, and the thickness of the flexible transparent substrate is 80 μm. And
A laminate preparation step of preparing a laminate in which an unpatterned transparent conductor layer is formed on a flexible transparent substrate;
A pattern forming portion having a transparent conductor layer on a flexible transparent substrate by removing a part of the transparent conductor layer, and a pattern having no transparent conductor layer on a flexible transparent substrate A patterning step of patterning the opening, and a heat treatment step of heating the laminate after the transparent conductor layer is patterned,
In the heat treatment step, the absolute value of the difference H ₁ -H ₂ the dimensional change rate of H ₂ dimensional change H ₁ and the pattern opening of the pattern forming portion is less than 0.03%, the manufacturing method of the transparent conductive film . A method for producing a transparent conductive film having a transparent conductor layer patterned on one surface of a flexible transparent substrate having a transparent film substrate, wherein the transparent conductive film is flexible and transparent It has a pattern forming part having a transparent conductor layer on the substrate, and a pattern opening having no transparent conductor layer on the flexible transparent substrate, and the thickness of the flexible transparent substrate is 80 μm. And
A laminate preparation step of preparing a laminate in which an unpatterned transparent conductor layer is formed on a flexible transparent substrate;
A pattern forming portion having a transparent conductor layer on a flexible transparent substrate by removing a part of the transparent conductor layer, and a pattern having no transparent conductor layer on a flexible transparent substrate A patterning step of patterning the opening, and a heat treatment step of heating the laminate after the transparent conductor layer is patterned,
The manufacturing method of the transparent conductive film whose heating temperature in the said heat processing process is less than 100 degreeC. In the heat treatment step, the absolute value of the difference H ₁ -H ₂ the dimensional change rate of H ₂ dimensional change H ₁ and the pattern opening of the pattern forming portion is less than 0.03%, according to claim 2 A method for producing a transparent conductive film. Removing part of the transparent conductor layer by wet etching using an etchant; and
The manufacturing method of the transparent conductive film of any one of Claims 1-3 which heat-drys the said laminated body in the said heat processing process.   The transparent conductive material according to any one of claims 1 to 4, wherein the flexible transparent substrate is formed by forming an undercoat layer on the transparent conductor layer forming surface side of the transparent film substrate. A method for producing a film.   The said transparent conductor layer is a manufacturing method of the transparent conductive film of any one of Claims 1-5 which consists of tin dope indium oxide.   The said transparent transparent base material is a manufacturing method of the transparent conductive film of any one of Claims 1-6 in which the polyethylene terephthalate film is used as the said transparent film base material.

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