JP2018049054A - Photosensitive conductive film, method for forming conductive film, method for forming conductive pattern and method for forming conductive film substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive conductive film from which such a conductive pattern can be easily formed with enough resolution that shows a small difference in a linear resistance value between an X-axis direction and a Y-axis direction orthogonal to each other within a plane and that has high electrostatic endurance, and a method for forming a conductive film, a method for forming a conductive pattern and a method for manufacturing a conductive film substrate using the above photosensitive conductive film.SOLUTION: A photosensitive conductive film 10 of the present invention includes a support film 1, a conductive layer 2 disposed on the support film and containing conductive fibers, and a photosensitive resin layer 3 disposed on the conductive layer. The conductive fibers have at least curved conductive fibers. When a conductive pattern formed by using the photosensitive conductive film is measured for a linear resistance value between both ends of the pattern in an X-axis direction and a Y-axis direction orthogonal to each other within a plane, linear resistance value anisotropy between the X-axis direction and the Y-axis direction is less than 1.5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photosensitive conductive film, a method for forming a conductive film, a method for forming a conductive pattern, and a method for forming a conductive film substrate, and in particular, for devices such as flat panel displays such as liquid crystal display elements, touch screens, and solar cells. The present invention relates to a method for forming a conductive pattern used as an electrode wiring and a method for forming a conductive film substrate.

  Large electronic devices such as personal computers and televisions, small electronic devices such as car navigation systems, mobile phones, and electronic dictionaries, and display devices such as OA / FA devices that use liquid crystal display elements and touch screens are widespread. . In these liquid crystal display elements, touch screens, and devices such as solar cells, a transparent conductive film is used for part of wiring, pixel electrodes, or terminals that are required to be transparent.

  As a material for the transparent conductive film, ITO (Indium-Tin-Oxide), indium oxide, tin oxide, and the like, which exhibit high transmittance with respect to visible light, are conventionally used. In an electrode such as a substrate for a liquid crystal display element, a pattern obtained by patterning a transparent conductive film made of the above-mentioned material is mainly used.

  As a method for patterning a transparent conductive film, a method is generally used in which after forming a transparent conductive film, a resist pattern is formed by photolithography, and a predetermined portion of the conductive film is removed by wet etching to form a conductive pattern. In the case of an ITO and indium oxide film, a mixed liquid composed of two liquids of hydrochloric acid and ferric chloride is generally used as an etching liquid.

  The ITO film and the tin oxide film are generally formed by sputtering. However, in this method, the properties of the transparent conductive film are likely to change depending on the difference in sputtering method, sputtering power, gas pressure, substrate temperature, type of atmospheric gas, and the like. Differences in the film quality of the transparent conductive film due to fluctuations in sputtering conditions cause variations in the etching rate when the transparent conductive film is wet-etched, and are liable to reduce product yield due to patterning defects. In addition, since the conductive pattern forming method described above has undergone a sputtering process, a resist forming process, and an etching process, the process is long and a great burden is imposed on the cost.

  Recently, in order to solve the above problems, attempts have been made to form a transparent conductive pattern using a material in place of ITO, indium oxide, tin oxide and the like. For example, in Patent Document 1 below, after a conductive layer containing conductive fibers such as silver fibers is formed on a substrate, a photosensitive resin layer is formed on the conductive layer, and a pattern mask is formed thereon. A method of forming a conductive pattern that is exposed and developed is disclosed.

US Patent Application Publication No. 2010/021224

  However, in the method described in Patent Document 1, the conductive fibers are easily arranged in one direction, and a difference in the line resistance value between the X-axis direction and the Y-axis direction perpendicular to the surface can be made on the substrate on which the conductive pattern is formed. In other words, there is a problem that the resistance to static electricity is low and disconnection is likely to occur in the direction of high resistance.

  The present invention has been made in view of the above-described problems of the prior art, and has a small difference in line resistance between the X-axis direction and the Y-axis direction positioned in the in-plane perpendicular direction on the substrate, and has high electrostatic resistance. To provide a photosensitive conductive film capable of easily forming a conductive pattern with sufficient resolution, a method for forming a conductive film using the photosensitive conductive film, a method for forming a conductive pattern, and a conductive substrate. With the goal.

  In order to solve the above problems, the present invention comprises a support film, a conductive layer provided on the support film and containing conductive fibers, and a photosensitive resin layer provided on the conductive layer. A conductive film, wherein the conductive fiber has at least a curved conductive fiber, and the line resistance value at both ends of the conductive pattern when formed using the photosensitive conductive film is determined in the in-plane perpendicular direction. Provided is a photosensitive conductive film having a linear resistance anisotropy of less than 1.5 in the X-axis direction and the Y-axis direction when measured in the X-axis direction and the Y-axis direction.

  Moreover, in the photosensitive conductive film of the present invention, the curved conductive fibers have a length and a shortest distance between both ends A and B, respectively, and D and R, respectively, and the shape is all or part of the circumference. It is preferable that 0 ≦ R <2D / π is satisfied.

  According to the photosensitive conductive film of the present invention, by having the above configuration, the photosensitive conductive film is laminated so that the photosensitive resin layer is in close contact with the substrate, and the substrate is exposed and developed in a simple process. In FIG. 5, the difference in the line resistance value between the X-axis direction and the Y-axis direction in the in-plane perpendicular direction is small, and it is possible to form a conductive pattern with high electrostatic resistance with sufficient resolution.

  In the photosensitive conductive film of the present invention, the laminate of the conductive layer and the photosensitive resin layer has a minimum light transmittance in the wavelength region of 450 to 650 nm of 80 when the total film thickness of both layers is 1 to 10 μm. % Or more is preferable. When the conductive layer and the photosensitive resin layer satisfy such conditions, it is easy to increase the brightness in a display panel or the like.

  Moreover, in the photosensitive conductive film of this invention, it is preferable that the said conductive fiber is a silver fiber at the point which can adjust the electroconductivity of the electrically conductive film formed easily.

  From the viewpoint of further improving the adhesion between the substrate and the conductive pattern and the patterning property of the conductive film, the photosensitive resin layer contains a binder polymer, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator. It is preferable to do.

  The present invention also includes a laminating step of laminating the photosensitive conductive film of the present invention so that the photosensitive resin layer is in close contact with the substrate, and an exposure step of irradiating the photosensitive resin layer on the substrate with actinic rays. A method for forming a conductive film is provided.

  According to the method for forming a conductive film of the present invention, the above-described steps are performed using the photosensitive conductive film of the present invention, so that the line resistance difference between the X-axis direction and the Y-axis direction is small on the substrate. In addition, a conductive film having high electrostatic resistance (a conductive pattern can be formed) can be easily formed.

  The present invention also includes a step of laminating the photosensitive conductive film of the present invention so that the photosensitive resin layer is in close contact with the substrate, and an exposure step of irradiating a predetermined portion of the photosensitive resin layer on the substrate with actinic rays. And a developing process for forming a conductive pattern by developing the exposed photosensitive resin layer.

  According to the method for forming a conductive pattern of the present invention, the above-described steps are performed using the photosensitive conductive film of the present invention, whereby the X-axis direction and the Y-axis direction positioned in the in-plane perpendicular direction on the substrate. Thus, it is possible to easily form a conductive pattern having a small difference in line resistance and high resistance to static electricity with sufficient resolution.

  The present invention also provides a conductive film substrate forming method in which a conductive film is formed on a substrate by the conductive film forming method of the present invention.

  The present invention also provides a method for forming a conductive film substrate in which a conductive pattern is formed on a substrate by the method for forming a conductive pattern of the present invention.

  In the method for forming a conductive film substrate of the present invention, the conductive film or the conductive pattern preferably has a surface resistivity of 2000Ω / □ or less.

  According to the present invention, a conductive pattern having a small static resistance difference between the X-axis direction and the Y-axis direction positioned in the in-plane perpendicular direction and having a small electrostatic resistance is easily formed with sufficient resolution on the substrate. It is possible to provide a photosensitive conductive film, a conductive film forming method using the photosensitive conductive film, a conductive pattern forming method, and a conductive film substrate forming method.

It is a schematic cross section which shows one Embodiment of the photosensitive conductive film of this invention. It is a figure which shows typically the shape example of the conductive fiber contained in a photosensitive conductive film. It is a schematic cross section for demonstrating one Embodiment of the formation method of the conductive pattern of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In the present specification, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. Similarly, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, and “(meth) acryloyl” means “acryloyl” and corresponding “methacryloyl”.

  FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive conductive film of the present invention. A photosensitive conductive film 10 shown in FIG. 1 includes a support film 1, a conductive layer 2 provided on the support film 1 and containing conductive fibers, and a photosensitive resin layer 3 provided on the conductive layer 2. .

  Hereinafter, each of the support film 1 constituting the photosensitive conductive film 10, the conductive layer 2 containing conductive fibers, and the photosensitive resin layer 3 will be described in detail.

  Examples of the support film 1 include polymer films having heat resistance and solvent resistance such as polyethylene terephthalate film, polyethylene film, polypropylene film, and polycarbonate film. Among these, a polyethylene terephthalate film is preferable from the viewpoint of transparency and heat resistance. In addition, since these polymer films must be removable from the photosensitive resin layer later, they must not be subjected to a surface treatment or material that makes removal impossible.

  Moreover, it is preferable that the thickness of the support film 1 is 5-300 micrometers, It is more preferable that it is 10-200 micrometers, It is especially preferable that it is 15-100 micrometers. When the thickness of the support film is less than 5 μm, the mechanical strength decreases, and the photosensitive resin composition is applied to form the conductive fiber dispersion or the photosensitive resin layer 3 in order to form the conductive layer 2. In the process of carrying out, or the process of peeling a support film before developing the exposed photosensitive resin layer 3, there exists a tendency for a support film to become easy to tear. On the other hand, if the thickness of the support film exceeds 300 μm, the pattern resolution tends to decrease when the actinic ray is irradiated to the photosensitive resin layer via the support film, and the price tends to increase.

  The haze value of the support film 1 is preferably 0.01 to 5.0%, more preferably 0.01 to 3.0%, from the viewpoint of improving sensitivity and resolution. -2.0% is particularly preferred, and 0.01-1.0% is very particularly preferred. In addition, haze value can be measured based on JISK7105, for example, can be measured with commercially available turbidimeters such as NDH-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd., trade name).

  Examples of the conductive fibers contained in the conductive layer 2 include metal fibers such as gold, silver, and platinum, and carbon fibers such as carbon nanotubes. These can be used alone or in combination of two or more. From the viewpoint of conductivity, it is preferable to use gold fiber or silver fiber. Gold fiber and silver fiber can be used individually by 1 type or in combination of 2 or more types. Furthermore, silver fiber is more preferable from the viewpoint of easily adjusting the conductivity of the formed conductive film.

The metal fiber can be prepared by, for example, a method of reducing metal ions with a reducing agent such as NaBH ₄ or a polyol method.

  Commercially available products such as Unipym's Hipco single-walled carbon nanotubes can be used as the carbon nanotubes.

  The fiber diameter of the conductive fiber is preferably 1 nm to 50 nm, more preferably 2 nm to 20 nm, and particularly preferably 3 nm to 10 nm. The fiber length of the conductive fiber is preferably 1 μm to 100 μm, more preferably 2 μm to 50 μm, and particularly preferably 3 μm to 10 μm. The fiber diameter and fiber length can be measured with a scanning electron microscope.

  The thickness of the conductive layer 2 varies depending on the use of the conductive film or conductive pattern formed using the photosensitive conductive film of the present invention and the required conductivity, but is preferably 1 μm or less, preferably 1 nm to 0.5 μm. It is more preferable that the thickness is 5 nm to 0.1 μm. When the thickness of the conductive layer 2 is 1 μm or less, the light transmittance in the wavelength region of 450 to 650 nm is high, the pattern forming property is excellent, and it is particularly suitable for the production of a transparent electrode.

  The conductive layer 2 preferably has a network structure in which conductive fibers are in contact with each other. The conductive layer 2 having such a network structure may be formed on the surface of the photosensitive resin layer 3 on the support film side, but conductivity is obtained in the surface direction on the surface exposed when the support film is peeled off. If it is, it may be formed in the form included in the support film side surface layer of the photosensitive resin layer 3. In addition, the thickness of the conductive layer 2 having a network structure indicates a value measured by a scanning electron micrograph.

  The photosensitive conductive film of the present invention has an X-axis direction and a Y-axis direction when the line resistance values at both ends of the conductive pattern when the conductive pattern is formed are measured in the X-axis direction and the Y-axis direction perpendicular to the surface. It is necessary that the line resistance anisotropy is less than 1.5. By setting the linear resistance anisotropy in the X-axis direction and the Y-axis direction to less than 1.5, it is possible to easily form a conductive pattern having high electrostatic resistance with sufficient resolution. When the line resistance value anisotropy is 1.5 or more, a significant reduction in static electricity resistance of the conductive pattern is observed, and disconnection of the conductive pattern is likely to occur. The linear resistance anisotropy between the X-axis direction and the Y-axis direction is obtained by measuring the linear resistance value of the conductive pattern in the X-axis direction and the Y-axis direction, respectively. Evaluator / Y-axis resistance value). Here, as the X-axis direction and the Y-axis direction, it is practical to select one of the longitudinal direction of the photosensitive conductive film and the direction perpendicular thereto. In the present invention, the line resistance value measured in both directions is used. , The axis with the higher line resistance value and the axis with the lower line resistance are referred to as an X axis and a Y axis for convenience. Therefore, it means that the line resistance value anisotropy increases as the ratio of the two line resistance values increases, and the line resistance value anisotropy decreases as the ratio of the two line resistance values approaches 1.

  The present invention is characterized in that the conductive fiber contains a curved one in order to reduce the linear resistance anisotropy between the X-axis direction and the Y-axis direction. Accordingly, a preferred shape of the curved conductive fiber used in the present invention will be described with reference to FIG.

  FIG. 2 is a diagram schematically showing an example of the shape of conductive fibers contained in the photosensitive conductive film. Although the conductive fiber actually contained in the photosensitive conductive film of the present invention is not uniformly expressed in a shape as shown in FIG. 2, it is fundamental in defining the shape of the conductive fiber. In order to explain the concept, five types of typical shapes are shown in FIG. As shown in (a) to (e) of FIG. 2, each of the conductive fibers 4 has a circumferential shape when the length and the shortest distance between both ends A and B are D and R, respectively. Assume that it is all or part of it.

  In FIG. 2, (a) has a linear shape in which the conductive fiber 4 is not curved at all, and R = D. On the other hand, (e) is a shape that curves in a state where both ends A and B of the conductive fiber 4 are in contact with each other and constitutes the entire circumference of radius R / 2, where R = 0. is there. (C) in FIG. 2 is located in the middle of (a) and (e), and the shortest distance R between both ends A and B is the diameter of the circle, and the conductive fiber 4 is curved to form a semicircular circumference of the circle. In this case (c), R = 2D / π. In FIG. 2, (b) and (d) show the intermediate state between (a) and (c) and the intermediate state between (c) and (e), respectively. Therefore, the shape of the conductive fiber 4 satisfies the relationship of 2D / π <R <D in the case of (b) and 0 <R <2D / π in the case of (d).

  Further, in the rightmost column of FIGS. 2B to 2D, modified examples 5 and 6 of conductive fibers are shown. Reference numeral 5 indicates that two of the shape elements constituting a part of the circle are connected at the end of at least one of A and B under the conditions satisfying the respective relationships (b) to (d) in R and D. One conductive fiber is shown. Reference numeral 6 denotes one conductive fiber in which three of the shape elements are connected at at least one end of A and B. In these conductive fibers 5 and 6 as well, it is easily understood that the shape elements constituting a part of the circle satisfy the relationships shown in (b) to (d), respectively. FIG. 2 shows conductive fibers having two and three of the shape elements. Similarly, even when the number of the shape elements is four or more, the shape elements are (b) to ( The relationship d) is satisfied.

  As shown in FIG. 2A, the longitudinal direction of the linear conductive fiber 4 is assumed to be the X axis, and the in-plane right angle method with respect to the X axis is assumed to be the Y axis. When a plurality of conductive fibers 4 included in the photosensitive conductive film are arranged parallel to the X axis as in (a), the line resistance values of the conductive pattern are in the X axis direction and the Y axis direction. The line resistance value anisotropy between the X-axis direction and the Y-axis direction increases. On the other hand, when containing a plurality of conductive fibers 4 having the shape shown in (e), the conductive fibers 4 can come into contact with each other in the Y-axis direction. And the ratio of the line resistance values in the X-axis direction and the Y-axis direction is close to 1.

  Therefore, in order to reduce the linear resistance anisotropy between the X-axis direction and the Y-axis direction as much as possible, it is necessary to make the shape of the conductive fiber 4 close to (e). Preferably contains conductive fibers 4 where R satisfies 0 ≦ R <2D / π (see (d) and (e) of FIG. 2). On the other hand, when the conductive fibers having the shapes shown in FIGS. 2A to 2C, that is, R ≧ 2D / π, are contained, the line resistance values in the X axis direction and the Y axis direction are different from each other. And the ratio of the line resistance values in the X-axis direction and the Y-axis direction is 1.5 or more.

  As described above, in the present invention, in the line resistance values measured in both directions, the axis with the higher line resistance value is referred to as the X axis for convenience. Therefore, when the longitudinal direction of the conductive fiber 4 shown in FIG. 2A shows a lower line resistance value than the perpendicular direction, the longitudinal direction of the conductive fiber 4 is the Y-axis direction and is perpendicular to it. Is set as the X-axis direction.

  As described above, the photosensitive conductive film of the present invention preferably contains at least curved conductive fibers, and the curved conductive fibers satisfy 0 ≦ R <2D / π. However, the conductive fibers contained in the photosensitive conductive film of the present invention do not necessarily have to be occupied by curved conductive fibers that satisfy 0 ≦ R <2D / π. The conductive fiber is preferably 50% by mass or more or 50% by number or more, more preferably 70% by mass or more or 70% by number or more in terms of mass or number in terms of the total conductive fiber, respectively. There is an effect.

  The content of the curved conductive fiber satisfying 0 ≦ R <2D / π can be adjusted as follows. For example, as described later, when a conductive fiber dispersion is applied to form a conductive layer, a curved conductive fiber satisfying 0 ≦ R <2D / π in the conductive fiber dispersion, A conductive fiber having a shape (including a linear one) is used in advance. In that case, the blending amount of the curved conductive fiber satisfying 0 ≦ R <2D / π is preferably 50% by mass or more, more preferably 70% by mass or more based on the total amount of the conductive fiber. Moreover, in this invention, it is also possible to adjust the shape of a conductive fiber in the step of the coating process of a conductive fiber dispersion liquid. In that case, the conductive layer formed after coating is observed using an optical microscope or an electron microscope, and the result of analysis based on the observed image data is a curved conductive that satisfies 0 ≦ R <2D / π. The fiber content can be determined. The coating conditions may be optimized so that the content thus obtained is preferably 50% by number, more preferably 70% by number or more based on the total amount of the conductive fibers. In the present invention, by setting the content of the curved conductive fiber satisfying 0 ≦ R <2D / π to a more preferable range of 70% by mass or more or 70% by number or more, the X-axis direction and the Y-axis direction The linear resistance anisotropy can be made very small, 1.1 or less.

  The conductive layer 2 containing conductive fibers is, for example, conductive having the above-described conductive fibers added to the support film 1 with water and / or an organic solvent and, if necessary, a dispersion stabilizer such as a surfactant. It can be formed by coating and then drying the fiber dispersion. After drying, the conductive layer 2 formed on the support film 1 may be laminated as necessary. The coating can be performed by a known method such as a roll coating method, a comma coating method, a gravure coating method, an air knife coating method, a die coating method, a bar coating method, or a spray coating method. The drying can be performed at 30 to 150 ° C. for about 1 to 30 minutes using a hot air convection dryer or the like. In the conductive layer 2, the conductive fiber may coexist with a surfactant or a dispersion stabilizer.

  The photosensitive resin layer 3 is formed of a photosensitive resin composition containing (a) a binder polymer, (b) a photopolymerizable compound having an ethylenically unsaturated bond, and (c) a photopolymerization initiator. Can be mentioned.

  (A) As a binder polymer, for example, obtained by reaction of acrylic resin, styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, phenol resin, ester resin, urethane resin, epoxy resin and (meth) acrylic acid Examples thereof include epoxy acrylate resins, acid-modified epoxy acrylate resins obtained by reaction of epoxy acrylate resins and acid anhydrides, and the like. These resins can be used singly or in combination of two or more. From the viewpoint of excellent alkali developability and film formability, it is preferable to use an acrylic resin, and it is more preferable that the acrylic resin has a monomer unit derived from (meth) acrylic acid and (meth) acrylic acid alkyl ester as a constituent unit. . Here, “acrylic resin” means a polymer mainly having monomer units derived from a polymerizable monomer having a (meth) acrylic group. In this specification, “(meth) acrylic acid” means “acrylic acid” and “methacrylic acid” corresponding thereto, and “(meth) acrylic acid alkyl ester” means “acrylic acid alkyl ester” and the same. The corresponding “alkyl methacrylate ester” is meant.

  The said acrylic resin can use what is manufactured by radically polymerizing the polymerizable monomer which has a (meth) acryl group. This acrylic resin can be used individually by 1 type or in combination of 2 or more types.

  Examples of the polymerizable monomer having a (meth) acryl group include acrylamide such as diacetone acrylamide, (meth) acrylic acid alkyl ester, (meth) acrylic acid tetrahydrofurfuryl ester, and (meth) acrylic acid dimethylamino. Ethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (Meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid and the like.

  The acrylic resin is substituted at the α-position or aromatic ring such as styrene, vinyltoluene, α-methylstyrene, etc., in addition to the polymerizable monomer having the (meth) acryl group as described above. Polymerizable styrene derivatives, esters of vinyl alcohol such as acrylonitrile and vinyl-n-butyl ether, maleic acid monoester such as maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid One or two or more polymerizable monomers such as cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid and the like may be copolymerized.

Examples of the (meth) acrylic acid alkyl ester include compounds represented by the following general formula (1), and compounds in which the alkyl group of these compounds is substituted with a hydroxyl group, an epoxy group, a halogen group, or the like.
^{_{CH 2 = C (R 1)}} -COOR 2 ... (1)

Here, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 12 carbon atoms. Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and These structural isomers are mentioned.

  Examples of the compound represented by the general formula (1) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (meth) ) Acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid nonyl ester, (meth) ) Acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester. These can be used alone or in combination of two or more.

  Moreover, it is preferable that (a) binder polymer has a carboxyl group from a viewpoint of making alkali developability more favorable. Examples of the polymerizable monomer having a carboxyl group include (meth) acrylic acid as described above.

  The ratio of the carboxyl group of the binder polymer is 12 to 50% by mass as the ratio of the polymerizable monomer having a carboxyl group to the total polymerizable monomer used from the viewpoint of balancing the alkali developability and alkali resistance. It is preferable that it is 12-40 mass%, It is especially preferable that it is 15-30 mass%, It is very preferable that it is 15-25 mass%. When the ratio of the polymerizable monomer having a carboxyl group is less than 12% by mass, the alkali developability tends to be inferior, and when it exceeds 50% by mass, the alkali resistance tends to be inferior.

  The weight average molecular weight of the binder polymer is preferably from 5,000 to 300,000, more preferably from 20,000 to 150,000, and particularly preferably from 30,000 to 100,000, from the viewpoint of balancing the mechanical strength and alkali developability. When the weight average molecular weight is less than 5000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long. In addition, the weight average molecular weight in this invention is a value measured by the gel permeation chromatography method (GPC), and converted with the analytical curve created using standard polystyrene.

  These binder polymers are used individually by 1 type or in combination of 2 or more types. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymerization components, two or more types of binder polymers having different weight average molecular weights, and two or more types of binder polymers having different degrees of dispersion are used. A binder polymer is mentioned.

  Next, (b) the photopolymerizable compound having an ethylenically unsaturated bond will be described.

  The photopolymerizable compound having an ethylenically unsaturated bond is preferably a photopolymerizable compound having an ethylenically unsaturated bond. Examples of the photopolymerizable compound having an ethylenically unsaturated bond include a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, 2,2-bis (4-((meth) acryloxy). Polyethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane Such as bisphenol A (meth) acrylate compounds, compounds obtained by reacting glycidyl group-containing compounds with α, β-unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having a urethane bond, γ-chloro- β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl- β '-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β'-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester, and the like. These may be used alone or in combination of two or more.

  Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynonane) Xyl) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane. Among these, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as “BPE-500” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as “BPE-1300” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These may be used alone or in combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 2 propylene groups. Polypropylene glycol di (meth) acrylate being 14, polyethylene polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane diethoxytri (meth) acrylate, trimethylolpropane triethoxytri (meth) acrylate, trimethylolpropane tetraeth Xyltri (meth) acrylate, trimethylolpropane pentaethoxytri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, polypropylene glycol di (meth) having 2 to 14 propylene groups ) Acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the urethane monomer include a (meth) acryl monomer having a hydroxyl group at the β-position and a diisocyanate compound such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction product, tris [(meth) acryloxytetraethylene glycol isocyanate] hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate, and the like. “EO” represents ethylene oxide, and an EO-modified compound has a block structure of an ethylene oxide group. “PO” represents propylene oxide, and the PO-modified compound has a block structure of a propylene oxide group. Examples of the EO-modified urethane di (meth) acrylate include “UA-11” (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name). Examples of the EO and PO-modified urethane di (meth) acrylate include “UA-13” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).

  The content ratio of the photopolymerizable compound is preferably 30 to 80 parts by mass, and more preferably 40 to 70 parts by mass with respect to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. If this content is less than 30 parts by mass, photocuring will be insufficient, and the transferred conductive film (conductive layer and photosensitive resin layer) will tend to have insufficient coating properties. When wound, it tends to be difficult to store.

  Next, (c) the photopolymerization initiator will be described.

  Examples of the photopolymerization initiator include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4. '-Dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1 Aromatic ketones such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone 1-chloroanthraquinone Quinones such as 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether Benzoin ether compounds such as benzoin, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1- [9- Oxime ester compounds such as ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (O-acetyloxime), benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl)- 4,5-diphenylimidazo Dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o -Methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole dimer such as 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 9- Examples thereof include acridine derivatives such as phenylacridine and 1,7-bis (9,9′-acridinyl) heptane, N-phenylglycine, N-phenylglycine derivatives, coumarin compounds, and oxazole compounds. Further, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may be the same to give the target compound, or differently give an asymmetric compound. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. Among these, from the viewpoint of transparency, aromatic ketone compounds such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and 1,2-octanedione-1- [4 Oxime ester compounds such as-(phenylthio) phenyl] -2- (O-benzoyloxime) are more preferred. These are used alone or in combination of two or more.

  The content ratio of the photopolymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound. It is particularly preferably 1 to 5 parts by mass. If this content is less than 0.1 parts by mass, the photosensitivity tends to be insufficient, and if it exceeds 20 parts by mass, the absorption on the surface of the photosensitive resin layer increases during exposure, and the internal photocuring is caused. There is a tendency to become insufficient.

  For the photosensitive resin layer 3, a plasticizer such as p-toluenesulfonamide, a filler, an antifoaming agent, a flame retardant, a stabilizer, an adhesion imparting agent, a leveling agent, a peeling accelerator, and an antioxidant, if necessary. Additives such as an agent, a fragrance, an imaging agent, and a thermal crosslinking agent can be contained alone or in combination of two or more. The addition amount of these additives is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the binder polymer and the photopolymerizable compound.

  The photosensitive resin layer 3 is formed on the support film 1 on which the conductive layer 2 is formed, as required, methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl. It can form by apply | coating and drying the solution of the photosensitive resin composition about 10-60 mass% of solid content melt | dissolved in solvents, such as ether, or these mixed solvents. However, in this case, the amount of the remaining organic solvent in the photosensitive resin layer after drying is preferably 2% by mass or less in order to prevent the organic solvent from diffusing in the subsequent step.

  The coating can be performed by a known method such as a roll coating method, a comma coating method, a gravure coating method, an air knife coating method, a die coating method, a bar coating method, or a spray coating method. After coating, drying for removing the organic solvent and the like can be performed at 70 to 150 ° C. for about 5 to 30 minutes with a hot air convection dryer or the like.

  Although the thickness of the photosensitive resin layer 3 changes with uses, it is preferable that it is 1-200 micrometers in thickness after drying, it is more preferable that it is 1-15 micrometers, and it is especially preferable that it is 1-10 micrometers. If the thickness is less than 1 μm, coating tends to be difficult, and if it exceeds 200 μm, the sensitivity due to the decrease in light transmission is insufficient, and the photocuring property of the photosensitive resin layer to be transferred tends to decrease.

  In the photosensitive conductive film of the present embodiment, the laminate of the conductive layer 2 and the photosensitive resin layer 3 has minimum light transmission in a wavelength region of 450 to 650 nm when the total film thickness of both layers is 1 to 10 μm. The rate is preferably 80% or more, and more preferably 85% or more. When the conductive layer and the photosensitive resin layer satisfy such conditions, it is easy to increase the brightness in a display panel or the like.

  In the photosensitive conductive film of the present invention, a protective film can be laminated so as to be in contact with the surface of the photosensitive resin layer 3 opposite to the support film 1 side.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as a polyethylene terephthalate film, a polypropylene film, and a polyethylene film can be used. Moreover, you may use the polymer film similar to the above-mentioned support body film as a protective film.

  The adhesive force between the protective film and the photosensitive resin layer is greater than the adhesive force between the conductive layer 2 and the photosensitive resin layer 3 and the support film 1 in order to facilitate the peeling of the protective film from the photosensitive resin layer. Is preferably small.

Moreover, it is preferable that the number of fish eyes with a diameter of 80 micrometers or more contained in a protective film is 5 pieces / m < ² > or less. "Fish eye" means that when a material is melted by heat, kneaded, extruded, biaxially stretched, casting method, etc., foreign materials, undissolved materials, oxidized degradation products, etc. It is taken in.

  The thickness of the protective film is preferably 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. When the thickness of the protective film is less than 1 μm, the protective film tends to be broken during lamination, and when it exceeds 100 μm, the price tends to increase.

  The photosensitive conductive film may further have layers such as an adhesive layer and a gas barrier layer on the support film.

  The photosensitive conductive film can be stored, for example, in the form of a flat plate as it is or in the form of a roll wound around a cylindrical core. In addition, it is preferable to wind up in this case so that a support film may become the outermost side.

  Moreover, when the photosensitive conductive film does not have a protective film, this photosensitive conductive film can be stored as it is in the form of a flat plate.

  The core is not particularly limited as long as it is conventionally used. For example, plastic such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, ABS resin (acrylonitrile-butadiene-styrene copolymer) Is mentioned. Moreover, it is preferable to install an end face separator on the end face of the photosensitive conductive film wound up in a roll shape from the viewpoint of end face protection, and in addition, it is preferable to install a moisture-proof end face separator from the viewpoint of edge fusion resistance. Moreover, when packing a photosensitive conductive film, it is preferable to wrap and wrap in a black sheet with small moisture permeability.

<Method for Forming Conductive Film>
The conductive film forming method of the present invention includes a laminating step of laminating the photosensitive conductive film of the present invention so that the photosensitive resin layer is in close contact with the substrate, and irradiating the photosensitive resin layer on the substrate with actinic rays. An exposure step. When the photosensitive conductive film has a protective film, the photosensitive conductive film from which the protective film has been peeled is laminated on the substrate from the photosensitive resin layer side. By the laminating process, the photosensitive resin layer, the conductive layer, and the support film are laminated in this order on the substrate.

  Examples of the substrate include a glass substrate and a plastic substrate such as polycarbonate. The substrate preferably has a minimum light transmittance of 80% or more in a wavelength region of 450 to 650 nm.

The laminating step is performed, for example, by a method of laminating the photosensitive conductive film by removing the protective film, if any, and then pressing the photosensitive resin layer side against the substrate while heating. In addition, it is preferable to laminate | stack this operation under pressure reduction from the viewpoint of adhesiveness and followable | trackability. In the lamination of the photosensitive conductive film, the photosensitive resin layer and / or the substrate is preferably heated to 70 to 130 ° C., and the pressure is about 0.1 to 1.0 MPa (about 1 to 10 kgf / cm ² ). However, these conditions are not particularly limited. In addition, if the photosensitive resin layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the substrate in advance, but it is also possible to perform pre-heat treatment of the substrate in order to further improve the lamination property. .

  In the exposure step, the photosensitive resin layer is cured by irradiation with actinic rays, and the conductive layer is fixed by the cured product, whereby a conductive film is formed on the substrate. As the active light source, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that effectively emits ultraviolet light, visible light, or the like is used. Also, an Ar ion laser, a semiconductor laser, or the like that effectively emits ultraviolet light, visible light, or the like is used. Further, those that effectively radiate visible light, such as photographic flood bulbs and solar lamps, are also used.

  When the support film on the conductive layer is transparent to actinic rays, it can be irradiated with actinic rays through the support film. When the support film is light-shielding, it is photosensitive after removing the support film. Actinic rays are irradiated to the resin layer.

  In addition, when the substrate is transparent to actinic rays, actinic rays can be irradiated from the substrate side through the substrate, but in terms of resolution, the actinic rays are applied from the conductive layer side to the conductive layer and the photosensitive resin layer. Is preferably irradiated.

Through the above steps, a conductive film substrate having a conductive film on the substrate is obtained. In the method for forming a conductive film of the present embodiment, the formed conductive film is subjected to heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ^{2 as} necessary after peeling off the support film. It may be further cured by performing.

  Thus, according to the method for forming a conductive film of the present invention, it is possible to easily form a transparent conductive film on a substrate such as glass or plastic.

<Method for forming conductive pattern>
Next, the method for forming a conductive pattern of the present invention will be described with reference to FIG.

  The conductive pattern forming method according to the present embodiment includes a step of laminating the photosensitive conductive film 10 described above so that the photosensitive resin layer 3 is in close contact with the substrate 20 (FIG. 3A), and the substrate 20 An exposure step (FIG. 3B) for irradiating a predetermined portion of the upper photosensitive resin layer 3 with actinic rays, and a development step for forming the conductive pattern by developing the exposed photosensitive resin layer 3 are provided. . Through these steps, the conductive film substrate 40 including the conductive film (conductive pattern) 2a patterned on the substrate 20 is obtained ((c) in FIG. 3).

The laminating step is performed, for example, by a method of laminating the photosensitive conductive film by removing the protective film, if any, and then pressing the photosensitive resin layer side against the substrate while heating. In addition, it is preferable to laminate | stack this operation under pressure reduction from the viewpoint of adhesiveness and followable | trackability. In the lamination of the photosensitive conductive film, the photosensitive resin layer and / or the substrate is preferably heated to 70 to 130 ° C., and the pressure is about 0.1 to 1.0 MPa (about 1 to 10 kgf / cm ² ). However, these conditions are not particularly limited. In addition, if the photosensitive resin layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the substrate in advance, but it is also possible to perform pre-heat treatment of the substrate in order to further improve the lamination property. .

  Examples of the exposure method in the exposure step include a method of irradiating an actinic ray in an image form through a negative or positive mask pattern called an artwork (mask exposure method). As the active light source, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that effectively emits ultraviolet light, visible light, or the like is used. Also, an Ar ion laser, a semiconductor laser, or the like that effectively emits ultraviolet light, visible light, or the like is used. Further, those that effectively radiate visible light, such as photographic flood bulbs and solar lamps, are also used. Alternatively, a method of irradiating actinic rays in an image form by a direct drawing method using a laser exposure method or the like may be employed.

  When the support film on the conductive layer is transparent to actinic rays, it can be irradiated with actinic rays through the support film. When the support film is light-shielding, it is photosensitive after removing the support film. Actinic rays are irradiated to the resin layer.

  In addition, when the substrate is transparent to actinic rays, actinic rays can be irradiated from the substrate side through the substrate, but in terms of resolution, the actinic rays are applied from the conductive layer side to the conductive layer and the photosensitive resin layer. Is preferably irradiated.

  In the development process of the present embodiment, portions other than the exposed portion of the photosensitive resin layer are removed. Specifically, when a transparent support film is present on the conductive layer, the support film is first removed, and then a portion other than the exposed portion of the photosensitive resin layer is removed by wet development. Thereby, the conductive layer containing conductive fibers remains on the cured resin layer 3b having a predetermined pattern, and the conductive pattern 2a is formed.

  The wet development is performed by a known method such as spraying, rocking immersion, brushing, or scraping, using a developer corresponding to a photosensitive resin such as an alkaline aqueous solution, an aqueous developer, or an organic solvent developer. .

  As the developing solution, a safe and stable solution having good operability such as an alkaline aqueous solution is used. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium, or ammonium carbonate or bicarbonate, potassium phosphate, and phosphoric acid. Alkali metal phosphates such as sodium and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used.

  Moreover, as alkaline aqueous solution used for image development, 0.1-5 mass% sodium carbonate aqueous solution, 0.1-5 mass% potassium carbonate aqueous solution, 0.1-5 mass% sodium hydroxide aqueous solution, 0.1-5 mass % Sodium tetraborate aqueous solution and the like are preferable. Moreover, it is preferable to make pH of the alkaline aqueous solution used for image development into the range of 9-11, and the temperature is adjusted according to the developability of the photosensitive resin layer. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.

  Further, an aqueous developer composed of water or an aqueous alkali solution and one or more organic solvents can be used. Here, as the base contained in the alkaline aqueous solution, in addition to the above-mentioned bases, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1 , 3-propanediol, 1,3-diamino-2-propanol, morpholine. Examples of the organic solvent include 3 acetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether. Is mentioned. These are used individually by 1 type or in combination of 2 or more types.

  The aqueous developer preferably has an organic solvent concentration of 2 to 90% by mass, and the temperature can be adjusted according to the developability. Furthermore, the pH of the aqueous developer is preferably as low as possible within the range where the resist can be sufficiently developed, preferably pH 8-12, more preferably pH 9-10. In addition, a small amount of a surfactant, an antifoaming agent, or the like can be added to the aqueous developer.

  Examples of the organic solvent developer include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. These organic solvents preferably add water in the range of 1 to 20% by mass in order to prevent ignition.

  Two or more of the above-described developing solutions may be used in combination as necessary.

  Examples of the development method include a dip method, a battle method, a spray method, brushing, and slapping. Among these, it is preferable to use a high-pressure spray system from the viewpoint of improving the resolution.

In the method for forming a conductive pattern of the present embodiment, the conductive pattern may be further cured by heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ² as necessary after development. Good.

  Thus, according to the method for forming a conductive pattern of the present invention, a transparent conductive pattern can be easily formed on a substrate such as glass or plastic without forming an etching resist like an inorganic film such as ITO. Is possible.

  The conductive film substrate of the present invention is obtained by the conductive film formation method or conductive pattern formation method described above, but from the viewpoint of being able to be effectively used as a transparent electrode, the surface resistivity of the conductive film or conductive pattern is 2000Ω / □ or less. Preferably, it is 1000Ω / □ or less, more preferably 500Ω / □ or less. The surface resistivity can be adjusted by, for example, the concentration of the conductive fiber dispersion or the coating amount.

  In the conductive film substrate of the present invention, the minimum light transmittance in the wavelength region of 450 to 650 nm is preferably 80% or more, and more preferably 85% or more.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

(Conductive fiber dispersion 1 (silver fiber dispersion))
[Preparation of silver fiber by polyol method]
In a 2000 ml three-necked flask, 500 ml of ethylene glycol was placed and heated to 160 ° C. with an oil bath while stirring with a magnetic stirrer under a nitrogen atmosphere. A solution prepared by dissolving ₂ mg of PtCl ₂ separately prepared in 50 ml of ethylene glycol was added dropwise thereto. After 4 to 5 minutes, a solution in which 5 g of AgNO ₃ was dissolved in 300 ml of ethylene glycol and a solution in which 5 g of polyvinylpyrrolidone having a weight average molecular weight of 40,000 (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 150 ml of ethylene glycol were respectively obtained. From the dropping funnel in 1 minute, and then stirred at 160 ° C. for 60 minutes.

  The reaction solution was allowed to stand at 30 ° C. or lower, diluted 10 times with acetone, centrifuged at 2000 rpm for 20 minutes with a centrifuge, and the supernatant was decanted. Acetone was added to the precipitate, and after stirring, the mixture was centrifuged under the same conditions as described above, and acetone was decanted. Then, it centrifuged twice similarly using distilled water, and obtained the silver fiber. When the obtained silver fiber was observed with an optical microscope, the fiber diameter (diameter) was about 5 nm, and the fiber length D was about 5 μm.

[Preparation of silver fiber dispersion]
The conductive fiber dispersion 1 was obtained by dispersing 0.2% by mass of the silver fiber obtained above and 0.1% by mass of dodecyl-pentaethylene glycol in pure water.

<Preparation of solution of photosensitive resin composition>
<Synthesis of acrylic resin>
In a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas introduction tube, a mixture of methyl cellosolve and toluene (methyl cellosolve / toluene = 3/2 (mass ratio), hereinafter “solution s 400 g) was added, stirred while blowing nitrogen gas, and heated to 80 ° C. On the other hand, a solution (hereinafter referred to as “solution a”) prepared by mixing 100 g of methacrylic acid, 250 g of methyl methacrylate, 100 g of ethyl acrylate and 50 g of styrene as a monomer and 0.8 g of azobisisobutyronitrile was prepared. . Next, the solution a was added dropwise to the solution s heated to 80 ° C. over 4 hours, and then kept at 80 ° C. with stirring for 2 hours. Further, a solution obtained by dissolving 1.2 g of azobisisobutyronitrile in 100 g of the solution s was dropped into the flask over 10 minutes. And the solution after dripping was heat-retained at 80 degreeC for 3 hours, stirring, Then, it heated at 90 degreeC over 30 minutes. The mixture was kept at 90 ° C. for 2 hours and then cooled to obtain a binder polymer solution. Acetone was added to this binder polymer solution to prepare a non-volatile component (solid content) of 50% by mass to obtain a binder polymer solution as component (a). The obtained binder polymer had a weight average molecular weight of 80,000. This was designated as acrylic polymer A.

  The materials shown in Table 1 were blended in the blending amounts (unit: parts by mass) shown in the same table to prepare a solution of the photosensitive resin composition.

表中の ＊１ メタクリル酸：メタクリル酸メチル：アクリル酸エチル：及びスチレン＝２０：５０：２０：１０の質量比率のアクリルポリマー。

* 1 Acrylic polymer having a mass ratio of methacrylic acid: methyl methacrylate: ethyl acrylate: and styrene = 20: 50: 20: 10 in the table.

<Preparation of photosensitive conductive film-1>
Example 1
Discharge amount 0.6L of the conductive fiber dispersion 1 obtained above on a 50 μm-thick polyethylene terephthalate film (PET film, manufactured by Teijin Ltd., trade name “G2-50”) as a support film by a die coating method. / Min at a coating speed of 20 m / min, dried for 3 minutes with a hot air convection dryer at 100 ° C., and pressurized at a linear pressure of 10 kg / cm at room temperature to form a conductive layer on the support film. Formed. The thickness of the conductive layer after drying was about 0.01 μm.

  Next, the solution of the photosensitive resin composition is uniformly applied onto a 50 μm-thick polyethylene terephthalate film on which the conductive layer is formed, and dried for 10 minutes with a 100 ° C. hot air convection dryer to form a photosensitive resin layer. Formed. Thereafter, the photosensitive resin layer was covered with a protective film made of polyethylene (manufactured by Tamapoly Co., Ltd., trade name “NF-13”) to obtain a photosensitive conductive film. In addition, the film thickness after drying of the photosensitive resin layer was 5 micrometers.

(Example 2)
Discharge amount 0.4L of the conductive fiber dispersion 1 obtained above by die coating on a 50 μm thick polyethylene terephthalate film (PET film, trade name “G2-50” manufactured by Teijin Limited) as a support film. / Min at a coating speed of 20 m / min, dried for 10 minutes with a hot air convection dryer at 100 ° C., and pressurized at a linear pressure of 10 kg / cm at room temperature to form a conductive layer on the support film. Formed. The thickness of the conductive layer after drying was about 0.01 μm.

  Next, the solution of the photosensitive resin composition is uniformly applied onto a 50 μm-thick polyethylene terephthalate film on which the conductive layer is formed, and dried for 10 minutes with a 100 ° C. hot air convection dryer to form a photosensitive resin layer. Formed. Thereafter, the photosensitive resin layer was covered with a protective film made of polyethylene (manufactured by Tamapoly Co., Ltd., trade name “NF-13”) to obtain a photosensitive conductive film. In addition, the film thickness after drying of the photosensitive resin layer was 5 micrometers.

(Comparative Example 1)
The conductive fiber dispersion 1 obtained above is uniformly applied at 25 g / m ² on a 50 μm-thick polyethylene terephthalate film (PET film, manufactured by Teijin Ltd., trade name “G2-50”) as a support film. The film was dried with a hot air convection dryer at 100 ° C. for 3 minutes, and pressed with a linear pressure of 10 kg / cm at room temperature, thereby forming a conductive layer on the support film. The thickness of the conductive layer after drying was about 0.01 μm.

  Next, the solution of the photosensitive resin composition is uniformly applied onto a 50 μm-thick polyethylene terephthalate film on which the conductive layer is formed, and dried for 10 minutes with a 100 ° C. hot air convection dryer to form a photosensitive resin layer. Formed. Thereafter, the photosensitive resin layer was covered with a protective film made of polyethylene (manufactured by Tamapoly Co., Ltd., trade name “NF-13”) to obtain a photosensitive conductive film. In addition, the film thickness after drying of the photosensitive resin layer was 5 micrometers.

<Preparation of photosensitive conductive film-2>
(Example 3)
A conductive layer was formed in the same manner as in Example 1, and the photosensitive conductive layer was formed in the same manner as in Example 1 except that the photosensitive resin layer was formed so that the total film thickness of the conductive layer and the photosensitive resin layer was 10 μm. A film was prepared.

<Formation of conductive film and conductive film substrate>
A polycarbonate substrate having a thickness of 1 mm was heated to 80 ° C., and the photosensitive resin film obtained in Examples 1, 2, 3 and Comparative Example 1 was formed on the surface of the polycarbonate substrate while the protective film was peeled off while the photosensitive resin layer was removed. Was laminated under the conditions of 120 ° C. and 0.4 MPa. After lamination, when the substrate was cooled and the temperature of the substrate reached 23 ° C., using an exposure machine (trade name “HMW-201B” manufactured by Oak Co., Ltd.) having a high-pressure mercury lamp from the support film side, 1000 mJ / The conductive layer and the photosensitive resin layer were irradiated with light with an exposure amount of cm ² . After exposure, the film was allowed to stand at room temperature (25 ° C.) for 15 minutes, and then the PET film as the support film was peeled off to form a conductive film containing silver fibers on the polycarbonate substrate.

[Measurement of surface resistivity]
Prepared are polycarbonate substrates with conductive films of Examples 1, 2, and 3 and Comparative Example 1 prepared by the above method, and a JIS-based four-probe method using a low resistivity meter (Loresta GP, manufactured by Mitsubishi Chemical Corporation). The surface resistivity was measured according to K7194. The evaluation results are shown in Table 2.

[Measurement of light transmittance]
Prepare a polycarbonate substrate with conductive film of Examples 1, 2, 3 and Comparative Example 1 prepared by the above method, using a spectrophotometer (trade name “U-3310” manufactured by Hitachi High-Technologies Corporation), The minimum light transmittance in the wavelength region of 450 to 650 nm was measured. The evaluation results are shown in Table 2.

<Formation of conductive pattern and conductive pattern substrate>
A polycarbonate substrate having a thickness of 1 mm is heated to 80 ° C., and the photosensitive resin layer is formed on the surface of each photosensitive conductive film produced in Examples 1, 2, 3 and Comparative Example 1 while peeling off the protective film. It was made to oppose to a board | substrate and it laminated on 120 degreeC and 0.4 MPa conditions. After lamination, when the substrate is cooled and the temperature of the substrate reaches 23 ° C., a photomask having a wiring pattern with a line width / space width of 1/1 mm and a length of 120 mm is closely attached to the PET film surface as a support film I let you. Then, the conductive layer and the photosensitive resin layer were irradiated with light at an exposure amount of 200 mJ / cm ² using an exposure machine (trade name “HMW-201B”, manufactured by Oak Co., Ltd.) having a high-pressure mercury lamp lamp.

  After the exposure, the film was allowed to stand at room temperature (25 ° C.) for 15 minutes, and then the PET film as the support film was peeled off, and developed by spraying a 1% by mass aqueous sodium carbonate solution at 30 ° C. for 30 seconds. After development, a conductive pattern having a line width / space width of about 1/1 mm of a conductive film containing silver fibers was formed on a polycarbonate substrate. It was confirmed that each conductive pattern was well formed.

<Evaluation of wire resistance anisotropy>
In the same manner as above, wiring patterns are formed in two directions perpendicular to the surface of the polycarbonate substrate (X-axis direction and Y-axis direction), and tester + and-probe pins are applied to both ends of the pattern in each direction. The wire resistance value was measured and the wire resistance value anisotropy was evaluated. Table 2 summarizes the ratios of the respective line resistance values measured in the X-axis direction and the Y-axis direction for the photosensitive conductive films produced in Examples 1, 2, 3 and Comparative Example 1. The X-axis direction resistance value shown in Table 2 means the axial resistance value that indicates a higher line resistance value in the line resistance values measured in two in-plane perpendicular directions of the polycarbonate substrate.

  As shown in Table 2, the photosensitive conductive films produced in Examples 1, 2, and 3 have linear resistance anisotropy (X-axis direction resistance value / Y-axis direction resistance value) in the X-axis direction and the Y-axis direction. ) Were 1.01, 1.13 and 1.02. As a result of observing the conductive pattern of the photosensitive conductive film produced in Examples 1, 2, and 3 with an optical microscope or an electron microscope, as a conductive fiber contained in the conductive pattern, (d) and (e) in FIG. It has been found that there are many conductive fibers having the shape shown.

  On the other hand, the comparative example has a large anisotropy in which the line resistance anisotropy in the X-axis direction and the Y-axis direction is 1.52. Although the conductive pattern was observed using the optical microscope or the electron microscope also about the photosensitive conductive film of a comparative example, the shape shown to (a)-(c) of FIG. 2 is shown in the conductive fiber contained in a conductive pattern. Many conductive fibers have been present, and few conductive fibers having the shapes shown in FIGS. 2D and 2E were observed. Therefore, in the photosensitive conductive film of the comparative example, disconnection may occur at some positions in the conductive pattern after formation. Thus, it was confirmed that the comparative example having high linear resistance anisotropy in the X-axis direction and the Y-axis direction has low electrostatic resistance.

  According to the present invention, a photosensitive conductive film that can easily form a conductive pattern having a small difference in line resistance between the X-axis direction and the Y-axis direction and high electrostatic resistance on a substrate with sufficient resolution, And the formation method of the electrically conductive film using this photosensitive conductive film, the formation method of an electrically conductive pattern, and an electrically conductive film board | substrate can be provided.

DESCRIPTION OF SYMBOLS 1 ... Support film, 2 ... Conductive layer, 2a ... Conductive pattern, 3 ... Photosensitive resin layer, 3b ... Resin hardened layer, 4, 5, 6 ... Conductive fiber, 10 ... Photosensitive conductive film, 20 ... Substrate, 40 ... conductive film substrate.

Claims (11)

  A photosensitive conductive film comprising a support film, a conductive layer provided on the support film and containing conductive fibers, and a photosensitive resin layer provided on the conductive layer, wherein the conductive fibers However, it has at least curved conductive fibers, and when it is formed using the photosensitive conductive film, the line resistance values at both ends of the conductive pattern are measured in the X-axis direction and the Y-axis direction perpendicular to the surface. A photosensitive conductive film having a linear resistance anisotropy of less than 1.5 in the X-axis direction and the Y-axis direction.   The curved conductive fiber has a length and a shortest distance between both ends A and B, respectively, and D and R, respectively, and assuming that the shape forms all or part of the circumference, 0 ≦ The photosensitive conductive film of Claim 1 which satisfy | fills R <2D / (pi).   The laminate of the conductive layer and the photosensitive resin layer has a minimum light transmittance of 80% or more in a wavelength region of 450 to 650 nm when a total film thickness of both layers is 1 to 10 μm. 2. The photosensitive conductive film according to 2.   The photosensitive conductive film as described in any one of Claims 1-3 whose said conductive fiber is silver fiber.   The photosensitive conductive film as described in any one of Claims 1-4 in which the said photosensitive resin layer contains the photopolymerizable compound and photoinitiator which have a binder polymer, an ethylenically unsaturated bond. A laminating step of laminating the photosensitive conductive film according to any one of claims 1 to 5 so that the photosensitive resin layer is in close contact with a substrate;
An exposure step of irradiating the photosensitive resin layer on the substrate with actinic rays;
A method for forming a conductive film. Laminating the photosensitive conductive film according to any one of claims 1 to 5 so that the photosensitive resin layer is in close contact with a substrate;
An exposure step of irradiating a predetermined portion of the photosensitive resin layer on the substrate with an actinic ray;
A developing step of forming a conductive pattern by developing the exposed photosensitive resin layer;
A method for forming a conductive pattern.   A method for forming a conductive film substrate, comprising forming a conductive film on the substrate by the method for forming a conductive film according to claim 6.   The method for forming a conductive film substrate according to claim 8, wherein the conductive film has a surface resistivity of 2000Ω / □ or less.   A method for forming a conductive film substrate, comprising forming a conductive pattern on the substrate by the method for forming a conductive pattern according to claim 7.   The manufacturing method of the electrically conductive film substrate of Claim 10 whose surface resistivity of the said electrically conductive pattern is 2000 ohms / square or less.

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