JP2019144657A - Conductive pattern formation method, conductive pattern base material, and touch sensor panel - Google Patents

Abstract

To provide a conductive pattern formation method capable of improving ESD resistance without deteriorating visibility, a conductive pattern base material, and a touch sensor panel.SOLUTION: In a conductive pattern formation method, a conductive pattern 3 of a conductive network using conductive fibers is formed on a base material 2, and the conductive pattern 3 is formed so that the orientation of the conductive fibers of the conductive pattern 3 in a conduction direction CD is larger than the orientation of the conductive fibers in a vertical direction VD vertical to the conduction direction CD.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for forming a conductive pattern, a conductive pattern substrate, and a touch panel sensor.

  Liquid crystal is used for large electronic devices such as personal computers and televisions, small electronic devices such as car navigation systems, smartphones and electronic dictionaries, OA (Office Automation) devices, and FA (Factory Automation) devices. A display element or a touch panel (touch panel sensor) is used.

  Conventionally, ITO (Indium-Tin-Oxide), indium oxide, tin oxide, and the like have been used as the material for the transparent conductive film because of its high transmittance for visible light. As electrodes provided on a substrate for a liquid crystal display element or the like, a pattern obtained by patterning a transparent conductive film made of the above-mentioned material is mainly used.

  In recent years, attempts have been made to form a transparent conductive pattern using a material in place of ITO, indium oxide, tin oxide, or the like. For example, in the following Patent Document 1, a photosensitive conductive film having a conductive film containing a conductive fiber and a photosensitive resin layer is provided on a substrate, and exposure and development through a pattern mask are performed on these. Thus, a method of forming a conductive pattern is disclosed.

JP 2017-045687 A

  By the way, in the conductive pattern containing a conductive fiber, ESD (Electro Static Discharge) which a conductive fiber breaks by static electricity becomes a problem. In order to improve the ESD resistance, it is effective to lower the surface resistance value of the conductive fiber. However, in order to reduce the surface resistance value of the conductive fiber, it is necessary to increase the amount of the conductive fiber, and as a result, there is a problem that visibility (permeability) deteriorates.

  Then, an object of this invention is to provide the formation method of a conductive pattern, a conductive pattern base material, and a touch panel sensor which can improve ESD tolerance, without deteriorating visibility.

  As a result of intensive studies on the above problems, the present inventors have obtained knowledge that ESD resistance can be improved without deteriorating visibility by imparting anisotropy to conductive fibers in a conductive pattern. It was.

  Patent Document 1 describes that, in the past, when the photosensitive conductive film has anisotropy, the take-off position is inclined to eliminate the difference in line resistance between the X electrode and the Y electrode. . However, in the prior art described in Patent Document 1, the photosensitive conductive film itself has only anisotropy, and the X electrode and the Y electrode are isotropic. This is because the conductive pattern formed of ITO, indium oxide, tin oxide, or the like is isotropic, and the conductive pattern formed of the photosensitive conductive film is naturally required to be isotropic.

  The method for forming a conductive pattern according to the present invention is a method for forming a conductive pattern of a conductive network using a conductive fiber on a substrate, the conductive pattern in the conductive direction of the conductive pattern. The conductive pattern is formed so that the degree of orientation is greater than the degree of orientation of the conductive fibers in the vertical direction, which is a direction perpendicular to the conductive direction.

  In this method of forming a conductive pattern, the degree of orientation of the conductive fibers in the conductive direction is larger than the degree of orientation of the conductive fibers in the vertical direction. The resistance value becomes smaller. Thereby, even if it does not increase electroconductive fiber, ESD tolerance can be improved, without worsening visibility (permeability).

  A layer forming step of forming on the substrate a photosensitive resin layer having a conductive network in which the orientation degree of the conductive fibers in the MD direction and the orientation degree of the conductive fibers in the TD direction are different, and a mask pattern on the photosensitive resin layer An exposure step of irradiating with actinic rays through, and a development step of forming a conductive pattern on the substrate by removing unexposed portions of the photosensitive resin layer. In the exposure step, a mask pattern for the substrate Alternatively, the orientation of the conductive fibers in the conductive direction may be larger than the orientation of the conductive fibers in the vertical direction. In this method of forming a conductive pattern, in the exposure process, by adjusting the orientation of the mask pattern with respect to the substrate, a conductive pattern in which the orientation degree of the conductive fibers in the conduction direction is larger than the orientation degree of the conductive fibers in the vertical direction is obtained. Can be formed.

  The conductive pattern base material according to the present invention includes a base material and a conductive pattern having a conductive network formed on the base material and using conductive fibers. In the conductive pattern, in the conductive direction of the conductive pattern. The orientation degree of the conductive fibers is larger than the orientation degree of the conductive fibers in the vertical direction, which is a direction perpendicular to the conduction direction.

  In this conductive pattern base material, since the degree of orientation of the conductive fibers in the conductive direction is larger than the degree of orientation of the conductive fibers in the vertical direction, the resistance value in the conductive direction of the conductive pattern compared to the case where the degree of orientation of both is equal. Becomes smaller. Thereby, even if it does not increase electroconductive fiber, ESD tolerance can be improved, without worsening visibility (permeability).

  The conductive pattern base material according to the present invention includes a base material and a conductive pattern having a conductive network formed on the base material and using conductive fibers. In the conductive pattern, in the conductive direction of the conductive pattern. The resistance value per unit length is smaller than the resistance value per unit length in the vertical direction, which is a direction perpendicular to the conduction direction.

  In this conductive pattern base material, the resistance value per unit length of the conductive pattern in the conductive direction is smaller than the resistance value per unit length of the conductive pattern in the vertical direction, so even without increasing the conductive fibers, ESD resistance can be improved without deteriorating visibility (transmittance).

  In any one of the conductive pattern substrates described above, the ratio of the orientation degree of the conductive fibers in the conductive direction to the orientation degree of the conductive fibers in the vertical direction of the conductive pattern is greater than 1.0 and less than 3.0. Also good. In this conductive pattern substrate, the ratio of the degree of orientation of the conductive fibers in the conductive direction to the degree of orientation of the conductive fibers in the vertical direction of the conductive pattern is greater than 1.0 and less than 3.0, thus ensuring ease of manufacture. However, the resistance value in the conductive direction of the conductive pattern can be further reduced.

  In any one of the conductive pattern substrates described above, the ratio of the resistance value per unit length in the conductive direction to the resistance value per unit length in the vertical direction of the conductive pattern is 0.3 or more and less than 1.0. May be. In this conductive pattern base material, the ratio of the resistance value per unit length in the conductive direction to the resistance value per unit length in the vertical direction of the conductive pattern is 0.3 or more and less than 1.0. While ensuring, the resistance value in the conductive direction of the conductive pattern can be further reduced.

  The touch panel sensor according to the present invention includes any one of the above conductive pattern base materials. Since this touch panel includes the above-described conductive pattern base material, ESD resistance can be improved without deteriorating visibility.

  According to the present invention, ESD tolerance can be improved without deteriorating visibility.

It is a schematic cross section which shows an example of the conductive pattern base material of this embodiment. It is the figure which expanded a part of conductive pattern typically. It is a schematic cross section which shows an example of the photosensitive conductive film with a support film. It is a partially cutaway perspective view showing an example of a photosensitive conductive film with a support film. 5A to 5C are schematic cross-sectional views for explaining a method of forming a conductive pattern using a photosensitive conductive film. It is a schematic plan view which shows an example of the touch panel sensor of this embodiment. 7A and 7C are schematic plan views for explaining a method for manufacturing a touch panel sensor, and FIG. 7B is a schematic cross-sectional view taken along the line II in FIG. 7A. 7 (d) is a schematic cross-sectional view taken along the line II-II in FIG. 7 (b). It is a schematic cross section which shows the other example of the conductive pattern base material of this embodiment. It is a schematic cross section which shows the other example of the conductive pattern base material of this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Moreover, the numerical value range shown using "to" in this specification shows the range which includes the numerical value described before and behind "to" as a minimum value and a maximum value, respectively.

(Conductive pattern substrate)
As shown in FIG. 1, the conductive pattern substrate 1 of this embodiment includes a substrate 2, a conductive pattern 3 formed on the substrate 2, and a resin layer 4. The conductive pattern 3 is formed by a conductive network using conductive fibers.

<Base material>
The base material 2 supports a conductive pattern. Although it can use without a restriction | limiting especially as the base material 2, For example, the glass, plastic, ceramic, resin-made base materials etc. which are used for a touch panel sensor are mentioned. Examples of the resin base material include a polyester resin, a polystyrene resin, an olefin resin, a polybutylene terephthalate resin, a polycarbonate resin, and an acrylic resin base material. The thickness of the base material 2 can be appropriately selected according to the purpose of use, and a film-like base material may be used. Examples of the film-like substrate include polyethylene terephthalate film, polycarbonate film, and cycloolefin polymer film. Moreover, the thing by which the decoration step of several micrometers was given to these is mentioned. This step is normally required to be about 10 μm, and preferably 10 μm or less. The base material 2 preferably has a minimum light transmittance of 80% or more in a wavelength region of 450 to 650 nm, more preferably 85% or more, and still more preferably 90% or more. When the base material 2 satisfies such a condition, it is easy to increase the brightness in a display panel or the like.

<Conductive pattern>
The conductive pattern 3 is a plurality of patterned electrodes, wiring, and the like. The pattern shape of the conductive pattern 3 is not particularly limited, and includes, for example, a stripe shape, a shape in which diamond shapes are continuous in one direction, and the like.

<Conductive fiber>
Examples of the conductive fiber included in the conductive network forming the conductive pattern 3 include metal fibers such as gold, silver, copper, and platinum, or carbon fibers such as carbon nanotubes. These can be used alone or in combination of two or more. From the viewpoint of excellent conductivity, it is preferable to use gold fiber or silver fiber. Furthermore, from the viewpoint of easily adjusting the conductivity of the conductive pattern 3, silver fibers (silver nanowires) are more preferable.

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 or more, more preferably 2 nm or more, further preferably 3 nm or more, and particularly preferably 10 nm or more from the viewpoint of obtaining excellent electrostatic resistance. Preferably, it is very preferably 20 nm or more. The fiber diameter of the conductive fiber is preferably 50 nm or less, more preferably 45 nm or less, and still more preferably 40 nm or less, from the viewpoint of easily obtaining excellent visibility. From these viewpoints, the fiber diameter of the conductive fiber is preferably 1 to 50 nm, more preferably 2 to 45 nm, still more preferably 3 to 40 nm, and particularly preferably 10 to 40 nm. Preferably, the thickness is 20 to 40 nm. The fiber diameter of the conductive fiber can be measured with a scanning electron microscope.

  The fiber length of the conductive fiber is preferably 1 μm or more, more preferably 2 μm or more, and more preferably 3 μm or more from the viewpoint of easily reducing the amount of the conductive fiber used for obtaining sufficient visibility. More preferably. The fiber length of the conductive fiber is preferably 100 μm or less, more preferably 50 μm or less, further preferably 10 μm or less, and more preferably 5 μm or less from the viewpoint of easily suppressing the aggregation of the conductive fibers. It is particularly preferred. From these viewpoints, the fiber length of the conductive fiber is preferably 1 to 100 μm, more preferably 2 to 50 μm, still more preferably 3 to 10 μm, and particularly preferably 3 to 5 μm. preferable. The fiber length of the conductive fiber can be measured with a scanning electron microscope.

  The thickness of the conductive pattern 3 varies depending on the use of the conductive pattern substrate 1 and required conductivity, but is preferably in the following range. The thickness of the conductive pattern 3 is preferably 1 μm or less, more preferably 0.5 μm or less from the viewpoint of high light transmittance in a wavelength region of 450 to 650 nm, and particularly suitable for a transparent electrode. More preferably, it is 0.1 μm or less. From the viewpoint of ensuring uniform conductivity, the thickness of the conductive pattern 3 is preferably 1 nm or more, more preferably 5 nm or more, further preferably 10 nm or more, and preferably 50 nm or more. Particularly preferred. From these viewpoints, the thickness of the conductive pattern 3 is preferably 1 μm or less, more preferably 1 nm to 0.5 μm, still more preferably 5 nm to 0.1 μm, and 10 nm to 0.1 μm. It is particularly preferable that the thickness is 50 nm to 0.1 μm.

  The metal fiber preferably has a network structure containing conductive fibers. When the conductive pattern 3 includes conductive fibers and the conductive pattern substrate 1 has the resin layer 4, such a network structure is, for example, (1) a form embedded in the resin layer 4, (2) the resin layer 4 And a part of the resin layer 4 may be exposed from the main surface of the resin layer 4 and (3) a form exposed on the main surface of the resin layer 4. In addition, the thickness of the conductive pattern 3 having a network structure indicates a value measured by a scanning electron micrograph.

  As shown in FIG. 2, the conductive direction of the conductive pattern 3 is referred to as “conductive direction CD”, and the direction perpendicular to the conductive direction CD of the conductive pattern 3 is referred to as “vertical direction VD”. The conductive direction CD is a direction in which a current flows in the conductive pattern 3 and is also referred to as a pattern direction. In the conductive pattern 3, the degree of orientation of the conductive fibers F in the conductive direction CD is larger than the degree of orientation of the conductive fibers F in the vertical direction VD. In this case, the ratio of the orientation degree of the conductive fibers F in the conduction direction CD to the orientation degree of the conductive fibers F in the vertical direction VD of the conductive pattern 3 obtains excellent low resistance (ESD resistance) in the conduction direction CD. From the viewpoint, it is preferably larger than 1.0, more preferably 1.2 or more, and particularly preferably 1.5 or more. This ratio is preferably less than 3.0, more preferably 2.5 or less, and particularly preferably 2.0 or less from the viewpoint of ease of production. From these viewpoints, this ratio is preferably greater than 1.0 and less than 3.0, more preferably 1.2 or more and 2.5 or less, and 1.5 or more and 2.0 or less. Is particularly preferred.

  The conductive network of the conductive pattern 3 includes a large number of conductive fibers F, and these conductive fibers F face various directions. For this reason, the above degree of orientation does not indicate the degree of orientation of individual conductive fibers F, but indicates the degree of overall orientation of many conductive fibers F. That is, the greater the number of conductive fibers F that are directed toward the conductive direction CD than the vertical direction VD, the higher the degree of orientation of the conductive fibers F in the conductive direction CD and the vertical direction VD than the conductive direction CD. As the number of conductive fibers F facing the side increases, the degree of orientation of the conductive fibers F in the vertical direction VD increases.

  Here, when the degree of orientation of the conductive fiber F in the conductive direction CD increases, the resistance value of the conductive pattern 3 in the direction of conduction CD decreases, and when the degree of orientation of the conductive fiber F in the vertical direction VD increases, the vertical direction VD. The resistance value of the conductive pattern 3 becomes smaller. For this reason, in the conductive pattern 3, the resistance value per unit length (line resistance value) in the conductive direction CD is smaller than the resistance value per unit length (line resistance value) in the vertical direction VD. In this case, the ratio (R2 / R1) of the resistance value R2 per unit length in the conduction direction CD to the resistance value R1 per unit length in the vertical direction VD of the conductive pattern 3 is an excellent low resistance in the conduction direction CD. From the viewpoint of obtaining properties (ESD resistance), it is preferably less than 1.0, more preferably 0.83 or less, and particularly preferably 0.67 or less. This ratio (R2 / R1) is preferably 0.3 or more, more preferably 0.4 or more, and particularly preferably 0.5 or more, from the viewpoint of ease of production. From these viewpoints, this ratio (R2 / R1) is preferably 0.3 or more and less than 1.0, more preferably 0.4 or more and 0.83 or less, and 0.5 or more and 0.67. It is particularly preferred that The resistance value per unit length in the conductive direction CD and the vertical direction VD of the conductive pattern 3 can be measured by a tester.

<Resin layer>
The material of the resin layer 4 is not particularly limited. For example, acrylic resin, styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, phenol resin, ester resin, urethane resin, epoxy resin ( An epoxy acrylate resin obtained by a reaction of (meth) acrylic acid, an acid-modified epoxy acrylate resin obtained by a reaction of an epoxy acrylate resin and an acid anhydride can be used.

  The resin layer 4 may be a cured resin obtained by curing a photosensitive resin composition. As the photosensitive resin composition, for example, a photosensitive resin composition containing (a) a binder polymer, (b) a photopolymerizable compound, and (c) a photopolymerization initiator described in International Publication No. 2014/002770 pamphlet. Is mentioned.

  From the viewpoint of ensuring the transparency of the conductive pattern substrate 1, the conductive pattern 3 and the resin layer 4 have a minimum light transmittance of 80 in the wavelength region of 450 to 650 nm when the total film thickness of both layers is 1 to 10 μm. % Or more, preferably 85% or more, and more preferably 90% or more. When satisfy | filling such conditions, the visibility at the time of applying the conductive pattern base material 1 to a display panel etc. improves.

(Method for forming conductive pattern)
Next, a method for forming a conductive pattern will be described. Here, as an example, a method for forming a conductive pattern (conductive pattern substrate) using a photosensitive conductive film (transfer type conductive film) will be described.

<Photosensitive conductive film>
First, the photosensitive conductive film will be described. The photosensitive conductive film 12 is prepared as a photosensitive conductive film 10 with a support film, for example, as shown in FIGS. The photosensitive conductive film 10 with a support film includes a support film 11 and a photosensitive conductive film 12 provided on the support film 11. The photosensitive conductive film 12 includes a conductive network 13 provided on the support film 11 and a photosensitive resin layer 14 provided on the conductive network 13. In this case, the photosensitive conductive film 12 has the conductive network 13 and the photosensitive resin layer 14 in this order from the support film 11 side.

<Support film>
As the support film 11, for example, a polymer film can be used. Examples of the polymer film include a polyethylene terephthalate film, a polyethylene film, a polypropylene film, and a polycarbonate film. Among these, a polyethylene terephthalate film is preferable from the viewpoints of transparency and heat resistance.

  The above polymer film may be subjected to a release treatment so that peeling from the photosensitive conductive film 12 is facilitated later.

  From the viewpoint of mechanical strength, the thickness of the support film 11 is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. In order to form the photosensitive resin layer 14, for example, by applying the conductive fiber dispersion or the conductive fiber solution to form the conductive network 13 by setting the thickness of the support film 11 to the above numerical value or more. It is possible to prevent the support film 11 from being broken in the step of applying the photosensitive resin composition. Moreover, the same effect can be expected in the step of peeling the support film 11 from the photosensitive conductive film 12 during the exposure step or the development step described later. In addition, from the viewpoint of sufficiently ensuring the resolution of the conductive pattern when the photosensitive resin layer 14 is irradiated with actinic rays through the support film 11, the thickness of the support film 11 is preferably 300 μm or less, and 200 μm or less. More preferably, it is more preferably 100 μm or less.

  From the above viewpoint, the thickness of the support film 11 is preferably 5 to 300 μm, more preferably 10 to 200 μm, and particularly preferably 15 to 100 μm.

  The haze value of the support film 11 is preferably 0.01 to 5.0%, more preferably 0.01 to 3.0%, from the viewpoint of improving sensitivity and resolution. More preferably, it is -2.0%, and it is especially preferable that it is 0.01-1.5%. The haze value can be measured according to JIS K 7105. For example, it can be measured with a commercially available turbidimeter such as NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd., trade name).

<Conductive network>
The conductive network 13 includes conductive fibers included in the conductive pattern 3 of the conductive pattern substrate 1 and can be formed from a plurality of conductive fibers.

  An organic conductor can be used for the conductive network 13 together with the conductive fibers. Examples of the organic conductor include a conductive polymer. As the conductive polymer, at least one polymer selected from the group consisting of polythiophene, polythiophene derivatives, polyaniline, and polyaniline derivatives can be used. For example, polyethylenedioxythiophene, polyhexylthiophene, polyaniline and the like can be mentioned.

  When the conductive network 13 further includes an organic conductor to form a conductive layer, the conductive layer preferably further includes a photosensitive resin composition. The photosensitive resin composition can use the component which comprises the photosensitive resin layer mentioned later.

  In the present embodiment, the conductive network 13 is provided on one main surface side of the photosensitive resin layer 14.

  Further, the boundary between the conductive network 13 and the photosensitive resin layer 14 is not necessarily clear. The conductive network 13 only needs to have conductivity in the surface direction of the photosensitive resin layer 14. The conductive network provided on one main surface side of the photosensitive resin layer is, for example, (1) a form embedded in the photosensitive resin layer 14, (2) embedded in the photosensitive resin layer 14, and a part thereof. It may be present in a form exposed from the main surface of the photosensitive resin layer 14 and (3) a form exposed on the main surface of the photosensitive resin layer 14.

  The thickness of the photosensitive resin layer 14 described below indicates the thickness including a part of the conductive network 13 when the conductive network 13 is buried in the photosensitive resin layer 14. Further, when at least a part of the conductive network 13 is exposed from the photosensitive resin layer 14, it indicates the thickness of the photosensitive resin layer 14 itself excluding the part.

  The conductive network 13 is, for example, a conductive fiber obtained by adding the above-described conductive fiber, water and / or an organic solvent, and, if necessary, a dispersion stabilizer such as an organic conductor and a surfactant to the support film 11. It can be formed by applying the dispersion and drying. When the conductive fiber dispersion contains metal nanowires, a metal salt may be added in order to promote fusion between the metal nanowires. After drying, the conductive network 13 formed on the support film 11 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 network 13, the conductive fiber and the organic conductor may coexist with the surfactant and the dispersion stabilizer. In this specification, the conductive network includes a residue after drying derived from a solvent, an additive, and the like contained in a coating liquid in which conductive fibers are dispersed.

<Photosensitive resin layer>
The photosensitive resin layer 14 is made of a photosensitive resin composition containing (A) a binder polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a metal complex and / or a heteroatom compound. Can be formed.

<Binder polymer>
(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.

  Among these, it is preferable to use an acrylic resin from the viewpoint of excellent alkali developability and film formability. Also. More preferably, the acrylic resin has a structural unit derived from (meth) acrylic acid and a (meth) acrylic acid alkyl ester as a structural unit. Here, the “acrylic resin” means a polymer mainly having a structural unit derived from a polymerizable monomer having a (meth) acryloyl group.

<Polymerizable compound>
(B) As the polymerizable compound, a polymerizable compound having an ethylenically unsaturated bond is preferable. A known compound can be used as the polymerizable compound having an ethylenically unsaturated bond. For example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid, and having a urethane bond (meth) Urethane monomers such as acrylate compounds, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β Examples thereof include phthalic acid compounds such as -hydroxypropyl-β '-(meth) acryloyloxyethyl-o-phthalate, and (meth) acrylic acid alkyl esters.

  The content ratio of the (B) polymerizable compound is preferably 30 to 80 parts by mass and 40 to 70 parts by mass with respect to 100 parts by mass of the total amount of the (A) binder polymer and the (B) polymerizable compound. It is more preferable, and it is still more preferable that it is 40-60 mass parts. It is preferably 30 parts by mass or more in terms of excellent photocurability and coatability on the formed conductive network 13, and 80 parts by mass in terms of excellent storage stability when wound as a film. The following is preferable.

<Photopolymerization initiator>
(C) As a photoinitiator, if the photosensitive resin layer 14 can be hardened by irradiation of actinic light, it will not be restrict | limited in particular. From the viewpoint of excellent photocurability, it is preferable to use a radical polymerization initiator. For example, benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2 Aromatic ketones such as -benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1; benzoin Benzoin ether compounds such as methyl ether, benzoin ethyl ether and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin; 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O -Benzoyloxime), 1- [9-ethyl Oxime ester compounds such as 6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (O-acetyloxime); benzyl derivatives such as benzyldimethyl ketal; 2- (o-chlorophenyl) -4, 5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4, 5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4, 5-diphenylimidazole dimer, 2 2,4,5-triarylimidazole dimers such as-(o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Acridine derivatives such as 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane; 2,4,6- Trimethyl benzoyl - diphenyl - phosphine oxide, such as phosphine oxide; N- phenylglycine, N- phenylglycine derivatives, coumarin-based compounds, and oxazole compounds.

  Among these, an oxime ester compound or a phosphine oxide compound is preferable from the viewpoints of transparency and pattern forming ability when the thickness of the photosensitive resin layer 14 is 10 μm or less.

  The content ratio of (C) the photopolymerization initiator is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of (A) binder polymer and (B) polymerizable compound, and 1 to 10 parts by mass. More preferably, it is 1 to 5 parts by mass. In terms of excellent photosensitivity, it is preferably 0.1 parts by mass or more, and in terms of excellent photocurability inside the photosensitive resin layer 14, it is preferably 20 parts by mass or less.

<Metal complex and / or heteroatom compound>
Examples of the metal complex of component (D) include acetylacetone metal complex, ammine metal complex, cyano metal complex, chloro metal complex, fluoro metal complex, bromo metal complex, sulfato metal complex, thiocyanate metal complex, and acetate metal complex. From the viewpoint of solubility and stability in the photosensitive resin layer, an acetylacetone metal complex is preferable.

<Other ingredients>
Various additives can be contained in the photosensitive resin layer 14 as necessary. Additives include plasticizers such as p-toluenesulfonamide, fillers, antifoaming agents, flame retardants, adhesion promoters, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, A rust preventive agent or the like can be contained. 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 (A) the binder polymer and (B) the polymerizable compound.

  The photosensitive resin layer 14 is formed on the conductive network 13 formed on the support film 11 as necessary, with methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, It can be formed by applying a solution of a photosensitive resin composition having a solid content of about 10 to 60% by mass dissolved in a solvent such as propylene glycol monomethyl ether or a mixed solvent thereof and then drying. 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. In the photosensitive conductive film of the present invention, another layer may be interposed between the photosensitive resin layer and the conductive network.

  Coating can be performed by a known method. Examples thereof include 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, and 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.

<Other layers>
The photosensitive conductive film of the present invention may be provided with other appropriately selected layers as long as the effects of the present invention are obtained. There is no restriction | limiting in particular as another layer, According to the objective, it can select suitably, For example, a cushion layer, an oxygen shielding layer, a peeling layer, an adhesive layer etc. are mentioned. The photosensitive conductive film may have these layers individually by 1 type, and may have 2 or more types. Moreover, you may have 2 or more of the same kind of layers.

<Orientation of conductive fiber in conductive network>
By applying the photosensitive resin layer 14, the conductive network 13 has anisotropy in which the orientation degree of the conductive fibers in the MD (Machine Direction) direction and the orientation degree of the conductive fibers in the TD (Traverse Direction) direction are different. It will have. Specifically, the orientation degree of the conductive fibers in the MD direction is larger than the orientation degree of the conductive fibers in the TD direction.

  As a method for increasing the ratio of the orientation degree of the conductive fibers in the MD direction to the orientation degree of the conductive fibers in the TD direction, for example, a method for increasing the coating speed of the photosensitive resin layer 14, There is a method of blowing air in the MD direction during the work.

[Method of forming conductive pattern]
The conductive pattern forming method is a method for forming a conductive pattern of a conductive network using conductive fibers on a substrate, and the degree of orientation of the conductive fibers in the conductive direction of the conductive pattern is determined by the conductive pattern. The conductive pattern is formed so as to be larger than the degree of orientation of the conductive fibers in the vertical direction which is a direction perpendicular to the direction.

  This method includes a layer forming step of forming on a substrate a photosensitive resin layer having a conductive network in which the orientation degree of the conductive fibers in the MD direction and the orientation degree of the conductive fibers in the TD direction are different, and the photosensitive resin It has the exposure process which irradiates an active ray through a mask pattern to a layer, and the image development process which forms a conductive pattern on a base material by removing the unexposed part of the photosensitive resin layer. In the exposure step, the orientation of the mask pattern with respect to the substrate is set so that the orientation degree of the conductive fibers is larger than the orientation degree of the conductive fibers in the vertical direction.

[Layer formation process]
In the layer forming step, for example, as shown in FIG. 5A, the photosensitive conductive film 10 with a support film is laminated by pressing the photosensitive resin layer 14 side to the substrate 2 while heating the substrate 2. it can. In addition, it is preferable that this process is performed under reduced pressure from the viewpoint of adhesiveness and followability. The degree of vacuum is preferably 10 hPa or less, but this condition is not particularly limited. The lamination of the photosensitive conductive film with support film 10 is preferably performed while heating the photosensitive resin layer 14 and / or the substrate 2 to 70 to 130 ° C., and the pressure bonding pressure is about 0.1 to 1.0 MPa ( Although it is preferable to set it as 1-10 kgf / cm < ² >), there is no restriction | limiting in particular in these conditions. In addition, if the photosensitive resin layer 14 is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the base material 2 in advance. Can also be done.

[Exposure process]
As an exposure method in the exposure step, a method of irradiating actinic rays L in a pattern through a negative or positive mask pattern 15 (shading mask) called an artwork as shown in FIG. 5B (mask exposure method) Is mentioned.

  At this time, the orientation of the mask pattern 15 with respect to the substrate 2 is set such that the orientation degree of the conductive fibers in the conduction direction CD is larger than the orientation degree of the conductive fibers in the vertical direction VD. That is, by adjusting the direction of at least one of the base material 2 and the mask pattern 15, the MD direction of the conductive network 13 and the conductive direction CD of the conductive pattern 3 are set to be substantially the same (including the same) direction.

  As a light source of actinic rays in the exposure step, a known light source can be mentioned. For example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, or a xenon lamp that can effectively radiate ultraviolet rays, visible light, or the like is used. Ar ion lasers and semiconductor lasers are also 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 a pattern by a direct drawing method using a laser exposure method or the like may be employed.

Exposure at the exposure step may vary depending on the composition of the device and the photosensitive resin composition used, preferably ^{5mJ / cm 2 ~1000mJ / cm 2} , more preferably 10mJ ^/ cm ² ~200mJ ^/ cm 2 is there. In terms of excellent photocurability, it is preferably 10 mJ / cm ² or more, and in terms of resolution, it is preferably 200 mJ / cm ² or less.

  The exposure process can be performed in air, vacuum, or the like, and the exposure atmosphere is not particularly limited. In this embodiment, when the photosensitive conductive film 12 is exposed without peeling off the support film 11, the influence of oxygen is reduced and the film is easily cured.

[Development process]
In the development process, the unexposed areas in the exposure process of the photosensitive conductive film 12 are removed. Specifically, the uncured portion (unexposed portion) of the photosensitive resin layer 14 is removed together with the conductive network 13 by wet development. Thereby, as shown in FIG.5 (c), the conductive pattern base material 1 which has the conductive pattern 3 which consists of the resin cured layer (cured film) 14a hardened | cured by the exposure process and the conductive network 13a is obtained.

  The wet development can be performed by a known method such as spraying, rocking dipping, brushing, or scrubbing using, for example, an alkaline aqueous solution, an aqueous developer, or an organic solvent developer.

  As the developer, an alkaline aqueous solution is preferably used because it is safe and stable and has good operability. As alkaline aqueous solution, 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 An aqueous solution or the like is preferable. The pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and the temperature can be 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.

  Examples of the development method include a dip method, a paddle method, a high-pressure spray method, brushing, and scrubbing. 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 is further cured by performing heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ² as necessary after development. Also good.

  As described above, in the method for forming a conductive pattern according to the present embodiment, the degree of orientation of the conductive fibers in the conductive direction CD is larger than the degree of orientation of the conductive fibers in the vertical direction VD. Compared with the case where it is equal, the resistance value in the conductive direction CD of the conductive pattern 3 becomes smaller. Thereby, even if it does not increase electroconductive fiber, ESD tolerance can be improved, without worsening visibility (permeability).

  Then, in the exposure process, by adjusting the orientation of the mask pattern 15 with respect to the substrate 2, the conductive pattern 3 in which the orientation degree of the conductive fibers in the conduction direction CD is larger than the orientation degree of the conductive fibers in the vertical direction VD is formed. can do.

  In the conductive pattern substrate according to the present embodiment, since the degree of orientation of the conductive fibers in the conductive direction CD is larger than the degree of orientation of the conductive fibers in the vertical direction VD, the conductive pattern is compared with the case where the degree of orientation of both is equal. 3 in the conduction direction CD becomes smaller. Thereby, even if it does not increase electroconductive fiber, ESD tolerance can be improved, without worsening visibility (permeability).

  In the conductive pattern substrate according to the present embodiment, the resistance value R2 per unit length of the conductive pattern 3 in the conductive direction CD is smaller than the resistance value R1 per unit length of the conductive pattern 3 in the vertical direction VD. Even if the conductive fibers are not increased, the ESD resistance can be improved without deteriorating the visibility (permeability).

  And since the ratio of the orientation degree of the conductive fiber in the conductive direction CD with respect to the orientation degree of the conductive fiber in the vertical direction VD of the conductive pattern 3 is more than 1.0 and less than 3.0, it ensures the manufacturability. The resistance value in the conductive direction of the conductive pattern 3 can be further reduced.

  Similarly, the ratio (R2 / R1) of the resistance value R2 per unit length in the conductive direction CD to the resistance value R1 per unit length in the vertical direction VD of the conductive pattern 3 is 0.3 or more and less than 1.0. Therefore, the resistance value in the conductive direction of the conductive pattern 3 can be further reduced while ensuring ease of manufacture.

(Touch panel sensor)
Next, the touch panel sensor according to the present embodiment will be described. The touch panel sensor according to the present embodiment includes the conductive pattern substrate 1 described above.

  FIG. 6 is a schematic plan view illustrating an example of a capacitive touch panel sensor. The touch panel sensor shown in FIG. 6 has a touch screen 102 for detecting a touch position on one surface of a base material 101 such as a transparent substrate. A transparent electrode that detects a change in capacitance and uses this position as an X position coordinate. 103 (conductive pattern) and a transparent electrode 104 (conductive pattern) having a Y position coordinate. Each of the transparent electrodes 103 and 104 having the X and Y position coordinates includes a lead wire 105 for connecting to a driver element circuit for controlling an electric signal as a touch panel sensor, and the lead wire 105 and the transparent electrode 103. A connection electrode 106 for connecting 104 is disposed. Furthermore, a connection terminal 107 connected to the driver element circuit is disposed at the end of the lead-out wiring 105 opposite to the connection electrode 106.

  Next, a method for manufacturing a touch panel sensor will be described with reference to FIG. 7 (a) and 7 (c) are schematic plan views for explaining a method for manufacturing a touch panel sensor, and FIG. 7 (b) is a schematic cross-sectional view taken along the line II of FIG. 7 (a). FIG.7 (d) is a schematic cross section in the II-II line | wire of FIG.7 (c).

  In the present embodiment, first, as shown in FIGS. 7A and 7B, the transparent electrode 103 (X electrode) is formed on the substrate 101. Specifically, the photosensitive conductive film 10 with a support film is laminated so that the photosensitive resin layer 14 is in close contact with the substrate 101. The transferred photosensitive conductive film 12 (conductive network 13 and photosensitive resin layer 14) is irradiated with actinic rays in a pattern through a mask pattern 15. At this time, the orientation of the mask pattern 15 with respect to the substrate 101 is set such that the orientation degree of the conductive fibers in the conduction direction CD is larger than the orientation degree of the conductive fibers in the vertical direction VD. By performing development after the exposure step, the conductive network 13 is removed together with the photosensitive resin layer 14 that is not sufficiently cured, and a conductive network 13a having a predetermined pattern is formed. A transparent electrode 103 (conductive pattern) for detecting the X position coordinate is formed by the conductive network 13a having the predetermined pattern.

  Subsequently, as shown in FIGS. 7C and 7D, a transparent electrode 104 (conductive pattern) is formed. Specifically, the photosensitive electrode film 10 with a new support film is further laminated on the base material 101 including the transparent electrode 103 formed by the above process, and the transparent electrode 104 is formed by the same operation as described above. The

  Next, on the surface of the base material 101, a lead-out wiring 105 for connecting to an external circuit and a connection electrode 106 for connecting the lead-out line and the transparent electrodes 103 and 104 are formed. The lead-out wiring 105 and the connection electrode 106 may be formed after the formation of the transparent electrodes 103 and 104, or may be formed simultaneously with the formation of each transparent electrode. The lead-out wiring 105 can be formed at the same time as the connection electrode 106 is formed by screen printing using a conductive paste material containing flaky silver, for example.

  As described above, since the touch panel sensor according to the present embodiment includes the conductive pattern base material 1 described above, the ESD resistance can be improved without deteriorating the visibility.

  The method for forming a conductive pattern, the conductive pattern base material, and the touch panel sensor of the present invention are not limited to the embodiment described above, and can be appropriately changed without departing from the gist of the present invention.

  For example, although the conductive pattern base material of the above-described embodiment has been described as including a single conductive pattern, the conductive pattern substrate may include two or more conductive patterns. For example, when the conductive pattern base material includes two layers of conductive patterns, the conductive pattern 3 and the resin layer 4, the conductive pattern 5 and the resin layer 6 are the base material as in the conductive pattern base material 1A shown in FIG. The conductive pattern 3 and the resin layer 4, and the conductive pattern 5 and the resin layer 6 may be disposed on the base material 2 as in the conductive pattern base material 1 </ b> B shown in FIG. 9. It may be arranged on the opposite side. In the conductive pattern substrate 1 </ b> A shown in FIG. 8, the resin layer 4, the conductive pattern 3, the resin layer 6, and the conductive pattern 5 are arranged in this order on one main surface of the substrate 2. In the conductive pattern base material 1B shown in FIG. 9, the resin layer 4 and the conductive pattern 3 are arranged in this order on one main surface of the base material 2, and on the other main surface of the base material 2, The resin layer 6 and the conductive pattern 5 are arranged in this order.

  Moreover, although the conductive pattern base material of the said embodiment and the conductive pattern 3 and the resin layer 4 were directly formed on the base material 2, it is between the base material 2, the conductive pattern 3, and the resin layer 4. Other components may intervene. For example, another conductive pattern formed of ITO, indium oxide, tin oxide, or the like may be formed between the base material 2 and the conductive pattern 3 and the resin layer 4.

  In the touch panel sensor of the above embodiment, both the transparent electrode 103 having the X position coordinate and the transparent electrode 104 having the Y position coordinate are described as being formed by a conductive network using conductive fibers. Any one of them may be formed of ITO, indium oxide, tin oxide, or the like.

  In the conductive pattern substrate and touch panel sensor of the above embodiment, the conductive pattern of the conductive network using conductive fibers has been described as being formed on the substrate via a resin layer. You may form directly on the base material by adhesives, such as OCA (Optical Clear Adhesive), without passing through a layer.

DESCRIPTION OF SYMBOLS 1,1A, 1B ... Conductive pattern base material, 2 ... Base material, 3 ... Conductive pattern, 4 ... Resin layer, 5 ... Conductive pattern, 6 ... Resin layer, 10 ... Photosensitive conductive film with support film, 11 ... Support film , 12 ... photosensitive conductive film, 13 ... conductive network, 13a ... conductive network, 14 ... photosensitive resin layer, 14a ... cured resin layer, 15 ... mask pattern, 101 ... base material, 102 ... touch screen, 103 ... Transparent electrode (conductive pattern), 104 ... Transparent electrode (conductive pattern), 105 ... Lead-out wiring, 106 ... Connection electrode, 107 ... Connection terminal, CD ... Conduction direction, VD ... Vertical direction.

Claims (7)

A conductive pattern forming method for forming a conductive pattern of a conductive network using conductive fibers on a substrate,
Forming the conductive pattern such that the degree of orientation of the conductive fibers in the conductive direction of the conductive pattern is greater than the degree of orientation of the conductive fibers in the vertical direction, which is a direction perpendicular to the conductive direction;
A method for forming a conductive pattern. A layer forming step of forming on the base material a photosensitive resin layer having the conductive network in which the degree of orientation of the conductive fibers in the MD direction and the degree of orientation of the conductive fibers in the TD direction are different;
An exposure step of irradiating the photosensitive resin layer with actinic rays through a mask pattern;
A development step of forming the conductive pattern on the substrate by removing an unexposed portion of the photosensitive resin layer,
In the exposure step, the orientation of the mask pattern relative to the base material is such that the orientation degree of the conductive fibers in the conductive direction is larger than the orientation degree of the conductive fibers in the vertical direction.
The method for forming a conductive pattern according to claim 1. A substrate;
A conductive pattern formed on the base material and having a conductive network using conductive fibers,
In the conductive pattern, the degree of orientation of the conductive fibers in the conductive direction of the conductive pattern is greater than the degree of orientation of the conductive fibers in the vertical direction, which is a direction perpendicular to the conductive direction.
Conductive pattern base material. A substrate;
A conductive pattern formed on the base material and having a conductive network using conductive fibers,
In the conductive pattern, a resistance value per unit length in the conductive direction of the conductive pattern is smaller than a resistance value per unit length in a vertical direction that is a direction perpendicular to the conductive direction.
Conductive pattern base material. The ratio of the orientation degree of the conductive fiber in the conductive direction to the orientation degree of the conductive fiber in the vertical direction of the conductive pattern is greater than 1.0 and less than 3.0.
The conductive pattern base material according to claim 3 or 4. The ratio of the resistance value per unit length in the conductive direction to the resistance value per unit length in the vertical direction of the conductive pattern is 0.3 or more and less than 1.0.
The electroconductive pattern base material as described in any one of Claims 3-5.   A touch panel sensor comprising the conductive pattern substrate according to any one of claims 3 to 6.

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