TWI592761B - Method for forming conductive pattern and conductive pattern substrate - Google Patents

Description

Method for forming conductive pattern and conductive pattern substrate

The present invention relates to a method for forming a conductive pattern and a conductive pattern substrate, and more particularly to electrode wiring for a flat panel display, a touch panel (touch screen), a solar cell, an illumination device, etc., which can be used as a liquid crystal display element or the like. A method of forming a conductive pattern and a conductive pattern substrate.

Large-scale electronic devices such as computers and televisions, small electronic devices such as car navigation, mobile phones, and electronic dictionaries, and display devices such as office automation (OA) and factory automation (FA) devices, etc. Components, touch panels, etc. In these liquid crystal display elements and touch panels, wirings requiring transparency, pixel electrodes, or a part of terminals are used as transparent conductive films. Further, a transparent conductive film is also used in devices such as solar cells and illumination.

Conventionally, since the material for a transparent conductive film exhibits a high transmittance to visible light, indium tin oxide (Indium-Tin-Oxide: ITO), indium oxide, tin oxide, or the like is used. Among the electrodes provided on the substrate for a liquid crystal display element or the like, a pattern of a transparent conductive film containing the above-described material is mainstream.

As a method of patterning a transparent conductive film, it is usually on a substrate such as a substrate. After the transparent conductive film is formed, a photoresist 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 the ITO film and the indium oxide film, it is preferred to use a mixed solution containing two liquids of hydrochloric acid and ferric chloride.

The ITO film, the tin oxide film, and the like are usually formed by a sputtering method, but the properties of the transparent conductive film are easily changed depending on the difference in sputtering method, sputtering power, gas pressure, substrate temperature, type of ambient gas, and the like. The difference in the film quality of the transparent conductive film due to the fluctuation of the sputtering conditions is a cause of unevenness in the etching rate when the transparent conductive film is wet-etched, and the yield of the product due to the patterning failure is likely to be lowered. In addition, the method for forming the conductive pattern includes a sputtering step, a photoresist forming step, and an etching step, and the step is long and the cost is also a large burden.

Recently, in order to solve the above problems, attempts have been made to form a transparent conductive pattern instead of a material such as ITO, indium oxide, or tin oxide. For example, Patent Document 1 discloses a method of forming a conductive pattern in which a conductive layer containing conductive fibers such as silver fibers is formed on a substrate, and then a photosensitive resin layer is formed on the conductive layer, and a pattern mask is formed thereon. Exposure and development.

Patent Document 2 discloses that a conductive film for transfer including at least a peelable conductive layer on a support and an adhesive layer on a conductive layer is used, and a conductive layer is attached to the substrate via the adhesive layer. The method, and reveals that the transferred conductive layer can also be patterned.

Patent Document 3 discloses that a conductive pattern can be formed by employing the following method. A method of forming a conductive pattern by using a photosensitive conductive film provided on a support film and a photosensitive resin layer provided on the conductive layer, and laminating the photosensitive resin layer in close contact with the substrate .

Prior art literature Patent literature

Patent Document 1: US Patent Application Publication No. 2007/0074316

Patent Document 2: Japanese Patent Laid-Open Publication No. 2007-257963

Patent Document 3: International Publication No. 2010/021224

However, in the methods described in Patent Document 1 and Patent Document 2, there is a problem that the steps of forming the conductive pattern are complicated.

On the other hand, the method described in Patent Document 3 is a method for forming a conductive pattern more easily. However, since the photosensitive resin layer is interposed between the substrate and the conductive layer, the connection terminal or the like provided on the surface of the substrate cannot be electrically conductive. The pattern is easily connected. The above problem also occurs in the method described in Patent Document 2.

An object of the present invention is to provide a method of forming a conductive pattern and a conductive pattern substrate which can easily form a conductive pattern having a sufficiently small surface resistivity on a substrate with sufficient resolution.

In order to solve the above problems, the present invention provides a method for forming a conductive pattern, comprising: preparing a photosensitive conductive film having a support film, a conductive layer containing conductive fibers, and a photosensitive resin layer containing a photosensitive resin; To guide a laminating step of laminating a conductive layer and a photosensitive resin layer in such a manner that the electric layer is in close contact with the substrate; and a patterning step of forming a conductive pattern by exposing and developing the photosensitive resin layer on the substrate.

According to the method for forming a conductive pattern of the present invention, a conductive pattern having a sufficiently small surface resistivity can be easily formed on a substrate with sufficient resolution. Further, the connection terminals and the like provided on the surface of the substrate can be easily connected to the conductive pattern.

Although the reason for the above-described effects of the present invention is not necessarily understood, the inventors of the present invention presumed that the conductive layer containing the conductive fibers and the photosensitive resin layer are laminated to conduct electricity when laminated on the substrate from the conductive layer side. The photosensitive resin layer is moderately impregnated in the layer, whereby adhesion is obtained on the surface of the conductive layer opposite to the photosensitive resin layer, and patterning can be performed by sufficient resolution in subsequent exposure and development.

The photosensitive resin layer is preferably a photopolymerizable compound containing a binder polymer, having an ethylenically unsaturated bond, and a photopolymerization initiator. By including such a component, the photosensitive resin layer can further improve the adhesion, the adhesion between the substrate and the conductive pattern, and the patterning property of the conductive pattern.

The above binder polymer preferably has a carboxyl group. The developability of the photosensitive resin layer can be improved by containing a binder polymer having a carboxyl group.

In the method of forming a conductive pattern of the present invention, the laminated body of the conductive layer and the photosensitive resin layer may have a minimum light transmittance of 80% or more in a wavelength region of 450 nm to 650 nm. When the conductive layer and the photosensitive resin layer satisfy such conditions, it is easy to achieve high luminance in a display panel or the like.

The conductive fiber may be a silver fiber. The conductivity of the formed conductive pattern is more easily adjusted by being a silver fiber.

The present invention further provides a conductive pattern substrate comprising: a substrate, and a conductive pattern formed on the substrate by the method of forming the conductive pattern of the present invention.

Since the conductive pattern substrate is formed into a conductive pattern by the method for forming a conductive pattern of the present invention, it is possible to provide a conductive pattern having a sufficiently small surface resistivity and a sufficient resolution. Further, the formed conductive pattern can be electrically connected to a connection terminal or the like provided on the surface of the substrate.

In the conductive pattern substrate, the surface resistivity of the conductive pattern is preferably 2000 Ω/□ or less. By setting the surface resistivity of the conductive pattern to such a range, the function as a wiring or an electrode can be more effectively exhibited.

According to the present invention, it is possible to provide a method of forming a conductive pattern and a conductive pattern substrate in which a conductive pattern having a sufficiently small surface resistivity can be easily formed on a substrate with sufficient resolution. Further, according to the present invention, the connection terminal or the like provided on the surface of the substrate can be easily connected to the conductive pattern. Moreover, according to the method for forming a conductive pattern of the present invention, the adhesion between the substrate and the conductive layer can be made sufficient, and the adhesion to the substrate of the obtained conductive pattern can be made sufficient.

Further, according to the present invention, since the conductive pattern can be directly formed on the object, the three-dimensional conductive wiring can be easily formed. For example, on a substrate provided with a conductive pattern that has been formed, insulation is formed in a predetermined portion of the conductive pattern by an insulating resin or the like. After the film, the photosensitive conductive film is laminated to form a conductive pattern, whereby conduction between the fabricated conductive pattern not covered by the insulating film and the newly formed conductive pattern can be achieved, and a conductive pattern can be disposed in the insulating film portion. Cross section (bridge). In this case, an oxide conductor such as ITO or a metal such as Cu can be used as the conductive pattern to be formed, and conduction with these conductive patterns can be easily obtained.

1‧‧‧First film (support film)

2‧‧‧ Conductive layer

2a‧‧‧ conductive pattern

3‧‧‧Photosensitive resin layer

3b‧‧‧ resin hardened layer

4‧‧‧Photosensitive layer

5‧‧‧Second film (cover film)

10‧‧‧Photosensitive conductive film

20‧‧‧Substrate

40‧‧‧Conductive pattern substrate

50‧‧‧Roller

101‧‧‧Transparent substrate

103‧‧‧Transparent Electrode (X Position Coordinate)

104‧‧‧Transparent Electrode (Y Position Coordinate)

104a‧‧‧Part of transparent electrode

104b‧‧‧Bridge of transparent electrode

105a, 105b‧‧‧ lead wiring

106‧‧‧Insulation film

L‧‧‧ actinic ray

X‧‧‧ position coordinates

Y‧‧‧ position coordinates

FIG. 1 is a schematic cross-sectional view showing an example of a photosensitive conductive film.

2 is a schematic cross-sectional view showing an example of a method of producing a photosensitive conductive film.

3(a) to 3(d) are schematic cross-sectional views for explaining one embodiment of a method of forming a conductive pattern of the present invention, and Fig. 3(a) is a schematic cross-sectional view showing a lamination step, and Fig. 3 (Fig. 3 ( b) is a schematic cross-sectional view showing a laminate in which a photosensitive film is transferred, FIG. 3(c) is a schematic cross-sectional view showing an exposure step, and FIG. 3(d) is a schematic cross-sectional view showing a development step.

4 is a plan view showing an example of a capacitive touch panel in which a transparent electrode is present on the same plane.

5 is a partially cutaway perspective view showing an example of a capacitive touch panel in which a transparent electrode is present on the same plane.

Figure 6 is a partial cross-sectional view taken along line VI-VI of Figure 5 .

7(a) and 7(b) are diagrams for explaining an example of a method of manufacturing a capacitive touch panel in which a transparent electrode is present on the same plane, and Fig. 7(a) is a view showing the same. FIG. 7(b) is a partially cutaway perspective view showing the obtained capacitive touch panel.

8(a) to 8(c) are diagrams for explaining an example of a method of manufacturing a capacitive touch panel in which a transparent electrode is present on the same plane, and Fig. 8(a) is along the line of Fig. 7(a) A partial cross-sectional view of line VIII a-VIII a, FIG. 8(b) is a partial cross-sectional view showing a step of providing an insulating film, and FIG. 8(c) is a line along line VIII c-VIII c of FIG. 7(b) Partial section view.

Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, in this specification, "(meth)acrylate" means "acrylate" and "methacrylate". Similarly, the term "(meth)acrylic group" means "acrylic group" and "methacrylic acid group", and the term "(meth)acryloyl group" means "acryloyl group" and "methacryloyl group". base".

The method for forming a conductive pattern according to the present embodiment includes preparing a photosensitive conductive film including a support film, a conductive layer containing conductive fibers, and a photosensitive resin layer containing a photosensitive resin, and bonding the conductive layer to the substrate a lamination step of laminating a conductive layer and a photosensitive resin layer; and a patterning step of forming a conductive pattern by exposing and developing the photosensitive resin layer on the substrate.

In the present specification, the boundary between the conductive layer and the photosensitive resin layer need not necessarily be specified. The conductive layer may have conductivity in the surface direction of the photosensitive layer, and may be a form in which a photosensitive resin layer is mixed in the conductive layer. For example, it can be included in the conductive layer The composition immersed in the photosensitive resin layer or the composition constituting the photosensitive resin layer may be present on the surface of the conductive layer.

FIG. 1 is a schematic cross-sectional view showing an example of a photosensitive conductive film. The photosensitive conductive film 10 shown in FIG. 1 includes a first film (support film) 1, a photosensitive layer 4 provided on the first film 1, and a second film (cover film) 5 provided on the photosensitive layer 4. The photosensitive layer 4 includes a conductive layer 2 containing conductive fibers and a photosensitive resin layer 3 provided on the conductive layer 2 on the support film 1.

Hereinafter, the support film 1 constituting the photosensitive conductive film 10, the conductive layer 2 containing the conductive fibers, the photosensitive resin layer 3, and the cover film 5 will be described in detail.

Examples of the support film 1 include a polymer film having heat resistance and solvent resistance such as a polyethylene terephthalate film, a polyethylene film, a polypropylene film, or a polycarbonate film. Among these, from the viewpoints of transparency, heat resistance and the like, a polyethylene terephthalate film and a polypropylene film are preferable.

In order to easily peel off from the conductive layer 2 afterwards, the above polymer film is preferably a mold release treatment.

In the present embodiment, the support film 1 can be peeled off more preferentially than the cover film 5. Therefore, the adhesion strength between the cover film 5 and the photosensitive resin layer 3 is preferably larger than the adhesion strength between the conductive layer 2 and the support film 1. It is preferable that these polymer films are adjusted in thickness, material selection, and surface treatment so that the cover film 5 is more easily peeled off. When the thickness is adjusted, the ratio of the thickness of the support film 1 to the thickness of the cover film 5 is preferably 1:1 to 1:10, more preferably 1:1.5 to 1:5. And then the best is 1:2~1: 5.

The thickness of the support film 1 is preferably from 5 μm to 100 μm, more preferably from 10 μm to 50 μm, particularly preferably from 15 μm to 25 μm. By setting the thickness of the support film 1 to 5 μm or more, more sufficient mechanical strength can be obtained. For example, in the step of applying the conductive fiber dispersion for forming the conductive layer 2 or the photosensitive resin composition for forming the photosensitive resin layer 3, it is difficult to cause breakage of the support film or the like, and the workability is excellent. By setting the thickness of the support film 1 to 100 μm or less, the peeling strength of the support film 1 and the conductive layer 2 can be made moderate, and peeling can be easily performed.

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 nano-tubes. These may be used alone or in combination of two or more. From the viewpoint of conductivity, it is preferred to use silver fibers and/or silver fibers, and it is more preferable to use silver fibers from the viewpoint of easily adjusting the conductivity of the formed conductive patterns. The gold fiber and the silver fiber may be used alone or in combination of two or more.

The metal fiber can be produced, for example, by a method of reducing a metal ion using a reducing agent such as NaBH ₄ or a polyol method. Further, as the carbon nanotube, a commercially available product such as a Hipco single-layer carbon nanotube of Unidym Co., Ltd. can be used.

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

The thickness of the conductive layer 2 varies depending on the conductive pattern formed by using the photosensitive conductive film of the present invention, the use thereof, the required conductivity, and the like, and is preferably 1 μm or less, more preferably 1 nm to 0.5 μm, and particularly preferably 5 nm. ~0.1μm. When the thickness of the conductive layer 2 is 1 μm or less, the light transmittance in the wavelength region of 450 nm to 650 nm is high, and the pattern formation property is also excellent, and it is particularly suitable for the production of a transparent electrode. The thickness of the conductive layer 2 refers to a value measured by a scanning electron micrograph.

The conductive layer 2 is preferably a mesh structure in which conductive fibers are in contact with each other. The conductive layer 2 having such a mesh structure can be formed on the side of the support film side of the photosensitive resin layer 3, but can be contained if the conductivity is obtained in the surface direction of the surface exposed when the support film is peeled off. It is formed in the form of the surface layer of the support film side of the photosensitive resin layer 3.

The conductive layer 2 containing the conductive fibers can be applied to the support by, for example, a conductive fiber dispersion containing the above-mentioned conductive fibers, a water and/or an organic solvent, and a dispersion stabilizer such as an optional surfactant. After the film 1 is dried, it is formed. Further, after drying, the formed conductive layer 2 can be further pressurized. By pressurizing the conductive layer, the contact between the conductive fibers is increased, and the conductivity can be improved. The linear pressure at this time is preferably 0.6 MPa to 2.0 MPa, and more preferably 1.0 MPa to 1.5 MPa. In the conductive layer 2, the conductive fibers may coexist with a surfactant, a dispersion stabilizer, or the like.

The coating can be carried out, for example, by a roll coating method, a comma coat method, a gravure coating method, an air knife coating method, a die coating method, a bar coating method, and a spray coating method. The method of knowing is carried out. Further, the drying may be carried out at 30 ° C to 150 ° C for 1 minute to 30 minutes by a hot air convection dryer or the like.

The photosensitive resin layer 3 is exemplified by a photosensitive resin composition containing (A) a binder polymer, (B) a photopolymerizable compound having an ethylenically unsaturated bond, and (C) a photopolymerization initiator. Former.

Examples of the (A) binder polymer include an acrylic resin, a styrene resin, an epoxy resin, a guanamine resin, a guanamine epoxy resin, an alkyd resin, and a phenol resin. These can be used individually or in combination of 2 or more types. (A) The binder polymer can be produced by radical polymerization or the like of a polymerizable monomer.

Examples of the polymerizable monomer include a polymerizable styrene derivative substituted with an α-position or an aromatic ring such as styrene, vinyltoluene or α-methylstyrene; diacetone acrylamide or the like. Ethylene amide; acrylonitrile; ethers of vinyl alcohols such as vinyl n-butyl ether; alkyl (meth)acrylate, aryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, Methyl) dimethylaminoethyl acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furylacrylic acid, β-styrylacrylic acid, butene Diacid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, cyclohexyl maleate, etc. Acid monoester, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid and the like.

As the above alkyl (meth)acrylate, (meth)acrylic acid is exemplified. Methyl ester, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate , octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, (A) Base) lauryl acrylate, dicyclopentyl (meth) acrylate, and the like.

The aryl (meth)acrylate may, for example, be benzyl (meth)acrylate.

Further, examples of the polymerizable monomer include a bifunctional (meth)acrylate. Specific examples thereof include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and dipropylene glycol. Di(meth)acrylate, tripropylene glycol di(meth)acrylate. These can be used individually or in combination of 2 or more types.

In the present embodiment, the (A) binder polymer is preferably a copolymer containing a structural unit derived from (a) (meth)acrylic acid and (b) alkyl (meth)acrylate.

The (A) binder polymer preferably has a carboxyl group from the viewpoint of improving alkali developability. As the polymerizable monomer having a carboxyl group for obtaining such a binder polymer, (meth)acrylic acid or the like as described above can be mentioned.

(A) The ratio of the carboxyl group of the binder polymer is a ratio of the polymerizable monomer having a carboxyl group to the total of the polymerizable monomer used to obtain the binder polymer, and preferably 10% by mass to 50% % by mass, more preferably 12% by mass to 40% by mass, particularly preferably 15% by mass to 30% by mass, and excellently 15% by mass to 255% by mass %. The ratio is preferably 10% by mass or more in terms of excellent alkali developability, and is preferably 50% by mass or less from the viewpoint of excellent alkali resistance.

The weight average molecular weight of the (A) binder polymer is preferably from 10,000 to 200,000, but from the viewpoint of resolution, it is preferably from 15,000 to 150,000, more preferably from 30,000 to 150,000, and particularly preferably from 30,000 to 100,000. In addition, the measurement conditions of the weight average molecular weight are the same measurement conditions as the Example of this specification.

As the photopolymerizable compound of the component (B), a photopolymerizable compound having an ethylenically unsaturated bond can be used.

Examples of the photopolymerizable compound having an ethylenically unsaturated bond include a monofunctional vinyl monomer, a difunctional vinyl monomer, and a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated bonds. .

Examples of the monofunctional vinyl monomer include (meth)acrylic acid and alkyl (meth)acrylate which are exemplified as monomers used for the synthesis of the copolymer which is a preferred example of the component (A). A monomer that can be copolymerized with these.

Examples of the difunctional vinyl monomer include polyethylene glycol di(meth)acrylate (the amount of the ethoxy group is 2 to 14), trimethylolpropane di(meth)acrylate, and poly Propylene glycol di(meth) acrylate (the number of propyl groups is 2 to 14); bisphenol A polyoxyethylene di(meth) acrylate (2,2-bis(4-(methyl) propylene oxime) Polyethoxyphenyl)propane), bisphenol A diglycidyl ether di(meth)acrylate; polybasic acid (phthalic anhydride, etc.) and a substance having a hydroxyl group and an ethylenically unsaturated bond (Acrylic acid β Esterified product of -hydroxyethyl ester, β-hydroxyethyl methacrylate, etc. Wait. Examples of the bisphenol A polyoxyethylene dimethacrylate include bisphenol A dioxyethylene diacrylate, bisphenol A dioxyethylene dimethacrylate, bisphenol A trioxyethylene diacrylate, and double Phenol A trioxyethylene dimethacrylate, bisphenol A pentaoxyethylene diacrylate, bisphenol A pentaoxyethylene dimethacrylate, bisphenol A decaoxyethylene diacrylate, bisphenol A decaoxyethylene two Methacrylate and the like.

Examples of the polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated bonds include trimethylolpropane tri(meth)acrylate and tetramethylol methane tri(meth)acrylate. a compound obtained by reacting a polyhydric alcohol such as tetramethylol methane tetra(meth)acrylate, dipentaerythritol penta (meth) acrylate or dipentaerythritol hexa(meth) acrylate with an α,β-unsaturated carboxylic acid a compound obtained by adding a glycidyl group-containing compound such as trimethylolpropane triglycidyl ether triacrylate to an α,β-unsaturated carboxylic acid.

As the (C) photopolymerization initiator, benzophenone, N, N, N', N'-tetramethyl-4,4'-diaminobenzophenone (michlerone) can be mentioned. ,N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl Benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholine Aromatic ketones such as ketone-acetone-1; 2-ethyl fluorene, phenanthrenequinone, 2-tert-butyl fluorene, octamethyl hydrazine, 1,2-benzopyrene, 2,3-benzo Bismuth, 2-phenylindole, 2,3-diphenylanthracene, 1-chloroindole, 2-methylindole, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl Anthraquinones such as 1,4-naphthoquinone and 2,3-dimethylhydrazine; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin, methyl benzoin, ethyl benzoin, etc. Aroma compounds; 1,2-octanedione, 1-[4-(phenylthio)phenyl-, 2-(O-benzylidenehydrazide)], ethyl ketone, 1-[9-ethyl An oxime ester compound such as -6-(2-methylbenzhydryl)-9H-indazol-3-yl]-, 1-(O-ethenylhydrazine); 2,4,6-trimethylbenzene a phosphine oxide compound such as formazan-diphenyl-phosphine oxide; a benzoin derivative such as benzoin dimethyl ketal; and a 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer. , 2-(o-chlorophenyl)-4,5-bis(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, etc. 2,4,5- Triaryl imidazole dimer; acridine derivative such as 9-phenyl acridine, 1,7-bis(9,9'-acridinyl)heptane; N-phenylglycine, N-phenylglycine An amine derivative, a coumarin compound, an oxazole compound, and the like. Further, the substituents of the aryl groups of the two 2,4,5-triarylimidazoles may form the same and symmetrical compounds, and may also form compounds which are different from each other in symmetry. Further, a thioxanthone-based compound may be combined with a tertiary amine compound as in the combination of diethylthioxanthone and dimethylaminobenzoic acid.

Among these, an oxime ester compound or a phosphine oxide compound is preferable in terms of the transparency of the photosensitive resin layer to be formed and the pattern forming ability at the time of film formation.

The amount of the (A) binder polymer is preferably 40 parts by mass to 80 parts by mass based on 100 parts by mass of the total of the (A) binder polymer and (B) the photopolymerizable compound having an ethylenically unsaturated bond. The mass part is more preferably 50 parts by mass to 70 parts by mass. When the amount is 40 parts by mass or more, the coating property (coating property) is excellent, and the phenomenon that the resin oozes from the end portion of the photosensitive conductive film (photosensitive element) can be further suppressed (also referred to as edge). Edge fusion). In addition, by adjusting the tone When the amount is set to 80 parts by mass or less, the sensitivity can be improved, and sufficient mechanical strength can be obtained.

The amount of the photopolymerizable compound having the ethylenically unsaturated bond (B) is more than 100 parts by mass based on the total amount of the (A) binder polymer and (B) the photopolymerizable compound having an ethylenically unsaturated bond. Preferably, it is 20 parts by mass to 60 parts by mass, more preferably 30 parts by mass to 50 parts by mass. By setting the blending amount to 20 parts by mass or more, the sensitivity can be improved, and sufficient mechanical strength can be obtained. In addition, when the blending amount is 60 parts by mass or less, the coating property (coating property) is excellent, and edge fusion can be further suppressed.

The amount of the photopolymerization initiator (C) is preferably 0.1 part by mass based on 100 parts by mass of the total of the (A) binder polymer and (B) the photopolymerizable compound having an ethylenically unsaturated bond. 20 parts by mass, more preferably 0.2 parts by mass to 10 parts by mass. By setting the blending amount to 0.1 part by mass or more, the sensitivity can be improved. By setting the blending amount to 20 parts by mass or less, the curing of the photosensitive resin layer by exposure can be performed more uniformly.

In the photosensitive resin composition of the present invention, if necessary, a dye such as malachite green, a photochromic agent such as tribromomethylphenylphosphonium or leuco crystal violet, or a thermochromic preventing agent may be added. Plasticizers such as toluene sulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion imparting agents, leveling agents, peeling accelerators, antioxidants, perfumes, imaging agents, thermal crosslinking agents Wait. These additives are 100 parts by mass based on the total amount of the (A) binder polymer and (B) photopolymerizable compound The amount of addition may be from 0.01 part by mass to 20 parts by mass, respectively. These can be used individually or in combination of 2 or more types.

The photosensitive resin layer 3 can be dissolved and dissolved on methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, and ethyl cellosolve as needed on the conductive layer 2 formed on the support film 1. a solvent such as toluene, N,N-dimethylformamide or propylene glycol monomethyl ether or a mixed solvent of these, and a solid content of a solution of a photosensitive resin composition of about 10% by mass to 60% by mass, followed by drying form. In this case, in order to prevent the diffusion of the organic solvent in the subsequent step, the amount of the residual organic solvent in the photosensitive resin layer after drying is preferably 2% by mass or less.

The coating can be carried out by a known method such as a roll coating method, a notch wheel 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 the application, the drying for removing the organic solvent or the like can be carried out at 70 ° C to 150 ° C for 5 minutes to 30 minutes by a hot air convection dryer or the like.

The thickness of the photosensitive resin layer 3 varies depending on the application, and is preferably 0.05 μm to 50 μm after drying, more preferably 0.05 μm to 15 μm, still more preferably 0.1 μm to 10 μm, particularly preferably 0.1 μm to 8 μm. Good is 0.1μm~5μm. By setting the thickness to 0.05 μm or more, the photosensitive resin layer 3 obtained by coating is easily formed. In addition, by setting the thickness to 50 μm or less, the light transmittance is good, and sufficient sensitivity can be obtained, and the photosensitive layer after transfer can be excellent in photocurability.

The cover film 5 is exemplified as a polymer film which can be used as the support film 1. At this time, the support film 1 is preferably peeled off more preferentially than the cover film 5. The manner of separation is adjusted by film thickness control of the support film and the cover film, surface treatment, and the like.

The thickness of the cover film 5 is preferably from 10 μm to 200 μm, more preferably from 15 μm to 150 μm, particularly preferably from 15 μm to 100 μm.

The haze value of the cover film 5 is preferably from 0.01% to 5.0%, more preferably from 0.01% to 3.0%, even more preferably from 0.01% to 2.0%, particularly preferably from the viewpoint of good sensitivity and resolution. %~1.0%. In addition, the haze value can be measured in accordance with JIS K 7105, and can be measured by a commercially available turbidity meter or the like such as NDH-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd., trade name).

In the photosensitive conductive film of the present embodiment, a method of manufacturing a conductive layer and a photosensitive resin layer on the support film in this order is described. However, the method for producing the photosensitive conductive film is not limited thereto. 2 is a schematic cross-sectional view showing an example of a method of producing a photosensitive conductive film. The manufacturing method shown in FIG. 2 is characterized in that a conductive layer 2 is formed on the first film (support film) 1, and a photosensitive resin layer 3 is formed on the second film (cover film) 5. The two films obtained as described above were laminated by a roller 50 so that the conductive layer 2 and the photosensitive resin layer 3 were laminated, thereby producing a photosensitive conductive film. According to this manufacturing method, since the conductive layer and the photosensitive resin layer are separately formed, it is easier to control the structure (for example, the mesh structure of the conductive layer) in each layer than the method of manufacturing the repeated coating solution. Preferably, the film on which the conductive layer is formed and/or the film on which the photosensitive resin layer is formed are heated to 60 to 130 ° C for lamination, and the pressure of the pressure is preferably set to 0.2 MPa. About 0.8MPa.

In the present embodiment, the laminated body (photosensitive layer 4) of the conductive layer 2 and the photosensitive resin layer 3 preferably has a minimum light transmittance of 80% or more, more preferably 85% or more in a wavelength region of 450 nm to 650 nm. . When the photosensitive layer 4 satisfies such conditions, it is easy to achieve high luminance in a display panel or the like. When the total thickness of the two layers of the conductive layer 2 and the photosensitive resin layer 3 constituting the photosensitive layer 4 is 1 μm to 10 μm, the minimum light transmittance in the wavelength region of 450 nm to 650 nm is preferably 80%. More preferably, it is 85% or more. When the conductive layer and the photosensitive resin layer satisfy such conditions, it is easy to achieve high luminance in a display panel or the like.

The photosensitive conductive film may further have a layer such as an adhesive layer or a gas barrier layer on the support film or the cover film or on both films.

The photosensitive conductive film can be stored, for example, in a flat plate shape or in a roll shape wound around a cylindrical core.

The core is not particularly limited as long as it is a previously used core, and examples thereof include a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, and an ABS (Acrylonitrile Butadiene Styrene) resin (propylene). Plastics such as nitrile-butadiene-styrene copolymer. Further, from the viewpoint of protecting the end face, it is preferable to provide an end face spacer on the end surface of the photosensitive conductive film wound in a roll shape, and further, it is preferable to provide a moisture-proof end face separation from the viewpoint of edge fusion resistance. Pieces. Further, when the photosensitive conductive film is bundled, it is preferably packaged by being wrapped in a black sheet having a small moisture permeability.

<Method of Forming Conductive Pattern>

3(a) to 3(d) are schematic cross-sectional views for explaining a method of forming a conductive pattern according to the embodiment. The method of the present embodiment includes a step of laminating the support film 1 of the photosensitive conductive film 10 described above and laminating the conductive layer 2 in close contact with the substrate 20 (Fig. 3(a) and Fig. 3(b) The patterning step of forming a conductive pattern by exposing and developing the photosensitive layer on the substrate (Fig. 3(c) and Fig. 3(d)). The patterning step includes an exposure step of irradiating a prescribed portion of the photosensitive layer 4 having the cover film 5 with an actinic ray (Fig. 3(c)), and then a developing step of peeling off the cover film 5 to develop the photosensitive layer 4 ( Figure 3 (d)).

As the substrate 20, a substrate such as a glass substrate or a plastic substrate such as polycarbonate can be used. The thickness of the substrate 20 can be appropriately selected depending on the purpose of use, and a film-form substrate can also be used. Examples of the film-form substrate include a polyethylene terephthalate film, a polycarbonate film, and a cycloolefin polymer film. As the substrate 20, a substrate on which a transparent electrode or the like has been formed by ITO or the like can be used. The substrate 20 preferably has a minimum light transmittance of 80% or more in a wavelength region of 450 nm to 650 nm. When the substrate 20 satisfies such conditions, it is easy to achieve high luminance in a display panel or the like.

The lamination step is carried out, for example, by removing the support film 1 of the photosensitive conductive film 10, and then laminating the conductive layer 2 side to the substrate 20 such as a glass substrate while heating, and laminating. Further, from the viewpoint of adhesion and followability, it is preferable to carry out the lamination under reduced pressure. The laminate of the photosensitive conductive film 10 is preferably such that the conductive layer 2 and the photosensitive resin layer 3 and/or the substrate 20 are heated to 70 ° C to 130 ° C. These conditions are not particularly limited. Further, when the conductive layer 2 and the photosensitive resin layer 3 are heated to 70° C. to 130° C. as described above, it is not necessary to preheat the substrate 20 in advance, and in order to further improve the buildup property, the substrate 20 may be preliminarily prepared. Heat treatment.

In the laminate of the photosensitive conductive film 10, the pressure of the pressure is preferably about 0.1 MPa to 1.0 MPa (about 1 kgf/cm ² to 10 kgf/cm ² ), more preferably 0.2 MPa to 0.8 MPa.

In the exposure step, the photosensitive resin layer is cured by irradiating the actinic ray, and the conductive layer is fixed by the cured product, thereby forming a conductive pattern on the substrate. The exposure method in the exposure step includes a method of irradiating the actinic ray L in an image form by a negative or positive mask pattern called an artwork (mask exposure method). As the light source of the actinic ray, a known light source such as 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 can be used to efficiently emit ultraviolet rays, visible light or the like. Further, it is possible to effectively emit ultraviolet rays, visible light, or the like using an Ar ion laser or a semiconductor laser. Moreover, it is also possible to use a photo with a flood light bulb, a sun light, or the like to effectively emit visible light. Further, a method of irradiating the actinic rays imagewise by using a direct imaging method such as a laser exposure method may be employed.

The exposure amount of the actinic ray L at this time varies depending on the apparatus to be used, the composition of the photosensitive resin composition, and the like, and is preferably ⁵ mJ/cm ² to 1000 mJ/cm ² , more preferably 10 mJ/cm ² to 200 mJ/ Cm ² . 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. By setting the exposure amount to 1000 mJ/cm ² or less, discoloration of the photosensitive layer can be suppressed.

When the cover film 5 on the photosensitive resin layer is transparent to the actinic ray L, the actinic ray can be irradiated by the cover film 5, and when the cover film 5 is light-shielding, the cover film 5 is removed and the photosensitive resin is removed. The layer illuminates the actinic ray.

In addition, as described above, the photosensitive conductive film used in the present invention is selected such that the thickness and material of the support film 1 and the cover film 5 are selected, surface treatment, etc., so that the support film is peeled off from the cover film. Adjust the bonding strength of the two films.

In addition, when the base material 20 is transparent to the actinic ray L, the actinic ray may be irradiated from the substrate side through the substrate, but in terms of resolution, the photosensitive resin layer is preferably applied from the photosensitive resin layer side. Irradiating actinic rays.

According to the method of forming a conductive pattern of the present embodiment, by providing the photosensitive layer 4 by laminating the separately prepared photosensitive conductive film 10 on the substrate 20, the photosensitive layer 4 can be formed on the substrate 20 more easily, and Achieve productivity improvement. Further, 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 a glass substrate or a plastic substrate.

In the developing step (step of forming a conductive pattern), the unexposed portion (portion other than the exposed portion) of the photosensitive layer is removed. Specifically, when the transparent cover film 5 is present on the photosensitive layer, the cover film 5 is first removed, and then the unexposed portion of the photosensitive layer is removed by wet development. Thereby, the conductive layer 2 containing the conductive fibers remains under the resin-hardened layer 3b having a predetermined pattern, and the conductive pattern 2a is formed. Thus, as shown in FIG. 3(d), the conductive pattern substrate 40 having the conductive pattern can be obtained.

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

As the developer, an alkaline aqueous solution or the like can be used, which is safe, stable, and excellent in workability. As the base of the alkaline aqueous solution, a hydroxide of an alkali metal such as lithium, sodium or potassium (aluminum hydroxide); a carbonate of a lithium, sodium, potassium or ammonium carbonate or a bicarbonate (carbonate); lithium can be used. , borate or polyborate such as sodium, potassium or ammonium; alkali metal phosphate such as potassium phosphate or sodium phosphate; alkali metal pyrophosphate such as sodium pyrophosphate or potassium pyrophosphate.

The alkaline aqueous solution used for development is preferably 0.1% by mass to 5% by mass of sodium carbonate aqueous solution, 0.1% by mass to 5% by mass of potassium carbonate aqueous solution, 0.1% by mass to 5% by mass of sodium hydroxide aqueous solution, and 0.1% by mass to 55%. A mass% sodium tetraborate aqueous solution or the like. Further, the pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and the temperature thereof is adjusted depending on the developability of the photosensitive resin layer. Further, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution.

Further, an aqueous developing solution containing water or an aqueous alkaline solution and one or more organic solvents can be used. Here, examples of the base contained in the alkaline aqueous solution include borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, and 2-amino group. 2-hydroxymethyl-1, 3-propanediol, 1,3-diaminopropanol-2, morpholine, and the like.

Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethanol, isopropanol, butanol, and diethylene glycol. Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether. These may be used alone or in combination of two or more.

The aqueous developing solution preferably has a concentration of the organic solvent of 2% by mass to 90% by mass, and the temperature thereof can be adjusted depending on the developability. Further, the pH of the aqueous developing solution is preferably as small as possible within a range in which the photosensitive resin layer can be sufficiently developed, and preferably has a pH of 8 to 12, more preferably a pH of 9 to 10. . Further, a small amount of a surfactant, an antifoaming agent, or the like may be added to the aqueous developing solution.

Examples of the organic solvent-based developing solution include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, and methyl isobutyl ketone. Γ-butyrolactone and the like. In order to prevent ignition, these organic solvents preferably add water in a range of 1% by mass to 20% by mass. The above developer may be used in combination of two or more kinds as needed.

Examples of the development method include a immersion method, a paddle method, a high pressure spray method, a spray method, a brushing, and a scratch. Among these, from the viewpoint of improving the resolution, it is preferred to use a high pressure spray method.

The method of forming a conductive pattern according to the present embodiment, after development if necessary, can be exposed by heating for about ² to about 60 ℃ ~ 250 ℃ or 0.2J / cm ² ~ 10J / cm and the conductive pattern is further cured.

As described above, according to the method of forming the conductive pattern of the present embodiment, an etching resist such as an inorganic film such as ITO can be formed without forming an etching resist. A transparent conductive pattern is easily formed on a substrate such as a board or a plastic substrate.

The conductive pattern substrate of the present invention can be obtained by the above-described method of forming a conductive pattern. The surface resistivity of the conductive pattern is preferably 2000 Ω/□ or less, more preferably 1000 Ω/□ or less, and particularly preferably 500 Ω/□ or less from the viewpoint of being effectively used as a transparent electrode or the like. The surface resistivity can be adjusted, for example, by the concentration of the conductive fiber dispersion, the amount of coating, and the like.

The conductive pattern substrate of the present invention preferably has a minimum light transmittance of 80% or more, more preferably 85% or more in a wavelength region of 450 nm to 650 nm. When the conductive pattern substrate 40 satisfies such conditions, the visibility in the display panel or the like is improved.

The method of forming the conductive pattern of the present invention can be preferably used, for example, to form a transparent electrode of a capacitive touch panel. 4 is a plan view showing an example of a capacitive touch panel in which a transparent electrode (X position coordinate) 103 and a transparent electrode (Y position coordinate) 104 are present on the same plane, and FIG. 5 is a partially broken perspective view thereof. Figure 6 is a partial cross-sectional view taken along line VI-VI of Figure 5 . The capacitive touch panel has a transparent electrode 103 as a X position coordinate and a transparent electrode 104 as a Y position coordinate on the transparent substrate 101. Each of the transparent electrodes 103 and the transparent electrodes 104, which are the X-position coordinates and the Y-position coordinates, has a lead-out wiring 105a and a lead-out wiring for connecting to a control circuit of a driving element circuit (not shown) that controls an electrical signal of the touch panel ( Lead wiring) 105b.

An insulating film 106 is provided at a portion where the transparent electrode (X position coordinate) 103 and the transparent electrode (Y position coordinate) 104 intersect. The above insulating film is selected from the group consisting of electrical insulation A material with properties, transparency, and developability. As such a material, a film and a transparent photosensitive film etc. are mentioned.

A method of manufacturing a capacitive touch panel by the method of forming a conductive pattern of the present invention will be described. First, a transparent electrode (X position coordinate) 103 is formed on the transparent substrate 101. Specifically, a photosensitive conductive film is laminated in such a manner that the conductive layer is in contact with the transparent substrate 101 (laminating step). The transferred photosensitive layer (the conductive layer and the photosensitive resin layer) is irradiated with actinic rays in a pattern through a light-shielding mask so as to have a desired shape (exposure step). Then, the light-shielding mask is removed, and then the support film is peeled off and developed, whereby the unexposed portion of the photosensitive layer is removed to form a conductive pattern (developing step). The transparent electrode 103 for detecting the X position coordinate is formed by the conductive pattern.

Next, a transparent electrode (Y position coordinate) 104 is formed. An insulating film 106 is disposed on a portion of the transparent electrode 103 formed by the above steps (for example, a portion where the transparent electrode 103 and the transparent electrode 104 are to be crossed), and a new photosensitive conductive film is further laminated on the transparent substrate 101. The same operation as described above forms the transparent electrode 104 for detecting the Y position coordinate. According to the method of forming a conductive pattern of the present invention, a transparent electrode is formed, whereby a transparent electrode (X position coordinate) 103 and a transparent electrode (Y position coordinate) 104 can be formed on the same plane. Further, since the conductive pattern is formed on the transparent substrate 101 side, when the lead wiring 105a and the lead wiring 105b are formed, it is easy to achieve conduction between the formed conductive pattern and the lead wiring.

Next, a surface of the transparent substrate 101 is formed to be connected to an external circuit. The lead wiring 105a and the lead wiring 105b. The lead wiring can be formed, for example, by a screen printing method using a conductive paste material containing silver or the like in the form of flakes.

Further, in the method of manufacturing the capacitive touch panel, one of the transparent electrodes (for example, the transparent electrode (X position coordinate) 103), the lead wiring 105a, and the lead wiring 105b can be known by using a transparent conductive material. The method is previously formed on the transparent substrate 101. In this case, a transparent electrode (X position coordinate) 103 and a transparent electrode (Y position coordinate) 104 can be formed in the same plane, and a conductive pattern having more excellent adhesion and resolution can be obtained. Further, by patterning by the above steps, a conductive pattern of the bridged transparent electrode (Y-position coordinate) 104 can be formed.

Moreover, the method of manufacturing the capacitive touch panel by the method of forming a conductive pattern of the present invention is not limited to the above method. For example, a substrate in which a transparent electrode (X position coordinate) 103 and a transparent electrode which is a transparent electrode 104 for detecting a Y position coordinate are formed in advance on the transparent substrate 101 by a known method using a transparent conductive material a part of. 7(a) and 7(b) are views showing an example of a method of manufacturing a capacitive touch panel in which a transparent electrode is present on the same plane, and FIG. 7(a) shows a part of a substrate including a transparent electrode. FIG. 7(b) is a partially cutaway perspective view showing the obtained capacitive touch panel. 8(a) to 8(c) are diagrams for explaining an example of a method of manufacturing a capacitive touch panel in which a transparent electrode is present on the same plane.

First, prepare as shown in Fig. 7(a) and Fig. 8(a) in advance. The transparent electrode (X position coordinate) 103 and the substrate of the portion 104a of the transparent electrode are provided with an insulating film 106 (a portion sandwiched by a portion 104a of the transparent electrode) of the transparent electrode 103 (Fig. 8(b)). Then, a photosensitive conductive film is laminated on the substrate, and a conductive pattern is formed by the same method as the above-described exposure step and development step. The bridge portion 104b of the transparent electrode can be formed by the conductive pattern (Fig. 8(c)). A portion 104a of the transparent electrode formed in advance can be electrically connected to each other by the bridge portion 104b of the transparent electrode, thereby forming a transparent electrode (Y position coordinate) 104.

The previously formed transparent electrode can be formed, for example, by a known method using ITO or the like.

In addition to the transparent conductive material, the lead wiring 105a and the lead wiring 105b can be formed by a known method using a metal such as Cu or Ag. In the method of forming a conductive pattern of the present invention, a substrate on which the lead wiring 105a and the lead wiring 105b are formed in advance can be used. When such a substrate is used, according to the conductive pattern forming method of the present invention, direct conduction with the lead wiring can be realized, and a transparent electrode (Y position coordinate) can be formed in a state of being insulated from the transparent electrode (X position coordinate), and The conductive pattern substrate can be manufactured more easily.

Example

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

<Preparation of Conductive Fiber Dispersion (Silver Fiber Dispersion)

[Preparation of Silver Fiber by Polyol Method]

In a 2000 mL three-necked flask, 500 mL of ethylene glycol was added, and the mixture was heated to 160 ° C in an oil bath while stirring under a nitrogen atmosphere with a magnetic stirrer. A separately prepared solution obtained by dissolving 2 mg of PtCl ₂ in 50 mL of ethylene glycol was added dropwise thereto. After 4 minutes to 5 minutes, the solution was added dropwise from the dropping funnel for 1 minute: a solution obtained by dissolving 5 g of AgNO ₃ in 300 mL of ethylene glycol, and a polyvinylpyrrolidone having a weight average molecular weight of 40,000 (and pure light) 5 g of a solution obtained by dissolving in 150 mL of ethylene glycol was stirred at 160 ° C for 60 minutes.

The reaction solution was allowed to stand at 30 ° C or lower, diluted with acetone to 10 times, centrifuged at 2000 rpm for 20 minutes by a centrifugal separator, and the supernatant was decanted. After acetone was added to the precipitate and stirred, the mixture was centrifuged under the same conditions as above, and acetone was decanted. Then, centrifugal separation was carried out twice in the same manner using distilled water to obtain silver fibers. The obtained silver fiber was observed by an optical microscope, and as a result, the fiber diameter (diameter) was about 5 nm, and the fiber length was about 5 μm.

[Preparation of Silver Fiber Dispersion]

The silver fiber obtained above was dispersed in a concentration of 0.2% by mass in pure water, and dodecyl-pentaethylene glycol was dispersed so as to have a concentration of 0.1% by mass to obtain a conductive fiber dispersion 1 .

<Preparation of Solution of Photosensitive Resin Composition>

[Synthesis of Acrylic Resin]

With mixer, reflux cooler, thermometer, dropping funnel and nitrogen introduction In a flask of the tube, 400 g of a mixture of methyl cellosolve and toluene (methyl cellosolve/toluene = 3/2 (mass ratio), hereinafter referred to as "solution s") was added, and the mixture was stirred while blowing nitrogen gas. Heat to 80 ° C. On the other hand, a solution obtained by mixing 100 g of methacrylic acid as a monomer, 250 g of methyl methacrylate, 100 g of ethyl acrylate, and 50 g of styrene, and 0.8 g of azobisisobutyronitrile as a starter was prepared. (hereinafter referred to as "solution a"). Next, the solution a was added dropwise to the solution s heated to 80 ° C for 4 hours, and then kept at 80 ° C for 2 hours while stirring. Next, a solution obtained by dissolving 1.2 g of azobisisobutyronitrile in 100 g of the solution s was added dropwise to the flask over 10 minutes. Next, while stirring the dropwise addition solution, the mixture was kept at 80 ° C for 3 hours, and then heated to 90 ° C for 30 minutes. After holding at 90 ° C for 2 hours, cooling was carried out to obtain a binder polymer solution. To the binder polymer solution, acetone was added and prepared in a nonvolatile content (solid content) of 50% by mass to obtain a binder polymer solution as the component (A). The weight average molecular weight of the obtained binder polymer was 80,000 in terms of standard polystyrene by Gel Permeation Chromatography (GPC). This was made into the acrylic polymer A. Further, the measurement conditions of GPC for measuring the weight average molecular weight are as follows.

[GPC measurement conditions]

Model: Hitachi L6000 (manufactured by Hitachi, Ltd.)

Testing: L3300RI (manufactured by Hitachi, Ltd.)

Pipe column: Gelpack GL-R440+GL-R450+GL-R400M (manufactured by Hitachi Chemical Co., Ltd.)

Column specifications: diameter 10.7mm × 300mm

Solvent: tetrahydrofuran (THF)

Sample concentration: 120 mg of a resin solution having a NV (nonvolatile content concentration) of 50% by mass was collected and dissolved in 5 mL of THF.

Injection volume: 200μL

Pressure: 4.9MPa

Flow rate: 2.05mL/min

[Preparation of Solution of Photosensitive Resin Composition]

The materials shown in Table 1 were formulated in the same amount as the one shown in the same table (unit: parts by mass) to prepare a solution of the photosensitive resin composition.

<Production of Photosensitive Conductive Film>

(Example 1)

The above-mentioned conductive fiber was uniformly coated at 25 g/m ² on a polyethylene terephthalate film (PET film, manufactured by Teijin Co., Ltd., trade name: G2-16) having a thickness of 16 μm as a support film. The dispersion 1 was dried by a hot air convection dryer at 100 ° C for 10 minutes, and pressurized at a room pressure (25 ° C) at a line pressure of 1 MPa to form a conductive layer containing conductive fibers on the support film. Further, as a result of measurement by a scanning electron microscope photograph, the film thickness after drying of the conductive layer was about 0.1 μm.

Then, the solution of the photosensitive resin composition was uniformly applied to a polyethylene terephthalate film (PET film, manufactured by Teijin Co., Ltd., trade name: G2-50) having a thickness of 50 μm prepared separately. The photosensitive resin layer was formed by drying with a hot air convection dryer at 100 ° C for 10 minutes. In addition, by scanning type The electron micrograph was measured, and as a result, the film thickness after drying of the photosensitive resin layer was 5 μm.

The PET film having the conductive layer obtained as described above and the PET film on which the photosensitive resin layer was formed were disposed such that the conductive layer and the photosensitive resin layer faced each other, and laminated at 120 ° C and 0.4 MPa. A target photosensitive conductive film is produced.

<Measurement of surface resistivity and light transmittance>

The polycarbonate substrate having a thickness of 1 mm was heated to 80° C., and the support film (the PET film having a thickness of 16 μm) obtained in Example 1 was peeled off while the conductive layer was formed. It was opposed to the polycarbonate substrate and laminated at 120 ° C and 0.4 MPa. After lamination, the substrate was cooled and, when the temperature of the substrate was 23 ° C, from the side of the cover film (PET film having a thickness of 50 μm), an exposure machine having an ultrahigh pressure mercury lamp (manufactured by OAK Co., Ltd.) was used. In the product name: EXM-1201), the photosensitive layer (the conductive layer and the photosensitive resin layer) was irradiated with light at an exposure amount of 1000 mJ/cm ² . After the exposure, it was allowed to stand at room temperature (25 ° C) for 15 minutes, and then the PET film as a cover film was peeled off, whereby a conductive film containing silver fibers was formed on the polycarbonate substrate to obtain a conductive film substrate. The obtained conductive film substrate was evaluated for surface resistivity and minimum light transmittance in a wavelength region of 450 nm to 650 nm. The surface resistivity of the conductive film measured by the following measuring apparatus was 100 Ω/□, and the minimum light transmittance (including the substrate) in the wavelength region of 450 nm to 650 nm was 90%.

[Measurement of surface resistivity]

The measurement was performed using a non-contact type surface resistance meter (manufactured by Napson Co., Ltd., EC-80P).

[Measurement of light transmittance]

The minimum light transmittance in a wavelength region of 450 nm to 650 nm was measured using a spectrophotometer (manufactured by Hitachi High-Technologies Co., Ltd., trade name "U-3310").

<Formation of Conductive Patterns>

The polycarbonate substrate having a thickness of 1 mm was heated to 80 ° C, and the support film was peeled off while the conductive layer was opposed to the polycarbonate substrate, and laminated at 120 ° C and 0.4 MPa. The photosensitive conductive film obtained in Example 1. After lamination, the substrate was cooled, and when the temperature of the substrate was 23 ° C, a mask having a wiring pattern having a line width/gap width of 200 μm/200 μm and a length of 100 mm was adhered to the PET film surface as a cover film. Next, the photosensitive layer (conductive layer and photosensitive resin layer) was irradiated with an exposure amount of 30 mJ/cm ² using an exposure machine (manufactured by Oak Industries, Inc., trade name: EXM-1201) having an ultrahigh pressure mercury lamp. .

After the exposure, the film was allowed to stand at room temperature (25 ° C) for 15 minutes, and then the PET film as a cover film was peeled off, and a 1% by mass aqueous sodium carbonate solution was sprayed at 30 ° C for 30 seconds to develop. After development, a conductive pattern containing silver fibers having a line width/gap width of about 200 μm/200 μm was formed on the polycarbonate substrate. It was confirmed that the respective conductive patterns were well formed.

[Industrial availability]

According to the method for forming a conductive pattern of the present invention, a conductive pattern having sufficient adhesion to a substrate and having a sufficiently small surface resistivity can be formed with sufficient resolution. Further, the connection terminals and the like provided on the surface of the substrate can be easily connected to the conductive pattern.

1‧‧‧First film (support film)

2‧‧‧ Conductive layer

3‧‧‧Photosensitive resin layer

4‧‧‧Photosensitive layer

5‧‧‧Second film (cover film)

10‧‧‧Photosensitive conductive film

Claims (6)

A method for forming a conductive pattern, comprising: a laminating step of preparing a photosensitive conductive film having a support film, a conductive layer containing conductive fibers, and a photosensitive resin layer containing a photosensitive resin in order to make the conductive layer Laminating the conductive layer and the photosensitive resin layer in close contact with the substrate; and a patterning step of forming a conductive pattern by exposing and developing the photosensitive resin layer on the substrate, wherein the conductive layer The laminate of the photosensitive resin layer has a minimum light transmittance of 80% or more in a wavelength region of 450 nm to 650 nm. The method for forming a conductive pattern according to the first aspect of the invention, wherein the photosensitive resin layer contains a binder polymer, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator. The method of forming a conductive pattern according to claim 2, wherein the binder polymer has a carboxyl group. The method of forming a conductive pattern according to any one of claims 1 to 3, wherein the conductive fiber is a silver fiber. A conductive pattern substrate comprising: a substrate, and a conductive pattern formed on the substrate by a method of forming a conductive pattern according to any one of claims 1 to 4. The conductive pattern substrate according to claim 5, wherein the conductive pattern has a surface resistivity of 2000 Ω/□ or less.