WO2017018427A1

WO2017018427A1 - Method for producing conductive film, and conductive film

Info

Publication number: WO2017018427A1
Application number: PCT/JP2016/071920
Authority: WO
Inventors: 正彦鳥羽; 内田　博
Original assignee: 昭和電工株式会社
Priority date: 2015-07-30
Filing date: 2016-07-26
Publication date: 2017-02-02
Also published as: KR102000956B1; TW201718247A; JPWO2017018427A1; KR20170133483A; CN107615408A; TWI693160B; JP6664396B2; CN107615408B

Abstract

[Problem] To provide: a method for producing a conductive film that exhibits good adhesion to a substrate, high environmental resistance and high scratch resistance; and a conductive film. [Solution] A first resin layer is formed on a substrate using a first resin composition containing a first functional group (S1); after drying the first resin layer to such an extent that a conductive material does not sink into the layer (S2), a conductive pattern that has an opening when viewed in plan is formed on the first resin layer (S3, S4); and a second resin layer is formed so as to cover at least a part of the conductive pattern using a second resin composition containing a second functional group that is co-curable with the first functional group in the first resin layer, and the first resin layer and the second resin layer are co-cured (S5).

Description

Conductive film manufacturing method and conductive film

The present invention relates to a method for producing a conductive film and a conductive film.

Conductive films have been developed and produced in various ways for various electronic parts. For example, the transparent conductive film may be a liquid crystal display (LCD), a plasma display panel (PDP), an organic electroluminescence display, a transparent electrode of a solar cell (PV) and a touch panel (TP), an antistatic (ESD) film, and an electromagnetic shielding ( It is used in various fields such as EMI) film. Conventionally, those using ITO (indium tin oxide) have been used as these transparent conductive films. However, the supply stability of indium is low, the manufacturing cost is high, the flexibility is not high, and the temperature is high during film formation. There was a problem that was necessary. Therefore, a search for a transparent conductive film that replaces ITO has been actively pursued. Among them, transparent conductive films containing metal nanowires have excellent conductivity, optical properties, and flexibility, can be formed by wet processes, have low manufacturing costs, and require high temperatures during film formation Therefore, it is suitable as an ITO alternative transparent conductive film.

For example, a transparent conductive film containing silver nanowires and having high conductivity, optical characteristics, and flexibility is known (see Patent Document 1). Patent Document 2 below discloses a method for producing a transparent conductive film having a transparent conductive layer containing metal nanowires on a transparent substrate.

In such a transparent conductive film, it is necessary that the adhesion between the conductive layer and the substrate is high, and in addition, the transparent conductive film containing metal nanowires in particular has a surface area per mass of metal such as silver. However, since it reacts with various compounds easily, there is a problem that it lacks environmental resistance. For this reason, nanostructures corrode due to the influence of various chemicals and cleaning liquids used in the process, the influence of oxygen and moisture in the air exposed by long-term storage, etc., and the conductivity tends to decrease. In particular, in applications such as electronic materials, a physical cleaning process using a brush or the like is often used in order to prevent adhesion of fine impurities, dust, and dust to the surface of the substrate. The problem is that the surface is also damaged by the process.

In order to solve this problem, many attempts have been made to laminate a protective film on the surface of a transparent conductive film containing silver nanowires to impart environmental resistance and scratch resistance to the transparent conductive film. (See Patent Documents 3 to 4).

Thus, the transparent conductive film is required to have high adhesion between the conductive layer and the substrate, environmental resistance, and scratch resistance.

Special table 2010-507199 Japanese Patent No. 5609008 JP 2014-191894 A JP 2013-200903 A

An object of the present invention is to provide a method for producing a conductive film and a conductive film having high adhesion between the conductive layer and the substrate, environmental resistance, and scratch resistance.

In order to achieve the above object, an embodiment of the present invention is a method for producing a conductive film, wherein a first resin layer is formed using a first resin composition containing a first functional group on a substrate. Forming a conductive pattern having an opening in plan view on the first resin layer, and forming the first resin layer so as to cover at least part of the conductive pattern. Forming a second resin layer using a second resin composition containing a second functional group co-curable with a functional group; and co-curing the first resin layer and the second resin layer And a step of allowing

The conductive pattern is preferably formed after the surface of the first resin layer is no longer viscous.

In addition, the first functional group only needs to include a site having reactivity in a subsequent process such as a carboxy group, a hydroxy group, an epoxy group, a (meth) acryloyl group, a vinyl group, or an allyl group. The composition preferably contains any of a carboxy-containing polyurethane, a phenol novolac-type epoxy resin, a phenoxy resin, a mixture of a carboxy-containing polyurethane and an epoxy compound having less than an equivalent amount based on a carboxy group, and a diallyl phthalate resin.

The second resin composition includes a mixture of a carboxy-containing polyurethane and an epoxy compound, a phenol novolac type epoxy resin, a phenoxy resin, a mixture of a carboxy-containing polyurethane and an epoxy compound having an equivalent amount or more based on a carboxy group, and a diallyl phthalate resin. It is preferred to include any mixture of acrylate monomers.

Further, it is preferable that the substrate, the first resin layer, the conductive pattern, and the second resin layer are each transparent.

Another embodiment of the present invention is a conductive film having a first resin layer containing a first functional group on a substrate, and an opening in the plan view on the first resin layer. A second resin layer including a second functional group is formed so as to cover at least a part of the conductive pattern, and the first resin is formed in the opening of the conductive pattern. It has a curing reaction portion between the first functional group of the layer and the second functional group of the second resin layer.

The total light transmittance of the conductive film is preferably 70% or more.

The conductive pattern may include metal nanowires that randomly have cross contact portions.

The conductive pattern may include a fine metal line pattern formed regularly or irregularly.

According to the present invention, it is possible to provide a conductive film having good adhesion to a substrate, environmental resistance, scratch resistance and optical properties.

It is process drawing of the manufacturing method of the electrically conductive film concerning embodiment. It is the conceptual diagram which expanded the electrically conductive pattern concerning embodiment partially. It is a figure which shows the environmental tolerance evaluation result of the conductive film of Example 1 and Comparative Example 7.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described.

The method for producing a conductive film according to the embodiment includes a step of forming a first resin layer using a first resin composition containing a first functional group on a substrate, and a plan view on the first resin layer. A step of forming a conductive pattern having an opening, and a second functional group co-curing with the first functional group of the first resin layer so as to cover at least a part of the conductive pattern. A step of forming a second resin layer using the resin composition, and a step of co-curing the first resin layer and the second resin layer.

FIG. 1 shows a process diagram of a method for producing a conductive film according to the present embodiment. In FIG. 1, first, a first resin layer (undercoat layer) 12 is formed on a substrate 10 (S1: first resin layer forming step). Here, the first resin layer 12 can be used as long as it has excellent adhesion to the substrate 10.

The method for carrying out the above S1 (first resin layer forming step) is not limited. For example, screen printing, gravure printing and offset printing thereof, contact printing such as bar coater, die coater, gravure coater, ink jet printing, spray coating And non-contact printing such as a dispenser.

Although it does not specifically limit as a base material which comprises the board | substrate 10, Resin films, such as a glass substrate, a PET (polyethylene terephthalate) film, a PEN (polyethylene naphthalate) film, etc. can be used.

Moreover, after the 1st resin layer 12 is formed on the surface of the board | substrate 10, it can co-cure with the 2nd functional group which the 2nd resin composition which comprises the 2nd resin layer mentioned later contains. It is comprised by the 1st resin composition containing the functional group of.

Next, the first resin layer 12 is a conductive material for forming a conductive pattern, which will be described later, by forming the first resin composition on the surface of the substrate 10 in layers and then heating it at room temperature or an appropriate temperature. Is preferably cured or dried to such an extent that it does not sink into the first resin layer 12 (S2: first resin composition drying step). The degree of curing or drying can be determined by the result of a test with a spread meter according to JIS K 5701 being 0 mm, that is, a state where there is no fluidity, but a resin composition that forms a solid resin layer at room temperature is used. For example, it is preferable because the conductive material does not completely sink into the first resin layer 12 in the conductive pattern forming step described later. After the first resin layer 12 is formed (S1), cured or dried (S2), a conductive pattern 14 having an opening in plan view is formed on the first resin layer 12. The “conductive pattern” includes a case where the entire surface is formed in a solid shape. A conductive pattern 14 having an opening in a plan view shown in FIG. 2A to be described later is, for example, an ink in which metal nanowires are dispersed in a dispersion medium on the first resin layer 12 (hereinafter referred to as “metal nanowire ink”). May be obtained by pattern printing (S3: printing step) and firing by irradiating or heating the metal nanowire ink (S4: firing step). The surface of the conductive pattern including the fired metal nanowires is exposed above the surface of the first resin layer 12.

Here, as shown in FIGS. 2A and 2B, the “opening” means that there is a gap between the metal nanowires 18 and the fine metal wires 19, and the second resin composition described later is the first resin. The penetration part of the thickness direction which can contact a composition is meant. 2A and 2B are conceptual views in which the conductive pattern 14 is partially enlarged.

When the metal nanowire ink is used, the metal nanowires 18 are randomly deposited on the substrate to have cross contact portions by printing, and the metal nanowires 18 are electrically connected to each other at the cross contact portions. Conductivity) is exhibited by the inclusion (FIG. 2A). In this case, the opening 20 has an irregular shape due to the metal nanowires 18 deposited randomly. Even when a solid film is printed using metal nanowire ink, a conductive pattern having openings 20 penetrating in the thickness direction can be obtained. The term “metal nanowire” as used herein means one having a shape with a diameter of several tens to several hundreds of nm and a length of several μm to several tens of μm.

Further, in the example shown in FIG. 2 (b), regular-shaped (rectangular) openings 20 are formed by the thin metal wires 19. The fine metal wire 19 can be formed using a metal foil or a metal nanoparticle ink described later. In the example of FIG. 2B, the thin metal wires 19 are arranged in a lattice pattern and have intersecting portions, but may be formed so as to be parallel to a certain direction and have no intersecting portions, for example. Further, the fine metal wires 19 may be irregularly arranged, and the openings 20 may be irregularly shaped.

The printing method performed in the above S3 (printing step) is not limited, and any printing method capable of pattern printing the metal nanowire ink can be adopted. For example, screen printing, gravure printing and offset printing thereof, contact printing such as bar coater, die coater and gravure coater, non-contact printing such as ink jet printing, spray coating, dispenser and the like can be mentioned. In the case of performing the contact printing, after the first resin layer 12 is formed on the substrate 10 by, for example, applying the first resin composition, the touch-dried state (tack-free) is obtained. A state having no viscosity (tack-free) is preferable. Thereby, even if the printing apparatus contacts the first resin layer 12, good printing can be performed. In addition, in the 1st resin composition which comprises the 1st resin layer 12, when co-curing with the 2nd resin composition which comprises the 2nd resin layer 16, in order to shorten hardening time, A curing accelerator may be mixed. When the 1st resin composition contains the epoxy compound mentioned later, it is desirable to mix a hardening accelerator.

On the other hand, in the case of performing non-contact printing such as an ink jet method, the first resin layer 12 does not need to be dry to the touch, and the conductive material does not completely sink into the first resin layer 12. It is sufficient that the surface of the conductive material is exposed on the surface of the first resin layer 12.

Note that the ink used for printing the conductive pattern 14 is not limited to the metal nanowire ink, and for example, metal nanoparticle ink can be used. However, when metal nanoparticle ink is used, the conductive particles must be in close contact with each other in order to exhibit conductivity, and when formed as a solid film, the opening 20 in plan view is There is almost no. Therefore, in order to form a pattern having the opening 20, it is necessary to form a fine line pattern (pattern of the metal fine line 19) having the opening 20 as shown in FIG. 2B, for example. The fine line pattern may be formed regularly or irregularly, and may be formed so as to have an intersection as in a mesh pattern. The term “metal nanoparticles” as used herein means those having a spherical shape, preferably a spherical shape, a square shape, a flat [plate] shape or the like having a particle size of the order of nm.

When the substrate on which the conductive pattern 14 after printing is formed has a total light transmittance of 80% or more, there is a sufficient gap for the first resin layer 12 and the second resin layer 16 described later to contact each other. It is preferable because it is secured.

Next, a second resin layer (overcoat layer) 16 is formed so as to cover at least a part of the conductive pattern (S5: second resin layer forming step). This step can be performed by the same method as the above-described S1 (first resin layer forming step). “At least a part” includes all. For example, in the case where a part of the electrode part for electrical connection with the outside is left exposed, the part is not covered. In such a case, a part is covered. Here, the second resin layer 16 includes a second functional group that can be co-cured with the first functional group included in the first resin composition constituting the first resin layer 12. It is comprised with a resin composition. After the second resin layer forming step (S5), the first resin layer 12 and the second resin layer 16 are co-cured based on the first functional group and the second functional group (S6: co-curing step). (Not shown)). That is, the first functional group contained in the first resin layer 12 and the second functional group contained in the second resin layer 16 are cured and reacted. The conductive pattern 14 has an opening 20 in the thickness direction, and the second resin composition constituting the second resin layer 16 enters the opening 20 and is cured at the interface with the first resin layer 12. react. That is, the opening 20 of the conductive pattern 14 has a curing reaction portion between the first functional group of the first resin layer 12 and the second functional group of the second resin layer 16. As a result, the conductive pattern 14 is sandwiched between the first resin layer 12 and the second resin layer 16 and held in the opening 20 of the conductive pattern 14, so that the conductive pattern 14 has good adhesion to the substrate 10. A pattern 14 is obtained. Examples of combinations of the first functional group of the first resin layer 12 and the second functional group of the second resin layer 16 include carboxy group / epoxy group, epoxy group / carboxy group, hydroxy group / carboxy group, ( Examples thereof include, but are not limited to, (meth) acryloyl group / vinyl group, vinyl group / (meth) acryloyl group, allyl group / (meth) acryloyl group, and the like.

As a combination of the first resin composition constituting the first resin layer 12 and the second resin composition constituting the second resin layer 16, (first resin layer: second resin layer) ) (Carboxy group-containing polyurethane (first functional group is carboxy group): mixture of carboxy group-containing polyurethane and epoxy compound (second functional group is epoxy group)), (phenol novolac type epoxy resin (first 1 functional group is an epoxy group): phenol novolac type epoxy resin (second functional group is an epoxy group)), (phenoxy resin (first functional group is an epoxy group): phenoxy resin (second functional group is an epoxy group) Group)), (carboxy group-containing polyurethane (first functional group is carboxy group): phenoxy resin (second functional group is epoxy group)), (carboxy group-containing polyurethane and Mixture with less than equivalent epoxy compound based on ruxoxy group (first functional group is carboxy group): Mixture of carboxy group-containing polyurethane and more than equivalent epoxy compound based on carboxy group (second functional group is epoxy group) ), (Diallyl phthalate resin (first functional group is allyl group): mixture of diallyl phthalate resin and acrylate monomer (second functional group is allyl group and acryloyl group)) and the like.

Among the combinations described above, when the first resin composition includes a carboxy group-containing polyurethane and the second resin composition includes a carboxy group-containing polyurethane and an epoxy compound, the first resin layer 12 and the first resin composition When the second resin layer 16 is heated, the carboxy group (first functional group) of the carboxy group-containing polyurethane contained in the first resin layer 12 and the second resin layer 16 becomes an epoxy group ( 2nd functional group) and co-curing. A combination in which the first resin composition includes a carboxy group-containing polyurethane and an epoxy compound having an equivalent weight on a carboxy group basis, and the second resin composition includes a carboxy group-containing polyurethane and an epoxy compound having an equivalent weight or more on a carboxy group basis. In the case of co-curing in the same way. In the case of a combination of phenol novolac type epoxy resin compositions and phenoxy resin compositions, co-curing is performed by adding an appropriate curing agent for epoxy resin and heating. In this case, both the first functional group and the second functional group are epoxy groups. When the first resin composition includes a carboxy group-containing polyurethane and the second resin composition includes a phenoxy resin, the first resin layer 12 and the second resin layer 16 are heated. As a result, the carboxy group (first functional group) and the epoxy group (second functional group) are bonded and co-cured. Further, the first resin composition contains a diallyl phthalate resin (the first functional group is an allyl group), and the second resin composition contains a diallyl phthalate resin and an acrylate monomer (the second functional group is an allyl group). In the case of a combination of acryloyl group and acryloyl group), it undergoes addition polymerization and co-curing by light irradiation.

Here, it is preferable that the substrate 10, the first resin layer 12, the conductive pattern 14, and the second resin layer 16 are transparent. Thereby, it can apply to transparent elements, such as a touch panel. Here, “transparent” means that the total light transmittance is 80% or more. The total light transmittance of the conductive film of the present invention having such a constitution is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more.

Hereinafter, embodiments of the present invention will be specifically described. In addition, the following examples are for facilitating understanding of the present invention, and the present invention is not limited to these examples.

In this example, the molecular weight and acid value of the resin, the total light transmittance and the surface resistance of the conductive pattern were measured as follows.

<Molecular weight>
It is a value in terms of polystyrene measured by gel permeation chromatography (hereinafter referred to as GPC).

The measurement conditions for GPC are as follows.
Device name: HPLC unit HSS-2000 manufactured by JASCO Corporation
Column: Shodex column LF-804
Mobile phase: Tetrahydrofuran flow rate: 1.0 mL / min
Detector: RI-2031Plus manufactured by JASCO Corporation
Temperature: 40.0 ° C
Sample volume: sample loop 100 μl Sample concentration: adjusted to about 0.1% by mass

<Acid value>
About 0.2 g of a sample is precisely weighed in a 100 ml Erlenmeyer flask with a precision balance, and 10 ml of a mixed solvent of ethanol / toluene = 1/2 (mass ratio) is added and dissolved therein. Furthermore, add 1 to 3 drops of phenolphthalein ethanol solution as an indicator to this container and stir well until the sample is uniform. This is titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds. The value obtained from the result using the following calculation formula is defined as the acid value of the resin.
Acid value (mg-KOH / g) = [B × f × 5.611] / S
B: Amount of 0.1N potassium hydroxide-ethanol solution used (ml)
f: Factor of 0.1N potassium hydroxide-ethanol solution S: Amount of sample collected (g)

<Total light transmittance>
It is the value measured using a turbidimeter (NDH2000, manufactured by Nippon Denshoku Industries Co., Ltd.) after cutting the conductive pattern formed on the substrate with a 50 mm square.

<Surface resistance>
The resistivity was measured with a Loresta (registered trademark) GP MCP-T610 type (manufactured by Mitsubishi Chemical Analytech) by the 4-terminal method. The ESP mode was used for the measurement mode and the terminals used.
<Synthesis example of carboxy group-containing polyurethane>

[Synthesis Example 1]
C-1015N (manufactured by Kuraray Co., Ltd., polycarbonate diol, raw material diol molar ratio: 1,9-nonanediol: 2-methyl-1,8-octane was added to a 2 L three-necked flask equipped with a stirrer, thermometer and condenser. Diol = 15: 85, molecular weight 964) 143.6 g, 2,2-dimethylolbutanoic acid (made by Nippon Kasei Co., Ltd.) 27.32 g as a dihydroxyl compound having a carboxy group, and propylene glycol monomethyl ether acetate (product) (Name: methoxypropyl acetate, manufactured by Daicel Corporation) 259 g was charged, and the 2,2-dimethylolbutanoic acid was dissolved at 90 ° C.

The temperature of the reaction solution was lowered to 70 ° C., and 87.5 g of Desmodur (registered trademark) -W (methylenebis (4-cyclohexylisocyanate), manufactured by Sumika Bayer Urethane Co., Ltd.) was added as polyisocyanate over 30 minutes with a dropping funnel. It was dripped. After completion of the dropwise addition, the temperature was raised to 120 ° C., and the reaction was carried out at 120 ° C. for 6 hours. After confirming that the isocyanate almost disappeared by IR, 0.5 g of isobutanol was added, and the reaction was further carried out at 120 ° C. for 6 hours. went. The weight average molecular weight of the obtained carboxy group-containing polyurethane was 32300, and the acid value of the resin was 40 mgKOH / g.

[Synthesis Example 2]
C-1015N (manufactured by Kuraray Co., Ltd.) 44.8 g, 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) 16.1 g, and propylene glycol monomethyl ether acetate (manufactured by Daicel Corporation) 100.3 g as a solvent, A carboxy group-containing polyurethane was obtained in the same manner as in Synthesis Example 1 except that 40.7 g of Desmodule (registered trademark) -W (manufactured by Sumika Bayer Urethane Co., Ltd.) was used. The weight average molecular weight of the obtained carboxy group-containing polyurethane was 29200, and the acid value of the resin was 60 mgKOH / g.

[Example 1]
As shown in Table 1, on the PET (polyethylene terephthalate) substrate (Lumilar (registered trademark) 125T60 manufactured by Toray Industries, Inc.), the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 and cure azole (registered) Trademark) 2P4MHZ-PW (2-phenyl-4-methyl-5-hydroxymethylimidazole, 1 part by mass added to 100 parts by mass of the resin), and the resin content concentration including the curing accelerator is 30% by mass. Ink diluted with propylene glycol monomethyl ether acetate (corresponding to the first resin composition) was printed with a bar coater, dried at 100 ° C. for 1 hour, and a film thickness of 10 μm (Mitutoyo high precision Digimatic Micro Meter MDH-25M 293-100, measured arbitrarily at 5 points, the average value) under) Over coat layer (corresponding to the first resin layer) was formed. The thickness of the undercoat layer was determined by measuring the thickness including the substrate after formation of the undercoat layer and drying, and subtracting the thickness of the substrate.

After drying, the tackiness was evaluated based on JIS Z0237. Any ball that does not stop is indicated as no tack, and any ball that stops is indicated as tacky.

After confirming that there was no tack (tack-free), a silver nanowire dispersion (0.125 g of silver nanowire (average diameter of wire: about 40 nm, average length: about 10 μm, 100 silver nanowires that were arbitrarily observed by SEM) Is dispersed in 50 g of ethanol (preparing a 0.25% by mass silver nanowire dispersion)), and 0.05 g of the dispersion is used so that it does not protrude from the undercoat layer with a bar coater. did. The silver nanowire dispersion was successfully coated. After the silver nanowire dispersion was applied, it was baked at 100 ° C. for 1 hour to form a solid conductive pattern. The surface resistance after firing was 80Ω / □, and the total light transmittance was 89%.

Thereafter, as an overcoat layer (corresponding to the second resin layer), 10 g of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 and 0.69 g of an epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical) were added to a curing accelerator. (Shikoku Kasei Co., Ltd. (registered trademark) 2P4MHZ-PW) containing 1 part by mass of 100 parts by mass of a total amount of carboxy group-containing polyurethane resin and epoxy compound (Mitsubishi Chemical Corporation jER (registered trademark) 828) 2), diluted with propylene glycol monomethyl ether acetate so that the concentration of the resin component containing a curing accelerator is 30% by mass), and printed with a bar coater so as to cover almost the entire surface of the conductive pattern. Co-curing was performed at 1 ° C. for 1 hour. The total film thickness including the undercoat layer was 20 μm. When 6 parts by mass of an epoxy compound (JER (registered trademark) 828 manufactured by Mitsubishi Chemical Corporation) is blended with 100 parts by mass of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1, the carboxy of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 Group and epoxy group of epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical) are equivalent. As shown in Table 1, the overcoat layer of Example 1 (corresponding to the second resin layer) was a carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 and an epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical Corporation). )) To 100: 7 (described as 100/7 in Table 1), the epoxy compound (Mitsubishi) with respect to the carboxy group of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 The composition has a small excess of epoxy group of chemical jER (registered trademark) 828).

The following characteristics evaluation was performed about the obtained electroconductive film. The results are shown in Table 1.

[Adhesion evaluation (peeling test)]
A cross-cut test JIS K5600 was performed on the cured film as an adhesion evaluation. The results are shown in Tables 1 and 2 as “Peel Test”. In addition, it means that adhesiveness (peeling resistance) is so high that the numerical value of a test result is small (0 is the best). In Table 1, the peel test result of Example 1 is 0, indicating that the adhesion (peel resistance) is high.

[Abrasion resistance test]
As a scratch resistance test, scratch resistance was simply determined by paper friction. The used paper was reciprocated five times on the overcoat layer using a JK wiper. The presence or absence of scratches or scratches was confirmed visually and under a microscope. The results are shown in Tables 1 and 2 as “scratch resistance test”.
A: There are no scratches or scratches visually or under a microscope.
○: Scratches are not visible with visual inspection, but slight scratch marks are visible with a microscope.
Δ: Scratches are not visible with the naked eye, but scratches / scratches are visible with a microscope.
X: Scratches and scuff marks can be identified visually.

[Environmental resistance]
As environmental resistance, it was stored in a constant temperature and humidity chamber (TH402A manufactured by ETAC) in an atmosphere of 85 ° C. and 85% RH (relative humidity), and the surface resistance change until after about 1100 hours was measured as a ratio from the initial surface resistance. . The results are shown in FIG.

〔optical properties〕
As an optical characteristic, HAZE (haze) and light transmittance measurement of the obtained conductive film were measured using Haze meter NDH 2000 (manufactured by Nippon Denshoku). The results are listed as “optical properties” in Tables 1 and 2.
○: Total light transmittance 80% or more and HAZE 20% or less ×: Total light transmittance 80% or more and HAZE 20% or more

[Examples 2 to 6]
An undercoat layer, a conductive pattern, and an overcoat layer were formed by the same thickness configuration and the same steps using the ink prepared in the same manner as in Example 1 except that the material configuration shown in Table 1 was changed. Table 1 shows the results of the same adhesion evaluation (peeling test), scratch resistance test, and optical property evaluation as in Example 1. When 9 parts by mass of an epoxy compound (JER (registered trademark) 828 manufactured by Mitsubishi Chemical) was blended with 100 parts by mass of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 2 used in the overcoat layer of Example 2, synthesis was performed. The carboxy group of the carboxy group-containing polyurethane resin synthesized in Example 2 is equivalent to the epoxy group of the epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical). As shown in Table 1, the overcoat layer of Example 2 (corresponding to the second resin layer) was composed of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 2 and an epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical). )) To 100: 10 (described as 100/10 in Table 1), the epoxy compound (Mitsubishi) with respect to the carboxy group of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 2 The composition has a small excess of epoxy group of chemical jER (registered trademark) 828).

Further, as shown in Table 1, the undercoat layer of Example 6 (corresponding to the first resin layer) was a carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 and an epoxy compound (JER (registered trademark) manufactured by Mitsubishi Chemical Corporation). ) 828) is 100 to 3 (described as 100/3 in Table 1), so that the carboxy group of the carboxy group-containing polyurethane resin synthesized in Synthesis Example 1 remains in a half amount. It has become. The overcoat layer (corresponding to the second resin layer) of Example 6 is the same as that of Example 1.

[Example 7]
An undercoat layer, a conductive pattern, and an overcoat layer were formed by the same thickness configuration and the same steps using the ink prepared in the same manner as in Example 1 except that the material configuration shown in Table 1 was changed. In this case, IRGACURE (registered trademark) 184 (manufactured by BASF) was used as a curing accelerator for the overcoat layer instead of Curesol (registered trademark) 2P4MHZ-PW (manufactured by Shikoku Kasei). Note that, instead of curing at 140 ° C. for 1 hour, co-curing was performed by exposing about 40 mW / cm ² using a small UV irradiation apparatus QRU-2161-Z11-00 (Oak Manufacturing Co., Ltd.). Table 1 shows the results of the same adhesion evaluation (peeling test), scratch resistance test, and optical property evaluation as in Example 1.

[Comparative Example 1]
It changed into the material structure shown in Table 2, and formed the undercoat layer. The undercoat layer was in a liquid state and was very sticky, and silver nanowire ink could not be printed by other printing methods such as inkjet. In other examples, the molecular weight is 10,000 or more, whereas the resin of Comparative Example 1 is considered to be caused by the low molecular weight of 4100.

[Comparative Examples 2 to 5]
An undercoat layer, a conductive pattern, and an overcoat layer were formed by the same thickness configuration and the same steps using the ink prepared in the same manner as in Example 1 except that the material configuration shown in Table 2 was changed. However, in Comparative Example 4, UV light of about 40 mW / cm ² was exposed and a treatment corresponding to co-curing was performed. Table 2 shows the results of the same adhesion evaluation (peeling test), scratch resistance test, and optical property evaluation as in Example 1.

In Examples 1 to 4, the same resin component is used for the undercoat layer and the overcoat layer, and when co-cured, the undercoat layer and the overcoat layer are in close contact with each other and peeling does not occur.

In Example 5, different resin components are used for the undercoat layer and the overcoat layer, but since they have a co-curable functional group, there is no separation between the undercoat layer and the overcoat layer after curing. On the other hand, in Comparative Examples 4 and 5, resins having different curing mechanisms are used for the undercoat layer and the overcoat layer. In Comparative Example 4, when UV curing is performed, and in Comparative Example 5, heat curing is performed, the undercoat is used. The layer and the overcoat layer were not co-cured, and peeling occurred between the undercoat layer and the overcoat layer.

In Example 6, as an undercoat layer, an epoxy compound (jER (registered trademark) 828 manufactured by Mitsubishi Chemical) was added at a ratio in which a half amount of the functional group (carboxy group) remained in the carboxy group-containing polyurethane. Under the condition of time drying, it should be in a semi-cured state, and the residual functional group adheres to the overcoat layer by chemical bonding, so there is no peeling between the undercoat layer and the overcoat layer. On the other hand, in Comparative Examples 2 and 3, the resin used for the undercoat layer and the overcoat layer is in a condition that can be completely cured, and the undercoat layer is formed when the undercoat layer is formed (dried at 100 ° C. for 1 hour). Since the residual functional group that reacts with the overcoat layer disappears in the coat layer, peeling occurred between the undercoat layer and the overcoat layer (peeling test result is 5).

From Examples 1 to 6 and Comparative Examples 2 to 5, the superiority of co-curing can be seen.

[Comparative Example 6]
The configuration is the same as that of Example 1 except that no undercoat layer is provided. Table 2 shows the results of the same adhesion evaluation (peeling test), scratch resistance test, and optical property evaluation as in Example 1. Although the peel test and scratch resistance test were good, but there was no undercoat layer, when the PET substrate after the silver nanowire dispersion was applied was heated, the total light transmittance decreased by 5% or more, but was 80% or more. However, HAZE, which was 2% before heating, exceeds 50% after heating, and the optical properties are greatly impaired. Due to heating, oligomers are precipitated from the PET substrate and the surface roughness is increased, so that the optical properties are impaired.

[Comparative Example 7]
This is a comparative example in which no overcoat layer is provided. Table 2 shows the results of the same adhesion evaluation (peeling test), scratch resistance test, and optical property evaluation as in Example 1. Since there is no overcoat layer, scratches occur in the metal part by the scratch resistance test, and from the result of environmental resistance similar to Example 1 shown in FIG. 3, after about 700 hours, the resistance starts to increase significantly, It turns out that environmental tolerance is low.

DESCRIPTION OF SYMBOLS 10 board | substrate, 12 1st resin layer, 14 conductive pattern, 16 2nd resin layer, 18 metal nanowire, 19 metal fine wire, 20 opening part.

Claims

Forming a first resin layer using a first resin composition containing a first functional group on a substrate;
Forming a conductive pattern having an opening in a plan view on the first resin layer;
A second resin layer using a second resin composition containing a second functional group that can be co-cured with the first functional group of the first resin layer so as to cover at least a part of the conductive pattern Forming a step;
Co-curing the first resin layer and the second resin layer;
The manufacturing method of the conductive film containing this.
The method for producing a conductive film according to claim 1, wherein the conductive pattern is formed after the surface of the first resin layer is no longer viscous.
The method for producing a conductive film according to claim 1 or 2, wherein the first functional group includes any of a carboxy group, a hydroxy group, an epoxy group, a (meth) acryloyl group, a vinyl group, and an allyl group.
The first resin composition includes any one of a carboxy-containing polyurethane, a phenol novolac-type epoxy resin, a phenoxy resin, a mixture of a carboxy-containing polyurethane and an epoxy compound having less than an equivalent amount based on a carboxy group, and a diallyl phthalate resin. The manufacturing method of the electrically conductive film as described in any one of 1-3.
The second resin composition is a mixture of a carboxy-containing polyurethane and an epoxy compound, a phenol novolac type epoxy resin, a phenoxy resin, a mixture of a carboxy-containing polyurethane and an epoxy compound having an equivalent amount or more based on a carboxy group, a diallyl phthalate resin and an acrylate The manufacturing method of the electrically conductive film as described in any one of Claim 1 to 4 containing any of a mixture with a monomer.
The method for producing a conductive film according to any one of claims 1 to 5, wherein the substrate, the first resin layer, the conductive pattern, and the second resin layer are each transparent.
The substrate has a first resin layer containing a first functional group, and has a conductive pattern having an opening in a plan view on the first resin layer, and covers at least a part of the conductive pattern. The second resin layer containing the second functional group is formed, and the first functional group of the first resin layer and the second resin layer of the second resin layer are formed in the opening portion of the conductive pattern. The conductive film which has a hardening reaction part with the functional group of.
The conductive film according to claim 7, wherein the total light transmittance is 70% or more.
The conductive film according to claim 7 or 8, wherein the conductive pattern includes metal nanowires having disordered cross contact portions.
The conductive film according to claim 7 or 8, wherein the conductive pattern includes a fine metal wire pattern formed regularly or irregularly.