KR101118962B1 - Conductive ink, and laminated body with conductive pattern and its manufacturing method - Google Patents

Abstract

A conductive ink of low temperature treatment type and capable of forming a high-definition conductive pattern by screen printing, without requiring a special manufacturing process, and having excellent resistance stability and The laminated body which has a conductive pattern using the same, and its manufacturing method are provided. The electroconductive ink which concerns on this invention is 1.0-10.0 (g / cm <3>) of tap density, 0.3-50 micrometers of D50 particle diameters, electroconductive particle of 0.3-5.0 m <2> / g BET specific surface area, and number average molecular weight (Mn) 10,000 An alcohol exchange reaction is possible with an epoxy resin having a hydroxyl value of 2 to 300 (mgKOH / g) and a hydroxyl group in the epoxy resin, and 0.2 to 20 parts by weight of a metal chelate with respect to 100 parts by weight of the epoxy resin. The storage elastic modulus (G ') containing the thing is 5,000-50,000 (Pa).

Description

A conductive body and a laminate having a conductive pattern and a method for manufacturing the same {CONDUCTIVE INK, AND LAMINATED BODY WITH CONDUCTIVE PATTERN AND ITS MANUFACTURING METHOD}

The present invention relates to a laminate having a conductive ink and a conductive pattern obtained by using the conductive ink and a method for producing the same.

Generally as an electronic component, a thin film formation means for electromagnetic wave shields, or a formation means of a conductive circuit, the etching method and the printing method are known. An etching method means the extensive processing technique which melt | dissolves and removes the surface and shape of a metal chemically or electrochemically, and contains the surface treatment. Etching is a kind of chemical processing, and is mainly performed to obtain a desired pattern shape on a metal film. However, in general, the process is complicated, and since wastewater treatment is required in a later step, there is also a problem in cost. Moreover, since the electrically conductive circuit formed by the etching method is formed from metal materials, such as aluminum and copper, there exists a problem that it is weak with respect to physical shocks, such as bending.

Therefore, in order to solve these problems and to form a conductive circuit more inexpensively, electroconductive ink attracts attention. By printing a conductive ink, a conductive circuit can be easily formed. In addition, since miniaturization and weight reduction of the electronic components, improvement in productivity, and low cost can be expected, research and development on conductive inks have been energetic, and many proposals have been made (for example, Patent Documents 1 to 9).

Patent Document 1 describes a method for producing a thermocompression bonding member that forms a solvent absorbing layer and screen-prints a conductive paste on the upper layer.

Patent Document 2 discloses a high-definition image by printing a conductive substrate containing spherical or granular metal particles having a specific average particle diameter and a maximum particle diameter on a substrate having a roughened surface. A technique for forming a conductive circuit is disclosed.

Patent Literature 3 discloses ink for screen printing that controls TI values (thixotropy index, thixotropy index) in order to form a high-definition color filter or the like.

In addition, Patent Document 4 contains a conductive powder having a tap density in the range of 2.5 to 6 g / cm 3, and an average particle diameter in the range of 0.02 to 1 μm in a range of 60 to 90 wt%, and containing 10 organic components. Disclosed is a conductor ink for flat plate offset printing, which is contained in a range of 40% by weight.

Patent Document 5 includes a silane-based coupling agent in the range of 0.001 to 5.0% by weight relative to the solid content of the conductive paint as a copper powder having an average particle diameter of 20 µm or less, or a silver plated copper powder, a thermoplastic resin, an additive, and an adhesion improving agent. A conductive paint dispersed in an organic solvent is disclosed.

Moreover, in order to provide the electrically conductive paste which has high adhesiveness with respect to a polyimide substrate, and is excellent in bending resistance and solvent resistance in patent document 6, 1 or 2 types of aluminum compounds and a silane coupling agent are provided. The electrically conductive paste using the binder resin contained above is disclosed.

Patent document 7 has excellent resistance change rate of the conductor after applying an electric field for a long time under conductivity, migration resistance, and high temperature and high humidity, and exhibits silver or silver white, and shrinkage and deformation of the substrate even when the substrate is a PET film. In order to provide the electrically conductive paste which does not cause a defect, the electrically conductive paste containing the thermoplastic resin containing an OH group, the scale-shaped composite conductive powder, the scale-shaped silver powder, and the solvent is disclosed.

Moreover, in patent document 8, in order to provide the electrically conductive paste which can provide favorable electroconductivity, the electrically conductive paste containing a flat conductive powder, an indeterminate conductive powder, a thermoplastic synthetic resin, and a solvent is disclosed. As examples of the thermoplastic synthetic resin, an epoxy resin, an acrylic resin, a phenoxy resin, ethyl cellulose, polyvinyl butyral and the like can be used.

In addition, Patent Literature 9 discloses a conductive paste in which a boiling point is more than 500 in a solvent having a boiling point of 200 to 250 ° C, while dissolving an epoxy resin having a molecular weight of more than 10000 and dispersing a conductive filler. It is.

Japanese Patent Application Laid-Open No. 06-68924 International Publication No. 2003/103352 Japanese Laid-Open Patent Publication No. 2003-238876 Japanese Laid-Open Patent Publication No. 2001-234106 Japanese Laid-open Patent Publication 2005-29639 Japanese Laid-Open Patent Publication No. 2006-310022 Japanese Laid-Open Patent Publication No. 2003-68139 Japanese Laid-Open Patent Publication No. 2003-331648 Japanese Laid-Open Patent Publication No. 2005-183301

However, the characteristics and performance required for the conductive ink are strict, and more excellent conductive ink is required.

Conductive ink can be classified into a high temperature baking type and a low temperature treatment type such as Patent Document 4. Since the high temperature baking type applies a high temperature to the base material and the electronic component when forming the conductive pattern, it is likely to cause damage to the electronic component or problems due to heat shrinkage. For this reason, in recent years, the demand of low temperature processing type is rapidly increasing.

In addition, from the viewpoint of improving the yield of the product and reducing the manufacturing cost, simplification of the manufacturing process is required. For this reason, the conductive ink which can print without going through the process of forming a solvent absorption layer like the said patent document 1, and the process of performing the roughening process of a base material like the said patent document 2 is calculated | required.

In recent years, high definition of printing of conductive ink has also been demanded. For example, in order to cope with high definition of the conductive circuit pattern, a pattern capable of forming a line / space (100 μm or less / 100 μm or less) (hereinafter abbreviated as “L / S”) having a width of 100 μm or less Performance is required. In addition, due to the miniaturization of portable terminals such as mobile phones and game machines, the introduction of touch screen panels, and the like, the definition of the conductive circuit pattern is further advanced, and the finer L / S having a width of 60 µm or less (60 µm or less / 60) There is also a demand for a pattern performance capable of forming m) or less.

As a printing method of electroconductive ink, the flat plate offset printing method like patent document 4, the screen printing method, etc. are known. Among these, according to the screen printing method, it is possible to ensure the printing pattern of several micrometers or more in thickness. On the other hand, according to other methods, such as a flat plate offset printing method, forming a printing pattern of about 1-2 micrometers thickness becomes a limit. For this reason, the screen printing method is suitable for realizing low resistance of conductive patterns such as conductive circuits.

However, as described in Patent Literature 4, the screen printing method is inherently unsuitable for applications and fields in which high-definition printing accuracy is required. This is because the screen printing method is a method of printing the printing ink through the mesh of the opening of the screen printing plate while filling the screen printing ink on the screen printing plate and pressing with a squeegee or the like. That is, the screen printing method is a method of bending and printing the screen printing plate by pressing with a squeegee or the like. For this reason, even if it is going to form the wiring pattern of L / S of 100 micrometers or less by the screen printing method, it is a fact that the line width of a printed matter becomes larger than the target line width. As a result, a problem arises such that neighboring wirings approach or contact each other, or an edge portion of the wiring is blurred and the boundary line becomes unclear.

This problem occurs because the specific gravity of the conductive particles contained in the conductive ink is larger than that of the general printing ink and is contained in a large amount. The conductive ink is allowed to pass through the opening of the screen plate and flows out as if it is protruded outward from the printing area by the weight of the conductive particles themselves, or the like, after being transferred to the substrate and then dried and solidified. This problem becomes particularly remarkable in the high-definition pattern in which the L / S wiring pattern corresponds to 100 µm or less.

In addition, in order to print a fine conductive pattern (circuit pattern), it is necessary to use a fine screen mesh. In order to use fine screen mesh, it is preferable to use electroconductive particle with a small particle diameter as much as possible. However, the electroconductive particle with a small particle diameter is easy to flow through the movement of the solvent and binder resin contained in the electroconductive ink in the drying and solidification after printing, compared with a large particle diameter. For this reason, the phenomenon "thickness" of the line width which protrudes outward rather than a printing area | region becomes more likely to generate | occur | produce.

Moreover, not only the above-mentioned high-definition property but also resistance value stability are mentioned as the item requested | required of the conductive circuit pattern used for the touch screen panel currently used widely in portable terminals, such as a mobile telephone and a game machine, a personal computer. There are various types of touch screen panels, and examples thereof include an optical method, an ultrasonic method, a resistive film method, a capacitive method, and a piezoelectric method. Among these, the resistive film method is most often used because of the simple structure. In the resistive touch panel, two transparent conductive substrates on which a transparent conductive film is formed are disposed to face each other at intervals of approximately 10 to 150 µm. In a portion touched by a finger, a pen, or the like, both transparent electrode substrates are brought into contact with each other to operate as a switch, so as to select a menu on the display screen, input handwritten characters, and the like.

The structure of the resistive touch screen panel will be described in more detail.

For example, a transparent conductive film is formed so that the plastic film is partially exposed by indium oxide (hereinafter referred to as ITO) doped with tin on a transparent plastic film, and a conductive ink is used on the plastic film and the transparent conductive film. A conductive circuit (also called a conductive pattern) is formed. And an insulating layer is formed on a conductive circuit, and it becomes a transparent conductive substrate. Subsequently, two transparent conductive substrates are joined by a double-sided adhesive in a state where the transparent conductive films face each other at intervals not directly contacting each other.

However, when the touch panel is exposed to a high temperature, high humidity environment, a problem often arises that the resistance between terminals thereafter, that is, the resistance between two transparent conductive substrates increases. There was a big problem in the stability of the resistance value of the conductive ink. For example, in-vehicle touch panels used in car navigation systems or the like may be exposed to a high temperature, high humidity environment, and improvement in durability of the touch panel against such environmental loads is required.

This invention is made | formed in view of the said background, The objective is not so-called high temperature baking type but low temperature processing type electroconductive ink, and it is possible to form a high-definition electroconductive pattern by screen printing. In addition, a laminate having a conductive ink having excellent resistance stability, a conductive pattern using the same, and a method for producing the same, without requiring a special manufacturing process as an essential component.

The present invention,

Electroconductive particles having a tap density of 1.0 to 10.0 (g / cm 3), a D50 particle diameter (50% particle diameter) of 0.3 to 5 μm, a BET specific surface area of 0.3 to 5.0 m 2 / g, and a number average molecular weight (Mn) of 10,000 to 300,000, And an epoxy resin having a hydroxyl value of 2 to 300 (mgKOH / g) and a hydroxyl group in the epoxy resin, and an alcohol exchange reaction is possible, and contains 0.2 to 20 parts by weight of a metal chelate with respect to 100 parts by weight of the epoxy resin. and,
Storage modulus (G ') is 5,000 to 50,000 (Pa),
The said metal chelate relates to the conductive ink which is any of aluminum chelate, titanium chelate, and zirconium chelate.

In the said invention, it is preferable that electroconductive particle is silver,

It is preferable that the said epoxy resin is a bisphenol-type epoxy resin.

In any one of said invention, it is more preferable that the said epoxy resin is 15,000-100,000 in number average molecular weight (Mn). More preferably, the number average molecular weight (Mn) of the said epoxy resin is 20,000-100,000, and hydroxyl value is 50-250 (mgKOH / g).

In any one of said invention, it is more preferable that the tap density of the said electroconductive particle is 2.0-10.0 (g / cm <3>).

In any one of said invention, it is more preferable that the said storage elastic modulus (G ') is 5,000-20,000 (Pa).

Moreover, in any one of said invention, it is preferable that the said metal chelate is aluminum chelate,

The aluminum chelate preferably has a group selected from the group consisting of an acetylacetonate group, a methyl acetoacetate group and an ethyl acetoacetate group.

And the electroconductive ink in any one of said invention can be used suitably for screen printing.

Moreover, in any one of said invention, it is preferable to further contain the hardening | curing agent which has a functional group which can react with at least one of the hydroxyl group or epoxy group which the said epoxy resin has,

The curing agent is preferably one or more selected from the group consisting of an isocyanate compound, an amine compound, an acid anhydride compound, a mercapto compound, an imidazole compound, a dicyandiamide compound, and an organic acid hydrazide compound,

It is preferable to contain 0.5-50 weight part of said hardening | curing agents with respect to 100 weight part of epoxy resins.

Moreover, this invention relates to the laminated body which has a base material and the conductive pattern formed on the said base material, and the said conductive pattern has the conductive pattern formed with the conductive ink in any one of said invention.

The laminate having the above conductive pattern may further include an insulating layer laminated so as to cover the above conductive pattern.

Moreover, the laminated body which has any one of said conductive patterns can further form another conductive film which has a predetermined pattern electrically connected with the said conductive pattern in the lower layer side of the said conductive pattern on the said base material.

It is preferable that the said other conductive film is a transparent conductive film which has the indium oxide doped with tin as a main component.

The laminate having any of the above conductive patterns is suitably used for touch screen panel applications.

Moreover, this invention is equipped with the process of forming the conductive pattern of a desired pattern shape by screen printing on a base material,

The said conductive pattern relates to the manufacturing method of the laminated body which has a conductive pattern using the conductive ink as described in any one of the said embodiments.

Moreover, this invention desires by screen printing using the process of forming the transparent conductive film of a predetermined pattern so that it may partially expose on a base material, and the conductive ink in any one of the said embodiments on the said base material and the said transparent conductive film. A step of forming a conductive pattern having a shape to be formed, and a step of forming an insulating layer on the base material, the transparent conductive film, and the conductive pattern,

The said transparent conductive film is related with the manufacturing method of the laminated body which has a conductive pattern which is a film which has the indium oxide doped with tin as a main component.

It is preferable that the said base material is a polyester film.

According to the conductive ink according to the present invention, it is not a so-called high temperature baking type but a low temperature processing type conductive ink, and it is possible to form a high-definition conductive pattern by screen printing, and also requires a special manufacturing process. The present invention provides a conductive ink having excellent resistance stability. Moreover, the outstanding effect that the laminated body which has a conductive pattern formed using the said conductive ink, and its manufacturing method can be provided.

1 is a schematic cross-sectional configuration diagram of an essential part of an example of a resistive touch screen panel to which the conductive ink of the present invention is applied to a wiring structure, and corresponds to the II cut line in FIG. 2.
Fig. 2 is a perspective view showing the laminated state of a suitable resistive touch screen panel by applying the conductive ink of the present invention to a wiring structure.

(Form to carry out invention)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. In addition, in this specification, description of "the arbitrary number A-the arbitrary number B" is a range larger than the number A and the number A, and means the range smaller than the number B and the number B.

The electroconductive ink of this invention is 1.0-10.0 (g / cm <3>) of tap density, 0.3-5 micrometers of D50 particle diameters, electroconductive particle of 0.3-5.0 m <2> / g BET specific surface area, and number average molecular weight (Mn) 10,000-1000,000 And an alcohol exchange reaction of the hydroxyl group in the epoxy resin with a hydroxyl value of 2 to 300 (mgKOH / g) and the hydroxyl group in the epoxy resin, and containing 0.2 to 20 parts by weight of a metal chelate with respect to 100 parts by weight of the epoxy resin.

As electroconductive particle used for the conductive ink of this invention, gold, silver, copper, silver plating copper powder, silver-copper composite powder, silver-copper alloy, amorphous copper, nickel, chromium, palladium, rhodium, ruthenium, indium, Metal powders such as silicon, aluminum, tungsten, molybdenum and platinum, inorganic powders coated with these metals, powders of metal oxides such as silver oxide, indium oxide, tin oxide, zinc oxide and ruthenium oxide, and inorganic powders coated with these metal oxides , And carbon black, graphite and the like can be used. You may use these electroconductive particle 1 type or in combination of 2 or more types. Among these electroconductive particles, silver is preferable in terms of cost, high conductivity, and small increase in resistivity due to oxidation. In addition, when using specific electroconductive particle, such as silver, a trace amount of other electroconductive particle may be contained in the range which does not affect printability and a characteristic. Alternatively, the composite particles may be conductive particles containing silver as a main component, and may contain a small amount of other conductive components within a range that does not affect printability and properties.

The shape of this electroconductive particle will not be specifically limited if the said characteristic is satisfy | filled, Amorphous form, agglomerated form, scale form, microcrystalline form, spherical form, flake shape, etc. can be used suitably. From the standpoint of the printability of the high-definition pattern and the adhesiveness of the conductor pattern to the base material, the spherical particles having a small particle size or the aggregated shape are preferably relatively small as the aggregates.

The electroconductive particle used for the electroconductive ink which concerns on this invention is 1.0-10.0 (g / cm <3>) of tap density, Preferably it is 2.0-10.0 (g / cm <3>), More preferably, 2.0-6.0 (g / cm <3>). ) Range.

Moreover, D50 particle diameter of electroconductive particle is 0.3-5 micrometers, It is preferable that it is the range of 0.3-1.2 micrometer, It is more preferable that it is the range of 0.3-1 micrometer.

Moreover, BET specific surface area is 0.3-5.0 m <2> / g, It is preferable that it is the range of 0.8-2.3 m <2> / g, It is more preferable that it is the range which is 0.8-2.0 m <2> / g.

If the tap density of electroconductive particle is less than 1.0 (g / cm <3>), since electroconductive particle becomes large and a space | gap becomes large between electroconductive particle, the contact point of electroconductive particle becomes small and the volume resistivity of printed matter becomes large. Moreover, the dispersibility at the time of using electroconductive ink worsens, and the printability of a high-definition pattern is inferior.

On the other hand, when the tap density exceeds 10.0 (g / cm 3), the cost of the conductive particles is high, and the manufacturing cost of the high definition conductive circuit is high. Moreover, when using electroconductive ink, electroconductive particle will become easy to precipitate over time.

The tap density in this invention means the weight per volume after putting a fixed amount of powder in a fixed container, vibrating up and down. The larger the value, the larger the packing density and the larger the contact point between the particles when the conductive particles are used. Thus, good conductivity can be obtained. However, in the present invention, it is preferable to use conductive particles having a tap density of 10.0 (g / cm 3) or less. Titration

In addition, tap density was measured based on JISZ2512: 2006 method. Specifically, electroconductive particle (powder amount 100g) was extract | collected to the graduated glass container (capacity 100 ml), and it tapped on the conditions of 3 mm of tap strokes and 100 times of tap collection | recovery with a predetermined touching apparatus.

When the D50 particle diameter of the conductive particles is less than 0.3 µm, the dispersibility of the conductive particles deteriorates when the conductive ink is used, so that poor contact between the conductive particles occurs and the resistance value of the printed matter may increase. Moreover, the cost of electroconductive particle becomes expensive.

On the other hand, when D50 particle diameter exceeds 5 micrometers, there exists a possibility that the printability of a high-definition pattern may fall.

In addition, the D50 particle diameter of electroconductive particle measured the cumulative particle size (D50) of volume particle size distribution using the Shimadzu Corporation Corporation laser diffraction particle size distribution measuring apparatus "SALAD-3000".

If the BET specific surface area of electroconductive particle is less than 0.3 m <2> / g, the contact point of electroconductive particle will become small and contact resistance will become large.

In addition, when the BET specific surface area exceeds 5.0 m 2 / g, since a large amount of resin is required to coat the surface of the conductive particles, the wettability with respect to the epoxy resin as the binder resin is inferior, and the fluidity when the conductive ink is used becomes poor. It is not preferable because the leveling property of the surface of a printing coating film falls. Moreover, since much resin is needed to coat | cover the surface of electroconductive particle, the adhesiveness of the electrically conductive pattern with respect to a base material also falls.

The BET specific surface area is a method of adsorbing the adsorption occupied area on the surface of powder particles at the temperature of the liquid nitrogen, and obtaining the specific surface area of the sample from the amount. The BET method uses low temperature and low humidity physical adsorption of an inert gas. A BET specific surface area is defined as the value computed using the following formula (1) using the surface formula measured using the Shimadzu Corporation Corporation flow type specific surface area measuring apparatus "FlowSorb II."

Equation (1): Specific surface area (m 2 / g) = surface area (m 2) / powder mass (g)

It is preferable to contain 60-95 weight% of electroconductive particles in 100 weight% of total of electroconductive particle and the epoxy resin mentioned later, and, as for the conductive ink of this invention, it is more preferable to contain 70-95 weight%, 85- It is more preferable to contain 95 weight%. If the electroconductive particle is less than 60 weight%, electroconductivity is not enough, and when it exceeds 95 weight%, an epoxy resin will become small and adhesiveness to the base material of electroconductive ink and the mechanical strength of a coating film may fall, and are unpreferable.

Next, the metal chelate will be described. In the present invention, the metal chelate reacts with the hydroxyl group in the epoxy resin (to be described later) used in the conductive ink, and is required for imparting rheological properties necessary for the printability of the high-definition pattern in the screen printing method. As such a metal chelate, it is a chelate compound which reacted with the metal alkoxide, the chelating agent, such as (beta) -diketone and ketoester (such as ethyl acetoacetate), and aluminum chelate, zirconium chelate, titanium chelate, etc. are mentioned. Aluminum chelate is suitably used in view of cost, availability and the like.

As the metal chelate, the aluminum chelate used in the present invention has a molecular weight of preferably 420 or less, and preferably an acetylacetonate complex of aluminum. The acetylacetonate complex is an acetylacetonate group: -OC (CH ₃ ) = CH-CO (CH ₃ ) or a methylacetoacetate group: -OC (CH ₃ ) = CH-CO-O-CH ₃ or ethyl Acetoacetate group: -OC (CH ₃ ) = CH-CO-OC ₂ H ₅ . As an aluminum chelate used for this invention, what has 1-3 these groups in 1 molecule is preferable, The aluminum chelate which has 1-3 acetylacetonate groups, or the aluminum chelate which has 1-3 ethylacetoacetate groups is more preferable.

Aluminum chelates having a molecular weight greater than 420, aluminum chelates having four or more acetylacetonate groups in one molecule, aluminum chelates having four or more ethylacetoacetate groups, or aluminum chelates having long alkyl groups also have wettability with conductive particles. This may be inhibited and the resistivity may increase.

Representative examples of the aluminum chelate include ethyl acetoacetate aluminum diisopropionate, aluminum tris (ethylacetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum tris (acetylacetonate), aluminum monoacetylacetonate bis (ethyl Acetoacetate), aluminum di-n-butoxide monomethylacetoacetate, aluminum diisobutoxide monomethylacetoacetate, aluminum disec-butoxide monomethylacetoacetate, and the like.

Among the metal chelates, those having a molecular weight of 350 or more and 1,000 or less are preferable as the zirconium chelate used in the present invention. Moreover, as zirconium chelate, the zirconium chelate which contains 1-4 acetylacetonate groups and 0-2 ethylacetoacetate groups is more preferable as an acetylacetonate complex. Zirconium chelates having a molecular weight of less than 350 may cause an unstable dispersion state of the conductive ink and increase the resistivity.

Typical examples of zirconium chelate include zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium monobutoxyacetylacetonate bis (ethylacetoacetate), zirconium dibutoxybis (ethylacetoacetate), zirconium tetraacetylacetonate Etc. can be mentioned.

Among the metal chelates, those having a molecular weight of 250 or more and 1,500 or less are preferable as the titanium chelate used in the present invention. In addition, there may be mentioned preferred examples, alkoxy titanium which may be represented by _{^{(HOR 1 O) 2 Ti (}} OR 2) 2 or ^{_{(H 2 NR 1 O) 2}} Ti (OR 2) 2 of the titanium chelate. Here, R ¹ and R ² are hydrocarbon groups. For example, di-i-propoxybis (acetylacetonate) titanium, di-n-butoxybis (triethanol aluminate) titanium, titanium-i-propoxyoctylene glycolate, titanium stearate, titanium acetylaceto Nitrate, titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium ethyl acetoacetate, titanium lactate, titanium triethanol aluminate and the like. Zirconium chelates having a molecular weight of less than 250 may cause an unstable dispersion state of the conductive ink and increase the resistivity.

As for content of the metal chelate used for this invention, a metal chelate is the range of 0.2-20 weight part with respect to 100 weight part of epoxy resins mentioned later, It is more preferable that it is the range of 2-10 weight part. If the metal chelate is less than 0.2 part by weight, the effect of imparting the elastic properties necessary for the printability of the high-definition pattern in the screen printing method is small. If the metal chelate is more than 20 parts by weight, the impartment of the elastic properties of the conductive ink is too large. In addition, the resistance value of the conductive ink may increase.

Here, the viscosity of the conductive ink in screen printing will be described. In order to perform screen printing with high precision, although the printing agent conditions, such as screen mesh and an emulsion thickness, are set suitably, and a base material is selected suitably, much examination has been made especially about the viscosity of the ink for screen printing. The amount of transfer of ink to the substrate largely depends on the amount of passage of the ink from the screen openings, and when the amount of passage increases, the thin line portion spreads and the thickness tends to occur. The ink passing amount tends to be lower in viscosity of the ink, and when the ink viscosity is too low, when the ink is passed through the opening of the screen plate, the ink may adhere to the back surface around the opening of the screen plate. And printing with high precision cannot be performed.

Therefore, in order to suppress the passage amount of ink, the method of making ink viscosity high was taken. However, only by increasing the viscosity, it is difficult to sufficiently pass the ink from the opening of the screen plate, and printing with high precision cannot be performed. In particular, in continuous printing, fine lines are faint or broken easily occur. Therefore, in order to perform high-precision screen printing, it is generally said that it is necessary to have a low viscosity when an external force is applied by squeegee or the like, and to have high viscosity, so-called thixotropy, in the state where no external force is applied. Has been lost.

The conventional idea regarding the relationship between the screen printing and the thixotropy property of the ink for screen printing is explained. Considering the behavior at the time of printing of the screen printing ink, the printing ink moves on the screen printing plate by a squeegee in a rotational motion called rolling, and is filled in an opening of a predetermined pattern formed on the screen, and on the substrate through the opening. Supplied and transferred to the substrate. As the screen printing ink capable of forming a high-definition printing pattern, it is necessary to show a lower viscosity at the time of filling and transition, and to rapidly increase the viscosity when it is transferred to the substrate and to maintain the printed shape on the substrate. Has been. The viscosity at the time of filling and transition of this ink is considered to correspond to the viscosity at the time of high speed rotation by a rotational viscometer. Moreover, although it becomes a stationary state when the external force is not applied to ink, the viscosity in this stationary state is considered to correspond to the viscosity at the low speed rotation by a rotational viscometer.

That is, the viscosity is measured at different rotational speeds using a rotational viscometer (which can be divided into a double cylinder, a cone-circle, a parallel disk, etc., depending on the shape of the measurement section), and the relationship between the rotational speed and the viscosity is logarithmic. When plotted in a graph, it has been considered that the screen printing ink showing a state in which a line connecting each plot becomes a straight line having a constant inclination or a state close thereto is a screen printing ink capable of forming a high-definition printing pattern.

Further, in the rotational viscometer, there is no absolute index indicating whether the viscosity of the rotational speed corresponds to the viscosity at the high speed rotation and the low speed rotation described above, but it is about 10 to 100 times the n rotation (low speed rotation). It is common to make a high speed rotation, and to calculate the ratio of the viscosity at the time of high speed rotation and the viscosity at the time of low speed rotation, and to evaluate it as TI value (thixotropy index, thixotropy index).

The same applies to the conductive ink, and the viscosity in the case of any rotational speed = shearing speed (/ sec) is measured in shear stress Pa (so-called static steady flow measurement), and also in different rotational speeds. = Viscosity in the case of different shear rates The shear stress Pa is calculated | required, and thixotropy is often evaluated from the relationship of both viscosity.

In general, printable inks containing polymer materials such as synthetic resins have properties (viscoelasticity) that combine elasticity (elastic deformation) with flow (viscosity flow), but the ratio of viscous behavior compared with elastic behavior Since this is high, the viscosity behavior is often grasped | ascertained by a certain rotation speed, ie, a steady flow as mentioned above.

However, the viscosity measured by steady flow varies greatly with time, and reproducible data are often not obtained, and the fluidity (viscosity flow) of the actual ink and the printing are also obtained from data such as a TI value obtained by a rotational viscometer. It is difficult to assess sex. In particular, when high-definition printing such as a line width of 50 µm is required, it is not enough to simply grasp and control the viscous flow.

Conventionally, the conductive ink has controlled the passage amount only by the viscous flow (so-called viscosity), and the method of making a viscosity high in order to suppress the passage amount was taken. However, only by increasing the viscosity, thin lines are faint or breakage easily occurs in continuous printing. In the steady flow measurement, even when using a conductive ink provided with only so-called thixotropy, which has a high viscosity at low shear rate and a low viscosity at high shear rate, it is not possible to sufficiently control the passing amount. It is difficult to print one pattern (for example, a conductive pattern of L / S having a width of 40 µm / width of 60 µm between wirings).

Thus, the conductive ink according to the present invention, by reacting an epoxy resin and a metal chelate in a specific physical range, imparted specific elastic properties, thereby controlling the ink passing amount. This produces a remarkable effect in printing a fine conductive pattern (for example, a conductive pattern of L / S having a width of 40 µm / width of 60 µm between wirings).

That is, the conductive ink of the present invention has a storage modulus (G ') of 5,000 to 50,000 (Pa) at 25 ° C, a frequency of 1 (Hz) and a vibrational stress of 50 (Pa) in the elastic property, and a loss modulus of elasticity. The value obtained by dividing (G ″) by the storage elastic modulus (G ′), which is required to give a printability of a high-definition pattern, is that tanδ is 1 or less. It is preferable that tanδ is 0.3 or more. In many cases, the storage modulus G 'exceeds 50,000, resulting in poor fluidity as ink, which may cause problems in printability.

If the storage modulus (G ′) at 25 ° C., frequency 1 (Hz), and vibrational stress of 50 (Pa) is less than 5,000 Pa, the elasticity is weak, ink passes through the opening of the screen and is transferred to the substrate. It becomes difficult to maintain the shape of a pattern, and the printability of a high-definition pattern is inferior.

On the other hand, when the storage elastic modulus G 'of the conductive ink exceeds 50,000 Pa, the elasticity becomes too strong, and the ink cannot be rolled on the screen printing plate, and it is difficult to be filled in a predetermined pattern formed on the screen. Can't.

It is preferable that it is 5,000-30,000, and, as for storage elastic modulus G ', it is more preferable that it is 5,000-20,000.

In addition, when tan δ of the conductive ink exceeds 1, there is a tendency for the elastic properties to decrease, resulting in deterioration in high-definition pattern printability.

Although the viscoelastic behavior evaluation of a conductive ink has each method, the measuring method which fixed the frequency of sine vibration and changed the vibration stress is preferable when measuring the dynamic viscoelasticity of dispersion systems, such as conductive ink. Do.

Next, an epoxy resin is demonstrated.

As an epoxy resin used for this invention, it has an epoxy group and a hydroxyl group, a number average molecular weight (Mn) is 10,000-300,000, Preferably it is 15,000-100,000, More preferably, it is 18,000-100,000, More preferably, it is 20,000- 100,000, and particularly preferably 20,000 to 70,000. Considering the availability of a commercial item or the ease of manufacture, it is preferable that a number average molecular weight is 15,000-100,000, 15,000-70,000 are more preferable, It is still more preferable that it is about 15,000-55,000.

The hydroxyl value is preferably 2 to 300 (mgKOH / g), the hydroxyl value is preferably 10 to 250 (mgKOH / g), more preferably 50 to 250 (mgKOH / g), and 80 to 200 (mgKOH / g). ) Is more preferred.

In addition, the epoxy equivalent of an epoxy resin is related with the number average molecular weight of an epoxy resin. In consideration of the fact that the resistance between terminals in the case of printing the conductive ink according to the present invention on the conductive film becomes good, it is preferable that the epoxy equivalent is 5,000 or more. Although an upper limit is not specifically limited, Usually, it is 100,000 or less from the preferable range of a number average molecular weight. More preferable epoxy equivalent is the range of 5,000-50,000, and the range of 6,800-18,000 is especially preferable in consideration of the availability of a commercial item.

As an epoxy resin, bisphenol-type epoxy resins, such as bisphenol A, bisphenol F, bisphenol S, bisphenol AD, are preferable, for example, The phenoxy resin which is what is called a bisphenol type high molecular weight epoxy resin can be used suitably.

Here, in order for a hydroxyl group to carry out alcohol-exchange reaction with the alkoxy group of a metal chelate as mentioned later, and to give rheological characteristics, such as storage elastic modulus (G ') required for the printability of the high-definition pattern in the screen printing method, When using a hardening | curing agent, it is necessary as a functional group which reacts as an excess hydroxyl group after using for reaction with the alkoxide group of a metal chelate.

If the number average molecular weight (Mn) of the epoxy resin is less than 10,000, sufficient storage modulus (G ') is not obtained even when using a metal chelate, and if it exceeds 300,000, the storage modulus (G') becomes too high, which causes problems in screen printability. May occur.

If the hydroxyl value is less than 2 (mgKOH / g), sufficient storage modulus (G ') is not obtained even when the metal chelate is used. If the hydroxyl value is more than 300 (mgKOH / g), the storage modulus (G') is too high. As a result, problems may occur in screen printability of fine patterns.

As a manufacturing method of a general bisphenol-type epoxy resin, there are two types of methods, a tape method and an advanced method.

The tappy process is a method of condensing epichlorohydrin and bisphenols such as bisphenol A and bisphenol F to a predetermined molecular weight in the presence of an alkali catalyst, if necessary.

The advanced method condenses bisphenol-type epoxy monomers such as so-called bisphenol A-type epoxy monomers and bisphenol F-type epoxy monomers and bisphenols having a epoxy group at both ends of the bisphenols to a predetermined molecular weight in the presence of an alkali catalyst, if necessary. Or a commercially available epoxy resin as an epoxy monomer, and in the same manner as described above, a commercially available epoxy resin and bisphenols are condensed to a predetermined molecular weight in the presence of an alkali catalyst, if necessary. .

The bisphenol type polymer epoxy resin suitably used in the present invention is a conventional method, for example, Japanese Patent Application Laid-Open No. Hei 07-109331, Japanese Patent Application Laid-Open No. Hei 10-77329, and Japanese Patent Application Laid-Open No. 11-147930. As described in JP 2006-36801 A and the like, it can be obtained by appropriately adjusting the type and amount of the alkali catalyst, the type and amount of the organic solvent to be used, the reaction temperature and time, and the like.

The conductive ink which concerns on this invention can form a conductive pattern by printing on a base material, and can manufacture the laminated body which has a conductive pattern. The laminate having this conductive pattern may further include an insulating layer so as to cover the conductive pattern. Moreover, on the lower layer side of this conductive pattern, another conductive film which has a predetermined pattern electrically connected with the conductive pattern can be further formed on a base material. Of course, you may form another conductive film in the upper layer of a conductive pattern, and it is also possible to laminate | stack multiple layers and patterns which consist of electroconductive ink. Moreover, it is also possible to form or coat a conductive pattern by methods other than printing.

The conductive pattern formed by the conductive ink according to the present invention exhibits particularly strong power when it is connected to transparent conductive films such as an ITO layer and can realize the resistance stability required in the related art. Therefore, the laminated body which has a conductive pattern formed with the conductive ink which concerns on this invention is especially suitable for a touch screen panel.

When the epoxy resin of the above-mentioned specific physical range used for this invention exposes a touch screen panel under high temperature, high humidity compared with other resins, such as a polyester resin and a polyurethane resin, the raise of the resistance value between terminals of a touch screen panel is raised. Effective for suppressing

In the laminate for touch screen panels, the conductive pattern (hereinafter also referred to as the "conductive ink pattern") formed by the conductive ink and the transparent conductive film are an ITO layer / conductive ink pattern when the ITO layer is used as the transparent conductive film. It becomes a laminated structure called / insulation layer / adhesive layer or ITO layer / conductive ink pattern / adhesive layer.

When the adhesiveness of the conductive ink pattern to the ITO layer is remarkably bad, the conductive ink pattern is peeled from the ITO layer in the adhesion test with cellophane tape without exposing under high temperature and high humidity. In some cases, it may peel off without using a cellophane tape.

When the adhesiveness of the conductive ink pattern to the ITO layer is slightly improved, it is in close contact with the ITO layer in the initial state. However, the conductive ink pattern is peeled from the ITO layer when the adhesion test is performed after exposure under high temperature and high humidity.

If the adhesion of the conductive ink pattern to the ITO layer is further improved, the conductive ink pattern will not be peeled from the ITO layer even after the adhesion test after exposure under high temperature and high humidity. By the way, even when the said characteristic is obtained, when it exposes under high temperature, high humidity in the state which an insulating layer and an adhesive contact with a conductive ink pattern, and performs an adhesive test from an insulating layer etc., an electroconductive ink pattern with an ITO layer and an insulating layer It is easy to peel off from the interface of. For this reason, when it has a laminated structure of an ITO layer / conductive ink pattern / insulating layer, the improvement of adhesive further layer is needed.

In the conductive ink for forming a touch screen panel laminate having a laminated structure of an ITO layer / conductive ink pattern / insulating layer, the insulating layer may be exposed even under high temperature and high humidity in a state in which the insulating layer and the adhesive are in contact with the conductive ink pattern. By the adhesion test from above, it is required that the conductive ink pattern does not come off from the ITO layer together with the insulating layer.

When the use of the touch screen panel is expanded and the required performance is increased, even if it is exposed under high temperature, high humidity, it is strongly demanded not to rise as far as possible to obtain resistance between terminals.

In the conductive ink using other resins such as polyester resins and polyurethane resins, when exposed under high temperature and high humidity, there is a problem that the resistance between terminals increases significantly compared to before exposure.

On the other hand, by using the electroconductive ink which concerns on this invention, the raise of the resistance value between terminals can be made small. This is by using the epoxy resin of the specific physical range mentioned above. That is, with the conductive ink according to the present invention, in a laminate having a conductive pattern having a laminated structure of an ITO layer / conductive ink pattern / insulating layer, which has conventionally been particularly problematic in resistance stability, good resistance stability can be obtained. I knew that.

In addition, although the example which uses an ITO film as a transparent conductive film was described above, you may apply transparent conductive films, such as indium zinc oxide (IZO: ZnO) and zinc oxide (ZnO).

By adding a hardening | curing agent to the electroconductive ink of this invention, the raise of the resistance value between terminals before and behind high temperature, high humidity exposure can further be suppressed.

As such a hardening | curing agent, what can react with an epoxy group and a hydroxyl group is used, and what reacts with an epoxy group is preferable. As a hardening | curing agent, an isocyanate compound, an amine compound, an acid anhydride compound, a mercapto compound, an imidazole compound, a dicyandiamide compound, an organic acid hydrazide compound, etc. are mentioned.

For example, when reacting with the hydroxyl group of an epoxy resin, an isocyanate compound can be used as a hardening | curing agent.

When reacting with the epoxy group of an epoxy resin, an amine compound, an acid anhydride compound, a mercapto compound, an imidazole compound, a dicyandiamide compound, and an organic acid hydrazide compound can be used as a hardening | curing agent.

Non-blocking isocyanate, blocked isocyanate, etc. are mentioned as an isocyanate compound which can be used as a hardening | curing agent.

As an isocyanate compound, a polyisocyanate compound is preferable. As a polyisocyanate compound, conventionally well-known aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, or blocky isocyanate which is these blockchains can be used, These may use a single type and 2 or more types. As aromatic polyisocyanate, the trimethylol propane adduct of tolylene diisocyanate, the isocyanurate body of tolylene diisocyanate, the oligomer of 4,4'- diphenylmethane diisocyanate, etc. are mentioned.

Examples of the aliphatic polyisocyanates include biuret bodies of hexamethylene diisocyanate, isocyanurates of hexamethylene diisocyanate, uretdiions of hexamethylene diisocyanate, tolylene diisocyanate and hexamethylene diisocyanate. Isocyanurate body of a polymer is mentioned. As alicyclic polyisocyanate, the isocyanurate body of isophorone diisocyanate is mentioned. As the blocked isocyanate, conventionally known ones in which polyisocyanate is blocked with ε-caprolactam, butanone oxime, phenol, active methylene compound and the like can be used.

As an amine compound in the hardening | curing agent used for the conductive ink of this invention, aliphatic amines, such as diethylene triamine, triethylene tetratamine, tetraethylene pentamine, dipropylene diamine, and diethylaminopropylamine, N-amino, for example. Alicyclic amines such as ethyl piperazine, mensendiamine, isophoronediamine, hydrogenated m-xylenediamine, aromatics such as m-xylenediamine, m-phenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone Amines and the like. Moreover, amine adducts, ketamines which modified | denatured these amines, polyamide resin etc. which have reactive primary amine and secondary amine in the molecule | numerator produced | generated by condensation of dimer acid and a polyamine are mentioned.

Examples of the acid anhydride compound in the curing agent used in the conductive ink of the present invention include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid, ethylene glycol bistrimellitate, and glycerol tritrimelli Tate, maleic anhydride, tetrahydro phthalic anhydride, methyltetrahydro phthalic anhydride, endomethylenetetrahydro phthalic anhydride, methylendomethylenetetrahydro phthalic anhydride, methylbutenyltetrahydro phthalic anhydride, dodecenyl succinic anhydride, hexahydro phthalic anhydride, Methyl hexahydro phthalic anhydride, succinic anhydride, methylcyclohexene dicarboxylic acid anhydride, an alkyl styrene maleic anhydride copolymer, chloric anhydride, polyazela anhydride, methylnadic acid anhydride, etc. are mentioned.

As a mercapto compound in the hardening | curing agent used for the conductive ink of this invention, a liquid polymercaptan, a polysulfide resin, etc. are mentioned.

Among the curing agents used in the conductive ink of the present invention, the imidazole compound is 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, or 2,4-dimethyl. Improved storage stability, such as imidazole compounds such as midazoles and 2-phenylimidazoles, and types in which these imidazole compounds react with an epoxy resin and insoluble in a solvent, or a type in which an imidazole compound is enclosed in a microcapsule. One latent hardener is mentioned.

Dicyandiamide (DICY) etc. are mentioned as a dicyandiamide compound among the hardening | curing agents used for the electroconductive ink of this invention.

Although the conductive ink of this invention does not need to add a hardening | curing agent, it is preferable to contain 0.5-50 weight part of hardening | curing agents with respect to 100 weight part of epoxy resins. By making a hardening agent 0.5 weight part or more, adhesiveness, heat resistance, etc. which are sufficient for a printed matter can be provided. On the other hand, when a hardening | curing agent exceeds 50 weight part, an unreacted hardening | curing agent will remain in a conductive ink easily, and it is difficult to provide sufficient adhesiveness, heat resistance, etc.

The electroconductive ink of this invention can be made to contain the hardening accelerator etc. which accelerate the thermosetting of an epoxy resin and a hardening | curing agent.

As such a hardening accelerator, an organic tin compound, an amine compound, etc. can be used in reaction of the hydroxyl group of an epoxy resin with an isocyanate compound. Examples of the organic tin compound include stanas octoate (SO), dibutyl tin dilaurate (DBTDL), and the like. As the amine compound, diazabicyclooctane (DABCO), N-ethyl morpholine (NEM), triethylamine (TEA), N, N, N ', N ", N" -pentamethyldiethyltriamine (PMDETA) Etc. can be mentioned.

Moreover, as a hardening accelerator in reaction with the epoxy group of an epoxy resin, and the above-mentioned hardening | curing agent, Dicyandiamide, tertiary amine compound, phosphine compound, imidazole compound, dicarboxylic acid hydrazide, aliphatic or aromatic dimethylurea, etc. Alkyl urea etc. are mentioned. Examples of the tertiary amine compound include triethylamine, benzyldimethylamine, 1,8-diazabicyclo (5.4.0) undecene-7,1,5-diazabicyclo (4.3.0) nonene-5, and the like. have. Examples of the phosphine compound include triphenylphosphine and tributylphosphine. As an imidazole compound, the imidazole compound mentioned by the hardening | curing agent mentioned above is mentioned. For example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2,4-dimethylimidazole, 2-phenylimidazole, etc. The latent hardening accelerator which improved storage stability, such as the imidazole compound and the type in which the imidazole compound reacted with an epoxy resin, insoluble in a solvent, or the type which enclosed the imidazole compound in the microcapsule, is mentioned. As carboxylic acid hydrazide, succinic acid hydrazide, adipic acid hydrazide, etc. are mentioned.

The conductive ink of the present invention can be dissolved and diluted with various solvents, and the solid content is preferably 50 to 90% by weight.

The solvent for dilution can be selected according to the kind of solubility of resin used, a printing method, etc.

For example, although ester type, ketone type solvent, glycol ether type solvent, aliphatic type solvent, alicyclic type solvent, aromatic type solvent, alcohol type solvent, water, etc. can be mixed 1 type or 2 types or more, These can be used, It is not limited to.

For example, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate, dimethyl carbonate, etc. are mentioned as an ester solvent.

Acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanone etc. are mentioned as a ketone solvent.

Examples of the glycol ether solvents include acetate esters of these monoethers, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol, such as ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, and ethylene glycol monobutyl ether. Monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and the like, and acetic acid esters of these monoethers.

Examples of the aliphatic solvents include n-heptane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, and the like.

Toluene, xylene, tetralin, etc. are mentioned as an aromatic solvent.

The electroconductive ink of this invention can be obtained by mix | blending electroconductive particle, an epoxy resin, a metal chelate, a solvent, etc. in a predetermined ratio, mixing in a disper, mixing and disperse | distributing in 3 rolls etc. as needed.

Moreover, the conductive ink of this invention is a dispersing agent, an anti-friction improver, an infrared absorber, an ultraviolet absorber, a fragrance | flavor, antioxidant, an organic pigment, an inorganic pigment, an antifoamer, a silane coupling agent, a plasticizer, a flame retardant, a humectant, etc. as needed. Can be added.

By printing on a base material by various printing methods using the conductive ink of this invention, a high-definition conductive pattern can be formed. As a conductive pattern, it is a conductive circuit pattern, various wiring patterns, an electrode pattern, etc., and is not specifically limited. A conductive circuit pattern can be used suitably for the wiring of the circuit board of an electronic component.

It does not specifically limit as a base film, For example, a polyimide film, a polyparaphenylene terephthalamide film, a polyether nitrile film, a polyether sulfone film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyvinyl chloride film, etc. Can be mentioned.

In addition, a so-called ITO film and ITO layer formed by sputtering, wet coating, or the like on a polymer film such as polyethylene terephthalate, polyester film of polyethylene naphthalate, polycarbonate, polyether sulfone, acrylic resin or the like as a base film You may use ITO glass etc. which were formed on glass. Moreover, a ceramic, a glass base material, etc. can also be used. Especially in a touch screen panel, the ITO film which formed the ITO layer on the polyester film, and the ITO glass which formed the ITO layer on the glass are used a lot.

Further, if necessary, an anchor coating layer is formed on the substrate, and conductive ink is printed on the anchor coating layer for the purpose of further improving the printability of the high-definition pattern wiring which is the conductive pattern formed of the conductive ink according to the present invention. It may be. The anchor coating layer is not particularly limited as long as the adhesion to the substrate and the adhesion of the conductive ink are good, and also inorganic fillers such as resin beads and metal oxides can be added as necessary. The method of forming an anchor coating layer is not specifically limited, either, It can obtain by apply | coating, drying, and hardening by a conventionally well-known coating method.

Although the conductive ink of this invention can be suitably applied especially to screen printing, you may apply by the conventionally well-known various printing methods. In the screen printing method, in order to cope with the high definition of the conductive circuit pattern, it is preferable to use a screen of a fine mesh, particularly preferably a mesh of about 400 to 650 mesh. The open area of the screen at this time is preferably about 20 to 50%. The screen diameter is preferably about 10 to 70 µm.

As a kind of screen board, a polyester screen, a combination screen, a metal screen, a nylon screen, etc. are mentioned. In addition, when printing the thing of the high viscosity paste state, a high tension stainless steel screen can be used.

Screen squeegees may be in any shape, circular, rectangular, or square, and may also be used with a polishing squeegee in order to reduce the attack angle (the angle between the plate and the squeegee in printing). The other printing conditions may be appropriately designed for conventionally known conditions.

The conductive ink according to the present invention is heated, dried and solidified after printing on a substrate such as a substrate. In addition, when the hardening | curing agent is added to electroconductive ink, it hardens this.

When it does not contain a hardening | curing agent, in order to fully volatilize a solvent, and when it contains a hardening agent, in order to fully volatilize a solvent, and to react with a hardening | curing agent and an epoxy resin, heating temperature is 80-230 degreeC and a heating time as 10 to 120 minutes are preferable. Thereby, the laminated body which has a conductive pattern can be obtained. The laminated body which has a conductive pattern can form an insulating layer so that a conductive pattern may be coat | covered as needed. It does not specifically limit as an insulating layer, A well-known insulating layer is applicable. Moreover, the laminated body which has a conductive pattern can be set as the structure electrically connected with the conductive film formed in the other layer. For example, it can be set as the structure which abuts and electrically connects transparent conductive layers, such as an ITO film, and the conductive pattern formed with the conductive ink which concerns on this invention.

The laminated body which has a conductive pattern which concerns on this invention can be used suitably especially when forming a wiring structure on the transparent electrode of a touchscreen panel.

Here, an example in which the conductive ink of the present invention is applied to a resistive touch screen panel will be described with reference to FIGS. 1 and 2. 1 and 2 are simple conceptual views of the resistive touch screen panel, and the number of wirings, the wiring width, and the distance between the wirings and the wirings are shown as conceptual views. In addition, in FIG. 2, the lamination | stacking state of each board | substrate side is shown in the state which looked at the lower substrate hydrazide side and the upper substrate 2 side looking up, with the viewpoint in the middle of three layers and the position of the adhesive material 5. Shown schematically.

The touch screen panel includes a lower substrate 1 and an upper substrate 2 made of a substrate of glass or plastic film (polyethylene terephthalate film, polyethylene naphthalate film, acrylic resin film, polycarbonate film, and the like). On the lower substrate 1 and the upper substrate 2, transparent electrodes 6 and 7, such as ITO, are partially formed, respectively. As a result, the lower substrate 1, the upper substrate 2 and the transparent electrodes 6, 7 are exposed, respectively.

Lower drive electrodes 13 and 14 made of the conductive ink pattern layer 3 are formed at both ends of the transparent electrode 6 on the lower substrate 1, respectively. The conductive ink pattern layer 3 is covered with the insulating layer 4. As shown in FIG. 1, the conductive ink pattern layer 3 is in contact with the substrate 1, transparent electrodes 6 such as ITO, and the insulating layer 4.

Similarly, upper driving electrodes 9 and 10 made of the conductive ink pattern layer 3 are formed at both ends of the transparent electrode 7 on the upper substrate 2, respectively.

Specifically, screen printing, drying and curing of the transparent electrode 7 end portion of the upper substrate 2 side using the conductive ink of the present invention, and the low-resistance conductive ink pattern layer 3 To form. Subsequently, an insulating resist (not shown) is printed on the conductive ink pattern layer 3 and the upper substrate 2 and transparent electrode 7 ends in the vicinity of the conductive ink pattern layer 3 by screen printing or the like. Thereafter, drying and curing are performed to form an insulating layer to form an insulating resist laminate of the present invention. The same applies to the lower substrate 1 side.

In order to prevent the transparent electrodes 6 and 7 from coming into contact with the place on the transparent electrode 6 formed on the lower substrate 1 other than at the time of the original input, the transparent electrode 6 is shown in FIG. In place on the dot), minute dot spacers 8 are formed at regular intervals.

In addition, the insulation on the lower substrate 1 side is spaced apart at regular intervals (for example, at intervals of 10 to 150 µm) such that the transparent electrodes 6 and 7 do not come into contact except at the time of input, which is the original purpose (see FIG. 1). The layer 4 and the upper substrate 2, the lower substrate 1 and the upper substrate 2, and the insulating layer 4 on the lower substrate 1 and the upper substrate 2 side are respectively attached to the adhesive material 5. Are laminated by lamination. The adhesive material 5 can be arrange | positioned in frame shape. As shown in FIG. 2, the lower side driving electrodes 13 and 14 on the lower substrate 1 side and the upper side driving electrodes 9 and 10 on the upper substrate 2 side are viewed in plan view. It can be formed to be orthogonal.

In addition, upper connection electrodes 11 and 12 are connected to upper drive electrodes 9 and 10 on the upper substrate 2 side with conductive adhesives, respectively. Similarly, the lower side drive electrodes 13 and 14 on the lower substrate 1 side are connected to the lower side connection electrodes 15 and 16 with conductive adhesives, respectively.

The touch screen panel in which the conductive ink pattern layer 3 is formed by using the conductive ink of the present invention on each of the lower substrate 1 side and the upper substrate 2 side has good resistance value stability and various electronics over a long period of time. It can be used stably as a component to switch the function of the device and has excellent electrical characteristics.

According to the conductive ink which concerns on this invention, the epoxy resin of the number average molecular weights (Mn) is 10,000-300,000, the hydroxyl value is 2-300 (mgKOH / g), and with respect to 100 weight part of the epoxy resins, Highly detailed pattern printing can be performed by containing 0.2-20 weight part of metal chelates, and making storage elastic modulus G 'into the range of 5,000-50,000 (Pa). This is because by using the storage elastic modulus G 'in the above range, it is possible to suppress the spread of the ink after passing through the screen printing plate and transitioning to the substrate while using small conductive particles. As a result of intensive studies by the present inventors, it was found that by using the specific epoxy resin and using the metal chelate of the compounding ratio, the storage elastic modulus (G ′) in the specific range can be easily adjusted.

(Example)

Hereinafter, the present invention will be described in detail with reference to examples. In addition, in an Example, "part" and "%" mean "weight part" and "weight%", respectively, and a hydroxyl value means KOHmg / g, respectively.

(Binder 1)

Japan Epoxy Resin Co., Ltd. make 40 parts of JER1256 (weight average molecular weight 57,400, number average molecular weight 25,000, epoxy equivalent 7,500, hydroxyl value 190) dissolve in 60 parts of isophorone, binder 40% nonvolatile content (1) ) Solution.

(Binder 2)

40 parts of JEP4250 (weight average molecular weight 57,600, number average molecular weight 24,000, epoxy equivalent 8,500, hydroxyl value 180) made in Japan Epoxy Resin Co., Ltd. was dissolved in 60 parts of isophorone, and a binder having a nonvolatile content of 40% (2 ) Solution.

(Binder 3)

Japan Epoxy Resin Co., Ltd. make 40 parts of JER1009 (weight average molecular weight 27,700, number average molecular weight 5,200, epoxy equivalent 2,500, hydroxyl value 220) in 60 parts of isophorone, binder 40% non-volatile content (3 ) Solution.

(Binder 4) Synthesis of Epoxy Resin

100 parts of bisphenol A liquid epoxy resin of the number average molecular weight 380, epoxy equivalent 190, 59.1 parts of bisphenol A of the hydroxyl equivalent 114 (epoxy group / hydroxyl molar ratio 1.015), to a reaction apparatus provided with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube. 106 parts of diethylene glycol monoethyl ether acetate were added. After heating to 100 degreeC under nitrogen stream and melt | dissolving and homogenizing, 0.9 part of 50 weight% tetramethylammonium chloride aqueous solution was added as a catalyst, the temperature was raised to 160 degreeC, and the polymerization reaction was performed at 160 degreeC for 7 hours. Further, 132 parts of isophorone were added to obtain a binder (4) solution having a nonvolatile content of 40%.

The obtained epoxy resin had a weight average molecular weight of 145,000, a number average molecular weight of 54,000, an epoxy equivalent of 16,500 and a hydroxyl value of 194 per solid content.

(Binder 5) Synthesis of Epoxy Resin

100 parts of bisphenol A liquid epoxy resin of the number average molecular weight 380, epoxy equivalent 190, 57.6 parts of bisphenol A of the hydroxyl equivalent 114 (epoxy group / hydroxyl group molar ratio 1.041), 105 parts of diethylene glycol monoethyl ether acetate were added thereto. After dissolving and homogenizing by heating at 100 degreeC under nitrogen stream, 0.7 part of 50 weight% tetramethylammonium chloride aqueous solution was added as a catalyst, the temperature was raised to 160 degreeC, and the polymerization reaction was performed at 160 degreeC for 7 hours. Furthermore, 131 parts of isophorone were added and the binder (5) solution of 40% of non volatile matters was obtained.

In addition, the obtained epoxy resin had a weight average molecular weight of 51,600, a number average molecular weight of 17,000, an epoxy equivalent of 6,900, and a hydroxyl value of 185 per solid content.

(Binder 6) Synthesis of Epoxy Resin

100 parts of bisphenol A liquid epoxy resin of the number average molecular weight 380, epoxy equivalent 190, and 57.4 parts of bisphenol A of the hydroxyl equivalent 114 (epoxy / hydroxyl molar ratio 1.045), to a reaction apparatus provided with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, 128 parts of diethylene glycol monoethyl ether acetates were added. After heating to 100 degreeC under nitrogen stream and melt | dissolving and homogenizing, 0.4 part of tripropylamines were added as a catalyst, and the polymerization reaction was performed at 160 degreeC for 7 hours. Furthermore, after lowering the temperature in the reaction system to 70 ° C, 35 parts of phenyl isocyanate and 0.04 part of dibutyltin dilaurate were added, and the mixture was allowed to react for 6 hours after the temperature was raised to 100 ° C. Furthermore, 161 parts of isophorone were added and the binder (6) solution of 40% of non volatile matter was obtained.

In addition, the obtained epoxy resin had a weight average molecular weight of 60,500, a number average molecular weight of 27,000, an epoxy equivalent of 8,800, and a hydroxyl value of 92 per solid content.

(Binder 7) Synthesis of Polyester Resin

20.3 parts of dimethyl terephthalate, 20.3 parts of dimethyl isophthalate, 12.9 parts of ethylene glycol, 18.2 parts of neopentyl glycol, and tetrabutyl titer in a reactor equipped with a stirrer, a thermometer, a rectifying pipe, a nitrogen gas inlet tube, and a decompression device. 0.03 parts of nate was added, and the mixture was gradually heated to 180 ° C while stirring under a nitrogen stream, and transesterified at 180 ° C for 3 hours. Subsequently, 28.3 parts of sebacic acid were put, it heated gradually to 180-240 degreeC, and esterification was performed. The reaction was carried out at 240 ° C. for 2 hours, the acid value was measured, and when the temperature became 15 or less, the reaction can was gradually reduced to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out, and the weight average molecular weight was 52,900 and water. The polyester resin whose average molecular weight is 23,000, the hydroxyl value is 5, and the acid value is 1 was obtained. 40 parts of polyester resins were melt | dissolved in 60 parts of isophorone, and the binder (7) solution of 40% of non volatile matters was obtained.

(Binder 8) Synthesis of Polyurethane Resin

Polyester polyol obtained from isophthalic acid and 3-methyl-1,5-pentanediol in the reaction apparatus provided with the stirrer, the thermometer, the reflux cooling tube, and the nitrogen gas introduction tube (Kurare Polyol P-made by Kuraray Co., Ltd.). 2030 ", Mn = 2033) 127.4 parts, dimethylol butanoic acid 4.2 parts, 19.2 parts of isophorone diisocyanate, and 32.5 parts of diethylene glycol monoethyl ether acetate were made to react at 90 degreeC under nitrogen stream for 3 hours, and then diethylene glycol 115 parts of monoethyl ether acetate were added and the solution of the polyurethane resin whose weight average molecular weight is 48,600, the number average molecular weight is 18,000, the hydroxyl value is 4, and the acid value is 10 was obtained. 26 parts of isophorone were added to 100 parts of polyurethane resin solutions, and the binder (8) solution of 40% of non volatile matters was obtained.

In addition, the weight average molecular weight, number average molecular weight, epoxy equivalent, acid value, and hydroxyl value of binder (1)-(8) were calculated | required according to the following method.

<Measurement of weight average molecular weight and number average molecular weight>

Device: GPC (gel permeation chromatography)

A model: Shodex GPC-101 by Showa Denko Corporation

Column: Showa Denko Corporation GPC KF-G + KF805L + KF803L + KF8 02

Detector: Differential refractive index detector Showa Denko Corporation Shodex RI-71

Eluent: THF

Flow rate: sample side: 1 mL / min, reference side: 0.5 mL / min

Temperature: 40 ° C

Sample: 0.2% THF solution (100 μL injection)

Calibration curve: The calibration curve was created using 12 points of standard polystyrenes of the following molecular weight by Toso Corporation.

F128 (1.09 × 10 ⁶ ), F80 (7.06 × 10 ⁵ ), F40 (4.27 × 10 ⁵ ), F20 (1.90 × 10 ⁵ ), F10 (9.64 × 10 ⁴ ), F4 (3.79 × 10 ⁴ ), F2 ( 1.81 × 10 ⁴ ), F1 (1.02 × 10 ⁴ ), A5000 (5.97 × 10 ³ ), A2500 (2.63 × 10 ³ ), A1000 (1.05 × 10 ³ ), A500 (5.0 × 10 ² ).

Base line: Except for the binder 3, since the peak was not detected in the residence time of 25 minutes (molecular weight 3, 150) from the first ascending point of the first peak of a GPC curve, this was made into the end point. And the molecular weight was computed using the line which connected both points as a base line.

The main peak of the binder 3 was still detected at the residence time of 25 minutes. Thus, the baseline was set in the same manner as in the case of other binders, with the residence time 30 minutes (molecular weight 250) of which a plurality of small peaks continuous on the low molecular weight side of the main peak was hardly detected. Saved.

<Measurement of epoxy equivalent>

It measured in accordance with JIS K 7236.

<Measurement of hydroxyl value, acid value>

It measured in accordance with JIS K 0070.

[Silver powder A]

Spherical silver powder manufactured by DOWA Electronics Co., Ltd. (tap density of 5.5 g / cm 3, D50 particle size of 0.9 μm, specific surface area of 0.93 m 2 / g) was used as silver powder A.

[Silver powder B]

The spherical silver powder manufactured by DOWA Electronics Co., Ltd. (tap density 4.0 g / cm <3>, D50 particle diameter 0.5 micrometer, specific surface area 1.77 m <2> / g) was made into silver powder B.

[Silver powder C]

Spherical silver powder manufactured by METALOR (Tap density 2.2 g / cm 3, D50 particle size 0.8 μm, specific surface area 1.40 m 2 / g) was used as the silver powder C.

[Silver powder D]

Spherical silver powder manufactured by Mitsui Ginjoku Co., Ltd. (tap density of 4.5 g / cm 3, D50 particle diameter of 0.25 μm, specific surface area of 1.70 m 2 / g) was defined as silver powder D.

[Silver powder E]

The flake silver powder (tap density of 4.8 g / cm <3>, D50 particle diameter of 7.9 micrometers, specific surface area 0.95 m <2> / g) by Fukuda Kinzo Co., Ltd. was made into silver powder E.

[Silver powder F]

A spherical silver powder manufactured by Mitsui Kinzo Co., Ltd. (tap density 0.9 g / cm 3, D50 particle diameter 5.1 μm, specific surface area 1.91 m 2 / g) was used as the silver powder F.

[Silver powder G]

 Metallic flake silver powder (tap density 6.1g / cm <3>, D50 particle diameter 15.3micrometer, specific surface area 0.09m <2> / g) was made into silver powder G.

[Silver powder H]

The flake silver powder (Tap density 2.9g / cm <3>, D50 particle diameter 5.2micrometer, specific surface area 5.60m <2> / g) by SINO-PLATINUM was made into silver powder H.

<Measurement of Tap Density, D50 Particle Size, and BET Specific Surface Area of Silver Powder>

1) D50 particle size

The cumulative particle size (D50) of the volume particle size distribution was measured using a laser diffraction particle size distribution measuring apparatus "SALAD-3000" manufactured by Shimadzu Corporation.

2) tap density

It measured based on JISZ2512: 2006 method.

3) BET specific surface area

The value calculated by the following formula was defined and described with the specific surface area from the surface area measured using the Shimadzu Corporation Corporation flow type specific surface area measuring apparatus "Flowsorb II".

Specific surface area (㎡ / g) = surface area (㎡) / powder mass (g)

[Metal Chelate A]

Kawaken Fine Chemicals ALCH (General formula (1), 90% of solid content) was made into metal chelate A as aluminum chelate.

General formula (1)

[Metal Chelate B]

As a titanium chelate, Orgastics TC-100 (titanium acetylacetonate, 75% solids) manufactured by Matsumoto Fine Chemical Co., Ltd. was used as the metal chelate B.

[Metal Chelate C]

As a zirconium chelate, Orgastics ZC-540 (zirconium tributoxy monoacetylacetonate, 45% of solid content) by Matsumoto Fine Chemical Co., Ltd. was made into metal chelate C.

[Hardener 1]

Block type hexamethylene diisocyanate hardening | curing agent and Duranate MF-K60X (Asahi Kasei Chemicals make, 60% of solid content) were used as the hardening | curing agent (1).

[Hardener 2]

The imidazole hardening | curing agent and Cureduct P-0505 (made by Shikoku Chemical Co., Ltd., solid content 100%) was used as the hardening | curing agent (2).

Example 1 <Preparation of Conductive Ink>

Binder (1) solution containing 40 parts by weight of epoxy resin: 100 parts by weight of a metal chelate A containing 0.91 parts by weight of aluminum ethyl acetoacetate diisopropionate: 0.9 parts by weight, silver powder A: 330 parts by weight, Ethylene glycol monoethyl ether acetate: 40 parts by weight were mixed with a disper, followed by dispersion with 3 rolls to prepare a conductive ink.

The obtained conductive ink is about 79 weight% of solid content, silver content is about 89 weight% and epoxy weight is 11 weight% in 370 weight part of total of an epoxy resin and silver powder.

And using a Rheometer "AR-G2" manufactured by T. Instruments Inc., the temperature was fixed at a frequency of 1 Hz at a temperature of 25 ° C., and the storage modulus was in the range of 1.0 to 100,000 Pa of vibration stress. As a result of measuring dynamic viscoelastic properties such as (G '), the storage elastic modulus (G') of the conductive ink of Example 1 was 7,200, and tan δ was 0.89.

Examples 2-9, Comparative Examples 1-9 <Preparation of conductive ink>

The silver powder, the binder resin solution, the metal chelate, the hardening | curing agent, and the solvent were mixed with the disper at the compounding ratio shown in Table 1, 2, and it disperse | distributed with 3 rolls, and it carried out similarly to Example 1, and prepared the conductive ink. The characteristic of the obtained electroconductive ink was measured by the following method.

[Creation of Test Piece]

The conductive inks of Examples 1 to 12 and Comparative Examples 1 to 9 were screen-printed in a pattern shape of 15 mm x 30 mm on a corona-treated polyethylene terephthalate film (hereinafter referred to as PET) having a thickness of 75 µm, and then It dried for 30 minutes and obtained the electroconductive printed matter of 8-10 micrometers in film thickness.

<Measurement of film thickness>

The film thickness of the said printed matter was measured using the Sendai Nikon MH-15M type measuring instrument.

<Measurement of Surface Resistance>

The surface resistance value of the said printed matter was measured using the Mitsubishi Kagaku Corporation Loresta APMCP-T400 measuring instrument in 25 degreeC and 50% humidity environment.

<Calculation of Volume Resistivity>

The volume resistivity was computed from the surface resistance value and film thickness measured by the said method. The target value of the volume resistivity is 5.0 × 10 ⁻⁵ Ω · cm or less. In addition, although 5.0 * 10 <^-5> ohm exceeding 8.0 * 10 <^-5> ohm * cm or less is practical once, when it exceeds 8.0x10 < ^-5 >, it is not practical.

Volume resistivity (Ω? Cm) = (surface resistivity: Ω / □) × (film thickness: cm)

<Adhesion to ITO Laminated Film>

A part of ITO laminated film (Nitato Denko KK make, V270L-TEMP, 75 micrometer thickness) was etched with hydrochloric acid, the ITO layer was removed, and the base material (polyethylene terephthalate film) was prepared. In addition, each conductive ink of Examples 1-9 and Comparative Examples 1-9 was screened on the ITO laminated part and the part exposed to the base material, and the pattern of 15 mm x 30 mm so that the film thickness after drying might be 8-10 micrometers. It printed and dried for 30 minutes in 150 degreeC oven, and evaluated the adhesiveness of this printed matter. Evaluation methods and evaluation criteria are as follows.

<Tape adhesion test>: In accordance with JIS K5600, the tape adhesion test was performed.

Into the conductive ink layer on each of the ITO remaining portions and the ITO etching portions, 100 grids of 10 squares × 10 squares were carved with a cutter at intervals of 1 m in width, and Nichiban Kasei Co., Ltd. cellophane tape (25 mm width) was applied to the printed surface. It peeled rapidly and evaluated in the remaining grid state.

○: no peeling (adhesive good level)

(Triangle | delta): A grid edge falls slightly (it is a bad adhesion, but is practically usable level)

X: Peeling of one grid or more is observed (adhesive defect level)

<Adhesiveness to Polyimide Film>

Film thickness after drying each conductive ink of Examples 1-9 and Comparative Examples 1-9 on a polyimide film (Toray DuPont Co., Ltd. make, Kapton 100H, 25 micrometers in thickness). The pattern of 15 mm x 30 mm was screen-printed so that it might become micrometer. Then, it dried in 180 degreeC oven for 30 minutes, and evaluated the adhesiveness of this printed matter. Evaluation methods and evaluation criteria are as follows.

Nichiban Co., Ltd. cellophane tape (25 mm width) was affixed on the printed matter surface, and it peeled rapidly, and evaluated the adhesiveness of the printed matter.

 (Circle): There is no peeling and adhesiveness is favorable.

 (Triangle | delta): There exists a little peeling and adhesiveness is inferior.

 X: There exists whole surface peeling, and adhesiveness is bad.

[Evaluation of Fine Line Printability]

Using the high-precision screen printing apparatus (SERIA manufactured by Tokai Seiki Co., Ltd.), the conductive inks of Examples 1 to 9 and Comparative Examples 1 to 9 were lined with a line width of 40 µm and a line width in an area of 200 mm x 200 mm. In a screen plate having a large number of fine wiring patterns of 60 μm (L / S = 40 μm / 60 μm), 20 sheets were continuously printed on a 75 μm thick corona treated PET. Then, it dried at 150 degreeC for 30 minutes. The conditions of printing are as follows.

(Screen printing conditions)

? Screen: stainless steel plate 650 mesh

? Emulsion Thickness: 10㎛

? Screen edging: 650 × 550mm

? Squeegee angle: 70 °

? Squeegee Adduct Angle: 50 °

? Squeegee Hardness: 80 °

? Squeegee Speed: 20mm / sec

? Squeegee pressure: 10 kg

? Clearance: 3.5mm

(Evaluation of nonuniformity of line width)

The fine wiring part of the screen-printed wiring pattern was image | photographed by the magnification of 500 times using the digital microscope (VHX-900 by Keyence Co., Ltd.). The thin line width after printing was read using the small-scale general-purpose image analyzer "LUZEX AP" made by Nireko Corporation.

Specifically, for each of the fifth and twentieth printed matters, eight arbitrary thin lines are selected, and 3,680 lines are measured at 460 points and eight points in total, and the minimum, maximum, average, The standard deviation and the thickness "(average value-40 micrometers) / 40 micrometer (%)" of the thickness of the thin wire were calculated | required.

The average value, standard deviation, and the thickness of the thin line are shown in Tables 1 and 2.

In addition, a standard deviation shows the linearity (the unevenness | corrugation of a thin wire | line) of a thin wire | line.

In addition, the evaluation criteria of the thickness "(average value-40 micrometers) / 40 micrometer (%)" of the thickness of a thin wire are as follows.

Less than 25%: The thickness of the line width is hardly recognized, and the fine line printability is good.

25-40%: Although the thickness of the line width is slightly recognized, the thin line printability is practically practical.

More than 40%: The thickness of the line width is recognized, and the fine line printability is poor.

In addition, the shape of the fine wiring part of a printed wiring pattern was evaluated based on the following reference | standard. The results are shown in Tables 1 and 2.

(Circle): As for the micro-wiring part, the nonuniformity, bleeding, and blur of the thickness by meandering did not generate | occur | produce, and the boundary line of the micro-wiring part was clear and favorable.

(Triangle | delta): Although the fine wiring part showed the thickness nonuniformity by meandering to some extent, bleeding and blurring did not generate | occur | produce, and it was a level which is satisfactory practically.

X: As for the micro-wiring part, the nonuniformity of the thickness by meandering was seen, there were bleeding and blurring, and the boundary line was obscure.

[Resistance Stability Evaluation]

The movable electrode substrate which consists of a transparent conductive film, and the fixed electrode substrate which consists of a glass electrode substrate were bonded together by the double-sided adhesive layer by double-sided tape, and the resistive-type touchscreen panel of the structure shown in FIG. 1 and FIG. 2 mentioned above was produced.

Printing is performed by screen printing on the substrate from which the ITO transparent electrode film | membrane part and ITO were removed by etching using the drive electrode, the processing circuit, and the connection electrode of FIG. It carried out and dried at 135 degreeC for 30 minutes.

Next, on the said drive electrode and a processing circuit, the polyurethane resin type insulation resist (Toyo Inking Co., Ltd. make, Rio resist NSP-11) was printed by screen printing, and it dried at 120 degreeC for 30 minutes. The completed upper and lower electrode substrates were bonded together with a double-sided tape to produce a resistive touch screen panel. In addition, in order to make the terminal of the extraction circuit terminal A and B, the insulating resist layer was not formed (not shown).

About the obtained resistive touch screen panel, the resistance value between terminals between the terminal A of FIG. 2 and the terminal B was measured in 25 degreeC and 50% of humidity environment. Subsequently, the terminal-to-terminal resistance value after storing for 240 hours in 60 degreeC and 90% environment was measured in 25 degreeC and 50% humidity environment, and the following reference | standard evaluated in the rate of increase of the terminal-to-terminal resistance value after an environmental storage test. The results are shown in Tables 1 and 2. In addition, the resistance value between terminals was measured using the Sanwadenki Keiki Co., Ltd. PC500 type tester.

(Circle): The increase rate of the resistance value between terminals after an environmental preservation test is 0 to 10%.

(Triangle | delta): The increase rate of the resistance value between terminals after an environmental preservation test is 10 to 20%.

X: The rate of increase of the resistance between terminals after the environmental preservation test exceeded 20%

The increase rate of the resistance value between terminals after environmental preservation test is 20% or less, and is a level which is satisfactory practically in the touch screen panel of a standard specification.

As is apparent from Table 1, the conductive inks of Examples 1 to 12 exhibit good (volume resistivity, thin line printability, adhesion to ITO laminated film).

In Example 10 in which the curing agent (1) was added, the adhesion to the polyimide film is improved. Moreover, when used for a touch screen panel, even if it exposes in a high temperature, high humidity environment, it is favorable because there is little increase of the resistance between terminals.

On the other hand, Example 11 which added the hardening | curing agent 2 and Example 12 which added the hardening | curing agent 3 are equivalent in the case of not adding a hardening | curing agent, but are excellent in the fine line printability. In addition, when used for a touch screen panel, it is excellent in the point that the resistance of a terminal raises little, even if it is exposed to high temperature, high humidity environment.

On the other hand, as shown in Table 2, in Comparative Example 1, since the binder resin was a polyester resin, the resistance between terminals of the touch panel increased at 60 ° C., 90%, and 240 hours, resulting in poor resistance stability.

In addition, in Comparative Example 2, since the binder resin was a urethane resin, resistance stability was poor.

In Comparative Example 3, although the binder resin is an epoxy resin, resistance stability is poor because the number average molecular weight is less than 10,000, and since the elastic component of the conductive ink is small, fine wire printability is also poor.

Further, in Comparative Example 3 using an epoxy resin having a hydroxyl value of 220 (mgKOH / g) and a number average molecular weight of 5,200, the storage modulus (G ') was 3,500 even when a metal chelate was used, resulting in a sufficient storage modulus (G'). Couldn't get it. Moreover, in the comparative example 9 which does not add a metal chelate, storage elastic modulus (G ') was remarkably low as 1,100. In Comparative Example 9, high-definition printing could not be obtained.

In Comparative Example 4, the D50 particle diameter of the used silver powder was less than 0.3 µm, the volume resistivity of the ink coating film was high, and the level was unusable.

On the other hand, in the comparative example 5, since the D50 particle diameter of the used silver powder exceeded 5 micrometers, and the fine line was grayed out at the time of printing 20 sheets by thin line printability, the line width was not able to be measured. When the mesh portion of the screen printing plate after printing was observed, a state where silver was filled to the mesh was observed in many places. It is considered to be a problem due to the larger D50 particle size of silver powder.

In the comparative example 6, the tap density of the silver powder used was less than 1.0 g / cm <3>, and the volume resistivity of the ink coating film was high and it was the level which cannot be used.

In the comparative example 7, the specific surface area of the silver powder used was less than 0.3 m <2> / g, and the volume resistivity of the ink coating film was high, and it was the level which cannot be used. In addition, since the D50 particle diameter of the silver powder used exceeded 5 micrometers and 20 sheets were printed by thin-line printability similarly to the comparative example 5, since the thin line was grayed out by the clogging of the mesh, line width was measured. Could not.

Since the specific surface area of the used silver powder exceeded 5.0 m <2> / g, and many binder resins were needed in order to coat | cover the surface of electroconductive particle, the comparative example 8 was inferior to adhesiveness with respect to an ITO etching film and a polyimide film. .

In Comparative Example 9, the metal chelate was not used, the elastic component of the conductive ink was small, and it was difficult to maintain the shape after the ink had transferred to the substrate, and the lines were easily "thick".

About Example 3 and the comparative example 9, viscosity was measured and thixotropy was further evaluated.

Here, in Example 3 and Comparative Example 9, only the point of using a binder (1) solution and silver powder C and containing only a metal chelate is different.

(Viscosity measurement method)

Measuring instrument: E type viscometer TVE-22H made by Togyo Sangyo Co., Ltd.

Rotor: Cone Rotor ＃ 7 (θ3 °, R7.7mm)

Measuring temperature: 25 ℃

Sample volume: 0.1 mL

RPM: 2rpm, 5rpm, 20rpm

Measurement method: 0.1 mL of silver paste samples are measured using a 1 mL silage and set in a viscometer. After standing for 1 minute, the viscosity after stirring for 2 minutes at 2 rpm is measured. Then, the viscosity after stirring for 2 minutes at 5 rpm and 20 rpm is measured, respectively.

The TI value is calculated by the following equation.

TI = (viscosity of 2 rpm) / (viscosity of 20 rpm)

For Example 3 containing a metal chelate, 2 rpm: 150 Pas, 5 rpm: 95 Pas, 20 rpm: 56 Pas, and a TI value of 2.68.

On the other hand, in the comparative example 9 which does not contain a metal chelate, it was 2 rpm: 168 Pas, 5 rpm: 92 Pas, 20 rpm: 46 Pas, and was TI value: 3.66.

In other words, there is not much difference in both in terms of viscosity and thixotropy. However, the storage elastic modulus G 'of Example 3 is 6,100, and the storage elastic modulus G' of Comparative Example 9 is 1,100, which shows completely different results in printability.

The conductive ink according to the present invention is particularly suitable for screen printing, but may be applied to other printing methods.

The conductive ink according to the present invention may be applied not only to printing applications but also to conductive adhesive applications, electromagnetic shielding materials and the like.

Moreover, since the laminated body which has a conductive pattern formed using the conductive ink which concerns on this invention has little electroconductive change in high humidity, it can be used suitably for the formation of the conductive circuit for printed wiring boards, an electronic device, etc.

This application is filed in Japanese Patent Application No. 2010-23964, filed February 5, 2010, Japanese Patent Application No. 2010-103992, filed April 28, 2010, and Japanese Application No. 2010- filed May 6, 2010. 106202, claims priority based on Japanese Patent Application No. 2010-276401, filed December 10, 2010, the entire disclosure of which is hereby incorporated by reference.

1: lower substrate
2: upper substrate
3: conductive ink pattern layer
4: insulation layer
5: adhesive material (bonding)
6: transparent electrode of lower substrate
7: transparent electrode of upper substrate
8: dot spacer
9, 10: upper side driving electrode
11, 12: upper connection electrode
13, 14: lower side driving electrode
15, 16: lower connection electrode
17: processing circuit

Claims (21)

Electroconductive particle whose tap density is 1.0-10.0 (g / cm <3>), D50 particle diameter is 0.3-5 micrometers, BET specific surface area 0.3-5.0 m <2> / g,
An epoxy resin having a number average molecular weight (Mn) of 10,000 to 300,000 and a hydroxyl value of 2 to 300 (mgKOH / g);
An alcohol exchange reaction with the hydroxyl group in the said epoxy resin is possible, and contains 0.2-20 weight part of metal chelates with respect to 100 weight part of said epoxy resins,
Storage modulus (G ') is 5,000 to 50,000 (Pa),
The conductive ink, wherein the metal chelate is any one of aluminum chelate, titanium chelate and zirconium chelate. The method of claim 1,
The said electroconductive particle is silver, The electroconductive ink characterized by the above-mentioned. The method of claim 1,
The electroconductive ink whose said epoxy resin is a bisphenol-type epoxy resin. The method of claim 1,
The conductive ink whose number average molecular weight (Mn) of the said epoxy resin is 15,000-100,000. The method of claim 1,
The electroconductive ink whose number average molecular weight (Mn) of the said epoxy resin is 20,000-100,000, and the said hydroxyl value is 50-250 (mgKOH / g). The method of claim 1,
The electroconductive ink whose tap density of the said electroconductive particle is 2.0-10.0 (g / cm <3>). The method of claim 1,
The said metal chelate contains 2-10 weight part with respect to 100 weight part of said epoxy resins. The method of claim 1,
A conductive ink having a storage modulus (G ') of 5,000 to 20,000 (Pa). The method of claim 1,
The electroconductive ink which further contains the hardening | curing agent which has a functional group which can react with the hydroxyl group or epoxy group which the said epoxy resin has. The method of claim 1,
It is for screen printing, The conductive ink characterized by the above-mentioned. The method of claim 1,
And the metal chelate is aluminum chelate. 10. The method of claim 9,
Conductive ink containing 0.5 weight part-50 weight part of said hardening | curing agents with respect to 100 weight part of said epoxy resins. 10. The method of claim 9,
A conductive ink, wherein the curing agent is at least one selected from the group consisting of isocyanate compounds, amine compounds, acid anhydride compounds, mercapto compounds, imidazole compounds, dicyandiamide compounds, and organic acid hydrazide compounds. The method of claim 11,
And said aluminum chelate has a group selected from the group consisting of an acetylacetonate group, a methyl acetoacetate group and an ethyl acetoacetate group. Materials and
And a conductive pattern formed on the substrate,
The laminated body which has a conductive pattern in which the said conductive pattern is formed of the electroconductive ink in any one of Claims 1-14. 16. The method of claim 15,
The laminated body which has a conductive pattern which further includes the insulating layer laminated | stacked so that the said conductive pattern may be covered. 16. The method of claim 15,
The laminated body which has a conductive pattern in which the other conductive film which has a predetermined pattern electrically connected with the said conductive pattern on the lower layer side of the said conductive pattern is further formed on the said base material. 16. The method of claim 15,
The said other conductive film is a laminated body which has a conductive pattern which is a transparent conductive film which has the indium oxide doped with tin as a main component. 16. The method of claim 15,
A laminate having a conductive pattern used for touch screen panel applications. Providing a conductive pattern of a desired pattern shape on the substrate by screen printing;
The said conductive pattern uses the electroconductive ink in any one of Claims 1-14, The manufacturing method of the laminated body which has a conductive pattern. Forming a transparent conductive film having a predetermined pattern on the substrate so as to be partially exposed,
Forming a conductive pattern of a desired shape by screen printing on the substrate and the transparent conductive film using the conductive ink according to any one of claims 1 to 14,
A step of forming an insulating layer on the base material, the transparent conductive film, and the conductive pattern,
The said transparent conductive film is a manufacturing method of the laminated body which has a conductive pattern which is a film which has the indium oxide doped with tin as a main component.

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