JP2015181160A - Conducting pattern forming method, and conductive wiring line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a conducting pattern forming method by which a break of a conducting pattern accompanying volume contraction is suppressed when forming a thick conducting pattern of a low resistance value on a base material; and a conductive wiring line formed by the forming method.SOLUTION: A conducting pattern forming method for forming a conducting pattern 1 arranged by laminating a first pattern 11 and a second pattern 12 comprises the steps of: forming the first pattern 11 on a base material 2 by printing an ink composition for conductor formation on a base material 2, and solidifying the ink composition; and forming the second pattern 12 on the first pattern 11 by printing an ink composition for conductor formation on the first pattern 11, and solidifying the ink composition. In the conducting pattern forming method, the second pattern 12 is made thicker than the first pattern 11; and the percentage of the blend amount of volatile components removed from the ink compositions by vaporizing the ink compositions used for forming the first pattern 11 and the second pattern 12 in a condition for forming the second pattern 12 is 20 mass% or more to the total amount of blended components.

Description

  The present invention relates to a method for forming a conductive pattern, and a conductive wiring formed by the method.

  Various methods for forming a conductive pattern on a substrate by using a printing method have been studied. By applying this method to the formation of conductive wiring, a flexible, on-demand electronic device with low environmental impact Is expected to develop. Usually, the ink composition used in this case is a mixture of a metal or a material that forms the metal, and the metal is formed by heat treatment.

  On the other hand, in order to form a conductive wiring having a low resistance value, for example, it is effective to increase the thickness of the wiring. For example, in wiring with a 13.56 MHz RFID antenna or the like, it is required to make the wiring thick in order to cover the amount of current necessary for chip driving. From this point of view, it is important to form a thick conductive wiring on the substrate.

  On the other hand, as an ink composition that can be applied to a printing method and can form a conductor, for example, a conductive paste (see Patent Document 1) containing silver and other conductive particles and a binder as essential components, silver nano A silver ink composition containing particles (see Patent Document 2) and a silver ink composition (see Patent Document 3) containing silver β-ketocarboxylate are disclosed.

JP 2001-217639 A Special table 2010-500475 gazette JP 2012-046728 A

However, since the ink composition disclosed in Patent Document 1 contains a binder, there is a problem in that the resistance value cannot be lowered even if the conductive wiring is thickened.
In addition, the ink compositions disclosed in Patent Documents 2 and 3 do not require a binder, but instead contain a relatively large amount of a solvent component, and when thickly coated on a substrate, At the time of the heat treatment for forming the metal, there is a problem that the volume shrinks as the solvent is removed, and the resulting conductive wiring is disconnected.

  The present invention has been made in view of the above circumstances, and when forming a conductive pattern having a low resistance value and a large thickness on a substrate, formation of a conductive pattern in which disconnection of the conductive pattern due to volume shrinkage is suppressed. It is an object to provide a method and a conductive wiring formed by the forming method.

In order to solve the above problems, the present invention prints an ink composition for forming a conductor on a base material and solidifies it to form a first pattern on the base material, thereby forming a conductor. An ink composition for printing is further printed on the first pattern and solidified to form a second pattern on the first pattern, and the first pattern and the second pattern are laminated. In the method of forming a conductive pattern for forming a pattern, the second pattern is thicker than the first pattern, and the ink composition used for forming the first pattern and the second pattern is formed under the conditions for forming the second pattern. Provided is a method for forming a conductive pattern characterized in that the proportion of the volatile component blended and removed from the ink composition is 20% by mass or more based on the total amount of the blended component That.
In the method for forming a conductive pattern of the present invention, it is preferable that the ink composition is solidified by heat treatment in an atmosphere having a relative humidity of 40% or more when the second pattern is formed.
The present invention also provides a conductive wiring formed by the method for forming a conductive pattern.

  ADVANTAGE OF THE INVENTION According to this invention, when forming a conductive pattern with a low resistance value on a base material and a thick conductive pattern, the formation method of the conductive pattern by which the disconnection of the conductive pattern accompanying volume shrinkage is suppressed, and this formation method are formed. Conductive wiring is provided.

It is sectional drawing which illustrates typically the conductive pattern which concerns on this invention with a base material. It is sectional drawing for demonstrating typically the formation method of the conductive pattern which concerns on this invention. It is imaging data of a conductive pattern, (a) is each imaging data of the conductive pattern in Example 1, and (b) is each imaging data of the conductive pattern in Comparative Example 1. It is the imaging data by the scanning electron microscope (SEM) of the cross section of the conductive pattern in Example 1. FIG.

In the method for forming a conductive pattern according to the present invention, an ink composition for forming a conductor is printed on a substrate and solidified to form a first pattern on the substrate, thereby forming a conductor. An ink composition for printing is further printed on the first pattern and solidified to form a second pattern on the first pattern, and the first pattern and the second pattern are laminated. In the method of forming a conductive pattern for forming a pattern, the second pattern is thicker than the first pattern, and the ink composition used for forming the first pattern and the second pattern is formed under the conditions for forming the second pattern. The proportion of the volatile component blended and removed from the ink composition is 20% by mass or more based on the total amount of the blended components.
According to this manufacturing method, even if a thick conductive pattern is formed using an ink composition used for forming a conductive pattern with a high proportion of the volatile component, the volume accompanying removal of the volatile component The occurrence of disconnection due to the contraction of the conductive pattern is significantly suppressed in the conductive pattern. Moreover, a conductive pattern having a low resistance value can be formed by using an ink composition containing no binder.

<< Conductive pattern >>
FIG. 1 is a cross-sectional view schematically illustrating a conductive pattern formed by a method according to the present invention together with a substrate.
The conductive pattern 1 shown here is provided on the base material 2 via the receiving layer 3, and the first pattern 11 and the second pattern 12 are laminated in this order from the receiving layer 3 side. . That is, the base material 1 ′ with a conductive pattern shown here is obtained by laminating the receiving layer 3 and the conductive pattern 1 on the base material 2 in this order.

<Base material>
The base material 2 can select arbitrary shapes according to the objective, For example, it is preferable that it is a film form or a sheet form, it is preferable that thickness is 0.5-5000 micrometers, and it is 0.5-2500 micrometers. It is more preferable. When the thickness of the base material 2 is equal to or higher than the lower limit value, the structure of the receiving layer 3 can be more stably maintained. The handleability when forming the pattern 1 becomes better.

The material of the substrate 2 is not particularly limited and may be selected according to the purpose. However, a material having heat resistance that does not change when the conductive pattern 1 is formed by heat treatment of the ink composition described later is preferable.
Specifically, the material of the substrate 2 is polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polymethylpentene (PMP), polycycloolefin, polystyrene (PS). , Acrylic resin such as polyvinyl acetate (PVAc) and polymethyl methacrylate (PMMA), AS resin, ABS resin, polyamide (PA), polyimide, polyamideimide (PAI), polyacetal, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyphenylene sulfide (PPS), polysulfone (PSF), polyethersulfone (PES) , Polyether ketone (PEK), polyether ether ketone (PEEK), polycarbonate (PC), polyurethane, polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyarylate, epoxy resin, melamine resin, phenol resin, A synthetic resin such as urea resin can be exemplified.
Moreover, as a material of the base material 2, in addition to the above, ceramics such as glass and silicon, and paper can be exemplified.
The substrate 2 may be a combination of two or more materials such as glass epoxy resin and polymer alloy.

The substrate 2 may be composed of a single layer, or may be composed of two or more layers. When the base material 2 consists of multiple layers, these multiple layers may be the same as or different from each other. That is, all the layers may be the same, all the layers may be different, or only some of the layers may be different. And when several layers differ from each other, the combination of these several layers is not specifically limited. Here, the plurality of layers being different from each other means that at least one of the material and the thickness of each layer is different from each other.
In addition, when the base material 2 consists of multiple layers, it is good to make it the thickness of the total of each layer be the thickness of said preferable base material 2.

<Receptive layer>
The receiving layer 3 improves the adhesiveness between the conductive pattern 1 (first pattern 11) and the substrate 2. That is, the receiving layer 3 and the conductive pattern 1 (first pattern 11), and the receiving layer 3 and the base material 2 have high adhesion, respectively. Is prevented from peeling.
In addition, in the base material 1 ′ with a conductive pattern, the receiving layer 3 may not be provided.

The receiving layer 3 is preferably formed by curing various resins (base resins). In this case, the type of the resin may be appropriately selected according to the type of the substrate 2, and the photocurable resin and the thermosetting resin may be selected. Any of the functional resins may be used.
A preferable example of the receiving layer 3 is one formed using urethane (meth) acrylate, and a more preferable example is one formed using polycarbonate skeleton-containing urethane (meth) acrylate. Such a receiving layer 3 suppresses peeling of the conductive pattern 1 (first pattern 11) from the base material 2 (receiving layer 3) when the substrate 1 ′ with conductive pattern is placed under high temperature and high humidity conditions. High effect.
In this specification, “(meth) acrylate” is a concept including both “acrylate” and “methacrylate”.

  The polycarbonate skeleton-containing urethane (meth) acrylate is a base resin (prepolymer) and is not particularly limited, but preferably has a weight average molecular weight of 2000 to 20000, more preferably 2300 to 17000. When the weight average molecular weight is in such a range, the effect of suppressing peeling of the conductive pattern 1 when placed under a high temperature and high humidity condition becomes higher. In addition, in this specification, the weight average molecular weight of base resins, such as resin and polycarbonate frame | skeleton containing urethane (meth) acrylate, is calculated | required on the polystyrene conversion basis by GPC (gel permeation chromatography).

  The polycarbonate skeleton-containing urethane (meth) acrylate is preferably a cured film of which the pencil hardness according to JIS K 5600-5-4 is 2B or less, and more preferably 6B or less. .

The polycarbonate skeleton-containing urethane (meth) acrylate preferably has a viscosity of 20 Pa · s or less at 20 to 60 ° C., more preferably 10 Pa · s or less. When the viscosity is in such a range, when the composition for a receiving layer described later is prepared by mixing with a solvent, it is easy to stir and handleability becomes better.
In this specification, “viscosity” means a value measured using an ultrasonic vibration viscometer unless otherwise specified.

  The polycarbonate skeleton-containing urethane (meth) acrylate preferably has a glass transition point (Tg) of a cured film of -18 to 35 ° C, more preferably -15 to 30 ° C.

The polycarbonate skeleton-containing urethane (meth) acrylate preferably has a Young's modulus of a cured film of 1 to 300 N / mm ² , more preferably 3 to 250 N / mm ² .

  The polycarbonate skeleton-containing urethane (meth) acrylate preferably has a cured shrinkage of 2 to 7%, more preferably 3 to 6%, as a cured product.

The polycarbonate skeleton-containing urethane (meth) acrylate is preferably a cured product having a mechanical strength of ² to 50 N / mm ^2, and more preferably ³ to 45 N / mm ² .

  The polycarbonate skeleton-containing urethane (meth) acrylate is preferably a urethane acrylate having a polycarbonate skeleton (hereinafter sometimes referred to as “polycarbonate skeleton-containing urethane acrylate”).

  When the receiving layer 3 is formed by curing various resins (base resins), the content of the cured product is preferably 90% by mass or more, and more preferably 95% by mass or more. The effect by having provided the receiving layer 3 becomes higher because content of the said hardened | cured material is more than the said lower limit.

  The shape of the receiving layer 3 when the substrate 1 ′ with a conductive pattern is viewed in plan so that one main surface (the surface on which the receiving layer 3 is formed) 2a of the substrate 2 is looked down from above is Depending on the shape of the conductive pattern 1 to be described later, it may be set arbitrarily. For example, the receiving layer 3 may be provided on the entire surface of the base material 2, or the receiving layer 3 may be provided on only a part of the surface of the base material 2. May be patterned.

  The thickness of the receiving layer 3 is preferably 0.001 to 20 μm, and more preferably 0.002 to 5 μm. When the thickness of the receiving layer 3 is not less than the lower limit, the adhesion of the conductive pattern 1 is further improved, and when the thickness of the receiving layer 3 is not more than the upper limit, the structure of the receiving layer 3 is further improved. It can be held stably.

<Conductive pattern>
The conductive pattern 1 is formed by laminating a first pattern 11 and a second pattern 12 in this order, and the second pattern 12 may be provided on the entire surface 11 a of the first pattern 11. It may be provided only on a part of the surface 11a.

The second pattern 12 is thicker than the first pattern 11. That is, the thickness _{H 11} of the first pattern 11, the thickness _{H 12} of the second pattern _12, satisfy the relationship of H _{12> H 11.} If this condition is satisfied, the thickness H ₁₁ of the first pattern 11, the thickness H ₁₂ of the second pattern 12 is not particularly limited. However, for example, as shown below, it is preferable that the thickness (H ₁₁ + H ₁₂ ) of the conductive pattern 1 is thick.

The thickness _{H 11} of the first pattern 11 is preferably 16μm or less, more preferably at most 13 .mu.m, particularly preferably 10μm or less. By H ₁₁ is equal to or less than the upper limit, breakage inhibiting effect of the conductive pattern 1 becomes higher.
The thickness _{H 11} of the first pattern 11, is preferably 0.5μm or more, more preferably 1.0μm or more, and particularly preferably 1.5μm or more. By H ₁₁ is equal to or more than the lower limit, the conductive pattern 1 can be easily thicker.
The thickness _{H 12} is the second pattern 12, is preferably 100μm or less, more preferably at most 85 .mu.m, particularly preferably 75μm or less. By H ₁₂ is equal to or less than the upper limit, breakage inhibiting effect of the conductive pattern 1 becomes higher.
The thickness _{H 12} of the second pattern 12 is preferably 30μm or more, more preferably 40μm or more, and particularly preferably 45μm or more. By H ₁₂ is equal to or more than the lower limit, the conductive pattern 1 can be easily thicker.

The thickness of the above-mentioned conductive pattern 1 _{(H 11 +} H ₁₂₎ is an example of a preferred, the thickness of the conductive pattern 1 is not limited to these.
For example, the thickness _{H 11} of the first pattern 11 is preferably 7μm or less, more preferably 5μm or less, particularly preferably may be 3μm or less.
The thickness _{H 11} of the first pattern 11 is preferably 0.3μm or more, more preferably 0.5μm or more, particularly preferably may be 0.7μm or more.
The thickness _{H 12} of the second pattern 12 is preferably 30μm or less, more preferably 20μm or less, particularly preferably may be 10μm or less.
The thickness _{H 12} is the second pattern 12 is preferably 0.9μm or more, more preferably 1.2μm or more, and particularly preferably may be 1.5μm or more.

The shape of the conductive pattern 1 when the substrate 1 ′ with a conductive pattern is viewed in plan so that one main surface 2a of the substrate 2 is looked down from above can be arbitrarily set according to the purpose. The conductive pattern 1 may be provided on the entire surface 3a, or the conductive pattern 1 may be provided on only a part of the surface 3a of the receiving layer 3.
The conductive pattern 1 is useful as a conductive wiring, for example.

The material of the first pattern 11 and the second pattern 12 is not particularly limited as long as the pattern can be formed by a method described later and has conductivity, but is usually a metal or a metal as a main component. Those that do are preferred. Here, “having a metal as a main component” means that the ratio of metals is sufficiently high so that it can be regarded as consisting of only metals, and the metal in the first pattern 11 and the second pattern 12 The ratio is preferably 99% by mass or more. The upper limit of the ratio of the metal in the first pattern 11 and the second pattern 12 is, for example, 99.9% by mass, 99.8% by mass, 99.7% by mass, 99.6% by mass, 99.5% by mass. 99.4 mass%, 99.3 mass%, 99.2 mass%, and 99.1 mass%.
The first pattern 11 and the second pattern 12 may be made of the same material or different materials. For example, the conductive components such as metal species may be the same or different, but the conductive components are the same. It is preferable that the materials (components and their ratios) are the same.
And it is preferable that the said metal is silver or copper, and it is more preferable that it is silver.

Even if the conductive pattern 1 is thick (H ₁₁ + H ₁₂ ), disconnection is suppressed by forming the conductive pattern 1 by a method described later.
The conductive pattern 1 is excellent in conductivity. For example, when formed using a β-ketocarboxylate described later as a metal forming material, the volume resistivity is preferably 30 μΩ · cm or less, more preferably 25 μΩ · cm. cm or less, more preferably 20 μΩ · cm or less, and particularly preferably 17 μΩ · cm or less.

The base material 1 ′ with a conductive pattern is not limited to that shown in FIG. 1, and other configurations may be added, or some configurations may be appropriately changed. For example, another layer other than the receiving layer 3 and the conductive pattern 1 may be provided on the substrate 2, and the other layer may be an overcoat layer (not shown) that covers the receiving layer 3 and the conductive pattern 1. Can be illustrated.
Moreover, although what has provided the conductive pattern 1 through the receiving layer 3 on the one main surface 2a of the base material 2 as the base material 1 'with a conductive pattern is shown here, the base material 1' with the conductive pattern May be provided with the conductive pattern 1 on the other main surface 2b of the base material 2 in the same manner (on both main surfaces of the base material 2) via the receiving layer 3.

<< Method for Forming Conductive Pattern >>
A method for forming the conductive pattern 1 shown in FIG. 1 will be described below. FIG. 2 is a cross-sectional view for schematically explaining the method for forming a conductive pattern according to the present invention.
In the forming method according to the present invention, as shown in FIG. 2B, the first pattern 11 is formed on the substrate 2 (hereinafter, this step may be abbreviated as “first pattern forming step”). . Here, the first pattern 11 is illustrated as being provided on the substrate 2 via the receptor layer 3, and in this case, the receptor layer 3 is formed on the substrate 2 (hereinafter referred to as the first pattern 11). This step may be abbreviated as “receiving layer forming step”), and the first pattern 11 is formed on the receiving layer 3.

<Receptive layer forming step>
In this step, as shown in FIG. 2A, the receiving layer 3 is formed on the surface (one main surface) 2a of the substrate 2.
The receiving layer 3 is, for example, a composition comprising a resin (base resin), a polymerization initiator, and a solvent for forming the cured product (cured resin), which is a main component thereof (hereinafter referred to as “receiving layer use”). The composition may be abbreviated as “composition”, and may be deposited on the substrate 2 and the resin may be cured by means such as light irradiation or heating. At this time, other processes such as a drying process and a heating process may be performed as necessary, and the heating process may also serve as a drying process.

  The said polymerization initiator is not specifically limited, What is necessary is just to select suitably according to the kind of resin to be used.

  The solvent may be any solvent that does not inhibit the polymerization reaction, and may be appropriately selected from known solvents such as cyclohexanone, 1,2-dimethoxyethane (dimethyl cellosolve), propylene glycol monomethyl ether acetate, and the like.

  The resins, polymerization initiators and solvents may be used singly or in combination of two or more. When two or more are used in combination, their combination and ratio can be arbitrarily adjusted. .

In the composition for the receiving layer, the ratio of the amount of the resin to the total amount of the components is preferably 30 to 70% by mass, and more preferably 40 to 60% by mass.
In the composition for the receiving layer, the ratio of the amount of the polymerization initiator to the total amount of the compounding components is preferably 1 to 10% by mass, and more preferably 1 to 4% by mass.
In the composition for the receiving layer, the ratio of the amount of the solvent to the total amount of the components is preferably 15 to 65% by mass, and more preferably 25 to 60% by mass.

In addition to the resin, the polymerization initiator, and the solvent, the receiving layer composition may be blended with other components not corresponding to these.
The other components can be arbitrarily selected according to the purpose and are not particularly limited.
The other components in the composition for the receiving layer may be used singly or in combination of two or more. In the case of using two or more in combination, the combination and ratio thereof are arbitrary. Can be adjusted.
In the composition for the receiving layer, the ratio of the amount of the other components to the total amount of the components is preferably 10% by mass or less, and more preferably 5% by mass or less.

  The composition for receiving layer is obtained by mix | blending the said resin, a polymerization initiator, a solvent, and the said other component as needed. After the blending of each component, the obtained product may be used as it is as the composition for the receiving layer, or the product obtained by performing a known purification operation as necessary may be used as the composition for the receiving layer.

At the time of blending each component, all the components may be added and then mixed, or some components may be mixed while being added sequentially, or all components may be mixed while being added sequentially. Good.
The mixing method is not particularly limited, a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer, a three-roller, a kneader, a bead mill or the like; a method of mixing by adding ultrasonic waves, etc. What is necessary is just to select suitably from a well-known method.

  In the composition for the receiving layer, all the compounding components may be dissolved, or a part of the components may be dispersed without dissolving, but it is preferable that all the compounding components are dissolved, It is preferable that the components which are not dissolved are uniformly dispersed. In the case of uniformly dispersing the undissolved component, for example, it is preferable to apply a method of dispersing using the above-described three-roll, kneader or bead mill.

The temperature at the time of blending is not particularly limited as long as each blending component does not deteriorate, but it is preferably 40 to 60 ° C. And the temperature at the time of mixing | blending is good to adjust suitably so that the mixture obtained by mix | blending may become the viscosity which is easy to stir according to the kind and quantity of a mixing | blending component.
Further, the blending time is not particularly limited as long as each blending component does not deteriorate, but it is preferably 5 minutes to 12 hours, more preferably 1 to 6 hours, and further preferably 2 to 4 hours. .

The composition for receiving layer can be made to adhere on the base material 2 by well-known methods, such as a printing method, the apply | coating method, and the immersion method, for example.
Examples of the printing method include screen printing method, flexographic printing method, offset printing method, dip printing method, ink jet printing method, dispenser printing method, gravure printing method, gravure offset printing method, pad printing method, spray printing method and the like. Can be illustrated.
Examples of the coating method include spin coaters, air knife coaters, curtain coaters, die coaters, blade coaters, roll coaters, gate roll coaters, bar coaters, rod coaters, gravure coaters, and other methods such as wire bars. It can be illustrated.

In the receiving layer forming step, the thickness of the receiving layer 3 can be adjusted by adjusting the amount of the receiving layer composition to be deposited on the substrate 2 or the blending amount of the resin in the receiving layer composition.
For example, the thickness at the time of adhesion of the composition for receiving layer on the substrate 2 is preferably 0.1 to 1000 μm, more preferably 0.1 to 100 μm, and 1 to 10 μm. Is more preferable.

  The receptor layer composition may be dried and heated by any known method, for example, under normal pressure, reduced pressure, or blowing conditions, and may be performed in air or in an inert gas atmosphere. Any of these may be used. The treatment temperature is not particularly limited, and may be set as appropriate according to the purpose. For example, the drying treatment may be either a heat drying treatment or a room temperature drying treatment. In the case of a heat drying treatment, for example, the drying treatment can be preferably performed at 60 to 100 ° C. for 2 to 10 minutes.

In the receiving layer forming step, the substrate 2 may be heat-treated (annealed) before the receiving layer composition is attached. By subjecting the base material 2 to heat treatment, when the composition for receiving layer is heat-treated in this step, or when the ink composition is heat-treated (baked) at the time of forming a conductive pattern to be described later, Shrinkage of the material 2 is suppressed and dimensional stability is improved.
The conditions for the heat treatment of the base material 2 before adhering the composition for the receiving layer may be appropriately adjusted according to the type of the base material 2 and are not particularly limited, but are heated at 60 to 200 ° C. for 10 to 60 minutes. For example, when a silver ink composition to be described later is used, the conditions may be the same as those for the heating (firing) treatment.

Moreover, in this invention, you may plasma-treat the formation surface of the receiving layer 3 of the base material 2 before making the composition for receiving layers adhere. By subjecting the substrate 2 to plasma treatment, bleeding of the ink composition on the receiving layer 3 may be suppressed during the formation of a conductive pattern described later.
The plasma treatment may be performed by a known method. For example, in the case of atmospheric pressure plasma treatment, it can be performed under conditions of a voltage of 290 to 300 W, an air velocity of 1.0 to 5.0 m / min, and the like.

<First pattern formation process>
As shown in FIG. 2B, the first pattern 11 is formed by printing an ink composition for forming a conductor on the receiving layer 3 (the surface 3a of the receiving layer 3), and the printed ink composition. It is formed by solidifying. When the receiving layer 3 is not provided, the ink composition may be printed on the substrate 2 (surface 2a of the substrate 2) and solidified. In the present specification, “solidification of the ink composition” means to reduce or remove the volatile component from the ink composition unless otherwise specified. Depending on the conditions, the formation of a conductor may also occur. Shall be included.

The ink composition is for forming a conductor, is formed by blending a conductor forming material, and is vaporized under the formation conditions (conditions for forming a conductor) of the second pattern 12 described later. The proportion of the volatile component to be removed from the ink composition is 20% by mass or more, preferably 23% by mass or more, based on the total amount of the compounding components. Thus, in this step, an ink composition having a high proportion of volatile components is used.
The ink composition may be either a solution or a dispersion, but in the case of a dispersion, it is preferable that the non-dissolved material is uniformly dispersed.

  The volatile component is not particularly limited. For example, when a silver ink composition described later is used as the ink composition, examples of the volatile component include a nitrogen-containing compound, a reducing agent, alcohol, a solvent other than alcohol, and the like described later.

  The first pattern 11 formed in this step is thin as described above. That is, since the thickness of the printing layer of the ink composition is thin, even when this ink composition is solidified, the degree of volume shrinkage due to the removal of volatile components is small, and as a result, in the first pattern 11 formed as a result The occurrence of disconnection is suppressed.

  The printing method of the ink composition in this step is not particularly limited, and may be the same as in the case of the composition for the receiving layer. Screen printing method, flexographic printing method, offset printing method, dip printing method, inkjet printing method, Examples thereof include a dispenser printing method, a gravure printing method, a gravure offset printing method, a pad printing method, and a spray printing method.

  Although the printed ink composition is solidified, at least a part of the volatile component is removed in this process to form the first pattern 11. The solidification at this time may be performed up to the formation of the conductor, or may be limited to the drying of the ink composition without performing the formation of the conductor. Although the 1st pattern 11 functions also as a base for forming the 2nd pattern 12 mentioned below, the printed ink composition should just be dried to such an extent that such a foundation can be formed. This is because the conductor is always formed from the ink composition when the second pattern 12 described later is formed. At this time, the conductor is also formed in the first pattern 11 simultaneously with the second pattern 12. By doing so, the process can be simplified. Moreover, the solidification of the ink composition in this step is limited to the drying of the ink composition, so that the first pattern 11 formed in this step can be heated excessively for solidifying the ink composition, for example. Processing is suppressed, and as a result, occurrence of disconnection is suppressed to a higher degree. If the ink composition is solidified and only the ink composition is dried without performing the formation of the conductor, it means that no conductor is formed in the ink composition during the solidification process. It does not mean that the formation of a very small amount of a conductor that causes negligible changes in the properties of the ink composition accompanying the formation of the conductor during the solidification process is included.

  In this step, the ink composition is preferably solidified by heat treatment from the viewpoint of performing in a short time.

In this step, when the ink composition is heat-treated and only the ink composition is dried without performing the formation of the conductor, the temperature during the heat-treatment (heating temperature) is the ink composition. Although it should just adjust suitably according to the kind of compounding component, it is preferable that it is 50-110 degreeC, and it is more preferable that it is 70-90 degreeC. Moreover, what is necessary is just to adjust a heating time according to heating temperature, Usually, it is preferable that it is 0.2 to 12 hours, and it is more preferable that it is 0.4 to 5 hours. Such heat treatment conditions are particularly suitable when a silver ink composition described later is used as the ink composition.
Further, in this step, when the heat treatment of the ink composition is performed until the formation of the conductor, the temperature (heating temperature) at the time of the heat treatment is appropriately adjusted according to the type of the composition component of the ink composition. However, it is preferably 60 to 200 ° C, more preferably 70 to 180 ° C. Moreover, what is necessary is just to adjust heating time according to heating temperature, Usually, it is preferable that it is 0.2 to 12 hours, and it is more preferable that it is 0.4 to 10 hours. Such heat treatment conditions are particularly suitable when a silver ink composition described later is used as the ink composition.

  When the ink composition is attached to a substrate having low heat resistance and subjected to heating (firing) treatment, in this step, the heating temperature is preferably less than 130 ° C, more preferably 125 ° C or less, It is particularly preferable that the temperature be 120 ° C. or lower.

  The method for heat treatment of the ink composition in this step is not particularly limited, and for example, heating by an electric furnace, heating by a thermal head, heating by far infrared irradiation, or the like can be performed. Moreover, the heat treatment of the silver ink composition may be performed in the air, in an inert gas atmosphere, or may be performed under normal pressure or reduced pressure.

  In this step, the thickness of the first pattern 11 can be adjusted by adjusting the amount of the ink composition deposited on the receiving layer 3 or the blending amount of the conductor-forming component in the ink composition.

In the present invention, it is preferable to use a metal ink composition containing a metal or a metal forming material as the ink composition.
The metal or metal forming material to be blended may be only one kind, or two or more kinds, and in the case of two or more kinds, the combination and ratio can be arbitrarily adjusted.

The metal to be blended is preferably in the form of particles or fibers (tube shape, wire shape, etc.), and more preferably nanoparticles or nanowires. And it is preferable that the metal mix | blended is silver or copper.
In the present specification, “nanoparticle” means a particle having a particle size of 1 nm or more and less than 1000 nm, preferably 1 to 100 nm, and “nanowire” means a width of 1 nm or more and less than 1000 nm, preferably It means a wire that is 1 to 100 nm.

The metal forming material to be blended may be any material having a corresponding metal atom (element) and capable of generating a metal by structural change such as decomposition, metal salt, metal complex, organometallic compound (metal-carbon bond). Compound) and the like. The metal salt and the metal complex may be any of a metal compound having an organic group and a metal compound having no organic group. Among these, the metal forming material is preferably a metal salt, and more preferably a silver salt or a copper salt.
The metal forming material is preferably one that decomposes by heating to form a metal.
By using a metal forming material, a metal is generated from the material, and the first pattern 11 including the metal is formed.

In the present invention, it is preferable to use a silver ink composition containing a silver forming material as the ink composition.
Hereinafter, the silver ink composition will be described in more detail.

[Silver carboxylate]
Examples of the metal silver forming material include silver carboxylate having a group represented by the formula “—COOAg”.
In this invention, silver carboxylate may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types together, the combination and ratio can be adjusted arbitrarily.
The silver carboxylate is not particularly limited as long as it has a group represented by the formula “—COOAg”. For example, the number of groups represented by the formula “—COOAg” may be only one, or two or more. Further, the position of the group represented by the formula “—COOAg” in the silver carboxylate is not particularly limited.

The silver carboxylate is represented by the following general formula (1) β-ketocarboxylate silver (hereinafter sometimes abbreviated as “β-ketocarboxylate (1)”) and the following general formula (4). It is preferably one or more selected from the group consisting of silver carboxylates (hereinafter sometimes abbreviated as “silver carboxylate (4)”).
In the present specification, the simple description of “silver carboxylate” is not limited to “silver β-ketocarboxylate (1)” and “silver carboxylate (4)”, unless otherwise specified. It is intended to mean “silver carboxylate having a group represented by the formula“ —COOAg ””.

(In the formula, R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a phenyl group, a hydroxyl group, an amino group, or a general formula “R ¹ -CY” in which one or more hydrogen atoms may be substituted with a substituent. ¹ ₂ − ”,“ CY ¹ ₃ − ”,“ R ¹ —CHY ¹ — ”,“ R ² O— ”,“ R ⁵ R ⁴ N— ”,“ (R ³ O) ₂ CY ¹ — ”or“ R ⁶ —C (═O) —CY ¹ ₂ — ”;
Y ¹ is each independently a fluorine atom, a chlorine atom, a bromine atom or a hydrogen atom; R ¹ is an aliphatic hydrocarbon group having 1 to 19 carbon atoms or a phenyl group; R ² is an aliphatic having 1 to 20 carbon atoms R ³ is an aliphatic hydrocarbon group having 1 to 16 carbon atoms; R ⁴ and R ⁵ are each independently an aliphatic hydrocarbon group having 1 to 18 carbon atoms; R ⁶ is An aliphatic hydrocarbon group having 1 to 19 carbon atoms, a hydroxyl group or a group represented by the formula “AgO—”;
X ¹ is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a phenyl group or benzyl group in which one or more hydrogen atoms may be substituted with a substituent, a cyano group, N - phthaloyl-3-aminopropyl group, 2-ethoxyethyl vinyl group, or the general formula ^{"R 7} O -", ^{"R 7} S -", ^"R 7 -C (= O) -" or ^"R 7 -C ( ═O) —O— ”;
R ⁷ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a thienyl group, or a phenyl group or diphenyl group in which one or more hydrogen atoms may be substituted with a substituent. )

(In the formula, R ⁸ is an aliphatic hydrocarbon group having 1 to 19 carbon atoms, a carboxy group or a group represented by the formula “—C (═O) —OAg”, and the aliphatic hydrocarbon group is a methylene group. And one or more of the methylene groups may be substituted with a carbonyl group.)

(Silver β-ketocarboxylate (1))
The β-ketocarboxylate silver (1) is represented by the general formula (1).
In the formula, R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a phenyl group, a hydroxyl group, an amino group, or a general formula “R ¹ -CY ¹ ” in which one or more hydrogen atoms may be substituted with a substituent. " _2- ", "CY ¹ _3- ", "R ¹ -CHY ^1- ", "R ² O-", "R ⁵ R ⁴ N-", "(R ³ O) ₂ CY ^1- " or "R ^6- C (═O) —CY ¹ ₂ — ”.

  The aliphatic hydrocarbon group having 1 to 20 carbon atoms in R may be any of linear, branched and cyclic (aliphatic cyclic group), and when it is cyclic, it may be monocyclic or polycyclic. . Further, the aliphatic hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. Preferred examples of the aliphatic hydrocarbon group for R include an alkyl group, an alkenyl group, and an alkynyl group.

Examples of the linear or branched alkyl group represented by R include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n -Pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 2-methylbutyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4- Methylpentyl group, 1,1-dimethylbutyl group, 2,2-dimethylbutyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 3-ethylbutyl group 1-ethyl-1-methylpropyl group, n-heptyl group, 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, -Methylhexyl group, 5-methylhexyl group, 1,1-dimethylpentyl group, 2,2-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group 4,4-dimethylpentyl group, 1-ethylpentyl group, 2-ethylpentyl group, 3-ethylpentyl group, 4-ethylpentyl group, 2,2,3-trimethylbutyl group, 1-propylbutyl group, n -Octyl group, isooctyl group, 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 1-ethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl Group, 4-ethylhexyl group, 5-ethylhexyl group, 1,1-dimethylhexyl group, 2,2-dimethylhexyl group, 3, -Dimethylhexyl group, 4,4-dimethylhexyl group, 5,5-dimethylhexyl group, 1-propylpentyl group, 2-propylpentyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group And pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group and icosyl group.
Examples of the cyclic alkyl group in R include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, norbornyl group, isobornyl group, 1-adamantyl group, 2- Examples thereof include an adamantyl group and a tricyclodecyl group.

Examples of the alkenyl group in R include a vinyl group (ethenyl group, —CH═CH ₂ ), an allyl group (2-propenyl group, —CH ₂ —CH═CH ₂ ), and a 1-propenyl group (—CH═CH—CH). ₃ ), isopropenyl group (—C (CH ₃ ) ═CH ₂ ), 1-butenyl group (—CH═CH—CH ₂ —CH ₃ ), 2-butenyl group (—CH ₂ —CH═CH—CH _3). ), 3-butenyl group (—CH ₂ —CH ₂ —CH═CH ₂ ), cyclohexenyl group, cyclopentenyl group and the like, one single bond (C—C) between carbon atoms of the alkyl group in R Is a group in which is substituted with a double bond (C═C).
As the alkynyl group in R, one single bond (C—C) between carbon atoms of the alkyl group in R, such as ethynyl group (—C≡CH), propargyl group (—CH ₂ —C≡CH) and the like. ) Is substituted with a triple bond (C≡C).

  In the aliphatic hydrocarbon group having 1 to 20 carbon atoms in R, one or more hydrogen atoms may be substituted with a substituent, and preferred examples of the substituent include a fluorine atom, a chlorine atom, and a bromine atom. . Moreover, the number and position of substituents are not particularly limited. When the number of substituents is plural, the plural substituents may be the same as or different from each other. That is, all the substituents may be the same, all the substituents may be different, or only some of the substituents may be different.

The phenyl group in R may have one or more hydrogen atoms substituted with a substituent, and the preferred substituent is a saturated or unsaturated monovalent aliphatic hydrocarbon group having 1 to 16 carbon atoms. , A monovalent group formed by bonding the aliphatic hydrocarbon group to an oxygen atom, a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group (—OH), a cyano group (—C≡N), a phenoxy group (—O— C ₆ H ₅ ) and the like can be exemplified, and the number and position of substituents are not particularly limited. When the number of substituents is plural, the plural substituents may be the same as or different from each other.
Examples of the aliphatic hydrocarbon group that is a substituent include the same aliphatic hydrocarbon groups as those described above for R except that the number of carbon atoms is 1 to 16.

Y ^{1 in} R is independently a fluorine atom, a chlorine atom, a bromine atom or a hydrogen atom. In the general formulas “R ¹ —CY ¹ ₂ —”, “CY ¹ ₃ —” and “R ⁶ —C (═O) —CY ¹ ₂ —”, a plurality of Y ¹ may be the same as each other. May be different.

R ¹ in R is an aliphatic hydrocarbon group having 1 to 19 carbon atoms or a phenyl group (C ₆ H ₅ —), and the aliphatic hydrocarbon group in R ¹ has 1 to 19 carbon atoms. Except for this point, the same aliphatic hydrocarbon groups as those in R can be exemplified.
R ² in R is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and examples thereof are the same as the aliphatic hydrocarbon group in R.
R ³ in R is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, and examples thereof are the same as the aliphatic hydrocarbon group in R except that the carbon number is 1 to 16.
R ⁴ and R ⁵ in R are each independently an aliphatic hydrocarbon group having 1 to 18 carbon atoms. That is, R ⁴ and R ⁵ may be the same as or different from each other, and examples thereof are the same as the aliphatic hydrocarbon group in R except that the number of carbon atoms is 1 to 18.
R ⁶ in R is an aliphatic hydrocarbon group having 1 to 19 carbon atoms, a hydroxyl group, or a group represented by the formula “AgO—”, and the aliphatic hydrocarbon group in R ⁶ has 1 to 1 carbon atoms. Except for being 19, the same aliphatic hydrocarbon groups as those described above for R can be exemplified.

R is, among these, a linear or branched alkyl group, the general formula ^{"R 6 -C (= O) -CY} 1 2 - " group represented by be a hydroxyl group or a phenyl group preferable. R ⁶ is preferably a linear or branched alkyl group, a hydroxyl group, or a group represented by the formula “AgO—”.

In the general formula (1), each X ¹ is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a phenyl group in which one or more hydrogen atoms may be substituted with a substituent, or A benzyl group (C ₆ H ₅ —CH ₂ —), a cyano group, an N-phthaloyl-3-aminopropyl group, a 2-ethoxyvinyl group (C ₂ H ₅ —O—CH═CH—), or a general formula “R ⁷ O— ”,“ R ⁷ S— ”,“ R ⁷ —C (═O) — ”or“ R ⁷ —C (═O) —O— ”.
Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms in X ¹ include those similar to the aliphatic hydrocarbon group in R.

Examples of the halogen atom in X ¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
In the phenyl group and benzyl group in X ¹ , one or more hydrogen atoms may be substituted with a substituent. Preferred examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), nitro group (-NO ₂₎ or the like can be exemplified, the number and position of the substituent is not particularly limited. When the number of substituents is plural, the plural substituents may be the same as or different from each other.

R ⁷ in X ¹ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, a thienyl group (C ₄ H ₃ S—), a phenyl group in which one or more hydrogen atoms may be substituted with a substituent, or diphenyl group (biphenyl _{group, C 6 H 5 -C 6 H} 4 -) is. Examples of the aliphatic hydrocarbon group for R ⁷ include those similar to the aliphatic hydrocarbon group for R except that the aliphatic hydrocarbon group has 1 to 10 carbon atoms. Further, examples of the substituent of the phenyl group and a diphenyl group in R ^7, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom) can be exemplified the like, the number and position of the substituent is not particularly limited. When the number of substituents is plural, the plural substituents may be the same as or different from each other.
When R ⁷ is a thienyl group or a diphenyl group, there are no particular limitations on the bonding position of these groups with an adjacent group or atom (oxygen atom, sulfur atom, carbonyl group, carbonyloxy group) in X ¹ . For example, the thienyl group may be a 2-thienyl group or a 3-thienyl group.

In the general formula (1), two X ^{1 s} may be bonded as one group through a double bond with a carbon atom sandwiched between two carbonyl groups. A group represented by the formula “═CH—C ₆ H ₄ —NO ₂ ” can be exemplified.

X ¹ is preferably a hydrogen atom, a linear or branched alkyl group, a benzyl group, or a group represented by the general formula “R ⁷ —C (═O) —” among the above. It is preferable that at least one X ¹ is a hydrogen atom.

β-ketocarboxylate silver (1) is silver 2-methylacetoacetate (CH ₃ —C (═O) —CH (CH ₃ ) —C (═O) —OAg), silver acetoacetate (CH ₃ —C (= O) —CH ₂ —C (═O) —OAg), silver 2-ethylacetoacetate (CH ₃ —C (═O) —CH (CH ₂ CH ₃ ) —C (═O) —OAg), silver propionyl acetate _{(CH 3 CH 2 -C (=} O) -CH 2 -C (= O) -OAg), isobutyryl silver acetate _{((CH 3) 2 CH-} C (= O) -CH 2 -C (= O) - OAg), silver pivaloyl acetate ((CH ₃ ) ₃ C—C (═O) —CH ₂ —C (═O) —OAg), silver caproyl acetate (CH ₃ (CH ₂ ) ₃ CH ₂ —C (═O) _{) -CH 2 -C (= O)} -OAg), 2-n- Buchiruaseto silver acetate _{(CH 3 -C (= O)} -CH (C _{H 2 CH 2 CH 2 CH 3} ) -C (= O) -OAg), 2- benzyl acetoacetate silver _{(CH 3 -C (= O)} -CH (CH 2 C 6 H 5) -C (= O) -OAg), silver benzoylacetate _{(C 6 H 5 -C (=} O) -CH 2 -C (= O) -OAg), Pibaroiruaseto silver acetate _{((CH 3) 3 C-} C (= O) -CH 2 _{-C (= O) -CH 2 -C} (= O) -OAg), isobutyryl acetoacetate silver _{((CH 3) 2 CH-} C (= O) -CH 2 -C (= O) -CH 2 -C (= O) -OAg), 2- acetyl pivaloyl silver acetate _{((CH 3) 3 C-} C (= O) -CH (-C (= O) -CH 3) -C (= O) -OAg), 2- acetyl isobutyryl silver acetate _{((CH 3) 2 CH-} C (= O) -CH (-C (= O) -CH 3) -C (= O) - Ag), or is preferably acetone dicarboxylic silver _{(AgO-C (= O)} -CH 2 -C (= O) -CH 2 -C (= O) -OAg).

  The β-ketocarboxylate (1) can further reduce the concentration of the remaining raw materials and impurities in the conductor (metal silver) formed by post-treatment such as drying treatment or heating (firing) treatment. The smaller the raw materials and impurities, for example, the better the contact between the formed metal silvers, the easier the conduction, and the lower the resistivity.

  The β-ketocarboxylate (1) is decomposed at a low temperature of preferably 60 to 210 ° C., more preferably 60 to 200 ° C. without using a reducing agent known in the art, as described later, It is possible to form metallic silver. And by using together with a reducing agent, it decomposes at a lower temperature to form metallic silver. The reducing agent will be described later.

  In this invention, (beta) -ketocarboxylate (1) may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types together, the combination and ratio can be adjusted arbitrarily.

(Silver carboxylate (4))
The silver carboxylate (4) is represented by the general formula (4).
In the formula, R ⁸ is an aliphatic hydrocarbon group having 1 to 19 carbon atoms, a carboxy group (—COOH), or a group represented by the formula “—C (═O) —OAg”.
Examples of the aliphatic hydrocarbon group for R ⁸ include those similar to the aliphatic hydrocarbon group for R except that the aliphatic hydrocarbon group has 1 to 19 carbon atoms. However, the aliphatic hydrocarbon group for R ⁸ preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms.

When the aliphatic hydrocarbon group for R ⁸ has a methylene group (—CH ₂ —), one or more of the methylene groups may be substituted with a carbonyl group. The number and position of the methylene groups that may be substituted with a carbonyl group are not particularly limited, and all methylene groups may be substituted with a carbonyl group. Here, the “methylene group” is not only a single group represented by the formula “—CH ₂ —” but also one alkylene group in which a plurality of groups represented by the formula “—CH ₂ —” are linked. And a group represented by the formula “—CH ₂ —”.

Silver carboxylate (4) is silver pyruvate (CH ₃ —C (═O) —C (═O) —OAg), silver acetate (CH ₃ —C (═O) —OAg), silver butyrate (CH _{3 - (CH 2) 2 -C (} = O) -OAg), isobutyric acid silver _{((CH 3) 2 CH-} C (= O) -OAg), hexane silver 2-ethylhexyl _(CH 3 - _{(CH 2} ) ₃ —CH (CH ₂ CH ₃ ) —C (═O) —OAg), silver neodecanoate (CH ₃ — (CH ₂ ) ₅ —C (CH ₃ ) ₂ —C (═O) —OAg), Shu It is preferably silver oxide (AgO—C (═O) —C (═O) —OAg) or silver malonate (AgO—C (═O) —CH ₂ —C (═O) —OAg). Also, 2 of the silver oxalate (AgO-C (= O) -C (= O) -OAg) and malonic silver _{(AgO-C (= O)} -CH 2 -C (= O) -OAg) Of the groups represented by the formula “—COOAg”, one is a group represented by the formula “—COOH” (HO—C (═O) —C (═O) —OAg, HO) _{-C (= O) -CH 2 -C} (= O) -OAg) it is also preferred.

  As in the case of silver β-ketocarboxylate (1), silver carboxylate (4) is also a conductor (metal silver) formed by post-treatment such as drying treatment or heating (firing) treatment. The concentration can be further reduced. And by using together with a reducing agent, it decomposes at a lower temperature to form metallic silver.

  In this invention, silver carboxylate (4) may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types together, the combination and ratio can be adjusted arbitrarily.

The silver carboxylate is silver 2-methylacetoacetate, silver acetoacetate, silver 2-ethylacetoacetate, silver propionylacetate, silver isobutyrylacetate, silver pivaloylacetate, silver caproylacetate, silver 2-n-butylacetoacetate, 2-benzylacetoacetate Silver acetate, silver benzoyl acetate, silver pivaloyl acetoacetate, silver isobutyryl acetoacetate, silver acetone dicarboxylate, silver pyruvate, silver acetate, silver butyrate, silver isobutyrate, silver 2-ethylhexanoate, silver neodecanoate, silver It is preferably at least one selected from the group consisting of silver oxide and silver malonate.
Among these silver carboxylates, silver 2-methylacetoacetate and silver acetoacetate are excellent in compatibility with the nitrogen-containing compounds (among others amine compounds) described later, and are particularly suitable for increasing the concentration of silver ink compositions. It is mentioned as a thing.

In the silver ink composition, the content of silver derived from the metal silver forming material is preferably 5% by mass or more, and more preferably 10% by mass or more. By being in such a range, the formed conductor (metal silver) becomes superior in quality. The upper limit of the silver content is not particularly limited as long as the effects of the present invention are not impaired, but it is preferably 25% by mass in consideration of handling properties and the like.
In the present specification, “silver derived from a metallic silver forming material” means silver in the metallic silver forming material blended during the production of the silver ink composition, unless otherwise specified. It is a concept that includes both silver constituting the metal silver forming material after blending, and silver and silver itself in the decomposition product generated by decomposition of the metal silver forming material after blending.

[Nitrogen-containing compounds]
The silver ink composition, in particular, when the metal silver forming material is the silver carboxylate, in addition to the metal silver forming material, an amine compound having a carbon number of 25 or less, a quaternary ammonium salt, ammonia, and the above A compound in which one or more nitrogen-containing compounds selected from the group consisting of an ammonium salt formed by reacting an amine compound or ammonia with an acid (hereinafter sometimes simply referred to as “nitrogen-containing compound”) is preferable. . The nitrogen-containing compound to be blended may be only one kind, or two or more kinds. When two or more kinds are used in combination, the combination and ratio can be arbitrarily adjusted.
Hereinafter, an amine compound having 25 or less carbon atoms is referred to as “amine compound”, a quaternary ammonium salt having 25 or less carbon atoms is referred to as “quaternary ammonium salt”, and an ammonium salt obtained by reacting an amine compound having 25 or less carbon atoms with an acid. Is sometimes abbreviated as “ammonium salt derived from an amine compound”, and an ammonium salt formed by reacting ammonia with an acid is sometimes abbreviated as “ammonium salt derived from ammonia”.

(Amine compound, quaternary ammonium salt)
The amine compound has 1 to 25 carbon atoms, and may be any of primary amine, secondary amine, and tertiary amine. The quaternary ammonium salt has 4 to 25 carbon atoms. The amine compound and the quaternary ammonium salt may be either chain or cyclic. Further, the number of nitrogen atoms constituting the amine moiety or ammonium salt moiety (for example, the nitrogen atom constituting the amino group (—NH ₂ ) of the primary amine) may be one, or two or more.

  Examples of the primary amine include monoalkylamines, monoarylamines, mono (heteroaryl) amines, and diamines in which one or more hydrogen atoms may be substituted with a substituent.

The alkyl group constituting the monoalkylamine may be linear, branched or cyclic, and examples thereof are the same as the alkyl group in R, and are linear or branched having 1 to 19 carbon atoms. It is preferably a chain alkyl group or a cyclic alkyl group having 3 to 7 carbon atoms.
Specific examples of preferable monoalkylamine include n-butylamine, n-hexylamine, n-octylamine, n-dodecylamine, n-octadecylamine, isobutylamine, sec-butylamine, tert-butylamine, 3-amino. Examples include pentane, 3-methylbutylamine, 2-heptylamine (2-aminoheptane), 2-aminooctane, 2-ethylhexylamine, and 1,2-dimethyl-n-propylamine.

  Examples of the aryl group constituting the monoarylamine include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and the like, and preferably has 6 to 10 carbon atoms.

The heteroaryl group constituting the mono (heteroaryl) amine has a heteroatom as an atom constituting the aromatic ring skeleton, and the heteroatom includes a nitrogen atom, a sulfur atom, an oxygen atom, and a boron atom. Can be illustrated. Moreover, the number of the said hetero atom which comprises an aromatic ring frame is not specifically limited, One may be sufficient and two or more may be sufficient. When there are two or more, these heteroatoms may be the same or different from each other. That is, these heteroatoms may all be the same, may all be different, or may be partially different.
The heteroaryl group may be monocyclic or polycyclic, and the number of ring members (the number of atoms constituting the ring skeleton) is not particularly limited, but is preferably a 3- to 12-membered ring.

Examples of the monoaryl group having 1 to 4 nitrogen atoms as the heteroaryl group include pyrrolyl group, pyrrolinyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrimidyl group, pyrazinyl group, pyridazinyl group, triazolyl group, and tetrazolyl group. , A pyrrolidinyl group, an imidazolidinyl group, a piperidinyl group, a pyrazolidinyl group, and a piperazinyl group are preferable, and a 3- to 8-membered ring is preferable, and a 5- to 6-membered ring is more preferable.
Examples of the monoaryl group having one oxygen atom as the heteroaryl group include a furanyl group, preferably a 3- to 8-membered ring, and more preferably a 5- to 6-membered ring.
Examples of the monoaryl group having one sulfur atom as the heteroaryl group include a thienyl group, preferably a 3- to 8-membered ring, and more preferably a 5- to 6-membered ring.
Examples of the monoaryl group having 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms as the heteroaryl group include an oxazolyl group, an isoxazolyl group, an oxadiazolyl group, and a morpholinyl group. It is preferable that it is a 5- to 6-membered ring.
Examples of the monoaryl group having 1 to 2 sulfur atoms and 1 to 3 nitrogen atoms as the heteroaryl group include a thiazolyl group, a thiadiazolyl group, and a thiazolidinyl group, and a 3- to 8-membered ring. Preferably, it is a 5-6 membered ring.
Examples of the polyaryl group having 1 to 5 nitrogen atoms as the heteroaryl group include indolyl group, isoindolyl group, indolizinyl group, benzimidazolyl group, quinolyl group, isoquinolyl group, indazolyl group, benzotriazolyl group, tetra Examples include a zolopyridyl group, a tetrazolopyridazinyl group, and a dihydrotriazolopyridazinyl group, preferably a 7-12 membered ring, and more preferably a 9-10 membered ring.
Examples of the polyaryl group having 1 to 3 sulfur atoms as the heteroaryl group include a dithiaphthalenyl group and a benzothiophenyl group, preferably a 7 to 12 membered ring, preferably a 9 to 10 membered ring. More preferably, it is a ring.
Examples of the polyaryl group having 1 to 2 oxygen atoms and 1 to 3 nitrogen atoms as the heteroaryl group include a benzoxazolyl group and a benzooxadiazolyl group. It is preferable that it is a 9-10 membered ring.
Examples of the polyaryl group having 1 to 2 sulfur atoms and 1 to 3 nitrogen atoms as the heteroaryl group include a benzothiazolyl group and a benzothiadiazolyl group, and is a 7 to 12 membered ring. Preferably, it is a 9-10 membered ring.

The diamine only needs to have two amino groups, and the positional relationship between the two amino groups is not particularly limited. As the preferred diamine, in the monoalkylamine, monoarylamine or mono (heteroaryl) amine, one hydrogen atom other than the hydrogen atom constituting the amino group (—NH ₂ ) is substituted with an amino group. The thing can be illustrated.
The diamine preferably has 1 to 10 carbon atoms, and more preferable examples include ethylenediamine, 1,3-diaminopropane, and 1,4-diaminobutane.

  Examples of the secondary amine include dialkylamine, diarylamine, di (heteroaryl) amine and the like in which one or more hydrogen atoms may be substituted with a substituent.

The alkyl group that constitutes the dialkylamine is the same as the alkyl group that constitutes the monoalkylamine, and is a linear or branched alkyl group having 1 to 9 carbon atoms, or 3 to 7 carbon atoms. A cyclic alkyl group is preferred. Two alkyl groups in one molecule of dialkylamine may be the same as or different from each other.
Specific examples of preferable dialkylamine include N-methyl-n-hexylamine, diisobutylamine, and di (2-ethylhexyl) amine.

  The aryl group constituting the diarylamine is the same as the aryl group constituting the monoarylamine, and preferably has 6 to 10 carbon atoms. Two aryl groups in one molecule of diarylamine may be the same as or different from each other.

  The heteroaryl group constituting the di (heteroaryl) amine is the same as the heteroaryl group constituting the mono (heteroaryl) amine, and is preferably a 6-12 membered ring. Two heteroaryl groups in one molecule of di (heteroaryl) amine may be the same or different from each other.

  Examples of the tertiary amine include trialkylamine and dialkylmonoarylamine in which one or more hydrogen atoms may be substituted with a substituent.

The alkyl group constituting the trialkylamine is the same as the alkyl group constituting the monoalkylamine, and is a linear or branched alkyl group having 1 to 19 carbon atoms, or 3 to 7 carbon atoms. The cyclic alkyl group is preferably. Further, the three alkyl groups in one molecule of trialkylamine may be the same as or different from each other. That is, all three alkyl groups may be the same, all may be different, or only a part may be different.
Preferable examples of the trialkylamine include N, N-dimethyl-n-octadecylamine and N, N-dimethylcyclohexylamine.

The alkyl group constituting the dialkyl monoarylamine is the same as the alkyl group constituting the monoalkylamine, and is a linear or branched alkyl group having 1 to 6 carbon atoms, or 3 to 3 carbon atoms. 7 is a cyclic alkyl group. Two alkyl groups in one molecule of dialkyl monoarylamine may be the same or different from each other.
The aryl group constituting the dialkyl monoarylamine is the same as the aryl group constituting the monoarylamine, and preferably has 6 to 10 carbon atoms.

In the present invention, examples of the quaternary ammonium salt include halogenated tetraalkylammonium, in which one or more hydrogen atoms may be substituted with a substituent.
The alkyl group constituting the halogenated tetraalkylammonium is the same as the alkyl group constituting the monoalkylamine, and preferably has 1 to 19 carbon atoms. Further, the four alkyl groups in one molecule of the tetraalkylammonium halide may be the same as or different from each other. That is, all four alkyl groups may be the same, all may be different, or only a part may be different.
Examples of the halogen constituting the halogenated tetraalkylammonium include fluorine, chlorine, bromine and iodine.
Specific examples of the preferred tetraalkylammonium halide include dodecyltrimethylammonium bromide.

So far, the chain amine compound and the quaternary organic ammonium salt have been mainly described. However, in the amine compound and the quaternary ammonium salt, the nitrogen atom constituting the amine moiety or the ammonium salt moiety is a ring skeleton structure ( A heterocyclic compound which is a part of a heterocyclic skeleton structure) may be used. That is, the amine compound may be a cyclic amine, and the quaternary ammonium salt may be a cyclic ammonium salt. At this time, the ring (ring containing the nitrogen atom constituting the amine moiety or ammonium salt moiety) structure may be either monocyclic or polycyclic, and the number of ring members (number of atoms constituting the ring skeleton) is also particularly limited. Any of an aliphatic ring and an aromatic ring may be sufficient.
If it is a cyclic amine, a pyridine can be illustrated as a preferable thing.

  In the primary amine, secondary amine, tertiary amine and quaternary ammonium salt, the “hydrogen atom optionally substituted with a substituent” means a nitrogen atom constituting an amine moiety or an ammonium salt moiety. A hydrogen atom other than a hydrogen atom bonded to. The number of substituents at this time is not particularly limited, and may be one or two or more, and all of the hydrogen atoms may be substituted with a substituent. When the number of substituents is plural, the plural substituents may be the same as or different from each other. That is, the plurality of substituents may all be the same, may all be different, or only some may be different. Further, the position of the substituent is not particularly limited.

Examples of the substituent in the amine compound and the quaternary ammonium salt include an alkyl group, an aryl group, a halogen atom, a cyano group, a nitro group, a hydroxyl group, and a trifluoromethyl group (—CF ₃ ). Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

When the alkyl group constituting the monoalkylamine has a substituent, the alkyl group has an aryl group as a substituent, a linear or branched alkyl group having 1 to 9 carbon atoms, or a substituent Preferably, a cyclic alkyl group having 3 to 7 carbon atoms having an alkyl group having 1 to 5 carbon atoms is preferable, and specific examples of monoalkylamine having such a substituent include 2-phenylethylamine , Benzylamine, and 2,3-dimethylcyclohexylamine.
In addition, the aryl group and the alkyl group which are substituents may further have one or more hydrogen atoms substituted with halogen atoms, and as monoalkylamines having such substituents substituted with halogen atoms, And 2-bromobenzylamine. Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  When the aryl group constituting the monoarylamine has a substituent, the aryl group is preferably an aryl group having 6 to 10 carbon atoms having a halogen atom as the substituent, and monoaryl having such a substituent. Specific examples of the amine include bromophenylamine. Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  When the alkyl group constituting the dialkylamine has a substituent, the alkyl group is preferably a linear or branched alkyl group having 1 to 9 carbon atoms and having a hydroxyl group or an aryl group as a substituent, Specific examples of the dialkylamine having such a substituent include diethanolamine and N-methylbenzylamine.

The amine compound is n-propylamine, n-butylamine, n-hexylamine, n-octylamine, n-dodecylamine, n-octadecylamine, isobutylamine, sec-butylamine, tert-butylamine, 3-aminopentane, 3-methylbutylamine, 2-heptylamine, 2-aminooctane, 2-ethylhexylamine, 2-phenylethylamine, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, N-methyl-n-hexylamine, Diisobutylamine, N-methylbenzylamine, di (2-ethylhexyl) amine, 1,2-dimethyl-n-propylamine, N, N-dimethyl-n-octadecylamine or N, N-dimethylcyclohexylamine. It is preferable.
Among these amine compounds, 2-ethylhexylamine is excellent in compatibility with the silver carboxylate and is particularly suitable for increasing the concentration of the silver ink composition, and further the surface roughness of the formed conductor. It is mentioned as being particularly suitable for reduction.

(Ammonium salts derived from amine compounds)
In the present invention, the ammonium salt derived from the amine compound is an ammonium salt obtained by reacting the amine compound with an acid, and the acid may be an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, or an organic acid such as acetic acid. However, the type of acid is not particularly limited.
Examples of the ammonium salt derived from the amine compound include, but are not limited to, n-propylamine hydrochloride, N-methyl-n-hexylamine hydrochloride, N, N-dimethyl-n-octadecylamine hydrochloride and the like. .

(Ammonium salt derived from ammonia)
In the present invention, the ammonium salt derived from ammonia is an ammonium salt formed by reacting ammonia with an acid, and examples of the acid include the same ones as in the case of the ammonium salt derived from the amine compound.
Examples of the ammonium salt derived from ammonia include ammonium chloride, but are not limited thereto.

In the present invention, the amine compound, the quaternary ammonium salt, the ammonium salt derived from the amine compound and the ammonium salt derived from ammonia may be used singly or in combination of two or more. . When using 2 or more types together, the combination and ratio can be adjusted arbitrarily.
And as said nitrogen-containing compound, you may use individually by 1 type selected from the group which consists of said amine compound, quaternary ammonium salt, ammonium salt derived from an amine compound, and ammonium salt derived from ammonia, More than one species may be used in combination. When using 2 or more types together, the combination and ratio can be adjusted arbitrarily.

  In the silver ink composition, the compounding amount of the nitrogen-containing compound is preferably 0.3 to 15 mol, more preferably 0.3 to 5 mol, per mol of the metal silver forming material. preferable. When the blending amount of the nitrogen-containing compound is within such a range, the silver ink composition is further improved in stability and the quality of the conductor (metal silver) is further improved. Furthermore, the conductor can be formed more stably without performing heat treatment at a high temperature.

[Reducing agent]
In addition to the metallic silver forming material, the silver ink composition may further contain a reducing agent. By blending a reducing agent, the silver ink composition can more easily form metallic silver. For example, a conductor (metal silver) having sufficient conductivity even without heat treatment or heat treatment at a low temperature. Can be formed.

The reducing agent is one or more reducing compounds selected from the group consisting of oxalic acid, hydrazine and a compound represented by the following general formula (5) (hereinafter sometimes abbreviated as “compound (5)”). (Hereinafter, sometimes simply abbreviated as “reducing compound”).
HC (= O) -R ²¹ (5)
(In the formula, R ²¹ represents an alkyl group having 20 or less carbon atoms, an alkoxy group, an N, N-dialkylamino group, a hydroxyl group, or an amino group.)

(Reducing compounds)
The reducing compound is one or more selected from the group consisting of oxalic acid (HOOC-COOH), hydrazine (H ₂ N—NH ₂ ) and the compound represented by the general formula (5) (compound (5)). belongs to. That is, the reducing compound to be blended may be only one kind, or two or more kinds. When two or more kinds are used in combination, the combination and ratio can be arbitrarily adjusted.

The alkyl group having 20 or less carbon atoms in R ²¹ has 1 to 20 carbon atoms, and may be linear, branched or cyclic, and is the same as the alkyl group in R of the general formula (1) The thing can be illustrated.

The alkoxy group having 20 or less carbon atoms in R ²¹ has 1 to 20 carbon atoms, and examples thereof include monovalent groups in which the alkyl group in R ²¹ is bonded to an oxygen atom.

The N, N-dialkylamino group having 20 or less carbon atoms in R ²¹ has 2 to 20 carbon atoms, and the two alkyl groups bonded to the nitrogen atom may be the same as or different from each other, Each alkyl group has 1 to 19 carbon atoms. However, the total value of the carbon number of these two alkyl groups is 2-20.
The alkyl group bonded to the nitrogen atom may be linear, branched or cyclic, respectively, and the alkyl in R of the general formula (1) except that it has 1 to 19 carbon atoms. The thing similar to group can be illustrated.

As the reducing compound, hydrazine may be a monohydrate (H ₂ N—NH ₂ .H ₂ O).

Preferred examples of the reducing compound include formic acid (HC (═O) —OH); methyl formate (HC (═O) —OCH ₃ ), ethyl formate (HC (═O) —OCH). Formic acid esters such as ₂ CH ₃ ) and butyl formate (HC (═O) —O (CH ₂ ) ₃ CH ₃ ); propanal (HC (═O) —CH ₂ CH ₃ ), butanal (H Aldehydes such as —C (═O) — (CH ₂ ) ₂ CH ₃ ) and hexanal (HC— (O) — (CH ₂ ) ₄ CH ₃ ); formamide (HC— (O) —NH ₂ ), N, N-dimethylformamide (HC (═O) —N (CH ₃ ) ₂ ) and other formamides (groups represented by the formula “HC (═O) —N (—) —”) And oxalic acid.

  In the silver ink composition, the compounding amount of the reducing agent is preferably 0.04 to 3.5 mol, and preferably 0.06 to 2.5 mol per 1 mol of the metal silver forming material. Is more preferable. When the blending amount of the reducing agent is within such a range, the silver ink composition can form a conductor (metal silver) more easily and more stably.

[alcohol]
The silver ink composition may further contain an alcohol in addition to the metal silver forming material.

  The alcohol is preferably an acetylene alcohol represented by the following general formula (2) (hereinafter sometimes abbreviated as “acetylene alcohol (2)”).

(In the formula, R ′ and R ″ are each independently an alkyl group having 1 to 20 carbon atoms or a phenyl group in which one or more hydrogen atoms may be substituted with a substituent.)

(Acetylene alcohol (2))
The acetylene alcohol (2) is represented by the general formula (2).
In the formula, R ′ and R ″ are each independently an alkyl group having 1 to 20 carbon atoms, or a phenyl group in which one or more hydrogen atoms may be substituted with a substituent.
The alkyl group having 1 to 20 carbon atoms in R ′ and R ″ may be linear, branched or cyclic, and when it is cyclic, it may be monocyclic or polycyclic. Examples of the alkyl group in R ′ and R ″ include the same alkyl groups as in R.

  Examples of the substituent in which the hydrogen atom of the phenyl group in R ′ and R ″ may be substituted include a saturated or unsaturated monovalent aliphatic hydrocarbon group having 1 to 16 carbon atoms, the aliphatic carbonization Examples thereof include a monovalent group formed by bonding a hydrogen group to an oxygen atom, a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, a cyano group, a phenoxy group, and the like, and the hydrogen atom of the phenyl group in R may be substituted. This is the same as the substituent. And the number and position of a substituent are not specifically limited, When there are two or more substituents, these several substituents may mutually be same or different.

  R ′ and R ″ are preferably an alkyl group having 1 to 20 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 10 carbon atoms.

  Examples of preferable acetylene alcohol (2) include 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-butyn-3-ol, and 3-methyl-1-pentyn-3-ol.

  When acetylene alcohol (2) is used, the amount of acetylene alcohol (2) in the silver ink composition is preferably 0.03 to 0.7 mole per mole of the metal silver forming material. 0.05 to 0.3 mol is more preferable. When the blending amount of acetylene alcohol (2) is within such a range, the stability of the silver ink composition is further improved.

  The said alcohol may be used individually by 1 type, and may use 2 or more types together. When two or more kinds are used in combination, the combination and ratio can be arbitrarily adjusted.

[Other ingredients]
The silver ink composition may contain other components other than the metal silver forming material, nitrogen-containing compound, reducing agent and alcohol.
The other components in the silver ink composition can be arbitrarily selected according to the purpose, and are not particularly limited. Preferred examples thereof include solvents other than alcohol, and can be arbitrarily selected according to the type and amount of compounding components. it can.
One of these other components in the silver ink composition may be used alone, or two or more thereof may be used in combination. When two or more kinds are used in combination, the combination and ratio can be arbitrarily adjusted.

  The silver ink composition preferably contains one or both of the metal silver forming material, the nitrogen-containing compound, and the reducing agent and alcohol. The silver carboxylate, the nitrogen-containing compound, and the reducing agent and More preferably, one or both of alcohols are blended.

  In the silver ink composition, the ratio of the blending amount of the other components to the total amount of the blending components is preferably 10% by mass or less, more preferably 5% by mass or less, and 0 mass, ie other components. Even if it is not added, the silver ink composition exhibits its effect sufficiently.

  In the silver ink composition, all the compounding components may be dissolved, or some or all of the components may be dispersed without dissolving, but it is preferable that all the compounding components are dissolved. The undissolved component is preferably dispersed uniformly.

[Method for producing silver ink composition]
The silver ink composition is obtained by blending components other than the metallic silver forming material and the metallic silver forming material. After the blending of each component, the resulting product may be used as it is as a silver ink composition, or a product obtained by performing a known purification operation as necessary may be used as a silver ink composition. In the present invention, in particular, when β-ketocarboxylate (1) is used as the material for forming the metal silver, impurities that impede conductivity are not generated at the time of blending the above components, or such Since the generation amount of impurities can be suppressed to a very small amount, a conductor (metal silver) having sufficient conductivity can be obtained even if a silver ink composition that has not been subjected to a purification operation is used.

At the time of blending each component, all the components may be added and then mixed, or some components may be mixed while being added sequentially, or all components may be mixed while being added sequentially. Good. However, in this invention, it is preferable to mix | blend the said reducing agent by dripping, and exists in the tendency which can further reduce the surface roughness of metal silver by suppressing the fluctuation | variation of dripping speed | rate.
The mixing method is not particularly limited, a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer, a three-roller, a kneader, a bead mill or the like; a method of mixing by adding ultrasonic waves, etc. What is necessary is just to select suitably from a well-known method.
In the silver ink composition, when the undissolved component is uniformly dispersed, for example, a method of dispersing using the above-described three rolls, kneader, bead mill or the like is preferably applied.

The temperature at the time of blending is not particularly limited as long as each blending component does not deteriorate, but is preferably −5 to 60 ° C. And the temperature at the time of mixing | blending is good to adjust suitably so that the mixture obtained by mix | blending may become the viscosity which is easy to stir according to the kind and quantity of a mixing | blending component.
Further, the blending time is not particularly limited as long as each blending component does not deteriorate, but it is preferably 10 minutes to 36 hours.

[carbon dioxide]
The silver ink composition may be further supplied with carbon dioxide. Such a silver ink composition has a high viscosity. For example, a flexographic printing method, a screen printing method, a gravure printing method, a gravure offset printing method, a pad printing method, etc. Suitable for application.

Carbon dioxide may be supplied at any time during the production of the silver ink composition.
In the present invention, for example, carbon dioxide is supplied to the first mixture in which the metal silver forming material and the nitrogen-containing compound are blended to form a second mixture, and if necessary, the second mixture It is preferable that a silver ink composition is produced by further blending the reducing agent with the mixture. Moreover, when mix | blending the said alcohol or another component, these can be mix | blended at the time of manufacture of any one or both of a 1st mixture and a 2nd mixture, and can be arbitrarily selected according to the objective.

  The first mixture can be produced by the same method as the above silver ink composition except that the blending components are different.

  The first mixture may have all of the compounding components dissolved, or may be in a state of being dispersed without dissolving some of the components, but preferably all of the compounding components are dissolved and dissolved. It is preferable that the components not dispersed are uniformly dispersed.

  Although the compounding temperature at the time of manufacture of a 1st mixture is not specifically limited unless each compounding component deteriorates, it is preferable that it is -5-30 degreeC. Moreover, what is necessary is just to adjust a compounding time suitably according to the kind of compounding component, and the temperature at the time of a compounding, For example, it is preferable that it is 0.5 to 12 hours.

Carbon dioxide (CO ₂ ) supplied to the first mixture may be either gaseous or solid (dry ice), or both gaseous and solid. By supplying carbon dioxide, it is estimated that this carbon dioxide dissolves in the first mixture and acts on the components in the first mixture, thereby increasing the viscosity of the obtained second mixture.

  Carbon dioxide gas may be supplied by various known methods of blowing gas into the liquid, and a suitable supply method may be selected as appropriate. For example, a method in which one end of a pipe is immersed in the first mixture, the other end is connected to a carbon dioxide gas supply source, and the carbon dioxide gas is supplied to the first mixture through the pipe. At this time, the carbon dioxide gas may be supplied directly from the end of the pipe. For example, a plurality of voids that can serve as gas flow paths, such as a porous one, are provided to diffuse the introduced gas. A gas diffusion member that can be discharged as minute bubbles may be connected to the end of the pipe, and the carbon dioxide gas may be supplied through the gas diffusion member. Moreover, you may supply a carbon dioxide gas, stirring the 1st mixture by the method similar to the time of manufacture of a 1st mixture. By doing in this way, carbon dioxide can be supplied efficiently.

  The supply amount of the carbon dioxide gas is not particularly limited as long as it is appropriately adjusted according to the amount of the first mixture at the supply destination and the viscosity of the target silver ink composition or the second mixture. For example, in order to obtain about 100 to 1000 g of a silver ink composition having a viscosity at 20 to 25 ° C. of 5 Pa · s or more, it is preferable to supply 100 L or more of carbon dioxide gas, and more preferably 200 L or more. In addition, although the viscosity at 20-25 degreeC of a silver ink composition was demonstrated here, the temperature at the time of use of a silver ink composition is not limited to 20-25 degreeC, It can select arbitrarily.

The flow rate of carbon dioxide gas may be appropriately adjusted in consideration of the required supply amount of carbon dioxide gas, but is preferably 0.5 mL / min or more per 1 g of the first mixture, and is 1 mL / min or more. It is more preferable that The upper limit value of the flow rate is not particularly limited, but is preferably 40 mL / min per 1 g of the mixture in consideration of handling properties and the like.
The carbon dioxide gas supply time may be appropriately adjusted in consideration of the required supply amount and flow rate of carbon dioxide gas.

  The temperature of the first mixture at the time of supplying carbon dioxide gas is preferably 5 to 70 ° C, more preferably 7 to 60 ° C, and particularly preferably 10 to 50 ° C. When the temperature is equal to or higher than the lower limit value, carbon dioxide can be supplied more efficiently, and when the temperature is equal to or lower than the upper limit value, a silver ink composition having better quality with fewer impurities can be obtained.

  The flow rate and supply time of the carbon dioxide gas, and the temperature at the time of supplying the carbon dioxide gas may be adjusted to a suitable range while considering each value. For example, even if the temperature is set lower, the carbon dioxide gas flow rate is set higher, the carbon dioxide gas supply time is set longer, or both are performed efficiently. Can supply carbon. Moreover, even if the flow rate of carbon dioxide gas is set to a small value, the carbon dioxide gas can be efficiently produced by increasing the temperature, setting the carbon dioxide gas supply time longer, or both. Can supply. That is, a silver ink of good quality can be obtained by flexibly combining the numerical values in the above numerical range exemplified as the flow rate of carbon dioxide gas and the temperature at the time of carbon dioxide gas supply while considering the supply time of carbon dioxide gas. A composition is obtained efficiently.

The carbon dioxide gas is preferably supplied while stirring the first mixture. By doing in this way, the supplied carbon dioxide gas diffuses more uniformly in the first mixture, and carbon dioxide can be supplied more efficiently.
The stirring method at this time may be the same as in the case of the mixing method at the time of producing the above silver ink composition not using carbon dioxide.

The supply of dry ice (solid carbon dioxide) may be performed by adding dry ice to the first mixture. The total amount of dry ice may be added all at once, or may be added stepwise (continuously across a time zone during which no addition is performed).
What is necessary is just to adjust the usage-amount of dry ice in consideration of the supply amount of said carbon dioxide gas.
During and after the addition of dry ice, the first mixture is preferably stirred. For example, the first mixture is preferably stirred in the same manner as in the production of the above silver ink composition without using carbon dioxide. By doing in this way, carbon dioxide can be supplied efficiently.
The temperature at the time of stirring may be the same as that at the time of supplying carbon dioxide gas. Moreover, what is necessary is just to adjust stirring time suitably according to stirring temperature.

  The viscosity of the second mixture may be appropriately adjusted depending on the purpose, such as a silver ink composition or a method of handling the second mixture, and is not particularly limited. For example, when the silver ink composition is applied to a printing method using a high viscosity ink such as a screen printing method or a flexographic printing method, the viscosity of the second mixture at 20 to 25 ° C. is 3 Pa · s or more. It is preferable. In addition, although the viscosity at 20-25 degreeC of the 2nd mixture was demonstrated here, the temperature at the time of use of a 2nd mixture is not limited to 20-25 degreeC, It can select arbitrarily.

If necessary, the second mixture may be further blended with one or more selected from the group consisting of the reducing agent, alcohol and other components to form a silver ink composition.
The silver ink composition at this time can be manufactured by the same method as the above silver ink composition not using carbon dioxide except that the blending components are different. The obtained silver ink composition may have all of the compounding components dissolved therein or may be in a state where some of the components are dispersed without dissolving, but all of the compounding components are dissolved. Preferably, the undissolved component is preferably dispersed uniformly.

The temperature at the time of blending the reducing agent is not particularly limited as long as each blended component does not deteriorate, but is preferably −5 to 60 ° C. And the temperature at the time of mixing | blending is good to adjust suitably so that the mixture obtained by mix | blending may become the viscosity which is easy to stir according to the kind and quantity of a mixing | blending component.
Moreover, what is necessary is just to adjust a compounding time suitably according to the kind of compounding component, and the temperature at the time of a compounding, For example, it is preferable that it is 0.5 to 12 hours.

  As described above, the other components may be blended during the production of either the first mixture or the second mixture, or may be blended during the production of both. That is, in the process of producing the silver ink composition through the first mixture and the second mixture, the ratio of the blended amount of the other components to the total amount of blended components other than carbon dioxide ([other components (mass)] / [Formation material of metallic silver, nitrogen-containing compound, reducing agent, alcohol, and other components (mass)] × 100) is preferably 10% by mass or less, and more preferably 5% by mass or less. , 0 mass, that is, the silver ink composition exhibits its effect sufficiently even if other components are not blended.

  The silver ink composition to which carbon dioxide is supplied is, for example, a viscosity at 20 to 25 ° C. when the silver ink composition is applied to a printing method using a high viscosity ink such as a screen printing method or a flexographic printing method. Is preferably 1 Pa · s or more.

  For example, when a reducing agent is blended, the resulting blend (silver ink composition) tends to generate heat relatively easily. And when the temperature at the time of mixing | blending of a reducing agent is high, since this compounding will be in the state similar to the time of the heat processing of the silver ink composition mentioned later, by the decomposition | disassembly acceleration | stimulation effect | action of the said metal silver formation material by a reducing agent It is presumed that the formation of metal silver may be started in at least a part of the metal silver forming material. A silver ink composition containing such metallic silver may be able to form a conductor by performing post-treatment under milder conditions than the silver ink composition not containing metallic silver at the time of forming the conductor. Further, even when the amount of the reducing agent is sufficiently large, the conductor may be formed by performing the post-treatment under the same mild conditions. In this way, by adopting conditions that promote the decomposition of the metal silver forming material, the conductor can be used as a post-treatment, either by a heat treatment at a lower temperature or by a drying treatment at normal temperature without performing the heat treatment. Can be formed. Moreover, the silver ink composition containing such metal silver can be handled in the same manner as the silver ink composition not containing metal silver, and the handleability is not particularly inferior.

  The second mixture in the present invention has a higher viscosity than usual due to the supply of carbon dioxide as described above. On the other hand, when the reducing agent is blended into the second mixture, depending on the type of the second mixture or the reducing agent, formation of metallic silver is started in at least part of the metallic silver forming material as described above. Metallic silver may precipitate. Here, when the viscosity of the second mixture is high, the aggregation of the precipitated metallic silver is suppressed, and the dispersibility of the metallic silver in the obtained silver ink composition is improved. A conductor obtained by forming metallic silver by a method described later using such a silver ink composition is obtained by blending a reducing agent in a mixture having a low viscosity, that is, carbon dioxide is not supplied. In addition, it has higher electrical conductivity (lower volume resistivity), lower surface roughness, and more favorable characteristics than a conductor using a silver ink composition.

  In the present invention, it is also preferable to produce a silver ink composition by supplying carbon dioxide to a mixture comprising the metallic silver forming material, nitrogen-containing compound and alcohol. In this case, a method similar to the above can be adopted as a method for supplying carbon dioxide.

[concentrated]
The silver ink composition may be further concentrated at any stage during the production process. Such a silver ink composition has a high viscosity similar to that supplied with carbon dioxide as described above, such as flexographic printing, screen printing, gravure printing, gravure offset printing, pad printing, etc. It is suitable for application to printing methods that require thick ink.

Concentration may be performed at any time during the production of the silver ink composition. For example, the mixture after blending all the components may be concentrated, or the mixture at a stage where some of the components are not blended may be concentrated.
In the present invention, for example, it is preferable to produce a silver ink composition by concentrating a mixture containing the metallic silver forming material, nitrogen-containing compound and alcohol. When components other than the metal silver forming material, nitrogen-containing compound and alcohol (for example, reducing agent, other components, etc.) are used, these components may be blended independently before and after concentration.

  Thus, the silver ink composition concentrated in the production process has, for example, a viscosity at 20 ° C. of preferably 100 mPa · s or more, more preferably 120 mPa · s or more, and preferably 500 mPa · s or less. Preferably it is 450 mPa · s or less. When the viscosity is in such a range, the silver ink composition is more suitable for application to printing. Although the viscosity at 20 ° C. of the silver ink composition has been described here, the temperature at the time of use of the silver ink composition is not limited to 20 ° C. and can be arbitrarily selected.

  The concentration method may be appropriately selected from known methods, and preferred methods include heat concentration under normal pressure, and vacuum concentration under normal temperature or under heating conditions. Among these, vacuum concentration under normal temperature or heating conditions is preferable.

  The concentration conditions such as temperature, time, and pressure may be adjusted as appropriate according to the blending components and amount of the mixture. For example, the temperature during concentration is preferably 18 ° C. or higher, more preferably 20 ° C. or higher, and particularly preferably 23 ° C. or higher. A silver ink composition is more efficiently obtained because the lower limit of the temperature at the time of concentration is in such a range. The temperature during concentration is preferably 70 ° C. or less, more preferably 60 ° C. or less, and particularly preferably 50 ° C. or less. When the upper limit value of the temperature at the time of concentration is in such a range, a silver ink composition having better quality with fewer impurities can be obtained.

  The concentration time is preferably 10 minutes or more, more preferably 15 minutes or more, and particularly preferably 20 minutes or more. When the lower limit value of the concentration time is in such a range, a silver ink composition having a higher viscosity can be obtained. Further, the concentration time is preferably 180 minutes or less, more preferably 120 minutes or less, and particularly preferably 90 minutes or less. When the upper limit value of the concentration time is in such a range, a silver ink composition having better quality with fewer impurities can be obtained more efficiently.

  The pressure during concentration is preferably 500 hPa (hectopascal) or less, more preferably 300 hPa or less, further preferably 150 hPa or less, and particularly preferably 100 hPa or less. When the upper limit value of the pressure during concentration is in such a range, a silver ink composition having better quality with fewer impurities can be obtained more efficiently. Moreover, the lower limit of the pressure at the time of concentration is not specifically limited.

  The temperature at the time of concentration, the concentration time, and the pressure at the time of concentration may be adjusted to a suitable range while taking each value into consideration. For example, even if the temperature during concentration is set low, the mixture is efficiently concentrated by setting the pressure during concentration low, setting the concentration time long, or both. it can. In addition, even if the pressure during concentration is set high, the mixture can be efficiently concentrated by increasing the temperature during concentration, or by setting the concentration time longer, or both. . In other words, a silver ink composition of good quality can be efficiently obtained by flexibly combining the numerical values in the above numerical ranges, which are exemplified as the temperature during concentration, the concentration time, and the pressure during concentration, while considering each other's values. Is obtained.

The mixture is preferably concentrated with stirring. By doing so, the mixture at the time of concentration can be made more uniform, for example, even if some components are not dissolved, it can be more uniformly dispersed, so the concentration process can be made more stable. It can be carried out. As a result, the quality of the final concentrate (ie, silver ink composition) is better.
The stirring method at this time may be the same as in the production of the silver ink composition, and if the container containing the mixture is capable of rotating or rotating, the container is moved to stir the mixture. Also good.

  Up to this point, the silver ink composition has been mainly described. However, the ink composition used in this step preferably has a viscosity at 20 to 25 ° C. of 0.5 to 50000 mPa · s, for example, 0.5 More preferably, it is -10000 mPa * s, and it is especially preferable that it is 2000-5000 mPa * s. However, the temperature when the ink composition is used is not limited to 20 to 25 ° C., and can be arbitrarily selected.

<Conductive pattern formation process>
In the formation method according to the present invention, as shown in FIG. 2C, the second pattern 12 is then formed on the first pattern 11, and the first pattern 11 and the second pattern 12 are laminated. Pattern 1 is formed (hereinafter, this process may be abbreviated as “conductive pattern formation process”).

  In this step, an ink composition for forming a conductor is further printed on the first pattern 11 (the surface 11a of the first pattern 11), and the printed ink composition is solidified to form the first pattern. The second pattern 12 is formed on the conductive pattern 1 to form the conductive pattern 1.

The ink composition used in this step is for forming a conductor, is formed by blending a conductor forming material, and is vaporized under the conditions for forming the second pattern 12 (conditions for forming a conductor). The proportion of the volatile component to be removed from the ink composition is 20% by mass or more, preferably 23% by mass or more, based on the total amount of the compounding components. Thus, in this step, an ink composition having a high proportion of volatile components is used.
The ink composition may be either a solution or a dispersion, but in the case of a dispersion, it is preferable that the non-dissolved material is uniformly dispersed.

  In the ink composition printed in this step, the volatile component is removed during the solidification process to form the second pattern 12 that is a conductor. In addition, when the formation of the first pattern 11 is not performed until the formation of the conductor, the conductor is formed in the first pattern 11 simultaneously with the second pattern 12 in this step. That is, only the second pattern 12 may be formed in this step, or both the first pattern 11 and the second pattern 12 may be formed.

  The ink composition used in this step may be the same as or different from the one used for forming the first pattern 11, but the material used to form the first pattern 11 is a blended conductor forming material. The same as the ink composition used for forming the first pattern 11 is more preferable. Thus, by using an ink composition having a composition similar to or the same as that used for forming the first pattern 11, a higher effect of suppressing disconnection of the conductive pattern 1 can be obtained.

  The volatile component is not particularly limited. For example, among the compounds exemplified as the compounding component of the silver ink composition, the nitrogen-containing compound, the reducing agent, alcohol, and a solvent other than alcohol can be exemplified.

  In this step, the second pattern 12 may be formed by attaching the ink composition to a desired location on the first pattern 11 and performing a heating (firing) treatment.

  The printing method of the ink composition in this step is not particularly limited, and may be the same as in the case of the composition for the receiving layer. Screen printing method, flexographic printing method, offset printing method, dip printing method, inkjet printing method, Examples thereof include a dispenser printing method, a gravure printing method, a gravure offset printing method, a pad printing method, and a spray printing method.

  The printed ink composition is solidified, and the condition for solidification at this time is that the second pattern 12 is formed on the first pattern 11 to make these laminates conductive patterns, that is, the ink composition is conductive from the ink composition. What is necessary is just the conditions which form a body.

  In this step, the ink composition is preferably solidified by heat treatment from the viewpoint of performing in a short time as in the first pattern forming step.

  The temperature (heating temperature) at the time of the heat treatment in this step may be appropriately adjusted according to the type of the composition component of the ink composition so that the conductor is formed satisfactorily, but is 60 to 200 ° C. It is preferable that it is 70-180 degreeC. Moreover, what is necessary is just to adjust a heating time according to heating temperature, Usually, it is preferable that it is 1 minute-12 hours, and it is more preferable that it is 1 minute-10 hours. Such heat treatment conditions are particularly suitable when the silver ink composition is used as the ink composition. Among the silver metal forming materials, the silver carboxylate, particularly β-ketocarboxylate silver (1) is different from the metal silver forming material such as silver oxide. Decomposes at low temperatures even when not in use. And reflecting such decomposition temperature, the silver ink composition using such a metallic silver forming material can form metallic silver at a temperature much lower than that of the conventional one.

  When the ink composition is attached to a substrate having low heat resistance and is heated (baked), the heating temperature is preferably less than 130 ° C, more preferably 125 ° C or less, and 120 ° C or less. It is particularly preferred.

  The method of heat treatment of the ink composition in this step is not particularly limited, and for example, heating by an electric furnace, heating by a thermal head, heating by far infrared irradiation, heating by blowing a hot gas, etc. it can. In addition, the heat treatment of the ink composition may be performed in the air, in an inert gas atmosphere, or may be performed under humidified conditions. And you may carry out under any of normal pressure, pressure reduction, and pressurization.

  In the present specification, “humidification” means that the humidity is artificially increased unless otherwise specified, and preferably the relative humidity is 5% or more. At the time of heat treatment, since the humidity in the treatment environment becomes extremely low due to the high treatment temperature, it can be said that the relative humidity of 5% is clearly artificially increased.

  Among these, in this step (when the second pattern 12 is formed), the heat treatment of the ink composition is preferably performed under humidified conditions, more preferably in an atmosphere with a relative humidity of 40% or more, and relative humidity. More preferably, it is carried out in an atmosphere of 60% or higher, particularly preferably in an atmosphere of relative humidity of 80% or higher, and may be carried out by spraying high-pressure steam heated to 100 ° C. or higher. Thus, the heat processing under humidification conditions can form the conductive pattern 1 having a low resistance value (excellent conductivity) in a short time.

  Solidification of the ink composition in this step (during formation of the second pattern 12) is performed by first drying the ink composition without performing formation of the conductor, and then performing formation of the conductor. A two-stage process may be performed. For example, the first-stage heat treatment for drying the ink composition can be performed under the same conditions as those for forming the first pattern 11 described above. Further, the second-stage heat treatment up to the formation of the conductor can be performed under the above-described conditions cited as the conditions for forming the second pattern 12 in this step. Thus, by making it solidify in two steps, the affinity of the 1st pattern 11 and the 2nd pattern 12 can be improved.

When solidifying the ink composition in this step (at the time of forming the second pattern 12) is performed in a two-step process as described above, it may be performed under the following conditions.
That is, in the first-stage heat treatment of the ink composition printed on the first pattern 11, the heating temperature is preferably 60 to 155 ° C., and more preferably 70 to 155 ° C. Moreover, what is necessary is just to adjust a heating time according to heating temperature, Usually, it is preferable that it is 5 second-12 hours, and it is more preferable that it is 30 second-2 hours.
In the second stage heat treatment of the ink composition printed on the first pattern 11, the heating temperature is preferably 60 to 200 ° C, more preferably 70 to 180 ° C. Moreover, what is necessary is just to adjust a heating time according to heating temperature, Usually, it is preferable that they are 5 second-12 hours, and it is more preferable that they are 30 seconds-10 hours.
By solidifying in two stages in this way, it may be possible to further improve the affinity between the first pattern 11 and the second pattern 12.

  When the ink composition is attached to a substrate having low heat resistance and is heated (baked), the heating temperature in the first and second stage heat treatment is preferably less than 130 ° C., and 125 ° C. It is more preferable that the temperature is 120 ° C. or less.

When heat treatment under humidified conditions is employed, the ink composition is heat-treated in the first stage of heat treatment under non-humidified conditions, as described above, rather than forming the conductor as described above. It is particularly preferable that the second-stage heat treatment is performed by a two-stage method in which the formation of the conductor is performed to the end as described above under humidified conditions.
In the present specification, “non-humidification” means that the above “humidification” is not performed, that is, the humidity is not artificially increased, and preferably the relative humidity is less than 5%. .

When performing the above-mentioned heat treatment by a two-stage method, the heating temperature during the heat treatment under non-humidifying conditions in the first stage is preferably 60 to 110 ° C, more preferably 70 to 90 ° C. preferable. The heating time is preferably 5 seconds to 3 hours, more preferably 30 seconds to 2 hours, and particularly preferably 30 seconds to 1 hour.
When performing the above-mentioned heat treatment by a two-stage method, the heating temperature during the heat treatment under the second-stage humidification condition is preferably 60 to 155 ° C, more preferably 70 to 155 ° C. . The heating time is preferably 1 minute to 2 hours, more preferably 1 minute to 1 hour, and particularly preferably 1 minute to 30 minutes.
When the ink composition is attached to a substrate having low heat resistance and is heated (baked), the heating in the first stage of the non-humidifying condition and the heating in the second stage of the humidifying condition are performed. All of the temperatures are preferably less than 130 ° C, more preferably 125 ° C or less, and particularly preferably 120 ° C or less.

  In the present invention, in the process of forming the conductive pattern 1 by laminating the first pattern 11 and the second pattern 12, this ink composition (the first composition associated with the solidification of the ink composition used for forming the second pattern 12). The amount of the volatile component removed from the ink composition forming the two patterns 12 is determined by the solidification of the ink composition used for forming the first pattern 11 to form the ink composition (first pattern 11). The amount of the volatile component removed from the ink composition).

  The second pattern 12 formed in this step is thick as described above, and the conductive pattern 1 can also be thick. Thus, even if the conductive pattern 1 is thick, the occurrence of disconnection is suppressed. This is because the second pattern 12 is laminated on the first pattern 11, and even if the volatile component is removed by solidification of the ink composition in this step, It is estimated that this is because the shrinkage of the volume of the two patterns 12 is suppressed. Even if a crack or the like occurs in the second pattern 12, the first pattern 11 does not originally have a disconnection, and as a result, the conductive pattern 1 does not disconnect.

  In addition, the conductive pattern 1 has a laminated structure of the first pattern 11 and the second pattern 12 regardless of the thickness thereof, so that it is more disconnected than a single-layered conductive pattern having the same thickness. Is significantly suppressed.

  When manufacturing what provided other layers other than the receiving layer 3 and the conductive pattern 1 on the base material 2 as base material 1 'with a conductive pattern, in said formation method, other things are carried out at predetermined timing. What is necessary is just to add the process of forming a layer suitably.

  The conductive pattern according to the present invention is useful as a conductive wiring, and the base material with a conductive pattern is extremely useful as a component of circuit boards and the like of various electronic devices.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples.

[Example 1]
<Formation of conductive pattern>
(Manufacture of silver ink composition)
Add 2-methyl acetoacetate silver to 2-ethylhexylamine (0.4 times molar amount with respect to 2-methylacetoacetate silver described later) in a beaker so that the liquid temperature is 50 ° C. or less. The mixture was stirred for 15 minutes to obtain a liquid material. To this liquid, formic acid (0.7-fold molar amount with respect to silver 2-methylacetoacetate) was added dropwise over 30 minutes using a syringe pump so that the temperature of the reaction solution was 50 ° C. or lower. After the formic acid was dropped, the reaction solution was further stirred at 25 ° C. for 1 hour to obtain a silver ink composition. Table 1 shows the types and blending ratios of each blending component. In Table 1, “nitrogen-containing compound (molar ratio)” means the compounding amount (number of moles) of nitrogen-containing compound per mol of compounding material of the metallic silver ([number of moles of nitrogen-containing compound] / [metal The number of moles of silver forming material]). Similarly, the “reducing agent (molar ratio)” is the amount (mole number) of the reducing agent per mole of the metal silver forming material ([mole number of reducing agent] / [mole of metal silver forming material). Number]). The same applies to the following similar tables.
Of the above-described blending components of the obtained silver ink composition, volatile components that are vaporized and removed under the formation conditions of the second pattern described later are 2-ethylhexylamine and formic acid, and their total blending amount The ratio is 27.3 mass% with respect to the total amount of the blending components (total blending amount of all the blending components).

(Production of composition for receiving layer)
UV curable polycarbonate skeleton-containing urethane acrylate ("UV-3310B" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., weight average molecular weight 13000), cyclohexanone (manufactured by Wako Pure Chemical Industries, Ltd.), and A photopolymerization initiator (“Irgacure 127” manufactured by BASF Japan) was added and stirred at 50 ° C. for 2 hours to prepare a composition for a receiving layer. In addition, the compounding quantity currently displayed by the mass% unit in Table 2 means the ratio of each compounding component with respect to the total amount of a compounding component.

(Formation of conductive pattern)
Using a bar coater (bar No. 010), the composition for the receiving layer obtained above was applied on one main surface (surface) of a substrate (thickness 2 mm) made of polycarbonate / ABS resin alloy, After drying in an oven at 80 ° C. for 5 minutes, an ozone-less high-pressure mercury lamp is used to irradiate the dried coating film with ultraviolet light at a light intensity of 800 mJ / cm ² , and the polycarbonate skeleton-containing urethane The acrylate was cured to form a receiving layer (thickness 3 μm or less) on the entire surface of the substrate.

Next, dispenser printing was performed on the receiving layer using the silver ink composition obtained above. At this time, the discharge pressure was 70 kPa, and the distance (gap) between the discharge port and the receiving layer surface was 0.05 mm. Then, the printed substrate is placed in an oven and heated at 80 ° C. for 30 minutes to remove volatile components and solidify the silver ink composition to form a first pattern on the receiving layer. did.
Furthermore, dispenser printing was performed using the silver ink composition obtained above so as to overlap the formed first pattern. At this time, the discharge pressure was 150 kPa, and the distance (gap) between the discharge port and the receiving layer surface was 0.25 mm. And the volatile component was removed from the silver ink composition by putting the base material which performed this printing in oven, and heat-processing at 80 degreeC for 30 minute (s). Next, this base material was further heat-treated for 2 minutes in a high-temperature and high-humidity tank having a temperature of 80 ° C. and a relative humidity of 99%, thereby forming a conductive pattern in which the second pattern was laminated on the first pattern.

<Evaluation of conductive pattern>
(Measurement of the thickness of the first pattern and the second pattern)
About the obtained conductive pattern, the thickness of the 1st pattern and the 2nd pattern was measured using the shape measurement laser microscope ("VKX-100" by Keyence Corporation). The measurement was performed at five locations on the conductive pattern, and the average value was calculated. The results are shown in Table 3.

(Confirmation of disconnection of conductive pattern)
The presence or absence of disconnection in the obtained conductive pattern was confirmed by visual observation. The results are shown in Table 3. Moreover, the imaging data of the obtained conductive pattern are shown in FIG. In FIG. 3, (a) is the imaging data of the conductive pattern of the present embodiment. Further, FIG. 4 shows imaging data of a cross section of the conductive pattern by a field emission scanning electron microscope (FE-SEM: JSM-7500F, JEOL). FIG. 4 also shows enlarged data of 20000 times in addition to data of 500 times magnification at an acceleration voltage of 5 kV.

(Measurement of volume resistivity of conductive pattern)
For the obtained conductive pattern, the line resistance value R (Ω), the cross-sectional area A (cm ² ), and the line length L (cm) were measured, and the volume resistivity ρ was calculated by the equation “ρ = R × A / L”. (ΜΩ · cm) was calculated. The wire resistance value R is measured using a digital multimeter ("PC5000a" manufactured by Sanwa Denki Keiki Co., Ltd.), and the cross-sectional area A is measured using a shape measurement laser microscope ("VK-X100" manufactured by Keyence Corporation). did. The results are shown in Table 3.

[Example 2]
During the formation of the conductive pattern, the base material after the removal of the volatile component of the silver ink composition printed on the first pattern is heated in a high-temperature and high-humidity tank at 80 ° C. and a relative humidity of 99%. Example 2 was conducted except that the high-pressure steam at 120 ° C. was sprayed for 2 minutes under the condition of 15.7 kg / hour per area of 350 mm × 525 mm on the printed surface of the substrate instead of performing for 2 minutes. The conductive pattern was formed and evaluated in the same manner as in 1. The results are shown in Table 3.

[Example 3]
At the time of forming the conductive pattern, the conductive pattern was formed and evaluated in the same manner as in Example 2 except that the time for spraying high-pressure water vapor at 120 ° C. was changed to 5 minutes instead of 2 minutes. The results are shown in Table 3.

[Example 4]
During the formation of the conductive pattern, the base material after the removal of the volatile component of the silver ink composition printed on the first pattern is heated in a high-temperature and high-humidity tank at 80 ° C. and a relative humidity of 99%. The conductive pattern was formed in the same manner as in Example 1 except that the substrate was placed in an oven that was not humidity-controlled and heat-treated at 120 ° C. for 30 minutes. evaluated. The results are shown in Table 3.

[Example 5]
In the same manner as in Example 4 except that, when the conductive pattern is formed, the temperature when the substrate is placed in an oven that is not humidity-controlled and heat-treated for 30 minutes is set to 80 ° C. instead of 120 ° C. A conductive pattern was formed and evaluated. The results are shown in Table 3.

[Comparative Example 1]
Except that the first pattern was not formed on the receiving layer of the substrate (that is, only the second pattern was formed on the receiving layer of the substrate using the silver ink composition to form a conductive pattern). A conductive pattern was formed and evaluated in the same manner as in Example 1. The results are shown in Table 3. Moreover, the imaging data of the obtained conductive pattern are shown in FIG. In FIG. 3, (b) is the imaging data of the conductive pattern of this comparative example.

As is clear from the above results, in Examples 1 to 5, although the conductive pattern was formed thick, volume shrinkage was suppressed, no disconnection occurred, and the volume resistivity was low. . As shown in FIG. 3A (Example 1), the conductive pattern has no disconnection due to volume shrinkage, and this was the same in Examples 2 to 5. Further, as is clear from Examples 1 to 3, in the heat treatment after removing the volatile component of the silver ink composition printed on the first pattern, the higher the heating temperature, the longer the heat treatment time. There was a tendency that the volume resistivity of the conductive pattern was low. This is presumed to be due to the fact that the formation of metal silver in the silver ink composition proceeds at a higher rate and the degree of fusion between the formed metal silver increases as the degree of heating increases. Further, as is clear from the comparison between Examples 1 to 3 and Examples 4 to 5, a conductive pattern having a low volume resistivity (resistance value) could be formed in a short time by heat treatment under humidified conditions. . As shown in FIG. 4, in the cross section of the conductive pattern of Example 1, the interface Z between the first pattern and the second pattern was confirmed. This was the same in Examples 2 to 5.
On the other hand, in Comparative Example 1, since the conductive pattern was formed as a single layer thickly, as shown in FIG. 3B, the conductive pattern had a large degree of volume shrinkage, a disconnection occurred, and the volume resistivity. Could not be measured. It is clear from the comparison between FIGS. 3A and 3B that the conductive pattern of Comparative Example 1 has a larger volume shrinkage than the conductive pattern of Example 1.

[Example 6]
<Formation and evaluation of conductive pattern>
The blending amounts of the blending components at the time of producing the silver ink composition are as shown in Table 4, the discharge pressure of the silver ink composition at the time of forming the first pattern is set to 80 kPa instead of 70 kPa, and the silver ink composition at the time of forming the second pattern A conductive pattern was formed and evaluated in the same manner as in Example 2 except that the discharge pressure of the object was changed to 200 kPa instead of 150 kPa. The results are shown in Table 5. In Table 4, "-" in the column of the blending component means that the component is not blended.

[Example 7]
<Formation of conductive pattern>
(Manufacture of silver ink composition)
In a beaker, 2-ethylhexylamine (1.3 times the molar amount relative to 2-methylacetoacetate silver described later) and isobutylamine (based on 2-methylacetoacetate silver described later) so that the liquid temperature becomes 50 ° C. A liquid product was obtained by adding silver 2-methylacetoacetate to a mixture of 0.2 molar amount and stirring for 15 minutes using a mechanical stirrer. To this liquid, formic acid (0.4 times molar amount with respect to silver 2-methylacetoacetate) was added dropwise over 30 minutes using a syringe pump so that the temperature of the reaction solution was 50 ° C. or lower. After completion of the formic acid dropwise addition, the reaction solution was further stirred at 25 ° C. for 1 hour and then maintained at 25 ° C. ”(Hereinafter sometimes abbreviated as“ DMHO ”) (0.05-fold molar amount relative to silver 2-methylacetoacetate), and the reaction solution is further stirred for about 2 minutes, whereby a silver ink composition is obtained. Got. Table 4 shows the types and mixing ratios of the respective components. In Table 4, “alcohol (molar ratio)” means the blending amount (number of moles) of alcohol per mole of forming material of metallic silver ([number of moles of alcohol] / [mol of forming material of metallic silver] Number]).
Of the above-described blended components of the obtained silver ink composition, volatile components that are removed by vaporization under the second pattern formation conditions are 2-ethylhexylamine, isobutylamine, formic acid, and DMHO. The ratio of the total blending amount is 48.2% by mass with respect to the total amount of the blending components (total blending amount of all the blending components).

(Formation of conductive pattern)
Using the silver ink composition obtained above, the discharge pressure of the silver ink composition at the time of forming the first pattern was changed to 80 kPa instead of 70 kPa, and the discharge pressure of the silver ink composition at the time of forming the second pattern was changed to 150 kPa. A conductive pattern was formed in the same manner as in Example 1 except that the pressure was 200 kPa.

<Evaluation of conductive pattern>
The obtained conductive pattern was evaluated in the same manner as in Example 1. The results are shown in Table 5.

[Example 8]
During the formation of the conductive pattern, the base material after the removal of the volatile component of the silver ink composition printed on the first pattern is heated in a high-temperature and high-humidity tank at 80 ° C. and a relative humidity of 99%. Was carried out by spraying high-pressure steam at 120 ° C. for 2 minutes under the condition of 15.7 kg / hour per 350 mm × 525 mm area (same as in Example 2). The conductive pattern was formed and evaluated in the same manner as in Example 7 except for the point). The results are shown in Table 5.

[Example 9]
<Formation of conductive pattern>
(Manufacture of silver ink composition)
2-Ethylhexylamine (2.3 times mole amount based on 2-methylacetoacetate silver described later) and DMHO (0.10 times mole amount based on silver 2-methylacetoacetate described later) were added to the flask. The mixture was further stirred, and silver 2-methylacetoacetate was added and stirred so that the liquid temperature was 50 ° C. or lower. And the silver ink composition was obtained by maintaining the pressure of 30 hPa, concentrating under reduced pressure for 60 minutes, adjusting the temperature of the whole quantity of the obtained mixture with a 25 degreeC water bath. Table 4 shows the types and mixing ratios of the respective components. The mass reduction rate in the process of obtaining the silver ink composition from the mixture was 10.0%.

(Formation of conductive pattern)
Instead of performing the heat treatment of the silver ink composition printed on the first pattern at 80 ° C. for 30 minutes when using the silver ink composition obtained above and forming the conductive pattern. A conductive pattern was formed in the same manner as in Example 7 except that the process was performed at 150 ° C. for 30 minutes.

<Evaluation of conductive pattern>
The obtained conductive pattern was evaluated in the same manner as in Example 7. The results are shown in Table 5.

[Example 10]
During the formation of the conductive pattern, the base material after the removal of the volatile component of the silver ink composition printed on the first pattern is heated in a high-temperature and high-humidity tank at 80 ° C. and a relative humidity of 99%. Was carried out by spraying high-pressure steam at 120 ° C. for 5 minutes under the condition of 15.7 kg / hour per 350 mm × 525 mm area on the printed surface of the substrate (same as in Example 3). A conductive pattern was formed and evaluated in the same manner as in Example 9 except for the point). The results are shown in Table 5.

[Comparative Example 2]
The first pattern was not formed on the receiving layer of the substrate (that is, the conductive pattern was formed by forming only the second pattern using the silver ink composition on the receiving layer of the substrate), and the first A conductive pattern was formed and evaluated in the same manner as in Example 7 except that the discharge pressure of the silver ink composition at the time of forming the two patterns was changed to 450 kPa instead of 200 kPa. The results are shown in Table 5.

As is clear from the above results, in Examples 6 to 10, the volume shrinkage of the conductive pattern was suppressed, no disconnection occurred, and the volume resistivity was low. As a result of visual observation, all of these conductive patterns are in the same state as in the case of Example 1 shown in FIG. 3A. Also, in the cross section of these conductive patterns, Example 1 shown in FIG. As in the case of, the interface Z between the first pattern and the second pattern could be confirmed.
On the other hand, in Comparative Example 2, the conductive pattern is formed thick with a single layer, so that the conductive pattern has a large degree of volume shrinkage and the disconnection is similar to the case of Comparative Example 1 shown in FIG. The volume resistivity could not be measured.

  In Examples 6 to 10, both the first pattern and the second pattern are thinner than Examples 1 to 5, but unlike Comparative Example 2 in which the thickness of the conductive pattern is the same, the conductivity associated with the shrinkage of the volume. The disconnection of the pattern was suppressed. From this, it has confirmed that the effect of this invention was expressed in the range of the thickness of a wide conductive pattern.

  The present invention can be used for wiring boards in various electronic devices.

DESCRIPTION OF SYMBOLS 1 ... Conductive pattern, 11 ... 1st pattern, 11a ... The surface of a 1st pattern, 12 ... 2nd pattern, 2 ... Base material, 2a ... One main of a base material Surface, 2b ... the other main surface of the substrate, 3 ... the receiving layer, 3a ... the surface of the receiving layer, H ₁₁ ... the thickness of the first pattern, H ₁₂ ... the second pattern Thickness, Z ... the interface between the first pattern and the second pattern

Claims (3)

An ink composition for forming a conductor is printed on a substrate and solidified to form a first pattern on the substrate,
An ink composition for forming a conductor is further printed on the first pattern and solidified to form a second pattern on the first pattern, and the first pattern and the second pattern are laminated. In the method of forming a conductive pattern for forming a conductive pattern,
The second pattern is thicker than the first pattern,
In the ink composition used for forming the first pattern and the second pattern, the ratio of the amount of the volatile component vaporized under the conditions for forming the second pattern and removed from the ink composition is the total amount of the compounded components. It is 20 mass% or more with respect to the formation method of the conductive pattern characterized by the above-mentioned.   2. The method for forming a conductive pattern according to claim 1, wherein the ink composition is solidified by heat treatment in an atmosphere having a relative humidity of 40% or more when forming the second pattern.   A conductive wiring formed by the method for forming a conductive pattern according to claim 1.