JP2014024330A - Ink-receiving layer and method for forming conductive pattern - Google Patents

Abstract

The present invention provides an ink receiving layer capable of forming a conductive pattern having good conductivity and good substrate adhesion formed on a substrate.
A conductive pattern can be formed by heating or baking after applying or patterning an ink (I) containing a polyol (A) having at least two hydroxyl groups in the molecule. A resin soluble in the polyol (A) in the ink (I), which is an ink receiving layer (R) formed on the surface of the substrate (K), and the ink receiving layer (R) forms a surface layer. The coating layer (R2) made of (S) and the polyol (A) in the ink (I) coated or patterned at the time of firing, located between the substrate (K) and the coating layer (R2). An ink receiving layer comprising: a fine particle-containing layer (R1) comprising at least a fine particle (M) whose metal oxide on the surface thereof is reduced to exhibit conductivity and a binder resin (B).
[Selection figure] None

Description

The present invention relates to an ink receiving layer capable of forming a conductive pattern by heating and baking after applying or patterning an ink containing at least a polyol formed on the surface of a substrate, and a method for forming the conductive pattern.

Conventionally, a droplet discharge method is known as a method for forming a fine wiring pattern such as a circuit pattern on a printed wiring board. This method is a method of forming a wiring pattern by, for example, discharging a functional liquid containing a pattern forming component from a droplet discharge head onto a substrate. However, according to this method, a photolithography step is not necessary. There is an advantage that the process is greatly simplified. In this pattern formation, it is possible to form a conductive pattern of metal fine particles by performing patterning using a metal fine particle dispersion as a functional liquid containing a pattern forming component, followed by firing.
In recent years, from the viewpoint of cost reduction and migration resistance, it is desired to use a dispersion solution in which fine particles of base metal such as copper are used for conductive ink discharged by a droplet discharge method such as an inkjet process. However, since the base metal is a metal that is easily oxidized, there is a problem that it is difficult to form a conductive pattern that is oxidized during firing and has excellent conductivity. In order to solve this problem, by adding a reducing substance to the metal fine particle dispersion, it is possible to sinter in a low temperature / inert atmosphere by suppressing oxidation of the metal during calcination and promoting reduction. Become.
Moreover, in order to keep the metal particles in the ink before firing in a state where it is not oxidized at all, it is necessary to store it in an oxygen-free environment, which is a factor in increasing the cost. It is also important to understand and ease storage conditions.

On the other hand, when forming a conductive pattern using a metal fine particle dispersion, a thin film layer (receiving layer) for receiving the metal fine particle dispersion is provided on the substrate surface for the purpose of improving adhesion to the substrate and patterning. It has been proposed. A general metal fine particle dispersion receiving layer has a porous structure composed of inorganic particles and a binder, and the metal fine particle dispersion liquid is absorbed by the porous layer, so that the metal fine particles in the metal fine particle dispersion are dispersed. The structure remains on the surface of the receiving layer.
Patent Document 1 discloses a step of forming a microvoid-type receiving layer above a substrate and a liquid (droplet) containing at least one of conductive fine particles and an organometallic compound on the receiving layer, or A conductive pattern is formed by contacting at least one of the conductive fine particles and the organometallic compound, or the conductive fine particles and the organometallic compound by the step of providing on the receiving layer and in the receiving layer and heat treatment. And a method of forming a conductive film pattern comprising the steps.

  Patent Document 2 discloses an ink-jet base material comprising a water-soluble resin or an emulsion resin and a gel-forming organic material, and the gel-forming organic material is a hydrophilic anionic resin or natural polymer type. A base material that gels or thickens the ink by bringing the gel-forming organic substance into contact with the undried ink with a thickener or gelling agent, a polymer flocculant, or the like.

Patent Document 3 discloses a thin film pattern forming method capable of forming a fine thin film pattern with high accuracy and stability. The method of forming the thin film pattern is a method of forming a thin film pattern of a functional material on a substrate. The receiving layer pattern is formed by arranging a receiving layer ink (first functional liquid) containing a receiving layer material on the substrate. And a functional layer forming step of forming a conductive layer pattern by disposing a conductive layer ink (second functional liquid) containing conductive fine particles to the receiving layer pattern. ing.
In Patent Document 4, a highly oil-absorbing inorganic material is provided on a support for the purpose of providing an ink jet recording medium having high ink absorbability, excellent water resistance, antistatic property, and anti-powder property and high safety. An ink jet recording medium provided with at least one ink receiving layer containing a pigment and a binder resin, wherein the ink receiving layer further contains particulate titanium oxide coated with tin oxide. Has been.

JP 2004006578 A Japanese Patent No. 4300801 JP 2006-26522 A JP 2010-094987 A

  In Patent Document 1 described above, even when an ink containing conductive fine particles and a solvent that exhibits a reducing effect is patterned on the receiving layer, the solvent is absorbed in the receiving layer, and the amount of the reducing solvent is not sufficient. It is difficult to form a sufficient reducing atmosphere when firing the metal fine particles.

  The use of the base material disclosed in Patent Document 2 can prevent the occurrence of pattern thickness unevenness, but cannot improve the adhesion to the substrate and the conductivity. In the method for forming a conductive layer pattern disclosed in Patent Document 3, a thin thin film pattern can be formed, but it cannot be expected to improve adhesion and conductivity to the substrate.

  The inkjet recording medium disclosed in Patent Document 4 contains particulate titanium oxide coated with tin oxide as an antistatic agent, but since the specific gravity of titanium oxide is large, when applied in a WET state, In the layer, tin oxide-coated titanium oxide having a high specific gravity is likely to gather below, and accordingly, the number of contact points between the particulate titanium oxide particles coated with tin oxide increases, so that the antistatic function is easily exhibited. However, it is tin oxide that has a conductive function in the recording medium, and when the tin oxide particles come into contact with each other, an energization path is developed and an antistatic function is exhibited, but the conductivity is improved. I can't expect it.

  The present invention solves the above-mentioned problems of the prior art, and can form a conductive pattern on the surface of the receiving layer even if the ink such as an inkjet ink does not contain fine particles that develop conductivity, or To provide an ink receiving layer formed on a substrate and a method for forming the conductive pattern, which can improve the adhesion and conductivity of the conductive pattern formed on the surface of the receiving layer to the receiving layer (or substrate). With the goal.

The present inventors have improved the above-mentioned problems of the prior art, and the metal oxide is reduced on the substrate to exhibit conductivity, a particle-containing layer made of a binder resin, and a polyol on the layer. By providing a coating layer containing a soluble component, it was found that the above-mentioned problems can be solved by applying or patterning an ink containing at least a polyol, followed by baking, and the present invention has been completed.
That is, the gist of the present invention is the invention described in the following (1) to (10). (1) It is possible to form a conductive pattern by heating or baking after applying or patterning the ink (I) containing at least the polyol (A) having two or more hydroxyl groups in the molecule, An ink receiving layer (R) formed on the surface of the substrate (K),
A coating layer (R2) comprising a resin (S) soluble in the polyol (A) in the ink (I), wherein the ink receiving layer (R) forms a surface layer; and
Located between the substrate (K) and the coat layer (R2), at the time of firing, at least the metal oxide on the surface is reduced by the polyol (A) in the coated or patterned ink (I). A fine particle-containing layer (R1) comprising fine particles (M) exhibiting electrical conductivity and a binder resin (B);
An ink receiving layer (hereinafter sometimes referred to as a first embodiment).
(2) The metal oxide constituting at least the surface of the fine particles (M) in the fine particle-containing layer (R1) is formed from one or more oxides selected from copper oxide and cuprous oxide. The ink receiving layer according to (1), characterized in that it is characterized in that
(3) The ink receiving layer according to (1) or (2), wherein the binder resin (B) in the fine particle-containing layer (R1) is a water-soluble binder resin.

(4) The ink receiving layer according to any one of (1) to (3), wherein the water-soluble binder resin is polyvinyl alcohol.
(5) The fine particle-containing layer (R1) is composed of 50 to 95% by volume of fine particles (M) and 50 to 5% by volume of a binder resin (B) (a total of 100% by volume), The ink receiving layer according to any one of (1) to (4).
(6) The ink receiving layer according to any one of (1) to (5), wherein the resin (S) in the coat layer (R2) is made of a water-soluble resin.
(7) The ink receiving layer according to any one of (1) to (6), wherein the thickness of the coat layer (R2) is 0.5 to 50 μm.

(8) The ink (I) containing at least the polyol (A) is applied or patterned on the surface of the ink receiving layer (R) according to any one of (1) to (7), and the ink (I) is applied. After the coating layer (R2) of the ink receiving layer (R) is dissolved and penetrated into the fine particle-containing layer (R1),
By reducing and sintering the metal oxide that forms at least the surface of the fine particles (M) of the ink (I) permeation portion by heat treatment, the conductivity or the patterned portion of the ink (I) is expressed. A method for forming a conductive pattern (hereinafter sometimes referred to as a second mode).
(9) In the ink (I), polyol (A), copper fine particles (P ₁ ), copper fine particles (P ₂ ) whose surfaces are covered with copper oxide (Cu ₂ O), and copper oxide (Cu _2). The copper fine particles (P) composed of one or more selected from O) fine particles (P ₃ ) are 10 to 100/90 to 0 (parts by mass) of [polyol (A) / copper fine particles (P)] (mass ratio). The conductive pattern forming method according to (8), wherein the total number of the conductive patterns is 100 parts by mass).
(10) X-ray diffraction peak intensity of the copper fine particles (P) when the peak height of the Cu (111) plane is H1 and the peak height of the Cu ₂ O (111) plane is H2 in the X-ray diffraction measurement. Ratio (H2 / [H1 + H2]) is 0.91 or less, The method for forming a conductive pattern as described in (9) above, wherein
(11) The polyol (A) constituting the ink (I) is ethylene glycol, diethylene glycol, glycerin, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol. 1,4-butanediol, 2-butene-1,4-diol, pentanediol, hexanediol, octanediol, 1,1,1-trishydroxymethylethane, 2-ethyl-2-hydroxymethyl-1,3 -Propanediol, 1,2,6-hexanetriol, 1,2,3-hexanetriol, 1,2,4-butanetriol, threitol, erythritol, pentaerythritol, xylitol, sorbitol, pentitol, One or two selected from terpineol and hexitol Characterized in that it is a top, a method of forming the conductive pattern according to any one of (8) to (10).

(A) The ink receiving layer (R) (first aspect) described in (1) above is provided even if the ink for forming the conductive pattern does not contain conductive fine particles. Since the fine particles (M) made of the metal oxide therein are reduced during sintering and develop conductivity, it is not necessary to consider the storage stability of the ink (I).
In addition, the ink receiving layer (R) (first embodiment) described in (1) above has copper fine particles (P ₁ ) in the ink (I) for forming a conductive pattern, and the surface is copper oxide (Cu _2). When the copper fine particles (P) composed of one kind selected from the copper fine particles (P ₂ ) covered with O) and the copper oxide (Cu ₂ O) fine particles (P ₃ ) are contained, during sintering Further, as a result of the copper fine particles (P) and the fine particles (M) in the fine particle-containing layer (R1) being reduced and integrated during sintering, adhesion and conductivity are improved.
(B) The conductive pattern forming method (second aspect) described in (8) above enables the use of ink (I) that does not contain conductive fine particles, and copper fine particles in the ink (I). _(P 1), the surface oxide _(Cu 2 O) copper particles _(P 2) is covered with, and oxide _(Cu 2 O) particles _{(P 3)} consists of one or more selected from fine copper particles ( When P) is contained, the copper fine particles (P) and the fine particles (M) having a metal oxide on the surface in the ink receiving layer (R) are sintered and integrated during sintering. Thus, since the conductive pattern is formed, the adhesion and conductivity between the conductive pattern and the substrate are improved.

It is a conceptual diagram of the cross section of the receiving layer (R) formed on the board | substrate (K) of this invention. FIG. 2 is a conceptual diagram of a cross section in which ink (I) is patterned on the surface of the receiving layer (R) of the present invention shown in FIG. 1. The conductive layer is formed by patterning the ink (I) composed of the copper fine particles (P) and the polyol (A) on the surface of the receiving layer (R) of the present invention shown in FIG. It is a conceptual diagram of the cross section of the state made. FIG. 2 is a conceptual diagram of a cross section in a state where a conductive sintered body is formed by patterning the ink (I) made of the polyol (A) on the surface of the receiving layer (R) of the present invention shown in FIG. is there.

Hereinafter, [1] ink receiving layer (R) (first embodiment), [2] conductive pattern forming method (second embodiment) will be described.
[1] Ink receiving layer (R) (first embodiment)
The “ink-receiving layer (R)” according to the first aspect of the present invention is coated or patterned with an ink (I) containing at least a polyol (A) having two or more hydroxyl groups in the molecule. An ink receiving layer (R) formed on the surface of the substrate (K), on which a conductive pattern can be formed later by heating and baking, wherein the ink receiving layer (R) forms a surface layer. The coating layer (R2) made of the resin (S) soluble in the polyol (A) in (I), and positioned between the substrate (K) and the coating layer (R2) and applied during firing. A fine particle-containing layer (M) containing fine particles (M) in which at least the metal oxide on the surface is reduced by the polyol (A) in the patterned ink (I) and exhibiting conductivity, and a binder resin (B) R1).

  An example of the ink receiving layer (R) of the present invention is shown in FIG. FIG. 1 shows an ink receiving layer (R) in which a fine particle-containing layer (R1) 13 composed of fine particles (M) 15 and a binder resin (B) 16 and a coat layer (R2) 12 are formed on a substrate (K) 11. FIG.

(1) Substrate (K)
The substrate (K) used in the present invention is not particularly limited, and an inorganic material substrate such as a glass substrate, a paper-based substrate whose main material is paper, a resin substrate, and the like can be widely used. Examples of the resin substrate include polyester resin, polycarbonate resin, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polycycloolefin resin, and polyethylene naphthalate resin. Among these, it is preferable to use a polyimide resin, a polyamideimide resin, or a polyester resin from the viewpoints of heat resistance, mechanical characteristics, thermal characteristics, and the like, and among these, a polyimide resin is particularly preferable.
In addition, when using a glass substrate, it is desirable to perform an acid washing | cleaning, water washing, and a drying process in this order beforehand. When using a resin substrate, it is preferable to surface-treat the surface beforehand by one or more operations selected from corona treatment, electron beam irradiation, plasma treatment, and etching treatment.

(2) Ink receiving layer (R) The ink receiving layer (R) is a coating layer (R2) made of a resin (S) soluble in the polyol (A) in the ink (I), which forms a surface layer, and At least the metal oxide on the surface is reduced by the polyol (A) in the coated or patterned ink (I), which is located between the substrate (K) and the coat layer (R2) during firing. And a fine particle-containing layer (R1) composed of fine particles (M) exhibiting conductivity and a binder resin (B).

(2-1) Fine particle-containing layer (R1)
The fine particle-containing layer (R1) is composed of fine particles (M) in which at least the metal oxide on the surface thereof is reduced by the polyol (A) in the ink (I) to exhibit conductivity, and the binder resin (B). .
(I) Fine particles (M) The fine particles (M) in the fine particle-containing layer (R1) maintain a non-conductive state even after sintering in portions where the ink (I) is not applied or patterned, and the ink (I) In order for the portion coated with or patterned to exhibit conductivity after sintering, at least the surface of the fine particles (M) needs to be formed of a metal oxide before sintering. ) There may be an unoxidized metal portion inside.
In addition, after sintering, at least the metal oxide on the surface of the fine particles (M) may be reduced to develop conductivity, and after sintering, the metal oxide portion is present inside the fine particles (M). May be.
Examples of the metal oxide that forms at least the surface portion of the fine particles (M) include conductive base metal oxides. Among these, one or more kinds of oxides selected from copper oxide and cuprous oxide are included. It is preferably formed from a product. In addition, since the electrical resistivity of cuprous oxide is as large as 1 × 10 ⁵ times that of copper oxide and short-circuiting between wiring patterns hardly occurs, it is particularly desirable.
Further, the fine particles (M) do not have conductivity before sintering, and at least the surface thereof is reduced by the polyol (A) contained in the ink (I) by sintering, and a sintered body is formed and becomes conductive. In order to express the properties, the average primary particle diameter of the fine particles (M) is preferably about 0.01 to 10 μm.

(Ii) Binder resin (B) The binder resin (B) binds the fine particles (M) to form the shape of the fine particle-containing layer (R1), and applies the coated or patterned polyol (A) to the fine particle-containing layer. Necessary to penetrate into (R1). Since the binder resin (B) is heated when used in an electronic device or the like, a material having a high glass transition point is preferable. Examples of hydrophilic polymers include polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, polyurethane, etc., and lipophilic polymers include vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic. Examples thereof include resins, phenol resins, polyesters, polyurethanes, epoxy resins, silicone resins, fluororesins, butyral resins, melamine resins, natural rubber, and synthetic rubbers. Two or more of these polymers can be used in combination.

The binder resin (B) used in the present invention is preferably a water-soluble resin because it is preferably dissolved and applied in an aqueous solvent when forming the ink receiving layer (R).
Furthermore, polyvinyl alcohol is more preferable as the water-soluble resin. The polybilyl alcohol includes, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol such as polyvinyl alcohol having a cation-modified terminal and anion-modified polyvinyl alcohol having an anionic group. In consideration of handling and high versatility, it is preferable to use ordinary polyvinyl alcohol.
As the normal polyvinyl alcohol, those having an average polymerization degree of 1000 or more are preferably used, and those having an average polymerization degree of 1000 to 2400 are particularly preferable. The saponification degree is preferably 70 to 100%, particularly preferably 80 to 99.5%. When an organic solvent is used when obtaining the fine particle-containing layer forming coating solution, a resin that is easily dissolved in an organic solvent such as alcohol, aromatic solvent, ketone, or ether can be used.
The binder resin (B) improves the film strength of the ink receiving layer by bonding fine particles (M) to each other at the time of forming the ink receiving layer (R), and the adhesion between the ink receiving layer (R) and the substrate (K). Improves sex.

(Iii) Composition of the fine particle-containing layer (R1) The proportion of the fine particles (M) and the binder resin (B) in the fine particle-containing layer (R1) is 50 to 95% by volume of the fine particles (M) and the binder resin (B) 50. It is preferable to consist of -5 volume% (the sum total of volume% is 100 volume%). If the blending ratio of the binder resin (B) is less than the lower limit of the above range, the bond between the fine particles (M) may be reduced, and the adhesion between the substrate (K) and the coat layer (R2) may also be reduced. On the other hand, if the blending ratio of the binder resin (B) exceeds the upper limit of the above range, sufficient conductivity may not be exhibited after sintering.

(Iv) Coating Solution for Forming Fine Particle-Containing Layer The coating solution for forming a fine particle-containing layer comprises at least fine particles (M), a binder resin (B), and a solvent, and the solvent is preferably an aqueous solvent. The aqueous solvent is a solvent containing water as a main component, and the proportion of water in the aqueous solvent is usually preferably 65% by mass or more. As a solvent other than water, alcohols such as methanol, ethanol and isopropyl alcohol or ketones such as methyl ethyl ketone can be used.

(V) Formation of Fine Particle-Containing Layer (R1) The fine particle-containing layer (R1) is a coating liquid for forming an ink receiving layer comprising at least fine particles (M), a binder resin (B), and a solvent on a substrate (K). After coating, the solvent is removed by evaporation.
The method for applying the fine particle-containing layer forming coating solution onto the substrate (K) can be selected from known methods such as spin coating, dip coating, drop coating, roller coating, stamping, and inkjet.
The thickness of the fine particle-containing layer (R1) thus formed is preferably about 1 to 100 μm.

(2-2) Coat layer (R2)
The coat layer (R2) is a layer made of a resin (S) that is soluble in the polyol (A) in the ink (I) and forms the surface layer.
In the portion where the ink (I) is applied or patterned, the coat layer (R2) is melted into the polyol (A), and the polyol (A) in the ink (I) penetrates into the fine particle-containing layer (R1). As a result, when the fine particles (M) are heated and fired, the polyol (A) component that has permeated into the fine particle-containing layer (R1) is easily decomposed to reduce the metal oxide on the surface of the fine particles (M), thereby making it conductive. The sintered body is formed.
On the other hand, the coating layer (R2) portion where the ink (I) is not applied or patterned is the polyol (A) component volatilized during firing without the resin (S) being melted, and the reduction in the firing atmosphere. It functions as a protective film that prevents the surface of the fine particles (M) where the ink (I) is not applied or patterned by the active substance (hydrogen or the like) from being reduced.

(I) Component of resin (S) The main component for forming the coat layer (R2) is preferably dissolved and applied in an aqueous solvent when the coat layer (R2) is formed, as in the case of the binder resin. Accordingly, it is desirable that the water-soluble resin be the same as the binder resin (B) used for the fine particle-containing layer (R1). Furthermore, as the water-soluble resin, polyvinyl alcohol is more preferable. The polybilyl alcohol includes, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol such as polyvinyl alcohol having a cation-modified terminal and anion-modified polyvinyl alcohol having an anionic group. In consideration of handling and high versatility, it is preferable to use ordinary polyvinyl alcohol.
As the normal polyvinyl alcohol, those having an average polymerization degree of 1000 or more are preferably used, and those having an average polymerization degree of 1000 to 2400 are particularly preferable. The saponification degree is preferably 70 to 100%, particularly preferably 80 to 99.5%.

For the coat layer (R2), a material having high compatibility with the actually used polyol (A) can be selected as the water-soluble resin. As a compatibility index, a solubility parameter (SP value) is known, and a material having an SP value close to that of the polyol (A) may be selected. This SP value is calculated by the following formula (1).
SP value = (ΣE / ΣV) ^1/2 (1)
In the above formula (1), ΣE represents the cohesive energy (cal / mol), and ΣV represents the molar molecular volume (cm ³ / mol).
For example, when glycerin is used as the polyol (A), since the SP value of glycerin is 16.5, as a cellulose polymer compound having an SP value close to this, for example, methyl cellulose (SP value: 17.2) Carboxymethylcellulose (SP value: 14.8), hydroxyethylcellulose (SP value: 13.8), hydroxyethylmethylcellulose (SP value: 15.1), hydroxypropylmethylcellulose (SP value: 13.1), and the like. Among these, methylcellulose having the closest SP value is more preferable. The resin (S) forming the coat layer (R2) improves the adhesion with the fine particle-containing layer (R1), improves the film strength of the coat layer (R2), and forms a conductive pattern on the ink receiving layer (R). Enables the formation of Moreover, when using an organic solvent when obtaining the coating layer forming coating solution, a resin that is easily dissolved in an organic solvent such as alcohol, aromatic solvent, ketone, or ether can be used.

(Ii) Formation Method of Coat Layer (R2) FIG. 1 shows an example in which an ink receiving layer (R) comprising a fine particle-containing layer (R1) 13 and a coat layer (R2) 12 is formed on a substrate (K) 11. The conceptual diagram of the cross section of a certain receiving layer (R) is shown. The coating liquid for forming a coat layer composed of the resin (S) and an aqueous solvent is applied on the fine particle-containing layer (R1), and then the solvent is removed by evaporation. As a method for applying the coating liquid for forming a coating layer onto the fine particle-containing layer (R1), the same method as that for applying the coating liquid for forming a fine particle-containing layer can be employed. The thickness of the coat layer (R2) thus formed is preferably 0.5 to 50 μm.

[2] Method for forming conductive pattern (second embodiment)
In the “method for forming a conductive pattern” of the second aspect of the present invention, the ink (I) containing at least the polyol (A) is applied or patterned on the surface of the ink receiving layer (R) according to the first aspect. After the ink (I) was dissolved in the coating layer (R2) of the ink receiving layer (R) and then penetrated into the fine particle-containing layer (R1),
By conducting heat treatment, the metal oxide that forms at least the surface of the fine particles (M) of the ink (I) permeation portion is reduced and sintered to develop conductivity.

1 to 3 are conceptual views showing steps of patterning the ink (I) on the ink receiving layer (R) and forming a conductive pattern when the copper (P) is contained in the ink (I). FIG.
FIG. 1 shows an ink receiving layer (R1) 13 comprising a fine particle (M) 15 and a binder resin (B) 16 and a coating layer (R2) 12 on a substrate (K) 11 as described above. It is a conceptual diagram of the cross section in which R) was formed. FIG. 2 is a conceptual diagram of a cross section in a state where the ink (I) 17 containing the copper fine particles (P) is patterned on the coat layer (R2) 12 of FIG. FIG. 3 shows a state in which the ink (I) 17 containing the copper fine particles (P) is patterned on the coat layer (R2) 12 shown in FIG. 2, and is further baked to form the conductive pattern 18 on the receiving layer (R). It is a conceptual diagram of the cross section of the formed state. In the fine particle-containing layer (R1) 14, the fine particles (M) 15 where the ink (I) containing the copper fine particles (P) is patterned are reduced, sintered, and contained in the ink (I). The conductive sintered body 18 is formed by sintering together with (P).

1, 2 and 4 are conceptual diagrams showing the steps of patterning the ink (I) on the ink receiving layer (R) and forming the conductive pattern when the ink (I) is made of the polyol (A). is there.
The ink receiving layer (R) in FIG. 1 is as described above, and the patterning of the ink (I) made of the polyol (A) is performed except that the copper fine particles (P) are not contained in the ink (I). As described for FIG. 2 above. FIG. 4 shows a state in which ink (I) 17 containing copper fine particles (P) is patterned on the receiving layer (R) 14 shown in FIG. 2, and is further baked to form a conductive pattern on the receiving layer (R). It is a conceptual diagram of the cross section of the state made. In the fine particle-containing layer (R1), the fine particles (M) where the ink (I) is patterned are reduced and sintered to form the conductive sintered body 18.

(1) Ink (I)
The ink (I) contains at least a polyol (A) having two or more hydroxyl groups in the molecule, but is further covered with copper fine particles (P ₁ ) and the surface covered with copper oxide (Cu ₂ O). Copper fine particles (P) made of at least one selected from broken copper fine particles (P ₂ ) and copper oxide (Cu ₂ O) fine particles (P ₃ ) can be contained. In this case, it is preferable that 10 to 100 parts by mass of the polyol (A) and 90 to 0 parts by mass of the copper fine particles (P) are contained.
(A) When using the ink (I) comprising the polyol (A) Even if the ink (I) does not contain fine particles that develop electrical conductivity, the ink (I) is applied or patterned on the receiving layer (R). If a conductive pattern can be formed on the surface of the receiving layer (R) by heat treatment such as baking after the formation, the problem of ink storage stability can be improved.
On the other hand, if the ink (I) contains fine particles that develop conductivity, the conductive fine particles and the fine particles (M) are reduced and integrated during the sintering. , Adhesion and conductivity are improved. The polyol (A) which is a component of the ink (I) will be described below.

The polyol (A) is an organic compound having two or more hydroxyl groups in the molecule, and is preferably a polyol having a boiling point in the range of 100 to 350 ° C. at normal pressure. When the boiling point of the polyol is less than 100 ° C., temperature control may be necessary to avoid evaporation during storage, while it becomes easier to form a reducing gas atmosphere by vaporizing at 350 ° C. or lower during firing, If it exceeds 350 ° C., removal may be difficult during firing.
When the ink (I) is put into the receptor layer (R), the polyol (A) dissolves the coat layer (R2) of the patterned portion and penetrates the fine particle-containing layer (R1), and fine particles ( M) The effect of reducing the metal oxide on the surface is exhibited. Even when ink (I) containing metal particles that are easily oxidized such as copper or copper alloy is used in the ink receiving layer (R), hydrogen gas is used during firing. An ink-receiving layer (R) that can form a conductive material having excellent conductivity can be obtained without using a reducing gas such as. The polyol (A) is reduced by evaporating and reducing the fine particles (M) and the binder resin (B) in the fine particle-containing layer (R1) after application or patterning of the ink (I). As a result, an effect of promoting reduction and firing of the metal oxide on the surface of the fine particles (M) is exhibited.

  Examples of the polyol (A) include ethylene glycol, diethylene glycol, glycerin, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2 -Butene-1,4-diol, pentanediol, hexanediol, octanediol, 1,1,1-trishydroxymethylethane, 2-ethyl-2-hydroxymethyl-1,3-propanediol, 1,2,6 -Hexanetriol, 1,2,3-hexanetriol, 1,2,4-butanetriol, threitol, erythritol, pentaerythritol, xylitol, sorbitol, pentitol, terpineol, and hexitol. Use of one or more selected from It is desirable polyols usable in the present invention (A) is not limited to the polyols exemplified above. Of the polyols exemplified above, the highest boiling point is 330 ° C. of erythritol. These polyols (A) are thermally decomposed during firing to generate hydrogen radicals, which express the function of reducing metal oxides on the surface of the fine particles (M). In addition, it is possible to form a highly conductive metal film with good firing, and firing at a relatively low temperature.

(B) When using the ink (I) containing the polyol (A) and the copper fine particles (P) The polyol (A) is described in the section “When using the ink (I) comprising the polyol (A)”. This is the same as the polyol (A) described.
(I) Copper fine particles (P)
The ink (I), copper particles _(P 1), the surface oxide _(Cu 2 O) covered with copper particles _(P 2), and selected from oxide _(Cu 2 O) particles _{(P 3)} When the copper fine particles (P) composed of one or more kinds are contained, the copper fine particles (P) are obtained by sintering after applying or patterning the ink (I) to the ink receiving layer (R) by sintering, As a result of the reduction of the fine particles (M) in which at least the surface of the fine particle-containing layer (R1) is formed of a metal oxide, the effect of being integrated and improving the conductivity and adhesion can be obtained.
In the present invention, the copper fine particles (P ₁ ) include those containing only copper fine particles and those having a very small amount of oxide on the surface, and the copper fine particles (P ₂ ) are oxidized on the surface. The fine particles are covered with copper (Cu ₂ O), and the fine particles contain components composed of copper fine particles. The copper oxide fine particles (P ₃ ) are entirely composed of copper oxide (Cu ₂ O). It is the fine particle which consists of.

As the metal fine particles in the ink (I), conductive metal fine particles other than the copper fine particles (P) can be used. However, copper oxide is used as the fine particles (M) in the fine particle-containing layer (R1). When used, it is desirable to use only copper fine particles (P) containing no other metal component as the metal fine particles to be contained in the ink (I). The average particle diameter of the primary particles of the copper fine particles (P) contained in the ink (I) is preferably 5 to 100 nm in consideration of the sinterability with the fine particles (M) in the fine particle-containing layer (R1).
Further, as described above, the ink (I) can form an ink composed only of the polyol (A) component not containing the copper fine particles (P), while the polyol (A) is 10 to 100% by mass, and It can form so that it may become a ratio of 90 to 0 mass% of copper fine particles (P) (the sum total of the mass% is 100 mass%). When the copper fine particles (P) are contained in the ink (I), the copper fine particles (P) are 30 to 90% by mass of the polyol (A) and 70 to 10% by mass of the copper fine particles (P) in the ink (I). It is more preferable that it is contained at a ratio of (% by mass is 100% by mass in total). When the content of the copper fine particles (P) is less than the lower limit of the above range, the conductor film thickness after firing is small, and the effect of containing the copper fine particles (P) is not remarkable. May increase and patterning may become difficult.

(Ii) When the copper fine particles (P) are contained in the other component ink (I) in the ink (I), the dispersibility of the copper fine particles (P) in the ink (I) is improved. In order to enable firing at a lower temperature, in addition to the polyol (A) as an organic solvent, an organic solvent (A2) having an amide group described below, an ether compound (A3), an alcohol (A4), A ketone compound (A5), an amine compound (A6), etc. can be mix | blended.

Examples of the organic solvent (A2) having an amide group include N-methylacetamide, N-methylformamide, N-methylpropanamide, formamide, N, N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, Examples thereof include one or more selected from N, N-dimethylformamide, 1-methyl-2-pyrrolidone, hexamethylphosphoric triamide, 2-pyrrolidinone, ε-caprolactam, and acetamide.
Furthermore, as other components, ether compounds represented by the general formula R ¹ —O—R ² (R ¹ and R ² are each an independent alkyl group having 1 to 4 carbon atoms) ( A3), an alcohol (A4) represented by the general formula R ³ —OH (R ³ is an alkyl group and has 1 to 4 carbon atoms), R ⁴ —C (═O) —R ⁵ ( R ⁴ and R ⁵ are independent alkyl groups each having 1 to 2 carbon atoms.) And a ketone compound (A5) represented by the general formula R ⁶ — (N—R ⁷ ) —R An amine compound (A6) represented by ⁸ (R ⁶ , R ⁷ , and R ⁸ are each an independent alkyl group or hydrogen and having 0 to 2 carbon atoms) can be exemplified.

  Specific examples of the ether compound (A3) include diethyl ether, methyl propyl ether, dipropyl ether, diisopropyl ether, methyl t-butyl ether, t-amyl methyl ether, divinyl ether, ethyl vinyl ether, and allyl ether. Examples of the alcohol (A4) include one selected from methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, and 2-methyl 2-propanol. 1 or 2 or more types can be exemplified, and specific examples of the ketone compound (A5) include one or more selected from acetone, methyl ethyl ketone, and diethyl ketone, and the amine type As a specific example of the compound (A6), triethyl Min and / or diethylamine can be exemplified.

(Iii) When the dispersant ink (I) contains copper fine particles (P), a dispersant can be blended.
The dispersant covers at least a part of the surface of the copper fine particles (P) in the ink (I) and exerts an action of dispersing the copper fine particles (P) in a state where the secondary cohesiveness is low. Preferred as the dispersant is a water-soluble polymer compound, an amine polymer such as polyvinylpyrrolidone or polyethyleneimine; a hydrocarbon polymer having a carboxylic acid group such as polyacrylic acid or carboxymethylcellulose; polyacrylamide Such as acrylamide; polyvinyl alcohol, polyethylene oxide, starch, and one or more selected from gelatin and gelatin.

  Specific examples of the water-soluble polymer compounds exemplified above include polyvinylpyrrolidone (molecular weight: 1000 to 500,000), polyethyleneimine (molecular weight: 100 to 100,000), carboxymethylcellulose (carboxymethyl of hydroxyl group Na salt of alkali cellulose) Substitution degree: 0.4 or more, molecular weight: 1000 to 100,000, polyacrylamide (molecular weight: 100 to 6,000,000), polyvinyl alcohol (molecular weight: 1000 to 100,000), polyethylene glycol (molecular weight) : 100-50,000), polyethylene oxide (molecular weight: 50,000-900,000), gelatin (average molecular weight: 61,000-67,000), water-soluble starch and the like.

The number average molecular weight of each polymer compound is shown in the parenthesis, and those within such molecular weight range can be suitably used as a dispersant. In addition, these 2 or more types can also be mixed and used.
Further, the addition amount of the dispersant is preferably 0.01 to 10 as a mass ratio ([dispersant / copper fine particles (P)] mass ratio) to the copper fine particles (P) present in the dispersion solution. When the addition ratio of the dispersant exceeds the mass ratio 10, the viscosity of the solution may increase. On the other hand, when the mass ratio is less than 0.01, the particles may be coarsened or the particles may form a strong aggregate due to the crosslinking effect. A more preferable mass ratio of the addition amount is 0.5 to 5.
In the ink (I) thus obtained, the copper fine particles (P) are dispersed in a state where at least a part of the surface is covered with the dispersant. Although the mechanism by which such a dispersant disperses the copper fine particles (P) has not been completely elucidated, when a polymer dispersant is used, for example, an unshared electron pair of a functional group present in the polymer is removed. It is expected that a repulsive force is generated in which the atomic portion is adsorbed on the surface of copper or copper fine particles (P) to form a molecular layer, and the copper or copper fine particles (P) do not approach each other.

(Iv) Measurement of oxidation degree of copper fine particles (P ₂ ) and the like whose surface is covered with copper oxide (Cu ₂ O) The measurement of the oxidation degree of the copper fine particles (P) is performed on the Cu (111) surface in X-ray diffraction measurement The X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) is 0.91 or less when the peak height is H1 and the peak height of the Cu ₂ O (111) plane is H2. If it exceeds 0.91, the resistivity of the conductive pattern after firing may increase.
According to X-ray diffraction using CuKα as the X-ray source, the (111) plane of copper (I) (Cu ₂ O) has a peak around 2θ = 36 degrees, and the (111) plane of copper (Cu) is A peak appears around 2θ = 43 degrees. Note that only copper (I) (Cu ₂ O) is present as copper oxide, and copper (II) (CuO) is not usually present.
In copper oxide (Cu ₂ O) and copper (Cu) in copper fine particles (P ₂ ) containing copper oxide (Cu ₂ O) and mixed fine particles composed of copper fine particles (P ₁ ) and copper fine particles (P ₂ ) The ratio of the copper oxide (Cu ₂ O) of the copper oxide (Cu ₂ O) is such that the peak height of the Cu (111) surface existing near 2θ = 43 degrees in the X-ray diffraction measurement is Cu ₂ O (111 ) When the peak height of the surface is H2, it is obtained from the X-ray diffraction peak intensity ratio (H2 / [H1 + H2]).

(C) Improvement of dispersibility of copper fine particles (P) In order to further improve the dispersibility of the copper fine particles (P) in the ink (I), it is desirable to employ a stirring means. As a stirring method of the dispersion solution, a known stirring method can be adopted, but an ultrasonic irradiation method is preferably adopted.
The ultrasonic irradiation time is not particularly limited and can be arbitrarily selected. For example, when the ultrasonic irradiation time is arbitrarily set between 5 and 60 minutes, the average secondary aggregation size tends to be smaller as the irradiation time is longer. Further, when the ultrasonic wave irradiation time is lengthened, the dispersibility is further improved.

(2) Application or patterning of ink (I) A liquid film patterned by applying or patterning ink (I) is formed on the ink receiving layer (R). The application or patterning is not particularly limited, and includes ejection and transfer means.
The specific method for patterning is not particularly limited, and methods such as screen printing, mask printing, spray coating, bar coating, knife coating, spin coating, ink jet printing, and dispenser printing can be used. According to the pattern forming method, it is possible to form a dense pattern having a line width of 25 μm and a line spacing of about 25 μm. FIG. 2 shows a conceptual diagram of a cross section in a state where the ink (I) 17 is patterned on the coat layer (R2) 12 of FIG.

(3) Formation of conductive pattern After ink (I) is applied or patterned, it is baked by heating to form a conductive pattern. The firing conditions are, for example, about 190 to 250 ° C. for about 20 to 40 minutes, preferably about 190 to 220 ° C. for about 20 to 40 minutes, although depending on the coating thickness. The conductive pattern thus obtained has good conductivity, and its electric resistance value is 1.0 Ωcm or less, for example, about 1.0 × 10 ⁻⁵ Ωcm to 1 × 10 ⁻³ Ωcm. It is possible to achieve. Further, in the conductive pattern, when the copper fine particles (P) are contained in the ink (I), the fine particles (M) and the copper fine particles (P) in the fine particle containing layer (R1) are integrated by sintering. As a result, the anchor effect is exhibited and the adhesion to the ink receiving layer (R) is extremely improved.

FIG. 3 shows a state where the ink (I) containing the copper fine particles (P) and the polyol (A) is patterned on the receiving layer (R) shown in FIG. It is a conceptual diagram of the cross section in the state in which the pattern was formed. In the fine particle-containing layer (R1), the fine particles (M) where the ink (I) containing the copper fine particles (P) is patterned are reduced to form a conductive sintered body, and the ink (I) It is integrated with the copper sintered body contained and sintered.
FIG. 4 shows a state in which the receiving layer (R) shown in FIG. 2 does not contain the copper fine particles (P) and the ink (I) containing the polyol (A) is patterned, and is further baked to receive the receiving layer (R). 2) is a conceptual diagram of a cross-section in a state in which a conductive pattern is formed. In the fine particle-containing layer (R1), the fine particles (M) where the ink (I) is patterned are reduced to form a conductive sintered body.

The present invention will be described more specifically with reference to examples. In addition, this invention is not limited to a following example. The raw materials used in the examples and comparative examples and the evaluation methods are described below.
(1) Raw materials (a) Glass substrate Made by Matsunami Glass Industry Co., Ltd., trade name: Micro Slide Glass
(B) Binder resin polyvinyl alcohol (Kuraray Co., Ltd., trade name: PVA117)

(2) Evaluation method (b) X-ray diffraction peak intensity ratio X-ray diffraction measurement device for copper fine particles (manufactured by Rigaku Corporation, X-ray diffraction measurement device, model: Geigerflex RAD-A), containing copper oxide X-ray diffraction measurement of Cu fine particles using CuKα as an X-ray source is performed, and the peak height of the Cu (111) surface existing near 2θ = 43 ° is set to Cu ₂ O existing near H1, θ = 36 °. The X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) was determined when the peak height of the (111) plane was H2.
(B) Conductivity In accordance with JIS D0202-1988, the electrical resistance value of the conductive pattern is evaluated by the DC four-terminal method (use measuring machine: Keithley, Digital Multimeter DMM2000 type (four-terminal electrical resistance measurement mode)). did. The evaluation criteria are as follows.
◎: Resistance value is 50Ω or less ○: Resistance value is more than 50Ω to 500Ω or less ×: Resistance value is more than 500Ω or no continuity (c) Process simplicity and economy Evaluation of process simplicity and economy in Table 1 Was described. In the evaluation, considering that the ink containing copper fine particles (P) is more expensive than glycerin, and that advanced technology is required to optimize ejection conditions and maintain heads for optimal inkjet ejection. . The evaluation criteria are as follows.
A: Excellent in both process simplicity and economy.
○: Slightly superior in both process simplicity and economy.

[Example 1]
An ink receiving layer was formed on a glass substrate. Next, an ink was prepared, and the ink was patterned on the formed ink receiving layer to form a pattern. Thereafter, the pattern on the ink receiving layer was baked to form a conductive pattern, and then the conductivity was evaluated.
(1) Formation of ink receiving layer 10 ml of an aqueous copper acetate solution in which 0.2 g of copper acetate ((CH ₃ COO) ₂ Cu · 1H ₂ O) was dissolved in 10 ml (ml) of distilled water and 5 as a metal ion reducing agent 100 ml of a sodium borohydride aqueous solution in which sodium borohydride and distilled water were mixed so as to be 0.0 mol / liter (l) was prepared. Thereafter, 0.5 g of polyvinyl pyrrolidone (PVP, number average molecular weight of about 3500) as a water-soluble polymer dispersant is added to the aqueous solution of sodium borohydride and dissolved by stirring. Then, the acetic acid is added in a nitrogen gas atmosphere. 10 ml of an aqueous copper solution was added dropwise.
As a result of reacting this mixed liquid with sufficient stirring for about 60 minutes, a dispersion liquid in which copper fine particles having a particle diameter of 5 to 10 nm were dispersed was obtained.

Next, 5 ml of chloroform as an aggregation accelerator was added to 100 ml of the dispersion liquid in which the copper fine particles obtained by the above method were dispersed, and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge, and copper fine particles were collected by precipitation. The collected copper fine particles and 30 ml of distilled water are put into a test tube, stirred well using an ultrasonic homogenizer, and then washed three times with water to collect the particle components with a centrifuge, followed by the same test tube. The obtained copper fine particles and 30 ml of 1-butanol were added and stirred well, and then alcohol washing for recovering the copper fine particles with a centrifuge was performed three times. The copper fine particles recovered by the above steps were heat-treated in the atmosphere at 200 ° C. for 1 hour to obtain cuprous oxide particles having an average primary particle size of 0.02 μm.
Dissolve 1.5 parts by mass of polyvinyl alcohol in 48.5 parts by mass of ion-exchanged water heated to 90 ° C., and then add 50 parts by mass of cuprous oxide particles and stir to obtain a dispersion of cuprous oxide particles. Then, a coating solution for forming a fine particle-containing layer was prepared.
Next, this fine particle-containing layer forming coating solution was applied onto a glass substrate by drop coating so that the thickness after drying was 50 μm, and dried at room temperature for 12 hours to form a fine particle-containing layer.
Thereafter, 1 part by mass of methylcellulose (Metroses SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 99 parts by mass of ion-exchanged water to prepare a coating solution for forming a coat layer. Next, this coating layer forming coating solution is applied onto the fine particle-containing layer layer formed on the glass substrate by drop coating so that the thickness after drying becomes 5 μm, and dried at 80 ° C. for 1 hour. As a result, a coat layer was formed.

(2) Formation of pattern on ink receiving layer (i) Preparation of ink Copper acetate in which 0.2 g of copper acetate ((CH ₃ COO) ₂ Cu · 1H ₂ O) was dissolved in 10 ml (ml) of distilled water 10 ml of an aqueous solution and 100 ml of an aqueous sodium borohydride solution prepared by mixing sodium borohydride and distilled water so as to be 5.0 mol / liter (l) as a metal ion reducing agent were prepared. Thereafter, 0.5 g of polyvinyl pyrrolidone (PVP, number average molecular weight of about 3500) as a water-soluble polymer dispersant is added to the aqueous solution of sodium borohydride and dissolved by stirring. Then, the acetic acid is added in a nitrogen gas atmosphere. 10 ml of an aqueous copper solution was added dropwise.
As a result of reacting this mixed liquid with sufficient stirring for about 60 minutes, a dispersion liquid in which copper fine particles having a particle diameter of 5 to 10 nm were dispersed was obtained.
Next, 5 ml of chloroform as an aggregation accelerator was added to 100 ml of the dispersion liquid in which the copper fine particles obtained by the above method were dispersed, and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge, and copper fine particles were collected by precipitation. The collected copper fine particles and 30 ml of distilled water are put into a test tube, stirred well using an ultrasonic homogenizer, and then washed three times with water to collect the particle components with a centrifuge, followed by the same test tube. The obtained copper fine particles and 30 ml of 1-butanol were added and stirred well, and then alcohol washing for recovering the copper fine particles with a centrifuge was performed three times.
The obtained copper fine particles (corresponding to the copper fine particles (P ₁ ) of the present invention) have a peak height of the Cu (111) plane of H1 and a peak height of the Cu ₂ O (111) plane in X-ray diffraction measurement. The X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) with respect to H2 was 0.09.

The copper fine particles recovered by the above steps are mixed organic solvents composed of 50% by volume of N-methylacetamide, 10% by volume of triethylamine, and 40% by volume of glycerin as a mixed organic solvent (described as an organic solvent in Table 1). The ink was prepared by dispersing in 10 ml and applying ultrasonic vibration to the dispersion using an ultrasonic homogenizer for 1 hour.
(Ii) Formation of ink pattern On an ink receiving layer formed on a glass substrate, the ink is applied onto the surface of the ink receiving layer using an ink jet apparatus (manufactured by Microjet, model: LaboJet-300). A pattern having a width of 200 μm and a length of 20 mm was formed.

(3) Formation of conductive pattern by baking pattern A conductive pattern (wiring material) was formed by baking the pattern formed on the ink receiving layer at 250 ° C. for 30 minutes in a nitrogen atmosphere.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Example 2]
The same procedure as in Example 1 was used, except that the ink receiving layer described in Example 1 was an ink composed of only glycerin not containing copper fine particles (corresponding to the copper fine particles (P) of the present invention). A pattern similar to that described in Example 1 was formed on the ink receiving layer.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Example 3]
On the ink receiving layer described in Example 1, an ink containing copper fine particles (corresponding to copper fine particles (P ₂ ) of the present invention) whose surface was covered with copper oxide instead of copper fine particles was used. Except for the above, a pattern similar to that described in Example 1 was formed on the ink receiving layer in the same manner as in Example 1. The copper oxide fine particles were obtained by stirring the copper fine particles of Example 1 for 10 minutes in the air at room temperature. In X-ray diffraction measurement, the peak height of the Cu (111) plane was H1, Cu ₂ O. The X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) when the peak height of the (111) plane was H2 was 0.32.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Example 4]
On the ink receiving layer described in Example 1, an ink containing copper fine particles (corresponding to the copper fine particles (P ₂ ) of the present invention) whose surface is covered with copper oxide is used instead of the copper fine particles. Except for this, a pattern similar to that described in Example 1 was formed on the ink receiving layer in the same manner as in Example 1. The copper fine particles were obtained by stirring the copper fine particles obtained by the same method as described in Example 1 until the particle color became green at room temperature in the atmosphere. In the X-ray diffraction measurement, Cu ( The X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) was 0.91 when the peak height of the 111) plane was H1 and the peak height of the Cu ₂ O (111) plane was H2.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Example 5]
On the ink receiving layer described in Example 1, an ink containing copper fine particles (corresponding to copper fine particles (P ₂ ) of the present invention) whose surface was covered with copper oxide instead of copper fine particles was used. Except for the above, a pattern similar to that described in Example 1 was formed on the ink receiving layer in the same manner as in Example 1. The copper fine particles were obtained by stirring the copper fine particles obtained by the same method as described in Example 1 in the atmosphere at room temperature until the particle color became stronger green than in Example 4,
In the X-ray diffraction measurement, the X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) is 0 when the peak height of the Cu (111) plane is H1 and the peak height of the Cu ₂ O (111) plane is H2. .94.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Example 6]
The ink receiving layer described in Example 1 was used. As the ink, the copper fine particles described in Example 1 (corresponding to the copper fine particles (P ₁ ) of the present invention) and the surface described in Example 5 were used. Mixed fine particles composed of copper fine particles covered with copper oxide (corresponding to the copper fine particles (P ₂ ) of the present invention) were used. The mixing ratio is the X-ray diffraction peak intensity ratio (H2 / [H1 + H2]) when the peak height of the Cu (111) plane is H1 and the peak height of the Cu ₂ O (111) plane is H2 in the X-ray diffraction measurement. ) Was adjusted to 0.91.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 1]
As Comparative Example 1, the same ink as used in Example 1 was used, and the ink receiving layer was prepared by the following method.
1.5 parts by mass of polyvinyl alcohol is dissolved in 83 parts by mass of ion-exchanged water heated to 90 ° C., and then alumina particles (manufactured by Sumitomo Chemical Co., Ltd., trade name: AA-07, Sumiko Random, average primary particle size 700 nm) A dispersion solution of alumina particles was prepared by adding 13.5 parts by mass. The dispersion was cooled to room temperature to prepare a coating solution for forming an ink receiving layer. Next, this ink receiving layer forming coating solution was applied onto a glass substrate by drop coating so that the thickness after drying was 50 μm and dried at room temperature for 12 hours to form an ink receiving layer.
The volume ratio of the alumina particles to the total amount of alumina particles and polyvinyl alcohol (solid content) in the ink receiving layer was 80% by volume.
In the same manner as described in Example 1, the receiving layer was baked after patterning the ink, and the conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 2]
Using the same ink as used in Example 2 for the ink receiving layer prepared by the method described in Comparative Example 1, patterning the ink in the same manner as described in Example 1, and then baking the ink. The conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 3]
Using the same ink as used in Example 3 for the ink receiving layer prepared by the method described in Comparative Example 1, patterning the ink in the same manner as described in Example 1, and then baking the ink. The conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 4]
Using the same ink as used in Example 4 for the ink receiving layer prepared by the method described in Comparative Example 1, patterning the ink in the same manner as described in Example 1, and then baking the ink. The conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 5]
Using the same ink as used in Example 5 for the ink receiving layer prepared by the method described in Comparative Example 1, patterning the ink in the same manner as described in Example 1, and then baking the ink. The conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

[Comparative Example 6]
Using the same ink as used in Example 6 for the ink receiving layer prepared by the method described in Comparative Example 1, patterning the ink in the same manner as described in Example 1, and then baking the ink. The conductivity was evaluated by the method described in Example 1.
Table 1 shows the results of evaluating the conductivity of the obtained conductive pattern.

11 Substrate (K)
12 Coat layer (R2)
13 Fine particle-containing layer (R1)
14 Ink receiving layer (R)
15 Fine particles (M)
16 Binder resin (B)
17 Ink (I)
18 Conductive sintered body

Claims (11)

A substrate (K) on which a conductive pattern can be formed by heating or baking after applying or patterning the ink (I) containing at least a polyol (A) having two or more hydroxyl groups in the molecule. ) An ink receiving layer (R) formed on the surface,
A coating layer (R2) comprising a resin (S) soluble in the polyol (A) in the ink (I), wherein the ink receiving layer (R) forms a surface layer; and
Located between the substrate (K) and the coat layer (R2), at the time of firing, at least the metal oxide on the surface is reduced by the polyol (A) in the coated or patterned ink (I). A fine particle-containing layer (R1) comprising fine particles (M) exhibiting electrical conductivity and a binder resin (B);
An ink receiving layer comprising:   The metal oxide constituting at least the surface of the fine particles (M) in the fine particle-containing layer (R1) is formed from one or more oxides selected from copper oxide and cuprous oxide. The ink receiving layer according to claim 1.   The ink receiving layer according to claim 1 or 2, wherein the binder resin (B) in the fine particle-containing layer (R1) is a water-soluble resin.   The ink-receiving layer according to claim 1, wherein the water-soluble binder resin is polyvinyl alcohol.   The fine particle-containing layer (R1) is composed of 50 to 95% by volume of fine particles (M) and 50 to 5% by volume of a binder resin (B) (the total of the volume% is 100% by volume). 5. The ink receiving layer according to any one of items 1 to 4.   6. The ink receiving layer according to claim 1, wherein the resin (S) in the coating layer (R2) is made of a water-soluble resin.   The ink receiving layer according to any one of claims 1 to 6, wherein the coat layer (R2) has a thickness of 0.5 to 50 µm. The ink (I) containing at least the polyol (A) is applied or patterned on the surface of the ink receiving layer (R) according to any one of claims 1 to 7, and the ink (I) is applied to the ink receiving layer (R). After the coating layer (R2) was dissolved and permeated into the fine particle-containing layer (R1),
By reducing and sintering the metal oxide that forms at least the surface of the fine particles (M) of the ink (I) permeation portion by heat treatment, the conductivity or the patterned portion of the ink (I) is expressed. A method for forming a conductive pattern, characterized in that: During the ink (I), the polyol (A), fine copper particles _(P 1), the surface oxide _(Cu 2 O) covered with copper particles _(P 2), and oxide _(Cu 2 O) particles Copper fine particles (P) composed of one or more selected from (P ₃ ) are [polyol (A) / copper fine particles (P)] (mass ratio) of 10 to 100/90 to 0 (total parts by mass) The conductive pattern forming method according to claim 8, wherein the conductive pattern is contained in a ratio of 100 parts by mass. X-ray diffraction peak intensity ratio (H2) of the copper fine particles (P) when the peak height of the Cu (111) plane is H1 and the peak height of the Cu ₂ O (111) plane is H2 in the X-ray diffraction measurement. / [H1 + H2]) is 0.91 or less, The formation method of the conductive pattern of Claim 9 characterized by the above-mentioned. The polyol (A) constituting the ink (I) is ethylene glycol, diethylene glycol, glycerin, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1, 4-butanediol, 2-butene-1,4-diol, pentanediol, hexanediol, octanediol, 1,1,1-trishydroxymethylethane, 2-ethyl-2-hydroxymethyl-1,3-propanediol 1,2,6-hexanetriol, 1,2,3-hexanetriol, 1,2,4-butanetriol, threitol, erythritol, pentaerythritol, xylitol, sorbitol, pentitol, terpineol, and One or more selected from hexitol Wherein the method of forming a conductive pattern according to any one of claims 8 10.

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