WO2016052292A1

WO2016052292A1 - Silver metal, method for producing silver metal, and laminate

Info

Publication number: WO2016052292A1
Application number: PCT/JP2015/076895
Authority: WO
Inventors: 格宮本; 関口　卓也
Original assignee: トッパン・フォームズ株式会社
Priority date: 2014-09-29
Filing date: 2015-09-24
Publication date: 2016-04-07
Also published as: JP6712949B2; JPWO2016052292A1

Abstract

This silver metal is configured of crystallites having a crystallite diameter of 15 nm or more, and has a volume resistivity of 8 μΩ·cm or less. This laminate is provided with a layer, which is formed of the silver metal, on a base.

Description

Metal silver, metal silver production method and laminate

The present invention relates to metallic silver, a method for producing the same, and a laminate including a layer made of the metallic silver on a substrate.
This application claims priority based on Japanese Patent Application No. 2014-197818 filed in Japan on September 29, 2014, the contents of which are incorporated herein by reference.

A laminate in which a patterned silver layer is provided on a base material is used to configure wiring, electrodes, antennas and the like in electronic devices such as communication devices.
The silver layer is formed, for example, by a method of preparing a silver ink composition containing metallic silver or a material for forming the silver, depositing the composition on a substrate, and heating (baking) the deposited composition. Is done. In recent years, since it is easy to form a silver layer having good characteristics, a technique for forming metallic silver using a silver ink composition containing a metallic silver forming material instead of metallic silver itself has become widely used. It is coming.

Such a silver ink composition includes a metal complex compound obtained by reacting one or more metals or metal compounds with one or more specific ammonium carbamate or ammonium carbonate compounds, and additives. In addition, a conductive ink composition in which the metal is silver is disclosed (see Patent Document 1).

However, the silver ink composition disclosed in Patent Document 1 has a heating (firing) temperature required for forming metallic silver having sufficient conductivity of 130 ° C. or higher, and the substrate used has a certain degree of heat resistance. There is a problem that the material of the base material is limited.

Japanese translation of PCT publication 2008-531810

The present invention provides a metallic silver which can be obtained by a heat treatment at a lower temperature and has sufficient conductivity, a method for producing the same, and a laminate comprising a layer made of the metallic silver on a substrate. This is the issue.

The present invention provides metallic silver having a crystallite diameter of 15 nm or more and a volume resistivity of 8 μΩ · cm or less.
The metal silver of the present invention may have a crystallite diameter of 16.5 nm or more and 80 nm or less.

The metallic silver of the present invention may be formed using silver β-ketocarboxylate represented by the following general formula (1).

(Wherein R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one or more hydrogen atoms may be substituted with a substituent, a phenyl group, a hydroxyl group, an amino group, or a group represented by the general formula “R ¹ -CY 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-ethoxyvinyl group, or “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. )

Further, the present invention uses silver β-ketocarboxylate represented by the following general formula (1) to form metallic silver having a crystallite diameter of 15 nm or more and a volume resistivity of 8 μΩ · cm or less. The manufacturing method of metallic silver which has the process to perform is provided.

(Wherein R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one or more hydrogen atoms may be substituted with a substituent, a phenyl group, a hydroxyl group, an amino group, or a group represented by the general formula “R ¹ -CY 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-ethoxyvinyl group, or “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 method for producing metallic silver of the present invention, in the step of forming metallic silver, the silver ink composition containing the β-ketocarboxylate is heat-treated under non-humidified conditions, and further humidified conditions. The metallic silver may be formed by heat treatment under or in contact with a heated liquid.

Moreover, this invention provides the laminated body provided with the layer which consists of the said metal silver on a base material.
In the laminate of the present invention, the base material may have a thickness of 0.5 to 5000 μm, and the metal silver layer may have a thickness of 0.01 to 5 μm.
In the laminate of the present invention, the base material may have a deflection temperature under load of 120 ° C. or less when the deflection amount is 0.25 mm with a bending stress of 1.8 MPa as defined by ASTM D648. Good.

The metallic silver of the present invention can be obtained by heat treatment at a lower temperature, has sufficient conductivity, and can constitute a laminate comprising a layer made of the metallic silver on a substrate.

It is sectional drawing which shows typically an example of the laminated body of this invention.

Favorable examples of the metallic silver of the present invention, its production method and laminate are described below. However, the present invention is not limited to these examples. For example, additions, omissions, substitutions, and other changes (amount, number, position, size, etc.) are possible without departing from the spirit of the present invention. It is.

<< Metallic silver >>
The metallic silver of the present invention has a crystallite diameter of 15 nm or more and a volume resistivity of 8 μΩ · cm or less.
Even if the metallic silver is formed by performing a post-treatment such as a drying treatment or a heating (firing) treatment at a temperature as low as less than 130 ° C., the crystallite diameter is 15 nm or more. By being constituted, the volume resistivity is 8 μΩ · cm or less, and the conductivity is sufficiently high.

The crystallite diameter of metallic silver is determined by a known method. For example, metal silver is subjected to X-ray diffraction measurement, and from the measurement result of the obtained X-ray diffraction peak, Scherrer's formula “D = kλ / βcos θ (where, D is the crystallite size (nm); k is a constant (0.9 is used here); λ is the X-ray wavelength (CuKα line) 0.154 nm; β is the peak half-width (rad) And θ is an angle that is ½ of the measurement angle.) ”Can be used to calculate the crystallite diameter of metallic silver.
The X-ray diffraction measurement can be performed using, for example, a thin film X-ray diffraction apparatus.

The crystallite diameter of the metallic silver is 15 nm or more, preferably 15.5 nm or more, more preferably 16 nm or more, and particularly preferably 16.5 nm or more.
The upper limit of the crystallite diameter of the metallic silver is not particularly limited, but is preferably 80 nm because the degree of increase in the effect of the present invention obtained is limited with respect to the increase in crystallite diameter. , 70 nm is more preferable. For example, it may be 40 nm, but is not limited thereto.

The volume resistivity of the metallic silver is 8 μΩ · cm or less, and can be any of 7.6 μΩ · cm or less, 7.3 μΩ · cm or less, 7 μΩ · cm or less, and the like.
On the other hand, the volume resistivity of the metallic silver is preferably as low as possible, and the lower limit is not particularly limited, but can be, for example, either 1.59 μΩ · cm or 2.5 μΩ · cm.
The volume resistivity of the metal silver usually tends to decrease as the crystallite diameter of the metal silver increases.

<< Method for producing metallic silver >>
The metallic silver is prepared by preparing a composition (silver ink composition) for forming the metallic silver and adhering it to a desired location such as a base material to be described later, followed by solidification treatment such as drying treatment or heating (firing) treatment. It can manufacture by selecting suitably and performing. The heat treatment may be performed also as a drying treatment.

<Silver ink composition>
In the present invention, it is preferable to use a silver ink composition containing a metallic silver forming material as the silver ink composition.
The metallic silver 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 silver forming material may be any material that has silver atoms (elements) and generates metallic silver by structural change such as decomposition, and is a silver salt, a silver complex, an organic silver compound (a compound having a silver-carbon bond) ) Etc. can be illustrated. The silver salt and the silver complex may be either a silver compound having an organic group or a silver compound having no organic group. Among these, the metal silver forming material is preferably a silver salt.
By using a metallic silver forming material, metallic silver is produced from the material. The metallic silver in this case is of high purity, and the ratio of metallic silver is sufficiently high that it can be regarded as consisting of only metallic silver. The metallic silver ratio is preferably 97% by mass or more, more preferably 98% by mass. % Or more, particularly preferably 99% by mass or more. The upper limit of the ratio of metallic silver is, for example, 100% by mass, 99.9% by mass, 99.8% by mass, 99.7% by mass, 99.6% by mass, 99.5% by mass, 99.4% by mass. , 99.3% by mass, 99.2% by mass, and 99.1% by mass, but is not limited thereto.

As the silver ink composition, a liquid one is preferable, and one in which a metal silver forming material is dissolved or uniformly dispersed is preferable.

[Silver carboxylate]
Examples of the material for forming metallic silver include silver carboxylate having a group represented by the formula “—COOAg”, and such silver carboxylate is suitable for forming metallic silver having a crystallite diameter of 15 nm or more. It is a thing.
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 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 this 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 ””.

(Wherein 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”, wherein 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 (1) is more suitable for forming metallic silver represented by the general formula (1) and having a crystallite diameter of 15 nm or more.
In the formula, R is an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a phenyl group, a hydroxyl group, an amino group, or a group represented by the 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 may be monocyclic or polycyclic when cyclic. . 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 in R include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, 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, isooctyl, 1-methylheptyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 1-ethylhexyl, 2-ethylhexyl, 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 the 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), etc. ) 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.

In the phenyl group in R, one or more hydrogen atoms may be substituted with a substituent. Preferred examples of the substituent include 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 for 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—”. The aliphatic hydrocarbon group in R ⁶ has 1 to Except for being 19, the same aliphatic hydrocarbon groups as those described above for R can be exemplified.

Among them, R is a linear or branched alkyl group, a group represented by the general formula “R ⁶ —C (═O) —CY ¹ ₂ —”, 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 independently represents 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 the 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), A nitro group (—NO ₂ ) 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.

R ⁷ in X ¹ represents 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 A diphenyl group (biphenyl group, C ₆ H ₅ —C ₆ H ₄ —); 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 either 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. Examples thereof include a group represented by the formula “═CH—C ₆ H ₄ —NO ₂ ”.

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.

Silver β-ketocarboxylate (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), silver isobutyryl 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-butylacetoacetate silver (CH ₃ —C (═O) —CH (C H ₂ CH ₂ CH ₂ CH ₃ ) —C (═O) —OAg), silver 2-benzylacetoacetate (CH ₃ —C (═O) —CH (CH ₂ C ₆ H ₅ ) —C (═O) —OAg), silver benzoyl acetate (C ₆ H ₅ —C (═O) —CH ₂ —C (═O) —OAg), silver pivaloyl acetoacetate ((CH ₃ ) ₃ C—C (═O) —CH ₂ —C (═O) —CH ₂ —C (═O) —OAg), silver isobutyrylacetoacetate ((CH ₃ ) ₂ CH—C (═O) —CH ₂ —C (═O) —CH ₂ -C (= O) -OAg), silver 2-acetylpivaloyl acetate ((CH ₃ ) ₃ CC (= 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).

Β-ketocarboxylate (1) can further reduce the concentration of the remaining raw materials and impurities in the conductor (metal silver) formed by solidification 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 will be 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 the present invention, silver β-ketocarboxylate (1) may be used alone or in combination of two or more. 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) and is more suitable for forming metallic silver having a crystallite diameter of 15 nm or more.
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 of alkylene groups 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) includes 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), silver isobutyrate ((CH ₃ ) ₂ CH—C (═O) —OAg), silver 2-ethylhexanoate (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). Further, silver oxalate (AgO—C (═O) —C (═O) —OAg) and silver malonate (AgO—C (═O) —CH ₂ —C (═O) —OAg) Of the groups represented by the formula “—COOAg”, one of the groups represented by the formula “—COOH” (HO—C (═O) —C (═O) —OAg, HO) Also preferred is —C (═O) —CH ₂ —C (═O) —OAg).

Similarly to the β-ketocarboxylate silver (1), silver carboxylate (4) is also used in the conductor (metal silver) formed by solidification 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 the present invention, the silver carboxylate (4) may be used alone or in combination of two or more. 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 a nitrogen-containing compound (particularly an amine compound) 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 is preferably one in which a nitrogen-containing compound is further blended in addition to the metal silver forming material, particularly when the metal silver forming material is the silver carboxylate. The nitrogen-containing compound is preferably used in order to form metallic silver having a crystallite diameter of 15 nm or more.
The nitrogen-containing compound is an amine compound having 25 or less carbon atoms (hereinafter sometimes abbreviated as “amine compound”), a quaternary ammonium salt having 25 or less carbon atoms (hereinafter abbreviated as “quaternary ammonium salt”). Ammonia, an ammonium salt formed by reacting an amine compound having 25 or less carbon atoms with an acid (hereinafter sometimes abbreviated as “ammonium salt derived from an amine compound”), and ammonia reacting with an acid. One or more selected from the group consisting of ammonium salts (hereinafter sometimes abbreviated as “ammonium salts derived from ammonia”). That is, 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.

(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.
Preferred examples of the monoalkylamine include n-butylamine, n-hexylamine, n-octylamine, n-dodecylamine, n-octadecylamine, sec-butylamine, tert-butylamine, 3-aminopentane, 3 Examples include -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 skeleton 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 either 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, tetrazolyl group A pyrrolidinyl group, an imidazolidinyl group, a piperidinyl group, a pyrazolidinyl group, and a piperazinyl group, which are preferably 3- to 8-membered rings, and more preferably 5- to 6-membered rings.
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. Preferably, 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 is a 3- to 8-membered ring. A 5- to 6-membered ring is preferable.
Examples of the polyaryl 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 thereof 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. Preferably, it is a 9 to 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 to 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 constituting the dialkylamine is the same as the alkyl group constituting the monoalkylamine, and is a linear or branched alkyl group having 1 to 9 carbon atoms, or having 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 dialkylamines 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 a monoalkylamine having such a substituent is specifically 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 a halogen atom as a substituent and having 6 to 10 carbon atoms, and the 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, sec-butylamine, tert-butylamine, 3-aminopentane, 3-methyl. Butylamine, 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 is preferable. .
Among these amine compounds, 2-ethylhexylamine is excellent in compatibility with the above-mentioned silver carboxylate, particularly suitable for increasing the concentration of the silver ink composition, and particularly for reducing the surface roughness of metallic silver. Listed as suitable.

(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]
The silver ink composition preferably contains a reducing agent in addition to the metal silver forming material. The reducing agent is preferably used to form metallic silver having a crystallite diameter of 15 nm or more. By blending a reducing agent, the silver ink composition can more easily form metallic silver. For example, a conductor (metal silver) having sufficient conductivity can be formed even by heat treatment at a low temperature.

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)
(Wherein R ²¹ represents an alkyl group having 20 or less carbon atoms, an alkoxy group, or an N, N-dialkylamino group, a hydroxyl group, or an amino group.)

(Reducing compounds)
The reducing compound is at least one 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)). It is. 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 in 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 to 20.
The alkyl group bonded to the nitrogen atom may be linear, branched or cyclic, respectively, and the alkyl group 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 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). ₂ CH ₃ ), formic acid esters such as 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 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 carbon 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 mol per mol 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 alcohol may be used alone or in combination of two or more. 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 metallic 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 include solvents other than alcohol.

The solvent can be arbitrarily selected according to the type and amount of the compounding components. Preferred examples of the solvent include liquid alkanes under normal temperature and normal pressure conditions, and the alkane may be linear, branched or cyclic, and preferably has 15 or less carbon atoms, more preferably. Examples thereof include pentane, hexane, cyclohexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane and the like.

The other components in the silver ink composition may be used alone or in combination of two or more. When two or more kinds are used in combination, the combination and ratio can be arbitrarily adjusted.

What is necessary is just to select suitably the compounding quantity of the said other component in a silver ink composition according to the kind of said other component.
For example, when the other component is a solvent other than alcohol, the blending amount of the solvent may be selected according to the purpose, such as the viscosity of the silver ink composition, but is usually blended in the silver ink composition. The ratio of the amount of the solvent to the total amount of the components is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less.
Further, when the other component is a component other than the solvent, in the silver ink composition, the ratio of the blending amount of the other component to the total amount of the blending component is preferably 10% by mass or less. % Or less is more preferable.
The ratio of the blended amount of the other components with respect to the total amount of the blended components is 0 mass, that is, even if the other components are not blended, 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 metal silver forming material, no impurities that inhibit conductivity are generated at the time of blending each of 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 compounding is not particularly limited as long as each compounding component does not deteriorate, but it 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.
Also, 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.

The compounding temperature at the time of producing the first mixture is not particularly limited as long as each compounding component does not deteriorate, but it is preferably −5 to 30 ° C. In addition, the blending time may be appropriately adjusted according to the type of blending component and the temperature at the time of blending, but is preferably 0.5 to 12 hours, for example.

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.

The carbon dioxide gas may be supplied by various known methods for 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 carbon dioxide gas is not particularly limited, and may be 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. Although the viscosity at 20 to 25 ° C. of the silver ink composition has been described here, the temperature at the time of using the silver ink composition is not limited to 20 to 25 ° C. and can be arbitrarily selected. In the present specification, “viscosity” means a value measured using an ultrasonic vibration viscometer unless otherwise specified.

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 carbon dioxide gas, and the temperature at the time of supplying 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 according to the purpose, such as a method for handling the silver ink composition or 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. Here, the viscosity of the second mixture at 20 to 25 ° C. has been described, but the temperature at the time of use of the second mixture is not limited to 20 to 25 ° C. and can be arbitrarily selected.

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 produced 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.
In addition, the blending time may be appropriately adjusted according to the type of blending component and the temperature at the time of blending, but is preferably 0.5 to 12 hours, for example.

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 25% by mass or less when the other components are solvents other than alcohol. Is more preferable, it is more preferable that it is 20 mass% or less, and it is especially preferable that it is 15 mass% or less. On the other hand, when the said other component is components other than the said solvent, it is preferable that the ratio of the said compounding quantity is 10 mass% or less, and it is more preferable that it is 5 mass% or less. And even if the ratio of the said compounding quantity is 0 mass, ie, it does not mix | blend another component, a silver ink composition fully expresses the effect.

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 containing the metallic silver forming material, alcohol and nitrogen-containing compound. In this case, a method similar to the above can be adopted as a method for supplying carbon dioxide.

When the silver ink composition is subjected to a drying treatment, it may be carried out by a known method, for example, under normal pressure, under reduced pressure, or under a blowing condition, either under the atmosphere or under an inert gas atmosphere. You may do it. Also, the drying temperature is not particularly limited, and may be either heat drying or room temperature drying. As a preferable drying method when the heat treatment is unnecessary, a method of drying in the atmosphere at 18 to 30 ° C. can be exemplified.

When the silver ink composition is heated (baked), the conditions may be adjusted as appropriate according to the type of ingredients of the silver ink composition. Usually, the heating temperature is preferably 60 to 370 ° C., more preferably 70 to 280 ° C. The heating time may be adjusted according to the heating temperature, but it is usually preferably 1 minute to 24 hours, and more preferably 1 minute to 12 hours. Among the metal silver forming materials, the silver carboxylate, particularly silver β-ketocarboxylate (1) is different from the metal silver forming material such as silver oxide, for example, using a reducing agent known in the art. Even if not, it decomposes at low temperature. Reflecting such decomposition temperature, the silver ink composition can form metallic silver at an extremely lower temperature than the conventional one as described above.

As will be described later, when the silver 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. Preferably, it is 120 degrees C or less especially.

The method for heat treatment of the silver ink composition 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, or the like can be performed. Further, the heat treatment of the silver 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 this specification, “humidification” means that the humidity is artificially increased unless otherwise specified, and the relative humidity is preferably 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.

The relative humidity when the heat treatment of the silver ink composition is performed under humidified conditions is preferably 10% or more, more preferably 30% or more, further preferably 50% or more, and 70%. It is particularly preferable that it be 90% or more, or 100%. And you may perform the heat processing under humidification conditions by spraying the high pressure steam heated to 100 degreeC or more. Thus, by heat-processing under humidification conditions, highly pure metallic silver can be formed in a short time.

The heat treatment of the silver ink composition may be performed in two stages. For example, in the first stage heat treatment, there is exemplified a method in which the silver ink composition is mainly dried rather than the formation of metal silver, and the formation of metal silver is completed in the second stage heat treatment.
In the first-stage heat treatment, the heating temperature may be appropriately adjusted according to the type of compounding component of the silver ink composition, but is preferably 60 to 110 ° C, more preferably 70 to 90 ° C. preferable. The heating time may be adjusted according to the heating temperature, but it is usually preferably 5 seconds to 12 hours, and more preferably 30 seconds to 2 hours.
In the second stage heat treatment, the heating temperature may be appropriately adjusted according to the type of compounding component of the silver ink composition so that metallic silver is formed satisfactorily, but it should be 60 to 280 ° C. Preferably, the temperature is 70 to 260 ° C. The heating time may be adjusted according to the heating temperature, but it is usually preferably 1 minute to 12 hours, and more preferably 1 minute to 10 hours.
As will be described later, when the silver ink composition is attached to a substrate having low heat resistance and is heated (baked), the heating temperature in the first and second stages is less than 130 ° C. It is preferably 125 ° C. or lower, more preferably 120 ° C. or lower.

The heat treatment of the silver ink composition described so far is performed in the gas phase. However, when the heat treatment of the silver ink composition is performed in two steps, the heat treatment in the second step is performed in the gas phase. You may carry out in a liquid phase instead of inside. The silver ink composition that has been completely or partially dried through the first stage heat treatment can be subjected to the second stage heat treatment without impairing its shape by contacting with the heated liquid. And it is preferable to perform the heat processing in the liquid phase of the 2nd step after performing the heat processing of the 1st step of a silver ink composition by immersing a silver ink composition in the heated liquid. The heating temperature and heating time in the heat treatment in the liquid phase are the same as the heating temperature and heating time in the second-stage heat treatment described above.
The heated liquid is preferably hot water (heated water), and the second stage heat treatment is performed by immersing the silver ink composition subjected to the first stage heat treatment in hot water, that is, by hot water bathing. Preferably it is done.
When the second stage heat treatment is performed in the liquid phase, the metallic silver formed by this heat treatment may be further dried.

When the second stage heat treatment of the silver ink composition is performed in a liquid phase, the first stage heat treatment of the silver ink composition is preferably performed under non-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 heat treatment under humidified conditions is employed, the heat treatment of the silver ink composition is not the formation of metallic silver as described above under non-humidified conditions in the first stage heat treatment. It is particularly preferable to perform drying in a two-stage method in which the formation of metallic silver is performed to the end as described above under humidified conditions in the second-stage heat treatment.

When the second stage heat treatment is performed under humidified conditions, the heating temperature during the heat treatment under the first stage non-humidified conditions is preferably 60 to 110 ° C., and preferably 70 to 90 ° C. More preferred. The heating time is preferably 5 seconds to 1 hour, more preferably 30 seconds to 30 minutes, and particularly preferably 30 seconds to 10 minutes.
The heating temperature during the heat treatment under the second-stage humidification condition, which is performed after the heat treatment under the first-stage non-humidification conditions, is preferably 60 to 140 ° C, and preferably 70 to 130 ° C. Is more preferable. 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.
As will be described later, when the silver ink composition is attached to a substrate having low heat resistance and heated (baked), the heat treatment under the first non-humidifying condition and the second humidifying condition are performed. The heating temperature in the heat treatment at is preferably less than 130 ° C, more preferably 125 ° C or less, and particularly preferably 120 ° C or less.

As described above, preferred examples of the method for producing metallic silver include those having the step of forming metallic silver using β-ketocarboxylate silver (1). For example, in the step of forming metallic silver, a silver ink composition containing silver β-ketocarboxylate (1) is heat-treated under non-humidified conditions and then further humidified or heated. What forms the said metal silver is mentioned by making it contact with the liquid which was made and heat-processing.

<< Laminate >>
The laminate of the present invention comprises a layer made of the above-described metallic silver of the present invention (hereinafter sometimes abbreviated as “silver layer”) on a substrate.
The metallic silver can be formed by subjecting the silver ink composition for forming it to a post-treatment such as drying or heating (firing) at a temperature as low as less than 130 ° C. The silver layer can be formed even when a material having a low thickness is used, and a wide variety of base materials can be used. Moreover, since the silver layer of the said laminated body consists of said metallic silver, a volume resistivity will be 8 microhm * cm or less, and it has sufficiently high electroconductivity.

FIG. 1 is a cross-sectional view schematically showing an example of the laminate of the present invention.
The laminated body 1 shown here is formed by laminating a silver layer 12 on the surface (one main surface) 11a of a base material 11.

<Base material>
The base material 11 will not be specifically limited if the composition for forming the above-mentioned metallic silver can be used.
Specifically, the material of the substrate 11 is polyethylene (PE); polypropylene (PP); polyvinyl chloride (PVC); polyvinylidene chloride (PVDC); polymethylpentene (PMP); polycycloolefin; polystyrene (PS). An acrylic resin such as polymethyl methacrylate (PMMA); an AS resin; an ABS resin; a polyamide (PA) such as nylon 6, 6 and nylon 6; a polyimide; a polyamideimide (PAI); a polyacetal ( POM); polyethylene terephthalate (PET); polybutylene terephthalate (PBT); polytrimethylene terephthalate (PTT); polyethylene naphthalate (PEN); polybutylene naphthalate (PBN); polyphenylene sulfide (PPS); Polyethersulfone (PES); Polyetherketone (PEK); Polyetheretherketone (PEEK); Polycarbonate (PC); Polyurethane; Polyphenyleneether (PPE); Modified polyphenyleneether (m-PPE); Polyarylate An epoxy resin; a melamine resin; a phenol resin; and a synthetic resin such as a urea resin.
In addition to the above, the material of the base material 11 can be exemplified by ceramics such as glass and silicon, and paper.
The substrate 11 may be a combination of two or more materials such as glass epoxy resin and polymer alloy.

In the present invention, as the base material 11 having low heat resistance, a material having a deflection temperature under a load of 0.25 mm with a bending stress of 1.8 MPa as defined by ASTM D648 is 120 ° C. or less. It can be illustrated.
Preferred examples of such a material for the substrate 11 include polyethylene, polypropylene homopolymer, ABS resin, polyacetal copolymer, polyethylene terephthalate, nylon 6,6, nylon 6, polycarbonate / ABS resin alloy, and the like.

The substrate 11 can be selected in any shape depending on the purpose, and is preferably in the form of a film or a sheet, for example, preferably having a thickness of 0.5 to 5000 μm, and 0.5 to 2500 μm. It is more preferable. When the thickness of the base material 11 is equal to or greater than the lower limit value, the structure of the silver layer can be more stably maintained, and when the thickness of the base material 11 is equal to or less than the upper limit value, handling at the time of forming the silver layer The property becomes better.

The substrate 11 may be composed of a single layer, or may be composed of two or more layers. When the base material 11 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 11 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 11.

<Silver layer>
The silver layer 12 is made of the above-described metallic silver of the present invention.
The shape of the silver layer 12 when the laminate 1 is viewed in plan so that one main surface (surface) 11a of the substrate 11 is looked down from above can be arbitrarily set according to the purpose, and the surface of the substrate 11 The silver layer 12 may be provided on the entire surface of 11a, or the silver layer 12 may be provided on only a part of the surface 11a of the base material 11. In this case, the silver layer 12 is patterned. May be.
The patterned silver layer 12 is useful as a wiring, for example.

The thickness of the silver layer 12 can be arbitrarily set according to the purpose, but is preferably 0.01 to 5 μm, and more preferably 0.05 to 3 μm. When the thickness of the silver layer 12 is equal to or more than the lower limit value, the conductivity can be further improved, and the structure of the silver layer 12 can be more stably maintained. Moreover, the laminated body 1 can be made thinner by the thickness of the silver layer 12 being the said upper limit or less.

The silver layer 12 may be composed of a single layer or may be composed of two or more layers. When the silver layer 12 consists of a plurality of layers, these layers may be the same as or different from each other, and can be configured in the same manner as in the case of the substrate 11. For example, the silver layer 12 composed of a plurality of layers may be configured such that the total thickness of each layer is the thickness of the preferred silver layer 12 described above.

The silver layer 12 is excellent in conductivity, and its volume resistivity is 8 μΩ · cm or less as described above.

The laminated body of the present invention is not limited to that shown in FIG. 1, and other configurations may be added or a part of the configuration may be appropriately changed within a range not impairing the effects of the present invention. For example, another layer other than the silver layer 12 may be provided on the base material 11, and the other layer may include a receiving layer (not shown) provided between the base material 11 and the silver layer 12, An overcoat layer (not shown) for covering the silver layer 12 can be exemplified. The receptor layer improves the adhesion between the silver layer and the substrate.
In addition, here, the laminate 1 is shown having a silver layer 12 on one main surface (surface) 11a of the base material 11, but the laminate of the present invention is the other main surface of the base material 11. Similarly, the surface (back surface) 11b may be provided with the silver layer 12 (on both main surfaces of the base material 11).

<< Manufacturing Method of Laminate >>
The laminate of the present invention can be produced, for example, by a production method having a step of forming a silver layer on a substrate (hereinafter sometimes abbreviated as “silver layer formation step”).

<Silver layer formation process>
In the silver layer forming step, a silver layer is formed on the surface of the substrate (in FIG. 1, the surface (main surface) 11a of the substrate 11).

For the silver layer, the silver ink composition for forming the above-described metallic silver is attached to a desired location on the surface (main surface) of the substrate, and solidification treatment such as drying treatment or heating (firing) treatment is appropriately performed. It can be formed by selecting and performing. The heat treatment may be performed also as a drying treatment.

A silver ink composition can be made to adhere to a base material 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, jet dispenser printing method, gravure printing method, gravure offset printing method, pad printing. Laws can be exemplified.
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 silver layer forming step, the thickness of the silver layer can be adjusted by adjusting the amount of the silver ink composition to be deposited on the substrate, or the blending amount of the metallic silver forming material in the silver ink composition. .

In the silver layer forming step, the substrate may be heat-treated (annealed) before the silver ink composition is attached. By heat-treating the base material, for example, when the silver ink composition is heat-treated (baked), shrinkage of the base material is suppressed and dimensional stability is improved.
The conditions for the heat treatment of the base material before adhering the silver ink composition may be appropriately adjusted according to the type of the base material, and are not particularly limited, but the heat treatment is performed at 60 to 200 ° C. for 10 to 60 minutes. For example, it may be the same as the conditions of the heating (firing) treatment of the silver ink composition in the silver layer forming step.

In the present invention, the surface of the substrate may be plasma-treated before the silver ink composition is attached. By subjecting the substrate to plasma treatment, bleeding of the silver ink composition may be suppressed.
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.

Except for these points, the silver layer can be formed by the same method as the method for producing metallic silver described above.

When manufacturing the laminate of the present invention in which other layers other than the silver layer are provided on the base material, in the above manufacturing method, a step of forming other layers at a predetermined timing is appropriately added. You can do it.
For example, in the case of producing a laminate having a receiving layer between a substrate and a silver layer, a receiving layer is formed on the surface of the substrate (receiving layer) before the silver layer is formed on the substrate. Layer formation step), a silver layer may be formed on the receiving layer (silver layer formation step). The receiving layer is prepared by preparing a composition (composition for receiving layer) in which components for forming the receiving layer such as various resins are blended, and depositing the composition on the substrate, for example, drying treatment, heat treatment, etc. It can form by performing operation for forming a receiving layer. The receiving layer composition can be deposited on the substrate in the same manner as the silver ink composition.

<< Electronic equipment, transparent conductive film >>
The said laminated body is suitable for comprising various electronic devices, a transparent conductive film, etc.
For example, the electronic device can be configured to use the laminate and include the base material as a casing (exterior material), and at least a part of the casing (exterior material) is configured with the base material in the laminate. Except for this point, the configuration can be the same as that of a known electronic device. For example, a flat or curved portion of an exterior material in a communication device such as a mobile phone is used as the base material, and a thin wire made of the metallic silver is formed on the exterior material (base material), and the thin wire is used as a circuit. The laminate can be used as a circuit board. For example, a cellular phone can be configured by combining a voice input unit, a voice output unit, an operation switch, a display unit, and the like in addition to the laminate. Further, by using the patterned silver layer as an antenna, the laminated body can be used as an antenna structure, and the configuration is the same as that of a known data transmitting / receiving body except that the antenna structure is used. Thus, a new data receiving / transmitting body can be obtained. For example, in the laminate, an IC chip electrically connected to the silver layer is provided on the base material to form an antenna portion, whereby a non-contact type data receiving / transmitting body can be configured.

In addition, the transparent conductive film can be configured to use the laminate and include a silver layer as an ultrafine wiring or an ultrathin wiring, except that the silver layer is provided as an ultrafine wiring or an ultrathin wiring. A structure similar to that of the conductive film can be employed. For example, in addition to the laminate, a touch panel or an optical display can be configured by combining with a transparent substrate or the like.
The line width of the ultrafine wiring is preferably 1 to 20 μm, more preferably 1.3 to 15 μm, and particularly preferably 1.5 to 13 μm.
In addition, the cross-sectional shape of the ultrafine wiring is preferably a semi-elliptical shape in which approximately half the region in the minor axis direction of the ellipse is cut off.
On the other hand, the thickness of the ultra-thin wiring is preferably 5 nm to 10 μm, more preferably 7 nm to 5 μm, and particularly preferably 10 nm to 1 μm.
The cross-sectional shape of the ultrathin wiring is the same as the cross-sectional shape of the ultrafine wiring.
In the transparent conductive film, the silver layer preferably satisfies at least one of such a line width and thickness. If the silver layer has such a line width or thickness, its presence is difficult to recognize by visual observation, which is preferable as a transparent conductive film.

In the laminate, the silver layer can be formed at a low temperature, and a wide range of materials such as a base material can be selected. Thus, the degree of freedom in design is greatly improved, and electronic devices, transparent conductive films, etc. Can be made more rational.
The above electronic devices, transparent conductive films, and the like can maintain high performance over a long period of time.

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]
<Manufacture of laminates>
(Manufacture of silver ink composition)
Add 2-methylacetoacetic acid silver to 2-ethylhexylamine (0.4 times molar amount relative to 2-methylacetoacetate silver described later) in a beaker so that the liquid temperature is 50 ° C. or less, and 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]). “Other components (mass%)” means the ratio of the blending amount (mass) of other components to the total amount (mass) of the blending components of the silver ink composition ([blending amount (mass) of other components] / [ Total amount (mass) of compounding components of silver ink composition] × 100). In Table 1, “-” in the column of the blending component means that the component is not blended. The same applies to the following tables.

(Manufacture of laminates)
On one main surface (surface) of a substrate (thickness 2 mm) made of polycarbonate / ABS resin alloy, the silver ink composition obtained above was applied by spin coating. The spin coating was performed under conditions of 7500 rpm and 30 seconds. The base material has a deflection temperature under load of 120 ° C. or less when the deflection amount is 0.25 mm with a bending stress of 1.8 MPa as defined by ASTM D648.
Next, the coated base material is dried at 80 ° C. for 1 minute by blowing hot air (wind speed: 15 m / second), and further placed in a steam atmosphere at 80 ° C. and 100% relative humidity for 2 minutes. By heating (firing) treatment, a silver layer having a size of 30 mm × 30 mm and a thickness of 1 to 2 μm was formed on the substrate to obtain a laminate. Table 2 shows the conditions for the heat treatment.

<Evaluation of laminate>
(Calculation of crystallite diameter of metallic silver)
The silver layer formed as described above was subjected to X-ray diffraction measurement using a thin film X-ray diffractometer (Bruker AXS, D8 DISCOVER with GADDS). CuKα rays (wavelength λ: 0.154 nm) were used as the X-ray source, and the measurement angle (2θ) was set to 20 to 100 °. Each measurement angle and Miller index of the peak indicated by X-ray diffraction are as follows, and the crystallite diameter in consideration of the crystal orientation was calculated.
Measurement angle: 38.1 ° (111), 44.2 ° (200), 64.4 ° (220), 77.4 ° (311), 81.5 ° (222), 97.8 ° (400)
Here, based on the Stokes-Wilson theory, the crystallite size was calculated based on the Scherrer equation described above in consideration of the size expansion independent of the crystal shape. The results are shown in Table 2.

(Measurement of volume resistivity of silver layer)
About the laminated body obtained above, the thickness T (cm) of the formed silver layer was measured using a laser microscope ("VK-X100" manufactured by Keyence Corporation). In addition, the surface resistance value of the formed silver layer was measured by a four-terminal method using a resistivity meter (“Loresta MCP-T610, PSP type probe” manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The surface resistivity R (Ω / □) was calculated by multiplying the resistivity correction coefficient (4.04) calculated from the layer pattern shape and the probe shape. Then, the volume resistivity ρ (μΩ · cm) of the silver layer was calculated by the formula “ρ = R × T”. The results are shown in Table 2.

[Example 2]
<Manufacture of laminates>
(Manufacture of silver ink composition)
Add 2-methylacetoacetic acid silver to 2-ethylhexylamine (0.4 times molar amount relative to 2-methylacetoacetate silver described later) in a beaker so that the liquid temperature is 50 ° C. or less, and The mixture was stirred for 15 minutes to obtain a liquid material. To this liquid, formic acid (0.6-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 completion of the formic acid dropwise addition, the reaction solution was further stirred at 25 ° C. for 1 hour, and then dodecane was added to the reaction solution so that the ratio of the compounding amount to the total amount of the compounding components was 11% by mass. A silver ink composition was obtained by stirring at 25 ° C. until Table 1 shows the types and blending ratios of each blending component.

(Manufacture of laminates)
Lamination was performed in the same manner as in Example 1 except that the silver ink composition obtained above was used, and that the spin coating conditions were changed to 4500 rpm and 15 seconds instead of 7500 rpm and 30 seconds when forming the silver layer. Got the body.

<Evaluation of laminate>
The laminate obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Manufacture and evaluation of laminate>
[Example 3]
As shown in Tables 1 and 2, at the time of forming the silver layer, instead of heating the coated substrate in a steam atmosphere at 80 ° C. and 100% relative humidity for 2 minutes, 120 ° C. and relative humidity 100 A laminate was manufactured and evaluated in the same manner as in Example 1 except that it was heat-treated for 2 minutes in a water vapor atmosphere of 2%. The results are shown in Table 2.

[Example 4]
As shown in Tables 1 and 2, when the silver layer was formed, the coated substrate was dried at 80 ° C. for 1 minute, and then this substrate was placed in a steam atmosphere at 80 ° C. and 100% relative humidity for 2 minutes. Instead of heat treatment, a laminate was produced in the same manner as in Example 2 except that the coated substrate was heat treated at 80 ° C. for 60 minutes by blowing hot air (wind speed: 15 m / second) and evaluated. did. The results are shown in Table 2.

[Example 5]
As shown in Tables 1 and 2, when the silver layer was formed, the coated substrate was dried at 80 ° C. for 1 minute, and then this substrate was placed in a steam atmosphere at 80 ° C. and 100% relative humidity for 2 minutes. Instead of heat treatment, a laminate was produced in the same manner as in Example 2 except that the coated substrate was heat treated at 120 ° C. for 60 minutes by blowing hot air (wind speed: 15 m / second) and evaluated. did. The results are shown in Table 2.

[Comparative Example 1]
As shown in Tables 1 and 2, the silver ink composition containing metal silver particles (“TEC-PA-010” manufactured by INK TEC) was used. A laminate was produced and evaluated in the same manner as in Example 1 except that 7500 rpm and 15 seconds were used instead of 30 seconds. The results are shown in Table 2.

[Comparative Example 2]
As shown in Tables 1 and 2, the silver ink composition containing metal silver particles (“TEC-PA-010” manufactured by INK TEC) was used, and the spin coating conditions were set at 7500 rpm when the silver layer was formed. , 7500 rpm for 15 seconds instead of 30 seconds, the coated substrate is dried at 80 ° C. for 1 minute, and then the substrate is heated for 2 minutes in a steam atmosphere at 80 ° C. and 100% relative humidity. Instead of processing, a laminated body was manufactured and evaluated in the same manner as in Example 1 except that the coated substrate was heated at 80 ° C. for 60 minutes by blowing hot air (wind speed: 15 m / second). . The results are shown in Table 2.

[Comparative Example 3]
As shown in Tables 1 and 2, the silver ink composition containing metal silver particles (“TEC-PA-010” manufactured by INK TEC) was used, and the spin coating conditions were set at 7500 rpm when the silver layer was formed. , 7500 rpm for 15 seconds instead of 30 seconds, the coated substrate is dried at 80 ° C. for 1 minute, and then the substrate is heated for 2 minutes in a steam atmosphere at 80 ° C. and 100% relative humidity. Instead of processing, a laminate was produced and evaluated in the same manner as in Example 1 except that the coated substrate was heated at 120 ° C. for 60 minutes by blowing hot air (wind speed: 15 m / sec). . The results are shown in Table 2.

As is clear from the above results, in the laminates of Examples 1 to 5, the silver layer has a sufficiently low volume resistivity and excellent conductivity even though it was formed at a low heat treatment temperature of 120 ° C. or less. It was. In these examples, the crystallite diameter of metallic silver constituting the silver layer was 16.8 nm or more.
On the other hand, in the laminates of Comparative Examples 1 to 3, it is considered that the heat treatment temperature was lower than that of the silver ink composition used, and the silver layer has a high volume resistivity and poor conductivity. It was.

[Example 6]
<Manufacture of laminates>
(Manufacture of silver ink composition)
In the same manner as in Example 1, a silver ink composition was obtained. Table 3 shows the types and mixing ratios of the respective components.

(Manufacture of laminates)
Using the silver ink composition obtained above, a base material coated with the silver ink composition was obtained in the same manner as in Example 1.
Subsequently, the coated base material is dried at 80 ° C. for 1 minute by blowing hot air (wind speed: 15 m / second), and then the coated base material is baked at 80 ° C. for 2 minutes (80 ° C. A silver layer having a size of 30 mm × 30 mm and a thickness of 1 to 2 μm was formed on the substrate by immersing in hot water (2 minutes) and heating (firing) to obtain a laminate. As the hot water, distilled water heated to 80 ° C. was used. Table 4 shows the conditions for the heat treatment.

<Evaluation of laminate>
About the silver layer formed above, the crystallite diameter of metallic silver was computed by the same method as Example 1. The results are shown in Table 4.
Further, the volume resistivity ρ (μΩ · cm) of the silver layer obtained above was calculated in the same manner as in Example 1. The results are shown in Table 4.

[Example 7]
<Manufacture of laminates>
(Manufacture of silver ink composition)
Add silver acetoacetate to 2-ethylhexylamine (1.0 times the molar amount of silver acetoacetate described later) in a beaker so that the liquid temperature is 50 ° C. or less, and use a mechanical stirrer for 15 minutes. By stirring, a liquid material was obtained. To this liquid, formic acid (1.2 times molar amount with respect to silver acetoacetate) 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 3 shows the types and mixing ratios of the respective components.

(Manufacture of laminates)
A silver layer was formed by the same method as in Example 6 except that the silver ink composition obtained above was used to produce a laminate. Table 4 shows the conditions for the heat treatment.

<Evaluation of laminate>
About the silver layer formed above, the crystallite diameter of metallic silver was computed by the same method as Example 6. The results are shown in Table 4.
Further, the volume resistivity ρ (μΩ · cm) of the silver layer obtained above was calculated in the same manner as in Example 6. The results are shown in Table 4.

<Manufacture and evaluation of laminate>
[Example 8]
As shown in Tables 3 and 4, at the time of forming the silver layer, instead of heat-treating the coated substrate at 80 ° C. for 2 minutes, 2 ° A laminate was produced and evaluated in the same manner as in Example 7, except that the heat treatment was performed for a minute. The results are shown in Table 4.

[Example 9]
<Manufacture of laminates>
(Manufacture of silver ink composition)
Using a mechanical stirrer, add silver acetonedicarboxylate to 2-ethylhexylamine (2.0 times molar amount relative to silver acetonedicarboxylate described later) in a beaker so that the liquid temperature is 50 ° C. or less. A liquid was obtained by stirring for 15 minutes. To this liquid, formic acid (2.0 times the molar amount with respect to silver acetone dicarboxylate) was added dropwise over 30 minutes using a syringe pump so that the temperature of the reaction solution would be 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 3 shows the types and mixing ratios of the respective components.

<Manufacture and evaluation of laminate>
[Example 10]
As shown in Tables 3 and 4, at the time of forming the silver layer, instead of heat-treating the coated substrate at 80 ° C. for 2 minutes, 2 ° C. in a water vapor atmosphere at 80 ° C. and 100% relative humidity. A laminate was produced and evaluated in the same manner as in Example 9 except that the heat treatment was performed for a minute. The results are shown in Table 4.

<Manufacture and evaluation of laminate>
[Comparative Example 4]
As shown in Tables 1 to 4, at the time of forming the silver layer, instead of heat-treating the coated base material in a steam atmosphere at 80 ° C. and 100% relative humidity for 2 minutes, it was performed at 80 ° C. for 2 minutes. A laminate was produced and evaluated in the same manner as in Comparative Example 1 except that it was heat-treated by hot water bathing. As the hot water, distilled water heated to 80 ° C. was used. The results are shown in Table 4.

<Manufacture and evaluation of laminate>
[Comparative Example 5]
As shown in Tables 3 and 4, at the time of forming the silver layer, instead of drying the coated substrate at 80 ° C. for 1 minute by blowing hot air (wind speed: 15 m / second), blowing hot air (wind speed) : 15 m / sec), a laminate was produced and evaluated in the same manner as in Comparative Example 4 except that the coated substrate was dried at 120 ° C. for 1 minute. The results are shown in Table 4.

As is clear from the above results, in the laminates of Examples 6 to 10, the silver layer was formed despite the fact that it was formed at a low heat treatment temperature of 80 ° C. or less, and the heat treatment method was changed. Had a sufficiently low volume resistivity and excellent conductivity. In these examples, the crystallite diameter of metallic silver constituting the silver layer was 22.1 nm or more.
On the other hand, in the laminates of Comparative Examples 4 to 5, it is considered that the heat treatment temperature was lower than that of the silver ink composition used, and the silver layer has a high volume resistivity and poor conductivity. It was.

The present invention can be used for various electronic devices having a metallic silver layer on a substrate, such as a wiring board, an electromagnetic wave shield, a touch panel, and an antenna of a wireless communication device casing.

DESCRIPTION OF SYMBOLS 1 Laminated body 11 Base material 11a One main surface (surface) of a base material
11b The other main surface (back surface) of the base material
12 Silver layer

Claims

Metal silver with a crystallite diameter of 15 nm or more and a volume resistivity of 8 μΩ · cm or less.
The metallic silver according to claim 1, wherein the crystallite diameter is 16.5 nm or more and 80 nm or less.
The metallic silver according to claim 1, which is formed using silver β-ketocarboxylate represented by the following general formula (1).

(Wherein R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one or more hydrogen atoms may be substituted with a substituent, a phenyl group, a hydroxyl group, an amino group, or a group represented by the general formula “R 1 -CY 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-ethoxyvinyl group, or “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. )
A metal having a step of forming silver metal having a crystallite diameter of 15 nm or more and a volume resistivity of 8 μΩ · cm or less, using silver β-ketocarboxylate represented by the following general formula (1) Silver production method.

(Wherein R represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one or more hydrogen atoms may be substituted with a substituent, a phenyl group, a hydroxyl group, an amino group, or a group represented by the general formula “R 1 -CY 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-ethoxyvinyl group, or “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 step of forming the metallic silver, the silver ink composition containing the β-ketocarboxylate is heat-treated under non-humidified conditions, and then further contacted with the heated liquid under humidified conditions. The method for producing metallic silver according to claim 4, wherein the metallic silver is formed by heat treatment.
A laminate comprising a layer of metallic silver according to claim 1 on a substrate.
The laminate according to claim 6, wherein the thickness of the base material is 0.5 to 5000 µm, and the thickness of the layer made of metallic silver is 0.01 to 5 µm.
The laminate according to claim 6, wherein the base material has a deflection temperature under load of 120 ° C. or less when a deflection amount is 0.25 mm under a bending stress of 1.8 MPa as defined by ASTM D648.