JP6278659B2 - Silver ink composition, conductor and electronic device - Google Patents

Description

  The present invention relates to a silver ink composition suitable for application to an intaglio printing method, and a conductor and an electronic device obtained using the silver ink composition.

  The intaglio printing method is a printing method in which an intaglio having a concave portion corresponding to a pattern forming portion on the surface is used, and an ink composition filled in the concave portion is transferred to a substrate. Conventionally, this intaglio printing method has a problem of so-called plate fogging, in which an extra ink composition other than the intended purpose is transferred to the printing material, and the intended printing pattern cannot be obtained. This problem will be described more specifically with reference to FIG.

In the intaglio printing method, first, the ink composition 6 is placed on the surface 9a of the intaglio 9 as shown in FIG.
Next, using the doctor blade 90, the ink composition 6 placed on the intaglio plate 9 is spread (doctored) on the surface 9a of the intaglio plate 9, and as shown in FIG. 6 is filled. At this time, the ink composition 6 is applied by moving the doctor blade 90 in the direction of the arrow on the intaglio 9 while maintaining the state where the tip of the doctor blade 90 is in contact with the surface 9a of the intaglio 9. As a result, the ink composition 6 is filled in the concave portion 91, but usually, on the surface 9 a of the intaglio 9 other than the concave portion 91, there is a region where the ink composition 6 is left in a thin film shape.

  Next, as shown in FIG. 1 (c), the pad 8 is lowered relative to the intaglio 9 in the direction of the arrow, and the surface 8 a of the pad 8 is directly on the surface 9 a of the intaglio 9 or via the ink composition 6. The ink composition 6 is transferred onto the surface 8a of the pad 8, as shown in FIG. At this time, if the physical properties of the ink composition 6 are not appropriate, not only the ink composition 6 in the recess 91 but also the excess ink composition 6 left on the surface 9 a of the intaglio 9 is also on the surface 8 a of the pad 8. Will be transcribed.

Then, as shown in FIG. 1 (d), the pad 8 is lowered relative to the printing material (base material) 7 in the direction of the arrow, and the surface 8 a to which the ink composition 6 is adhered becomes the surface 7 a of the printing material 7. Then, the ink composition 6 on the pad 8 is transferred to the surface 7a of the substrate 7 as shown in FIG. When the desired pattern is printed, the excess ink composition 6 on the pad 8 is also transferred to the surface 7a of the substrate 7 at the same time, so-called plate fogging occurs, and finally The target print pattern cannot be obtained.
Here, the method using the pad 8 (pad printing method) has been described, but a method using a roll-shaped rubber blanket without using the pad 8 (intaglio offset printing method) or without using these intermediate transfer members. There is also a method of printing by directly contacting the intaglio 9 with the surface 7a of the substrate 7 (direct gravure printing method), and these methods also cause the same plate fog.

  Therefore, in order to suppress plate fogging, it is usually necessary to finely adjust the ink composition so that the ink composition has appropriate physical properties by adjusting the blending components and blending amount of the ink composition.

  On the other hand, a silver ink composition in which metallic silver or a material for forming the same is blended is attracting attention as being capable of forming a precise pattern of metallic silver on a base material. Various uses have been studied. And like the conventional ink composition, application to the intaglio printing method is expected. However, in such a silver ink composition, the metal silver to be formed is required to have high conductivity, and higher printability is required. Here, it has been very difficult in the past to finely adjust the physical properties of the silver ink composition so that metallic silver having high conductivity can be formed and plate fogging during printing can be suppressed.

As a silver ink composition, for example, a metal silver nanoparticle paste that can be applied to an intaglio offset printing method without using a resin by adjusting the mixing ratio of amines having hydroxyl groups and amines not having hydroxyl groups Is disclosed (see Patent Document 1). This silver ink composition is said to be capable of forming metallic silver by heat treatment at about 120 ° C.
However, it is not clear whether the silver ink composition disclosed in Patent Document 1 can sufficiently suppress plate fogging during printing.

  Furthermore, as a silver ink composition, what mix | blended carboxylate silver, such as (beta) -ketocarboxylate silver, is disclosed, and it is metal by heat processing at a low temperature rather than the silver ink composition of patent document 1. Since silver can be formed, its use is also expected in the intaglio printing method.

JP 2009-238625 A JP 2009-114232 A

  However, a silver ink composition containing silver carboxylate as disclosed in Patent Document 2 has also been known to be particularly suitable for suppressing plate fogging in the intaglio printing method. Absent.

  The present invention has been made in view of the above circumstances, and is obtained by using a silver ink composition that contains silver carboxylate and can suppress plate fogging in an intaglio printing method, and the silver ink composition. It is an object to provide an electrical conductor and an electronic device.

In order to solve the above problems, the present invention provides a silver ink composition for intaglio printing, wherein the silver ink composition comprises silver carboxylate having a group represented by the formula “—COOAg”, and 2-ethylhexyl. amine, 2-amino octane and 2-heptyl one or more nitrogen-containing compound selected from the group consisting of amine, and one or more reducing compound selected or formic acid and oxalic acid, et al., is being formulated, the The blending amount A (mol) of silver carboxylate, the blending amount B (mol) of the nitrogen-containing compound, and the blending amount C (mol) of the reducing compound satisfy the following formula (I) -1. A silver ink composition is provided.
0.5 ≦ C / A ≦ 0.35B / A + 0.5 (I) −1

The present invention also provides a conductor obtained by forming metallic silver using the silver ink composition.
According to another aspect of the present invention, there is provided an electronic apparatus including the conductor on a base material and the base material as a casing.

  ADVANTAGE OF THE INVENTION According to this invention, silver carboxylate is mix | blended and the silver ink composition which can suppress the plate fog in an intaglio printing method, and the conductor and electronic device which were obtained using this silver ink composition are provided. The

It is sectional drawing for demonstrating generation | occurrence | production of the plate fog in the conventional intaglio printing method. It is sectional drawing which illustrates typically 1st embodiment of the intaglio printing method. It is sectional drawing which illustrates typically 2nd embodiment of the intaglio printing method. It is the graph which plotted the value of B / A and C / A in each silver ink composition in an Example and a comparative example.

<Silver ink composition>
The silver ink composition according to the present invention comprises a silver carboxylate having a group represented by the formula “—COOAg”, an amine compound having a carbon number of 25 or less, a quaternary ammonium salt, ammonia, and the amine compound or ammonia. One or more nitrogen-containing compounds selected from the group consisting of ammonium salts that react with acids (hereinafter sometimes simply referred to as “nitrogen-containing compounds”), oxalic acid, hydrazine, and the following general formula (5) One or more reducing compounds selected from the group consisting of compounds represented by the formula (hereinafter sometimes abbreviated as “compound (5)”) are blended, and the blending amount A of the above-mentioned silver carboxylate (Mol), the compounding amount B (mol) of the nitrogen-containing compound, and the compounding amount C (mol) of the reducing compound satisfy the following formula (I).
HC (= O) -R ²¹ (5)
(In the formula, R ²¹ represents an alkyl group having 20 or less carbon atoms, an alkoxy group, an N, N-dialkylamino group, a hydroxyl group, or an amino group.)
C / A ≦ 0.35B / A + 0.5 (I)

  The silver ink composition is particularly excellent for intaglio printing, and the compounding amounts A (mol) to C (mol) satisfy the specific relationship represented by the formula (I), whereby intaglio printing. There is a remarkable effect that can suppress plate fogging in the law. The relationship represented by the formula (I) or a similar formula is not known at all in the ink compositions used in various printing methods as well as the silver ink composition.

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

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

（式中、Ｒは１個以上の水素原子が置換基で置換されていてもよい炭素数１〜２０の脂肪族炭化水素基若しくはフェニル基、水酸基、アミノ基、又は一般式「Ｒ^１−ＣＹ^１ _２−」、「ＣＹ^１ _３−」、「Ｒ^１−ＣＨＹ^１−」、「Ｒ^２Ｏ−」、「Ｒ^５Ｒ^４Ｎ−」、「（Ｒ^３Ｏ）_２ＣＹ^１−」若しくは「Ｒ^６−Ｃ（＝Ｏ）−ＣＹ^１ _２−」で表される基であり；
Ｙ^１はそれぞれ独立にフッ素原子、塩素原子、臭素原子又は水素原子であり；Ｒ^１は炭素数１〜１９の脂肪族炭化水素基又はフェニル基であり；Ｒ^２は炭素数１〜２０の脂肪族炭化水素基であり；Ｒ^３は炭素数１〜１６の脂肪族炭化水素基であり；Ｒ^４及びＲ^５はそれぞれ独立に炭素数１〜１８の脂肪族炭化水素基であり；Ｒ^６は炭素数１〜１９の脂肪族炭化水素基、水酸基又は式「ＡｇＯ−」で表される基であり；
Ｘ^１はそれぞれ独立に水素原子、炭素数１〜２０の脂肪族炭化水素基、ハロゲン原子、１個以上の水素原子が置換基で置換されていてもよいフェニル基若しくはベンジル基、シアノ基、Ｎ−フタロイル−３−アミノプロピル基、２−エトキシビニル基、又は一般式「Ｒ^７Ｏ−」、「Ｒ^７Ｓ−」、「Ｒ^７−Ｃ（＝Ｏ）−」若しくは「Ｒ^７−Ｃ（＝Ｏ）−Ｏ−」で表される基であり；
Ｒ^７は、炭素数１〜１０の脂肪族炭化水素基、チエニル基、又は１個以上の水素原子が置換基で置換されていてもよいフェニル基若しくはジフェニル基である。）

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

（式中、Ｒ^８は炭素数１〜１９の脂肪族炭化水素基、カルボキシ基又は式「−Ｃ（＝Ｏ）−ＯＡｇ」で表される基であり、前記脂肪族炭化水素基がメチレン基を有する場合、１個以上の該メチレン基はカルボニル基で置換されていてもよい。）

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In the silver ink composition, the content of silver derived from the silver carboxylate is preferably 5% by mass or more, and more preferably 10% by mass or more. By being in such a range, the formed conductor is more excellent 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 carboxylate” means silver in the silver carboxylate blended at the time of producing the silver ink composition, unless otherwise specified. The concept includes both silver constituting silver carboxylate, silver in the decomposition product generated by decomposition of the silver carboxylate after blending, and silver itself.

[Nitrogen-containing compounds]
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.
Specific examples of preferable 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 frame is not specifically limited, One may be sufficient and two or more may be sufficient. When there are two or more, these heteroatoms may be the same or different from each other. That is, these heteroatoms may all be the same, may all be different, or may be partially different.
The heteroaryl group may be monocyclic or polycyclic, and the number of ring members (the number of atoms constituting the ring skeleton) is not particularly limited, but is preferably a 3- to 12-membered ring.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The amine compound is n-propylamine, n-butylamine, n-hexylamine, n-octylamine, n-dodecylamine, n-octadecylamine, 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 preferred. .
Among these amine compounds, 2-ethylhexylamine is excellent in compatibility with the silver carboxylate, particularly suitable for increasing the concentration of the silver ink composition, and further for reducing the surface roughness of the conductive layer 4. Particularly 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 0.1 to 15 mol, and more preferably 0.2 to 5 mol, per mol of the silver carboxylate. That is, regarding the blending amount B (mol) of the nitrogen-containing compound and the blending amount A (mol) of silver carboxylate, the value of B / A is preferably 0.1 to 15, and preferably 0.2 to 5. It is more 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 compounds]
The reducing compound is one or more selected from the group consisting of oxalic acid, hydrazine and a compound represented by the following general formula (5) (compound (5)). 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.
HC (= O) -R ²¹ (5)
(In the formula, R ²¹ represents an alkyl group having 20 or less carbon atoms, an alkoxy group, an N, N-dialkylamino group, a hydroxyl group, or an amino group.)

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

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

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

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

The reducing compound preferably has one or both of a carboxy group (—COOH) and a carbonyl group (—C (═O) —). In this case, the reducing compound has one or more carboxy groups or carbonyl groups. More preferred are formic acid (HC (═O) —OH); methyl formate (HC (═O) —OCH ₃ ), ethyl formate (HC—═O) —OCH. Formic acid esters such as ₂ CH ₃ ) and butyl formate (HC (═O) —O (CH ₂ ) ₃ CH ₃ ); propanal (HC (═O) —CH ₂ CH ₃ ), butanal (H Aldehydes such as —C (═O) — (CH ₂ ) ₂ CH ₃ ) and hexanal (HC— (O) — (CH ₂ ) ₄ CH ₃ ); formamide (HC— (O) —NH ₂ ), N, N-dimethylformamide (HC (= ) -N _{(CH 3) 2)} formamides (formula "H-C (= O) -N (-) - " such as a compound having a group represented by); oxalate can be exemplified.
Among them, the reducing compound is more preferably one having one carboxy group or carbonyl group, and particularly preferably formic acid or formic acid ester.

In the silver ink composition, the compounding amount of the reducing compound is preferably 0.04 to 3.5 mol, and 0.06 to 2.5 mol per mol of the silver carboxylate. Is more preferable. That is, with respect to the compounding amount C (mol) of the reducing compound and the compounding amount A (mol) of silver carboxylate, the value of C / A is preferably 0.04 to 3.5, and 0.06 to 2 .5 is more preferable. When the blending amount of the reducing compound is within such a range, the silver ink composition can form a conductor (metal silver) more easily and more stably.
Furthermore, in the silver ink composition, the compounding amount of the reducing compound is more preferably 0.4 mol or more, and particularly preferably 0.5 mol or more, per mol of the carboxylate silver. . That is, the value of C / A is more preferably 0.4 or more, and particularly preferably 0.5 or more. When the blending amount of the reducing compound is within such a range, the silver ink composition is preferably a conductor having high conductivity even at a lower temperature, for example, preferably 100 ° C. or less, more preferably 90 ° C. or less. (Metal silver) can be formed.

[Blending amounts A, B and C]
In the silver ink composition according to the present invention, as described above, it is preferable that the nitrogen-containing compound and the reducing compound have the above-described blending amount with respect to the silver carboxylate, but the blending amount of the silver carboxylate It is necessary that A (mol), the blending amount B (mol) of the nitrogen-containing compound, and the blending amount C (mol) of the reducing compound satisfy the following formula (I). By satisfying the following formula (I), the silver ink composition exhibits a remarkable effect that can suppress plate fogging in the intaglio printing method.
C / A ≦ 0.35B / A + 0.5 (I)
The above formula (I) is obtained by considering the presence or absence of plate fogging when various values of B / A and C / A are changed in the silver ink composition and this silver ink composition is applied to the intaglio printing method. It is derived.

As a particularly preferable silver ink composition, in addition to a high effect of suppressing plate fogging in the intaglio printing method, it is possible to form a conductor (metal silver) having a high conductivity even at a lower temperature. Those satisfying C / A, that is, those satisfying the following formula (I) -1 are mentioned (in the formula, A, B and C are the same as described above).
0.5 ≦ C / A ≦ 0.35B / A + 0.5 (I) -1

[alcohol]
In addition to the silver carboxylate, the nitrogen-containing compound and the reducing compound, the silver ink composition may further contain an alcohol.

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

（式中、Ｒ’及びＲ’’は、それぞれ独立に炭素数１〜２０のアルキル基、又は１個以上の水素原子が置換基で置換されていてもよいフェニル基である。）

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

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

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

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

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

  When acetylene alcohol (2) is used, in the silver ink composition, the blending amount of acetylene alcohol (2) is preferably 0.03 to 0.7 mole per mole of the above-mentioned silver carboxylate. It is more preferable that it is 0.05-0.3 mol. When the blending amount of acetylene alcohol (2) is within such a range, the stability of the silver ink composition is further improved.

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

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

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

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

[Method for producing silver ink composition]
The silver ink composition is obtained by blending the silver carboxylate and components other than the silver carboxylate. 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, particularly when β-ketocarboxylate (1) is used as the silver carboxylate, no impurities that inhibit conductivity are generated at the time of blending the above components, or such impurities Since the production amount 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 compound 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.
The mixing method is not particularly limited, a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer, a three-roller, a kneader, a bead mill or the like; a method of mixing by adding ultrasonic waves, etc. What is necessary is just to select suitably from a well-known method.
In the silver ink composition, when the undissolved component is uniformly dispersed, for example, a method of dispersing using the above-described three rolls, kneader, bead mill or the like is preferably applied.

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

<Conductor>
The conductor according to the present invention is obtained by forming metallic silver using the above-described silver ink composition according to the present invention, and is composed mainly of metallic silver. Here, “having metallic silver as a main component” means that the ratio of metallic silver is sufficiently high so that it can be regarded as being composed solely of metallic silver. For example, the ratio of metallic silver in a conductor Is preferably 99% by mass or more.

The conductor can be produced, for example, by attaching a silver ink composition on a substrate and appropriately performing post-treatment such as drying or heating (firing). The heat treatment may be performed also as a drying treatment.
The substrate is preferably in the form of a film or a sheet, and preferably has a thickness of 0.5 to 5000 μm.

The material of the base material is not particularly limited, and may be selected according to the purpose. However, a material having heat resistance that does not deteriorate during formation of the conductor by heat treatment of the silver ink composition is preferable.
Specifically, the material of the base material is polyethylene (PE), polypropylene (PP), polycycloolefin, polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer, polyvinyl alcohol, vinylon, polyvinylidene chloride (PVDC). , Polymethylpentene (PMP), polystyrene (PS), polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA), polybutyl methacrylate (PBMA), polymethyl acrylate (PMA) ), Polyethyl acrylate (PEA), polybutyl acrylate (PBA), AS resin, ABS resin, polyamide (PA), polyimide (PI), polyamideimide (PAI), polyacetal, polyethylene terephthalate (PET), glycol modified Polyeth Terephthalate (PET-G), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyphenylene sulfide (PPS), polysulfone (PSF), Polyethersulfone (PES), polyetherketone (PEK), polyetheretherketone (PEEK), polycarbonate (PC), polyurethane, polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyarylate, epoxy resin, Examples thereof include synthetic resins such as melamine resin, phenol resin, and urea resin.
In addition to the above, examples of the material for the substrate include ceramics such as glass and silicon; papers such as fine paper, thin paper, glassine paper, and sulfuric acid paper.
The base material may be a combination of two or more materials such as glass epoxy resin and polymer alloy.

The substrate may be composed of a single layer, or may be composed of two or more layers. When a base material 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 a base material consists of multiple layers, it is good to make it the total thickness of each layer be the thickness of said preferable base material.

The silver ink composition according to the present invention can be deposited on a substrate by a known method such as a printing method or a coating method, but is particularly excellent in application of an intaglio printing method.
As the intaglio printing method, a known method can be applied, and more specifically, a pad printing method, an intaglio offset printing method, a direct gravure printing method and the like can be exemplified.

FIG. 2 is a cross-sectional view schematically illustrating the first embodiment of the intaglio printing method.
The intaglio printing method shown here corresponds to a pad printing method in which ink is transferred using a pad.

In the present embodiment, first, as shown in FIG. 2A, the silver ink composition 1 is placed on the surface 9 a of the intaglio 9. The silver ink composition 1 relates to the above-described present invention.
The intaglio 9 is the same as that shown in FIG. 1, and has a concave portion 91 corresponding to the pattern forming portion on the surface 9a, and is made of a material such as metal. The surface 9a of the intaglio 9 is a pattern forming surface.

  Next, using the doctor blade 90, the silver ink composition 1 placed on the intaglio plate 9 is spread (doctored) on the surface 9a of the intaglio plate 9, and as shown in FIG. Fill composition 1. At this time, the silver ink composition 1 is applied by moving the doctor blade 90 in the direction of the arrow on the intaglio 9 while maintaining the state where the tip of the doctor blade 90 is in contact with the surface 9a of the intaglio 9. . As a result, the silver ink composition 1 is filled in the concave portion 91, but usually, on the surface 9 a of the intaglio 9 other than the concave portion 91, there is a region where the silver ink composition 1 is left in a thin film shape.

  Next, as shown in FIG. 2 (c), the pad 8 is lowered relative to the intaglio 9 in the direction of the arrow, and the surface 8a of the pad 8 is directly in the region including the recess 91 in the surface 9a of the intaglio 9. Alternatively, the silver ink composition 1 is contacted (closely contacted), and the pad 8 is pulled up relative to the intaglio 9 to bring the silver ink onto the surface 8a of the pad 8 as shown in FIG. The composition 1 is transferred. At this time, the silver ink composition 1 is transferred from the concave portion 91 of the intaglio 9 onto the surface 8a of the pad 8 reflecting the pattern of the concave portion 91, but remains on the surface 9a of the intaglio 9 other than the concave portion 91. The excess silver ink composition 1 thus formed remains on the surface 9a, and the transfer of the pad 8 onto the surface 8a is suppressed. The reason why the transfer of the excess silver ink composition 1 to the pad 8 is suppressed in this way is that no special operation is performed immediately before the contact (transfer) between the intaglio 9 and the pad 8 (a series of steps). The amount of the silver ink composition 1 existing in the form of a thin film on the surface 9a of the intaglio 9 other than the concave portion 91 is smaller than that of the silver ink composition 1 existing in the concave portion 91. This is presumed to be because the dryness is high (dryer).

Next, as shown in FIG. 2 (d), the pad 8 to which the silver ink composition 1 has been transferred is lowered relative to the base material (printed material) 7 in the direction of the arrow, and the silver ink composition of the pad 8. As shown in FIG. 2 (e), the surface 8a onto which the object 1 is transferred is brought into contact (contact) with the surface 7a of the substrate 7, and the pad 8 is further lifted relative to the substrate 7. The silver ink composition 1 is transferred from the surface 8 a of the pad 8 to the surface 7 a of the base material 7. As a result, the silver ink composition 1 is printed on the substrate 7 in a pattern corresponding to the recess 91. At this time, since the excess silver ink composition 1 other than the desired pattern is not adhered on the surface 8a of the pad 8, the plate fog is suppressed, and the substrate 7 is not printed for purposes other than the intended purpose. The material of the base material 7 is as described above.
As described above, by using the silver ink composition according to the present invention, even if printing is performed by the same method as that shown in FIG. 1, plate fog is suppressed.

  Next, the silver ink composition 1 printed on the base material 7 is post-treated to form metallic silver from the silver carboxylate, and as shown in FIG. Form.

FIG. 3 is a cross-sectional view schematically illustrating a second embodiment of the intaglio printing method.
The intaglio printing method shown here corresponds to a direct gravure printing method in which ink is directly transferred from an intaglio to a substrate.

  In the present embodiment, as in the first embodiment, first, as shown in FIG. 3A, the silver ink composition 1 is spread (doctored) on the surface 9a of the intaglio 9 to form the recess 91. Is filled with the silver ink composition 1. The silver ink composition 1 relates to the above-described present invention, as in the case of the first embodiment.

Next, the base material (printed material) 7 is lowered relative to the intaglio plate 9 in the direction of the arrow, and the surface 7a of the base material is directly or in a region including the concave portion 91 on the surface 9a of the intaglio plate 9 or the silver ink composition. 1 is contacted (closely contacted) through 1 and the substrate 7 is further pulled up relative to the intaglio 9 to form a silver ink composition on the surface 7a of the substrate 7 as shown in FIG. 1 is transferred. At this time, the silver ink composition 1 is transferred from the concave portion 91 of the intaglio 9 onto the surface 7 a of the substrate 7 in a manner reflecting the pattern of the concave portion 91, but a thin film is formed on the surface 9 a of the intaglio 9 other than the concave portion 91. The excess silver ink composition 1 left in the shape remains on the surface 9a for the same reason as in the first embodiment, and the transfer onto the surface 7a of the substrate 7 is suppressed. Thereby, the silver ink composition 1 is printed on the base material 7 in a pattern corresponding to the concave portion 91. At this time, plate fogging is suppressed, so that the base material 7 is not printed for any purpose.
Thus, by using the silver ink composition according to the present invention, even if printing is performed by the same method as that shown in FIG. 1, plate fog is suppressed as in the case of the first embodiment. .

  Next, as in the first embodiment, the silver ink composition 1 printed on the base material 7 is post-treated to form metallic silver from the silver carboxylate, and FIG. As shown, a conductor 1 'is formed.

  The intaglio printing method using the silver ink composition according to the present invention is not limited to the first and second embodiments shown here. For example, the first or second embodiment is within the range not impairing the effects of the present invention. Other embodiments, such as those in which some of the embodiments are appropriately changed, may be used.

The thickness of the conductor is not particularly limited as long as it is appropriately adjusted according to the application. For example, the thickness of the conductor when used as a wiring in an electronic device or the like is preferably 0.01 to 10 μm, and more preferably 0.05 to 2 μm.
In the present invention, for example, the thickness of the conductor can be adjusted by adjusting the amount of the silver ink composition to be deposited on the substrate or the blending amount of the silver carboxylate in the silver ink composition.

  The silver ink composition may be dried by a known method. For example, the silver ink composition may be dried under normal pressure, reduced pressure, or air blowing conditions, and may be performed in the air or in an inert gas atmosphere. Good. 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 compounding component of the silver ink composition. Usually, it is preferable that heating temperature is 60-200 degreeC, and it is more preferable that it is 70-180 degreeC. Although what is necessary is just to adjust a heating time according to heating temperature, Usually, it is preferable that it is 0.2 to 12 hours, and it is more preferable that it is 0.4 to 10 hours. Among the silver carboxylates, silver β-ketocarboxylate (1) is decomposed at a low temperature without using a reducing agent or the like known in the art, unlike metal silver forming materials such as silver oxide. Reflecting such decomposition temperature, the silver ink composition can form metallic silver at an extremely lower temperature than the conventional one as described above.

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

  The conductor is obtained by using the silver ink composition, and has a sufficiently high conductivity, so that it is extremely useful as a component of various electronic devices such as communication devices. For example, the patterned conductor can be used as a wiring (circuit). Further, the patterned conductor can be used as an antenna, and a new data receiving / transmitting body can be obtained by adopting the same configuration as a known data receiving / transmitting body except that such an antenna is used. . For example, a non-contact type data receiving / transmitting body can be configured by providing an IC chip electrically connected to the conductor on the substrate to form an antenna portion.

  When printing is performed by applying the intaglio printing method using the silver ink composition, since plate fog is suppressed, a precise printing pattern of the silver ink composition can be obtained. Since the said conductor is obtained by post-processing this printing pattern, it can be set as a more precise pattern. Therefore, the conductor has not only a good appearance, but also, for example, when used as a wiring, a short circuit is suppressed, and thus an electronic device including such a wiring exhibits excellent operational stability.

<Electronic equipment>
The electronic device according to the present invention is characterized in that the above-described conductor according to the present invention is provided on a base material, the base material is provided as a casing, except that the conductor according to the present invention is provided. The structure can be similar to that of a known electronic device. Preferred examples of the electronic apparatus according to the present invention include those in which wiring (circuit) is formed of the conductor, and examples in which a substrate provided with a conductor is used as a circuit board. In addition, as the base material in the electronic apparatus, the same base material as that in the conductor manufacturing method described above can be used.
The electronic device can constitute a mobile phone by combining, for example, a voice input unit, a voice output unit, an operation switch, a display unit and the like in addition to a circuit board. In addition, the conductor can be formed at a low temperature as described above, and since a wide range of materials such as a base material can be selected, the degree of freedom in design is dramatically improved and a more rational structure is provided. Is also possible.
The electronic device according to the present invention 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 silver ink composition>
Add 2-methylacetoacetic acid silver (81.18 g, A = 0.364 mol) to 2-ethylhexylamine (18.82 g, B = 0.146 mol) in a beaker so that the liquid temperature is 50 ° C. or less. Then, a liquid material was obtained by stirring for 15 minutes using a mechanical stirrer. To this liquid, formic acid (10.05 g, C = 0.218 mol) 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 1.5 hours to obtain a silver ink composition. Table 1 shows the types and blending amounts (molar ratios) of the blending components. Moreover, the graph which plotted the value of B / A and C / A is shown in FIG.

<Evaluation of silver ink composition>
Using a pad printing machine (Murata Gold Leaf Co., Ltd.), the obtained silver ink composition was pad printed on the surface of a polyethylene terephthalate (PET) film ("Lumirror S10" manufactured by Toray Industries Inc., thickness 100 μm) under the following conditions. And about the printing surface of the said film, the presence or absence of plate fogging was confirmed by visual observation. The results are shown in Table 1. In Table 1, “◯” in the evaluation results means that there was no plate covering, and “×” means that there was plate covering.
(Printing conditions)
Pad: Silicone resin material Plate: Metal plate Blade: Steel material triangular blade, wall thickness 0.9mm
Blade air set pressure: 0.4 MPa

[Examples 2 to 5, Comparative Examples 1 to 6]
The silver ink composition was prepared in the same manner as in Example 1 except that the blending amount (molar ratio) of each blending component was the value shown in Table 1, and the B / A and C / A values were as shown in FIG. Manufactured and evaluated. The results are shown in Table 1.

As is clear from Table 1 and FIG. 4, in the silver ink compositions of Examples 1 to 5 satisfying the formula (I), no plate fogging was observed, and the printing pattern was clear. In FIG. 4, a solid line indicates a function represented by C / A = 0.35B / A + 0.5, and a dotted line indicates C / A = 0.5. In each of the silver ink compositions of Examples 1 to 5, the value of C / A is located below the solid line and above the dotted line, and satisfies the formula (I) -1. It is preferable.
On the other hand, in the silver ink compositions of Comparative Examples 1 to 6 that did not satisfy the formula (I), plate fogging was recognized in all cases.

  The present invention can be used for a circuit board provided with silver wiring (circuit) in an electronic apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Silver ink composition, 1 '... Conductor, 6 ... Ink composition, 7 ... Base material, 7a ... Surface of base material, 8 ... Pad, 8a ... -Pad surface, 9 ... Intaglio, 9a ... Intaglio surface, 91 ... Recess, 90 ... Doctor blade

Claims (3)

A silver ink composition for intaglio printing,
The silver ink composition includes silver carboxylate having a group represented by the formula “—COOAg”;
One or more nitrogen-containing compounds selected from the group consisting of 2-ethylhexylamine, 2-aminooctane and 2-heptylamine ;
And one or more reducing compounds selected or formic acid and oxalic acid, et al., Is being formulated,
The blending amount A (mol) of the silver carboxylate, the blending amount B (mol) of the nitrogen-containing compound, and the blending amount C (mol) of the reducing compound satisfy the following formula (I) -1. A silver ink composition.
0.5 ≦ C / A ≦ 0.35B / A + 0.5 (I) −1   A conductor obtained by forming metallic silver using the silver ink composition according to claim 1.   An electronic device comprising the conductor according to claim 2 on a base material, and the base material as a housing.

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