JP6992582B2 - Conductive composition, cured product and laminated body using the conductive composition - Google Patents

Description

The present invention relates to a conductive composition, a cured product and a laminated body using the conductive composition.

In recent years, the introduction of RFID tags has progressed mainly in the apparel industry, and it is predicted that the introduction of RFID tags will also progress in other retailers in the future.
Therefore, in order to reduce the cost of manufacturing RFID tags, there is a method of forming an RFID antenna by patterning a conductive paste on a paper substrate by screen printing or the like, and mounting an IC chip on the pattern to manufacture the RFID tag. Proposed. Various conductive pastes such as silver paste and silver nanoink can be applied as the conductive paste used for forming the RFID antenna, but there is a demand for a conductive paste that can be cured at a heat resistant temperature of paper or lower. Further, since the communication distance of the RFID antenna is inversely proportional to the volume resistivity of the cured product, a conductive paste having a low volume resistivity of the cured product, that is, having good conductivity is required.

Further, the paper base material has large surface irregularities unlike the conventionally used plastic substrate having high smoothness such as polyethylene terephthalate. Therefore, in particular, when a conductive paste containing a large amount of foreign matter having a large particle size is used, the leveling property (flatness) when applied on a paper substrate to form a coating film tends to deteriorate. When the leveling property is poor, the smoothness of the cured product obtained by curing the coating film tends to be poor.
In general, the antenna circuit of an RFID tag is required to have high smoothness on the surface of printed matter because the unevenness of the surface has a great influence on the communication distance and the communication accuracy. Therefore, the conductive paste for forming the RFID antenna is required to have high leveling property.

In recent years, attempts have been made to use copper particles, which are cheaper than silver, as conductive particles in the conductive paste used for printing on a substrate and forming a circuit.
Patent Document 1 describes a technique relating to a conductive composition comprising a metal powder such as copper particles, a formaldehyde condensation type resin, and a phenylenediamine derivative. Further, Patent Document 2 describes a technique relating to a conductive composition containing a metal powder such as copper particles, a fatty acid metal salt, and a metal oxide.

Japanese Unexamined Patent Publication No. 58-22168 International Publication No. 2015/118760

However, in the conductive composition described in Patent Document 1, a hard film is gradually formed on the surface when exposed to the atmosphere, and this film is crushed and mixed as a large foreign substance during screen printing, so that the cured product has smoothness. There is a problem that it is bad.
Further, the conductive composition described in Patent Document 2 has a problem that sufficient conductivity is not exhibited when the conductive composition is cured at a high curing temperature and below the heat resistance of paper.
Therefore, the present invention is a conductive composition having less film formation when exposed to the atmosphere, good leveling property when applied to a substrate, and high conductivity of a cured product cured at a relatively low temperature. Further, it is an object of the present invention to provide a conductive composition having excellent smoothness of a cured product formed on a substrate.

As a result of diligent studies, the present inventors have found that the above-mentioned problems can be solved by a conductive composition having a specific composition, and have completed the present invention.
That is, the gist of the present invention is the following [1] to [7].

（R¹、R²、R³、R⁴はそれぞれ独立して水素原子、メチル基、又はエチル基のいずれかであり、R⁵、R⁶、R⁷、R⁸はそれぞれ独立して水素原子、又はメチル基のいずれかである。）
［２］前記（ｂ）熱硬化性樹脂がフェノール樹脂である、上記［１］に記載の導電性組成物。
［３］前記（ａ）銅粒子が表面被覆銅粒子である、上記［１］又は［２］に記載の導電性組成物。
［４］前記（ｃ）芳香族アミン化合物の２つのアミノ基である（－ＮＲ^１Ｒ^２）及び（－ＮＲ^３Ｒ^４）の少なくとも一方が第１級アミノ基である、上記［１］～［３］のいずれかに記載の導電性組成物。
［５］上記［１］～［４］のいずれかに記載の導電性組成物の硬化体。
［６］基材と、該基材上に設けられた上記［５］に記載の硬化体とを備える積層体。
［７］前記基材が紙基材である、上記［６］に記載の積層体。 [1] For 100 parts by mass of (a) copper particles, (b) 10 to 40 parts by mass of a thermosetting resin, and (c) 0.5 of an aromatic amine compound represented by the following general formula (I). Contains 0.05 to 1.3 parts by mass of a metal salt of at least one fatty acid selected from the group consisting of (d) a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid. The conductive composition, wherein the compounding ratio ((c) / (d)) of the above (c) and (d) is 1 to 20.

(R ¹ , R ² , R ³ , and R ⁴ are independent hydrogen atoms, methyl groups, or ethyl groups, respectively, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are independent hydrogen atoms, respectively. , Or either a methyl group.)
[2] The conductive composition according to the above [1], wherein the thermosetting resin (b) is a phenol resin.
[3] The conductive composition according to the above [1] or [2], wherein the (a) copper particles are surface-coated copper particles.
[4] At least one of the two amino groups (-NR ¹ R ² ) and (-NR ³ R ⁴ ) of the (c) aromatic amine compound is a primary amino group, the above [1] to The conductive composition according to any one of [3].
[5] A cured product of the conductive composition according to any one of the above [1] to [4].
[6] A laminate comprising a base material and the cured product according to the above [5] provided on the base material.
[7] The laminate according to the above [6], wherein the base material is a paper base material.

According to the present invention, the conductive composition has less film formation when exposed to the atmosphere, has good leveling property when applied to a substrate, and has high conductivity even when cured at a relatively low temperature. Further, it is possible to provide a conductive composition having excellent smoothness of the cured product formed on the substrate.

（Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４はそれぞれ独立して水素原子、メチル基、又はエチル基のいずれかであり、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８はそれぞれ独立して水素原子、又はメチル基のいずれかである。） The conductive composition of the present invention comprises (a) 100 parts by mass of copper particles, (b) 10 to 40 parts by mass of a thermosetting resin, and (c) an aromatic represented by the following general formula (I). 0.5 to 2 parts by mass of the amine compound, (d) a metal salt of at least one fatty acid selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid of 0.05 to It is a conductive composition containing 1.3 parts by mass and having a compounding ratio ((c) / (d)) of 1 to 20 of (c) and (d).

(R ¹ , R ² , R ³ , and R ⁴ are independently hydrogen atoms, methyl groups, or ethyl groups, respectively, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are independent hydrogen atoms, respectively. , Or either a methyl group.)

Hereinafter, embodiments of the present invention will be described in detail.
In the present specification, when a preferable numerical range (for example, a content range) is described stepwise, each lower limit value and upper limit value can be combined independently. For example, in the description of "preferably 10 to 100, more preferably 20 to 90", it may be "10 to 90" or "20 to 100".

［式（２）中、ｍは０～３の整数、ｎは０～２の整数であり、ｎ＝０のとき、ｍは０～３のいずれか、ｎ＝１またはｎ＝２のとき、ｍは１～３のいずれかである。］ <Copper particles (a)>
The conductive composition of the present invention contains copper particles (a). The copper particles (a) are not particularly limited, and known copper particles generally used for copper paste and copper ink can be used. The shape may be spherical, plate-shaped, dendritic, rod-shaped, fibrous, hollow, or porous. Above all, a plate shape is preferable from the viewpoint of improving conductivity.
The average particle size of the copper particles (a) is not particularly limited, but the copper particles so that the conductive composition containing the copper particles (a) can be printed well in various printing methods such as IJ printing and screen printing. It is preferable to control the particle size. Specifically, the average particle size of the copper particles (a) is preferably 5 nm to 20 μm, more preferably 10 nm to 10 μm, and even more preferably 100 nm to 10 μm.
When the average particle size of the copper particles (a) is 10 nm to 10 μm, it becomes easy to prevent self-aggregation and oxidation of the particles, and it becomes suitable for drawing fine wiring of 100 μm or less. Further, when the average particle size of the copper particles (a) is 100 nm to 10 μm, it is possible to improve the continuous printability in screen printing of the conductive composition.
Further, the copper particles (a) may be of one type, but two or more types may be used in combination. For example, copper particles having different shapes and different average particle sizes may be mixed and used.
The average particle size of the copper particles means a value obtained by additively averaging the ferret diameters of 100 randomly selected particles obtained by observing with a transmission electron microscope or a scanning electron microscope. It shall be.
Although commercially available copper particles may be used as they are, it is preferable to use surface-coated copper particles whose surface is coated for the purpose of improving oxidation resistance and the like. Above all, it is preferable to use surface-coated copper particles whose surface is coated with an amine compound, and it is more preferable to use surface-coated copper particles whose surface is coated with an amine compound represented by the following formula (II).

[In equation (2), m is an integer of 0 to 3, n is an integer of 0 to 2, and when n = 0, m is any of 0 to 3, and n = 1 or n = 2. m is any one of 1 to 3. ]

The surface-coated copper particles whose surface is coated with the amine compound are preferably surface-coated copper particles further coated with an aliphatic monocarboxylic acid from the viewpoint of obtaining better oxidation resistance.
As a result, the surface of the copper particles is coated with the first coating layer formed of the amine compound and the second coating layer formed of the aliphatic monocarboxylic acid. The first coating layer is preferably formed on the surface of copper particles, and the second coating layer is formed on the first coating layer.
As the aliphatic monocarboxylic acid, an aliphatic monocarboxylic acid having 8 to 20 carbon atoms is preferable. Examples of the aliphatic monocarboxylic acid include a linear saturated aliphatic monocarboxylic acid, a linear unsaturated aliphatic monocarboxylic acid, a branched saturated aliphatic monocarboxylic acid, and a branched unsaturated aliphatic monocarboxylic acid. Specific examples of the linear saturated aliphatic monocarboxylic acid having 8 to 20 carbon atoms include caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, and margarine. Examples include acid, stearic acid, nonadecylic acid and arachidic acid. Examples of the linear unsaturated aliphatic monocarboxylic acid having 8 to 20 carbon atoms include myristoleic acid, palmitoleic acid, petroselinic acid, and oleic acid. Examples of the branched saturated aliphatic monocarboxylic acid having 8 to 20 carbon atoms include 2-ethylhexanoic acid. The above-mentioned aliphatic monocarboxylic acid may be used alone or in combination of a plurality of types.

The method for producing the surface-coated copper particles is not particularly limited. As a method for obtaining surface-coated copper particles whose surface is coated with an amine compound, for example, after washing the copper particles with an aqueous solution of ammonium chloride or the like, the washed copper particles are added to the solution of the amine compound, and if necessary. All you have to do is heat it.
As a method for producing surface-coated copper particles coated with a first coating layer formed of an amine compound and a second coating layer formed of an aliphatic monocarboxylic acid, for example, a surface whose surface is coated with an amine compound is used. Examples thereof include a method of adding coated copper particles to a solution of an aliphatic monocarboxylic acid. After the addition, it may be heated if necessary.

<Thermosetting resin (b)>
The conductive composition of the present invention contains a thermosetting resin (b). The content of the thermosetting resin (b) in the conductive composition is 10 to 40 parts by mass with respect to 100 parts by mass of the copper particles (a). When the content of the thermosetting resin (b) is less than 10 parts by mass, the fluidity of the conductive composition at the time of printing is lowered, and when the content of the thermosetting resin (b) exceeds 40 parts by mass. The conductivity of the cured product of the conductive composition is reduced. The content of the thermosetting resin (b) is preferably 15 to 25 parts by mass.

The thermosetting resin (b) is, for example, an epoxy resin, a melamine resin, a phenol resin, a silicon resin, an oxazine resin, a urea resin, a polyurethane resin, an unsaturated polyester resin, a vinyl ester resin, a xylene resin, an acrylic resin, an oxetane resin, and the like. Examples thereof include diallyl phthalate resin, oligoester acrylate resin, bismalade triazine resin, furan resin and the like. Any one of these thermosetting resins (b) may be used, or two or more of them may be mixed and used. Among these, a resin showing a condensation reaction is preferable. Since the resin exhibiting a condensation reaction has a large curing shrinkage, the copper particles are closer to each other, and a cured product having good conductivity can be obtained. Specifically, a resin showing dehydration condensation such as a phenol resin is more preferable. Further, by using a phenol resin, it becomes easy to obtain a cured product having high conductivity even if it is cured at a relatively low temperature.
Among the phenolic resins, the resol type phenolic resin is preferable. By using the resol type phenol resin, it becomes easy to suppress the surface oxidation of the copper particles (a) and improve the conductivity of the cured product. Specific examples of the resol-type phenol resin include phenols, unmodified resol-type phenol resins produced from aldehydes, phenols, and modified resol-type phenol resins produced by adding various modifiers to aldehydes. And so on.
The resol type phenol resin is also available as a commercial product. Examples of commercially available resole-type phenolic resins include REGITOP (registered trademark) PL-5208, PL-2407, and PL-6317 (manufactured by Gun Ei Chemical Industry Co., Ltd.). One type of resole-type phenolic resin may be used alone, or two or more types may be used in combination.

一般式（Ｉ）において、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４はそれぞれ独立して水素原子、メチル基、又はエチル基のいずれかであり、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８はそれぞれ独立して水素原子、又はメチル基のいずれかである。芳香族アミン化合物（ｃ）を用いることで、導電性組成物をより低温で硬化させやすくなる。
導電性組成物中の芳香族アミン化合物（ｃ）の含有量は、銅粒子(a)１００質量部に対して０．５～２質量部である。芳香族アミン化合物（ｃ）の含有量が０．５質量部未満である場合は、銅粒子（ａ）に対する酸化抑制効果が小さくなり、得られる硬化体の体積抵抗率が高くなり導電性が低下する。芳香族アミン化合物（ｃ）の含有量が２質量部を超える場合は、芳香族アミン化合物（ｃ）の自己縮合により導電性組成物の表面上に被膜を形成しやすくなり、導電性組成物を基材に塗布する際のレベリング性が悪くなりやすい。導電性組成物の被膜形成を抑制し、かつ硬化体の導電性を向上させる観点から、導電性組成物中の芳香族アミン化合物（ｃ）の含有量は、０．８～２質量部であることが好ましい。 <Aromatic amine compound (c)>
The conductive composition of the present invention contains the aromatic amine compound (c) represented by the following general formula (I).

In the general formula (I), R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, a methyl group, or an ethyl group, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are. Each is either a hydrogen atom or a methyl group independently. By using the aromatic amine compound (c), it becomes easier to cure the conductive composition at a lower temperature.
The content of the aromatic amine compound (c) in the conductive composition is 0.5 to 2 parts by mass with respect to 100 parts by mass of the copper particles (a). When the content of the aromatic amine compound (c) is less than 0.5 parts by mass, the effect of suppressing oxidation on the copper particles (a) is small, the volume resistivity of the obtained cured product is high, and the conductivity is lowered. do. When the content of the aromatic amine compound (c) exceeds 2 parts by mass, the self-condensation of the aromatic amine compound (c) facilitates the formation of a film on the surface of the conductive composition, thereby forming the conductive composition. The leveling property when applied to the base material tends to deteriorate. From the viewpoint of suppressing the formation of a film of the conductive composition and improving the conductivity of the cured product, the content of the aromatic amine compound (c) in the conductive composition is 0.8 to 2 parts by mass. Is preferable.

The aromatic amine compound represented by the general formula (I) has a reducing ability and a chelating ability for copper particles, and by these two effects, copper oxide present on the surface of the copper particles is removed, and the conductivity of the cured product is obtained. It is possible to improve the sex. The reducing ability and chelating ability of the secondary amine are larger than those of the tertiary amine, and the primary amine is larger than the secondary amine.
Therefore, it is preferable that at least one of the two amino groups (-NR ¹ R ² and -NR ³ R ⁴ ) in the general formula (I) is a primary amine, and both are primary amines. Is more preferable. That is, in the general formula (I), among R ¹ , R ² , R ³ , and R ⁴ , it is preferable that both R ¹ and R ² are hydrogen atoms, and R ¹ , R ² , R ³ , and R ⁴ have a hydrogen atom. It is preferable that all are hydrogen atoms.
Specific examples of the compound represented by the general formula (I) include 1,4-phenylenediamine, 2-methyl-1,4-phenylenediamine, and 2,5-dimethyl-1,4-phenylenediamine, 2. , 3,5,6-Tetramethyl-1,4-phenylenediamine, N, N-dimethyl-1,4-phenylenediamine, N, N-diethyl-1,4-phenylenediamine, N, N, N', N'-tetramethyl-1,4-phenylenediamine can be mentioned. Among these, 1,4-phenylenediamine is preferable from the viewpoint of further improving the conductivity of the cured product of the conductive composition.

<Fatty acid metal salt (d)>
The conductive composition of the present invention contains at least one fatty acid metal salt (d) selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid.
The fatty acid metal salt (d) is at least one fatty acid metal salt selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid.
When a fatty acid metal salt having less than 12 carbon atoms is used, a film is easily formed on the surface of the conductive composition. On the other hand, in the case of a fatty acid metal salt having more than 24 carbon atoms, it is not possible to obtain an effect commensurate with the increase in the number of carbon atoms, and it is difficult to obtain the fatty acid metal salt.

導電性組成物を基材に印刷する際に、この被膜が破砕され、異物となって基材表面の凹凸を大きくし、レベリング性を悪化させているものと考えられる。これに対して、炭素数１２～２４の脂肪酸の亜鉛塩及び該脂肪酸のマグネシウム塩からなる群から選択される少なくとも１種の脂肪酸金属塩（ｄ）を配合すると、導電性組成物の被膜の形成が抑制されるようになる。この理由は定かではないが、脂肪酸金属塩（ｄ）の一部が導電性組成物の表面にブリードすることで、組成物の表面の酸素暴露を抑制して、式（ＩＩＩ）の反応を進行し難くなるためと考えられる。 By containing the fatty acid metal salt (d) in the conductive composition, it becomes easy to suppress the formation of a film of the conductive composition, and it becomes easy to improve the leveling property of the conductive composition and the smoothness of the cured product. The reason why such an effect is obtained is not clear, but it is estimated as follows.
The conductive compound containing copper particles and an aromatic amine compound undergoes polymerization by self-condensation of the amine compound represented by the following formula (III) on the surface of the conductive composition under atmospheric exposure, and is formed on the surface of the conductive composition. Form a film.

It is considered that when the conductive composition is printed on the substrate, the film is crushed and becomes foreign matter to increase the unevenness of the surface of the substrate and deteriorate the leveling property. On the other hand, when at least one fatty acid metal salt (d) selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid is blended, a film of a conductive composition is formed. Will be suppressed. Although the reason for this is not clear, a part of the fatty acid metal salt (d) bleeds on the surface of the conductive composition to suppress oxygen exposure on the surface of the composition and proceed with the reaction of the formula (III). It is thought that it becomes difficult to do.

The blending amount of the fatty acid metal salt (d) in the conductive composition is 0.05 to 1.3 parts by mass with respect to 100 parts by mass of the copper particles (a). When the blending amount of the fatty acid metal salt (d) is less than 0.05 parts by mass, a film is easily formed on the surface of the conductive composition, and the leveling property when the conductive composition is applied to the substrate is deteriorated. Tend. On the other hand, when the blending amount of the fatty acid metal salt (d) exceeds 1.3 parts by mass, the conductivity of the cured product tends to be low.
The blending amount of the fatty acid metal salt (d) in the conductive composition shall be 0.08 to 1.3 parts by mass with respect to 100 parts by mass of the copper particles (a) from the viewpoint of further suppressing the formation of a film. Is preferable.
The compounding ratio ((c) / (d)) of the aromatic amine compound (c) and the fatty acid metal salt (d) in the conductive composition of the present invention is 1 to 20. When the compounding ratio ((c) / (d)) is smaller than 1, the amount of the aliphatic metal salt (d) is too large with respect to the amount of the aromatic amine compound (c), so that the cured product is conductive. The sex gets worse. When the compounding ratio ((c) / (d)) is larger than 20, the amount of the aliphatic metal salt (d) is too small with respect to the amount of the aromatic amine compound (c), so that the conductive composition The formation of a film on the surface of the surface becomes remarkable. The compounding ratio ((c) / (d)) is preferably 1 to 15.

The fatty acid metal salt (d) is at least one fatty acid metal salt selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid. From the viewpoint of more easily suppressing the formation of a film of the conductive composition, it is preferable to use a magnesium salt of fatty acid.
The fatty acid having 12 to 24 carbon atoms in the fatty acid metal salt (d) may be linear, may have a branched chain, or may be a saturated fatty acid or an unsaturated fatty acid. .. Specific examples of fatty acids having 12 to 24 carbon atoms include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and lignoseric acid, branched fatty acids such as isopalmitic acid and isostearic acid, and palmitrain. Examples thereof include unsaturated fatty acids such as acid, oleic acid, linoleic acid, linolenic acid, ellagic acid and erucic acid. The fatty acid of the fatty acid metal salt preferably has 16 to 22 carbon atoms.
The particle size of the fatty acid metal salt (d) is not particularly limited, but is preferably 0.01 to 10 μm. When the particle size is 0.01 μm or more, aggregation of the fatty acid metal salt is easily suppressed, and when the particle size is 10 μm or less, the smoothness of the cured product is good. The shape of the fatty acid metal salt (d) is not particularly limited, and examples thereof include a spherical shape, a needle shape, and a plate shape.
The fatty acid metal salt (d) may be used alone, but a plurality of fatty acid metal salts having different metal types, shapes, average particle sizes and the like may be used in combination.
The aliphatic metal salt (d) may be produced by a direct method or a metathesis method, but it is difficult to contain components other than the fatty acid metal salt and is a cured product. From the viewpoint of improving the conductivity of the above, it is preferable that the product is produced by a metathesis method.
The direct method is a method of reacting a fatty acid with an inorganic metal oxide or an inorganic metal hydroxide to obtain an aliphatic metal salt, and the compound decomposition method is a method of using a solution of an alkali metal salt or an ammonium salt of a fatty acid. This is a method for obtaining a fatty acid metal salt by reacting with an inorganic metal salt.

<Diluent>
The conductive composition of the present invention may contain a diluent. The content of the diluent in the conductive composition is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the copper particles (a), from the viewpoint of improving the applicability to the substrate. It is more preferably 20 parts by mass.
Examples of the diluent include ether-based alcohols, non-ether-based alcohols, esters, ketones, terpenes, and other hydrocarbons.
Examples of ether-based alcohols include diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-isopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, and ethylene. Glycolmethyl ethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monomethyl Examples thereof include ether, diethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and propylene glycol monomethyl ether. In particular, it is preferable to use diethylene glycol monoethyl ether or diethylene glycol monoethyl ether acetate in terms of coatability on a substrate.

Examples of non-ether alcohols include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol and the like.
Examples of the esters include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methylmethoxypropionate, ethylethoxypropionate, diethyl oxalate, diethyl malonate and the like.
Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like.
Examples of terpenes include turpentine, turpentine, borneol, α-pinene and the like. In particular, it is preferable to use telepineol in terms of conductivity and coatability to a substrate.
Other hydrocarbons include tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorbenzene, o-dichlorobenzene, hexane, heptane, octane, diacetone alcohol, propylene carbonate and the like. Can be mentioned.

Total of copper particles (a), thermosetting resin (b), aromatic amine compound (c), fatty acid metal salt (d), and optionally compounded diluent in the conductive composition of the present invention. The content of the above is preferably 70% by mass or more, more preferably 90% by mass or more, and further preferably 100% by mass based on the total amount of the conductive composition.
In addition to the above-mentioned components, various known surfactants, dispersants, coupling agents, curing agents, conductive auxiliary agents, defoaming agents and the like are added to the conductive composition of the present invention, if necessary. The agent may be blended.

The conductive composition of the present invention includes copper particles (a), a thermosetting resin (b), an aromatic amine compound (c), a fatty acid metal salt (d), a diluent to be blended as necessary, and others. It can be produced by mixing the additive with a kneading device or the like. As the kneading device, use a 3-roll mill, ultrasonic disperser, sand mill, attritor, pearl mill, super mill, ball mill, impeller, desperzer, KD mill, colloid mill, dynatron, planetary mill, pressurized kneader, etc. Can be done.

<Laminated body>
The conductive composition of the present invention can be applied onto the surface of a base material to form a coating film, and then the coating film can be cured to form a cured product. In this way, it is possible to obtain a laminated body including the base material and the cured body of the conductive composition provided on the base material.
As a method for applying the conductive composition, a desired method such as casting method, gravure printing, screen printing, coating using a coater, spin coating and the like can be adopted.
The conductive composition of the present invention can be cured at a relatively low temperature to obtain a cured product having good conductivity. Therefore, the conditions for curing the coating film are preferably 80 to 200 ° C., more preferably 120 to 150 ° C., when the coating film is cured in a hot air circulation oven or the like. The curing time is preferably 5 to 30 minutes. When curing with an infrared heater or the like, the surface temperature of the coating film is preferably 80 to 200 ° C., and the curing time is preferably 0.5 to 15 minutes. It is also possible to combine and cure both a hot air circulation oven and an infrared heater. When a substrate having low heat resistance such as a paper substrate is used, it is preferable to cure it at a low temperature of 160 ° C. or lower.
Examples of the base material include paper base materials such as high-quality paper, art paper, coated paper, matte paper, and synthetic paper, polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). , Polyethylene naphthalate (PEN), polyether sulfone (PES), fluororesin, resin base material such as liquid crystal polymer, ceramic base material, glass base material, metal base material and the like. The conductive composition of the present invention has high leveling property when applied to a substrate, and has good conductivity even when cured at a relatively low temperature. Therefore, the conductive composition of the present invention can be suitably used for a paper substrate having a relatively large surface unevenness and a low heat resistant temperature. A laminate using a paper base material as a base material can be suitably used, for example, for RFID antenna applications.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The conductive compositions produced by the methods of each Example and Comparative Example were evaluated by the following evaluation methods.
<Judgment on reduction of surface film generation>
The conductive composition produced by the methods of each Example and Comparative Example was allowed to stand at 25 ° C. under atmospheric exposure, and the time until a film was formed on the surface of the composition was evaluated by visual observation according to the following criteria. did.
60 minutes or more until film formation: ◎
30 minutes or more and less than 60 minutes until film formation: ○
Less than 30 minutes until film formation: ×

<Judgment of leveling property (flatness)>
The conductive composition produced by the methods of each Example and Comparative Example was applied on a paper substrate (Ulite DRY, Nippon Paper Industries) with a width of 1 cm, a length of 3 cm, and a thickness of 30 μm by a metal mask to form a coating film. .. The leveling property was evaluated according to the following criteria by visually observing the shape on the surface of the coating film after 1 minute had passed since the coating film was formed.
No unevenness and no color unevenness: ◎
There is no unevenness and color unevenness occurs: ○
There is unevenness: ×

<Judgment of smoothness of cured product>
The conductive composition produced by the methods of each Example and Comparative Example was applied on a paper substrate (Ulite DRY, Nippon Paper Industries) with a width of 1 cm, a length of 3 cm, and a thickness of 30 μm by a metal mask to form a coating film. .. The coating film was cured at 150 ° C. for 30 minutes using a hot air circulation oven to form a cured product. The surface of the cured product is magnified at a magnification of 200 times using a color 3D laser microscope (“VK-9700” manufactured by KEYENCE CORPORATION), the surface roughness (Ra) is measured, and foreign matter is further formed on the surface of the cured product. I observed if there was any. The smoothness of the cured product was determined according to the following criteria.
Ra is 3 μm or less, and there is no foreign matter on the surface of the cured product: ◎
Ra is more than 3 μm and 6 μm or less, and there is no foreign matter on the surface of the cured product: ○
Ra is over 6 μm, or there is foreign matter on the surface of the cured product: ×

<Determining the conductivity of the cured product>
The volume resistivity of the cured product of the conductive composition produced by the methods of each Example and Comparative Example was evaluated according to the method shown below in accordance with JIS K7194.
Measuring equipment type: resistivity meter MCP-T610 (manufactured by Mitsubishi Chemical Corporation)
Measurement conditions: 4 probe method Probe: ASP
Measurement sample (cured body): After applying the conductive composition to the substrate so as to have a width of 1 cm, a length of 3 cm, and a thickness of 30 μm, the volume resistivity of the cured body obtained by curing at 150 ° C. × 15 minutes was measured. ..
Number of measurements: The measurement was performed 5 times, and the average value of the volume resistivity was calculated.
From the volume resistivity of the obtained cured product, the conductivity was evaluated according to the following criteria.
Less than 30 μΩ ・ cm: ◎
30 μΩ ・ cm or more and less than 50 μΩ ・ cm: ○
50 μΩ ・ cm or more: ×

(Example 1)
<Surface-coated copper particles (manufacturing of copper particles (1)>
An ammonium chloride aqueous solution was prepared by dissolving 5 g of ammonium chloride in 100 g of water. 50 g of copper particles [“1400YP” manufactured by Mitsui Mining & Smelting Co., Ltd .; particle size (D50) 6.9 μm, specific surface area 0.26 m ² / g, shape is plate-like] were added to the ammonium chloride aqueous solution and subjected to nitrogen bubbling. , 30 ° C. for 60 minutes. The stirring was carried out using a mechanical stirrer at a rotation speed of 150 rpm. Hereinafter, stirring was performed at the same rotation speed using the same stirring device. After the stirring was completed, the copper particles were filtered off by vacuum filtration using a Kiriyama funnel of 5C filter paper, and subsequently, the copper particles were washed twice with 150 g of water on the Kiriyama funnel.
The washed copper particles were added to 250 g of a 40% by mass diethylenetriamine aqueous solution, and the mixture was heated and stirred at 60 ° C. for 1 hour with nitrogen bubbling.
After the stirring was stopped and the mixture was allowed to stand for 5 minutes, about 200 g of the supernatant liquid was withdrawn and removed. Subsequently, 200 g of isopropanol was added to the precipitate as a cleaning solvent, and the mixture was stirred at 30 ° C. for 3 minutes. After stopping the stirring and allowing to stand for 5 minutes, about 200 g of the supernatant liquid was withdrawn and removed, and then 250 g of 2% by mass isopropanol laurate solution was added, and then the mixture was stirred at 30 ° C. for 30 minutes. After the stirring was completed, the copper particles were filtered off by vacuum filtration using a Kiriyama funnel of 5C filter paper. The obtained copper particles were dried under reduced pressure at 25 ° C. for 3 hours to obtain surface-coated copper particles (copper particles (1)).

<Preparation of conductive composition>
100 parts by mass of surface-coated copper particles (copper particles (1)) treated by the above method, 30 parts by mass of resol type phenol resin solution (PL-5208, manufactured by Gunei Chemical Industry Co., Ltd.) (resol type which is a solid content) 17.4 parts by mass of phenol resin, 12.6 parts by mass of ethylcarbitol as a solvent), 1.4 parts by mass of 1,4-phenylenediamine, and 0.5 parts by mass of Mg stearate were mixed. Next, using a planetary mixer [ARV-310, manufactured by Shinky Co., Ltd.], the mixture was stirred at a rotation speed of 1500 rpm for 30 seconds at room temperature to perform primary kneading.
Next, using a 3-roll mill [EXAKT-M80S, manufactured by Nagase Screen Printing Laboratory Co., Ltd.], the conductive composition was subjected to secondary kneading by passing it 5 times under the conditions of room temperature and a distance between rolls of 5 μm. Got
The degree of reduction in surface film formation, leveling property, smoothness of the cured product, and conductivity of the cured product of the obtained conductive composition were evaluated. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 2)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of Mg stearate was changed to 0.1 parts by mass, and each evaluation was performed in the same manner as in Example 1. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 3)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of Mg stearate was changed to 1.0 part by mass, and each evaluation was performed in the same manner as in Example 1. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 4)
Same as Example 1 except that the copper particles (1) were changed to copper particles (2) [“FCC-TB” manufactured by Fukuda Metal Foil Powder Industry Co., Ltd .; particle size (D50) 7.0 μm, shape dendritic shape]. A conductive composition was prepared, and each evaluation was performed in the same manner as in Example 1. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 5)
A conductive composition was prepared in the same manner as in Example 4 except that 1,4-phenylenediamine was changed to N, N'-dimethylphenylenediamine, and each evaluation was performed in the same manner as in Example 4. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 6)
A conductive composition was prepared in the same manner as in Example 4 except that 1,4-phenylenediamine was changed to 2,5-dimethyl-1,4-phenylenediamine, and each evaluation was performed in the same manner as in Example 4. rice field. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 7)
A conductive composition was prepared in the same manner as in Example 1 except that Mg stearate was changed to Zn laurate, and each evaluation was performed in the same manner as in Example 1. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Example 8)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of Mg stearate was changed to 0.2 parts by mass and 0.2 part by mass of Zn laurate was added, and the same as in Example 1. Each evaluation was performed. Table 1 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 1)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of Mg stearate was changed to 0.05 parts by mass, and each evaluation was performed in the same manner as in Example 1. Table 2 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 2)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of Mg stearate was changed to 2.0 parts by mass, and each evaluation was performed in the same manner as in Example 1. Table 2 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 3)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of 1,4-phenylenediamine was changed to 0.1 parts by mass, and each evaluation was carried out in the same manner as in Example 1. Table 2 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 4)
A conductive composition was prepared in the same manner as in Example 1 except that the amount of 1,4-phenylenediamine was changed to 3.0 parts by mass, and each evaluation was carried out in the same manner as in Example 1. Table 2 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 5)
The same as in Example 1 except that the copper particles (1) were changed to FCC-TB (Fukuda Metal Foil Powder Industry) (copper particles (2)) and the amount of 1,4-phenylenediamine was set to 0 parts by mass. The conductive composition was prepared and evaluated in the same manner as in Example 1. Table 2 shows the blending amount of each component of the conductive composition and the evaluation results.

(Comparative Example 6)
Conductivity is the same as in Example 1 except that the copper particles (1) are changed to FCC-TB (Fukuda Metal Foil Powder Industry) (copper particles (2)) and the amount of Mg stearate is 0 parts by mass. The composition was prepared, and the generation, leveling property, smoothness and volume resistivity of the cured product of the obtained conductive composition were evaluated.

(Comparative Example 7)
A conductive composition was prepared in the same manner as in Example 1 except that Mg stearate was changed to Zn 2-methylpropanoate. Smoothness and volume resistivity were evaluated respectively.

(Comparative Example 8)
A conductive composition was prepared in the same manner as in Example 1 except that Mg stearate was changed to Ca stearate. The volume resistivity was evaluated respectively.

From the results in Table 1, each conductive composition of each example satisfying the requirements of the present invention is less likely to generate a surface film, has good leveling property, and has the conductivity of a cured product cured at a low temperature and the conductivity. It was excellent in smoothness. Among them, the use of a fatty acid metal salt having a relatively large number of carbon atoms in the fatty acid resulted in better conductivity.
On the other hand, from the results of the comparative examples shown in Table 2, when the amount of the aromatic amine compound in the conductive composition is small, the conductivity is low, and when the amount of the aromatic amine compound is large, a surface coating is likely to occur. , It was found that the leveling property was inferior.
The conductive composition containing a small amount of fatty acid metal salt tends to form a surface film and is inferior in leveling property. In addition, the cured product of the conductive composition containing a large amount of fatty acid metal salt had low conductivity.
A conductive composition using a calcium salt of a fatty acid as a fatty acid metal salt tends to form a surface film and is inferior in leveling property.

Claims (7)

(A) With respect to 100 parts by mass of copper particles
(B) 10 to 40 parts by mass of thermosetting resin,
(C) 0.5 to 2 parts by mass of the aromatic amine compound represented by the following general formula (I).
(D) Contains 0.05 to 1.3 parts by mass of at least one fatty acid metal salt selected from the group consisting of a zinc salt of a fatty acid having 12 to 24 carbon atoms and a magnesium salt of the fatty acid.
Moreover, the conductive composition in which the compounding ratio ((c) / (d)) of the above (c) and (d) is 1 to 20.

(R ¹ , R ² , R ³ , and R ⁴ are independent hydrogen atoms, methyl groups, or ethyl groups, respectively, and R ⁵ , R ⁶ , R ⁷ , and R ⁸ are independent hydrogen atoms, respectively. , Or either a methyl group.) The conductive composition according to claim 1, wherein the thermosetting resin (b) is a phenol resin. The conductive composition according to claim 1 or 2, wherein the (a) copper particles are surface-coated copper particles. Any one of claims 1 to 3, wherein at least one of the two amino groups (-NR ¹ R ² ) and (-NR ³ R ⁴ ) of the (c) aromatic amine compound is a primary amino group. The conductive composition according to. A cured product of the conductive composition according to any one of claims 1 to 4. A laminate comprising a base material and the cured product according to claim 5 provided on the base material. The laminate according to claim 6, wherein the base material is a paper base material.