TWI537986B - Conductive composition, conductive film, and method for forming a conductive film - Google Patents

Description

Conductive composition, conductive film, and method of forming conductive film

The present invention relates to a conductive composition which can be used, for example, in the formation of a conductive film of an electronic component, and a method of forming a conductive film using the conductive composition.

As a method of forming a conductive circuit of various electronic components, a subtractive method, an addition method, or the like is known. In the addition method, a conductive composition is applied onto a substrate by a technique such as screen printing to form a pattern, and the conductive composition is fired at a predetermined temperature to form a conductive film (conductive circuit).

Patent Document 1 discloses a conductive composition containing a solvent of a polyol having two or more OH groups such as copper powder, ethylene glycol or diethylene glycol, and a solvent derived from malic acid or citric acid. An additive made up of two or more COOH and a compound having one or more OH groups. The conductive composition can be fired not only in an inert gas atmosphere but also in an air atmosphere at a low temperature. Further, according to the conductive composition, it is possible to prevent oxidation of copper particles of the filler, and it is possible to form a conductive film having good conductivity.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-258123

However, the temperature range in which the conductive composition disclosed in Patent Document 1 can be fired in an atmospheric environment is extremely limited in the range of 150 to 200 °C. Therefore, in the conductive composition disclosed in Patent Document 1, it is difficult to control the firing temperature, and there is a problem that practical use is difficult.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a conductive composition which can be fired in an air atmosphere, and a method of forming a conductive film using the conductive composition.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific carboxylic acid and a specific amine compound can be added to a metal powder mainly composed of a base metal such as copper to obtain an atmosphere that can be fired in an atmosphere. Conductive composition.

That is, the conductive composition of the present invention is characterized in that it contains the following components.

(A) Metal powder with the base metal as the main body, and

(B) an amine compound represented by the following general formula (1), or an aliphatic amine having two or more amine groups, and

(C) fatty hydroxy acid.

R ₂ -HN-R ₁ -OR ₃ ‧‧‧(1)

(wherein R ₁ represents an alkylene group having 2 to 8 carbon atoms, and R ₂ and R ₃ each represent an H atom or an alkyl group having 1 to 4 carbon atoms.)

In the conductive composition of the present invention, the component (B) is preferably an aliphatic amine having an OH group.

The component (B) is preferably at least one selected from the group consisting of 3-amino-1-propanol, 3-methoxypropylamine, N-methylethanolamine, and 1,3-diaminopropane. 3-amino-1-propanol is particularly preferred.

In the conductive composition of the present invention, the component (C) is preferably at least one selected from the group consisting of glycolic acid, lactic acid, and citric acid, and particularly preferably glycolic acid.

The conductive composition of the present invention is preferably a linear epoxy resin having one or more OH groups in the molecule.

The component (A) is preferably at least one selected from the group consisting of copper, nickel, zinc, tin, and solder.

Moreover, the present invention provides a conductive film obtained by coating the conductive composition on a substrate and then heating it at 70 ° C or more and 500 ° C or less.

Furthermore, the present invention provides a method for forming a conductive film, which comprises a method of forming a conductive film in which a heat treatment step of heating at 70 ° C to 500 ° C is performed after coating any one of the conductive compositions on a substrate. In this method, the aforementioned heat treatment step is preferably carried out in an atmospheric environment.

According to the present invention, it is possible to provide a conductive composition which can be fired in an atmosphere, and a method of forming a conductive film using the conductive composition.

[Best Mode for Carrying Out the Invention]

Hereinafter, the form for carrying out the invention will be described in detail.

The conductive composition in the present embodiment contains (A) a metal powder mainly composed of a base metal, and (B) an amine compound represented by the following general formula (1), or two or more amines. a base of an aliphatic amine, with (C) an aliphatic hydroxy acid.

R ₂ -HN-R ₁ -OR ₃ ‧‧‧(1)

(wherein R ₁ represents an alkylene group having 2 to 8 carbon atoms, and R ₂ and R ₃ each represent an H atom or an alkyl group having 1 to 4 carbon atoms.)

The "metal powder mainly composed of a base metal" of the component (A) means a metal powder containing 50% by weight or more of the base metal and preferably 70% by weight or more, more preferably 90% by weight or more. Therefore, it is not only a metal powder made of a base metal, but also a metal powder made of a mixture of a base metal and other metals, and as long as it contains a base metal of 50% by weight or more, it is included herein. "Metal powder with the base metal as the main body". Further, the metal powder formed of an alloy of a base metal and another metal (for example, a solder of an alloy of tin and another metal) may be used as long as it contains 50% by weight or more of the tin metal. "Metal powder with the base metal as the main body".

The term "pepper metal" is generally used as a relative term for "precious metal". Moreover, "peer metal" means all the metals other than gold and silver. Further, "pepper metal" refers to a metal which has a chemical tendency and a large ionization tendency and which is easily oxidized in a high temperature environment.

Examples of the "metametal" which can be used in the present invention include iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, cadmium, indium, tin, antimony, and the like. Among them, the use of copper is the best. This is because the low electrical resistance of copper makes it possible to obtain high conductivity, and at the same time, it is not easily affected by the movement of electrons when the conductive circuit used in a printed circuit board is formed.

The average particle diameter of the "metal powder mainly composed of a base metal" of the component (A) is not particularly limited, and is preferably 1 nm or more and 100 μm or less, more preferably 100 nm or more and 10 μm or less, and when the average particle diameter is within this range, The conductive composition can be used as a conductive paste for circuit pattern printing. Further, in the present specification, the average particle diameter is measured by a laser diffraction scattering type particle size distribution, and is referred to as an average particle diameter on a number basis. The metal powder mainly composed of a base metal can be produced by a known method such as an electrolytic method, a reduction method or an atomization method.

Specific examples of the amine compound represented by the above formula (1) include 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 3-methoxypropylamine. , N-methylethanolamine, N-methylpropanolamine, and the like.

As the compound represented by the above formula (1), an aliphatic amine having an OH group is preferably used. That is, it is preferred that R ₂ and R ₃ in the above formula (1) are both H atoms.

As the compound represented by the above formula (1), 3-amino-1-propanol is preferably used.

The "aliphatic amine having two or more amine groups (-NH ₂ )" as the component (B) is a compound in which a H atom of a linear or branched saturated hydrocarbon is substituted with two or more amine groups. the meaning of. In other words, the diamine in which the H atom of the linear or branched saturated hydrocarbon is substituted with two amine groups is an example of the compound represented by the following general formula (2).

H ₂ NR ₄ -NH ₂ ‧‧‧(2)

(wherein R ₄ represents an alkylene group.)

In the above formula (2), R ₄ is preferably an alkylene group having 2 to 12 carbon atoms, more preferably an alkylene group having 2 to 8 carbon atoms.

Specific examples of the compound represented by the above formula (2) include 1,3-diamine propane, 1,4-diamine butane, 1,5-diamine pentane, and 1,8-diamine octane. 1,10-diamine decane, and the like. Among them, the use of 1,3-diamine propane is preferred.

The "aliphatic hydroxy acid" of the above component (C) means an aliphatic carboxylic acid having an OH group, and specific examples thereof include glycolic acid, lactic acid, glyceric acid, hydroxybutyric acid, malic acid, tartaric acid, and citric acid. - hydroxypropionic acid and the like. Among them, it is preferred to use at least one selected from the group consisting of glycolic acid, lactic acid, and citric acid, and glycolic acid is preferred.

Further, the conductive composition of the present invention preferably contains a linear epoxy resin having one or more OH groups in the (D) molecule. The term "linear" as used herein means that there is no benzene ring in the molecule, and at least three or more carbons have a linear structure in addition to the terminal epoxy group. The epoxy resin which can be used in the present invention is not particularly limited, and for example, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerin polyglycidyl ether, glycerol polyglycidyl ether, and the like can be used. Hydroxymethylpropane polyglycidyl ether and the like. These have the structures of the following formulas (3) to (7) (again, n in the formula (4) is 1 to 10).

1

By adding the above-mentioned (D) component "linear epoxy resin having an OH group" to the components (A) to (C), the coating property and adhesion of the conductive composition to the substrate can be improved. On the other hand, when the "OH-free epoxy resin" is added to the above components (A) to (C), since the compatibility of the epoxy resin with respect to the above components (B) and (C) is not good, it is not This effect may be fully obtained.

Further, when the (D) component "linear epoxy resin having an OH group" is added to the above components (A) to (C), oxygen is blocked by the epoxy resin, and the surface of the base metal particles can be prevented. Oxidation. Thereby, it becomes possible to burn the conductive composition at a relatively high temperature, and it is possible to form a conductive film having high conductivity.

By mixing the above components (A) to (C) and the component (D) added as needed, a paste-like conductive composition can be obtained.

Further, the components (A) to (C) may be mixed in any order. For example, the components (A) to (C) may be simultaneously mixed, or the components (B) and (C) may be previously mixed. The component (A) is then added to the mixture from the back.

The mixing ratio of the components (A) to (C) in the conductive composition of the present invention is not particularly limited, but is 1 to 50 parts by weight based on 100 parts by weight of the component (A). The component (C) is preferably 1 to 50 parts by weight. It is preferably 5 to 25 parts by weight of the component (B) and 5 to 25 parts by weight of the component (C) with respect to 100 parts by weight of the component (A). It is preferably 5 to 10 parts by weight of the component (B) and 5 to 10 parts by weight of the component (C) with respect to 100 parts by weight of the component (A).

When the mixing ratio of the components (B) and (C) is less than the above range, a conductive film having high conductivity may not be obtained. When the mixing ratio of the components (B) and (C) is more than the above range, the viscosity of the conductive composition is too low, which may adversely affect the coating performance of the substrate during screen printing.

In addition to the above components (A) to (D), the conductive composition of the present invention may be added with a solvent or an organic binder for adjusting the viscosity suitable for printing on a substrate, as needed. As a solvent or an organic binder, for example, those disclosed in JP-A-2007-258123 and the like can be used. As a solvent for diluting the conductive composition to lower the viscosity, for example, methanol, ethanol, 1,3-propanediol, ethylene glycol monoacetate, ethyl hydroxyacetate or the like can be used.

Next, a method of forming a conductive film using the conductive composition obtained as described above on a substrate will be described.

After mixing the components (A) to (C) and the component (D) as needed, and preparing a paste-like conductive composition, the conductive composition is applied onto a substrate. As the coating method, for example, a known method such as a screen printing method can be used.

After the paste-like conductive composition is applied onto the substrate, the conductive composition is fired at a temperature of 70 ° C to 500 ° C (heat treatment step). When the baking temperature is less than this range, the volatilization or thermal decomposition of the organic substance in the conductive composition is insufficient, and the conductivity of the conductive film is inhibited by the organic residue. On the other hand, when the baking temperature is higher than this range, the surface of the base metal in the conductive composition is easily oxidized, and a conductive film having high conductivity cannot be obtained. The firing temperature is preferably in the range of 150 ° C to 500 ° C.

The preferred range of the firing temperature differs depending on the type of the base metal of the above component (A). Further, it depends on whether or not the conductive composition contains the component (D).

For example, copper is used as the base metal of the above component (A), and in the case where the component (D) is not contained, it is preferably burned at 150 ° C to 400 ° C, and fired at 200 to 350 ° C. Better. Copper is used as the base metal of the above component (A), and in the case of containing the above component (D), it is preferred to burn at 250 to 500 ° C, and it is more preferable to burn at 350 to 500 ° C. Nickel is used as the base metal of the above component (A), and in the case where the component (D) is not contained, it is preferred to burn at 150 ° C to 400 ° C to burn at 200 to 350 ° C. good. Nickel is used as the base metal of the above component (A), and in the case of containing the above component (D), it is preferred to burn at 250 to 500 ° C, and it is more preferable to burn at 350 to 500 ° C. Solder is used as the base metal of the above component (A), and in the case where the component (D) is not contained, the conductive composition is preferably burned at 80 ° C to 300 ° C to be 80 to 150 ° C. Medium burn is better. When tin is used as the base metal of the above component (A), and in the case where the component (D) is not contained, it is preferred to burn at 80 ° C to 230 ° C to burn at 80 to 150 ° C. good.

Further, depending on the type of the base metal of the component (A), the conductive composition can be formed by drying only the conductive composition at about room temperature (20 ° C). For example, when zinc is used as the base metal of the component (A), the conductive film can be formed only by drying the conductive composition at about room temperature.

Zinc is used as the base metal of the component (A), and in the case where the component (D) is not contained, the conductive composition is preferably dried at room temperature or at a temperature of 300 ° C or lower. Lower firing is preferred to burn at 80 to 150 ° C to make it better. Zinc is used as the base metal of the above component (A), and in the case of containing the above component (D), it is preferred to burn at 100 to 300 ° C, and it is more preferable to burn at 150 to 300 ° C.

Further, the step of heating and baking the conductive composition at 70 ° C or higher and 500 ° C or lower may be carried out in an atmosphere in which air (oxygen) is present around the conductive composition, or in a nitrogen atmosphere in which oxygen is removed from the atmosphere. . The step of drying the conductive composition at around room temperature may be carried out in an atmosphere in which atmospheric (oxygen) is present around the conductive composition, or in a nitrogen atmosphere in which oxygen is removed from the atmosphere.

The conductive film thus obtained has high conductivity in the film due to the presence of particles made of a base metal. In particular, when copper is used as the component (A), since the electrical resistance of copper is low and the material is hardly affected by the movement of electrons, a conductive film having high conductivity and mobility can be obtained.

The conductive film obtained by burning the conductive composition of the invention can be used for forming a circuit pattern in a conductive circuit of various electronic components, for example, a printed substrate.

The conductive composition of the present invention can be fired in an atmosphere in which oxygen is present. Therefore, it is not necessary to burn a conductive composition at a low cost in order to make the inside of the baking furnace a bulky device in a nitrogen atmosphere.

According to the conductive composition of the present invention, a conductive film having high conductivity can be formed. The reason why such an effect is obtained by the conductive composition of the present invention is considered to be as follows.

That is, in the conductive composition, since the component (C) is contained, the thin oxide layer on the surface of the particles formed of the base metal is removed by the flux effect of the organic acid.

In the surface of the particles from which the oxide layer is removed, the components (B) and (C) above are considered to form a certain complex. Then, when the conductive composition is heated in the atmosphere, the complex becomes a protective layer, and it is considered that thermal decomposition is performed while suppressing oxidation of the surface of the particles formed by the base metal. Thereby, even when the conductive composition is fired in an air atmosphere, a conductive film having high conductivity can be formed.

Further, the reason for obtaining the effects of the present invention described above is estimated by the inventors of the present invention based on the knowledge obtained by the current field observation, and does not limit the scope of the present invention.

Example

Hereinafter, Examples 1 to 12 of the present invention will be described, but the present invention is not limited thereto.

Example 1

100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C), and conductivity is prepared. Composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 200 ° C for 10 minutes to form a conductive film. Further, the prepared composition was applied onto the substrate in the same manner, and then heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance values of the two conductive films thus obtained were measured, the results of 0.8 × 10 ^-4 [Ω‧ cm] and 0.5 × 10 ^-4 [Ω‧ cm] were obtained.

Example 2

100 parts by weight of copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of lactic acid as the component (C), and a conductive composition was prepared. Things. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 2.5 × 10 ^-4 [Ω‧ cm] was obtained.

Example 3

100 parts by weight of the copper powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of citric acid as the component (C), and conductivity is prepared. Composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.5 × 10 ^-4 [Ω‧ cm] was obtained.

Example 4

100 parts by weight of copper powder as the component (A), 5 parts by weight of 1,3-diaminopropane as the component (B), and 10 parts by weight of glycolic acid as the component (C), and a conductive composition was prepared. Things. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.0 × 10 ^-4 [Ω‧ cm] was obtained.

Example 5

100 parts by weight of the copper powder as the component (A), and 10 parts by weight of the 3-methoxypropylamine as the component (B), and 10 parts by weight of the glycolic acid of the component (C), were prepared to prepare a conductive composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.9 × 10 ^-4 [Ω‧ cm] was obtained.

Example 6

100 parts by weight of the copper powder as the component (A), and 10 parts by weight of N-methylethanolamine as the component (B), and 10 parts by weight of glycolic acid as the component (C), were prepared to prepare a conductive composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 1.1 × 10 ^-4 [Ω‧ cm] was obtained.

Example 7

100 parts by weight of copper powder as the component (A), 2 parts by weight of 3-amino-1-propanol as the component (B), 5 parts by weight of glycolic acid as the component (C), and 10 parts by weight of the sorbitol polyglycidyl ether of the above component (D), and a conductive composition was prepared. As the copper powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 500 ° C for 10 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.2 × 10 ^-4 [Ω‧ cm] was obtained.

Example 8

100 parts by weight of the nickel powder as the component (A), and 10 parts by weight of the 3-amino-1-propanol as the component (B), and 10 parts by weight of the glycolic acid of the component (C), the conductivity was adjusted. Composition. As the nickel powder, a spherical powder having an average particle diameter of 1 μm was used. After the obtained composition was coated on a substrate, it was heated at 150 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 5.0 × 10 ^-4 [Ω‧ cm] was obtained.

Example 9

100 parts by weight of zinc powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C), and conductivity is prepared. Composition. As the zinc powder, a spherical powder having an average particle diameter of 4 μm is used. After the obtained composition was coated on a substrate, it was heated at 150 ° C for 5 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.2 × 10 ^-4 [Ω‧ cm] was obtained.

Example 10

100 parts by weight of the solder powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C), and conductivity is prepared. Composition. As the solder powder, a spherical powder having an average particle diameter of 4 μm made of an alloy having a weight ratio of Sn:Ag:Cu=96.5:3:0.5 was used. After the obtained composition was coated on a substrate, it was heated at 150 ° C for 10 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.6 × 10 ^-4 [Ω‧ cm] was obtained.

Example 11

100 parts by weight of zinc powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C), and conductivity is prepared. Composition. As the zinc powder, a spherical powder having an average particle diameter of 4 μm is used. After the obtained composition was coated on a substrate, it was dried by leaving it at room temperature (20 ° C) for 24 hours to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 2.0 × 10 ^-4 [Ω‧ cm] was obtained.

Example 12

100 parts by weight of the tin powder as the component (A), 10 parts by weight of 3-amino-1-propanol as the component (B), and 10 parts by weight of glycolic acid as the component (C), and conductivity is prepared. Composition. As the tin powder, a spherical powder having an average particle diameter of 5 μm was used. After the obtained composition was coated on a substrate, it was heated at 150 ° C for 10 minutes to form a conductive film. When the specific resistance value of the conductive film thus obtained was measured, a result of 0.6 × 10 ^-4 [Ω‧ cm] was obtained.

Hereinafter, Comparative Examples 1 to 4 relating to the present invention will be described.

Comparative example 1

100 parts by weight of copper powder, 10 parts by weight of 3-amino-1-propanol, and 10 parts by weight of propionic acid were mixed to prepare a composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm is used. After the obtained composition was coated on a substrate, it was heated at 200 ° C for 10 minutes to form a film. The film thus obtained is a substance having no conductivity and cannot be called a [conductive film].

Comparative example 2

100 parts by weight of copper powder, 10 parts by weight of 3-amino-1-propanol, and 10 parts by weight of p-hydroxybenzoic acid were mixed to prepare a composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm is used. After the obtained composition was coated on a substrate, it was heated at 200 ° C for 10 minutes to form a film. The film thus obtained is a substance having no conductivity and cannot be called a [conductive film].

Comparative example 3

100 parts by weight of copper powder, 10 parts by weight of 1-aminopropane, and 10 parts by weight of glycolic acid were mixed to prepare a composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm is used. After the obtained composition was coated on a substrate, it was heated at 200 ° C for 10 minutes to form a film. The film thus obtained is a substance having no conductivity and cannot be called a [conductive film].

Comparative example 4

100 parts by weight of copper powder and 10 parts by weight of lactic acid were mixed to prepare a composition. As the copper powder, a spherical powder having an average particle diameter of 1 μm is used. After the obtained composition was coated on a substrate, it was heated at 300 ° C for 5 minutes to form a film. The film thus obtained is a substance having no conductivity and cannot be called a [conductive film].

The results of the above Examples 1 to 12 and the above Comparative Examples 1 to 4 were sorted and shown in Tables 1 and 2 below.

As is clear from the results of Examples 1 to 12, according to the conductive composition of the present invention, it was judged that a conductive film having a lower specific resistance value (that is, a higher conductivity) was obtained.

As a result of the comparison of the first, second, and third examples, it was found that the conductive composition of the glycolic acid as the component (C) was used, and it was judged that higher conductivity was obtained when other hydroxy acids (lactic acid or citric acid) were used. Conductive film.

As a result of comparing the results of the first, fourth, fifth, and sixth examples, it was found that the conductive composition of 3-amino-1-propanol as the component (B) was used, and it was judged that the other amine compound (1,3-di) was used. When amine alkane, 3-methoxypropylamine, or N-methylethanolamine), a conductive film having high conductivity can be obtained.

As a result of the comparison of the examples 1 and 7, it is understood that the conductive composition containing the component (D) other than the above components (A) to (C) has a ratio of the component (D). The conductive composition (Example 1) can be fired at a higher temperature, and a conductive film having high conductivity can be obtained.

As a result of the comparison between the first embodiment and the comparative example 1, it was found that when the (C) component was substituted with an aliphatic carboxylic acid having no OH group, it was judged that a conductive film having high conductivity was not obtained.

As a result of the comparison between the first embodiment and the comparative example 2, it was found that the conductive film having high conductivity was not obtained when the aromatic hydroxy acid was replaced by the component (C).

As a result of the comparison between the first embodiment and the comparative example 3, it was found that the conductive film having high conductivity was not obtained when the component (B) was substituted with an amine compound having one amine group and no OH group.

As a result of observing the results of Comparative Example 4, it was found that when the composition containing only the components (A) and (C) described above was fired, it was judged that a conductive film having high conductivity was not obtained.

Claims (8)

An electroconductive composition comprising (A) a metal powder mainly composed of a base metal, and (B) an amine compound represented by the following general formula (1), R ₂ -HN-R ₁ -OR ₃ . . . (1) (wherein R ₁ represents an alkylene group having 2 to 8 carbon atoms, R ₂ and R ₃ are each an H atom or an alkyl group having 1 to 4 carbon atoms), or 2 or more An amine-based aliphatic amine; and (C) an aliphatic hydroxy acid, wherein the component (B) is selected from the group consisting of 3-amino-1-propanol, 3-methoxypropylamine, N-methylethanolamine, And at least one of 1,3-diaminopropane. The conductive composition according to claim 1, wherein the component (B) is an aliphatic amine having an OH group. The conductive composition according to claim 1 or 2, wherein the component (C) is at least one selected from the group consisting of glycolic acid, lactic acid, and citric acid. The conductive composition according to claim 1 or 2, further comprising a linear epoxy resin having one or more OH groups in the molecule. The conductive composition according to claim 1 or 2, wherein the component (A) is at least one selected from the group consisting of copper, nickel, zinc, tin, and solder. A conductive film obtained by applying the conductive composition according to any one of claims 1 to 5 to a substrate, and then heating it at 70 ° C or more and 500 ° C or less. A method of forming a conductive film, which comprises applying a conductive composition according to any one of claims 1 to 5 to a substrate, and then heating the substrate at 70 ° C or higher and 500 ° C or lower. The method for forming a conductive film according to claim 7, wherein the heat treatment step is performed in an atmospheric environment.