JP2016039009A - Method for manufacturing conductive laminate, and conductive laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a conductive laminate in which it is possible to achieve both making the laminate into a conductor at low temperatures and adhesion to the substrate.SOLUTION: Provided is a method for manufacturing a conductive laminate including: a step for forming a conductive material-containing layer on a substrate by applying a conductive material comprising a copper-containing particle having a copper-containing core particle and organic matter, present in at least a portion of the surface of said core particle, comprising a material derived from alkylamine having a number of carbon atoms of 7 or less, and a dispersion medium; and a step for forming a copper layer by heat-treating the conductive material-containing layer at a temperature in a range of -40°C to +40°C with respect to the glass transition point of the substrate.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a conductive laminate and a conductive laminate.

  As a method for forming a metal pattern, a step of applying a conductive material such as ink or paste containing metal particles such as copper onto a substrate by ink jet printing, screen printing, etc., and heating the conductive material to sinter the metal particles In addition, a method including a conductor-forming step for developing conductivity is known. As the metal particles contained in the conductive material, those in which an organic substance as a coating material is attached to the surface in order to suppress the oxidation of the metal and enhance the storage stability are known.

  Patent Document 1 describes a copper particle coated with an alkylamine and a method for producing the same. The method described in Patent Document 1 includes a step of mixing a copper precursor such as copper oxalate with a reducing compound such as hydrazine to obtain a composite compound, and a step of heating the composite compound in the presence of an alkylamine. have. It is reported that the copper particles obtained by this method can be stored for a long period of time in the air by appropriately selecting the type of alkylamine as a coating material and show good conductivity when heated at 300 ° C. or lower. ing. The alkylamine is preferably an alkylamine having 12 or more carbon atoms.

In general, the conductive material is produced by dispersing conductive particles in a vehicle composition obtained by dissolving a resin component serving as a binder resin in an organic solvent.
Patent Document 2 describes a conductive paste composition containing a conductive metal powder, an organic vehicle, and the like. For the purpose of removing the organic binder, heat treatment is usually performed at 250 ° C. to 330 ° C. in an air atmosphere, nitrogen atmosphere, etc., and the organic vehicle is burned, and then in a neutral or reducing atmosphere so that the metal powder does not participate, Sintering at 1300 ° C. is described.
Patent Document 3 discloses a method for producing a metallic copper film in which a copper-based particle deposition layer containing copper oxide is treated at 120 ° C. or more and 140 ° C. or less in a treatment gas containing both an organic compound containing phosphorus or nitrogen and formic acid. Have been described.

JP 2012-72418 A JP 2012-226865 A JP 2013-175560 A

Since the organic vehicle contains a resin component, the adhesion of the conductive material after sintering to the base material can be improved. However, in order to remove the resin component, heat treatment at a high temperature is necessary as described above, and it is difficult to form a metal pattern on a substrate having low heat resistance.
Moreover, in the method of processing a copper oxide deposition layer in a processing gas atmosphere, it is necessary to introduce a processing gas when performing the conductor process, and the process is complicated. Furthermore, as a method for improving the adhesion to the substrate, a method of forming a metal particle-containing layer after forming an adhesive base layer is known. However, there is a problem that the number of steps increases and becomes complicated, and the production efficiency is low.

  In view of the above problems, an object of the present invention is to provide a method for producing a conductive laminate and a conductive laminate capable of achieving both low-temperature conductorization and adhesion to a substrate. Moreover, it aims at providing the electroconductive laminated body which is excellent in adhesiveness with a base material.

Means for solving the above problems are as follows.
<1> A copper-containing core particle containing copper and an organic substance containing a substance derived from an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particle on a base material Providing a conductive material containing particles and a dispersion medium to form a conductive material-containing layer;
A step of heat-treating the conductive material-containing layer at a temperature within a range of −40 ° C. to + 40 ° C. with respect to the glass transition point of the base material to form a copper layer;
The manufacturing method of the electroconductive laminated body containing this.

<2> The method for producing a conductive laminate according to <1>, wherein the temperature of the heat treatment is 100 ° C to 200 ° C.
<3> The method for producing a conductive laminate according to <1> or <2>, wherein the base material contains a thermoplastic resin.
<4> A conductive laminate obtained by the method for producing a conductive laminate according to any one of <1> to <3>.

<5> a base material;
Copper-containing particles having, on the base material, copper-containing core particles, and an organic substance containing a substance derived from alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particles, and A conductor made of a sintered material of a conductive material containing a dispersion medium, and at least a part of the conductor fused to the substrate;
A conductive laminate comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of an electroconductive laminated body and electroconductive laminated body which can be made compatible with low temperature conductorization and adhesiveness with a base material can be provided. Moreover, the electroconductive laminated body which is excellent in adhesiveness with a base material can be provided.

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. Further, in the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. Means.

  In this specification, “room temperature” means 25 ° C.

  In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. .

In this specification, the term “layer” includes a configuration formed in a part in addition to a configuration formed in the entire surface when observed as a plan view.
In this specification, the term “laminated body” indicates that layers are stacked, and two or more layers may be bonded, or two or more layers may be detachable.

  In the present specification, the term “glass transition point of the substrate” refers to a temperature at which the phase morphology of the substrate changes. The glass transition point is measured by differential scanning calorimetry (DSC).

  In the present specification, the term “conducting” means that the metal-containing particles are sintered to be changed into a conductive object. “Conductor” refers to an object having electrical conductivity.

[Method for producing conductive laminate]
The method for producing a conductive laminate of the present invention includes a core particle containing copper on a base material, and a substance derived from an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particle. A step of forming a conductive material-containing layer by applying a conductive material containing copper-containing particles and a dispersion medium (hereinafter also referred to as a “conductive material application step”), and a conductive material-containing layer. And a step of forming a copper layer by heat treatment at a temperature in the range of −40 ° C. to + 40 ° C. with respect to the glass transition point of the material (hereinafter also referred to as “heat treatment step”).
The manufacturing method of the electroconductive laminated body of this invention may include the other process as needed.

The manufacturing method of the electroconductive laminated body of this invention can make a copper layer a conductor at a low temperature and a simple process by taking the said structure, and can obtain a copper layer. As a result, a copper layer can be formed on a substrate having relatively low heat resistance, and adhesion with the substrate can be improved.
The reason is guessed as follows.
While metal particles with organic coatings have the advantage that oxidation is suppressed even when stored in the atmosphere, when conducting conductive materials are sintered, the organic coating that hinders conductorization is removed by thermal decomposition. Need to be heated. The copper-containing particles in the present invention have core particles containing copper, and an organic substance containing a substance derived from an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particles. It is considered that the oxidation of the copper-containing particles can be suppressed, and further, since the molecular weight of the alkylamine constituting the organic substance in the present invention is relatively small, it is easily decomposed easily even at a relatively low temperature. . Therefore, it is considered that the copper-containing particles can be made conductive and organic substances can be removed even at low temperatures.
Moreover, it is guessed that by performing heat treatment at a temperature close to the glass transition point of the base material, the surface of the base material is melted and adhesion with the copper layer on the base material can be improved.
As a result, it is considered that both low-temperature conductorization and adhesion to the substrate can be achieved.

<Conductive material application process>
In the conductive material application step, on the base material, core particles containing copper, and an organic substance containing a substance derived from an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particles, A conductive material-containing layer is formed by applying a conductive material containing copper-containing particles and a dispersion medium.

(Method for applying conductive material)
The method for forming the conductive material-containing layer by applying the conductive material on the substrate is not particularly limited as long as the conductive material-containing layer can be formed in any shape at any location on the substrate. Examples of such methods include inkjet methods, super inkjet methods, screen printing methods, transfer printing methods, offset printing methods, jet printing printing methods, dispenser methods, jet dispenser methods, needle dispenser methods, comma coater methods, slit coater methods, and die coater methods. , Gravure coater method, letterpress printing method, intaglio printing method, gravure printing method, soft lithographic method, dip pen lithographic method, particle deposition method, spray coater method, spin coater method, dip coater method, electrodeposition coating method, etc. it can. Among these, at least one selected from the group consisting of an inkjet method, a super inkjet method, a screen printing method, an offset printing method, a jet printing method, a dispenser method, a needle dispenser method, a comma coater method, a slit coater method, a die coater method, and a gravure coater method. A seed method is preferred.
For example, a paste-like conductive material may be applied to the substrate by a screen printing method, and an ink-like conductive material may be applied to the substrate by an inkjet printing method.

(Characteristics of conductive material containing layer)
The shape of the conductive material-containing layer formed on the substrate is not particularly limited and can be appropriately selected according to the purpose.
Further, the thickness of the conductive material-containing layer is not particularly limited and can be appropriately selected according to the purpose. For example, the thickness may be 0.2 μm to 50 μm, and is preferably 0.8 μm to 20 μm from the viewpoint of conductivity and connection reliability.

(Base material)
The material of the base material is not particularly limited, and may or may not have conductivity. Examples thereof include semiconductors such as ITO, ZnO, SnO, and Si, carbon materials such as glass, graphite, and graphite, and resins.

The method for producing a conductive laminate of the present invention can be suitably applied particularly to a support made of a material having relatively low heat resistance. As such a material, a thermoplastic resin is preferable, and from the viewpoint of making a conductor at low temperature, a thermoplastic resin having a glass transition point of 50 ° C to 200 ° C is more preferable, and a glass transition point is 90 ° C to 190 ° C. Certain thermoplastic resins are more preferred.
The content of the thermoplastic resin in the substrate is preferably 50% by mass or more.

  As the thermoplastic resin, polyethylene naphthalate, polyvinyl chloride, polystyrene, ABS, polymethyl methacrylate, polyamide, polycarbonate, polyphenylene sulfide, polyphenylene oxide, polytetrafluoroethylene, polyacrylonitrile, polybutylene terephthalate, polyethylene terephthalate and the like are preferable. . The shape of the substrate is not particularly limited, and may be a plate shape, a rod shape, a roll shape, or the like.

(Conductive material)
The conductive material used in the method for producing a conductive laminate of the present invention is derived from a core particle containing copper and an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particle. An organic substance containing a substance and a copper-containing particle having a dispersion medium and a dispersion medium, and may contain other components as necessary.

  Since the conductive material in the present invention includes copper-containing particles whose shape is controlled, the particles themselves are excellent in dispersibility. Therefore, characteristics such as thixotropy and storage stability of the conductive material can be controlled without adding a dispersant or the like. As a result, it is possible to reduce the amount of the additive that hinders conductorization, and to realize conductor formation at a lower temperature. In the present invention, “conducting” means that the resistivity of the sintered product obtained by sintering the copper-containing particles contained in the conductive material is 300 μΩcm or less.

  The state of the conductive material of the present invention is not particularly limited and can be selected according to the application. For example, when the conductive material is applied to the screen printing method, the viscosity is preferably 0.1 Pa · s to 30 Pa · s, and more preferably 1 Pa · s to 30 Pa · s. When the conductive material is applied to the ink jet printing method, the viscosity is preferably 0.1 mPa · s to 30 mPa · s, and more preferably 5 mPa · s to 20 mPa · s.

-Copper-containing particles-
The copper-containing particles in the present invention have core particles containing copper and organic substances containing a substance derived from alkylamine present on at least a part of the surface of the core particles, and the alkylamine is a hydrocarbon group. An alkylamine having 7 or less carbon atoms (hereinafter also referred to as a specific alkylamine) is included. Presence of the organic substance and alkylamine is confirmed by, for example, heating the copper-containing particles at a temperature equal to or higher than the temperature at which the organic substance or alkylamine is thermally decomposed in a nitrogen atmosphere, and comparing the mass of the copper-containing particles before and after heating. be able to.

  The copper containing particle | grains in this invention are excellent in oxidation resistance by having the organic substance containing the substance derived from an alkylamine in at least one part of the surface of the core particle containing copper. Furthermore, the copper containing particle | grains in this invention can be conductorized at low temperature (for example, 150 degrees C or less). This is presumably because the alkylamine constituting the organic substance has a relatively small molecular weight, and thus is easily thermally decomposed even at a relatively low temperature.

(Specific alkylamine)
In the present invention, the specific alkylamine is a primary amine represented by RNH ₂ (R is a hydrocarbon group having 7 or less carbon atoms, and may be cyclic or branched), R ₁ R ₂ NH (R ₁ and R ₂ are hydrocarbon groups which may be the same or different, and may be cyclic or branched, and the total number of carbon atoms is 7 or less. It means a diamine in which two amino groups are bonded to a hydrocarbon chain having a number of 7 or less. The specific alkylamine may have one or more double bonds, and may have atoms such as oxygen, silicon, nitrogen, sulfur, and phosphorus. The specific alkylamine may be one kind or two or more kinds.

  If the number of carbon atoms of the specific alkylamine exceeds 7, the temperature required for conductorization may not be sufficiently lowered. From the viewpoint of more effectively achieving both oxidation resistance and conductorization at low temperature, the carbon number of the specific alkylamine is preferably 7 or less, and more preferably 6 or less. The number of carbon atoms of the specific alkylamine is preferably 4 or more, more preferably 4-6.

  Specific examples of primary amines having 7 or less carbon atoms include ethylamine, 2-ethoxyethylamine, propylamine, butylamine, isobutylamine, pentylamine, isopentylamine, hexylamine, cyclohexylamine, heptylamine and the like. Can do.

  Specific examples of the secondary amine having 7 or less carbon atoms include diethylamine, dipropylamine, dibutylamine, ethylpropylamine, and ethylpentylamine.

  Specific examples of the alkyldiamine having 7 or less carbon atoms include ethylenediamine, N, N-dimethylethylenediamine, N, N′-dimethylethylenediamine, N, N-diethylethylenediamine, N, N′-diethylethylenediamine, 1,3 -Propanediamine, 2,2-dimethyl-1,3-propanediamine, N, N-dimethyl-1,3-diaminopropane, N, N'-dimethyl-1,3-diaminopropane, N, N-diethyl- 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diamino-2-methylpentane, 1,6-diaminohexane, N, N′-dimethyl-1,6-diaminohexane, 1, Examples thereof include 7-diaminoheptane.

  The organic substance present on at least part of the surface of the core particle containing copper may contain a substance derived from an alkylamine other than the specific alkylamine. Examples of alkylamines other than the specific alkylamine include primary amines, secondary amines and alkyldiamines having 8 or more carbon atoms. In the alkylamine other than the specific alkylamine, the hydrocarbon group may be cyclic or branched, and may have one or more double bonds, and atoms such as oxygen, silicon, nitrogen, sulfur, phosphorus, etc. You may have. Only one type of alkylamine other than the specific alkylamine may be used, or two or more types may be used.

  Examples of the primary amine having 8 or more carbon atoms include octylamine, nonylamine, decylamine, dodecylamine, hexadecylamine, and oleylamine.

  Examples of the secondary amine having 8 or more carbon atoms include dibutylamine, dipentylamine, and dihexylamine.

  Specific examples of the alkyldiamine having 8 or more carbon atoms include 1,8-diaminooctane, 1,9-diaminononane, 1,12-diaminododecane and the like.

  When the organic substance present on at least a part of the surface of the core particle containing copper contains a substance derived from an alkylamine other than the specific alkylamine, the ratio of the substance derived from the specific alkylamine in the total organic substance is 50% by mass or more. Preferably, it is 60% by mass or more, and more preferably 70% by mass or more.

  It is preferable that the organic substance which exists in at least one part of the surface of the core particle containing copper is 0.1-20 mass% with respect to the sum total of the core particle and organic substance containing copper. When the ratio of the specific organic substance is 0.1% by mass or more, sufficient oxidation resistance tends to be obtained. When the proportion of the organic substance is 20% by mass or less, conductorization at a low temperature tends to be easily achieved. The ratio of the organic substance to the total of the core particles containing copper and the organic substance is more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more. Further, the ratio of the organic substance to the total of the core particles containing copper and the organic substance is more preferably 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 3% by mass or less.

  The size of the copper-containing particles in the present invention is not particularly limited and can be selected according to the application. When manufacturing a copper containing particle | grain by the method mentioned later, the median diameter of the length of the major axis of 200 copper containing particles generally selected at random is in the range of 10 nm-500 nm. From the viewpoint of lowering the conductorization temperature, the center of the long axis length of 200 randomly selected copper-containing particles is preferably 10 nm to 300 nm, and more preferably 10 nm to 200 nm. .

  In the present invention, the length of the major axis means the distance between two planes selected so that the distance between the two planes circumscribing the particle and parallel to each other is maximized. In the present invention, the median value of the length of the major axis is the two values (100th and 101st) located at the center when the major axis length values of 200 copper-containing particles are arranged in ascending order. Means the arithmetic mean. The length of the major axis of the copper-containing particles can be measured by a usual method such as observation with an electron microscope.

  The shape of the copper-containing particles in the present invention is not particularly limited. For example, a spherical shape, a long granular shape, a flat shape, a fibrous shape, and the like can be given, and can be selected according to the use of the copper-containing particles. From the viewpoint of the printing paste, it is preferably spherical or long granular.

  The copper-containing particles in the present invention contain at least metallic copper, and may contain other substances as necessary. Examples of substances other than copper include metals such as gold, silver, platinum, tin, and nickel, or compounds containing these metal elements, fatty acid copper described later, organic compounds derived from reducing compounds or alkylamines, copper oxide, copper chloride, etc. Can be mentioned. From the viewpoint of forming a copper pattern with excellent conductivity, the content of copper metal in the copper-containing particles is preferably 70% by mass or more, more preferably 80% by mass or more, and 85% by mass or more. More preferably.

  In the copper-containing particles of the present invention, oxidation is suppressed because organic substances are present on at least a part of the surface, and the oxide content is small. For example, in one embodiment, the content of oxide in the copper-containing particles is 5% by mass or less, and in another embodiment, the content of oxide in the core particles is 1% by mass or less. The content rate of the oxide in a core particle can be measured by XRD, for example.

-Method for producing copper-containing particles-
The method for producing the copper-containing particles in the present invention is not particularly limited. For example, by a method having a step of heating a composition containing a metal salt of a fatty acid having a carbon number of 9 or less and copper, a reducing compound, and an alkylamine containing an alkylamine having a carbon number of 7 or less. The copper-containing particles of the present invention can be produced.

  The method uses a metal salt of fatty acid and copper having 9 or less carbon atoms as a copper precursor. As a result, compared to the method described in Patent Document 1 using silver oxalate or the like as a copper precursor, it became possible to use an alkylamine having a lower boiling point (that is, a lower molecular weight) as a reaction medium. Conceivable. As a result, it is considered that the organic matter present on the surface of the obtained copper-containing particles is more easily thermally decomposed, and the conductorization can be performed at a low temperature.

-Fatty acid-
The fatty acid used in the above method is a monovalent carboxylic acid represented by RCOOH (R is a chain hydrocarbon group, which may be linear or branched). The fatty acid used in the present invention may be either a saturated fatty acid or an unsaturated fatty acid. From the viewpoint of improving the particle coverage and preventing oxidation, linear saturated fatty acids are preferred. Only one type or two or more types of fatty acids may be used.

  From the viewpoint of lowering the conductorization temperature, the fatty acid preferably has 9 or less carbon atoms. Examples of saturated fatty acids having 9 or less carbon atoms include acetic acid (2 carbon atoms), propionic acid (3 carbon atoms), butyric acid and isobutyric acid (4 carbon atoms), valeric acid and isovaleric acid (5 carbon atoms), capron Examples include acids (carbon number 6), enanthic acid and isoenanthic acid (carbon number 7), caprylic acid, isocaprylic acid and isocaproic acid (carbon number 8), nonanoic acid and isononanoic acid (carbon number 9). Examples of the unsaturated fatty acid having 9 or less carbon atoms include those having one or more double bonds in the hydrocarbon group of the saturated fatty acid.

  The type of fatty acid used in the production of the copper-containing particles in the present invention can affect properties such as dispersibility of the obtained copper-containing particles in a dispersion medium and sinterability. For this reason, it is preferable to select the kind of fatty acid according to the use of copper-containing particles. From the viewpoint of uniforming the particle diameter, it is preferable to use a fatty acid having 9 or less carbon atoms and a fatty acid having 4 or less carbon atoms in combination. For example, nonanoic acid having 9 carbon atoms and acetic acid having 2 carbon atoms are preferably used in combination. The ratio in particular when using together the fatty acid having 9 or less carbon atoms and the fatty acid having 4 or less carbon atoms is not limited.

  The method for obtaining a salt compound (fatty acid copper) of fatty acid and copper having 9 or less carbon atoms is not particularly limited. For example, it may be obtained by mixing copper hydroxide and a fatty acid in a solvent, or commercially available fatty acid copper may be used. Alternatively, by mixing copper hydroxide, a fatty acid and a reducing compound in a solvent, the formation of fatty acid copper and the formation of a complex formed between the fatty acid copper and the reducing compound are performed in the same process. Also good.

-Reducing compound-
The reducing compound used in the above method is considered to form a complex compound such as a complex between both compounds when mixed with fatty acid copper. As a result, the reducing compound becomes an electron donor to the copper ion in the fatty acid copper, and the reduction of the copper ion is likely to occur, and the liberation of copper atoms due to spontaneous pyrolysis than the fatty acid copper in a state where no complex is formed. This is likely to occur. A reducing compound may be used individually by 1 type, or may use 2 or more types together.

  Specific examples of reducing compounds include hydrazine, hydrazine derivatives, hydrazine hydrochloride, hydrazine sulfate, hydrazine hydrate and other hydrazine compounds, hydroxylamine, hydroxylamine derivatives such as hydroxylamine compounds, sodium borohydride, sodium sulfite, hydrogen sulfite. Examples thereof include sodium compounds such as sodium, sodium thiosulfate, and sodium hypophosphite.

  A reducing compound having an amino group is preferable from the viewpoints of easily forming a coordination bond to a copper atom in fatty acid copper, and easily forming a complex while maintaining the structure of fatty acid copper. Examples of the reducing compound having an amino group include hydrazine and derivatives thereof, hydroxylamine and derivatives thereof, and the like.

  From the viewpoint of lowering the heating temperature (for example, 150 ° C. or lower) in the step of heating the composition containing fatty acid copper, the reducing compound and the alkylamine in the method (hereinafter also referred to as the heating step), the evaporation of the alkylamine or It is preferable to select a reducing compound capable of forming a complex that causes reduction and liberation of a copper atom in a temperature range that does not cause decomposition. Examples of such reducing compounds include hydrazine and its derivatives, hydroxylamine and its derivatives, and the like. These reducing compounds can form a complex by forming a coordinate bond with a copper atom by a nitrogen atom forming a skeleton. In addition, since these reducing compounds generally have a stronger reducing power than alkylamines, the resulting complexes tend to spontaneously decompose under relatively mild conditions, and tend to reduce and release copper atoms.

  By selecting a suitable one of these derivatives instead of hydrazine or hydroxylamine, the reactivity with the fatty acid copper can be adjusted, and a complex that generates spontaneous decomposition under a desired condition can be generated. Examples of hydrazine derivatives include methyl hydrazine, ethyl hydrazine, n-propyl hydrazine, isopropyl hydrazine, n-butyl hydrazine, isobutyl hydrazine, sec-butyl hydrazine, t-butyl hydrazine, n-pentyl hydrazine, isopentyl hydrazine, and neo-pentyl hydrazine. , T-pentylhydrazine, n-hexylhydrazine, isohexylhydrazine, n-heptylhydrazine, n-octylhydrazine, n-nonylhydrazine, n-decylhydrazine, n-undecylhydrazine, n-dodecylhydrazine, cyclohexylhydrazine, phenyl Examples include hydrazine, 4-methylphenylhydrazine, benzylhydrazine, 2-phenylethylhydrazine, 2-hydrazinoethanol, and acetohydrazine. Rukoto can. Examples of hydroxylamine derivatives include N, N-di (sulfoethyl) hydroxylamine, monomethylhydroxylamine, dimethylhydroxylamine, monoethylhydroxylamine, diethylhydroxylamine, N, N-di (carboxyethyl) hydroxylamine and the like. Can do.

  The ratio of the copper and the reducing compound contained in the fatty acid copper is not particularly limited as long as a desired complex is formed. For example, the ratio (copper: reducing compound) can be in the range of 1: 1 to 1: 4 on a molar basis, preferably in the range of 1: 1 to 1: 3, and 1: 1 to 1 : The range of 2 is more preferable.

-Alkylamine-
The alkylamine used in the above method is considered to function as a reaction medium for the decomposition reaction of the complex formed from the fatty acid copper and the reducing compound. Furthermore, it is considered that protons generated by the reducing action of the reducing compound are captured, and the reaction solution is inclined to be acidic and copper atoms are prevented from being oxidized.

  The alkylamine contains at least one alkylamine (specific alkylamine) in which the hydrocarbon group has 7 or less carbon atoms. Thereby, the copper containing particle | grains which are excellent in oxidation resistance and can be made into a conductor at low temperature can be manufactured. The specific alkylamine may be used alone or in combination of two or more, and the kind and preferred embodiment thereof are the same as those described in relation to the organic substance present on the surface of the copper-containing particle of the present invention. The alkylamine may contain an alkylamine other than the specific alkylamine, and the type and preferred embodiment thereof are the same as those described in relation to the organic substance present on the surface of the copper-containing particle of the present invention. When the alkylamine contains an alkylamine other than the specific alkylamine, the proportion of the specific alkylamine in the entire alkylamine is preferably 50% by mass or more, more preferably 60% by mass or more, and 70% by mass or more. More preferably.

  The ratio of copper and alkylamine contained in fatty acid copper is not particularly limited as long as desired copper-containing particles are obtained. For example, the ratio (copper: alkylamine) can be in a range of 1: 1 to 1: 8 on a molar basis, preferably in a range of 1: 1 to 1: 6, and 1: 1 to 1: A range of 4 is more preferable.

-Heating process-
In the said method, the method in particular for implementing the process of heating the composition containing fatty-acid copper, a reducing compound, and an alkylamine is not restrict | limited. For example, a method in which fatty acid copper and a reducing compound are mixed in a solvent and then heated by adding an alkylamine, a method in which fatty acid copper and an alkylamine are mixed with a solvent, and then a method in which a reducing compound is further added and heated, a fatty acid A method of heating copper hydroxide, a fatty acid, a reducing compound, and an alkylamine, which are copper starting materials, in a solvent, a method of heating, a method of mixing a fatty acid copper and an alkylamine in a solvent, and then adding a reducing compound and heating Etc.

  From the viewpoint of obtaining particles having a uniform shape and size, the composition containing the fatty acid copper, the reducing compound and the alkylamine is a first step for obtaining a mixture of the fatty acid copper and the alkylamine, and the mixture of the fatty acid copper and the alkylamine. It is preferable to obtain by the method including the 2nd process of adding a reducing compound. In this case, the first step of obtaining a mixture of fatty acid copper and alkylamine and the second step of adding a reducing compound to the mixture of fatty acid copper and alkylamine may be performed continuously in the same container, but separately. You may go.

  A method of obtaining a composition comprising fatty acid copper, a reducing compound and an alkylamine comprises a first step of obtaining a mixture of fatty acid copper and alkylamine, and a second step of adding the reducing compound to the mixture of fatty acid copper and alkylamine. When it is included, the first step is preferably performed at 0 ° C. or higher and 100 ° C. or lower, more preferably performed at 10 ° C. or higher and 90 ° C. or lower, and further preferably performed at 25 ° C. or higher and 80 ° C. or lower. The second step is preferably performed at a temperature at which the reduction reaction is suppressed. For example, it is preferably performed at 10 ° C. or less, more preferably 5 ° C. or less, and further preferably 0 ° C. or less.

  The composition containing fatty acid copper, reducing compound and alkylamine is heated at a temperature at which a complex formed from fatty acid copper and the reducing compound is decomposed. For example, the heating is preferably performed at 150 ° C. or less, more preferably at 130 ° C. or less, and further preferably at 100 ° C. or less. In the said method, a heating process can be performed at comparatively low temperature by using specific fatty acid copper as a copper precursor.

  The composition containing fatty acid copper, a reducing compound and an alkylamine may further contain a solvent. From the viewpoint of promoting the formation of a complex of fatty acid copper and a reducing compound, it is preferable to include a polar solvent. Here, the polar solvent is preferably a solvent having solubility in water at 25 ° C., and more preferably an alcohol solvent. The reason why the formation of the complex is promoted by using alcohol as the solvent is not clear, but it is considered that the contact with the water-soluble reducing compound is promoted while dissolving the solid fatty acid copper. A solvent may be used individually by 1 type, or may use 2 or more types together.

  As alcohol which shows the solubility with respect to water at 25 degreeC, C1-C8 can be mentioned and the alcohol which has one hydroxyl group in a molecule | numerator can be mentioned. Examples of such alcohols include linear alkyl alcohols, phenols, and those obtained by replacing hydrogen atoms of hydrocarbons having an ether bond in the molecule with hydroxyl groups. From the viewpoint of expressing a stronger polarity, an alcohol having two or more hydroxyl groups in the molecule is also preferably used. Moreover, you may use alcohol containing a sulfur atom, a phosphorus atom, a silicon atom, etc. according to the use of the copper containing particle | grains manufactured.

  Specific examples of alcohol used as a solvent include methanol, ethanol, 1-propanol, 2-propanol, butanol, pentanol, hexanol, heptanol, octanol, allyl alcohol, benzyl alcohol, pinacol, propylene glycol, menthol, catechol, hydroquinone, Examples include salicyl alcohol, glycerin, pentaerythritol, sucrose, glucose, xylitol, methoxyethanol, triethylene glycol monomethyl ether, ethylene glycol, triethylene glycol, tetraethylene glycol, and pentaethylene glycol.

  Among the alcohols, methanol, ethanol, 1-propanol and 2-propanol having a very high solubility in water are preferable, 1-propanol and 2-propanol are more preferable, and 1-propanol is more preferable.

(Dispersion medium)
The dispersion medium used for the conductive material of the conductive material of the present invention is not particularly limited, and can be selected from organic solvents generally used for the production of conductive inks, conductive pastes, and the like according to applications. For example, terpineol, isobornylcyclohexanol, dihydroterpineol, dihydroterpineol acetate and the like are preferable from the viewpoint of viscosity adjustment.

(Other ingredients)
In addition to the above-described components, the conductive material in the present invention can further contain other components that are usually used in the technical field, if necessary. Examples of other components include a thixotropic agent.

(Method for producing conductive material)
The manufacturing method of the electrically conductive material in this invention is not specifically limited, The method normally used in the said technical field can be used.
For example, it can prepare by disperse | distributing the copper containing particle | grains in this invention, and the other component contained as needed in a dispersion medium. Dispersion treatment includes Ishikawa-type stirrer, rotation-revolution stirrer, ultra-thin high-speed rotary disperser, media disperser such as roll mill, ultrasonic disperser, bead mill, cavitation stirrer such as homomixer and silverson stirrer, Artema An opposing collision method such as Iser can be used. Moreover, you may use combining these methods suitably.

<Heat treatment process>
In the heat treatment step, the conductive material-containing layer formed in the conductive material application step is heat-treated at a temperature within a range of −40 ° C. to + 40 ° C. with respect to the glass transition point of the base material to form a copper layer. Thereby, the conductive material is sintered and the copper-containing particles are made into a conductor. When the heat treatment temperature is within the above range, the adhesion of the copper layer to the substrate tends to be improved.

  The heat treatment temperature in the heat treatment step is preferably in the range of −40 ° C. to + 40 ° C. with respect to the glass transition point of the base material from the viewpoint of adhesion to the base material, and in the range of −30 ° C. to + 30 ° C. More preferably, it is more preferably −25 ° C. to + 25 ° C.

It is preferable that the heat processing temperature is 100 to 200 degreeC from a viewpoint of conductorization and the influence on a base material. When the heat treatment temperature is 100 ° C. or higher, sufficient conductive material conductivity and adhesion to the base material can be obtained, and when it is 200 ° C. or lower, thermal damage to the base material tends to be suppressed.
The heat treatment step may be performed at a constant rate of temperature increase or irregularly.
The heat treatment time is not particularly limited, and can be selected in consideration of the heat treatment temperature, the heat treatment atmosphere, the amount of copper-containing particles, and the like. The heat treatment time is preferably 10 minutes to 120 minutes from the viewpoint of achieving both sufficient conductivity and mass productivity.

  The atmosphere in the heat treatment step is not particularly limited as long as it is an inert gas atmosphere, and an atmospheric gas used in a normal conductor treatment can be used. Examples of the inert gas include nitrogen gas and argon gas.

  In one embodiment, in the heat treatment step, a conductive material-containing layer formed on a base material having a glass transition point of 70 ° C. to 200 ° C. in an inert gas atmosphere is −40 ° C. to the glass transition point. The heat treatment is preferably performed at a temperature within the range of + 40 ° C. for 10 minutes to 120 minutes.

[Conductive laminate]
The conductive laminate of the present invention is obtained by the method for producing a conductive laminate of the present invention.
The conductive laminate of the present invention is derived from a base material, a core particle containing copper on the base material, and an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particle. An organic substance containing a substance, and a conductor (copper layer) that is made of a sintered material of a conductive material containing copper-containing particles and a dispersion medium, and at least a part of which is fused to the base material. Since at least a part of the conductor (copper layer) in the present invention is fused to the base material, the adhesiveness to the base material is excellent.

  Hereinafter, although the copper containing particle | grains of this invention are demonstrated based on an Example, this invention is not limited to these Examples at all.

<Example 1>
[1.1] Synthesis of copper nonanoate To 91.5 g (0.94 mmol) of copper hydroxide (Kanto Chemical Co., Ltd., special grade), 150 mL of 1-propanol (Kanto Chemical Co., Ltd., special grade) was added and stirred. 370.9 g (2.34 mmol) of nonanoic acid (Kanto Chemical Co., Inc., 90% or more) was added. The obtained mixture was heated and stirred at 90 ° C. for 30 minutes in a separable flask. The obtained solution was filtered while heated to remove undissolved substances. Thereafter, the mixture was allowed to cool, and the produced copper nonanoate was suction filtered and washed with hexane until the cleaning liquid became transparent. The obtained powder was dried in an explosion-proof oven at 50 ° C. for 3 hours to obtain copper (II) nonanoate. The yield was 340 g (yield 96 mass%).

[1.2] Synthesis of copper particles 15.01 g (0.040 mol) of copper (II) nonanoate obtained above and 7.21 g of copper (II) acetate anhydride (Kanto Chemical Co., Ltd., special grade) 040 mol) is put into a separable flask, 10 mL of 1-propanol and 32.1 g (0.32 mol) of hexylamine (Tokyo Chemical Industry Co., Ltd., purity 99%) are added, and the mixture is heated and stirred at 80 ° C. in an oil bath. Dissolved. After transferring to an ice bath and cooling to an internal temperature of 5 ° C., a solution obtained by dissolving 7.72 mL (0.16 mol) of hydrazine monohydrate (Kanto Chemical Co., Ltd., special grade) in 12 mL of 1-propanol Added to the copper solution and stirred in an ice bath. The molar ratio of copper: hexylamine is 1: 4. Subsequently, it heated and stirred at 90 degreeC in the oil bath. At that time, the reduction reaction accompanied with foaming progressed, and the reaction was completed within 10 minutes. The inner wall of the separable flask had a copper luster and the solution turned dark red. Centrifugation was performed at 4000 rpm (rotation / min) for 1 minute to obtain a solid. The process of further washing the solid with 15 mL of hexane was repeated three times to remove the acid residue, thereby obtaining a copper cake containing copper powder powder having copper luster.

<Evaluation of low temperature conductor>
The copper particle cake obtained in Example 1 (60 parts by mass), terpineol (20 parts by mass) and isobornylcyclohexanol (trade name: Tersolve MTPH, Nippon Terpene Chemical Co., Ltd.) (20 parts by mass) were mixed. Thus, a conductive material was produced.
The obtained conductive material was coated on a polyethylene naphthalate (PEN) film (glass transition point: 155 ° C.) using a bar coater to form a coating layer having a thickness of about 1 μm. The obtained PEN film with a coating layer was placed in a baking furnace and heated to thermally decompose the organic matter on the surface of the copper particles, and the copper particles were sintered together to obtain a metallic copper thin film. Heating was performed by heating to 140 ° C. at a rate of temperature increase of 40 ° C./min and holding for 60 minutes in an atmosphere in which the oxygen concentration in nitrogen was 100 ppm.

  Film resistivity obtained by measuring the volume resistivity of the obtained metallic copper thin film with a four-end needle surface resistance measuring instrument and a non-contact surface / layer cross-sectional shape measurement system (VertScan, Ryoka System Co., Ltd.) Calculated from the thickness. The result was 30 μΩcm, and a conductor having a sufficiently low volume resistivity was formed.

<Evaluation of adhesion>
The adhesion between the metal copper thin film obtained in Example 1 and the substrate (PEN film) was evaluated by a 2 mm square crosscut test in accordance with JIS K5600 (1999). “A” if none of the grids peels off, “B” if the coating peels off at the intersection of the cut, “C” if the coating peels off along the cut line and at the intersection, and more If it was a partial or full peeling, it was set as “D”. The result was “A”, and the adhesion to the substrate was excellent.

  From the above, it was found that the copper-containing particles can be made into a low-temperature conductor and the adhesion between the copper layer and the substrate can be improved by a simple process by the method for producing a conductive laminate of the present invention.

<Comparative Example 1>
A conductive material was prepared and evaluated in the same manner as in Example 1 except that a polyethylene terephthalate (PET) film (glass transition point: 69 ° C.) was used instead of the PEN film used in Example 1. As a result, although the adhesiveness of the conductive material of Comparative Example 1 was “A” and excellent in adhesiveness, conduction was not obtained. When the cross-sectional shape of the thin film obtained using the conductive material of Comparative Example 1 was observed by focused ion beam (FIB) processing observation, the sintered body was buried in the PET film and a conduction path could not be obtained.

Claims (5)

Copper-containing particles having a core particle containing copper and an organic substance containing a substance derived from an alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particle on a base material and dispersion Providing a conductive material containing a medium to form a conductive material-containing layer;
A step of heat-treating the conductive material-containing layer at a temperature within a range of −40 ° C. to + 40 ° C. with respect to the glass transition point of the base material to form a copper layer;
The manufacturing method of the electroconductive laminated body containing this.   The method for producing a conductive laminate according to claim 1, wherein a temperature of the heat treatment is 100 ° C. to 200 ° C.   The manufacturing method of the electroconductive laminated body of Claim 1 or Claim 2 in which the said base material contains a thermoplastic resin.   The electroconductive laminated body obtained by the manufacturing method of the electroconductive laminated body of any one of Claims 1-3. A substrate;
Copper-containing particles having, on the base material, copper-containing core particles, and an organic substance containing a substance derived from alkylamine having 7 or less carbon atoms present on at least a part of the surface of the core particles, and A conductor made of a sintered material of a conductive material containing a dispersion medium, and at least a part of the conductor fused to the substrate;
A conductive laminate comprising: