JP6263630B2 - Conductive film forming composition and conductive film forming method - Google Patents

Description

  The present invention relates to a conductive film forming composition and a conductive film forming method. In more detail, this invention relates to the composition for electrically conductive film formation containing a cupric oxide nanoparticle and an alcohol compound.

As a method for forming a metal film on a base material, a dispersion of metal particles or metal oxide particles is applied to the base material by a printing method, and heated and sintered, so that the electrical property such as wiring on the metal film or the circuit board is obtained. A technique for forming an electrical conduction site is known.
Since the above method is simpler, energy-saving, and resource-saving than conventional high-heat / vacuum processes (sputtering) and plating processes, it is highly anticipated in the development of next-generation electronics.

  For example, Patent Document 1 discloses copper, silver, or indium high-valent compound, linear, branched or cyclic alcohol having 1 to 18 carbon atoms and a group VIII metal catalyst, A composition for forming a conductive film of silver or indium is described. Moreover, the manufacturing method of the electrically conductive film of copper, silver, or indium characterized by forming a film | membrane using the composition for electrically conductive film formation, and carrying out heating reduction then is described. Furthermore, a metal catalyst containing copper oxide, silver oxide or the like as the high valence compound, ethylene glycol, glycerin or the like as the alcohol, and ruthenium, rhodium or iridium as the metal catalyst is described.

JP 2010-121206 A

  On the other hand, in recent years, in order to meet the demand for miniaturization and high functionality of electronic devices, wirings are further miniaturized and highly integrated. Accordingly, it is required that a conductive film exhibiting excellent adhesion and conductivity can be formed on the substrate.

  When the present inventors formed a conductive film using the composition for forming a conductive film of Patent Document 1 and evaluated substrate adhesion and conductivity, it was found that there was room for further improvement.

Then, this invention makes it a subject to provide the composition for electrically conductive film formation which can form the electrically conductive film excellent in base-material adhesiveness and electroconductivity.
Moreover, this invention also makes it a subject to provide the electrically conductive film formation method using the said composition for electrically conductive film formation.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors are a conductive film-forming composition containing cupric oxide nanoparticles and an alcohol compound, and the average of cupric oxide nanoparticles is 1 According to the conductive film-forming composition in which the secondary particle size, average aspect ratio and particle size distribution, and electrical conductivity of the conductive film-forming composition are controlled within a predetermined range, the substrate adhesion and conductivity are excellent. Knowing that a conductive film can be formed, the present invention has been completed.

That is, the present invention provides the following (1) to (10).
(1) A composition for forming a conductive film comprising cupric oxide nanoparticles and an alcohol compound,
The content of the alcohol compound is 20 to 1000 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles,
The average primary particle diameter of cupric oxide nanoparticles is 3 to 25 nm,
The average aspect ratio of the cupric oxide nanoparticles is more than 1.1 and not more than 5.0,
The ratio of particles having a primary particle diameter exceeding 30 nm among cupric oxide nanoparticles is less than 30%, and the electrical conductivity of the conductive film forming composition is 2 to 240 mS / m. Composition.
(2) The composition for electrically conductive film formation as described in (1) which is a nanoparticle by which the cupric oxide nanoparticle was granulated by the wet granulation method.
(3) The composition for forming a conductive film according to (1) or (2), wherein the cupric oxide nanoparticles are nanoparticles generated by thermal decomposition of copper hydroxide.
(4) The composition for forming a conductive film according to any one of (1) to (3), further comprising fine particles of a Group 8-10 heavy metal element and / or a salt of a Group 8-10 heavy metal element. .
(5) The total content of the fine particles of Group 8 to 10 heavy metal element and the salt of Group 8 to 10 heavy metal element is 0.01 to 10 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles. The composition for electrically conductive film formation as described in (4).
(6) Composition for electrically conductive film formation of any one of (1)-(5) whose content of alcohol compound is 50-500 mass parts with respect to 100 mass parts of cupric oxide nanoparticles. .
(7) The composition for electrically conductive film formation of any one of (1)-(6) whose average primary particle diameter of a cupric oxide nanoparticle is 5-20 nm.
(8) The composition for electrically conductive film formation of any one of (1)-(7) whose average primary particle diameter of a cupric oxide nanoparticle is 5-15 nm.
(9) The conductive film-forming composition according to any one of (1) to (8), wherein the cupric oxide nanoparticles have an average aspect ratio of 1.2 or more and 2.0 or less.
(10) A step of applying the conductive film-forming composition according to any one of (1) to (9) on a resin base material to form a conductive film precursor film on the resin base material; A conductive film forming method comprising a step of heating a film precursor film at a temperature of 110 ° C. or higher and 150 ° C. or lower in an inert gas atmosphere to form a conductive film on a resin substrate.

ADVANTAGE OF THE INVENTION According to this invention, the composition for electrically conductive film formation which can form the electrically conductive film excellent in base-material adhesiveness and electroconductivity can be provided.
Moreover, this invention can also provide the electrically conductive film formation method using the said composition for electrically conductive film formation.

  The conductive film formed using the composition for forming a conductive film of the present invention is excellent in substrate adhesion and conductivity, and can meet the recent demand for downsizing and high functionality of electronic devices.

Below, the suitable aspect of the composition for electrically conductive film formation of this invention is demonstrated.
First, the feature point compared with the prior art of this invention is explained in full detail.

  As a characteristic point of the present invention, the content of the alcohol compound is 20 to 1000 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles, and the average primary particle diameter of cupric oxide nanoparticles is 3. The point that the average aspect ratio of cupric oxide nanoparticles is more than 1.1 and 5.0 or less, and the proportion of particles whose primary particle diameter exceeds 30 nm is 30%. The point which is less than% and the electrical conductivity of the composition for electrically conductive film formation are 2-240 mS / m. However, the characteristic points of the present invention are not limited to these.

  In Japanese Patent Application Laid-Open No. 2010-121206 (Patent Document 1) cited as a conventional technique, copper oxide (I), copper oxide (II) or copper nitride (I) is desirable as a high valence compound of copper, and its shape Describes that particles are preferable in that a metal film having high density can be obtained, and that the average particle diameter is desirably 5 nm to 500 μm. However, there is no description regarding the content ratio between the high valence compound of copper and the alcohol, the particle size distribution of the particles, and the average aspect ratio, and there is no description regarding the electrical conductivity of the conductive film forming composition. From the results of Examples and Comparative Examples to be described later, those skilled in the art can understand that the technique described in Patent Document 1 does not necessarily form a conductive film excellent in substrate adhesion and conductivity. Will.

  In the present invention, the content ratio between the cupric oxide nanoparticles and the alcohol compound is specified, and not only the average primary particle size of the cupric oxide nanoparticles but also the particle size distribution and the average aspect ratio are specified. Furthermore, the base-material adhesiveness and electroconductivity of the electrically conductive film obtained become excellent by making electric conductivity of the composition for electrically conductive film into the predetermined range.

[Composition for forming conductive film]
<Cupric oxide nanoparticles>
The composition for electrically conductive film formation of this invention contains a cupric oxide nanoparticle. In the cupric oxide nanoparticles, cupric oxide is reduced to metallic copper by a sintering treatment described later, and constitutes a metal conductor in the conductive film.

  The “cupric oxide” in the present invention is a compound substantially free of unoxidized copper and cuprous oxide, and specifically, a crystal by X-ray diffraction (XRD). In structural analysis, peaks derived from cupric oxide (strong diffraction peaks derived from (002) and (111) planes near 35.5 ° and 38 °, respectively) were detected and derived from cuprous oxide. Peak [strong diffraction peaks derived from (111) plane and (200) plane near 36.4 ° and 42.2 °, respectively] and a peak derived from metallic copper ((111) plane near 43.5 ° It refers to a compound from which a strong diffraction peak derived from] is not detected. The phrase “substantially free of unoxidized copper and cuprous oxide” means that the content of metal copper and cuprous oxide is 1% by mass or less with respect to cupric oxide.

  The average primary particle diameter of cupric oxide nanoparticles is 3 to 25 nm, preferably 5 to 20 nm, and more preferably 5 to 15 nm. Within this range, good dispersion stability can be obtained, and reduction from cupric oxide to metallic copper is easy, and even when sintered at a lower sintering temperature, the conductive film has high conductivity. Can be produced.

  The average primary particle diameter of cupric oxide nanoparticles is the horizontal ferret diameter and vertical of 1000 particles randomly selected from a scanning electron microscope (hereinafter sometimes referred to as “SEM”) image. The ferret diameter is measured, and the measured value of the smaller one is calculated as the primary particle diameter of the particles by arithmetic averaging. However, when the horizontal ferret diameter and the vertical ferret diameter are equal, either measurement value may be used.

  The average aspect ratio of the cupric oxide nanoparticles is more than 1.1 and 5.0 or less, preferably 1.2 or more and 4.0 or less, more preferably 1.2 or more and 3.0 or less, It is more preferably 2.5 or more and 2.5 or less, and still more preferably 1.2 or more and 2.0 or less. The average aspect ratio is obtained by measuring and averaging the aspect ratios of the 1000 particles. When the average aspect ratio is within this range, the base material adhesion and conductivity of the obtained conductive film are more excellent. This is probably because the cupric oxide nanoparticles have a more spherical shape, so that the filling rate is increased and a denser conductive film can be formed.

  The average aspect ratio of cupric oxide nanoparticles is calculated by dividing the smaller measured value of the horizontal ferret diameter and the vertical ferret diameter of 1000 randomly selected particles by the smaller measured value. This is the average of the values obtained.

  Of the cupric oxide nanoparticles (out of the total number of cupric oxide nanoparticles), the proportion of particles having a primary particle diameter exceeding 30 nm is less than 30%, preferably less than 20%, and less than 15%. More preferably, it is less than 10%, more preferably less than 5%. By increasing the proportion of cupric oxide nanoparticles with a smaller primary particle size, the reduction of cupric oxide is more likely to proceed during sintering and the fusion with metallic copper produced by the reduction is also possible. This is because it becomes easier to proceed and the adhesion to the substrate and the conductivity are improved.

As a synthesis method (granulation method) of cupric oxide nanoparticles, there are a dry granulation method in which granulation is performed in a gas phase and a wet granulation method in which granulation is performed in a liquid phase. A wet granulation method is suitable for producing particles having a smaller diameter.
Specifically, as described in JP2003-183024A, etc., a dispersion of copper hydroxide particles is produced by reacting a divalent copper salt such as copper nitrate with a base in a solvent. Then, a method of synthesizing cupric oxide by heating and dehydrating copper hydroxide to obtain a dispersion of cupric oxide nanoparticles is preferable. It can be synthesized at a lower temperature and in a shorter time, and can be easily controlled to have a desired particle shape / distribution.
When granulating by the above reaction, it is preferable to use water or a polyhydric alcohol having a boiling point of 150 to 300 ° C. as a solvent. It is preferable because it does not volatilize during heating and dehydration and is excellent in dispersion stability of the prepared cupric oxide nanoparticles.
In the present invention, it is preferable to remove electrolytes such as nitrate ions and sodium ions from the obtained dispersion of cupric oxide nanoparticles. When manufacturing the composition for forming a conductive film, the cupric oxide nanoparticles are blended in the state of a dispersion, so that if the amount of electrolytic mass brought in is large, the electrical conductivity of the composition for forming a conductive film falls within a predetermined range. This is because it becomes difficult to fit in the substrate, and the base material adhesion and conductivity of the obtained conductive film deteriorate.
As a method for removing the electrolyte from the dispersion of cupric oxide nanoparticles, the dispersion is centrifuged to recover the cupric oxide nanoparticles, and water or a polyhydric alcohol having a boiling point of 150 to 300 ° C. is used. A method of repeating the operation of redispersing in the dispersion medium once or more, preferably 2 times or more, more preferably 3 times or more can be mentioned. Centrifugal force at the time of centrifugation is not particularly limited, preferably 5000 × g or more, preferably 10,000 × g or more, more preferably 20000 × g or more, in order to avoid excessive aggregation of cupric oxide nanoparticles, 30000xg or less is preferable. Further, for example, the electrolyte may be removed by a method such as ultrafiltration or dialysis, but is not limited thereto.
In addition, as the polyhydric alcohol having a boiling point of 150 to 300 ° C., an alcohol compound or a solvent that can be used as a solvent may be used.

<Alcohol compound>
The composition for electrically conductive film formation of this invention contains an alcohol compound. The alcohol compound functions as a reducing agent that reduces cupric oxide of the cupric oxide nanoparticles to metallic copper.

  Specific examples of the alcohol compound include methanol, ethanol, propanol, 2-propanol, allyl alcohol, butanol, 2-butanol, pentanol, 2-pentanol, 3-pentanol, cyclopentanol, hexanol, 2-hexanol, 3-hexanol, cyclohexanol, heptanol, 2-heptanol, 3-heptanol, 4-heptanol, cycloheptanol, octanol, 2-octanol, 3-octanol, 4-octanol, cyclooctanol, nonanol, 2- Nonanol, 3,5,5-trimethyl-1-hexanol, 3-methyl-3-octanol, 3-ethyl-2,2-dimethyl-3-pentanol, 2,6-dimethyl-4-heptanol, decanol, 2 -De Diol, 3,7-dimethyl-1-octanol, 3,7-dimethyl-3-octanol, undecanol, dodecanol, 2-dodecanol, 2-butyl-1-octanol, tridecanol, tetradecanol, 2-tetradecanol, Monovalent alcohols such as pentadecanol, hexadecanol, 2-hexadecanol, heptadecanol, octadecanol, 1-phenethyl alcohol, 2-phenethyl alcohol; ethylene glycol, 1,3-propanediol, 1, 2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,5-hexanediol, 1,6 -Hexanediol, 2,5-hexanediol, 1,7-hept Diol, 1,2-octanediol, 1,8-octanediol, 1,3-nonanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 2,7-dimethyl- 3,6-octanediol, 2,2-dibutyl-1,3-propanediol, 1,2-dodecanediol, 1,12-dodecanediol, 1,2-tetradecanediol, 1,14-tetradecanediol, 2, 2,4-trimethyl-1,3-pentanediol, 2,4-pentanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1-hydroxymethyl-2- (2-hydroxyethyl) cyclohexane 1-hydroxy-2- (3-hydroxypropyl) cyclohexane, 1-hydroxy-2- (2 -Hydroxyethyl) cyclohexane, 1-hydroxymethyl-2- (2-hydroxyethyl) benzene, 1-hydroxymethyl-2- (3-hydroxypropyl) benzene, 1-hydroxy-2- (2-hydroxyethyl) benzene, Divalent alcohols such as 1,2-benzyldimethylol, 1,3-benzyldimethylol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol Glycerin (propane-1,2,3-triol), butane-1,2,4-triol, hexane-1,2,6-triol, 3-methylpentane-1,3,5-triol, trimethylolpropane (2- (hydroxymethyl) Trivalent alcohols such as 2-ethylpropane-1,3-diol); cyclooctane-1,3,5,7-tetraol, pentaerythritol (2,2-bis (hydroxymethyl) -1,3-propane) Diols) and the like.

  The alcohol compound is not particularly limited as long as it is a compound having one or more alcoholic hydroxy groups in the molecule, but a polyhydric alcohol having two or more alcoholic hydroxy groups in the molecule is preferred, and a divalent or trivalent alcohol is preferred. More preferred is trivalent alcohol.

  The alcohol compound preferably has a boiling point of 180 ° C. or higher, more preferably 230 ° C. or higher, and further preferably 250 ° C. or higher.

  When a polyhydric alcohol having a boiling point of 180 ° C. or higher is used, the polyhydric alcohol remains in the film even during the sintering process of the cupric oxide nanoparticles, and the cupric oxide can be sufficiently reduced to metallic copper. The resulting conductive film has good conductivity, and when a polyhydric alcohol having a boiling point of 250 ° C. or higher is used, the substrate adhesion is further improved. Examples of the polyhydric alcohol having a boiling point of 180 ° C. or higher include ethylene glycol (boiling point 197 ° C., divalent), 1,4-butanediol (boiling point 230 ° C., divalent), 1,6-hexanediol (boiling point 250 ° C., Dimethyl), trimethylolpropane (boiling point 250 ° C. or higher, trivalent), and the like. Among these, trimethylolpropane is particularly preferable.

<Particles of Group 8-10 Heavy Metal Element and / or Salt of Group 8-10 Heavy Metal Element>
The composition for forming a conductive film of the present invention may contain fine particles of a Group 8-10 heavy metal element and / or a salt of a Group 8-10 heavy metal element. In other words, fine particles and / or salts containing at least one metal element selected from the group consisting of groups 8 to 10 of the periodic table may be included.

<< Group 8-10 heavy metal fine particles >>
As the fine particles of Group 8-10 heavy metal elements (hereinafter sometimes referred to as “heavy metal fine particles”), specifically, iron (Fe), cobalt (Co), nickel (Ni), rubidium (Ru), rhodium ( Rh), palladium (Pd), osmium (Os), iridium (Ir), fine particles made of a simple substance or an alloy of group 8-10 heavy metal elements such as platinum (Pt). Examples of the alloy include ruthenium-platinum alloy and silver-palladium alloy. As the heavy metal fine particles, fine particles of palladium or platinum are preferable. The size of the heavy metal fine particles is not particularly limited, but is preferably 1 nm to 50 nm, and more preferably 1 nm to 10 nm. By using heavy metal fine particles having a small particle diameter, the surface area is increased and the activity of the copper oxide reduction reaction is improved.

<Group 8-10 heavy metal element salt>
Specific examples of salts of Group 8-10 heavy metal elements (hereinafter sometimes referred to as “heavy metal salts”) include ruthenium trichloride, ruthenium tribromide, rhodium trichloride, iridium trichloride, sodium hexachloroiridate, Palladium dichloride, potassium tetrachloroparadate, platinum dichloride, potassium tetrachloroplatinate, halide salts such as nickel dichloride, iron trichloride, cobalt trichloride, acetates such as ruthenium acetate, rhodium acetate, palladium acetate, Ruthenium trifluoroacetate, rhodium trifluoroacetate, palladium trifluoroacetate, etc., sulfates such as ferrous sulfate, ruthenium nitrate, rhodium nitrate, cobalt nitrate, nickel nitrates such as nickel nitrate, cobalt carbonate, nickel carbonate Such as carbonates, cobalt hydroxide, nickel hydroxide, etc. Oxide, tri (acetylacetonato) ruthenium, di (acetylacetonato) can be exemplified nickel, di (acetylacetonato) acetylacetonate salts such as palladium or the like. Of these, palladium or platinum salts are preferred.

<Polymer compound>
The composition for forming a conductive film of the present invention may contain a polymer compound.
Examples of the polymer compound include poly-N-vinyl compounds such as polyvinyl pyrrolidone and polyvinyl caprolactone, polyurethane, cellulose compounds and derivatives thereof, epoxy compounds, polyester compounds, chlorinated polyolefins, thermoplastic resins such as polyacryl compounds, heat A curable resin can be used. These polymer compounds have different effects, but all have a function as a binder and a function as a reducing agent. Among these, polyvinylpyrrolidone is preferable because it has a good balance between the binder effect and the reducing agent effect.

<solvent>
The composition for forming a conductive film of the present invention may contain a solvent.
Examples of the solvent include methanol, ethanol, propanol, 2-propanol, allyl alcohol, butanol, 2-butanol, pentanol, 2-pentanol, 3-pentanol, cyclopentanol, hexanol, 2-hexanol, 3- Alcohol solvents such as hexanol, cyclohexanol, ether solvents such as diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dioxane, triglyme, tetraglyme, methyl acetate, butyl acetate, benzyl benzoate , Ester solvents such as dimethyl carbonate, ethylene carbonate, γ-butyrolactone, caprolactone, benzene, toluene, ethyl Hydrocarbon solvents such as benzene, tetralin, hexane, octane, cyclohexane, halogenated hydrocarbon solvents such as dichloromethane, trichloroethane, chlorobenzene, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone (N -Methyl-2-pyrrolidone), amides such as hexamethylphosphoric triamide, N, N-dimethylimidazolidinone or cyclic amide solvents, sulfone solvents such as dimethylsulfone, sulfoxide solvents such as dimethylsulfoxide, water, etc. Is mentioned. A solvent can be used individually by 1 type or in combination of 2 or more types.
As the solvent, those having a boiling point of less than 180 ° C. are preferable. This is because the solvent can be sufficiently removed from the composition for forming a conductive film by applying the composition for forming a conductive film on a substrate, followed by drying, heating, or light irradiation.
As the solvent, water, an alcohol solvent, an amide solvent or a mixed solvent of two or more of these are preferable, and water and alcohol having a boiling point of less than 180 ° C. are preferable because the dispersibility of the cupric oxide nanoparticles is good. A mixed solvent with a system solvent is preferred. The mixing ratio of water and an alcohol solvent having a boiling point of less than 180 ° C. is not particularly limited, but is preferably a volume ratio of water / alcohol solvent = 1/1.

<Other ingredients>
In addition to cupric oxide nanoparticles, alcohol compounds, heavy metal fine particles and / or heavy metal salts, polymer compounds and solvents, the conductive film-forming composition of the present invention may contain other components.

  For example, the composition for forming a conductive film may contain a surfactant. Surfactant plays the role which improves the dispersibility of a cupric oxide nanoparticle. The type of the surfactant is not particularly limited, and examples thereof include an anionic surfactant, a cationic surfactant, a nonionic surfactant, a fluorine surfactant, and an amphoteric surfactant. These surfactants can be used alone or in combination of two or more.

[Method for producing composition for forming conductive film]
The conductive film-forming composition of the present invention comprises cupric oxide nanoparticles, an alcohol compound, optionally heavy metal fine particles and / or heavy metal salts, optionally a polymer compound, optionally a solvent, and optionally other It can be produced by mixing the ingredients.

  The electrical conductivity of the composition for forming a conductive film of the present invention is 2 to 240 mS / m, preferably 2 to 130 mS / m, and more preferably 2 to 50 mS / m. Within this range, the substrate adhesion and conductivity of the conductive film will be more excellent.

In order to make the electric conductivity within the above range, it is desirable to remove the electrolyte from the components blended in the conductive film forming composition. For example, cupric oxide nanoparticles are usually handled in the state of a dispersion dispersed in a dispersion medium such as water, alcohol, or a mixture thereof, but nitrate ions that are impurities when cupric oxide nanoparticles are synthesized. It is desirable to remove sodium ions as much as possible. As a method for removing nitrate ions and sodium ions, for example, the operation of precipitating cupric oxide nanoparticles by centrifugation, replacing the dispersion medium with one not containing these ions, and redispersing is preferably performed once or more. Is a method of repeating 2 times or more, more preferably 3 times or more.
In addition, it is preferable to measure the electrical conductivity of the composition for electrically conductive film formation using an electrical conductivity meter.

  Content of the alcohol compound in the composition for electrically conductive film formation of this invention is 20-1000 mass parts with respect to 100 mass parts of cupric oxide nanoparticles, 50-500 mass parts is preferable, 50-300 Part by mass is more preferable. Within this range, at least one of the substrate adhesion and conductivity of the conductive film is more excellent.

  The total content of heavy metal fine particles and heavy metal salt in the composition for forming a conductive film of the present invention is not particularly limited, but is preferably 0.005 to 50 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles. 0.01-10 parts by mass is more preferable, 0.05-10 parts by mass is further preferable, 0.1-10 parts by mass is more preferable, 0.5-10 parts by mass is still more preferable, 0.5- 5 parts by mass is even more preferable. Within this range, at least one of the substrate adhesion and conductivity of the conductive film is further improved.

  When the composition for electrically conductive film formation of this invention contains a high molecular compound, content in the composition for electrically conductive film formation is although it does not specifically limit, It is 0.00 with respect to 100 mass parts of cupric oxide nanoparticles. 001 to 5 parts by mass is preferable, 0.001 to 3 parts by mass is more preferable, 0.001 to 1 part by mass is further preferable, and 0.001 to 0.1 part by mass is even more preferable. Within this range, at least one of the substrate adhesion and conductivity of the conductive film is further improved.

  When the composition for electrically conductive film formation of this invention contains a solvent, content in the composition for electrically conductive film formation is although it does not specifically limit, 1-10000 mass parts with respect to 100 mass parts of cupric oxide nanoparticles Is preferable, 10-1000 mass parts is more preferable, and 10-500 mass parts is further more preferable.

  The viscosity of the composition for forming a conductive film is preferably adjusted to a viscosity suitable for printing applications such as inkjet and screen printing. When performing inkjet discharge, 1-50 cP is preferable and 1-40 cP is more preferable. When performing screen printing, 1000-100000 cP is preferable and 10000-80000 cP is more preferable.

  The preparation method in particular of the composition for electrically conductive film formation is not restrict | limited, A well-known method is employable. For example, cupric oxide nanoparticles (dispersion), an alcohol compound, optionally heavy metal fine particles and / or heavy metal salts, optionally a polymer compound, optionally a solvent, and optionally other components were added. Thereafter, the composition can be obtained by dispersing the components by a known means such as an ultrasonic method (for example, treatment with an ultrasonic homogenizer), a mixer method, a three-roll method, or a ball mill method.

[Method for producing conductive film]
The method for producing a conductive film on a substrate using the composition for forming a conductive film of the present invention comprises at least a coating film forming step and a sintering step. Furthermore, if desired, a drying step may be provided.

<Coating film formation process>
A coating-film formation process is a process of providing the composition for electrically conductive film formation of this invention on a base material, and forming a coating film. By this step, a coating film before being subjected to the sintering treatment in the sintering step is obtained. You may perform the drying process which dries the coating film provided on the base material before performing a sintering process.

A well-known thing can be used as a base material used at this process. Examples of the material used for the substrate include resin, paper, glass, silicon-based semiconductor, compound semiconductor, metal oxide, metal nitride, wood, or a composite thereof.
More specifically, low density polyethylene resin, high density polyethylene resin, ABS resin, acrylic resin, styrene resin, vinyl chloride resin, polyester resin (polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene) Resin base materials such as terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN)), polyacetal resin, polysulfone resin, polyetherimide resin, polyetherketone resin, polyimide resin, cellulose derivative; Uncoated printing paper, finely coated printing paper, coated printing paper (art paper, coated paper), special printing paper, copy paper (PPC paper), unbleached wrapping paper (double kraft paper for heavy bags, bilateral Kraft paper), bleached wrapping paper (bleached kraft paper, pure white roll paper), Paper substrates such as cartons, chip balls, and cardboard; glass substrates such as soda glass, borosilicate glass, silica glass, and quartz glass; silicon-based semiconductor substrates such as amorphous silicon and polysilicon; CdS, CdTe, GaAs, and the like Compound semiconductor substrate; metal substrate such as copper plate, iron plate, aluminum plate; alumina, sapphire, zirconia, titania, yttrium oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), Nesa (oxidation) Tin), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), aluminum nitride base material, other inorganic groups such as silicon carbide Materials: Paper-phenol resin, paper-epoxy resin, paper-polyester tree Resin composites, glass cloth - - Paper equal epoxy resin (glass epoxy resin), glass cloth - polyimide resin, glass cloth - Glass and fluorine resin - composite groups of the resin composites like materials and the like. Among these, a resin base material is preferably used.

The method for applying the conductive film forming composition onto the substrate is not particularly limited, and a known method can be adopted. For example, coating methods such as a screen printing method, a dip coating method, a spray coating method, a spin coating method, and an ink jet method can be used.
The shape of application is not particularly limited, and may be a surface covering the entire surface of the substrate or a pattern (for example, a wiring or a dot).
The coating amount of the composition for forming a conductive film on the substrate may be appropriately adjusted according to the desired thickness of the conductive film, but the thickness (thickness) of the coating film is usually 0.01 to 1000 μm. Is preferable, 0.1-100 micrometers is more preferable, 0.1-50 micrometers is further more preferable, and 1-30 micrometers is still more preferable.

<Drying process>
This step is a step of performing drying treatment on the formed coating film and removing at least a part of the solvent contained in the composition for forming a conductive film. If desired, this step can be performed after the above-described coating film forming step and before the sintering step described later.

  By removing the remaining solvent in the drying step, the generation of minute cracks and voids due to the vaporization and expansion of the solvent can be suppressed in the sintering step described later. This is preferable in terms of adhesion between the film and the substrate.

  A drying process can be performed by heating using a warm air dryer etc., and as drying temperature, 50 to 100 degreeC is preferable and 70-90 degreeC is more preferable. In the present invention, the drying treatment may be performed in either a non-oxidizing atmosphere or an oxidizing atmosphere. Examples of the non-oxidizing atmosphere include an inert gas atmosphere such as nitrogen and argon, and a reducing gas atmosphere such as hydrogen. Examples of the oxidizing atmosphere include an air atmosphere and an oxygen atmosphere.

<Sintering process>
This step is a step in which a conductive film is formed by performing a heat treatment and / or a light irradiation treatment on the coating film formed on the substrate (or the dried coating film when the drying process is performed).
By performing the heat treatment and / or the light irradiation treatment, the copper oxide of the cupric oxide nanoparticles is reduced to produce metallic copper, and the reduction of the produced metallic copper particles and metallic silver particles can be performed. Promoted to form a metal conductor in the metal conductive film.

The heating temperature is not particularly limited in that a conductive film that is superior in conductivity can be formed in a short time, but the heating temperature is preferably 110 to 180 ° C, more preferably 110 to 150 ° C. The heating time is preferably 5 to 120 minutes and more preferably 5 to 30 minutes.
The heating means is not particularly limited, and known heating means such as an oven and a hot plate can be used.
In the present invention, the conductive film can be formed by heat treatment at a relatively low temperature, and therefore, the process cost is low.

Unlike the heat treatment described above, the light irradiation treatment can reduce and sinter to metallic copper by irradiating light on the portion to which the coating film is applied at room temperature for a short time, and heating for a long time. The base material is not deteriorated by, and the adhesion of the conductive film to the base material becomes better.
The light source used in the light irradiation treatment is not particularly limited, and examples thereof include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Further, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are also used.
Specific examples of preferred embodiments include scanning exposure with an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, and infrared lamp exposure.
The light irradiation is preferably light irradiation with a flash lamp, and more preferably pulsed light irradiation with a flash lamp. Irradiation with high-energy pulsed light can concentrate and heat the surface of the portion to which the coating film has been applied in a very short time, so that the influence of heat on the substrate can be extremely reduced.
The irradiation energy of the pulse light is preferably 1~100J / cm ^2, more preferably 1~30J / cm ^2, preferably 1μ seconds ~100m sec as a pulse width, and more preferably 10μ sec ~10m seconds. The irradiation time of the pulsed light is preferably 1 to 100 milliseconds, more preferably 1 to 50 milliseconds, and further preferably 1 to 20 milliseconds.
In addition, when a light irradiation process is implemented, it is estimated that the cupric oxide nanoparticle absorbs light and works as a photothermal conversion substance that converts it into heat, and plays a role of transferring heat into the coating film.

  The heat treatment and the light irradiation treatment may be performed alone or both may be performed simultaneously. Moreover, after performing one process, you may perform the other process further.

  In the present invention, the heat treatment and the light irradiation treatment may be performed in either a non-oxidizing atmosphere or an oxidizing atmosphere. Examples of the non-oxidizing atmosphere include an inert gas atmosphere such as nitrogen and argon, and a reducing gas atmosphere such as hydrogen. Examples of the oxidizing atmosphere include an air atmosphere and an oxygen atmosphere.

[Conductive film]
By conducting the above-described method for producing a conductive film using the conductive film forming composition of the present invention, a conductive film containing a metal conductor substantially made of metallic copper is produced.
The film thickness (thickness) of the conductive film is not particularly limited, and an optimum film thickness is appropriately selected according to the application used. For example, from the point of use of an organic thin film transistor electrode, 10 to 1000 nm is preferable, 10 to 500 nm is more preferable, 20 to 200 nm is further preferable, and 50 to 150 nm is even more preferable. Further, for example, from the viewpoint of printed wiring board use, 0.01 to 1000 μm is preferable, 0.1 to 100 μm is more preferable, 0.1 to 50 μm is further preferable, and 1 to 30 μm is even more preferable.
The film thickness is a value (average value) obtained by measuring three or more thicknesses at arbitrary points on the conductive film and arithmetically averaging the values.

The conductive film may be provided on the entire surface of the base material or in a pattern. The patterned conductive film is useful as a conductor wiring (wiring) such as a printed wiring board.
As a method of obtaining a patterned conductive film, the above-mentioned composition for forming a conductive film was applied to a substrate in a pattern, and the above heat treatment and / or light irradiation treatment was performed, or the entire surface of the substrate was provided. For example, a method of etching the conductive film in a pattern may be used.
The etching method is not particularly limited, and a known subtractive method, semi-additive method, or the like can be employed.

  When a patterned conductive film is configured as a multilayer wiring board, an insulating layer (insulating resin layer, interlayer insulating film, solder resist) is further laminated on the surface of the patterned conductive film, and further wiring (metal) is formed on the surface. Pattern) may be formed.

The material of the insulating film is not particularly limited. For example, epoxy resin, glass epoxy resin, aramid resin, crystalline polyolefin resin, amorphous polyolefin resin, fluorine-containing resin (polytetrafluoroethylene, perfluorinated polyimide, perfluorinated) Amorphous resin), polyimide resin, polyether sulfone resin, polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal resin, and the like.
Among these, from the viewpoints of adhesion, dimensional stability, heat resistance, electrical insulation, and the like, it is preferable to contain an epoxy resin, a polyimide resin, or a liquid crystal resin, and more preferably an epoxy resin. Specifically, ABF TECH-13, ABF GX-13, etc. are mentioned.

  The solder resist, which is a kind of insulating layer material used for wiring protection, is described in detail in, for example, Japanese Patent Application Laid-Open No. 10-204150, Japanese Patent Application Laid-Open No. 2003-222993, and the like. These materials can also be applied to the present invention if desired. A commercially available solder resist may be used, and specific examples include PFR800 manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR4000 (trade name), SR7200G manufactured by Hitachi Chemical Co., Ltd., and the like.

  The base material (base material with a conductive film) having the conductive film obtained above can be used for various applications. For example, a printed wiring board, TFT, FPC, RFID, etc. are mentioned.

[Synthesis of cupric oxide nanoparticles]
Table 1 shows the granulation materials, granulation raw materials, reaction conditions, and purification methods used in Synthesis Examples 1-18.

<Synthesis Example 1>
Copper nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in purified water to prepare a 0.1 mol / L aqueous copper nitrate solution. Next, sodium hydroxide was dissolved in purified water to prepare a 0.2 mol / L sodium hydroxide aqueous solution.
100 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) was placed in a 200 mL heat-resistant glass flask and heated to 90 ° C. in an oil bath. To this flask, 20 mL each of the prepared 0.1 mol / L aqueous copper nitrate solution and 0.2 mol / L aqueous sodium hydroxide solution was added within 10 seconds and heated at 90 ° C. for 10 minutes. Nanoparticles were obtained as a dispersion. This dispersion contains sodium ions and nitrate ions in addition to cupric oxide nanoparticles.
The obtained dispersion was centrifuged at 20000 × g for 30 minutes, and the precipitate was redispersed in water. This centrifugation-redispersion process was repeated three times. By this treatment, sodium ions and nitrate ions were removed from the cupric oxide nanoparticle dispersion to obtain a cupric oxide dispersion having a particle concentration of 20% by mass.
To the obtained cupric oxide nanoparticle dispersion liquid, zirconia beads having the same mass as the dispersoid were added, and stirred and dispersed with Awatori Rentaro for 3 minutes to obtain a cupric oxide nanoparticle dispersion liquid.
By XRD analysis, strong diffraction peaks derived from the (002) and (111) planes were observed near 35.5 ° and 38 °, respectively, and it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the proportion of particles having a primary particle size of 30 m or more was 2%. Met.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 1”.

<Synthesis Example 2>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 0.05 mol aqueous copper nitrate solution (20 mL) and 0.1 mol / L aqueous sodium hydroxide solution (20 mL) Was synthesized in the same manner as the cupric oxide nanoparticle 1 except that a cupric oxide nanoparticle dispersion was obtained.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 3 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 2”.

<Synthesis Example 3>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 3 mol / mL aqueous copper nitrate solution (20 mL) and 6 mol / L aqueous sodium hydroxide solution (20 mL) were used. Except for the point used, it was synthesized in the same manner as cupric oxide nanoparticle 1 to obtain a cupric oxide nanoparticle dispersion.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 8 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 3”.

<Synthesis Example 4>
It was synthesized in the same manner as cupric oxide nanoparticle 1 except that a mixed solvent (100 mL) in which ethylene glycol and water were mixed at a volume ratio of 1: 1 was used instead of ethylene glycol (100 mL). A cupric nanoparticle dispersion was obtained.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 9 nm, the average aspect ratio was 2.3, and the proportion of particles having a primary particle size of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 4”.

<Synthesis Example 5>
A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticle 1 except that water (100 mL) was used instead of ethylene glycol (100 mL).
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 17 nm, the average aspect ratio was 3.8, and the proportion of particles having a primary particle size of 30 nm or more was 15%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 5”.

<Synthesis Example 6>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 0.5 mol aqueous copper nitrate solution (20 mL) and 1.0 mol / L aqueous sodium hydroxide solution (20 mL) Was synthesized in the same manner as cupric oxide nanoparticle 1 except that water (100 mL) was used instead of ethylene glycol (100 mL), and cupric oxide nanoparticle dispersion was obtained. Obtained.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 24 nm, the average aspect ratio was 4.8, and the proportion of particles having a primary particle size of 30 nm or more was 20%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 6”.

<Synthesis Example 7>
The reaction conditions were synthesized in the same manner as cupric oxide nanoparticles 1 except that the reaction conditions were changed from heating at 90 ° C. for 10 minutes to heating at 100 ° C. for 10 minutes to obtain a cupric oxide nanoparticle dispersion. It was.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 4 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 7”.

<Synthesis Example 8>
Instead of 0.1 mol / L copper nitrate aqueous solution (20 mL) and 0.2 mol / L sodium hydroxide aqueous solution (20 mL), 0.5 mol / L copper nitrate aqueous solution (20 mL) and 1.0 mol / L sodium hydroxide aqueous solution ( 20 mL), and the reaction conditions were changed from 90 ° C. for 10 minutes to 100 ° C. for 10 minutes. A dicopper nanoparticle dispersion was obtained.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 8 nm, the average aspect ratio was 2.0, and the proportion of particles having a primary particle size of 30 nm or more was 10%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 8”.

<Synthesis Example 9>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 0.9 mol / L aqueous copper nitrate solution (20 mL) and 1.8 mol / L aqueous sodium hydroxide solution ( 20 mL), and the reaction conditions were changed from 90 ° C. for 10 minutes to 100 ° C. for 10 minutes. A dicopper nanoparticle dispersion was obtained.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 15 nm, the average aspect ratio was 2.4, and the ratio of particles having a primary particle diameter of 30 nm or more was 30%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 9”.

<Synthesis Example 10>
A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticles 1 except that the number of repetitions of centrifugation at 20000 × G for 30 minutes was changed from 3 to 2 times. It was.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 10”.

<Synthesis Example 11>
A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticle 1 except that the number of repetitions of centrifugation at 20000 × G for 30 minutes was changed from 3 to 1. It was.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 11”.

<Synthesis Example 12>
A cupric oxide nanoparticle dispersion was synthesized in the same manner as cupric oxide nanoparticles 1 except that centrifugation at 20000 × G for 30 minutes was changed to centrifugation at 5000 × G for 30 minutes. Got.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 12”.

<Synthesis Example 13>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 10 mol / mL aqueous copper nitrate solution (20 mL) and 20 mol / L aqueous sodium hydroxide solution (20 mL) were used. Except for the point used, it was synthesized in the same manner as cupric oxide nanoparticle 1 to obtain a cupric oxide nanoparticle dispersion.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 49 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 90%. It was super.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 13”.

<Synthesis Example 14>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 5.0 mol / mL aqueous copper nitrate solution (20 mL) and 10 mol / L aqueous sodium hydroxide solution (20 mL) ) Was used in the same manner as in cupric oxide nanoparticles 1 to obtain a cupric oxide nanoparticle dispersion.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 30 nm, the average aspect ratio was 1.5, and the proportion of particles having a primary particle diameter of 30 nm or more was 40%. Met.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 14”.

<Synthesis Example 15>
The dispersion of cupric oxide nanoparticles 1 and the dispersion of cupric oxide nanoparticles 11 are mixed at a mass ratio of cupric oxide nanoparticles 1 / cupric oxide nanoparticles 11 = 1/1, and oxidized. A dispersion of cupric nanoparticles was obtained.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 22 nm, the average aspect ratio was 1.5, and the proportion of particles having a primary particle size of 30 nm or more was 50%. It was.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 15”.

<Synthesis Example 16>
Instead of 0.1 mol / L aqueous copper nitrate solution (20 mL) and 0.2 mol / L aqueous sodium hydroxide solution (20 mL), 10 mol / mL aqueous copper nitrate solution (20 mL) and 20 mol / L aqueous sodium hydroxide solution (20 mL) were used. A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticle 1, except that water (100 mL) was used instead of ethylene glycol (100 mL). It was.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle size of the obtained cupric oxide nanoparticles was 15 nm, the average aspect ratio was 8.0, and the proportion of particles having a primary particle size of 30 nm or more was 20%. Met.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 16”.

<Synthesis Example 17>
A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticles 1 except that no centrifugation was performed at 20000 × g for 30 minutes.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 17”.

<Synthesis Example 18>
A cupric oxide nanoparticle dispersion was obtained by synthesizing in the same manner as cupric oxide nanoparticle 1 except that the number of repetitions of centrifugation at 20000 × G for 30 minutes was changed from 3 to 10 times. It was.
By XRD analysis, it was confirmed that the obtained nanoparticles were cupric oxide.
As a result of TEM observation, the average primary particle diameter of the obtained cupric oxide nanoparticles was 5 nm, the average aspect ratio was 1.5, and the ratio of particles having a primary particle diameter of 30 nm or more was 5%. Was less than.
The cupric oxide nanoparticles thus obtained are hereinafter referred to as “cupric oxide nanoparticles 18”.

[Example 1]
<Preparation of composition for forming conductive film>
Cupric oxide nanoparticles 1 (obtained in Synthesis Example 1, 100 parts by mass), trimethylolpropane (Tokyo Chemical Industry Co., Ltd., 200 parts by mass), palladium acetate (Tokyo Chemical Industry Co., Ltd., 1 part by mass) ) And the mixture was processed for 5 minutes with a rotation and revolution mixer (manufactured by THINKY, manufactured by Awatori Netaro ARE-310) to obtain a composition for forming a conductive film. Table 2 shows each component of the composition for forming a conductive film and its content.
The electrical conductivity of the obtained composition for forming a conductive film was measured with an electrical conductivity meter (CM-30R, manufactured by Toa DK Corporation). The electric conductivity [mS / m] is shown in the electric conductivity column of Table 2.
Hereinafter, this composition for forming a conductive film is referred to as “Composition 1 for forming a conductive film”.

<Formation of conductive film>
On a PET substrate (Teijin ^(R) Tetron ^(R) film K, thickness 50 μm, manufactured by Teijin DuPont Films Ltd.), the conductive film forming composition 1 was applied in a stripe shape (L / S = 1 mm / 1 mm), Then, the coating film by which the electrically conductive film precursor layer was pattern-printed was obtained by making it dry at 100 degreeC for 10 minute (s). Then, the electrically conductive film was formed on the PET base material by heating at 150 degreeC for 1 hour on the hotplate which controlled the oxygen concentration to 50 ppm or less.

<Performance evaluation of conductive film>
<< Base material adhesion >>
A cellophane tape (width 24 mm) manufactured by Nichiban Co., Ltd. was adhered to the obtained conductive film and then peeled off. The appearance of the conductive film after peeling was visually observed to evaluate the adhesion. The evaluation criteria are as follows. In practice, it is preferably 3 or more.
“5”: Adhesion of the conductive film is not observed on the tape, and peeling at the interface between the conductive film and the substrate is not observed.
“4”: The conductive film is slightly attached to the tape, but peeling at the interface between the conductive film and the substrate is not observed.
"3": Adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of less than 5% at the interface between the conductive film and the substrate.
“2”: Adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of 5% or more and less than 50% at the interface between the conductive film and the substrate.
"1": Adhesion of the conductive film is clearly seen on the tape, and the peeled area is seen in the range of 50% or more at the interface between the conductive film and the substrate.

"Conductivity"
About the obtained electrically conductive film, volume resistivity was measured using the four-probe method resistivity meter, and electroconductivity was evaluated. The evaluation criteria are as follows.
“5”: Volume resistivity is less than 50 μΩ · cm “4”: Volume resistivity is 50 μΩ · cm or more and less than 100 μΩ · cm “3”: Volume resistivity is 100 μΩ · cm or more and less than 300 μΩ · cm “2”: Volume resistance Rate is 300 μΩ · cm or more and less than 1000 μΩ · cm “1”: Volume resistivity is 1000 μΩ · cm or more

  In Table 2, the content of each component of the composition for forming a conductive film was expressed in parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles.

[Examples 2 to 9]
Examples 2-9 are replaced with cupric oxide nanoparticles 1 (Example 1) as cupric oxide nanoparticles, except that cupric oxide nanoparticles 2-9 were used, respectively. A conductive film forming composition was prepared in the same manner as in Example 1, a conductive film was formed, and the conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 10 to 13]
In Examples 10 to 13, the content of the alcohol compound (trimethylolpropane) is changed from 200 parts by mass (Example 1) to 50 parts by mass (Example 10), 500 parts by mass (Example 11), and 1000 parts by mass. Except for the point changed to (Example 12) or 2000 parts by mass (Example 13), a conductive film-forming composition was prepared in the same manner as in Example 1, a conductive film was formed, and the conductive film was evaluated. .
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 14 to 19]
In Examples 14 to 19, the content of the fine particles of Group 8 to 10 heavy metal element or heavy metal salt (palladium acetate) is changed from 1 part by weight (Example 1) to 5 parts by weight (Example 14), 10 parts by weight. (Example 15), 20 parts by mass (Example 16), 0.5 parts by mass (Example 17), 0.05 parts by mass (Example 18) or 0.008 parts by mass (Example 19) The electrical conductivity of the composition for forming a conductive film is 17 mS / m (Example 14), 26 mS / m (Example 15), 32 mS / m (Example 16), 8 mS / m (Example 17), Except for the point being 6 mS / m (Example 18) or 5 mS / m (Example 19), a conductive film-forming composition was prepared in the same manner as in Example 1 to form a conductive film. evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 20 to 24]
Examples 20-24 do not contain fine particles or heavy metal salts of Group 8-10 heavy metal elements (Example 20), or palladium acetate (Example 1) as fine particles or salts of Group 8-10 heavy metal elements. Instead, palladium trifluoroacetate (Example 21), palladium fine particles (Example 22), platinum fine particles (Example 23) or ruthenium fine particles (Example 24) were used, and the electrical properties of the conductive film forming composition A conductive film forming composition was prepared in the same manner as in Example 1 except that the conductivity was 4 mS / m (Example 20) and 5 mS / m (Examples 22 to 24), and a conductive film was formed. The conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 25 to 27]
In Examples 25 to 27, instead of trimethylolpropane (Example 1) as an alcohol compound, ethylene glycol (Example 25), 1,4-butanediol (Example 26) or 1,6-hexanediol ( A composition for forming a conductive film was prepared in the same manner as in Example 1 except that Example 27) was used, a conductive film was formed, and the conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 28 to 30]
In Examples 28 to 30, as cupric oxide nanoparticles, instead of cupric oxide nanoparticles 1 (Example 1), cupric oxide nanoparticles 10 (Example 28), cupric oxide nanoparticles were used. 11 (Example 29) or cupric oxide nanoparticles 12 (Example 30), and the electrical conductivity of the composition for forming a conductive film was 46 mS / m (Example 28), 122 mS / m (Example) Except for the point of Example 29) or 240 mS / m, the composition for electrically conductive film formation was prepared like Example 1, the electrically conductive film was formed, and the electrically conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Examples 31 to 33]
In Examples 31 to 33, cupric oxide nanoparticles were used in place of cupric oxide nanoparticles 1 (Example 1) as cupric oxide nanoparticles, and polyvinylpyrrolidone was used as the polymer compound. Of 0.1 part by mass (Example 31), 1 part by mass (Example 32) or 5 parts by mass (Example 33), and the electrical conductivity of the composition for forming a conductive film is 38 mS / m (Implementation) A conductive film-forming composition was prepared, a conductive film was formed, and the conductive film was evaluated in the same manner as in Example 1, except that it was Example 31, 32) or 49 mS / m (Example 33). .
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Comparative Examples 1-4]
In Comparative Examples 1 to 4, except that cupric oxide nanoparticles 13 to 16 (Comparative Examples 1 to 4, respectively) were used instead of cupric oxide nanoparticles 1 as cupric oxide nanoparticles. Then, in the same manner as in Example 1, a composition for forming a conductive film was prepared, a conductive film was formed, and the conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Comparative Example 5]
In Comparative Example 5, cupric oxide nanoparticles were used in place of cupric oxide nanoparticles 1 as cupric oxide nanoparticles, and the electrical conductivity of the conductive film forming composition was 1200 mS / Except for the point being m, a conductive film-forming composition was prepared in the same manner as in Example 1, a conductive film was formed, and the conductive film was evaluated.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

[Comparative Example 6]
In Comparative Example 6, as the cupric oxide nanoparticles, instead of cupric oxide nanoparticles 1, cupric oxide nanoparticles 18 were used, palladium acetate was not contained, and a conductive film forming composition. A conductive film-forming composition was prepared, a conductive film was formed, and the conductive film was evaluated in the same manner as in Example 1, except that the electrical conductivity was 1 mS / m.
The evaluation results of the substrate adhesion and the conductivity are shown in Table 2.

In Table 2, A, B, C and D represent the following components, respectively.
A: Cupric oxide nanoparticles B: Alcohol compound C: Fine particles of group 8-10 heavy metal element and / or salt of group 8-10 heavy metal element D: Polymer compound

[Contrast between Example and Comparative Example]
The conductive films of Examples 1 to 33 were superior in both base material adhesion and conductivity as compared with the conductive films of Comparative Examples 1 to 6.

[Contrast of Examples 1, 2 to 9]
Of the cupric oxide nanoparticles, Example 9 in which the proportion of particles having a primary particle diameter of more than 30 nm is less than 30% and Example 6 in which the ratio of particles is less than 20% is evaluated as “Evaluation of substrate adhesion of conductive film” 4 ”and the evaluation of conductivity was“ 3 ”, which met the practical requirement level.
In Example 5 in which the ratio of the particles having a primary particle diameter exceeding 30 nm among cupric oxide nanoparticles is less than 15%, both the base material adhesion and the conductive evaluation of the conductive film are “4”, The conductivity was superior to Examples 6 and 9.
In Example 8 in which the ratio of particles having a primary particle diameter exceeding 30 nm among cupric oxide nanoparticles is less than 10%, the evaluation of the substrate adhesion of the conductive film was “5”, and the evaluation of conductivity was “ 4 ”, the substrate adhesion and conductivity were superior to those of Examples 6 and 9, and the substrate adhesion was superior to that of Example 5.
In Examples 1 to 4 and 7, in which the ratio of particles having a primary particle diameter exceeding 30 nm among cupric oxide nanoparticles is less than 5%, both the base material adhesion of the conductive film and the evaluation of the conductivity were “5”. It was particularly excellent.

[Comparison of Examples 1 and 10 to 13]
In Example 13 in which the content of the alcohol compound is 2000 parts by mass with respect to 100 parts by mass of the cupric oxide nanoparticles, the evaluation of the substrate adhesion of the conductive film is “3”, and the evaluation of the conductivity is “4”. And met practical requirements.
In Example 12 in which the content of the alcohol compound is 1000 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles, the base material adhesion and conductivity evaluation of the conductive film are both “4”. Compared to 13, the substrate adhesion was excellent.
In Example 11 in which the content of the alcohol compound is 500 parts by mass with respect to 100 parts by mass of the cupric oxide nanoparticles, the evaluation of the adhesion of the conductive film to the base material is “4”, and the evaluation of the conductivity is “5”. The substrate adhesion and conductivity were excellent compared to Example 13, and the conductivity was excellent compared to Example 12.
In Example 1 in which the content of the alcohol compound is 50 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles and 200 parts by mass, the base material adhesion and conductivity of the conductive film are evaluated. Both were “5” and were particularly excellent.

[Comparison between Examples 1 and 14 to 19]
Example 19 in which the total content of the heavy metal fine particles and the heavy metal salt is 0.008 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles is 20 parts by mass, and the base material adhesion of the conductive film is The evaluation of the property was “4” and the evaluation of the conductivity was “3”, which met the practical requirement level.
In Example 18 in which the total content of the heavy metal fine particles and the heavy metal salt was 0.05 parts by mass with respect to 100 parts by mass of the cupric oxide nanoparticles, both the base material adhesion of the conductive film and the evaluation of the conductivity were “ 4 ”and the conductivity was superior to those of Examples 16 and 19.
In Example 15 in which the total content of the heavy metal fine particles and the heavy metal salt was 10 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles, the evaluation of the adhesion of the conductive film to the base material was “4”. The evaluation was “5”, and the conductivity was superior to those of Examples 16, 18 and 19.
Example 17 in which the total content of the heavy metal fine particles and the heavy metal salt is 0.5 parts by mass with respect to 100 parts by mass of cupric oxide nanoparticles, Example 1 that is 1 part by mass, and implementation that is 5 parts by mass In Example 14, the base material adhesion and conductivity evaluation of the conductive film were both “5”, which was particularly excellent.

[Comparison of Examples 1, 20 to 24]
In Example 20, which did not contain heavy metal fine particles and / or heavy metal salt, the substrate adhesion and conductivity evaluation of the conductive film were both “3”, reaching the practical requirement level.
In Example 24 including the ruthenium fine particles as the heavy metal fine particles and / or the heavy metal salt, both the base material adhesion and the conductive evaluation of the conductive film were “3”, and the practical requirement level was reached.
In Example 23 containing platinum fine particles as heavy metal fine particles and / or heavy metal salts, the substrate adhesion evaluation of the conductive film was “3”, and the conductivity evaluation was “4”, compared with Examples 20 and 24. The conductivity was excellent.
Example 22 containing palladium fine particles as heavy metal fine particles and / or heavy metal salt is both “4” in the evaluation of the adhesion of the conductive film to the base material and the conductivity, which is superior to Examples 20 and 24, Compared with Example 23, the substrate adhesion was excellent.
In Example 21 containing heavy metal fine particles and / or palladium trifluoroacetate as a heavy metal salt, the evaluation of the adhesion of the conductive film to the substrate was “5” and the evaluation of conductivity was “4”. The substrate adhesion was superior, and the substrate adhesion and conductivity were superior to Examples 20 and 23.
In Example 1 containing heavy metal fine particles and / or palladium acetate as a heavy metal salt, both the base material adhesion and the conductive evaluation of the conductive film were “5”, which was particularly excellent.

[Contrast of Examples 1, 25 to 27]
In Example 25 containing ethylene glycol (boiling point 197 ° C.) as the alcohol compound, the base material adhesion and the conductive evaluation of the conductive film were both “3”, and the practical requirement level was reached.
In Example 26 containing 1,4-butanediol (boiling point 230 ° C.) as an alcohol compound, the evaluation of the adhesion of the conductive film to the substrate was “3”, the evaluation of conductivity was “4”, and the conductivity was carried out. Compared to Example 25.
In Example 27 containing 1,6-hexanediol (boiling point 250 ° C.) as an alcohol compound and Example 1 containing trimethylolpropane (boiling point 250 ° C. or higher), both the base material adhesion and the conductive evaluation of the conductive film were evaluated. “5”, which was particularly excellent.

[Comparison between Example 1 and 28-30]
In Example 30 in which the electrical conductivity of the composition for forming a conductive film was 240 mS / m, both the base material adhesion and the conductive evaluation of the conductive film were “3”, and the practical requirements were reached. .
In Example 29 in which the electrical conductivity of the composition for forming a conductive film is 122 mS / m, both the base material adhesion and the conductive evaluation of the conductive film are “4”. Both conductivity and conductivity were excellent.
Example 30 in which the electrical conductivity of the composition for forming a conductive film is 46 mS / m and Example 1 in which the electrical conductivity is 10 mS / m are “5” for both the base material adhesion and the conductive evaluation of the conductive film, Especially excellent.

[Contrast of Examples 1, 31 to 33]
In Example 33 containing 5 parts by mass of the polymer compound with respect to 100 parts by mass of cupric oxide nanoparticles, both the base material adhesion and the electrical conductivity of the conductive film were evaluated as “3”. Had reached.
In Example 32 containing 1 part by mass of the polymer compound with respect to 100 parts by mass of cupric oxide nanoparticles, the base material adhesion evaluation of the conductive film was “4”, and the conductivity evaluation was “5”. Compared with Example 33, both substrate adhesion and conductivity were excellent.
In Example 31 containing 0.1 part by mass of the polymer compound with respect to 100 parts by mass of cupric oxide nanoparticles and Example 1 not containing the polymer compound, the base material adhesion and conductivity of the conductive film were evaluated. Both were “5” and were particularly excellent.

Claims (10)

A composition for forming a conductive film comprising cupric oxide nanoparticles and an alcohol compound,
Content of the said alcohol compound is 20-1000 mass parts with respect to 100 mass parts of said cupric oxide nanoparticles,
The average primary particle diameter of the cupric oxide nanoparticles is 3 to 25 nm,
The cupric oxide nanoparticles have an average aspect ratio of more than 1.1 and not more than 5.0,
Of the cupric oxide nanoparticles, the proportion of particles having a primary particle diameter exceeding 30 nm is less than 30%, and
The composition for electrically conductive film formation whose electrical conductivity of the said composition for electrically conductive film formation is 2-240 mS / m.   The composition for electrically conductive film formation of Claim 1 which is a nanoparticle by which the said cupric oxide nanoparticle was granulated by the wet granulation method.   The composition for electrically conductive film formation of Claim 1 or 2 whose said cupric oxide nanoparticle is a nanoparticle produced | generated by the thermal decomposition of copper hydroxide.   Furthermore, the composition for electrically conductive film formation of any one of Claims 1-3 containing the microparticles | fine-particles of a Group 8-10 heavy metal element, and / or the salt of a Group 8-10 heavy metal element.   The composition for electrically conductive film formation of Claim 4 whose total content of the said microparticles | fine-particles and the said salt is 0.01-10 mass parts with respect to 100 mass parts of said cupric oxide nanoparticles.   The composition for electrically conductive film formation of any one of Claims 1-5 whose content of the said alcohol compound is 50-500 mass parts with respect to 100 mass parts of said cupric oxide nanoparticles.   The composition for electrically conductive film formation of any one of Claims 1-6 whose average primary particle diameter of the said cupric oxide nanoparticle is 5-20 nm.   The composition for electrically conductive film formation of any one of Claims 1-7 whose average primary particle diameter of the said cupric oxide nanoparticle is 5-15 nm.   The composition for electrically conductive film formation of any one of Claims 1-8 whose average aspect-ratio of the said cupric oxide nanoparticle is 1.2 or more and 2.0 or less. The process for apply | coating the composition for electrically conductive film formation of any one of Claims 1-9 on a resin base material, and forming a electrically conductive film precursor film | membrane on the said resin base material, and the said electrically conductive film precursor A conductive film forming method comprising a step of heating a film at a temperature of 110 ° C. to 150 ° C. in an inert gas atmosphere to form a conductive film on the resin substrate.