JP2020094170A - Conductive composition for molded film, molded film and production method of the same, and molded article and production method of the same - Google Patents

Abstract

To provide a conductive composition for a molded film, from which a molded film can be produced that suppresses reduction in the conductivity due to a tensile force and a stress under a high-temperature condition, a molded film that suppresses reduction in the conductivity due to a tensile force and a stress under a high-temperature condition, and a molded article excellent in conductivity and a production method of the article.SOLUTION: The conductive composition for a molded film comprises a resin (A), flake-like conductive fine particles (B), and wire-like fine particles (C), in which the flake-like conducive fine particles (B) have an average particle diameter of 3 μm or more and less than 30 μm, and comprise at least one type of conductive fine particles selected from a silver powder, a copper powder, a silver-coated powder, a copper ally powder and carbon fine particles. The content of the conductive fine particles (B) is 50 to 85% in the whole solid content of the composition.SELECTED DRAWING: Figure 1

Description

The present invention relates to a conductive composition for a molded film, a molded film and a method for manufacturing the same, a molded body and a method for manufacturing the same.

Patent Document 1 discloses a resin molded body, a base film embedded so as to be flush with one surface of the resin molded body, and a conductive circuit arranged between the resin molded body and the base film. Specific conductive circuit integrated molded articles having and are disclosed.
In Patent Document 1, as a method of manufacturing the conductive circuit integrated molded article, a base film on which a specific conductive circuit is formed is arranged on a cavity surface of an injection molding die, and then a molten resin is injected to obtain a resin. It is described that a molded body is injection molded.
In Patent Document 1, the conductive circuit is formed by etching a specific transparent metal thin film.

As a method of forming a conductive circuit that replaces the etching method, a printing method using a conductive ink is under study. According to the method of printing the conductive ink, compared with the etching method, the conductive circuit can be easily formed without complicated steps, the productivity is improved, and the cost can be reduced.
For example, in Patent Document 2, as a low temperature treatment type conductive ink capable of forming a high-definition conductive pattern by screen printing, a specific conductive material containing specific conductive fine particles and a specific epoxy resin is used. Inks are disclosed. According to screen printing, it is possible to increase the thickness of the conductive pattern and reduce the resistance of the conductive pattern.

Further, in Patent Document 3, as a method for producing a decorative sheet capable of expressing a three-dimensional three-dimensional effect, a laminate having a printed layer printed in a pattern on a transparent resin layer, and a base film. A method is disclosed in which the decorative layer is formed into an uneven shape along the pattern of the printed layer by thermocompression bonding with a laminated sheet having a decorative layer thereon.

JP 2012-11169 A JP, 2011-252140, A JP, 2007-2966848, A

According to the method of Patent Document 1, a conductor can be easily provided on the surface of the molded body. On the other hand, there is an increasing demand for forming a conductive circuit on the surface of a substrate having various shapes such as a substrate having an uneven surface or a curved surface. When a film having a conductive layer is bonded to the surface of such a base material to form a conductive circuit, the film needs to be deformed according to the surface shape of the base material. When the film is deformed, a large tensile force may be locally generated in the conductive layer. The tensile force causes breakage of the conductive layer, which causes a problem of decrease in conductivity. Further, when forming a conductive circuit on a base material having such an uneven surface or a curved surface, after the film having the conductive layer is deformed, or at the same time as the deformation, the film and the base material are integrated. However, stress stress due to friction with the plastic substrate at high temperature is applied to the conductive circuit in this integration step. The stress stress under high temperature also causes breakage of the conductive layer, resulting in a decrease in conductivity.

The present invention has been made in view of such circumstances, a conductive composition for a molded film capable of producing a molded film in which a decrease in conductivity due to a tensile force and a stress stress under high temperature is suppressed, a tensile force and It is an object of the present invention to provide a molded film in which a decrease in conductivity due to stress stress under high temperature is suppressed, a molded product having excellent conductivity, and a method for producing the molded product.

The conductive composition for molded film according to the present embodiment,
A conductive composition for producing a molded film for forming a conductive layer on a substrate surface having an uneven surface or a three-dimensional curved surface,
Contains resin (A), flaky conductive fine particles (B), and wire fine particles (C),
The flaky conductive fine particles (B) are flakes having an average particle size of 3 μm or more and less than 30 μm.
Containing conductive fine particles composed of one or more kinds selected from silver powder, copper powder, silver-coated powder, copper alloy powder, and carbon fine particles,
The content of the conductive fine particles (B) is 50 to 85% of the total solid content of the composition.

One embodiment of the conductive composition for molded film of the present embodiment is that the wire-shaped fine particles (C) are wire-shaped fine particles composed of one or more kinds selected from silver nanowires, carbon nanotubes, and ceramic-based wire-shaped fine particles. ..

In one embodiment of the conductive composition for molded film of the present embodiment, the wire-shaped fine particles (C) are one or more selected from a metal oxide wire, a metal hydroxide wire, and a metal oxoate wire. It is a ceramic-based fine wire particle.

In one embodiment of the conductive composition for molded film of the present embodiment, the resin (A) has a first reactive functional group selected from a hydroxy group, an amino group, a carboxyl group, and an acid anhydride group. Have two or more in the molecule,
Further, it contains a crosslinking agent (D) having two or more second reactive functional groups capable of forming a crosslink with the first reactive functional group in one molecule.

In one embodiment of the conductive composition for molded film of the present embodiment, the resin (A) has one or more glass transition points at 0° C. or higher and lower than 150° C., and also has a glass transition point at lower than 0° C. There is no resin.

Molded film according to the present embodiment is a molded film having a conductive layer on the base film,
The conductive layer is a cured product of the conductive composition for molded film of the present embodiment.

One embodiment of the molded film of the present embodiment is a molded film having a decorative layer and a conductive layer on a base film,
The conductive layer is a cured product of the conductive composition for molded film of the present embodiment.

In one embodiment of the molded film of the present embodiment, the base film is a film selected from polycarbonate, polymethylmethacrylate, polypropylene, and polyethylene terephthalate, or a laminated film thereof.

The molded body according to the present embodiment is a molded body in which a conductive layer is laminated on a base material,
The conductive layer is a cured product of the conductive composition for molded film of the present embodiment.

The first manufacturing method of the molded body according to the present embodiment, a step of producing a molded film by printing the conductive composition for a molded film of the present embodiment on a base film, and drying,
Placing the molded film on a substrate,
A step of integrating the molded film and the base material by an overlay molding method.

The second manufacturing method of the molded body according to the present embodiment, a step of producing a molded film by printing the conductive composition for a molded film of the present embodiment on a base film, and drying,
A step of molding the molded film into a predetermined shape,
Placing the molded film after molding in a mold for injection molding,
Molding the base material by injection molding, and integrating the molded film and the base material.

A third method for producing a molded body according to the present embodiment is a step of producing a molded film by printing the conductive composition for a molded film according to the present embodiment on a base film, and drying the composition.
Placing the molding film in a mold for injection molding,
Molding the base material by injection molding and transferring the conductive layer in the molded film to the base material side.

According to the present invention, a conductive composition for a molded film capable of producing a molded film in which a decrease in conductivity due to tensile force and stress stress under high temperature is suppressed, and a decrease in conductivity due to tensile force and stress stress under high temperature are suppressed. It is possible to provide the formed film, the formed body having excellent conductivity, and the manufacturing method thereof.

It is a typical sectional view showing an example of a forming film of this embodiment. It is a typical sectional view showing another example of the forming film of this embodiment. It is a schematic process drawing which shows an example of the 1st manufacturing method of a molded object. It is a typical process drawing which shows another example of the 2nd manufacturing method of a molded object. It is a typical process drawing which shows another example of the 3rd manufacturing method of a molded object.

Hereinafter, the conductive composition for a molded film, the molded film, the molded body and the method for producing the same according to the present embodiment will be described in detail in order.
In the present embodiment, the cured product includes not only a product cured by a chemical reaction but also a product cured without a chemical reaction such as a product hardened by evaporating a solvent.

[Conductive composition for molded film]
Contains resin (A), flaky conductive fine particles (B), and wire fine particles (C),
The flaky conductive fine particles (B) are flakes having an average particle size of 3 μm or more and less than 30 μm.
Containing conductive fine particles composed of one or more kinds selected from silver powder, copper powder, silver-coated powder, copper alloy powder, and carbon fine particles,
The content of the conductive fine particles (B) is 50 to 85% of the total solid content of the composition.

The present inventors have investigated a screen-printable conductive composition for producing a molded film that can be applied to an uneven substrate surface and has process suitability for an integration step with a plastic substrate. I went. In order to apply to the production of a molded film, the resin structure and the conductive fine particles and the wire-shaped fine particles were variously adjusted and examined, and the shape and the addition amount of the conductive fine particles contained in the conductive composition gave the obtained molding. The magnitude of the change in resistance value that occurs when the film is stretched at a high temperature capable of molding is different, and not only the shape of the conductive fine particles, but also the presence or absence of the addition of fine particles having a specific shape different from the conductive fine particles, It was found that when a high-viscosity thermoplastic resin melted on a molded film is pressed under high pressure, the presence or absence of disconnection and the magnitude of change in resistance value are different. The present inventors have conducted a study based on such findings, as a conductive composition on the resin film does not include any conductive particles in the form of flakes as conductive particles or a conductive material that does not include any wire-shaped particles When the composition is printed and dried by heating, when the molded film is deformed by pulling at a high temperature corresponding to its softening point, the adhesion is deteriorated at the contact surface between the conductive composition and the resin film, or cracking of the conductive layer occurs. It was also found that when the molten high-viscosity thermoplastic resin was pressed against the molded film at a high pressure, the wiring was broken or thinned due to the high temperature and the flowing pressure. The same was true when a conductive layer was provided on the decorative layer.

Even if the molded film has a conductive layer such that the adhesiveness is reduced at the contact surface with the resin film or the conductive layer is cracked when deformed by pulling at such a high temperature, it is flat However, it has become a problem when used as a film circuit board, etc., or when it is used while being bent on a two-dimensional curved surface. However, when it is used as a molding film that follows and integrates the shape of a non-flat substrate surface, for example, an uneven shape or a three-dimensional curved surface shape, the molding film will be deformed. Therefore, it is estimated that the conductive layer cannot follow the deformation of the resin film and peeling or disconnection occurs, so that the conductivity of the conductive layer is lowered.
In addition, the uneven surface and the three-dimensional curved surface in the present invention indicate not only a surface having a smooth curved cross section but also a general three-dimensional surface having an acute angle or a rectangular shape. That is, it refers to a three-dimensional shape that cannot be realized only by deforming the plane without expanding and contracting, and refers to, for example, a three-dimensional shape such as a hemispherical shape, a conical shape, a cylindrical shape, and a quadrangular prism shape. In addition, when a certain three-dimensional shape has both the above-mentioned plane or two-dimensional curved surface and three-dimensional curved surface elements in a continuous three-dimensional surface, for example, the planar shape is combined with one or more partial hemispherical shapes. The three-dimensional shape is a three-dimensional curved surface because it is a three-dimensional shape that cannot be realized by deforming the plane without expanding and contracting as a whole. That is, the uneven surface and the three-dimensional curved surface in the present invention cannot be realized by bending a flexible substrate or the like, and can be realized by, for example, shaping the moldable film by three-dimensional molding under heating.

As a result of intensive studies based on these findings, the present inventors have found that the flaky conductive fine particles containing the flake conductive fine particles having an average particle diameter of 3 μm or more and less than 30 μm and the wire fine particles ( When the content of B) satisfies the relationship of occupying 50 to 85% of the total solid content of the composition, when the molded film is pulled, and the molten high-viscosity thermoplastic resin is pressure-welded on the molded film at high pressure. The present invention has been completed by finding that the change in the resistance value generated at that time is small.
That is, the conductive composition for a molded film of the present invention can be made conductive by screen printing or the like by using the flake-shaped conductive fine particles having an average particle diameter of 3 μm or more and less than 30 μm in combination with the wire-shaped fine particles. A molded film having an excellent thick conductive layer can be easily produced. In addition, the molded film produced by using the conductive composition for a molded film can suppress the decrease in conductivity even when used on a non-flat substrate surface. Further, by using the molding film, it is possible to obtain a molding in which a conductive circuit is formed on an arbitrary surface such as an uneven surface or a curved surface on a substrate made of a three-dimensional plastic having practical strength.

The conductive composition for molded film of the present embodiment contains at least the resin (A), the flake-shaped conductive fine particles (B), and the wire-shaped fine particles (C). It may contain other components. Hereinafter, each component of the conductive composition for a molded film will be described.

<Resin (A)>
The conductive composition of the present embodiment contains a binder resin (A) in order to impart film-forming properties and adhesion to the base film and the decorative layer. Further, in the present embodiment, by containing the resin (A), flexibility can be imparted to the conductive layer. Therefore, by containing the resin (A), breakage of the conductive layer due to stretching is suppressed.

The resin (A) can be appropriately selected and used from the resins used for the conductive composition.
Examples of the resin (A) include acrylic resin, vinyl ether resin, polyether resin, polyester resin, polyurethane resin, epoxy resin, phenoxy resin, polycarbonate resin, polyvinyl chloride resin, polyolefin resin, styrene. Examples thereof include block copolymer resins, polyamide resins, and polyimide resins, which may be used alone or in combination of two or more.

In the present embodiment, the resin (A) preferably has a substituent selected from a hydroxy group, an amino group, a carboxyl group, and an acid anhydride group, among others. The presence of the substituent improves the affinity for the flaky conductive fine particles (B) and the wire fine particles (C) described later, and also improves the adhesion to the base film and the like.
Further, in the present embodiment, the resin (A) preferably has two or more substituents selected from a hydroxy group, an amino group, a carboxyl group and an acid anhydride group in one molecule. In this case, the resin (A) can be three-dimensionally cross-linked by combining with a cross-linking agent (D) described later, and can be suitably used in applications where hardness is required for the conductive layer.

When the resin (A) has a functional group selected from a hydroxy group, an amino group, a carboxyl group, and an acid anhydride group, the functional group value is preferably 1 mgKOH/g or more and 400 mgKOH/g or less, It is preferably 2 mgKOH/g or more and 350 mgKOH/g or less. The details of the method of calculating the functional group value will be described in Examples below.
When the resin (A) has a plurality of types of functional groups, the functional group value is the total thereof. For example, when the resin (A) has a hydroxy group and a carboxyl group, the functional group value represents the sum of the hydroxyl value and the acid value of the resin (A).

The glass transition temperature (Tg) of the resin (A) is a resin from the viewpoint of maintaining both conductivity during molding tension and resistance to friction stress stress with the base plastic at high temperature in the integration step with the plastic base. The glass transition temperature (Tg) of (A) is preferably 0° C. or higher and 150° C. or lower, and more preferably 5° C. or higher and 120° C. or lower.

In the present embodiment, the resin (A) may be used by synthesizing it according to the examples described later or other known methods, or may be a commercially available product having desired physical properties. In the present embodiment, the resin (A) may be used alone or in combination of two or more.

The content ratio of the resin (A) in the conductive composition of the present embodiment may be appropriately adjusted according to the application etc. and is not particularly limited, but 5% by mass or more based on the total solid content contained in the conductive composition. It is preferably 50% by mass or less, and more preferably 8% by mass or more and 40% by mass or less. When the content ratio of the resin (A) is at least the above lower limit value, the film-forming property and the adhesion to the base film and the like can be improved, and the conductive layer can be provided with flexibility. Further, when the content ratio of the resin (A) is not more than the above upper limit value, the content ratio of the flaky conductive fine particles (B) can be relatively increased, and a conductive layer having excellent conductivity can be formed. it can.

<Flake conductive fine particles (B)>
The flake-like conductive fine particles (B) are those in which a plurality of flake-like conductive fine particles come into contact with each other in the conductive layer to exhibit conductivity, and in the present embodiment, conductivity is obtained without heating at high temperature. It is used by appropriately selecting from the ones.
Examples of the flaky conductive fine particles used in this embodiment include metal fine particles, carbon fine particles, and conductive oxide fine particles.
Examples of the metal fine particles include, for example, gold, silver, copper, nickel, chromium, palladium, rhodium, ruthenium, indium, aluminum, tungsten, molbutene, platinum, and other simple metal powders, copper-nickel alloy, silver-palladium alloy, Examples thereof include alloy powders such as copper-tin alloys, silver-copper alloys, and copper-manganese alloys, and metal-coated powders obtained by coating the surface of the single metal powder or alloy powder with silver or the like. Examples of the carbon fine particles include carbon black, graphite and carbon nanotubes. Examples of the conductive oxide fine particles include silver oxide, indium oxide, tin oxide, zinc oxide, ruthenium oxide and the like.

In the present embodiment, among them, it is preferable to include one or more kinds of flaky conductive fine particles selected from silver powder, copper powder, silver coating powder, copper alloy powder, conductive oxide powder, and carbon fine particles. By using these flaky conductive fine particles (B), a conductive layer having excellent conductivity can be formed without sintering, and further stretchability when molded into a three-dimensional shape as a molding film described later. It is possible to form a conductive layer having excellent conductivity holding property and conductivity.

The shape of the flaky conductive fine particles (B) is not particularly limited as long as it is a two-dimensional flat shape. In addition, the "flake shape" in the present invention refers to a general two-dimensional flat shape called a scale shape, a scale shape, a plate shape, a flat shape, a sheet shape and the like. Among them, the aspect ratio is 3 or more and 500 or less from the viewpoints of maintaining printability, maintaining conductivity during molding tension, and resistance to friction stress stress with the base plastic under high temperature in the integration step with the plastic base. Those are particularly preferable.

The average particle size of the flaky conductive fine particles is not particularly limited, but the dispersibility and printability in the conductive composition are maintained, the conductivity is maintained during molding, and the injection molding process resistance by the molten resin or the molded resin is used. From the viewpoint of resistance to friction under high temperature, 3 μm or more and 30 μm or less is preferable, and 4 μm or more and 25 μm or less is more preferable.
In this embodiment, the average particle size of the flaky conductive fine particles (B) is calculated as follows. In accordance with the laser diffraction/scattering method described in JISM8511 (2014), a laser diffraction/scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd.: Microtrack 9220FRA) was used, and a commercially available surfactant polyoxyethylene octylphenyl was used as a dispersant. An appropriate amount of conductive fine particles (B) was added to an aqueous solution containing 0.5% by volume of ether (manufactured by Roche Diagnostics KK: Triton X-100), and ultrasonic waves of 40 W were irradiated for 180 seconds while stirring. After that, measurement was performed. The value of the obtained median diameter (D50) was used as the average particle diameter of the flaky conductive fine particles (B).

In the present embodiment, the flaky conductive fine particles (B) may be used alone or in combination of two or more.
The content ratio of the flaky conductive fine particles (B) in the conductive composition of the present embodiment may be appropriately adjusted depending on the application etc., but is not particularly limited, but with respect to the total solid content contained in the conductive composition, It is preferably 50% by mass or more and 85% by mass or less, and more preferably 55% by mass or more and 80% by mass or less. When the content ratio of the flaky conductive fine particles (B) is at least the above lower limit value, a conductive layer having excellent conductivity can be formed. Further, when the content ratio of the flaky conductive fine particles (B) is not more than the above upper limit value, the content ratio of the resin (A) can be increased, and the film forming property and the adhesion to the base film and the like are improved. Further, flexibility can be imparted to the conductive layer.

In addition, the flaky conductive fine particles (B) may be used together with the non-flake conductive fine particles (B′). As the conductive particles other than flakes (B′), conductive particles made of the metal, carbon, or conductive oxide having a shape other than the wire-shaped particles described later, such as spherical, chain-shaped, and dendritic, are used. be able to. The content ratio of the conductive particles (B′) other than flakes may be appropriately adjusted according to the application etc., and is not particularly limited, but the flaky conductive particles (B) and the conductive particles other than flakes (B′) It is preferable that the total of () is 55% by mass or more and 90% by mass or less.

<Wire-shaped fine particles (C)>
The wire-shaped fine particles (C) are used to reinforce the coating film strength at high temperature without impairing the conductivity and stretchability of the conductive layer, and in the first to third production methods described below, the molded film and the It is used to impart a function of retaining the shape and conductivity of the wiring made of the conductive layer to a strong shear stress applied to the conductive layer at a high temperature when integrated with the base material. In the present embodiment, it is appropriately selected from inorganic or organic fine particles having a wire shape. In addition, the wire shape in the present embodiment refers to a shape having a long axis in a one-dimensional direction, and includes a wire shape, a whisker shape, a needle shape, a rod shape, a rod shape or a tube shape in other expressions.
Examples of the wire-shaped fine particles (C) used in the present embodiment include carbon-based wire-shaped fine particles, metal-based wire-shaped fine particles, and ceramic-based wire-shaped fine particles.
Examples of the carbon-based wire-shaped fine particles include single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanohorns, carbon microcoils, and short fibrous carbon fiber particles. The metal-based wire-shaped fine particles include, for example, simple metal powders such as gold, silver, copper, nickel, chromium, palladium, rhodium, ruthenium, indium, aluminum, tungsten, molbutene, platinum, copper-nickel alloy, and silver. -Palladium alloys, copper-tin alloys, silver-copper alloys, copper-manganese alloys, and other alloys made of metallic materials such as silver, nanowires, nanorods, microrods, whiskers, needle-shaped particles, fibrous particles, and the like. .. Examples of the ceramic-based wire-shaped fine particles include metal oxides such as silicon dioxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, zinc oxide and indium oxide, aluminum hydroxide, aluminum oxide hydroxide (boehmite), magnesium hydroxide. , Nanowires made of inorganic salts and ceramic materials such as metal hydroxides such as calcium hydroxide, potassium titanate, barium sulfate, magnesium sulfate, calcium silicate (wollastonite) and magnesium silicate , Nanorods, microrods, whiskers, acicular particles, fibrous particles and the like. Further, the surface of these wire-shaped fine particles may be subjected to surface metal coating or surface ceramic coating by using a known fine particle surface coating method such as a plating method or a hydrothermal method.

In the present embodiment, it is preferable to include at least one kind of wire-shaped fine particles selected from among silver nanowires, carbon nanotubes, and ceramic-based wire-shaped fine particles, and among them, metal oxide wires, metal hydroxide wires, and metals. It is particularly preferable to include ceramic-based wire-shaped fine particles composed of one or more selected from oxo acid wires. By using these wire-shaped fine particles (C), the high temperature in the integration step with the plastic base material is not impaired without impairing the stretchability and the holding performance of conductivity when molded into a three-dimensional shape as a molding film described later. It is possible to provide resistance to frictional stress and stress, and it is possible to form a conductive layer having excellent resistance to a process of integrating with a base material.

In the present embodiment, the wire fine particles (C) may be used alone or in combination of two or more.
The content ratio of the wire-shaped fine particles (C) in the conductive composition of the present embodiment may be appropriately adjusted according to the application etc., and is not particularly limited, but it is 0..% to the total solid content contained in the conductive composition. It is preferably 1% by mass or more and 10% by mass or less, and more preferably 0.2% by mass or more and 9% by mass or less. When the content ratio of the wire-shaped fine particles (C) is at least the above lower limit value, it is possible to form a conductive layer having excellent resistance to the base material forming process. Further, when the content ratio of the wire-shaped fine particles (C) is not more than the above upper limit value, the content ratio of the resin (A) can be increased, the film forming property and the adhesion to the base film and the like are improved, and Good printability can be imparted.

<Crosslinking agent (D)>

In the present embodiment, a crosslinking agent (D) may be additionally used for crosslinking the resin (A). As the cross-linking agent (D), one having two or more reactive functional groups capable of forming a cross-link with the reactive functional group of the resin (A) in one molecule can be appropriately selected and used. Examples of such a reactive functional group include an epoxy group, an isocyanate group, a blocked isocyanate group, an alkyloxyamino group, an aziridinyl group, an oxetanyl group, a carbodiimide group, and a β-hydroxyalkylamide group.
The crosslinking agent (D) is preferably used in an amount of 0.05 parts by mass or more and 30 parts by mass or less, and more preferably 0.3 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of the resin (A).

Further, in the present embodiment, the resin (A) has two or more first reactive functional groups selected from a hydroxy group or an amino group in one molecule, and the cross-linking agent (D) is a blocked isocyanate. It is particularly preferable to select and combine.
Examples of blocked isocyanates include difunctional isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, and isophorone diisocyanate, or their allophanate bodies, biuret bodies, adduct bodies, prepolymer bodies, isocyanurate bodies. There is no particular limitation as long as the isocyanate group of a bifunctional or higher-functional isocyanate composed of, for example, is protected (blocked) with ε-caprolactam, MEK oxime, or the like. Specifically, the isocyanate group of the above isocyanate compound is blocked with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, 3,5-dimethylpyrazole, diisopropylamine, diethyl malonate, ethyl acetoacetate, phenol, etc. Is mentioned.
When used in such a combination, the conductive layer is particularly excellent in toughness and excellent in substrate adhesion at high temperature due to the cross-linking structure generated by cross-linking, so that the decrease in conductivity due to tensile force is particularly suppressed. Obtainable.

<Arbitrary ingredients>
The conductive composition of the present invention may further contain other components, if necessary. As such other components, in addition to the solvent (E), a dispersant, a friction resistance improver, an infrared absorber, an ultraviolet absorber, a fragrance, an antioxidant, an organic pigment, an inorganic pigment, an antifoaming agent, a silane. Coupling agents, plasticizers, flame retardants, moisturizers, etc.

The solvent (E) is not particularly limited, but preferably has a boiling point of 180° C. or higher and 270° C. or lower from the viewpoint of continuous screen printability. Examples of the solvent include, but are not limited to, diethylene glycol monoethyl ether acetate, gamma butyrolactone, isophorone, tetralin, and dipropylene glycol monomethyl ether acetate.

<Method for producing conductive composition>
In the method for producing a conductive composition of the present embodiment, the resin (A), the flaky conductive fine particles (B), the wire fine particles (C), and other components used as necessary are dissolved or dispersed. Any method may be used, and it can be produced by mixing by a known mixing means.

[Molded film]
The molded film of the present embodiment is a molded film having a conductive layer on the base film,
The conductive layer is a cured product of the conductive composition for molded film.
According to the molded film of the present embodiment, it is possible to obtain a molded body in which a conductive circuit is formed on any base material surface such as an uneven surface or a curved surface.
According to the molded film of the present embodiment, it is possible to obtain a molded body in which a conductive circuit is formed on any base material surface such as an uneven surface or a curved surface.
The layer structure of the molded film of this embodiment will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic cross-sectional views showing an example of the molded film of this embodiment.
The molded film 10 shown in the example of FIG. 1 includes a conductive layer 2 on a base film 1. The conductive layer 2 may be formed on the entire surface of the base film 1 or may be formed in a desired pattern like the example of FIG.
The molded film 10 shown in the example of FIG. 2 has the decorative layer 3 on the base film 1 and the conductive layer 2 on the decorative layer 3. Further, as shown in the example of FIG. 2, the molded film 10 may be provided with the electronic component 4 and the pin 5 for connecting to the extraction circuit on the conductive layer 2.
Although not shown, a resin layer for protecting the conductive layer or the electronic component may be provided on the conductive layer 2 or the electronic component 4, and the resin layer serves as a base material described later. It may be an adhesive layer or an adhesive layer for improving the adhesiveness of.
Although not shown, in the case where the molded film 10 of the present embodiment includes the decorative layer 3, the decorative layer 3 is provided on one surface of the base film 1 and the conductive film is provided on the other surface in addition to the example of FIG. A layer structure including the layer 2 may be used.
The molded film of the present embodiment has at least a base film and a conductive layer, and may have other layers as necessary. Each layer of such a molded film will be described below.

<Base film>
In the present embodiment, the base film can be appropriately selected from those having flexibility and stretchability such that they can follow the shape of the base material surface under the molding temperature condition at the time of forming the base material. It is preferably selected according to the method for producing the molded body.
For example, when adopting an overlay molding method or a film insert method, which will be described later, as a method for producing a molded body, it is necessary to consider that the base film remains in the molded body and thus has a function as a protective layer for the conductive layer. Then, the base film can be selected.
On the other hand, when adopting an in-mold transfer method, which will be described later, as a method for producing a molded body, it is preferable to select a base film having releasability.

The base film can be appropriately selected from the above viewpoints, for example, polycarbonate, polymethyl methacrylate, polypropylene, polyethylene terephthalate, polystyrene, polyimide, polyamide, polyether sulfone, polyethylene naphthalate, polybutylene terephthalate, polyvinyl chloride, polyethylene. , Polypropylene, cycloolefin polymer, ABS (acrylonitrile-butadiene-styrene copolymer resin), AES (acrylonitrile-ethylene-styrene copolymer resin), kaidak (acrylic modified vinyl chloride resin), modified polyphenylene ether, and two or more of these resins. It may be a film made of a polymer alloy or the like, or a laminated film thereof. Among them, a film selected from polycarbonate, polymethylmethacrylate, polyethylene terephthalate, or a laminated film thereof is preferable. Among them, a laminated film of polycarbonate and polymethylmethacrylate is preferable as the laminated film.
The method for producing a laminated film of polycarbonate and polymethylmethacrylate is not particularly limited, and may be laminated by laminating a polycarbonate film and a polymethylmethacrylate film, or as a laminated film by coextrusion of polycarbonate and polymethylmethacrylate. Good.
It is also preferable that the surface of these base films is subjected to a modification treatment such as corona treatment.

In addition, if necessary, an anchor coat layer may be provided on the base film and the conductive composition may be printed on the anchor coat layer for the purpose of improving the printability of the conductive composition. The anchor coat layer is not particularly limited as long as it has good adhesiveness with the base film, and further has good adhesiveness with the conductive composition and can follow the film at the time of molding, and an organic filler such as resin beads or a metal. An inorganic filler such as an oxide may also be added if necessary. The method for providing the anchor coat layer is not particularly limited, and it can be obtained by coating, drying and curing by a conventionally known coating method.
Further, if necessary, a hard coat layer may be provided on the base film to prevent the surface of the molded product from being scratched, and a conductive composition and, if necessary, a decorative layer may be printed on the opposite surface. The hard coat layer is not particularly limited as long as it has good adhesion to the base film, and further has good surface hardness and follows the film at the time of molding, and also an organic filler such as resin beads or an inorganic filler such as a metal oxide. May also be added if necessary. The method for providing the hard coat layer is not particularly limited, and the hard coat layer can be obtained by coating, drying and curing by a conventionally known coating method.

When the molded film of this embodiment has a decorative layer, it is preferable to select a transparent base film.

The thickness of the base film is not particularly limited, but may be, for example, 10 μm or more and 500 μm or less, and preferably 20 μm or more and 450 μm or less.

<Conductive layer>
In the molded film of this embodiment, the conductive layer is a cured product of the conductive composition. The conductive layer may be a patterned conductive layer or a solid-coated conductive layer.
The method for forming the conductive layer is not particularly limited, but in the present embodiment, screen printing, pad printing, stencil printing, screen offset printing, dispenser printing, gravure offset printing, reverse offset printing, microcontact printing. It is preferably formed by a method, and more preferably formed by a screen printing method.
In the screen printing method, it is preferable to use a fine mesh screen, particularly preferably a fine mesh screen of about 300 to 650 mesh, in order to cope with the high definition of the conductive circuit pattern. The open area of the screen at this time is preferably about 20 to 50%. The screen wire diameter is preferably about 10 to 70 μm.
Examples of the type of screen plate include a polyester screen, a combination screen, a metal screen, a nylon screen and the like. Further, when printing a high-viscosity paste state, a high-tensile stainless screen can be used.
The screen-printed squeegee may have a round shape, a rectangular shape, or a square shape, and an abrasive squeegee can be used to reduce the attack angle (angle between the plate and the squeegee at the time of printing). Other printing conditions and the like may be appropriately designed according to conventionally known conditions.

After printing the conductive composition by screen printing, it is heated to dry and crosslink to cure.
It is preferable that the heating temperature is 80 to 230° C. and the heating time is 10 to 120 minutes in order to sufficiently volatilize the solvent and the crosslinking reaction. As a result, a patterned conductive layer can be obtained.
Although the pattern of the conductive layer is not particularly limited, for example, a solid pattern such as a straight line, a curved line, a mesh, a partial square, a circle, a rhombus shape or the like, a solid pattern or any combination thereof, or the entire conductive layer is a solid surface. It may be a pattern and is not limited as long as the conductive layer functions as a conductive circuit or a part of a conductive circuit.
The patterned conductive layer may be provided with an insulating layer so as to cover the conductive pattern, if necessary. The insulating layer is not particularly limited, and a known insulating layer can be applied.

The thickness of the conductive layer may be appropriately adjusted according to the required conductivity and the like, and is not particularly limited, but may be, for example, 0.5 μm or more and 20 μm or less, and preferably 1 μm or more and 15 μm or less.

<Decorative layer>
The molded film of the present embodiment may have a decorative layer from the viewpoint of the design of the molded product obtained.
The decorative layer may be a layer having a monochromatic tint, or may have an arbitrary pattern.
The decorative layer can be formed, for example, by preparing a decorative ink containing a coloring material, a resin, and a solvent, and then applying the decorative ink to a base film by a known printing means. ..
The colorant can be appropriately selected and used from known pigments and dyes. Further, as the resin, it is preferable to appropriately select and use the same resin as the resin (A) in the conductive composition of the present embodiment.
The thickness of the decorative layer is not particularly limited, but may be, for example, 0.5 μm or more and 10 μm or less, and preferably 1 μm or more and 5 μm or less.

[Molded body]
The molded product of the present embodiment is a molded product in which at least a conductive layer is laminated on a substrate, and the conductive layer is a cured product of the conductive composition for a molded film according to any one of claims 1 to 5. Is characterized in that Since the molded body of the present embodiment is formed of the molded film using the conductive composition for a molded film of the present embodiment, the molded body has a conductive circuit formed on any surface such as an uneven surface or a curved surface.
Hereinafter, three embodiments will be described with respect to the method for manufacturing the molded body of the present embodiment. The molded product of the present embodiment may be any one as long as it is manufactured using the conductive composition of the present embodiment, and is not limited to these methods.

<First manufacturing method>
The first manufacturing method of the molded body according to the present embodiment, a step of producing a molded film by printing the conductive composition for a molded film of the present embodiment on a base film, and drying,
Placing the molded film on a substrate,
A step of integrating the molded film and the base material by an overlay molding method.
Hereinafter, a description will be given with reference to FIG. 3, but since the method for manufacturing the molded film is as described above, the description thereof is omitted here.

FIG. 3 is a schematic process diagram showing an example of the first method for manufacturing a molded body. FIGS. 3(A) to 3(C) respectively illustrate the molding film 10 and the base material 20 arranged in the chamber box of a TOM (Three dimension Overlay Method) molding machine, and FIGS. ) Omits the chamber box.
In the first manufacturing method, first, the base material 20 is placed on the table of the lower chamber box 22. Next, the molded film 10 of the present embodiment is placed on the base material 20 through the space between the upper chamber box 21 and the lower chamber box 22. At this time, the molded film 10 may be arranged so that the conductive layer faces either the base material 20 side or the side opposite to the base material 20, and is selected depending on the intended use of the final molded body. Next, the upper and lower chamber boxes are evacuated, and then the molded film is heated. Next, the substrate 20 is raised 15 by raising the table. Then, only the upper chamber box 21 is exposed to the atmosphere (FIG. 3(B)). At this time, the molded film is pressed 16 toward the base material side, and the molded film 10 and the base material 20 are bonded and integrated (FIG. 3C). In this way, the molded body 30 can be obtained.

In the first manufacturing method, the base material 20 can be prepared in advance by an arbitrary method. In the first manufacturing method, the material of the base material 20 is not particularly limited, and may be made of resin or metal.

In the first manufacturing method, the frictional stress with the base plastic at high temperature in the above-mentioned step of integrating the base with the base means that the molded film in FIG. 3(C) is applied to the base side. This is due to the frictional stress between the conductive circuit of the molding film and the base material under high temperature when the molding film 10 and the base material 20 are bonded and integrated with each other under pressure 16. That is, in the first manufacturing method, the conductive layer simultaneously receives a load due to a tensile stress at the time of molding and a friction stress stress with the base plastic at a high temperature.

<Second manufacturing method>
The second manufacturing method of the molded body according to the present embodiment, a step of producing a molded film by printing the conductive composition for a molded film of the present embodiment on a base film, and drying,
A step of molding the molded film into a predetermined shape,
Placing the molded film after molding in a mold for injection molding,
Molding the base material by injection molding, and integrating the molded film and the base material. Hereinafter, description will be made with reference to FIG. The second manufacturing method may be called a film insert method.

FIG. 4 is a schematic process drawing showing an example of the second manufacturing method of a molded body. In the second manufacturing method, the molded film 10 is molded into a predetermined shape in advance by the mold 11 (FIG. 4(A)). The molded film 10 is heated and softened, or while being softened, suction is performed on the mold by vacuum, or pressing is performed on the mold by compressed air, or both of them are used together, and the molded film 10 is molded (FIG. 4). (B)). At this time, the molded film 10 may be molded so that the conductive layer faces either the base material 20 side described later or the opposite side to the base material 20, and is selected depending on the intended use of the final molded body. .. Next, the molded film 10 after molding is placed in the mold 12 for injection molding (FIG. 4(C) to FIG. 4(D)). Next, the resin is injected 14 from the opening 13 to form the base material 20, and the molded film 10 and the base material 20 are integrated to obtain a molded body 30 (FIG. 4(E)). ..

In the second manufacturing method, it is not necessary to prepare the base material 20 in advance, and the molding of the base material and the integration with the molded film can be performed at the same time. The material of the base material 20 can be appropriately selected and used from known resins used for injection molding.

In the second manufacturing method, the frictional stress with the base material plastic at high temperature in the step of integrating the base material described above means that the resin is injected 14 from the opening 13 in FIG. 4(E). , Due to the frictional stress received by the injection of the high temperature molten resin into the mold of the conductive layer on the molding film when the molding film 10 and the base material 20 are integrated while forming the base material 20. To do. That is, in the second manufacturing method, the conductive layer is subjected to a load due to a tensile stress at the time of molding, and then subjected to a friction stress stress with the base plastic at a high temperature in another step.

<Third manufacturing method>
A third method for producing a molded body according to the present embodiment is a step of producing a molded film by printing the conductive composition for a molded film of the present embodiment by screen printing on a base film and drying the composition.
Placing the molding film in a mold for injection molding,
Molding the base material by injection molding and transferring the conductive layer in the molded film to the base material side.
Hereinafter, description will be made with reference to FIG. The third manufacturing method may be referred to as an in-mold transfer method.

FIG. 5 is a schematic process diagram showing an example of a third method for manufacturing a molded body. In the third manufacturing method, as the molded film 10, a base film having peelability is selected and used. The molding film 10 is arranged in a mold 12 for injection molding so that the conductive layer faces the base material 20 side described later (FIG. 5A). Next, the resin is injected 14 from the opening 13 to form the base material 20, the molding film 10 and the base material 20 are brought into close contact with each other, and at least the conductive layer is transferred to the base material 20 side (see FIG. B)), a molded body 30 is obtained (FIG. 5(C)). When the molded film 10 has a decorative layer, the decorative layer and the conductive layer are transferred.

In the third manufacturing method, since it is not necessary to cut the base film, a long base film can be arranged as shown in the example of FIG. The material of the base material 20 can be appropriately selected and used from known resins used for injection molding.

In the third manufacturing method, the frictional stress with the base material plastic at high temperature in the step of integrating the base material described above means that the resin is injected 14 from the opening 13 in FIG. 5C. When the base material 20 is formed and the molding film 10 and the base material 20 are brought into close contact with each other, the conductive layer on the molding film is caused by frictional stress received by injection of high-temperature molten resin into the mold. is there. That is, in the third manufacturing method, the conductive layer is simultaneously subjected to a load due to a tensile stress at the time of molding and a friction stress stress with the base plastic at a high temperature.

The molded body thus obtained can be used for mounting circuits, touch sensors, and various electronic components on plastic housings such as home appliances, automobile parts, robots and drones. In addition, it is extremely useful for making electronic devices lighter, thinner, shorter, smaller, more flexible in design, and more multifunctional.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples do not limit the present invention in any way. In addition, "part" in an Example represents a "mass part", and "%" represents the "mass %."
In addition, the weight average molecular weight in the examples is a polystyrene reduced molecular weight measured by GPC (gel permeation chromatography) "HLC-8320" manufactured by Tosoh Corporation.

The "functional group value" in the examples is based on the molecular weight per functional group of each raw material (this is referred to as the functional group equivalent), and the molar amount of the functional group per 1 g of raw material is calculated by the following formula. It is expressed as a potassium hydroxide-equivalent mass (mg).
(Functional group value) [mgKOH/g]=(56.1×1000)/(functional group equivalent)
The functional group value is, for example, an acid value when the functional group is a carboxyl group, a hydroxyl value when the functional group is a hydroxy group, and a general term for the amount expressed as an amine value when the functional group is an amino group. Therefore, when comparing the functional group ratios of substances having different functional groups, it can be considered that the substances have the same molar amount of functional groups if the functional group values are the same.

When the titration of potassium hydroxide is used to quantify the functional group such as a carboxyl group and a hydroxy group, the above-mentioned functional group value is the water used for neutralization using a publicly known measuring method defined in JIS K 0070, for example. The measured values (acid value and hydroxyl value) can be directly obtained from an appropriate amount of potassium oxide, and can be treated in the same manner as the values calculated by the above calculation formula.
Further, even when the titration with the above-mentioned potassium hydroxide is not used for the quantitative determination of the functional group value such as isocyanate group, by using the above-mentioned functional group equivalent derived from each measured value showing the functional group amount and the above-mentioned calculation formula. For convenience, it can be calculated as a potassium hydroxide equivalent amount. A specific calculation example is shown below.

Calculation example: As a compound having an isocyanate group, the amount of isocyanate measured by the method specified in JIS K 6806 (a method of reacting an isocyanate group with n-dibutylamine and titrating the remaining n-dibutylamine with an aqueous hydrochloric acid solution). Is calculated to be 23% for a trifunctional isocyanate compound “X”. The functional group equivalent of the trifunctional isocyanate compound "X" is derived from the above isocyanate amount (%) and the molecular weight of the isocyanate group (NCO=44 g/mol) as follows.
(Functional group equivalent of "X")=1/(0.23/44)=191.3
From the functional group equivalent of the trifunctional isocyanate compound "X" and the above formula for calculating the functional group value, the functional group value of the trifunctional isocyanate compound "X" can be calculated as follows.
(Functional group value of trifunctional isocyanate compound "X") [mgKOH/g]
=(56.1×1000)/191.3=293.3

<Resin (A1) to (A4)>
The following resins were used as the resins (A1) to (A4).
Resin (A1): selected from nitrile butadiene rubber resin manufactured by Nippon Zeon Co., Nipol 1042, weight average molecular weight 450,000, glass transition point -40°C, hydroxy group, amino group, carboxyl group, and acid anhydride group. Does not contain a functional group.
-Resin (A2): styrene maleic anhydride resin manufactured by Clay Valley, SMA EF30, weight average molecular weight 9,500, glass transition point 130°C, acid anhydride group (acid value 215 mgKOH/g) in 2 or more per molecule. contains.
Resin (A3): cellulose ester resin manufactured by Eastman Chemical Co., CAB551-0.2, weight average molecular weight 70,000, glass transition point 100° C., hydroxy group (functional group value 54 mgKOH/g) in 2 molecules per molecule. Contains more than
-Resin (A4): Acrylic resin manufactured by Mitsubishi Chemical Co., Dianal BR-77, weight average molecular weight of 65,000, glass transition point 80°C, carboxyl group (functional group value 19 mgKOH/g) is contained in 2 or more in 1 molecule. To do.

<Synthesis Example 1: Synthesis of resin (A5)>
40.6 parts of dimethyl isophthalate, 12.9 parts of ethylene glycol, 18.2 parts of neopentyl glycol, and tetrabutyl titanate were placed in a reactor equipped with a stirrer, a thermometer, a rectification pipe, a nitrogen gas introduction pipe, and a pressure reducing device. 0.03 parts was charged, the mixture was gradually heated to 180° C. with stirring under a nitrogen stream, and the transesterification reaction was carried out at 180° C. for 3 hours. Then, 28.3 parts of sebacic acid was charged and gradually heated to 180 to 240° C. to carry out an esterification reaction. After reacting at 240° C. for 2 hours and measuring the acid value, the pressure inside the reactor was gradually reduced to 1 to 2 Torr when it became 15 or less, and when the predetermined viscosity was reached, the reaction was stopped and the surface was removed after removal. By transferring to a fluorinated pallet and cooling, a polyester resin (A5) having a weight average molecular weight of 45,000, a glass transition point of 58° C., and two or more hydroxy groups (functional group value 5 mgKOH/g) in one molecule. Of solids were obtained.

<Synthesis Example 2: Synthesis of resin (A6)>
A polyester polyol obtained from adipic acid and terephthalic acid and 3-methyl-1,5-pentanediol was added to a reactor equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube (Kuraray Polyol P- manufactured by Kuraray Co., Ltd. 2011") 127.4 parts, isophorone diisocyanate 19.2 parts, and diethylene glycol monoethyl ether acetate 32.5 parts were charged and reacted under a nitrogen stream at 90°C for 3 hours, and then isophorone diamine 5.5 parts was added. By further reacting at 90° C. for 2 hours, a weight average molecular weight of 35,000, a glass transition point of 5° C., and a urethane resin (A5) containing 2 or more amino groups (functional group value 4 mgKOH/g) in one molecule 40% A urethane resin (A6) solution having a nonvolatile content of 40% and containing 60% of diethylene glycol monoethyl ether acetate solvent was obtained.

The following were used as the conductive fine particles, the solvent, and the crosslinking agent.
<Flake-shaped conductive fine particles (B1) to (B3)>
Conductive fine particles (B1): Fukuda Metal Foil Powder Co., Ltd., flake silver powder, average particle diameter 5.2 μm
Conductive fine particles (B2): manufactured by DOWA Electronics Co., Ltd., flaky silver-coated copper powder, silver coating amount 10%, average particle diameter 4.0 μm.
Conductive fine particles (B3): manufactured by Ito Graphite Co., Ltd., flake graphite, average particle diameter 15 μm

<Conductive fine particles other than flakes (B'4) to (B'5)>
-Conductive fine particles (B'4): manufactured by DOWA Electronics, spherical silver powder, average particle size 0.8 μm
Conductive fine particles (B'5): manufactured by DOWA Electronics Co., Ltd., chained spherical silver powder, average particle diameter 5.9 μm

<Wire-like fine particles (C1) to (C7)>
・Wire-shaped fine particles (C1):
Oxial, single-walled carbon nanotube, TUBALL SWCNT 93%, average fiber length 7 μm, average diameter 2 nm
・Wire-shaped fine particles (C2):
Made by PlasmaChem, silver nanowires, average fiber length 25 μm, average diameter 50 nm
・Wire-shaped fine particles (C3):
Made by Ishihara Sangyo Co., Ltd., acicular titanium oxide, average fiber length 1.7 μm, average diameter 0.13 μm
・Wire-shaped fine particles (C4):
Kawai Lime Co., wire-shaped synthetic boehmite (aluminum oxide hydroxide), average fiber length 6.0 μm, average diameter 1.0 μm
・Wire-shaped fine particles (C5):
Ube Material Co., Ltd., wire-shaped basic magnesium sulfate, average fiber length 21 μm, average diameter 0.8 μm
・Wire-shaped fine particles (C6):
Otsuka Chemical Co., wire potassium titanate, average fiber length 15 μm, average diameter 0.4 μm
・Wire-shaped fine particles (C7):
NYCO Minerals, Wollastonite (Needle Calcium Silicate), Average Fiber Length 9.0 μm, Average Diameter 3.0 μm

<Silver surface treatment of wire-shaped fine particles (C8)>
First, in a 3 L round-bottomed flask, 20 g of stannous chloride was dissolved in 1.0 L of 0.5% dilute hydrochloric acid, 50 g of the wire-shaped fine particles (C5) were added as core particles, and the mixture was stirred at 25° C. for 1 hour. The particles were filtered off and washed with water to obtain adsorption-treated wire-shaped particles. Next, 40 g of edetic acid disodium salt, 20 g of sodium hydroxide, and 15 mL of 37% formaldehyde aqueous solution are added to 2 L of purified water to dissolve and put in a 3 L round bottom flask, and then the adsorption-treated wire-like particles are immersed therein. Thus, the adsorption-processed wire-shaped particle slurry was prepared. Next, 30 g of silver nitrate, 35 mL of 25% ammonia water, and 50 mL of purified water were mixed to prepare a basic silver nitrate aqueous solution, which was added dropwise to the above adsorption-treated wire-shaped particle slurry over 20 minutes while stirring at 25°C. A 10% aqueous solution of sodium hydroxide was further added thereto to adjust the pH to 12, and the mixture was stirred at 25° C. for 2 hours to deposit silver on the surface of the adsorption-treated wire-shaped particles. Then, after washing with water and filtration, it was dried at 60° C. for 12 hours using a vacuum dryer to obtain a silver-coated wire-shaped particle precursor. The silver-coated wire-like particle precursor was loosened into lump-like aggregated particles using a 325-mesh stainless mesh and a shaker, and then spread over a stainless steel vat to have a thickness of 1 mm, and placed in an electric muffle furnace for 30 minutes. After the temperature was raised to 0° C., the temperature was maintained at the same temperature for 3 hours, the silver crystals in the silver coating layer were explained in detail, and wire-like fine particles (C8) coated with silver were obtained. The coating amount of silver was 30% based on 100 parts by mass of the wire-shaped fine particles (C8) coated with silver.

<Crosslinking agents (D1) to (D4)>
-Crosslinking agent (D1):
Blockeden Chemicals' blocked isocyanate solution, Trixene BI 7963, contains 3 blocked isocyanate groups in one molecule (functional group value 168 mg KOH/g), non-volatile content 70% (solvent (E3): 2-methoxypropanol)
-Crosslinking agent (D2):
Sumika Covestrourethane block isocyanate solution, Desmodur BL-3475, containing 3 blocked isocyanate groups in one molecule (functional group value 147 mgKOH/g), nonvolatile content 70% (solvent (E4) : 1:1 mixed solvent of solvent naphtha and solvent (E5) butyl acetate)
・Crosslinking agent (D3):
Glycidylamine manufactured by Nippon Kayaku Co., GAN, containing two epoxy groups in one molecule (functional group value 449 mgKOH/g), non-volatile content 100%
-Crosslinking agent (D4):
Nagase Chemtex's glycidyl ether, Ex-411, containing 4 epoxy groups in one molecule (functional group value 245 mg KOH/g), nonvolatile content 100%

<Solvent>
-Solvent (E1): 1,2,3,4-tetrahydronaphthalene, boiling point 209°C
-Solvent (E2): diethylene glycol monoethyl ether acetate, boiling point 217°C
-Solvent (E3): 2-methoxypropanol, boiling point 120°C
・Solvent (E4): Solvent naphtha, boiling point 171°C
・Solvent (E5): Butyl acetate, boiling point 126°C

<Production Example 1: Preparation of decorative ink (G1)>
175 parts of resin solution (A6) (70 parts as resin (A6) only) were prepared, and 20 parts of phthalocyanine blue pigment (LIONOL BLUE FG7351 manufactured by Toyo Color Co., Ltd.) and titanium oxide pigment (TIPAQUE CR-93 manufactured by Ishihara Sangyo Co., Ltd.) were prepared. ) After stirring and mixing 10 parts by mass and kneading with a three-roll mill (manufactured by Kodaira Seisakusho), 5 parts of an isocyanate cross-linking agent (Desmodur N3300 manufactured by Sumika Covestrourethane Co., nonvolatile content 100%) and a solvent (E2) 90 Then, a decorative ink (G1) was obtained by adding parts and stirring and mixing uniformly.

<Example 1: Preparation of conductive composition (F1) for molded film>
20.0 parts of resin (A1) is dissolved in 30.0 parts of solvent (E1), 80.0 parts of flaky conductive fine particles (B1) and 0.5 parts of wire fine particles (C1) are mixed by stirring, and 3 After kneading with the present roll mill (manufactured by Kodaira Seisakusho), the mixture was uniformly stirred and mixed with a planetary mixer to obtain a conductive composition (F1) for a molded film.

<Examples 2 to 22: Preparation of conductive compositions (F2) to (F22) for molded film>
In Example 1, types and blends of resin, solvent, flaky conductive fine particles, wire fine particles, and a crosslinking agent (when a crosslinking agent is used, the crosslinking agent was added immediately before uniform stirring and mixing by a planetary mixer) Conductive compositions (F2) to (F22) for molded films were obtained in the same manner as in Example 1 except that the amounts were changed as shown in Table 1.
In addition, all the numerical values of each material in Tables 1 to 3 are parts by mass.

<Comparative Examples 1 to 3: Preparation of Conductive Compositions (F23) to (F25) for Molded Film>
A conductive composition for a molded film (F23) was prepared in the same manner as in Example 1 except that the types and amounts of the resin, solvent, conductive fine particles and cross-linking agent were changed as shown in Table 3. ~ (F25) were obtained.

<Examples 23 to 44 and Comparative Examples 4 to 6>
Polycarbonate (PC) film (manufactured by Teijin Ltd., Panlite 2151, thickness 300 μm) base material (300 mm×210 mm), conductive compositions (F1) to (F**) for molding film were screen printed (Mino). It was printed by a screen company, Minomat SR5575 semi-automatic screen printer). Then, by heating in a hot air drying oven at 120° C. for 30 minutes, a conductive layer having a rectangular solid shape with a width of 15 mm, a length of 30 mm and a thickness of 10 μm and a linear pattern with a line width of 3 mm, a length of 60 mm and a thickness of 10 μm is formed. A molded film provided was obtained.

<Example 45>
Polycarbonate film (manufactured by Teijin Ltd., Panlite 2151, thickness 300 μm) A base material (300 mm×210 mm) was coated with the decorative ink (G1) using a blade coater so that the dry film thickness was 2 μm. , And heated at 120° C. for 30 minutes to form a decorative layer.
Then, in the above-mentioned Example 33, the above-mentioned film with a decorative layer was used in place of the polycarbonate film, and the conductive film was formed on the decorative layer, in the same manner as in the above-mentioned Example 37, the polycarbonate film and the decorative ink. A molded film having layers and conductors laminated in this order was obtained.

<Example 46>
In the above examples, a polycarbonate resin/acrylic resin two-kind two-layer coextrusion film (Technoloy C001, thickness 125 μm, manufactured by Sumitomo Chemical Co., Ltd.) base material (300 mm×210 mm) was used in place of the acrylic resin film base material, and a polycarbonate resin was used. A molded film was obtained in the same manner as in Example 45 except that the conductive composition for molded film was printed on the side.

<Examples 47 to 69 and Comparative Examples 7 to 9>
In Examples 23 to 44, an acrylic resin film (Sumitomo Chemical Co., Ltd., Technoloy S001G, thickness 250 μm) base material (300 mm×210 mm) was used in place of the polycarbonate film base material, and a hot air drying oven was used. Molded films were obtained in the same manner as in Examples 23 to 45 except that the drying conditions were 80° C. and 30 minutes.

[(1) Volume resistivity measurement]
About the rectangular solid conductive layer of 15 mm×30 mm formed on the molded films of Examples 23 to 69 and Comparative Examples 4 to 9, a resistivity meter (Mitsubishi Chemical Analytech, Loresta GP MCP-T610 type) was used. The volume resistivity (Ω·cm) was measured using a resistivity meter, conforming to JIS-K7194, 4-terminal 4-probe method constant current application method (4-terminal probe at 0.5 cm intervals). The results are shown in Tables 1-3.

[(2) Evaluation of peel adhesion]
For a rectangular solid conductive layer of 15 mm×30 mm formed on the molded films of Examples 23 to 69 and Comparative Examples 4 to 9, a 1 mm-interval cross-cut guide manufactured by Gardner was used with a cutter knife. A 10×10 square grid-shaped cut was made so as to penetrate the conductive layer, cellophane tape manufactured by Nichiban Co., Ltd. was attached, the air that had been bitten in was removed to make it adhere well, and then it was peeled vertically. The degree of peeling of the coating film was evaluated according to the ASTM-D3519 standard as follows. The results are shown in Tables 1-3.
(Peel adhesion evaluation criteria)
A: Evaluation 5B to 4B, excellent adhesion B: Evaluation is 5B to 4B, but the coating film undergoes cohesive failure and part of the coating film on the surface side is detached C: Evaluation 3B or less, adhesiveness Inferior to

[(3) Wiring resistance evaluation]
70 mm in the longitudinal direction and 10 mm in the width direction were cut out so that the conductive layer having a linear pattern of 3 mm×60 mm formed on the molded films of Examples 23 to 69 and Comparative Examples 4 to 9 was located at the center, and measured. For coupons. On the surface opposite to the conductive layer on the measurement coupon, use a marker perpendicular to the conductive layer from the end in the longitudinal direction at an interval of 4 cm with an oil-based marker.
I added a book. According to this mark, the resistance value was measured using a tester at positions at 4 cm intervals, and this was taken as the wiring resistance (Ω). The results are shown in Tables 1-3.

[(4) Hot stretching evaluation 1]
The measurement coupons of Examples 23 to 46 and Comparative Examples 4 to 6 were stretched in the heating oven at 160° C. in the longitudinal direction at a stretching speed of 10 mm/min to an elongation rate of 50%. After taking out from the oven and cooling, the presence or absence of disconnection was evaluated using an optical microscope. In addition, the wiring resistance (Ω) at the position corresponding to the 4 cm interval based on the original mark was measured by the same method as the above-mentioned measurement of the wiring resistance, and the wiring resistance after expansion/contraction/wiring resistance before expansion/contraction was measured during hot stretching. The rate of change (times) was evaluated according to the following criteria. The results are shown in Tables 1 and 3.
(Presence or absence of disconnection)
A: No disconnection was observed.
B: 1-2 small cracks were confirmed C: Severe disconnection or peeling of the conductive coating film was confirmed (resistance change rate during hot stretching)
A: 5 times or more and less than 10 times B: 10 times or more and less than 100 times C: 100 times or more

The expansion rate is a value calculated as follows.
(Elongation rate) [%]={(length after stretching-length before stretching)/(length before stretching)}×100

[(5) Hot stretching evaluation 2]
In the heat drawing evaluation 1, the evaluation was performed according to the following criteria in the same manner as the heat drawing evaluation 1 except that the elongation ratio was changed to 100%. The results are shown in Tables 1 and 3.
(Presence or absence of disconnection)
A: No disconnection was observed.
B: 1-2 small cracks were confirmed C: Severe disconnection or peeling of the conductive coating film was confirmed (resistance change rate during hot stretching)
A: 10 times or more and less than 100 times B: 100 times or more and less than 1000 times C: 1000 times or more

[(6) Hot stretching evaluation 3]
The measurement coupons of Examples 47 to 69 and Comparative Examples 7 to 9 were stretched in a heating oven at 120° C. in the longitudinal direction at a stretching speed of 10 mm/min to an elongation rate of 50%. After taking out from the oven and cooling, the presence or absence of disconnection was evaluated using an optical microscope. Also, the wiring resistance (Ω) at the position corresponding to the 4 mm interval based on the original mark reference is measured by the same method as the above-mentioned measurement of the wiring resistance, and the wiring resistance after expansion/contraction/wiring resistance before expansion/contraction is the resistance during thermal stretching. The rate of change (times) was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
(Presence or absence of disconnection)
A: No disconnection was observed.
B: 1-2 small cracks were confirmed C: Severe disconnection or peeling of the conductive coating film was confirmed (resistance change rate during hot stretching)
A: 5 times or more and less than 10 times B: 10 times or more and less than 100 times C: 100 times or more

[(7) Hot stretch evaluation 4]
In the heat stretching evaluation 3, the same evaluation as the heat stretching evaluation 3 was performed except that the elongation ratio was changed to 100%. The results are shown in Tables 2 and 3.
(Presence or absence of disconnection)
A: No disconnection was observed.
B: 1-2 small cracks were confirmed C: Severe disconnection or peeling of the conductive coating film was confirmed (resistance change rate during hot stretching)
A: 10 times or more and less than 100 times B: 100 times or more and less than 1000 times C: 1000 times or more

[(8) Process resistance evaluation 1 at the time of manufacturing a molded body by overlay molding]
A hemispherical ABS resin molded product having a radius of 4 cm was aligned so as to face the surface on the conductor side so as to overlap with the position of the linear pattern of 3 mm×60 mm of the molded films of Examples 23 to 69 and Comparative Examples 4 to 6. A TOM molding machine (manufactured by Fuse Vacuum Co., Ltd.) was used to perform overlay molding at a set temperature of 160° C. to obtain a molded body in which the hemispherical molded film and the ABS resin molded product were integrated. The scraping of the linear pattern wiring and the resistance variation rate of this molded body were confirmed. The resistance fluctuation rate is measured by measuring the wiring resistance (Ω) at the position corresponding to the 6 cm interval based on the original mark standard, and the wiring resistance after expansion/contraction/wiring resistance before expansion/contraction is defined as the resistance fluctuation rate during thermal stretching (double), It evaluated by the standard of. The results are shown in Tables 1 and 3.
(Presence or absence of disconnection and resistance change rate)
A: Wiring is not scraped, and the resistance variation rate is 10 times or more and less than 50 times. B: End chipping due to wiring shaving at one or two places is confirmed, or the resistance variation rate is 50 times or more and 500 times. Less than C: One or more disconnection due to wiring scraping is confirmed

[(9) Process resistance evaluation 2 at the time of manufacturing a molded body by overlay molding]
Using the linear patterns of 3 mm×60 mm of the molded films of Examples 47 to 69 and Comparative Examples 7 to 9 and performing the overlay molding at 120° C., the process resistance during the production of the molded product by the overlay molding. A molded product was obtained in the same manner as in Evaluation 1, and the abrasion of the linear pattern wiring and the resistance variation rate during overlay molding were evaluated. The results are shown in Tables 2 and 3.

[(10) Process resistance evaluation 1 at the time of manufacturing a molded product by film insert molding]
A block-shaped metal mold having a hemispherical recess having a radius of 4 cm in the center thereof is placed opposite to the conductor side so as to overlap with the position of the linear pattern of 3 mm×60 mm of the molded films of Examples 23 to 46 and Comparative Examples 4 to 6. Of the molding film having a patterned conductor inside which is formed in a hemispherical shape by performing overlay molding at a preset temperature of 160° C. using a TOM molding machine (manufactured by Fuse Vacuum Co., Ltd.). Obtained.
Next, the hemispherical molded film is set in an injection molding machine (IS170(i5), manufactured by Toshiba Machine Co., Ltd.) equipped with a valve gate type in-mold test mold, and PC/ABS resin is set. (LUPOYPC/ABSHI5002, manufactured by LG Kagaku Co., Ltd.) was injection-molded to obtain a molded body integrated with a molding film with a patterned conductor (injection conditions: screw diameter 40 mm, cylinder temperature 260° C., mold) Temperature (fixed side,
(Movable side) 60° C., injection pressure 160 MPa (80%), holding pressure 100 MPa, injection speed 6
0 mm/sec (28%), injection time 4 seconds, cooling time 20 seconds). Washout (deformation or disconnection of the wiring pattern due to the temperature and injection pressure of the molten thermoplastic resin) and the resistance variation rate due to the injection of the molten resin in a linear pattern of this molded body were confirmed. The resistance fluctuation rate is measured by measuring the wiring resistance (Ω) at the position corresponding to the 6 cm interval based on the original mark standard, and the wiring resistance after expansion/contraction/wiring resistance before expansion/contraction is defined as the resistance fluctuation rate during thermal stretching (double), It evaluated by the standard of. The results are shown in Tables 1 and 3.
(Presence or absence of disconnection and resistance change rate)
A: No wiring washout was observed, and the resistance fluctuation rate was 10 times or more and less than 50 times B: Wiring distortion due to a slight washout was confirmed, or the resistance fluctuation rate was 50 times or more and less than 500 times C : One or more disconnection due to wiring washout is confirmed

[(11) Process resistance evaluation 2 at the time of manufacturing a molded body by film insert molding]
Using the linear patterns of 3 mm×60 mm of the molded films of Examples 47 to 69 and Comparative Examples 7 to 9 and performing the overlay molding at 120° C., the process resistance during the production of the molded product by the overlay molding. A molded product was obtained in the same manner as in Evaluation 1, and the degree of washout and the resistance variation rate due to the injection of the molten resin in the linear pattern during film insert molding were evaluated. The results are shown in Tables 2 and 3.

[Summary of results]
Comparative Examples 4 and 7 containing no wire-like fine particles, Comparative Examples 5 and 8 using conductive fine particles which are not flake-like conductive fine particles having an average particle diameter of 3 to 30 um, or containing wire-like fine particles but containing conductive fine particles The conductive layer formed by using the conductive composition of Comparative Examples 6 and 9 not containing was not broken during the integration step with the resin substrate due to friction with the molded substrate and washout due to injection of the molten resin. It became clear that the resistance value increased.

On the other hand, from the results of Examples 23 to 69, the conductive composition of the present embodiment does not cause disconnection due to friction with the molded substrate and injection of molten resin during the integration step with the resin substrate, The increase in the resistance value was also kept satisfactorily. This is because the conductive fine particles of the conductive composition of the present embodiment are flake-shaped conductive fine particles having an average particle diameter of 3 to 30 μm and include wire-shaped fine particles. By forming a high-strength filler aggregation network with fine particles, while exhibiting excellent high-temperature cohesive force and electrical conductivity retention characteristics that resist friction with a molded substrate and injection of molten resin, it also impairs stretchability during molding. It is presumed that they were compatible with each other. In addition, compatibility of the above characteristics is required when the metal oxide wire, the metal hydroxide wire, the metal sulfate wire, the ceramic wire-like fine particles such as the metal silicate wire are used together with the flaky conductive fine particles. It was especially excellent in that it is difficult to impair the stretchability during molding by exerting the cohesive force at high temperature. Although there are unclear points in the mechanism for expressing such properties, the mechanical rigidity and high dispersibility of the ceramic-based wire-like fine particles are to form a filler aggregation network that is strong and does not excessively hinder the deformability. thinking. Further, even when the resin contains a specific functional group and is used in combination with crosslinking by a crosslinking agent, or when the resin has a glass transition point of 0° C. or higher and lower than 150° C., these properties are further excellent.

Further, due to the above characteristics, according to the molded film provided with the conductive layer of the conductive composition of the present invention, an excellent wiring-integrated molded body was obtained even if the substrate surface had a three-dimensional shape not flat.

As described above, the molded film and the wiring-integrated molded body using the conductive composition of the present embodiment can be directly applied to plastic housings and three-dimensionally shaped components such as home electric appliances, automobile parts, robots and drones. It is possible to build a lightweight and space-saving circuit without damaging the touch sensor, antenna, planar heating element, electromagnetic wave shield, inductor (coil), resistor, and mounting various electronic components. To In addition, it is extremely useful for making electronic devices lighter, thinner, shorter, smaller, more flexible in design, and more multifunctional.

1 Base Film 2 Conductive Layer 3 Decorative Layer 4 Electronic Component 5 Pin 10 Molding Film 11 Mold 12 Injection Molding Mold 13 Opening 14 Injection 15 Rise 16 Pressurization 17 Resin 20 Base Material 21 Upper Chamber Box 22 Lower Chamber Box 30 molded body

Claims (12)

A conductive composition for producing a molded film for forming a conductive layer on a substrate surface having an uneven surface or a three-dimensional curved surface,
Contains resin (A), flaky conductive fine particles (B), and wire fine particles (C),
The flaky conductive fine particles (B) have an average particle size of 3 μm or more and less than 30 μm, and one or more kinds of conductive particles selected from the group consisting of silver powder, copper powder, silver-coated powder, copper alloy powder, and carbon fine particles. Containing fine particles,
A conductive composition for a molded film, wherein the content of the conductive fine particles (B) is 50 to 85 mass% in the entire solid content of the composition. The electrically conductive composition for a molded film according to claim 1, wherein the wire-shaped fine particles (C) include one or more kinds of wire-shaped fine particles selected from the group consisting of silver nanowires, carbon nanotubes, and ceramic-based wire-shaped fine particles. .. The molding film according to claim 2, wherein the ceramic-based wire-shaped fine particles include at least one ceramic-based wire-shaped fine particle selected from the group consisting of a metal oxide wire, a metal hydroxide wire, and a metal oxoate wire. Conductive composition for use. The resin (A) has two or more first reactive functional groups selected from the group consisting of a hydroxy group, an amino group, a carboxyl group, and an acid anhydride group in one molecule,
The cross-linking agent (D) having two or more second reactive functional groups capable of forming a cross-link with the first reactive functional group in one molecule, further comprising: A conductive composition for a molded film. 5. The resin (A) according to claim 1, wherein the resin (A) has a glass transition temperature of 0° C. or higher and lower than 150° C. and a glass transition temperature of 0° C. or lower. Conductive composition for molded film. A molded film having a conductive layer on a base film,
A molded film, wherein the conductive layer is a cured product of the conductive composition for a molded film according to any one of claims 1 to 5. On the base film, a decorative film, and a molded film having a conductive layer,
A molded film, wherein the conductive layer is a cured product of the conductive composition for a molded film according to any one of claims 1 to 5. The molded film according to claim 6 or 7, wherein the base film is a film selected from polycarbonate, polymethylmethacrylate, polypropylene, and polyethylene terephthalate, or a laminated film thereof. A molded body in which a conductive layer is laminated on a base material,
A molded product, wherein the conductive layer is a cured product of the conductive composition for a molded film according to any one of claims 1 to 5. A step of printing the conductive composition for molded film according to any one of claims 1 to 5 on a base film to produce a molded film;
Placing the molded film on a substrate,
A method for producing a molded body, comprising the step of integrating the molded film and the base material by an overlay molding method. A step of printing the conductive composition for molded film according to any one of claims 1 to 5 on a base film to produce a molded film;
A step of molding the molded film into a predetermined shape,
Placing the molded film after molding in a mold for injection molding,
A method for producing a molded body, comprising the steps of molding a base material by injection molding and integrating the molding film and the base material. A step of printing the conductive composition for molded film according to any one of claims 1 to 5 on a base film to produce a molded film;
Placing the molding film in a mold for injection molding,
Molding the base material by injection molding and transferring the conductive layer in the molding film to the base material side.

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