Conductive Composition for Forming Film, Forming Film and Method for Producing the Same, Molded Body and Method for Producing the Same

Abstract

To provide a conductive composition for a molding film that enables manufacture of a molding film in which lowering of conductivity by tensile force is suppressed.SOLUTION: A conductive composition for a molding film contains a resin (A), conductive fine particles (B) and a solvent (C), where the solvent (C) contains a specific arylalkyl alcohol solvent (C1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a conductive composition for a molded film, a molded film and a method for producing the same, a molded body and a method for producing the same.

Background Art

[0002] Patent Document 1 discloses a specific integrated conductive circuit molded article having a resin molded body, a base film embedded flush with one surface of the resin molded body, and a conductive circuit disposed between the resin molded body and the base film. Patent Document 1 describes, as a method for manufacturing the integrated conductive circuit molded article, a method in which a base film having a specific conductive circuit formed thereon is placed on the cavity surface of an injection mold, and then molten resin is injected to injection-mold the resin molded body. In Patent Document 1, the conductive circuit is formed by etching a specific transparent metal thin film.

[0003] As a method for forming a conductive circuit in place of the etching method, a printing method using conductive ink has been studied. According to the method of printing conductive ink, compared with the etching method, there are no complicated steps, a conductive circuit can be easily formed, productivity can be improved, and cost reduction can be achieved. For example, Patent Document 2 discloses a specific conductive ink containing specific conductive fine particles and a specific epoxy resin as a low-temperature treatment type conductive ink capable of forming a high-definition conductive pattern by screen printing. According to screen printing, thickening of the conductive pattern is possible, and reduction of the resistance of the conductive pattern is said to be achievable.

[0004] Further, Patent Document 3 discloses a method for manufacturing a decorative sheet capable of expressing a three-dimensional stereoscopic effect, in which a laminate having a printed layer printed in a pattern on a transparent resin layer and a laminated sheet having a decorative layer on a base film are thermocompression-bonded to make the decorative layer have an uneven shape along the pattern of the printed layer.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] According to the method of Patent Document 1, a conductor can be easily provided on the surface of a molded body. On the other hand, there is an increasing demand to form conductive circuits on the surfaces of base materials with various shapes, such as base materials having uneven surfaces or curved surfaces. When forming a conductive circuit by laminating a film having a conductive layer on such a base material surface, 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 partially generated in the conductive layer. Due to the tensile force, breakage of the conductive layer may occur, resulting in a problem of reduced conductivity. Further, when forming a conductive circuit on a base material having such an uneven surface or curved surface, after deforming the film having the conductive layer or simultaneously with deforming the film, it is necessary to integrate the film and the base material. However, in this integration process, stress stress due to friction with a plastic base material at high temperature is applied to the conductive circuit. Also due to the high-temperature stress stress, breakage of the conductive layer may occur, resulting in a problem of reduced conductivity.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide a conductive composition for a molded film capable of manufacturing a molded film in which a decrease in conductivity due to tensile force and stress stress at high temperature is suppressed, a molded film in which a decrease in conductivity due to tensile force and stress stress at high temperature is suppressed, and a molded body having excellent conductivity and a method for manufacturing the same.

Means for Solving the Problems

[0008] The conductive composition for a molding film according to the present embodiment is a conductive composition for manufacturing a molding film for forming a conductive layer on the surface of a substrate having an uneven surface or a three-dimensional curved surface, containing a resin (A), conductive fine particles (B), and a solvent (C), wherein the solvent (C) includes a solvent (C1) represented by the following formulas (1) to (3).

[0009]

Chemical formula

[0010] In the formula, R 1 represents a divalent alkylene group having 2 to 5 carbon atoms, R 2 ~R 6 each represents a hydrogen atom or a methyl group. Also, R 7 ~R 11 each represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a methoxy group, and among R 7 ~R 11 at least one is a methyl group, an ethyl group, an isopropyl group, or a methoxy group.

[0011] One embodiment of the conductive composition for a molding film of the present embodiment is that the conductive fine particles (B) include one or more conductive fine particles selected from silver powder, copper powder, silver-coated powder, copper alloy powder, conductive oxide powder, and carbon fine particles.

[0012] One embodiment of the conductive composition for a molding film of the present embodiment is that the resin (A) has a cyclic structure in the main chain.

[0013] One embodiment of the conductive composition for a molding film of the present embodiment is that the resin (A) has an aromatic ring structure and an ester bond in the main chain.

[0014] One embodiment of the conductive composition for a formed film of the present embodiment is such that the content of the solvent (C1) is 40 parts by mass or more in total per 100 parts by mass of the solvent (C).

[0015] One embodiment of the conductive composition for a formed film of the present embodiment is such that the solvent (C1) is a solvent represented by the formula (1), and R in the formula 1 is one selected from the group consisting of a 1,1-ethylene group, a 1,2-ethylene group, a 1,1-propylene group, a 1,2-propylene group, a 2,2-propylene group, or a 1,3-propylene group, or is a solvent represented by the formula (3), and among R 7 ~R 11 one or two of them are a methyl group, an ethyl group, or a methoxy group.

[0016] The formed film according to the present embodiment is a formed film having a conductive layer on a base film, wherein the conductive layer is a cured product of the conductive composition for a formed film of the present embodiment.

[0017] One embodiment of the formed film of the present embodiment is a formed film having a decorative layer and a conductive layer on a base film, wherein the conductive layer is a cured product of the conductive composition for a formed film of the present embodiment.

[0018] One embodiment of the formed film of the present embodiment is such that the base film is a film selected from polycarbonate, polymethyl methacrylate, polypropylene, and polyethylene terephthalate, or a laminated film thereof.

[0019] The formed body according to the present embodiment is a formed body having a conductive layer laminated on a base material, wherein the conductive layer is a cured product of the conductive composition for a formed film of the present embodiment.

[0020] The first manufacturing method of the formed body according to the present embodiment includes a step of manufacturing a formed film by printing the conductive composition for a formed film of the present embodiment on a base film and drying it. A step of disposing the formed film on a base material; A step of integrating the formed film and the base material by an overlay forming method.

[0021] The second manufacturing method of the formed body according to the present embodiment includes a step of manufacturing a formed film by printing the conductive composition for the formed film of the present embodiment on a base film and drying it; A step of forming the formed film into a predetermined shape; A step of disposing the formed film after forming in a mold for injection molding; A step of forming a base material by injection molding and integrating the formed film and the base material.

[0022] The third manufacturing method of the formed body according to the present embodiment includes a step of manufacturing a formed film by printing the conductive composition for the formed film of the present embodiment on a base film and drying it; A step of disposing the formed film in a mold for injection molding; A step of forming a base material by injection molding and transferring the conductive layer in the formed film to the base material side.

Advantages of the Invention

[0023] According to the present invention, it is possible to provide a conductive composition for a formed film capable of manufacturing a formed film in which a decrease in conductivity due to tensile force and stress at high temperature is suppressed, a formed film in which a decrease in conductivity due to tensile force and stress at high temperature is suppressed, and a formed body excellent in conductivity and a manufacturing method thereof.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0025] Hereinafter, the conductive composition for a molded film, the molded film, the molded body, and the manufacturing method thereof according to the present embodiment will be described in detail in order. In the present embodiment, the cured product includes not only those cured by a chemical reaction but also those cured without a chemical reaction, such as those hardened by volatilization of a solvent.

[0026] [Conductive Composition for Molded Film] It contains a resin (A), conductive fine particles (B), and a solvent (C). The solvent (C) includes a solvent (C1) represented by the following formulas (1) to (3).

[0027] [Chemical Formula]

[0028] In the formula, R 1 represents a divalent alkylene group having 2 to 5 carbon atoms. R 2 to R 6 each represent a hydrogen atom or a methyl group. Also, R 7 to R 11 each represent a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a methoxy group, and at least one of R 7 to R 11 is a methyl group, an ethyl group, an isopropyl group, or a methoxy group.

[0029] In order to manufacture a molding film that can be applied to a non-flat substrate surface and has process suitability for the integration process with a plastic substrate, the inventors examined a screen-printable conductive composition. In order to apply it to the manufacture of a molding film, various adjustments and examinations were made on the resin structure, conductive fine particles, and solvent. As a result, depending on the type of solvent contained in the conductive composition, particularly the use of a solvent having a specific aromatic alcohol structure, the frequency of cracks generated when the obtained molding film was subjected to tensile deformation at a high temperature at which it could be molded differed. Furthermore, depending on the glass transition temperature and main chain structure of the resin combined with the above mixed solvent, the frequency of printing defects such as chipping and streaking when printing at high speed, and the magnitude of the change in resistance value during tensile deformation when the degree of deformation was particularly large at the above high temperature were found to be different. As a result of investigations based on such findings, when a conductive composition containing no solvent having a specific aromatic alcohol structure was printed and heat-dried on a resin film, significant deterioration in the conductivity of the conductive layer pattern and cracking of the conductive layer occurred when the molding film was deformed by pulling at a high temperature corresponding to its softening point. Furthermore, it became clear that when the printing speed was increased during printing of the above conductive composition, the frequency of occurrence of printing defects such as chipping and streaking increased significantly. The same was true when a conductive layer was provided on a decorative layer.

[0030] Even in the case of a molding film having a conductive layer that causes cracking of the conductive layer and a large change in resistance value when deformed by pulling at such a high temperature, there is no problem when it is used alone as a flat film circuit board or the like, or when it is used in a bent state on a two-dimensional curved surface. However, when it is used as a molding film that follows and integrates with the shape of a non-flat substrate surface, such as an uneven shape or a three-dimensional curved surface shape, the molding film will be deformed. Therefore, it is predicted that the conductivity of the conductive layer will decrease due to the inability of the conductive layer to follow the deformation of the resin film and peeling or disconnection from the base film. In addition, the uneven surface and three-dimensional curved surface in the present invention refer not only to a surface having a smooth curved cross-section, but also to the entire three-dimensional surface having acute-angled corners or rectangular shapes. That is, it refers to a three-dimensional shape that cannot be formed only by deforming a plane without stretching or shrinking it, and for example, three-dimensional shapes such as hemispherical, conical, cylindrical, and quadrangular prism shapes. In addition, when a certain three-dimensional shape has both elements of the above-mentioned plane or two-dimensional curved surface and three-dimensional curved surface in a continuous three-dimensional surface, for example, regarding a three-dimensional shape in which one or more partial hemispherical shapes are combined with a planar shape, since it is a three-dimensional shape that cannot be formed by deforming it without stretching or shrinking the plane as a whole, this is also considered to be a three-dimensional curved surface. That is, the uneven surface and three-dimensional curved surface in the present invention cannot be realized by bending a flexible substrate or the like, and can be realized, for example, by shaping by three-dimensional molding under heating of a formable film.

[0031] As a result of intensive studies based on these findings, the inventors of the present invention have found that when a solvent having a specific aromatic alcohol structure is contained, the change in resistance value that occurs when the formed film is pulled with a particularly large degree of deformation is small, and when the printing speed during printing the conductive composition is increased and printing is performed in a state where productivity is increased, the occurrence of printing defects such as chipping and streaking is highly suppressed, and thus the present invention has been completed. That is, the conductive composition for a formed film of the present invention can easily produce a formed film having a conductive layer of a thick film excellent in conductivity by screen printing or the like by using a resin, conductive fine particles, and a solvent having a specific aromatic alcohol structure in combination. In addition, the formed film produced using the conductive composition for a formed film suppresses a decrease in conductivity even when used on a non-flat substrate surface. Furthermore, by using the formed film, a molded body 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 shaped plastic having practical strength can be obtained.

[0032] The conductive composition for a formed film of the present embodiment contains at least a resin (A), conductive fine particles (B), and a solvent (C), and may further contain other components as necessary. Hereinafter, each component of such a conductive composition for a formed film will be described.

[0033] <Resin (A)> The conductive composition of the present embodiment contains a binder resin (A) in order to impart film-forming properties and adhesion to a base film or a 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), disconnection of the conductive layer due to stretching is suppressed.

[0034] The resin (A) can be appropriately selected from resins used for the conductive composition applications. Examples of the resin (A) include acrylic resins, vinyl ether resins, polyether resins, polyester resins, polyurethane resins, epoxy resins, phenoxy resins, polycarbonate resins, polyvinyl chloride resins, polyolefin resins, styrene block copolymers, polyamide resins, polyimide resins, etc. It can be used alone or in combination of two or more.

[0035] As for the main chain structure of the resin (A), due to the high affinity with the solvent (C) described later, particularly (C1), the spread and entanglement of larger molecular chains of the resin (A) in the conductive composition enhance the conductivity maintenance during forming and stretching and the defect suppression performance during printing. In this regard, it is preferable that the main chain structure includes a cyclic structure, and it is particularly preferable that the main chain structure has both an aromatic ring structure and an ester bond. In addition, the cyclic structure in the present invention refers to an alicyclic structure, an aromatic ring structure, or a heterocyclic structure with one ring having 4 to 14 members. Examples of the alicyclic structure include monocyclic structures such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cyclohexene ring, cycloheptane ring, cyclooctane ring, cyclodecane ring, cyclotetradecane ring, and condensed ring structures such as bornane ring, isobornane ring, adamantane ring, decalin ring, steroid skeleton, etc. Examples of the aromatic ring structure include monocyclic structures such as benzene ring, furan ring, 1,4-dioxin ring, pyrrole ring, pyridine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, thiophene ring, triazole ring, tetrazole ring, and condensed ring structures such as naphthalene ring, tetralin ring, azulene ring, anthracene ring, perylene ring, indane ring, indole ring, benzofuran ring, benzimidazole ring, benzoxazole ring, etc. In the present invention, as in the above examples, a structure in which an aromatic ring structure is condensed or directly bonded to an alicyclic structure, or a hetero ring structure exhibiting aromaticity is regarded as an aromatic ring structure. In the present invention, the hetero ring structure refers to a ring structure containing hetero atoms (non-carbon atoms) other than the above aromatic ring structure, and examples thereof include tetrahydrofuran ring, pyran ring, tetrahydropyran ring, pyrrolidine ring, piperidine ring, piperazine ring, isocyanurate ring, etc. The linking site of the cyclic structure in the main chain structure of the resin (A) is not particularly limited as long as it is linked to the main chain through two or more covalent bonds from any one to two atoms constituting the cyclic structure.

[0036] In this embodiment, it is also preferable that the resin (A) 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 crosslinked by combining with a crosslinking agent (D) described later, and can be suitably used in applications where hardness is required for the conductive layer.

[0037] 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, and more preferably 2 mgKOH / g or more and 350 mgKOH / g or less. The details of the calculation method of the functional group value will be described in the 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 total of the hydroxyl value and the acid value of the resin (A).

[0038] From the viewpoint of both maintaining conductivity during molding and drawing and withstanding frictional stress at high temperatures in the process of integrating with the plastic substrate in the integration process of the resin (A) and the plastic substrate, the glass transition temperature (Tg) of the resin (A) is preferably 0°C or more and 130°C or less, and more preferably 5°C or more and 120°C or less. Also, from the same viewpoint, when the resin (A) has a plurality of glass transition points, it is preferable that none of the glass transition points is less than 0°C.

[0039] In this embodiment, the resin (A) may be synthesized and used by the examples described below or other known methods, or a commercially available product having desired physical properties may be used. In this embodiment, the resin (A) can be used alone or in combination of two or more.

[0040] The content ratio of the resin (A) in the conductive composition of this embodiment may be appropriately adjusted according to the use and the like and is not particularly limited, but is preferably 5% by mass or more and 50% by mass or less, and more preferably 8% by mass or more and 40% by mass or less with respect to the total solid content contained in the conductive composition. If the content ratio of the resin (A) is at least the above lower limit value, the film-forming property and the adhesion to a base film or the like can be improved, and flexibility can be imparted to the conductive layer. Also, if the content ratio of the resin (A) is at most the above upper limit value, the content ratio of the conductive fine particles (B) can be relatively increased, and a conductive layer excellent in conductivity can be formed.

[0041] <Conductive fine particles (B)> The conductive fine particles (B) are those in which a plurality of conductive fine particles come into contact within the conductive layer to exhibit conductivity, and in the present embodiment, they are appropriately selected and used from those that can obtain conductivity without heating at a high temperature. Examples of the conductive fine particles used in the present embodiment include metal fine particles, carbon fine particles, and conductive oxide fine particles. Examples of the metal fine particles include, for example, simple metal powders such as gold, silver, copper, nickel, chromium, palladium, rhodium, ruthenium, indium, aluminum, tungsten, molybdenum, and platinum, alloy powders such as copper-nickel alloy, silver-palladium alloy, copper-tin alloy, silver-copper alloy, and copper-manganese alloy, and metal-coated powders in which the surface of the simple metal powder or alloy powder is coated 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, and ruthenium oxide.

[0042] In the present embodiment, among them, it is preferably included one or more kinds of conductive fine particles selected from silver powder, copper powder, silver-coated powder, copper alloy powder, conductive oxide powder, and carbon fine particles. By using these conductive fine particles (B), a conductive layer excellent in conductivity can be formed without sintering, and further, a conductive layer excellent in stretchability and conductivity retention performance when formed into a three-dimensional shape as a molding film described later can be formed.

[0043] The shape of the conductive fine particles (B) is not particularly limited, and spherical, flake-shaped, chain-aggregated, etc. can be appropriately used, but from the viewpoints of maintaining printability and maintaining conductivity during molding tension, flake-shaped or chain-aggregated ones are particularly preferred. In the present invention, the term "spherical" refers to all particles having an aspect ratio of less than 2, specifically about 1 or more and 2 or less, including a true sphere, an oval shape, a crushed sphere, a gravel shape, and a polyhedral shape. The term "flake-like" in the present invention refers to all two-dimensional planar flat shapes such as scaly, flaky, plate-like, flat, and sheet-like shapes. Among them, those having an aspect ratio of 3 or more and 500 or less are particularly preferred. Further, the term "chain-aggregated" in the present invention refers to all amorphous shapes in which a plurality of the above spherical conductive fine particles are directly fused and bonded.

[0044] The D50 particle size of the conductive fine particles (B) is not particularly limited. However, from the viewpoints of dispersibility and printability retention in the conductive composition, conductivity maintenance during molding, injection molding process resistance by the molten resin, and friction resistance at high temperatures against the molded resin, it is preferably 0.2 μm or more and less than 30 μm, and particularly preferably 0.7 μm or more and less than 15 μm. In this embodiment, the average particle size of the conductive fine particles (B) is calculated as follows. In accordance with the laser diffraction / scattering method described in JIS M8511 (2014), using a laser diffraction / scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd.: Microtrac 9220FRA), an appropriate amount of the conductive fine particles (B) was added to an aqueous solution containing 0.5% by volume of a commercially available surfactant polyoxyethylene octylphenyl ether (manufactured by Roche Diagnostics K.K.: Triton X-100) as a dispersant, and after irradiating with 40 W of ultrasonic waves for 180 seconds while stirring, the measurement was performed. The value of the obtained median diameter (D50) was taken as the average particle size of the conductive fine particles (B).

[0045] In this embodiment, the conductive fine particles (B) can be used alone or in combination of two or more. The content ratio of the conductive fine particles (B) in the conductive composition of the present embodiment may be appropriately adjusted according to the use and the like and is not particularly limited, but it is preferably 50% by mass or more and 90% by mass or less, and more preferably 55% by mass or more and 85% by mass or less with respect to the total amount of the solid content contained in the conductive composition. If the content ratio of the conductive fine particles (B) is equal to or higher than the above lower limit value, a conductive layer excellent in conductivity can be formed. Further, if the content ratio of the conductive fine particles (B) is equal to or lower 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 flexibility can be imparted to the conductive layer.

[0046] <Solvent (C)> In the present embodiment, the solvent (C) is contained in order to dissolve the resin (A) to impart fluidity and printability, or to adjust the spread and entanglement of the molecular chains in the composition of the resin (A). Further, in the present embodiment, by containing the solvent (C), the spread of the above molecular chains is adjusted and wettability at the time of printing on the base film is imparted, so that the patterning accuracy at the time of printing can be improved.

[0047] The solvent (C) of the present invention contains a high-boiling solvent (C1) having a specific structure described later. By containing the solvent (C1), not only is the solubility of the resin (A) and the suppression of infiltration into the base film excellent, but also appropriate wettability with respect to the base film at the time of printing is imparted, so that the patterning accuracy at the time of printing, particularly at high speed, is improved. Further, the polymer chains of the resin (A) are widely spread in the solvent (C) to exhibit appropriate fluidity, and when the conductive layer is formed, the polymer chains are well entangled with each other, so that the effect of suppressing local stress concentration on a microscale that leads to the disconnection of the connection (conductive path) between the conductive particles in the conductive layer can be obtained.

[0048] The solvent (C1) of the present invention can be used without particular limitation as long as it is a solvent having the structures of the following formulas (1) to (3).

[0049]

Chemical formula

[0050] In the formula, R 1 represents a divalent alkylene group having 2 to 5 carbon atoms, R 2 ~R 6 each represents a hydrogen atom or a methyl group. Also, R 7 ~R 11 each represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a methoxy group, and among R 7 ~R 11 at least one is a methyl group, an ethyl group, an isopropyl group, or a methoxy group.

[0051] The solvent (C1) can be used alone or in combination of two or more. Also, even if the solvent (C1) is a solid at normal temperature when used alone, it can be used without problem as long as it becomes a liquid as a mixed solvent with other solvents (C1) having different structures or the other solvents (C2) described later. Furthermore, as the solvent (C1), it is particularly preferable that the boiling point is 180°C or higher and 270°C or lower.

[0052] Specific examples of such a solvent (C1) include those having the structures listed below.

[0053]

Chemical formula

[0054]

Chemical formula

[0055]

Chemical formula

[0056]

Chemical formula

[0057]

Chemical formula

[0058] [Chemical formula]

[0059] [Chemical formula]

[0060] [Chemical formula]

[0061] [Chemical formula]

[0062] Furthermore, more preferable examples of the solvent (C1) include the solvent represented by the formula (1), and R in the formula 1 is one selected from the group consisting of a 1,1-ethylene group (ethylidene group), 1,2-ethylene group, 1,1-propylene group (propylidene group), 1,2-propylene group (methylethylene group), 2,2-propylene group (dimethylmethylene group), or 1,3-propylene group (propanylene group), or the solvent represented by the formula (3), and among R 7 ~R 11 one or two of them being a methyl group, ethyl group, or methoxy group are particularly preferable. By using these, a better balance of wettability with respect to the base film during printing is achieved, and the polymer chains of the resin (A) are more widely spread in the solvent (C), exhibiting appropriate fluidity and being particularly preferable in that the polymer chains are well intertwined when forming the conductive layer. Specific examples of such particularly preferred solvents (C1) include 2-phenylethanol, 1-phenylethanol, 2-(2-methylphenyl)ethanol, 2-(3-methylphenyl)ethanol, 2-(4-methylphenyl)ethanol, 3-phenyl-1-propanol, 1-phenyl-1-propanol, 1-phenyl-2-propanol, 2-phenyl-1-propanol, 2-methylbenzyl alcohol, 3-methylbenzyl alcohol, 4-methylbenzyl alcohol, 2-methoxybenzyl alcohol, 3-methoxybenzyl alcohol, 4-methoxybenzyl alcohol, 3,4-dimethylbenzyl alcohol, and the like.

[0063] The solvent (C) of the present invention may contain a solvent (C2) other than the solvent (C1). The solvent (C2) preferably has a boiling point of 180°C or higher and 270°C or lower. Examples include glycol esters such as 2-ethoxy(2-ethoxy)ethyl acetate and 2-ethoxy(2-ethoxy)butyl acetate, and glycol ethers such as 2-ethoxy(2-ethoxy)ethanol, 2-butoxy(2-ethoxy)ethanol, and diethylene glycol diethyl ether, but are not particularly limited.

[0064] From the viewpoint of effectively exhibiting the above-described high-speed printing suitability and the characteristic of suppressing the disconnection of the conductive path, the content of the solvent (C1) in 100 parts by mass of the solvent (C) of the present invention is preferably 40 parts by mass or more and 100 parts by mass or less.

[0065] <Optional component> The conductive composition of the present invention may further contain other components as necessary. Such other components include, in addition to the crosslinking agent (D) described later, a dispersant, an anti-friction improver, an infrared absorber, an ultraviolet absorber, a fragrance, an antioxidant, an organic pigment, an inorganic pigment, an antifoaming agent, a silane coupling agent, a plasticizer, a flame retardant, a moisturizing agent, and the like.

[0066] <Crosslinking agent (D)>

[0067] In this embodiment, a crosslinking agent (D) may be additionally used to crosslink the resin (A). As the crosslinking agent (D), it can be appropriately selected from those having two or more reactive functional groups capable of forming a crosslink with the reactive functional groups of the resin (A) in one molecule. Examples of such reactive functional groups include an epoxy group, an isocyanate group, a blocked isocyanate group, an alkyloxyamino group, an aziridinyl group, an oxetanyl group, a carbodiimide group, a β-hydroxyalkylamide group, and the like. 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, more preferably 0.3 parts by mass or more and 25 parts by mass or less, based on 100 parts by mass of the resin (A).

[0068] Furthermore, in this embodiment, it is particularly preferable that the resin (A) has two or more first reactive functional groups selected from a hydroxy group or an amino group, and the crosslinking agent (D) is selected and combined with a blocked isocyanate. The blocked isocyanate may be an isocyanate compound in which the isocyanate groups of a bifunctional isocyanate such as hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate or their allophanate, biuret, adduct, prepolymer, isocyanurate forms, etc., having two or more functional groups, are protected (blocked) with ε-caprolactam, MEK oxime, etc., and is not particularly limited. Specifically, those in which the isocyanate groups of the above isocyanate compounds are blocked with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, 3,5-dimethylpyrazole, diisopropylamine, diethyl malonate, ethyl acetoacetate, phenol, etc. can be mentioned. By using such a combination, a conductive layer with particularly excellent toughness and excellent substrate adhesion at high temperatures due to the crosslinking point structure generated by crosslinking can be obtained, and thus a decrease in conductivity due to tensile force is particularly suppressed.

[0069] <Method for Manufacturing Conductive Composition> The manufacturing method of the conductive composition of the present embodiment may be any method for dissolving or dispersing the resin (A), the conductive fine particles (B), the wire-shaped fine particles (C), and other components used as necessary, and can be manufactured by mixing them using known mixing means.

[0070] [Molded Film] The molded film of the present embodiment is a molded film provided with a conductive layer on a base film, characterized in that the conductive layer is a cured product of the conductive composition for the molded film. According to the molded film of the present embodiment, a molded body having a conductive circuit formed on an arbitrary base material surface such as a concave-convex surface or a curved surface can be obtained. According to the molded film of the present embodiment, a molded body having a conductive circuit formed on an arbitrary base material surface such as a concave-convex surface or a curved surface can be obtained. The layer structure of the molded film of the present embodiment will be described with reference to FIGS. 1 and 2. FIGS. 1 and 2 are schematic cross-sectional views showing an example of the molded film of the present 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 as in the example of FIG. 1. The molded film 10 shown in the example of FIG. 2 has a decorative layer 3 on the base film 1, and includes a conductive layer 2 on the decorative layer 3. Further, as shown in the example of FIG. 2, the molded film 10 may include an electronic component 4 and a pin 5 for connecting to an extraction circuit on the conductive layer 2. Also, although not shown, a resin layer for protecting the conductive layer or the electronic component may be provided on the conductive layer 2 or on the electronic component 4, and the resin layer may be an adhesive layer or an adhesive layer for improving the adhesion to a base material described later. Also, although not shown, when the molded film 10 of the present embodiment includes a decorative layer 3, in addition to the example of FIG. 2, a layer structure in which the decorative layer 3 is provided on one surface of the base film 1 and the conductive layer 2 is provided on the other surface may also be used. The formed film of this embodiment includes at least a base film and a conductive layer, and may optionally have other layers. Each layer of such a formed film will be described below.

[0071] <Base film> In this embodiment, the base film can be appropriately selected from those having flexibility and stretchability such that it can follow the shape of the base material surface under the forming temperature conditions during base material formation, and it is preferably selected according to the use of the formed body, the manufacturing method of the formed body, etc. For example, when adopting the overlay forming method or the film insert method described later as the manufacturing method of the formed body, since the base film remains in the formed body, the base film can be selected considering functions such as serving as a protective layer for the conductive layer. On the other hand, when adopting the in-mold transfer method described later as the manufacturing method of the formed body, it is preferable to select a base film having peelability.

[0072] The base film can be appropriately selected from the above viewpoints. For example, films such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polystyrene, polyimide, polyamide, polyethersulfone, polyethylene naphthalate, polybutylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, cycloolefin polymer, ABS (acrylonitrile-butadiene-styrene copolymer resin), AES (acrylonitrile-ethylene-styrene copolymer resin), Kydax (acrylic-modified vinyl chloride resin), modified polyphenylene ether, and polymer alloys composed of two or more of these resins, or laminated films of these may be used. Among them, films selected from polycarbonate, polymethyl methacrylate, polypropylene, and polyethylene terephthalate, or laminated films of these are preferable. As the laminated film, among others, a laminated film of polycarbonate and polymethyl methacrylate is preferable. The method for manufacturing the laminated film of polycarbonate and polymethyl methacrylate is not particularly limited. The polycarbonate film and the polymethyl methacrylate film may be laminated by bonding them together, or the polycarbonate and the polymethyl methacrylate may be co-extruded to form a laminated film. Also, it is preferable that the surfaces of these base films are subjected to a surface modification treatment such as corona treatment.

[0073] Furthermore, if necessary, for the purpose of improving the printability of the conductive composition, an anchor coat layer may be provided on the base film, and the conductive composition may be printed on the anchor coat layer. The anchor coat layer is not particularly limited as long as it has good adhesion to the base film and further good adhesion to the conductive composition and follows the film during molding. Also, organic fillers such as resin beads and inorganic fillers such as metal oxides may be added as necessary. The method for providing the anchor coat layer is not particularly limited, and it can be obtained by coating, drying, and curing using a conventionally known coating method. Moreover, if necessary, for preventing damage to the surface of the molded body, a hard coat layer may be provided on the base film, and the 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 good surface hardness and follows the film during molding. Also, organic fillers such as resin beads and inorganic fillers such as metal oxides may be added as necessary. The method for providing the hard coat layer is not particularly limited, and it can be obtained by coating, drying, and curing using a conventionally known coating method.

[0074] Also, when the molded film of the present embodiment has a decorative layer, it is preferable to select a base film having transparency.

[0075] The thickness of the base film is not particularly limited, but for example, it can be 10 μm or more and 500 μm or less, and preferably 20 μm or more and 450 μm or less.

[0076] <Conductive layer> In the formed 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. In this embodiment, it is preferably formed by a screen printing method, a pad printing method, a stencil printing method, a screen offset printing method, a dispenser printing method, a gravure offset printing method, an inversion offset printing method, or a microcontact printing method, and more preferably formed by a screen printing method. In the screen printing method, in order to cope with the high definition of the conductive circuit pattern, it is preferable to use a fine mesh screen, particularly preferably a fine mesh screen of about 300 to 650 meshes. At this time, the open area of the screen is preferably about 20 to 50%. The screen wire diameter is preferably about 10 to 70 μm. Examples of the types of screen plates include polyester screens, combination screens, metal screens, nylon screens, etc. Also, when printing a high-viscosity paste-like material, a high-tension stainless steel screen can be used. The squeegee for screen printing can be any shape such as round, rectangular, or square, and a polished squeegee can also be used to reduce the attack angle (the angle between the plate and the squeegee during printing). Other printing conditions, etc. can be appropriately designed according to conventionally known conditions.

[0077] After printing the conductive composition by screen printing, it is heated to perform drying and cross-linking reactions for curing. For sufficient volatilization of the solvent and cross-linking reaction, the heating temperature is preferably 80 to 230 °C, and the heating time is preferably 10 to 120 minutes. Thereby, a patterned conductive layer can be obtained. The pattern of the conductive layer is not particularly limited. For example, it may be a straight line, a curve, a mesh, a solid pattern or a cut-out pattern such as a partial square, circle, diamond shape, etc. and any combination thereof, or the entire conductive layer may be a solid pattern on one side, 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.

[0078] The film thickness of the conductive layer may be appropriately adjusted according to the required conductivity and the like, and is not particularly limited. For example, it can be 0.5 μm or more and 20 μm or less, and preferably 1 μm or more and 15 μm or less.

[0079] <Decoration layer> From the viewpoint of the design property of the obtained molded body, the molded film of the present embodiment may have a decoration layer. The decoration layer may be a layer having a single color tone, or may be one with an arbitrary pattern. As an example, the decoration layer can be formed by preparing a decoration ink containing a coloring material, a resin, and a solvent, and then applying the decoration ink to the base film by a known printing means. As the coloring material, it can be appropriately selected and used from known pigments and dyes. As the resin, it is preferably appropriately selected and used from those similar to the resin (A) in the conductive composition of the present embodiment. The thickness of the decoration layer is not particularly limited, but for example, it can be 0.5 μm or more and 10 μm or less, and preferably 1 μm or more and 5 μm or less.

[0080] [Molded body] The molded body of the present embodiment is a molded body in which at least a conductive layer is laminated on a base material, 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. Since the molded body of the present embodiment is formed by a molded film using the conductive composition for a molded film of the present embodiment, it becomes a molded body in which a conductive circuit is formed on an arbitrary surface such as a concave-convex surface or a curved surface. Hereinafter, three embodiments of the method for manufacturing the molded body of the present embodiment will be described. Note that the molded body of the present embodiment may be manufactured using the conductive composition of the present embodiment, and is not limited to these methods.

[0081] <First manufacturing method> The first manufacturing method of the molded body according to the present embodiment includes a step of manufacturing a molded film by printing the conductive composition for the molded film of the present embodiment on a base film and drying it, a step of disposing the molded film on a base material, and a step of integrating the molded film and the base material by an overlay molding method. Hereinafter, although it will be described with reference to FIG. 3, since the manufacturing method of the molded film is as described above, the description here will be omitted.

[0082] FIG. 3 is a schematic process diagram showing an example of the first manufacturing method of the molded body. FIGS. 3(A) to (C) illustrate a molded film 10 and a base material 20 disposed in a chamber box of a TOM (Three dimension Overlay Method) molding machine, and the chamber box is omitted in FIGS. 3(B) and (C). 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 passed between the upper chamber box 21 and the lower chamber box 22 and disposed on the base material 20. At this time, the conductive layer of the molded film 10 may be disposed so as to face either the base material 20 side or the side opposite to the base material 20, and is selected according to the use of the final molded body. Next, after the upper and lower chamber boxes are evacuated, the molded film is heated. Next, the base material 20 is raised by raising the table. Next, only the inside of the upper chamber box 21 is opened to the atmosphere (FIG. 3(B)). At this time, the molded film is pressed against the base material side, and the molded film 10 and the base material 20 are bonded and integrated (FIG. 3(C)). In this way, the molded body 30 can be obtained.

[0083] In the first manufacturing method, the base material 20 can be prepared in any method in advance. In the first manufacturing method, the material of the base material 20 is not particularly limited, and it may be made of resin or metal.

[0084] In the first manufacturing method, the frictional stress between the base material and the plastic of the base material at high temperature in the integration process with the base material described above is caused by the frictional stress between the conductive circuit of the formed film and the base material at high temperature when the formed film in FIG. 3(C) is pressed against the base material side and the formed film 10 and the base material 20 are bonded and integrated. That is, in the first manufacturing method, the conductive layer simultaneously receives the load due to the tensile stress during forming and the frictional stress between the base material plastic and the base material at high temperature.

[0085] <Second Manufacturing Method> The second manufacturing method of the molded body according to the present embodiment includes a step of manufacturing a formed film by printing the conductive composition for the formed film of the present embodiment on a base film and drying it, a step of forming the formed film into a predetermined shape, a step of disposing the formed film after forming in a mold for injection molding, and a step of forming a base material by injection molding and integrating the formed film and the base material. Hereinafter, it will be described with reference to FIG. 4. Note that the second manufacturing method is sometimes referred to as a film insert method.

[0086] FIG. 4 is a schematic process diagram showing an example of the second manufacturing method of the molded body. In the second manufacturing method, the formed film 10 is previously formed into a predetermined shape by a mold 11 (FIG. 4(A)). After the formed film 10 is heated and softened, or while being softened, it is formed by suction to the mold by vacuum or pressing to the mold by compressed air, or both are used in combination, and is formed by the mold 11 (FIG. 4(B)). At this time, the formed film 10 may be formed so that the conductive layer faces either the base material 20 side described later or the side opposite to the base material 20, and is selected according to the use of the final molded body. Next, the formed film 10 after forming is disposed in an injection molding mold 12 (FIGS. 4(C) to 4(D)). Next, resin is injected 14 from the opening 13 to form the base material 20 and integrate the formed film 10 and the base material 20 to obtain a molded body 30 (FIG. 4(E)).

[0087] In the second manufacturing method, it is not necessary to prepare the base material 20 in advance, and the forming of the base material and the integration with the formed film can be carried out simultaneously. The material of the base material 20 can be appropriately selected from known resins used for injection molding.

[0088] In addition, in this second manufacturing method, the frictional stress between the base material plastic at high temperature in the integration step with the aforementioned base material refers to injecting resin 14 from the opening 13 in FIG. 4(E) to form the base material 20, and at the same time, when integrating the formed film 10 and the base material 20, it is caused by the frictional stress received by the conductive layer on the formed film due to the injection of the high-temperature molten resin into the mold. That is, in this second manufacturing method, after the conductive layer receives the load due to the tensile stress during forming, it will receive the frictional stress between the base material plastic at high temperature in a separate process.

[0089] <The Third Manufacturing Method> The third manufacturing method of the molded body according to this embodiment includes a step of manufacturing a formed film by printing the conductive composition for the formed film of this embodiment on a base film by screen printing and drying, a step of disposing the formed film in a mold for injection molding, and a step of forming a base material by injection molding and transferring the conductive layer in the formed film to the base material side. The following will be described with reference to FIG. 5. Note that the third manufacturing method is sometimes referred to as the in-mold transfer method.

[0090] FIG. 5 is a schematic process diagram showing an example of a third manufacturing method of a molded body. In the third manufacturing method, the molding film 10 is selected and used as a base film having releasability. The molding film 10 is disposed in an injection molding die 12 such that the conductive layer faces the base material 20 side described later (FIG. 5(A)). Next, resin is injected 14 from the opening 13 to form the base material 20, and the molding film 10 and the base material 20 are adhered to each other, and at least the conductive layer is transferred to the base material 20 side (FIG. 5(B)), and a molded body 30 is obtained (FIG. 5(C)). When the molding film 10 has a decorative layer, the decorative layer and the conductive layer are transferred.

[0091] In the third manufacturing method, since it is not necessary to cut the base film, a long base film can be disposed as shown in the example of FIG. 5. The material of the base material 20 can be appropriately selected from known resins used for injection molding.

[0092] In the third manufacturing method described above, the frictional stress with the base material plastic at high temperature in the integration process with the base material is the frictional stress received by the conductive layer on the molding film due to the injection of the high-temperature molten resin into the mold when resin is injected 14 from the opening 13 in FIG. 5(C) to form the base material 20 and the molding film 10 and the base material 20 are adhered to each other. That is, in the third manufacturing method, the conductive layer simultaneously receives the load due to the tensile stress during molding and the frictional stress with the base material plastic at high temperature.

[0093] The molded body obtained in this way enables mounting of circuits, touch sensors, and various electronic components on plastic casings such as home appliances, automotive parts, robots, and drones. It is also extremely useful for making electronic devices thinner, lighter, more compact, with improved design freedom, and more multifunctional.

Example

[0094] The present invention will be described in more detail below with reference to examples. However, the following examples do not limit the present invention in any way. In the examples, "parts" represents "parts by mass", and "%" represents "% by mass". In addition, the weight-average molecular weight in the examples is the molecular weight in terms of polystyrene in the measurement using GPC (gel permeation chromatography) "HLC-8320" manufactured by Tosoh Corporation.

[0095] In addition, the "functional group value" in the examples is expressed as the mass (mg) in terms of equimolar amount of potassium hydroxide of the amount of functional groups per gram of the raw material by the following calculation formula based on the molecular weight per functional group of each raw material (this is defined as the functional group equivalent). (Functional group value) [mg KOH / g] = (56.1 × 1000) / (Functional group equivalent) The above functional group value is a general term for amounts expressed as acid value when the functional group is a carboxyl group, hydroxyl value when the functional group is a hydroxy group, amine value when the functional group is an amino group, etc. When comparing the functional group ratios of substances having different functional groups, if the above functional group values are the same, it can be considered that they have the same molar amount of functional groups.

[0096] When the above functional group value uses titration with potassium hydroxide for the quantification of functional groups such as carboxyl groups and hydroxy groups, for example, the measured values (acid value and hydroxyl value) can be directly obtained from the appropriate amount of potassium hydroxide used for neutralization using a publicly known and commonly used measurement method defined in JIS K 0070, and can be treated in the same manner as the calculated value by the above calculation formula. In addition, even when titration with the above potassium hydroxide is not used for the quantification of the functional group value such as isocyanate groups, the above functional group equivalent and the above calculation formula derived from each measured value representing the amount of functional groups can be used to conveniently calculate the amount in terms of potassium hydroxide conversion. Specific calculation examples are shown below.

[0097] Calculation example: For the trifunctional isocyanate compound "X" with an isocyanate content of 23% measured by the method defined in JIS K 6806 (a method of reacting the isocyanate group with n-dibutylamine and titrating the remaining n-dibutylamine with an aqueous hydrochloric acid solution), calculate as follows. The functional group equivalent of the trifunctional isocyanate compound "X" is derived as follows from the above isocyanate content (%) and the molecular weight of the isocyanate group (NCO = 44 g / mol). (Functional group equivalent of "X") = 1 / (0.23 / 44) = 191.3 From the functional group equivalent of this trifunctional isocyanate compound "X" and the above calculation formula for 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

[0098] <Resins (A1) to (A3)> The following resins were used as resins (A1) to (A3). · Resin (A1): Acrylic resin manufactured by Mitsubishi Chemical Corporation, Dianal BR-106, weight average molecular weight 60,000, glass transition point 50°C, having no cyclic structure and ester bond in the main chain. · Resin (A2): Cellulose ester resin manufactured by Eastman Chemical Company, CAB551-0.2, weight average molecular weight 70,000, glass transition point 100°C, having a hydroxy group (functional group value 54 mgKOH / g), having a cyclic structure in the main chain and no ester bond. · Resin (A3): Phenoxy resin manufactured by InChem, PKHC, weight average molecular weight 43,000, glass transition point 67°C, having a hydroxy group (functional group value 198 mgKOH / g), having a cyclic structure (aromatic ring structure) in the main chain and no ester bond.

[0099] <Synthesis example 1: Synthesis of resin (A4)> Into a reactor equipped with a stirrer, a thermometer, a rectification tube, a nitrogen gas introduction tube, and a decompression device, 20.0 parts of dimethyl isophthalate, 9.0 parts of dimethyl terephthalate, 12.0 parts of ethylene glycol, 18.0 parts of neopentyl glycol, and 0.03 part of tetrabutyl titanate were charged. While stirring under a nitrogen stream, it was gradually heated to 180°C, and transesterification reaction was carried out at 180°C for 3 hours. The acid value was measured. When it became 15 or less, the inside of the reactor was gradually decompressed to 1 to 2 Torr. When a predetermined viscosity was reached, the reaction was stopped and taken out, and then transferred to a fluorine-treated pallet and cooled to obtain a solid of a polyester resin (A4) having a weight average molecular weight of 40,000, a glass transition point of 59°C, a hydroxy group (functional group value 5 mgKOH / g), and having an aromatic ring structure and an ester bond in the main chain.

[0100] <Synthesis Example 2: Synthesis of Resin (A5)> Into a reactor equipped with a stirrer, a thermometer, a reflux condenser tube, and a nitrogen gas introduction tube, 127.0 parts of a polyester polyol (Kuraray's "Kuraray Polyol P-2030") obtained from isophthalic acid and 3-methyl-1,5-pentanediol, 19.0 parts of isophorone diisocyanate, and 36.5 parts of toluene were charged. The reaction was carried out at 90°C for 3 hours under a nitrogen stream. Then, 5.5 parts of isophoronediamine was added and the reaction was further carried out at 90°C for 2 hours. After that, it was cooled to stop the reaction. Finally, after taking it out, it was transferred to a fluorine-treated pallet and dried in a hot air drying oven at 120°C for 5 hours and further vacuum dried for 24 hours to obtain a solid of a urethane resin (A5) having a weight average molecular weight of 35,000, a glass transition point of 5°C, an amino group (functional group value 4 mgKOH / g), and having an aromatic ring structure and an ester bond in the main chain.

[0101] The following were used as conductive fine particles, a solvent, and a crosslinking agent. <Conductive Fine Particles (B1) to (B5)> · Conductive fine particles (B1): Flaky silver powder manufactured by Fukuda Metal Foil Powder Co., Ltd., average particle diameter 5.2 μm · Conductive fine particles (B2): Chain-aggregated silver powder manufactured by Fukuda Metal Foil Powder Co., Ltd., average particle diameter 1.7 μm · Conductive particles (B3): Manufactured by Mitsui Mining & Smelting Co., Ltd., silver-coated copper powder, silver coating amount 10%, average particle diameter 2.0 μm · Conductive particles (B4): Manufactured by Ishihara Sangyo Co., Ltd., needle-shaped conductive Sb-doped tin oxide powder, average particle diameter 2.9 μm · Conductive particles (B5): Manufactured by Ito Kasei Co., Ltd., expanded graphite, average particle diameter 15 μm

[0102] <Solvents (C1-1) to (C1-10)> The following were used as the solvent (C1). Regarding the molecular structure in the formula, R 2 ~R 11 is hydrogen when not otherwise specified. · Solvent (C1-1): 2-Phenylethanol, where R in formula (1) 1 corresponds to a 1,2-ethylene group · Solvent (C1-2): 1-Phenylethanol (DL form), where R in formula (1) 1 corresponds to a 1,1-ethylene group · Solvent (C1-3): 2-(2-Methylphenyl)ethanol, where R in formula (1) 1 is a 1,2-ethylene group and R 2 is a methyl group · Solvent (C1-4): 3-Phenyl-1-propanol, where R in formula (1) 1 corresponds to a 1,3-propylene group · Solvent (C1-5): 1-Phenyl-1-propanol, where R in formula (1) 1 corresponds to a 1,1-propylene group · Solvent (C1-6): 2-Phenyl-2-propanol, where R in formula (1) 1 corresponds to a 2,2-propylene group · Solvent (C1-7): 4-Phenyl-2-butanol, where R in formula (1) 1 corresponds to a 1,3-butylene group · Solvent (C1-8): 2-Phenoxyethanol, where R in formula (2) 1 corresponds to a 1,2-ethylene group · Solvent (C1-9): 2-Phenoxy-1-propanol, where R in formula (2) 1 corresponds to a 1,2-propylene group · Solvent (C1-10): 3-methylbenzyl alcohol, R in formula (3) 8 corresponds to those where R is a methyl group · Solvent (C1-11): 4-methoxybenzyl alcohol, R in formula (3) 9 corresponds to those where R is a methoxy group · Solvent (C1-12): 3,4-dimethylbenzyl alcohol, R and 8 R 9 corresponds to those where both are methyl groups · Solvent (C1-13): 4-isopropylbenzyl alcohol, R in formula (3) 9 corresponds to those where R is an isopropyl group

[0103] <Other solvents (C2-1) to (C2-4)> As other solvents (C2) that do not correspond to solvent (C1), the following were used. · Solvent (C2-1): Benzyl alcohol · Solvent (C2-2): Dipropylene glycol monomethyl ether · Solvent (C2-3): Diethylene glycol monobutyl ether acetate · Solvent (C2-4): 2-Methoxypropanol

[0104] <Crosslinking agent (D1)> · Crosslinking agent (D1): Block isocyanate solution manufactured by Baxeneden Chemicals, Trixene BI7982, containing 3 blocked isocyanate groups in one molecule (functional group value 195 mg KOH / g), non-volatile content 70% (solvent (C2-4): 2-methoxypropanol)

[0105] <Production Example 1: Preparation of Decorative Ink (E1)> Prepare 200 parts of a resin solution consisting of 80 parts of resin (A1) and 120 parts of solvent (C2-3) (using only resin (A6)), add 20 parts of phthalocyanine blue pigment (LIONOL BLUE FG7351 manufactured by Toyo Color Co., Ltd.) and 10 parts by mass of titanium oxide pigment (TIPAQUE CR-93 manufactured by Ishihara Sangyo Co., Ltd.), stir and mix, knead with a three-roll mill (manufactured by Kodaira Seisakusho), then add 5 parts of an isocyanate crosslinking agent (Desmodur N3300 manufactured by Sumika Covestro Urethane Co., Ltd., non-volatile content 100%) and 90 parts of solvent (C2-3), and stir and mix uniformly to obtain a decorative ink (E1).

[0106] <Example 1: Preparation of Conductive Composition (F1) for Molded Film> Dissolve 20.0 parts of resin (A1) in 30.0 parts of solvent (C1-1), stir and mix with 80.0 parts of conductive fine particles (B1), knead with a three-roll mill (manufactured by Kodaira Seisakusho), and then stir and mix uniformly with a planetary mixer to obtain a conductive composition (F1) for molded film.

[0107] <Examples 2 to 69: Preparation of Conductive Compositions (F2) to (F69) for Molded Film> In Example 1 (conductive composition (F1)), except that the types and amounts of the resin, solvent, conductive fine particles, and crosslinking agent (when using a crosslinking agent, the crosslinking agent was added immediately before uniform stirring and mixing with a planetary mixer) were changed as shown in Tables 1 to 5, conductive compositions (F2) to (F69) for molded film were obtained in the same manner as in Example 1 (conductive composition (F1)). Note that all the numerical values of each material in Tables 1 to 5 are in parts by mass.

[0108] <Comparative Examples 1 to 6: Preparation of Conductive Compositions (F70) to (F75) for Molded Film> In Example 1 (conductive composition (F1)), except that the types and amounts of the resin, solvent, conductive fine particles, and crosslinking agent were changed as shown in Table 5, conductive compositions (F70) to (F75) for molded film were obtained in the same manner as in Example 1 (conductive composition (F1)).

[0109] <Examples 70 to 138 and Comparative Examples 7 to 12> On a polycarbonate (PC) base film (manufactured by Teijin Limited, Panlite 2151, thickness 300 μm, 300 mm × 210 mm), conductive compositions (F1) to (F65) for a formed film were each printed at a printing speed of 100 mm by a screen printing machine (manufactured by Minos Screen Co., Ltd., Minomat SR5575 semi-automatic screen printing machine). Subsequently, by heating in a hot air drying oven at 120°C for 30 minutes, a formed film provided with a conductive layer having a square solid pattern with a width of 15 mm, a length of 30 mm, and a thickness of 10 μm, a linear pattern with a line width of 3 mm, a length of 60 mm, and a thickness of 10 μm, and a stripe pattern with a line width of 150 μm, a line pitch of 150 μm, and a length of 60 mm was obtained.

[0110] <Example 139> On a polycarbonate base film (manufactured by Teijin Limited, Panlite 2151, thickness 300 μm, 300 mm × 210 mm), decorative ink (G1) was applied using a blade coater so that the dry film thickness became 2 μm, and heated at 120°C for 30 minutes to form a decorative layer. Subsequently, in Example 73, except that the film with the above decorative layer was used instead of the polycarbonate base film and a conductive layer was formed on the decorative layer, in the same manner as in Example 73, a formed film in which a polycarbonate film, a decorative ink layer, and a conductor were laminated in this order was obtained.

[0111] <Example 140> In Example 73, except that a polycarbonate resin / acrylic resin two-layer coextruded film (manufactured by Sumitomo Chemical Co., Ltd., Technolo C001, thickness 125 μm, 300 mm × 210 mm) was used instead of the polycarbonate base film and the conductive composition for the formed film was printed on the polycarbonate resin side, a formed film was obtained in the same manner as in Example 73.

[0112] <Example 141> In Example 73, an acrylic resin film (Sumitomo Chemical Co., Ltd., Technolo S001G, thickness 250 μm, 300 mm × 210 mm) was used instead of the polycarbonate-based film, and the drying conditions in the hot air drying oven were set to 80 °C for 30 minutes. Otherwise, a formed film was obtained in the same manner as in Example 73.

[0113] <Example 142> In Example 73, an easily moldable PET resin film (Morino Kako Co., Ltd., Emron PETG resin sheet, thickness 250 μm, 300 mm × 210 mm) was used instead of the polycarbonate-based film, and the drying conditions in the hot air drying oven were set to 70 °C for 30 minutes. Otherwise, a formed film was obtained in the same manner as in Example 73.

[0114] <Example 143> In Example 73, a polypropylene film (Idemitsu Unitech Co., Ltd., Purethermo AG-306, thickness 200 μm, 300 mm × 210 mm) was used instead of the polycarbonate film, and the drying conditions in the hot air drying oven were set to 80 °C for 30 minutes. Otherwise, a formed film was obtained in the same manner as in Example 73.

[0115] [(1) Measurement of volume resistivity] Regarding the 15 mm × 30 mm square paste-like conductive layer formed on the formed films of Examples 70 to 143 and Comparative Examples 7 to 12, the volume resistivity (Ω·cm) was measured using a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., Loresta GP MCP-T610 type resistivity meter, conforming to JIS-K7194, 4-terminal 4-probe method for constant current application) (4-terminal probe with a 0.5 cm interval). The results are shown in Tables 1 to 5.

[0116] [(2) Evaluation of peel adhesion] For the 15 mm × 30 mm square-shaped solid conductive layers formed on the formed films of Examples 70 to 143 and Comparative Examples 7 to 12, using a Gardner 1 mm interval cross-cut guide, a cutter knife was used to make 10x10 grid-like cuts through the conductive layer. A Nichiban cellophane tape was attached, air was expelled by pressing it down well, and after it was closely adhered, it was vertically peeled off. The degree of peeling of the coating film was evaluated as follows according to the ASTM-D3519 standard. The results are shown in Tables 1 to 5. (Adhesion Peelability Evaluation Criteria) A: Evaluation 5B to 4B, excellent adhesion B: Although the evaluation is 5B to 4B, the coating film undergoes cohesive failure and a part of the coating film on the surface side peels off. C: Evaluation 3B or less, poor adhesion

[0117] [(3) High-Speed Printability Evaluation] For the stripe patterns with a line width of 150 μm, a line interval of 150 μm, and a length of 60 mm formed on the formed films of Examples 70 to 143 and Comparative Examples 7 to 12, observation was carried out using a digital microscope (VHX-6000 manufactured by Keyence Corporation) and evaluated as follows. The results are shown in Tables 1 to 5. (High-Speed Printability Evaluation Criteria) A: No chipping or galling of the pattern, excellent linearity B: Although there is a slight constriction in the pattern, there is no chipping or galling or it is very slight. C: Chipping or galling of the pattern is prominent, poor fine printability

[0118] [(4) Wiring Resistance Evaluation] For the formed films of Examples 70 to 143 and Comparative Examples 7 to 12, a 3 mm × 60 mm linear pattern conductive layer was cut out in the longitudinal direction by 70 mm and in the width direction by 10 mm so that the conductive layer was in the middle to make a measurement coupon. On the surface of the measurement coupon opposite to the conductive layer, two lines were drawn with an oil-based magic pen at 4 cm intervals using a line perpendicular to the conductive layer from the longitudinal end as a mark. According to this mark, the resistance value was measured at positions with a 4 cm interval using a tester, and this was taken as the wiring resistance (Ω). The results are shown in Tables 1 to 5.

[0119] [(5) Heat elongation evaluation 1] The measurement coupons of Examples 70 to 140 and Comparative Examples 7 to 12 were stretched to an elongation rate of 125% at a pulling speed of 10 mm / min in the longitudinal direction in a heating oven at 160°C. After being taken out of the oven and cooled, the presence or absence of disconnection was evaluated using an optical microscope. Also, in the same manner as the measurement of the wiring resistance described above, the wiring resistance (Ω) at positions corresponding to an interval of 4 cm based on the original mark was measured, and the ratio of the wiring resistance after expansion and contraction to the wiring resistance before expansion and contraction was defined as the resistance fluctuation rate during heat elongation (times), and the evaluation was performed according to the following criteria respectively. The results are shown in Tables 1 to 4. (Presence or absence of disconnection) A: No disconnection was observed. B: 1 to 2 minor cracks were confirmed C: Severe disconnection or peeling of the conductive coating was confirmed (Resistance fluctuation rate during heat elongation) 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

[0120] The elongation rate is a value calculated as follows. (Elongation rate) [%] = {(Length after stretching - Length before stretching) / (Length before stretching)} × 100

[0121] [(6) Heat elongation evaluation 2] In the heat elongation evaluation 1, except that the elongation rate was changed to 150%, the evaluation was performed according to the following criteria in the same manner as the heat elongation evaluation 1. The results are shown in Tables 1 to 4. (Presence or absence of disconnection) A: No disconnection was observed. B: 1 to 2 minor cracks were confirmed C: Severe disconnection or peeling of the conductive coating was confirmed (Resistance fluctuation rate during heat elongation) 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

[0122] [(7) Thermal elongation evaluation 3] The measurement coupons of Examples 141 to 143 were stretched in a heating oven at 120°C in the longitudinal direction at a pulling speed of 10 mm / min until the elongation rate reached 125%. After being taken out of the oven and cooled, the presence or absence of disconnection was evaluated using an optical microscope. Also, in the same manner as the measurement of the wiring resistance, the wiring resistance (Ω) at positions corresponding to an interval of 4 mm based on the original mark was measured, and the ratio of the wiring resistance after expansion and contraction to the wiring resistance before expansion and contraction was defined as the resistance fluctuation rate during thermal elongation (times), and evaluated according to the following criteria respectively. The results are shown in Table 4. (Presence or absence of disconnection) A: No disconnection was observed. B: 1 to 2 minor cracks were confirmed. C: Severe disconnection or peeling of the conductive coating was confirmed. (Resistance fluctuation rate during thermal elongation) 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

[0123] [(8) Thermal elongation evaluation 4] In the thermal elongation evaluation 3, except that the elongation rate was changed to 150%, it was evaluated according to the following criteria in the same manner as the thermal elongation evaluation 3. The results are shown in Table 4. (Presence or absence of disconnection) A: No disconnection was observed. B: 1 to 2 minor cracks were confirmed. C: Severe disconnection or peeling of the conductive coating was confirmed. (Resistance fluctuation rate during thermal elongation) 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

[0124] [(9) Process tolerance evaluation 1 during manufacturing of molded body by overlay molding] A rectangular ABS resin molded product with a height of 10 mm and a length and width of 30 mm x 30 mm was aligned so as to face the surface on the conductor side so as to overlap the position of the 3 mm x 60 mm linear pattern of the molded films of Examples 70 to 140 and Comparative Examples 7 to 12 above. Overlay molding was performed at a set temperature of 160°C using a TOM molding machine (manufactured by Busch Vacuum Co., Ltd.) to obtain a molded body in which the molded film formed in a rectangular parallelepiped shape and the ABS resin molded product were integrated. The peeling of the linear pattern wiring and the resistance fluctuation rate of this molded body were confirmed. The resistance fluctuation rate was measured by measuring the wiring resistance (Ω) at positions corresponding to intervals of 6 cm based on the original mark reference, and the ratio of the wiring resistance after stretching and shrinking to the wiring resistance before stretching and shrinking was defined as the resistance fluctuation rate during thermal stretching (times), and each was evaluated according to the following criteria. The results are shown in Tables 1 to 4. (Presence or absence of disconnection and resistance fluctuation rate) A: No peeling of the wiring was observed, and the resistance fluctuation rate was 10 times or more and less than 50 times B: End chipping due to peeling of the wiring at 1 to 2 locations was confirmed, or the resistance fluctuation rate was 50 times or more and less than 500 times C: One or more disconnections due to peeling of the wiring were confirmed

[0125] [(10) Process tolerance evaluation 2 during molded body production by overlay molding] Using the 3 mm x 60 mm linear pattern of the molded films of Examples 131 to 140 above, a molded body was obtained in the same manner as in Process Tolerance Evaluation 1 during molded body production by the above overlay molding, except that overlay molding was performed at 120°C, and the peeling of the linear pattern wiring and the resistance fluctuation rate during overlay molding were evaluated. The results are shown in Table 4.

[0126] [(11) Process tolerance evaluation 1 during molded body production by film insert molding] A block-shaped metal mold with a 10-mm step and a 30-mm x 30-mm rectangular parallelepiped-shaped protrusion at the center was aligned with the opposite surface of the conductor side so as to overlap the position of the 3-mm x 60-mm linear pattern of the molded films of Examples 70 to 140 and Comparative Examples 7 to 12, and overlay molding was performed at a set temperature of 160°C using a TOM molding machine (manufactured by Busch Vacuum Co., Ltd.), thereby obtaining a molding film having a patterned conductor inside in the shape of a rectangular parallelepiped. Next, the molded film formed in the shape of a rectangular parallelepiped was set in an injection molding machine (IS170(i5), manufactured by Toshiba Machine Co., Ltd.) equipped with an in-mold molding test mold of the valve gate type, and PC / ABS resin (LUPOY PC / ABS HI5002, manufactured by LG Chem, Ltd.) was injection molded to obtain a molded body integrated with the 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 60 mm / sec (28%), injection time 4 sec, cooling time 20 sec). The washout (deformation or disconnection of the wiring pattern due to the temperature and injection pressure of the molten thermoplastic resin) of the molten resin of the linear pattern of this molded body and the resistance change rate were confirmed. The resistance change rate was measured by measuring the wiring resistance (Ω) at positions corresponding to intervals of 6 cm based on the original mark reference, and the ratio of the wiring resistance after stretching and contraction to the wiring resistance before stretching and contraction was defined as the resistance change rate during heat stretching (times), and the evaluation was performed according to the following criteria respectively. The results are shown in Tables 1 to 4. (Presence or absence of disconnection and resistance change rate) A: No washout of the wiring was observed, and the resistance change rate was 10 times or more and less than 50 times B: Distortion of the wiring due to slight washout was confirmed, or the resistance change rate was 50 times or more and less than 500 times C: Disconnection due to washout of the wiring was confirmed at one or more locations

[0127] [(12) Process tolerance evaluation 2 during molded body manufacturing by film insert molding] Using the 3 mm × 60 mm linear pattern of the formed films of Examples 141 to 143 above, a molded article was obtained in the same manner as in the process tolerance evaluation 1 during the production of the molded article by the overlay molding except that the overlay molding was performed at 120°C, and the degree of washout and the resistance fluctuation rate due to the injection of the molten resin into the linear pattern during the film insert molding were evaluated. The results are shown in Table 4.

[0128] [Table 1]

[0129] [Table 2]

[0130] [Table 3]

[0131] [Table 4]

[0132] [Table 5]

[0133] [Summary of Results] The conductive layers formed using the conductive compositions of Comparative Examples 1 to 6 that do not contain the solvent (C1) as a solvent component were found to break or have an increase in resistance value during stretching at high temperatures during the three-dimensional molding process of the molded film, particularly when the stretching elongation was large. In addition, there was a tendency for pattern chipping and streaking to occur during printing at a high printing speed.

[0134] On the other hand, from the results of Examples 70 to 143, even when the stretching elongation was large during stretching at a high temperature in the three-dimensional molding process of the molded film, the conductive composition of the present embodiment did not break, and the increase in the resistance value was also well suppressed. This is because the solvent component of the conductive composition of the present embodiment contains a solvent (C1) having a specific aromatic alcohol structure, so that the polymer chains of the resin (A) component are widely spread in the solvent (C) and the polymer chains are well entangled with each other when the conductive layer is formed, thereby exhibiting excellent high-temperature cohesive force and conductive holding characteristics of the conductive layer that can withstand stretching at a high temperature and a large elongation during molding, and it is presumed that both are achieved without impairing the printability at a high printing speed. At the same time, due to the inclusion of the solvent (C1), the solvent infiltration in the vicinity of the interface with the conductive layer of the base film, which is important as a conductive layer scaffold, was highly suppressed, which is also presumed to have contributed to the suppression of breakage during stretching at a high temperature and a large elongation during molding and the suppression of printing defects (presumably due to suppressing the increase in the viscosity of the conductive composition by the absorption of the solvent at the moment of contact with the substrate during printing). The balance of the characteristics of stretching at a high temperature and a large elongation during molding and printability at a high printing speed is further particularly excellent in that when used in combination with a resin having a cyclic structure in the main chain, especially a resin having both an aromatic ring structure and an ester bond as the cyclic structure, it is particularly difficult for the resistance value to increase and for defects to occur during printing. This is considered to be due to the fact that it becomes more difficult for the polymer chains to slip out from the entanglement of the resin (A) polymer chains during softening at the molding temperature, and it becomes difficult to form voids that serve as notches for breakage. Although there are still unclear points in the mechanism for expressing such characteristics, due to the higher polar affinity resulting from the structural similarity between the resin (A) and the solvent (C1), the polymer chains of the resin (A) component are more widely spread in the solvent (C) to exhibit appropriate fluidity, and the polymer chains are well entangled with each other when the conductive layer is formed, and it is presumed that this is to exhibit toughness that can suppress local stress concentration at the microscale, which leads to the cutting of the connection (conductive path) between conductive particles in the conductive layer.

[0135] Also, due to the above characteristics, according to the molded film provided with the conductive layer of the conductive composition of the present invention, even for a three-dimensional shape with a non-flat substrate surface, particularly a complex three-dimensional shape with steep steps or the like, an excellent integrated wiring molded body can be obtained.

[0136] Thus, the molded film and the integrated wiring molded body using the conductive composition of the present embodiment can directly form a lightweight and space-saving circuit, a touch sensor, an antenna, a heating element (heater), an electromagnetic shield, an inductor (coil), a resistor, and mount various electronic components in plastic casings and three-dimensional shaped parts such as home appliances, automotive parts, robots, and drones, without sacrificing the design freedom. Further, it is extremely useful for making electronic devices thinner, lighter, more compact, improving the design freedom, and adding more functions.

Explanation of Reference Numerals

[0137] 1 Base film 2 Conductive layer 3 Decorative layer 4 Electronic component 5 Pin 10 Molded film 11 Mold 12 Injection mold 13 Opening 14 Injection 15 Ascent 16 Pressurization 17 Resin 20 Base material 21 Upper chamber box 22 Lower chamber box 30 Molded body

Claims

1. A conductive composition for manufacturing a molding film for forming a conductive layer on a substrate surface having uneven surfaces or three-dimensional curved surfaces, comprising a resin (A), conductive fine particles (B), and a solvent (C), wherein the solvent (C) includes a solvent (C1) represented by the following formulas (1) to (3), the resin (A) includes a resin having an aromatic ring structure and an ester bond in the main chain, and the solvent (C1) satisfies the following condition (A) and / or (B), a conductive composition for a molding film. 【Chemical Formula 1】 [In the formula, R １ represents a divalent alkylene group having 2 to 5 carbon atoms, R ２ to R ６ each independently represents a hydrogen atom or a methyl group. Also, R ７ to R １１ each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a methoxy group, and among R ７ to R １１ at least one is a methyl group, an ethyl group, or a methoxy group. ] Condition (A): The solvent (C1) includes the solvent represented by the formula (1), and R1 in the formula (1) is one selected from the group consisting of 1,1-ethylene group, 1,2-ethylene group, 1,1-propylene group, 1,2-propylene group, 2,2-propylene group, or 1,3-propylene group. Condition (B): The solvent (C1) includes the solvent represented by the formula (3), and among R7 to R11 in the formula (3), one or two are a methyl group, an ethyl group, or a methoxy group.

2. The conductive composition for a molding film according to claim 1, wherein the conductive fine particles (B) include one or more conductive fine particles selected from the group consisting of silver powder, copper powder, silver-coated powder, copper alloy powder, conductive oxide powder, and carbon fine particles.

3. The conductive composition for a molded film according to claim 1 or 2, wherein the content of the solvent (C1) is 40 parts by mass or more in total in 100 parts by mass of the solvent (C).

4. A molded film having a conductive layer on a base film, The molded film, wherein the conductive layer is made of a cured product of the conductive composition for a molded film according to any one of claims 1 to 3.

5. A molded film having a decorative layer and a conductive layer on a base film, The molded film, wherein the conductive layer is made of a cured product of the conductive composition for a molded film according to any one of claims 1 to 3.

6. The molded film according to claim 4 or 5, wherein the base film is a film selected from polycarbonate, polymethyl methacrylate, polypropylene, and polyethylene terephthalate, or a laminated film thereof.

7. A molded body having a conductive layer laminated on a base material, The molded body, wherein the conductive layer is a cured product of the conductive composition for a molded film according to any one of claims 1 to 3.

8. A step of manufacturing a molded film by printing the conductive composition for a molded film according to any one of claims 1 to 3 on a base film and drying it, A step of disposing the molded film on a base material, A method for manufacturing a molded body, comprising a step of integrating the molded film and the base material by an overlay molding method.

9. A step of manufacturing a molded film by printing the conductive composition for a molded film according to any one of claims 1 to 3 on a base film and drying it, A step of shaping the molded film into a predetermined shape, A step of disposing the shaped molded film in a mold for injection molding, A method for manufacturing a molded article, comprising a step of molding a base material by injection molding and integrating the molding film and the base material.

10. A step of manufacturing a molding film by printing the conductive composition for a molding film according to any one of claims 1 to 3 on a base film and drying it; A step of disposing the molding film in a mold for injection molding; A method for manufacturing a molded article, comprising a step of molding a base material by injection molding and transferring the conductive layer in the molding film to the base material side.

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