Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/08—Metals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L11/00—Compositions of homopolymers or copolymers of chloroprene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/26—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment
  • C08L23/32—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment by reaction with compounds containing phosphorus or sulfur
  • C08L23/34—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment by reaction with compounds containing phosphorus or sulfur by chlorosulfonation
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
  • C08L9/02—Copolymers with acrylonitrile
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D109/00—Coating compositions based on homopolymers or copolymers of conjugated diene hydrocarbons
  • C09D109/02—Copolymers with acrylonitrile
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D111/00—Coating compositions based on homopolymers or copolymers of chloroprene
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D123/00—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers
  • C09D123/26—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers modified by chemical after-treatment
  • C09D123/32—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers modified by chemical after-treatment by reaction with compounds containing phosphorus or sulfur
  • C09D123/34—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers modified by chemical after-treatment by reaction with compounds containing phosphorus or sulfur by chlorosulfonation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/20—Conductive material dispersed in non-conductive organic material
  • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys

Definitions

• the first invention of the present application relates to a conductive film suitable for stretchable electrodes and wirings because it has high conductivity and can maintain high conductivity even when external forces such as stretching, twisting and compression act.
• the second invention of the present application relates to a conductive film suitable for electrodes and wiring, which has high conductivity, has a small change in conductivity after repeated expansion and contraction, and has excellent adhesion to a substrate.
• the electrodes and wiring can follow the deformation of a base material made of an elastomer or the like or a dielectric film. That is, for example, in an actuator, the dielectric film expands and contracts depending on the magnitude of the applied voltage. For this reason, the electrodes arranged on the front and back of the dielectric film must be able to expand and contract according to the expansion and contraction of the dielectric film so as not to hinder the movement of the dielectric film. In addition to being extendable and contractible, it is required that the change in electrical resistance be small when it is expanded and contracted.
• robots and wearable electronic devices use many wires for power supply and signal transmission, but generally the wires themselves have almost no elasticity, so there is room to prevent the movement of robots and humans. It is necessary to dispose the electric wire and it is a practical impediment. Therefore, the request
• a conductive material exhibiting high stretchability is desired. For example, by using a film of a stretchable conductive material, it is possible to develop a device that can be fitted in close contact with a flexible and curved human body. Applications of these devices range from measuring electrophysiological signals to delivering advanced therapies and human-machine interfaces.
• stretchable conductive materials are the use of organic conductive materials, but conventional materials are flexible but cannot be stretched and cannot cover curved surfaces. . Therefore, it lacks performance and reliability for integration into a complicated integrated circuit.
• Other materials, such as films of metal nanowires and carbon nanotubes, are promising to some extent, but are difficult to develop because they are unreliable and expensive.
• the elongation required for the stretchable conductive film varies depending on the application used. In applications such as wiring, antennas, and electrodes in the fields of assumed healthcare, displays, solar cells, PFID, etc., the specific resistance is less than 1 ⁇ 10 ⁇ 3 ⁇ cm and can be extended by about 100%. It is hoped that. In general, in a conductive film that can be applied or printed and formed by applying or printing a conductive paste in which conductive metal powder is uniformly dispersed in a resin, the specific resistance increases greatly when subjected to elongation. End up.
• the specific resistance at the time of elongation is desirably less than 1 ⁇ 10 ⁇ 2 ⁇ cm.
• the change in specific resistance is small not only when expanding and contracting but also when an external force such as twisting or compression is applied.
• an external force such as twisting or compression
• the wire is repeatedly deformed, and accordingly, the wiring itself is repeatedly stretched and contracted. Even in such a situation, it is desired that the specific resistance is small.
• the wiring and electrodes on the base material are repeatedly subjected to the expansion and contraction action, the adhesion between the base material and the conductive film is reduced, and there is a possibility of causing disconnection or the like.
• Non-Patent Document 1 One is a method of constructing a wave-like structure to give stretchability even to a brittle material (see Non-Patent Document 1).
• a metal thin film is formed on silicone rubber by vapor deposition, plating, photoresist treatment, or the like.
• the metal thin film shows only a few percent of expansion / contraction, there are zigzag or continuous horseshoe-like shapes, corrugated metal thin films, or saddle-shaped metal thin films obtained by forming metal thin films on pre-stretched silicone rubber, etc. Shows elasticity.
• the conductivity decreases by two orders of magnitude or more.
• silicone rubber since silicone rubber has a low surface energy, it has a drawback that it is easily peeled when stretched because the adhesion between the wiring and the substrate is weak. Therefore, with this method, it is difficult to achieve both stable high conductivity and high extensibility. Moreover, there is a problem that the manufacturing cost is high.
• the other is a composite material of conductive material and elastomer.
• the advantage of this material is excellent printability and stretchability.
• Commercially available silver pastes used for electrodes and wiring have a high elastic modulus binder resin with a high elastic modulus because of high filling and silver powder blended in a high elastic modulus binder resin. When it elongates, cracks are generated and the electrical conductivity is significantly reduced. Therefore, in order to give flexibility, study of rubber and elastomer as binders, silver flakes with high aspect ratio and high conductivity as conductive materials, carbon nanotubes, metal nanowires, etc. to reduce the filling degree of conductive materials Is being considered.
• an object of the first invention of the present application is a self-supporting film that has a high conductivity and does not have a holding part for holding a base material and a conductive film. Even in such a state, an object is to provide a conductive film which can be expanded, contracted, twisted and compressed and which is homogeneous and has no anisotropy.
• An object of the second invention of the present application is to provide a conductive film that has high conductivity, can be expanded and contracted, has a small decrease in conductivity even after repeated expansion and contraction, and has excellent adhesion to a substrate.
• the first invention of the present application comprises the following configurations (1) to (7).
• Each of the two orthogonal directions can be stretched by 36% or more of the original length, and when the two orthogonal directions are stretched by 100% of the original length, the specific resistance of both at the same elongation rate A difference is less than 10%,
• (3) In a conductive film twist test the conductive film can be twisted without causing film breakage to a twist angle of 3600 ° with respect to the conductive film plane, and the twist angle is 0 ° to 3600 °
• the conductive metal powder (A) is at least one selected from the group consisting of at least silver, gold, platinum, palladium, copper, nickel, and aluminum (1) to (4) The electroconductive film in any one of.
• the resin (B) is at least one selected from the group consisting of rubber containing at least a nitrile group, acrylic rubber, butyl rubber, chloroprene rubber, and chlorosulfonated polyethylene rubber (1)
• (7) The conductive film according to any one of (1) to (6), which is produced by coating or printing.
• the second invention of the present application has the following configurations (8) to (16).
• the conductive metal powder (A) is at least one selected from the group consisting of at least silver, gold, platinum, palladium, copper, nickel, and aluminum (8) to (10) The electroconductive film in any one of.
• the resin (B) is at least one selected from the group consisting of rubber containing at least a nitrile group, acrylic rubber, butyl rubber, chlorosulfonated polyethylene rubber, and chloroprene rubber (8 ) To (11).
• a conductive paste in which the conductive metal powder (B) is uniformly dispersed in the resin (A) can be produced by coating or printing, and an effective conductive network in the conductive film. Therefore, even when subjected to stretching, twisting, compression, and repeated stretching, the conductive network does not break, so the decrease in conductivity is small, and there is anisotropy in conductivity and stretchability. small.
• the conductive film of the present invention is a conductive film in which the conductive metal powder (A) and the resin (B) are contained, and the conductivity is the conductive metal powder (in the insulating resin (B) ( Depends on the formation of the conductive network of A).
• the amount of the conductive metal powder (A) is increased, a conductive network starts to be formed at a certain threshold value or more.
• the conductivity of the film is reduced or lost. Therefore, it is important to provide resistance to the external force of the conductive network.
• the performance with respect to the external force of the conductive film of the present invention will be described.
• Stretchability The stretch rate required for a stretchable conductive film varies depending on the intended use. For applications such as wiring, antennas, and electrodes in fields such as healthcare, displays, solar cells, and PFIDs, the specific resistance is less than 1.0 ⁇ 10 ⁇ 3 ⁇ cm, and the growth is about 5% to 100%. Rate is desired.
• the stretchable conductive film of the present invention can be stretched by 36% or more of the original length in at least one direction, and even when stretched by 36% or more, the decrease in conductivity is small.
• the specific resistance increase ratio according to the evaluation method described below is less than 10, preferably less than More preferably, it is less than 5.
• the specific resistance is less than 1.0 ⁇ 10 ⁇ 2 ⁇ cm.
• the conductive film of the present invention is produced by applying a conductive paste or printing means such as screen printing, and is desired to have no anisotropy in many applications. If the conductivity and mechanical properties differ depending on the direction, it is not preferable as a wiring or electrode.
• conductive fillers and non-conductive fillers with a high aspect ratio such as carbon nanotubes and carbon nanophones are blended, for example, in the case of coating, the conductive fillers and non-conductive fillers are oriented in the coating direction. The physical properties will be different between the direction of application and the direction perpendicular thereto, which is undesirable.
• the conductive film of the present invention can be stretched by 36% or more in two orthogonal directions, and the ratio of both at the same stretch ratio when stretched by 36% or more of the original length in the two orthogonal directions.
• the difference in resistance is preferably within 10%, more preferably within 5%.
• the conductive film receives a torsional effect as an external force in addition to the stretching effect depending on the application.
• a conductive film for example, in the case of a conductive film having a width of 20 mm, a length of 50 mm, and a thickness of 100 ⁇ m, the film is broken to a twist angle of 3600 ° when the lower end is fixed and the upper end is twisted 10 turns (3600 °). It is possible to twist the conductive film without causing it, and the specific resistance is preferably less than 1.0 ⁇ 10 ⁇ 2 ⁇ cm.
• the conductive film receives a compression action as an external force in addition to the extension action depending on the application.
• the specific resistance is preferably less than 1.0 ⁇ 10 ⁇ 3 ⁇ cm when compressed by 10% in the thickness direction.
• the conductive film of the present invention is a conductive film having a high resistance to repeated expansion and contraction, and the specific resistance after repeating 20% elongation 1000 times is less than 1.0 ⁇ 10 ⁇ 2 ⁇ cm. Preferably, it is less than 5.0 ⁇ 10 ⁇ 3 ⁇ cm.
• the conductive composite film of the present invention is a conductive composite film comprising a conductive film and a base material layer, and is conductive not only in a natural state but also when subjected to an elongation action. Excellent adhesion between film and substrate. If the adhesiveness is poor, there is a possibility that the wiring and electrodes on the base material will be disconnected or short-circuited during elongation.
• As the adhesion test there are generally known a cross-cut test, a peel test, a pencil scratching method, an Eriksen test, a bending test, etc. Among them, the cross-cut test using the 100th check is extremely easy to operate.
• the conductive composite film of the present invention has 95/100 or more remaining in a cross-cut test with 100 squares when (number of squares remaining without peeling in the test) / (number of squares before test). Preferably, 100/100 remains.
• the stretchable conductive film may be subjected to a large elongation action rarely depending on the application. Is required to be maintained to some extent.
• the conductive film of the present invention preferably has a specific resistance of less than 1.0 ⁇ 10 3 ⁇ cm even when stretched 3 times, and more preferably does not break even when stretched 10 times.
• the conductive film of the present invention is a conductive film containing a conductive metal powder (A) and a resin (B), and preferably the conductive metal powder (A) is uniformly dispersed in the resin (B).
• the conductive metal powder (A) and the resin (B) are not particularly limited, but preferred embodiments are shown below.
• the conductive metal powder (A) is used for imparting conductivity in the formed conductive film or conductive pattern.
• the conductive metal powder (A) is preferably a noble metal powder such as silver powder, gold powder, platinum powder or palladium powder, or a base metal powder such as copper powder, nickel powder, aluminum powder or brass powder. Further, a plating powder obtained by plating different kinds of particles made of an inorganic material such as a base metal or silica with a noble metal such as silver, a base metal powder obtained by alloying with a noble metal such as silver, or the like can be given. These metal powders may be used alone or in combination. Among these, those containing silver powder and / or copper powder as the main component (50% by weight or more) are particularly preferable from the viewpoint of easily obtaining a coating film exhibiting high conductivity and price. Silver powder is particularly preferable from the viewpoints of conductivity, processability, reliability, and the like.
• Examples of the shape of the conductive metal powder (A) include a known flake shape (flaky shape), spherical shape, dendritic shape (dendritic shape), and aggregated shape (a shape in which spherical primary particles are aggregated three-dimensionally). And so on.
• flake shape flake shape
• spherical shape dendritic shape
• aggregated shape a shape in which spherical primary particles are aggregated three-dimensionally.
• amorphous aggregated silver powder and flaky silver powder are preferable, and are used for imparting conductivity in the formed conductive film or conductive pattern.
• the amorphous agglomerated silver powder is a three-dimensionally aggregated spherical or irregularly shaped primary particle.
• Amorphous silver powder and flaky silver powder have a larger specific surface area than spherical silver powder, etc., so they can form a conductive workpiece even at low filling levels, and the conductive film is subjected to external forces such as stretching, twisting, or compression. However, it is preferable because the conductive network can be maintained. Since the amorphous agglomerated silver powder is not in a monodispersed form, the particles are in physical contact with each other, so that it is easy to form a conductive nitrate work.
• the particle diameter of the conductive metal powder (A) is not particularly limited, but from the viewpoint of imparting fine pattern properties, those having an average diameter of 0.5 to 10 ⁇ m are preferable.
• metal powder having an average diameter larger than 10 ⁇ m is used, the shape of the formed pattern is poor, and the resolution of the patterned fine line may be reduced.
• the average diameter is smaller than 0.5 ⁇ m, when blended in a large amount, the cohesive force of the metal powder may increase and printability may be deteriorated, and it is expensive, which is not preferable in terms of cost.
• the blending amount of the conductive metal powder (A) in the conductive paste is determined in consideration of conductivity and stretchability.
• the volume% in the solid content is large, the electrical conductivity increases, but the amount of rubber decreases and the stretchability deteriorates.
• the volume% is small, the stretchability is improved, but it is difficult to form a conductive network and the conductivity is lowered. Therefore, the blending amount of the conductive metal powder (A) in the solid content of the conductive paste is 20 to 50% by volume (70 to 90% by weight), and preferably 25 to 40% by volume (78 to 88% by weight). .
• the volume% in the solid content is obtained by measuring the weight of each solid content of each component contained in the paste and calculating (the weight of each solid content / the specific gravity of each solid content) to calculate the solid content of each component. It can be determined by calculating the volume.
• metal nanoparticles can be further blended as conductive metal powder for the purpose of improving conductivity and improving printability. Since metal nanoparticles have a function of imparting conductivity between conductive networks, an improvement in conductivity can be expected. Moreover, it can mix
• the average particle size of the metal nanoparticles is preferably 2 to 100 nm. Specific examples include silver, bismuth, platinum, gold, nickel, tin, copper, and zinc. From the viewpoint of conductivity, copper, silver, platinum, and gold are preferable, and silver and / or copper is the main component (50 (% By weight or more) is particularly preferable.
• the blending amount of the metal nanoparticles in the solid content of the conductive paste is preferably 0.5 to 5% by volume.
• Examples of the resin (B) include thermoplastic resins, thermosetting resins, and rubbers, but rubbers are preferable in order to develop the stretchability of the film.
• rubber urethane rubber, acrylic rubber, silicone rubber, butadiene rubber, nitrile group-containing rubber such as nitrile rubber and hydrogenated nitrile rubber, isoprene rubber, sulfurized rubber, styrene butadiene rubber, butyl rubber, chlorosulfonated polyethylene rubber, ethylene propylene
• examples include rubber and vinylidene fluoride copolymer. Among these, nitrile group-containing rubber, acrylic rubber, butyl rubber, chloroprene rubber, and chlorosulfonated polyethylene rubber are preferable, and nitrile group-containing rubber is particularly preferable.
• Resin (B) is required to have good affinity with conductive metal powder (B) in order to achieve uniform dispersion of conductive metal powder (A).
• the nitrile group has a high affinity with the metal, and because of the strong affinity of the nitrile group to the metal particles, the affinity with the conductive metal powder (B) is increased, which is effective for the expression of conductivity, and external force It is possible to form a conductive network that is not easily cut or broken. Therefore, it is preferable to contain a rubber containing a nitrile group as the resin (B).
• the conductive film of the present invention has high conductivity and is resistant to external forces such as stretching, twisting, and compression, and therefore can maintain high conductivity even when an external force is applied.
• the metal powder (B) preferably has an average particle size of 0.5 ⁇ m to 10 ⁇ m, and is preferably selected from flaky metal powder or aggregated metal powder. In addition, metal nanoparticles having an average particle size of 100 nm or less can be further included.
• the rubber containing a nitrile group is not particularly limited as long as it is a rubber or elastomer containing a nitrile group, but nitrile rubber and hydrogenated nitrile rubber are preferable.
• Nitrile rubber is a copolymer of butadiene and acrylonitrile. If the amount of bound acrylonitrile is large, the affinity with metal increases, but the rubber elasticity contributing to stretchability decreases conversely. Accordingly, the amount of bound acrylonitrile in the acrylonitrile butadiene copolymer rubber is preferably 18 to 50% by weight, particularly preferably 40 to 50% by weight.
• the blending amount of the resin (B) in the conductive paste if the volume% in the solid content is small, the conductivity is increased, but the stretchability is deteriorated. On the other hand, when the volume% is large, the stretchability is improved, but the conductivity is lowered. Therefore, the blending amount of the resin (A) in the solid content of the conductive paste is 50 to 80% by volume (10 to 30% by weight), and preferably 60 to 75% by volume (12 to 22% by weight).
• An inorganic substance can be added to the conductive film of the present invention as long as the conductivity, stretchability, homogeneity, twistability, and compressibility are not impaired.
• inorganic substances include silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, diamond carbon lactam, and other carbides; boron nitride Various nitrides such as titanium nitride and zirconium nitride, various borides such as zirconium boride; various oxidations such as titanium oxide (titania), calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica and colloidal silica Products: various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate; sulfides such as molybdenum disul
• thixotropic agents antifoaming agents, flame retardants, tackifiers, hydrolysis inhibitors, leveling agents, plasticizers, antioxidants, UV absorbers, laser absorbers, flame retardants, pigments, dyes, etc. Can be blended.
• the conductive paste that forms the conductive film of the present invention preferably contains an organic solvent.
• the organic solvent to be used preferably has a boiling point of 100 ° C. or higher and lower than 300 ° C., more preferably 150 ° C. or higher and lower than 290 ° C. If the boiling point of the organic solvent is too low, the solvent volatilizes during the paste manufacturing process or use of the paste, and there is a concern that the component ratio of the conductive paste is likely to change. On the other hand, if the boiling point of the organic solvent is too high, when a low-temperature drying step is required (for example, 150 ° C. or less), a large amount of the solvent may remain in the coating film, causing a decrease in the reliability of the coating film. There are concerns.
• high-boiling solvents examples include cyclohexanone, toluene, isophorone, ⁇ -butyrolactone, benzyl alcohol, Exsorb Chemical's Solvesso 100, 150, 200, propylene glycol monomethyl ether acetate, terpionol, butyl glycol acetate, diamylbenzene ( Boiling point: 260 to 280 ° C., triamylbenzene (boiling point: 300 to 320 ° C.), n-dodecanol (boiling point: 255 to 29 ° C.), diethylene glycol (boiling point: 245 ° C.), ethylene glycol monoethyl ether acetate (boiling point: 145 ° C), diethylene glycol monoethyl ether acetate (boiling point 217 ° C), diethylene glycol monobutyl ether acetate (boiling point: 247 °
• AF Solvent No. 4 (boiling point: 240 to 265 ° C.), No. 5 (boiling point: 275 to 306 ° C.), No. 6 (boiling point: 296 to 317 ° C.) manufactured by Nippon Oil Corporation No. 7, (boiling point: 259-282 ° C.), and No. 0 solvent H (boiling point: 245-265 ° C.), etc., and two or more of them may be included if necessary.
• Such an organic solvent is appropriately contained so that the conductive paste has a viscosity suitable for printing or the like.
• the content of the organic solvent in the conductive paste is determined by the method of dispersing the conductive metal powder, the viscosity of the conductive paste suitable for the method of forming the conductive film, the drying method, and the like.
• the conductive paste for forming the conductive film of the present invention can uniformly disperse the conductive metal powder in the resin by using a conventionally known method of dispersing the powder in a liquid. For example, after mixing a metal powder, a dispersion of a conductive material, and a resin solution, they can be uniformly dispersed by an ultrasonic method, a mixer method, a three-roll mill method, a ball mill method, or the like. These means can be used in combination.
• the conductive paste for forming the conductive film of the present invention is applied or printed on a substrate to form a coating film, and then the organic solvent contained in the coating film is volatilized and dried to dry the conductive film or A conductive pattern can be formed. Moreover, a conductive pattern can be formed on the coating film by laser etching.
• the range of the film thickness is not particularly limited, but 1 ⁇ m to 1 mm is preferable. If the thickness is less than 1 ⁇ m, film defects such as pinholes are likely to occur, which may be a problem. If it exceeds 1 mm, the solvent tends to remain inside the film, and the reproducibility of film properties may be inferior.
• the substrate to which the conductive paste is applied is not particularly limited, but a flexible or stretchable substrate is preferable in order to make use of the stretchability of the stretchable conductive film.
• the conductive film provided on the stretchable base material relaxes the tensile stress to some extent when the base film itself is stretched, so that the occurrence of microcracks in the conductive film is suppressed.
• flexible substrates include paper, cloth, polyethylene terephthalate, polyvinyl chloride, polyethylene, polyimide, and the like.
• the stretchable substrate examples include polyurethane, polydimethylsiloxane (PDMS), nitrile rubber, butadiene rubber, SBS elastomer, SEBS elastomer, spandex cloth, and knit cloth. These base materials can be creased and are preferably stretchable in the surface direction. In this respect, a base material made of rubber or elastomer is preferable.
• the conductive composite film preferably has good adhesion between the conductive film and the substrate. If the adhesion is poor, the wiring made of the conductive film may be peeled off from the base material due to the stretching action or repeated stretching action, causing a problem of disconnection or short circuit.
• the step of applying the conductive paste on the base material is not particularly limited, and can be performed by, for example, a coating method, a printing method, or the like.
• the printing method include screen printing method, planographic offset printing method, ink jet method, flexographic printing method, gravure printing method, gravure offset printing method, stamping method, dispensing method, squeegee printing and the like.
• the step of heating the substrate coated with the conductive paste can be performed in the air, in a vacuum atmosphere, in an inert gas atmosphere, in a reducing gas atmosphere, or the like.
• the heating temperature is in the range of 20 to 200 ° C., and is selected in consideration of the required conductivity and the heat resistance of the substrate.
• the organic solvent is volatilized, the curing reaction proceeds under heating in some cases, and the conductivity, adhesion, and surface hardness of the conductive film after drying become good. If it is less than 20 degreeC, a solvent may remain in a coating film and electroconductivity may not be acquired. If treated for a long period of time, conductivity is exhibited, but the specific resistance may be significantly inferior.
• a preferred heating temperature is 70 to 180 ° C.
• the heat shrink of a coating film becomes small, the conductive network of the silver powder in a coating film cannot fully be formed, and a specific resistance may become high.
• the elongation rate and repeated stretchability may also deteriorate due to the denseness of the coating film.
• the temperature exceeds 180 ° C., the base material is limited due to heat resistance, and when treated for a long time, the rubber (B) containing a nitrile group may be thermally deteriorated, and the elongation rate and repeated stretchability may be deteriorated.
• a holding part such as a stretchable cover coat may be provided on the conductive film on the substrate.
• the cover coat material is not particularly limited as long as it is a stretchable material having good adhesion to the conductive film.
• a preferred material is the resin (B) of the present invention.
• Examples 5 to 12, Comparative Examples 6 to 11 A resin is dissolved in ethylene glycol monomethyl ether acetate, and a solution in which silver particles are uniformly dispersed in this solution is blended so that each component has a volume% in the solid content described in Table 2 or Table 3.
• the conductive paste was obtained by kneading with this roll mill.
• Examples 1 to 7, Comparative Examples 6 to 7 A conductive paste was formed on a Teflon (registered trademark) sheet with a wire bar and dried at 150 ° C. for 30 minutes to prepare a sheet-like conductive film having a thickness of 100 ⁇ m. Tests for specific resistance, homogeneity, twistability, and compressibility were conducted using the conductive film. The conductive film was evaluated for specific resistance when a natural state and an external force acted by a method described later. Table 1 shows the compositions of the conductive films of Examples 1 to 4 and Comparative Examples 1 to 5 and the evaluation results thereof. In addition, the conductive film was subjected to an extension test and a repeated extension test by a method described later. Table 2 shows the compositions of the conductive films of Examples 5 to 7 and Comparative Examples 6 to 7 and the evaluation results.
• SWeNT MW100 was dispersed by sonication in a silver nanoparticle dispersion prepared from benzyl mercaptan and silver nitrate. Thereafter, filtration and washing are performed to obtain carbon nanotube CNT-B modified with silver nanoparticles.
• CSM chlorosulfonated polyethylene rubber
• CSM-TS530 chlorosulfonated polyethylene rubber
• NBR Nitrile rubber (Nipol DN003, acrylonitrile content 50% by weight, manufactured by Zeon Corporation)
• CR Chloroprene rubber (DOR-40, manufactured by Denka)
• UR Urethane rubber (Coatron KYU-1, manufactured by Sanyo Chemical Industries)
• EPDM ethylene propylene rubber (EP11, manufactured by JSR) 11)
• PVDF / ionic liquid vinylidene fluoride copolymer (Daiel G-801, manufactured by Daikin) / 1-butyl-methylpyridinium tetrafluoroborate (50 wt / 50 wt)
• the evaluation methods of the conductive films of Examples 1 to 4 and Comparative Examples 1 to 5 are as follows. [Evaluation of resistivity] The conductive film was cut into a width of 20 mm and a length of 50 mm to prepare a test piece. The sheet resistance and film thickness of the conductive film test piece in the natural state (elongation rate 0%) were measured, and the specific resistance was calculated. Thickness gauge SMD-565L (manufactured by TECLOCK) was used for the film thickness, and sheet resistance was measured for four test pieces using Loresta-GP MCP-T610 (manufactured by Mitsubishi Chemical Analytech), and the average value was used. . The specific resistance was calculated by the following formula.
• Elongation rate (%) ( ⁇ L 0 / L 0 ) ⁇ 100
• L 0 represents the distance between the marked lines of the test piece
• ⁇ L 0 represents the increment of the marked line Korean distance of the test piece.
• the sheet resistance at the time of extension was read as a value 30 seconds after reaching a predetermined degree of extension.
• R 100 represents the specific resistance after 100% elongation
• R 0 represents the specific resistance in the natural state.
• the conductive film was cut into a width of 20 mm and a length of 50 mm in the application direction and in a direction perpendicular to the application direction, respectively, to prepare a sample piece. Using each of the test pieces, the specific resistance at an elongation rate of 20%, 35%, 50%, and 100% was measured. The difference in specific resistance between the test pieces in the direction perpendicular to the coating direction and the coating direction was compared to evaluate the homogeneity.
• the conductive film was cut to a width of 20 mm and a length of 50 mm to obtain a sample piece. One end of the sample piece was fixed, and the specific resistance was measured when the other end was twisted once (360 °) and 10 times (3600 °).
• the conductive films of Examples 1 to 4 can maintain not only good conductivity in the natural state but also high conductivity even when stretched by 36% or more, and homogeneity. Excellent twisting and compressibility.
• the conductive films of Comparative Examples 1 to 5 have higher specific resistance than the Examples 1 to 4 or poor homogeneity, and the specific resistance greatly increases due to the stretching action, twisting action, and compression action.
• the conductive films of Examples 5 to 7 can maintain higher conductivity even when stretched than those of Comparative Examples 6 to 7, and are conductive even after repeated stretching. The decline is small. Further, as is apparent from the results in Table 3, the conductive composite films of Examples 8 to 12 can maintain high conductivity even when stretched, and the decrease in conductivity is small after repeated expansion and contraction. There is almost no decline in the above. On the other hand, the conductive films of Comparative Examples 8 to 11 cause breakage due to elongation or the adhesiveness greatly decreases due to repeated expansion and contraction, as compared with Examples 8 to 12.
• the conductive paste of the present invention has high conductivity and high stretchability, excellent repeated stretchability, and excellent multi-adhesion with a substrate, it can be folded using rubber or an elastomer material, stretchable It can be suitably used for electrodes and wirings of flexible LED arrays, stretchable solar cells, stretchable antennas, stretchable batteries, actuators, healthcare devices, medical sensors, wearable computers, and the like.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Dispersion Chemistry (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Conductive Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (1)

Family

ID=56405821

Family Applications (1)

Country Status (3)

Cited By (6)

Citations (7)

Family Cites Families (2)

• 2016
  • 2016-01-13 WO PCT/JP2016/050764 patent/WO2016114278A1/ja active Application Filing
  • 2016-01-13 TW TW105100863A patent/TWI684999B/zh active
  • 2016-01-13 JP JP2016502559A patent/JP6690528B2/ja active Active

Patent Citations (7)

Also Published As

Similar Documents

Legal Events