JP2017118085A - Conductive circuit for flexible base material, article for stretching and bending, conductive composition for flexible base material, and method of forming conductive circuit for flexible base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive circuit for flexible base material having sufficient followability and adhesiveness for the flexible base material, and capable of ensuring electrical conductivity even if it is stretched or bent repeatedly, and to provide an article for stretching and bending, a conductive composition for flexible base material, and a method of forming the conductive circuit for flexible base material.SOLUTION: A conductive circuit for flexible base material is provided on a flexible base material having elasticity and flexibility, and includes a pattern wiring part formed by hardening a conductive composition containing a block-copolymer and a conductive material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive circuit for a flexible substrate, an article for stretching and bending, a conductive composition for a flexible substrate, and a method for forming a conductive circuit for a flexible substrate. In particular, the present invention relates to a conductive circuit for a flexible substrate, an article for stretching and bending, a conductive composition for a flexible substrate, and a conductive circuit for a flexible substrate, which are used for a stretchable and flexible fabric. It relates to a method of forming.

  As a circuit board in which a conductive pattern is formed on a flexible base material, a flexible circuit board using a polyimide film or the like as a base material is well known. This circuit board can be deformed and loaded into a narrow interior of a small electronic device such as a portable terminal device. A circuit board in which a conductive pattern is formed on a base material that is more flexible than a plastic film such as a polyimide film can be applied to applications where a conventional flexible circuit board is used, and can be expected to be applied to wearable electronic devices.

  On the other hand, as a method for forming a conductive pattern on a substrate, a method for obtaining a predetermined pattern by etching after attaching a conductive sheet to the substrate, a method for obtaining a predetermined pattern by plating or sputtering, and a method for conducting by printing or inkjet. There are many methods such as a method of obtaining a predetermined pattern by applying an organic binder (conductive paste) containing particles.

  However, flexible base materials such as cloth and rubber tend to expand and contract, bend and twist more than plastic films, and tend to have a greater degree of expansion and contraction, bending and twisting. In this case, the conductive layer also undergoes the same deformation, but the conductive layer is a metal or a metal-rich material, and cannot follow the deformation of the base material, so that the conductivity is expected to decrease. Therefore, it is not easy to form a reliable conductive pattern on such a substrate.

  Therefore, conventionally, a method for providing a flexible circuit board with excellent peel strength of the conductive film has been proposed (see, for example, Patent Document 1). Patent Document 1 discloses a flexible circuit board in which a conductive circuit pattern is formed on a flexible substrate, and the substrate is formed by depositing nanofibers formed of a polymer organic compound in a nonwoven fabric shape. A flexible circuit board is proposed which is a nanofiber film, and the conductive film constituting the circuit pattern is formed in a form that wraps around the fiber peripheral surface of the nanofiber constituting the surface layer of the nanofiber film and is bonded to the surface layer. Yes.

Japanese Patent Laying-Open No. 2015-088536

  However, in the flexible circuit board described in Patent Document 1, since a thermosetting epoxy resin is used as the binder of the conductive paste, a heating process is essential for the curing process after applying the conductive paste. There must be a substrate with excellent heat resistance. In addition, since the epoxy resin has a high elastic modulus, when fixed to a flexible substrate, a crack or crack may occur in the fixed portion due to the difference in elastic modulus. When a material such as a hard epoxy resin is used for forming the circuit, when the substrate is stretched or bent, a crack or a cut occurs in the circuit, and the circuit is electrically disconnected.

  Accordingly, an object of the present invention is to provide a flexible substrate conductive circuit that has sufficient followability and adhesiveness with respect to a flexible substrate, and that can ensure electrical conductivity even when repeatedly expanded, contracted, bent, and the like. And an object for bending, a conductive composition for a flexible substrate, and a method for forming a conductive circuit for a flexible substrate.

  In order to achieve the above object, the present invention provides a patterned wiring portion that is provided on a flexible base material having elasticity and flexibility, and is obtained by curing a conductive composition containing a block copolymer and a conductive material. A conductive circuit for a flexible substrate is provided.

  Moreover, in the said conductive circuit for flexible base materials, it is preferable that a flexible base material is cloth, leather, or an elastomer raw material.

  Moreover, in the conductive circuit for a flexible substrate, the block copolymer contains a plurality of blocks, and one block in one block copolymer and one block in another block copolymer It is preferable that the block which consists of the same kind of monomer interacts.

  In order to achieve the above object, the present invention provides a patterned wiring portion obtained by curing a conductive composition containing a block copolymer and a conductive material on a flexible base material having stretchability and flexibility. A telescopic and bending article is provided.

  In order to achieve the above object, the present invention provides a flexible substrate used for a pattern wiring portion on a flexible substrate having a stretchability and a flexibility, which contains a block copolymer and a conductive material. A conductive composition is provided.

  In order to achieve the above object, the present invention provides a conductive composition containing a block copolymer and a conductive material on the surface of a flexible substrate having stretchability and flexibility using an ink jet or jet dispenser. There is provided a method for forming a conductive circuit for a flexible substrate, comprising a coating step of coating a product and a drying step of drying a conductive composition applied to the surface.

  According to the method for forming a conductive circuit for flexible substrate, an article for stretching and bending, a conductive composition for flexible substrate, and a conductive circuit for flexible substrate according to the present invention, Conductive circuit for flexible base material that has sufficient followability and adhesiveness and can ensure electrical conductivity even if it is repeatedly stretched or bent, an article for stretching and bending, a conductive composition for flexible base material, And the formation method of the conductive circuit for flexible base materials can be provided.

It is a schematic diagram of the application example of the conductive circuit for flexible base materials concerning embodiment of this invention.

[Outline of conductive circuit for flexible substrate]
The conductive circuit for a flexible substrate according to the present embodiment is provided on a flexible substrate having elasticity and flexibility, has conductivity, and is used for deformation of the flexible substrate. And a pattern wiring portion that deforms following the deformation. The flexible base material is, for example, a cloth, and the pattern wiring portion is also expanded, bent, bent and / or folded according to the expansion / contraction, bending, folding or folding of the cloth. And, the pattern wiring part according to the present embodiment is formed including a block copolymer and a conductive material, and the occurrence of cracks and cracks is also suppressed by expansion and contraction, bending, folding and folding, and Since it is not cut | disconnected, electrical conductivity can be maintained. In particular, in the conductive circuit for a flexible substrate according to the present embodiment, the flexible substrate extends in the plane direction, the flexible substrate is bent while extending in the plane direction, and / or is flexible. When the conductive substrate is bent or folded, the pattern wiring portion is also stretched, bent, and / or folded or folded according to the bending or folding. There is virtually no disconnection. Accordingly, the conductive circuit for flexible substrate according to the present embodiment can be applied to an article or the like made of an elastomer material such as clothes, leather products, rubber, and the like including, for example, a stretchable or bent region.

[Details of conductive circuit for flexible substrate]
The conductive circuit for a flexible substrate according to the present embodiment is provided by adhering to a flexible substrate having elasticity and flexibility, and the flexible substrate, and expanding and contracting according to deformation of the flexible substrate. Or a pattern wiring part which bends. Specifically, the conductive circuit is an insulating flexible substrate having stretchability and flexibility, and a conductive composition provided on the flexible substrate and containing a block copolymer and a conductive material. And a pattern wiring portion configured using a cured product.

(Flexible substrate)
The flexible substrate is mainly composed of a material that can be repeatedly deformed by external force (for example, deformation due to expansion and contraction or bending). The flexible base material is preferably formed using a material that is likely to have a throwing effect when the conductive composition is applied. Specifically, the flexible substrate is mainly composed of cloth, leather, and / or an elastomer material.

  Examples of the fabric include woven fabrics, knitted fabrics (knitted fabrics), laces, felts, and / or non-woven fabrics that are formed by bonding or intertwining fibers without weaving. As the woven fabric, various woven fabrics such as satin formed using fibers such as silk, polyamide-based synthetic fiber, polyurethane, and polyester, and campus formed using cotton, hemp, flax and the like can be used.

  In addition, the woven structure is, for example, a three-fold structure such as plain weave, oblique weave, satin weave, changed structure, changed texture such as changed oblique weave, vertical double weave, single double structure such as weft double weave, Warp pile weaves such as fresh velvet, towels, and velours, weave pile weaves such as benjin, weft velvet, velvet, and call heaven. These woven fabrics can be woven using a weaving machine such as rapier fiber or air jet fiber. The number of layers of the woven fabric may be a single layer or may have a multilayer structure of two or more layers.

  The type of knitted fabric may be a weft knitted fabric or a warp knitted fabric. Examples of the weft knitting structure include flat knitting, rubber knitting, double-sided knitting, pearl knitting, tuck knitting, floating knitting, one-side knitting, lace knitting, and splicing knitting. Examples of the warp knitting structure include a single denby knitting, a single atlas knitting, a double cord knitting, a half tricot knitting, a back hair knitting, and a jacquard knitting. The knitting can be knitted using a knitting machine such as a circular loom, a flat knitting machine, a rashal knitting machine or the like. The number of layers of the knitted fabric may be a single layer or may have a multilayer structure of two or more layers. As the leather, either natural leather or artificial leather can be used. In addition, the shape of a flexible base material can be made into various shapes including a solid shape according to a use.

  As the elastomer material, a conventionally known resin or rubber from which a molded article having elasticity and flexibility can be obtained can be used. For example, the elastomer material is formed from a thermoplastic resin, a thermosetting resin, a crosslinked rubber, or a vulcanized rubber. Materials. Examples of such resins include vinyl resins, acrylic resins, butadiene resins, silicone resins, polyurethane resins, and modified silicone resins.

  These elastomers may be used alone or in combination of two or more.

(Pattern wiring part)
The inventors of the present invention applied the conductive composition to the flexible substrate and cured it, and then not only stretched the flexible substrate but also folded or folded the cured conductive composition. We have investigated a conductive composition that can maintain the electrical resistance within a good range and has good resistance (wear resistance) even when the cured product rubs against an external object. And it discovered that the specific block copolymer whose other part exhibits cohesion was suitable for a flexible substrate. Therefore, the pattern wiring portion according to this embodiment is configured using a conductive composition containing a predetermined block copolymer used as a binder and a conductive material. The conductive composition can be prepared, for example, by mixing a predetermined amount of a block copolymer and a predetermined amount of a conductive material.

(Block copolymer)
The block copolymer is a copolymer composed of a linear polymer having a plurality of different polymers as partial constituent components (block (polymer unit)). That is, in the block copolymer, the first block composed of the monomer unit of the first compound and the second block composed of the monomer unit of the second compound different from the first compound are covalently bonded. It is a bonded copolymer. The block copolymer according to the present embodiment preferably has a configuration in which the second block is sandwiched between a plurality of first blocks (that is, has a triblock structure of first block-second block-first block). Is preferred).

  In the block copolymer according to the present embodiment, the block copolymer contains a plurality of blocks, one block in one block copolymer, and a block in another block copolymer. And it is preferable that the said block and the block which consists of the same kind of monomers exert interactions, such as intermolecular interaction, and aggregate.

  That is, in the block copolymer according to this embodiment, the first block in one block copolymer and the first block in the other block copolymer interact and aggregate. On the other hand, the second block different from the first block in one block copolymer and the other block copolymer does not substantially interact with each other, or has a small interaction compared to the interaction between the first blocks. In addition, it has a configuration that allows it to move freely. Thereby, the block copolymer according to the present embodiment is a part that freely moves when a plurality of block copolymers are assembled (a part that exhibits rubber-like elasticity, that is, flexibility, and the second block corresponds to the block copolymer. And a portion that is difficult to move (a portion that aggregates and corresponds to the first block).

  In other words, the block copolymer of the present embodiment preferably includes a soft segment and a hard segment. The soft segment is a block made of a flexible and highly flexible polymer chain, and the hard segment is a block made of a polymer chain that is easily crystallized or aggregated and has higher rigidity than the soft segment. The block copolymer according to this embodiment preferably has a configuration in which soft segments are sandwiched between hard segments (that is, a triblock structure of “hard segment-soft segment-hard segment”).

As a block copolymer containing a soft segment and a hard segment, the block copolymer represented by following formula (1) is mentioned.
XY (1)
In the formula, X is a block (hard segment) having a glass transition point T _gx > 30 ° C., and Y is a block (soft segment) having a glass transition point T _gy <0 ° C. By using the block copolymer represented by Formula (1), the cured product of the conductive composition according to the present embodiment exhibits toughness. The glass transition point The _{T g} can be measured using differential scanning calorimetry (DSC).

  More specifically, examples of the block copolymer include a block copolymer represented by the following formula (2).

_{X 1 -Y-X 2 (2} )
In formula (2), X ₁ and X ₂ each independently represent a block having a glass transition point _Tg of 0 ° C. or higher. Y represents a block having a glass transition point _Tg of less than 0 ° C. X ₁ and X ₂ are preferably blocks having a _Tg of 50 ° C. or higher, and Y is preferably a block having a _Tg of −20 ° C. or lower. Here, X ₁ and X ₂ may be different blocks, but are preferably the same block. Further, the block copolymer represented by formula (2), a glass transition temperature T _g is less than Y corresponds to the soft segment, the glass transition point T _g is a block larger X corresponds to the hard segment Is preferred. In addition, when Formula (1) and Formula (2) are compared, it is preferable to use the block copolymer of Formula (2) from the viewpoint of tensile elongation at break.

  And it is preferable that a block copolymer is solid in the range of 20 to 30 degreeC at least. By being solid in this temperature range, good tackiness can be secured when applied to a flexible substrate and / or when dried after application.

Examples of X, X ₁ and / or X ₂ include polymethyl (meth) acrylate (PMMA) and polystyrene (PS). Examples of Y include polybutyl acrylate (PBA) and polybutadiene (PB).

As the block copolymer, various block copolymers can be used. For example, an acrylic triblock copolymer produced by a living polymerization method can be used. Specifically, polymethyl methacrylate-polybutadiene-polystyrene copolymer, polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate copolymer, and these copolymers were subjected to carboxylic acid modification treatment or hydrophilic group modification treatment. A block copolymer such as a copolymer, a polymethyl methacrylate-polybutyl acrylate copolymer, and a polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate copolymer can be used. In this embodiment, even if the cured product of the conductive composition is subjected to deformation such as expansion, contraction, and / or folding, cracks and cracks are unlikely to occur in the pattern wiring portion made of the cured product, From the viewpoint of not being electrically disconnected, X, X ₁ and X ₂ are preferably PMMA, and Y is preferably PBA.

  The block copolymer containing the (meth) acrylate polymer block as described above can be obtained, for example, by the synthesis method described in JP-A-2007-516326 or JP-A-2005-515281. For example, after polymerizing Y units using an alkoxyamine compound represented by any one of the following formulas (3) to (6) as an initiator, a desired copolymer is synthesized by polymerizing the X units.

  In the above formula, n represents 2. Z represents a divalent organic group, preferably 1,2-ethanedioxy, 1,3-propanedioxy, 1,4-butanedioxy, 1,6-hexanedioxy group, 1,3,5- It is an organic group selected from tris (2-ethoxy) cyanuric acid, polyaminoamine, polyethyleneamine, 1,3,5-tris (2-ethylamino) cyanuric acid, polythioxy, phosphonate, and polyphosphonate. Ar represents a divalent aryl group.

  The weight average molecular weight of the block copolymer is preferably from 20,000 to 400,000, more preferably from 50,000 to 300,000. From the viewpoint of exhibiting toughness and flexibility in the cured product of the conductive composition, the weight average molecular weight is preferably 20,000 or more. In this case, the conductive composition is formed into a thin film or a flexible substrate. It is possible to exhibit excellent tackiness when dried after coating. In addition, the weight average molecular weight is preferably 400,000 or less from the viewpoint of ensuring the viscosity of the conductive composition capable of improving workability. In this case, the conductive composition can be easily printed on the flexible substrate. Printability and processability can be ensured. Furthermore, the weight average molecular weight is preferably 50,000 or more from the viewpoint of exerting the performance of mitigating external impact on the cured product of the conductive composition according to the present embodiment.

  The content of the block copolymer in the conductive composition according to the present embodiment is preferably, for example, 20% by mass or more and 50% by mass or less based on the total solid content contained in the conductive composition. For example, 85 mass% or more and 100 mass% or less are preferable on the basis of the total mass of an organic component. When the content of the block copolymer is within these ranges, the stretchability of the cured product is improved.

(Conductive material)
The conductive material is formed using a material having electrical conductivity. Specifically, a conductive filler can be used as the conductive material.

  Examples of the conductive filler include carbon particles, metal particles such as silver, copper, nickel, gold, tin, zinc, platinum, palladium, iron, tungsten, morbden, solder, or alloy particles, or the surface of these particles such as metal. Conductive particles such as particles prepared by covering with a conductive coating can be used. In addition, for example, polymer particles that are non-conductive particles composed of polyethylene, polystyrene, phenol resin, epoxy resin, acrylic resin, or benzoguanamine resin, or inorganic particles composed of glass beads, silica, graphite, or ceramic. Conductive particles obtained by applying a conductive coating such as metal to the surface can also be used. In the present embodiment, it is preferable to use a conductive filler composed of silver.

  As the shape of the conductive filler, various shapes (for example, a spherical shape, an ellipse, a cylindrical shape, a flake, a flat plate, a granule, or the like) can be adopted. The conductive filler can also have a slightly rough or jagged surface. A combination of the particle shape, size, and / or hardness of the conductive filler can be used for the conductive material according to the present embodiment. In addition, for the purpose of further improving the conductivity of the conductive composition, a plurality of conductive fillers having different particle shapes, sizes, and / or hardnesses of the conductive filler can be combined. In addition, the conductive filler to combine is not restricted to two types, Three or more types may be sufficient. In the present embodiment, the conductive filler preferably has a shape in which the conductive fillers contained in the block copolymer are in electrical contact with each other even when the pattern wiring portion is elongated. For example, it is preferable to use a flaky conductive filler made of silver, or to use a flaky conductive filler made of silver in combination with another conductive filler.

  Here, in the present embodiment, the flake shape includes shapes such as a flat shape, a flake shape, and a scale shape, and includes a shape in which a three-dimensional silver powder such as a spherical shape or a lump shape is crushed in one direction. Moreover, granular means the shape of all the conductive fillers which do not have flake shape. Examples of the granular form include a shape in which the powder is aggregated in a bunch of grapes, a spherical shape, a substantially spherical shape, a lump shape, a dendritic shape, and a mixture of silver powders having these shapes.

  The size of the conductive filler is equal to or less than the thickness of the pattern wiring part to be manufactured, or the conductive filler is placed inside the pattern wiring part due to the arrangement of the conductive filler inside the pattern wiring part. Preferably, the size of the conductive filler is not more than the size corresponding to the film thickness of the thin film. ).

  Moreover, when using silver as a conductive filler, this conductive filler can be manufactured by various methods. For example, when flaky silver powder is used as a conductive filler, it can be produced by mechanically pulverizing silver powder such as spherical silver powder and / or bulk silver powder using an apparatus such as a jet mill, a roll mill, or a ball mill. Moreover, when using granular silver powder as an electroconductive filler, it can manufacture by an electrolysis method, a grinding | pulverization method, the heat processing method, the atomizing method, or the reduction method.

  The conductive composition according to the present embodiment has a conductivity of 300 parts by weight or more and 800 parts by weight or less with respect to 100 parts by weight of the block copolymer from the viewpoint of exerting appropriate flexibility and electrical conductivity in the pattern wiring part. It is preferable that a filler is included.

(Other additives)
Other additives may be added to the conductive composition according to the present embodiment as necessary. Other additives include moisture curable resins, diluents, curing catalysts, fillers, plasticizers, stabilizers, colorants, physical property modifiers, thixotropic agents, dehydrating agents (storage stability improvers), and tackifiers. Agents, anti-sagging agents, ultraviolet absorbers, antioxidants, flame retardants, moisture absorbers, flexibility imparting agents, migration inhibitors, corrosion inhibitors, radical polymerization initiators, and various compounds such as toluene and alcohol A solvent is mentioned.

(Moisture curable resin)
A moisture curable resin may be further added to the conductive composition according to the present embodiment. Conventionally known resins can be used as the moisture curable resin, and examples thereof include modified silicone resins and urethane resins. In particular, the addition of a modified silicone resin is preferred in that the physical properties can be adjusted and the adhesion to the substrate can be improved.

  Moreover, when adding moisture hardening type resin further, it may be used independently and may use 2 or more types together. The elastic modulus of the block copolymer or moisture curable resin used as the binder is 0.1 to 500 MPa, and preferably 1 to 100 MPa.

(Wiring protection part)
The conductive circuit for a flexible substrate according to the present embodiment can further include a wiring protection part that covers the surface of the pattern wiring part. The wiring protection part is mainly formed from a material that expands and / or bends according to expansion and contraction and / or bending of the flexible base material. For example, the wiring protection part can be formed using the above-described elastomer such as a modified silicone resin. When the conductive circuit further includes a wiring protection part, durability against extension and bending of the pattern wiring part and / or wear resistance can be improved.

(Method for producing conductive circuit for flexible substrate)
The conductive circuit for a flexible substrate according to the present embodiment uses, for example, a technique such as a mesh screen plate, a stencil plate, an offset, a gravure, a flexo, a spray, a roller coater, a dipping, an inkjet, and / or a jet dispenser. It is formed by applying, printing, or spraying the conductive composition onto a flexible substrate. From the viewpoint of exerting the anchoring effect on the flexible substrate by the conductive composition and forming a precise wiring pattern used in an electronic circuit or the like on the flexible substrate, the coating diameter of the conductive composition is 5 μm to 50 μm. It is preferable to form the pattern wiring portion using an ink jet or a jet dispenser that can be adjusted to a degree. By using an ink jet or a jet dispenser, the degree of freedom in pattern design can be increased.

  For example, the conductive circuit for a flexible substrate can be manufactured by the following steps. First, a flexible substrate is prepared, and the conductive composition according to the present embodiment is applied to a predetermined region of the surface of the flexible substrate using a gravure printing machine, an inkjet, a jet dispenser, or the like ( Application process). Next, the conductive composition applied on the flexible substrate is dried (drying step). In the drying step, for example, drying is performed in an environment of 100 ° C. The shape of the conductive composition can be a thin film or a flat plate (sheet) thicker than the thin film. Moreover, the circuit of a desired pattern can be formed on a flexible base material by using a predetermined mask pattern in the coating process. Thereby, the conductive circuit for flexible base materials concerning this Embodiment can be manufactured.

(Elastic and bending articles)
The article for expansion and contraction and bending according to the present embodiment includes a conductive composition containing a block copolymer and a conductive material in a predetermined region on a flexible base material having elasticity and flexibility. It is configured to include a pattern wiring portion that is obtained by being formed into a predetermined pattern and cured. For example, as an article for expansion and contraction and bending according to the present embodiment, sportswear, outdoor wear, raincoats, umbrellas, men's clothing, women's clothing, work that are formed using cloth, leather, and / or an elastomer material Mention may be made of products such as clothing, protective clothing, medical clothing, nursing clothing, footwear, bags, curtains, tarpaulins, tents and car seats.

(Conductive circuit for flexible substrate with light emitting element)
FIG. 1 shows an outline of an application example of the conductive circuit for flexible substrate according to the present embodiment.

  As an application example of the conductive circuit for a flexible substrate according to the present embodiment, an example in which the light emitting element 30 is mounted on the pattern wiring unit 20 and the pattern wiring unit 22 formed on the flexible substrate 10 of a substantially rectangular cloth. Indicates. As shown to Fig.1 (a), the pattern wiring part 20 as a 1st pattern wiring part and the pattern wiring part 20 are electrically insulated in the predetermined area | region of the flexible base material 10 2nd. And a pattern wiring portion 22 as a pattern wiring portion. The pattern wiring portion 20 includes a first thin wire portion 20a extending along one side of the flexible substrate 10, and a second thin wire portion 20b extending substantially perpendicular to the first thin wire portion 20a from one end portion of the first thin wire portion 20a. And an element mounting portion 200 provided at a predetermined interval along the longitudinal direction of the second thin wire portion 20b.

  The pattern wiring portion 22 is spaced a predetermined distance from the first thin wire portion 20a, and the first thin wire portion 22a provided substantially parallel to the first thin wire portion 20a, and the first thin wire portion from one end of the first thin wire portion 22a. The second thin wire portion 22b extending substantially perpendicular to the portion 22a and the element mounting portions 220 provided at predetermined intervals along the longitudinal direction of the second thin wire portion 22b are formed. The second thin wire portion 22b is provided substantially parallel to the second thin wire portion 20b. The plurality of element mounting portions 200 and the plurality of element mounting portions 220 are provided at positions facing each other with a predetermined interval. The light emitting element 30 is fixed on the element mounting part 200 and the element mounting part 220 with a conductive adhesive such as silver paste. Thereby, the light emitting element 30 emits light by supplying power to the light emitting element 30 via the pattern wiring unit 20 and the pattern wiring unit 22. The light emitting element 30 is, for example, a light emitting diode.

Here, when the flexible base material 10 extends, the pattern wiring portion 20 bonded to the flexible base material 10 also extends. For example, as shown in FIG. 1 (b), if the length of the under flexible substrate 10 and _{A 1,} which stretched flexible substrate 10 to the _{A 2 (However, A} 1 <A _2), The pattern wiring part 20 is also extended from the original length B ₁ to B ₂ (B ₁ <B ₂ ). When the flexible substrate 10 is folded or folded, the pattern wiring portion 20 is also folded or folded following the deformation of the flexible substrate 10. Thus, since the pattern wiring part 20 deform | transforms according to a deformation | transformation of the flexible base material 10, it can prevent being cut | disconnected electrically.

(Effect of embodiment)
The conductive circuit for flexible substrate according to the present embodiment is formed using a conductive composition containing a block copolymer and a conductive material on a flexible substrate having stretchability and flexibility. Since the pattern wiring portion is provided, the block substrate that follows the deformation of the flexible base material (for example, the deformation of the fiber when the flexible base material is formed of cloth) and is in contact with or bonded to the fiber is shared. The polymer is deformed. Therefore, in the conductive circuit for flexible substrate according to the present embodiment, the pattern wiring portion is not electrically cut even if deformation such as stretching, bending, and / or folding is applied. Thereby, the conductive circuit for flexible substrates according to the present embodiment can be applied to articles such as clothes that are deformed such as expansion and contraction and bending.

  In addition, the conductive composition according to the present embodiment includes a block copolymer having a configuration in which a flexible block is sandwiched between blocks that are likely to interact such as aggregation. As a result, the conductive circuit for flexible substrate according to the present embodiment is deformed following the deformation even when it is repeatedly stretched, bent, folded, etc., so that the resistance of the pattern wiring portion is increased. It can be kept low.

  In addition, since the conductive circuit for flexible substrate according to the present embodiment includes a pattern wiring portion that deforms in accordance with the deformation of the flexible substrate, for example, when the conductive circuit is used for clothes or the like, the conductive circuit is conductive. Even if the circuit is present at a portion where the circuit is bent (for example, a portion corresponding to the shoulder, elbow, knee, etc. of the clothes), the user wearing the clothes does not substantially feel the difficulty of bending. Thereby, according to the conductive circuit for flexible base materials which concerns on this Embodiment, the clothes etc. with the conductive circuit which can implement | achieve good comfort can be provided.

  Hereinafter, the conductive circuit for flexible substrate according to the present embodiment will be described in detail using examples.

  A conductive circuit according to Example 1 was produced as follows. First, the electroconductive composition was prepared by mixing the compounding substance of Table 1 in the ratio of Table 1. Next, the obtained conductive composition was applied to a cloth made of cotton / polyester blended yarn (70% cotton, 30% polyester). For application of the conductive composition, a jet dispenser Aerojet manufactured by Musashi Engineering Co., Ltd. was used. Moreover, the electroconductive composition was made into the shape of a thin wire | line (length: 10 cm, width: 3 mm). After coating the conductive composition, the cloth coated with the conductive composition was cured at 23 ° C. and 50% RH for 24 hours. As a result, a conductive circuit according to Example 1 was obtained.

In Table 1, the details of the compounding substances are as follows. The unit of the numerical value is “g”.
* 1 (Binder): Acrylic elastomer, product name “Clarity (registered trademark) LA2330”, manufactured by Kuraray Co., Ltd. * 2 (Binder): Acrylic elastomer, product name “Clarity (registered trademark) LA4285”, manufactured by Kuraray Co., Ltd. * 3 (Conductive material): Conductive filler, product name “Silcoat (registered trademark) AgC-224”, manufactured by Fukuda Metal Foil Powder Co., Ltd. * 4 (Conductive material): Conductive filler, product name “Silcoat (registered trademark) ) AgC-201Z ", manufactured by Fukuda Metal Foil Powder Co., Ltd.

(Measurement of electrical resistance of the pattern wiring part after stretching the flexible substrate: holding resistance after stretching)
The conductive circuit according to Example 1 was expanded and contracted 10 times as the flexible base material along the longitudinal direction of the pattern wiring portion. The length of extension was set to a length that would make the pattern wiring part 1.2 times longer. After repeatedly expanding and contracting, the electric resistance value of the pattern wiring portion was measured using a digital multimeter KE 1052 (manufactured by Kyoritsu Electric Instruments Co., Ltd.). And it evaluated based on the following references | standards. The evaluation results are shown in Table 1.
○: No disconnection occurred in the circuit after repeated expansion (digital multimeter shows resistance value).
Δ: Disconnection occurs in a part of the circuit after repeated stretching (although the digital multimeter shows a resistance value, it is out of the practical range).
X: Disconnection occurred in the circuit after repeated stretching (digital multimeter does not show resistance value).

(Shore hardness)
The hardness (Shore A hardness) of the pattern wiring portion of the conductive circuit according to Example 1, that is, the cured product of the conductive composition according to Example 1, was measured according to JIS K6253 (hardness test method). And it evaluated based on the following references | standards. That is, the Shore A hardness is from 3 to 90, preferably from 5 to 90, more preferably from 10 to 80, particularly preferably from 15 to 80, and most preferably from 20 to 80. In addition, from the viewpoint of ensuring the wear resistance of the cured product of the conductive composition, the hardness is preferably a predetermined hardness or higher (that is, a Shore A hardness of 3 or higher).

(Conductivity)
The conductive composition according to Example 1 was applied in a thin line shape (length: 10 cm, width: 2 mm) on a PET film, dried in an environment of 100 ° C. for 15 minutes, and then the electrical conductivity of the conductive composition. The resistance value was measured using a digital multimeter KE 1052 (manufactured by Kyoritsu Electric Instruments Co., Ltd.).

(Conductivity after U-shaped folding test)
The conductive composition according to Example 1 was applied in a thin line shape (length: 10 cm, width: 2 mm) on a PET film, dried in an environment of 100 ° C. for 15 minutes, and then a U-shaped folding tester ( The U-shaped folding test was performed 10,000 times using DLDMMLH-4U (manufactured by Yuasa System Equipment Co., Ltd.). The U-shaped folding test is a test in which a sample is continuously horizontally moved and bent according to preset test conditions. The U-shaped folding test conditions were set such that the bending radius was 10 mm, the test stroke was ± 40 mm, and the test speed was 40 rpm. The electrical resistance value of the conductive composition after the U-shaped folding test was measured using a digital multimeter KE 1052 (manufactured by Kyoritsu Electric Instruments Co., Ltd.).

(Example 2, Comparative Examples 1-2)
Moreover, as shown in Table 1, after obtaining the conductive circuit according to Example 2 in the same manner as in Example 1 except that the compounding substances were changed, the characteristics of the obtained conductive circuit were the same as in Example 1. evaluated. The results are shown in Table 1. Further, as shown in Table 2, in Comparative Examples 1 and 2, after obtaining a conductive circuit in the same manner as in Example 1 except that a predetermined conductive paste was used as a compounding substance, the obtained conductive circuit was obtained. The characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 2. However, since the hardness of Shore A hardness exceeded 90, the hardness was measured by Shore D hardness.

In addition, the detail of the compounding substance of Table 2 is as follows. The unit of the numerical value is “g”.
* 5 (Conductive paste): Acrylic resin conductive paste, product name “Dotite D550”, manufactured by Fujikura Kasei Co., Ltd. * 6 (Conductive paste): Epoxy resin conductive paste, product name “LS-450-7H” ”Made by Asahi Chemical Research Co., Ltd.

  As shown in Table 1, in the conductive circuits according to Example 1 and Example 2, the pattern wiring part is not cracked or cracked after repeated expansion and contraction or after the U-shaped folding test, and the pattern wiring part is electrically It has been shown to maintain continuity. Furthermore, Shore A hardness was 40-50, and it was shown that it is the most preferable hardness. On the other hand, as shown in Table 2, in Comparative Example 1 and Comparative Example 2, the pattern wiring portion was cut or cracked, and the Shore D hardness also showed a large value. And in the comparative example 1 and the comparative example 2, the electroconductivity after a U-shaped folding test showed 7 times or more of an Example, and it was shown that there is no practicality.

  While the embodiments and examples of the present invention have been described above, the embodiments and examples described above do not limit the invention according to the claims. In addition, all the combinations of features described in the embodiments and examples are not necessarily essential to the means for solving the problems of the invention, and various combinations are possible without departing from the technical idea of the present invention. It should be noted that variations are possible.

DESCRIPTION OF SYMBOLS 1 Conductive circuit 10 Flexible base material 20, 22 Pattern wiring part 20a, 22a 1st thin wire | line part 20b, 22b 2nd thin wire | line part 30 Light emitting element 200,220 Element mounting part

Claims (6)

A conductive circuit for a flexible substrate, comprising a pattern wiring portion provided on a flexible substrate having stretchability and flexibility, and obtained by curing a conductive composition containing a block copolymer and a conductive material.   The conductive circuit for a flexible substrate according to claim 1, wherein the flexible substrate is cloth, leather, or an elastomer material.   The block copolymer contains a plurality of blocks, one block in one block copolymer, and a block composed of the same type of monomer as the one block in the other block copolymer. The conductive circuit for flexible substrates according to claim 1 or 2, which interacts.   An article for stretching and bending comprising a pattern wiring portion obtained by curing a conductive composition containing a block copolymer and a conductive material on a flexible substrate having stretchability and flexibility.   The conductive composition for flexible base materials used for the pattern wiring part on the flexible base material which has a stretchability and a flexibility containing a block copolymer and an electroconductive material. An application step of applying a conductive composition containing a block copolymer and a conductive material to the surface of a flexible substrate having stretchability and flexibility using an ink jet or a jet dispenser;
A method for forming a conductive circuit for a flexible substrate, comprising: a drying step of drying the conductive composition applied to the surface.