JP7063271B2 - Elastic conductor sheet, elastic wiring, fabric with elastic wiring, and method of restoring conductivity - Google Patents

Description

The present invention relates to a conductive material used in a garment-type wearable electronic device used by incorporating an electronic function or an electric function into a garment, and more specifically, an elastic electric wiring is formed, and the present invention is more naturally worn. Regarding clothing-type electronic devices with a feeling.

Recently, wearable electronic devices have been developed that are intended to be used in a state where electronic devices having input / output, calculation, and communication functions are in close contact with or in close contact with the body. As wearable electronic devices, devices having an accessory-type outer shape such as wristwatches, glasses, and earphones, and textile-integrated devices incorporating electronic functions in clothes are known. An example of such a textile integrated device is disclosed in Patent Document 1.

Electronic devices require electrical wiring for power supply and signal transmission. In particular, textile-integrated wearable electronic devices are required to have elasticity in their electrical wiring in accordance with their stretchable clothing. Normally, electrical wiring made of metal wire or metal leaf does not have practical elasticity in nature, so the metal wire or metal leaf is arranged in a wavy or repeated horseshoe shape to give it a pseudo-stretchable function. The method is used.
In the case of a metal wire, the metal wire can be regarded as an embroidery thread and sewn on clothes to form wiring. However, it is self-evident that such a method is not suitable for mass production.
The method of forming wiring by etching a metal foil is common as a method for manufacturing a printed wiring board. A method is known in which a metal foil is attached to an elastic resin sheet and a corrugated wiring is formed by a method similar to that of a printed wiring board to form a pseudo elastic wiring. (Refer to Non-Patent Document 1) Such a method is to give a pseudo expansion / contraction characteristic by twisting deformation of the corrugated wiring part, but since the metal foil is also deformed in the thickness direction due to the twisting deformation, it can be used as a part of clothes. When used, it gave a very uncomfortable feeling of wearing and was not preferable. Further, when the metal foil is subjected to excessive deformation such as during washing, permanent plastic deformation occurs in the metal foil, and there is a problem in the durability of the wiring.

As a method for realizing elastic conductor wiring, a method using a special conductive paste has been proposed. Conductive particles such as silver particles, carbon particles, and carbon nanotubes are kneaded with elastomers such as urethane resin with elasticity, natural rubber, synthetic rubber, and solvents to form a paste, which is used directly on clothes or as an elastic film base. The wiring is printed and drawn in combination with materials.
A conductive composition composed of conductive particles and a stretchable binder resin can realize a conductor that can be stretched macroscopically. Microscopically, the conductive composition obtained from such a paste has a resin binder portion that is deformed when subjected to an external force, and the conductivity is maintained within a range in which the electrical chain of the conductive particles is not interrupted. Is. The resistivity observed macroscopically is higher than that of metal wire or metal foil, but since the composition itself has elasticity, it is not necessary to take a shape such as corrugated wiring, and the wiring width and thickness. Since the degree of freedom is high, it is practically possible to realize wiring with lower resistivity than metal wire.

Patent Document 2 discloses a technique of suppressing a decrease in conductivity during elongation by combining silver particles and silicone rubber and further coating a conductive film on a silicone rubber substrate with silicone rubber. Patent Document 3 discloses a combination of silver particles and a polyurethane emulsion, and it is said that a conductive film having high conductivity and high elongation can be obtained. Furthermore, many examples have been proposed in which attempts are made to improve the characteristics by combining conductive particles having a high aspect ratio such as carbon nanotubes and silver fillers.

Patent Document 4 discloses a technique for directly forming electrical wiring on clothes by using a printing method.

Japanese Unexamined Patent Publication No. 2-234901 Japanese Unexamined Patent Publication No. 2007-173226 Japanese Unexamined Patent Publication No. 2012-54192 Japanese Patent No. 3723565

The stretchable conductor composition is mainly composed of conductive particles and a flexible resin. As such an elastic conductor, a composition in which a crosslinked elastomer such as rubber is used as a resin binder and carbon black or metal particles are blended is generally known. Such a stretchable conductor composition is formed via a paste or slurry obtained by mixing, dissolving and dispersing a solvent or the like in a precursor of a metal-based conductive particle and a crosslinked elastomer, if necessary. When it is used as a paste, it becomes easy to form a wiring pattern by screen printing or the like.

A similar technique, for example, a conductive paste, is used when wiring is formed on a fabric constituting a garment using a stretchable conductor composition obtained from a stretchable conductive paste using a stretchable binder by a printing method. There are various differences compared to the membrane circuit forming technology that was used, which leads to technical difficulties.
Normally, in a membrane circuit using an engineering plastic film such as a PET film as a base material, the entire circuit has flexibility, but the elastic modulus of the base material itself with respect to a stretch load is very high, so that the stretchability is substantially shown. not. On the other hand, when the wiring made of the elastic conductor composition is formed by using a cloth or a flexible polymer sheet as a base material, it is possible to realize the wiring having elasticity. A properly designed and manufactured stretchable conductor wiring can maintain conductivity even when stretched from about 10% to a maximum of 100% or more.

However, the stretchable conductive film made of conductive particles and the stretchable binder resin is a dispersion system, and the elastic range, that is, the range in which the Hooke's law is established and the tensile load and the strain (elongation) are linearly proportional to each other is narrow. At most, it's only a few percent. If the deformation exceeds the elastic range, minute cracks are generated inside the coating film, and the gaps generated by the cracks widen, so that the coating film continues to be deformed. In this state, since the coating around the cracks is still flexible, the coating does not completely break, and microscopic internal structural changes such as an increase in the number and width of cracks are macroscopically fatal to the coating. It is an area that seems to continue to stretch flexibly without being destroyed. Although the coating film does not break in this region, the conduction path is gradually narrowed due to the chain of conductive particles due to the growth of microcracks in the internal structure, and as a result, the conductivity of the coating film is lowered.

The stretchable conductive film stretched to the plastic deformation region shrinks except for the tensile load and returns to a length close to the initial length, but the resistance value returns to the initial value because the connection of the conductive particles is broken. It does not return to, and becomes a higher value than the initial value. As described above, when the stretching beyond the elastic region is repeated, the resistance value of the stretchable conductive film gradually increases, and finally reaches non-conduction. As described above, the conventional stretchable conductive film has a problem that the conductivity is lowered due to repeated stretching and contraction, and when the stretchable dynamic film is used for wiring of clothes-type electronic devices, the stretchable and stretchable film occurs repeatedly in actual use. Furthermore, durability against repeated expansion and contraction has become a problem due to the water flow applied during washing and the like.

As a result of diligent studies to achieve such an object, the present inventor has found that by imparting specific properties to the stretchable conductive film, the repeatability of stretchability is practically greatly improved, and the following invention is made. Reached.
That is, the present invention has the following configuration.
[1] In an elastic conductor sheet composed of a conductive filler and a binder resin, the film thickness unevenness of the sheet is 10% or less, and the elongation recovery rate after 20% elongation at 25 ° C. is 92% or more. Elastic conductor sheet characterized by that.
[2] The stretchable conductor sheet according to [1], wherein the stretch recovery rate is 96% or more when heated at 60 ° C. with the stretch load removed after 20% stretching at 25 ° C.
[3] The initial conductivity of the stretchable conductor sheet in the direction of the sheet surface is 1 × 10 ² S / cm or more, and the ratio of decrease in conductivity due to mechanical load is within 1/1000 of the initial conductivity. The elastic conductor sheet according to [1] or [2], wherein the conductivity recovery rate by heating at 60 ° C. is 10% or more.
[4] Conductive filler 15 to 35% by mass consisting of 65 to 85% by mass of a binder resin having a stretch recovery rate of 99% or more after 20% stretching and a glass transition temperature of 0 ° C. or less and 90% by mass or more of metal particles. The elastic conductor sheet according to any one of [1] to [3], which is composed of%.
[5] When the number average molecular weight of the binder resin is Mn and the weight average molecular weight is Mw,
The elastic conductor sheet according to any one of [1] to [4], wherein Mw / Mn> 4 or more.
[6] The insulating fabric layer having a stretch recovery rate of 99% or more at 50% stretch and a heat resistance of 60 ° C. or higher, and the stretchable conductor sheet according to any one of [1] to [5]. Elastic conductor / fabric laminate with layers.
[7] The stretchable conductor sheet according to any one of [1] to [5], or the stretchable conductor sheet according to [6], which is obtained by heating the stretchable conductor sheet to 60 ° C. or higher with the stretch load removed. A method for recovering the conductivity of an elastic conductor / fabric laminate.

Further, the present invention has the following configuration.
[8] At least
A stretchable insulating polymer layer having a tensile yield elongation of 70% or more and a heat distortion temperature of 60 ° C. or more.
Elastic conductor layer composed of conductive filler and binder resin,
Elastic wiring composed of.
[9] The stretchable wiring according to [8], wherein the stretchable conductor layer has a stretch recovery rate of 92% or more after stretching at 25 ° C. by 20%.
[10] The initial conductivity of the stretchable conductor layer in the plane direction is 1 × 10 ² S / cm or more.
When the ratio of decrease in conductivity due to mechanical load is in the range of 1/1000 or more of the initial conductivity,
The elastic wiring according to [8] or [9], wherein the conductivity recovery rate by heating at 60 ° C. is 10% or more.
[11] The stretchable conductor layer has a stretch recovery rate of 99% or more after stretching by 20%, a binder resin having a glass transition temperature of 0 ° C. or less of 65 to 85% by mass, and metal particles from 90% by mass or more. The elastic wiring according to any one of [8] to [10], which is composed of 15 to 35% by mass of the conductive filler.
[12] When the number average molecular weight of the binder resin is Mn and the weight average molecular weight is Mw,
The elastic wiring according to any one of [8] to [11], wherein Mw / Mn> 4 or more.
[13] The stretchable wiring according to any one of [8] to [12] is provided on an insulating fabric having a stretch recovery rate of 99% or more at 50% stretch and a heat resistance of 60 ° C. or higher. A fabric with elastic wiring that features things.
[14] The method for recovering conductivity of elastic wiring according to any one of [8] to [12], wherein the elastic wiring is heated to 60 ° C. or higher with the extension load removed.
[15] The method for recovering conductivity of a fabric with elastic wiring according to [13] by heating the fabric with elastic wiring to 60 ° C. or higher in a state where the extension load is removed.

The stretchable conductor sheet and the stretchable conductor layer of the present invention have a dispersed structure composed of conductive particles and a stretchable binder resin. As described above, the flexible coating having such a dispersion structure has an elastic deformation region in which Hooke's law is established according to the degree of elongation when stretched, and a plastic deformation region deviating from Hooke's law. As described above, the elastic region is narrow and microcracks occur inside the coating film in the composition region. The composition region observed here is a plastic region observed from a macroscopic point of view. Although irreversible structural changes occur due to the occurrence of minute cracks inside the coating film, the binder resin portion in which the cracks do not occur is elastically deformed.
Hereinafter, unless otherwise specified, the stretchable conductor sheet has the same meaning as the stretchable conductor layer, is composed of the same stretchable conductor composition, and the stretchable conductor layer in the stretchable laminate and the stretchable wiring has a predetermined size. It is a processed elastic conductor sheet.

The main object of the present invention is to suppress a decrease in practical conductive performance by adjusting the stretch recovery rate of the stretchable conductor sheet viewed macroscopically to be 92% or more. That is, even if the conductive path due to particle contact is cut by microcracks generated when the stretchable conductor sheet is stretched, if the stretchable conductor sheet itself has a sufficiently high stretch recovery rate, it is cut off once. The contact between the conductive particles is reproduced, and the resistivity is lowered, that is, the conductivity is restored. The stretch recovery of the stretchable conductor sheet is mainly due to the flexibility of the binder resin, and this effect is enhanced by using the binder resin which has a high recovery rate and at the same time exhibits a strong shrinkage force. When the polymer is stretched by a tensile load, the polymer chain originally in the crimped state becomes a stretched form. In such a state, when an operation of increasing the degree of freedom of the polymer chain, that is, a plasticization operation with heating or a solvent is performed, the stretched polymer chain tries to return to the original crimped state and develops a contractile force. .. As in the present invention, the binder resin showing a predetermined stretch recovery rate as the stretchable conductor sheet also has such an effect. Therefore, the stretchable conductor sheet whose conductivity has been reduced by actual use such as repeated stretching has the stretch load removed. By heating to an appropriate temperature in the state, the stretch recovery rate can be further increased, and at the same time, the contact state between the conductive particles that has been cut off is also recovered.

Further, in the present invention, the recovery effect can be further enhanced by widening the molecular weight distribution of the binder resin. That is, the relatively high molecular weight resin component dominates the elasticity, and at the same time, the relatively low molecular weight component acts to fill the microcracks in a self-repairing manner, so that the mechanical dimensions can be restored and the conductivity can be restored at the same time. Be promoted. Such an effect can be further promoted by heating to an appropriate temperature with the extension load removed.

It is a schematic diagram for demonstrating the tensile yield elongation in this invention. It is a schematic diagram for demonstrating the stretch recovery rate in this invention. It is a schematic diagram which shows the manufacturing process of the wear with wiring by the direct printing method in this invention. It is a schematic diagram which shows the manufacturing process of the wear with wiring by the printing transfer method in this invention. It is a schematic diagram which shows an example of the state which the wiring is laid on the shirt. It is a schematic diagram which shows an example of the shape of a wiring.

The elastic conductor sheet, the elastic conductor layer, and the elastic wiring in the present invention include, at least, an elastic insulating polymer layer having a tensile yield elongation of 70% or more and a heat distortion temperature of 60 ° C. or more. It is composed of an elastic conductor layer composed of a conductive filler and a binder resin.

1
In the present invention, the tensile yield elongation is a curve (S-) obtained by a general tensile test when the vertical axis is weighted (or strength) and the horizontal axis is strain (or elongation or elongation). In the S-curve), it is the elongation at the first point where an increase in elongation is observed without an increase in weight, that is, the yield point. Generally, the yield point is regarded as a point that roughly indicates the boundary that changes from elastic deformation to plastic deformation.
FIG. 1A is a schematic view showing a typical SS curve obtained in a tensile test, and is shown in the figure.
SR: Tensile breaking strength
SB: Tensile strength
SS: Tensile yield strength
ER: Tensile breaking elongation
EB: Tensile elongation
ES: Tension yield elongation.
The tensile yield elongation of the stretchable insulating polymer layer in the present invention is preferably 80% or more, more preferably 95% or more, still more preferably 120% or more.
The upper limit of the tensile yield elongation is 450%, preferably 360%. If the tensile yield strength is higher than necessary, the mechanical strength of the insulating protective layer may be impaired.

The heat distortion temperature in the present invention means that the resin occupies any of fluidity, adhesiveness, and adhesiveness at the temperature. The heat distortion temperature is noticeable deformation or adhesion to the elastic insulating polymer layer when the elastic insulating polymer layer adjusted to the predetermined temperature is brought into contact with the metal adjusted to the same predetermined temperature. Judgment is made based on whether or not property or adhesiveness is generated. In the present invention, as a simple method, the iron heated to a predetermined temperature is brought into contact with the iron, and after the stretchable insulating polymer layer is sufficiently heated (1 minute), the iron is separated from the stretchable insulating polymer layer. It is possible to use a method of determining whether or not the stretchable insulating polymer layer is deformed and whether or not it exhibits adhesiveness / adhesiveness when the iron is released, and whether or not it has reached the thermal deformation temperature.
The heat distortion temperature of the elastic insulating polymer layer in the present invention is indispensable to be 60 ° C. or higher, preferably 75 ° C. or higher, more preferably 90 ° C. or higher, and further preferably 110 ° C. or higher. The upper limit of the heat distortion temperature depends on the heat resistance of the dough, but is preferably 180 ° C. It is preferably 160 ° C. If the heat distortion temperature is lower than this range, the elastic wiring may block, and if the heat distortion temperature exceeds this range, flexibility may be impaired.

As the stretchable insulating polymer layer having a tensile yield elongation of 70% or more and a heat distortion temperature of 60 ° C. or more in the present invention, a non-crosslinked or crosslinked elastomer can be used. As the non-crosslinked elastomer used in the present invention, a thermoplastic elastomer resin having an elastic coefficient of preferably 1 to 1000 MPa and preferably a glass transition temperature in the range of −60 ° C. to 15 ° C. can be used. Examples include thermoplastic synthetic resin, synthetic rubber, and natural rubber. More specifically, urethane rubber, acrylic rubber, silicone rubber, butadiene rubber, nitrile group-containing rubber such as nitrile rubber and hydride nitrile rubber, isoprene rubber, sulfide rubber, styrene butadiene rubber, butyl rubber, chlorosulfonated polyethylene rubber, Examples thereof include ethylene propylene rubber and vinylidene fluoride copolymer. Among these, nitrile group-containing rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, and styrene-butadiene rubber are preferable, and nitrile group-containing rubber is particularly preferable.
As the cross-linked elastomer in the present invention, a cross-linked rubber obtained by blending a cross-linking agent with the non-cross-linked elastomer described above can be preferably used. As the cross-linking agent, sulfur, a sulfur-based cross-linking agent (so-called vulcanizing agent), an organic peroxide, a metal oxide, an organic amine compound and the like can be used. In the present invention, it is preferable to use a non-sulfur-based cross-linking agent. In the case of a cross-linking agent containing sulfur or sulfur, the liberated sulfur-containing component may act on the conductive particles of the conductive layer to cause inconveniences such as a decrease in conductivity.
In the crosslinked elastomer in the present invention, the crosslinking density is preferably relatively low in order to keep the yield elongation above a predetermined range. In the present invention, it is preferable to keep the crosslink density so that the gel fraction using tetrahydrofuran as a solvent is 90% by mass or less, preferably 80% by mass or less.

The stretchable insulating polymer layer in the present invention can be self-adhesively / bonded or bonded to the fabric or the stretchable conductor layer by another adhesive means such as a hot melt adhesive layer after being formed independently.
Further, the stretchable insulating polymer layer in the present invention can be formed by melt-extruding a polymer material forming the stretchable insulating polymer layer onto a fabric or a stretchable conductor layer.
Further, in the stretchable insulating polymer layer in the present invention, the polymer material forming the stretchable insulating polymer layer is mixed with a solvent as needed, a cross-linking agent added as needed, an additive and the like. It can be formed by inking, printing or applying on a fabric or a stretchable conductor layer, and drying and curing. The solvents, additives, etc. that can be used are the same as the materials that can be used for the elastic conductor layer described later.

In the stretchable conductor sheet and the stretchable conductor layer of the present invention, the film thickness unevenness of the sheet or the conductor layer is 10% or less, and the stretch recovery rate after 20% stretching at 25 ° C. is 92% or more. Mandatory.
In the present invention, the film thickness unevenness of the stretchable conductor sheet is preferably 8% or less. When the film thickness unevenness is large, the elongation of the thin film thickness portion is selectively increased when an extension load is applied, so that the deterioration is partially accelerated and the electrical conductivity when viewed comprehensively. This is because the degree of reduction increases, and the mechanical and electrical damage of the seat also increases. In the present invention, such an effect can be more remarkably exhibited by setting the film thickness unevenness of the sheet to 10% or less.

For the film thickness unevenness [%] in the present invention, the thickness of 10 points was randomly measured on a 10 cm square sheet, and the thickness was 100 × (maximum film thickness-minimum film thickness) / average film thickness (10-point average). Ask.
The film thickness unevenness of the stretchable conductor sheet of the present invention is preferably 8% or less, more preferably 6% or less, still more preferably 4% or less.

The stretch recovery rate in the present invention means that when the stretchable conductive sheet is suspended, a load is applied to stretch it, and the load is removed to cause contraction, the initial length is L ₀ . When the length when stretched by 20% to a predetermined% is L ₁ , and the length when the stretch load is removed is L ₂ .
(Number 1)
Stretch recovery rate = ((L ₁ -L ₂ ) / (L ₁ -L ₀ )) x 100 [%]
(Number 2)
Residual distortion factor = ((L ₂ -L ₀ ) / L ₀ ) × 100 [%]
L ₀ Initial length L ₃ Elongation = L ₁ -L ₀
L ₄ Recovery length = L ₁ -L ₂
L ₅ residual strain = L ₂ -L ₀
Is defined. A similar measurement method is specified in the JIS L 1096 fabric test method for woven fabrics and knitted fabrics, but the recovery rate is not the recovery rate after stretching under a constant load, but the recovery rate when stretched to a certain length. different. In actual use, the load applied to the stretchable conductor layer is often repeatedly stretched to a predetermined length regardless of the load, so that the stretch recovery rate by the constant load method cannot express practical performance. Unless otherwise specified, the stretch recovery rate is evaluated in an environment of 25 ° C ± 3 ° C.

The stretchable conductor sheet, the stretchable conductor layer, and the stretchable wiring in the present invention have a stretch recovery rate of 96% or more when heated at 60 ° C. with the stretch load removed after 20% stretch at 25 ° C. Is preferable.
Here, the state in which the extension load is removed means a state in which the load applied at the time of extension during suspension is removed, and the own weight acting as the extension load is also removed. Ideally, it should be in a zero gravity state or floated in a high-density fluid at the same level as the stretchable conductor sheet, but practically, if the sample is handled by lying horizontally on a table placed horizontally, It can be treated as a state in which the extension load is practically removed.

As means for heating to 60 ° C, direct heating with a hot plate, iron, trouser press, etc., irradiation with hot air with a dryer, hot blaster, etc., steam irradiation, irradiation with strong light, infrared heating, radiant heating from a heater, etc. Can be used. Immersion in hot water is also an effective method.
The stretch recovery rate after heating can be obtained by the same method as the stretch recovery rate at 25 ° C. except that the recovery length after heating is used. The stretch recovery rate after heating is preferably 97% or more, more preferably 98% or more, and further preferably 98.8% or more.

It is preferable that the initial conductivity in the plane direction of the stretchable conductor sheet, the stretchable conductor layer, and the stretchable wiring is 1 × 10 ^-3 S / cm or more. Conductivity is the reciprocal of specific resistance. The initial conductivity of the elastic conductor sheet of the present invention is preferably 1 × 10 − ² S / cm or more, more preferably 1 × 10 ^-1 S / cm or more, and even more preferably 1 × 10 ⁰ S. / Cm or more.
The conductivity is S [1 / (Ω · cm)], and the resistance value of the conductive film having a width W [cm], a length L [cm], and a thickness t [cm] in the length L direction is R [Ω]. ], Then
S = (1 / R) · (L / (t · W))
You can ask for it at.

In the present invention, when the conductivity reduction ratio in the sheet surface direction of the stretchable conductor sheet is within 1/1000 of the initial conductivity by the mechanical load test, the conductivity recovery rate by heating at 60 ° C. is 10%. The above is preferable. Here,
Conductivity reduction ratio by mechanical load test = conductivity after mechanical load test / initial conductivity,
Conductivity recovery rate after mechanical load test = Conductivity after heating at 100 × 60 ° C. after mechanical load test / Initial conductivity,
Is. In the stretchable conductor sheet showing the stretch recovery rate in the present invention, the electrical contact between the conductive particles is restored at the time of stretch recovery, and the contact between the conductive particles becomes closer due to the shrinkage force generated by heating. Can be expressed.
The conductivity recovery rate by heating at 60 ° C. after the mechanical load test is more preferably 15% or more, further preferably 25% or more, still more preferably 35% or more.

Further, in the present invention, when the ratio of decrease in conductivity of the stretchable conductor sheet in the sheet surface direction after the washing test is within 1/1000 of the initial conductivity, the conductivity recovery rate by heating at 60 ° C. is 10%. The above is preferable. Here,
Ratio of decrease in conductivity after washing test = conductivity after washing test / initial conductivity,
Conductivity recovery rate after washing test = Conductivity after heating at 100 × 60 ° C after washing test / Initial conductivity,
Is. In the washing test, a mechanical load is applied in both the expansion and contraction direction and the compression direction in water or water containing detergent, and more complicated deformation than a simple mechanical load is applied to the conductive sheet. The stretchable conductor sheet shown can exhibit such characteristics because the electrical contact between the conductive particles is restored when the stretch is restored, and the contact between the conductive particles becomes closer due to the shrinkage force generated by heating.
The conductivity recovery rate by heating at 60 ° C. after the washing test is more preferably 15% or more, further preferably 25% or more, still more preferably 35% or more.

The stretchable conductor sheet, the stretchable conductor layer, and the stretchable wiring of the present invention are composed of at least a conductive filler mainly composed of metal particles and a binder resin.
The conductive particles of the present invention are particles having a specific resistance of 1 × 10 ⁻² Ωcm or less and having a particle diameter of 0.5 μm or more and 5 μm or less. Examples of the substance having a specific resistance of 1 × 10 ⁻² Ωcm or less include metals, alloys, and doped semiconductors. The conductive particles preferably used in the present invention include metals such as silver, gold, platinum, palladium, copper, nickel, aluminum, zinc, lead and tin, alloy particles such as brass, bronze, white copper and solder, and silver-coated copper. Hybrid grains, as well as metal-plated polymer particles, metal-plated glass particles, metal-coated ceramic particles, and the like can be used.

In the present invention, it is preferable to mainly use flake-shaped silver particles or amorphous aggregated silver powder. It should be noted that the term "used mainly" here means that 90% by mass or more of the conductive particles are used. The amorphous agglomerated powder is a three-dimensional aggregate of spherical or amorphous primary particles. Amorphous agglomerated powder and flake-like powder have a larger specific surface area than spherical powder and the like, and are preferable because they can form a conductive nate work even with a low filling amount. Since the amorphous agglomerated powder is not in the form of monodisperse, it is more preferable because the particles are in physical contact with each other and easily form a conductive nate work.

As for the particle size of the conductive particles, the average particle size (50% D) measured by the dynamic light scattering method is 0.5 to 5 μm, more preferably 0.7 to 3 μm. If the average particle size exceeds a predetermined range, it becomes difficult to form fine wiring, and clogging occurs in the case of screen printing or the like. If the average particle size is less than 0.5 μm, the particles cannot be contacted with each other at low filling, and the conductivity may deteriorate.

In the present invention, carbon black having a DBP oil absorption amount in the range of 100 to 550 can be used as the conductive filler. There are many types of carbon black with different raw materials and manufacturing methods, and each has its own characteristics. DBP oil absorption is a parameter indicating the liquid absorption and retention performance of carbon black, and is measured based on ISO4656: 2012. In the present invention, the DBP oil absorption amount is preferably 160 or more and 530 or less, more preferably 210 or more and 510 or less, and further preferably 260 or more and 500 or less. If the amount of DBP oil absorption is less than this range, the gaps between the lines are likely to be filled when the fine lines are printed, and the fine line printability is deteriorated. If the amount of DBP oil absorbed exceeds this range, the viscosity of the paste tends to increase, and it becomes necessary to increase the amount of the solvent to be blended in order to adjust the viscosity. Therefore, when fine lines are printed, the solvent easily bleeds between the lines. Similarly, the fine line printability is reduced.
The blending amount of carbon black is 0.5% by mass or more and 2.0% by mass or less, preferably 0.7% by mass or more and 1.6% by mass or less, based on the total amount of the metal-based filler and carbon black.

In the present invention, non-conductive particles having an average particle diameter of 0.3 μm or more and 10 μm or less may be included. The non-conductive particles in the present invention are mainly metal oxide particles, which are silicon oxide, titanium oxide, magnesium oxide, calcium oxide, aluminum oxide, iron oxide, metal sulfate, metal carbonate, and metal. Titanate or the like can be used. In the present invention, it is preferable to use barium sulfate particles among such non-conductive particles.

The binder resin used for the stretchable conductor sheet, the stretchable conductor layer, and the stretchable wiring of the present invention preferably has a stretch recovery rate of 99% or more after stretching by 20%, and further has a stretch recovery rate of 99.5% or more. Is preferable, and further preferably 99.85% or more. The stretch recovery rate of the binder resin is measured in an environment of 25 ± 3 ° C. by molding the binder resin on a sheet having a thickness of 20 to 200 μm and a film thickness unevenness of 10% or less. If the stretch recovery rate of the binder resin is less than this range, it becomes difficult to increase the stretch recovery rate of the stretchable conductor sheet to a predetermined range or more.

A non-crosslinked elastomer can be used as the binder resin in the present invention. The non-crosslinked elastomer preferably has a thermoplastic rate of 1 to 1000 MPa, and preferably a thermoplastic elastomer resin having a glass transition temperature in the range of −40 ° C. to 0 ° C. can be used, and is a thermoplastic synthetic resin. Examples include rigid rubber and natural rubber. In order to develop the elasticity of the coating film (sheet), rubber or polyester resin is preferable. Examples of rubber include urethane rubber, acrylic rubber, silicone rubber, butadiene rubber, nitrile group-containing rubber such as nitrile rubber and hydride nitrile rubber, isoprene rubber, sulfide rubber, styrene butadiene rubber, butyl rubber, chlorosulfonated polyethylene rubber, and ethylene propylene. Examples include rubber and vinylidene fluoride copolymer. Among these, nitrile group-containing rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, and styrene-butadiene rubber are preferable, and nitrile group-containing rubber is particularly preferable.
The elastic modulus of the flexible resin is preferably 3 to 600 MPa, more preferably 10 to 500 MPa, still more preferably 15 to 300 MPa, still more preferably 20 to 150 MPa, and particularly preferably 25 to 100 MPa.

The rubber containing a nitrile group is not particularly limited as long as it is a rubber containing a nitrile group or an elastomer, but nitrile rubber and hydride nitrile rubber are preferable. Nitrile rubber is a copolymer of butadiene and acrylonitrile, and when the amount of bonded acrylonitrile is large, the affinity with the metal increases, but the rubber elasticity that contributes to elasticity decreases. Therefore, the amount of bonded acrylonitrile is preferably 18 to 50% by mass, more preferably 30 to 50% by mass, and 40 to 50% by mass in 100% by mass of the nitrile-containing rubber (for example, acrylonitrile butadiene copolymer rubber). It is particularly preferable to be% by mass.

In the polyester resin and urethane rubber, the glass transition temperature is preferably −40 ° C. to 0 ° C. Further, it is preferable to have a block copolymer structure composed of a hard segment and a soft segment. The elastic modulus of the non-crosslinked elastomer of the present invention is preferably in the range of 1 to 1000 MPa, more preferably 3 to 600 MPa, still more preferably 10 to 500 MPa, still more preferably 30 to 300 MPa. Further, the non-crosslinked elastomer of the present invention preferably has a glass transition temperature of 0 ° C. or lower, preferably −5 ° C. or lower, and more preferably −10 ° C. or lower.

The glass transition temperature of the binder resin is preferably 0 ° C. or lower, more preferably −8 ° C. or lower, still more preferably −16 ° C. or lower, still more preferably −24 ° C. or lower. When the glass transition temperature exceeds this range, the stretch recovery characteristic is less likely to be exhibited.
The stretchable conductor sheet of the present invention is preferably composed of at least 65 to 85% by mass of the binder resin and 15 to 35% by mass of the conductive filler composed of 90% by mass or more of the metal particles.
The glass transition temperature can be determined by differential scanning calorimetry (DSC) according to a conventional method.

In the present invention, when the number average molecular weight of the binder resin is Mn and the weight average molecular weight is Mw, it is essential that Mw / Mn> 4 or more, and Mw / Mn> 4.4 or more. It is even more preferably Mw / Mn> 4.8 or more, and even more preferably Mw / Mn> 5.2 or more. Mw / Mn is a factor representing the molecular weight distribution, and the larger the Mw / Mn, the wider the molecular weight distribution. In the binder resin component having a wide molecular weight distribution, the relatively high molecular weight component dominates the stretch recovery property. On the other hand, the relatively low molecular weight component has the effect of bleeding into the microcracks generated during stretching and reconnecting between the microcracks in a self-repairing manner when the stretching is restored.
The number average molecular weight and the weight average molecular weight can be obtained by a GPC (gel permeation chromatography) analysis method according to a conventional method.

The binder resin does not have to be a single resin, and a high molecular weight resin having a high elongation recovery rate and a different low molecular weight resin having a high self-repairing function may be mixed and used. In the present invention, a binder resin having two or more peaks in the molecular weight distribution obtained by blending a resin having a peak in the weight average molecular weight of 800 to 4000 and a resin having a peak in the range of 4000 to 100,000. It is preferable to use.

In the present invention, the non-crosslinked elastomer is used as the main binder resin, but a branching component can be added to obtain a high molecular weight binder resin. When the number of branched components is large, the molecular structure may be almost the same as that of the crosslinked structure. As described above, in the present invention, a crosslinked high molecular weight elastomer and a low molecular weight non-crosslinked elastomer can be appropriately blended and used.

The stretchable conductor sheet in the present invention is a single film in the form of a sheet or a film composed of a stretchable conductor composition.
The stretchable conductor sheet of the present invention can be formed into a sheet by directly melting and mixing a conductive filler and a binder resin and forming a sheet by a method such as extrusion molding. Such a method can be suitably applied when the binder resin has a relatively low temperature and a relatively low melt viscosity.
As a suitable production method in the present invention, a paste for forming a stretchable conductor is obtained by adding a solvent component to at least a conductive filler and a binder resin, mixing and stirring, and kneading, and the obtained paste is used for a coating method. The method of making a sheet can be exemplified.
Similarly, a paste for forming an elastic conductor can be obtained, and the obtained paste can be used to obtain a sheet or an electrical wiring pattern by a method of directly patterning by a printing method or the like.
As the printing method, a screen printing method, a flat plate offset printing method, a paste jet method, a flexo printing method, a gravure printing method, a gravure offset printing method, a stamping method, a stencil method, and the like can be used. Further, a method of directly drawing wiring using a dispenser or the like can also be interpreted as printing in a broad sense and used.

The solvent used for the paste for forming the stretchable conductor of the present invention is preferably an organic solvent having a boiling point of 200 ° C. or higher and a saturated vapor pressure of 20 Pa or lower at 20 ° C. If the boiling point of the organic solvent is too low, the solvent may volatilize during the paste manufacturing process or when the paste is used, and the component ratio constituting the conductive paste may change easily. On the other hand, if the boiling point of the organic solvent is too high, the amount of residual solvent in the dry-cured coating film increases, which may cause a decrease in the reliability of the coating film. In addition, since it takes a long time to dry and cure, edge sagging during the drying process becomes large, and it becomes difficult to keep the wiring space narrow.

The organic solvent in the present invention includes benzyl alcohol (vapor pressure: 3 Pa, boiling point: 205 ° C.), tarpionale (vapor pressure: 3.1 Pa, boiling point: 219 ° C.), diethylene glycol (vapor pressure: 0.11 Pa, boiling point: 245 ° C.). , Diethylene glycol monoethyl ether acetate (vapor pressure: 5.6 Pa, boiling point 217 ° C), Diethylene glycol monobutyl ether acetate (vapor pressure: 5.3 Pa, boiling point: 247 ° C), diethylene glycol dibutyl ether (vapor pressure: 0.01 mmHg or less, boiling point: 255 ° C) ), Triethylene glycol (vapor pressure: 0.11 Pa, boiling point: 276 ° C), triethylene glycol monomethyl ether (vapor pressure: 0.1 Pa or less, boiling point: 249 ° C), triethylene glycol monoethyl ether (vapor pressure: 0.3 Pa,) Boiling point: 256 ° C.), Triethylene glycol monobutyl ether (vapor pressure: 1Pa, boiling point: 271 ° C.), Tetraethylene glycol (vapor pressure: 1Pa, boiling point: 327 ° C.), Tetraethylene glycol monobutyl ether (vapor pressure: 0.01Pa or less) , Boiling pressure: 304 ° C.), Tripropylene glycol (vapor pressure: 0.01 Pa or less, boiling point: 267 ° C.), Tripropylene glycol monomethyl ether (vapor pressure: 3 Pa, boiling point: 243 ° C.), Diethylene glycol monobutyl ether (vapor pressure: 3 Pa, Boiling point: 230 ° C.) can be used.
The solvent in the present invention may contain two or more of them, if necessary. Such an organic solvent is appropriately contained so that the paste for forming the stretchable conductor composition has a viscosity suitable for printing and the like.

The paste for forming an elastic conductor of the present invention can be obtained by mixing and dispersing with a disperser such as a dissolver, a three-roll mill, a self-revolving mixer, an attritor, a ball mill, and a sand mill.

The paste for forming an elastic conductor of the present invention contains known organic and inorganic additives such as imparting printability, adjusting color tone, leveling, antioxidant, and ultraviolet absorber, as long as the contents of the invention are not impaired. Can be blended.

By drying and curing the stretchable conductor forming paste thus obtained, an electric wiring pattern made of a stretchable conductor sheet or a stretchable conductor showing a predetermined stretch recovery rate, which is substantially free of solvent, is obtained. be able to.
When the stretchable conductor sheet is obtained, the stretchable conductor forming paste can be applied to a film substrate or the like coated with a mold release agent with a die coater, a slit coater, a comma coater, a gravure coater or the like, and dried to form a sheet.

In the present invention, the elastic conductor sheet described above can be used to form electrical wiring on an insulating fabric having a recovery rate of 99% or more at 50% elongation and heat resistance of 60 ° C. or more. .. In the present invention, the heat resistance of the fabric is evaluated by the heat shrinkage temperature of the material fiber.
The electrical wiring can be manufactured by cutting an elastic conductor sheet into a predetermined shape and attaching it to a cloth with an adhesive or the like. Further, it is also possible to obtain an electric wiring pattern having a predetermined shape by a printing method after forming a base layer directly on the cloth or with an insulating resin in advance.
Further, a predetermined pattern can be formed by printing or the like on another substrate having releasability and transferred to the cloth. In the present invention, an insulating cover layer is formed on the wiring as needed.
As the printing method, a screen printing method, a flat plate offset printing method, a paste jet method, a flexo printing method, a gravure printing method, a gravure offset printing method, a stamping method, a stencil method, and the like can be used. In the present invention, it is preferable to use the screen printing method and the stencil method. Further, the method of directly drawing the wiring using a dispenser or the like may be interpreted as printing in a broad sense.
In the present invention, it is possible to manufacture a garment having an electric wiring made of an elastic conductor composition by these methods.

In the elastic conductor sheet in the present invention, the cloth having the electric wiring made of the elastic conductor, and the clothes having the electric wiring, for example, an iron, a trouser press, and a hair in a state where the extension load of the elastic conductor portion is removed. By heating to 60 ° C. or higher using a dryer or the like, it is possible to recover the conductive performance from a state in which the conductivity is deteriorated due to a load such as repeated stretching to a state in which it can be practically used in actual use. Such a process is called a conductivity recovery process. The heating temperature used for the conductivity recovery treatment is preferably 75 ° C. or higher, more preferably 90 ° C. or higher, and even more preferably 110 ° C. or higher. The upper limit of the temperature of the conductivity recovery treatment depends on the heat resistance of the shared base material and the like. In woven and knitted fabrics made of general chemical fibers, the upper limit is about 150 ° C. Of course, when relatively high heat resistant fibers such as cotton, heat resistant fiber materials such as aramid fiber, polybenzazole fiber, and polyimide fiber, and heat resistant flexible resin such as silicone resin are used as the base material, Not limited to this, the range of 180 ° C to 300 ° C may be used with care so as not to cause excessive heat damage to the binder resin.

Hereinafter, the present invention will be described in more detail and concretely with reference to Examples. The evaluation results in the examples were measured by the following methods.

<Tension yield elongation>
The resin material used for the stretchable insulating polymer layer is formed into a sheet with an arbitrary thickness in the range of 20 μm to 200 μm, and then punched into a dumbbell mold specified by ISO 527-2-1A to test pieces. And said. Then, the SS curve was obtained using a tensile tester, the yield point was obtained as shown in FIG. 1A, and the elongation at that time was taken as the tensile yield elongation.

<Heat distortion temperature>
A sheet of stretchable insulating polymer is placed on a hot plate and heated to a predetermined temperature. Then, an electric iron having an iron hot plate heated to the same predetermined temperature is placed on a sheet of elastic insulating polymer for 1 minute, and then the electric iron is lifted, and when the electric iron is lifted, the sheet of elastic insulating polymer is ironed. When it was lifted together with the hot plate, it was judged to be adhesive or adhesive. If the trace of the iron could be visually determined, it was determined to be thermally deformed. The measurement was carried out by raising the predetermined temperature in increments of 60 ° C to 5 ° C, and the lowest temperature at which either heat distortion or adhesion / adhesiveness was observed was defined as the heat distortion temperature. When the temperature reached 180 ° C, the test was stopped there. If the fabric was deformed or abnormal, the test was stopped at that temperature, and it was determined that the heat distortion temperature was above that temperature.

<Amount of nitrile>
The composition ratio obtained by NMR analysis of the obtained resin material was converted into mass% based on the mass ratio of the monomers.

<Moony viscosity>
The measurement was performed using the SMV-300RT "Moony Viscometer" manufactured by Shimadzu Corporation.

<Elastic modulus>
The binder resin was formed into a sheet having an arbitrary thickness in the range of 20 μm to 200 μm, and then punched into a dumbbell mold specified by ISO 527-2-1A to obtain a test piece.
A tensile test was performed by the method specified in ISO 527-1 to obtain a stress-strain diagram of the resin material, and the elastic modulus was calculated by a conventional method.

<Glass transition temperature>
The glass transition temperature was determined by differential scanning calorimetry (DSC) according to a conventional method.

<Molecular weight>
A sample of the binder resin material was added to THF (tetrahydrofuran) so that the concentration of the resin in the solution was 0.4% by mass, and the mixture was stirred at room temperature for 1 hour and then left for 24 hours. Next, the obtained resin solution was diluted 4-fold with THF, passed through a 0.45 μm filter, and the filtrate was subjected to number average molecular weight, weight average molecular weight, and dispersion ratio (Mw / Mn) using GPC. I asked.

When the obtained sample is a prepared conductive paste or a cured product of the paste, the paste material is added to THF (tetrahydrofuran) so that the concentration of the sample in the solution is 2.0% by mass, and the solution is stirred. While raising the temperature to the boiling point of THF, holding for 30 minutes, cooling to room temperature, and leaving for 24 hours. Next, the obtained resin solution was diluted 4-fold with THF, passed through a 0.45 μm filter to remove inorganic components, and the filtrate was subjected to GPC measurement to add low molecular weight components such as additives to a molecular weight of 500. The components were regarded as less than the components and deleted, and the number average molecular weight, the weight average molecular weight, and the dispersion ratio (Mw / Mn) were obtained for the portion having a molecular weight of 500 or more.

<Resin stretch recovery rate>
The resin material was formed into a sheet having an arbitrary thickness in the range of 20 μm to 200 μm, and then punched into a dumbbell mold specified by ISO 527-2-1A to obtain a test piece.
Then, marks were made at 33 mm (effective length 66 mm) from the center of the dumbbell-shaped test piece having a width of 10 mm and a length of 80 mm, and the initial distance L ₀ between the marks was accurately measured. Next, the outside of the marked part is sandwiched by a clamp, the distance between the marks, which is 66 mm, is extended to an extension length of 79.2 mm (+ 13.2 mm, equivalent to an extension degree of 20%), and then separated from the clamp to a predetermined temperature (especially). It was placed on a fluororesin sheet held horizontally at 25 ° C. (unless otherwise noted), and the distance L ₂ after stretching between the marks was measured, and the stretching recovery rate was determined according to the following formula.
Initial length L ₀ = 66.0 mm
Extension length L ₁ = 79.2 mm
Length after stretching L ₂ = Measured stretching L ₃ = L ₁ -L ₀ = 13.2 mm
Recovery length L ₄ = L ₁ -L ₂
Stretch recovery rate = ((L ₁ -L ₂ ) / (L ₁ -L ₀ )) x 100 [%]

<Stretch recovery rate of fabric>
The fabric material was punched into a dumbbell shape specified by ISO 527-2-1A to obtain a test piece. The extending direction of the cloth was defined as the length direction of the dumbbell.
Next, as in the measurement of the stretch recovery rate of the resin, marks 33 mm (effective length 66 mm) from the center of the dumbbell type test piece having a width of 10 mm and a length of 80 mm, respectively, and the stretch length is 99 mm (+ 33 mm). The stretch recovery rate was obtained by operating in the same manner as the stretch recovery rate of the resin except that the stretch was stretched to 50%.

<Heat resistance of fabric>
The heat resistance of the fabric was determined by the heat shrinkage temperature required by JIS L1013: 2010 Chemical Fiber Filament Yarn Test Method 8.19.2.

<Average particle size>
The average particle size of the filler was measured using a light scattering type particle size distribution measuring device LB-500 manufactured by HORIBA, Ltd.

<Conductivity>
If the conductor sheet is large enough, punch it into a dumbbell type specified by ISO 527-2-1A, and use the 10 mm wide and 80 mm long part in the center of the dumbbell type test piece as the test piece. Using. When the conductor sheet can be molded, it is heat-compressed into a sheet having a thickness of 200 ± 20 μm, and then punched into a dumbbell mold specified by ISO 527-2-1A to obtain a test piece in the same manner. If the size of the conductor sheet is too small to obtain the specified dumbbell shape, a rectangle with a recoverable width and length is cut out and used as a test piece, and the width, thickness, and length for which the conductivity is measured are measured. Was converted using.
Test piece: Measure the resistance value [Ω] of the part with a width of 10 mm and a length of 80 mm using a milliohm meter manufactured by Agilent Technologies, and multiply by the aspect ratio (1/8) of the test piece to obtain the sheet resistance value “Ω]. □ ”was asked.
Further, the resistivity value [Ω] was multiplied by the cross-sectional area (width 1 [cm] mm × thickness [cm]) and divided by the length (8 cm) to obtain the specific resistance [Ωcm]. Further, the reciprocal of the specific resistance was obtained and used as the conductivity.

<Stretch recovery rate of conductive sheet material>
A test piece similar to that used for the measurement of conductivity was used.
Next, as in the measurement of the stretch recovery rate of the resin, marks 33 mm (effective length 66 mm) from the center of the dumbbell type test piece having a width of 10 mm and a length of 80 mm, respectively, and the stretch length is 99 mm (+ 33 mm). The stretch recovery rate of the conductive sheet was obtained by operating in the same manner as the stretch recovery rate of the resin except that the stretch was stretched to (corresponding to a stretch degree of 50%).

<Repeat expansion and contraction durability of conductive sheet material (mechanical load test)>
(1) Preparation of test piece When the conductor sheet was large enough, it was punched into a dumbbell shape specified by ISO 527-2-1A to make a test piece. When the conductor sheet can be molded, it is formed into a sheet having an arbitrary thickness of 20 to 200 μm, and then punched into a dumbbell mold specified by ISO 527-2-1A to obtain a test piece. .. If the size of the conductor sheet is too small to obtain the specified dumbbell shape, a rectangle with a recoverable width and length is cut out and used as a test piece, and the width, thickness, and length for which the conductivity is measured are measured. Was converted using.
(2) Repeated expansion and contraction test The IPC bending tester made by Yamashita Materials was modified, the reciprocating stroke of the tester was set to 13.2 mm, the test piece was clamped to the movable plate side, and the other end was clamped to another fixed end. Using the part of the dumbbell type test piece with a width of 10 mm and a length of 80 mm, adjust the effective length to 66 mm (corresponding to an extension degree of 20%) so that the sample can be repeatedly expanded. Using the modified device, aluminum foil was wrapped around 0 to 5 mm outside both ends of the effective expansion and contraction length of 66 mm, sandwiched between metal clips, and repeatedly stretched while monitoring the resistance value with a tester. The resistance value is read every 10 times up to 600 times of repeated stretching, and every 50 times or more, the stretching rate is stopped at 0%, and the value 1 minute after the stop is read and recorded. The number of times the resistance value reached 100 times the initial value was recorded, and the test was terminated there.

<Recovery rate of thermal conductivity of elastic conductor layer and elastic conductor / fabric laminate>
In the repeated expansion / contraction durability (mechanical load) of the conductive sheet, when the conductivity reduction ratio is 1/1000 or more, the test piece after the repeated expansion / contraction durability (mechanical load) test is removed from the extension load and its own weight. Place it on a fluororesin sheet held horizontally without any load other than that, heat it in a dry oven at 60 ° C for 10 minutes, return it to room temperature, measure the conductivity, and restore conductivity. I asked for the rate. Similarly, the stretchable conductor / fabric laminate is placed on a fluororesin sheet held horizontally in a state where no load other than its own weight is applied, and heated in a dry oven at 60 ° C. for 10 minutes. The temperature was returned to room temperature, the conductivity was measured, and the conductivity recovery rate was determined.
(Number 3)
Conductivity reduction ratio = Conductivity at the time of measurement / Initial conductivity Recovery rate of conductivity = 100 × 60 ° C. Conductivity after heating / Initial conductivity

<Film thickness spot>
The elastic conductor layer was immersed in liquid nitrogen to be sufficiently cooled, and then bent in any direction to break the sheet into a test piece whose cross section could be observed. Observe the cross section of the obtained test piece with a microscope having a length measuring function, measure the thickness of the conductor part of the elastic conductor layer at intervals of about 1 mm in the plane direction at 10 points, and measure the thickness unevenness by the following formula. Asked. From the maximum film thickness, the minimum film thickness, and the average film thickness of the obtained 10 points, the film thickness unevenness was determined according to the following formula.
(Number 4)
Film thickness unevenness [%] = 100 x (maximum film thickness-minimum film thickness) / average film thickness

<Washing durability>
(1) Preparation of test piece A dumbbell-shaped punched elastic conductor layer was punched to 40 mm x 180 mm in the center of a 50 mm x 200 mm fabric (tricot knitted fabric, heat resistance> 100 ° C, stretch recovery rate 100%). A hot melt adhesive layer MOB100 [manufactured by Nisshinbo Co., Ltd.] was layered, sandwiched between fluororesin sheets, and hot-pressed at 120 ° C. to laminate them into test pieces. Both the tricot knitted fabric and the hot melt adhesive layer MOB100 have sufficient extensibility, with a stretch recovery rate of 100% at 100% elongation.
(2) Washing test
A 30-cycle washing test was conducted according to the 105 method specified in the labeling symbols and labeling methods for handling JIS L 0217 textile products.
Washing liquid: Neutral detergent 0.5% solution Water flow: Weak bath ratio: 1:60
Washing cycle Washing 30 ° C for 5 minutes Rinse 30 ° C for 2 minutes twice This cycle is one cycle and repeated 30 times.
(3) Evaluation In the washing test of the conductive sheet, when the rate of decrease in conductivity after the test is 1/1000 or more, the stretch load is removed from the test piece after the washing test, and no load other than its own weight is applied. After standing still on a fluororesin sheet held horizontally at 60 ° C. for 10 minutes in a dry oven, the mixture was returned to room temperature, the conductivity was measured, and the conductivity recovery rate was determined.
Ratio of decrease in conductivity after washing test = Conductivity after washing test / Initial conductivity Recovery rate of conductivity after washing test = Conductivity after heating at 100 × 60 ° C after washing test / Initial conductivity.
In calculating the conductivity, the value of the sheet thickness before being attached to the cloth was used for convenience.

[Manufacturing Examples 1 to 5]
<Polymerization of synthetic rubber materials>
In a stainless steel reaction vessel equipped with a stirrer and a water-cooled jacket, butadiene 61 parts by mass Acrylonitrile 39 parts by mass Deionized water 270 parts by mass Sodium dodecylbenzene sulfonate 0.5 parts by mass Naphthalene sulfonate sodium condensate 2.5 parts by mass t -Dodecyl mercaptan 0.3 part by mass Triethanolamine 0.2 part by mass 0.1 part by mass of sodium carbonate The bath temperature was kept at 5 ° C. while flowing nitrogen, and the mixture was gently stirred. Next, an aqueous solution prepared by dissolving 3 parts by mass of potassium persulfate in 19.7 parts by mass of deionized water was added dropwise over 30 minutes, and after continuing the reaction for another 20 hours, 0.5 parts by mass of hydroquinone was added to 19.5 parts by mass of deionized water. An aqueous solution dissolved in a mass portion was added to perform a polymerization termination operation.
Next, in order to distill off the unreacted monomer, the pressure inside the reaction vessel was first reduced, and steam was further introduced to recover the unreacted monomer to obtain a synthetic rubber latex (L1) made of NBR.
Salt and dilute sulfuric acid are added to the obtained latex to aggregate and filter, and the deionized water having a volume ratio of 20 times the volume of the resin is divided into 5 times, the resin is redispersed in the deionized water, and the filtration is repeated for washing. , Dryed in air to obtain a synthetic rubber resin. Table 1 shows the glass transition temperature, number average molecular weight, weight average molecular weight, dispersion ratio, gel fraction, and elongation recovery rate of the obtained synthetic rubber resin.
Hereinafter, by changing the amount of the polymerization initiator (potassium persulfate) added, the polymerization temperature, and the raw material charging ratio, Table 1. NBR1, NBR2, NBR3, NBR4, and SBR1 shown in

[Binder resin]
The resin materials were blended at the blending ratios shown in Table 2 and kneaded at a temperature at which they were sufficiently melted to obtain a binder resin. The characteristics of each binder resin are shown in Table 2. Shown in.
In the table, in the SBR + cross-linking agent, SBR is SBR1 obtained in the production example, and as the cross-linking agent, non-sulfur-based perbutyl P [manufactured by NOF CORPORATION] is 0.1% by mass with respect to the total amount of the resin. bottom
As the urethane in the table, UR-8700 [manufactured by Toyobo Co., Ltd.] was used.

[Paste]
First, the binder resin is dissolved in half the amount of the predetermined solvent, metal particles, carbon particles, and other components are added to the obtained solution, premixed, and then dispersed in a three-roll mill. As a result, it was made into a paste, and the paste shown in Table 3 was obtained as Pag1. Similarly, the paste was adjusted according to the composition ratio shown in Table 3.

Table 3. Carbon-based particles CB01: Scale graphite graphite BF-1AT (average particle size 1 μm) manufactured by Chuetsu Graphite Mfg. Co., Ltd.
Carbon-based particles CB02: Graphite powder made by Lion Specialty Chemicals Co., Ltd. Ketjen Black EC300J BET Specific surface area 800 (m2 / g)
Metallic particles Ag01: Made by Fukuda Metal Foil Powder Industry Co., Ltd. Fine flake-shaped silver powder Ag-XF301 (average particle diameter 6 μm)
Metallic particles Ag02: Aggregated silver powder G-35 manufactured by DOWA Electronics Co., Ltd. (average particle diameter 6.0 μm)
Metallic particles Ag03: Mitsui Mining & Smelting Co., Ltd. Micro-diameter silver powder SPQ03R (average particle diameter 0.7 μm)
Non-conductive particles TiO2: Titanium oxide particles R-62N manufactured by Sakai Chemical Industry Co., Ltd. (average particle size is 0.3 μm)
Non-conductive particles SiO2: Fumed silica AEROSIL 200 manufactured by Nihon Aerosil Co., Ltd. (BET specific surface area 200 m2 / g)
Solvent BC: Butyl carbitol acetate Solvent IP: Isophorone.

The obtained stretchable conductor forming paste is applied to a polyester film having a width of 600 mm and treated with a silicone-based mold release agent so as to have an effective width of 500 mm using a comma coater, thereby expanding and contracting as shown in Table 4. A sex conductor layer was obtained.
The obtained sheet was peeled off from the release-treated polyester film, and the thickness and thickness unevenness were evaluated. The results are shown in Table 4. Shown in. Subsequently, the initial conductivity of the stretchable conductor layer and the conductivity after mechanical loading (after repeated stretching durability test) were evaluated, and the conductivity reduction ratio was determined. Furthermore, the thermal conductivity recovery rate of the stretchable conductor layer after mechanical loading was determined. The results are shown in Table 4. In the sample using the binder resin having a narrow molecular weight distribution, the decrease in conductivity is remarkable. Further, for a sample having a conductivity reduction ratio of 1/1000 or less, the effect of recovering conductivity by heating is low. Further, it can be seen that when a binder resin having a wide molecular weight distribution is used, the recovery rate by heating the conductivity is high.

The obtained elastic conductor layer was attached to a tricot fabric by a predetermined method to obtain an elastic conductor / fabric laminate. The table below shows the results of obtaining the initial conductivity of the stretchable conductor portion of the obtained stretchable conductor / fabric laminate, the conductivity after the washing test, the conductivity reduction ratio after the washing test, and the conductivity recovery rate after the washing test. Shown in 4.

[Example 2 of paste formation] Preparation of paste for electrode surface layer (stretchable carbon paste) The carbon paste for the electrode surface layer was prepared according to the composition shown in Table 3.

[Example 3 of paste formation] Paste for forming a stretchable insulating polymer layer (stretchable insulating ink: cover coat resin ink, ink for base layer)
A paste for forming an elastic insulating polymer layer was prepared according to the composition shown in Table 3. Table 5 shows the characteristics of the coating film obtained from the obtained stretchable insulating polymer layer forming paste.

[Application Example 1]
A clothing-type electronic device for electrocardiogram measurement was manufactured by the direct printing method shown in FIG. I turned the knit sports shirt over, put it in the temporary support so that the back would not wrinkle, and fixed it by hitting pins on both shoulders and left and right hem of the shirt.
Next, the wiring including the conductor pattern shown in FIG. 5 is subjected to the stretchable conductor layer with the stretchable conductor forming paste Pag5 and the stretchable cover layer with the stretchable insulating polymer layer forming paste Pcc1 according to the process shown in FIG. Further, an elastic carbon layer is printed using the electrode surface layer paste Pcb1, screen-printed on each layer, dried and cured under predetermined conditions, printed and laminated, and has an electrode and wiring for electrocardiographic measurement. I got a shirt. The electrode surface layer for electrocardiographic measurement is a circle with a diameter of 30 mm. The insulating cover layer has a donut shape with an inner diameter of 30 mm and an outer diameter of 36 mm at the electrode portion, the wiring portion extending from the electrode has a width of 14 mm, and the end of the wiring portion has a diameter of 10 mm for attaching a hook for connecting to the sensor. Circular electrodes are similarly printed with carbon paste. The thickness of the carbon paste layer is 18 μm in dry film thickness, the insulating cover layer is 30 μm, and the elastic conductor layer is 28 μm in thickness. Prior to printing the stretchable conductor layer, the base layer is formed with the stretchable insulating polymer layer forming paste, which is omitted in the figure. ,

The obtained sports shirt with electrodes and wiring has a circular electrode with a diameter of 30 mm at the intersection of the left and right posterior axillary lines and the 7th rib, and an elastic conductor with a width of 10 mm from the circular electrode to the center of the posterior neck. The electrical wiring is formed inside. The wiring extending from the left and right electrodes to the center of the back neck has a gap of 5 mm at the center of the neck, and both are not short-circuited.
Subsequently, a stainless steel hook is attached to the front surface side of the central end of the rear neck, and the elastic conductor composition layer is made of a conductive thread in which a thin metal wire is twisted to secure electrical continuity with the wiring portion on the back side. And the stainless steel hook were electrically connected.

Connect the heartbeat sensor WHS-2 made by Union Tool via the stainless steel hook, and receive the heartbeat data with the Apple smartphone incorporating the application "myBeat" dedicated to the heartbeat sensor WHS-2, and screen. I set it so that it can be displayed. As described above, a sports shirt incorporating a heart rate measurement function was produced. The wiring pattern is shown in FIG. 5, and the arrangement of the wiring pattern with respect to the shirt is shown in FIG.
The subjects were made to wear this sports shirt, and sports training was conducted while acquiring electrocardiographic data. The obtained electrocardiographic data had low noise and high resolution, and had the quality that the mental state, physical condition, fatigue, drowsiness, tension, etc. could be analyzed from changes in heartbeat interval, electrocardiographic waveform, etc. as an electrocardiogram. ..
This sports shirt was washed after each training, and after drying, the electrode portion and the wiring portion were heat-treated with a household iron whose surface temperature was adjusted to 80 ° C. For heat treatment, place the sports shirt inside out on the ironing board in the same way as normal ironing, cover the wiring part with a 38 μm thick polyimide film XENOMAX (manufactured by Toyobo Co., Ltd.) as a release sheet, and hit the ironing plate from above. Then, the operation of moving at a speed of 5 to 10 cm / sec was repeated 5 times.
By performing such washing and ironing after drying each time, it was possible to maintain a state in which electrocardiographic measurement can be performed satisfactorily even after a total of 100 uses.

On the other hand, in the sports shirts used in the same manner except that the ironing treatment was omitted, the noise of the electrocardiographic measurement increased after 30 times of washing, which made the electrocardiographic measurement during training difficult. After 31 times, by ironing, it was possible to maintain the state where electrocardiographic measurement was possible up to 80 times.

[Application Example 2]
By the printing transfer method shown in FIG. 3, a sports shirt having the same pattern of wiring as in Application Example 1 was used except that Pag11 was used as a paste for forming an elastic conductor and Pcc2 was used as a paste for forming an elastic insulating polymer layer. A prototype was made using the same material. Using the obtained sports shirt, sports training was performed while collecting electrocardiographic data in the same manner as in Application Example 1, and washing, drying, and ironing were repeated in the same manner. As a result, even in Application Example 2, the sportswear maintained a state in which electrocardiographic measurement was possible even after a total of 100 uses.

[Application Example 3]
By the print transfer method shown in FIG. 3, a sports shirt having the same pattern of wiring as in Application Example 1 was used except that Pag11 was used as a paste for forming an elastic conductor and Pcc3 was used as a paste for forming an elastic insulating polymer layer. A prototype was made using the same material. Using the obtained sports shirt, sports training was performed while collecting electrocardiographic data in the same manner as in Application Example 1, and washing, drying, and ironing were repeated in the same manner. As a result, even in Application Example 3, the sportswear maintained a state in which electrocardiographic measurement was possible even after a total of 100 uses.

[Application Example 4]
The stretchable conductor layer obtained from the stretchable conductor forming paste Pag4 in Example 1 was used, and the stretchable insulating polymer layer was an elastomer sheet "Mobilon" with a hot melt layer manufactured by Nisshinbo Co., Ltd., and the electrode surface was used. A sports shirt with electrodes and wiring was obtained by a method in which the layers were omitted and each sheet was cut out into a predetermined shape and laminated and laminated.
Hereinafter, as in Application Example 1, sports training was performed while collecting electrocardiographic data, and washing, drying, and ironing were repeated in the same manner. Results In Application Example 3, the sportswear maintained a state in which electrocardiographic measurement was possible even after a total of 250 uses.

Industrial application field

As described above, the stretchable electrical wiring obtained by using the stretchable insulating polymer layer and the stretchable conductor layer in the present invention has the property of regenerating the reduced conductivity by appropriately heat-treating. Therefore, it has a useful property that the practical life can be extended by using household equipment without using a special device.
By using the elastic electrical wiring of the present invention in a wearable smart device, information possessed by the human body, that is, a sensor provided with biometric information such as myoelectric potential and electrocardiographic potential, body temperature, pulse, blood pressure, etc. on clothing, etc. Clothes with a wearable device for detection or an electric heating device, wearable devices with a sensor for measuring garment pressure, garments for measuring body size using garment pressure, soles Socks-type devices for measuring pressure, wiring parts for clothes, tents, bags, etc. with flexible solar cell modules integrated in textiles, low-frequency treatment devices with joints, wiring parts for thermal treatment machines, etc. It can be applied to sensing units and the like. Such a wearable device can be applied not only to a human body but also to an animal such as a pet or a domestic animal, or a mechanical device having an expansion / contraction part, a bending part, etc. It can also be used as electrical wiring for systems that are connected and used. It can also be applied as a wiring material for implant devices to be embedded in the body.

1. 1. Fabric 2. Temporary support 3. Elastic conductor composition layer 4. Elastic cover layer 5. Elastic carbon layer 6. Release support 7. Adhesive layer

Claims (11)

In the stretchable conductor sheet composed of the conductive filler and the binder resin, the film thickness unevenness of the sheet is 10% or less, and the elongation recovery rate after 20% elongation at 25 ° C. is 92% or more .
The initial conductivity of the stretchable conductor sheet in the sheet surface direction is 1 × 10 ² S / cm or more, and the ratio of decrease in conductivity due to mechanical load is in the range of 1/1000 or more and 0.03471 or less of the initial conductivity. The elastic conductor sheet is characterized in that the conductivity recovery rate by heating at 60 ° C. is 10% or more . The stretchable conductor sheet according to claim 1, wherein the stretch recovery rate is 96% or more when heated at 60 ° C with the stretch load removed after 20% stretch at 25 ° C. When the number average molecular weight of the binder resin is Mn and the weight average molecular weight is Mw,
The stretchable conductor sheet according to any one of claims 1 to 2 , wherein Mw / Mn> 4. Elasticity having an insulating fabric layer having a stretch recovery rate of 99% or more at 50% stretch and a heat resistance of 60 ° C. or higher, and a layer of the stretchable conductor sheet according to any one of claims 1 to 3 . Conductor / fabric laminate. The stretchable conductor sheet according to any one of claims 1 to 3 , or the stretchability according to claim 4 , by heating the stretchable conductor sheet to 60 ° C. or higher with the stretch load removed. A method for recovering conductivity of a conductor / fabric laminate. at least,
A stretchable insulating polymer layer having a tensile yield elongation of 70% or more and a heat distortion temperature of 60 ° C. or more.
It is composed of an elastic conductor layer, which is composed of a conductive filler and a binder resin .
The initial conductivity of the stretchable conductor layer in the plane direction is 1 × 10 ² S / cm or more, and the ratio of decrease in conductivity due to mechanical load is in the range of 1/1000 or more and 0.03471 or less of the initial conductivity. In some cases, elastic wiring having a conductivity recovery rate of 10% or more by heating at 60 ° C. The stretchable wiring according to claim 6 , wherein the stretchable conductor layer has a stretch recovery rate of 92% or more after stretching by 20% at 25 ° C. When the number average molecular weight of the binder resin is Mn and the weight average molecular weight is Mw,
The elastic wiring according to any one of claims 6 to 7 , wherein Mw / Mn> 4. The stretchable wiring according to any one of claims 6 to 8 is provided on an insulating fabric having a stretch recovery rate of 99% or more at the time of stretching by 50% and a heat resistance of 60 ° C. or higher. Cloth with elastic wiring. The method for recovering conductivity of elastic wiring according to any one of claims 6 to 9 , wherein the elastic wiring is heated to 60 ° C. or higher with the extension load removed. The method for recovering conductivity of a fabric with elastic wiring according to claim 10 , wherein the fabric with elastic wiring is heated to 60 ° C. or higher in a state where the extension load is removed.

Images