WO2022054487A1

WO2022054487A1 - Stretchable capacitor and wearable sensing system

Info

Publication number: WO2022054487A1
Application number: PCT/JP2021/029495
Authority: WO
Inventors: 雄一郎表; 翔太森本; 達彦入江; 祐輔清水; 郷司前田
Original assignee: 東洋紡株式会社
Priority date: 2020-09-14
Filing date: 2021-08-10
Publication date: 2022-03-17
Also published as: JPWO2022054487A1

Abstract

The present invention provides: a stretchable capacitor which has a structure that is able to be sewed on a clothing fabric; and a wearable sensing system which uses this capacitor.　A capacitor which has a layered structure wherein at least a stretchable conductive layer, a stretchable dielectric layer and a stretchable conductive layer are sequentially stacked in this order. The stretchable dielectric layer has a structure which comprises a stretchable sheet-like fabric, and a composite layer that contains a resin and fibers that contribute to bonding of the fabric and the conductive layers. A stretchable capacitor having this structure is able to be sewed on a clothing fabric, and is thus able to increase the degree of freedom in deformation of the fabric in comparison to stretchable capacitors that are surface-bonded with use of a hot melt adhesive or the like, thereby being capable of reducing a feeling of strangeness or discomfort felt by a wearer.

Description

Elastic capacitors and sensing wear

The present invention is a stretchable capacitor that can detect its own deformation as a change in capacitance, and a garment provided with the stretchable capacitor. The present invention relates to sensing wear capable of substantially non-invasively detecting changes in body shape due to changes in capacitance, that is, movements of limbs, body shape, posture, breathing, mastication, swallowing, pulsation, fetal movement, and the like.

A method of optically capturing the state of the body and the movement of facial expressions, converting them into data, reflecting them in CG, and moving a human body model or the like in a virtual space has been put into practical use as a production method for movies and the like. Such a method requires a large-scale device.
On the other hand, in order to detect changes in the shape of the body and the state of movement, attempts have been made to incorporate various sensors into clothes for measurement.
Patent Document 1 and Patent Document 2 disclose an elastic capacitor element having a structure in which a dielectric layer made of an elastomer is sandwiched between electrodes, and a displacement amount and a strain amount are detected from a change in capacitance caused by deformation of the capacitor. It is disclosed that it can be used for sensing.

Patent Document 3 discloses a method of sensing a joint angle using a bending capacitor whose capacitance changes depending on the bending angle as a sensor. Patent Document 4 discloses sensing wear in which a strain sensor is bonded to a garment fabric using a hot melt adhesive layer.

Japanese Patent No. 4650538 Japanese Unexamined Patent Publication No. 7-75630 Japanese Patent No. 62574444 Japanese Patent No. 6264825

As described above, many attempts have been made to attach a strain sensor or a displacement sensor to clothing to detect a posture including movements of the wearer's limbs, or even finer movements such as heartbeat, pulse, and respiration.
The sensing method using a sensor attached to clothes can reduce the discomfort and discomfort of the wearer compared to the sensing method in which the sensor is directly attached to the body, and it is possible to exercise and live without being aware of the sensor. It has the advantage of being able to monitor a person's more natural condition. On the other hand, there is a difficult point in that sensing is continued under certain conditions due to slippage of clothes.
If the area of the sensor element is increased, some deviation can be tolerated. Especially in the detection method using the change in capacitance of the capacitor element that can be expanded and contracted, it is relatively easy to increase the area of the sensor element. In addition, increasing the area also contributes to the improvement of sensor sensitivity.

When attaching these sensor elements to clothing fabric, as seen in the prior patent documents, a bonding method using a hot melt adhesive is convenient. The hot melt adhesive invades the garment fabric and forms a composite layer of the fibers of the garment fabric and the hot melt adhesive resin on the adhesive surface and adheres to the adhesive surface. Since this composite layer has a structure similar to that of fiber reinforced plastic, it restricts the degree of freedom of deformation of the garment fabric to be adhered.
When the sensor element is small, only a part of the garment fabric loses the degree of freedom of deformation, so that a big problem does not occur. However, if a large-area sensor element is attached to a garment, the degree of freedom of deformation in a considerable area of the garment fabric is hindered. Since the purpose of sensing is the movement of limbs and changes in body movement, the sensor is naturally attached to a place where deformation is likely to occur, and the degree of freedom of deformation of the clothing fabric in such a place is hindered. It can be said that the mounting method is such that it falls over.

The present invention has been made in view of such circumstances, and an object of the present invention is to easily realize a sensor element having a large area and to attach the cloth to clothes without impairing the degree of freedom of deformation of the cloth. It is the provision of a stretchable capacitor that can be used as a sensor element having an applicable structure, and the provision of sensing wear in which the stretchable capacitor is attached by a method that does not hinder the degree of freedom of deformation of the garment fabric.

As a result of diligent studies to achieve the above object, the present inventors have found a novel structure of a stretchable capacitor that can be sewn to a garment fabric by introducing a cloth structure into a dielectric layer, and the stretchable capacitor having such a structure. By sewing the fabric on the fabric, we have found sensing wear that reduces the discomfort of wearing by suppressing the inhibition of the degree of freedom of deformation of the fabric as much as possible, and have reached the following invention.

That is, the present invention has the following configuration.
[1] In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
A stretchable capacitor, wherein the stretchable dielectric layer has a stretchable sheet-like cloth and a composite layer containing a fiber and a resin that contribute to adhesion between the conductive layer and the cloth.
[2] The stretchable capacitor according to [1], wherein the stretchable sheet-shaped cloth is a knit cloth having a 2-way tricot structure.
[3] The stretchable capacitor according to [1] or [2], wherein the stretchable dielectric layer further has a resin layer.
[4] In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
A stretchable capacitor, wherein the stretchable dielectric layer is composed of a resin layer and a composite layer containing fibers and a resin.
[5] In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
A stretchable capacitor, wherein the stretchable dielectric layer is a composite layer containing a fiber and a resin.
[6] A. Of [1] to [5], wherein a part or all of the surface of the elastic conductive layer opposite to the dielectric layer is covered with the elastic insulating layer. The elastic capacitor described in either.
[7] Sensing wear characterized in that the elastic capacitor according to any one of [1] to [6] is sewn.
[8] The sensing wear according to [7], wherein the stretchable capacitor is sewn only on the peripheral portion of the stretchable capacitor.
[9] The sensing wear according to [7] or [8], wherein the elastic capacitor is sewn to be 50% or less of the peripheral length of the elastic capacitor.

The present invention further preferably has the following configuration.
[10] The sensing wear is characterized in that the sensing wear is provided with electrical wiring for connecting a stretchable capacitor and a device for detecting the capacitance of the stretchable capacitor.
[11] The elastic capacitor according to [1] and the sensing wear according to [7], wherein the elastic conductive layer constituting the elastic capacitor has a specific resistance of 1 × 10 ^-3 Ωcm or less. ..
[12] The stretchable conductive layer constituting the stretchable capacitor includes at least a conductive layer mainly using a metal-based conductive filler and a conductive layer using a carbon-based conductive filler. [1] Elastic capacitor and the sensing wear according to [7].
[13] The elastic capacitor according to [1] and [7], wherein the softening temperature of the resin constituting the composite layer containing the fiber and the resin contributing to the adhesion of the fabric is 50 ° C. or higher and 200 ° C. or lower. ] The sensing wear described in.
[14] The resin according to [1], wherein the resin constituting the composite layer containing the fibers and the resin contributing to the adhesion of the fabric is a stretchable insulating polymer having a tensile yield elongation of 70% or more. The elastic capacitor and the sensing wear according to [7].
[15] The stretchable capacitor according to [1] and the sensing wear according to [7], wherein the stress at 20% elongation in the plane direction of the stretchable capacitor is 15 N / cm or less.
[16] It is a garment for the upper body of the human body, and the elastic condenser is placed at least in any of the elbow part, the upper arm circumference, the lower arm circumference, the shoulder part, the back, the chest circumference, the abdomen circumference, and the flank part. The sensing wear according to [7], which is a feature.
[17] It is a garment for the lower half of the human body, and is characterized in that the elastic capacitor is arranged at least at any of the knee part, the ankle part, the thigh part, the shin part, the hip joint part, and the waist part. The sensing wear according to [7].
[18] The sensing wear according to [7], which has a glove shape and is characterized in that the elastic capacitor is arranged at least in one or more parts of each joint of a wrist and a finger.
[19] The sensing wear according to [7], which has a sock shape and is characterized in that the elastic capacitor is arranged at least at one or more of one or more joints of ankles and toes.
[20] The sensing wear according to [7], which has a belt shape using an elastic material.

The elastic capacitor of the present invention uses a cloth as a dielectric layer. Here, the cloth is a stretchable sheet-like material, which is a pseudo-planar material obtained by combining threads, and is classified into a woven fabric, a knitted fabric, and a non-woven fabric. In the present invention, it is preferable to use a cloth having a knit structure, and it is preferable to use a cloth having a 2-way tricot structure, but such a cloth can be sewn. It is possible in terms of shape to sew a stretchable capacitor using a conventional stretchable resin sheet as a dielectric layer, that is, to sew it to another material (fabric) with a sewing thread. However, when the sheet member sewn in this way is deformed, a large deformation stress is applied to the vicinity of the hole through which the sewing thread penetrates, and the sheet member is easily broken. Therefore, it cannot be practically used in sensing wear that is subject to a large deformation load when it is attached / detached or washed.
However, in the present invention, since the dielectric layer includes a fabric which is a fiber structure, it can be attached to a garment fabric by sewing, that is, can be sewn. This does not mean that it can be simply attached, but it means that it can be used as a sensing wear having sufficient practicality as clothes, that is, a load at the time of putting on and taking off and sufficient washing durability.

The fact that it can be attached by sewing means that there are more variations in the form of attaching elastic capacitors to clothes than when attaching with hot melt adhesive. That is, when a hot melt adhesive is used, the entire surface is adhered to the garment fabric by press working, but in the case of sewing, it is easy to limit the part to be fixed to the garment fabric to a part of the area. It becomes. For example, if only the peripheral part of the rectangle is sewn in an applique manner (assuming that the elastic capacitor is a rectangle), the central part of the rectangle can be made free and the degree of freedom of clothes deformation can be increased. For example, if only the short side of the rectangle is sewn, the degree of freedom is further increased. As an extreme example, it is easy to attach it by fixing only the corners of the rectangle. Even when a hot melt adhesive is used, it is possible to apply the adhesive in a limited area in the same manner, but it is necessary to limit the area in which the adhesive is placed in advance. In addition, even if the pasting area is limited, a certain area is required, so the degree of restraint of the garment fabric is greater than that of sewing that can be attached at "points", and it is better to attach by sewing. Is superior.

FIG. 1 is a schematic view showing a cross-sectional structure of an example of an embodiment of an elastic capacitor used in the present invention. In this example, the conductive layer has a two-layer structure, and most of the conductive layer is covered with a cover insulating layer. The composite layer containing the resin and the fiber exists only in the surface layer of the fabric, and the resin does not penetrate into the central portion (in the thickness direction) of the fabric. FIG. 2 is a schematic view showing a cross-sectional structure of an example of an aspect of the stretchable capacitor used in the present invention. In this example, only the portion of the conductive layer that comes into contact with the snap fastener has a two-layer structure. FIG. 3 is a schematic view showing a cross-sectional structure of an example of an aspect of the stretchable capacitor used in the present invention. In this example, the resin penetrates to the center of the fabric, and the thickness of the composite layer containing the resin and the fiber is substantially equal to the thickness of the fabric. FIG. 4 is a schematic view showing a cross-sectional structure of an example of an aspect of the stretchable capacitor used in the present invention. In this example, the fabric, the composite layer, and the resin layer (hot melt adhesive layer) for adhering the conductive layer are included, and almost all of the resin contained in the composite layer has penetrated into the fabric. FIG. 5 is a schematic view showing a cross-sectional structure of an example of an aspect of the stretchable capacitor used in the present invention. This figure shows a cross-sectional structure obtained when the elastic conductive layer is first adhered to the fabric and then the cover insulating layer is adhered. FIG. 6 is a process diagram showing an outline of the method for manufacturing a stretchable capacitor of the present invention. FIG. 7 is the first half of a process diagram showing details of an example of the method for manufacturing a stretchable capacitor of the present invention. FIG. 8 is the latter half of the process diagram showing the details of an example of the method for manufacturing the stretchable capacitor of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 6 is a process diagram showing an outline of a manufacturing method for obtaining the stretchable capacitor of the present invention. From both the front and back sides of the stretchable cloth 100, a resin layer (hot melt adhesive layer) of a laminate having a layer structure of release paper 400 / elastic conductive layer 200 / resin layer (hot melt adhesive layer) 300 is used as the cloth. The basic form of the stretchable capacitor of the present invention can be obtained by facing (step J), bonding by heating and pressurizing (step K), and peeling off the release paper 400 (step L). In step K, the resin of the resin layer (hot melt adhesive layer) permeates the fabric to form a stretchable composite layer containing fibers and resin. The composite layer can bond the conductive layer and the cloth. That is, the composite layer contributes to the adhesion between the conductive layer and the fabric. Here, the cloth is a pseudo-planar material obtained by combining threads, and includes a woven fabric, a knit, and a non-woven fabric.

As the stretchable cloth, a woven fabric, a knitted fabric (knit), or a non-woven fabric can be used. As for the woven fabric, even if the yarn itself constituting the woven fabric is not stretchable, it can be expanded and contracted by using it in the bias direction. Knitting achieves high elasticity. In the case of a non-woven fabric, it becomes a stretchable cloth when the constituent threads have extensibility.
In the present invention, it is preferable to use a knitted fabric as the fabric, particularly preferably a tricot knitted fabric, and further preferably a 2-way tricot (also referred to as a double tricot) knit fabric.
As the yarn constituting the fabric of the present invention, it is preferable to use a yarn made of fibers having high heat resistance. As the fibers preferably used, animal hair fibers such as acrylonitrile, polyester, polytriacetate, viscose rayon, cotton, silk and wool can be used. Further, heat-resistant fibers such as heat-resistant polyamide, liquid crystal polymer, aromatic polyamide, aromatic polyimide, and polyparaphenylene bisbenzoxazole can be used.

The average thickness of the fabric of the present invention is preferably 20 μm to 1 mm, more preferably 50 μm to 800 μm. The basis weight of the fabric is preferably 100 to 300 g / m ² , more preferably 150 to 250 g / m ² .

As the elastic conductive layer of the present invention, a composite conductive material containing a conductive filler (conductive particles) and a flexible binder resin (flexible resin) can be used. The elastic conductive layer is preferably used by laminating a first elastic conductive layer mainly using a metal filler and a second elastic conductive layer mainly using a carbon-based filler. When the elastic conductive layer is surely covered with the cover insulating layer and does not come into direct contact with the outside air, the elastic conductive layer may be formed only by the first elastic conductive layer using a metal-based filler. ..

The first elastic conductive layer of the present invention is preferably composed mainly of at least a metal filler (metal particles) and a flexible resin having a tensile elastic modulus of 1 MPa or more and 1000 MPa or less. The blending amount of the flexible resin is preferably 7 to 35% by mass, more preferably 9 to 28% by mass, and further preferably 12 to 20% by mass with respect to the total of the metal particles and the flexible resin. Is. The total amount of the metal particles and the flexible resin contained in the first elastic conductive layer is preferably 90% by mass or more, more preferably 95% by mass or more, and further. It is preferably 100% by mass.
The first elastic conductive layer can be obtained by kneading and mixing metal particles and a flexible resin and molding them into a sheet shape (film shape). The stretchable conductive layer of the present invention is preferably made into a paste for forming a stretchable conductor by adding a solvent or the like to metal particles and a flexible resin, or is made into a slurry, and then coated and dried to form a sheet (film). It can be processed. Further, it is also possible to give a predetermined shape by printing after making a paste.

The conductive particles of the present invention are preferably particles having a specific resistance of 1 × 10 ^-1 Ωcm or less and having a particle diameter of 100 μm or less. Examples of the substance having a specific resistance of 1 × 10 ^-1 Ωcm or less include metals, alloys, carbons, doped semiconductors, and conductive polymers. The conductive particles (metal fillers) preferably used in the present invention are 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. Hybrid particles such as coated copper, 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 use flake-shaped powder or amorphous agglomerated powder, and it is more preferable to mainly use flake-shaped silver particles or amorphous agglomerated 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 aggregated powder and flake-shaped powder have a larger specific surface area than spherical powder and the like, and are preferable because they can form a conductive network 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 network.
The particle size of the flake-like powder is not particularly limited, but an average particle size (50% D) measured by a dynamic light scattering method is preferably 0.5 to 20 μm. More preferably, it is 3 to 12 μm. If the average particle size exceeds 20 μm, it becomes difficult to form fine wiring, and clogging may occur 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.
The particle size of the amorphous agglomerated powder is not particularly limited, but the average particle size (50% D) measured by the light scattering method is preferably 1 to 20 μm. More preferably, it is 3 to 12 μm. If the average particle size exceeds 20 μm, the dispersibility may decrease and it may be difficult to make a paste. If the average particle size is less than 1 μm, the effect as agglomerated powder is lost, and good conductivity may not be maintained with low filling.

Examples of the flexible resin in the present invention include thermoplastic resins, thermosetting resins, rubbers and the like having a tensile elastic modulus of 1 to 1000 MPa. Urethane resin or rubber is preferable in order to develop the elasticity of the film. 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. Examples thereof include propylene rubber and vinylidene fluoride copolymer. Among these, nitrile group-containing rubber, chloroprene rubber, and chlorosulfonated polyethylene rubber are preferable, and nitrile group-containing rubber is particularly preferable. The range of the elastic modulus more preferable in the present invention is 2 to 480 MPa, more preferably 3 to 240 MPa, still more preferably 4 to 120 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 hydrogenated nitrile rubber are preferable. Nitrile rubber is a copolymer of butadiene and acrylonitrile, and when the amount of bound acrylonitrile is large, the affinity with the metal increases, but the rubber elasticity that contributes to elasticity decreases. Therefore, the amount of bonded acrylonitrile in the acrylonitrile butadiene copolymer rubber is preferably 18 to 50% by mass, particularly preferably 40 to 50% by mass.
The blending amount of the flexible resin in the present invention is 7 to 35% by mass, preferably 9 to 28% by mass, more preferably 9 to 28% by mass, based on the total of the conductive particles, preferably the non-conductive particles and the flexible resin to be added. Is 12 to 20% by mass.

The non-stretchable specific resistance of the first stretchable conductive layer used in the present invention is preferably 3 × 10 ^-3 Ωcm or less, more preferably 1 × 10 ^-3 Ωcm or less, and 3 × 10 -3 Ωcm or less. It is more preferably ^-4 Ωcm or less, and even more preferably 1 × 10 ^-4 Ωcm or less. If the resistivity exceeds this range, the resistance distribution in the conductive layer becomes remarkable, the time constant of the device becomes large, a problem arises in responsiveness, and high frequency characteristics and pulse responsiveness may deteriorate. The lower limit of resistivity depends on the conductive material used in principle.

It is preferable that the second elastic conductive layer of the present invention is mainly composed of a carbon-based conductive filler (carbon-based filler) and the flexible resin. The blending amount of the flexible resin is preferably 7 to 35% by mass, more preferably 9 to 28% by mass, and further preferably 12 to 20% by mass with respect to the total of the carbon-based filler and the flexible resin. Is. The total amount of the metal particles and the flexible resin contained in the second stretchable conductive layer is preferably 90% by mass or more, more preferably 95% by mass or more, and further. It is preferably 100% by mass. The second elastic conductive layer can be obtained by kneading and mixing a carbon-based filler and a flexible resin and molding it into a sheet shape (film shape). The stretchable conductive layer of the present invention is preferably in the form of a paste or slurry for forming a stretchable conductor by adding a solvent or the like to a carbon-based filler and a flexible resin, and then applied and dried to form a sheet (film). Can be processed into. Further, it is also possible to give a predetermined shape by printing after making a paste.

As the carbon-based filler, black smoke, Ketjen black, furnace black, carbon nanotube, carbon nanocone, fullerene, etc. can be used. The flexible resin used in combination with the carbon-based filler and other conditions are the same as those of the metal-based filler.

The present invention has a structure in which a stretchable dielectric layer is sandwiched between two stretchable conductive layers. The stretchable dielectric layer has a stretchable sheet-like cloth and a composite layer containing fibers and resins that contribute to the adhesion between the conductive layer and the cloth. It is also preferable that the dielectric layer further contains a resin layer. The fabric is preferably an aggregate of entangled fibers, and the gap between the fibers is usually air, but in the composite layer, the resin is mixed in the gap between the fibers. However, it does not prevent the voids from remaining between the fibers. A layer containing resin in a part or all of a cloth (fiber) is called a composite layer, and a layer not containing resin is called a cloth (fiber). In the above configuration, it can be said that the stretchable dielectric layer includes a stretchable sheet-like cloth, and a part or all of the cloth is impregnated with the resin. The resin contained in the composite layer is preferably one that can contribute to adhering the conductive layer and the fabric. Further, it is preferable that the resin layer exists between the cloth and the stretchable conductive layer and can improve the adhesiveness between the cloth (composite layer) and the stretchable conductive layer. The resin and the resin layer contained in the composite layer may be the same or different, but are preferably the same. The parts constituting the two elastic conductive layers may be the same or different, but are preferably the same. The average thickness of the stretchable conductive layer is preferably 10 to 200 μm, more preferably 20 to 100 μm.

It is preferable to use a hot melt adhesive as the resin when the elastic conductive layer is adhered and laminated on the fabric, or when the cover insulating layer is adhered to the elastic conductive layer. As the hot melt adhesive in the present invention, a polymer material having a softening temperature of about 50 ° C. to 200 ° C. can be used, and it is preferable that the hot melt adhesive has flexibility having the same degree of elasticity as the dielectric layer. Molecular materials can be used.
Such hot melt adhesives include ethylene-based copolymers, styrene-based block copolymers, olefin-based (co) copolymers, and the like, and further use them as a base polymer to impart a crystalline polar group. Polymer materials containing compounds, amorphous poly α-olefins, tackifier resins, polypropylene waxes and other formulations, styrene-ethylene propylene-styrene block copolymer rubber or styrene-butadiene-styrene block copolymer rubber, and these. Adhesive-imparting resin component and / or polymer material to which a liquid plasticizer such as process oil is added, modified polyolefin and its formulation, styrene-based block copolymer and its formulation, acid-modified polypropylene, acid-modified styrene-based block Polymers, blends thereof, styrene-based block copolymers, blends such as ethylene-based polymers, polyester-urethane copolymers and their blends can be used.

In the present invention, a hot melt sheet obtained by processing a polyester urethane resin, a polyether urethane resin, or the like having a softening temperature of 40 ° C to 120 ° C into a sheet can be preferably used. The hot melt adhesive resin of the present invention is preferably a stretchable insulating polymer having a tensile yield elongation of 70% or more. The average thickness of the resin layer is preferably 10 to 200 μm, more preferably 20 to 100 μm.

A process of manufacturing the elastic capacitor of the present invention will be described with reference to FIGS. 7 and 8.
First, by the steps of FIGS. 7A to 7H, a part of the elastic conductive layer to be attached to the elastic cloth 100 is manufactured.
FIG. 7A is the first release paper 410. Although it is referred to as "paper" for convenience, not only the release-treated paper but also PET, polyester, polypropylene, polyethylene, polyvinylidene chloride and other films that have been released-treated as necessary are used as the release paper. May be. Further, a silicone rubber sheet, a fluororesin sheet, or the like can also be used.
In FIG. 7B, the elastic conductive layer 200 and the first hot melt adhesive layer 310 are formed on the release paper (shown upside down for convenience of explanation). Although the elastic conductive layer is shown as one layer here for the sake of simplicity, in the case of dividing into two layers, the second conductive layer is first applied on the release paper, and then the first conductive layer is applied. Dry to form a conductive layer.
In FIG. 7 (C), it is cut into a required shape and size.
In FIG. 7D, the flexible sheet of the laminate in which the separately prepared flexible sheet 600, the third hot melt adhesive layer 330, and the third release paper 430 are laminated is opposed to the first hot melt layer. , In FIG. 7 (E), both are heated and pressed to be bonded. Here, the flexible sheet is a sheet made of a stretchable flexible material having a relatively high heat distortion temperature, and a sheet made of crosslinked polyurethane, crosslinked rubber, silicone rubber sheet, fluororubber sheet, or other crosslinked elastomer can be used.
In FIG. 7 (F), the first release paper was peeled off and removed.
In FIG. 7 (G), a cover insulating layer with a hot-melt adhesive layer, which has been subjected to external processing including a window by punching at a predetermined position in advance, is laminated on the elastic conductive layer.
In FIG. 7 (H), both are pressurized and heated to be bonded to obtain an elastic conductor component.

The obtained elastic conductor parts are in a form protected by release paper on both sides. The elastic conductive layer is in a state where the surface and the side surface are all covered with the cover insulating layer or the hot melt adhesive layer, and only the window portion previously formed by punching in the cover insulating layer is not insulated.

Next, in FIGS. 8 (I) to 8 (L), the parts of the stretchable conductive layer are attached to the front and back surfaces of the fabric to obtain the stretchable capacitor of the present invention.
First, in FIG. 8 (I), the third release paper is peeled off.
Next, in FIG. 8 (J), two front and back elastic conductive layer parts are arranged with the cloth sandwiched between them, and in FIG. 8 (K), the whole is pressurized and heated to be laminated.
Finally, as shown in FIG. 8 (L), the second release paper left on the front and back is removed to obtain the elastic capacitor of the present invention.

FIG. 1 illustrates a cross section of the elastic capacitor obtained in FIG. 8 (L) with a snap fastener 800 functioning as a connector for external connection attached. Although omitted in FIGS. 7 and 8, in this figure, the stretchable conductive layer is shown in a two-layer structure consisting of a first stretchable conductive layer and a second stretchable conductive layer. On the contrary, the flexible sheet shown in FIGS. 7 and 8 is sandwiched between the third hot melt adhesive layer and the first hot melt adhesive layer, and here, the third hot melt adhesive layer is used. The illustration is omitted because it is considered to be included. The portion where the elastic conductive layers on the front and back faces each other with the cloth sandwiched therein is a substantial capacitor element, and this portion S is the sensing region. Further, the T portion located outside the snap fastener portion in the figure is a sewable region that does not affect the sensing region. Since the fabric exists in the entire region, the elastic capacitor can be sewn on the entire surface, but it is preferable that the woven portion does not enter the sensing region as much as possible from the viewpoint of sensing accuracy and stability. In FIG. 1, the composite layer containing the resin and the fiber exists only in the surface layer of the fabric, and the resin does not penetrate into the central portion (in the thickness direction) of the fabric. Therefore, what functions as a dielectric layer is a composite layer on the front and back surfaces and a fabric layer that is not impregnated by the resin. It is preferable to use a metal snap fastener, and a stainless steel material is preferable as the material.

FIG. 2 is a schematic view showing a cross-sectional structure of another example of the aspect of the stretchable capacitor used in the present invention. In this example, most of the stretchable conductive layer is the first stretchable conductive layer, and the second stretchable conductive layer is used only in the portion in contact with the snap fastener. When the material of the metal filler used for the first elastic conductive layer and the material of the snap fastener are dissimilar metals, the battery is locally formed when the elastic capacitor comes into contact with a liquid containing electrical material such as sweat. And any metal galvanic corrosion may occur. In order to prevent this, a conductive coating made of a carbon-based conductive material is used for the contact point with the metal.

FIG. 3 is a schematic view showing a cross-sectional structure of another example of the aspect of the stretchable capacitor used in the present invention. In this example, the resin of the hot melt adhesive penetrates to the center of the fabric, and the thickness of the composite layer containing the resin and the fiber is substantially equal to the thickness of the fabric. That is, the dielectric layer of the elastic capacitor is virtually all a composite layer, and high dielectric constant liquids such as moisture and sweat or electrolytes are prevented from entering the sensing region between the electrodes. Disturbance is reduced.

FIG. 4 is a schematic view showing a cross-sectional structure of another example of the aspect of the stretchable capacitor used in the present invention. In this example, the resin (hot melt adhesive layer) for adhering the fabric and the conductive layer is relatively thin, and almost all of the resin permeates the fabric, and the portion is a composite layer. It shows the state. Since the thickness of the dielectric layer is thin, the capacitance is increased and the measurement sensitivity is increased.
As described in FIGS. 7 and 8, the above is the case where the stretchable conductor component in the form in which the cover insulating layer is previously bonded to the stretchable conductor is used.

FIG. 5 is a schematic view showing a cross-sectional structure of another example of the aspect of the stretchable capacitor used in the present invention. Here, as shown in FIG. 5, the cross-sectional structure obtained when the elastic conductive layer is first adhered to the fabric and then the cover insulating layer is adhered is shown. Compared to the structures of FIGS. 1 to 4, since a flexible sheet is not required, the dielectric layer can be made thinner.

In the present invention, the change in capacitance of the elastic capacitor that changes according to the expansion and contraction deformation of the elastic capacitor in the surface direction is mainly due to the expansion and contraction of the elastic dielectric layer in the surface direction, and the thickness of the elastic dielectric layer. It is a change in capacitance due to a change in direction. In order to exhibit such characteristics, it is preferable that the Poisson's ratio of the material used for the elastic dielectric layer is high. The Poisson's ratio of the stretchable dielectric layer of the present invention is preferably 0.28 or more, more preferably 0.38 or more, and even more preferably 0.48 or more. In order to increase the Poisson's ratio, it is better that the amount of inorganic components blended in the elastic dielectric layer is small.

The stretchable capacitor of the present invention preferably has a stress of 15 N / cm or less at the time of 20% elongation in the plane direction. The stress during elongation depends on the physical characteristics of the material constituting the stretchable capacitor and the thickness of the detection portion of the stretchable capacitor. In particular, when a resin and a fabric satisfying the above-mentioned conditions are used, it is preferable to configure the total thickness to be 700 μm or less, preferably 450 μm or less, and more preferably 250 μm or less.

In the present invention, it is a garment for the upper body of the human body, and sensing in which the elastic capacitor is arranged at least at any of the elbow portion, the upper arm circumference, the lower arm circumference, the shoulder portion, the back, the chest circumference, the abdominal circumference, and the flank portion. Can be wear.
In the present invention, it is a garment for the lower half of the human body, and is a sensing wear in which the elastic capacitor is arranged at least at any of the knee part, the ankle part, the thigh part, the shin part, the hip joint part, and the waist part. You can also do it.
In the present invention, the shape is a glove, and the sensing wear may be a sensing wear in which the elastic capacitor is arranged at least at one or more of each joint of the wrist and the finger.
In the present invention, it is a sock-shaped sensing wear in which the elastic capacitor is arranged at least at one or more of each joint of the ankle and the toe.
In the present invention, a belt-shaped sensing wear using an elastic material can also be used.

In the present invention, the stretchable capacitor can be sewn and attached to the fabric of the above-exemplified garment. That is, it can be made into sensing wear by sewing. The sewing may be machine-sewn with a sewing machine or hand-sewn. The thread for sewing is not particularly limited, and a sewing thread made of a general insulating material may be used.
It is preferable that the sewn portion is only the peripheral portion of the elastic capacitor. The peripheral portion refers to a portion having a width of 8 mm from the outer shape of the elastic capacitor element. In the present invention, it is preferable to sew only the periphery of the elastic capacitor element like an appliqué. Further, more preferably, the sewing range (the length of the sewn portion) is set to 50% or less, preferably 30% or less of the peripheral length of the expansion / contractor capacitor, thereby reducing the discomfort felt by the wearer with respect to the sensing wear. can do. The lower limit is not particularly limited, but is preferably 3% or more, and more preferably 5% or more.
In the present invention, the deformation and strain amount of the sensing area can be read by measuring the capacitance between the conductor layers on the front and back of the elastic capacitor.

As described above, the elastic capacitor of the present invention can be attached to clothes by sewing, and the clothes to which the elastic capacitor which is a sensing element is attached by sewing appropriately exceeds the fixed areas of both. As a result, the wearer is less likely to feel discomfort or discomfort.
The sensing wear of the present invention can sense the posture of the body, the pulse, the heartbeat, the respiration, etc. due to the change in the circumference of the body, and can be further applied to motion capture. Further, the present invention can be applied not only to the human body but also to animals and mechanical devices.

100: Stretchable sheet-like cloth 150: Composite layer 151: Composite layer of first resin layer (first hot melt adhesive layer) and cloth 152: Second resin layer (second hot melt adhesive layer) Composite layer 200 with fabric: Elastic conductive layer 210: First elastic conductive layer 220: Second elastic conductive layer 300: Resin layer (hot melt adhesive layer)
310: First resin layer (first hot melt adhesive layer)
320: Second resin layer (second hot melt adhesive layer)
330: Third resin layer (third hot melt adhesive layer)
400: Release paper 410: First release paper 420: Second release paper 430: Third release paper 500: Cover insulating layer 600: Flexible sheet 800: Snap fastener S: Sensing area T: Sewingable area

Claims

In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
The stretchable dielectric layer includes a fabric and a composite layer, the fabric and the composite layer are stretchable, the composite layer contains fibers and a resin, and the composite layer adheres to the conductive layer and the fabric. A stretchable capacitor characterized by contributing.
The stretchable capacitor according to claim 1, wherein the stretchable sheet-shaped cloth is a knit cloth having a 2-way tricot structure.
The stretchable capacitor according to claim 1 or 2, wherein the stretchable dielectric layer further has a resin layer.
In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
The elastic dielectric layer includes a resin layer and a composite layer, the resin layer and the composite layer are stretchable, the composite layer contains fibers and a resin, and the resin layer and the composite layer are the conductive layer and the above. A stretchable capacitor characterized by contributing to adhesion to the dielectric layer.
In an elastic capacitor having a structure in which an elastic dielectric layer is sandwiched between two elastic conductive layers.
The elastic capacitor is a stretchable capacitor, wherein the stretchable dielectric layer is a composite layer, the composite layer contains fibers and a resin, and the composite layer contributes to adhesion between the conductive layer and the dielectric layer.
The invention according to any one of claims 1 to 5, wherein a part or all of the surface of the elastic conductive layer opposite to the dielectric layer is covered with the elastic insulating layer. Elastic capacitor.
Sensing wear characterized in that the elastic capacitor according to any one of claims 1 to 6 is sewn.
The sensing wear according to claim 7, wherein the sewn portion of the stretchable capacitor is only the peripheral portion of the stretchable capacitor.
The sensing wear according to claim 7 or 8, wherein the length of the sewn portion of the stretchable capacitor is 50% or less of the peripheral length of the stretchable capacitor.