JP5250287B2 - Gel electrode - Google Patents

Description

  The present invention relates to a gel electrode. In more detail, this invention relates to the gel electrode provided with the electroconductive layer which consists of a porous body layer which has a specific resistance value.

Gel electrodes provided with an adhesive gel are used in a wide range of fields such as electrocardiogram electrodes and electrical stimulator electrodes used for muscle training.
For example, Japanese Patent Publication No. 6-49076 (Patent Document 1), Japanese Patent No. 28212265 (Patent Document 2), Japanese Translation of PCT International Publication No. 2006-517130 (Patent Document 3), Japanese Patent Application Laid-Open No. 2001-204827 (Patent Document). Various gel electrodes have been reported in 4) and the like. The gel electrodes described in these publications usually have a conductive layer and a conductive gel pressure-sensitive adhesive layer in this order on a support substrate, and some lead wires are between the conductive layer and the conductive gel pressure-sensitive adhesive layer. Or it has the structure inserted in the whole surface.
Japanese Patent Publication No. 6-49076 Japanese Patent No. 282265 JP-T-2006-517130 JP 2001-204827 A

  When peeling the gel electrode described in the above publication from an adherend (for example, skin), it is common to use a lead wire. However, in this method, the mounting base portion of the lead wire is broken or the support base material is lifted from the conductive layer, the contact between the lead wire and the conductive layer becomes unstable, and the current from the lead wire is There is a problem that the conductive gel pressure-sensitive adhesive layer does not flow stably to the adherend. It can be considered that this problem is not caused by peeling from the adherend using a lead wire, but by using a conductive gel pressure-sensitive adhesive layer. However, since the conductive gel pressure-sensitive adhesive layer has high adhesiveness, the conductive gel pressure-sensitive adhesive layer strongly adheres to the finger and has been unpopular with users. Further, since the conductive gel pressure-sensitive adhesive layer is directly touched, the adhesiveness of this layer may be lowered after a number of peeling and pasting.

Thus, according to the present invention, a conductive layer is provided on a support substrate, and a region having a conductive gel pressure-sensitive adhesive layer is provided on the conductive layer and a region not provided with the conductive gel pressure-sensitive adhesive layer. having a lead wire on the region, provided with a reinforcement on the lead wire, wherein the conductive layer, Ri porous layer der having the following resistance 20 [Omega / 20 mm,
The porous layer is made of woven fabric, said woven fabric, a gel electrode, wherein Rukoto constituted by yarns having a metal coating is provided.

  According to the present invention, it is possible to provide a gel electrode that is not easily damaged during handling and has little performance deterioration over a long period of use. In addition, a uniform current distribution can be obtained in a wide frequency range, and a gel electrode having stable electrical performance can be provided.

The gel electrode of the present invention can be particularly suitably used for repeated use. Such applications include electrical electrodes for electrostimulation, electrodes for electrocardiogram, electrodes for living bodies such as electrodes for static elimination, and industrial electrodes such as electrodes for exploration. Among these, it is preferable to use it for a biological electrode.
(Configuration of gel electrode)
The gel electrode of the present invention includes a supporting substrate, a conductive layer, a conductive gel pressure-sensitive adhesive layer, a lead wire, and a reinforcing material. The conductive layer is located on the support substrate, and the conductive gel adhesive layer and the lead wire are located on the conductive layer. Moreover, it has an area | region with a conductive gel adhesive layer and an area | region which is not provided on a conductive layer. Furthermore, the lead wire is located on a region of the conductive layer that does not include the conductive gel adhesive layer. Further, a reinforcing material is located on the lead wire. Here, the conductive layer is composed of a porous layer having a resistance value of 20Ω / 20 mm or less.

  In the gel electrode, the lead wire is located on the region of the conductive layer not provided with the conductive gel adhesive layer, and the reinforcing material is located on the lead wire. That is, unlike the conventional gel electrode, since the lead wire is not located between the conductive layer and the conductive gel adhesive layer, even if the user peels off the gel electrode using the lead wire, Floating and breakage of the supporting substrate and the conductive layer can be suppressed. In addition, by using a conductive layer having a specific resistance value, a sufficient current can be passed through the adherend without the need to place lead wires on the entire surface of the conductive gel adhesive layer as in the prior art. .

The planar shape of the gel electrode is not particularly limited. For example, a square, a circle, an ellipse, etc. can be set arbitrarily. Furthermore, the region of the conductive layer not provided with the conductive gel pressure-sensitive adhesive layer where the lead wire is located (end portion) may be a protrusion extending from a part of the region provided with the conductive gel pressure-sensitive adhesive layer, It does not have to be a protrusion. When it is a protrusion, the gel electrode can be more easily separated. The protrusion can be provided with a function of fixing the lead wire as well as a function as a knob portion when the gel electrode is peeled off. In addition, it is preferable that the area | region of the conductive layer which is not provided with a conductive gel adhesive layer occupies the area of 2.5 to 25% of the gel electrode whole surface.
The lead wire is located on the region of the conductive layer that does not include the conductive gel adhesive layer, and the current supply location is specified, but even if it is specified, the conductive layer has a specific resistance value. Therefore, current can be easily supplied to the entire surface of the gel electrode.

As a planar shape of a gel electrode, the structure shown to Fig.1 (a)-(c) is mentioned, for example. These configurations are examples of the configuration having the above-described protrusion shape. In the figure, 1 is a conductive layer, 2 is a conductive gel adhesive layer, 3 is a reinforcing material, 4 is a lead wire, and 5 is a terminal. In FIG. 1 (a), the planar shape of the conductive gel pressure-sensitive adhesive layer is substantially square, FIG. 1 (b) is rectangular, and FIG. 1 (c) is round. In these gel electrodes, since the portion where the reinforcing material 3 is located has a protruding shape, it can be used as a knob portion when the gel electrode is peeled off.
The conductive gel pressure-sensitive adhesive layer may have a separate film for protecting the gel surface.

(Gel electrode manufacturing method)
Taking the configuration of FIG. 1 (a) as an example, a method for producing a gel electrode will be described with reference to FIGS. 2 (a) to 2 (d).
First, the conductive layer 1 is laminated on the support base 6. An adhesive layer may be provided on the support substrate 6 in order to more firmly fix the conductive layer 1, the conductive gel pressure-sensitive adhesive layer 2, and the support substrate 6. Next, the reinforcing material 3 is laminated on the end portion on the conductive layer 1. Here, a double-sided release sheet 7 may be sandwiched between ends of the reinforcing material 3 and the conductive layer 1 in order to facilitate formation of the lead wires 4 later. In addition, an adhesive layer may be provided on the surface of the reinforcing material 3 on the conductive layer 1 side in order to more firmly fix the support base material 6, the conductive layer 1, the reinforcing material 3, and the lead wire 4. . Further, the reinforcing material 3 may be firmly fixed to the supporting base material 6 and the conductive layer 1 by thermally fusing the inner end portions of the reinforcing material 3 and the supporting base material 6.

Next, the conductive gel pressure-sensitive adhesive layer 2 is laminated on the conductive layer 1. The conductive gel pressure-sensitive adhesive layer 2 may extend on the reinforcing material 3. Considering the ease of peeling of the gel electrode, it is preferable that the reinforcing material 3 is covered with the conductive gel pressure-sensitive adhesive layer 2 in an area of 50% or less. By these steps, the configuration of FIG. 2B, which is a plan view of FIG. 2A and a cross-sectional view thereof, is obtained. Note that a separator film 8 may be laminated on the conductive gel pressure-sensitive adhesive layer 2.
Thereafter, the double-sided release sheet 7 is removed, the lead wire 4 is sandwiched between the reinforcing material 3 and the conductive layer 1, and the lead wire 4 is fixed to the gel electrode by heat-sealing the portion as necessary. Through these steps, the gel electrode shown in FIG. 2D, which is a plan view of FIG. 2C and a cross-sectional view thereof, can be formed.

Below, each member which comprises a gel electrode is demonstrated.
(Conductive gel adhesive layer)
For the conductive gel pressure-sensitive adhesive layer, a conductive polymer gel having adhesiveness can be used. Having adhesiveness means that wetting is good and uniformly adheres at the interface of the adherend surface, and the conductive gel pressure-sensitive adhesive layer does not collapse during peeling. By using a conductive gel pressure-sensitive adhesive layer having such an adhesive property, it adheres uniformly to the surface of the adherend (for example, the skin) and efficiently applies electrical energy when a current is applied to the gel electrode. Can communicate. In addition, the conductive gel pressure-sensitive adhesive layer does not collapse at the time of peeling, and peeling and sticking can be repeated.
The conductive gel pressure-sensitive adhesive layer preferably has a thickness of 100 to 2500 μm.

The conductive gel adhesive material includes a conductive polymer gel containing a plasticizer, a solvent component, and an electrolyte salt in a polymer matrix obtained by copolymerizing a polymerizable monomer and a crosslinkable monomer. It can be used suitably.
(1) Polymerizable monomer The polymerizable monomer is not particularly limited as long as it is a monomer having one polymerizable carbon-carbon double bond in the molecule. For example, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol (meth) acrylate, (poly) glycerin (meth) acrylate, etc. (Meth) acrylic acid derivative, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-dimethyl (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methylolacrylamide, acryloylmorpholine, diacetone acrylamide, N, N-dimethylaminopropyl (meth) acrylamide and its salt, tertiary butylacrylamide sulfone (Meth) acrylamide derivatives such as acids and salts thereof, N-vinylamide derivatives such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, sulfonic acid-based single quantities such as vinylsulfonic acid, allylsulfonic acid and salts thereof The body is mentioned. These monomers may be used alone or in combination of two or more. In the above examples, (meth) acryl means acryl or methacryl.

(2) Crosslinkable monomer As the crosslinkable monomer, it is preferable to use a monomer having two or more double bonds having a polymerizable property in the molecule. Specifically, methylene bis (meth) acrylamide, ethylene bis (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin tri Polyfunctional (meth) acrylamides such as (meth) acrylate or (meth) acrylate, tetraallyloxyethane, diallylammonium chloride and the like can be mentioned. These monomers may be used alone or in combination of two or more.

(3) Plasticizer As the plasticizer, it is preferable to use a polyhydric alcohol that improves plasticity. In addition, it is preferable to use a polyhydric alcohol that has a holding power for the solvent component and also serves as a wetting agent. The gel has good viscoelastic properties by including a plasticizer in the polymer matrix.
Polyhydric alcohols include diols such as ethylene glycol, propylene glycol, butanediol and pentanediol, polyhydric alcohols having two or more valences such as glycerin, pentaerythritol and sorbitol, and polyhydric alcohol condensates such as polyethylene glycol and polyglycerin. In addition, modified polyhydric alcohols such as polyoxyethylene glycerin can be used. These polyhydric alcohols may be used alone or in combination of two or more. Among these polyhydric alcohols, it is desirable that they are liquid at room temperature in terms of maintaining the viscoelastic properties of the gel, ensuring the transparency of the gel body after the polymerization reaction, and improving the handling properties during production. . Examples of such a polyhydric alcohol include glycerin and polyglycerin.

(4) Solvent component The solvent component is preferably a polar solvent having a high boiling point and a low vapor pressure at room temperature, and is preferably compatible with the polymerizable monomer and the crosslinkable monomer. Solvent components include water, alcohols such as methanol, ethanol and isopropanol, cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, N, N-dimethylformamide, N, N-dimethylacetamide, N, N′-dimethyl- Examples thereof include amides such as 2-imidazolidinone and N-methyl-2-pyrrolidone, sulfolane, dimethyl sulfoxide and the like. These solvent components may be used alone or in combination of two or more. You may mix. Moreover, it is preferable that a solvent component contains 10 weight% or more of water with respect to the whole quantity.

(5) Electrolyte salt The conductivity of the conductive gel pressure-sensitive adhesive layer is obtained when the gel contains an electrolyte salt.
Examples of the electrolyte salt include alkali metal halides such as sodium halide, potassium halide, magnesium halide and calcium halide, alkaline earth metal halides or other metal halides, hypochlorites of various metals, Inorganic salts such as chlorite, chlorate, perchlorate, sulfate, nitrate, phosphate, ammonium salt and various complex salts, and monovalent organic carboxylates such as acetic acid, benzoic acid, lactic acid, tartaric acid Or monovalent or divalent salts of polyvalent carboxylic acids such as fumaric acid, succinic acid, adivic acid, citric acid, metal salts and organic ammonium salts of organic acids such as sulfonic acids and amino acids, poly (meta ) Polymer electrolyte salts such as acrylic acid, polyvinyl sulfonic acid, polytertiary butylacrylamide sulfonic acid, polyallylamine, polyethyleneimine It can be used. These electrolyte salts may be used alone or in combination of two or more.

(6) Other additives Gels may contain preservatives, bactericides, antifungal agents, rust inhibitors, antioxidants, stabilizers, pH adjusters, fragrances, surfactants, colorants, etc. You may add another additive suitably. As a method of adding, there are a method of dissolving or dispersing other additives in the compounding solution in advance to form a polymer matrix, and a method of adding the polymer gel once generated later.

(7) Concentration of polymer matrix The polymer matrix constituting the conductive gel pressure-sensitive adhesive layer is preferably contained in an amount of 5 to 50% by weight, more preferably 5%, based on the total amount of the conductive gel pressure-sensitive adhesive layer. -40% by weight. If it is less than 5% by weight, the gel concentration of the resulting gel is low, so that the solvent component cannot be used and the gel tends to bleed and may have a low waist strength. On the other hand, if it exceeds 50% by weight, the exotherm during polymerization becomes too large, and the solvent may boil beyond the boiling point of the solvent, resulting in production problems. Moreover, when boiled, since air bubbles mix, transparency may be impaired and a good gel may not be obtained.

(8) Addition amount of crosslinkable monomer The addition amount of the crosslinkable monomer is preferably 0.05 to 10% by weight based on the total amount of the polymer matrix. If it is less than 0.05% by weight, the crosslink density is low, and the shape stability may be poor. Moreover, when it exceeds 10 weight%, it may become a hard and brittle gel. Moreover, in the case of such a gel, it may become cloudy at the time of superposition | polymerization bridge | crosslinking, transparency may be impaired, and a favorable gel may not be obtained.

(9) Concentration of plasticizer The concentration of the plasticizer in the gel is preferably 10 to 80% by weight, more preferably 20 to 70% by weight. If it is less than 10% by weight, the wetting power (solvent holding power) of the gel is poor, the gel is not stable over time, the flexibility is poor, and even when tackiness is required, it is often difficult to impart tackiness. Moreover, when it exceeds 80 weight%, the density | concentration of a polymer matrix or a solvent component may become relatively small.

(10) Concentration of solvent component The concentration of the solvent component is preferably 5 to 50% by weight, more preferably 5 to 40% by weight. If it is less than 5% by weight, the gel has low flexibility (high rigidity), and it is difficult to add an electrolyte salt, so that good conductivity may not be obtained. On the other hand, when the amount exceeds 50% by weight, the equilibrium solvent retention amount of the gel may be greatly exceeded, so that bleed of the solvent component may occur. Moreover, the solvent component which cannot be held out flows out, and the change of the physical property of a gel with time may become large.

(11) Concentration of electrolyte salt The concentration of the electrolyte salt is preferably 0.05 to 13% by weight, more preferably 0.1 to 10% by weight. If it exceeds 13% by weight, dissolution of the electrolyte salt becomes difficult, so that precipitation of crystals may occur inside the gel or dissolution of other components may be inhibited. Further, even if a salt exceeding substantially 13% by weight is added, the ionization limit, in other words, the conductive performance reaches its peak, which is not preferable from the viewpoint of cost. Further, if the addition is less than 0.05% by weight, sufficient conductivity may not be obtained.

(12) Manufacturing method of conductive gel pressure-sensitive adhesive layer The conductive gel pressure-sensitive adhesive layer dissolves a polymerizable monomer, a crosslinkable monomer, a plasticizer, a solvent component, an electrolyte salt, and optionally a polymerization initiator. The uniformly mixed monomer compounded liquid can be obtained by polymerization crosslinking by heating or ultraviolet irradiation by a known method. Further, a pre-formed polymer matrix may be impregnated with a wetting agent or a solvent. Furthermore, a polymer mixture obtained by polymerizing only a polymerizable monomer to obtain a polymer, and then dissolving or uniformly dispersing a wetting agent, a solvent, etc., is a mixed solution obtained by adding a crosslinking agent and optionally a catalyst. By immersing the polymer in, a conductive gel pressure-sensitive adhesive layer can be formed by causing a crosslinking reaction between the polymer and the crosslinking agent.

When the monomer compounding liquid is liquid, for example, a conductive gel pressure-sensitive adhesive layer having an arbitrary shape can be obtained by pouring into a molded resin mold or the like to cause polymerization crosslinking.
Moreover, a sheet-like electroconductive gel adhesive layer can be obtained by pouring a monomer compounding liquid between two films kept at a constant interval to cause polymerization crosslinking.
Furthermore, the monomer compounded liquid is printed on the film in an arbitrary shape using a silk screen or the like, and immediately after that, the conductive gel pressure-sensitive adhesive layer having an arbitrary shape is obtained by polymerization or crosslinking by heating or ultraviolet irradiation by a known method. be able to.

(Supporting substrate)
The support base material is a base material sheet used as a surface material of the gel electrode, and is preferably flexible and non-conductive. In particular, the gel electrode preferably has sufficient flexibility and tensile strength. Examples of the supporting substrate include polyethylene terephthalate (PET) nonwoven fabric, polypropylene (PP) nonwoven fabric, cellulose nonwoven fabric, rayon nonwoven fabric, polyvinyl chloride film, polyethylene (PE) film, polypropylene (PP) film, acrylic resin film, and the like. Is mentioned. Among these, it is more preferable to employ a polypropylene (PP) spunbonded nonwoven fabric having high tensile strength and flexibility. In addition, the thickness of the support base material is not particularly limited, but can be appropriately set between 10 and 500 μm, for example.

(Conductive layer)
The conductive layer is a porous layer having a resistance value of 20 Ω / 20 mm or less, and is not particularly limited as long as it can conduct electricity to the adherend without problems through a flexible and conductive gel adhesive layer. For example, a knit woven with a conductive plated thread, a cloth, a knit woven with a thread containing conductive fibers, a cloth, a knit woven with conductive fibers, a cloth, or the like can be employed. Examples of the substance that imparts conductivity to the conductive layer include silver, a silver-silver chloride compound, stainless steel, titanium, nickel, molybdenum, carbon black, and graphite. These substances may be contained alone or in combination of two or more in the conductive layer. Among these conductive layers, a knit woven with a thread containing metal plated fibers has no directionality in conductivity, low resistance, and has deformability and flexibility. Therefore, it can adhere | attach on the to-be-adhered body (for example, skin) whose surface is a curved surface without discomfort. If the conductivity is directional, the electrical characteristics of the electrodes may vary.

  A more preferred conductive layer is a tulle woven fabric. In the tulle weave, it is preferable that the opening has a hexagon because the difference in directionality of conductivity can be further reduced. Furthermore, the conductive layer preferably has an aperture ratio of 40 to 80%. The opening ratio in this range can satisfy both the conductivity of the conductive layer, the adhesiveness between the support base and the conductive gel pressure-sensitive adhesive layer, and the adhesiveness between the support base and the reinforcing material.

(Lead)
In the present invention, the lead wire is not directly contacted with the conductive gel pressure-sensitive adhesive layer having metal corrosiveness. Therefore, the lead wire is not limited to a corrosion-resistant material such as stainless steel, and is used in this field. Any line can be used. Examples of the material of the lead wire include stainless steel, copper, silver, gold, and carbon. A metal wire made of a metal wire is preferable because of its low electrical resistance, and a metal wire having a resistance value of 4 Ω / cm or less is preferred. It is particularly preferable to use copper from the viewpoint of low electrical resistance, suppression of heat generation during use, flexibility, less discomfort when the gel electrode is mounted, and cost reduction. The stranded outer diameter of the lead wire is preferably in the range of 0.2 to 1.0 mm. The lead wire preferably overlaps the conductive layer by 5 to 20 mm.
The lead wire may be coated with a resin at a portion outside the gel electrode. The outer diameter of the coating is preferably 0.5 to 2.0 mm.

(Reinforcing material)
The reinforcing material is not particularly limited, and examples thereof include polyolefin resins such as polyethylene and polypropylene, and polyester resins such as polyethylene terephthalate and polyethylene naphthalate. The thickness of the reinforcing material can be, for example, 25 to 125 μm.
An adhesive layer may be provided on the surface of the reinforcing material in order to bond the conductive layer, the supporting base material, and the reinforcing material more firmly. As the adhesive layer, for example, a layer made of a hot melt adhesive can be used.

(Separate film)
As a separate film, it does not specifically limit, For example, the film which consists of polyester resin, such as polyolefin resin, such as polyethylene and polypropylene which carried out silicon peeling process, polyethylene terephthalate, and polyethylene naphthalate, can be used.
(Double-sided release sheet)
The double-sided release sheet is not particularly limited, and for example, a sheet made of a silicone release-treated polyolefin resin such as polyethylene or polypropylene, or a polyester resin such as polyethylene terephthalate or polyethylene naphthalate can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited by these Examples. In addition, the resistance value of the conductive layer, the opening ratio of the conductive layer, the initial impedance, the impedance after 100 times of pasting / peeling, the impedance distribution, the root portion of the lead wire after 30 times of pasting / peeling in Examples and Comparative Examples The measurement method of the situation, the strength 3kg static load of the lead wire attachment part is described below.

(Resistance value of conductive layer)
Three pieces having a length of 50 mm and a width of 20 mm are cut out from the material used for the conductive layer as a measurement sample. In this cutout, the length direction of the slice is defined as direction A. Further, three pieces having a length of 50 mm and a width of 20 mm are cut out so that the direction B perpendicular to the direction A is the length direction. The resistance value between both ends in the length direction of the measurement samples having the length directions A and B was measured at a frequency of 1 kHz using an LCR meter (ELC-131D manufactured by Custom Co., Ltd.). Let the arithmetic mean value be the resistance value in each direction. This resistance value is a value measured using two measuring jigs having a width of 20 mm and sandwiching the entire sample width of 20 mm. The unit is Ω / 20 mm.
The resistance value of the conductive layer is required to be 20Ω / 20 mm or less in both directions A and B. It is preferable that it is 10 Ω / 20 mm or less.

(Opening ratio of conductive layer)
A conductive layer 50 mm long × 50 mm wide is placed on a plane, and an enlarged photograph of 15 to 20 times is taken, and the area of the opening with respect to the entire area on the photograph is obtained. From the total area and the area of the opening, the aperture ratio is calculated by the following formula.
Opening ratio (%) = area of opening / total area × 100
(Lead wire resistance)
Using a LCR meter (ELC-131D made by Custom Co., Ltd.) for the resistance value between both ends of a 5 cm long lead wire, the value measured at a frequency of 1 kHz is divided by 5, and the resistance value per 1 cm lead wire (Ω / cm).

(First impedance)
A measurement circuit diagram is shown in FIG. The measurement is performed as follows. That is, the electrode plate 10 (SUS plate) is thoroughly wiped with ethanol, degreased, and dried. Next, the gel electrode 11 is attached to the electrode plate 10, and the voltage Vb when a current of 10 μA is applied between the electrode plate 10 and the lead wire 4 at a frequency of 1 KHz is measured. The impedance is calculated from the obtained voltage.

(Impedance after affixing and peeling 100 times)
Wipe the electrode plate thoroughly with ethanol, degrease and dry. Next, a gel electrode is attached to the electrode plate. After 1 minute, peel off with the knob. In Comparative Examples 1 and 2, since there is no knob, the gel at the end is peeled off. This is repeated 100 times. Next, after being attached to the electrode plate, the impedance is calculated in the same manner as the initial impedance.

(Impedance distribution)
An outline of the measurement is shown in FIGS. 4 (a) and 4 (b). 4A shows measurement points, and FIG. 4B is a circuit diagram for measurement. The measurement is performed as follows. That is, the electrode terminal 12 (SUS terminal, φ6 mm) is thoroughly wiped with ethanol, degreased, and dried. Next, the electrode terminal 12 is attached to the gel electrode 11, the frequency Vb is changed between 10 Hz to 100 KHz between the electrode terminal 12 and the lead wire 4, and the voltage Vb when a current of 10 μA is applied is measured. The impedance is calculated from the obtained voltage. This calculation is performed for 50 measurement points 13 shown in FIG.

(Situation of lead wire base after 30 times of application / peeling)
The gel electrode is attached to the skin of a human body cleaned with alcohol and peeled off with the lead wire. After repeating this 30 times, the breakage state of the base portion of the lead wire attachment portion is observed.

(Strength of 3 kg static load at the lead wire mounting part)
The two ends of the gel electrode opposite to the lead wire attachment part are clamped and fixed, and a static load of 3 kg is applied in the vertical direction of the lead wire. Measure the time until the lead wire attachment breaks.

Example of preparation of polymer hydrogel used in Examples 1-3 and Comparative Examples 1-3 First, acrylamide (Ml) and N, N-dimethylacrylamide (M2) as a polymerizable monomer, a crosslinkable monomer N, N-methylenebisacrylamide (Cl) as an electrolyte salt, sodium chloride (N) as an electrolyte salt, Na citrate as a pH adjuster: 1: 1 mixture of citric acid (N2), glycerin as a wetting agent (N2) G) and polyglycerin (hexamer) (G2) were blended. Ion exchange water as a solvent was added to the obtained blend to make 100% by weight. The obtained mixture was dissolved and stirred to obtain a monomer compounding solution. Next, 0.3 parts by weight of 1-hydroxy-cyclohexyl phenyl ketone (trade name Irgacure 184, manufactured by Ciba Specialty Chemicals) is added as a photopolymerization initiator to 100 parts by weight of the monomer compounded solution, and further stirred. And dissolved. Table 1 shows the blending amounts of the components constituting the monomer blending solutions used in Examples 1 to 3 and Comparative Examples 1 to 3. However, the numerical value of Table 1 is weight% with respect to the compounding liquid total amount which added ion-exchange water.

The obtained monomer mixture was adjusted to an initial temperature of 25 ° C., and then thinly spread on a polyethylene terephthalate film subjected to silicon release treatment. Next, a spacer having a thickness of 1.0 mm was placed on the side surface of the film, and a polyethylene terephthalate film subjected to silicon release treatment was placed thereon. Thereafter, the monomer blend solution is irradiated with ultraviolet rays having an intensity of 50 mW / cm ² for 60 seconds to perform polymerization and crosslinking reaction of the monomer, thereby forming a sheet-like conductive gel pressure-sensitive adhesive layer having a thickness of 1.0 mm. Obtained.

Examples 1 to 3 (Preparation of gel electrode)
On one side of a PP (polypropylene) spunbonded nonwoven fabric (weight per unit: 70 g / m ² , manufactured by Shinwa Co., Ltd.), a hot melt adhesive (BPS4668 manufactured by Toyo Ink Manufacturing Co., Ltd.) was applied at 40 g / m ² (when dried) and dried. An adhesive tape material (support base material) 6 was obtained. A conductive layer 1 made of conductive fibers (SE-200-5 manufactured by Seiren Co., Ltd., opening ratio: 62%) woven with silver-plated yarn was laminated thereon. This was cut into a length of 70 mm and a width of 50 mm. Further, a reinforcing material 3 (reinforcing material, peach coat manufactured by Nisshinbo Co., Ltd.) made of a PET film having a length of 25 mm, a width of 50 mm, and a thickness of 75 μm prepared in advance at the end portion thereof was pasted with matching widths. On one side of the reinforcing material 3, a hot melt pressure-sensitive adhesive (BPS4668 manufactured by Toyo Ink Manufacturing Co., Ltd.) was applied at 40 g / m ² (when dried) to form a dried layer. Furthermore, a paper separator (double-sided release sheet) 7 subjected to double-sided silicon release treatment was disposed on the adhesive surface of the reinforcing material 3 with a width of 15 mm from the end. Furthermore, the reinforcing material 3 was firmly fixed to the nonwoven fabric by heat-sealing a width of 10 mm on the center side of the reinforcing material 3 with a heat sealer at a temperature of 160 ° C. for 2 seconds. Further, the conductive gel pressure-sensitive adhesive layer 2 cut to a length of 55 mm × width of 50 mm was pasted so that the width of the conductive gel adhesive layer 2 was adjusted to the surface of the conductive layer 1 and about 10 mm from the end portion to the reinforcing material 3. The obtained laminate was cut into an offset electrode shape shown in FIG. Further, the paper separator 7 at the offset portion is removed, the lead wire 4 is sandwiched between the reinforcing material 3 and the conductive layer 1, and the portion is heat-sealed by a heat sealing machine at a temperature of 160 ° C. for 4 seconds, thereby leading the lead. The wire 4 was firmly fixed to the offset part. Table 1 shows the lead wire types.
The gel electrode shown in FIG.2 (c) was obtained by the said process.

Comparative Example 1
On one side of the same PP (polypropylene) spunbond nonwoven fabric (support base material) 6 as in the example, a hot melt pressure-sensitive adhesive (BPS4668 manufactured by Toyo Ink Manufacturing Co., Ltd.) is applied and dried to form the pressure-sensitive adhesive layer 14. It was set as the nonwoven fabric adhesive tape material. A conductive layer 1 made of a carbon-kneaded film (EB90NES manufactured by Kureha Elastomer Co., Ltd.) was prepared. Each was cut into a length of 50 mm and a width of 50 mm, and the lead wires 4 were sandwiched and bonded as shown in FIG. Further, the conductive gel pressure-sensitive adhesive layer 2 cut to a length of 50 mm and a width of 50 mm was pasted on the conductive layer 1 with the same width. Furthermore, the separator film 8 was bonded to the conductive gel pressure-sensitive adhesive layer 2. Table 1 shows the lead wire types.
A gel electrode was obtained by the above process.

Comparative Example 2
A gel electrode was obtained in the same manner as in Comparative Example 1 except that conductive fibers (SE-200-5 manufactured by Seiren Co., Ltd.) were used instead of the carbon kneaded film.

  Table 2 shows the resistance value of the conductive layer of the gel electrode obtained, the initial impedance of the gel electrode, the impedance after 100 times of application / peeling, the condition of the lead wire root portion, and the strength of the lead wire attachment portion 3 kg static load Shown in

From Table 2, it can be seen that the change in impedance of the gel electrode of the example is suppressed because the lead wire is more firmly fixed as compared with Comparative Examples 1 and 2.
About the gel electrode of Example 1 and Comparative Example 1, impedance distribution of 50 places is shown to Fig.6 (a) and (b). The table on the left side of FIG. 6A shows measured values of the impedance distribution for each frequency of the gel electrode of Comparative Example 1, and the graph on the right side graphs it. The table on the left side of FIG. 6B shows measured values of the impedance distribution for each frequency of the gel electrode of Example 1, and the graph on the right side graphs it. As is clear from these figures, the gel electrode of Example 1 can obtain a uniform impedance over the entire surface of the gel electrode at any frequency.

The gel electrode obtained in Examples 1 and 3 was used in a high-output electrical stimulation device (ES-520 manufactured by Ito Super Short Wave Company), and the initial temperature of the gel electrode and the temperature after 10 minutes were measured. The temperature rise was measured by thermography under the following conditions.
Electrical stimulation device output: 5 kHz, 30 mA
Use site: Abdomen use gel electrode size: 50 × 50
The results are shown in Table 3.

From Table 3 above, it can be seen that the gel electrode of the example has suppressed temperature rise at the peripheral part and the central part.
Since the lead wire of Example 1 is made of stainless steel, a temperature increase is observed at the terminal portion. In Example 3, since the lead wire is made of copper, the temperature rise is also suppressed in the terminal portion. Therefore, it can be seen that it is preferable to use a material having low resistance for the lead wire.

It is a schematic plan view of the gel electrode of this invention. It is the schematic of the manufacturing process of the gel electrode of this invention. It is a schematic circuit diagram of the measuring method of an impedance. It is a schematic circuit diagram of the measuring method of impedance distribution. 2 is a schematic view of a gel electrode of Comparative Example 1. FIG. It is explanatory drawing of the impedance distribution of the gel electrode of Example 1 and Comparative Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive layer 2 Conductive gel adhesive layer 3 Reinforcement material 4 Lead wire 5 Terminal 6 Support base material 7 Double-sided peeling sheet 8 Separator film 10 Electrode plate 11 Gel electrode 12 Electrode terminal 13 Measuring point 14 Adhesive layer

Claims (6)

Provided with a conductive layer on a support substrate, a region with a conductive gel pressure-sensitive adhesive layer on the conductive layer and a region without a conductive gel pressure-sensitive adhesive layer, and a lead wire on a region without the conductive gel pressure-sensitive adhesive layer. and includes a reinforcing member on the lead wire, wherein the conductive layer, Ri porous layer der having the following resistance 20 [Omega / 20 mm,
Gel electrode to which the porous layer is made of woven fabric, said fabric, characterized in Rukoto constituted by yarns having a metal coating. The gel electrode according to claim 1 , wherein the woven fabric is a tulle woven fabric having an aperture ratio of 40 to 80%. The lead wire is made of a metal wire having the following resistance value 4ohm / cm claim 1 or 2 in the gel electrode according. The gel electrode according to any one of claims 1 to 3 , wherein the lead wire is made of a copper wire. The gel electrode according to any one of claims 1 to 4 , wherein the reinforcing material is heat-sealed with the support base material via the conductive layer. The support base material provided with the conductive layer has a region including the conductive gel pressure-sensitive adhesive layer selected from a square, a circle, and an ellipse in plan view, and the conductive material extending from a part of the region. The gel electrode according to any one of claims 1 to 5 , wherein the gel electrode has no conductive gel pressure-sensitive adhesive layer and has a protrusion on which the lead wire is positioned.