Bio-electrode composition, bio-electrode, and method for producing bio-electrode

Abstract

The objective of this invention is to provide a bioelectrode composition for a bioelectrode contact layer that exhibits excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, maintains conductivity without significant reduction when wetted or dried, and possesses excellent flexibility, elasticity, and adhesion; a bioelectrode composition for forming a bioelectrode contact layer; and a method for manufacturing the same. The solution to this objective is a bioelectrode composition containing (A) an ionic resin, characterized in that: component (A) comprises a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of trissulfonium methylide.

Description

[Technical Field]

[0001] The present invention relates to a bioelectric electrode that contacts the skin of a living organism and uses electrical signals from the skin to detect bodily states such as heart rate, a method for manufacturing the same, and a bioelectric electrode composition that can be ideally used in the bioelectric electrode. [Previous Technology]

[0002] In recent years, with the popularization of IoT (Internet of Things), the development of wearable devices has also progressed. Clocks and glasses that can connect to the Internet are representative examples. In addition, there is a need for wearable devices that can constantly monitor the body's condition in the medical and sports fields, which are areas that will grow in the future.

[0003] In the medical field, there has been research on wearable devices that use sensors with weak currents to monitor the state of the body's organs, such as electrocardiograms (ECGs) which use electrical signals to sense the heart's movement. ECG measurements are performed by attaching electrodes coated with conductive paste to the body, but this is a short-term, one-time measurement. In contrast, the development of medical wearable devices, as described above, focuses on devices that can continuously monitor health status over several weeks. Therefore, the bioelectrodes used in medical wearable devices must not change conductivity over prolonged use and must not cause skin allergies. Furthermore, in addition to these requirements, they must be lightweight and manufactured at low cost.

[0004] Regarding wearable medical devices, there are types that are attached to the body and types that are incorporated into clothing. For the type attached to the body, a bioelectrode using a material containing a conductive paste, namely a water-soluble gel containing water and electrolytes, has been proposed (Patent Document 1). The water-soluble gel contains sodium, potassium, and calcium as electrolytes in a water-soluble polymer used to retain water, and converts changes in ion concentration from the skin into electrical properties. On the other hand, for the type incorporated into clothing, a method has been proposed to use a fabric made by incorporating a conductive polymer such as PEDOT-PSS (poly-3,4-ethylenedioxythiophene-polystyrenesulfonate) and a silver paste into fibers as electrodes (Patent Document 2).

[0005] However, in the case of using water-soluble gels containing water and electrolytes, there is a problem that the conductivity may be lost due to dehydration. On the other hand, when using metals with high ion mobility, such as copper, there is a risk of skin allergies, which varies from person to person. When using conductive polymers such as PEDOT-PSS, there is also a risk of skin allergies due to the strong acidity of the conductive polymer, and there is also a problem that the conductive polymer may peel off from the fibers during washing.

[0006] Furthermore, considering their excellent conductivity, the use of metal nanowires, carbon black, and carbon nanotubes as electrode materials has been explored (Patent Documents 3, 4, 5). Metal nanowires, due to their high probability of contact between conductors, can conduct electricity with a relatively small amount. However, because metal nanowires are materials with sharp tips, they can cause skin allergies. Thus, even if they do not cause allergic reactions themselves, the shape and irritant properties of the material can lead to a deterioration in biocompatibility, making it difficult to balance conductivity and biocompatibility.

[0007] Metal films are considered excellent bioelectrodes due to their high conductivity, but this is not necessarily the case. The heartbeat releases not only weak electric currents from the skin, but also sodium, potassium, and calcium ions. Therefore, it is necessary to convert the change in ion concentration into an electric current. However, precious metals, which are difficult to ionize, are inefficient at converting ions from the skin into an electric current. Therefore, bioelectrodes using precious metals have high impedance and high resistance when conducting electricity through the skin.

[0008] On the other hand, batteries with added ionic liquids have been explored (Patent Document 6). Ionic liquids have the characteristics of high thermal and chemical stability and excellent conductivity, and are widely used in battery applications. However, as shown in Patent Document 6, ionic liquids with small molecular weights are soluble in water. Therefore, if a bioelectrode with added ionic liquid is used, the ionic liquid will be extracted from sweat from the skin, which not only reduces conductivity, but also causes skin roughness due to the penetration of the ionic liquid into the skin.

[0009] Furthermore, batteries using lithium salts of polymeric sulfonylimide have been explored (Non-Patent Document 1). However, while lithium-based materials are used in batteries due to their high ion mobility, they are not biocompatible materials. In addition, lithium salts suspended in polysiloxane fluorosulfonic acid have also been explored (Non-Patent Document 2).

[0010] Some researchers have proposed bioelectrode materials that incorporate ionic polymers into polysiloxane adhesives (Patent Documents 7 and 8). These bioelectrode materials not only have high ionic conductivity, but those with added conductive powders such as carbon and silver also have high electronic conductivity, thus functioning as excellent bioelectrodes. By combining highly ionicly conductive and non-skin-penetrating ionic polymers into polysiloxane adhesives that have low skin allergy, high water repellency, and the ability to suppress itching or redness after peeling, a stable bioelectrode material can be obtained without peeling even during long-term application, including daily bathing and exercise. However, further improvements are needed to enhance the comfort of long-term application.

[0011] The health effects of perfluoroalkyl compounds (PFAS) have been pointed out, and the European REACH protocol has imposed restrictions on the manufacture and sale of PFAS compounds. The development of materials without PFAS structures has become an urgent priority. [Prior Art Documents] [Patent Documents]

[0012] [Patent Document 1] International Publication No. WO2013-039151 [Patent Document 2] Japanese Patent Application Publication No. 2015-100673 [Patent Document 3] Japanese Patent Application Publication No. Hei 5-095924 [Patent Document 4] Japanese Patent Application Publication No. 2003-225217 [Patent Document 5] Japanese Patent Application Publication No. 2015-019806 [Patent Document 6] Japanese Patent Application Publication No. 2004-527902 [Patent Document 7] Japanese Patent Application Publication No. 2018-126496 [Patent Document 8] Japanese Patent Application Publication No. 2018-130533 [Non-Patent Documents]

[0013] [Non-patent literature 1] J. Mater. Chem. A, 2016, 4, p10038-10069 [Non-patent literature 2] J. of the Electrochemical Society, 150(8) A1090-A1094 (2003) [Summary of the Invention]

[0014] [Problem to be Solved by the Invention] The present invention is made to solve the above-mentioned problems, and aims to provide a bioelectric electrode composition for forming a bioelectric contact layer for a bioelectric electrode that can form excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, and has excellent flexibility and adhesion; a bioelectric electrode for forming a bioelectric contact layer using the bioelectric electrode composition; and a method for manufacturing the same. [Means for Solving the Problem]

[0015] In order to solve the above-mentioned problems, the present invention provides a bio-electrode composition containing (A) an ionic resin, wherein the aforementioned (A) component comprises a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of trissulfonium methide.

[0016] If so, it is a bioelectric electrode composition for a bioelectric electrode contact layer that can form a bioelectric electrode with excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, does not significantly reduce its conductivity whether it is wetted or dried, and is soft, flexible and has excellent adhesion.

[0017] Furthermore, the aforementioned resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of strontium methyl compounds should preferably have a chemical structure represented by the following general formula (1). [Chemical 1] In the formula, RA is a hydrogen atom or a methyl group. X1 is independently a single bond, a phenyl group, or a linker group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms. R1 and R2 are independently hydrocarbon groups, which may also contain heteroatoms, having 1 to 20 carbon atoms. M+ is any one of ammonium ion, lithium ion, sodium ion, and potassium ion.

[0018] The structure is selected from the ammonium salt, lithium salt, sodium salt, and potassium salt of benzoyl methyl compounds, and specific examples can be listed as such.

[0019] Furthermore, the aforementioned resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of methyl benzoate shall preferably contain an ammonium ion represented by the following general formula (2) as the aforementioned M+. [Formula 2] In the formula, R101d, R101e, R101f, and R101g are respectively a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also have one or more selected from ether, carbonyl, ester, hydroxyl, amino, nitro, sulfonyl, sulfinyl, halogen atom, and sulfur atom. R101d and R101e, R101d, R101e and R101f can also form a ring together with the nitrogen atom they are bonded to. When forming a ring, R101d and R101e, and R101d, R101e and R101f are alkyl groups with 3 to 10 carbon atoms, or form an aromatic heterocycle with a nitrogen atom in the formula.

[0020] Ammonium ions in the ammonium salts of succinate methyl compounds can be specifically listed as follows.

[0021] It is advisable to use a resin other than the aforementioned component (A) as component (B).

[0022] By using a resin containing component (B), the components contained in the composition can be maintained while the adhesiveness of the composition is further improved.

[0023] Furthermore, the aforementioned component (B) should preferably be selected from one or more of polysiloxane resin, (meth)acrylate resin, and polyurethane resin.

[0024] (B) The resin of the component can ideally be used.

[0025] Furthermore, the aforementioned component (B) should preferably be adhesive.

[0026] (B) It is more ideal for the resin of component (B) to be an adhesive resin.

[0027] Furthermore, the aforementioned component (B) shall preferably include a polysiloxane resin having RxSiO(4-x) / 2 units (R being a substituted or unsubstituted monovalent hydrocarbon group with 1 to 10 carbon atoms, and x being in the range of 2.5 to 3.5) and SiO2 units.

[0028] (B) The resin of the component can also ideally be such a polysiloxane resin.

[0029] It is advisable to include carbon powder and / or metal powder as component (C).

[0030] By using such component (C), the conductivity of the composition can be improved.

[0031] At this time, the aforementioned toner should preferably be either carbon black or carbon nanotubes, or both.

[0032] Toner can be ideally used in this way.

[0033] Furthermore, the aforementioned metal powder should preferably be selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

[0034] At this time, the aforementioned metal powder should preferably be silver powder.

[0035] Metal powders can be ideally used in this way.

[0036] Furthermore, the aforementioned bio-electrode composition should preferably contain organic solvents as component (D).

[0037] If so, it is a composition with excellent coatability.

[0038] Furthermore, the present invention provides a bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, wherein the aforementioned bio-contact layer is a hardened form of the aforementioned bioelectrode composition.

[0039] If so, it is a bioelectrode with excellent conductivity and biocompatibility, lightweight and can be manufactured at low cost, whose conductivity will not be significantly reduced whether it is wetted or dried, and has a soft, flexible and adhesive bioelectrode contact layer.

[0040] Furthermore, the aforementioned conductive substrate preferably includes one or more of the following: gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0041] Conductive substrates can ideally be used in this way.

[0042] Furthermore, the present invention provides a method for manufacturing a bioelectrode, which is a method for manufacturing a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, wherein the bioelectrode composition is coated on the aforementioned conductive substrate and hardened thereon, thereby forming the aforementioned bioelectrode contact layer.

[0043] The bioelectrode of the present invention can be manufactured in this manner.

[0044] Furthermore, the aforementioned conductive substrate shall preferably be one or more selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0045] Conductive substrates can ideally be used in this manner. [Effects of the Invention]

[0046] As described above, if it is the bio-electrode composition of the present invention, it can provide a bio-electrode composition for forming a bio-contact layer of a bio-electrode that can form excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, does not significantly reduce its conductivity when wetted or dried, and is soft, elastic and adhesive. It also provides a bio-electrode composition for forming a bio-contact layer of a bio-electrode composition, a bio-electrode for forming a bio-contact layer, and a method for manufacturing the same.

Implementation Method

[0048] As described above, the development is required to develop a bioelectric electrode composition for a bioelectric electrode that can form a bioelectric contact layer with excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, is soft, elastic and adhesive, can be attached to the skin for a long time and can still stably collect biological signals even when wetted or dried due to bathing, etc., and will not leave residue on the skin after being peeled off.

[0049] With the beating of the heart, sodium, potassium, and calcium ions are released from the skin surface. Bioelectrodes need to convert the increase or decrease of ions released from the skin into electrical signals. Therefore, materials with excellent ion conductivity are needed to transmit the increase or decrease of ions.

[0050] For a bioelectrode membrane to adhere to the skin and stably acquire biological signals, softness, elasticity, and adhesion are essential. The stratum corneum of the epidermis regenerates daily, and old keratin (debris) accumulates between the bioelectrode membrane and the skin. This old keratin easily peels off the epidermis, causing the bioelectrode to detach and preventing the collection of biological signals. Therefore, the bioelectrode must maintain its adhesion even after prolonged application. On the other hand, if residue is left on the skin after prolonged application and removal, it may cause rashes and rough skin.

[0051] Regarding biological signals, there are ECG for sensing heart movement, RPM for sensing lung respiration, EEG for detecting brain waves, EGG for detecting visceral movement, and EMG for detecting muscle movement, etc. The dry electrode of the present invention can be used as a sensor for detecting them. Furthermore, it can also be used as an electrode for providing electrical signals to the body.

[0052] If the acid that forms a neutral salt has a high acidity, the ions will be strongly polarized and the ionic conductivity will be improved. In the case of lithium-ion batteries, lithium salts of bis(trifluoromethanesulfonyl)imino acid and tris(trifluoromethanesulfonyl)methyl acid exhibit high ionic conductivity for this reason. On the other hand, there is a problem that the higher the acid strength in the acidic state before it becomes a neutral salt, the stronger the biological irritation of the salt. That is, there is a trade-off between ionic conductivity and biological irritation. However, salts suitable for biological electrodes must balance high ionic conductivity and low biological irritation.

[0053] In sulphuryl methyl compounds, the carbon atom that is electron-withdrawn from the sulfonyl group in the 3rd direction carries a negative charge, and it is still acidic even if there is no fluorine atom at the front end of the sulfonyl group. When the carbon atom at the front end of the sulfonyl group has a fluorine atom, the acidity will be too high, and its neutralized salt will be highly irritating to the skin. However, sulphuryl methyl compounds without fluorine atoms can moderately balance high ionic conductivity and low biological irritation. By not having a fluorine atom, it does not fall under the definition of PFAS and has a low environmental impact.

[0054] In strontium methyl compounds, the steric hindrance around the negatively charged carbon atoms is high, and the distance between them and the positively charged ammonium, lithium, sodium, and potassium atoms increases. Therefore, it is easy to induce jumping motions of ammonium, lithium, sodium, potassium, etc., thereby exhibiting high ionic conductivity.

[0055] The larger the molecular weight of an ionic compound, the lower its permeability to the skin and the lower its irritation to the skin. Considering this point of view, ionic compounds should preferably be high molecular weight polymers. Therefore, the ionic compound is made into a form with polymerizable double bonds and polymerized to form a polymer, or bonded with polysiloxane, polyurethane, polyether, polyester, etc., thereby avoiding the problem of skin irritation.

[0056] Furthermore, by using a mixture of the salt with, for example, polysiloxane-based, acrylic-based, or carbamate-based adhesives (resins), it can always adhere closely to the skin to obtain a stable electrical signal over a long period of time.

[0057] That is, the present invention is a bio-electrode composition containing (A) an ionic resin, wherein the aforementioned (A) component comprises a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of succinate methyl compounds.

[0058] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0059] <Bioelectrode Composition> The bioelectrode composition of the present invention contains (A) a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of strontium methyl compounds. Hereinafter, each component will be described in more detail.

[0060] [(A) Ionic resin having ammonium salt, lithium salt, sodium salt, or potassium salt of strontium methylate] The bio-electrode composition of the present invention is characterized by containing (A) an ionic resin having a structure selected from ammonium salt, lithium salt, sodium salt, or potassium salt of strontium methylate.

[0061] An ionic resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of methyl sulfide shall preferably have a substructure represented by the following general formula (1´). [Chemical 3] In the formula, R1 and R2 are each independently a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms. M+ is any one of ammonium ion, lithium ion, sodium ion, and potassium ion.

[0062] The substructures of the ammonium, lithium, sodium, and potassium salts of the trimethylolpropionate described in general formula (1´) are bonded to, for example, a resin selected from a resin polymerized from monomers having double bonds, a polysiloxane resin, or a polyurethane resin.

[0063] (Repeating Unit a) The substructures of the ammonium, lithium, sodium, and potassium salts of the methylated derivatives described in the above general formula (1´) are preferably bonded to the resin formed by polymerizing the monomers as repeating unit a represented by the following general formula (1). [Chemical 4] In the formula, RA is a hydrogen atom or a methyl group. X1 is independently a single bond, a phenyl group, or a linking group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms. R1 and R2 are independently hydrocarbon groups containing 1 to 20 carbon atoms, which may also contain heteroatoms. M+ is any one of the following: ammonium ion, lithium ion, sodium ion, and potassium ion.

[0064] The monomer used to obtain the repeating unit a represented by the above general formula (1) is represented by the following general formula (1)-1. [Chemical 5] In the general formula, RA, R1, R2, X1, M+ are as described above.

[0065] The monomer (anionic part) represented by the above general formula (1)-1 can be specifically exemplified as follows.

[0066] [Chemical 6]

[0067] [Chemical 7]

[0068] [Chemical 8]

[0069] [Chemical 9]

[0070] [Chemical 10]

[0071] [Chemical 11]

[0072] [Chemical 12]

[0073] [Chemical 13]

[0074] [Chemical 14]

[0075] [Chemical 15]

[0076] [Chemical 16]

[0077] [Chemical 17]

[0078] [Chemical 18]

[0079] [Chemical 19] In the formula, RA is as described above.

[0080] The method for synthesizing the above-mentioned monomers may be the method shown in Japanese Patent Application Publication No. 2020-055797.

[0081] Also, component (A) should preferably contain an ammonium ion (ammonium cation) represented by the following general formula (2) as M+ in repeating unit a. [Chemical 20] In the formula, R101d, R101e, R101f, and R101g are respectively a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also have one or more selected from ether, carbonyl, ester, hydroxyl, amino, nitro, sulfonyl, sulfinyl, halogen atom, and sulfur atom. R101d and R101e, R101d, R101e and R101f can also form a ring together with the nitrogen atom they are bonded to. When forming a ring, R101d and R101e, and R101d, R101e and R101f are alkyl groups with 3 to 10 carbon atoms, or form an aromatic heterocycle with a nitrogen atom in the formula.

[0082] The ammonium ion represented by the above general formula (2) can be specifically exemplified as follows.

[0083] [Chemical 21]

[0084] [Chemical 22]

[0085] [Chemical 23]

[0086] [Chemical 24]

[0087] [Chemical 25]

[0088] [Chemical 26]

[0089] [Chemical 27]

[0090] [Chemical 28]

[0091] [Chemical 29]

[0092] [Chemical 30]

[0093] [Chemical 31]

[0094] [Chemical 32]

[0095] [Chemical 33]

[0096] [Chemical 34]

[0097] [Chemical 35]

[0098] [Chemical 36]

[0099] The ammonium ions represented by the above general formula (2) are preferably tertiary or quaternary ammonium ions.

[0100] (Repeating Unit b) In the bio-electrode composition of the present invention, in addition to the repeating unit a formed by polymerizing monomers having polymerizable double bonds as described above, repeating units b having ethylene glycol dimethyl ether chains may also be copolymerized to improve conductivity. Specific examples of monomers used to obtain repeating units b having ethylene glycol dimethyl ether chains are shown below. By copolymerizing repeating units having ethylene glycol dimethyl ether chains, the movement of ions released from the skin within the dry electrode membrane can be facilitated, and the sensitivity of the dry electrode can be improved.

[0101] [Chemistry 37]

[0102] [Chemistry 38]

[0103] [Chemistry 39]

[0104] [Chemical 40]R is a hydrogen atom or a methyl group.

[0105] (Repeating Unit c) In the bio-electrode composition (A) of the present invention, in addition to the repeating units a and b described above, a hydrophilic repeating unit c having hydroxyl, carboxyl, ammonium salt, betaine, acetylamine, pyrrolidone, lactone ring, acetylamine ring, sulfonyl lactone ring, sodium salt of sulfonic acid, or potassium salt of sulfonic acid may be copolymerized to improve conductivity. Specific examples of monomers used to obtain the hydrophilic repeating unit c are shown below. By copolymerizing these repeating units containing hydrophilic groups, the sensitivity of ions released from the skin can be improved, and the sensitivity of the dry electrode can be enhanced.

[0106] [Chemistry 41]

[0107] [Chemistry 42]

[0108] [Chemical 43]R is a methyl or hydrogen atom.

[0109] (Repeating unit d) The (A) ionic resin in the bioelectrode composition of the present invention may have repeating units d that impart adhesive ability.

[0110] Used to obtain a single unit of repeating unit d, specifically exemplified as follows.

[0111] [Chemistry 44]

[0112] [Chemistry 45]

[0113] [Chemistry 46]

[0114] [Chemistry 47]

[0115] [Chemistry 48]

[0116] (Repeating unit e) In addition, the crosslinkable repeating unit e can also be copolymerized. Examples of crosslinkable repeating units include repeating units having an ethylene oxide ring or an oxobutane ring.

[0117] Monomers used to obtain repeating units e having ethylene oxide rings or oxobutane rings, specifically as follows.

[0118] [Chemistry 49]

[0119] [Chemical 50]R is a methyl or hydrogen atom.

[0120] (Repeating Unit f) In addition to having repeating units selected from a, b, c, d, and e above, component (A) of the bioelectrode composition of the present invention may also have silicon-containing repeating units f. Specific examples are as follows.

[0121] [Chemistry 51]

[0122] [Chemistry 52]

[0123] The repeating units having alkoxysilyl groups can be copolymerized, and the alkoxysilyl groups can be hydrolyzed to form a silsesquioxane structure as disclosed in Japanese Patent Application Publication No. 2022-164579. Alternatively, it can be reacted with silanol on the surface of silica to form a complex with silica as disclosed in Japanese Patent Application Publication No. 2022-64291.

[0124] (Repeating unit g) The (A) component of the bio-electrode composition of the present invention may have a repeating unit g containing fluorine, in addition to having repeating units a and selected from b to f as described above.

[0125] A monomer used to obtain a repeating unit g containing fluorine, as exemplified below.

[0126] [Chemistry 53]

[0127] [Chemistry 54]

[0128] [Transformation 55]

[0129] [Chemistry 56]

[0130] [Chemistry 57]

[0131] [Transformation 58]

[0132] [Chemical 59]R is a hydrogen atom or a methyl group.

[0133] (Repeating unit h) The (A) component of the bio-electrode composition of the present invention may have a repeating unit h containing a cyano group, in addition to having repeating units selected from b to g as described above.

[0134] The monomer used to obtain the repeating unit h containing cyano group can be specifically exemplified as follows.

[0135] [Chemical 60]

[0136] [Chemistry 61]

[0137] [Chemical 62]

[0138] [Chemical 63]R is a hydrogen atom or a methyl group.

[0139] (Repeating Unit i) The (A) component of the bioelectrode composition of the present invention may have a repeating unit i containing a nitro group, in addition to having repeating units selected from b to h as described above.

[0140] A monomer used to obtain a repeating unit i containing a nitro group, specifically exemplified below.

[0141] [Chemical 64]

[0142] [Chemical 65]

[0143] [Chemistry 66]

[0144] [Chemical 67]

[0145] [Transformation 68]

[0146] [Transformation 69]

[0147] As one method for synthesizing an ionic resin of component (A), a method can be listed whereby a desired monomer among the monomers that provide repeating units a, b, c, d, e, f, g, h, i is added to an organic solvent and subjected to heating polymerization to obtain a copolymer polymer compound.

[0148] Examples of organic solvents used in polymerization include: toluene, benzene, tetrahydrofuran, diethyl ether, dialkylene, etc. Examples of polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid) ester, benzoyl peroxide, lauryl peroxide, etc. The heating temperature is preferably 50~80℃, and the reaction time is preferably 2~100 hours, with 5~20 hours being more preferred.

[0149] Here, the proportions of repeating units a, b, c, d, e, f, g, h, i in the ionic resin of component (A) are 0 < a ≦ 1.0, 0 ≦ b < 1.0, 0 ≦ c < 1.0, 0 ≦ d < 1.0, 0 ≦ e < 0.9, 0 ≦ f < 0.9, 0 ≦ g < 0.9, 0 ≦ h < 0.9, 0 ≦ i < 0.9, preferably 0.05 ≦ a ≦ 0.9, 0.01 ≦ b ≦ 0.9, 0≦c≦0.8, 0≦d≦0.8, 0≦e<0.8, 0≦f<0.8, 0≦g<0.8, 0≦h<0.8, 0≦i<0.8 are better than 0.1≦a≦0.8, 0.05≦b≦0.8, 0≦c≦0.7, 0≦d≦0.5, 0≦e≦0.3, 0≦f≦0.7, 0≦g≦0.7, 0≦h≦0.7, 0≦i≦0.7.

[0150] In addition, for example, a+b+c+d+e+f+g+h+i=1 means that in a polymer compound containing repeating units a, b, c, d, e, f, g, h, i, the total amount of repeating units a, b, c, d, e, f, g, h, i relative to the total amount of all repeating units is 100 mol%. a+b+c+d+e+f+g+h+i<1 means that the total amount of repeating units a, b, c, d, e, f, g, h, i relative to the total amount of all repeating units is less than 100 mol% and there are other repeating units besides a, b, c, d, e, f, g, h, i.

[0151] The molecular weight of the ionic resin of component (A), in terms of weight average molecular weight, should preferably be 500 or more, preferably 1,000 or more but less than 1,000,000, and even more preferably 2,000 or more but less than 500,000. Furthermore, if there is a small amount of ionic monomer (residual monomer) in the polymer compound not included in component (A) after polymerization, there is a concern that the residual monomer may penetrate the skin and cause allergies during biocompatibility testing; therefore, the amount of residual monomer should be reduced. The amount of residual monomer relative to 100 parts by mass of the polymer compound of component (A) before the condensation reaction should preferably be 10 parts by mass or less. Furthermore, component (A) can be used alone, or two or more monomers with different molecular weights, dispersities, and polymerization monomers can be mixed and used.

[0152] Furthermore, in this invention, the molecular weight (Mw) and dispersity (Mw / Mn) of the polymer can be obtained using gel permeation chromatography (GPC) with tetrahydrofuran (THF) as a solvent. GPC determination is typically performed at room temperature around 23°C, but can also be performed at higher or lower temperatures.

[0153] In the bio-electrode composition of the present invention, the amount of component (A) is not particularly limited. For example, it can be set to 1 to 50 parts by mass relative to 100 parts by mass of the composition. Alternatively, the amount of component (A) relative to 100 parts by mass of component (B) is preferably set to 0.1 to 300 parts by mass, and more preferably 1 to 200 parts by mass. Furthermore, component (A) can be used alone or in combination with two or more other components.

[0154] [(B) Resin] The (B) resin (a resin other than component (A)) incorporated in the bioelectrode composition of the present invention is a component used to be miscible with the above-mentioned (A) ionic resin (salt) and to prevent the dissolution of the salt, retain the conductivity improvers such as metal powder, carbon powder, silicon powder, and lithium titanate powder, and further improve adhesion. When the (A) ionic resin has sufficient adhesion, the (B) resin is not necessary. In addition, the (B) resin may be a resin other than component (A) above, preferably any one or both of thermosetting resin and photocuring resin, and preferably selected from one or more of polysiloxane resin, (meth)acrylate resin, and polyurethane resin.

[0155] Adhesive polysiloxanes can be categorized as either addition-reaction-curing or free-radical crosslinking-reaction-curing types. Addition-reaction-curing types may use, for example, those disclosed in Japanese Patent Application Publication No. 2015-193803, containing a diorganosiloxane having an alkenyl group, an MQ resin having R3SiO0.5 and SiO2 units, an organohydrogen polysiloxane having multiple SiH groups, a platinum catalyst, an addition reaction control agent, and an organic solvent. Free-radical crosslinking-reaction-curing types may use, for example, those disclosed in Japanese Patent Application Publication No. 2015-193803, containing, for example, a diorganosiloxane that may or may not have an alkenyl group, an MQ resin having R3SiO0.5 and SiO2 units, an organic peroxide, and an organic solvent. Here, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0156] Alternatively, a polysiloxane with silicol at the polymer ends or side chains, and a polysiloxane-resin monolithic compound formed by condensing MQ resin, can also be used. Since MQ resin contains a large amount of silicol, adding MQ resin improves adhesion, but because it lacks crosslinking properties, it does not form molecular bonds with the polysiloxane. By making the polysiloxane and resin monolithic as described above, adhesion can be increased.

[0157] Furthermore, modified siloxanes selected from amino, ethylene oxide, oxetyl, polyether, hydroxyl, carboxyl, mercapto, methacrylate, acrylic, phenolic, silanol, carboxylic anhydride, aryl, aralkyl, amide, ester, and lactone ring groups may also be added to the polysiloxane. Adding modified siloxanes improves the dispersibility of component (A) in the polysiloxane. Modification of any one end, two ends, or side chain of the siloxane is acceptable.

[0158] Furthermore, the aforementioned component (B) shall preferably include a polysiloxane resin having RxSiO(4-x) / 2 units (R being a substituted or unsubstituted monovalent hydrocarbon group with 1 to 10 carbon atoms, and x being in the range of 2.5 to 3.5) and SiO2 units.

[0159] Adhesive (meth)acrylate resins may use, for example, those with hydrophilic (meth)acrylates or long-chain hydrophobic (meth)acrylates as repeating units as described in Japanese Patent Application Publication No. 2016-011338. Depending on the circumstances, (meth)acrylates with functional groups or (meth)acrylates with siloxane bonds may also be copolymerized.

[0160] For example, the adhesive polyurethane resin may be one that has urethane bonds and polyether, polyester, polycarbonate or silicate bonds as described in Japanese Patent Application Publication No. 2016-065238.

[0161] Also, in order to prevent the reduction in conductivity caused by the detachment of the (A) component from the contact layer of the organism, among the biological electrode compositions of the present invention, (B) the resin should be the one with high compatibility with the component (A) above. Furthermore, in order to prevent the stripping of the biological contact layer obtained from the conductive substrate, among the biological electrode compositions of the present invention, (B) the resin should be the one with high adhesion to the conductive substrate. In order to make (B) resin a conductive substrate, and high compatibility with salt, the use of highly polar resins is effective. Such resins may enumerate resins having a selection consisting of an ether bond, an ester bond, an amide bond, an amide bond, an amide bond, a thiocarbamate bond, and more than one of the thiol groups, or a polyacrylic-based resin, a polyamide resin, a polyimide resin, a polyurethane resin, and a polythiamide-based resin. Also, on the other hand, the organism contact layer is susceptible to sweat from the organism since it comes into contact with the organism. Therefore, among the biological electrode compositions of the present invention, (B) the resin is preferable to be highly water repellent and not easily hydrolyzed. In order to make the resin highly water-repellent and not easily hydrolyzed, the use of resins containing silicon is effective.

[0162] Either of polyacrylic-based resins containing silicon atoms can be ideally used, including a polymer having polysilicone oxygen in the main chain, and a polymer having silicon atoms in the side chain. Polymers having polysilicone in the main chain may use siloxane or silicon sesquioxane having a propyl (meth)acrylate group. In this case, the (meth)acrylic acid can be partially polymerized and hardened by the addition of a photoradical generating agent.

[0163] Polyamide resins containing silicon atoms may be ideally used, for example, polyamide polysilicone resins as described in Bulletin 2011-079946 of Japan Special Opening and Bulletin 5981680 of U.S. Patent. Such polyamide polysilicone resins can, for example, be synthesized by combining a polysilicone with an amine group at both ends or a non-polysilicox compound with an amine group at both ends, with a nonpolysilicox with a carboxyl group at both ends or a polysilicone with a carboxyl group at both ends.

[0164] Also, a polyamide before cyclization obtained by reacting a carboxylic anhydride with an amine can also be used. Cross-linking of carboxyl groups of polyamide acids can also be performed using cross-linking agents of epoxy-based, oxycyclobutane-based systems, esterification reactions of carboxyl groups with hydroxyethyl (meth)acrylate, and photoradical cross-linking of (meth)acrylate moieties can also be implemented.

[0165] Polyimide resins containing silicon atoms may be ideally used, for example, polyimide polysilicone resins as described in Bulletin No. 2002-332305 of Japan Special Kai. Polyimide resins are very viscous, but can become low viscous by incorporating (meth)acrylic acid-based monomers as solvents and doping as cross-linkers.

[0166] Examples of polyurethane resins containing silicon atoms include polyurethane polysiloxane resins. Such polyurethane polysiloxane resins can be cross-linked by mixing compounds with isocyanate groups at both ends and compounds with hydroxyl groups at the ends, followed by heating. Furthermore, either or both of the compounds with isocyanate groups at both ends or the compounds with hydroxyl groups at the ends must contain silicon atoms (siloxane bonds). Alternatively, as described in Japanese Patent Application Publication No. 2005-320418, urethane (meth)acrylate monomers can be mixed into a polysiloxane and photocrosslinked. Furthermore, polymers containing both siloxane bonds and urethane bonds, and with (meth)acrylate groups at the ends, can also be photocrosslinked. In particular, materials with polysiloxane side chains and polyurethane main chains as described in Japanese Patent Application Publication No. 2018-123304 and Japanese Patent Application Publication No. 2019-70109 are more ideal due to their high strength and high elasticity.

[0167] Polythiocarbamate resins containing silicon atoms can be obtained by reacting a compound having a thiol group with a compound having an isocyanate group, either of which must contain silicon atoms. Furthermore, if the resin has a (meth)acrylate group at the end, it can also be photocured.

[0168] By adding the above-mentioned alkenyl diorganosiloxane, MQ resin having R3SiO0.5 and SiO2 units, and organic hydrogen polysiloxane having many SiH groups to a polysiloxane, and adding a modified siloxane having a group selected from amino, ethylene oxide, oxetane, polyether, hydroxyl, carboxyl, mercapto, methacrylic acid, acrylic acid, phenolic, silanol, carboxylic anhydride, aryl, aralkyl, amide, ester, and lactone ring groups, the compatibility with the above-mentioned salts will be improved.

[0169] Alkenyl diorganosiloxanes and organohydrogen polysiloxanes with many SiH groups can be crosslinked by an addition reaction using a platinum catalyst.

[0170] Examples of platinum catalysts include: chloroplatinic acid, alcoholic solutions of chloroplatinic acid, reaction products of chloroplatinic acid and alcohols, reaction products of chloroplatinic acid and olefin compounds, reaction products of chloroplatinic acid and vinyl-containing silicates, platinum-olefin complexes, platinum-vinyl-containing silicate complexes, and other platinum-based catalysts; rhodium complexes and ruthenium complexes, and other platinum group metal catalysts. Alternatively, catalysts can be prepared by dissolving / dispersing these catalysts in alcohol-based, hydrocarbon-based, or silicate-based solvents.

[0171] In addition, the amount of platinum catalyst added relative to 100 parts by weight of resin containing components (A) and (B) is preferably 5 to 2,000 ppm, and preferably in the range of 10 to 500 ppm.

[0172] In the bio-electrode composition of the present invention, the amount of component (B) relative to 100 parts by mass of ionic resin (A) is preferably 0 to 2000 parts by mass, and more preferably 10 to 1000 parts by mass. Furthermore, component (B) can be used alone or in combination with two or more other components.

[0173] Furthermore, when using addition-curing polysiloxane resin, an addition reaction control agent may also be added. This addition reaction control agent is added as a quencher to prevent the platinum catalyst from reacting in the solution and under low-temperature conditions before heat curing after coating formation. Specific examples include: 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclohexanol, 3-methyl-3-trimethylsiloxy-1-butyn, 3-methyl-3-trimethylsiloxy-1-pentyn, 3,5-dimethyl-3-trimethylsiloxy-1-hexyn, 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, etc.

[0174] The amount of addition reaction control agent added is preferably 0 to 10 parts by weight, and preferably 0.05 to 3 parts by weight, relative to 100 parts by weight of the resin totaling components (A) and (B).

[0175] (B) When the component has double bonds that can be cross-linked by free radicals, the addition of a free radical generating agent is effective. Free radical generating agents include photoradio ...

[0176] Examples of photoradical generators include: acetophenone, 4,4'-dimethoxybenzoin, benzoin, benzoin, benzophenone, 2-benzoylbenzoic acid, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, 4-benzoylbenzoic acid, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, methyl 2-benzoylbenzoate, 2-(1,3-benzodioxane-5-yl)-4,6-bis(trichloromethyl) -1,3,5-tris(2,3,5), 2-benzyl-2-(dimethylamino)-4'-pyrolinyl phenylbutanone, 4,4'-dichlorobenzophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4-diethylthioxanthone-9-one, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), 1,4-dibenzoylbenzene, 2-ethylanthraquinone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methylphenylacetone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, 2-isonitrosophenylacetone, 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone.

[0177] It can also be hardened by adding a thermally decomposable free radical generator. Examples of thermal free radical generators include: 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylpentanitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(methylpropanediamine) hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] hydrochloride, 2,2'-azobis(4-methoxy-2,4-dimethylpentanitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(cyclohexane-1-formitrile), 1[(1-cyano-1-methylethyl)azo]methoxymethylamine, 2,2'-azobis[ [2-Methyl-N-(2-hydroxyethyl)propionic acid], 2,2'-azobis[N-(2-propenyl)-2-methylpropionic acid], 2,2'-azobis(N-butyl-2-methylpropionic acid), dimethyl-2,2'-azobis(isobutyrate), 4,4'-azobis(4-cyanopentanic acid), dimethyl-2,2'-azobis(2-methylpropionic acid), benzoyl peroxide, tributyl hydroperoxide, cumene hydroperoxide, di(tributyl)peroxide, di(tripentyl)peroxide, di-n-butyl peroxide, diisopropylphenyl peroxide, etc.

[0178] In addition, the amount of free radical generator added should be in the range of 0.1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0179] Furthermore, as described later, the bio-contact layer is a hardened form of the bio-electrode composition. By hardening it, the adhesion of the bio-contact layer to both the skin and the conductive substrate becomes better. There are no particular limitations on the hardening method; general methods can be used, such as heat or light, or a cross-linking reaction using an acid or alkali catalyst. Regarding the cross-linking reaction, for example, the methods described in Chapter 2, pp. 51-371 of the cross-linking reaction manual published by Yoshiharu Maruzen (2013) can be appropriately selected for implementation.

[0180] [Ionic Polymer] In the bioelectrode composition of the present invention, an ionic polymer other than component (A) may be added. The ionic polymers disclosed in Japanese Patent Application Publication Nos. 2018-126496 and 2018-130533 are preferably used. The amount of the ionic polymer added is preferably in the range of 0.1 to 100 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0181] [(C) Carbon powder and / or metal powder] In order to improve electronic conductivity, carbon powder and / or metal powder may be added to the bio-electrode composition of the present invention.

[0182] [Metal Powder] In order to improve the electronic conductivity of the bio-electrode composition of the present invention, metal powder selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium may be added. The amount of metal powder added is preferably in the range of 1 to 50 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0183] Regarding the types of metal powder, from the perspective of conductivity, gold, silver, and platinum are preferable; from the perspective of price, silver, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, and chromium are preferable. From the perspective of biocompatibility, precious metals are preferable. Considering all these factors, silver is the best choice.

[0184] The shapes of metal powders can be spherical, disc-shaped, flake-shaped, and needle-shaped. The conductivity is the highest when flake-shaped powders are added, which is more ideal. It is more ideal to have relatively low density and large specific surface area, with metal powder size of less than 100 μm, tap density of less than 5 g / cm3, and specific surface area of ​​more than 0.5 m2 / g.

[0185] [Toner] Conductivity improver can be added to toner. Examples of toners include: carbon black, graphite, carbon nanotubes, carbon fibers, graphene, etc. Carbon nanotubes can be single-layer or multi-layered, and surface modification with organic groups is also acceptable. Carbon black and carbon nanotubes, or both, are particularly preferred. The amount of toner added should preferably be in the range of 1 to 50 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0186] [Silicon Powder] In the bioelectrode composition of the present invention, silicon powder may be added to improve the sensitivity of ion acceptance. Examples of silicon powder include powders composed of silicon, silicon monoxide, and silicon carbide. The particle size of the powder is preferably less than 100 μm, and more preferably less than 1 μm. The finer the particles, the larger their surface area, thus allowing them to accept more ions and become a highly sensitive bioelectrode. The amount of silicon powder added is preferably in the range of 1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0187] [Lithium titanate powder] In the bio-electrode composition of the present invention, lithium titanate powder may be added to improve the sensitivity of ion acceptance. Examples of lithium titanate powders include Li2TiO3, LiTiO2, and Li4Ti5O12 with a spinel structure, preferably a spinel structure. Alternatively, lithium titanate particles formed by combining with carbon may also be used. The particle size of the powder is preferably less than 100 μm, and less than 1 μm is more preferred. The finer the particles, the larger their surface area, thus accepting more ions and becoming a highly sensitive bio-electrode. They can also be composite powders combined with carbon. The amount of lithium titanate powder added is preferably in the range of 1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0188] [Crosslinking Agent] An epoxy-based crosslinking agent may also be added to the bioelectrode composition of the present invention. This crosslinking agent is a compound having multiple epoxy groups and oxocyclic butyl groups within one molecule. The amount added is 1 to 30 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0189] [Crosslinking Catalyst] In the bioelectrode composition of the present invention, a catalyst for crosslinking epoxy groups and oxetane groups may also be added. In this case, the catalyst described in paragraphs 0027 to 0029 of Japanese Patent Application Publication No. 2019-503406 may be used. The amount added is 0.01 to 10 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0190] [Ionic Additives] Ionic additives for improving ionic conductivity can be added to the bioelectrode composition of the present invention. Examples of such additives, considering biocompatibility, include: sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium saccharin, potassium acetylsulfamate, sodium formate, potassium formate, calcium formate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, betaine, salts disclosed in Japanese Patent Application Publication No. 2018-44147, Japanese Patent Application Publication No. 2018-59050, Japanese Patent Application Publication No. 2018-59052, and Japanese Patent Application Publication No. 2018-130534.

[0191] [(D) Organic Solvents] Furthermore, organic solvents may be added to the bioelectrode composition of the present invention. Specific examples of organic solvents include: toluene, xylene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, styrene, α-methylstyrene, styrene-butadiene, styrene-butadiene, isobutylbenzene, isopropyltoluene, diethylbenzene, 2-ethyl-p-xylene, 2-propyltoluene, 3-propyltoluene, 4-propyltoluene, 1,2,3,5-tetramethyltoluene, 1,2,4,5-tetramethyltoluene, tetrahydronaphthalene, 4-phenyl-1-butene, tert-pentylbenzene, pentylbenzene, 2-tert-butyltoluene, 3-tert-butyltoluene, 4-tert-butyltoluene, 5-isopropyl-m-xylene, 3-methylethylbenzene, tert-butyl-3-ethylbenzene, 4-tert-butyl-1-butene, etc. Aromatic hydrocarbon solvents such as 5-tributyl-m-xylene, 5-tributyl-p-xylene, 1,2-diisopropylbenzene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, dipropylbenzene, pentamethylbenzene, hexamethylbenzene, hexylbenzene, and 1,3,5-triethylbenzene; solvents containing n-heptane, isoheptane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, 1,6-heptadiene, 5-methyl-1-hexyne, norcamphene, norcamphene, dicyclopentadiene, 1-methyl-1,4-cyclohexadiene, 1-heptyne, 2-heptyne, cycloheptane, cycloheptene, 1,3-dimethylcyclopentane, ethylcyclopentane, methylcyclohexane, 1-methyl-1-cyclohexene, and 3-methyl-1-cyclohexene. Alkene, methylenecyclohexane, 4-methyl-1-cyclohexene, 2-methyl-1-hexene, 2-methyl-2-hexene, 1-heptene, 2-heptene, 3-heptene, n-octane, 2,2-dimethylhexane, 2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane, 3,3-dimethylhexane, 3,4-dimethylhexane, 3-ethyl-2-methylpentane, 3-ethyl-3-methylpentane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane, cyclooctane, cyclooctene, 1,2-dimethylcyclohexane, 1,3-dimethylcyclohexane, 1,4-dimethylcyclohexane, ethylcyclohexane Hexane, vinylcyclohexane, isopropylcyclopentane, 2,2-dimethyl-3-hexene, 2,4-dimethyl-1-hexene, 2,5-dimethyl-1-hexene, 2,5-dimethyl-2-hexene, 3,3-dimethyl-1-hexene, 3,4-dimethyl-1-hexene, 4,4-dimethyl-1-hexene, 2-ethyl-1-hexene, 2-methyl-1-heptene, 1-octene, 2-octene, 3-octene, 4-octene, 1,7-octadiene, 1-octyne, 2-octyne, 3-octyne, 4-octyne, n-nonane, 2,3-dimethylheptane, 2,4-dimethylheptane, 2,5-dimethylheptane, 3,3-dimethylheptane, 3,4-dimethylheptane, 3,5-Dimethylheptane, 4-Ethylheptane, 2-Methyloctane, 3-Methyloctane, 4-Methyloctane, 2,2,4,4-Tetramethylpentane, 2,2,4-Trimethylhexane, 2,2,5-Trimethylhexane, 2,2-Dimethyl-3-heptene, 2,3-Dimethyl-3-heptene, 2,4-Dimethyl-1-heptene, 2,6-Dimethyl-1-heptene, 2,6-Dimethyl-3-heptene, 3,5-Dimethyl-3-heptene, 2,4,4-Trimethyl-1-hexene, 3,5,5-Trimethyl-1-hexene, 1-Ethyl-2-methylcyclohexane, 1-Ethyl-3-methylcyclohexane, 1-Ethyl-4-methylcyclohexane Propylcyclohexane, isopropylcyclohexane, 1,1,3-trimethylcyclohexane, 1,1,4-trimethylcyclohexane, 1,2,3-trimethylcyclohexane, 1,2,4-trimethylcyclohexane, 1,3,5-trimethylcyclohexane, allylcyclohexane, hydrindane, 1,8-nonadiene, 1-nonyne, 2-nonyne, 3-nonyne, 4-nonyne, 1-nonene, 2-nonene, 3-nonene, 4-nonene, n-decane, 3,3-dimethyloctane, 3,5-dimethyloctane, 4,4-dimethyloctane, 3-ethyl-3-methylheptane, 2-methylnonane, 3-methylnonane, 4-methylnonane, tributylcyclohexane Alkane, Butylcyclohexane, Isobutylcyclohexane, 4-Isopropyl-1-methylcyclohexane, Pentylcyclopentane, 1,1,3,5-Tetramethylcyclohexane, Cyclododecane, 1-Dedecene, 2-Dedecene, 3-Dedecene, 4-Dedecene, 5-Dedecene, 1,9-Decadiene, Decahydronaphthalene, 1-Decayne, 2-Decayne, 3-Decayne, 4-Decayne, 5-Decayne, 1,5,9-Decatriene, 2,6-Dimethyl-2,4,6-Octatriene, Limonene, Myrcene, 1,2,3,4,5-Pentamethylcyclopentadiene, α-Phellandrene, Pinene, Terpinene, Tetrahydrodicyclopentadiene, 5,6-Dihydrodicyclopentadiene Cyclopentadiene, dicyclopentadiene, 1,4-decadiyne, 1,5-decadiyne, 1,9-decadiyne, 2,8-decadiyne, 4,6-decadiyne, n-Undecane, pentylcyclohexane, 1-Undecane, 1,10-Undecanediene, 1-Undecaneyne, 3-Undecaneyne, 5-Undecaneyne, tricyclo[6.2.1.02,7]undecane-4-ene, n-Dodecane, n-Trigedecane, n-Pentadecadecane, n-Hexadecane, 2-Methylundecane, 3-Methylundecane, 4-Methylundecane, 5-Methylundecane, 2,2,4,6,6-Pentamethylheptane, 1,3-Dimethyladamantane, 1-Ethyladamantane, 1,5,9-Cyclododecanetriene, 1,2,4-Trivinylcyclohexane, isoalkanes, and other aliphatic hydrocarbon solvents; cyclohexanone, cyclopentanone, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, methyl n-pentanone, and other ketone solvents; 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and other alcohol solvents; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monopentanone ... Ether solvents including heptayl alcohol ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, diisopropyl ether, diisobutyl ether, diisopentyl ether, din-n-pentyl ether, methylcyclopentyl ether, methylcyclohexyl ether, din-n-butyl ether, di(secondary butyl) ether, diisopentyl ether, di(secondary pentyl) ether, di(tertiary pentyl) ether, din-n-hexyl ether, anisole, etc.; ester solvents including propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tertiary butyl acetate, tertiary butyl propionate, propylene glycol monotertiary butyl ether acetate, etc.; lactone solvents including γ-butyrolactone; water, etc.

[0192] In addition, the amount of organic solvent added should be in the range of 10 to 50,000 parts by mass relative to 100 parts by mass of the resin totaling components (A) and (B).

[0193] [Other Additives] Silicon dioxide particles, polyether polysiloxane, or polyglycerol polysiloxane may also be mixed into the bioelectrode composition of the present invention. Silicon dioxide particles have a hydrophilic surface and good affinity with hydrophilic ionic polymers, polyether polysiloxane, or polyglycerol polysiloxane, and can improve the dispersibility of ionic polymers, polyether polysiloxane, or polyglycerol polysiloxane in hydrophobic polysiloxane adhesives. Silicon dioxide particles can be ideally used in either dry or wet processes.

[0194] [Polysiloxane compound with polyglycerol structure] In the bioelectrode composition of the present invention, in order to improve the moisturizing properties of the membrane and improve the sensitivity and ionic conductivity of ions released from the skin, a polysiloxane compound with a polyglycerol structure may be added. The amount of polysiloxane compound with a polyglycerol structure relative to 100 parts by weight of the total of components (A) and (B) is preferably 0.01 to 100 parts by weight, and more preferably 0.5 to 60 parts by weight. Furthermore, a single polysiloxane compound with a polyglycerol structure may be used alone, or two or more may be used in combination.

[0195] A polysiloxane having a polyglycerol structure is preferably represented by the following general formulas (4)' and (5)'.

[0196] In formulas (4)' and (5)', R1' is independently and may be the same or different, a hydrogen atom or a linear or branched alkyl group having 1 to 50 carbon atoms, or a phenyl group, and may contain an ether group, and may also be a polysiloxane chain represented by general formula (6)'. R2' is a group having a polyglycerol structure represented by formula (4)'-1 or formula (4)'-2. R3' is independently and may be the same or different, the aforementioned R1' group or the aforementioned R2' group. R4' is independently and may be the same or different, the aforementioned R1' group, the aforementioned R2' group or an oxygen atom. When R4' is an oxygen atom, two R4' groups may be bonded to form one ether group and form a ring together with the silicon atom. a' may be the same or different, 0 to 100, b' is 0 to 100, and a'+b' is 0 to 200. However, when b' is 0, at least one of R3' is the aforementioned R2' group. In formulas (4)'-1 and (4)'-2, (5)', (6)', R5' is an alkylene group having 2 to 10 carbon atoms or an arylalkylene group having 7 to 10 carbon atoms, R6' and R7' are alkylene groups having 2 to 6 carbon atoms, and R7' may also be an ether bond. c' is 0 to 20, and d' is 1 to 20.

[0197] Such a polysiloxane compound having a polyglycerol structure can be exemplified as follows.

[0198] [Chemical formula 71]

[0199] [Chemical formula 72]

[0200] [Chemical formula 73]

[0201] [Chemical formula 74]

[0202] [Chemical formula 75]

[0203] [Chemical formula 76]

[0204] [Chemical formula 77]

[0205] [Chemical formula 78]

[0206] [Chemical formula 79]

[0207] In the formula, a', b', c' and d' are as described above.

[0208] If it contains such a polysiloxane compound having a polyglycerol structure, it can exhibit better moisture retention. As a result, a biological electrode composition capable of forming a biological contact layer that is more sensitive to ions released to the skin can be prepared.

[0209] As described above, the bioelectrode composition of the present invention can form a bioelectrode composition with high adhesion, maintaining sufficient adhesion even after being peeled off and reattached from the skin, efficiently transmitting electrical signals from the skin to the device (i.e., excellent conductivity), without causing allergies even after prolonged skin contact (i.e., excellent biocompatibility), being lightweight, and manufactured at low cost, and whose conductivity does not significantly decrease even when wetted or dried. Furthermore, by adding carbon materials, conductivity can be further improved, and by combining with resins possessing adhesion and elasticity, bioelectrodes with high adhesion and high elasticity can be manufactured. In addition, additives can be used to improve elasticity and adhesion to the skin, and elasticity and adhesion can be adjusted by appropriately regulating the resin composition and the thickness of the bioelectrode contact layer.

[0210] <Bioelectrode> Furthermore, the present invention provides a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, wherein the aforementioned bioelectrode contact layer is a hardened form of the bioelectrode composition of the present invention.

[0211] Hereinafter, the bioelectrode of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

[0212] FIG1 is a schematic cross-sectional view showing an example of the bioelectrode of the present invention. The bioelectrode 1 of FIG1 has a conductive substrate 2 and a bio-contact layer 3 formed on the conductive substrate 2. The bio-contact layer 3 is composed of a hardened form of the bioelectrode composition of the present invention. The bio-contact layer 3 contains an ionic resin (A) 5. The bio-contact layer 3 may also contain a resin (B) 6 other than the ionic resin (A) and conductive powder 4. Referring to FIG1 and 2, the following description is based on the case where the bio-contact layer 3 is a layer in which the ionic resin (A) 5 and conductive powder 4 are dispersed in the resin (B) 6, but the bioelectrode of the present invention is not limited to this form.

[0213] When using the bioelectrode 1 of FIG1, as shown in FIG2, the bio-contact layer 3 (i.e., the layer in which ionic resin (A) 5 and conductive powder 4 are dispersed in resin (B) 6) is brought into contact with the bio-body 7. The ionic resin (A) 5 and conductive powder 4 are used to extract electrical signals from the bio-body 7 and conduct them to a sensor device (not shown) via the conductive substrate 2. Thus, in the bioelectrode of the present invention, since the aforementioned ionic resin (A) is used, conductivity and biocompatibility can be taken into account, and it also has adhesive properties. Therefore, the contact area with the skin is kept constant, and electrical signals from the skin can be stably obtained with high sensitivity.

[0214] Hereinafter, the constituent materials of the bioelectrode of the present invention will be described in more detail.

[0215] [Conductive Substrate] The bioelectrode of the present invention has a conductive substrate. This conductive substrate is typically electrically connected to a sensor device or the like, and conducts electrical signals taken from the organism through the bio-contact layer to the sensor device or the like.

[0216] If the conductive substrate is conductive, there are no particular restrictions. For example, it is preferable to contain one or more of the following: gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon and conductive polymers.

[0217] Furthermore, there are no particular limitations on the conductive substrate. It can be a rigid conductive substrate, a flexible conductive film, a fabric with a conductive paste coated on the surface, or a fabric mixed with a conductive polymer. The conductive substrate can also be a mesh woven from flat or textured metal wires, and can be appropriately selected according to the application of the bioelectrode.

[0218] [Bio-contact layer] The bio-electrode of the present invention has a bio-contact layer formed on a conductive substrate. This bio-contact layer, which is the part that actually contacts the organism when the bio-electrode is used, has conductivity and adhesion. The bio-contact layer is a hardened form of the bio-electrode composition of the present invention, that is, an adhesive resin layer composed of a hardened form containing the above-mentioned component (A), and, as needed, components (B), (C), (D), and other components.

[0219] Furthermore, the adhesive strength of the biological contact layer should preferably be in the range of 0.01 N / 25 mm or higher and 20 N / 25 mm or lower. The method for measuring adhesive strength, as shown in JIS Z 0237, is general. The substrate can be a metal substrate such as SUS (stainless steel) or a PET (polyethylene terephthalate) substrate, or it can be measured using human skin. Human skin has a lower surface energy than metals or various plastics, approaching the low energy of Teflon (registered trademark), making it less prone to adhesion.

[0220] In applications involving repeated application and peeling, peelability is more important than adhesiveness, so adhesiveness is not necessary.

[0221] The thickness of the bio-contact layer of the bio-electrode should preferably be 1 μm or more and 5 mm or less, preferably 2 μm or more and 3 mm or less. The thinner the bio-contact layer, the lower the adhesion, but the flexibility will be improved, it will be lighter and have better skin affinity. The thickness of the bio-contact layer can be selected by taking into account both adhesion and skin feel.

[0222] Furthermore, the bioelectrode of the present invention can also, like conventional bioelectrodes (such as the bioelectrode described in Japanese Patent Application Publication No. 2004-033468), have an additional adhesive film provided on the bio-contact layer to prevent the bioelectrode from peeling off from the body during use. When additionally providing the adhesive film, adhesive film materials such as acrylic, carbamate, and polysiloxane can be used to form the adhesive film. In particular, polysiloxane is more ideal because it has high oxygen permeability, which allows the skin to breathe even when attached, and it also has high water repellency, thus reducing the decrease in adhesion caused by sweat. In addition, it has low skin irritation. Furthermore, as described above, the bioelectrode of the present invention can prevent peeling off from the body by adding an adhesive agent to the bioelectrode composition or using a resin with good adhesion to the body, so it is not necessarily necessary to provide the aforementioned additional adhesive film.

[0223] There are no particular limitations on the wiring or other components of the bioelectrode and sensor device when the bioelectrode of the present invention is used to make a wearable device. For example, those described in Japanese Patent Application Publication No. 2004-033468 may be used.

[0224] As described above, the bioelectrode of the present invention, due to the formation of a bio-contact layer from the hardened composition of the bioelectrode of the present invention, can efficiently transmit electrical signals from the skin to the device (i.e., excellent conductivity), and even after prolonged use on the skin, there is no concern about causing allergies (i.e., excellent biocompatibility). It is lightweight, can be manufactured at low cost, and its conductivity does not significantly decrease even when wetted or dried. Furthermore, by adding conductive powder, conductivity can be further improved, and by combining it with a resin that has adhesiveness and elasticity, a bioelectrode with high adhesion and high elasticity can be manufactured. In addition, additives can be used to improve elasticity and adhesion to the skin, and elasticity and adhesion can also be adjusted by appropriately adjusting the composition of the resin and the thickness of the bio-contact layer. Therefore, the bioelectrode of the present invention, in this way, is particularly suitable as a bioelectrode for use in medical wearable devices.

[0225] <Method for Manufacturing a Bioelectrode> Furthermore, the present invention provides a method for manufacturing a bioelectrode, which is a method for manufacturing a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate. The bioelectrode composition of the present invention is coated onto the aforementioned conductive substrate and hardened thereon, thereby forming the aforementioned bioelectrode contact layer.

[0226] In addition, the conductive substrate used in the manufacturing method of the bioelectrode of the present invention can be the same as those described above.

[0227] There are no particular limitations on the method of coating bio-electrode components on a conductive substrate. For example, dip coating, spray coating, spin coating, rod coating, spool coating, die coating, roll coating, flow coating, doctor blade coating, calender coating, screen printing, flexographic printing, gravure printing, inkjet printing and other methods are suitable.

[0228] There are no particular restrictions on the curing method of the resin. It can be appropriately selected depending on the (A) and (B) components used in the bioelectrode composition. For example, it is advisable to use either heat or light, or both of them, to cure it. Alternatively, a catalyst that produces acid or alkali can be added to the above-mentioned bioelectrode composition in advance to induce a cross-linking reaction and thus cure it.

[0229] In addition, there is no particular limitation on the heating temperature. It depends on the appropriate selection of (A) and (B) components used in the bio-electrode composition. For example, it is advisable to be about 50~250°C.

[0230] Furthermore, when combining heating and light exposure, heating and light exposure can be performed simultaneously, or heating can be performed after light exposure, or light exposure can be performed after heating. Also, in order to allow the solvent to evaporate before heating after coating, air drying can be performed.

[0231] Applying water droplets or blowing water vapor or mist onto the hardened membrane surface improves its affinity with the skin, allowing for faster reception of biological signals. To further refine the size of the water droplets (water vapor or mist), a mixture of water and alcohol can be used. The membrane surface can also be moistened by contact with absorbent cotton or cloth containing water.

[0232] The water on the surface of the hardened membrane may also contain salt. The water-soluble salts that mix with water are selected from sodium salts, potassium salts, calcium salts, magnesium salts, and betaine.

[0233] The aforementioned water-soluble salt may specifically be a salt selected from sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium saccharin, potassium acetylsulfamate, sodium formate, potassium formate, calcium formate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, and betaine. Furthermore, the ionic resins mentioned in (A) are not included in the aforementioned water-soluble salts.

[0234] More specifically, in addition to the above, the following may also be listed: sodium acetate, sodium propionate, sodium trimethylacetate, sodium glycolate, sodium butyrate, sodium valerate, sodium hexanoate, sodium heptanoate, sodium caprylate, sodium nonanoate, sodium decanoate, sodium undecanoate, sodium laurate, sodium tridecanoate, sodium myristate, sodium pentadecanoate, sodium palmitate, sodium heptadecanate, sodium stearate, sodium benzoate, disodium adipic acid, disodium maleate, disodium phthalate, sodium butyrate, sodium 2-hydroxybutyrate, sodium 3-hydroxybutyrate, sodium 2-sideoxybutyrate, sodium stearate, sodium gluconate. Sodium methanesulfonate, sodium nonanesulfonate, sodium 1-decanesulfonate, sodium dodecanesulfonate, sodium undecanesulfonate, sodium cocoyl hydroxyethanesulfonate, sodium lauryl methyl propionate, sodium cocoyl methyl taurate, sodium cocoyl glutamate, sodium cocoyl sarcosinate, sodium lauryl methyl taurate, aminopropyl lauryl, potassium isobutyrate, potassium propionate, potassium trimethylacetate, potassium glycolate, potassium gluconate, potassium methanesulfonate, calcium stearate, calcium glycolate, calcium gluconate, calcium 3-methyl-2-sideoxybutyrate, calcium methanesulfonate. Betaine is a general term for intramolecular salts, specifically compounds formed by the addition of three methyl groups to the amino group of an amino acid. More specifically, examples include trimethylglycine, carnitine, trimethylglycine, and proline betaine.

[0235] The aforementioned water-soluble salt may further contain a monovalent alcohol or polyol having 1 to 4 carbon atoms. The aforementioned alcohol is preferably selected from ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol, polyethylene glycol, polypropylene glycol, polyglycerol, diglycerol, or polysiloxane compounds having a polyglycerol structure. It is more preferable that the aforementioned polysiloxane compounds having a polyglycerol structure are represented by the above general formulas (4)' to (6)'.

[0236] Regarding pretreatment methods using aqueous solutions containing water-soluble salts, the bioelectrode membrane can be applied to the hardened bioelectrode membrane using spraying, water droplet application, or similar methods. It can also be applied under high temperature and humidity conditions, such as a steam bath. After application, to prevent drying, a protective film can be layered on top of the permeable layer for further coating. The protective film needs to be peeled off before being applied to the skin; therefore, a peeling agent can be applied, or a peelable Teflon (registered trademark) film can be used. For long-term storage, the dry electrode covered with the peeling film should be sealed in a bag covered with aluminum or similar material. To prevent drying in the aluminum-covered bag, moisture should be pre-sealed inside.

[0237] Before attaching the bioelectrode of the present invention to the skin, the skin side may be moistened with water, alcohol, etc., or the skin may be wiped with a cloth or cotton wool containing water, alcohol, etc. The aforementioned salt may also be present in the water or alcohol.

[0238] As described above, the method for manufacturing the bioelectrode of the present invention can easily produce, at low cost, a bioelectrode with excellent conductivity and biocompatibility, which is lightweight and whose conductivity does not significantly decrease whether wetted or dried. [Example]

[0239] Hereinafter, the present invention will be specifically described using examples and comparative examples, but the present invention is not limited thereto.

[0240] (Synthesis of Monomers 1-11) In THF solvent, in the presence of sodium hydride, monomer 1 was obtained by reacting bis(cyclohexanesulfonyl)methane with 4-methylpropenyloxybenzenesulfonyl chloride and by neutralization reaction with trimethylbenzylammonium. Monomers 2-11 were synthesized by replacing bis(cyclohexanesulfonyl)methane and 4-methylpropenyloxybenzenesulfonyl chloride with other starting materials and by ion exchange reactions with trimethylbenzylammonium and other cations.

[0241] Monomers 1 to 11 are described below.

[0242] [Chemical 81]

[0243] [Chemical 82]

[0244] (Synthesis of Ionic Resins 1-1 to 1-11 and Comparative Ionic Resin 1) Ionic resins 1-1 to 1-11 and comparative ionic resin 1, which are incorporated into the bioelectrode composition solution as ionic materials (conductive materials), were synthesized as follows. A 30% by mass solution of each monomer in cyclopentanone was placed in a reaction vessel and mixed. The reaction vessel was cooled to -70°C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen blowing was repeated three times. After heating to room temperature, 0.02 mol of azobisisobutyronitrile (AIBN) as a polymerization initiator was added relative to 1 mol of the monomer total. The mixture was then heated to 60°C and reacted for 15 hours. The composition of the obtained polymer was confirmed by 1H-NMR after solvent drying. Furthermore, the molecular weight (Mw) and dispersion (Mw / Mn) of the obtained polymer were confirmed by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. The ionic resins 1-1 to 1-11 synthesized in this manner, and the comparative ionic resin 1 are shown below.

[0245] Ionic resin 1-1 Mw=83,000 Mw / Mn=2.94 [Chemical 83]

[0246] Ionic resin 1-2 Mw=77,100 Mw / Mn=2.93 [Chemical 84]

[0247] Ionic resin 1-3 Mw=69, 100 Mw / Mn=2.64 [Chemical 85]

[0248] Ionic resin 1-4 Mw=52,200 Mw / Mn=2.73 [Chemical 86]

[0249] Ionic resin 1-5 Mw=31,900 Mw / Mn=2.77 [Chemical 87]

[0250] Ionic resin 1-6 Mw=40,300 Mw / Mn=2.83 [Chemical 88]

[0251] Ionic resin 1-7 Mw=38,100 Mw / Mn=2.77 [Chemical 89] The number of repetitions in the formula represents the average value.

[0252] Ionic resin 1-8 Mw=42,700 Mw / Mn=1.95 [Chemical 90] The number of repetitions in the formula represents the average value.

[0253] Ionic resin 1-9 Mw=31,500 Mw / Mn=2.33 [Chemical 91] The number of repetitions in the formula represents the average value.

[0254] Ionic resin 1-10 Mw=29,800 Mw / Mn=1.95 [Chemical 92] The number of repetitions in the formula represents the average value.

[0255] Ionic resin 1-11 Mw=33,500 Mw / Mn=1.91 [Chemical 93] The number of repetitions in the formula represents the average value.

[0256] Comparison of ionic resins: 1 Mw = 26,500 Mw / Mn = 1.85 [Chem. 94]

[0257] The silicate compounds 1 to 4, which are incorporated into the bio-electrode composition solution as polysiloxane resins, are shown below.

[0258] (Silicone compound 1) The viscosity of a 30% toluene solution is 27,000 mPa·s, and the alkenyl content is 0.007 moles / 100g. The molecular chain ends with SiMe2Vi-terminated vinyl-containing polydimethylsiloxane is used as silicone compound 1.

[0259] (Silicone compound 2) A 60% toluene solution of polysiloxane (Me3SiO0.5 unit / SiO2 unit = 0.8) of MQ resin composed of Me3SiO0.5 unit and SiO2 unit is used as silicone compound 2.

[0260] (Siloxane Compound 3) A solution consisting of 40 parts by mass of a vinyl-containing polydimethylsiloxane with a viscosity of 42,000 mPa·s and an alkenyl content of 0.007 moles / 100g, and with OH-terminated molecular chains in a 30% toluene solution, 100 parts by mass of a polysiloxane solution of MQ resin composed of Me3SiO0.5 units and SiO2 units (Me3SiO0.5 units / SiO2 units = 0.8), and 26.7 parts by mass of toluene was heated for 4 hours by dry distillation, and then cooled to bond the polydimethylsiloxane to the MQ resin, which is then obtained as silicaane compound 3.

[0261] (Silicone compound 4) Used as methyl hydrosilicone oil, manufactured by Shin-Etsu Chemical Industry, KF-99.

[0262] The acrylic resin used as an acrylic resin in the bioelectrode composition solution is shown below. Acrylic resin 1 Mw=129,000 Mw / Mn=2.45 [Chem. 95]

[0263] The polyurethane resin incorporated into the bio-electrode composition solution and the carbamate-based resin is shown below. Polyurethane resin 1 Mw=83,000 Mw / Mn=4.02 [Chem. 96]

[0264] The polyglycerol polysiloxane compound incorporated into the bio-electrode composition solution is as follows.

[0265] [Chemical 97]

[0266] The cross-linking agent incorporated into the bio-electrode composition solution is shown below. Epoxy cross-linking agent 1 [Chemical 98]

[0267] The organic solvents incorporated into the bio-electrode composition solution are shown below. EDE: Diethylene glycol diethyl ether; ISOPAR GTM: Isoalkane-based solvent (standard petroleum preparation); ISOPAR MTM: Isoalkane-based solvent (standard petroleum preparation).

[0268] The platinum catalyst and conductivity improver (carbon black, carbon nanotubes) incorporated into the bio-electrode composition solution as additives are shown below. Platinum catalyst: Shin-Etsu Chemical Co., Ltd. CAT-PL-50T; Carbon black: Denka Co., Ltd. DENKA BLACK Li-400; Multilayer carbon nanotubes: Sigma-Aldrich, with diameters of 110~170nm and lengths of 5~9μm.

[0269] [Examples 1-11, Comparative Example 1] Bioelectrode composition solutions (bioelectrode composition solutions 1-11, comparative bioelectrode composition solution 1) were prepared by mixing ionic resin, resin, organic solvent and additives (platinum catalyst, conductivity improver) with the compositions recorded in Tables 1 and 2.

[0270] [Table 1] Bioelectrodes Composition solution Ionic resin (parts by weight) resin (parts by weight) organic solvents (parts by weight) additive (parts by weight) Bioelectrodes Composition Solution 1 Ionic resin 1-1 (70) Acrylic resin 1(30) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8) Bioelectrodes Composition solution 2 Ionic resin 1-2 (70) Acrylic resin 1(30) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8) Bioelectrodes Composition solution 3 Ionic resin 1-3 (30) Acrylic resin 1(70) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8) Bioelectrodes Composition solution 4 Ionic resin 1-4 (30) Acrylic resin 1(70) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8) Bioelectrodes Composition solution 5 Ionic resin 1-5 (40) Acrylic resin 1(60) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8) Bioelectrodes Composition solution 6 Ionic resin 1-6 (40) Polyurethane resin 1(60) EDE(60) Cyclopentanone (47) Multilayer carbon nanotubes (3) Bioelectrodes Composition solution 7 Ionic resins 1-7 (20) Silicon oxyalkane compound 1 (40) Siloxane compound 2 (100) Siloxane compounds 4(3) ISOPAR G(60) Cyclopentanone (47) CAT-PL-50T(1.5) Carbon black (8) Polyglycerol compound 1(8) Bioelectrodes Composition solution 8 Ionic resin 1-8 (10) Silicon oxyalkane compound 1 (40) Siloxane compound 2 (100) Siloxane compounds 4(3) ISOPAR G(60) Cyclopentanone (47) CAT-PL-50T(1.5) Carbon black (8) Polyglycerol compound 1(8) Bioelectrodes Composition solution 9 Ionic resins 1-9 (20) Silicon oxyalkane compound 3(126) Siloxane compounds 4(3) ISOPAR M(60) Cyclopentanone (47) CAT-PL-50T(1.5) Carbon black (8) Polyglycerol compound 1(8) Bioelectrodes 10% of the composition solution Ionic resin 1-10 (12) Silicon oxyalkane compound 3(126) Siloxane compounds 4(3) ISOPAR M(60) Cyclopentanone (47) CAT-PL-50T(1.5) Carbon black (12) Polyglycerol compound 1(8) Bioelectrodes Composition solution 11 Ionic resin 1-11 (12) Silicon oxyalkane compound 3(126) Siloxane compounds 4(3) ISOPAR M(60) Cyclopentanone (47) CAT-PL-50T(1.5) Carbon black (12) Polyglycerol compound 1(8)

[0271] [Table 2] Bioelectrodes Composition solution Ionic resin (parts by weight) resin (parts by weight) organic solvents (parts by weight) additive (parts by weight) Comparison of biological electrodes Composition Solution 1 Comparison of ionic resins 1 (70) Acrylic resin 1(30) EDE(60) Cyclopentanone (47) Epoxy crosslinking agent 1 (0.2) Carbon black (8)

[0272] (Biosignal Evaluation) As shown in Figure 3, conductive paste and DOTITE FA-333 manufactured by Fujikura Chemicals were screen-printed onto the ST-604 thermoplastic polyurethane (TPU) film 20 of Bemis Corporation. The film was then baked in an oven at 120°C for 10 minutes to print a keyhole-shaped conductive pattern 2 with a diameter of 2 cm. The bioelectrode composition solution described in Tables 1 and 2 was screen-printed onto the circular portion and overlapped thereon. After air drying at room temperature for 10 minutes, the film was baked in an oven at 125°C for 10 minutes to evaporate the solvent and harden the material, forming a biocontact layer 3 and fabricating a bioelectrode 1. Then, as shown in Figure 4, the polyurethane resin film 20 printed with the bioelectrode 1 was cut and double-sided tape 21 was attached. Three bioelectrode samples 10 were made from each composition solution.

[0273] (Measurement of the thickness of the biological contact layer) The thickness of the biological contact layer in the biological electrode prepared by the above biological signal evaluation test was measured using a micrometer. The results are shown in Table 3.

[0274] (Measurement of Biometric Information) The conductive wiring pattern made of conductive paste on the biometric electrodes was connected to the HCG-901 portable electrocardiogram (ECG) manufactured by Omron Healthcare (Group) Co., Ltd. using conductive wires. The positive electrode of the ECG was attached to position LA of the human body in Figure 5, the negative electrode to position LL, and the ground electrode to position RA. ECG measurement was started immediately after attachment and continued until the ECG waveform consisting of P, Q, R, S, and T waves, as shown in Figure 6, appeared. The results are shown in Table 3.

[0275] [Table 3] Example Bio-electrode composition solution Resin thickness (micrometer) Until the ECG message appears Time up to now (minutes) Example 1 Biological electrode composition solution 1 54 5 Example 2 Biological electrode composition solution 2 50 4 Example 3 Biological electrode composition solution 3 55 2 Example 4 Biological electrode composition solution 4 62 3 Example 5 Biological electrode composition solution 5 51 1 Example 6 Biological electrode composition solution 6 52 2 Example 7 Biological electrode composition solution 7 53 1 Example 8 Biological electrode composition solution 8 49 1 Example 9 Bio-electrode composition solution 9 52 1 Example 10 Bio-electrode composition solution 10 53 0 Example 11 Bio-electrode composition solution 11 57 0 Comparative Example 1 Comparison of biological electrode composition solutions 1 52 Not displayed

[0276] As shown in Table 3, Examples 1 to 11, which use a bio-electrode composition of the present invention to form a bio-contact layer by incorporating a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of strontium methyl compounds, can obtain bio-signals shortly after being applied to the body. On the other hand, bio-signals cannot be obtained when the ionic components do not contain specific structures.

[0277] This specification includes the following inventions.

[0278] [1]: A bio-electrode composition containing (A) an ionic resin, characterized in that: the aforementioned (A) component comprises a resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trissulfonium methide.

[0279] [2]: The bio-electrode composition described in [1] above, wherein the resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of succinate methyl compounds has a chemical structure represented by the following general formula (1). [Chemical 99] In the formula, RA is a hydrogen atom or a methyl group. X1 is independently a single bond, a phenyl group, or a linker group containing at least one of ester bonds, ether bonds, carbamate bonds, lactone rings, and halogen atoms with 1 to 20 carbon atoms. R1 and R2 are independently hydrocarbon groups with 1 to 20 carbon atoms, which may also contain heteroatoms. M+ is any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

[0280] [3]: The bio-electrode composition described in [2] above, wherein the resin having the structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from methyl sulfonate contains ammonium ions represented by the following general formula (2) as the aforementioned M+. [Chemical 100] In the formula, R101d, R101e, R101f, and R101g are respectively hydrogen atoms, straight-chain, branched, or cyclic alkyl groups having 1 to 12 carbon atoms, straight-chain, branched, or cyclic alkenyl or alkynyl groups having 2 to 12 carbon atoms, or aromatic groups having 4 to 20 carbon atoms, and may also have one or more of the following: ether group, carbonyl group, ester group, hydroxyl group, amino group, nitro group, sulfonyl group, sulfinyl group, halogen atom, and sulfur atom. R101d and R101e, R101d, R101e and R101f can also form a ring together with the nitrogen atom they are bonded to. When forming a ring, R101d and R101e, and R101d, R101e and R101f are alkyl groups with 3 to 10 carbon atoms, or form an aromatic heterocycle with a nitrogen atom in the formula.

[0281] [4]: The bio-electrode composition described in any of the above [1]~[3] contains resin other than the aforementioned component (A) as component (B).

[0282] [5]: The bio-electrode composition described in [4] above, wherein the aforementioned component (B) is selected from one or more of polysiloxane resin, (meth)acrylate resin and polyurethane resin.

[0283] [6]: The bio-electrode composition described in [4] or [5] above, wherein the aforementioned component (B) is adhesive.

[0284] [7]: The bio-electrode composition described in any of the above [4] to [6], wherein the aforementioned component (B) comprises a polysiloxane resin having RxSiO(4-x) / 2 units (R is a substituted or unsubstituted monovalent hydrocarbon group with 1 to 10 carbon atoms, and x is in the range of 2.5 to 3.5) and SiO2 units.

[0285] [8]: The bio-electrode composition described in any of the above [1] to [7] further contains carbon powder and / or metal powder as component (C).

[0286] [9]: The bio-electrode composition described in [8] above, wherein the aforementioned carbon powder is either carbon black or carbon nanotubes.

[0287]

[10] : The bio-electrode composition described in [8] or [9] above, wherein the aforementioned metal powder is selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium and indium.

[0288]

[11] : The bio-electrode composition described in any of the above [8]~

[10] , wherein the aforementioned metal powder is silver powder.

[0289]

[12] : The bio-electrode composition described in any of the above [1] to

[11] further contains an organic solvent as component (D).

[0290]

[13] : A bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, characterized in that: the aforementioned bioelectrode contact layer is a hardened form of the bioelectrode composition described in any one of [1] to

[12] above.

[0291]

[14] : The bio-electrode described in

[13] above, wherein the aforementioned conductive substrate comprises one or more selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0292]

[15] : A method for manufacturing a bioelectrode, which is a method for manufacturing a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, characterized in that: a bioelectrode composition as described in any one of [1] to

[12] above is coated on the aforementioned conductive substrate and hardened thereon, thereby forming the aforementioned bioelectrode contact layer.

[0293]

[16] : The method for manufacturing a bio-electrode as described in

[15] above, wherein the aforementioned conductive substrate is selected from one or more of gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0294] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and those having a substantially the same structure and performing the same effects as the technical concept described in the claims of the present invention are intended to be included within the technical scope of the present invention. [Simplified Explanation of the Diagram]

[0047] [Figure 1] is a schematic cross-sectional view showing an example of the bioelectrode of the present invention. [Figure 2] is a schematic cross-sectional view showing an example of the bioelectrode of the present invention being installed on a living organism. [Figure 3] is a schematic diagram of the bioelectrode obtained according to an embodiment of the present invention after printing. [Figure 4] is a schematic diagram showing a bioelectrode obtained according to an embodiment of the present invention being cut and an adhesive layer and wires being installed. [Figure 5] is a diagram showing the attachment of the electrode to the human body and the grounding point during the measurement of biosignals in an embodiment of the present invention. [Figure 6] is a frame of electrocardiogram waveform obtained using the bioelectrode of an embodiment of the present invention.

Claims

1. A bio-electrode composition comprising a (A) ionic resin, characterized in that: the (A) component comprises a resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trissulfonium methylide; the resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trissulfonium methylide has a chemical structure represented by the following general formula (1); wherein, RA is a hydrogen atom or a methyl group; X1 is independently a single bond, a phenyl group, or a linker group containing at least one of ester bonds, ether bonds, carbamate bonds, lactone rings, and halogen atoms with 1 to 20 carbon atoms; R1 and R2 are independently hydrocarbon groups with 1 to 20 carbon atoms, which may also contain heteroatoms; M+ is any one of an ammonium ion, a lithium ion, a sodium ion, and a potassium ion.

2. The bio-electrode composition as claimed in claim 1, wherein, The resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from strontium methyl compounds contains an ammonium ion represented by the following general formula (2) as the M+; In the formula, R101d, R101e, R101f, and R101g are hydrogen atoms, straight-chain, branched, or cyclic alkyl groups with 1 to 12 carbon atoms, straight-chain, branched, or cyclic alkenyl or alkynyl groups with 2 to 12 carbon atoms, or aromatic groups with 4 to 20 carbon atoms, and may also have one or more of the following: ether, carbonyl, ester, hydroxyl, amino, nitro, sulfonyl, sulfinyl, halogen atom, and sulfur atom; R101d and R101e, R101d and R101e and R101f may also form a ring together with the nitrogen atom they are bonded to, and when forming a ring, R101d and R101e and R101d and R101e and R101f are alkyl groups with 3 to 10 carbon atoms, or form an aromatic heterocycle with nitrogen atoms in the formula.

3. The bio-electrode composition of claim 1 further contains a resin other than component (A) as component (B).

4. The bio-electrode composition as described in claim 3, wherein, The component (B) is selected from one or more of polysiloxane resin, (meth)acrylate resin, and polyurethane resin.

5. The bio-electrode composition as claimed in claim 3, wherein, Component (B) is adhesive.

6. The bio-electrode composition as claimed in claim 4, wherein, The (B) component comprises a polysiloxane resin having RxSiO(4-x) / 2 units (R being a substituted or unsubstituted monovalent hydrocarbon group with 1 to 10 carbon atoms, and x being in the range of 2.5 to 3.5) and SiO2 units.

7. The bio-electrode composition of claim 3 further contains carbon powder and / or metal powder as component (C).

8. The bioelectrode composition as claimed in claim 7, wherein, The toner is either carbon black or carbon nanotubes, or both.

9. The bioelectrode composition as claimed in claim 7, wherein, The metal powder is selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

10. The bioelectrode composition as claimed in claim 9, wherein, The metal powder is silver powder.

11. The bioelectrode composition as claimed in claim 3, wherein, The bio-electrode composition also contains organic solvents as component (D).

12. A bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, characterized in that: the bio-contact layer is a hardened form of the bioelectrode composition of any one of claims 1 to 11.

13. The bioelectrode of claim 12, wherein, The conductive substrate comprises one or more of the following: gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

14. A method for manufacturing a bioelectrode, comprising manufacturing a bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, characterized in that: a bioelectrode composition as claimed in any one of claims 1 to 11 is coated on the conductive substrate and hardened thereon, thereby forming the bio-contact layer.

15. A method for manufacturing a bioelectrode as described in claim 14, wherein, The conductive substrate uses one or more materials selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

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