Bioelectrode composition, bioelectrode and production method of bioelectrode

Abstract

To provide a bioelectrode composition having excellent electrical conductivity and biocompatibility, being lightweight, produced at a low cost, preventing a significant drop in conductivity even when being wetted with water or dried, and capable of forming a bio-contact layer for a bioelectrode that is soft and has excellent stretchability and adhesiveness, a bioelectrode with a bio-contact layer formed of the bioelectrode composition, and a production method of the bioelectrode.SOLUTION: A bioelectrode composition containing (A) an ionic resin is characterized in that a component of the ionic resin (A) contains a resin having a structure selected from an ammonium salt, a lithium salt, a sodium salt and a potassium salt of trisulfonium methide.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bioelectrode that can be brought into contact with the skin of a living body and detect bodily conditions such as heart rate based on electrical signals from the skin, a method for manufacturing the same, and a bioelectrode composition that is suitable for use in a bioelectrode. [Background technology]

[0002] In recent years, the development of wearable devices has progressed along with the spread of IoT (Internet of Things). Typical examples are watches and eyeglasses that can connect to the internet. Furthermore, wearable devices that can constantly monitor the state of the body are needed in the medical and sports fields, and these are expected to be growth areas in the future.

[0003] In the medical field, wearable devices that monitor the state of the body's organs by sensing weak currents, such as in electrocardiograms, which detect heart activity through electrical signals, are being considered. Electrocardiograms are measured by attaching electrodes coated with conductive paste to the body, but this is a one-time, short-term measurement. In contrast, the goal of developing medical wearable devices like those mentioned above is to develop devices that can continuously monitor health status for several weeks. Therefore, bioelectrodes used in medical wearable devices must maintain their conductivity even after long-term use and not cause skin allergies. In addition to these, they must also be lightweight and low-cost to manufacture.

[0004] Wearable medical devices include those that are attached to the body and those that are incorporated into clothing. One proposed type of bioelectrode that is attached to the body uses a water-soluble gel containing water and electrolytes, the same materials used in the conductive paste mentioned above (Patent Document 1). The water-soluble gel contains sodium, potassium, and calcium as electrolytes in a water-soluble polymer that retains water, and converts changes in ion concentration from the skin into electricity. Meanwhile, one proposed type that is incorporated into clothing uses a cloth fabric with conductive polymers such as PEDOT-PSS (Poly-3,4-ethylenedioxythiophene-Polystyrenesulfonate) or silver paste incorporated into the fibers as an electrode (Patent Document 2).

[0005] However, when using the water-soluble gel containing water and electrolytes, there is a problem that the conductivity is lost when the water dries out. On the other hand, when using metals with a high tendency to ionize, such as copper, there is a risk of causing skin allergies in some people, and when using conductive polymers such as PEDOT-PSS, there is also a risk of causing skin allergies due to the conductive polymer's strong acidity, and there is also the problem of the conductive polymer peeling off from the fabric during washing.

[0006] Furthermore, due to their excellent electrical conductivity, the use of metal nanowires, carbon black, carbon nanotubes, and the like as electrode materials has also been investigated (Patent Documents 3, 4, and 5). Metal nanowires have a high probability of contact between wires, so they can conduct electricity with a small amount of additive. However, metal nanowires are thin materials with sharp tips, which can cause skin allergies. As such, even if the material itself does not cause an allergic reaction, the shape and irritation of the material can sometimes make the material less biocompatible, making it difficult to achieve both electrical conductivity and biocompatibility.

[0007] Metal films are highly conductive, so one might think they would function as excellent bioelectrodes, but this is not necessarily the case. When the heart beats, not only a weak current is released from the skin, but also sodium ions, potassium ions, and calcium ions. For this reason, it is necessary to convert the change in ion concentration into an electric current, but 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 there is high resistance to the passage of electricity between them and the skin.

[0008] Meanwhile, batteries containing ionic liquids are being investigated (Patent Document 6). Ionic liquids are characterized by high thermal and chemical stability and excellent electrical conductivity, and are finding widespread application in batteries. However, because the small molecular weight ionic liquids shown in Patent Document 6 are soluble in water, when a bioelectrode containing such liquid is used, the ionic liquid is extracted by sweat from the skin, resulting in not only a decrease in electrical conductivity but also in penetration into the skin, causing rough skin.

[0009] Batteries using lithium salts of polymeric sulfonimides have also been investigated (Non-Patent Document 1). However, although lithium is used in batteries due to its high ion mobility, it is not a biocompatible material. Furthermore, lithium salts of fluorosulfonic acid pendant on silicone have also been investigated (Non-Patent Document 2).

[0010] Bioelectrode materials that combine silicone adhesives with ionic polymers have been proposed (Patent Documents 7 and 8). These materials not only have high ionic conductivity, but also high electronic conductivity when conductive powders such as carbon or silver are added, making them excellent bioelectrodes. By combining silicone adhesives, which are hypoallergenic, highly water-repellent, and effective in reducing itching and redness after removal, with ionic polymers that have high ionic conductivity and do not pass through the skin, the resulting electrodes will not peel off even during long-term application, including daily bathing and exercise, and will provide stable biosignals. However, further improvements in comfort during long-term application are needed.

[0011] However, the health effects of perfluoroalkyl substances (PFAS) have been pointed out, and there are moves to impose restrictions on the manufacture and sale of PFAS compounds under the European REACH regulation, making it urgent to develop materials that do not contain PFAS structures. [Prior art documents] [Patent documents]

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

[0013] [Non-Patent Document 1] J.Mater.Chem.A,2016,4,p10038-10069 [Non-patent document 2] J. of the Electrochemical Society, 150(8) A1090-A1094 (2003) Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been made to solve the above problems, and aims to provide a bioelectrode composition that can form a biocontact layer for a bioelectrode that is excellent in conductivity and biocompatibility, lightweight, and can be produced at low cost, and that is soft, stretchable, and adhesive; a bioelectrode in which a biocontact layer is formed from the bioelectrode composition; and a method for producing the same. [Means for solving the problem]

[0015] In order to solve the above problems, the present invention provides: (A) a bioelectrode composition containing an ionic resin, The present invention provides a bioelectrode composition in which the component (A) contains a resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide.

[0016] Such a composition will be a bioelectrode composition that has excellent electrical conductivity and biocompatibility, is lightweight, can be produced at low cost, does not significantly decrease in electrical conductivity whether wet or dry, and can form a biocontact layer for a bioelectrode that is soft, stretchable, and adhesive.

[0017] Furthermore, the resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide preferably has a chemical structure represented by the following general formula (1). [ka] (In the formula, R A is a hydrogen atom or a methyl group. 1 R are each independently a single bond, a phenylene group, or a linking group having 1 to 20 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, a urethane bond, a lactone ring, and a halogen atom. 1 and R 2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. +is one of ammonium ion, lithium ion, sodium ion, and potassium ion.)

[0018] Specific examples of the structure selected from the ammonium salt, lithium salt, sodium salt and potassium salt of trisulfonium methide include the following.

[0019] Further, a resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of the trisulfonium methide is + It is preferable that the ammonium ion contained in the cation is represented by the following general formula (2). [ka] (In the formula, R 101d , R 101e , R 101f , R 101g R is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, 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 have one or more groups selected from an ether group, a carbonyl group, an ester group, a hydroxy group, an amino group, a nitro group, a sulfonyl group, a sulfinyl group, a halogen atom, and a sulfur atom. 101d and R 101e , R 101d and R 101e and R 101f may form a ring together with the nitrogen atom to which they are attached, and when they form a ring, R 101d and R 101e and R 101d and R 101e and R 101f is an alkylene group having 3 to 10 carbon atoms, or forms a heteroaromatic ring having the nitrogen atom in the ring.

[0020] Specific examples of the ammonium ion in the ammonium salt of trisulfonium methide include the following.

[0021] Furthermore, it is preferable that the component (B) contains a resin other than the component (A).

[0022] By including the resin of component (B), the components contained in the composition can be held in place and the adhesiveness of the composition can be further improved.

[0023] Furthermore, the component (B) is preferably at least one selected from silicone resins, (meth)acrylate resins, and urethane resins.

[0024] Such resins can be suitably used as the resin of component (B).

[0025] Furthermore, it is preferable that the component (B) has adhesive properties.

[0026] The resin of component (B) is preferably a resin having adhesive properties.

[0027] Furthermore, the component (B) may include R x SiO (4-x) / 2 It is preferable to use a silicone resin containing a unit (wherein R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and x is in the range of 2.5 to 3.5) and an SiO2 unit.

[0028] Such silicone resins can also be suitably used as the resin of component (B).

[0029] Furthermore, it is preferable that the component (C) contains carbon powder and / or metal powder.

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

[0031] In this case, the carbon powder is preferably either or both of carbon black and carbon nanotubes.

[0032] Such carbon powder can be suitably used.

[0033] The metal powder is preferably a powder of a metal selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

[0034] In this case, the metal powder is preferably silver powder.

[0035] Such metal powders can be suitably used.

[0036] It is also preferable that the bioelectrode composition further contains an organic solvent as component (D).

[0037] Such a composition will have excellent coating properties.

[0038] The present invention also provides a bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, wherein the biocontact layer is a cured product of the above-mentioned bioelectrode composition.

[0039] Such a bioelectrode set will have excellent conductivity and biocompatibility, be lightweight, and can be manufactured at low cost. Its conductivity will not decrease significantly whether it is wet or dry, and it will have a soft, stretchable, and adhesive biocontact layer.

[0040] Furthermore, it is preferable that the conductive substrate contains 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.

[0041] Such a material can be suitably used as the conductive substrate.

[0042] The present invention also provides a method for manufacturing a bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, in which the above-mentioned bioelectrode composition is applied to the conductive substrate and cured to form the biocontact layer.

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

[0044] Furthermore, it is preferable to use, as the conductive substrate, one containing at least one selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0045] Such a material can be suitably used as the conductive substrate. [Effects of the Invention]

[0046] As described above, the bioelectrode composition of the present invention has excellent conductivity and biocompatibility, is lightweight, can be produced at low cost, does not significantly decrease in conductivity whether wetted or dried, and can form a biocontact layer for a bioelectrode that is soft, stretchable, and adhesive; and can provide a bioelectrode having a biocontact layer formed from the bioelectrode composition, and a method for producing the same. [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a schematic cross-sectional view showing an example of a bioelectrode of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an example of a bioelectrode of the present invention attached to a living body. [Figure 3] FIG. 1 is a schematic diagram of a bioelectrode produced in an example of the present invention after printing. [Figure 4] FIG. 1 is a schematic diagram of one of the bioelectrodes prepared in the examples of the present invention, cut out and with an adhesive layer and an electric wire attached. [Figure 5]1 is a diagram showing the locations where electrodes and earths are attached to the human body when measuring biosignals in an embodiment of the present invention. FIG. [Figure 6] 1 is a diagram showing an electrocardiogram waveform obtained using a bioelectrode according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] As described above, there has been a need to develop a bioelectrode composition that can form a biocontact layer for a bioelectrode that is excellent in conductivity and biocompatibility, lightweight, can be manufactured at low cost, is soft, stretchable, and adhesive, can be attached to the skin for a long period of time to stably collect biosignals whether wetted by bathing or dried, and leaves no residue on the skin after being peeled off; a bioelectrode in which a biocontact layer is formed from such a bioelectrode composition; and a method for manufacturing the same.

[0049] Sodium, potassium, and calcium ions are released from the skin surface in tandem with the heartbeat. Bioelectrodes must convert the increase or decrease in the ions released from the skin into an electrical signal. To do this, materials with excellent ionic conductivity are required to transmit the increase or decrease in ions.

[0050] In order to stably obtain biosignals when attached to the skin, the bioelectrode film must be soft, stretchable, and adhesive. The keratin of the epidermis is regenerated daily, and old keratin (dirt) accumulates between the attached bioelectrode film and the skin. Because old keratin peels easily from the epidermis, biosignals cannot be collected if the bioelectrode peels off. For this reason, the bioelectrode must maintain its adhesiveness even when attached for a long period of time. However, if residue remains on the skin after being attached for a long period of time and then removed, it may cause rashes or rough skin.

[0051] Biosignals include ECG, which detects cardiac activity, RPM, which detects pulmonary respiration, EEG, which detects brain waves, EGG, which detects visceral activity, and EMG, which detects muscle activity, and the dry electrodes of the present invention are used as sensors to detect these signals, as well as electrodes to apply electrical signals to the body.

[0052] When the acid that forms the neutralized salt is highly acidic, the ions are strongly polarized, improving ionic conductivity. This is why lithium salts of bis(trifluoromethanesulfonyl)imide acid and tris(trifluoromethanesulfonyl)methide acid exhibit high ionic conductivity in lithium-ion batteries. On the other hand, the higher the acid strength of the acid before it becomes a neutralized salt, the more bioirritating the salt becomes. In other words, there is a trade-off between ionic conductivity and bioirritability. However, salts used in bioelectrodes must have both high ionic conductivity and low bioirritability.

[0053] In trisulfonium methides, the carbon atom has a negative charge due to the sulfonyl group attracting electrons from three directions, making it acidic even without a fluorine atom at the end of the sulfonyl group. If the carbon atom at the end of the sulfonyl group has a fluorine atom, the acidity is too high and the neutralized salt is highly irritating to the skin, but trisulfonium methides without fluorine atoms can achieve both moderately high ionic conductivity and low bioirritation. Because they do not contain fluorine atoms, they do not fall under the definition of PFAS and have a low environmental impact.

[0054] Trisulfonium methides have high steric hindrance around the negatively charged carbon atom, which increases the distance between them and the positively charged ammonium, lithium, sodium, and potassium ions. This facilitates hopping of ammonium ions, lithium, sodium, and potassium ions, resulting in high ionic conductivity.

[0055] The larger the molecular weight of an ionic compound, the less it penetrates into the skin and the less irritating it is to the skin. For this reason, a high molecular weight polymer type of ionic compound is preferred. Therefore, the problem of skin irritation has been avoided by polymerizing this ionic compound into a form having a polymerizable double bond, or by bonding it to silicone, polyurethane, polyether, polyester, etc.

[0056] Furthermore, by mixing this salt with, for example, a silicone-based, acrylic-based, or urethane-based adhesive (resin), the adhesive will always adhere to the skin, and a stable electrical signal can be obtained for a long period of time.

[0057] That is, the present invention is a bioelectrode composition containing (A) an ionic resin, wherein the component (A) contains a resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide.

[0058] The present invention will be described in detail below, 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 the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide. Each component will be described in more detail below.

[0060] [(A) Ionic resin having ammonium salt, lithium salt, sodium salt, or potassium salt of trisulfonium methide] The bioelectrode composition of the present invention is characterized by containing (A) an ionic resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide.

[0061] The ionic resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide preferably has a partial structure represented by the following general formula (1'). [ka] (In the formula, R 1 and R 2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. +is one of ammonium ion, lithium ion, sodium ion, and potassium ion.)

[0062] The partial structure of the ammonium salt, lithium salt, sodium salt, or potassium salt of the trisulfonium methide represented by general formula (1') is bonded to a resin selected from, for example, a resin obtained by polymerizing a monomer having a double bond, a silicone resin, and a polyurethane resin.

[0063] (Repeating unit a) The partial structure of the ammonium salt, lithium salt, sodium salt, or potassium salt of the trisulfonium methide represented by the general formula (1') above is preferably bonded to a resin obtained by polymerizing the monomer as a repeating unit a represented by the following general formula (1). [ka] (In the formula, R A is a hydrogen atom or a methyl group. 1 R are each independently a single bond, a phenylene group, or a linking group having 1 to 20 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, a urethane bond, a lactone ring, and a halogen atom. 1 and R 2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. + is one of ammonium ion, lithium ion, sodium ion, and potassium ion.)

[0064] The monomer for obtaining the repeating unit a represented by the above general formula (1) is represented by the following general formula (1)-1. [ka] (In the general formula, R A , R 1 , R 2 , X1, M + is as mentioned above.)

[0065] Specific examples of the monomer (anion portion) represented by the above general formula (1)-1 include the following.

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka] (In the formula, R A is as mentioned above.)

[0080] The method for synthesizing the above monomer can be the method described in JP-A-2020-055797.

[0081] In addition, component (A) is M in repeating unit a. + It is preferable that the ammonium ion (ammonium cation) is contained in the following general formula (2). [ka] (In the formula, R 101d , R 101e , R 101f , R 101g R is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, 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 have one or more groups selected from an ether group, a carbonyl group, an ester group, a hydroxy group, an amino group, a nitro group, a sulfonyl group, a sulfinyl group, a halogen atom, and a sulfur atom. 101d and R 101e , R 101d and R 101e and R 101fmay form a ring together with the nitrogen atom to which they are attached, and when they form a ring, R 101d and R 101e and R 101d and R 101e and R 101f is an alkylene group having 3 to 10 carbon atoms, or forms a heteroaromatic ring having the nitrogen atom in the ring.

[0082] Specific examples of the ammonium ion represented by the general formula (2) are as follows:

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] As the ammonium ion represented by the above general formula (2), a tertiary or quaternary ammonium ion is particularly preferred.

[0100] (Repeating unit b) In addition to the repeating unit a obtained by polymerizing the monomer having a polymerizable double bond, component (A) of the bioelectrode composition of the present invention can also be copolymerized with a repeating unit b having a glyme chain to improve conductivity. Specific examples of monomers for obtaining the repeating unit b having a glyme chain are listed below. Copolymerization of a repeating unit having a glyme chain can promote the movement of ions released from the skin within the dry electrode film, thereby increasing the sensitivity of the dry electrode.

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka] (R is a hydrogen atom or a methyl group.)

[0105] (Repeating unit c) In addition to the repeating units a and b described above, component (A) of the bioelectrode composition of the present invention can also contain a hydrophilic repeating unit c copolymerized with a hydroxyl group, a carboxyl group, an ammonium salt, a betaine, an amide group, a pyrrolidone, a lactone ring, a lactam ring, a sultone ring, a sodium salt of sulfonic acid, or a potassium salt of sulfonic acid to improve conductivity. Specific examples of monomers from which hydrophilic repeating unit c can be obtained are listed below. Copolymerizing repeating units containing these hydrophilic groups can increase sensitivity to ions released from the skin and improve the sensitivity of the dry electrode.

[0106] [ka]

[0107] [ka]

[0108] [ka] (R is a methyl group or a hydrogen atom.)

[0109] (Repeating unit d) The ionic resin (A) in the bioelectrode composition of the present invention can have a repeating unit d that imparts adhesive properties.

[0110] Specific examples of the monomer from which the repeating unit d is obtained include the following.

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] (Repeating unit e) Furthermore, a crosslinkable repeating unit e can also be copolymerized. Examples of the crosslinkable repeating unit include a repeating unit having an oxirane ring or an oxetane ring.

[0117] Specific examples of the monomers from which the repeating unit e having an oxirane ring or oxetane ring is derived include the following.

[0118] [ka]

[0119] [ka] (R is a methyl group or a hydrogen atom.)

[0120] (Repeating unit f) The component (A) of the bioelectrode composition of the present invention can have a silicon-containing repeating unit f in addition to the repeating units selected from the above a, b, c, d, and e. Specific examples include the following:

[0121] [ka]

[0122] [ka]

[0123] The repeating units having the above alkoxysilyl groups may be copolymerized, and the alkoxysilyl groups may be hydrolyzed to form a silsesquioxane structure as shown in JP 2022-164579 A, ​​or may be reacted with silanols on the silica surface to form a composite with silica as shown in JP 2022-64291 A.

[0124] (Repeating unit g) The component (A) of the bioelectrode composition of the present invention can have a repeating unit g containing fluorine in addition to the repeating units selected from the above a and b to f.

[0125] Specific examples of the monomer for obtaining the fluorine-containing repeating unit g include the following.

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka] (R is a hydrogen atom or a methyl group.)

[0133] (Repeating unit h) The component (A) of the bioelectrode composition of the present invention can have a repeating unit h having a cyano group in addition to the repeating units selected from the above a and b to g.

[0134] Specific examples of the monomer from which the repeating unit h having a cyano group is obtained include the following.

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] [ka] (R is a hydrogen atom or a methyl group.)

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

[0140] Specific examples of the monomer from which the repeating unit i having a nitro group is obtained include the following.

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] One method for synthesizing the ionic resin of component (A) is to heat-polymerize a desired monomer from among the monomers that give the repeating units a, b, c, d, e, f, g, h, and i in an organic solvent with the addition of a radical polymerization initiator to obtain a copolymer polymer compound.

[0148] Examples of organic solvents used during polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, and dioxane. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The heating temperature is preferably 50 to 80°C, and the reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

[0149] Here, the ratios of the repeating units a, b, c, d, e, f, g, h, and i in the ionic resin of component (A) are such that 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. More preferably, 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] Note that, for example, a + b + c + d + e + f + g + h + i = 1 indicates that in a polymer compound containing the repeating units a, b, c, d, e, f, g, h, and i, the total amount of the repeating units a, b, c, d, e, f, g, h, and i is 100 mol% with respect to the total amount of all repeating units. And a + b + c + d + e + f + g + h + i < 1 indicates that the total amount of the repeating units a, b, c, d, e, f, g, h, and i is less than 100 mol% with respect to the total amount of all repeating units and that there are other repeating units besides a, b, c, d, e, f, g, h, and i.

[0151] The molecular weight of the ionic resin of component (A) is preferably 500 or more as the weight average molecular weight, more preferably 1,000 or more and 1,000,000 or less, and even more preferably 2,000 or more and 500,000 or less. Also, if there is a small amount of ionic monomer (residual monomer) not incorporated into the polymer compound of component (A) after polymerization, there will be no risk of this penetrating the skin and causing an allergy in the biocompatibility test. Therefore, it is preferable to reduce the amount of the residual monomer. The amount of the residual monomer is preferably 10 parts by mass or less with respect to 100 parts by mass of the entire polymer compound before the condensation reaction of component (A). Also, component (A) may be used alone as one kind, or two or more kinds with different molecular weights, dispersities, and polymerization monomers may be used in combination.

[0152] In the present invention, the molecular weight (Mw) and dispersity (Mw / Mn) of the polymer can be determined by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. GPC measurement is usually performed at room temperature around 23°C, but may be performed at a higher or lower temperature.

[0153] In the bioelectrode composition of the present invention, the amount of component (A) is not particularly limited, but can be, for example, 1 to 50 parts by mass per 100 parts by mass of the composition. Alternatively, the amount of component (A) is preferably 0.1 to 300 parts by mass, more preferably 1 to 200 parts by mass, per 100 parts by mass of component (B). Furthermore, component (A) may be used alone or in combination of two or more types.

[0154] [(B) Resin] The (B) resin (a resin other than the (A) component) blended into the bioelectrode composition of the present invention is a component that is compatible with the (A) ionic resin (salt) to prevent the elution of the salt, retains conductivity enhancers such as metal powder, carbon powder, silicon powder, and lithium titanate powder, and further improves adhesiveness. If the (A) ionic resin has sufficient adhesiveness, the (B) resin is not necessarily required. The (B) resin may be any resin other than the (A) component, and is preferably either a thermosetting resin or a photocurable resin, or both, and is particularly preferably one or more selected from silicone resins, (meth)acrylate resins, and urethane resins.

[0155] The adhesive silicone resin may be an addition reaction curing type or a radical crosslinking reaction curing type. Examples of the addition reaction curing type include diorganosiloxane having an alkenyl group, RSiO, as described in JP 2015-193803 A. 0.5and SiO2 units, organohydrogenpolysiloxane having a plurality of SiH groups, platinum catalyst, addition reaction inhibitor, and organic solvent. Examples of radical crosslinking reaction curing types include diorganopolysiloxanes that may or may not have alkenyl groups, R3SiO 0.5 and those containing an MQ resin having SiO2 units, an organic peroxide, and an organic solvent can be used, where R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0156] It is also possible to use a polysiloxane-resin integrated compound formed by the condensation reaction of MQ resin with polysiloxane that has silanols at the polymer end or side chain. MQ resin contains a large amount of silanols, so adding this improves adhesive strength, but because it is not crosslinkable, it is not molecularly bonded to the polysiloxane. By integrating polysiloxane and resin as described above, adhesive strength can be increased.

[0157] In addition, modified siloxanes having a group selected from amino groups, oxirane groups, oxetane groups, polyether groups, hydroxy groups, carboxyl groups, mercapto groups, methacryl groups, acrylic groups, phenol groups, silanol groups, carboxylic anhydride groups, aryl groups, aralkyl groups, amide groups, ester groups, and lactone rings can also be added to the silicone resin. The addition of modified siloxanes improves the dispersibility of component (A) in the silicone resin. The modified siloxanes may be modified at one end, both ends, or the side chains of the siloxane.

[0158] Furthermore, the component (B) may include R x SiO (4-x) / 2 It is preferable to use a silicone resin containing a unit (wherein R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and x is in the range of 2.5 to 3.5) and an SiO2 unit.

[0159] The adhesive (meth)acrylate resin may be, for example, one having a hydrophilic (meth)acrylic acid ester or a long-chain hydrophobic (meth)acrylic acid ester as a repeating unit, as described in JP 2016-011338 A. In some cases, a (meth)acrylic acid ester having a functional group or a (meth)acrylic acid ester having a siloxane bond may be copolymerized.

[0160] As the adhesive urethane resin, for example, one having a urethane bond and a polyether or polyester bond, a polycarbonate bond, or a siloxane bond, as described in JP 2016-065238 A, can be used.

[0161] Furthermore, in order to prevent a decrease in conductivity due to shedding of component (A) from the biocontact layer, the (B) resin in the bioelectrode composition of the present invention is preferably highly compatible with the aforementioned component (A). Furthermore, in order to prevent peeling of the biocontact layer from the conductive substrate, the (B) resin in the bioelectrode composition of the present invention is preferably highly adhesive to the conductive substrate. To ensure high compatibility of the (B) resin with the conductive substrate and salt, it is effective to use a highly polar resin. Examples of such resins include resins having one or more selected from ether bonds, ester bonds, amide bonds, imide bonds, urethane bonds, thiourethane bonds, and thiol groups, as well as polyacrylic resins, polyamide resins, polyimide resins, polyurethane resins, and polythiourethane resins. On the other hand, since the biocontact layer comes into contact with the living body, it is susceptible to the effects of sweat from the living body. Therefore, in the bioelectrode composition of the present invention, the (B) resin is preferably highly water-repellent and resistant to hydrolysis. To ensure high water-repellency and resistance to hydrolysis, it is effective to use a resin containing silicon.

[0162] Silicon-containing polyacrylic resins include polymers with silicone in the main chain and polymers with silicon atoms in the side chain, both of which can be used suitably. Examples of polymers with silicone in the main chain include siloxanes or silsesquioxanes with (meth)acrylpropyl groups. In this case, the (meth)acryl moiety can be polymerized and cured by adding a photoradical generator.

[0163] Suitable examples of silicon-containing polyamide resins include the polyamide silicone resins described in JP 2011-079946 A and U.S. Patent No. 5,981,680. Such polyamide silicone resins can be synthesized by combining, for example, a silicone compound having amino groups at both ends or a non-silicone compound having amino groups at both ends with a non-silicone compound having carboxyl groups at both ends or a silicone compound having carboxyl groups at both ends.

[0164] Alternatively, polyamic acid obtained by reacting a carboxylic acid anhydride with an amine before cyclization may be used. To crosslink the carboxyl groups of the polyamic acid, an epoxy or oxetane crosslinking agent may be used, or the carboxyl groups may be esterified with hydroxyethyl (meth)acrylate to effect photoradical crosslinking of the (meth)acrylate moiety.

[0165] Suitable examples of silicon-containing polyimide resins include the polyimide silicone resins described in JP-A-2002-332305. Polyimide resins have very high viscosity, but can be made low-viscosity by blending a (meth)acrylic monomer as a solvent and crosslinking agent.

[0166] Examples of polyurethane resins containing silicon atoms include polyurethane silicone resins. In such polyurethane silicone resins, crosslinking via urethane bonds can be achieved by blending and heating a compound having isocyanate groups at both ends with a compound having hydroxyl groups at the ends. In this case, it is necessary for either the compound having isocyanate groups at both ends or the compound having hydroxyl groups at the ends, or both, to contain silicon atoms (siloxane bonds). Alternatively, as described in JP 2005-320418 A, photocrosslinking can be achieved by blending a urethane (meth)acrylate monomer with a polysiloxane. Furthermore, photocrosslinking can also be achieved by photocrosslinking a polymer having both siloxane and urethane bonds and (meth)acrylate groups at the ends. In particular, materials with a polyurethane main chain and silicone chains attached to side chains, as described in JP 2018-123304 A and JP 2019-70109 A, are preferred due to their high strength and high elasticity.

[0167] Silicon-containing polythiourethane resins can be obtained by reacting a compound having a thiol group with a compound having an isocyanate group, as long as either of them contains a silicon atom. Furthermore, if the compound has a (meth)acrylate group at its terminal, it can also be photocured.

[0168] In silicone resins, diorganosiloxanes having the above-mentioned alkenyl groups, R3SiO 0.5 In addition to MQ resins containing SiO2 units and organohydrogenpolysiloxanes containing multiple SiH groups, the addition of modified siloxanes containing groups selected from amino groups, oxirane groups, oxetane groups, polyether groups, hydroxyl groups, carboxyl groups, mercapto groups, methacryl groups, acrylic groups, phenol groups, silanol groups, carboxylic anhydride groups, aryl groups, aralkyl groups, amide groups, ester groups, and lactone rings increases compatibility with the above-mentioned salts.

[0169] Diorganosiloxanes having alkenyl groups and organohydrogenpolysiloxanes having multiple SiH groups can be crosslinked by an addition reaction using a platinum catalyst.

[0170] Examples of platinum catalysts include platinum catalysts such as chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reaction product of chloroplatinic acid and an alcohol, a reaction product of chloroplatinic acid and an olefin compound, a reaction product of chloroplatinic acid and a vinyl group-containing siloxane, a platinum-olefin complex, a platinum-vinyl group-containing siloxane complex, and platinum group metal catalysts such as a rhodium complex and a ruthenium complex. Furthermore, these catalysts may be dissolved or dispersed in an alcohol-based, hydrocarbon-based, or siloxane-based solvent and used.

[0171] The amount of platinum catalyst added is preferably in the range of 5 to 2,000 ppm, particularly 10 to 500 ppm, per 100 parts by mass of the resin (component (A) and component (B) combined).

[0172] In the bioelectrode composition of the present invention, the blending amount of component (B) is preferably 0 to 2000 parts by mass, more preferably 10 to 1000 parts by mass, per 100 parts by mass of ionic resin (A). Furthermore, component (B) may be used singly or in combination of two or more types.

[0173] When an addition-curing silicone resin is used, an addition reaction inhibitor may be added as a quencher to prevent the platinum catalyst from acting in the solution and in a low-temperature environment after coating formation and before heat curing. 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-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and 1,1,3,3-tetramethyl-1,3-divinyldisiloxane.

[0174] The amount of addition reaction inhibitor added is preferably in the range of 0 to 10 parts by mass, and particularly 0.05 to 3 parts by mass, per 100 parts by mass of the resin (component (A) and component (B) combined).

[0175] When component (B) has a radical-crosslinkable double bond, it is effective to add a radical generator, which can be a photoradical generator or a thermal radical generator.

[0176] Photoradical generators include acetophenone, 4,4'-dimethoxybenzyl, benzil, 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-benzodioxol-5-yl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-benzyl-2-(dimethylamino)-4' -morpholinobutyrophenone, 4,4'-dichlorobenzophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4-diethylthioxanthen-9-one, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), 1,4-dibenzoylbenzene, 2-ethylanthraquinone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-isonitrosopropiophenone, 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone, and 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone can be mentioned.

[0177] Curing can also be achieved by adding a thermally decomposing radical generator. Examples of thermal radical generators include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(methylpropionamidine) hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane]hydrochloride, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(cyclohexane-1-carbonitrile), 1[(1-cyano-1-methylethyl)azo]formamide, 2,2'-azobis[2-methyl-N -(2-hydroxyethyl)propionamide], 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), dimethyl-2,2'-azobis(isobutyrate), 4,4'-azobis(4-cyanopentanoic acid), dimethyl-2,2'-azobis(2-methylpropionate), benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, di-tert-amyl peroxide, di-n-butyl peroxide, dicumyl peroxide, and the like.

[0178] The amount of radical generator added is preferably in the range of 0.1 to 50 parts by mass per 100 parts by mass of the resin, which is the combined total of components (A) and (B).

[0179] As described below, the biocontact layer is a cured product of the bioelectrode composition. By curing, the biocontact layer exhibits good adhesion to both the skin and the conductive substrate. The curing method is not particularly limited, and a common method can be used, such as heat and / or light, or a crosslinking reaction using an acid or base catalyst. The crosslinking reaction can be carried out by appropriately selecting a method from the Crosslinking Reaction Handbook by Nakayama Yasuharu, Chapter 2, pp. 51-371, Maruzen Publishing (2013).

[0180] [Ionic polymer] An ionic polymer other than component (A) can be added to the bioelectrode composition of the present invention. The ionic polymers disclosed in JP-A-2018-126496 and JP-A-2018-130533 are preferably used. The amount of the ionic polymer added is preferably in the range of 0.1 to 100 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0181] [(C) Carbon powder and / or metal powder] Carbon powder and / or metal powder can be added to the bioelectrode composition of the present invention in order to increase electronic conductivity.

[0182] [Metal powder] To enhance electronic conductivity, the bioelectrode composition of the present invention may contain a metal powder selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium. The amount of metal powder added is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0183] As the type of metal powder, gold, silver, and platinum are preferred from the viewpoint of conductivity, and silver, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, and chromium are preferred from the viewpoint of cost. From the viewpoint of biocompatibility, noble metals are preferred, and from these viewpoints overall, silver is most preferred.

[0184] The shape of the metal powder can be spherical, discoid, flake, or needle-like, but the addition of flake-shaped powder is preferred because it has the highest conductivity. The metal powder size is 100 μm or less, and the tap density is 5 g / cm. 3 The specific surface area is 0.5m 2 Flakes with a relatively low density and a large specific surface area of ​​1 / g or more are preferred.

[0185] [Carbon powder] Carbon powder can be added as a conductivity improver. Examples of carbon powder include carbon black, graphite, carbon nanotubes, carbon fibers, and graphene. The carbon nanotubes may be single-walled or multi-walled, and their surfaces may be modified with organic groups. The carbon powder is particularly preferably either carbon black or carbon nanotubes, or both. The amount of carbon powder added is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0186] [Silicon powder] Silicon powder can be added to the bioelectrode composition of the present invention to enhance ion reception sensitivity. Examples of silicon powder include powders made of silicon, silicon monoxide, and silicon carbide. The particle size of the powder is preferably smaller than 100 μm, more preferably 1 μm or less. Finer particles have a larger surface area and can therefore receive more ions, resulting in a highly sensitive bioelectrode. The amount of silicon powder added is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the resin, which is the combined mass of components (A) and (B).

[0187] [Lithium titanate powder] Lithium titanate powder can be added to the bioelectrode composition of the present invention to enhance the sensitivity of ion reception. Examples of lithium titanate powder include Li2TiO3, LiTiO2, and spinel-structured Li4Ti5O. 12 The molecular formula is as follows, and spinel structure products are preferred. Lithium titanate particles composited with carbon can also be used. The particle diameter of the powder is preferably smaller than 100 μm, more preferably 1 μm or less. Finer particles have a larger surface area and can therefore receive more ions, resulting in a highly sensitive bioelectrode. These may also be composite powders with carbon. The amount of lithium titanate powder added is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0188] [Crosslinking agent] An epoxy-based crosslinking agent can also be added to the bioelectrode composition of the present invention. In this case, the crosslinking agent is a compound having multiple epoxy groups or oxetane groups in one molecule. The amount added is 1 to 30 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0189] [Crosslinking catalyst] A catalyst for crosslinking epoxy groups or oxetane groups can also be added to the bioelectrode composition of the present invention. In this case, the catalysts described in paragraphs 0027 to 0029 of JP-A-2019-503406 can be used. The amount of catalyst added is 0.01 to 10 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0190] [Ionic additives] The bioelectrode composition of the present invention can contain an ionic additive to increase ionic conductivity. Considering biocompatibility, examples of the additive include sodium chloride, potassium chloride, calcium chloride, magnesium chloride, saccharin sodium salt, acesulfame potassium, sodium carboxylate, potassium carboxylate, calcium carboxylate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, betaine, and the salts disclosed in Japanese Patent Application Laid-Open Nos. 2018-44147, 2018-59050, 2018-59052, and 2018-130534.

[0191] [(D) Organic solvent] In addition, an organic solvent can be added to the bioelectrode composition of the present invention. Specific examples of the organic solvent include toluene, xylene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, styrene, α-methylstyrene, butylbenzene, sec-butylbenzene, isobutylbenzene, cymene, diethylbenzene, 2-ethyl-p-xylene, 2-propyltoluene, 3-propyltoluene, 4-propyltoluene, 1,2,3,5-tetramethyltoluene, 1,2,4,5-tetramethyltoluene, tetrahydronaphthalene, and 4-phenyl-1-butene. tert-Amylbenzene, Amylbenzene, 2-tert-butyltoluene, 3-tert-butyltoluene, 4-tert-butyltoluene, 5-isopropyl-m-xylene, 3-methylethylbenzene, tert-butyl-3-ethylbenzene, 4-tert-butyl-o-xylene, 5-tert-butyl-m-xylene, tert-butyl-p-xylene, 1,2-diisopropylbenzene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, dipropylbenzene, pentamethylbenzene, hexamethylbenzene Aromatic hydrocarbon solvents such as diethylbenzene, hexylbenzene, and 1,3,5-triethylbenzene, n-heptane, isoheptane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, 1,6-heptadiene, 5-methyl-1-hexyne, norbornane, norbornene, dicyclopentadiene, 1-methyl-1,4-cyclohexadiene, 1-heptyne, 2-heptyne, cycloheptane, cycloheptene, 1,3-dimethylcyclopentane, ethylcyclopentane, methylcyclohexane, and 1-methyl-1-cyclohexene. hexane, 3-methyl-1-cyclohexene, 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, 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-methylcyclohexene cyclohexane, 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, tert-butylcyclohexane, butylcyclohexane, isobutylcyclohexane, 4-isopropyl-1-methylcyclohexane, pentylcyclopentane, 1,1,3,5-tetramethylcyclohexane, cyclododecane, 1-decene, 2-decene, 3-decene, 4-decene, 5-decene, 1,9-decadiene, decahydronaphthalene, 1-decyne, 2-decyne, 3-decyne, 4-decyne, 5-decyne, 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, dicyclopentadiene, 1,4-decadiyne, 1,5-decadiyne, 1,9-decadiyne, 2,8-decadiyne, 4,6-decadiyne, n-undecane, amylcyclohexane, 1-undecene, 1,10-undecadiene, 1-undecyne, 3-undecyne, 5-undecyne, tricyclo[6.2.1.0, 2,7]Undec-4-ene, n-dodecane, n-tridecane, n-pentadecane, n-hexadecane, 2-methylundecane, 3-methylundecane, 4-methylundecane, 5-methylundecane, 2,2,4,6,6-pentamethylheptane, 1,3-dimethyladamantane, 1-ethyladamantane, 1,5,9-cyclododecatriene, 1,2,Aliphatic hydrocarbon solvents such as 4-trivinylcyclohexane and isoparaffin; ketone solvents such as cyclohexanone, cyclopentanone, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, and methyl n-pentyl ketone; alcohol solvents such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; 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 monopentyl ether, and diethylene glycol monoheptyl ether. Examples of suitable solvents include ether solvents such as diethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, diisopropyl ether, diisobutyl ether, diisopentyl ether, di-n-pentyl ether, methylcyclopentyl ether, methylcyclohexyl ether, di-n-butyl ether, di-sec-butyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-amyl ether, di-n-hexyl ether, and anisole; ester solvents such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; lactone solvents such as γ-butyrolactone; and water.

[0192] The amount of organic solvent added is preferably in the range of 10 to 50,000 parts by mass per 100 parts by mass of the resin (component (A) and component (B) combined).

[0193] [Other additives] The bioelectrode composition of the present invention can also be mixed with silica particles, polyether silicone, or polyglycerin silicone. Silica particles have a hydrophilic surface and are compatible with hydrophilic ionic polymers, polyether silicone, and polyglycerin silicone, improving the dispersibility of ionic polymers, polyether silicone, and polyglycerin silicone in hydrophobic silicone adhesives. Silica particles can be used preferably in either dry or wet applications.

[0194] [Silicone compounds with polyglycerin structure] In the bioelectrode composition of the present invention, a silicone compound having a polyglycerin structure can be added to improve the moisture retention of the membrane and thereby improve the sensitivity and ionic conductivity of ions released from the skin. The amount of the silicone compound having a polyglycerin structure is preferably 0.01 to 100 parts by mass, more preferably 0.5 to 60 parts by mass, per 100 parts by mass of the total of components (A) and (B). Furthermore, the silicone compound having a polyglycerin structure may be used alone or in combination of two or more types.

[0195] The silicone compound having a polyglycerin structure is preferably one represented by the following general formulas (4)' and (5)'.

[0196] [ka] (In formulas (4)' and (5)', R 1 are each independent and may be the same or different, and each represent a hydrogen atom, a linear or branched alkyl group having 1 to 50 carbon atoms, or a phenyl group, and may contain an ether group or may be a silicone chain represented by general formula (6)'; R 2 R' is a group having a polyglycerin group structure represented by formula (4)'-1 or formula (4)'-2, 3' are each independent and may be the same or different, and 1 ' group or the R 2 ' is a group, and R 4 ' are each independent and may be the same or different, and 1 ' group, the R 2 R is a ' group or an oxygen atom. 4 If ' is an oxygen atom, two R 4 The a' groups may be bonded to form a single ether group and may form a ring together with the silicon atom. a' may be the same or different and is 0 to 100, b' is 0 to 100, and a'+b' is 0 to 200. However, when b' is 0, R 3 At least one of the R 2 In formulae (4)'-1, (4)'-2, (5)', and (6)', R 5 ' is an alkylene group having 2 to 10 carbon atoms or an aralkylene group having 7 to 10 carbon atoms, R 6 'R 7 ' is an alkylene group having 2 to 6 carbon atoms, and R 7 c' may be an ether bond, c' is 0 to 20, and d' is 1 to 20.

[0197] Examples of such silicone compounds having a polyglycerin structure include the following:

[0198] [ka]

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] [ka] (wherein a', b', c' and d' are as defined above)

[0208] If the composition contains a silicone compound having such a polyglycerin structure, it can exhibit better moisturizing properties, and as a result, it can be used as a bioelectrode composition that can form a biocontact layer that exhibits better sensitivity to ions released from the skin.

[0209] As described above, the bioelectrode composition of the present invention is a bioelectrode composition that can be used to form a biocontact layer for a bioelectrode that is highly adhesive, maintains sufficient adhesiveness even when peeled off and reattached to the skin, can efficiently transmit electrical signals from the skin to the device (i.e., has excellent conductivity), is not likely to cause allergies even when worn on the skin for long periods of time (i.e., has excellent biocompatibility), is lightweight, can be produced at low cost, and does not significantly decrease in conductivity even when wet or dry. Furthermore, the addition of a carbon material can further improve conductivity, and by combining it with a resin that has adhesiveness and stretchability, it is possible to produce a bioelectrode with particularly high adhesive strength and stretchability. Furthermore, additives can be used to improve stretchability and adhesion to the skin, and stretchability and adhesion can be adjusted by appropriately adjusting the resin composition and the thickness of the biocontact layer.

[0210] <Bioelectrode> The present invention also provides a bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, wherein the biocontact layer is a cured product of the bioelectrode composition of the present invention described above.

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

[0212] FIG. 1 is a schematic cross-sectional view showing an example of a bioelectrode of the present invention. The bioelectrode 1 in FIG. 1 has a conductive substrate 2 and a biocontact layer 3 formed on the conductive substrate 2. The biocontact layer 3 is made of a cured product of the bioelectrode composition of the present invention. The biocontact layer 3 contains an ionic resin (A) 5. The biocontact layer 3 may further contain a resin (B) 6 other than the ionic resin (A), and conductive powder 4. Below, with reference to FIGS. 1 and 2, we will explain a case where the biocontact 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 embodiment.

[0213] When using such a bioelectrode 1 as shown in Fig. 1, the biocontact layer 3 (i.e., a layer in which ionic resin (A) 5 and conductive powder 4 are dispersed in resin (B) 6) is brought into contact with a living body 7, and an electrical signal is extracted from the living body 7 by the ionic resin (A) 5 and the conductive powder 4, and this is conducted to a sensor device or the like (not shown) via the conductive substrate 2. In this way, the bioelectrode of the present invention can achieve both conductivity and biocompatibility by using the above-mentioned ionic resin (A), and since it also has adhesiveness, the contact area with the skin is constant, and electrical signals from the skin can be obtained stably and with high sensitivity.

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

[0215] [Conductive base material] The bioelectrode of the present invention has a conductive substrate. This conductive substrate is usually electrically connected to a sensor device or the like, and conducts an electrical signal extracted from a living body via a biocontact layer to the sensor device or the like.

[0216] The conductive substrate is not particularly limited as long as it is conductive, but it is preferable that the conductive substrate contains at least one material selected from the group consisting of gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0217] The conductive substrate is not particularly limited and may be a hard conductive substrate, a flexible conductive film, a fabric coated with a conductive paste, or a fabric with a conductive polymer kneaded in. The conductive substrate may be flat or uneven, or may be a mesh of woven metal wires, and may be selected appropriately depending on the application of the bioelectrode.

[0218] [Body contact layer] The bioelectrode of the present invention has a biocontact layer formed on a conductive substrate. This biocontact layer is the part that actually comes into contact with the living body when the bioelectrode is used, and is conductive and adhesive. The biocontact layer is a cured product of the bioelectrode composition of the present invention described above, i.e., an adhesive resin layer made of a cured product of a composition containing the above-mentioned component (A) and, if necessary, components (B), (C), (D), and other components.

[0219] The adhesive strength of the biological contact layer is preferably in the range of 0.01 N / 25 mm to 20 N / 25 mm. The adhesive strength is generally measured using the method specified in JIS Z 0237. While a metal substrate such as SUS (stainless steel) or a PET (polyethylene terephthalate) substrate can be used as the substrate, human skin can also be used for measurement. The surface energy of human skin is lower than that of metals and various plastics, and is close to that of Teflon (registered trademark), making it less adhesive.

[0220] For applications where adhesion and peeling are repeated many times, peelability is more important than adhesion, so adhesion is not necessarily required.

[0221] The thickness of the biocontact layer of the bioelectrode is preferably 1 μm to 5 mm, more preferably 2 μm to 3 mm. The thinner the biocontact layer, the weaker the adhesive strength, but the more flexible it is, the lighter it is, and the better it fits to the skin. The thickness of the biocontact layer can be selected based on the balance between adhesiveness and texture on the skin.

[0222] Furthermore, in the bioelectrode of the present invention, similar to conventional bioelectrodes (e.g., the bioelectrode described in JP 2004-033468 A), a separate adhesive film may be provided on the biocontact layer to prevent the bioelectrode from peeling off from the living body during use. When a separate adhesive film is provided, it may be formed using an adhesive film material such as an acrylic, urethane, or silicone type. Silicone types are particularly preferred because they have high oxygen permeability, allowing the skin to breathe while attached, are highly water-repellent, and are less likely to lose adhesiveness due to sweat, and are also less irritating to the skin. Note that the bioelectrode of the present invention does not necessarily require the separate adhesive film, because peeling off from the living body can be prevented by adding a tackifier to the bioelectrode composition or using a resin with good adhesiveness to the living body, as described above.

[0223] When using the bioelectrode of the present invention as a wearable device, the wiring between the bioelectrode and the sensor device and other components are not particularly limited, and for example, those described in JP 2004-033468 A can be applied.

[0224] As described above, the bioelectrode of the present invention, in which the biocontact layer is formed from the cured product of the bioelectrode composition of the present invention, can efficiently transmit electrical signals from the skin to the device (i.e., has excellent conductivity), is not likely to cause allergies even when worn on the skin for long periods of time (i.e., has excellent biocompatibility), is lightweight, can be manufactured at low cost, and does not significantly decrease in conductivity even when wet or dry. Furthermore, the addition of conductive powder can further improve conductivity, and by combining it with a resin that has adhesiveness and stretchability, a bioelectrode with particularly high adhesive strength and stretchability can be manufactured. Furthermore, additives can be used to improve stretchability and adhesion to the skin, and stretchability and adhesion can be adjusted by appropriately adjusting the resin composition and the thickness of the biocontact layer. Therefore, such a bioelectrode of the present invention is particularly suitable as a bioelectrode for use in medical wearable devices.

[0225] <Method of manufacturing bioelectrodes> The present invention also provides a method for manufacturing a bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, in which the bioelectrode composition of the present invention described above is applied to the conductive substrate and cured to form the biocontact layer.

[0226] The conductive substrate and the like used in the method for producing a bioelectrode of the present invention may be the same as those described above.

[0227] The method for applying the bioelectrode composition to the conductive substrate is not particularly limited, but suitable methods include, for example, dip coating, spray coating, spin coating, bar coating, comma coating, die coating, roll coating, flow coating, doctor coating, calendar coating, screen printing, flexographic printing, gravure printing, and inkjet printing.

[0228] The resin curing method is not particularly limited and may be appropriately selected depending on the components (A) and (B) used in the bioelectrode composition, but for example, it is preferable to cure it by either heat or light, or both. Alternatively, a catalyst that generates an acid or a base may be added to the bioelectrode composition to cause a crosslinking reaction and cure it.

[0229] The temperature for heating is not particularly limited and may be appropriately selected depending on the components (A) and (B) used in the bioelectrode composition, but is preferably about 50 to 250°C, for example.

[0230] When heating and light irradiation are combined, heating and light irradiation may be performed simultaneously, or heating may be performed after light irradiation, or light irradiation may be performed after heating. Furthermore, air drying may be performed after the coating film is heated to evaporate the solvent.

[0231] After the film has hardened, adding water droplets or spraying water vapor or mist on the surface improves its compatibility with the skin, allowing for quicker biosignals to be obtained. Water mixed with alcohol can also be used to reduce the size of the vapor or mist droplets. The film surface can also be moistened by contacting it with absorbent cotton or cloth soaked in water.

[0232] The water that wets the surface of the cured film may contain a salt, and the water-soluble salt that is mixed with water is selected from sodium salts, potassium salts, calcium salts, magnesium salts, and betaine.

[0233] Specifically, the water-soluble salt may be a salt selected from sodium chloride, potassium chloride, calcium chloride, magnesium chloride, saccharin sodium salt, acesulfame potassium, sodium carboxylate, potassium carboxylate, calcium carboxylate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, and betaine. Note that the above-mentioned (A) ionic resin is not included in the water-soluble salt.

[0234] More specifically, in addition to the above, sodium acetate, sodium propionate, sodium pivalate, sodium glycolate, sodium butyrate, sodium valerate, sodium caproate, sodium enanthate, sodium caprylate, sodium pelargonate, sodium caprate, sodium undecylate, sodium laurate, sodium tridecylate, sodium myristate, sodium pentadecylate, sodium palmitate, sodium margarate, sodium stearate, sodium benzoate, disodium adipate, disodium maleate, disodium phthalate, sodium butyrate, sodium 2-hydroxybutyrate, sodium 3-hydroxybutyrate, sodium 2-oxobutyrate, sodium stearate, glutamic acid ... Examples include sodium conate, sodium methanesulfonate, sodium 1-nonanesulfonate, sodium 1-decanesulfonate, sodium 1-dodecanesulfonate, sodium 1-undecanesulfonate, sodium cocoyl sethionate, sodium lauroylmethylalanine, sodium cocoyl methyl taurate, sodium cocoyl glutamate, sodium cocoyl sarcosinate, sodium lauroyl methyl taurate, laumidpropyl, potassium isobutyrate, potassium propionate, potassium pivalate, potassium glycolate, potassium gluconate, potassium methanesulfonate, calcium stearate, calcium glycolate, calcium gluconate, calcium 3-methyl-2-oxobutyrate, and calcium methanesulfonate. Betaine is a general term for an intramolecular salt, specifically a compound in which three methyl groups are attached to the amino group of an amino acid. More specifically, trimethylglycine, carnitine, trimethylglycine, and proline betaine are examples.

[0235] The water-soluble salt may further contain a monohydric alcohol or polyhydric alcohol having 1 to 4 carbon atoms. The alcohol is preferably selected from ethanol, isopropyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, glycerin, polyethylene glycol, polypropylene glycol, polyglycerin, diglycerin, or a silicone compound having a polyglycerin structure. It is more preferable that the silicone compound having a polyglycerin structure is one represented by the above general formulas (4)' to (6)'.

[0236] Pretreatment with a water-soluble salt-containing aqueous solution can be performed by spraying or dispensing the solution onto the cured bioelectrode membrane. It can also be applied under high temperature and humidity conditions, such as in a sauna. To prevent drying after application, a protective film can be further laminated on top of the permeation layer. Since the protective film must be removed immediately before application to the skin, it can be coated with a release agent or made of a peelable Teflon® film. For long-term storage, dry electrodes covered with a release film are preferably sealed in a bag covered with aluminum or other material. To prevent drying inside the aluminum-covered bag, it is preferable to seal moisture within the bag.

[0237] Before attaching the bioelectrode of the present invention to the skin, the skin side can be moistened with water, alcohol, etc., or the skin can be wiped with a cloth or absorbent cotton containing water, alcohol, etc. The water or alcohol can also contain the above-mentioned salt.

[0238] As described above, the manufacturing method of the bioelectrode of the present invention makes it possible to easily manufacture, at low cost, the bioelectrode of the present invention, which has excellent conductivity and biocompatibility, is lightweight, and whose conductivity does not decrease significantly whether it is wet or dried. [Example]

[0239] EXAMPLES The present invention will be specifically explained below using examples and comparative examples, but the present invention is not limited to these.

[0240] (Synthesis of Monomers 1 to 11) Monomer 1 was obtained by the reaction of bis(cyclohexanesulfonyl)methane with 4-methacryloyloxybenzenesulfonyl chloride in the presence of sodium hydride in THF solvent, followed by a neutralization reaction with trimethylbenzylammonium. Monomers 2 to 11 were synthesized by changing the raw materials from bis(cyclohexanesulfonyl)methane and 4-methacryloyloxybenzenesulfonyl chloride to other materials and carrying out an ion exchange reaction between trimethylbenzylammonium and other cations.

[0241] Monomers 1 to 11 are shown below.

[0242] [ka]

[0243] [ka]

[0244] (Synthesis of Ionic Resins 1-1 to 1-11 and Comparative Ionic Resin 1) Ionic resins 1-1 to 1-11, which were blended as ionic materials (conductive materials) in the bioelectrode composition solution, and comparative ionic resin 1 were synthesized as follows. A 30% by mass cyclopentanone solution of each monomer was placed in a reaction vessel and mixed, and the reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown were repeated three times. After the temperature was raised to room temperature, 0.02 moles of azobisisobutyronitrile (AIBN) per mole of the total monomers was added as a polymerization initiator, and the temperature was raised to 60°C, followed by reaction for 15 hours. The composition of the obtained polymer was determined after drying the solvent. 1 The polymers were analyzed by H-NMR. The molecular weight (Mw) and dispersity (Mw / Mn) of the polymers were analyzed by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. The ionic resins 1-1 to 1-11 synthesized in this manner and comparative ionic resin 1 are shown below.

[0245] Ionic Resin 1-1 Mw=83,000 Mw / Mn=2.94 [ka]

[0246] Ionic Resin 1-2 Mw=77,100 Mw / Mn=2.93 [ka]

[0247] Ionic Resin 1-3 Mw=69,100 Mw / Mn=2.64 [ka]

[0248] Ionic Resin 1-4 Mw=52,200 Mw / Mn=2.73 [ka]

[0249] Ionic Resin 1-5 Mw=31,900 Mw / Mn=2.77 [ka]

[0250] Ionic Resin 1-6 Mw=40,300 Mw / Mn=2.83 [ka]

[0251] Ionic Resin 1-7 Mw=38,100 Mw / Mn=2.77 [ka] (The number of repetitions in the formula indicates the average value.)

[0252] Ionic Resin 1-8 Mw=42,700 Mw / Mn=1.95 [ka] (The number of repetitions in the formula indicates the average value.)

[0253] Ionic Resin 1-9 Mw=31,500 Mw / Mn=2.33 [ka] (The number of repetitions in the formula indicates the average value.)

[0254] Ionic Resin 1-10 Mw=29,800 Mw / Mn=1.95 [ka] (The number of repetitions in the formula indicates the average value.)

[0255] Ionic Resin 1-11 Mw=33,500 Mw / Mn=1.91 [ka] (The number of repetitions in the formula indicates the average value.)

[0256] Comparative ionic resin 1 Mw=26,500 Mw / Mn=1.85 [ka]

[0257] Siloxane compounds 1 to 4 that were blended as silicone resins in the bioelectrode composition solution are shown below.

[0258] (Siloxane Compound 1) Siloxane compound 1 was a vinyl-containing polydimethylsiloxane with a viscosity of 27,000 mPa·s in a 30% toluene solution, an alkenyl group content of 0.007 mol / 100 g, and molecular chain ends blocked with SiMe2Vi groups.

[0259] (Siloxane Compound 2) Me3SiO 0.5 MQ resin polysiloxane (Me3SiO 0.5 A 60% toluene solution of siloxane compound 2 (SiO2 unit / SiO2 unit = 0.8) was used as siloxane compound 2.

[0260] (Siloxane Compound 3) 40 parts by mass of vinyl-containing polydimethylsiloxane whose molecular chain ends are capped with OH, having a viscosity of 42,000 mPa·s in a 30% toluene solution and an alkenyl group content of 0.007 mol / 100 g, Me3SiO 0.5 MQ resin polysiloxane (Me3SiO 0.5 A solution consisting of 100 parts by mass of a 60% toluene solution of SiO2 (SiO2 units / SiO2 units = 0.8) and 26.7 parts by mass of toluene was heated for 4 hours while dry distilling, and then cooled to obtain Siloxane Compound 3, in which polydimethylsiloxane was bonded to the MQ resin.

[0261] (Siloxane Compound 4) As the methyl hydrogen silicone oil, KF-99 manufactured by Shin-Etsu Chemical Co., Ltd. was used.

[0262] The acrylic resins blended as the acrylic resin in the bioelectrode composition solution are shown below. Acrylic resin 1 Mw=129,000 Mw / Mn=2.45 [ka]

[0263] The urethane resins blended as urethane-based resins in the bioelectrode composition solution are shown below. Urethane resin 1 Mw=83,000 Mw / Mn=4.02 [ka]

[0264] The polyglycerin silicone compound blended in the bioelectrode composition solution is shown below.

[0265] [ka]

[0266] The crosslinking agents incorporated into the bioelectrode composition solution are shown below. Epoxy Crosslinker 1 [ka]

[0267] The organic solvents added to the bioelectrode composition solution are shown below. EDE: Diethylene glycol diethyl ether Isopar G TM : Isoparaffin solvent, Standard Oil Isopar M TM : Isoparaffin solvent, Standard Oil

[0268] The platinum catalyst and conductivity improver (carbon black, carbon nanotube) added as additives to the bioelectrode composition solution are shown below. Platinum catalyst: Shin-Etsu Chemical Co., Ltd. CAT-PL-50T Carbon black: Denka Black Li-400 manufactured by Denka Multi-walled carbon nanotubes: Sigma-Aldrich, diameter 110-170 nm, length 5-9 μm

[0269] [Examples 1 to 11, Comparative Example 1] Ionic resin, resin, organic solvent, and additives (platinum catalyst, conductivity enhancer) were blended in the compositions shown in Tables 1 and 2 to prepare bioelectrode composition solutions (bioelectrode composition solutions 1 to 11, comparative bioelectrode composition solution 1).

[0270] [Table 1]

[0271] [Table 2]

[0272] (Biological signal evaluation) As shown in Figure 3, a conductive paste (Dotite FA-333, manufactured by Fujikura Kasei) was screen-printed onto a thermoplastic urethane (TPU) film 20 (Bemis) ST-604, and 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. A bioelectrode composition solution listed in Tables 1 and 2 was then screen-printed onto the circular portion on top of the TPU film. The solution was air-dried at room temperature for 10 minutes, and then baked in an oven at 125°C for 10 minutes to evaporate the solvent and harden the film, forming a biocontact layer 3, which became the bioelectrode 1. Next, as shown in Figure 4, the urethane film 20 with the printed bioelectrode 1 was cut out and double-sided tape 21 was attached to it, producing three bioelectrode samples 10 for each composition solution.

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

[0274] (Biological signal measurement) The conductive wiring pattern made of conductive paste on the bioelectrode was connected with a conductive wire to a portable electrocardiograph HCG-901 manufactured by Omron Healthcare Co., Ltd. The positive electrode of the electrocardiograph was attached to the LA position on the human body in Figure 5, the negative electrode to the LL position, and the ground to the RA position. Immediately after attachment, electrocardiogram measurement was started, and the time until the electrocardiogram waveform consisting of P, Q, R, S, and T waves shown in Figure 6 appeared was measured. The results are shown in Table 3.

[0275] [Table 3]

[0276] As shown in Table 3, in Examples 1 to 11 in which the biocontact layer was formed using the bioelectrode composition of the present invention containing a resin having a structure selected from the group consisting of ammonium salt, lithium salt, sodium salt, and potassium salt of trisulfonium methide, biosignals could be obtained in a short time after application to the body. On the other hand, when the ionic component with the specific structure was not contained, biosignals could not be obtained.

[0277] This specification includes the following inventions.

[0278] [1]: A bioelectrode composition containing (A) an ionic resin, characterized in that the component (A) contains a resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide.

[0279] [2]: The bioelectrode composition according to [1] above, characterized in that the resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of the trisulfonium methide has a chemical structure represented by the following general formula (1): [ka] (In the formula, R A is a hydrogen atom or a methyl group. 1R are each independently a single bond, a phenylene group, or a linking group having 1 to 20 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, a urethane bond, a lactone ring, and a halogen atom. 1 and R 2 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. + is one of ammonium ion, lithium ion, sodium ion, and potassium ion.)

[0280] [3]: The resin having a structure selected from the group consisting of ammonium salt, lithium salt, sodium salt, and potassium salt of the trisulfonium methide is + The bioelectrode composition according to the above [2], characterized in that it contains an ammonium ion represented by the following general formula (2) as the cation: [ka] (In the formula, R 101d , R 101e , R 101f , R 101g R is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, 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 have one or more groups selected from an ether group, a carbonyl group, an ester group, a hydroxy group, an amino group, a nitro group, a sulfonyl group, a sulfinyl group, a halogen atom, and a sulfur atom. 101d and R 101e , R 101d and R 101e and R 101f may form a ring together with the nitrogen atom to which they are attached, and when they form a ring, R 101d and R 101e and R 101d and R 101e and R 101f is an alkylene group having 3 to 10 carbon atoms, or forms a heteroaromatic ring having the nitrogen atom in the ring.

[0281] [4]: The bioelectrode composition according to any one of the above [1] to [3], further comprising, as component (B), a resin other than component (A).

[0282] [5]: The bioelectrode composition according to the above [4], wherein the component (B) is at least one selected from the group consisting of silicone resins, (meth)acrylate resins, and urethane resins.

[0283] [6]: The bioelectrode composition according to the above [4] or [5], wherein the component (B) has adhesive properties.

[0284] [7]: The component (B) is R x SiO (4-x) / 2 The bioelectrode composition according to any one of the above [4] to [6], characterized in that it contains a silicone resin having a unit (R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and x is in the range of 2.5 to 3.5) and an SiO2 unit.

[0285] [8]: The bioelectrode composition according to any one of the above [1] to [7], further comprising carbon powder and / or metal powder as component (C).

[0286] [9]: The bioelectrode composition according to the above [8], characterized in that the carbon powder is either or both of carbon black and carbon nanotubes.

[0287]

[10] : The bioelectrode composition according to [8] or [9] above, characterized in that the metal powder is a metal powder selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

[0288]

[11] : The bioelectrode composition according to any one of the above [8] to

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

[0289]

[12] : The bioelectrode composition according to any one of the above [1] to

[11] , characterized in that the bioelectrode composition further contains an organic solvent as component (D).

[0290]

[13] : A bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, characterized in that the biocontact layer is a cured product of the bioelectrode composition according to any one of [1] to

[12] above.

[0291]

[14] : The bioelectrode according to

[13] above, characterized in that the conductive substrate contains 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 having a conductive substrate and a biocontact layer formed on the conductive substrate, characterized in that the bioelectrode composition according to any one of [1] to

[12] above is applied to the conductive substrate and cured to form the biocontact layer.

[0293]

[16] : The method for manufacturing a bioelectrode according to

[15] above, characterized in that the conductive substrate contains 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.

[0294] The present invention is not limited to the above-described embodiments, which are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that provides similar effects is included within the technical scope of the present invention. [Explanation of symbols]

[0295] 1...bioelectrode, 2...conductive substrate (conductive pattern), 3...biocontact layer, 4...Conductive powder, 5...Ionic resin (A), 6...Resin (B), 7...Biomaterial, 10...bioelectrode sample, 20...thermoplastic urethane film, 21...Double-sided tape.

Claims

1. (A) A bioelectrode composition containing an ionic resin, A bioelectrode composition, characterized in that the component (A) contains a resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methide.

2. The bioelectrode composition according to claim 1, characterized in that the resin having a structure selected from the group consisting of ammonium salts, lithium salts, sodium salts, and potassium salts of the trisulfonium methide has a chemical structure represented by the following general formula (1): 【Chemistry 1】 (In the formula, R Ａ is a hydrogen atom or a methyl group. １ R are each independently a single bond, a phenylene group, or a linking group having 1 to 20 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, a urethane bond, a lactone ring, and a halogen atom. １ and R ２ are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. ＋ is one of ammonium ion, lithium ion, sodium ion, and potassium ion.

3. The resin having a structure selected from the group consisting of ammonium salt, lithium salt, sodium salt, and potassium salt of the trisulfonium methide is ＋ 3. The bioelectrode composition according to claim 2, wherein the ammonium ion is represented by the following general formula (2): 【Chemistry 2】 (In the formula, R １０１ｄ , R １０１ｅ , R １０１ｆ , R １０１ｇ R each represents a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, 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 have one or more groups selected from an ether group, a carbonyl group, an ester group, a hydroxy group, an amino group, a nitro group, a sulfonyl group, a sulfinyl group, a halogen atom, and a sulfur atom. １０１ｄ and R １０１ｅ , R １０１ｄ and R １０１ｅ and R １０１ｆ may form a ring together with the nitrogen atom to which they are attached, and when they form a ring, R １０１ｄ and R １０１ｅ and R １０１ｄ and R １０１ｅ and R １０１ｆ is an alkylene group having 3 to 10 carbon atoms, or forms a heteroaromatic ring having the nitrogen atom in the ring.

4. 2. The bioelectrode composition according to claim 1, further comprising a resin other than the component (A) as component (B).

5. 5. The bioelectrode composition according to claim 4, wherein the component (B) is at least one selected from the group consisting of silicone resins, (meth)acrylate resins, and urethane resins.

6. 5. The bioelectrode composition according to claim 4, wherein the component (B) has adhesive properties.

7. As the component (B), R ｘ SiO （４－ｘ）／２ units (R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and x is in the range of 2.5 to 3.5) and SiO ２ 6. The bioelectrode composition according to claim 5, which contains a silicone resin having a unit.

8. 5. The bioelectrode composition according to claim 4, further comprising carbon powder and / or metal powder as component (C).

9. 9. The bioelectrode composition according to claim 8, wherein the carbon powder is either or both of carbon black and carbon nanotubes.

10. 9. The bioelectrode composition according to claim 8, wherein the metal powder is selected from the group consisting of gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

11. 11. The bioelectrode composition according to claim 10, wherein the metal powder is silver powder.

12. 5. The bioelectrode composition according to claim 4, further comprising an organic solvent as component (D).

13. A bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, wherein the biocontact layer is a cured product of the bioelectrode composition according to any one of claims 1 to 12.

14. The bioelectrode according to claim 13, characterized in that the conductive substrate contains 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.

15. A method for manufacturing a bioelectrode having a conductive substrate and a biocontact layer formed on the conductive substrate, characterized in that the bioelectrode composition according to any one of claims 1 to 12 is applied to the conductive substrate and cured to form the biocontact layer.

16. 16. The method for manufacturing a bioelectrode according to claim 15, wherein the conductive substrate contains 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.

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