Biological electrode composition, biological electrode, and method for manufacturing biological electrode

Abstract

The invention relates to a biological electrode composition, a biological electrode, and a method for manufacturing the biological electrode. The present invention addresses the problem of providing a resin composition which has excellent electrical conductivity and biocompatibility, is lightweight, can be manufactured at low cost, does not significantly decrease in electrical conductivity regardless of being wetted or dried by water, and can be manufactured at low cost. The purpose of the present invention is to provide a biological electrode composition for a biological contact layer for a biological electrode, the biological electrode having a biological contact layer formed from the biological electrode composition, and a method for manufacturing the biological electrode composition. [Solution] This bioelectrode composition contains (A) an ionic resin, and is characterized in that the component (A) contains a resin having a structure selected from the group consisting of an ammonium salt, a lithium salt, a sodium salt, and a potassium salt of a trisulfonium methide.

Description

Technical Field

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

[0002] In recent years, with the popularization of IoT (Internet of Things), the development of wearable devices has also progressed. Clocks and glasses that can connect to the Internet are representative examples. Furthermore, the medical and sports fields also require wearable devices that can constantly monitor the body's condition, representing areas poised for future growth.

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

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

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

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

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

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

[0009] Furthermore, batteries using lithium salts of polymeric sulfonylimide have been explored (Non-Patent Literature 1). However, while lithium is used in batteries due to its high ion mobility, it is not a biocompatible material. In addition, lithium salts suspended in polysiloxane fluorosulfonic acid have also been explored (Non-Patent Literature 2).

[0010] Some researchers have proposed bioelectrode materials that incorporate ionic polymers into polysiloxane adhesives (Patent Documents 7 and 8). These bioelectrode materials not only exhibit high ionic conductivity, but those with added conductive powders such as carbon and silver also demonstrate high electronic conductivity, thus functioning as excellent bioelectrodes. By combining highly ionicly conductive and non-skin-penetrating ionic polymers into polysiloxane adhesives that offer low skin allergy, high water repellency, and suppression of itching or redness after peeling, a stable bioelectrode material can be achieved that does not peel off even with prolonged application, including daily bathing and exercise, while still providing a stable biosignal. However, further improvements are needed to enhance the comfort of long-term application.

[0011] There have been criticisms regarding the health effects of perfluoroalkyl compounds (PFAS), and the European REACH has imposed restrictions on the manufacture and sale of PFAS compounds. The development of materials without PFAS structures has become an urgent priority.

[0012] Existing technical documents

[0013] Patent documents

[0014] [Patent Document 1] International Publication No. WO2013-039151 (Supplementary Booklet)

[0015] [Patent Document 2] Japanese Patent Application Publication No. 2015-100673

[0016] [Patent Document 3] Japanese Patent Application Publication No. 5-095924

[0017] [Patent Document 4] Japanese Patent Application Publication No. 2003-225217

[0018] [Patent Document 5] Japanese Patent Application Publication No. 2015-019806

[0019] [Patent Document 6] Japanese Patent Publication No. 2004-527902

[0020] [Patent Document 7] Japanese Patent Application Publication No. 2018-126496

[0021] [Patent Document 8] Japanese Patent Application Publication No. 2018-130533

[0022] Non-patent literature

[0023] [Non-patent literature 1] J. Mater. Chem. A, 2016, 4, pp. 10038-10069

[0024] [Non-Patent Literature 2] J. of the Electrochemical Society, 150(8)A1090-A1094(2003) Summary of the Invention

[0025] [The problem that the invention aims to solve]

[0026] The present invention is made to solve the above-mentioned problems, and aims to provide a bioelectric electrode composition for forming a bioelectric contact layer for a bioelectric electrode that can form excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, and has excellent flexibility and adhesion; a bioelectric electrode that forms a bioelectric contact layer with the bioelectric electrode composition; and a method thereof.

[0027] [Methods for solving the problem]

[0028] To address the aforementioned issues, the present invention provides a bioelectrode composition containing (A) an ionic resin, wherein the aforementioned (A) component comprises a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of trissulfonium methylates.

[0029] If so, it is a bioelectric electrode composition that can form a bioelectric contact layer for bioelectric electrodes with excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, does not significantly reduce conductivity when wetted or dried, and is soft, flexible and has excellent adhesion.

[0030] Furthermore, the aforementioned resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates should preferably have a chemical structure represented by the following general formula (1).

[0031] [Chemistry 1]

[0032]

[0033] In the formula, R A It can be a hydrogen atom or a methyl group. X 1 Each is independently a single bond, a phenylene group, or a linking group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms. R 1 and R 2 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. M + It can be any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

[0034] The structures of ammonium, lithium, sodium, and potassium salts selected from trisulfite methylates are listed below.

[0035] Furthermore, the aforementioned resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates preferably contains an ammonium ion represented by the following general formula (2) as the aforementioned M + .

[0036] [Chemistry 2]

[0037]

[0038] In the formula, R 101d R 101e R 101f R 101gIt may contain a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also contain one or more of the following: ether group, carbonyl group, ester group, hydroxyl group, amino group, nitro group, sulfonyl group, sulfinyl group, halogen atom, and sulfur atom. 101d With R 101e R 101d With R 101e With R 101f They can also form rings together with the nitrogen atoms they are bonded to, and when forming rings, R 101d With R 101e and R 101d With R 101e With R 101f It is an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle forming a ring containing a nitrogen atom as shown in the formula.

[0039] The ammonium ions in the ammonium salts of trisulfonium methylates can be specifically listed as follows.

[0040] It is advisable to use a resin other than the aforementioned component (A) as component (B).

[0041] By using a resin containing component (B), the components contained in the composition can be retained while the adhesiveness of the composition is further improved.

[0042] Furthermore, the aforementioned component (B) should preferably be selected from one or more of polysiloxane resin, (meth)acrylate resin, and polyurethane resin.

[0043] (B) The resin of this composition is ideally suited for use.

[0044] Furthermore, the aforementioned component (B) should preferably be adhesive.

[0045] (B) It is ideal for the resin to be an adhesive resin.

[0046] Furthermore, the aforementioned component (B) should preferably contain R. x SiO (4-x) / 2 Polysiloxane resins with units (R being a monovalent hydrocarbon group with or without substituted carbons of 1 to 10, and x being in the range of 2.5 to 3.5) and SiO2 units.

[0047] (B) The resin of this type can also be ideally used.

[0048] It is advisable to include carbon powder and / or metal powder as component (C).

[0049] By using such a (C) component, the conductivity of the composition can be improved.

[0050] At this point, the aforementioned toner should preferably be either carbon black or carbon nanotubes, or both.

[0051] Toner is ideally suited for this purpose.

[0052] Furthermore, the aforementioned metal powder should preferably be selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium.

[0053] At this point, the aforementioned metal powder should preferably be silver powder.

[0054] Metal powders are ideal for use in this way.

[0055] Furthermore, the aforementioned bio-electrode composition should preferably contain organic solvents as component (D).

[0056] If so, it is a composition with excellent coatability.

[0057] Furthermore, the present invention provides a bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, wherein the aforementioned bio-contact layer is a hardened form of the aforementioned bioelectrode composition.

[0058] If so, it is a bioelectrode with excellent conductivity and biocompatibility, lightweight and low cost, whose conductivity does not decrease significantly when wetted or dried, and has a soft, flexible and adhesive bio-contact layer.

[0059] Furthermore, the aforementioned conductive substrate preferably includes 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.

[0060] Conductive substrates are ideal for use with such materials.

[0061] Furthermore, the present invention provides a method for manufacturing a bioelectrode, which is a method for manufacturing a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, wherein the bioelectrode composition is coated on the aforementioned conductive substrate and hardened thereon, thereby forming the aforementioned bioelectrode contact layer.

[0062] The bioelectrode of the present invention can be manufactured in this manner.

[0063] Furthermore, the aforementioned conductive substrate should preferably be one or more selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0064] Conductive substrates are ideal for use with such materials.

[0065] [The effects of the invention]

[0066] As described above, the bioelectrode composition of the present invention can provide a bioelectrode composition for forming a bioelectrode contact layer with excellent conductivity and biocompatibility, being lightweight and low-cost to manufacture, having conductivity that does not decrease significantly when wetted or dried, and being soft, flexible and adhesive; a bioelectrode with the bioelectrode composition forming the bioelectrode contact layer; and a method for manufacturing the same. Attached Figure Description

[0067] [ Figure 1 [Illustration 1] is a schematic cross-sectional view showing an example of the bioelectrode of the present invention.

[0068] [ Figure 2 [ ] is a schematic cross-sectional view showing an example of the bioelectrode of the present invention being installed in a living organism.

[0069] [ Figure 3 [Image] is a schematic diagram of the printed bio-electrode obtained according to an embodiment of the present invention.

[0070] [ Figure 4 [This is a schematic diagram of a bioelectrode prepared according to an embodiment of the present invention, with an adhesive layer and wires installed.]

[0071] [ Figure 5 [Image] is a diagram showing the electrodes attached to the human body and the grounding point during the measurement of biological signals in an embodiment of the present invention.

[0072] [ Figure 6 [Image] is a single frame of electrocardiogram waveform obtained using the bioelectric electrode of an embodiment of the present invention. Detailed Implementation

[0073] As described above, there is a requirement to develop a bioelectrode composition for a bioelectrode that can form a bioelectrode contact layer with excellent conductivity and biocompatibility, is lightweight, can be manufactured at low cost, is soft, elastic and adhesive, can be attached to the skin for a long time and can stably collect biological signals even when wetted or dried due to bathing, etc., and will not leave residue on the skin after being peeled off. The same applies to a bioelectrode composition for forming a bioelectrode contact layer and a method thereof.

[0074] As the heart beats, sodium, potassium, and calcium ions are released from the skin's surface. Bioelectrodes need to convert the increase or decrease in ion release from the skin into electrical signals. Therefore, materials with excellent ion conductivity are required to transmit these signals.

[0075] For a bioelectrode membrane to adhere to the skin and stably acquire biological signals, flexibility, elasticity, and adhesion are essential. The stratum corneum of the epidermis regenerates daily, and old keratinocytes (debris) accumulate between the bioelectrode membrane and the skin. These old keratinocytes easily peel off the epidermis, preventing the collection of biological signals due to electrode detachment. Therefore, the bioelectrode must maintain its adhesion even after prolonged application. On the other hand, leaving residue on the skin after prolonged application and removal can lead to rashes and rough skin.

[0076] Regarding biological signals, there are ECG for sensing heart movement, RPM for sensing lung respiration, EEG for detecting brain waves, EGG for detecting visceral movement, and EMG for detecting muscle movement, etc. The dry electrode of the present invention can be used as a sensor for detecting these signals. Furthermore, it can also be used as an electrode for providing electrical signals to the body.

[0077] If the acid that forms a neutral salt is highly acidic, the ions will be strongly polarized, improving ionic conductivity. This is why lithium salts of bis(trifluoromethanesulfonyl)imide acid and tri(trifluoromethanesulfonyl)methyl acid exhibit high ionic conductivity in lithium-ion batteries. On the other hand, there is a problem that the higher the acid strength in its acidic state before becoming a neutral salt, the stronger the biological irritation of the salt. In other words, ionic conductivity and biological irritation are a trade-off. However, salts suitable for biological electrodes must balance high ionic conductivity with low biological irritation.

[0078] In trisulfonyl methyl compounds, the carbon atom that is electron-withdrawn from the sulfonyl group in the 3rd direction carries a negative charge, and it remains acidic even if there is no fluorine atom at the front of the sulfonyl group. When the carbon atom at the front of the sulfonyl group has a fluorine atom, the acidity becomes too high, and its neutralized salt is highly irritating to the skin. However, trisulfonyl methyl compounds without a fluorine atom can moderately balance high ionic conductivity and low biological irritation. Because they do not have a fluorine atom, they do not fall under the definition of PFAS and have a low environmental impact.

[0079] In trisulfite methyl compounds, the negatively charged carbon atoms have a high steric hindrance, increasing the distance between them and the positively charged ammonium, lithium, sodium, and potassium atoms. This facilitates jumping motion of ammonium, lithium, sodium, and potassium atoms, thereby exhibiting high ionic conductivity.

[0080] The larger the molecular weight of an ionic compound, the lower its skin penetration and the lower its skin irritation. Considering this, ionic compounds should ideally be high-molecular-weight polymers. Therefore, the ionic compound is made into a form with polymerizable double bonds and polymerized to form a polymer, or bonded with polysiloxane, polyurethane, polyether, polyester, etc., thereby avoiding the problem of skin irritation.

[0081] Furthermore, by using a mixture of this salt with adhesives (resins) such as polysiloxane, acrylic, or urethane, it can maintain close contact with the skin and provide a stable electrical signal over a long period of time.

[0082] That is, the present invention is a bio-electrode composition containing (A) an ionic resin, wherein the aforementioned (A) component comprises a resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates.

[0083] The present invention will now be described in detail, but it is not limited thereto.

[0084] <Bioelectrode Components>

[0085] The bioelectrode composition of the present invention contains (A) a resin having a structure selected from ammonium salts, lithium salts, sodium salts, and potassium salts of trisulfonium methylates. The components will be described in more detail below.

[0086] [(A) Ionic resins containing ammonium, lithium, sodium, and potassium salts of trisulfonium methyl groups]

[0087] The bioelectrode composition of the present invention is characterized by containing (A) an ionic resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates.

[0088] Ionic resins having structures selected from ammonium, lithium, sodium, and potassium salts of trisulfite methylates preferably have a partial structure represented by the following general formula (1′).

[0089] [Chemistry 3]

[0090]

[0091] In the formula, R 1 and R 2 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. M + It can be any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

[0092] The partial structures of the ammonium, lithium, sodium, and potassium salts of the trisulfite methylated compounds described in general formula (1′) are bonded to, for example, resins selected from resins formed by polymerizing monomers having double bonds, polysiloxane resins, and polyurethane resins.

[0093] (Repeating unit a)

[0094] The ammonium, lithium, sodium, and potassium salts of the trisulfite methylated compounds described in the above general formula (1′) are preferably bonded to the resin formed by polymerizing the monomers as repeating unit a represented by the following general formula (1).

[0095] [Chemistry 4]

[0096]

[0097] In the formula, R A It can be a hydrogen atom or a methyl group. X 1 Each is independently a single bond, a phenylene group, or a linking group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms. R 1 and R 2 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. M + It can be any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

[0098] The monomer used to obtain the repeating unit a represented by the above general formula (1) is represented by the following general formula (1)-1.

[0099] [Chemistry 5]

[0100]

[0101] In the general formula, R A R 1 R 2 X1, M + As mentioned above.

[0102] The monomer (anionic part) represented by the above general formula (1)-1 can be specifically exemplified as follows.

[0103] [Chemistry 6]

[0104]

[0105] [Chemistry 7]

[0106]

[0107] [Chemistry 8]

[0108]

[0109] [Chemistry 9]

[0110]

[0111] [Chemistry 10]

[0112]

[0113] [Chemistry 11]

[0114]

[0115] [Chemistry 12]

[0116]

[0117] [Chemistry 13]

[0118]

[0119] [Chemistry 14]

[0120]

[0121] [Chemistry 15]

[0122]

[0123] [Chemistry 16]

[0124]

[0125] [Chemistry 17]

[0126]

[0127] [Chemistry 18]

[0128]

[0129] [Chemistry 19]

[0130]

[0131] In the formula, R A As mentioned above.

[0132] The method for synthesizing the above-mentioned monomers can be the method shown in Japanese Patent Application Publication No. 2020-055797.

[0133] Furthermore, component (A) should preferably contain ammonium ions (ammonium cations) represented by the following general formula (2) as M in repeating unit a. + The person.

[0134] [Chemistry 20]

[0135]

[0136] In the formula, R 101d R 101e R 101f R 101g It may contain a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also contain one or more of the following: ether group, carbonyl group, ester group, hydroxyl group, amino group, nitro group, sulfonyl group, sulfinyl group, halogen atom, and sulfur atom. 101d With R 101e R101d With R 101e With R 101f They can also form rings together with the nitrogen atoms they are bonded to, and when forming rings, R 101d With R 101e and R 101d With R 101e With R 101f It is an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle forming a ring containing a nitrogen atom as shown in the formula.

[0137] The ammonium ion represented by the above general formula (2) can be specifically exemplified as follows.

[0138] [Chemistry 21]

[0139]

[0140] [Chemistry 22]

[0141]

[0142] [Chemistry 23]

[0143]

[0144] [Chemistry 24]

[0145]

[0146] [Chemistry 25]

[0147]

[0148] [Chemistry 26]

[0149]

[0150] [Chemistry 27]

[0151]

[0152] [Chemistry 28]

[0153]

[0154] [Chemistry 29]

[0155]

[0156] [Chemistry 30]

[0157]

[0158] [Chemistry 31]

[0159]

[0160] [Chemistry 32]

[0161]

[0162] [Chemistry 33]

[0163]

[0164] [Chemistry 34]

[0165]

[0166] [Chemistry 35]

[0167]

[0168] [Chemistry 36]

[0169]

[0170] The ammonium ion represented by the above general formula (2) is preferably a tertiary or quaternary ammonium ion.

[0171] (Repeating unit b)

[0172] In the bioelectrode composition (A) of the present invention, in addition to the repeating unit a formed by polymerizing monomers having polymerizable double bonds as described above, repeating units b having ethylene glycol dimethyl ether (GME) chains may also be copolymerized to improve conductivity. Specific examples of monomers used to obtain repeating units b having GME chains are shown below. By copolymerizing repeating units having GME chains, the movement of ions released from the skin within the dry electrode membrane can be facilitated, and the sensitivity of the dry electrode can be improved.

[0173] [Chemistry 37]

[0174]

[0175] [Chemistry 38]

[0176]

[0177] [Chemistry 39]

[0178]

[0179] [Chemistry 40]

[0180]

[0181] R is a hydrogen atom or a methyl group.

[0182] (Repeating unit c)

[0183] In the bio-electrode composition (A) of the present invention, in addition to the repeating units a and b described above, a hydrophilic repeating unit c having hydroxyl, carboxyl, ammonium, betaine, amide, pyrrolidone, lactone ring, lactam ring, sulfonyl ring, sodium salt of sulfonic acid, or potassium salt of sulfonic acid may be copolymerized to improve conductivity. Specific examples of monomers used to obtain the hydrophilic repeating unit c are shown below. By copolymerizing these repeating units containing hydrophilic groups, the sensitivity of ions released from the skin can be improved, and the sensitivity of the dry electrode can be enhanced.

[0184] [Chemistry 41]

[0185]

[0186] [Chemistry 42]

[0187]

[0188] [Chemistry 43]

[0189]

[0190] R is a methyl group or a hydrogen atom.

[0191] (Repeating unit d)

[0192] The (A) ionic resin in the bioelectrode composition of the present invention may have repeating units d that impart adhesiveness.

[0193] The monomer used to obtain the repeating unit d can be specifically exemplified as follows.

[0194] [Chemistry 44]

[0195]

[0196] [Chemistry 45]

[0197]

[0198] [Chemistry 46]

[0199]

[0200] [Chemistry 47]

[0201]

[0202] [Chemistry 48]

[0203]

[0204] (Repeating unit e)

[0205] Furthermore, crosslinkable repeating units e can also be copolymerized. Examples of crosslinkable repeating units include repeating units having ethylene oxide rings or oxobutane rings.

[0206] Monomers used to obtain repeating units e having ethylene oxide rings or oxobutane rings can be specifically listed below.

[0207] [Chemistry 49]

[0208]

[0209] [Transformation 50]

[0210]

[0211] R is a methyl group or a hydrogen atom.

[0212] (Repeating unit f)

[0213] In addition to having repeating units selected from a, b, c, d, and e above, component (A) of the bioelectrode composition of the present invention may also have repeating units f containing silicon. Specific examples are as follows.

[0214] [Chemistry 51]

[0215]

[0216] [Chemistry 52]

[0217]

[0218] The repeating units having alkoxysilyl groups can be copolymerized, and the alkoxysilyl groups can be hydrolyzed to form a silsesquioxane structure as disclosed in Japanese Patent Application Publication No. 2022-164579. Alternatively, they can be reacted with silanols on the surface of silica to form a complex with silica, as disclosed in Japanese Patent Application Publication No. 2022-64291.

[0219] (Repeating unit g)

[0220] In addition to having the repeating units a and b to f mentioned above, component (A) of the bioelectrode composition of the present invention may also have a repeating unit g containing fluorine.

[0221] Monomers used to obtain fluorine-containing repeating units g can be exemplified as follows.

[0222] [Chemistry 53]

[0223]

[0224] [Chemistry 54]

[0225]

[0226] [Chemistry 55]

[0227]

[0228] [Chemistry 56]

[0229]

[0230] [Chemistry 57]

[0231]

[0232] [Chem.58]

[0233]

[0234] [Chemistry 59]

[0235]

[0236] R is a hydrogen atom or a methyl group.

[0237] (Repeating unit h)

[0238] In addition to having the repeating units a and b to g mentioned above, component (A) of the bioelectrode composition of the present invention may also have a repeating unit h containing a cyano group.

[0239] Monomers used to obtain repeating units h containing cyano groups can be exemplified as follows.

[0240] [Transformation 60]

[0241]

[0242] [Chemistry 61]

[0243]

[0244] [Chemistry 62]

[0245]

[0246] [Chemistry 63]

[0247]

[0248] R is a hydrogen atom or a methyl group.

[0249] (Repeating unit i)

[0250] In addition to having repeating units selected from b to h as described above, component (A) of the bioelectrode composition of the present invention may also have repeating units i containing nitro groups.

[0251] Monomers used to obtain repeating units i containing nitro groups can be exemplified as follows.

[0252] [Chemistry 64]

[0253]

[0254] [Chemistry 65]

[0255]

[0256] [Chemistry 66]

[0257]

[0258] [Chemistry 67]

[0259]

[0260] [Chemistry 68]

[0261]

[0262] [Chemistry 69]

[0263]

[0264] One method for synthesizing an ionic resin of component (A) is to take a desired monomer from monomers that provide repeating units a, b, c, d, e, f, g, h, i, add a free radical polymerization initiator to an organic solvent, and then perform heating polymerization to obtain a copolymer polymer.

[0265] Examples of organic solvents used in polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, and dioxane. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid) ester, benzoyl peroxide, and lauroyl peroxide. The heating temperature should preferably be 50–80°C, and the reaction time should preferably be 2–100 hours, with 5–20 hours being more preferable.

[0266] 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 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, they are 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, they are 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.

[0267] In addition, for example, a + b + c + d + e + f + g + h + i = 1 means 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% relative to the total amount of all repeating units. a + b + c + d + e + f + g + h + i < 1 means that the total amount of the repeating units a, b, c, d, e, f, g, h, and i is less than 100 mol% relative to the total amount of all repeating units and there are other repeating units in addition to a, b, c, d, e, f, g, h, and i.

[0268] Regarding the molecular weight of the ionic resin of component (A) in terms of the weight-average molecular weight, it is preferably 500 or more, 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 monomers (residual monomers) in the polymer compound that has not been incorporated into component (A) after polymerization, there is a concern that these residual monomers may penetrate the skin and cause allergies in the biocompatibility test. Therefore, the amount of residual monomers should be reduced. The amount of residual monomers is preferably 10 parts by mass or less relative to 100 parts by mass of the entire polymer compound of component (A) before the condensation reaction. Component (A) can be used alone as one kind, or two or more kinds with different molecular weights, dispersities, and polymerization monomers can be mixed and used.

[0269] In addition, in the present invention, the molecular weight (Mw) and dispersity (Mw / Mn) of the polymer can be obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. When measuring GPC, it is usually carried out at room temperature near 23 °C, and it can also be carried out at a temperature higher or lower than room temperature.

[0270] In the bioelectrode composition of the present invention, the amount of component (A) is not particularly limited; for example, it can be set to 1 to 50 parts by mass relative to 100 parts by mass of the composition. Alternatively, the amount of component (A) relative to 100 parts by mass of component (B) is preferably set to 0.1 to 300 parts by mass, and more preferably 1 to 200 parts by mass. Furthermore, component (A) can be used alone or in combination with two or more other components.

[0271] [(B) Resin]

[0272] The (B) resin (a resin other than component (A)) incorporated in the bioelectrode composition of the present invention is a component used to be miscible with the aforementioned ionic resin (salt) of (A) and to prevent the dissolution of the salt, retain conductivity improvers such as metal powder, carbon powder, silicon powder, and lithium titanate powder, and further improve adhesion. If the ionic resin of (A) has sufficient adhesion, the (B) resin is not necessary. Furthermore, the (B) resin may be a resin other than component (A), preferably any one or both of thermosetting resin and photocuring resin, and is particularly preferred to be selected from one or more of polysiloxane resin, (meth)acrylate resin, and polyurethane resin.

[0273] Adhesive polysiloxanes include addition-reaction curing type and free radical crosslinking reaction curing type. Addition-reaction curing type can use, for example, the siloxane containing an alkenyl group or an R3SiO group as described in Japanese Patent Application Publication No. 2015-193803. 0.5 And MQ resins with SiO2 units, hydrogen-rich polysiloxanes with multiple SiH groups, platinum catalysts, addition reaction control agents, and organic solvents. Furthermore, free radical crosslinking reaction hardening types can use, for example, polysiloxanes containing two organic groups (which may or may not have alkenyl groups) as described in Japanese Patent Application Publication No. 2015-193803, and polysiloxanes with R3SiO2 units. 0.5 And MQ resins, organic peroxides, and organic solvents with SiO2 units. Here, R is a monovalent hydrocarbon group with or without substitution of carbon atoms from 1 to 10.

[0274] Alternatively, polysiloxanes with silanols at the polymer ends or on the side chains can be used, as well as polysiloxane-resin monolithic compounds formed by condensing MQ resin. Since MQ resin contains many silanols, adding MQ resin improves adhesion, but because it lacks crosslinking properties, it does not form molecular bonds with the polysiloxane. By molding the polysiloxane and resin into a monolithic compound as described above, adhesion can be increased.

[0275] Furthermore, modified siloxanes having groups selected from amino, ethylene oxide, oxetyl, polyether, hydroxyl, carboxyl, mercapto, methacrylate, acrylate, phenolic, silanol, carboxylic anhydride, aryl, aralkyl, amide, ester, and lactone rings can also be added to polysiloxanes. Adding modified siloxanes improves the dispersibility of component (A) in the polysiloxane. Modification of the one-terminal, two-terminal, or side chain of the siloxane is acceptable.

[0276] Furthermore, the aforementioned component (B) should preferably contain R. x SiO (4-x) / 2 Polysiloxane resins with units (R being a monovalent hydrocarbon group with or without substituted carbons of 1 to 10, and x being in the range of 2.5 to 3.5) and SiO2 units.

[0277] The adhesive (meth)acrylate resin can use, for example, hydrophilic (meth)acrylates and long-chain hydrophobic (meth)acrylates as repeating units as described in Japanese Patent Application Publication No. 2016-011338. Depending on the circumstances, (meth)acrylates with functional groups and (meth)acrylates with siloxane bonds can also be copolymerized.

[0278] For example, adhesive polyurethane resins containing urethane bonds and polyether, polyester, polycarbonate, or siloxane bonds may be used as described in Japanese Patent Application Publication No. 2016-065238.

[0279] Furthermore, to prevent a decrease in conductivity caused by the detachment of component (A) from the bio-contact layer, the (B) resin in the bio-electrode composition of the present invention should preferably be highly compatible with component (A). Also, to prevent peeling of the bio-contact layer from the conductive substrate, the (B) resin in the bio-electrode composition of the present invention should preferably have high adhesion to the conductive substrate. Using a highly polar resin is effective in making the (B) resin a conductive substrate and highly compatible with salts. Examples of such resins include resins having one or more of the following: ether bonds, ester bonds, amide bonds, imide bonds, urethane bonds, thiourethane bonds, and thiol groups; or polyacrylic acid resins, polyamide resins, polyimide resins, polyurethane resins, and polythiourethane resins. Furthermore, since the bio-contact layer comes into contact with the body, it is easily affected by sweat from the body. Therefore, the (B) resin in the bio-electrode composition of the present invention should preferably be highly water-repellent and not easily hydrolyzed. To make the resin highly water-repellent and resistant to hydrolysis, using a silicone-containing resin is effective.

[0280] Polyacrylic resins containing silicon atoms include polymers with polysiloxane in the main chain and polymers with silicon atoms in the side chains; either type can be ideally used. Polymers with polysiloxane in the main chain can use siloxanes or silsesquioxanes containing propyl (meth)acrylate. In this case, by adding a photoradical generator, the (meth)acrylic acid can be partially polymerized and hardened.

[0281] Polyamide resins containing silicon atoms are ideally suited to use, for example, the polyamide polysiloxane resins described in Japanese Patent Application Publication No. 2011-079946 and US Patent No. 5981680. Such polyamide polysiloxane resins can be synthesized by combining polysiloxanes or non-polysiloxane compounds with amino groups at both ends with non-polysiloxanes or polysiloxanes with carboxyl groups at both ends.

[0282] Alternatively, uncyclized polyamic acid obtained by reacting carboxylic anhydride with an amine can also be used. Crosslinking of the carboxyl group of the polyamic acid can also be performed using epoxy or oxetane crosslinking agents, or by esterification of the carboxyl group with hydroxyethyl (meth)acrylate, followed by photoradical crosslinking of the (meth)acrylate portion.

[0283] Polyimide resins containing silicon atoms are ideally suited for applications such as the polyimide polysiloxane resin described in Japanese Patent Application Publication No. 2002-332305. Polyimide resins have very high viscosity, but by incorporating (meth)acrylic acid monomers as solvents and crosslinking agents, they can be made to have low viscosity.

[0284] Polyurethane resins containing silicon atoms include polyurethane polysiloxane resins. Such polyurethane polysiloxane resins can be cross-linked by mixing compounds with isocyanate groups at both ends and compounds with hydroxyl groups at the ends, followed by heating. Furthermore, in this case, either or both of the compounds with isocyanate groups at both ends or compounds with hydroxyl groups at the ends must contain silicon atoms (siloxane bonds). Alternatively, as described in Japanese Patent Application Publication No. 2005-320418, urethane (meth)acrylate monomers can be mixed into a polysiloxane and photocrosslinked. Furthermore, polymers containing both siloxane bonds and urethane bonds, and with (meth)acrylate groups at the ends, can also be photocrosslinked. In particular, materials with polysiloxane side chains and polyurethane main chains as described in Japanese Patent Application Publication Nos. 2018-123304 and 2019-70109 are ideal due to their high strength and high elongation properties.

[0285] Polythiocarbamate resins containing silicon atoms can be obtained by reacting a compound with a thiol group with a compound with an isocyanate group, either of which needs to contain silicon atoms. Furthermore, if the resin has a (meth)acrylate group at the end, it can also be photocured.

[0286] By adding the above-mentioned siloxanes with alkenyl groups and R3SiO to polysiloxane resins... 0.5 The compatibility of MQ resin with SiO2 unit, hydrogen polysiloxane with many SiH groups, and modified siloxane with groups selected from amino, ethylene oxide, oxetyl, polyether, hydroxyl, carboxyl, mercapto, methacrylate, acrylic, phenolic, silanol, carboxylic anhydride, aryl, aralkyl, amide, ester, lactone ring, and the above salts will be improved.

[0287] Alkenyl-based diorganosiloxanes and hydrogen polysiloxanes with many SiH groups can be crosslinked by addition reactions using platinum catalysts.

[0288] Platinum catalysts include: chloroplatinic acid, alcoholic solutions of chloroplatinic acid, reaction products of chloroplatinic acid with alcohols, reaction products of chloroplatinic acid with olefin compounds, reaction products of chloroplatinic acid with vinyl-containing siloxanes, platinum-olefin complexes, platinum-vinyl-containing siloxane complexes, and other platinum-based catalysts; as well as platinum group metal catalysts such as rhodium complexes and ruthenium complexes. Alternatively, catalysts prepared by dissolving / dispersing these catalysts in alcohol-based, hydrocarbon-based, or siloxane-based solvents can also be used.

[0289] In addition, the amount of platinum catalyst added relative to 100 parts by mass of the resin containing components (A) and (B) should preferably be 5 to 2,000 ppm, with a particularly favorable range of 10 to 500 ppm.

[0290] In the bioelectrode composition of the present invention, the amount of component (B) relative to 100 parts by mass of the ionic resin (A) is preferably 0 to 2000 parts by mass, and more preferably 10 to 1000 parts by mass. Furthermore, component (B) can be used alone or in combination with two or more other components.

[0291] Furthermore, when using addition-curing polysiloxane resins, addition reaction control agents may also be added. These addition reaction control agents are added as quenchers to prevent the platinum catalyst from reacting in solution and at low temperatures before heat curing after coating formation. Specific examples include: 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclohexanol, 3-methyl-3-trimethylsiloxy-1-butyn, 3-methyl-3-trimethylsiloxy-1-pentyn, 3,5-dimethyl-3-trimethylsiloxy-1-hexyn, 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, etc.

[0292] The amount of addition reaction control agent added relative to 100 parts by weight of the resin containing components (A) and (B) is preferably 0 to 10 parts by weight, and preferably in the range of 0.05 to 3 parts by weight.

[0293] (B) When the component has double bonds that can be cross-linked by free radicals, adding a free radical generator is effective. Free radical generators include photoradio ...

[0294] Examples of photoradical generators include: acetophenone, 4,4'-dimethoxybenzoin, benzoin, benzoin, benzophenone, 2-benzoylbenzoic acid, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzoin isobutyl ether, 4-benzoylbenzoic acid, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, methyl 2-benzoylbenzoate, 2-(1,3-benzodioxane-5-yl)-4,6-bis(trichloromethyl)-1, 3,5-Triazine, 2-Benzyl-2-(Dimethylamino)-4'-morpholinophenylbutanone, 4,4'-Dichlorobenzophenone, 2,2-Diethoxyacetophenone, 2,2-Dimethoxy-2-phenylacetophenone, 2,4-Diethylthioxanthone-9-one, Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), 1,4-Dibenzoylbenzene, 2-Ethylanthraquinone, 1-Hydroxycyclohexylphenyl ketone, 2-Hydroxy-2-methylphenylacetone, 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, 2-Isonitrosophenylacetone, 2-Pheny-2-(p-Toluenesulfonyloxy)acetophenone.

[0295] Hardening can also be achieved by adding thermally decomposable free radical generators. Examples of thermal free radical generators include: 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylpentanitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(methylpropanediidine) hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] hydrochloride, 2,2'-azobis(4-methoxy-2,4-dimethylpentanitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(cyclohexane-1-carboxynitrile), 1[(1-cyano-1-methylethyl)azo]formamide, 2,2'-azobis(isobutyronitrile), and others. Bis[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-cyanopentanic acid), dimethyl-2,2'-azobis(2-methylpropionate), benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, di(tert-butyl)peroxide, di(tert-pentyl)peroxide, di-n-butyl peroxide, diisopropylphenyl peroxide, etc.

[0296] In addition, the amount of free radical generator added should preferably be in the range of 0.1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0297] Furthermore, as described later, the bio-contact layer is a hardened form of the bio-electrode composition. By hardening it, the adhesion of the bio-contact layer to both the skin and the conductive substrate improves. There are no particular limitations on the hardening method; general methods can be used, such as heat or light, or a cross-linking reaction using an acid or base catalyst. Regarding the cross-linking reaction, for example, the methods described in Chapter 2, pp. 51–371 of the cross-linking reaction manual published by Yoshiharu Maruzen (2013) can be appropriately selected for implementation.

[0298] [Ionic polymers]

[0299] In the bioelectrode composition of the present invention, an ionic polymer other than component (A) may be added. The ionic polymer preferably used is that shown in Japanese Patent Application Publication No. 2018-126496 and Japanese Patent Application Publication No. 2018-130533. The amount of the ionic polymer added is preferably in the range of 0.1 to 100 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0300] (C) Carbon powder and / or metal powder

[0301] In order to improve electronic conductivity, carbon powder and / or metal powder may be added to the bio-electrode composition of the present invention.

[0302] [Metallic powder]

[0303] In order to improve electronic conductivity, metal powder selected from gold, silver, platinum, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, chromium, and indium may be added to the bioelectrode composition of the present invention. The amount of metal powder added is preferably in the range of 1 to 50 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0304] From a conductivity perspective, gold, silver, and platinum are the best choices for metal powders. From a price perspective, silver, copper, tin, titanium, nickel, aluminum, tungsten, molybdenum, ruthenium, and chromium are also suitable. From a biocompatibility perspective, precious metals are preferred. Considering all these factors, silver is the best choice.

[0305] Metal powders can take various shapes, including spherical, disc-shaped, flake-shaped, and needle-shaped. Flake-shaped powders exhibit the highest conductivity and are considered ideal. The metal powder should have a size of less than 100 μm and a tap density of 5 g / cm³. 3 The following has a specific surface area of ​​0.5m². 2 Thin flakes with relatively low density and large specific surface area above / g are ideal.

[0306] [Toner]

[0307] Conductivity improvers can be added toner. Examples of toners include: carbon black, graphite, carbon nanotubes, carbon fibers, and graphene. Carbon nanotubes can be single-layer or multi-layered, and surface modification with organic groups is acceptable. Carbon black and carbon nanotubes, or both, are particularly preferred. The amount of toner added should preferably be in the range of 1 to 50 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0308] Silicon powder

[0309] In the bioelectrode composition of the present invention, silicon powder may be added to improve the sensitivity of ion acceptance. Examples of silicon powder include powders composed of silicon, silicon monoxide, and silicon carbide. The particle size of the powder is preferably less than 100 μm, and more preferably less than 1 μm. The finer the particles, the larger their surface area, thus allowing them to accept more ions and become a highly sensitive bioelectrode. The amount of silicon powder added is preferably in the range of 1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0310] [Lithium titanate powder]

[0311] In the bioelectrode composition of the present invention, lithium titanate powder may be added to improve the sensitivity of ion acceptance. Examples of lithium titanate powders include Li₂TiO₃, LiTiO₂, and spinel-structured Li₄Ti₅O₃. 12 The molecular formula should preferably be a spinel structure. Alternatively, lithium titanate particles formed by combining lithium titanate with carbon can also be used. The particle size of the powder should preferably be less than 100 μm, and less than 1 μm is even better. The finer the particles, the larger their surface area, thus accepting more ions and becoming highly sensitive bioelectrodes. They can also be composite powders combined with carbon. The amount of lithium titanate powder added should preferably be in the range of 1 to 50 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0312] [Cross-linking agent]

[0313] In the bioelectrode composition of the present invention, an epoxy crosslinking agent may also be added. This crosslinking agent is a compound having multiple epoxy groups and oxocyclic butyl groups within one molecule. The amount added is 1 to 30 parts by mass relative to 100 parts by mass of the resin containing components (A) and (B).

[0314] [Cross-linking catalyst]

[0315] In the bioelectrode composition of the present invention, a catalyst for crosslinking epoxy groups and oxetane groups may also be added. The catalyst used in this case may be the one described in paragraphs 0027 to 0029 of Japanese Patent Application Publication No. 2019-503406. The amount added is 0.01 to 10 parts by weight relative to 100 parts by weight of the resin containing components (A) and (B).

[0316] [Ionic additives]

[0317] In the bioelectrode composition of the present invention, ionic additives for improving ionic conductivity can be added. Examples of such additives, considering biocompatibility, include: sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium saccharin, acesulfame potassium, sodium formate, potassium formate, calcium formate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, betaine, salts disclosed in Japanese Patent Application Publication No. 2018-44147, Japanese Patent Application Publication No. 2018-59050, Japanese Patent Application Publication No. 2018-59052, and Japanese Patent Application Publication No. 2018-130534.

[0318] [(D) Organic solvent]

[0319] Furthermore, organic solvents may be added to the bioelectrode composition of the present invention. Specific examples of organic solvents include: toluene, xylene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, styrene, α-methylstyrene, styrene-butadiene, sec-butadiene, isobutadiene, isopropyltoluene, diethylbenzene, 2-ethyl-p-xylene, 2-propyltoluene, 3-propyltoluene, 4-propyltoluene, 1,2,3,5-tetramethyltoluene, 1,2,4,5-tetramethyltoluene, tetrahydronaphthalene, 4-phenyl-1-butene, tert-pentylbenzene, pentylbenzene, 2-tert-butyltoluene, 3-tert-butyltoluene, 4-tert-butyltoluene, 5-isopropyl-m-xylene, 3-methylethylbenzene, tert-butyl-3-ethylbenzene, 4-tert-butyl-o-xylene, 5-tert-butyl-m-xylene, tert-... Aromatic hydrocarbon solvents such as butyl-p-xylene, 1,2-diisopropylbenzene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, dipropylbenzene, pentamethylbenzene, hexamethylbenzene, hexylbenzene, and 1,3,5-triethylbenzene; n-heptane, isoheptane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, 1,6-heptadiene, 5-methyl-1-hexyne, norbornene, norbornene, dicyclopentadiene, 1-methyl-1,4-cyclohexadiene, 1-heptyne, 2-heptyne, cycloheptane, cycloheptene, 1,3-dimethylcyclopentane, ethylcyclopentane, methylcyclohexane, 1-methyl-1-cyclohexene, 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-methylcyclohexane, Propylcyclohexane, Isopropylcyclohexane 1,1,3-Trimethylcyclohexane, 1,1,4-Trimethylcyclohexane, 1,2,3-Trimethylcyclohexane, 1,2,4-Trimethylcyclohexane, 1,3,5-Trimethylcyclohexane, Allylcyclohexane, Hydindane, 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-methyl Heptane, 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-decytriene, 2,6-dimethyl-2,4,6-octtriene, limonene, fragrance 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, pentylcyclohexane, 1-undecane, 1,10-undecadiene, 1-undecaneyne, 3-undecaneyne, 5-undecaneyne, tricyclic [6.2.1.0, 2,7[Aliphatic hydrocarbon solvents such as undecane, 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-cyclododecanetriene, 1,2,4-trivinylcyclohexane, and isoalkanes; 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-pentanone; 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, and propylene glycol monomethyl ether.] Ethers, 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, diethylene glycol monoheptyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, diisopropyl ether, diisobutyl ether, diisopentyl ether, di-n-pentyl ether, methyl cyclopentyl ether, methyl cyclohexyl ether, di-n-butyl ether, di(sec-butyl) ether Ether solvents such as diisopentyl ether, di(sec-pentyl) ether, di(tert-pentyl) 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 monotert-butyl ether acetate; lactone solvents such as γ-butyrolactone; and water.

[0320] In addition, the amount of organic solvent added should preferably be in the range of 10 to 50,000 parts by mass relative to 100 parts by mass of the resin totaling components (A) and (B).

[0321] [Other Additives]

[0322] In the bioelectrode composition of the present invention, silica particles, or polyether polysiloxane, or polyglycerol polysiloxane may also be mixed. Silica particles have a hydrophilic surface and exhibit good affinity with hydrophilic ionic polymers, polyether polysiloxane, or polyglycerol polysiloxane, and can improve the dispersibility of ionic polymers, polyether polysiloxane, or polyglycerol polysiloxane in hydrophobic polysiloxane adhesives. Silica particles can ideally be used in either dry or wet processes.

[0323] [Polysiloxane compounds with a polyglycerol structure]

[0324] In the bioelectrode composition of the present invention, a polysiloxane compound having a polyglycerol structure may be added to improve the moisturizing properties of the membrane and the sensitivity and ionic conductivity of ions released from the skin. The amount of the polysiloxane compound having a polyglycerol structure relative to 100 parts by weight of the total of components (A) and (B) is preferably 0.01 to 100 parts by weight, and more preferably 0.5 to 60 parts by weight. Furthermore, a single polysiloxane compound having a polyglycerol structure may be used, or two or more may be used in combination.

[0325] Polysiloxane compounds having a polyglycerol structure are preferably represented by the following general formulas (4)' and (5)'.

[0326] [Chemistry 70]

[0327]

[0328] In equations (4)' and (5)', R 1 ' is a linear or branched alkyl or phenyl group consisting of hydrogen atoms or carbon atoms numbering 1 to 50, and may also contain ether groups, and may also be a polysiloxane chain represented by general formula (6)', R 2 ' is a group with a polyglycerol structure represented by formula (4)'-1 or formula (4)'-2, R 3 'are independent and can be the same as or different from the aforementioned R' 1 'Base or the aforementioned R 2 'base, R 4 'are independent and can be the same as or different from the aforementioned R' 1 'Base, the aforementioned R 2 'Base or oxygen atom.' R 4 When it is an oxygen atom, there are 2 R atoms. 4 The ' group can also bond and form an ether group, which together with the silicon atom forms a ring. a' can be the same or different, ranging from 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 ' is the aforementioned R 2 In the base equations (4)'-1 and (4)'-2, (5)', and (6)', R 5 'is an alkylene group having 2 to 10 carbon atoms or an arylene group having 7 to 10 carbon atoms, R 6 '、R 7 ' is an alkylene group having 2 to 6 carbon atoms, R 7 'Can also be ether bonds, c' is 0-20, d' is 1-20. Such polysiloxane compounds with polyglycerol structures can be exemplified as follows.

[0329] [Chemistry 71]

[0330]

[0331] [Chemistry 72]

[0332]

[0333] [Chemistry 73]

[0334]

[0335] [Chemistry 74]

[0336]

[0337] [Chemistry 75]

[0338]

[0339] [Chemistry 76]

[0340]

[0341] [Chemistry 77]

[0342]

[0343] [Chemistry 78]

[0344]

[0345] [Chemistry 79]

[0346]

[0347] [Chemistry 80]

[0348]

[0349] In the formula, a', b', c' and d' are as described above.

[0350] If it contains a polysiloxane compound with such a polyglycerol structure, it can exhibit better moisturizing properties. As a result, it can be made into a bioelectrode composition that can form a bio-contact layer that exhibits better sensitivity to ions released by the skin.

[0351] As described above, the bioelectrode composition of the present invention can form a bioelectrode composition with high adhesion, maintaining sufficient adhesion even after being peeled off and reattached from the skin, efficiently transmitting electrical signals from the skin to the device (i.e., excellent conductivity), without causing allergies even after prolonged skin contact (i.e., excellent biocompatibility), lightweight, and low-cost manufacturing, and whose conductivity does not significantly decrease even when wetted or dried. Furthermore, by adding carbon materials, conductivity can be further improved, and by combining it with a resin possessing adhesion and elasticity, a bioelectrode with high adhesion and high elasticity can be manufactured. In addition, additives can be used to improve elasticity and adhesion to the skin, and elasticity and adhesion can be adjusted by appropriately regulating the resin composition and the thickness of the bioelectrode contact layer.

[0352] <Bioelectrodes>

[0353] Furthermore, the present invention provides a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate, wherein the aforementioned bioelectrode contact layer is a hardened form of the bioelectrode composition of the present invention.

[0354] The present invention will now be described in detail with reference to the drawings, but the invention is not limited thereto.

[0355] Figure 1 This is a schematic cross-sectional view showing an example of the bioelectrode of the present invention. Figure 1 The bioelectrode 1 comprises a conductive substrate 2 and a bio-contact layer 3 formed on the conductive substrate 2. The bio-contact layer 3 is composed of a hardened form of the bioelectrode composition of the present invention. The bio-contact layer 3 contains an ionic resin (A) 5. The bio-contact layer 3 may also further contain a resin (B) 6 other than the ionic resin (A), and conductive powder 4. See below for reference. Figure 1 , 2 The present invention describes a case in which the bio-contact layer 3 is an ionic resin (A) 5 and the conductive powder 4 is dispersed in resin (B) 6, but the bio-electrode of the present invention is not limited to this form.

[0356] Using such Figure 1 When using bioelectrode 1, such as Figure 2As shown, the bio-contact 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 the bio-body 7. Electrical signals are extracted from the bio-body 7 using the ionic resin (A) 5 and the conductive powder 4, and then conducted to a sensor device (not shown) via the conductive substrate 2. Thus, in the case of the bio-electrode of the present invention, since the aforementioned ionic resin (A) is used, both conductivity and biocompatibility can be achieved, and it also has adhesive properties. Therefore, the contact area with the skin is kept constant, and electrical signals from the skin can be stably obtained with high sensitivity.

[0357] The constituent materials of the bioelectrode of the present invention will be described in more detail below.

[0358] [Conductive substrate]

[0359] The bioelectrode of the present invention has a conductive substrate. This conductive substrate is typically electrically connected to a sensor device or the like, and conducts electrical signals taken from the organism via the bioelectrode contact layer to the sensor device or the like.

[0360] There are no particular restrictions on the conductive substrate if it is conductive, but it is preferable to contain one or more of the following: gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

[0361] Furthermore, there are no particular limitations on the conductive substrate. It can be a rigid conductive substrate, a flexible conductive film, a fabric with a conductive paste coated on its surface, or a fabric mixed with a conductive polymer. The conductive substrate can also be a mesh woven from flat or textured metal wires, and can be appropriately selected according to the application of the bioelectrode.

[0362] [Biological Contact Layer]

[0363] The bioelectrode of the present invention has a bio-contact layer formed on a conductive substrate. This bio-contact layer, which is the portion that actually contacts the organism during use of the bioelectrode, is conductive and adhesive. The bio-contact layer is a hardened form of the bioelectrode composition of the present invention, that is, an adhesive resin layer composed of a hardened form containing component (A) and, as needed, components (B), (C), (D), and other components.

[0364] Furthermore, the adhesion of the biological contact layer should preferably be in the range of 0.01 N / 25 mm or higher and 20 N / 25 mm or lower. The method shown in JIS Z 0237 for measuring adhesion is general; the substrate can be a metal substrate such as SUS (stainless steel) or a PET (polyethylene terephthalate) substrate, or it can be measured using human skin. Human skin has a lower surface energy than metals or various plastics, approaching the low energy of Teflon (registered trademark), making it less prone to adhesion.

[0365] In applications involving repeated application and peeling, peelability is more important than adhesiveness, so adhesiveness is not necessary.

[0366] The thickness of the bio-contact layer of a bioelectrode should ideally be between 1 μm and 5 mm, preferably between 2 μm and 3 mm. A thinner bio-contact layer results in lower adhesion but improves flexibility, lighter weight, and better skin affinity. The thickness of the bio-contact layer can be chosen by balancing adhesion and skin feel.

[0367] Furthermore, the bioelectrode of the present invention can also, like known bioelectrodes (such as the bioelectrode described in Japanese Patent Application Publication No. 2004-033468), have an additional adhesive film provided on the bio-contact layer to prevent the bioelectrode from peeling off from the body during use. When providing the additional adhesive film, acrylic, urethane, or polysiloxane adhesive film materials can be used to form the adhesive film. Polysiloxane is particularly desirable because it has high oxygen permeability, allowing the skin to breathe even when attached, and high water repellency, thus reducing adhesion loss due to sweat. Furthermore, it has low skin irritation. Additionally, as described above, the bioelectrode of the present invention prevents peeling off from the body by adding an adhesive agent to the bioelectrode composition or using a resin with good adhesion to the body; therefore, the aforementioned additional adhesive film is not necessarily required.

[0368] There are no particular limitations on the wiring or other components of the bioelectrode and sensor device when using the bioelectrode of the present invention to make a wearable device, for example, those described in Japanese Patent Application Publication No. 2004-033468 may be used.

[0369] As described above, the bioelectrode of the present invention, due to the formation of a bio-contact layer from the hardened composition of the bioelectrode of the present invention, can efficiently transmit electrical signals from the skin to the device (i.e., excellent conductivity), and even after prolonged use on the skin, there is no concern about causing allergies (i.e., excellent biocompatibility). It is lightweight, can be manufactured at low cost, and its conductivity does not significantly decrease even when wetted or dried. Furthermore, by adding conductive powder, conductivity can be further improved, and by combining it with a resin that has adhesiveness and elasticity, a bioelectrode with high adhesion and high elasticity can be manufactured. In addition, additives can be used to improve elasticity and adhesion to the skin, and elasticity and adhesion can also be adjusted by appropriately adjusting the resin composition and the thickness of the bio-contact layer. Therefore, the bioelectrode of the present invention, in this way, is particularly suitable as a bioelectrode for use in medical wearable devices.

[0370] <Manufacturing Methods of Bioelectrodes>

[0371] Furthermore, the present invention provides a method for manufacturing a bioelectrode, which is a method for manufacturing a bioelectrode having a conductive substrate and a bioelectrode contact layer formed on the conductive substrate. The method involves coating the bioelectrode composition of the present invention onto the aforementioned conductive substrate and hardening it, thereby forming the aforementioned bioelectrode contact layer.

[0372] Furthermore, the conductive substrate used in the method for manufacturing the bioelectrode of the present invention can be the same as those described above.

[0373] There are no particular limitations on the method of coating bio-electrode components on a conductive substrate. For example, dip coating, spray coating, spin coating, rod coating, spool coating, die coating, roll coating, flow coating, doctor blade coating, calender coating, screen printing, flexographic printing, gravure printing, inkjet printing, etc. are suitable methods.

[0374] There are no particular limitations on the curing method of the resin; it can be appropriately selected based on the (A) and (B) components used in the bio-electrode composition. For example, it is advisable to use either heat or light, or both, to cure it. Alternatively, a catalyst that produces acids or bases can be added to the aforementioned bio-electrode composition beforehand to induce a cross-linking reaction and thus cure it.

[0375] In addition, there are no particular restrictions on the heating temperature. It depends on the appropriate selection of (A) and (B) components used in the bio-electrode composition. For example, it is advisable to be about 50 to 250°C.

[0376] Furthermore, when combining heating and light exposure, heating and light exposure can be performed simultaneously, or heating can be performed after light exposure, or light exposure can be performed after heating. Also, in order to allow the solvent to evaporate before heating after coating, air drying can be performed.

[0377] Applying water droplets, or blowing water vapor or mist onto the hardened membrane surface, improves its affinity with the skin, allowing for faster reception of biological signals. To further refine the size of the water droplets (water vapor or mist), a mixture of water and alcohol can be used. The membrane surface can also be moistened by contact with water-containing absorbent cotton or cloth.

[0378] The water that wets the hardened membrane surface may also contain salt. Water-soluble salts that mix with water are selected from sodium salts, potassium salts, calcium salts, magnesium salts, and betaine.

[0379] The aforementioned water-soluble salts may specifically be salts selected from sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium saccharin, acesulfame potassium, sodium formate, potassium formate, calcium formate, sodium sulfonate, potassium sulfonate, calcium sulfonate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, and betaine. Furthermore, the ionic resins mentioned in (A) are not included in the aforementioned water-soluble salts.

[0380] More specifically, in addition to the above, the following can also be listed: sodium acetate, sodium propionate, sodium trimethylacetate, sodium glycolate, sodium butyrate, sodium valerate, sodium hexanoate, sodium heptanoate, sodium octanoate, sodium nonanoate, sodium decanoate, sodium undecanoate, sodium laurate, sodium tridecanoate, sodium myristate, sodium pentadecanoate, sodium palmitate, sodium heptadecanate, sodium stearate, sodium benzoate, disodium adipic acid, disodium maleate, disodium phthalate, sodium butyrate, sodium 2-hydroxybutyrate, sodium 3-hydroxybutyrate, sodium 2-oxobutyrate, sodium stearate, sodium gluconate, and methanesulfonate. Sodium 1-nonanesulfonate, sodium 1-decanesulfonate, sodium 1-dodecanesulfonate, sodium 1-undecanesulfonate, sodium cocoyl hydroxyethanesulfonate, sodium lauroyl methyl alanine, sodium cocoyl methyl taurate, sodium cocoyl glutamate, sodium cocoyl sarcosinate, sodium lauroyl methyl taurate, aminopropyl lauroyl, potassium isobutyrate, potassium propionate, potassium trimethylacetate, potassium glycolate, potassium gluconate, potassium methanesulfonate, calcium stearate, calcium glycolate, calcium gluconate, calcium 3-methyl-2-oxobutyrate, calcium methanesulfonate. Betaine is a general term for intramolecular salts, specifically compounds formed by the addition of three methyl groups to the amino group of amino acids. More specifically, examples include trimethylglycine, carnitine, trimethylglycine, and proline betaine.

[0381] The aforementioned water-soluble salt may further contain a monovalent alcohol or polyol having 1 to 4 carbon atoms. The aforementioned alcohol is preferably selected from ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerol, polyethylene glycol, polypropylene glycol, polyglycerol, diglycerol, or a polysiloxane compound having a polyglycerol structure. It is more preferable that the aforementioned polysiloxane compound having a polyglycerol structure is represented by the above general formulas (4)' to (6)'.

[0382] Regarding pretreatment methods using aqueous solutions containing water-soluble salts, the bioelectrode membrane can be applied to the hardened bioelectrode membrane using spraying, water droplet application, or similar methods. It can also be applied under high temperature and humidity conditions, such as a steam bath. To prevent drying after application, a protective film can be layered on top of the permeable layer. The protective film needs to be peeled off before being applied to the skin; therefore, a peeling agent or a peelable Teflon (registered trademark) film can be applied. For long-term storage, dry electrodes covered with a peeling film should be sealed in a bag covered with aluminum or similar material. To prevent drying in the aluminum-covered bag, moisture should be pre-sealed inside.

[0383] Before attaching the bioelectrode of the present invention to the skin, the skin side may be moistened with water, alcohol, or the skin may be wiped with a cloth or cotton ball containing water or alcohol. The aforementioned salt may also be present in the water or alcohol.

[0384] As described above, the bioelectrode manufacturing method of the present invention can easily manufacture bioelectrodes with excellent conductivity and biocompatibility at low cost, which are lightweight and whose conductivity does not decrease significantly whether wetted or dried.

[0385] Example

[0386] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited thereto.

[0387] (Synthesis of monomers 1-11)

[0388] In THF solvent, in the presence of sodium hydride, monomer 1 is obtained by reacting bis(cyclohexanesulfonyl)methane with 4-methacryloyloxybenzenesulfonyl chloride and by neutralizing it with trimethylbenzylammonium. Monomers 2-11 are synthesized by replacing bis(cyclohexanesulfonyl)methane and 4-methacryloyloxybenzenesulfonyl chloride with other starting materials and by ion exchange reactions with trimethylbenzylammonium and other cations.

[0389] Monomers 1 to 11 are described below.

[0390] [Chemistry 81]

[0391]

[0392] [Chemistry 82]

[0393]

[0394] (Synthesis of ionic resins 1-1 to 1-11 and comparative ionic resin 1)

[0395] Ionic resins 1-1 to 1-11, and comparative ionic resin 1, which are incorporated into the bio-electrode composition solution as ionic materials (conductive materials), were synthesized as follows. A 30% by mass solution of each monomer in cyclopentanone was placed in a reaction vessel and mixed. The reaction vessel was cooled to -70°C under nitrogen atmosphere, and the process of degassing under reduced pressure and nitrogen blowing was repeated three times. After heating to room temperature, 0.02 mol of azobisisobutyronitrile (AIBN) as a polymerization initiator was added relative to 1 mol of the monomers. The mixture was then heated to 60°C and allowed to react for 15 hours. The composition of the resulting polymer was determined by drying the solvent and then using... 1 The results were confirmed by ¹H-NMR. Furthermore, the molecular weight (Mw) and dispersity (Mw / Mn) of the obtained polymer were confirmed by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. The ionic resins 1-1 to 1-11 synthesized in this manner, and the comparative ionic resin 1, are shown below.

[0396] Ionic resin 1-1

[0397] Mw = 83,000

[0398] Mw / Mn = 2.94

[0399] [Chemistry 83]

[0400]

[0401] Ionic resin 1-2Mw=77, 100Mw / Mn=2.93

[0402] [Chemistry 84]

[0403]

[0404] Ionic resin 1-3Mw=69, 100Mw / Mn=2.64

[0405] [Chemistry 85]

[0406]

[0407] Ionic resin 1-4 Mw = 52,200 Mw / Mn = 2.73

[0408] [Chemistry 86]

[0409]

[0410] Ionic resin 1-5 Mw = 31,900 Mw / Mn = 2.77

[0411] [Chemistry 87]

[0412]

[0413] Ionic resin 1-6 Mw = 40, 300 Mw / Mn = 2.83

[0414] [Chemistry 88]

[0415]

[0416] Ionic resin 1-7 Mw = 38, 100 Mw / Mn = 2.77

[0417] [Chemistry 89]

[0418]

[0419] The number of repetitions in the formula represents the average value.

[0420] Ionic resin 1-8

[0421] Mw = 42,700

[0422] Mw / Mn = 1.95

[0423] [Chemistry 90]

[0424]

[0425] The number of repetitions in the formula represents the average value.

[0426] Ionic resins 1-9

[0427] Mw = 31,500

[0428] Mw / Mn = 2.33

[0429] [Chemistry 91]

[0430]

[0431] The number of repetitions in the formula represents the average value.

[0432] Ionic resin 1-10 Mw = 29,800

[0433] Mw / Mn = 1.95

[0434] [Chemistry 92]

[0435]

[0436] The number of repetitions in the formula represents the average value.

[0437] Ionic resin 1-11 Mw = 33,500

[0438] Mw / Mn = 1.91

[0439] [Chemistry 93]

[0440]

[0441] The number of repetitions in the formula represents the average value.

[0442] Comparison of ionic resins 1

[0443] Mw = 26,500

[0444] Mw / Mn = 1.85

[0445] [Chemistry 94]

[0446]

[0447] The siloxane compounds 1 to 4, which are incorporated into the bio-electrode composition solution as polysiloxane resins, are shown below.

[0448] (Siloxane compound 1)

[0449] The viscosity of a 30% toluene solution is 27,000 mPa·s, and the alkenyl content is 0.007 mol / 100g. A vinyl-containing polydimethylsiloxane with SiMe2Vi-terminated molecular chains is used as siloxane compound 1.

[0450] (Siloxane compound 2)

[0451] Let Me3SiO 0.5 The polysiloxane (Me3SiO) of MQ resin composed of unit and SiO2 unit 0.5 A 60% toluene solution of unit / SiO2 unit = 0.8 was used as siloxane compound 2.

[0452] (Siloxane compound 3)

[0453] Let 40 parts by mass of a vinyl-containing polydimethylsiloxane with a viscosity of 42,000 mPa·s and an alkenyl content of 0.007 mol / 100g, and whose molecular chain ends are capped with OH, be obtained from a 30% toluene solution, and be composed of Me3SiO2. 0.5 The polysiloxane (Me3SiO) of MQ resin composed of unit and SiO2 unit 0.5 A solution consisting of 100 parts by mass of a 60% toluene solution (unit / SiO2 unit = 0.8) and 26.7 parts by mass of toluene was heated for 4 hours by dry distillation, and then cooled to bond polydimethylsiloxane to MQ resin, which was then used as siloxane compound 3.

[0454] (Siloxane compound 4)

[0455] KF-99, manufactured by Shin-Etsu Chemical Industry Co., Ltd., is used as a methylhydrosilicone oil.

[0456] The acrylic resins used as acrylic resins in the bio-electrode composition solution are shown below.

[0457] Acrylic resin 1

[0458] Mw = 129,000

[0459] Mw / Mn = 2.45

[0460] [Chemistry 95]

[0461]

[0462] The polyurethane resins incorporated into the bio-electrode composition solution and incorporated into the urethane-based resins are shown below.

[0463] Polyurethane resin 1

[0464] Mw = 83,000

[0465] Mw / Mn = 4.02

[0466] [Chemistry 96]

[0467]

[0468] The polyglycerol polysiloxane compound incorporated into the bio-electrode composition solution is as follows.

[0469] [Chemistry 97]

[0470]

[0471] The cross-linking agent incorporated into the bio-electrode composition solution is shown below.

[0472] Epoxy crosslinking agent 1

[0473] [Chem. 98]

[0474]

[0475] The organic solvents incorporated into the bio-electrode composition solution are shown below.

[0476] EDE: Diethylene glycol diethyl ether

[0477] ISOPAR G TM Isoalkane-based solvents, standard petroleum products

[0478] ISOPAR M TM Isoalkane-based solvents, standard petroleum products

[0479] The platinum catalyst and conductivity improvers (carbon black, carbon nanotubes) incorporated into the bio-electrode composition solution as additives are shown below.

[0480] Platinum catalyst: Shin-Etsu Chemical Industry Co., Ltd. CAT-PL-50T

[0481] Carbon black: DENKA BLACK Li-400 manufactured by Denka Co., Ltd.

[0482] Multilayer carbon nanotubes: manufactured by Sigma-Aldrich, with diameters of 110–170 nm and lengths of 5–9 μm.

[0483] [Examples 1-11, Comparative Example 1]

[0484] Bioelectrode composition solutions (bioelectrode composition solutions 1-11, comparative bioelectrode composition solution 1) were prepared by mixing ionic resin, resin, organic solvent, and additives (platinum catalyst, conductivity improver) with the compositions recorded in Tables 1 and 2.

[0485] [Table 1]

[0486]

[0487] [Table 2]

[0488]

[0489] (Evaluation of biological signals)

[0490] like Figure 3 As shown, on Bemis's ST-604 thermoplastic polyurethane (TPU) film 20, a conductive paste made by Fujikura Chemicals and DOTITE FA-333 were screen-printed onto the film. The film was then baked in an oven at 120°C for 10 minutes to print a keyhole-shaped conductive pattern 2 with a diameter of 2 cm. The bio-electrode composition solution described in Tables 1 and 2 was screen-printed onto the circular portion overlapping it. After air drying at room temperature for 10 minutes, the solution was baked in an oven at 125°C for 10 minutes to evaporate the solvent and harden the film, forming a bio-contact layer 3, and thus fabricating the bio-electrode 1. Then, as... Figure 4 As shown, a polyurethane resin film 20 printed with bioelectrode 1 is cut out and double-sided tape 21 is attached. Three bioelectrode samples 10 are made for each composition solution.

[0491] (Measuring the thickness of the contact layer in organisms)

[0492] The thickness of the biological contact layer in the biological electrodes prepared in the above biological signal evaluation test was measured using a micrometer. The results are shown in Table 3.

[0493] (Measurement of biological information)

[0494] The conductive wiring pattern made of conductive paste from the bio-electrode is connected to the HCG-901 portable electrocardiogram manufactured by Omron Healthcare (stock) using conductive wires, and the positive electrode of the electrocardiogram is attached to it. Figure 5 The electrode is placed at position LA on the human body, the negative electrode at position LL, and the ground electrode at position RA. Electrocardiogram (ECG) measurements begin immediately after attachment and continue until... Figure 6 The time elapsed until the appearance of the electrocardiogram waveform consisting of P, Q, R, S, and T waves is shown in Table 3. The results are shown in Table 3.

[0495] [Table 3]

[0496]

[0497] As shown in Table 3, Examples 1 to 11, which use bioelectrode compositions of the present invention to form biocontact layers by incorporating resins with structures selected from ammonium, lithium, sodium, and potassium salts of trisulfonium methylates, can obtain bio-information shortly after being applied to the body. On the other hand, bio-signals cannot be obtained when ionic components without specific structures are not present.

[0498] This specification includes the following inventions.

[0499] [1]: A bioelectrode composition containing (A) ionic resin, characterized in that:

[0500] The aforementioned component (A) comprises a resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trissulfonium methylates.

[0501] [2]: The bio-electrode composition described in [1] above, wherein the resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates has a chemical structure represented by the following general formula (1).

[0502] [Chemistry 99]

[0503]

[0504] In the formula, R A It can be a hydrogen atom or a methyl group. X 1 Each is independently a single bond, a phenylene group, or a linking group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms. R 1 and R 2 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. M + It can be any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

[0505] [3]: The bio-electrode composition described in [2] above, wherein the resin having the structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates contains an ammonium ion represented by the following general formula (2) as the aforementioned M + .

[0506] [Chemistry 100]

[0507]

[0508] In the formula, R 101d R 101e R 101f R 101g It may contain a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also contain one or more of the following: ether group, carbonyl group, ester group, hydroxyl group, amino group, nitro group, sulfonyl group, sulfinyl group, halogen atom, and sulfur atom. 101d With R 101e R 101d With R 101e With R 101f They can also form rings together with the nitrogen atoms they are bonded to, and when forming rings, R 101d With R 101e and R 101d With R 101e With R 101f It is an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle forming a ring containing a nitrogen atom as shown in the formula.

[0509] [4]: The bio-electrode composition described in any of [1] to [3] above further contains resin other than the aforementioned component (A) as component (B).

[0510] [5]: The bio-electrode composition described in [4] above, wherein the aforementioned component (B) is selected from one or more of polysiloxane resin, (meth)acrylate resin and polyurethane resin.

[0511] [6]: Bioelectrode composition as described in [4] or [5] above, wherein the aforementioned component (B) is adhesive.

[0512] [7]: A bio-electrode composition as described in any of [4] to [6] above, wherein the aforementioned component (B) contains R x SiO (4-x) / 2 Polysiloxane resins with units (R being a monovalent hydrocarbon group with or without substituted carbons of 1 to 10, and x being in the range of 2.5 to 3.5) and SiO2 units.

[0513] [8]: The bio-electrode composition described in any of [1] to [7] above further contains carbon powder and / or metal powder as component (C).

[0514] [9]: The bio-electrode composition described in [8] above, wherein the aforementioned carbon powder is either carbon black or carbon nanotubes.

[0515]

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

[0516]

[11] : The bio-electrode composition described in any of [8] to

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

[0517]

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

[11] above, wherein the aforementioned bio-electrode composition further contains an organic solvent as component (D).

[0518]

[13] : A bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, characterized in that:

[0519] The aforementioned biological contact layer is a hardened form of the biological electrode composition described in any of [1] to

[12] above.

[0520]

[14] : The bioelectrode described in

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

[0521]

[15] : A method for manufacturing a bioelectrode, characterized in that:

[0522] The aforementioned biological contact layer is formed by coating the aforementioned conductive substrate with the biological electrode composition described in any one of [1] to

[12] above and hardening it.

[0523]

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

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

[0524] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and those having substantially the same structure and performing the same effects as the technical concept described in the claims of the present invention are intended to be included within the technical scope of the present invention.

[0525] Explanation of reference numerals in the attached figures

[0526] 1: Bioelectrodes

[0527] 2: Conductive substrate (conductive pattern)

[0528] 3: Contact layer of organisms

[0529] 4: Conductive powder

[0530] 5: Ionic resins (A)

[0531] 6: Resin (B)

[0532] 7: Organisms

[0533] 10: Biological electrode samples

[0534] 20: Thermoplastic polyurethane resin film

[0535] 21: Double-sided tape

[0536] LA: Positive electrode attachment point

[0537] LL: Negative electrode attachment point

[0538] RA: Grounding attachment point

Claims

1. A bioelectrode composition containing (A) an ionic resin, characterized in that: The (A) component comprises a resin having a structure of an ammonium salt, lithium salt, sodium salt, or potassium salt selected from trissulfonium methylates.

2. The bioelectrode composition according to claim 1, wherein, The resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates has a chemical structure represented by the following general formula (1); In the formula, R A X is a hydrogen atom or a methyl group; 1 Each is independently a single bond, a phenylene group, or a linking group containing at least one of the following: ester bond, ether bond, carbamate bond, lactone ring, and halogen atom, having 1 to 20 carbon atoms; R 1 and R 2 Each can be independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; M + It can be any one of ammonium ions, lithium ions, sodium ions, and potassium ions.

3. The bioelectrode composition according to claim 2, wherein, The resin having a structure of ammonium salt, lithium salt, sodium salt, or potassium salt selected from trisulfonium methylates contains ammonium ions represented by the following general formula (2) as the M + ; In the formula, R 101d R 101e R 101f R 101g They are respectively a hydrogen atom, a straight-chain, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a straight-chain, branched, or cyclic alkenyl or alkynyl group having 2 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, and may also have one or more of the following: ether group, carbonyl group, ester group, hydroxyl group, amino group, nitro group, sulfonyl group, sulfinyl group, halogen atom, and sulfur atom; R 101d With R 101e R 101d With R 101e With R 101f They can also form rings together with the nitrogen atoms they are bonded to, and when forming rings, R 101d With R 101e and R 101d With R 101e With R 101f It is an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle forming a ring containing a nitrogen atom as shown in the formula.

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

5. The bioelectrode composition according to claim 4, wherein, The component (B) is selected from one or more of polysiloxane resins, (meth)acrylate resins, and polyurethane resins.

6. The bioelectrode composition according to claim 4, wherein, Component (B) is adhesive.

7. The bioelectrode composition according to claim 5, wherein, Component (B) contains R x SiO (4-x) / 2 Polysiloxane resins with units (R being a monovalent hydrocarbon group with or without substituted carbons of 1 to 10, and x being in the range of 2.5 to 3.5) and SiO2 units.

8. The bio-electrode composition according to claim 4 further contains carbon powder and / or metal powder as component (C).

9. The bioelectrode composition according to claim 8, wherein, The toner is either carbon black or carbon nanotubes, or both.

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

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

12. The bioelectrode composition according to claim 4, wherein, The bio-electrode composition also contains organic solvents as component (D).

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

14. The bioelectrode according to claim 13, wherein, The conductive substrate comprises one or more selected from gold, silver, silver chloride, platinum, aluminum, magnesium, tin, tungsten, iron, copper, nickel, stainless steel, chromium, titanium, carbon, and conductive polymers.

15. A method for manufacturing a bioelectrode, comprising manufacturing a bioelectrode having a conductive substrate and a bio-contact layer formed on the conductive substrate, characterized in that: At The bio-electrode composition according to any one of claims 1 to 12 is coated onto the conductive substrate and then hardened thereon to form the bio-contact layer.

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

Images