Electroencephalographic electrode

Abstract

This electroencephalographic electrode (100) comprises a base part (90), a conductive layer (30) having electrical conductivity, and a linear conductive wire material (40). The base part (90) has a plurality of protruding parts (80), each of which is an elastic body having a conical shape, on one surface (24). The conductive layer (30) is formed in at least one of the protruding parts (80). The conductive wire material (40) penetrates the base part (90) and is electrically connected to the conductive layer (30). The protruding parts (80) include side surface parts (11) that are continuous with the one surface (24). The conductive wire material (40) is provided on at least one of a first side surface part (11a), a second side surface part (11b) that is located facing to the first side surface part (11a), and a bottom surface part (24a) of the one surface (24) that is located between the first side surface part (11a) and the second side surface part (11b).

Description

EEG measurement electrodes

[0001] The present invention relates to an electrode for measuring electroencephalograms.

[0002] Patent Document 1 discloses a biological electrode having an elastic columnar portion and a conductive wire. Patent Document 2 discloses an electrode for measuring electroencephalograms in which a conductive paste layer is provided between the electrode portion and a snap button.

[0003] International Publication No. 2020 / 095589 Japanese Patent Application Laid-Open No. 2022-23458

[0004] In the above-mentioned Patent Document 1, the conductive wire is attached to the elastic columnar portion, but depending on the position where the conductive wire is attached, it may be difficult to stably attach the conductive wire. If the conductive wire is not stably attached, the stability of the conductivity will be impaired. In the above-mentioned Patent Document 2, the electrode portion and the snap button are electrically connected via a conductive paste layer. However, if the adhesive strength between the electrode portion and the snap button is low, the stability of the conductivity will be impaired.

[0005] One example of a problem that the present invention aims to solve is stabilizing electrical conductivity.

[0006] According to the present invention, the following technologies are realized: 1. An electroencephalogram (EEG) measurement electrode comprising: a base portion having a plurality of cone-shaped protruding elastic portions on one surface; a conductive conductive layer formed on at least a portion of the protruding portions; and a linear conductive wire that penetrates the base portion and is electrically connected to the conductive layer, wherein the protruding portions include side portions that are continuous with the one surface, and the conductive wire is provided on at least one of a first side portion of the side portions, a second side portion facing the first side portion, and a bottom portion of the one surface that is between the first side portion and the second side portion. 2. The electroencephalogram measurement electrode described in 1., wherein the conductive wire is provided on the bottom surface. 3. The electroencephalogram measurement electrode described in 1. or 2., wherein the conductive wire penetrates from at least one of the first side portion, the second side portion, and the bottom surface toward the other surface opposite the one surface. 4. The electroencephalogram measuring electrode according to 1. or 2., wherein the conductive wire penetrates from at least one of the first side surface portion, the second side surface portion, and the bottom surface portion toward the side surface of the base portion. 5. The electroencephalogram measuring electrode according to 1. or 2., wherein the conductive wire includes a first penetration portion and a second penetration portion that penetrate the base portion, and a connection portion that connects the first penetration portion and the second penetration portion on the one surface side. 6. The electroencephalogram measuring electrode according to 1. or 2., wherein the conductive wire includes a ring-shaped portion that wraps around at least one of the protrusions. 7. The electroencephalogram measuring electrode according to 1. or 2., wherein the protrusion has a hexagonal pyramidal shape. 8. The electroencephalogram measuring electrode according to 1. or 2. 2. The electroencephalogram measuring electrode according to claim 1, wherein the plurality of conductive wires are evenly arranged at predetermined intervals with respect to the center of the one surface.9. An electrode for measuring electroencephalograms comprising: a base portion having a plurality of protruding elastic body portions on one surface; a conductive conductive layer formed on at least a portion of the protruding portions; a plate-shaped conductive plate provided on the other surface opposite to the one surface; and a linear conductive wire that penetrates the base portion and is electrically connected to the conductive layer, the conductive wire being in contact with the conductive plate and bent so as to follow the surface along which the conductive plate extends. 10. An electrode for measuring electroencephalograms comprising: a base portion having a plurality of protruding elastic body portions on one surface; a conductive conductive layer formed on at least a portion of the protruding portions; a plate-shaped conductive plate provided on the other surface opposite to the one surface; and a linear conductive wire that penetrates the base portion and is electrically connected to the conductive layer, the conductive wire being in contact with the conductive plate and penetrating the conductive plate. 11. An electrode for measuring electroencephalograms according to 9. or 10., wherein the conductive wire is fixed to the conductive plate by soldering, tape, or adhesive. 12. The electrode for measuring electroencephalograms according to 9. or 10., further comprising a cap member that presses the base portion and the conductive plate against each other.

[0007] According to the present invention, an electrode for measuring electroencephalograms that can stabilize conductivity can be provided.

[0008] FIG. 1 is a diagram schematically showing an EEG measuring device in a state where it is worn on a person's head. FIG. 2 is a schematic perspective view of a frame. FIG. 3 is a schematic front view of an EEG electrode unit. FIG. 4 is a schematic perspective view of an EEG measuring electrode. FIG. 5 is a schematic plan view of an EEG measuring electrode. FIG. 6 is a diagram schematically showing a cross section of an EEG measuring electrode according to a first embodiment. FIG. 7 is a diagram schematically showing a cross section of an EEG measuring electrode according to a second embodiment. FIG. 8 is a diagram schematically showing a cross section of an EEG measuring electrode according to a third embodiment. FIG. 9 is a diagram schematically showing a cross section of an EEG measuring electrode according to a fourth embodiment. FIG. 10 is a diagram schematically showing a cross section of an EEG measuring electrode according to a fifth embodiment. FIG. 11 is a schematic plan view of an EEG measuring electrode according to a sixth embodiment. FIG. 12 is a diagram schematically showing a cross section of an EEG measuring electrode according to the sixth embodiment. FIG. 13 is a diagram schematically showing a cross section of an EEG measuring electrode according to the seventh embodiment. FIG. 14 is a diagram schematically showing a cross section of an EEG measuring electrode according to an eighth embodiment.

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and their description will be omitted where appropriate. The drawings are schematic diagrams and do not correspond to the actual dimensional proportions.

[0010] <First Embodiment> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram schematically showing an electroencephalogram (EEG) measuring device 1 attached to a person's head 99. An electroencephalogram measuring method is carried out in which the EEG measuring device 1 is attached to the head 99 of a subject and electroencephalograms are measured. The EEG measuring device 1 is attached to the head 99, detects electroencephalograms as potential fluctuations from the living body, and outputs the detected electroencephalograms to an EEG display device (not shown). The EEG display device acquires the EEG detected by the EEG measuring device 1 and displays it on a monitor, stores the data, and performs well-known electroencephalogram analysis processing.

[0011] (Structure of EEG Measuring Device 1) As shown in Fig. 1 , the EEG measuring device 1 has a plurality of EEG electrode units 10 and a frame 20. In this embodiment, five EEG electrode units 10 (five units) are provided for five channels.

[0012] (Structure of Frame 20) Fig. 2 is a schematic perspective view of the frame 20. The frame 20 is formed in a belt-like shape from a hard material such as polyamide resin, and is curved so as to fit the shape of a human head 99.

[0013] The frame 20 is provided with five electrode unit mounting sections 21 as openings for mounting the EEG electrode units 10. The positions of the electrode unit mounting sections 21 (i.e., the mounting positions of the EEG electrode units 10) correspond to the positions T3, C3, Cz, C4, and T4 in the International 10-20 electrode placement method.

[0014] The inner circumferential surface of the electrode unit attachment section 21 is threaded, and the EEG electrode unit 10 is screwed into the threaded section 13 (see Figure 3) of the body 15. By adjusting the amount by which the EEG electrode unit 10 is screwed in, the amount of protrusion toward the head 99 can be adjusted, thereby controlling the amount and pressure of contact with the head 99 (scalp). In addition, the action of screwing in the EEG electrode unit 10 also pushes hair aside.

[0015] (Structure of EEG electrode unit 10) Fig. 3 is a schematic front view of the EEG electrode unit 10. The EEG electrode unit 10 has a substantially cylindrical body 15 and an EEG measurement electrode 100 provided on one end side (the lower side in the figure) of the body 15.

[0016] The body 15 integrally has a signal extraction section 12, a threaded section 13, and an electrode fixing section 14. The threaded section 13 is threaded into the side of a cylindrical shape. The signal extraction section 12 is provided at one end (upper side in the figure) of the threaded section 13. A signal output terminal is provided on the signal extraction section 12, and it is operated by an operator using a predetermined tool as necessary when screwing the EEG electrode unit 10 to the frame 20. A cylindrical electrode fixing section 14 is provided at the other end (lower side in the figure) of the threaded section 13. An EEG measurement electrode 100 is attached to the electrode fixing section 14.

[0017] (Electroencephalogram measuring electrode 100) Fig. 4 is a schematic perspective view of the electroencephalogram measuring electrode 100. Fig. 5 is a schematic plan view of the electroencephalogram measuring electrode 100. Fig. 6 is a diagram showing a schematic cross section of the electroencephalogram measuring electrode 100 according to the first embodiment. Fig. 6 particularly shows the A-A cross section of Fig. 5.

[0018] The electroencephalogram measuring electrode 100 includes a base portion 90, a plurality of protruding portions 80, an electrically conductive conductive layer 30, a linear conductive wire 40, and a snap button portion 70. The base portion 90 and the protruding portions 80 are integrally formed by a rubber-like elastic body. Note that the base portion 90 and the protruding portions 80 are not limited to being integrally formed, and may be formed separately and assembled with an adhesive or a fitting structure.

[0019] (Base portion 90) The base portion 90 is substantially cylindrical, with one end forming a circular first surface 24 and the other end forming a circular second surface 22. The second surface 22 is the surface opposite to the first surface 24. The second surface 22 may be attached to the snap button portion 70 with silver paste or the like. The base portion 90 may be made of resin or may be composed of a conductive material. The base portion 90 has a plurality of cone-shaped protrusions 80 made of an elastic body on the first surface 24.

[0020] (Protrusions 80) A plurality of protrusions 80 are aligned and provided on one surface 24. In the first embodiment, the protrusions 80 have a hexagonal pyramid shape. In the first embodiment, the protrusions 80 are substantially regular hexagonal pyramids. As the shape of the protrusions 80, various shapes can be adopted, such as a regular hexagonal pyramid, a polygonal pyramid such as a triangular pyramid or a square pyramid, or a cone.

[0021] In the first embodiment, 19 regular hexagonal protrusions 80 are arranged at equal intervals. More specifically, in Figures 5 and 6, three protrusions 80 are arranged in the first row, four in the second row, five in the third row, four in the fourth row, and three in the fifth row, with adjacent protrusions 80 arranged symmetrically in the vertical and horizontal directions. In the first embodiment, the multiple protrusions 80 are arranged symmetrically in the vertical and horizontal directions with respect to the center C of one surface 24. Note that adjacent protrusions 80 may be arranged so that their bases are in contact with each other without any gaps, or there may be gaps.

[0022] The protrusion 80 includes a side surface portion 11 that is continuous with the one surface 24. The side surface portion 11 is continuous with the one surface 24. In the first embodiment, the side surface portion 11 is a sloped portion of the surface of the protrusion 80. The side surface portion 11 according to the first embodiment includes the apex 61 of the protrusion 80. The side surface portion 11 according to the first embodiment connects the apex 61 of the protrusion 80 with the one surface 24. The side surface portion 11 includes a first side surface portion 11a and a second side surface portion 11b, which will be described later.

[0023] <Materials of the Base Portion 90 and the Protruding Portion 80> The materials of the base portion 90 and the protruding portion 80 will be described. The base portion 90 and the protruding portion 80 are configured to have a rubber-like elastic body. Specific examples of the rubber-like elastic body include rubber and thermoplastic elastomer (also simply referred to as "elastomer (TPE)"). An example of rubber is silicone rubber. Examples of thermoplastic elastomers include styrene-based TPE (TPS), olefin-based TPE (TPO), vinyl chloride-based TPE (TPVC), urethane-based TPE (TPU), ester-based TPE (TPEE), and amide-based TPE (TPAE).

[0024] When the base portion 90 and the protruding portion 80 are made of silicone rubber, the rubber hardness A is, for example, 15 or more and 55 or less, when the Type A durometer hardness of the surface (the protruding portion 80 and the base portion 90) of the electroencephalogram measuring electrode 100 measured at 37°C in accordance with JIS K 6253 (1997) is defined as rubber hardness A.

[0025] Here, the silicone rubber-based curable composition will be described. The silicone rubber can be composed of a cured product of the silicone rubber-based curable composition. The curing process of the silicone rubber-based curable resin composition is carried out, for example, by heating at 100 to 250°C for 1 to 30 minutes (primary curing) and then post-baking at 100 to 200°C for 1 to 4 hours (secondary curing).

[0026] The insulating silicone rubber is a silicone rubber that does not contain a conductive filler, and the conductive silicone rubber is a silicone rubber that contains a conductive filler.

[0027] The silicone rubber-based curable composition according to this embodiment can contain a vinyl group-containing organopolysiloxane (A). The vinyl group-containing organopolysiloxane (A) is a polymer that serves as the main component of the silicone rubber-based curable composition according to this embodiment.

[0028] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of vinyl group-containing linear organopolysiloxane. The same type of vinyl group-containing linear organopolysiloxanes may be different in the amount of vinyl groups in the molecule, the molecular weight distribution, or the amount of vinyl groups added, as long as they contain the same vinyl groups as functional groups and have a linear shape. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different vinyl group-containing organopolysiloxanes.

[0029] The vinyl group-containing organopolysiloxane (A) can include a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

[0030] The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, and these vinyl groups become crosslinking points during curing.

[0031] The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but preferably contains two or more vinyl groups in the molecule and is 15 mol% or less, and more preferably 0.01 to 12 mol%. This optimizes the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1), ensuring the formation of networks with the components described below. In this embodiment, the symbol "to" means that both ends of the symbol are included.

[0032] In this specification, the vinyl group content refers to the mol % of vinyl group-containing siloxane units when all units constituting the vinyl group-containing linear organopolysiloxane (A1) are taken as 100 mol %, where it is considered that there is one vinyl group per vinyl group-containing siloxane unit.

[0033] The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably within a range of, for example, about 1,000 to 10,000, and more preferably about 2,000 to 5,000. The degree of polymerization can be determined, for example, as the polystyrene-equivalent number average degree of polymerization (or number average molecular weight) measured by GPC (gel permeation chromatography) using chloroform as a developing solvent.

[0034] Furthermore, the specific gravity of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 0.9 to 1.1.

[0035] By using a vinyl group-containing linear organopolysiloxane (A1) having a degree of polymerization and specific gravity within the above ranges, the heat resistance, flame retardancy, chemical stability, and other properties of the resulting silicone rubber can be improved.

[0036] As the vinyl group-containing linear organopolysiloxane (A1), those having a structure represented by the following formula (1) are particularly preferred.

[0037]

[0038] In formula (1), R １ is a hydrocarbon group that is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a combination thereof having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups, with vinyl groups being preferred. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0039] Also, R ２ is a hydrocarbon group that is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a combination thereof having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0040] Also, R ３ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups.

[0041] Furthermore, R in formula (1) １ and R ２ Examples of the substituent of R include a methyl group and a vinyl group. ３ Examples of the substituent include a methyl group.

[0042] In addition, in formula (1), a plurality of R １ are independent of each other and may be different from each other or may be the same. ２ , and R ３ The same is true for .

[0043] Furthermore, m and n are the numbers of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1), where m is an integer of 0 to 2000 and n is an integer of 1000 to 10000. m is preferably 0 to 1000, and n is preferably 2000 to 5000.

[0044] Specific examples of the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1) include those represented by the following formula (1-1):

[0045]

[0046] In formula (1-1), R １ and R ２ are each independently a methyl group or a vinyl group, and at least one of them is a vinyl group.

[0047] Furthermore, the vinyl group-containing linear organopolysiloxane (A1) preferably contains a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more vinyl groups in the molecule and a vinyl group content of 0.4 mol% or less, and a second vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%. Combining a first vinyl group-containing linear organopolysiloxane (A1-1) with a vinyl group content typical of crude rubber, which is the raw material for silicone rubber, with a second vinyl group-containing linear organopolysiloxane (A1-2) with a high vinyl group content allows for uneven distribution of vinyl groups and more effectively creates a variation in crosslink density within the crosslinked network of the silicone rubber. As a result, the tear strength of the silicone rubber can be more effectively increased.

[0048] Specifically, the vinyl group-containing linear organopolysiloxane (A1) may be, for example, a vinyl group-containing linear organopolysiloxane represented by the above formula (1-1), １ is a vinyl group and / or R ２a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more units in the molecule in which R is a vinyl group and containing 0.4 mol% or less of the unit; １ is a vinyl group and / or R ２ It is preferable to use a second vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol % of units in which each of the units is a vinyl group.

[0049] The first vinyl group-containing linear organopolysiloxane (A1-1) preferably has a vinyl group content of 0.01 to 0.2 mol %, and the second vinyl group-containing linear organopolysiloxane (A1-2) preferably has a vinyl group content of 0.8 to 12 mol %.

[0050] Furthermore, when the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) are combined and blended, the ratio of (A1-1) to (A1-2) is not particularly limited, but for example, the weight ratio of (A1-1):(A1-2) is preferably 50:50 to 95:5, and more preferably 80:20 to 90:10.

[0051] The first and second vinyl group-containing linear organopolysiloxanes (A1-1) and (A1-2) may each be used alone or in combination of two or more.

[0052] The vinyl group-containing organopolysiloxane (A) may also contain a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

[0053] <<Organohydrogenpolysiloxane (B)>> The silicone rubber-based curable composition of this embodiment may contain a crosslinking agent. The crosslinking agent may contain an organohydrogenpolysiloxane (B). The organohydrogenpolysiloxane (B) is classified into a linear organohydrogenpolysiloxane (B1) having a linear structure and a branched organohydrogenpolysiloxane (B2) having a branched structure, and may contain either one or both of these.

[0054] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of crosslinking agent. The same type of crosslinking agent only needs to have a common structure, such as a linear or branched structure, and may have different molecular weight distributions or different functional groups in the molecule, or the amounts added may differ. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different crosslinking agents.

[0055] The linear organohydrogenpolysiloxane (B1) has a linear structure and a structure in which hydrogen is directly bonded to Si (≡Si—H), and is a polymer that undergoes a hydrosilylation reaction with the vinyl groups of the vinyl group-containing organopolysiloxane (A) and with vinyl groups of components blended into the silicone rubber-based curable composition, thereby crosslinking these components.

[0056] The molecular weight of the linear organohydrogenpolysiloxane (B1) is not particularly limited, but for example, the weight average molecular weight is preferably 20,000 or less, and more preferably 1,000 or more and 10,000 or less.

[0057] The weight average molecular weight of the linear organohydrogenpolysiloxane (B1) can be measured, for example, by gel permeation chromatography (GPC) using chloroform as a developing solvent, in terms of polystyrene.

[0058] Furthermore, it is generally preferred that the linear organohydrogenpolysiloxane (B1) does not contain a vinyl group, which can reliably prevent the crosslinking reaction from proceeding within the molecule of the linear organohydrogenpolysiloxane (B1).

[0059] As the linear organohydrogenpolysiloxane (B1) described above, for example, one having a structure represented by the following formula (2) is preferably used.

[0060]

[0061] In formula (2), R ４is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these, or a hydride group having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0062] Also, R ５ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these, or a hydride group having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl groups, allyl groups, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0063] In addition, in formula (2), a plurality of R ４ are independent of each other and may be different from each other or may be the same. ５ The same applies to multiple R ４ and R ５ At least two of these are hydride groups.

[0064] Also, R ６ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, and among these, methyl groups are preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups. ６ are independent of each other and may be different from each other or may be the same.

[0065] In addition, R in formula (2) ４ , R ５ , R ６Examples of the substituent include a methyl group and a vinyl group, and a methyl group is preferred from the viewpoint of preventing intramolecular crosslinking reactions.

[0066] Furthermore, m and n are the numbers of repeating units constituting the linear organohydrogenpolysiloxane (B1) represented by formula (2), where m is an integer of 2 to 150 and n is an integer of 2 to 150. Preferably, m is an integer of 2 to 100 and n is an integer of 2 to 100.

[0067] The linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

[0068] Because the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms regions with high crosslink density and is a component that significantly contributes to the formation of a sparsely crosslinked structure in the silicone rubber system. Similarly to the linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to Si (≡Si—H), and undergoes a hydrosilylation reaction with the vinyl groups of the vinyl group-containing organopolysiloxane (A) and with the vinyl groups of other components incorporated into the silicone rubber-based curable composition, forming a polymer that crosslinks these components.

[0069] The specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

[0070] Furthermore, it is generally preferred that the branched organohydrogenpolysiloxane (B2) does not contain a vinyl group, which can reliably prevent the crosslinking reaction from proceeding within the molecule of the branched organohydrogenpolysiloxane (B2).

[0071] The branched organohydrogenpolysiloxane (B2) is preferably one represented by the following average composition formula (c):

[0072] Average compositional formula (c) (H ａ (R ７ ) ３－ａ SiO １／２ ) ｍ (SiO ４／２ ) ｎ(In formula (c), R ７ is a monovalent organic group, a is an integer ranging from 1 to 3, and m is H ａ (R ７ ) ３－ａ SiO １／２ The number of units, n, is SiO ４／２ (the number of units)

[0073] In formula (c), R ７ is a monovalent organic group, preferably a substituted or unsubstituted alkyl group or aryl group having 1 to 10 carbon atoms, or a hydrocarbon group consisting of a combination thereof. Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, and propyl groups, with methyl being preferred. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0074] In formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer ranging from 1 to 3, preferably 1.

[0075] In addition, in formula (c), m is H ａ (R ７ ) ３－ａ SiO １／２ The number of units, n, is SiO ４／２ The number of units.

[0076] The branched organohydrogenpolysiloxane (B2) has a branched structure. The linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) differ in their structures, that is, whether they are linear or branched, and the number of alkyl groups R bonded to Si (R / Si), where the number of Si is 1, is in the range of 1.8 to 2.1 for the linear organohydrogenpolysiloxane (B1) and 0.8 to 1.7 for the branched organohydrogenpolysiloxane (B2).

[0077] Because the branched organohydrogenpolysiloxane (B2) has a branched structure, it leaves a residue amount of 5% or more when heated, for example, in a nitrogen atmosphere to 1,000° C. at a heating rate of 10° C. / min. In contrast, because the linear organohydrogenpolysiloxane (B1) is linear, it leaves a residue amount of almost zero after heating under the above conditions.

[0078] Specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

[0079]

[0080] In formula (3), R ７ is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group combining these, or a hydrogen atom. Examples of alkyl groups having 1 to 8 carbon atoms include methyl groups, ethyl groups, and propyl groups, with methyl groups being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups. R ７ Examples of the substituent include a methyl group.

[0081] In addition, in formula (3), a plurality of R ７ are independent of each other and may be different from each other or may be the same.

[0082] In addition, in formula (3), "-O-Si≡" indicates that Si has a branched structure that spreads three-dimensionally.

[0083] The branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

[0084] Furthermore, the amount of hydrogen atoms (hydride groups) directly bonded to Si in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) is not particularly limited. However, in the silicone rubber-based curable composition, the total amount of hydride groups in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) is preferably 0.5 to 5 moles, more preferably 1 to 3.5 moles, per mole of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1). This ensures the reliable formation of a crosslinked network between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1).

[0085] <<Silica Particles (C)>> The silicone rubber-based curable composition according to this embodiment contains a non-conductive filler. The non-conductive filler may contain silica particles (C) as needed. This can improve the hardness and mechanical strength of the elastomer.

[0086] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of non-conductive filler. Non-conductive fillers of the same type may have at least common constituent materials, but may differ in particle size, specific surface area, surface treatment agent, or the amount of surface treatment agent added. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different silane coupling agents.

[0087] The silica particles (C) are not particularly limited, but examples thereof include fumed silica, calcined silica, precipitated silica, etc. These may be used alone or in combination of two or more.

[0088] The silica particles (C) have a specific surface area of, for example, 50 to 400 m2 as measured by the BET method. ２ / g, and 100 to 400m ２The average primary particle size of the silica particles (C) is preferably, for example, 1 to 100 nm, and more preferably about 5 to 20 nm.

[0089] By using silica particles (C) having a specific surface area and average particle size within the above ranges, it is possible to improve the hardness and mechanical strength, particularly the tensile strength, of the silicone rubber formed.

[0090] <<Silane Coupling Agent (D)>> The silicone rubber-based curable composition of this embodiment can contain a silane coupling agent (D). The silane coupling agent (D) can have a hydrolyzable group. The hydrolyzable group is hydrolyzed by water to form a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl groups on the surface of the silica particles (C), thereby modifying the surface of the silica particles (C).

[0091] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of silane coupling agent. Silane coupling agents of the same type may have at least a common functional group, but may differ in other functional groups in the molecule or in the amount added. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different silane coupling agents.

[0092] Furthermore, this silane coupling agent (D) can contain a silane coupling agent having a hydrophobic group. This provides the hydrophobic group to the surface of the silica particles (C), thereby reducing the cohesive force of the silica particles (C) in the silicone rubber-based curable composition, and ultimately in the silicone rubber (reducing aggregation due to hydrogen bonding through silanol groups). This is presumably improving the dispersibility of the silica particles (C) in the silicone rubber-based curable composition. This increases the interface between the silica particles (C) and the rubber matrix, enhancing the reinforcing effect of the silica particles (C). Furthermore, it is presumed that the slipperiness of the silica particles (C) within the matrix improves during deformation of the rubber matrix. The improved dispersibility and slipperiness of the silica particles (C) improve the mechanical strength (e.g., tensile strength, tear strength, etc.) of the silicone rubber due to the silica particles (C).

[0093] Furthermore, the silane coupling agent (D) can contain a silane coupling agent having a vinyl group. This allows the vinyl group to be introduced onto the surface of the silica particles (C). Therefore, when the silicone rubber-based curable composition is cured, that is, when the vinyl group of the vinyl group-containing organopolysiloxane (A) and the hydride group of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction to form a network (crosslinked structure), the vinyl group of the silica particles (C) also participates in the hydrosilylation reaction with the hydride group of the organohydrogenpolysiloxane (B), and the silica particles (C) are also incorporated into the network. This allows the formed silicone rubber to have a low hardness and a high modulus.

[0094] As the silane coupling agent (D), a silane coupling agent having a hydrophobic group and a silane coupling agent having a vinyl group can be used in combination.

[0095] Examples of the silane coupling agent (D) include those represented by the following formula (4).

[0096] Y ｎ -Si-(X) ４－ｎ... (4) In the above formula (4), n represents an integer of 1 to 3. Y represents a functional group having a hydrophobic group, a hydrophilic group, or a vinyl group, and when n is 1, it is a hydrophobic group, and when n is 2 or 3, at least one of the groups is a hydrophobic group. X represents a hydrolyzable group.

[0097] The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group formed by combining these groups, such as a methyl group, an ethyl group, a propyl group, or a phenyl group, with a methyl group being particularly preferred.

[0098] Examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group, and among these, a hydroxyl group is particularly preferred. Although a hydrophilic group may be contained as a functional group, it is preferable that the hydrophilic group is not contained from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

[0099] Further, examples of the hydrolyzable group include an alkoxy group such as a methoxy group or an ethoxy group, a chloro group, or a silazane group. Among these, a silazane group is preferred because of its high reactivity with the silica particles (C). Note that, in the case of a compound having a silazane group as a hydrolyzable group, the (Y ｎ The resulting structure has two —Si— structures.

[0100] Specific examples of the silane coupling agent (D) represented by the above formula (4) are as follows. Examples of the silane coupling agent (D) having a hydrophobic group as the functional group include alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, and decyltrimethoxysilane; chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; and hexamethyldisilazane. Among these, silane coupling agents having a trimethylsilyl group containing one or more selected from the group consisting of hexamethyldisilazane, trimethylchlorosilane, trimethylmethoxysilane, and trimethylethoxysilane are preferred.

[0101] As the one having vinyl group as the functional group, for example, can be mentioned alkoxysilane such as methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; chlorosilane such as vinyltrichlorosilane, vinylmethyldichlorosilane; divinyltetramethyldisilazane.Among these, preferred is the silane coupling agent having vinyl group-containing organosilyl group, comprising one or more selected from the group consisting of methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, divinyltetramethyldisilazane, vinyltriethoxysilane, vinyltrimethoxysilane and vinylmethyldimethoxysilane.

[0102] Furthermore, when the silane coupling agent (D) contains two types of silane coupling agents, one having a trimethylsilyl group and the other having a vinyl group-containing organosilyl group, it is preferable that the silane coupling agent containing the hydrophobic group is hexamethyldisilazane, and the silane coupling agent containing the vinyl group is divinyltetramethyldisilazane.

[0103] When a silane coupling agent (D1) having a trimethylsilyl group and a silane coupling agent (D2) having a vinyl group-containing organosilyl group are used in combination, the ratio of (D1) to (D2) is not particularly limited, but for example, the weight ratio of (D1):(D2) is 1:0.001 to 1:0.35, preferably 1:0.01 to 1:0.20, and more preferably 1:0.03 to 1:0.15. By adjusting the weight ratio within this range, the desired physical properties of the silicone rubber can be obtained. Specifically, a balance can be achieved between the dispersibility of silica in the rubber and the crosslinkability of the rubber.

[0104] In this embodiment, the lower limit of the content of the silane coupling agent (D) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, relative to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). The upper limit of the content of the silane coupling agent (D) is preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 40% by mass or less, relative to 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A). By setting the content of the silane coupling agent (D) to the above lower limit or more, the adhesion between the columnar portion containing the elastomer and the conductive resin layer can be improved. This can also contribute to improving the mechanical strength of the silicone rubber. Setting the content of the silane coupling agent (D) to the above upper limit or less allows the silicone rubber to have appropriate mechanical properties.

[0105] <<Platinum or Platinum Compound (E)>> The silicone rubber-based curable composition according to this embodiment may contain a catalyst. The catalyst may contain platinum or a platinum compound (E). The platinum or platinum compound (E) is a catalytic component that acts as a catalyst during curing. The amount of platinum or platinum compound (E) added is a catalytic amount.

[0106] The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may contain the same type of catalyst. The same type of catalyst is sufficient as long as they have at least common constituent materials, and the catalyst may contain different compositions, and the amounts added may be different. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different catalysts.

[0107] As the platinum or platinum compound (E), known compounds can be used, such as platinum black, platinum supported on silica or carbon black, chloroplatinic acid or an alcohol solution of chloroplatinic acid, a complex salt of chloroplatinic acid and an olefin, and a complex salt of chloroplatinic acid and a vinylsiloxane.

[0108] The platinum or platinum compound (E) may be used alone or in combination of two or more.

[0109] In this embodiment, the content of platinum or platinum compound (E) in the silicone rubber-based curable composition refers to a catalytic amount and can be set as appropriate. Specifically, the amount is an amount such that the platinum group metal is 0.01 to 1000 ppm by weight, preferably 0.1 to 500 ppm, per 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A), silica particles (C), and silane coupling agent (D). By setting the content of platinum or platinum compound (E) to be equal to or greater than the above-mentioned lower limit, the silicone rubber-based curable composition can be cured at an appropriate rate. Furthermore, setting the content of platinum or platinum compound (E) to be equal to or less than the above-mentioned upper limit can contribute to reducing production costs.

[0110] <<Water (F)>> Furthermore, the silicone rubber-based hardening composition according to this embodiment may contain water (F) in addition to the above components (A) to (E).

[0111] Water (F) functions as a dispersion medium for dispersing the components contained in the silicone rubber-based curable composition, and is also a component that contributes to the reaction between the silica particles (C) and the silane coupling agent (D). Therefore, the silica particles (C) and the silane coupling agent (D) can be more reliably bonded to each other in the silicone rubber, and uniform properties can be exhibited overall.

[0112] (Other Components) Furthermore, the silicone rubber-based curable composition of this embodiment may further contain other components in addition to the above components (A) to (F). Examples of these other components include inorganic fillers other than the silica particles (C), such as diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica, as well as additives such as reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, and thermal conductivity improvers.

[0113] The conductive solution (conductive silicone rubber composition) according to this embodiment contains the above-mentioned conductive filler and solvent in addition to the above-mentioned silicone rubber-based curable composition that does not contain a conductive filler.

[0114] As the solvent, various known solvents can be used, including, for example, high-boiling point solvents, which may be used alone or in combination of two or more.

[0115] Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, cyclohexane, heptane, methylcyclohexane, ethylcyclohexane, octane, decane, dodecane, and tetradecane; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, trifluoromethylbenzene, and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, cyclopentyl ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, 1,4-dioxane, 1,3-dioxane, and tetrahydrofuran; haloalkanes such as dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, and 1,1,2-trichloroethane; carboxylic acid amides such as N,N-dimethylformamide and N,N-dimethylacetamide; and sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide. These may be used alone or in combination of two or more.

[0116] The conductive solution can have a viscosity suitable for various application methods such as spray application and dip application by adjusting the amount of solids in the solution.

[0117] Furthermore, when the conductive solution contains the conductive filler and the silica particles (C), the lower limit of the content of the silica particles (C) contained in the EEG measurement electrode 100 can be, for example, 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more, relative to 100% by mass of the total amount of the silica particles (C) and the conductive filler. This can improve the mechanical strength of the EEG measurement electrode 100. On the other hand, the upper limit of the content of the silica particles (C) contained in the EEG measurement electrode 100 can be, for example, 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less, relative to 100% by mass of the total amount of the silica particles (C) and the conductive filler. This can achieve a balance between the conductivity and the mechanical strength and flexibility of the EEG measurement electrode 100.

[0118] The conductive solution can be heated and dried as needed to obtain a conductive silicone rubber. The conductive silicone rubber may be configured to be free of silicone oil. This prevents the silicone oil from bleeding out onto the surface of the EEG electrode 100 (the protruding portion 80), thereby preventing a decrease in conductivity.

[0119] (Conductive layer 30) The conductive layer 30 is formed on at least a part of the protruding portion 80. In the first embodiment, the conductive layer 30 is provided so as to cover the entire surface of the protruding portion 80. In the first embodiment, the conductive layer 30 is provided so as to cover the entire side portion 11. The conductive layer 30 may be provided so as to cover at least a part of the one surface 24. In the first embodiment, the conductive layer 30 comes into contact with the head 99 (scalp).

[0120] <Material of Conductive Layer 30> The conductive layer 30 is, for example, a paste containing a highly conductive metal. The highly conductive metal includes one or more metals selected from the group consisting of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, and alloys thereof. In particular, silver, silver chloride, and copper are suitable from the viewpoints of availability and conductivity.

[0121] (Conductive Wire 40) The conductive wire 40 (40a, 40b, 40c, 40d) shown in FIG. 6 has a linear shape. The conductive wire 40 has a shape extending in one direction. The conductive wire 40 is conductive and electrically connected to the conductive layer 30 provided on the surface of the protrusion 80 (side surface portion 11). The conductive wire 40 penetrates the base portion 90. The conductive wire 40 is provided on at least one of the first side surface portion 11a, the second side surface portion 11b facing the first side surface portion 11a, and the bottom surface portion 24a of the one surface 24 between the first side surface portion 11a and the second side surface portion 11b. The conductive wire 40 penetrates from at least one of the first side surface portion 11a, the second side surface portion 11b, and the bottom surface portion 24a toward the other surface 22.

[0122] In the first embodiment, the conductive wire 40a is provided on the bottom surface 24a. The conductive wire 40a penetrates the base 90 (the other surface 22) and the snap button 70 in a direction along the center line C1. One end of the conductive wire 40a may be bent along the surface of the snap button 70.

[0123] As another example, the conductive wire 40d is also provided on the bottom surface portion 24a. The conductive wire 40d penetrates the base portion 90 (the other surface 22) but does not penetrate the snap button portion 70. The tip of the conductive wire 40d may be bent and sandwiched between the base portion 90 and the snap button portion 70.

[0124] As another example, the conductive wire 40b is provided on the first side surface 11a. The conductive wire 40b is provided on the first side surface 11a between the vertex 61 and the bottom surface 24a (one tip of the conductive wire 40b is provided away from the vertex 61 and the bottom surface 24a). The conductive wire 40b penetrates the protrusion 80, the base portion 90 (the other surface 22), and the snap button portion 70. The tip of the conductive wire 40b may be bent along the surface of the snap button portion 70.

[0125] As another example, the conductive wire 40c is provided on the second side surface portion 11b. The conductive wire 40c is provided on the second side surface portion 11b between the vertex 61 and the bottom surface portion 24a. The conductive wire 40c penetrates the protrusion 80 and the base portion 90 (the other surface 22), but does not penetrate the snap button portion 70. The tip of the conductive wire 40c may be bent and sandwiched between the base portion 90 and the snap button portion 70.

[0126] In the first embodiment, the plurality of conductive wires 40 are arranged symmetrically with respect to a center line C1 passing through the center C of the one surface 24 .

[0127] The thick lines B1 and B2 in FIG. 5 indicate locations where the conductive wires 40 according to the first embodiment can be arranged. The thick line B1 indicates the outer periphery of the protrusion 80a, including the center C. The thick line B2 indicates the outer periphery of the protrusion 80b arranged around the protrusion 80a. The plurality of conductive wires 40 may be arranged at predetermined intervals with respect to the center C of the one surface 24. For example, the plurality of conductive wires 40 may be arranged at equal intervals with respect to the center C along the cross-sectional line A-A shown in FIG. 5.

[0128] <Material of the Conductive Wire 40> The conductive wire 40 may be made of a known material, for example, a conductive fiber. The conductive fiber may be one or more types selected from the group consisting of metal fiber, metal-coated fiber, carbon fiber, conductive polymer fiber, conductive polymer-coated fiber, and conductive paste-coated fiber. These may be used alone or in combination of two or more types.

[0129] The metal material of the metal fibers and metal-coated fibers is not limited as long as it is conductive, but examples include copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, stainless steel, aluminum, silver / silver chloride, and alloys thereof. These may be used alone or in combination of two or more. Among these, silver can be used from the viewpoint of conductivity. Furthermore, it is preferable that the metal material does not contain metals that put a burden on the environment, such as chromium.

[0130] The fiber materials for the metal-coated fibers, conductive polymer-coated fibers, and conductive paste-coated fibers are not particularly limited, but may be synthetic fibers, semi-synthetic fibers, or natural fibers. Among these, polyester, nylon, polyurethane, silk, cotton, etc. are preferred. These may be used alone or in combination of two or more.

[0131] Examples of the carbon fiber include PAN-based carbon fiber and pitch-based carbon fiber.

[0132] The conductive polymer material for the conductive polymer fibers and conductive polymer-coated fibers may be, for example, a mixture of a conductive polymer such as polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylene vinylene, polynaphthalene, or a derivative thereof and a binder resin, or an aqueous solution of a conductive polymer such as PEDOT-PSS ((3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid)).

[0133] The resin material contained in the conductive paste of the conductive paste-coated fiber is not particularly limited, but preferably has elasticity, and may contain, for example, one or more selected from the group consisting of silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, and ethylene propylene rubber. These may be used alone or in combination of two or more.

[0134] The conductive filler contained in the conductive paste of the conductive paste-coated fiber is not particularly limited, and may be any known conductive material, but may include one or more selected from the group consisting of metal particles, metal fibers, metal-coated fibers, carbon black, acetylene black, graphite, carbon fibers, carbon nanotubes, conductive polymers, conductive polymer-coated fibers, and metal nanowires.

[0135] The metal constituting the conductive filler is not particularly limited, but may include, for example, at least one of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, silver / silver chloride, or alloys thereof, or two or more of these. Among these, silver or copper is preferred because of its high conductivity and easy availability.

[0136] The conductive wire 40 may be made of a twisted yarn in which a plurality of linear conductive fibers are twisted together, thereby preventing breakage of the conductive wire 40 during deformation.

[0137] In this embodiment, the coating of conductive fibers does not simply mean covering the outer surface of the fiber material, but also includes, in the case of a twisted yarn made by twisting together single fibers, impregnating the gaps between the fibers in the twisted yarn with metal, conductive polymer, or conductive paste to coat each of the single fibers that make up the twisted yarn.

[0138] The tensile breaking elongation of the conductive wire 40 is, for example, 1% to 50%, preferably 1.5% to 45%. By setting the elongation within this range, excessive deformation of the protrusion 80 can be suppressed while preventing breakage during deformation.

[0139] According to the first embodiment, the electroencephalogram measuring electrode 100 includes the protrusion 80, the base portion 90, the conductive layer 30, and the conductive wire 40. The conductive wire 40 according to the first embodiment is provided on at least one of the first side surface portion 11 a, the second side surface portion 11 b, and the bottom surface portion 24 a. By arranging the conductive wire 40 in a position that makes it easy to attach, conductivity can be stabilized.

[0140] Furthermore, the conductive wire 40 is provided on the bottom surface 24a, which allows the conductive wire 40 to be disposed in a more stable position, thereby making it possible to further stabilize the conductivity.

[0141] Furthermore, the protruding portion 80 according to the first embodiment has a hexagonal pyramidal shape, which stabilizes the protruding portion 80 and allows it to be securely placed against the person's head 99. Furthermore, since multiple protruding portions 80 can be arranged on the disk-shaped base portion 90 in a comfortable manner, more protruding portions 80 can be arranged on the base portion 90.

[0142] Furthermore, the plurality of conductive wires 40 according to the first embodiment may be disposed at equal intervals with respect to the center C of the one surface 24. This makes it possible to further stabilize the conductivity.

[0143] 7 is a diagram schematically illustrating a cross section of an electroencephalogram measuring electrode 100 according to a second embodiment. The conductive wire 40 according to the second embodiment penetrates from at least one of the first side surface portion 11 a, the second side surface portion 11 b, and the bottom surface portion 24 a toward the side surface 23 of the base portion 90. The conductive layer 30 according to the second embodiment is provided so as to cover the side surface 23 in addition to the side surface portion 11.

[0144] In the second embodiment, the conductive wire 40e is provided on the second side surface portion 11b. The conductive wire 40e penetrates the base portion 90 in a direction oblique to the center line C1. The tip of the conductive wire 40e may be bent along the surface of the side surface 23. The conductive wire 40e is electrically connected to the snap button 70 through the conductive layer 30 provided on the side surface 23.

[0145] In the second embodiment, the conductive wire 40f is provided on the bottom surface portion 24a. Like the conductive wire 40e, the conductive wire 40f penetrates the base portion 90 in a direction oblique to the center line C1. The tip of the conductive wire 40f may be bent along the surface of the side surface 23, and the tip may extend to the snap button 70. In this way, the conductive wire 40f is electrically connected to the snap button 70. The second embodiment also provides the same effects as the first embodiment.

[0146] <Third embodiment> Fig. 8 is a diagram schematically showing a cross section of an electroencephalogram measuring electrode 100 according to a third embodiment. The conductive wire 40 according to the third embodiment includes first through-portions 41 (41h, 41g) and second through-portions 42 (42h, 42g) that penetrate the base portion 90, and a connecting portion 43 (43h, 43g) that connects the first through-portion 41 and the second through-portion 42 on the one surface 24 side. In the third embodiment, the first through-portion 41 and the second through-portion 42 penetrate along the direction of the center line C1. The connecting portion 43 extends along the one surface 24. The first through-portion 41, the second through-portion 42, and the connecting portion 43 are continuous.

[0147] In the third embodiment, the connection portion 43g is provided on the bottom surface portion 24a. The first through portion 41g and the second through portion 42g penetrate the base portion 90.

[0148] In the third embodiment, the connecting portion 43h is provided on the first side surface portion 11a. The connecting portion 43h may be provided across multiple first side surface portions 11a (side surface portions 11). The first through portion 41h and the second through portion 42h penetrate the protruding portion 80 and the base portion 90.

[0149] In the conductive wire 40 according to the third embodiment, by fixing one conductive wire 40 in a loop shape, the conductive wire 40 is less likely to come off the base portion 90 .

[0150] <Fourth embodiment> Fig. 9 is a diagram schematically showing a cross section of an electroencephalogram measuring electrode 100 according to a fourth embodiment. The conductive wire 40 according to the fourth embodiment includes a loop-shaped portion 44 that is wound around at least one protrusion 80. The loop-shaped portion 44 may be wound across multiple protrusions 80. In the fourth embodiment, as in the third embodiment, the conductive wire 40 is less likely to come off the base portion 90 (protrusion 80).

[0151] Fifth Embodiment Fig. 10 is a diagram schematically illustrating a cross section of an electroencephalogram measuring electrode 100 according to a fifth embodiment. In the fifth embodiment, the shape of the protrusion 80 differs from that of the first embodiment. As shown in Fig. 10, the side surface portion 11 (first side surface portion 11a, second side surface portion 11b) according to the fifth embodiment may be configured not to include the vertex 61 of the protrusion 80. The protrusion 80 according to the fifth embodiment further includes an upper surface portion 16 in addition to the side surface portion 11. The upper surface portion 16 connects the side surface portion 11 and the vertex 61. The upper surface portion 16 is not continuous with the surface 24.

[0152] <Sixth embodiment> Fig. 11 is a schematic plan view of an electroencephalogram measuring electrode 100. Fig. 12 is a schematic cross-sectional view of the electroencephalogram measuring electrode 100 according to the sixth embodiment. Fig. 12 particularly shows the A-A cross section of Fig. 6.

[0153] The electroencephalogram measuring electrode 100 includes a base portion 90, a plurality of elastic protrusions 80, a conductive conductive layer 30, linear conductive wires 40, and a snap button 70. The base portion 90 and the protrusions 80 are integrally formed using a rubber-like elastic material. Note that the base portion 90 and the protrusions 80 are not limited to being integrally formed, and may be formed separately and assembled using an adhesive or a fitting structure. The snap button 70 includes a plate-shaped conductive plate 71 and a column-shaped columnar portion 72. The conductive plate 71 and the columnar portion 72 may be integrally formed.

[0154] The base portion 90 has a generally cylindrical shape, with one end forming a circular first surface 24 and the other end forming a circular second surface 22. The second surface 22 is the surface opposite to the first surface 24. The second surface 22 faces the side where the conductive plate 71 (snap button 70) is provided. The base portion 90 may be made of resin or a conductive material. The base portion 90 has a plurality of cone-shaped protrusions 80 made of an elastic body on the first surface 24. In the sixth embodiment, the diameter of the base portion 90 is larger than the diameter of the conductive plate 71. In the radial direction DR1 of the base portion 90, the end 90a of the base portion 90 is located outside the end 71a of the conductive plate 71.

[0155] (Conductive Wire 40) The conductive wire 40 (40a, 40b) shown in FIG. 6 has a linear shape. The conductive wire 40 has a shape extending in one direction. The conductive wire 40 is conductive. In the sixth embodiment, the conductive wire 40 is electrically connected to the conductive layer 30 provided on the one surface 24. The conductive wire 40 may also be electrically connected to the conductive layer 30 provided on the surface of the protruding portion 80 (side surface portion 11). The conductive wire 40 penetrates the base portion 90. The conductive wire 40 that penetrates the base portion 90 contacts the conductive plate 71. The conductive wire 40 is bent so as to follow the surface (first surface 71b and second surface 71c described below) on which the conductive plate 71 extends. The conductive wire 40 may also be fixed to the conductive plate 71 by soldering, tape, or adhesive. When the conductive wire 40 is fixed with tape or adhesive, the length of the bent portion (the length of the portion in contact with the conductive plate 71) is preferably 5 mm or more.

[0156] The conductive plate 71 includes a first surface 71b and a second surface 71c. The first surface 71b faces the base portion 90 (other surface 22). The first surface 71b is in contact with the base portion 90 (other surface 22). The second surface 71c is located on the opposite side of the first surface 71b. The first surface 71b and the second surface 71c are surfaces on which the conductive plate 71 extends.

[0157] In the sixth embodiment, the conductive wire 40a penetrates from the one surface 24 to the other surface 22. The conductive wire 40a penetrates the base portion 90 (the other surface 22) in a direction along the center line C1. One tip 40a1 of the conductive wire 40a is bent along the first surface 71b (the other surface 22). The tip 40a1 is sandwiched between the base portion 90 and the snap button 70. The tip 40a1 is sandwiched between the other surface 22 of the base portion 90 and the first surface 71b of the conductive plate 71. The conductive wire 40a is fixed to the conductive plate 71 by soldering or applying an adhesive to the tip 40a1. The conductive wire 40a is electrically connected to the conductive layer 30 provided on the one surface 24 and also to the conductive plate 71 (the snap button 70).

[0158] In the sixth embodiment, the conductive wire 40b also penetrates from the first surface 24 to the second surface 22. The conductive wire 40b also penetrates the base portion 90 (the second surface 22) in a direction along the center line C1. One end 40b1 of the conductive wire 40b is bent along the second surface 71c. The end 40b1 is not sandwiched between the base portion 90 and the snap button 70. In the radial direction DR1, the conductive wire 40b is located outside the end 71a of the conductive plate 71. The conductive wire 40b is fixed to the conductive plate 71 (the second surface 71c) by soldering or applying an adhesive to the end 40b1. The conductive wire 40b is electrically connected to the conductive layer 30 provided on the first surface 24 and also to the conductive plate 71 (the snap button 70). The materials exemplified in the first embodiment can be used for the conductive wire 40.

[0159] According to the sixth embodiment, the electroencephalogram measuring electrode 100 includes the protruding portion 80, the base portion 90, the conductive layer 30, the conductive plate 71, and the conductive wire 40.

[0160] Conventionally, a silver paste layer or the like is sandwiched between a base portion and a conductive plate (snap button portion), and electrical continuity between the conductive wire and the conductive plate (snap button portion) is achieved through the silver paste layer. That is, electrical continuity is achieved in the order of conductive layer, conductive wire, silver paste layer, and conductive plate (snap button portion). However, there are problems such as a decrease in adhesive strength between the base portion and the snap button portion, and a decrease in the probability of forming a conductive path between the conductive wire and the snap button depending on the thickness of the silver paste layer, resulting in unstable conductivity of the EEG measurement electrode.

[0161] However, the electroencephalogram measuring electrode 100 according to the sixth embodiment does not have a silver paste layer, and the conductive wire 40 according to the sixth embodiment is in contact with the conductive plate 71 and is bent so as to follow the surfaces (first surface 71b, second surface 71c) along which the conductive plate 71 extends. In this way, by adopting a configuration without using a silver paste layer, it is possible to stabilize the conductivity.

[0162] <Seventh embodiment> Fig. 13 is a diagram showing a schematic cross section of an electroencephalogram measuring electrode 100 according to the seventh embodiment. Unlike the sixth embodiment, the electroencephalogram measuring electrode 100 according to the seventh embodiment further includes a cap member 60. The cap member 60 has a hollow cylindrical shape. The cap member 60 houses a base portion 90 and a conductive plate 71. The cap member 60 presses the base portion 90 and the conductive plate 71 against each other. By using the cap member 60, the base portion 90 and the conductive plate 71 are tightly attached to each other. The cap member 60 may be made of resin.

[0163] The electroencephalogram measuring electrode 100 according to the seventh embodiment further includes the cap member 60, which improves the adhesion between the base portion 90 and the conductive plate 71, i.e., the adhesion between the conductive wire 40 and the conductive plate 71. This makes it possible to stabilize the conductivity.

[0164] 14 is a diagram schematically illustrating a cross section of an electroencephalogram measuring electrode 100 according to an eighth embodiment. The conductive wire 40 according to the eighth embodiment is in contact with the conductive plate 71 and passes through the conductive plate 71. The conductive wire 40a and the conductive wire 40b according to the eighth embodiment pass through both the base portion 90 and the conductive plate 71.

[0165] The tip 40a1 of the conductive wire 40a and the tip 40b1 of the conductive wire 40b are exposed from the second surface 71c. The tip 40a1 and the tip 40b1 may be bent along the second surface 71c, as in the sixth embodiment.

[0166] In the eighth embodiment, the conductive wires 40a and 40b may also be fixed to the conductive plate 71 by soldering or adhesive. The tip 40a1 of the conductive wire 40a and the tip 40b1 of the conductive wire 40b may be tied together to prevent the conductive wires 40 from slipping out of the conductive plate 71.

[0167] Although not shown, in the eighth embodiment, the electroencephalogram measuring electrode 100 may further include a cap member 60.

[0168] The conductive wire 40 according to the eighth embodiment is in contact with the conductive plate 71 and penetrates the conductive plate 71. In the eighth embodiment, the electroencephalogram measuring electrode 100 can also be configured without using a silver paste layer, thereby stabilizing conductivity.

[0169] Examples are described below. As an example, an electroencephalogram (EEG) measuring electrode 100 was used, in which the conductive wire 40 and the snap button 70 (conductive plate 71) were electrically connected without using a silver paste layer. As a comparative example, an electroencephalogram measuring electrode was used, in which the conductive wire and the snap button (conductive plate) were electrically connected by inserting a silver paste layer between the base and the snap button. Specifically, the average contact resistance [Ω] between the base and the snap button was measured for each lot (Lot 1 to Lot 5), and the yield rate [%] for each lot was calculated.

[0170] Figure 15 shows the evaluation results of the example and the comparative example. As shown in Figure 15, the example in which the conductive wire 40 is directly in contact with the snap button 70 (conductive plate 71) without using a silver paste layer has a higher yield rate. In other words, by adopting the configuration according to the embodiment, the yield rate can be improved. Note that "O.L." in "2 Lot" indicates that measurement was not possible.

[0171] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0172] The conductive wire 40 according to the first embodiment may be attached to the first side portion 11a, the second side portion 11b, and the bottom portion 24a in any manner, and may be attached by applying adhesive to the tip of the conductive wire 40, or by tying a knot at the tip of the conductive wire 40.

[0173] The apexes 61 of the protrusions 80 other than the protrusion 80 including the center C may be eccentric toward the outside in the radial direction of the base portion 90 .

[0174] The method for attaching the conductive wire 40 in the sixth embodiment to one surface 24 is arbitrary, and the conductive wire 40 may be attached by applying adhesive to the tip thereof, or by tying a knot at the tip thereof.

[0175] This application claims priority based on Japanese Patent Application Nos. 2024-013940, 2024-014018, and 2024-014021, filed on February 1, 2024, the disclosures of which are incorporated herein in their entirety by reference.

[0176] REFERENCE SIGNS LIST 11 Side portion 11a First side portion 11b Second side portion 16 Top surface portion 22 Other surface 23 Side surface 24 One surface 24a Bottom surface portion 30 Conductive layer 40 Conductive wire material 41 First through portion 42 Second through portion 43 Connection portion 44 Ring-shaped portion 50 Protruding portion 70 Snap button (snap button portion) 90 Base portion 99 Head 100 Electrode for measuring electroencephalograms

Claims

1. An electrode for measuring electroencephalograms, comprising: a base portion having a plurality of conical protrusions made of an elastic material on one surface; a conductive conductive layer formed on at least a portion of the protrusions; and a linear conductive wire that passes through the base portion and is electrically connected to the conductive layer, wherein the protrusions include side portions that are continuous with the one surface, and the conductive wire is provided on at least one of a first side portion of the side portions, a second side portion facing the first side portion, and a bottom portion of the one surface that is between the first side portion and the second side portion.

2. An electrode for measuring electroencephalograms according to claim 1, wherein the conductive wire is provided on the bottom surface.

3. An electrode for measuring electroencephalograms according to claim 1 or 2, wherein the conductive wire penetrates from at least one of the first side surface, the second side surface, and the bottom surface toward the other surface opposite the one surface.

4. An electrode for measuring electroencephalograms as described in claim 1 or 2, wherein the conductive wire penetrates from at least one of the first side surface portion, the second side surface portion, and the bottom surface portion toward the side surface of the base portion.

5. An electrode for measuring electroencephalograms according to claim 1 or 2, wherein the conductive wire includes a first penetration portion and a second penetration portion that penetrate the base portion, and a connecting portion that connects the first penetration portion and the second penetration portion on the one surface side.

6. An electrode for measuring electroencephalograms according to claim 1 or 2, wherein the conductive wire includes a loop-shaped portion wound around at least one of the protrusions.

7. An electrode for measuring electroencephalograms according to claim 1 or 2, wherein the protrusion has a hexagonal rod shape.

8. An electrode for measuring electroencephalograms according to claim 1 or 2, wherein the plurality of conductive wires are evenly arranged at predetermined intervals relative to the center of the one surface.

9. An electrode for measuring electroencephalograms, comprising: a base portion having a plurality of elastic protrusions on one surface; a conductive layer formed on at least a portion of the protrusions; a plate-shaped conductive plate provided on the other surface opposite the one surface; and a linear conductive wire that passes through the base portion and is electrically connected to the conductive layer, wherein the conductive wire is in contact with the conductive plate and is bent so as to follow the surface along which the conductive plate extends.

10. An electrode for measuring electroencephalograms, comprising: a base portion having a plurality of protrusions on one surface; a conductive layer formed on at least a portion of the protrusions; a plate-shaped conductive plate provided on the other surface opposite the one surface; and a linear conductive wire that passes through the base portion and is electrically connected to the conductive layer, wherein the conductive wire is in contact with the conductive plate and passes through the conductive plate.

11. An electrode for measuring electroencephalograms according to claim 9 or 10, wherein the conductive wire is fixed to the conductive plate by soldering, tape or adhesive.

12. An electrode for measuring electroencephalograms according to claim 9 or 10, further comprising a cap member for pressing the base portion and the conductive plate together.

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