Electroencephalogram detection electrode

Abstract

To provide an electrode for detecting brain waves which is resistant to the contamination of the scalp.SOLUTION: The brain wave detection electrode 50 has a base part 51, a projection part 60 of an elastic body projecting from the base part 51, and an electrode part 80 provided on the projection part 60, and a contact angle of a surface of the electrode part 80 to water is 100 ° or more and 150 ° or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electrode for detecting electroencephalograms. [Background technology]

[0002] Various developments have been made so far regarding electrodes for detecting brain waves. One known example of this type of technology is the technology described in Patent Document 1. The electrode for measuring brain waves (electrode for detecting brain waves) disclosed in Patent Document 1 includes a base portion, a protruding portion made of rubber and protruding from the base portion, and a contact portion made of metal and provided at the tip of the protruding portion, electrically connected to the outside of the electrode for measuring brain waves, and brought into contact with the scalp when measuring brain waves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5842198 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electroencephalogram (EEG) measuring device having an EEG detector configured with electrodes attached to protrusions (electrode tips) made of an elastic material such as rubber, the electrode tips are brought into contact with the scalp. Dirt that adheres to the electrodes (such as excess sebum, oxidized sebum, resident bacteria, dandruff, etc.) is generally non-conductive, and when such dirt adheres to the electrode tips, it becomes difficult for electricity to flow, increasing contact impedance and making it easier for noise to be mixed into the EEG.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide an electrode for detecting electroencephalograms that is resistant to scalp dirt. [Means for solving the problem]

[0006] According to the present invention, A base and a protruding portion of an elastic body protruding from the base; an electrode portion provided on the protrusion; and The electrode for detecting electroencephalograms is provided, wherein the contact angle of the surface of the electrode portion with respect to water is 100° or more and 150° or less. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an electrode for detecting electroencephalograms that is resistant to scalp dirt. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating an electroencephalogram measuring device according to an embodiment in a state where it is worn on a person's head. [Figure 2] FIG. 2 is a perspective view of a frame according to an embodiment. [Figure 3] FIG. 2 is a front view of an electroencephalogram electrode unit according to an embodiment. [Figure 4] FIG. 2 is a perspective view of an electrode for detecting an electroencephalogram according to an embodiment. [Figure 5] FIG. 2 is a plan view of an electrode for detecting an electroencephalogram according to an embodiment. [Figure 6] FIG. 2 is a cross-sectional view of an electrode for detecting an electroencephalogram according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Summary> Hereinafter, embodiments 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 worn on the head 99 of a person (subject). An electroencephalogram measuring method is carried out in which the electroencephalogram measuring device 1 is worn on the head 99 of the subject and electroencephalograms are measured. The electroencephalogram measuring device 1 is worn on the head 99, detects electroencephalograms as potential fluctuations from the living body, and outputs the detected electroencephalograms to an electroencephalogram display device (not shown). The electroencephalogram display device acquires the electroencephalograms detected by the electroencephalogram measuring device 1 and displays them on a monitor, stores the data, or performs well-known electroencephalogram analysis processing.

[0010] <Structure of the electroencephalogram measuring device 1> The electroencephalogram measuring device 1 has a plurality of electroencephalogram electrode units 10 and a frame 20. In this embodiment, five electroencephalogram electrode units 10 are provided for five channels (five units).

[0011] <Frame 20 Structure> 2 shows a 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.

[0012] 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.

[0013] The inner circumferential surface of the electrode unit attachment portion 21 is threaded, and the EEG electrode unit 10 is screwed into the threaded portion 13 (see Figure 3) of the body portion 11. 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.

[0014] <Structure of EEG electrode unit 10> 3 shows a front view of the EEG electrode unit 10. The EEG electrode unit 10 has a substantially cylindrical body 11 and an electrode 50 for detecting EEG provided on one end side (the lower side in the figure) thereof.

[0015] The body 11 integrally includes a signal output portion 12, a threaded portion 13, and an electrode fixing portion . The threaded portion 13 has a shape in which threads are engraved on the side of a cylindrical shape. A signal extraction portion 12 is provided at one end (upper side in the figure) of the threaded portion 13. A signal output terminal is provided at the signal extraction portion 12, and the signal extraction portion 12 is operated by an operator using a predetermined jig as necessary when screwing the EEG electrode unit 10 to the frame 20. A cylindrical electrode fixing portion 14 is provided at the other end (lower side in the figure) of the threaded portion 13. An EEG detection electrode 50 is attached to the electrode fixing portion 14.

[0016] <Structure of the brain wave detection electrode 50> Fig. 4 is a perspective view of the brain wave detection electrode 50. Fig. 5 is a plan view of the brain wave detection electrode 50. Fig. 6 is a cross-sectional view of the brain wave detection electrode 50, particularly showing the X1-X1 cross-section of Fig. 5.

[0017] The electroencephalogram detection electrode 50 has a base 51, a protruding portion 60, and an electrode portion 80. The base 51 and the protruding portion 60 are integrally formed by a rubber-like elastic body. Specific materials for the elastic body will be described later. The base 51 and the protruding portion 60 are not limited to being integrally formed, and may be formed separately and assembled with an adhesive or a fitting structure.

[0018] The base 51 is generally cylindrical, with one end forming a circular protrusion forming surface 52 and the other end forming a circular mounting surface 53. The mounting surface 53 is attached to the electrode fixing part 14 of the body 11 with an adhesive or the like. There are no particular limitations on the fixing structure between the mounting surface 53 and the electrode fixing part 14, and for example, a fitting structure with a concave-convex shape may be used.

[0019] <Protrusion 60> A plurality of protrusions 60 are aligned and provided on the protrusion-forming surface 52. In this example, seven square pyramidal protrusions 60 are arranged in a lattice pattern. More specifically, they are arranged in an oblique lattice pattern.

[0020] The protrusion 60 has an electrode portion 80 provided within a range of a predetermined height from the apex 61, and comes into contact with the head 99 (scalp). The shape of the protrusion 60 can be a regular square pyramid, or various other shapes such as a polygonal pyramid such as a triangular pyramid or a hexagonal pyramid, or a cone. Also, various lattice arrangements can be adopted.

[0021] <Structure of signal line 69> A conductive signal line 69 (shown by a dashed line in FIG. 6 ) connected to the electrode portion 80 is provided inside the protrusion 60. The signal line 69 may have various arrangement structures as long as it provides electrical continuity inside the protrusion 60. For example, the tip of the signal line 69 may be structured so as to protrude from the electrode formation surface 62 of the protrusion 60, be structured so as to be substantially flush with the electrode formation surface 62, or be structured so as to be buried. A protruding structure may be used from the viewpoint of connection stability with the electrode portion 80. The protruding portion of the tip of the signal line 69 is partially or entirely covered by the electrode portion 80.

[0022] The protruding structure of the tip of the signal wire 69 may be one that is not folded back, one that is folded back, or one that is wound around the surface of the tip of the protrusion 60. The extending direction of the signal wire 69 is not particularly limited, and the signal wire 69 may not coincide with the perpendicular line extending from the protrusion forming surface 52, but may be inclined relative to the perpendicular line.

[0023] <Materials for the EEG detection electrode 50> The material of the brain wave detection electrode 50 will be described. As described above, the brain wave detection electrode 50 is a rubber-like elastic body. Specific examples of rubber-like elastic bodies include rubber and thermoplastic elastomers (also simply referred to as "elastomers (TPE)"). Examples of rubber include silicone rubber (a cured product of a silicone rubber-based curable composition). 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] Here, the silicone rubber (silicone rubber-based curable composition) will be described. The silicone rubber can be a cured product of a silicone rubber-based curable composition. The curing step 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).

[0025] 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.

[0026] 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.

[0027] 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 organopolysiloxane 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 it contains the same vinyl groups as functional groups and has 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.

[0028] The vinyl group-containing organopolysiloxane (A) can contain a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

[0029] The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, which become crosslinking points during curing.

[0030] The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but preferably has two or more vinyl groups in the molecule and is 15 mol% or less, 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 a network with each of the components described below. In this embodiment, the symbol "to" means that both ends of the symbol are included.

[0031] In this specification, the vinyl group content refers to the mole percent of vinyl group-containing siloxane units when all units constituting the vinyl group-containing linear organopolysiloxane (A1) are taken as 100 mole percent, where it is considered that there is one vinyl group per vinyl group-containing siloxane unit.

[0032] 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.

[0033] 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.

[0034] By using a vinyl group-containing linear organopolysiloxane (A1) having a degree of polymerization and specific gravity within the above ranges, it is possible to improve the heat resistance, flame retardancy, chemical stability, etc. of the resulting silicone rubber.

[0035] As the vinyl group-containing linear organopolysiloxane (A1), those having a structure represented by the following formula (1) are particularly preferred.

[0036] [ka]

[0037] In formula (1), R 1 is a hydrocarbon group selected from substituted or unsubstituted alkyl groups, alkenyl groups, aryl groups, or combinations 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.

[0038] Also, R 2 is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a hydrocarbon group combining these groups, each having 1 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, and propyl groups, with methyl being preferred. Examples of alkenyl groups having 1 to 10 carbon atoms include vinyl, allyl, and butenyl groups. Examples of aryl groups having 1 to 10 carbon atoms include phenyl groups.

[0039] Also, R 3 is a substituted or unsubstituted alkyl group or aryl group having 1 to 8 carbon atoms, or a hydrocarbon group consisting of a combination thereof. Examples of alkyl groups having 1 to 8 carbon atoms include methyl, ethyl, and propyl groups, with methyl being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups.

[0040] 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.

[0041] In addition, in formula (1), multiple R 1are independent of each other and may be different or the same. 2 , and R 3 The same is true for .

[0042] 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.

[0043] Specific examples of the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1) include those represented by the following formula (1-1).

[0044] [ka]

[0045] 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.

[0046] 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 typical vinyl group content for raw rubber, 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, more effectively creating a crosslink density distribution within the crosslinked network of the silicone rubber. As a result, the tear strength of the silicone rubber can be more effectively increased.

[0047] 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 2 a 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.

[0048] 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 %.

[0049] 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.

[0050] 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.

[0051] The vinyl group-containing organopolysiloxane (A) may also contain a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

[0052] <<Organohydrogenpolysiloxane (B)>> The silicone rubber-based curable composition of this embodiment may contain a crosslinking agent. The crosslinking agent may contain 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.

[0053] 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 may have at least 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 may be added in different amounts. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different crosslinking agents.

[0054] 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 the components blended into the silicone rubber-based curable composition, thereby crosslinking these components.

[0055] 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.

[0056] 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.

[0057] 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).

[0058] As the linear organohydrogenpolysiloxane (B1) described above, for example, one having a structure represented by the following formula (2) is preferably used.

[0059] [ka]

[0060] In formula (2), R 4 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 the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, and a propyl group, with a methyl group being preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group, and a butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

[0061] 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 the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, and a propyl group, with a methyl group being preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group, and a butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

[0062] In addition, in formula (2), multiple R 4 are independent of each other and may be different or the same. 5 The same applies to multiple R 4 and R5 At least two of these are hydride groups.

[0063] 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, with methyl groups being 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.

[0064] In addition, R in formula (2) 4 ,R 5 ,R 6 Examples 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.

[0065] 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.

[0066] The linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

[0067] 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. Like the linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to silicon (≡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.

[0068] The specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

[0069] Furthermore, it is generally preferred that the branched organohydrogenpolysiloxane (B2) does not contain vinyl groups, which can reliably prevent crosslinking reactions from occurring within the molecules of the branched organohydrogenpolysiloxane (B2).

[0070] The branched organohydrogenpolysiloxane (B2) is preferably one represented by the following average composition formula (c).

[0071] Average composition 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)

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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. 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).

[0076] 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 1000°C at a heating rate of 10°C / min. In contrast, because the linear organohydrogenpolysiloxane (B1) is linear, it leaves almost no residue amount after heating under the above conditions.

[0077] Specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

[0078] [ka]

[0079] In formula (3), R 7 R 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, ethyl, and propyl groups, with methyl being preferred. Examples of aryl groups having 1 to 8 carbon atoms include phenyl groups. 7 Examples of the substituent include a methyl group.

[0080] In addition, in formula (3), multiple R 7 are independent of each other and may be different from each other or may be the same.

[0081] In addition, in formula (3), "-O-Si≡" indicates that Si has a branched structure that spreads three-dimensionally.

[0082] The branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

[0083] 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).

[0084] <<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.

[0085] 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 a common constituent material, but may differ in particle size, specific surface area, surface treatment agent, or 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.

[0086] 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.

[0087] 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 2 / g. The average primary particle size of the silica particles (C) is, for example, preferably from 1 to 100 nm, and more preferably from about 5 to 20 nm.

[0088] 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 of the silicone rubber formed, particularly the tensile strength.

[0089] <<Silane coupling agent (D)>> The silicone rubber-based curable composition of this embodiment may contain a silane coupling agent (D). The silane coupling agent (D) may have a hydrolyzable group, which is hydrolyzed by water to form a hydroxyl group, which 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).

[0090] 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.

[0091] The silane coupling agent (D) may also contain a silane coupling agent having a hydrophobic group. This provides the surface of the silica particles (C), thereby reducing the cohesive strength of the silica particles (C) in the silicone rubber-based curable composition and, ultimately, in the silicone rubber (reducing aggregation due to hydrogen bonding via silanol groups). This is thought to result in improved 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 thought that the sliding properties of the silica particles (C) within the matrix are improved during deformation of the rubber matrix. The improved dispersibility and sliding properties 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).

[0092] Furthermore, the silane coupling agent (D) may contain a silane coupling agent having a vinyl group. This introduces a vinyl group onto the surface of the silica particles (C). Therefore, during curing of the silicone rubber-based curable composition, i.e., when the vinyl groups of the vinyl group-containing organopolysiloxane (A) and the hydride groups of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction to form a network (crosslinked structure), the vinyl groups of the silica particles (C) also participate in the hydrosilylation reaction with the hydride groups of the organohydrogenpolysiloxane (B), thereby incorporating the silica particles (C) into the network. This allows for a silicone rubber with a low hardness and a high modulus to be formed.

[0093] 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.

[0094] Examples of the silane coupling agent (D) include those represented by the following formula (4).

[0095] 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.

[0096] 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.

[0097] 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).

[0098] Further, examples of the hydrolyzable group include alkoxy groups such as methoxy and ethoxy groups, chloro groups, and silazane groups. Among these, silazane groups are preferred because of their high reactivity with the silica particles (C). Note that, those having a silazane group as the hydrolyzable group have structural characteristics such that (Y n -Si-) structures.

[0099] Specific examples of the silane coupling agent (D) represented by the above formula (4) are as follows. As the functional group having hydrophobic group, for example, alkoxysilane such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane; chlorosilane such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane; hexamethyldisilazane.Among these, the silane coupling agent having trimethylsilyl group, including one or more selected from the group consisting of hexamethyldisilazane, trimethylchlorosilane, trimethylmethoxysilane and trimethylethoxysilane, is preferred.

[0100] As the functional group having a vinyl group, for example, alkoxysilanes such as methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane, vinylmethyldichlorosilane; divinyltetramethyldisilazane.Among these, preferred is the silane coupling agent having a vinyl group-containing organosilyl group, comprising one or more selected from the group consisting of methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, divinyltetramethyldisilazane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinylmethyldimethoxysilane.

[0101] 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 one having the hydrophobic group contains hexamethyldisilazane and the one having the vinyl group contains divinyltetramethyldisilazane.

[0102] When a silane coupling agent (D1) having a trimethylsilyl group and a silane coupling agent (D2) having a vinyl-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.

[0103] 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, based on 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, based on 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, it is possible to improve the adhesion between the columnar portion containing the elastomer and the conductive resin layer. It also contributes to improving the mechanical strength of the silicone rubber. Furthermore, by setting the content of the silane coupling agent (D) to the above upper limit or less, it is possible to provide the silicone rubber with appropriate mechanical properties.

[0104] <<Platinum or platinum compounds (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.

[0105] 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, or the amounts of the components added may be different. The insulating silicone rubber-based curable composition and the conductive silicone rubber-based curable composition may further contain different catalysts.

[0106] 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.

[0107] The platinum or platinum compound (E) may be used alone or in combination of two or more.

[0108] In this embodiment, the content of platinum or platinum compound (E) in the silicone rubber-based curable composition means a catalytic amount, which can be set as appropriate, but specifically, it is an amount such that the platinum group metal is 0.01 to 1000 ppm by weight, and 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 adjusting the content of platinum or platinum compound (E) to the above lower limit or more, the silicone rubber-based curable composition can be cured at an appropriate rate. Furthermore, by adjusting the content of platinum or platinum compound (E) to the above upper limit or less, production costs can be reduced.

[0109] <<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).

[0110] Water (F) functions as a dispersion medium to disperse the components contained in the silicone rubber-based curable composition, and also contributes to the reaction between the silica particles (C) and the silane coupling agent (D). This allows the silica particles (C) and the silane coupling agent (D) to be more reliably bonded to each other in the silicone rubber, allowing the composition to exhibit uniform properties overall.

[0111] (Other ingredients) Furthermore, the silicone rubber-based curable composition of this embodiment may further contain other components in addition to the above components (A) to (F), such as 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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 protrusions 60 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 protrusions 60. On the other hand, the upper limit of the content of the silica particles (C) contained in the protrusions 60 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 of the protrusions 60 and the mechanical strength and flexibility.

[0117] The conductive solution is heated and dried as needed to obtain a conductive silicone rubber. The conductive silicone rubber may be configured not to contain silicone oil, which can prevent the silicone oil from bleeding out onto the surface of the protrusion 60 and causing a decrease in conductivity.

[0118] <Material for signal line 69> The signal line 69 may be made of a known material, such as 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.

[0119] 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 strain on the environment, such as chromium.

[0120] 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.

[0121] Examples of the carbon fiber include PAN-based carbon fiber and pitch-based carbon fiber.

[0122] The conductive polymer material for the above-mentioned 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)).

[0123] 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.

[0124] 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.

[0125] 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.

[0126] The signal line 69 may be made of a twisted yarn made by twisting together a plurality of linear conductive fibers, which can prevent the signal line 69 from breaking when the device is deformed.

[0127] 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 single fiber that makes up the twisted yarn.

[0128] The tensile elongation at break of the signal line 69 is, for example, 1% to 50%, and preferably 1.5% to 45%. By keeping the elongation within this range, excessive deformation of the protrusion 60 can be suppressed while preventing breakage during deformation.

[0129] <Material of the electrode portion 80> The conductive material of the electrode portion 80 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 terms of availability and conductivity, silver, silver chloride, and copper are particularly suitable.

[0130] When forming the electrode part 80 with a paste containing a highly conductive metal, the top of the protrusion part 60 made of a rubber-like elastic body is dipped (dipped and coated) in a paste-like conductive solution containing a highly conductive metal. As a result, the electrode part 80 is formed on the surface of the electrode forming surface 62 of the protrusion part 60.

[0131] The electrode portion 80 may be formed as a conductive resin layer by applying a conductive solution containing a conductive filler and a solvent to the electrode formation surface 62 of the protrusion 60. In this case, by using the same material (silicone rubber) as the solvent for the protrusion 60, the adhesion of the electrode portion 80 (conductive resin layer) can be improved.

[0132] The conductive solution is heated and dried as needed to obtain a conductive silicone rubber. The conductive silicone rubber may be configured not to contain silicone oil, which can prevent the silicone oil from bleeding out onto the surface of the electrode part 80 and thereby prevent the conductivity from decreasing.

[0133] This improves the ability to push aside hair when the electroencephalogram measuring device 1 is attached to the head 99. Furthermore, it is possible to ensure a sufficient contact area of ​​the electrode forming surface 62 (i.e., the electrode section 80) when the electroencephalogram measuring device 1 is attached.

[0134] <Water contact angle of electrode portion 80> The contact angle of the surface of the electrode section 80 with water is 100° or more and 150° or less. The lower limit of the contact angle is preferably 105° or more, more preferably 108° or more. The upper limit is preferably 140° or less, more preferably 130° or less. The contact angle with water can be measured using a commercially available contact angle meter.

[0135] The contact angle can be set within a predetermined range by adjusting the surface roughness of the region of the protrusion 60 that is covered by the electrode portion 80 (i.e., the electrode formation surface 62). In other words, the surface roughness of the electrode portion 80 and the surface roughness of the protrusion 60 (electrode formation surface 62) can be made substantially the same. By setting the contact angle within the above range, water repellency is increased, and dirt (such as excess sebum, oxidized sebum, resident bacteria, dandruff, etc.) is less likely to adhere to the electrode unit 80. As a result, it is possible to prevent the contact impedance between the electrode unit 80 and the head 99 from increasing due to dirt, enabling stable electroencephalogram measurement.

[0136] <Surface roughness of protrusion 60> When the protrusion 60 is made of silicone rubber, the surface roughness of the electrode formation surface 62 of the protrusion 60 can be within the following ranges for the arithmetic mean height Sa, maximum height Sz, aspect ratio Str of the surface texture, arithmetic mean curvature of the peaks Spc, and developed surface area ratio Sdr of the interface, which are measured in accordance with ISO 25178.

[0137] The arithmetic mean height Sa is 1.0 μm or more and 5.0 μm or less. The lower limit is preferably 1.2 μm or more, more preferably 1.5 μm or more. The upper limit is preferably 4.5 μm or less, more preferably 4.0 μm or less.

[0138] The maximum height Sz is 20 μm or more and 50 μm or less. The lower limit is preferably 25 μm or more, more preferably 27 μm or more. The upper limit is preferably 60 μm or less, more preferably 50 μm or less.

[0139] The aspect ratio Str of the surface texture is 0.2 or more and 0.5 or less. The lower limit is preferably 0.25 or more, more preferably 0.27 or more. The upper limit is preferably 0.5 or less, more preferably 0.47 or less.

[0140] The arithmetic mean curve Spc of the peaks is 100 or more and 650 or less. The lower limit is preferably 120 or more, and more preferably 140 or more. The upper limit is preferably 650 or less, and more preferably 630 or less.

[0141] The developed surface area ratio Sdr of the interface is 0.01 or more and 0.7 or less. The lower limit is preferably 0.0.02 or more, more preferably 0.03 or more. The upper limit is preferably 0.6 or less, more preferably 0.5 or less.

[0142] Even when the protrusions 60 are made of the same silicone material, the water contact angle increases as the surface roughness (Sa, Spc, Sdr) increases. In other words, the water repellency of the electrode parts 80 of the protrusions 60 increases, making them more resistant to dirt. As a result, stable electroencephalogram measurement can be achieved.

[0143] <Breaking elongation of protrusion 60> The protrusions 60 preferably have a breaking elongation at 25° C. measured in accordance with JIS K7127 of 100% or more and 1100% or less, and more preferably 100 to 300%. By setting the breaking elongation to be equal to or greater than the above-mentioned lower limit, the protrusions 60 can flexibly stretch under tension, and by setting the breaking elongation to be equal to or less than the above-mentioned upper limit, the protrusions 60 can recover their shape after stretching. That is, the protrusions 60 deform appropriately when the EEG detection electrodes 50 are pressed against the head 99, and quickly recover from deformation when the force pressing the EEG detection electrodes 50 against the head 99 is reduced.

[0144] The breaking elongation can be achieved by appropriately selecting and combining known methods, such as the type and amount of raw materials for the protrusion 60, the method for preparing the raw materials, and the method for manufacturing the protrusion 60, and using a method different from conventional methods. Among these, for example, if silicone resin is selected as the raw material for the protrusion 60, factors for setting the above indicators within the desired numerical range include appropriately controlling the type and compounding ratio of the silicone resin, the crosslinking density and crosslinking structure of the resin, and improving the compounding ratio of the inorganic filler and the dispersibility of the inorganic filler. Furthermore, by adjusting the curing conditions, temperature, and time for obtaining the protrusions 60, the crosslink density and crosslinked structure of the resin can be appropriately controlled, and the above indexes can be set within the desired numerical range.

[0145] <Hardness of protrusion 60> When the protrusions 60 are made of silicone rubber, the hardness A of the cured product of the silicone rubber composition, measured as a Type A durometer hardness in accordance with JIS K6253 (1997), is 20 or more and 60 or less. The lower limit of hardness A is preferably 25 or more, and more preferably 35 or more. The upper limit is preferably 55 or less, and more preferably 50 or less.

[0146] By setting the rubber strength of the protrusion portion 60 within the above range, the desired strength can be achieved, and the protrusion portion 60 (electrode portion 80) can be stably abutted against the head 99 without causing discomfort such as pain when the EEG detection electrode 50 is pressed against the head 99.

[0147] Furthermore, by setting the strength of the protrusions 60 within the above ranges and the breaking elongation within the above ranges, it is possible to improve the balance between the strength of the protrusions 60 and their deformation and recovery.

[0148] <Method for manufacturing the brain wave detection electrode 50> An example of a method for manufacturing the electroencephalogram detection electrode 50 of this embodiment can include the following steps. First, the silicone rubber-based curable composition is molded under heat and pressure using a mold to obtain a molded body consisting of base 51 and protrusions 60. At this time, by providing the surface of the mold with an appropriate surface roughness, the surface roughness of the obtained protrusions 60 (i.e., electrode formation surface 62) can be set within the above-mentioned range. Next, a signal line 69 is passed through the inside of each protrusion 60 of the obtained molded body using a sewing needle. Thereafter, a paste-like conductive solution is dip-applied to the electrode formation surface 62 of the protrusion 60 of the obtained molded body, and after heating and drying, post-curing is performed. In this way, the electrode portion 80 can be formed on the electrode formation surface 62 of the protrusion 60. The surface of the electrode portion 80 reflects the surface roughness of the protrusion 60, and has a water contact angle (for example, 100 to 150°) corresponding to that surface roughness. In this manner, the electroencephalogram detecting electrode 50 can be manufactured. In the molding process, insert molding may be used in which the silicone rubber-based hardening composition is introduced into the molding space in which the signal line 69 is disposed, and then molded under pressure and heat.

[0149] <Summary of Features of the Electroencephalogram Measurement Device 1 (Electroencephalogram Detection Electrodes 50)> The features of the electroencephalogram measuring device 1 will be explained in summary, focusing on the protrusions 60 of the electroencephalogram detecting electrodes 50. (1) The electroencephalogram detection electrode 50 has a base 51 and an elastic projection 60 projecting from the base 51; an electrode portion 80 provided on the protrusion portion 60; and The contact angle of the surface of the electrode section 80 with water is 100° or more and 150° or less. By setting the contact angle within the above range, dirt is less likely to adhere to the electrode section 80, and stable electroencephalogram measurement becomes possible. (2) The surface of the protrusion 60 has a cured silicone rubber composition. By making at least the surface of the protrusion 60 out of silicone rubber, it is possible to realize an electroencephalogram detecting electrode 50 that is physically and chemically stable and resistant to dirt. (3) The hardness of the cured product of the silicone rubber composition is 20 or more and 60 or less, measured as a Type A durometer hardness in accordance with JIS K6253 (1997). By setting the hardness within the above range, it is possible to prevent the subject from feeling discomfort such as pain, and to achieve the desired strength. (4) The cured product of the silicone rubber composition has a breaking elongation of 100% or more and 1100% or less at 25°C, as measured in accordance with JIS K7127. By setting the breaking elongation within the above range, it is possible to improve the balance between the strength of the protrusions 60 and their deformation and recovery. (5) The surface roughness Sz of the cured product of the silicone rubber composition is 20 to 50 μm as measured in accordance with ISO 25178. By adjusting the surface roughness of the protrusions 60 in the areas covered by the electrode sections 80, the contact angle of water on the surfaces of the protrusions 60 can be set within a range that is resistant to dirt.

[0150] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations (modifications) other than those described above can also be adopted. [Example]

[0151] The present embodiment will be described in detail below with reference to examples, but the present embodiment is not limited to the descriptions of these examples. In the following examples, we describe the results of rubber hardness and surface roughness measurements and stain resistance tests using samples of silicone rubber and other rubbers (natural rubber, ethylene propylene diene rubber (EPDM), and acrylonitrile butadiene rubber (NBR)). The results are summarized in Table 1.

[0152] <Sample> A sample of silicone rubber (manufactured by Sumitomo Bakelite Co., Ltd., product name "DuraQ") was used in Examples 1 to 3. In Examples 1 to 3, molded articles with different surface shapes were used, with Example 1 being a normal molded article, Example 2 being a mirror-finished molded article, and Example 3 being a matte-finished molded article. In Comparative Example 1, natural rubber (manufactured by Tigers Polymer Co., Ltd., product name "TAKL 6503-HP", product number "2000-K") was used. In Comparative Example 2, EPDM (manufactured by Tigers Polymer Co., Ltd., product name "TAKL 6503-HP", product number "2000-K") was used.

[0153] <Rubber hardness> The rubber hardness A of Examples 1 to 3 and Comparative Examples 1 to 3 was measured in accordance with JIS K6253 A. In Examples 1 to 3, the rubber hardness was 35 degrees, and they were flexible. In Comparative Examples 1 to 3, the rubber hardness was 65 degrees or more, and it was confirmed that they were harder than in Examples 1 to 3.

[0154] <Surface roughness> The surface roughness of Examples 1 to 3 was measured in accordance with ISO 25178 using a measuring device (Keyence Corporation's "Laser Microscope VK-X1100"). The measured parameters were five types: (1) arithmetic mean height Sa, (2) maximum height Sz, (3) aspect ratio of surface texture Str, (4) arithmetic mean curvature of peaks Spc, and (5) developed surface area ratio of the interface Sdr. It was confirmed that, in the silicone rubbers of Examples 1 to 3, even when the material was the same, the water contact angle increased as the surface roughness (Sa, Sz, Spc, Sdr) increased.

[0155] <Water contact angle> The contact angle of each sample of Examples 1 to 3 and Comparative Examples 1 to 3 with respect to water was determined using a contact angle meter ("DROPMASTER-500" manufactured by Kyowa Interface Science Co., Ltd.) by the sessile drop method, in which 2 μL of purified water was deposited on the surface to be measured and the water contact angle was measured 7 seconds later. In Examples 1 to 3, the contact angle was 100° or more, but in Comparative Examples 1 to 3, the contact angle was less than 100°.

[0156] <Stain prevention performance> The following steps [1] to [3] were carried out for each sample in Example 1 and Comparative Examples 1 to 3, and the sample was evaluated. Specifically, the number of times required for wiping and the appearance after wiping were evaluated. Step [1]: The surface of the sample is cleaned with New Rack Wipe (manufactured by Asahi Kasei Advance Corporation) and dried. Step [2]: Draw lines with a white oil-based pen (Pentel White (product number: X100W-SD), manufactured by Pentel) and let it dry thoroughly. Step [3]: Use the New Lac Wipe to wipe and see how many wipes it takes to remove the permanent marker. The appearance after wiping was evaluated as "◯" if the ink was completely wiped off, and "×" if any ink remained unremoved. In Example 1, the ink was completely removed by wiping once. In Comparative Example 1, wiping was performed four times, and the ink on the surface was removed, but the ink had soaked into the sample and could not be completely removed. In Comparative Example 2, wiping was performed five times, and although the ink on the surface was removed, the ink soaked into the sample and could not be completely removed. The samples of Comparative Examples 1 to 3 had the most residual ink. In Comparative Example 3, the ink was wiped off five times, and although the ink on the surface was removed, the ink had soaked into the sample and could not be completely removed.

[0157] [Table 1] [Explanation of symbols]

[0158] 1. EEG measuring device 10 EEG electrode unit 20 frames 21 Electrode unit mounting part 50 Electrodes for detecting brain waves 51 Base 52 Projection forming surface 60 Protrusion 61 Projection body 62 Electrode formation surface

Claims

[Claim 1] A base and a protruding portion of an elastic body protruding from the base; an electrode portion provided on the protrusion; and An electrode for detecting brain waves, wherein the contact angle of the surface of the electrode portion with water is 100° or more and 150° or less.

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