JP2024010553A - Electrode for biological signal measurement, biological signal measurement device, and biological signal measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique to inhibit discomfort felt by a subject when an electrode for biological signal measurement is brought into contact with the subject's skin.

SOLUTION: An electrode 50 for brain wave measurement (an electrode for biological signal measurement) which acquires a brain wave (a biological signal) by being brought into contact with a subject's head 99 (skin) comprises: projection parts 60 which project from a base 51; and electrode parts 80 provided at at least the tip portions of the projection parts 60 to acquire the brain wave. The projection parts 60 are configured of elastic members and a specific heat of the elastic members at 30°C is 1500 J/kg°C - 1900 J/kg°C.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a biological signal measuring electrode, a biological signal measuring device, and a biological signal measuring method.

Until now, various developments have been made regarding electrodes for measuring biological signals. As this type of technology, for example, the technology described in Patent Document 1 and Patent Document 2 is known.

Patent Document 1 discloses a base portion, a protrusion portion made of rubber that protrudes from the base portion, and is provided at the tip of the protrusion portion and is electrically connected to the outside of the electroencephalogram measurement electrode, An electroencephalogram measurement electrode (electrode for electroencephalogram detection) is disclosed that includes a contact portion made of metal that comes into contact with the scalp during the measurement of the electroencephalogram.

Patent Document 2 discloses clothing for biological information measurement that has both heat retention and lightness, and is particularly suitable for knitted innerwear. Specifically, the clothing is formed with electrodes that contact the wearer's skin, and the clothing is made of a knitted fabric having a basis weight of 60 to 250 g/m ² and a thickness of 0.2 to 0.9 mm. The short fiber A has a single fiber fineness of 0.2 to 0.9 dtex; A blended yarn obtained by blending short fibers B with a difference in single fiber fineness of 0.4 dtex or more from the short fibers A at a mass ratio of 3:7 to 8:2 is applied to the entire knitted fabric. The blended yarn contains 50% by mass or more, and the fineness of the blended yarn is 40 to 100.

Patent No. 5842198 JP 2019-122564 Publication

By the way, when acquiring biological signals using electrodes for measuring biological signals, the tip of the electrode comes into contact with the subject's skin, but at this time the subject feels cold, which may have an inappropriate effect on the biological signal measurement. There was a need for countermeasure technology. In Patent Documents 1 and 2, such points were not taken into consideration.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a technique for suppressing a subject from feeling cold when a biological signal measuring electrode comes into contact with the subject's skin. purpose.

According to the present invention, the following technology is provided.
[1]
An electrode for measuring biological signals that is brought into contact with the skin of a subject to acquire biological signals,
a protrusion protruding from the base;
a conductive part that is provided at least at the tip of the protrusion and acquires the biological signal;
has
The protruding portion is made of an elastic member,
An electrode for measuring biological signals, wherein the elastic member has a specific heat of 1500 J/kg °C or more and 1900 J/kg °C or less at 30 °C.
[2]
The biological signal measuring electrode according to [1], wherein the elastic member is made of silicone rubber.
[3]
The silicone rubber contains a filler,
The biological signal measuring electrode according to [2], wherein the content of the filler in the entire silicone rubber is 20% by weight or more and 50% by weight or less.
[4]
The biological signal measuring electrode according to any one of [1] to [3], wherein the protrusion has a shape of a cone or a cone with its tip removed.
[5]
The height of the protrusion is 0.5 mm to 20 mm,
The biological signal measuring electrode according to any one of [1] to [4], wherein the width of the bottom surface of the protrusion is 2 mm to 5 mm.
[6]
The volume of each of the protrusions is 0.3 mm ³ to 131 mm ³ ,
The biological signal measuring electrode according to any one of [1] to [5].
[7]
The biological signal measuring electrode according to any one of [1] to [6], wherein the base portion and the protruding portion are integrally configured.
[8]
The biological signal measuring electrode according to any one of [1] to [7], wherein the conductive portion is provided in an area of at least 10% in the height direction from the tip portion of the protrusion.
[9]
The biological signal measuring electrode according to any one of [1] to [7], wherein the conductive part is provided only at the tip of the protrusion.
[10]
The conductive part has a first conductive part that covers a tip of the protrusion, and a second conductive part that covers a surface of the base where the protrusion is provided, and the first conductive part and the The electrode for measuring biological signals according to any one of [1] to [7], wherein the two conductive parts are connected.
[11]
The first conductive part is formed by further providing a conductive material on a conductive material provided in common to the base and the protrusion at the tip of the protrusion. Electrodes for measuring biological signals.
[12]
The biological signal measuring electrode according to [10], wherein the conductive material constituting the first conductive part and the conductive material constituting the second conductive part are different.
[13]
It has a signal line that outputs the biological signal acquired by the conductive part to the outside,
The biological signal measuring electrode according to any one of [10] to [12], wherein the signal line is connected to the second conductive part, passes through the inside of the base, and is output to the outside.
[14]
The biological signal measuring electrode according to any one of [1] to [13], wherein the elastic member includes a conductive material.
[15]
The biological signal measuring electrode according to any one of [1] to [14], wherein the biological signal is a brain wave.
[16]
A biosignal measuring device comprising the biosignal measuring electrode according to any one of [1] to [15].
[17]
A biosignal measuring method comprising: attaching the biosignal measuring device according to [16] to the head of a subject and measuring brain waves.

According to the present invention, it is possible to provide a technique for suppressing a subject from feeling cold when a biological signal measuring electrode comes into contact with the subject's skin.

FIG. 1 is a diagram schematically showing an electroencephalogram measurement device attached to a person's head according to an embodiment. FIG. 2 is a perspective view of a frame according to the first embodiment. FIG. 2 is a front view of the electroencephalogram electrode unit according to the first embodiment. FIG. 2 is a perspective view of an electroencephalogram measurement electrode according to the first embodiment. FIG. 2 is a plan view of an electroencephalogram measurement electrode according to the first embodiment. 6 is a cross-sectional view of the electroencephalogram measurement electrode according to the first embodiment, particularly showing a cross-sectional view taken along the line X1-X1 in FIG. 5. FIG. FIG. 3 is a cross-sectional view of an electroencephalogram measurement electrode according to a second embodiment. FIG. 7 is a cross-sectional view of an electroencephalogram measurement electrode according to a third embodiment. FIG. 7 is a cross-sectional view of an electroencephalogram measurement electrode according to a fourth embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a biological signal measurement technique will be described. Brain waves will be exemplified as a biological signal. In addition to brain waves, biological signals include, for example, cardiac potential, myoelectric potential, and skin potential.

<<First embodiment>>
<Summary>
Embodiments of the present invention will be described below with reference to the drawings.
In this embodiment, when the biological signal measurement electrode (more specifically, the electroencephalogram measurement electrode) comes into contact with the subject's skin (more specifically, the head), the subject feels cold. We will explain the technology to suppress this. The protruding part on which the conductive part (electrode part) for acquiring biological signals is provided is formed of an elastic member, and the specific heat of the protruding part (i.e., the elastic member), which has a large capacity in terms of heat capacity, is set within an appropriate range.

FIG. 1 is a diagram schematically showing an electroencephalogram measuring device 1 attached to a head 99 of a person (subject). An electroencephalogram measurement method is performed in which the electroencephalogram measurement device 1 is attached to the subject's head 99 and the electroencephalogram is measured. The brain wave measuring device 1 is attached to the head 99, detects brain waves as potential fluctuations from a living body, and outputs the detected brain waves to a brain wave display device (not shown). The electroencephalogram display device acquires the electroencephalograms detected by the electroencephalogram measurement device 1, displays them on a monitor, stores the data, and performs well-known electroencephalogram analysis processing.

<Structure of electroencephalogram measuring device 1>
The electroencephalogram measuring device 1 includes a plurality of electroencephalogram electrode units 10 and a frame 20. In this embodiment, the electroencephalogram electrode units 10 are provided for 5 channels (5 pieces).

<Structure of frame 20>
FIG. 2 shows a perspective view of the frame 20. The frame 20 is made of a hard material such as polyamide resin, and is formed into a band shape and curved to follow the shape of the human head 99.

The frame 20 is provided with five electrode unit attachment portions 21 as openings for attaching the electroencephalogram electrode units 10. The position of the electrode unit attachment part 21 (ie, the attachment position of the electroencephalogram electrode unit 10) corresponds to the positions of T3, C3, Cz, C4, and T4 in the international 10-20 electrode placement method.

The inner peripheral surface of the electrode unit attachment part 21 is threaded, and the electroencephalogram electrode unit 10 is screwed into the body part 11 by the threaded part 13 (see FIG. 3). By adjusting the amount by which the electroencephalogram electrode unit 10 is screwed in, the amount of protrusion toward the head 99 is adjusted, and the amount and contact pressure of contact with the head 99 (scalp) are controlled. Further, by screwing in the electroencephalogram electrode unit 10, hair is pushed aside.

<Structure of the electroencephalogram electrode unit 10>
FIG. 3 shows a front view of the electroencephalogram electrode unit 10. The electroencephalogram electrode unit 10 includes a substantially cylindrical body 11 and an electroencephalogram measurement electrode 50 provided at one end (lower side in the figure) of the body.

The body portion 11 integrally includes a signal extraction portion 12, a threaded portion 13, and an electrode fixing portion 14.
The threaded portion 13 is threaded on the side surface of a cylindrical shape. A signal extraction section 12 is provided at one end (upper side in the figure) of the threaded section 13. The signal extraction section 12 is provided with a signal output terminal, and is operated by an operator using a predetermined jig as necessary when screwing the electroencephalogram electrode unit 10 onto the frame 20. A cylindrical electrode fixing part 14 is provided at the other end of the threaded part 13 (lower side in the figure). An electroencephalogram measurement electrode 50 is attached to the electrode fixing part 14 .

<Structure of electroencephalogram measurement electrode 50>
FIG. 4 is a perspective view of the electroencephalogram measurement electrode 50. FIG. 5 is a plan view of the electroencephalogram measurement electrode 50. FIG. 6 is a cross-sectional view of the electroencephalogram measurement electrode 50, particularly a cross-sectional view taken along the line X1-X1 in FIG.

The electroencephalogram measurement electrode 50 has a base 51 , a protrusion 60 , and an electrode section 80 . The base portion 51 and the protruding portion 60 are integrally provided by a rubber-like elastic body (also referred to as an elastic member). The specific material of the elastic body will be described later. Note that the base portion 51 and the protruding portion 60 are not limited to being provided integrally, but may be provided separately and assembled using an adhesive or a fitting structure.

The base 51 has a substantially cylindrical shape, and has a circular protrusion forming surface 52 at one end and a circular mounting surface 53 at the other end. The attachment surface 53 is attached to the electrode fixing part 14 of the body part 11 with an adhesive or the like. Note that there is no particular restriction on the structure for fixing the mounting surface 53 and the electrode fixing part 14, and for example, a fitting structure with uneven shapes may be used.

<Shape of protrusion 60>
A plurality of protrusions 60 are provided on the protrusion forming surface 52 in an aligned manner. Here, 15 square pyramid protrusions 60 are arranged in a grid pattern. More specifically, they are arranged in an orthorhombic lattice shape.

An electrode portion 80 is provided on the protrusion 60 at a predetermined height range from the apex 61 and comes into contact with the head 99 (scalp).

As the shape of the protrusion 60, in addition to a regular square pyramid, various pyramid shapes such as a polygonal pyramid such as a triangular pyramid and a hexagonal pyramid, and a cone can be adopted. The cone may be a truncated cone (such as a truncated cone or a truncated pyramid) with its tip removed. Furthermore, various arrangements can be adopted as the grid arrangement.

The height H0 of the protrusion 60 can be 0.5 mm or more and 20 mm or less. The lower limit of the height H0 is preferably 1.0 mm or more, more preferably 2.0 mm or more. The upper limit of the height H0 is preferably 15 mm or less, more preferably 10 mm or less.

The width of the bottom surface of the protrusion 60 can be 2 mm or more and 5 mm or less. The lower limit of the width of the bottom surface is preferably 2.5 mm or more, more preferably 3.0 mm or more. The upper limit of the width of the bottom surface is preferably 4.5 mm or less, more preferably 4.0 mm or less.

The volume of each protrusion 60 is 0.3 mm ³ or more and 131 mm ³ or less.
The lower limit of the volume is preferably 1.0 mm ³ or more, more preferably 2.0 mm ³ or more. The upper limit of the volume is preferably 100 mm ³ or less, more preferably 75 mm ³ or less.

By making the shape and size of the protrusion 60 as described above, the protrusion 60 can appropriately contact the head 99, and while achieving flexibility that does not cause pain to the subject, the protrusion 60 can be prevented from being bent. Not enough strength can be ensured.

<Structure of signal line 69>
A conductive signal line 69 (indicated by a broken line in FIG. 6) connected to the electrode part 80 is provided inside the protrusion 60. The signal line 69 can adopt various arrangement structures as long as it conducts inside the protrusion 60. For example, the tip of the signal line 69 may have a structure that projects from the electrode formation surface of the protrusion 60 (that is, a region where the electrode portion 80 is provided), a structure that is substantially flush with it, or a structure that is buried. From the viewpoint of connection stability with the electrode section 80, a protruding structure may be used. The protruding portion at the tip of the signal line 69 is partially or entirely covered with an electrode portion 80 .

The protruding structure at the tip of the signal line 69 may be non-folded, folded, or wrapped around the surface of the tip of the protrusion 60. Further, the extending direction of the signal line 69 is not particularly limited, and may not coincide with the perpendicular line extending from the protrusion forming surface 52, but may be inclined with respect to the perpendicular line.

<Material of the electroencephalogram measurement electrode 50>
The material of the electroencephalogram measurement electrode 50 (base 51, protrusion 60) will be explained. The electroencephalogram measurement electrode 50 is a rubber-like elastic body as described above. Specific examples of the rubber-like elastic body include rubber and thermoplastic elastomer (also simply referred to as "elastomer (TPE)"). Examples of the rubber include silicone rubber (cured product of a silicone rubber-based curable composition). Examples of thermoplastic elastomers include styrene TPE (TPS), olefin TPE (TPO), vinyl chloride TPE (TPVC), urethane TPE (TPU), ester TPE (TPEE), amide TPE (TPAE), etc. There is.

Here, silicone rubber (silicone rubber-based curable composition) will be explained.
The above-mentioned silicone rubber can be composed of a cured product of a silicone rubber-based curable composition. The curing process of the silicone rubber-based curable resin composition includes, for example, 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). It is done by

Insulating silicone rubber is silicone rubber that does not contain conductive filler, and conductive silicone rubber is silicone rubber that contains conductive filler.

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 is the main component of the silicone rubber curable composition of this embodiment.

The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may contain the same type of vinyl group-containing linear organopolysiloxane. The same kind of vinyl group-containing linear organopolysiloxanes only need to have at least the same vinyl group as the same functional group and have a straight chain shape, and the amount of vinyl groups in the molecule, the molecular weight distribution, or the amount added is different. May be different.
The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may further contain different vinyl group-containing organopolysiloxanes.

The vinyl group-containing organopolysiloxane (A) may include a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, and the vinyl groups serve as crosslinking points during curing.

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%. Thereby, the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1) can be optimized, and a network with each component described below can be reliably formed. In this embodiment, "~" means that the numbers at both ends are included.

In addition, in this specification, the vinyl group content is the mol% of the vinyl group-containing siloxane unit when the total units constituting the vinyl group-containing linear organopolysiloxane (A1) is 100 mol%. . However, it is assumed that there is one vinyl group for one vinyl group-containing siloxane unit.

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

Further, 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.

By using a vinyl group-containing linear organopolysiloxane (A1) having a degree of polymerization and specific gravity within the above range, the heat resistance, flame retardance, chemical stability, etc. of the silicone rubber obtained can be improved. It is possible to improve the

The vinyl group-containing linear organopolysiloxane (A1) is particularly preferably one having a structure represented by the following formula (1).

In formula (1), R ¹ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, butenyl group, and among them, vinyl group is preferred. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ³ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group.

Further, examples of substituents for R ¹ and R ² in formula (1) include a methyl group and a vinyl group, and examples of substituents for R ³ include a methyl group.

In addition, in Formula (1), a plurality of R ¹ are mutually independent and may be different from each other or may be the same. Furthermore, the same applies to R ² and R ³ .

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

Further, specific structures of the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1) include, for example, those represented by the following formula (1-1).

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.

Furthermore, as the vinyl group-containing linear organopolysiloxane (A1), a first vinyl group-containing organopolysiloxane having two or more vinyl groups in the molecule and having a vinyl group content of 0.4 mol% or less It contains a linear organopolysiloxane (A1-1) and a second vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%. It is preferable to have one. As raw rubber which is a raw material for silicone rubber, a first vinyl group-containing linear organopolysiloxane (A1-1) having a general vinyl group content and a second vinyl group-containing straight chain organopolysiloxane (A1-1) having a high vinyl group content are used. By combining with chain organopolysiloxane (A1-2), vinyl groups can be unevenly distributed, and crosslink density can be more effectively formed in the crosslinked network of silicone rubber. As a result, the tear strength of silicone rubber can be increased more effectively.

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

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

Furthermore, when blending the first vinyl group-containing linear organopolysiloxane (A1-1) and the second vinyl group-containing linear organopolysiloxane (A1-2) in combination, (A1-1) The ratio of (A1-2) and (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 80:20 to 90: More preferably, it is 10.

Note that the first and second vinyl group-containing linear organopolysiloxanes (A1-1) and (A1-2) may be used alone or in combination of two or more. good.

The vinyl group-containing organopolysiloxane (A) may also include a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

<<Organohydrogenpolysiloxane (B)>>
The silicone rubber-based curable composition of this embodiment may also contain a crosslinking agent. The crosslinking agent can include organohydrogenpolysiloxane (B).
Organohydrogenpolysiloxane (B) is classified into linear organohydrogenpolysiloxane (B1) having a linear structure and branched organohydrogenpolysiloxane (B2) having a branched structure. Either one or both may be included.

The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may contain the same type of crosslinking agent. Crosslinking agents of the same type need only have at least a common structure such as a linear structure or a branched structure, and may have different molecular weight distributions or different functional groups, and may have different amounts added. You can.
The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may further contain different crosslinking agents.

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

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, more preferably 1,000 or more and 10,000 or less.

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

Further, it is generally preferable that the linear organohydrogenpolysiloxane (B1) does not have a vinyl group. Thereby, it is possible to accurately prevent the crosslinking reaction from proceeding within the molecules of the linear organohydrogenpolysiloxane (B1).

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

In formula (2), R ⁴ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

Further, R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, and propyl group, of which methyl group is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl group, allyl group, and butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

In addition, in formula (2), a plurality of R ⁴ are mutually independent and may be different from each other or may be the same. The same applies to ^R5 . However, at least two or more of the plurality of R ⁴ and R ⁵ are hydride groups.

Further, R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group. A plurality of R ⁶ 's are independent from each other and may be different from each other or the same.

In addition, examples of substituents for R ⁴ , R ⁵ , and R ⁶ in formula (2) include a methyl group, a vinyl group, and the like, and a methyl group is preferable from the viewpoint of preventing intramolecular crosslinking reactions.

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

Note that the linear organohydrogenpolysiloxane (B1) may be used alone or in combination of two or more.

Since the branched organohydrogenpolysiloxane (B2) has a branched structure, it forms a region with a high crosslinking density, and is a component that greatly contributes to the formation of a dense and dense crosslinking structure in the silicone rubber system. In addition, like the above linear organohydrogenpolysiloxane (B1), it has a structure in which hydrogen is directly bonded to Si (≡Si-H), and in addition to the vinyl group of the vinyl group-containing organopolysiloxane (A), silicone It is a polymer that undergoes a hydrosilylation reaction with the vinyl groups of the components blended into the rubber-based curable composition and crosslinks these components.

Further, the specific gravity of the branched organohydrogenpolysiloxane (B2) is in the range of 0.9 to 0.95.

Furthermore, it is preferable that the branched organohydrogenpolysiloxane (B2) usually does not have a vinyl group. Thereby, it is possible to accurately prevent the crosslinking reaction from proceeding within the molecules of the branched organohydrogenpolysiloxane (B2).

Further, as the branched organohydrogenpolysiloxane (B2), one represented by the following average composition formula (c) is preferable.

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 in the range of 1 to 3, m is the number of H _a (R ⁷ ) _3-a SiO _1/2 units, and n is SiO _4/ (It is a number of ₂ units)

In formula (c), R ⁷ is a monovalent organic group, preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group, or a hydrocarbon group combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group.

In formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer in the range of 1 to 3, preferably 1.

Further, in formula (c), m is the number of H _a (R ⁷ ) _3-a SiO _1/2 units, and n is the number of SiO _4/2 units.

The branched organohydrogenpolysiloxane (B2) has a branched structure. Linear organohydrogenpolysiloxane (B1) and branched organohydrogenpolysiloxane (B2) differ in that their structures are linear or branched. The number of bonded alkyl groups R (R/Si) is 1.8 to 2.1 in linear organohydrogenpolysiloxane (B1) and 0.8 to 1 in branched organohydrogenpolysiloxane (B2). The range is .7.

In addition, since the branched organohydrogenpolysiloxane (B2) has a branched structure, for example, the amount of residue when heated to 1000°C at a temperature increase rate of 10°C/min in a nitrogen atmosphere is 5% or more. becomes. On the other hand, since the linear organohydrogenpolysiloxane (B1) is linear, the amount of residue after heating under the above conditions becomes almost zero.

Further, specific examples of the branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3).

In formula (3), R ⁷ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, a hydrocarbon group combining these, or a hydrogen atom. Examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, etc. Among them, methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl group. Examples of the substituent for R ⁷ include a methyl group and the like.

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

Furthermore, in formula (3), "-O-Si≡" represents that Si has a branched structure that extends three-dimensionally.

Note that the branched organohydrogenpolysiloxane (B2) may be used alone or in combination of two or more.

Further, in the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2), the amount of hydrogen atoms (hydride groups) directly bonded to Si is not particularly limited. However, in the silicone rubber-based curable composition, for 1 mole of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1), linear organohydrogenpolysiloxane (B1) and branched organohydrogenpolysiloxane The total amount of hydride groups in the siloxane (B2) is preferably 0.5 to 5 mol, more preferably 1 to 3.5 mol. This ensures the formation of a crosslinked network between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1). can be done.

<<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) if necessary. This makes it possible to improve the hardness and mechanical strength of the elastomer.

The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may contain the same type of non-conductive filler. The non-conductive fillers of the same type only need to have at least the same constituent material, and may differ in particle size, specific surface area, surface treatment agent, or amount added.
Note that the insulating silicone rubber curable composition and the conductive silicone rubber curable composition may further contain different silane coupling agents.

The silica particles (C) are not particularly limited, but for example, fumed silica, calcined silica, precipitated silica, etc. are used. These may be used alone or in combination of two or more.

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

By using silica particles (C) having specific surface areas and average particle diameters within the above ranges, it is possible to improve the hardness and mechanical strength of the silicone rubber formed, especially the tensile strength.

<<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 become a hydroxyl group, and this hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl group on the surface of the silica particle (C), whereby the surface of the silica particle (C) can be modified.

The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may contain the same type of silane coupling agent. Silane coupling agents of the same type only need to have at least a common functional group, and other functional groups in the molecule and the amount added may be different.
Note that the insulating silicone rubber curable composition and the conductive silicone rubber curable composition may further contain different silane coupling agents.

Moreover, this silane coupling agent (D) can contain a silane coupling agent having a hydrophobic group. As a result, this hydrophobic group is imparted to the surface of the silica particles (C), so that the cohesive force of the silica particles (C) decreases (hydrogen caused by silanol groups) in the silicone rubber-based curable composition and even in the silicone rubber. It is presumed that the dispersibility of the silica particles (C) in the silicone rubber-based curable composition is improved as a result. This increases the interface between the silica particles (C) and the rubber matrix, increasing the reinforcing effect of the silica particles (C). Furthermore, it is presumed that when the rubber matrix deforms, the slipperiness of the silica particles (C) within the matrix improves. By improving the dispersibility and slipperiness of the silica particles (C), the mechanical strength (for example, tensile strength, tear strength, etc.) of the silicone rubber due to the silica particles (C) is improved.

Furthermore, the silane coupling agent (D) can include a silane coupling agent having a vinyl group. As a result, vinyl groups are introduced onto the surface of the silica particles (C). Therefore, during curing of the silicone rubber-based curable composition, the vinyl groups of the vinyl group-containing organopolysiloxane (A) and the hydride groups of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction. When a network (crosslinked structure) of these is formed, the vinyl groups of the silica particles (C) also participate in the hydrosilylation reaction with the hydride groups of the organohydrogenpolysiloxane (B), so Silica particles (C) also come to be taken in. This makes it possible to lower the hardness and increase the modulus of the silicone rubber formed.

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.

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

Y _n -Si-(X) _4-n ...(4)
In the above formula (4), n represents an integer from 1 to 3. Y represents a functional group having a hydrophobic group, a hydrophilic group, or a vinyl group; when n is 1, it is a hydrophobic group; when n is 2 or 3, at least one of them is a hydrophobic group; It is a hydrophobic group. X represents a hydrolyzable group.

The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group combining these, such as a methyl group, an ethyl group, a propyl group, a phenyl group, among others, Methyl group is preferred.

Further, examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group, among which a hydroxyl group is particularly preferred. Note that, although the hydrophilic group may be included as a functional group, it is preferably not included from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

Furthermore, examples of the hydrolyzable group include a methoxy group, an alkoxy group such as an ethoxy group, a chloro group, and a silazane group, among which a silazane group is preferred because of its high reactivity with the silica particles (C). Note that those having a silazane group as a hydrolyzable group have two structures of (Y _n -Si-) in the above formula (4) due to their structural characteristics.

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

Examples of those having a vinyl group as the functional group include methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, and vinyltrimethoxysilane. Alkoxysilanes such as silane and vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane and vinylmethyldichlorosilane; and divinyltetramethyldisilazane. Among these, methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, divinyltetramethyldisilazane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinyl A silane coupling agent having a vinyl group-containing organosilyl group containing one or more selected from the group consisting of methyldimethoxysilane is preferred.

In addition, when the silane coupling agent (D) contains two types, a silane coupling agent having a trimethylsilyl group and a silane coupling agent having a vinyl group-containing organosilyl group, those having a hydrophobic group include hexamethyldisilazane, The vinyl group-containing compound preferably includes divinyltetramethyldisilazane.

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 together, the ratio of (D1) and (D2) is not particularly limited, but for example, The weight ratio (D1):(D2) is 1:0.001 to 1:0.35, preferably 1:0.01 to 1:0.20, more preferably 1:0.03 to 1:0. It is .15. By setting the value within such a numerical range, desired physical properties of the silicone rubber can be obtained. Specifically, it is possible to balance the dispersibility of silica in the rubber and the crosslinkability of the rubber.

In the present embodiment, the lower limit of the content of the silane coupling agent (D) is preferably 1% by mass or more, based on 100 parts by weight of the vinyl group-containing organopolysiloxane (A), and 3% by mass or more. It is more preferably at least 5% by mass, even more preferably at least 5% by mass. Further, the upper limit of the content of the silane coupling agent (D) is preferably 100% by mass or less, and 80% by mass or less, based on 100 parts by weight of the vinyl group-containing organopolysiloxane (A). It is more preferable that the amount is 40% by mass or less.
By setting the content of the silane coupling agent (D) to the above lower limit or more, the adhesion between the columnar part containing the elastomer and the conductive resin layer can be improved. Moreover, it can contribute to improving the mechanical strength of silicone rubber. Furthermore, by controlling the content of the silane coupling agent (D) to be at most the above upper limit, the silicone rubber can have appropriate mechanical properties.

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

The insulating silicone rubber curable composition and the conductive silicone rubber curable composition may contain the same type of catalyst. Catalysts of the same type only need to have at least the same constituent materials, and the catalysts may contain different compositions and may have different amounts added.
Note that the insulating silicone rubber curable composition and the conductive silicone rubber curable composition may further contain different catalysts.

As platinum or platinum compound (E), known ones can be used, such as platinum black, platinum supported on silica, carbon black, etc., chloroplatinic acid or an alcoholic solution of chloroplatinic acid, chloroplatinic acid, etc. Examples include complex salts of platinic acid and olefins, complex salts of chloroplatinic acid and vinylsiloxane, and the like.

In addition, one type of platinum or platinum compound (E) may be used alone, or two or more types may be used in combination.

In this embodiment, the content of platinum or platinum compound (E) in the silicone rubber-based curable composition means a catalytic amount, and can be set appropriately, but specifically, the content of platinum or platinum compound (E) in the silicone rubber-based curable composition is The amount of platinum group metal is 0.01 to 1000 ppm by weight, preferably 0.01 to 1000 ppm by weight, based on 100 parts by weight of the total amount of (A), silica particles (C), and silane coupling agent (D). The amount is 1 to 500 ppm.
By setting 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 speed. Further, by controlling the content of platinum or platinum compound (E) to be equal to or less than the above upper limit value, it is possible to contribute to reduction in manufacturing costs.

<<Water (F)>>
Further, the silicone rubber-based curable composition according to the present embodiment may contain water (F) in addition to the above-mentioned components (A) to (E).

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

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

The conductive solution (conductive silicone rubber composition) according to the present embodiment contains the conductive filler and a solvent in addition to the silicone rubber curable composition that does not contain the conductive filler.

As the above-mentioned solvent, various known solvents can be used, and for example, high boiling point solvents can be included. These may be used alone or in combination of two or more.

Examples of the above-mentioned solvents include aliphatic hydrocarbons such as pentane, hexane, cyclohexane, heptane, methylcyclohexane, ethylcyclohexane, octane, decane, dodecane, and tetradecane; benzene, toluene, ethylbenzene, xylene, and trifluoromethylbenzene. , aromatic hydrocarbons such as benzotrifluoride; 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 - Ethers such as dioxane and tetrahydrofuran; Haloalkanes such as dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane; N,N-dimethyl Examples include carboxylic acid amides such as formamide 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.

The conductive solution can have a viscosity suitable for various coating methods such as spray coating and dip coating by adjusting the solid content in the solution.

Further, when the conductive solution contains the conductive filler and the silica particles (C), the lower limit of the content of the silica particles (C) included in the protrusion 60 is the lower limit of the content of the silica particles (C) and the conductive filler. For example, it can be 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more, based on the total amount of 100% by mass. Thereby, the mechanical strength of the protrusion 60 can be improved. On the other hand, the upper limit of the content of the silica particles (C) included in the protrusion 60 is, for example, 20% by mass or less with respect to 100% by mass of the total amount of the silica particles (C) and the conductive filler, Preferably it is 15% by mass or less, more preferably 10% by mass or less. This makes it possible to balance the conductivity, mechanical strength, and flexibility of the protrusion 60.

A conductive silicone rubber can be obtained by heating and drying the conductive solution as necessary.
The conductive silicone rubber may be configured without silicone oil. Thereby, it is possible to suppress conductivity from decreasing due to silicone oil bleeding out onto the surface of the protruding portion 60.

<Material of signal line 69>
The signal line 69 may be a known one, and may be made of conductive fiber, for example. As the conductive fiber, one or more 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 can be used. These may be used alone or in combination of two or more.

The metal materials for the metal fibers and metal-coated fibers are not limited as long as they have conductivity, but include copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, stainless steel, aluminum, and silver/chloride. Examples include silver 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. Moreover, it is preferable that the metal material does not contain metals that cause a load on the environment, such as chromium.

The fiber materials of the metal-coated fibers, conductive polymer-coated fibers, and conductive paste-coated fibers are not particularly limited, and may be any of synthetic fibers, semi-synthetic fibers, and natural fibers. Among these, it is preferable to use polyester, nylon, polyurethane, silk, cotton, and the like. These may be used alone or in combination of two or more.

Examples of the carbon fibers include PAN-based carbon fibers and pitch-based carbon fibers.

The conductive polymer material of the conductive polymer fiber and conductive polymer coated fiber is, for example, a mixture of a conductive polymer such as polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylene vinylene, polynaphthalene, and derivatives thereof and a binder resin; Alternatively, an aqueous solution of a conductive polymer such as PEDOT-PSS ((3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)) is used.

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

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

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

The signal line 69 may be made of twisted yarn made by twisting a plurality of linear conductive fibers. Thereby, disconnection of the signal line 69 during deformation can be suppressed.

In this embodiment, the coating of conductive fibers does not mean simply covering the outer surface of the fiber material, but also covers the fibers in the interstices of the twisted yarn, such as metal or conductive polymer, in the case of twisted yarn made by twisting single fibers together. , or impregnated with conductive paste to cover each single fiber constituting the twisted yarn.

The tensile elongation at break of the signal wire 69 is, for example, from 1% to 50%, preferably from 1.5% to 45%. By setting the value within such a numerical range, it is possible to suppress excessive deformation of the protrusion 60 while suppressing breakage during deformation.

<Electrode part 80 (conductive part)>
The electrode section 80 is provided only at the tip of the protrusion 60. That is, the electrode portion 80 is provided in an area of at least 10% in the height direction from the apex 61 of the protrusion 60 . In other words, when the height H0 of the protrusion 60 is the height H1 of the protrusion 60 from the apex 61, the ratio H1/H0 is 0.1 or more. By providing the electrode section 80 in such a range, the electrode section 80 can make good contact with the head 99, and brain wave acquisition can be stabilized.

The thickness of the electrode section 80 is 5 μm or more and 200 μm or less. The thickness of the electrode part 80 means the thickness in the normal direction to the surface of the protrusion part 60. The lower limit of the thickness is preferably 10 μm or more, more preferably 15 μm or more. The upper limit of the thickness is preferably 175 μm or less, more preferably 150 μm or less.

The conductive member of the electrode section 80 is, for example, a paste containing a highly conductive metal. The conductive metal includes one or more selected from the group consisting of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or alloys thereof. In particular, from the viewpoint of availability and conductivity, silver, silver chloride, and copper are suitable.

When forming the electrode portion 80 with a paste containing a highly conductive metal, the top of the protruding portion 60 made of a rubber-like elastic body is dipped (dip coating) in a paste-like conductive solution containing a highly conductive metal. do. As a result, the electrode portion 80 is formed on the electrode formation surface of the protrusion 60.

Note that the electrode part 80 as a conductive resin layer may be formed by applying a conductive solution containing a conductive filler and a solvent to the electrode formation surface of the protrusion part 60. At this time, by using the same material (silicone rubber) as the solvent for the protrusion 60, the adhesion of the electrode section 80 (conductive resin layer) can be improved.

A conductive silicone rubber can be obtained by heating and drying the conductive solution as necessary.
The conductive silicone rubber may be configured without silicone oil. It is possible to suppress conductivity from decreasing due to silicone oil bleeding out onto the surface of the electrode section 80.

Thereby, it is possible to improve the hair-sweeping performance 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 section 80 when the electroencephalogram measuring device 1 is attached.

<Suitable conditions for the protrusion 60>
Suitable conditions for the protrusion 60 will be explained from the viewpoint of suppressing the subject from feeling cold.
The specific heat at 30°C of the elastic member constituting the protrusion 60 is 1500 J/kg°C or more and 1900 J/kg°C or less. The lower limit of the specific heat is preferably 1550 J/kg °C or higher, more preferably 1600 J/kg °C or higher. The upper limit of the specific heat is preferably 1850 J/kg °C or less, more preferably 1800 J/kg °C or less.

Since the electrode portion 80 is thinly formed on the surface of the protrusion 60, the heat capacity of the electrode portion 80 is very small compared to the heat capacity of the protrusion 60 (elastic member). That is, from the viewpoint of the test subject feeling cold, the effect of the heat capacity of the electrode section 80 is small. Therefore, such discomfort can be avoided by setting the specific heat of the protrusion 60 (that is, its elastic member), which has a larger heat capacity than the electrode part 80, within the above-mentioned range.

The elastic member constituting the protrusion 60 is preferably made of silicone rubber among the materials mentioned above for the electroencephalogram measurement electrode 50. By employing silicone rubber, it is possible to achieve the above-mentioned specific heat range while achieving the desired strength. Further, the silicone rubber contains a filler, and the content of the filler with respect to the entire silicone rubber is 20% by mass or more and 50% by mass or less. The lower limit of the content is preferably 25% by mass or more, more preferably 30% by mass or more. The upper limit of the content is preferably 45% by mass or less, more preferably 40% by mass or less. By adjusting the content of the filler within the above range, it is possible to adjust the specific heat to a desired value.

<Method for manufacturing electroencephalogram measurement electrode 50>
An example of the method for manufacturing the electroencephalogram measurement electrode 50 of this embodiment can include the following steps.
First, using a mold, the silicone rubber-based curable composition is molded under heat and pressure to obtain a molded body consisting of the base portion 51 and the protruding portion 60.
Subsequently, a sewing needle is used to pass the signal wire 69 through each protrusion 60 of the obtained molded body. Thereafter, a paste-like conductive solution is dip-coated on the electrode forming surface of the protrusion 60 (ie, the region where the electrode portion 80 is provided) of the protrusion 60 of the obtained molded body, and after heating and drying, post-curing is performed. Thereby, the electrode part 80 can be formed on the electrode formation surface of the protrusion part 60.
Through the above steps, the electroencephalogram measurement electrode 50 can be manufactured.
In addition, during the above molding step, insert molding may be used in which the silicone rubber-based curable composition is introduced into a molding space in which the signal line 69 is disposed, and then pressurized and heat molded.

As described above, according to the present embodiment, by setting the specific heat at 30° C. of the elastic member constituting the protrusion 60 to 1500 J/kg °C or more and 1900 J/kg °C or less, the electroencephalogram measurement electrode 50 (that is, the protrusion 60) can be Even if the user comes into contact with the portion 99, it is possible to prevent the user from feeling cold and uncomfortable.

<<Second embodiment>>
Referring to FIG. 7, the electroencephalogram measurement electrode 50 of this embodiment will be described. FIG. 7 is a cross-sectional view of the electroencephalogram measurement electrode 50 of this embodiment.

The features of the electroencephalogram measurement electrode 50 of this embodiment mainly lie in the formation positions of the electrode portion 80 and the signal line 69, and the following explanation will focus mainly on these features.

The electrode portion 80 covers the entire protrusion 60 and the protrusion forming surface 52 . That is, the electrode portion 80 includes a first electrode portion 81 that covers the entire protrusion 60 and a second electrode portion 82 that covers the protrusion forming surface 52. The first electrode section 81 and the second electrode section 82 are electrically connected. Note that the first electrode section 81 and the second electrode section 82 may be integrally provided using the same conductive member, or may be provided using different conductive members. The thickness of the electrode part 80 can be 5 μm or more and 200 μm or less, similarly to the first embodiment. The lower limit of the thickness is preferably 10 μm or more, more preferably 15 μm or more. The upper limit of the thickness is preferably 175 μm or less, more preferably 150 μm or less.

The signal line 69 is formed by threading a conductive fiber between the attachment surface 53 and the protrusion forming surface 52 in the base portion 51 . On the protrusion forming surface 52, the end of the signal line 69 is exposed and arranged in a flat area where the protrusion 60 is not provided.
The exposed portion of the signal line 69 is covered with the second electrode section 82. Since the first electrode part 81 covering the tip of the protruding part 60 is electrically connected to the second electrode part 82, the first electrode part 81 in contact with the head 99 (scalp) detects the The biological signals (ie, brain waves) can be extracted to the outside via the second electrode section 82 and the signal line 69.

Also in this embodiment, the elastic member constituting the protrusion 60 is made of silicone rubber with a specific heat of 1500 to 1900 J/kg°C. Further, the shape and size of the protrusion 60 are similar to those in the first embodiment.
Since the first electrode part 81 and the second electrode part 82 are formed in a thin film shape, the heat capacity of the electrode part 80 is smaller than that of the protruding part 60 even in a configuration in which the second electrode part 82 is added. The heat capacity is very small. Therefore, whether or not the electrode portion 80 feels cold when it comes into contact with the head 99 depends on the heat capacity of the protrusion 60 . Therefore, by setting the specific heat of the elastic member constituting the protrusion 60 within the above range, when the electrode part 80 comes into contact with the head 99, the subject feels cold and uncomfortable, similar to the first embodiment. You can prevent it from being put away.

<<Third embodiment>>
Referring to FIG. 8, the electroencephalogram measurement electrode 50 of this embodiment will be described. FIG. 8 is a cross-sectional view of the electroencephalogram measurement electrode 50 of this embodiment. The electroencephalogram measurement electrode 50 of this embodiment is a modification of the electroencephalogram measurement electrode 50 of the second embodiment, and different parts will be explained.

In the electroencephalogram measurement electrode 50, the first electrode portion 81 is formed by further providing a conductive material on the conductive material provided in common to the base portion 51 and the projection portion 60 at the tip of the protrusion portion 60. There is. More specifically, the electrode portion 80 includes a first electrode portion 81 that covers the entire protrusion 60 and a second electrode portion 82 that covers the protrusion forming surface 52. The first electrode part 81 includes a lower electrode part 81 a that is integrally provided with the second electrode part 82 over the entire surface of the protrusion 60 , and a lower electrode part 81 a that is provided at a predetermined distance from the apex 61 (tip part) of the protrusion 60 toward the base 51 . It has an upper layer electrode portion 81b provided covering the lower layer electrode portion 81a in the region up to the height. By providing the upper layer electrode portion 81b on the lower layer electrode portion 81a, the tip portion (the region near the apex 61) of the electrode portion 80 can be reinforced.

As the conductive material for the first electrode section 81 and the second electrode section 82, the materials described in the first embodiment can be used. The conductive materials of the first electrode section 81 and the second electrode section 82 may be the same or different. Further, the conductive materials of the lower electrode part 81a and the upper electrode part 81b of the first electrode part 81 may be the same or different.

The thickness of the second electrode part 82 and the first lower electrode part 81a can be set to 5 μm or more and 200 μm or less, similarly to the first embodiment. The lower limit of the thickness is preferably 10 μm or more, more preferably 15 μm or more. The upper limit of the thickness is preferably 175 μm or less, more preferably 150 μm or less.
The thickness of the upper electrode portion 81b can be, for example, 5 μm or more and 200 μm or less. The lower limit of the thickness is preferably 10 μm or more, more preferably 15 μm or more. The upper limit of the thickness is preferably 175 μm or less, more preferably 150 μm or less.

A method for providing the electrode section 80 will be explained.
It is dipped in a paste-like first conductive solution containing a good conductive metal so as to cover the entire surface of the protrusion 60 and at least the protrusion forming surface 52 of the base 51, and then pulled up and dried. As a result, a conductive member (ie, the second electrode portion 82 and the lower electrode portion 81a) having a predetermined thickness is formed on the entire surface of the protrusion 60 and the protrusion forming surface 52. Subsequently, a new conductive member is formed at and near the apex 61 of the projection 60 so as to cover the lower electrode portion 81a. More specifically, with the apex 61 of the protrusion 60 on which the lower electrode part 81a is formed facing downward, a predetermined length is dipped ( (dip coating) and then pulled up and dried with the apex 61 facing downward. As a result, an expanded shape (that is, a long sphere) is formed such that the second conductive solution gathers at the apex 61 due to gravity.

Note that from the viewpoint of realizing a structure in which the first conductive member is formed with a constant thickness and the second conductive member has an expanded shape (that is, a long sphere), the first conductive member, which is the material of the first conductive member, is It is preferable to lower the viscosity of the first conductive solution and to increase the viscosity of the second conductive solution, which is the material of the second conductive member. The viscosity of the first conductive solution can be, for example, 0.1 to 1.0 Pa·s at 25°C. The viscosity of the second conductive solution can be, for example, 10 to 1000 Pa·s at 25°C.

≪Fourth embodiment≫
Referring to FIG. 9, the electroencephalogram measurement electrode 50 of this embodiment will be described. FIG. 9 is a cross-sectional view of the electroencephalogram measurement electrode 50.

The feature of the electroencephalogram measurement electrode 50 of this embodiment is mainly that the protrusion 60 itself is made of conductive silicone rubber, and the electrode part 80 and signal line 69 are omitted.

Also in this embodiment, the elastic member constituting the protrusion 60 is silicone rubber with a specific heat of 1500 to 1900 J/kg°C. Further, the shape and size of the protrusion 60 are similar to those in the first embodiment. However, even in a structure in which a conductor (conductive filler, carbon black, etc.) is blended with silicone rubber and the electrode part 80 is not provided, the function of the electrode part is still achieved. At this time, if the amount of the conductor is not taken into account, the specific heat will be less than 1500 J/kg°C, making the subject feel cold and uncomfortable. However, even if the protruding part 60 is not provided with the electrode part 80, by setting the specific heat to 1,500 to 1,900 J/kg° C., it is possible to prevent the subject from feeling cold and uncomfortable.

<Summary of features of the electroencephalogram measurement device 1 (electrode 50 for electroencephalogram measurement)>
The features of the invention have been explained using the first to fourth embodiments. Hereinafter, the features of the electroencephalogram measurement device 1 will be collectively explained, focusing on the protrusion 60 of the electroencephalogram measurement electrode 50.
[1] An electroencephalogram measurement electrode 50 (biological signal measurement electrode) that is brought into contact with the subject's head 99 (skin) to acquire brain waves (biological signals),
a protrusion 60 protruding from the base 51;
an electrode section 80 (conductive section) that is provided at least at the tip of the protruding section 60 and that acquires brain waves (biological signals);
has
The protrusion 60 is made of an elastic member,
An electroencephalogram measurement device 1 (electrode for biological signal measurement) in which the elastic member has a specific heat of 1500 J/kg °C or more and 1900 J/kg °C or less at 30 °C.
[2] The electroencephalogram measurement device 1 (biological signal measurement electrode) according to [1], wherein the elastic member is made of silicone rubber.
[3] Silicone rubber contains fillers,
The electroencephalogram measurement device 1 (biological signal measurement electrode) according to [2], wherein the filler content with respect to the entire silicone rubber is 20% by mass or more and 50% by mass or less.
[4] The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [3], wherein the protrusion 60 has a shape of a cone or a cone with its tip removed.
[5] The height of the protrusion 60 is 0.5 mm to 20 mm,
The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [4], wherein the width of the bottom surface of the protrusion 60 is 2 mm to 5 mm.
[6] The volume of each protrusion 60 is 0.3 mm ³ to 131 mm ³ .
The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [5].
[7] The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [6], wherein the base 51 and the protrusion 60 are integrally configured.
[8] The electroencephalogram measuring device 1 according to any one of [1] to [7], wherein the electrode portion 80 is provided in an area of at least 10% in the height direction from the tip portion of the protruding portion 60. (electrodes for measuring biological signals).
[9] The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [7], wherein the electrode part 80 is provided only at the tip of the protrusion 60.
[10] The electrode part 80 includes a first electrode part 81 that covers the tip of the protrusion 60, and a second electrode part 82 that covers the surface of the base 51 on which the protrusion 60 is provided (the protrusion forming surface 52). The electroencephalogram measuring device 1 (biological signal measuring electrode) according to any one of [1] to [7], wherein the first electrode part 81 and the second electrode part 82 are connected.
[11] The first electrode part 81 is formed by further providing a conductive material on the conductive material provided in common to the base 51 and the protrusion 60 at the tip of the protrusion 60. [10] ] Electroencephalogram measurement device 1 (biological signal measurement electrode).
[12] The electroencephalogram measurement device 1 (biosignal measurement) according to [10] or [11], wherein the conductive material constituting the first electrode part 81 and the conductive material constituting the second conductive part are different. electrode).
[13] It has a signal line 69 that outputs the biological signal (electroencephalogram signal) acquired by the electrode part 80 to the outside,
The signal line 69 is connected to the first electrode section 81, passes through the inside of the base section 51, and is output to the outside. measurement electrode).
[14] The electroencephalogram measurement device 1 (biological signal measurement electrode) according to any one of [1] to [13], wherein the elastic member includes a conductive material.
[15] The electroencephalogram measurement device 1 (biosignal measurement electrode) according to any one of [1] to [14], wherein the biosignal is an electroencephalogram.
[16] An electroencephalogram measurement device 1 (biosignal measurement electrode) comprising the electroencephalogram measurement electrode 50 (biosignal measurement electrode) according to any one of [1] to [15].
[17] A biosignal measurement method in which the electroencephalogram measurement device 1 (biosignal measurement electrode) described in [16] is attached to the subject's head 99 to measure brain waves.

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 may also be adopted.

Hereinafter, this embodiment will be described in detail with reference to Examples. Note that this embodiment is in no way limited to the description of these examples.
In the following examples, silicone rubber (Examples 1 to 6, Comparative Examples 2 and 3) and other rubbers (urethane rubber (Comparative Example 4), natural rubber (Comparative Example 5), ethylene propylene diene rubber (EPDM) Using samples of Example 6), acrylonitrile butadiene rubber (NBR) (Comparative Example 7)), and silicone rubber coated with silver paste (Comparative Example 1), the relationship between specific heat and discomfort upon contact at 30°C was measured. We conducted an experiment. In Examples 1 to 6 and Comparative Examples 2 to 7, a 1 mm thick sheet member was used, and in Comparative Example 1, a sample obtained by coating the 1 mm thick sheet member (silicone rubber) of Example 2 with silver paste was used. .
Table 1 shows formulation examples of Examples 1 to 6 and Comparative Examples 1 to 7 (However, Comparative Examples 4 to 7 are sample types and are marked with a "v" (check mark) in the corresponding column) and evaluation results. .

<Sample>
<Samples of Examples 1 to 6 and Comparative Examples 2 and 3>
The raw material components of the silicone rubber used in Examples 1 to 6 and Comparative Examples 2 and 3 are shown below.
(Vinyl group-containing organopolysiloxane (A))
・Low vinyl group-containing linear organopolysiloxane (A1-1): Vinyl group-containing dimethylpolysiloxane synthesized according to Synthesis Scheme 1 (structure represented by formula (1-1), with only R ¹ (terminal) being a vinyl group) structure)
・High vinyl group-containing linear organopolysiloxane (A1-2): vinyl group-containing dimethylpolysiloxane synthesized by synthesis scheme 2 (structure represented by formula (1-1), with R ¹ and R ² being vinyl groups) some structure)
・Low vinyl group-containing linear organopolysiloxane (A1-3): vinyl group-containing dimethylpolysiloxane synthesized by synthesis scheme 3 (structure represented by formula (1-1), with R ¹ and R ² being vinyl groups) some structure)

(Organohydrogenpolysiloxane (B))
・Manufactured by Momentive: “TC-25D”

(Silica particles (C))
・Silica particles (C-1): Silica fine particles (particle size 7 nm, specific surface area 300 m ² /g), “AEROSIL 300” manufactured by Nippon Aerosil Co., Ltd.
・Silica particles (C-2): Silica fine particles (particle size 7 nm, specific surface area 240 m ² /g), “AEROSIL R976” manufactured by Nippon Aerosil Co., Ltd.

(Alumina particles)
・Alumina particles: Alumina fine particles (particle size 13 nm, specific surface area 100 m ² /g), “AEROXIDE AluC” manufactured by Nippon Aerosil Co., Ltd.
(Carbon black)
・Carbon black: (particle size 20 nm, specific surface area 140 m ² /g), “MA600” manufactured by Mitsubishi Chemical Corporation
(Silver powder)
・Silver powder: (median diameter _d50 : 8.0 μm, aspect ratio 16.4, average major axis 4.6 μm), manufactured by Tokuriki Kagaku Kenkyusho Co., Ltd., “TC-101”,

(Silane coupling agent (D))
- Silane coupling agent (D-1): Hexamethyldisilazane (HMDZ), manufactured by Gelest, "HEXAMETHYLDISILAZANE (SIH6110.1)"
- Silane coupling agent (D-2): Divinyltetramethyldisilazane, manufactured by Gelest, "1,3-DIVINYLTETRAMETHYLDISILAZANE (SID4612.0)"

(Platinum or platinum compound (E))
・Manufactured by Momentive: “TC-25A”

(Synthesis of vinyl group-containing organopolysiloxane (A))
[Synthesis scheme 1: Synthesis of low vinyl group-containing linear organopolysiloxane (A1-1)]
A low vinyl group-containing linear organopolysiloxane (A1-1) was synthesized according to the following formula (5).
That is, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane and 0.1 g of potassium siliconate were placed in a 300 mL separable flask equipped with a cooling tube and stirring blade and replaced with Ar gas, and heated to 120° C. for 30 minutes. Stirred. At this time, an increase in viscosity was confirmed.
Thereafter, the temperature was raised to 155°C, and stirring was continued for 3 hours. After 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was further stirred at 155° C. for 4 hours.
Furthermore, after 4 hours, the mixture was diluted with 250 mL of toluene and washed three times with water. The organic layer after washing was washed several times with 1.5 L of methanol to purify it by reprecipitation and separate the oligomer and polymer. The obtained polymer was dried under reduced pressure at 60° C. overnight to obtain a low vinyl group-containing linear organopolysiloxane (A1-1) (Mn=2.2×10 ⁵ , Mw=4.8×10 ⁵ ). Furthermore, the vinyl group content calculated by H-NMR spectrum measurement was 0.04 mol%.

[Synthesis scheme 2: Synthesis of high vinyl group-containing linear organopolysiloxane (A1-2)]
In the synthesis step of (A1-1) above, in addition to 74.7 g (252 mmol) of octamethylcyclotetrasiloxane, 0.2 g (252 mmol) of 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane. By following the same synthesis process as (A1-1) except that 86 g (2.5 mmol) was used, a high vinyl group-containing linear organopolysiloxane (A1- 2) was synthesized. (Mn=2.3×10 ⁵ , Mw=5.0×10 ⁵ ). Furthermore, the vinyl group content calculated by H-NMR spectrum measurement was 0.93 mol%.

[Synthesis scheme 3: Synthesis of low vinyl group-containing linear organopolysiloxane (A1-3)]
In the synthesis step of (A1-2) above, 75.3 g (254 mmol) of octamethylcyclotetrasiloxane, 0.12 g (254 mmol) of 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane ( By following the same procedure as the synthesis step of (A1-2) except that 0.35 mmol) was used and the stirring time after heating to 155 ° C. was 3 hours, as in the above formula (6), A linear organopolysiloxane (A1-3) containing low vinyl groups was synthesized. (Mn=2.5×10 ⁵ , Mw=5.0×10 ⁵ ). Further, the vinyl group content calculated by H-NMR spectrum measurement was 0.13 mol%.

(Examples 1 to 4, Comparative Examples 2 and 3: Preparation of silicone rubber-based curable composition)
A silicone rubber-based curable composition was prepared as follows.
First, a mixture of a 90% vinyl group-containing organopolysiloxane (A), a silane coupling agent (D), and water (F) is kneaded in advance in the proportions shown in Table 1 below, and then the silica particles ( C) was added and further kneaded to obtain a kneaded product (silicone rubber compound). By adjusting the amount (blending ratio) of silica particles (C) added, the specific heat of the silicone rubber for evaluation finally obtained was adjusted.
Here, the kneading after addition of the silica particles (C) includes the first step of kneading for 1 hour at 60 to 90°C under a nitrogen atmosphere for the coupling reaction, and the removal of by-products (ammonia). For this purpose, a second step of kneading for 2 hours at 160 to 180°C under a reduced pressure atmosphere is performed, followed by cooling and adding the remaining 10% of the vinyl group-containing organopolysiloxane (A) twice. Added in portions and kneaded for 20 minutes.
Subsequently, organohydrogenpolysiloxane (B) (TC-25D) and platinum or platinum compound (E) (TC -25A) was added and kneaded with a roll to obtain a silicone rubber curable composition.

(Example 5: Preparation of silicone rubber-based curable composition)
In the preparation methods of Examples 1 to 4 and Comparative Examples 2 and 3, alumina particles were used instead of silica particles (C).

(Example 6: Preparation of silicone rubber-based curable composition)
In the preparation methods of Examples 1 to 4 and Comparative Examples 2 and 3, carbon black was used instead of silica particles (C).

(Preparation of silicone rubber for evaluation of Examples 1 to 6 and Comparative Examples 2 and 3)
In Examples 1 to 6 and Comparative Examples 2 and 3, the obtained silicone rubber-based curable compositions were pressed at 170° C. and 10 MPa for 10 minutes to form a sheet with a thickness of 1 mm, length of 150 mm, and width of 150 mm. At the same time, primary hardening was performed. Subsequently, it was heated at 200° C. for 4 hours to perform secondary curing. Through the above steps, a sheet-like silicone rubber (cured product of a silicone rubber-based curable composition) was obtained.

<Samples of Comparative Examples 1 and 4 to 7>
(Comparative example 1)
Silver paste was applied onto the surface of the PTFE sheet with a squeegee, heated, and then post-cured to obtain a sheet-like cured silver paste product with a film thickness of 250 μm.
The specifications of the silver paste are as follows.
Ag content based on the total amount of silver paste: 55% by weight
Viscosity (20℃) 19.5Pa・s

(Comparative example 4)
A sheet of urethane rubber (manufactured by Tigers Polymer Co., Ltd., product name "U70°") with a thickness of 1 mm, a length of 25 mm, and a width of 50 mm was used.
(Comparative example 5)
A sheet of natural rubber (manufactured by Tigers Polymer Co., Ltd., product name "TAKL 6503-HP", product number "2000-K") with a thickness of 1 mm, a length of 25 mm, and a width of 50 mm was used.
(Comparative example 6)
A sheet-like EPDM (manufactured by Tigers Polymer Co., Ltd., product name "TNKL 7007-HP", product number "275-E") with a thickness of 1 mm, a length of 25 mm, and a width of 50 mm was used.
(Comparative example 7)
A sheet of NBR (manufactured by Tigers Polymer Co., Ltd., product name "TNKL 7007-HP", product number "2100-N") with a thickness of 1 mm, a length of 25 mm, and a width of 50 mm was used.

(evaluation)
The samples of Examples 1 to 6 and Comparative Examples 1 to 7 were evaluated on the following items ("specific heat measurement", "discomfort upon contact").

<Specific heat measurement>
The specific heat at 30° C. of the samples of Examples 1 to 6 and Comparative Examples 1 to 7 was measured using a measuring device (differential scanning calorimeter "DSC25" manufactured by TA Instruments). The unit is J/kg°C.
For Examples 1 to 6 and Comparative Examples 2 to 7, samples cut to a diameter of 4 mm and a thickness of 1 mm were prepared and placed in a sample pan of a differential scanning calorimeter "DSC25" to measure specific heat.
For Comparative Example 1, a sample of four stacked sheets of cured silver paste with a film thickness of 250 μm cut to a diameter of 4 mm was placed in a sample pan of a differential scanning calorimeter "DSC25", and the specific heat was measured.

<Experiment on discomfort upon contact>
Using each sample of Examples 1 to 6 and Comparative Examples 1 to 7, the following procedure was performed. Four subjects (indicated by A to D in Table 2) applied a sample at the same temperature as room temperature to their foreheads in a room adjusted to 25°C to check for discomfort.
The evaluation was done on the following three levels a to c.
a: No discomfort b: Slight discomfort c: Discomfort (feels cold)
It was confirmed that when the specific heat was between 1500 J/kg°C and 1900 J/kg°C, the test subjects did not experience any discomfort.

1 Electroencephalogram measurement device 10 Electroencephalogram electrode unit 20 Frame 21 Electrode unit mounting part 50 Electroencephalogram detection electrode 51 Base 52 Projection forming surface 53 Mounting surface 60 Projection 61 Vertex 69 Signal line 80 Electrode part 81 First electrode part 81a Lower electrode Part 81b Upper layer electrode part 82 Second electrode part

Claims (17)

An electrode for measuring biological signals that is brought into contact with the skin of a subject to acquire biological signals,
a protrusion protruding from the base;
a conductive part that is provided at least at the tip of the protrusion and acquires the biological signal;
has
The protruding portion is made of an elastic member,
An electrode for measuring biological signals, wherein the elastic member has a specific heat of 1500 J/kg°C or more and 1900 J/kg°C or less at 30°C. The biological signal measuring electrode according to claim 1, wherein the elastic member is made of silicone rubber. The silicone rubber contains a filler,
The biological signal measuring electrode according to claim 2, wherein the content of the filler in the entire silicone rubber is 20% by mass or more and 50% by mass or less. The biological signal measuring electrode according to any one of claims 1 to 3, wherein the protrusion has a shape of a cone or a cone with its tip removed. The height of the protrusion is 0.5 mm to 20 mm,
The width of the bottom surface of the protrusion is 2 mm to 5 mm.
The biological signal measuring electrode according to claim 1. The volume of each of the protrusions is 0.3 mm ³ to 131 mm ³ ,
The biological signal measuring electrode according to claim 1. The biological signal measuring electrode according to claim 1, wherein the base portion and the protruding portion are integrally configured. The biological signal measuring electrode according to claim 1, wherein the conductive portion is provided in an area of at least 10% in the height direction from the tip portion of the protrusion. The biological signal measuring electrode according to claim 1, wherein the conductive part is provided only at the tip of the protrusion. The conductive part has a first conductive part that covers a tip of the protrusion, and a second conductive part that covers a surface of the base where the protrusion is provided, and the first conductive part and the The biological signal measuring electrode according to claim 1, wherein the two conductive parts are connected. The first conductive part is formed by further providing a conductive material on a conductive material provided in common to the base and the protrusion at the tip of the protrusion. Electrodes for measuring biological signals. The biological signal measuring electrode according to claim 10, wherein the conductive material that constitutes the first conductive part and the conductive material that constitutes the second conductive part are different. It has a signal line that outputs the biological signal acquired by the conductive part to the outside,
The biological signal measuring electrode according to claim 10, wherein the signal line is connected to the second conductive part, passes through the inside of the base, and is output to the outside. The biological signal measuring electrode according to claim 1, wherein the elastic member includes a conductive material. The electrode for measuring biological signals according to claim 1, wherein the biological signals are brain waves. A biosignal measuring device comprising the biosignal measuring electrode according to claim 1. A biosignal measuring method comprising: attaching the biosignal measuring device according to claim 16 to the head of a subject to measure brain waves.

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