JP7600591B2 - Stretchable conductive yarn, conductive structure, and wearable device - Google Patents

Description

The present invention relates to elastic conductive yarns, conductive structures, and wearable devices.

Various developments have been made on conductive threads. One such technology is described in Patent Document 1. Patent Document 1 describes a conductive thread made of a metal material that contains stainless steel fibers (claim 1 of Patent Document 1).

Special Publication No. 2005-525479

However, as a result of the inventor's investigations, it was found that there is room for improvement in terms of the stretching electrical properties of the metallic conductive yarn described in Patent Document 1 above.

After further investigation, the inventors discovered that by using an elastic conductive yarn having a structure in which a conductive elastomer layer is laminated on the surface of an insulating elastomer layer, it is possible to improve the elasticity and the electrical properties during elasticity, which led to the completion of the present invention.

According to the present invention,
An elastic conductive yarn comprising one or more yarns,
An elastic conductive yarn is provided, the yarn having, in one radial cross section of the yarn, an insulating elastomer layer and a conductive elastomer layer laminated on the surface of the insulating elastomer layer.

Further, according to the present invention,
There is provided a conductive structure composed of a knitted or woven fabric using the elastic conductive yarn.

Further, according to the present invention,
A wearable device is provided that includes the above-mentioned stretchable conductive yarn or the above-mentioned conductive structure.

The present invention provides an elastic conductive yarn with excellent elastic electrical properties, a conductive structure using the same, and a wearable device.

FIG. 2 is a diagram showing a schematic configuration of an elastic conductive thread according to the present embodiment. 1A is a cross-sectional view taken along line AA in FIG. 1, and FIGS. 1B to 1D are cross-sectional views of modified examples of the elastic conductive thread. 1 is a diagram showing a schematic configuration of a conductive structure according to an embodiment of the present invention;

The following describes an embodiment of the present invention with reference to the drawings. Note that in all drawings, similar components are given similar reference symbols and descriptions are omitted where appropriate. Also, the drawings are schematic and do not correspond to the actual dimensional ratios.

The elastic conductive yarn of this embodiment is described below.

The elastic conductive yarn of this embodiment includes one or more yarns, and the yarn has, in one radial cross section of the yarn, an insulating elastomer layer and a conductive elastomer layer laminated on the surface of the insulating elastomer layer.

According to this embodiment, it is possible to realize an elastic conductive thread with excellent elastic electrical properties, which maintains conductivity even when stretched or after repeated stretching.

The elastic conductive yarn may be used, for example, as a linear yarn as it is, or may be used as a knitted or woven fabric.

The elastic conductive yarn can be used for various electrical equipment applications, such as wearable devices, smart textiles, strain sensors, biosensor devices, elastic wiring, flexible electrodes, and conductive fabrics.

The elastic conductive yarn of this embodiment is described in detail below.

FIG. 1 is a perspective view showing a schematic example of an elastic conductive thread 100 of the present embodiment.
FIG. 2(a) is a cross-sectional view of the elastic conductive yarn 100 taken along line AA of FIG. 1(a).

In this specification, the radial cross section of the yarn is defined as a cross section parallel to the radial direction of the yarn and perpendicular to the axial direction at the portion where the yarn is in a straight state.

The elastic conductive yarn 100 in FIG. 1 has a yarn 50 with a tube structure.

In this specification, having elasticity means that the elongation rate when stretched in the extension direction of the thread can be extended, for example, to 10% or more, preferably 20% or more, more preferably 50% or more, and even more preferably up to 100% of the unstretched length. When stretchable conductive thread 100 is stretched in the extension direction of the thread, the conductive elastomer layer 20 can maintain a state in which it does not break within the above-mentioned range of elongation rates.

The thread 50 in FIG. 1 includes both an insulating tube structure including an insulating elastomer layer 10 and a conductive tube structure including a conductive elastomer layer 20. In other words, the thread 50 is configured as a tube structure in which a conductive tube structure is laminated on the outer periphery of an insulating tube structure.

As shown in FIG. 2(a), this thread 50 has at least a laminated structure in which a conductive elastomer layer 20 is laminated on the surface of an insulating elastomer layer 10 in a radial cross section of the thread 50.

The insulating elastomer layer 10 and the conductive elastomer layer 20 are each composed of an elastic elastomer. Conduction can be achieved by the conductive elastomer layer 20. Furthermore, since the conductive elastomer layer 20 is layered on the insulating elastomer layer 10, it is possible to improve durability even when stretched.

In the yarn 50, the insulating elastomer layer 10 and the conductive elastomer layer 20 are laminated in a state in which the layers are in surface contact with each other and may be chemically and/or physically bonded to each other and adhered to each other. Therefore, the yarn 50 can suppress the risk of damage such as peeling between the insulating elastomer layer 10 and the conductive elastomer layer 20 even during elongation or repeated elongation. Therefore, it is possible to realize an elastic conductive yarn 100 with highly reliable elongation electrical properties.

The conductive tube structure of the thread 50 may have one or more through holes (holes 30) that penetrate both ends of the thread 50 on the inside. This makes it possible to increase the ease with which the thread 50 can be stretched in response to external stress.

Next, modified examples of the structure of the elastic conductive yarn 100 will be described.
FIG. 2 is a cross-sectional view showing an example of a modified example of the elastic conductive thread 100.

The yarn in the stretchable conductive yarn may have at least one of an insulating tube structure including an insulating elastomer layer and a conductive tube structure including a conductive elastomer layer. The yarn may be composed of a multi-layer tube structure and may have one or more insulating tube structures and/or one or more conductive tube structures inside.

The yarns 50, 51, and 52 in FIG. 2 each have an insulating tube structure including insulating elastomer layers 10, 11, and 12. Also, the yarns 50, 51, 52, and 53 in FIG. 2 each have a conductive tube structure including conductive elastomer layers 20, 21, 22, 23, and 24. A conductive tube structure having two or more layers allows for multi-layer wiring of the yarn.

The yarn in the elastic conductive yarn may have either an insulating tube structure or a conductive tube structure provided on the outermost layer of the yarn.

The yarns 50, 51, and 53 in Fig. 2 have a conductive tube structure in the outermost layer. The conductive elastomer layers 20, 21, and 24 in the conductive tube structure provided in the outermost layer can realize a structure that is easy to connect to the outside.
2 has an insulating tube structure as the outermost layer. The insulating elastomer layer 12 in the insulating tube structure provided as the outermost layer functions as a protective member for protecting the conductive elastomer layer 23 provided on the inside.

The yarn in the stretchable conductive yarn may have at least one of an insulating tube structure including an insulating elastomer layer and a solid insulating core structure including an insulating elastomer layer.

2 each have an insulating tube structure including an insulating elastomer layer 10, 11, 12. The insulating tube structure can increase the ease of stretching the yarn against an external stress.
The yarn 53 of Figure 2 has a solid insulating core structure that includes an insulating elastomer layer 13. The insulating core structure can provide increased mechanical strength to the yarn.

The yarn in the elastic conductive yarn may have an insulating tube structure and a conductive tube structure including a conductive elastomer layer configured to cover at least one surface on the outer surface and the inner surface of the insulating tube structure. The yarn in the elastic conductive yarn may also have an insulating core structure and a conductive tube structure including a conductive elastomer layer configured to cover the outer surface of the insulating core structure.

The yarn 50 of FIG. 2 comprises an insulating tube structure including an insulating elastomer layer 10 and a conductive tube structure including a conductive elastomer layer 20 configured to cover at least a portion of a surface on an outer surface of the insulating tube structure.
The yarn 51 in FIG. 2 comprises an insulating tube structure including an insulating elastomer layer 11, and a conductive tube structure including conductive elastomer layers 21 and 22 configured to cover at least a portion of each of the outer and inner surfaces of the insulating tube structure.
The yarn 52 of FIG. 2 comprises an insulating tube structure including an insulating elastomer layer 12 and a conductive tube structure including a conductive elastomer layer 23 configured to cover at least a portion of a surface on an inner surface of the insulating tube structure.
The yarn 53 of FIG. 2 has a solid insulating core structure including an insulating elastomer layer 13 and a conductive tube structure including a conductive elastomer layer 24 arranged to cover the outer surface of the insulating core structure.

In this specification, when the conductive elastomer layer laminated on the insulating elastomer layer covers at least one of the outer and/or inner surfaces of the insulating elastomer layer, "covering" means covering at least a part or the entire surface.

The conductive elastomer layer may be configured in a tube structure within the same layer, but is not limited to this and may have various shapes. The conductive elastomer layer is formed by a coating method such as printing using a conductive filler, as will be described in detail later, so it can be formed in various wiring patterns such as linear and wavy.

In addition, the conductive elastomer layer in the same layer may be composed of a single integrated member, or may be composed of multiple members spaced apart from each other. For example, when the multiple members include a first conductive elastomer layer and a second conductive elastomer layer, the space between them may be composed of a gap, or may be filled with an insulating material such as the material that constitutes the insulating elastomer layer. This makes it possible to form two or more wiring patterns in the conductive elastomer layer of the same layer.

The conductive elastomer layer in the yarn may be a single layer, or may be composed of two or more layers. In the case of a multi-layer structure, insulating elastomer layers or other layers may be formed between the layers.

The elastic conductive thread may be composed of a single linear thread (conductive thread), or may be composed of a twisted thread in which multiple linear threads (conductive threads) are twisted together.

Next, we will explain the materials and characteristics that make up the elastic conductive thread 100.

The insulating elastomer layer may be made of an insulating elastomer, for example, a thermosetting elastomer such as silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, or ethylene propylene rubber. Among these, the elastomer may be one or more thermosetting elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. Preferably, the insulating elastomer layer may be made of silicone rubber. Silicone rubber is chemically stable among elastomers and has excellent mechanical strength.

The insulating elastomer layer may contain a non-conductive filler. This enhances the mechanical properties of the conductive elastomer layer. Known materials can be used as the non-conductive filler, but for example, silica particles, silicone rubber particles, talc, etc. may also be used.

The conductive elastomer layer may be made of a conductive elastomer, and may be configured to include, for example, a thermosetting elastomer such as silicone rubber, urethane rubber, fluororubber, nitrile rubber, acrylic rubber, styrene rubber, chloroprene rubber, ethylene propylene rubber, etc., and a conductive filler. Among these, the elastomer may be one or more thermosetting elastomers selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. Among these, the conductive elastomer layer may be configured to include silicone rubber. This can enhance the elasticity and conductivity of the conductive elastomer layer.
The conductive elastomer layer may contain a non-conductive filler in addition to the conductive filler, which can improve the stretch durability.

Examples of conductive fillers include powdered or fibrous metal-based fillers, carbon-based fillers, metal oxide fillers, metal-plated fillers, etc. Among these, metal-based fillers, preferably silver powder, may be used as the conductive filler.

The insulating elastomer layer and the conductive elastomer layer may be configured to contain the same thermosetting elastomer.

In this specification, "containing the same thermosetting elastomer" means containing at least one of the same type of elastomers among the types of thermosetting elastomers exemplified above.

The components of the silicone rubber-based curable composition are described in detail below.

The insulating elastomer layer and the conductive elastomer layer may be configured to contain the same silicone rubber.

In this specification, containing the same silicone rubber means that the silicone rubber-based curable composition contains at least the same type of vinyl group-containing linear organopolysiloxane, and may further contain one or more selected from the group consisting of the same type of crosslinking agent, the same type of non-conductive filler, the same type of silane coupling agent, and the same type of catalyst.

The insulating elastomer may be composed of a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane.
The conductive elastomer may also be composed of a conductive filler and a cured product of a silicone rubber-based curable composition that contains a vinyl group-containing organopolysiloxane.

The same type of vinyl group-containing linear organopolysiloxane is sufficient if it contains at least the same vinyl group as the functional group and has a linear shape, but may differ in the amount of vinyl groups in the molecule, the molecular weight distribution, or the amount added.

Crosslinking agents of the same type are sufficient if they have at least a common structure, such as a linear or branched structure, and may have different molecular weight distributions or functional groups in the molecule, or may have different amounts added.

Non-conductive fillers of the same type are sufficient if they have at least a common constituent material, but may differ in particle size, specific surface area, surface treatment agent, or amount of added surface treatment agent.

Silane coupling agents of the same type are sufficient if they have at least a common functional group, but may differ in other functional groups in the molecule or in the amount added.

Catalysts of the same type are those that have at least common constituent materials, but may contain different compositions or may be added in different amounts.

The silicone rubber-based curable composition constituting the same silicone rubber may further contain one or more different types of vinyl group-containing linear organopolysiloxanes, crosslinking agents, non-conductive fillers, silane coupling agents, and catalysts.

The silicone rubber-based hardening composition of this embodiment may 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-based hardening composition of this embodiment.

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, which become crosslinking points during curing.

The vinyl group content of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but for example, it is preferable that the vinyl group content is 15 mol% or less and that the vinyl group content is 2 or more in the molecule. This optimizes the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1), and ensures the formation of a network with each component described below.

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. However, it is considered that there is one vinyl group per vinyl group-containing siloxane unit.

The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably within the range of 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 number average degree of polymerization (or number average molecular weight) in terms of polystyrene in gel permeation chromatography (GPC) using chloroform as a developing solvent.

In this specification, "~" indicates that the upper and lower limits are included unless otherwise specified.

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.

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

As the vinyl group-containing linear organopolysiloxane (A1), it is particularly preferable that it has a structure represented by the following formula (1).

In formula (1), R ¹ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a hydrocarbon group consisting of a combination thereof, each 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, with a vinyl group being preferred. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

Furthermore, ^R2 is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a hydrocarbon group that is a combination of these groups, each 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, and among these, a methyl group is preferable. 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.

^R3 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group consisting of a combination thereof. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, and a propyl group, and among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group.

In addition, examples of the substituents of R ¹ and R ² in the formula (1) include a methyl group and a vinyl group, and examples of the substituent of R ³ include a methyl group.

In formula (1), the R ^1s are independent of each other and may be different from each other or may be the same. The same applies to R ² and R ³ .

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 from 0 to 2000 and n is an integer from 1000 to 10000. m is preferably 0 to 1000, and n is preferably 2000 to 5000.

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

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

The vinyl group-containing linear organopolysiloxane (A1) may contain a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more vinyl groups in the molecule and having a vinyl group content of 0.4 mol% or less. The vinyl group content of the first vinyl group-containing linear organopolysiloxane (A1-1) may be 0.1 mol% or less.

The vinyl group-containing linear organopolysiloxane (A1) may also contain a first vinyl group-containing 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 %.

By combining a first vinyl group-containing linear organopolysiloxane (A1-1) with a second vinyl group-containing linear organopolysiloxane (A1-2) with a high vinyl group content as the raw rubber, which is the raw material for silicone rubber, it is possible to unevenly distribute the vinyl groups and more effectively form a crosslink density distribution in the crosslinked network of the silicone rubber. As a result, the tear strength of the silicone rubber can be more effectively increased.

Specifically, as the vinyl group-containing linear organopolysiloxane (A1), it is preferable to use, for example, a first vinyl group-containing linear organopolysiloxane (A1-1) having two or more units in which R1 is a vinyl group and/or a unit in which R2 is a vinyl group in the molecule, and containing 0.4 mol% or less of these units in the above formula (1-1), and a second vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol% of units in which R1 is a vinyl group and/or units in which R2 is a vinyl group.

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

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.

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.

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

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

The linear organohydrogenpolysiloxane (B1) has a linear structure and a structure in which hydrogen is directly bonded to Si (≡Si-H), and undergoes a hydrosilylation reaction with the vinyl groups of the vinyl group-containing organopolysiloxane (A) and with the vinyl groups of the components blended into the silicone rubber-based curable composition, forming a polymer that crosslinks 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, and 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, by polystyrene conversion using GPC (gel permeation chromatography) with chloroform as the developing solvent.

In addition, it is generally preferred that the linear organohydrogenpolysiloxane (B1) does not have a vinyl group. This effectively prevents the crosslinking reaction from proceeding within the molecule of the linear organohydrogenpolysiloxane (B1).

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

In formula (2), ^R4 is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these groups, 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, and among these, a methyl group is preferable. 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.

Furthermore, ^R5 is a substituted or unsubstituted alkyl group, alkenyl group, aryl group, a hydrocarbon group combining these groups, 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, and among these, a methyl group is preferable. 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.

In addition, in formula (2), the multiple ^R4s are independent of each other and may be different from each other or may be the same. The same applies to ^R5 . However, among the multiple ^R4s and ^R5s , at least two or more are hydrido groups.

Furthermore, ^R6 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group that is a combination of these. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, and a propyl group, and among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. The multiple ^R6s are independent of each other and may be different from each other or the same.

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

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

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

The branched organohydrogenpolysiloxane (B2) has a branched structure, and therefore forms regions with high crosslink density, making it a component that contributes greatly to the formation of a sparsely-dense crosslink structure in the silicone rubber system. In addition, 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 the components blended into the silicone rubber-based hardening composition, forming a polymer that crosslinks these components.

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

Furthermore, it is generally preferred that the branched organohydrogenpolysiloxane (B2) does not have a vinyl group. This effectively prevents the crosslinking reaction from proceeding within the molecule of the branched organohydrogenpolysiloxane (B2).

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

Average composition formula (c)
(H _a (R ⁷ ) _3-a SiO _1/2 ) _m (SiO _4/2 ) _n
(In formula (c), ^R7 is a monovalent organic group, a is an integer ranging from 1 to 3, m is the number of H _a ( ^R7 ) _3-a SiO _1/2 units, and n is the number of SiO _4/2 units.)

In formula (c), ^R7 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 consisting of a combination thereof. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, and a propyl group, and among these, a methyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

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.

In addition, 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.

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

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

Specific examples of branched organohydrogenpolysiloxane (B2) include those having a structure represented by the following formula (3):

In formula (3), ^R7 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group consisting of a combination thereof, or a hydrogen atom. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, and a propyl group, and among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. Examples of the substituent of ^R7 include a methyl group.

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

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

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

In addition, 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 that a crosslinked network is formed between the linear organohydrogenpolysiloxane (B1) and the branched organohydrogenpolysiloxane (B2) and the vinyl group-containing linear organopolysiloxane (A1).

<<Silica Particles (C)>>
The silicone rubber-based hardenable composition of this embodiment may contain silica particles (C) as a non-conductive filler, if necessary.

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

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

By using silica particles (C) that have a specific surface area and average particle size within this range, the hardness and mechanical strength of the silicone rubber formed can be improved, particularly the tensile strength.

<<Silane coupling agent (D)>>
The silicone rubber-based hardenable composition of this embodiment may contain a silane coupling agent (D).
The silane coupling agent (D) may have a hydrolyzable group. The hydrolyzable group is hydrolyzed by water to become a hydroxyl group, and the hydroxyl group undergoes a dehydration condensation reaction with the hydroxyl group on the surface of the silica particles (C), thereby modifying the surface of the silica particles (C).

The silane coupling agent (D) may contain a silane coupling agent having a hydrophobic group. This provides the surface of the silica particles (C) with this hydrophobic group, which reduces the cohesive force of the silica particles (C) in the silicone rubber-based curable composition and, in turn, in the silicone rubber (less cohesion due to hydrogen bonds caused by silanol groups). As a result, it is presumed that the dispersibility of the silica particles in the silicone rubber-based curable composition is improved. This increases the interface between the silica particles and the rubber matrix, enhancing the reinforcing effect of the silica particles. Furthermore, it is presumed that the slipperiness of the silica particles in the matrix is improved during deformation of the rubber matrix. And, due to the improved dispersibility and slipperiness of the silica particles (C), the mechanical strength (e.g., tensile strength, tear strength, etc.) of the silicone rubber due to the silica particles (C) is improved.

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, when the silicone rubber-based curable composition is cured, that is, when the vinyl group of the vinyl group-containing organopolysiloxane (A) and the hydride group of the organohydrogenpolysiloxane (B) undergo a hydrosilylation reaction to form a network (crosslinked structure), the vinyl group of the silica particles (C) also participates in the hydrosilylation reaction with the hydride group of the organohydrogenpolysiloxane (B), and the silica particles (C) are also incorporated into the network. This allows the formed silicone rubber to have a low hardness and a high modulus.

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 of 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. 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 that is a combination of these. Examples include a methyl group, an ethyl group, a propyl group, and a phenyl group, and among these, a methyl group is particularly preferred.

Examples of hydrophilic groups include hydroxyl groups, sulfonic acid groups, carboxyl groups, and carbonyl groups, and among these, hydroxyl groups are particularly preferred. Note that hydrophilic groups may be included as functional groups, but from the viewpoint of imparting hydrophobicity to the silane coupling agent (D), it is preferable that they are not included.

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

Specific examples of the silane coupling agent (D) represented by the above formula (4) include, for example, alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, and decyltrimethoxysilane; chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and phenyltrichlorosilane; and hexamethyldisilazane, which have a hydrophobic group as a functional group. Examples of the silane having a vinyl group include alkoxysilanes such as methacryloxypropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinylmethyldimethoxysilane; chlorosilanes such as vinyltrichlorosilane and vinylmethyldichlorosilane; and divinyltetramethyldisilazane. Among these, taking into consideration the above description, it is particularly preferable that the silane having a hydrophobic group is hexamethyldisilazane, and the silane having a vinyl group is divinyltetramethyldisilazane.

In this embodiment, the lower limit of the content of the silane coupling agent (D) is preferably 1 mass% or more, more preferably 3 mass% or more, and even more preferably 5 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 mass% or less, more preferably 80 mass% or less, and even more preferably 40 mass% or less, based on 100 parts by weight of the total amount of the vinyl group-containing organopolysiloxane (A).
By making the content of silane coupling agent (D) above the lower limit, silicone rubber has appropriate adhesion to substrate, and when silica particles (C) are used, it can contribute to improving the mechanical strength of silicone rubber as a whole.In addition, by making the content of silane coupling agent (D) below the upper limit, silicone rubber can have appropriate mechanical properties.

<<Platinum or platinum compound (E)>>
The silicone rubber-based hardenable composition of this embodiment 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.

As the platinum or platinum compound (E), known substances 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 vinyl siloxane.

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

<<Water (F)>>
Furthermore, the silicone rubber-based hardenable composition of this embodiment may contain water (F) in addition to the above components (A) to (E).

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

Furthermore, when water (F) is contained, its content can be set appropriately, but specifically, for example, it is preferably in the range of 10 to 100 parts by weight, and more preferably in the range of 30 to 70 parts by weight, per 100 parts by weight of the silane coupling agent (D). This allows the reaction between the silane coupling agent (D) and the silica particles (C) to proceed more reliably.

(Other ingredients)
Furthermore, the silicone rubber-based hardening composition of the present 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.

In addition, the content ratio of each component in the silicone rubber-based hardening composition is not particularly limited, but is set, for example, as follows.

In this embodiment, the upper limit of the content of silica particles (C) may be, for example, 60 parts by weight or less, preferably 50 parts by weight or less, and more preferably 40 parts by weight or less, per 100 parts by weight of the total amount of vinyl group-containing organopolysiloxane (A). This allows for a balance between hardness, tensile strength, and other mechanical strengths. The lower limit of the content of silica particles (C) is not particularly limited, but may be, for example, 10 parts by weight or more, per 100 parts by weight of the total amount of vinyl group-containing organopolysiloxane (A).

The silane coupling agent (D) is preferably contained in an amount of 5 parts by weight or more and 100 parts by weight or less, and more preferably 5 parts by weight or more and 40 parts by weight or less, per 100 parts by weight of the vinyl group-containing organopolysiloxane (A). This can reliably improve the dispersibility of the silica particles (C) in the silicone rubber-based curable composition.

The content of organohydrogenpolysiloxane (B) is preferably, for example, 0.5 parts by weight or more and 20 parts by weight or less, and more preferably 0.8 parts by weight or more and 15 parts by weight or less, per 100 parts by weight of the total amount of vinyl group-containing organopolysiloxane (A), silica particles (C), and silane coupling agent (D). By keeping the content of (B) within the above range, a more effective curing reaction may be achieved.

The content of platinum or platinum compound (E) means a catalytic amount and can be set appropriately, but specifically, it is an amount such that the platinum group metal in this component is 0.01 to 1000 ppm by weight, preferably 0.1 to 500 ppm, relative to the total amount of vinyl group-containing organopolysiloxane (A), silica particles (C), and silane coupling agent (D). By making the content of platinum or platinum compound (E) equal to or greater than the above lower limit, the obtained silicone rubber composition can be sufficiently cured. By making the content of platinum or platinum compound (E) equal to or less than the above upper limit, the curing speed of the obtained silicone rubber composition can be improved.

Furthermore, when water (F) is contained, its content can be set appropriately, but specifically, for example, it is preferably in the range of 10 to 100 parts by weight, and more preferably in the range of 30 to 70 parts by weight, per 100 parts by weight of the silane coupling agent (D). This allows the reaction between the silane coupling agent (D) and the silica particles (C) to proceed more reliably.

<Method of manufacturing silicone rubber>
Next, a method for producing the silicone rubber of this embodiment will be described.
In the method for producing the silicone rubber of this embodiment, a silicone rubber-based hardening composition is prepared, and the silicone rubber can be obtained by hardening the silicone rubber-based hardening composition.
Details are provided below.

First, the components of the silicone rubber-based hardening composition are mixed uniformly using any kneading device to prepare the silicone rubber-based hardening composition.

[1] For example, a predetermined amount of vinyl group-containing organopolysiloxane (A), silica particles (C), and a silane coupling agent (D) are weighed out, and then kneaded using any kneading device to obtain a kneaded product containing these components (A), (C), and (D).

It is preferable to prepare this mixture by first kneading the vinyl group-containing organopolysiloxane (A) with the silane coupling agent (D) and then kneading (mixing) the silica particles (C). This further improves the dispersibility of the silica particles (C) in the vinyl group-containing organopolysiloxane (A).

When obtaining this kneaded mixture, water (F) may be added to the kneaded mixture of components (A), (C), and (D) as necessary. This allows the reaction between the silane coupling agent (D) and the silica particles (C) to proceed more reliably.

Furthermore, it is preferable that the kneading of each of the components (A), (C), and (D) is carried out through a first step of heating at a first temperature and a second step of heating at a second temperature. This allows the surface of the silica particles (C) to be surface-treated with the coupling agent (D) in the first step, and allows the by-products generated by the reaction between the silica particles (C) and the coupling agent (D) to be reliably removed from the kneaded mixture in the second step. Thereafter, component (A) may be added to the obtained kneaded mixture as necessary, and further kneaded. This allows the compatibility of the components in the kneaded mixture to be improved.

The first temperature is preferably, for example, about 40 to 120°C, and more preferably, for example, about 60 to 90°C. The second temperature is preferably, for example, about 130 to 210°C, and more preferably, for example, about 160 to 180°C.

The atmosphere in the first step is preferably an inert atmosphere such as a nitrogen atmosphere, and the atmosphere in the second step is preferably a reduced pressure atmosphere.

Furthermore, the time for the first step is, for example, preferably about 0.3 to 1.5 hours, and more preferably about 0.5 to 1.2 hours. The time for the second step is, for example, preferably about 0.7 to 3.0 hours, and more preferably about 1.0 to 2.0 hours.

By setting the above conditions for the first and second steps, the above effects can be obtained more significantly.

[2] Next, predetermined amounts of organohydrogenpolysiloxane (B) and platinum or platinum compound (E) are weighed out, and then, using any kneading device, the components (B) and (E) are kneaded into the mixture prepared in the above step [1] to obtain a silicone rubber-based curable composition. The obtained silicone rubber-based curable composition may be a paste containing a solvent.

When mixing the components (B) and (E), it is preferable to first mix the mixture prepared in step [1] above with the organohydrogenpolysiloxane (B), and then mix the mixture prepared in step [1] above with platinum or a platinum compound (E), and then mix the mixtures together. This allows the components (A) to (E) to be reliably dispersed in the silicone rubber-based curable composition without allowing the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) to proceed.

The temperature at which components (B) and (E) are kneaded is, for example, preferably about 10 to 70°C, and more preferably about 25 to 30°C, as the roll setting temperature.

Furthermore, the kneading time is preferably, for example, about 5 minutes to 1 hour, and more preferably about 10 to 40 minutes.

In the above steps [1] and [2], by setting the temperature within the above range, the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) can be more accurately prevented or suppressed. In addition, in the above steps [1] and [2], by setting the kneading time within the above range, each of the components (A) to (E) can be more reliably dispersed in the silicone rubber-based curable composition.

The kneading device used in each step [1] and [2] is not particularly limited, but may be, for example, a kneader, a two-roll mill, a Banbury mixer (continuous kneader), a pressure kneader, etc.

In addition, in this step [2], a reaction inhibitor such as 1-ethynylcyclohexanol may be added to the kneaded mixture. This makes it possible to more accurately prevent or inhibit the progress of the reaction between the vinyl group-containing organopolysiloxane (A) and the organohydrogenpolysiloxane (B) even if the temperature of the kneaded mixture is set to a relatively high temperature.

[3] Next, the silicone rubber-based curable composition is cured to form silicone rubber.

In this embodiment, the curing process of the silicone rubber-based curable resin composition is carried out, for example, by heating at 100 to 250°C for 1 to 30 minutes (first curing) and then post-baking at 200°C for 1 to 4 hours (secondary curing).

Through the above steps, a silicone rubber consisting of a cured product of the silicone rubber-based curable resin composition is obtained.

[3] Next, the silicone rubber-based hardening composition obtained in step [2] is dissolved in a solvent to obtain an insulating paste.
[3] Next, the silicone rubber-based hardening composition obtained in step [2] is dissolved in a solvent, and a conductive filler is added to obtain a conductive paste.

(Conductive filler)
As the conductive filler, a known conductive material may be used, but metal powder (G) may also be used.
The metal constituting the metal powder (G) is not particularly limited, but may include, for example, at least one of copper, silver, gold, nickel, tin, lead, zinc, bismuth, antimony, or metal powder alloyed with these, or two or more of these.
Of these, the metal powder (G) preferably contains silver or copper, that is, silver powder or copper powder, because of their high electrical conductivity and ready availability.
These metal powders (G) may also be coated with other metals.

In this embodiment, there is no restriction on the shape of the metal powder (G), but conventional shapes such as dendritic, spherical, and scale-shaped can be used. Among these, scale-shaped metal powder (G) may be used.

The particle size of the metal powder (G) is not limited, but is preferably 0.001 μm or more, more preferably 0.01 μm or more, and even more preferably 0.1 μm or more, in terms of average particle size D _50. The particle size of the metal powder (G) is preferably 1,000 μm or less, more preferably 100 μm or less, and even more preferably 20 μm or less, in terms of average particle size D ₅₀ .
By setting the average particle size _D50 in this range, the silicone rubber can exhibit appropriate electrical conductivity.
The particle size of the metal powder (G) can be defined as the average particle size of 200 arbitrarily selected metal powder particles, for example, by observing the conductive paste or silicone rubber molded using the conductive paste with a transmission electron microscope or the like and performing image analysis.

The content of the conductive filler in the conductive paste is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, based on 100% by mass of the conductive paste. The content of the conductive filler in the conductive paste is preferably 85% by mass or less, more preferably 75% by mass or less, and even more preferably 65% by mass or less, based on 100% by mass of the conductive paste.
By setting the content of the conductive filler to be equal to or greater than the above lower limit, the silicone rubber can have appropriate conductive properties, while by setting the content of the conductive filler to be equal to or less than the above upper limit, the silicone rubber can have appropriate flexibility.

The lower limit of the content of silica particles (C) in the conductive paste can be, for example, 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more, based on 100% by mass of the total amount of silica particles (C) and conductive filler. This can improve the mechanical strength of the silicone rubber. On the other hand, the upper limit of the content of silica particles (C) in the conductive paste can be, for example, 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the total amount of silica particles (C) and conductive filler. This can balance the elastic electrical properties and mechanical strength of the silicone rubber.

The content of the silicone rubber-based hardening composition in the conductive paste/insulating paste 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% by mass of the conductive paste/insulating paste. The content of the silicone rubber-based hardening composition in the conductive paste/insulating paste is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the conductive paste/insulating paste.
By making the content of the silicone rubber-based hardening composition equal to or greater than the above lower limit, the silicone rubber can have an appropriate degree of flexibility, while by making the content of the silicone rubber-based hardening composition equal to or less than the above upper limit, the mechanical strength of the silicone rubber can be improved.

(solvent)
The conductive paste and the insulating paste contain a solvent.
As the solvent, various known solvents can be used, including, for example, high boiling point solvents. These may be used alone or in combination of two or more kinds.

The lower limit of the boiling point of the high boiling point solvent is, for example, 100°C or higher, preferably 130°C or higher, and more preferably 150°C or higher. This can improve the printing stability of screen printing and the like. On the other hand, the upper limit of the boiling point of the high boiling point solvent is not particularly limited, but may be, for example, 300°C or lower, 290°C or lower, or 280°C or lower. This can suppress excessive thermal history during wiring formation, thereby preventing damage to the base and maintaining the shape of the wiring formed from the conductive paste in a good condition.

The solvent can be appropriately selected from the viewpoint of the solubility and boiling point of the silicone rubber-based curable resin composition, but can include, for example, aliphatic hydrocarbons having 5 to 20 carbon atoms, preferably aliphatic hydrocarbons having 8 to 18 carbon atoms, and more preferably aliphatic hydrocarbons having 10 to 15 carbon atoms.

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, mesitylene, trifluoromethylbenzene, and 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, and diethylene glycol dimethyl ether. Examples of the ethers include ethanol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl-n-propyl 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; sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide; and esters such as diethyl carbonate. These may be used alone or in combination of two or more.
The solvent used here may be appropriately selected from among solvents capable of uniformly dissolving or dispersing the components in the conductive paste.

The solvent may include a first solvent having an upper limit of the polar term (δ _p ) of the Hansen solubility parameter of, for example, 10 MPa ^1/2 or less, preferably 7 MPa ^1/2 or less, and more preferably 5.5 MPa ^1/2 or less. This allows the silicone rubber-based curable resin composition to have good dispersibility and solubility in the paste. The lower limit of the polar term (δ _p ) of the first solvent is not particularly limited, but may be, for example, 0 Pa ^1/2 or more.

The upper limit of the hydrogen bond term (δ _h ) of the Hansen solubility parameter in the first solvent is, for example, 20 MPa ^1/2 or less, preferably 10 MPa ^1/2 or less, and more preferably 7 MPa ^1/2 or less. This allows the silicone rubber-based curable resin composition to have good dispersibility and solubility in the paste. The lower limit of the hydrogen bond term (δ _h ) of the first solvent is not particularly limited, but may be, for example, 0 Pa ^1/2 or more.

Hansen solubility parameter (HSP) is an index that indicates the solubility of a substance, i.e., how much a substance dissolves in another substance. HSP expresses solubility as a three-dimensional vector. This three-dimensional vector can be typically expressed by a dispersion term (δ _d ), a polar term (δ _p ), and a hydrogen bond term (δ _h ). Vectors that are similar to each other can be judged to have high solubility. The similarity of vectors can be judged by the distance of the Hansen solubility parameter (HSP distance).

As used herein, the Hansen Solubility Parameter (HSP value) can be calculated using software called HSPiP (Hansen Solubility Parameters in Practice), where the computer software HSPiP developed by Hansen and Abbott includes a function for calculating HSP distances and a database of Hansen parameters for various resins and solvents or non-solvents.
The solubility of each resin in pure solvents and mixed solvents of good and poor solvents is investigated, and the results are entered into the HSPiP software to calculate D: dispersion term, P: polarity term, H: hydrogen bond term, and R0: radius of the solubility sphere.

The solvent of this embodiment may be selected, for example, from one in which the difference in HSP distance, polarity term, or hydrogen bond term between the elastomer or the structural units constituting the elastomer and the solvent is small.

The lower limit of the viscosity of the conductive paste and/or insulating paste when measured at a shear rate of 20 [1/s] at room temperature of 25°C is, for example, 1 Pa·s or more, preferably 5 Pa·s or more, and more preferably 10 Pa·s or more. This can improve film-forming properties. Also, shape retention can be improved even when forming a thick film. On the other hand, the upper limit of the viscosity of the conductive paste and/or insulating paste at room temperature of 25°C is, for example, 100 Pa·s or less, preferably 90 Pa·s or less, and more preferably 80 Pa·s or less. This can improve the printability of the paste.

The viscosity measured at room temperature of 25°C at a shear rate of 1 [1/s] is defined as η1, the viscosity measured at a shear rate of 5 [1/s] is defined as η5, and the thixotropic index is defined as the viscosity ratio (η1/η5).
In this case, the lower limit of the thixotropic index of the conductive paste and/or insulating paste is, for example, 1.0 or more, preferably 1.1 or more, and more preferably 1.2 or more. This allows the shape of the wiring obtained by the printing method to be stably maintained. On the other hand, the upper limit of the thixotropic index of the conductive paste and/or insulating paste is, for example, 3.0 or less, preferably 2.5 or less, and more preferably 2.0 or less. This allows the paste to be easily printed.

In this embodiment, the above silicone rubber-based curable composition is cured to obtain an insulating elastomer.
Furthermore, insulating elastomers having a tube structure or a solid core structure can be obtained by using the above silicone rubber-based hardening composition and various molding methods such as extrusion molding and compression molding.
Alternatively, the insulating paste may be used to form a coating film by various coating means such as printing, spraying, dipping, etc., and then dried to obtain an insulating elastomer.
As with the insulating paste, the conductive paste can be used to form a coating film by various coating means such as printing, spraying, dipping, etc., and then dried to obtain a conductive elastomer.
Using these insulating elastomers and conductive elastomers, insulating elastomer layers and conductive elastomer layers can be formed.

As an example of a manufacturing process for the stretchable conductive yarn 100, for example, a silicone rubber-based curable composition is used and extruded into a tube shape using an extruder to obtain an insulating tube structure including an insulating elastomer layer 10. A conductive paste is applied to the outer surface of the obtained insulating tube structure and dried, thereby forming a yarn 50 in which a conductive tube structure including a conductive elastomer layer 20 is laminated on the outer surface of the insulating tube structure.
As an example of a manufacturing process for the stretchable conductive yarn 100, an insulating tube structure including an insulating elastomer layer 12 is obtained by extrusion molding, and a conductive paste is applied to the inner hole of the obtained insulating tube structure and dried, thereby forming a yarn 52 in which a conductive tube structure including a conductive elastomer layer 23 is laminated on the inner surface of the insulating tube structure.

In this way, the conductive elastomer layer in the elastic conductive yarn may be composed of a coating layer (conductive silicone rubber) made of a conductive paste. This allows the pattern shape of the conductive elastomer layer to be freely selected. Furthermore, when the insulating elastomer layer is composed of a cured product of the above-mentioned silicone rubber-based curable composition, the adhesion between the coating layer made of the conductive paste and the insulating elastomer layer can be improved.

The lower limit of the conductive filler content in the yarn is, for example, 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more, based on 100% by mass of the conductive elastomer layer. This improves the stretch electrical properties of the elastic conductive yarn. On the other hand, the upper limit of the conductive filler content in the yarn is, for example, 90% by mass or less, preferably 88% by mass or less, and more preferably 85% by mass or less, based on 100% by mass of the conductive elastomer layer. This prevents the deterioration of rubber properties such as the elasticity of the elastic conductive yarn.

The lower limit of the breaking strength of a single thread in the elastic conductive yarn is, for example, 4 MPa or more, preferably 5 MPa or more, and more preferably 15 MPa or more. On the other hand, the upper limit of the breaking strength of a single thread in the elastic conductive yarn is, for example, 17 MPa or less, preferably 15 MPa or less, and more preferably 13 MPa or less.

The lower limit of the breaking elongation of a single thread in the elastic conductive yarn is, for example, 200% or more, preferably 300% or more, and more preferably 400% or more. On the other hand, the upper limit of the breaking elongation of a single thread in the elastic conductive yarn is, for example, 1500% or less, preferably 1400% or less, and more preferably 1300% or less.

The electrical resistance value R0 of a single thread in the stretchable conductive yarn when unstretched is, for example, 0.1 Ω/cm to 50 Ω/cm, preferably 0.3 Ω/cm to 35 Ω/cm, and more preferably 0.5 Ω/cm to 20 Ω/cm.
The electrical resistance value R0 is calculated from the following formula.
R0 (Ω/cm) = resistance value of unstretched thread (Ω) / length of unstretched thread (cm)

The electrical resistance value R50 of a single thread in the elastic conductive yarn when stretched by 50% is, for example, 0.1 Ω/cm to 400 Ω/cm, preferably 0.3 Ω/cm to 200 Ω/cm, and more preferably 0.5 Ω/cm to 100 Ω/cm.
The electrical resistance value R50 is calculated from the following formula.
R50 (Ω/cm) = resistance value of thread when stretched 50% (Ω) / length of thread when stretched 50% (cm)

The electrical resistance value R100 of a single thread in the elastic conductive yarn when stretched 100% is 0.5 Ω/cm to 800 Ω/cm, preferably 1 Ω/cm to 450 Ω/cm, and more preferably 1.5 to 250 Ω/cm.
The electrical resistance value R100 is calculated from the following formula.
R100 (Ω/cm) = resistance value of thread when stretched 100% (Ω) / length of thread when stretched 100% (cm)

The rate of change in the electrical resistance of an elastic conductive yarn before and after performing a 50% stretching operation 100 times is, for example, 200% or less, preferably 180% or less, and more preferably 150% or less, in the unstretched state of a single yarn.
The rate of change in electrical resistance is defined as (R0'-R0)/R0 x 100, where R0 is the resistance of the yarn when unstretched and R0' is the resistance of the yarn when unstretched after 100 stretching operations.

At least one of the insulating elastomer layer and the conductive elastomer layer contained in the elastic conductive yarn, and preferably both, may be composed of an elastomer having the following properties:

The lower limit of the tear strength of the elastomer is, for example, 25 N/mm or more, preferably 28 N/mm or more, more preferably 30 N/mm or more, even more preferably 33 N/mm or more, and even more preferably 35 N/mm or more. This can improve the durability of the elastomer during repeated use. Also, the mechanical strength of the elastomer can be improved.
On the other hand, the upper limit of the tear strength of the elastomer is not particularly limited, but may be, for example, 80 N/mm or less, or 70 N/mm or less, so that the various properties of the elastomer can be well balanced.

The lower limit of the tensile strength of the elastomer is, for example, 5.0 MPa or more, preferably 10.0 MPa or more, and more preferably 12.0 MPa or more. This can improve the mechanical strength of the elastomer. In addition, it is possible to realize an elastomer with excellent durability that can withstand repeated deformation.
On the other hand, the upper limit of the tensile strength of the elastomer is not particularly limited, but may be, for example, 25 MPa or less, or 20 MPa or less, so that the various properties of the elastomer can be well balanced.

The upper limit of the durometer hardness A of the elastomer is not particularly limited, but may be, for example, 80 or less, preferably 75 or less, and more preferably 70 or less. This allows the cured physical properties of the silicone rubber to be well balanced. This increases the deformability of the elastomer, which allows it to be easily deformed, such as by bending or stretching.
On the other hand, the lower limit of the durometer hardness A of the elastomer is not particularly limited, but is, for example, not less than 20, preferably not less than 25, and more preferably not less than 30. This can increase the mechanical strength of the elastomer.

In this embodiment, the following method can be used to measure the properties of the thread (conductive thread) in the elastic conductive yarn and the elastomer that constitutes the thread. To measure the properties of the conductive thread, the conductive thread may be used as is as a test piece.

(Measuring conditions for tear strength)
A crescent-shaped test piece is prepared using the elastomer, and the tear strength of the obtained crescent-shaped test piece is measured at 25° C. in accordance with JIS K6252 (2001).

(Measurement conditions for tensile strength)
A dumbbell-shaped No. 3 test piece is prepared using the elastomer, and the tensile strength of the obtained dumbbell-shaped No. 3 test piece is measured at 25° C. in accordance with JIS K6251 (2004).

(Conditions for measuring elongation at break)
A dumbbell-shaped No. 3 test piece is prepared using the elastomer, and the resulting dumbbell-shaped No. 3 test piece is subjected to measurement of breaking elongation at 25° C. in accordance with JIS K6251 (2004).

(Procedure for measuring durometer hardness A)
A sheet-like test piece is prepared using the elastomer, and the durometer hardness A of the obtained sheet-like test piece at 25° C. is measured in accordance with JIS K6253 (1997).

The electrical resistance value R0 of the conductive elastomer when unstretched is, for example, 0.1 Ω/cm to 50 Ω/cm, preferably 0.3 Ω/cm to 35 Ω/cm, and more preferably 0.5 Ω/cm to 20 Ω/cm.

The electrical resistance value R50 of the conductive elastomer at 50% elongation is, for example, 0.1 Ω/cm to 400 Ω/cm, preferably 0.3 Ω/cm to 200 Ω/cm, and more preferably 0.5 Ω/cm to 100 Ω/cm.
The electrical resistance value R100 of the conductive elastomer at 100% elongation is 0.5 Ω/cm to 800 Ω/cm, preferably 1 Ω/cm to 450 Ω/cm, and more preferably 1.5 to 250 Ω/cm.

FIG. 3 is a diagram illustrating an example of the structure of the conductive structure 200 of this embodiment.
The conductive structure 200 of this embodiment is composed of a knitted or woven fabric using elastic conductive yarn 100.

The wearable device of this embodiment is equipped with the elastic conductive yarn or conductive structure described above.

The sensor or stretchable wiring included in the wearable device may be made of the above-mentioned stretchable conductive yarn or conductive structure.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention.
Below, examples of reference forms are given.
1. An elastic conductive yarn comprising one or more yarns,
An elastic conductive yarn, wherein the yarn has, in one radial cross section of the yarn, an insulating elastomer layer and a conductive elastomer layer laminated on the surface of the insulating elastomer layer.
2. The elastic conductive yarn according to 1.,
The yarn has at least one of an insulating tube structure including the insulating elastomer layer and a conductive tube structure including the conductive elastomer layer.
3. The elastic conductive yarn according to 2.,
The yarn,
At least one of an insulating tube structure including the insulating elastomer layer and a solid insulating core structure including the insulating elastomer layer;
and a conductive tube structure including the conductive elastomer layer configured to cover at least one surface of the outer surface of the insulating tube structure, the inner surface of the insulating tube structure, and the outer surface of the insulating core structure.
4. The elastic conductive yarn according to 2. or 3.,
An elastic conductive yarn, in which either the insulating tube structure or the conductive tube structure is provided on the outermost layer of the yarn.
5. The elastic conductive yarn according to any one of 1. to 4.,
The insulating elastomer layer comprises one or more materials selected from the group consisting of silicone rubber and urethane rubber.
6. The elastic conductive yarn according to any one of 1. to 5.,
The insulating elastomer layer comprises a non-conductive filler.
7. The elastic conductive yarn according to any one of 1. to 6.,
An elastic conductive yarn, wherein the conductive elastomer layer comprises one or more selected from the group consisting of silicone rubber and urethane rubber, and a conductive filler.
8. The elastic conductive yarn according to any one of 1. to 4.,
the insulating elastomer layer is composed of a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane,
The conductive elastomer layer is composed of a conductive filler and a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane.
9. The stretchable conductive yarn according to 7. or 8.,
The conductive filler comprises silver powder.
10. The elastic conductive yarn according to any one of 7. to 9.,
The conductive filler content of the elastic conductive yarn is 70% by mass or more and 90% by mass or less, based on 100% by mass of the conductive elastomer layer.
11. The elastic conductive yarn according to any one of 1. to 10.,
An elastic conductive yarn, in which a conductive elastomer layer is composed of a coating layer made of a conductive paste.
12. The elastic conductive yarn according to any one of 1. to 11.,
An elastic conductive yarn, in which the breaking strength of a single yarn in the elastic conductive yarn is 4 MPa or more and 17 MPa or less.
13. The elastic conductive yarn according to any one of 1. to 12.,
An elastic conductive yarn, in which the breaking elongation of one of the yarns in the elastic conductive yarn is 200% or more and 1500% or less.
14. The elastic conductive yarn according to any one of 1. to 13.,
An elastic conductive yarn, in which the electrical resistance of a single thread in the elastic conductive yarn when unstretched is 0.1 Ω/cm or more and 50 Ω/cm or less.
15. The elastic conductive yarn according to any one of 1. to 14.,
An elastic conductive yarn, in which the electrical resistance value of a single thread in the elastic conductive yarn when stretched by 50% is 0.1 Ω/cm or more and 400 Ω/cm or less.
16. The elastic conductive yarn according to any one of 1. to 15.,
An elastic conductive yarn, in which the electrical resistance value of a single thread in the elastic conductive yarn when stretched 100% is 0.5 Ω/cm or more and 800 Ω/cm or less.
17. The elastic conductive yarn according to any one of 1. to 16.,
An elastic conductive thread, in which the rate of change in the electrical resistance of a single strand of the elastic conductive thread when unstretched is 200% or less before and after performing a 50% stretching operation 100 times.
18. A conductive structure comprising a knitted or woven fabric made using the elastic conductive yarn according to any one of 1. to 17.
19. A wearable device comprising the stretchable conductive yarn according to any one of 1. to 17., or the conductive structure according to 18..
20. The wearable device according to claim 19,
A wearable device, wherein a sensor or stretchable wiring in the wearable device is composed of the stretchable conductive yarn or the conductive structure.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the description of these examples.

(Vinyl Group-Containing Organopolysiloxane (A))
(A1-1): First vinyl group-containing linear organopolysiloxane: a vinyl group-containing dimethylpolysiloxane (structure represented by the above formula (1-1)) synthesized according to the following synthesis scheme 1.
(A1-2): Second vinyl group-containing linear organopolysiloxane: a vinyl group-containing dimethylpolysiloxane synthesized according to the following synthesis scheme 2 (a structure represented by the above formula (1-1) in which R ¹ and R ² are vinyl groups).

(Organohydrogenpolysiloxane (B))
(B-1): Organohydrogenpolysiloxane: "TC-25D" manufactured by Momentive Corporation

(Silica Particles (C))
(C): Silica fine particles (particle size 7 nm, specific surface area 300 m ² /g), manufactured by Nippon Aerosil Co., Ltd., "AEROSIL300"

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

(Platinum or platinum compound (E))
(E-1): Platinum compound (manufactured by Momentive, product name "TC-25A")

(Water (F))
(F): Pure water

(Metal Powder (G))
(G1): Silver powder, manufactured by Tokuriki Chemical Laboratory Co., Ltd., product name "TC-101", median diameter d ₅₀ : 8.0 μm, aspect ratio 16.4, average major axis 4.6 μm

(Synthesis of vinyl group-containing organopolysiloxane (A))
[Synthesis Scheme 1: Synthesis of First Vinyl Group-Containing Linear Organopolysiloxane (A1-1)]
A first 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 substituted with Ar gas, and the temperature was raised and the mixture was stirred for 30 minutes at 120° C. During this time, an increase in viscosity was confirmed.
The temperature was then 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.
After 4 hours, the mixture was diluted with 250 mL of toluene and washed three times with water. The washed organic layer was washed several times with 1.5 L of methanol for reprecipitation purification, and the oligomer and polymer were separated. The resulting polymer was dried overnight at 60° C. under reduced pressure to obtain a first vinyl group-containing linear organopolysiloxane (A1-1) (Mn=2.2×10 ⁵ , Mw=4.8×10 ⁵ ). The vinyl group content calculated by H-NMR spectrum measurement was 0.04 mol%.

[Synthesis Scheme 2: Synthesis of second vinyl group-containing linear organopolysiloxane (A1-2)]
A second vinyl-containing linear organopolysiloxane (A1-2) was synthesized as shown in formula (6) below in the same manner as in the synthesis of (A1-1) above, except that 0.86 g (2.5 mmol) of 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane was used in addition to 74.7 g (252 mmol) of octamethylcyclotetrasiloxane in the synthesis of (A1-1). The vinyl group content calculated by H-NMR spectrum measurement was 0.92 mol%.

(Preparation of Silicone Rubber-Based Curable Composition)
According to the following procedure, the silicone rubber-based hardenable compositions of Examples 1 to 8 and (A) in Table 1 were prepared.
First, a mixture of 90% vinyl group-containing organopolysiloxane (A), silane coupling agent (D), and water (F) was pre-kneaded in the proportions shown in Table 1 below, and then silica particles (C) were added to the mixture and further kneaded to obtain a kneaded product (silicone rubber compound).
Here, the kneading after the addition of the silica particles (C) was carried out through a first step of kneading for 1 hour under conditions of 60 to 90°C in a nitrogen atmosphere for the coupling reaction, and a second step of kneading for 2 hours under conditions of 160 to 180°C in a reduced pressure atmosphere for the removal of the by-product (ammonia), followed by cooling, and then adding the remaining 10% of the vinyl group-containing organopolysiloxane (A) in two portions and kneading for 20 minutes.
Next, organohydrogenpolysiloxane (B), platinum or a platinum compound (E) was added to 100 parts by weight of the resulting kneaded product (silicone rubber compound) in the proportions shown in Table 2 below, and the mixture was kneaded with a roll to obtain each silicone rubber-based curable composition.

(Preparation of Conductive Paste)
The obtained silicone rubber-based hardening composition (a) (13.7 parts by weight) was immersed in 31.8 parts by weight of tetradecane (solvent), then stirred with a centrifugal mixer, 54.5 parts by weight of metal powder (G1) was added, and the mixture was kneaded with a triple roll mill to obtain a conductive paste.

(Preparation of elastic conductive yarn)
The silicone rubber-based hardening compositions of Examples 1 to 8 were extruded into a tube using an extruder to obtain a tube member made of insulating silicone rubber.
The obtained conductive paste was applied to the inner layer and/or outer layer of this tube member to the film thickness shown in Tables 2 and 3, and then heat-cured at 180°C for 2 hours to form a conductive silicone rubber layer.
As a result of the above, the conductive layer coated tubes (elastic conductive yarns) of Examples 1 to 8 were obtained, in which a conductive elastomer layer was laminated on the inner surface and/or outer surface of an insulating tube structure composed of an insulating elastomer layer.
The dimensions of the tube member and the film thickness of the conductive silicone rubber layer were measured using a microscope on a radial cross section of the elastic conductive thread.

The obtained elastic conductive yarn was evaluated for the following items.
The evaluation results are shown in Tables 2 and 3. In each table, the diagonal lines indicate that a conductive silicone rubber layer was not formed.

(Tensile strength)
The conductive layer coated tube was used to measure the tensile strength at 25° C. in accordance with JIS K6251 (2004), with the unit being MPa.

(Elongation at break)
The breaking elongation was measured using the conductive layer coated tube in accordance with JIS K6251 (2004). The breaking elongation was calculated by [chuck movement distance (mm)]÷[initial chuck distance (35 mm)]×100. The unit is %.

(Electrical resistance when unstretched and stretched)
A 5 cm long conductive layer coated tube was fixed to a chuck after wrapping 5 mm of tape around each end for insulation. Measurement clips were attached to both ends of the central 3 cm portion, and the resistance of the outer conductive silicone rubber layer was measured when the tube was unstretched, stretched 50% in the length direction at a speed of 0.5 mm/sec, and stretched 100%.
From the obtained resistance values, each electrical resistance value (Ω/cm) was calculated based on the following formula.
R0 (Ω/cm) = resistance value of unstretched thread (Ω) / length of unstretched thread (cm)
R50 (Ω/cm) = resistance value of thread when stretched 50% (Ω) / length of thread when stretched 50% (cm)
R100 (Ω/cm) = resistance value of thread when stretched 100% (Ω) / length of thread when stretched 100% (cm)

(50%, rate of change in electrical resistance after 100 stretches)
A conductive layer-coated tube 5 cm long was wrapped with 5 mm of tape at each end for insulation and fixed to a chuck. The tube was stretched 50% in the length direction at a speed of 1.33 mm/sec, held for 10 seconds, released at the same speed, and held for 10 seconds. This test was repeated 100 times, after which the resistance of the outer conductive silicone rubber layer was measured, and the rate of change from the initial resistance was calculated according to the following formula.
The rate of change in electrical resistance was calculated from (R0'-R0)/R0 x 100, where R0 is the resistance of the yarn when unstretched and R0' is the resistance of the yarn when unstretched after 100 stretching operations.

In addition, when the conductive layer coated tubes of Examples 1 to 4 were used to measure the resistance values when unstretched, stretched to 50%, stretched to 100%, and after stretching to 50% 100 times in the same manner as above, it was found that neither the inner nor outer conductive silicone rubber layers broke and were conductive.
Furthermore, after the conductive layer coated tubes of Examples 1 to 8 were stretched 100 times by 50%, it was confirmed that no peeling occurred between the tube member and the conductive silicone rubber layer.

(Comparative Example 1)
A twisted yarn of stainless steel fiber (manufactured by Nippon Seisen Co., Ltd., Naslon (registered trademark), product number: 12-100/2, elongation: 1.6%) was prepared. The metallic conductive yarn of Comparative Example 1 could not be easily elongated.

The elastic conductive yarns of Examples 1 to 8 were found to have superior elasticity and electrical properties when stretched compared to Comparative Example 1.

10, 11, 12, 13 Insulating elastomer layer 20, 21, 22, 23, 24 Conductive elastomer layer 30 Hole 50, 51, 52, 53 Thread 100 Elastic conductive thread 200 Conductive structure

Claims (20)

An elastic conductive yarn comprising one or more yarns,
The yarn has , in one radial cross section of the yarn, an insulating elastomer layer and a conductive elastomer layer laminated on a surface of the insulating elastomer layer,
An elastic conductive yarn , wherein the conductive elastomer layer contains a powder or fibrous conductive filler . The elastic conductive yarn according to claim 1,
The yarn has at least one of an insulating tube structure including the insulating elastomer layer and a conductive tube structure including the conductive elastomer layer. The elastic conductive yarn according to claim 2,
The yarn,
At least one of an insulating tube structure including the insulating elastomer layer and a solid insulating core structure including the insulating elastomer layer;
and a conductive tube structure including the conductive elastomer layer configured to cover at least one surface of the outer surface of the insulating tube structure, the inner surface of the insulating tube structure, and the outer surface of the insulating core structure. The elastic conductive yarn according to claim 2 or 3,
An elastic conductive yarn, in which either the insulating tube structure or the conductive tube structure is provided on the outermost layer of the yarn. The elastic conductive yarn according to any one of claims 1 to 4,
The insulating elastomer layer comprises one or more materials selected from the group consisting of silicone rubber and urethane rubber. The elastic conductive yarn according to any one of claims 1 to 5,
The insulating elastomer layer comprises a non-conductive filler. The elastic conductive yarn according to any one of claims 1 to 6,
An elastic conductive yarn, wherein the conductive elastomer layer comprises one or more selected from the group consisting of silicone rubber and urethane rubber. The elastic conductive yarn according to any one of claims 1 to 4,
the insulating elastomer layer is composed of a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane,
The conductive elastomer layer is composed of the conductive filler and a cured product of a silicone rubber-based curable composition containing a vinyl group-containing organopolysiloxane. The elastic conductive yarn according to any one of claims 1 to 8 ,
The conductive filler comprises silver powder. The elastic conductive yarn according to any one of claims 1 to 9,
The conductive filler content of the elastic conductive yarn is 70% by mass or more and 90% by mass or less, based on 100% by mass of the conductive elastomer layer. The elastic conductive yarn according to any one of claims 1 to 10,
An elastic conductive yarn, in which a conductive elastomer layer is composed of a coating layer made of a conductive paste. The elastic conductive yarn according to any one of claims 1 to 11,
An elastic conductive yarn, in which the breaking strength of a single yarn in the elastic conductive yarn is 4 MPa or more and 17 MPa or less. The elastic conductive yarn according to any one of claims 1 to 12,
An elastic conductive yarn, in which the breaking elongation of one of the yarns in the elastic conductive yarn is 200% or more and 1500% or less. The elastic conductive yarn according to any one of claims 1 to 13,
An elastic conductive yarn, in which the electrical resistance of a single thread in the elastic conductive yarn when unstretched is 0.1 Ω/cm or more and 50 Ω/cm or less. The elastic conductive yarn according to any one of claims 1 to 14,
An elastic conductive yarn, in which the electrical resistance value of a single thread in the elastic conductive yarn when stretched by 50% is 0.1 Ω/cm or more and 400 Ω/cm or less. The elastic conductive yarn according to any one of claims 1 to 15,
An elastic conductive yarn, in which the electrical resistance value of a single thread in the elastic conductive yarn when stretched 100% is 0.5 Ω/cm or more and 800 Ω/cm or less. The elastic conductive yarn according to any one of claims 1 to 16,
An elastic conductive thread, in which the rate of change in the electrical resistance of a single strand of the elastic conductive thread when unstretched is 200% or less before and after performing a 50% stretching operation on the elastic conductive thread 100 times. A conductive structure made of a knitted or woven fabric using the elastic conductive yarn according to any one of claims 1 to 17. A wearable device comprising the elastic conductive yarn according to any one of claims 1 to 17, or the conductive structure according to claim 18 . 20. The wearable device of claim 19,
A wearable device, wherein a sensor or stretchable wiring in the wearable device is composed of the stretchable conductive yarn or the conductive structure.

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