JP2019067871A - Coaxial connector unit, force sensor, and actuator - Google Patents

Abstract

To provide a coaxial connector unit in which a short circuit between an inner conductor and an outer conductor is suppressed.SOLUTION: The coaxial connector unit is provided that includes: a piezoelectric base material comprising a long inner conductor, a piezoelectric body covering the outer circumferential surface of the inner conductor, and an outer conductor disposed on the outer periphery of the piezoelectric body; and a coaxial connector comprising a connection terminal electrically connected to the inner conductor by being applied with pressure.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to coaxial connector units, force sensors, and actuators.

In recent years, application of a piezoelectric material containing a helical chiral polymer to a piezoelectric device such as a sensor or an actuator has been considered. A film-shaped piezoelectric body is used for such a piezoelectric device.
Attention has been focused on the use of polymers having optical activity such as polypeptides and polylactic acid-based polymers as helical chiral polymers in the piezoelectric body. Among them, polylactic acid-based polymers are known to exhibit piezoelectricity only by mechanical stretching operation. It is known that a piezoelectric material using a polylactic acid-based polymer does not require poling treatment, and that the piezoelectricity does not decrease over several years.
For example, as a piezoelectric body containing a polylactic acid polymer, large piezoelectric constant d ₁₄ is the piezoelectric excellent in transparency has been reported (e.g., see Patent Documents 1 and 2).
Also, recently, attempts have been made to use a material having piezoelectricity by coating it on a conductor.
For example, a piezoelectric cable is known which is composed of a center conductor, a piezoelectric material layer, an outer conductor, and an outer jacket coaxially arranged in order from the center to the outer side (see, for example, Patent Document 3).

Patent No. 4934235 gazette International Publication No. 2010/104196 Japanese Patent Application Laid-Open No. 10-132669

By the way, a piezoelectric line (an example of a piezoelectric substrate) including an internal conductor, a piezoelectric body, and an external conductor coaxially arranged in order from the center to the outside in a coaxial structure type has a piezoelectric body which is an insulating portion. It is conceivable to use a small coaxial connector which is a tension sensor and is used for an ordinary coaxial cable for taking out an electrode.
Here, the connection between the central conductor of the coaxial cable and the connector is generally performed by soldering, and the insulating layer of the normal coaxial cable is a fluorine resin having high heat resistance, and the thickness of the insulating layer is large. Can withstand the heat of soldering.
However, when the connection between the central conductor of the piezoelectric line and the connector is performed by soldering, the material constituting the piezoelectric body, for example, polylactic acid may be melted, which may cause a short circuit between the central conductor and the outer conductor. Found out by the study of the

  An object of the present disclosure is to provide a coaxial connector unit in which a short circuit between an inner conductor and an outer conductor is suppressed, and a force sensor and an actuator using the coaxial connector unit.

  The specific means for achieving the said subject are as follows.

<1> A pressure is applied to a piezoelectric base material including a long inner conductor, a piezoelectric body covering the outer peripheral surface of the inner conductor, and an outer conductor disposed on the outer periphery of the piezoelectric body And a coaxial connector having a connection terminal electrically connected to the internal conductor.
<2> An insulating portion for holding the internal conductor and the connection terminal in a state of being electrically connected, and a conductive shell for supporting the connection terminal via the insulating portion <1 The coaxial connector unit according to>.
<3> The connection terminal includes a pair of contact portions that are located inside the insulating portion and capable of gripping an internal conductor disposed therebetween, and the insulating portion and the shell are bendable, The coaxial connector unit according to <2>, wherein the internal conductor is held by the pair of contact portions by bending the insulating portion and the shell, and the internal conductor and the connection terminal are electrically connected.
<4> The insulating portion has an insulator main body supporting one of the contact portions, and an insulation bending portion bent in the direction of the insulator main body, and the shell is a shell supporting the insulator main body It has a main body and a shell bending portion which is juxtaposed on the outside of the insulating bending portion and is bent in the direction of the shell main body, and the other contact portion is between the one contact portion and the insulating bending portion And the internal conductor is gripped by the pair of contact portions by bending the insulation bending portion and the shell bending portion, and the internal conductor and the connection terminal are electrically connected. The coaxial connector unit as described in 3>.
<5> The piezoelectric body contains a helical chiral polymer (A) having optical activity, and the main alignment direction of the helical chiral polymer (A) contained in the piezoelectric body in the longitudinal direction of the piezoelectric body is The coaxial connector unit according to any one of <1> to <4>, wherein the orientation degree F of the piezoelectric body determined in accordance with the following formula (b) is in the range of 0.5 to less than 1.0 .
Degree of orientation F = (180 ° -α) / 180 ° ··· (b)
(In formula (b), α represents the half width of the peak derived from the orientation measured by X-ray diffraction.)
<6> The coaxial connector unit according to any one of <1> to <5>, wherein the internal conductor is a tinsel wire.
<7> The piezoelectric body has a long flat plate shape, the average thickness of the piezoelectric body is 0.001 mm to 0.2 mm, and the width of the piezoelectric body is 0.1 mm to 30 mm, the piezoelectric body The coaxial connector unit according to any one of <1> to <6>, wherein the ratio of the width of the piezoelectric body to the average thickness of the two is 2 or more.

The force sensor provided with the coaxial connector unit as described in any one of <8><1>-<7>.
The actuator provided with the coaxial connector unit as described in any one of <9><1>-<8>.

  According to the present disclosure, it is possible to provide a coaxial connector unit in which a short circuit between an inner conductor and an outer conductor is suppressed, and a force sensor and an actuator using the coaxial connector unit.

It is sectional drawing which shows schematic structure of the coaxial connector unit of this indication. It is sectional drawing which shows schematic structure of the piezoelectric base material and coaxial connector which comprise the coaxial connector unit of this indication. It is a side view of the coaxial line structure which constitutes the piezoelectric substrate concerning a 1st embodiment. It is a side view of a piezoelectric substrate concerning a 1st embodiment. It is the X-X 'sectional view taken on the line of FIG. It is a side view of the coaxial line structure which constitutes the piezoelectric substrate concerning a 2nd embodiment. It is a side view of the piezoelectric substrate concerning a 2nd embodiment. It is a perspective view which shows the piezoelectric base material which concerns on 4th Embodiment, and is a figure which shows the polarization direction of PLLA when the twisting force of arrow X 1 direction is applied. It is a perspective view which shows the piezoelectric base material which concerns on 4th Embodiment, and is a figure which shows the polarization direction of PLLA when the twisting force of arrow X 2 direction is applied. It is a perspective view which shows the piezoelectric base material which concerns on 5th Embodiment, and is a figure which shows the polarization direction of PDLA when the twisting force of arrow X 1 direction is applied. It is a perspective view which shows the piezoelectric base material which concerns on 5th Embodiment, and is a figure which shows the polarization direction of PDLA when the twisting force of arrow X 2 direction is applied.

Hereinafter, embodiments of the present disclosure will be described. The present disclosure is not limited to the following embodiments.
In the present disclosure, a numerical range represented using “to” means a range including numerical values described before and after “to” as the lower limit value and the upper limit value.
In the present disclosure, the “main surface” of the long flat plate-like piezoelectric material (the first piezoelectric material and the second piezoelectric material) means a plane orthogonal to the thickness direction of the long flat plate-like piezoelectric material (in other words, , Surface including the length direction and the width direction).
Throughout the present disclosure, the "face" of a member means the "principal surface" of the member unless otherwise noted.
In the present disclosure, the thickness, width, and length satisfy the relationship of thickness <width <length, as normally defined.
In the present disclosure, an angle formed by two line segments is represented by a range of 0 ° or more and 90 ° or less.
In the present disclosure, “film” is a concept encompassing not only what is generally called “film” but also what is generally called “sheet”.
In the present disclosure, the “MD direction” is the machine direction of the film, ie, the stretching direction.
When an embodiment of the present disclosure is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Further, the sizes of the members in the respective drawings are conceptual, and the relative relationship between the sizes of the members is not limited thereto.

[Coaxial connector unit]
A coaxial connector unit according to the present disclosure includes: a piezoelectric base material including a long inner conductor, a piezoelectric body covering an outer peripheral surface of the inner conductor, and an outer conductor disposed on the outer periphery of the piezoelectric body; A coaxial connector having a connection terminal electrically connected to the inner conductor by applying pressure.
Here, since the pressure is applied to the inner conductor of the piezoelectric substrate and the connection terminal in the coaxial connector, the connection is electrically connected. Therefore, it is not necessary to connect the inner conductor and the connection terminal by soldering. A short circuit between the inner conductor and the outer conductor caused by melting of the piezoelectric body of the piezoelectric substrate can be suppressed.
Furthermore, other cables and circuit boards can be electrically connected to the inner conductor of the piezoelectric substrate using a coaxial connector, and the other cables and circuit boards can be electrically connected to the inner conductor of the piezoelectric substrate. No need for soldering to connect to
In addition, "the outer periphery" means the outer peripheral part of a piezoelectric material.

First, the configuration of the coaxial connector unit of the present disclosure will be described using FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a schematic configuration of a coaxial connector unit of the present disclosure, and FIG. 2 is a cross-sectional view showing a schematic configuration of a piezoelectric substrate and a coaxial connector that constitute the coaxial connector unit of the present disclosure.
As shown in FIG. 1, the coaxial connector unit 300 includes a piezoelectric base 100 and a coaxial connector 200. The piezoelectric base 100 includes an inner conductor 12, a piezoelectric body 14, and an outer conductor 16, and the coaxial connector The reference numeral 200 includes a connection terminal 2, an insulating portion 4 to be described later, and a shell 6. The piezoelectric substrate 100 further includes a protective layer 18 covering the outer circumferential surface of the outer conductor 16. The protective layer 18 has a protective function of a member constituting the piezoelectric substrate, and preferably has an insulating property.
Moreover, as shown in FIG. 2, the connection terminal 2 has a pair of contact parts 2A and 2B which mutually oppose. Furthermore, the insulating portion 4 has an insulator main body 4A for supporting the contact portion 2A, and an insulating bent portion 4B which is bent in the direction of the insulator main body 4A (in the direction of arrow Y in the figure). It has a shell main body 6A for supporting the main body 4A, and a shell bending portion 6B provided in parallel to the insulating bending portion 4B and bent in the direction of the shell main body 6A (the direction of the arrow Y in the drawing).

FIG. 1 shows a coaxial connector unit 300 in which the internal conductor 12 and the connection terminal 2 are electrically connected by the internal conductor 12 in the piezoelectric substrate 100 being held by a pair of contact portions constituting the connection terminal 2. It is a figure which shows schematic structure of.
FIG. 2 is a view showing a schematic configuration of the piezoelectric base 100 and the coaxial connector 200 before the internal conductor 12 and the connection terminal 2 are electrically connected, and the piezoelectric base 100 in the direction of the arrow X is shown. By moving and bending the insulating bent portion 4B and the shell bent portion 6B in the direction of the arrow Y, as shown in FIG. 1, the inner conductor is gripped by the pair of contact portions 2A and 2B. As a result, even when the coaxial connector unit 300 is moved to a large extent, it is suppressed that the internal conductor 12 is separated from the connection terminal 2 and the electrical connection is released, and the internal conductor 12 and the connection terminal 2 Electrical connection can be maintained for a long time.
Hereinafter, the specific aspect of the piezoelectric base material and coaxial connector which comprise a coaxial connector unit is demonstrated.

(Piezoelectric substrate)
A coaxial connector unit according to the present disclosure includes a piezoelectric base including an elongated inner conductor, a piezoelectric body covering an outer peripheral surface of the inner conductor, and an outer conductor disposed on the outer periphery of the piezoelectric body. . A preferred embodiment of the piezoelectric substrate of the present disclosure will be described.

  Next, the inner conductor, the piezoelectric body, the outer conductor, and the like included in the piezoelectric substrate of the present disclosure will be described.

<Internal conductor>
The piezoelectric substrate of the present disclosure comprises an inner conductor.
The inner conductor of the piezoelectric substrate is preferably a signal line conductor. The signal line conductor means a conductor for efficiently detecting an electrical signal from the piezoelectric body. More specifically, it is a conductor for detecting a voltage signal (charge signal) corresponding to the applied tension when tension is applied to the piezoelectric substrate.

The inner conductor can be a cord-like object provided with a core and a conductor A covering the periphery of the core. The inner conductor of such a configuration is also referred to as a tinsel wire.
Moreover, a conductive fiber can also be used as an internal conductor. Any conductive fiber may be used as the conductive fiber, and any known fiber may be used. For example, metal fibers, fibers made of a conductive polymer, carbon fibers, fibrous or particulate conductive fillers are dispersed. And fibers obtained by providing a layer having conductivity on the surface of a fibrous material. As a method of providing the layer which has electroconductivity on the surface of a fibrous material, a metal coat, a conductive polymer coat, winding of a conductive fiber etc. are mentioned. Among them, metal coatings are preferred in terms of conductivity, durability, flexibility and the like. Specific methods for coating the metal include vapor deposition, sputtering, electrolytic plating, electroless plating and the like, but electrolytic plating or electroless plating is preferable in terms of productivity and the like. Such metal-plated fibers can be referred to as metal-plated fibers.

  By appropriately selecting the types of core material and conductor A, a piezoelectric substrate suitable for high flexibility and flexibility (for example, applications such as wearable sensors installed in clothes) can be obtained.

  Specifically, for example, a structure in which a metal foil is spirally wound around a core material such as a fiber obtained by twisting a short fiber such as cotton yarn, a polyester fiber, a nylon fiber or the like as the inner conductor. What has is mentioned.

  When metal foil is wound around a core material and an internal conductor is produced, it is preferable that metal foil is flat wire shape. A flat rectangular wire metal foil can be produced by rolling a metal wire or slitting the metal foil into a narrow width. By forming the metal foil into a rectangular wire shape, it is possible to reduce the space between the inner conductor and the piezoelectric body wound around the inner conductor and to improve the adhesion to the piezoelectric body. As a result, it becomes easy to detect the charge fluctuation generated from the piezoelectric body, and the sensitivity to tension is further improved.

  When the metal foil is in the form of a rectangular wire, the ratio of the width to the thickness is preferably 2 or more in the cross section (preferably, a rectangular cross section).

  Although the material in particular of metal foil is not restrict | limited, Copper foil is preferable. By using copper with high electrical conductivity, it is possible to reduce the output impedance. Therefore, when tension is applied to the piezoelectric substrate, a voltage signal corresponding to the tension is more easily detected. As a result, the piezoelectric sensitivity tends to be further improved. In addition, since the copper foil fits into the deformation of the elastic deformation region at the time of bending deformation and becomes less likely to be plastically deformed, metal fatigue failure hardly occurs and it becomes possible to remarkably improve the repeated bending resistance.

  The core material in the inner conductor is located at the center of the inner conductor and has a function as a structural material to support tension. By appropriately selecting the material, the cross-sectional area, and the like of the core material, it is possible to design according to the values of the tension, the amount of strain, and the like applied to the internal conductor.

  The material of the core material is not particularly limited, and can be selected according to the desired characteristics of the piezoelectric substrate. Fibers (filaments) such as natural fibers and synthetic fibers are mentioned from the viewpoint of achieving both flexibility and strength at a high level.

  The thickness of the core material is not particularly limited, and can be selected according to the desired characteristics of the piezoelectric substrate. For example, the line outer diameter is preferably in the range of 0.1 mm to 10 mm.

<Piezoelectric (first piezoelectric)>
The piezoelectric substrate of the present disclosure includes a piezoelectric body (first piezoelectric body).
The piezoelectric body is not particularly limited as long as it is composed of a material having piezoelectricity, and examples include one containing an optically active helical chiral polymer (A).

In the piezoelectric substrate of the present disclosure, the piezoelectric body includes a helical chiral polymer (A) having optical activity, and the main orientation direction of the helical chiral polymer (A) contained in the piezoelectric body in the longitudinal direction of the piezoelectric body It is preferable that the orientation degree F of the piezoelectric body determined by the following formula (b) be in the range of 0.5 or more and less than 1.0.
Degree of orientation F = (180 ° -α) / 180 ° ··· (b)
(In formula (b), α represents the half width of the peak derived from the orientation measured by X-ray diffraction.)

Here, the degree of orientation F of the piezoelectric body is an index indicating the degree of orientation of the helical chiral polymer (A) contained in the piezoelectric body, and for example, a wide-angle X-ray diffractometer (manufactured by RIGAKU Co., Ltd., RINT 2550, accessory device: Degree of c-axis orientation measured by a rotating sample stage, X-ray source: CuKα, output: 40 kV, 370 mA, detector: scintillation counter).
More specifically, using the above-described wide-angle X-ray diffractometer, a long plate shaped slit obtained by slitting the sample (slitting direction of the piezoelectric body and the stretching direction of the piezoelectric body so as to be approximately parallel) The ribbon is fixed to the holder, and the azimuthal intensity distribution of the crystal plane peak [(110) plane / (200) plane] is measured. Then, in the obtained azimuth angle distribution curve (X-ray interference diagram), the crystallinity degree and the half width (α) of the peak are determined, and the orientation degree F of the piezoelectric body (C axis orientation degree from the above equation (b) Calculate).

More specifically, in the piezoelectric substrate of the above aspect, the piezoelectric material includes the helical chiral polymer (A), and the main alignment direction of the helical chiral polymer (A) is in the longitudinal direction of the piezoelectric material. And, when the orientation degree F of the piezoelectric body is 0.5 or more and less than 1.0, the piezoelectricity is suitably expressed.
As a result, when, for example, tension is applied to the piezoelectric substrate, the amount of generated charge increases.

Further, in the piezoelectric base material of the present disclosure, it is preferable that the piezoelectric body is elongated, and spirally wound in one direction along the outer peripheral surface of the inner conductor.
Here, “one direction” means that when the piezoelectric substrate of the present disclosure is viewed from one end side in the axial direction of the internal conductor, the piezoelectric body is wound from the front side to the back side of the internal conductor Say the direction. Specifically, it means rightward (right-handed or clockwise) or left-handed (left-handed or counterclockwise).

In addition, since the piezoelectric body is elongated, the piezoelectric body can be easily disposed in a spiral shape in one direction while maintaining the helical angle β with respect to the axial direction of the internal conductor.
Here, “helical angle β” means an angle between the axial direction of the inner conductor and the direction in which the piezoelectric body is disposed (the longitudinal direction of the piezoelectric body) with respect to the axial direction of the inner conductor.
Thereby, for example, when tension is applied in the longitudinal direction of the piezoelectric substrate, polarization of the helical chiral polymer (A) is easily generated in the radial direction of the piezoelectric substrate. As a result, a voltage signal (charge signal) proportional to tension is effectively detected, and the piezoelectric sensitivity is likely to be improved.

In the piezoelectric substrate of the present disclosure, in order to improve the piezoelectric sensitivity, the piezoelectric body has an angle (that is, a helical angle β) of 15 ° to 75 ° (45 ° ± 30 °) with respect to the axial direction of the inner conductor. It is preferable to hold | maintain and wind, and it is more preferable to hold | maintain the angle of 35 degrees-55 degrees (45 degrees +/- 10 degrees), and to wind.
By this, when tension (stress) is applied in the longitudinal direction of the piezoelectric substrate, a shear force is easily applied to the helical chiral polymer (A), and the helical chiral polymer (A) in the radial direction of the piezoelectric substrate Polarization is likely to occur.
Further, in the piezoelectric substrate of the present disclosure, when a tension (stress) is applied in the longitudinal direction of the piezoelectric substrate by arranging the piezoelectric body in a spiral in one direction, the helical chiral polymer (A) Shear force is applied to cause polarization of the helical chiral polymer (A) in the radial direction of the piezoelectric substrate. When the polarization direction is regarded as an aggregate of minute regions in which the helically wound piezoelectric body can be regarded as a plane with respect to the length direction, tension is applied to the plane of the constituting minute region. If shear force due to (stress) is applied to the helical chiral polymer, substantially coincides with the direction of the electric field generated due to the piezoelectric constant d _14.
Specifically, for example, in the case of a homopolymer of L-lactic acid (PLLA) whose molecular structure is a left-handed helical structure in polylactic acid, for example, a piezoelectric body whose longitudinal direction is along the main orientation direction of PLLA On the other hand, when tension (stress) is applied to the structure wound spirally in the left-handed direction, the electric field from the center of the circle of the circular cross section perpendicular to the tension in the radial direction is parallel to the radial direction ( Polarization) occurs. Also, contrary to this, tension (stress) is applied to the structure in which the piezoelectric body whose longitudinal direction is along the main orientation direction of PLLA is spirally wound to the right with respect to the inner conductor. In this case, an electric field (polarization) from the outside to the center of the circle of the circular cross section perpendicular to the tension is generated in parallel to the radial direction.

Also, for example, in the case of a homopolymer (PDLA) of D-lactic acid whose molecular structure is a right-handed helical structure, the piezoelectric body whose longitudinal direction is along the main orientation direction of PDLA When tension (stress) is applied to the wound structure, an electric field (polarization) is generated along the radial direction from the outside to the center of the circle of the circular cross section perpendicular to the tension. Also, contrary to this, tension (stress) is applied to a structure in which a piezoelectric body whose longitudinal direction is along the main orientation direction of PDLA is spirally wound on the inner conductor in a right-handed manner. As a result, an electric field (polarization) is generated parallel to the radial direction from the center of the circle of the circular cross section perpendicular to the tension.
As a result, when tension is applied in the longitudinal direction of the piezoelectric substrate, potential differences proportional to the tension are generated in the phase-aligned state at each portion of the piezoelectric body disposed in a spiral, so that it is effective. It is believed that a voltage signal proportional to tension is detected.
As a result, it is easy to obtain a piezoelectric substrate that is more excellent in piezoelectric sensitivity.
In addition, the piezoelectric base material of the present disclosure includes a structure in which a piezoelectric body is spirally wound around the inner conductor in a right-handed manner and a part of the piezoelectric body is spirally wound around a left-handed body. May be In the case of spirally winding a part of the piezoelectric body in the left-handed direction, it is preferable that the left-handed ratio is less than 50% with respect to the whole (total of right-handed and left-handed) from the viewpoint of suppressing the decrease .
In addition, the piezoelectric base material of the present disclosure includes a structure in which a piezoelectric body is spirally wound to the left and a part of the piezoelectric body is spirally wound to the right. May be In the case of spirally winding a part of the piezoelectric body in the right-handed direction, the right-handed portion should be less than 50% of the whole (total of right-handed and left-handed) from the viewpoint of suppressing the decrease in piezoelectric sensitivity. Is preferred.

Here, the fact that the main orientation direction of the helical chiral polymer (A) is in the longitudinal direction of the piezoelectric material means that the piezoelectric material is resistant to tension in the longitudinal direction (that is, the tensile strength in the longitudinal direction) Excellent). Therefore, even if the piezoelectric body is spirally wound in one direction with respect to the inner conductor, it becomes difficult to break.
Furthermore, the fact that the main orientation direction of the helical chiral polymer (A) is in the longitudinal direction of the piezoelectric material is, for example, when slitting the stretched piezoelectric film to obtain a piezoelectric material (for example, a slit ribbon) Is also advantageous in terms of productivity.
In the present disclosure, “in one direction, another direction is along” means that an angle formed by two line segments representing one direction and another direction is 0 ° or more and less than 30 ° (preferably 0 ° or more). 22.5 ° or less, more preferably 0 ° or more and 10 ° or less, further preferably 0 ° or more and 5 ° or less, and particularly preferably 0 ° or more and 3 ° or less).
Further, in the present disclosure, the main alignment direction of the helical chiral polymer (A) means the main alignment direction of the helical chiral polymer (A). The main orientation direction of the helical chiral polymer (A) can be confirmed by measuring the orientation degree F of the piezoelectric material.
When a raw material is melt-spun and drawn to produce a piezoelectric body, the main alignment direction of the helical chiral polymer (A) in the manufactured piezoelectric body means the main drawing direction. The main stretching direction refers to the stretching direction.
Similarly, when a film is stretched and slits of the stretched film are formed to produce a piezoelectric body, the main orientation direction of the helical chiral polymer (A) in the produced piezoelectric body means the main stretching direction. Here, the main stretching direction refers to the stretching direction in the case of uniaxial stretching, and refers to the stretching direction in which the stretching ratio is higher in the case of biaxial stretching.

The piezoelectric body preferably has a long flat plate shape or a fiber shape in order to improve the piezoelectric sensitivity.
Hereinafter, a piezoelectric body having a long flat plate shape (hereinafter, also referred to as a long flat plate-like piezoelectric body) and a piezoelectric body having a fiber shape (hereinafter, also referred to as a fibrous piezoelectric body) will be described in order.

-Long flat plate-like piezoelectric body-
By using a long flat plate-like piezoelectric material as the piezoelectric material, the contact surface to the internal conductor can be enlarged, and the charge generated by the piezoelectric effect can be efficiently detected as a voltage signal.
Hereinafter, the dimensions of the long flat piezoelectric material will be described in more detail.

  The average thickness (hereinafter, also simply referred to as “thickness”) of the long flat piezoelectric body is preferably 0.001 mm to 0.2 mm. When the thickness of the long flat piezoelectric material is 0.001 mm or more, sufficient strength tends to be secured. Furthermore, it tends to be excellent in manufacturing aptitude. On the other hand, when the thickness of the long flat piezoelectric material is 0.2 mm or less, the degree of freedom (flexibility) of deformation in the thickness direction tends to be improved.

  The width of the long flat piezoelectric body is preferably 0.1 mm to 30 mm, and more preferably 0.5 mm to 15 mm. When the width of the long flat piezoelectric material is 0.1 mm or more, sufficient strength tends to be secured. Furthermore, it tends to be excellent also in manufacturing aptitude (for example, the manufacturing aptitude in the slit process mentioned later). On the other hand, when the width of the long flat piezoelectric material is 30 mm or less, the degree of freedom (flexibility) of deformation tends to be improved.

  It is preferable that the ratio of the width to the thickness of the long plate-like piezoelectric body (hereinafter, also referred to as “ratio [width / thickness]”) is 2 or more. The main surface becomes clear if the ratio [width / thickness] of the long flat plate-like piezoelectric material is 2 or more, so the outer conductor is formed by aligning the direction along the length direction of the long flat plate-like piezoelectric material Easy to do.

  It is more preferable that the width of the long flat piezoelectric body is 0.5 mm to 15 mm. When the width of the long flat piezoelectric material is 0.5 mm or more, the strength tends to be further improved. Furthermore, since the twist of the long flat plate-like piezoelectric material can be further suppressed, the piezoelectric sensitivity and its stability tend to be further improved. On the other hand, when the width of the long flat piezoelectric material is 15 mm or less, the degree of freedom (flexibility) of deformation of the long flat piezoelectric material tends to be further improved.

  The long flat piezoelectric material preferably has a ratio of length to width (hereinafter also referred to as a ratio [length / width]) of 10 or more. When the ratio (length / width) of the long flat piezoelectric material is 10 or more, the freedom of deformation (flexibility) is further improved.

There is no limitation in particular in the manufacturing method of a long flat plate-like piezoelectric material, It can manufacture by a well-known method.
For example, as a method for producing a long flat plate-like piezoelectric material from a piezoelectric film, a raw material is formed into a film to obtain an unstretched film, and the obtained unstretched film is subjected to stretching and crystallization. The piezoelectric film can be obtained by slitting (cutting the piezoelectric film into a long shape).
Alternatively, the long flat piezoelectric body may be manufactured using a known flat yarn manufacturing method. For example, after a wide film obtained by inflation molding is slit into a narrow film, stretching by heat plate stretching, stretching by roll stretching, and crystallization are performed to obtain a long flat plate-like piezoelectric body. It is also good.
In addition, as for the said extending | stretching and crystallization, any may be first. Alternatively, the unstretched film may be sequentially subjected to preliminary crystallization, stretching, and crystallization (annealing). Stretching may be uniaxial stretching or biaxial stretching. In the case of biaxial stretching, preferably the stretching ratio of one (main stretching direction) is increased.
With respect to a method of producing a piezoelectric film, publicly known documents such as Japanese Patent No. 4934235, International Publication No. 2010/104196, International Publication No. 2013/054918, International Publication No. 2013/089148, etc. can be referred to as appropriate.

-Fibrous piezoelectric material-
By using a fibrous piezoelectric material as the piezoelectric material, it can be used as a form more excellent in flexibility and flexibility, and the charge generated by the piezoelectric effect can be efficiently detected as a voltage signal. Become.
Although there is no restriction | limiting in particular as a fiber shape, For example, the shape of a single fiber and the shape of a fiber bundle (bundle which consists of several fibers) are mentioned.
Hereinafter, the dimensions of the fibrous piezoelectric material will be described in more detail.
The average major axis diameter (hereinafter, also simply referred to as “major axis diameter”) of the cross section of the fibrous piezoelectric body orthogonal to the major axis direction of the internal conductor is 0.0001 mm to 10 mm from the viewpoint of improving the piezoelectric sensitivity. Is preferable, 0.001 mm to 5 mm is more preferable, and 0.002 mm to 1 mm is further preferable.
If the major axis diameter of the fibrous piezoelectric material is 0.0001 mm or more, the strength tends to be further improved. On the other hand, when the major axis diameter of the fibrous piezoelectric material is 10 mm or less, the degree of freedom (flexibility) of deformation of the fibrous piezoelectric material tends to be further improved.
Here, "the major axis diameter of the cross section" corresponds to the "diameter" when the cross section of the fibrous piezoelectric body is circular.
In the case where the cross section of the fibrous piezoelectric material has a shape different from a circular shape, “the major axis diameter of the cross section” is the longest distance in the cross section.
When the fibrous piezoelectric material is a piezoelectric material composed of fiber bundles, "the major axis diameter of the cross section" is the major diameter of the cross section of the piezoelectric material composed of the fiber bundles.
Specifically, examples of fibrous piezoelectric materials include monofilament yarns and multifilament yarns.

Monofilament Yarn The single yarn fineness of the monofilament yarn is preferably 3 dtex to 30 dtex, and more preferably 5 dtex to 20 dtex.
When the single yarn fineness is less than 3 dtex, it becomes difficult to handle the yarn in the fabric preparation process and the weaving process. On the other hand, if the single yarn fineness exceeds 30 dtex, fusion tends to occur between the yarns.
The monofilament yarn is preferably obtained by direct spinning and drawing in consideration of cost. The monofilament yarn may be one obtained.

Multifilament Yarn The total fineness of the multifilament yarn is preferably 30 dtex to 600 dtex, and more preferably 100 dtex to 400 dtex.
As the multifilament yarn, for example, in addition to one-step yarn such as spin-draw yarn, any two-step yarn obtained by drawing UDY (undrawn yarn) or POY (highly oriented undrawn yarn) can be adopted. . The multifilament yarn may be obtained.
Polylactic acid monofilament yarns, as the polylactic acid multifilament yarns commercially available, manufactured by Toray Industries of Ekodia _{(R) PLA,} Unitika of Terramac _(R), manufactured by Kuraray Co. Purasutachi _(R) can be used.

There is no limitation in particular in the manufacturing method of a fibrous piezoelectric material, It can manufacture by a well-known method.
For example, filament yarn (monofilament yarn, multifilament yarn) as a fibrous piezoelectric material can be obtained by melt-spinning a raw material (for example, polylactic acid) and then drawing it (melt-spinning drawing method). In addition, after spinning, it is preferable to maintain the ambient temperature in the vicinity of the yarn until cooling and solidification in a constant temperature range.
Also, the filament yarn may be obtained, for example, by further separating the filament yarn obtained by the above-mentioned melt spinning drawing method.

<Helical Chiral Polymer (A)>
The piezoelectric body in the present disclosure preferably includes a helical chiral polymer (A) having optical activity.
Here, the “helical chiral polymer having optical activity” refers to a polymer having a helical molecular structure and molecular optical activity.

Examples of the helical chiral polymer (A) include polypeptides, cellulose derivatives, polylactic acid-based polymers, polypropylene oxide, poly (β-hydroxybutyric acid) and the like.
Examples of the polypeptide include poly (γ-benzyl glutarate), poly (γ-methyl glutarate) and the like.
Examples of the cellulose derivative include cellulose acetate and cyanoethyl cellulose.

  The helical chiral polymer (A) preferably has an optical purity of 95.00% ee or more, more preferably 96.00% ee or more, from the viewpoint of improving the piezoelectricity of the piezoelectric material, and 99. More preferably, it is 00% ee or more, and even more preferably 99.99% ee or more. Desirably, it is 100.00% ee. By setting the optical purity of the helical chiral polymer (A) in the above range, it is considered that the packing property of the polymer crystal expressing piezoelectricity is enhanced, and as a result, the piezoelectricity is enhanced.

Here, the optical purity of the helical chiral polymer (A) is a value calculated by the following equation.
Optical purity (% ee) = 100 × | L volume-D volume | / (L volume + D volume)
That is, the optical purity of the helical chiral polymer (A) is
“The amount difference (absolute value) between the amount of L form [mass%] of helical chiral polymer (A) and the amount [mass%] of D form of helical chiral polymer (A)” to “helical chiral polymer "(N) divided by the total amount of the amount of L-form (mass%) of (A) [mass%] and the amount of the D-form of helical chiral polymer (A) (mass%)" (Multiplied) value.

  The amount of L form [mass%] of the helical chiral polymer (A) and the amount [mass%] of the D form of the helical chiral polymer (A) are obtained by a method using high performance liquid chromatography (HPLC). Use the value Details of the specific measurement will be described later.

  The helical chiral polymer (A) is preferably a polymer having a main chain containing a structural unit represented by the following formula (1) from the viewpoint of enhancing the optical purity and improving the piezoelectricity.

As a polymer which has a structural unit represented by the said Formula (1) as a principal chain, polylactic acid type polymer is mentioned.
Here, the polylactic acid-based polymer refers to “polylactic acid (polymer having only a structural unit derived from a monomer selected from L-lactic acid and D-lactic acid)”, “L-lactic acid or D-lactic acid, -A copolymer of lactic acid or a compound copolymerizable with D-lactic acid "or a mixture of both.
Among polylactic acid-based polymers, polylactic acid is preferred, and homopolymers of L-lactic acid (PLLA, also simply referred to as "L-form") or homopolymers of D-lactic acid (PDLA, also simply referred to as "D-form") are most preferred. preferable.

Polylactic acid is a polymer in which lactic acid is polymerized by ester bonds and is long connected.
It is known that polylactic acid can be produced by a lactide method via lactide; a direct polymerization method in which lactic acid is heated under reduced pressure in a solvent and polymerized while removing water;
As polylactic acid, homopolymers of L-lactic acid, homopolymers of D-lactic acid, block copolymers containing polymers of at least one of L-lactic acid and D-lactic acid, and at least one of L-lactic acid and D-lactic acid Included are graft copolymers comprising a polymer.

  Examples of the above-mentioned "compounds copolymerizable with L-lactic acid or D-lactic acid" include glycolic acid, dimethyl glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxybutanoic acid Hydroxy valeric acid, 3-hydroxy valeric acid, 4-hydroxy valeric acid, 5-hydroxy valeric acid, 2-hydroxy caproic acid, 3-hydroxy caproic acid, 4-hydroxy caproic acid, 5-hydroxy caproic acid, 6-hydroxy caprone Acid, 6-hydroxymethyl caproic acid, hydroxycarboxylic acid such as mandelic acid; glycolide, β-methyl-δ-valerolactone, γ-valerolactone, cyclic ester such as ε-caprolactone; oxalic acid, malonic acid, succinic acid, Glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, ung Polyvalent carboxylic acids such as cannic acid, dodecanedioic acid and terephthalic acid and anhydrides thereof; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butane Diol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, neopentyl Polyhydric alcohols such as glycol, tetramethylene glycol and 1,4-hexanedimethanol; polysaccharides such as cellulose; aminocarboxylic acids such as α-amino acid; and the like.

  As the above-mentioned “copolymer of L-lactic acid or D-lactic acid and a compound copolymerizable with the L-lactic acid or D-lactic acid”, a block copolymer or graft copolymer having a polylactic acid sequence capable of forming helical crystals is used. It can be mentioned.

The concentration of the structure derived from the copolymer component in the helical chiral polymer (A) is preferably 20 mol% or less.
For example, when the helical chiral polymer (A) is a polylactic acid-based polymer, a structure derived from lactic acid and a structure derived from a compound copolymerizable with lactic acid (copolymer component) in the polylactic acid-based polymer The concentration of the structure derived from the copolymer component is preferably 20 mol% or less based on the sum of the number of moles of and.

  The polylactic acid-based polymer can be obtained, for example, by the method of direct dehydration condensation of lactic acid described in JP-A-59-096123 and JP-A-7-033861; US Pat. No. 4,057,357 etc. The ring-opening polymerization method can be produced by using lactide which is a cyclic dimer of lactic acid, and the like.

  Furthermore, in order to make the optical purity 95.00% ee or more, for example, when polylactic acid is produced by the lactide method, the polylactic acid-based polymer obtained by each of the above-mentioned production methods is subjected to the optical purity by crystallization operation. It is preferable to polymerize lactide which has been improved to an optical purity of 95.00% ee or more.

-Weight average molecular weight-
The weight average molecular weight (Mw) of the helical chiral polymer (A) is preferably 50,000 to 1,000,000.
When the Mw of the helical chiral polymer (A) is 50,000 or more, the mechanical strength of the piezoelectric body is improved. The Mw is preferably 100,000 or more, and more preferably 200,000 or more.
On the other hand, when the Mw of the helical chiral polymer (A) is 1,000,000 or less, the formability at the time of obtaining a piezoelectric body by forming (for example, extrusion forming, melt spinning) is improved. The Mw is preferably 800,000 or less, and more preferably 300,000 or less.

  The molecular weight distribution (Mw / Mn) of the helical chiral polymer (A) is preferably 1.1 to 5 and more preferably 1.2 to 4 from the viewpoint of the strength of the piezoelectric body. Furthermore, it is preferable that it is 1.4-3.

The weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) of the helical chiral polymer (A) refer to values measured using gel permeation chromatography (GPC). Here, Mn is the number average molecular weight of the helical chiral polymer (A).
Hereafter, an example of the measuring method of Mw and Mw / Mn of helical chiral polymer (A) by GPC is shown.

-GPC measuring device-
GPC-100 manufactured by Waters
-Column-
Showa Denko KK Shodex LF-804
-Preparation of sample-
The piezoelectric body is dissolved in a solvent (eg, chloroform) at 40 ° C. to prepare a sample solution having a concentration of 1 mg / ml.
-Measurement conditions-
0.1 ml of the sample solution is introduced into the column at a flow rate of 1 ml / min with a solvent [chloroform] at a temperature of 40 ° C.

The sample concentration in the sample solution separated by the column is measured with a differential refractometer.
A universal calibration curve is prepared using a polystyrene standard sample, and the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the helical chiral polymer (A) are calculated.

A commercially available polylactic acid can be used as a polylactic acid-type polymer which is an example of a helical chiral polymer (A).
Examples of commercially available products, PURAC Co. PURASORB (PD, PL), manufactured by Mitsui Chemicals, Inc. of LACEA (H-100, H- 400), NatureWorks LLC Corp. ^Ingeo TM Biopolymer, and the like.
When a polylactic acid-based polymer is used as the helical chiral polymer (A), the polylactic acid polymer can have a weight-average molecular weight (Mw) of 50,000 or more by the lactide method or direct polymerization method. It is preferable to produce a system polymer.

The piezoelectric body in the present disclosure may contain only one type of helical chiral polymer (A) described above, or may contain two or more types.
The content (total content in the case of two or more types) of the helical chiral polymer (A) in the piezoelectric body in the present disclosure is preferably 80% by mass or more with respect to the total amount of the piezoelectric body.

<Stabilizer>
The piezoelectric body further contains, in one molecule, a stabilizer (B) having a weight average molecular weight of 200 to 60,000 having one or more functional groups selected from the group consisting of carbodiimide group, epoxy group, and isocyanate group. It is preferable to do. Thereby, the heat and humidity resistance can be further improved.

  As the stabilizer (B), the “stabilizer (B)” described in paragraphs 0039 to 0055 of WO 2013/054918 can be used.

As a compound (carbodiimide compound) which contains a carbodiimide group in one molecule which can be used as a stabilizer (B), a monocarbodiimide compound, a polycarbodiimide compound, and a cyclic carbodiimide compound are mentioned.
As the monocarbodiimide compound, dicyclohexyl carbodiimide, bis-2,6-diisopropylphenyl carbodiimide and the like are preferable.
Moreover, as a polycarbodiimide compound, what was manufactured by various methods can be used. Conventional methods for producing polycarbodiimides (for example, U.S. Pat. No. 2,941,956, JP-B-47-33279, J. 0 rg. Chem. 28, 2069-2075 (1963), Chemical Review 1981, Vol. 4, p 619-621) can be used. Specifically, the carbodiimide compound described in Japanese Patent No. 4084953 can also be used.
As polycarbodiimide compounds, poly (4,4'-dicyclohexylmethanecarbodiimide), poly (N, N'-di-2,6-diisopropylphenylcarbodiimide), poly (1,3,5-triisopropylphenylene-2, 4-carbodiimide, etc. are mentioned.
The cyclic carbodiimide compound can be synthesized based on the method described in JP-A-2011-256337 or the like.
As the carbodiimide compound, a commercially available product may be used. For example, B2756 (trade name) manufactured by Tokyo Kasei Kogyo Co., Ltd., Carbodilite LA-1 (trade name) manufactured by Nisshinbo Chemical Co., Ltd., Stabaxol P, Stabaxol P400 manufactured by Line Chemie Co., Stabaxol I (all trade names) and the like.

  As a compound (isocyanate compound) containing an isocyanate group in one molecule, which can be used as the stabilizer (B), 3- (triethoxysilyl) propyl isocyanate, 2,4-tolylene diisocyanate, 2,6-tridiisocyanate Di-isocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, Etc.

  As a compound (epoxy compound) containing an epoxy group in one molecule which can be used as a stabilizer (B), phenyl glycidyl ether, diethylene glycol diglycidyl ether, bisphenol A-diglycidyl ether, hydrogenated bisphenol A-diglycidyl ether And phenol novolac epoxy resins, cresol novolac epoxy resins, epoxidized polybutadiene and the like.

As described above, the weight average molecular weight of the stabilizer (B) is preferably 200 to 60,000, more preferably 200 to 30,000, and still more preferably 300 to 18,000.
When the molecular weight is within the above range, the stabilizer (B) is more easily moved, and the moist heat resistance improving effect is more effectively exerted.
The weight average molecular weight of the stabilizer (B) is particularly preferably 200 to 900. In addition, the weight average molecular weights 200-900 substantially correspond to the number average molecular weights 200-900. Moreover, in the case of weight average molecular weight 200-900, molecular weight distribution may be 1.0, and in this case, "weight average molecular weight 200-900" can also be rephrased simply as "molecular weight 200-900". .

  Hereinafter, specific examples (stabilizers B-1 to B-3) of the stabilizer (B) will be shown.

Hereinafter, the compound name, commercial item etc. are shown about said stabilizer B-1 to B-3.
-Stabilizer B-1 ... The compound name is bis-2, 6-diisopropylphenyl carbodiimide. The weight average molecular weight (in this example, equal to just "molecular weight") is 363. Examples of commercially available products include "Stabaxol I" manufactured by Rhine Chemie, and "B2756" manufactured by Tokyo Kasei.
-Stabilizer B-2 ... The compound name is poly (4,4'-dicyclohexylmethane carbodiimide). As a commercial item, "Nisshinbo Chemical Co., Ltd." carbodiimide light LA-1 "is mentioned as a thing of weight average molecular weight about 2000.
Stabilizer B-3 The compound name is poly (1,3,5-triisopropylphenylene-2,4-carbodiimide). As a commercially available product, "Stabaxol P" manufactured by Line Chemie Co., Ltd. may be mentioned as having a weight average molecular weight of about 3,000. Moreover, "Stabaxol P400" by a line chemistry company is mentioned as a thing of the weight average molecular weight 20000.

When the piezoelectric body contains the stabilizer (B), the piezoelectric body may contain only one type of stabilizer or may contain two or more types.
When the piezoelectric body contains a stabilizer (B), the content of the stabilizer (B) is 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the helical chiral polymer (A). The amount is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and particularly preferably 0.5 to 2 parts by mass.
When the content is 0.01 parts by mass or more, heat and humidity resistance is further improved.
Moreover, the fall of transparency is suppressed more as the said content is 10 mass parts or less.

As a preferable aspect of a stabilizer (B), it has one or more types of functional groups chosen from the group which consists of a carbodiimide group, an epoxy group, and an isocyanate group, and a number average molecular weight is a stabilizer of 200-900. (B1) A stabilizer having two or more functional groups selected from the group consisting of a carbodiimide group, an epoxy group, and an isocyanate group in one molecule, and a weight average molecular weight of 1,000 to 60,000 (B1) The aspect of using B2) together is mentioned. The weight average molecular weight of the stabilizer (B1) having a number average molecular weight of 200 to 900 is approximately 200 to 900, and the number average molecular weight and the weight average molecular weight of the stabilizer (B1) have substantially the same value. .
When the stabilizer (B1) and the stabilizer (B2) are used in combination as the stabilizer, it is preferable to include a large amount of the stabilizer (B1) from the viewpoint of improving the transparency.
Specifically, it is preferable that the amount of the stabilizer (B2) is in the range of 10 parts by mass to 150 parts by mass with respect to 100 parts by mass of the stabilizer (B1) from the viewpoint of coexistence of transparency and moist heat resistance The range of 50 parts by mass to 100 parts by mass is more preferable.

<Other ingredients>
The piezoelectric body may contain other components as needed.
Other components include known resins such as polyvinylidene fluoride, polyethylene resin and polystyrene resin; known inorganic fillers such as silica, hydroxyapatite and montmorillonite; known crystal nucleating agents such as phthalocyanine; stabilizer (B) And the like.
As the inorganic filler and the crystal nucleating agent, the components described in paragraphs 0057 to 0058 of WO 2013/054918 can also be mentioned.

<Degree of orientation F>
As described above, the orientation degree F of the piezoelectric body in the present disclosure is preferably 0.5 or more and less than 1.0, more preferably 0.7 or more and less than 1.0, and 0.8 or more. More preferably, it is less than 0.
If the orientation degree F of the piezoelectric body is 0.5 or more, the molecular chains (for example, polylactic acid molecular chains) of the helical chiral polymer (A) arranged in the stretching direction are large, and as a result, the ratio of formation of oriented crystals is It becomes possible to express higher and higher piezoelectricity.
If the orientation degree F of the piezoelectric body is less than 1.0, the longitudinal tear strength is further improved.

<Degree of crystallinity>
The crystallinity of the piezoelectric body in the present disclosure is a value measured by the above-mentioned X-ray diffraction measurement (wide-angle X-ray diffraction measurement).
The crystallinity of the piezoelectric body in the present disclosure is preferably 20% to 80%, more preferably 25% to 70%, and still more preferably 30% to 60%.
When the degree of crystallinity is 20% or more, high piezoelectricity is maintained. When the crystallinity degree is 80% or less, high transparency of the piezoelectric body is maintained.
When the crystallization degree is 80% or less, for example, when producing a piezoelectric film to be a raw material of a piezoelectric body by stretching, whitening and breakage do not easily occur, so that the piezoelectric body can be easily manufactured. In addition, when the crystallinity degree is 80% or less, for example, when manufacturing a raw material of a piezoelectric body (for example, polylactic acid) by melt spinning and drawing by stretching, it becomes a fiber having high flexibility and flexible properties, Easy to manufacture.

<Transparency (internal haze)>
In the piezoelectric body in the present disclosure, although transparency is not particularly required, it may be of course possible to have transparency.
The transparency of the piezoelectric body can be evaluated by measuring the internal haze. Here, the internal haze of the piezoelectric body refers to the haze excluding the haze due to the shape of the outer surface of the piezoelectric body.
When transparency is required for the piezoelectric body, the internal haze to visible light is preferably 5% or less, and from the viewpoint of further improving the transparency and longitudinal tear strength, 2.0% or less is more preferred. Preferably, 1.0% or less is more preferable. The lower limit of the internal haze of the piezoelectric body is not particularly limited, and the lower limit is, for example, 0.01%.
The internal haze of the piezoelectric body is measured using a haze measuring machine (TC-HIII DPK, manufactured by Tokyo Denshoku Co., Ltd., based on JIS-K7105) for a piezoelectric body with a thickness of 0.03 mm to 0.05 mm. Measured at 25 ° C.
Hereinafter, an example of the measuring method of the internal haze of a piezoelectric material is shown.
First, Sample 1 was prepared by sandwiching only silicone oil (Shin-Etsu Chemical (Shin-Etsu Silicone (trademark), model number: KF96-100CS) made by Shin-Etsu Chemical Co., Ltd.) between two glass plates, and the haze in the thickness direction of this sample 1 (Hereinafter, the haze (H2)) is measured.
Next, a sample 2 is prepared by sandwiching a plurality of piezoelectric bodies whose surfaces are uniformly coated with silicone oil between two glass plates described above without gaps, and a haze in the thickness direction of this sample 2 (hereinafter referred to as Measure the haze (H3)).
Next, the internal haze (H1) of the piezoelectric body is obtained by taking these differences as in the following formula.
Internal haze (H1) = haze (H3)-haze (H2)
Here, the measurement of the haze (H2) and the haze (H3) is performed using the following apparatus under the following measurement conditions, respectively.
Measuring device: HAZE METER TC-HIIIDPK manufactured by Tokyo Denshoku Co., Ltd.
Sample size: Width 30 mm × length 30 mm
Measurement conditions: conform to JIS-K7105 Measurement temperature: room temperature (25 ° C)

<Functional layer>
If necessary, the piezoelectric substrate may be provided with a functional layer. The type of functional layer is not particularly limited, and can be selected according to the application. For example, it is preferably at least one selected from the group consisting of an adhesive layer, a hard coat layer, an antistatic layer, an antiblock layer, a protective layer, and an electrode layer. The piezoelectric substrate having the functional layer makes it easier to apply to, for example, a piezoelectric device, a force sensor, an actuator, and a biological information acquisition device. The functional layer may be a single layer or two or more layers, and in the case of including two or more functional layers, the functional layers may be provided with different types of functional layers.

  When the piezoelectric substrate includes a functional layer, the functional layer may be provided on the side of at least one of the main surfaces of the piezoelectric body. When the functional layers are provided on both main surfaces of the piezoelectric body, the functional layers disposed on the front surface side and the functional layers disposed on the back surface side are different functional layers even though the functional layers are the same. It may be

  Although the film thickness of a functional layer is not specifically limited, The range of 0.01 micrometer-10 micrometers is preferable. The upper limit value of the thickness is more preferably 6 μm or less, still more preferably 3 μm or less. The lower limit value is more preferably 0.01 μm or more, and still more preferably 0.02 μm or more. When the functional layer comprises a plurality of functional layers, the thickness represents the total thickness of the plurality of functional layers.

  In the piezoelectric substrate of the present disclosure, the functional layer preferably includes an electrode layer. When the piezoelectric substrate is provided with the electrode layer, the piezoelectric substrate is used as one of components of, for example, a piezoelectric device (piezoelectric fabric, piezoelectric knit, etc.), a force sensor, an actuator, or a biological information acquisition device. The connection between the inner conductor and the outer conductor can be made more easily. Therefore, when tension is applied to the piezoelectric substrate, a voltage signal corresponding to the tension is easily detected.

  As a mode in case a piezoelectric base material is equipped with a functional layer, the state of the layered product by which a functional layer is arranged at least one side of a piezoelectric material is mentioned. In this case, it is preferable that the piezoelectric body and the functional layer be in a state of a laminate, and an electrode layer be provided as a surface layer on one surface of the laminate.

<Adhesive layer>
The piezoelectric substrate preferably comprises an adhesive layer between the inner conductor and the piezoelectric body. When the piezoelectric body includes the adhesive layer, the relative position between the internal conductor and the piezoelectric body does not easily shift. For this reason, tension is easily applied to the piezoelectric body, and shear stress is easily applied to the helical chiral polymer contained in the piezoelectric body. Therefore, it is possible to detect a voltage output that is effectively proportional to tension from the inner conductor (preferably the signal line conductor). In addition, the provision of the adhesive layer tends to further increase the absolute value of the generated charge amount per unit tensile force.
In the present disclosure, “adhesion” is a concept including “adhesion”. Also, "adhesive layer" is a concept including "adhesive layer".

  The material of the adhesive forming the adhesive layer is not particularly limited. For example, epoxy adhesives, urethane adhesives, vinyl acetate resin emulsion adhesives, (EVA) emulsion adhesives, acrylic resin emulsion adhesives, styrene-butadiene rubber latex adhesives, silicone resins Adhesive, α-olefin (isobutene-maleic anhydride resin) adhesive, vinyl chloride resin solvent type adhesive, rubber adhesive, elastic adhesive, chloroprene rubber solvent type adhesive, nitrile rubber solvent type An adhesive or the like, or a cyanoacrylate adhesive or the like can be used.

  The adhesive layer preferably has a modulus of elasticity equal to or greater than that of the piezoelectric body. In this case, strain due to tension applied to the piezoelectric substrate (piezoelectric strain) is less likely to be relaxed in the adhesive layer, and the strain transmission efficiency to the piezoelectric body is likely to be maintained. Therefore, when the piezoelectric substrate is applied to, for example, a sensor (preferably a force sensor), the sensitivity of the sensor is well maintained.

  The thickness of the adhesive layer is preferably as thin as possible, as long as no gap is formed between the piezoelectric substrate and the piezoelectric body and the bonding strength is not reduced. By reducing the thickness of the bonding portion, strain due to tension applied to the piezoelectric substrate is less likely to be relaxed in the adhesive portion, and the strain transmission efficiency to the piezoelectric body is likely to be maintained. Therefore, when the piezoelectric substrate is applied to, for example, a sensor (preferably a force sensor), the sensitivity of the sensor is well maintained.

<External conductor>
The piezoelectric substrate of the present disclosure includes an outer conductor disposed on the outer periphery of the piezoelectric body.
The outer conductor in the present disclosure is preferably a ground conductor.
The ground conductor refers to, for example, a conductor which is a pair of inner conductors (preferably, signal line conductors) when detecting a signal.

The ground conductor is not particularly limited, but mainly includes the following depending on the cross-sectional shape.
For example, as a ground conductor having a rectangular cross section, it is possible to use a copper foil ribbon obtained by rolling a copper wire of a circular cross section into a flat plate shape, an aluminum foil ribbon, or the like.
For example, as a ground conductor having a circular cross section, a copper wire is spirally wound around a copper wire, an aluminum wire, a SUS wire, a metal wire coated with an insulation film, a carbon fiber, a resin fiber integrated with the carbon fiber, and a fiber It is possible to use a cocoon thread.
Further, as the ground conductor, one obtained by coating an organic conductive material with an insulating material may be used.
Moreover, a conductive fiber can also be used as a ground conductor. A conductive fiber is synonymous with the conductive fiber applicable as an above-mentioned internal conductor, The preferable range is also the same.

The ground conductor is preferably disposed to wrap the inner conductor and the piezoelectric body so as not to short-circuit the inner conductor (preferably, the signal line conductor).
As a method of wrapping such an inner conductor, it is possible to select a method of winding by wrapping a copper foil etc. in a spiral and wrapping, or a method of wrapping a copper wire etc. in a tubular braid and wrapping in it. is there.
In addition, how to wrap the inner conductor is not limited to these methods. By enclosing the internal conductor, it becomes possible to perform electrostatic shielding, and it is possible to prevent the voltage change of the internal conductor due to the influence of external static electricity.
In addition, the arrangement of the ground conductor is one of the preferable modes in which the inner conductor and the piezoelectric body in the present disclosure are cylindrically enclosed.

  As a cross-sectional shape of the ground conductor, various cross-sectional shapes such as a circular shape, an elliptical shape, a rectangular shape, and an irregular shape can be applied. In particular, since the rectangular cross section can be in close contact with the inner conductor (preferably the signal line conductor), the piezoelectric body, and the insulator if necessary, charges generated by the piezoelectric effect efficiently Can be detected as a voltage signal.

<Second piezoelectric>
The piezoelectric substrate of the present disclosure may include an elongated second piezoelectric body together with the above-described first piezoelectric body.
The second piezoelectric body preferably has the same characteristics as the first piezoelectric body.
That is, the second piezoelectric body includes the helical chiral polymer (A) having optical activity, and the helical chiral polymer (A) contained in the second piezoelectric body in the longitudinal direction of the second piezoelectric body. It is preferable that the main orientation direction is along, and the degree of orientation F of the second piezoelectric body determined by the equation (a) from X-ray diffraction measurement is in the range of 0.5 or more and less than 1.0.
The second piezoelectric body preferably has the same characteristics as the first piezoelectric body also in the characteristics other than the above.
However, with regard to the winding direction of the first piezoelectric body and the second piezoelectric body, and the chirality of the helical chiral polymer (A) contained in the first piezoelectric body and the second piezoelectric body, the effects of the present disclosure can be obtained. It is preferable to select it according to the aspect of the piezoelectric substrate, from the viewpoint of more playing.
In addition, about the winding direction of a 1st piezoelectric material and a 2nd piezoelectric material, and an example of the preferable combination of the chirality of the helical chiral polymer (A) contained in a 1st piezoelectric material and a 2nd piezoelectric material, As described in the second embodiment described later.
In addition, the second piezoelectric body may have characteristics different from those of the first piezoelectric body.

Moreover, the piezoelectric base material of the present disclosure is a long coil spirally wound in a direction different from the one direction along the outer peripheral surface of the inner conductor coated with the first piezoelectric body which is the above-mentioned piezoelectric body. The second piezoelectric body includes the helical chiral polymer (A) having optical activity and is included in the second piezoelectric body in the longitudinal direction of the second piezoelectric body. The orientation direction F of the helical chiral polymer (A) is along, and the orientation degree F of the second piezoelectric body determined by the above equation (b) from the X-ray diffraction measurement is in the range of 0.5 or more and less than 1.0. The chirality of the helical chiral polymer (A) contained in the first piezoelectric body and the second piezoelectric body have a braid structure in which the first piezoelectric body and the second piezoelectric body are alternately intersected. It is also preferred that the chirality of the helical chiral polymer (A) contained be different from each other.
Thus, for example, when tension is applied in the longitudinal direction of the piezoelectric substrate, the helical chiral polymer (A) contained in the first piezoelectric body and the helical chiral polymer contained in the second piezoelectric body Polarization occurs in both (A). The polarization directions are all in the radial direction of the piezoelectric substrate.
Thereby, a voltage signal proportional to tension can be detected more effectively. As a result, the piezoelectric sensitivity can be more easily improved.
Further, by forming the braided structure with the first piezoelectric body and the second piezoelectric body, the flexible substrate is flexible even when a force is applied that causes the piezoelectric substrate to be flexible, as compared with the case where the braided structure is not formed. It becomes easy to bend and deform. Therefore, the piezoelectric substrate having the braid structure is suitable as one component of, for example, a wearable product (for example, a piezoelectric fabric, a piezoelectric fabric, a piezoelectric device, a force sensor, a biological information acquisition device, etc.) along a three-dimensional plane. It can be used for

<Insulator>
The piezoelectric substrate of the present disclosure may comprise an insulator. For example, the piezoelectric substrate of the second embodiment described later may be provided with an insulator.
The insulator is preferably spirally wound along the outer circumferential surface of the inner conductor. In this case, it is preferable to form a braid structure in which the piezoelectric body (first piezoelectric body) and the insulator are alternately intersected.
The winding direction of the insulator may be the same as or different from the winding direction of the piezoelectric body.
In the piezoelectric substrate according to the second embodiment, by forming the braid structure with the piezoelectric body and the insulator, it is easy to suppress the occurrence of an electrical short circuit between the inner conductor and the outer conductor when the piezoelectric substrate is bent and deformed. Has the advantage of

The insulator is not particularly limited, and examples thereof include vinyl chloride resin, polyethylene resin, polypropylene resin, ethylene / tetrafluoroethylene copolymer (ETFE), and tetrafluoroethylene / hexafluoropropylene copolymer (FEP). ), Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoropropylvinylether copolymer (PFA), fluororubber, polyester resin, polyimide resin, polyamide resin, polyethylene terephthalate resin (PET), rubber (including elastomers) Etc.).
The shape of the insulator is preferably an elongated shape in view of the winding on the inner conductor.

  Hereinafter, first to fifth embodiments of the piezoelectric substrate of the present disclosure will be described in order.

First Embodiment
FIG. 3 shows a side view of the coaxial line structure constituting the piezoelectric base according to the first embodiment, FIG. 4 shows a side view of the piezoelectric base according to the first embodiment, and FIG. The 4 XX 'line sectional view is shown.
As shown in FIG. 3, the coaxial line structure 10 constituting the piezoelectric substrate 100 (see FIG. 4) includes the elongated internal conductor 12A and the elongated first piezoelectric body 14A. .
As shown in FIG. 3, the first piezoelectric member 14A has a gap in a spiral in one direction so that the internal conductor 12A can not be seen from one end to the other at a helical angle β1 along the outer peripheral surface of the internal conductor 12A. It is wound without.
The “helical angle β1” means an angle formed by the axial direction G1 of the inner conductor 12A and the arrangement direction of the first piezoelectric body 14A with respect to the axial direction of the inner conductor 12A.
Further, in the coaxial wire structure 10, the first piezoelectric body 14A is wound around the internal conductor 12A in a left-handed manner. Specifically, when the coaxial line structure 10 is viewed from one end side (right end side in the case of FIG. 3) of the inner conductor 12A in the axial direction, the first piezoelectric body 14A is from the front side of the inner conductor 12A. It is wound by left winding toward the back side.
Further, in FIG. 3, the main alignment direction of the helical chiral polymer (A) contained in the first piezoelectric body 14A is indicated by a double arrow E1. That is, the arrangement direction of the first piezoelectric body 14A (the length direction of the first piezoelectric body 14A) is along the main alignment direction of the helical chiral polymer (A).
As shown in FIG. 4, in the piezoelectric substrate 100 according to the first embodiment, the outer conductor 16 is spirally wound in one direction in the outer periphery of the coaxial line structure 10 shown in FIG. . That is, the piezoelectric base 100 includes the elongated internal conductor 12A, the elongated first piezoelectric body 14A, and the outer conductor 16 in this order from the inside.

Hereinafter, the operation of the piezoelectric base 100 according to the first embodiment will be described.
For example, when tension is applied in the longitudinal direction of the piezoelectric substrate 100, a shear force is applied to the helical chiral polymer (A) contained in the first piezoelectric body 14A, and the helical chiral polymer (A) is polarized. . The polarization of this helical chiral polymer (A) occurs in the radial direction of the piezoelectric substrate 100 (the radial direction of the coaxial line structure 10), as shown by the arrows in FIG. It is thought that it will occur. This effectively detects a voltage signal proportional to the tension.

In addition, the piezoelectric base material 100 which concerns on 1st Embodiment is not limited to the said form. For example, in the piezoelectric substrate 100, an adhesive layer may be disposed between the internal conductor 12A and the first piezoelectric body 14A. As a result, even if tension is applied in the longitudinal direction of the piezoelectric base 100, the relative position between the first piezoelectric body 14A and the internal conductor 12A does not easily shift, so more tension is applied to the first piezoelectric body 14A. It becomes easy to be done.
In the piezoelectric substrate 100, the outer conductor 16 is spirally wound in one direction on the outer peripheral surface of the coaxial line structure 10, but the method of arranging the outer conductor 16 is not limited to this. That is, the outer conductor 16 may be disposed on at least a part of the outer periphery of the first piezoelectric body 14A. Also, the winding direction of the outer conductor 16 is not particularly limited.

  Next, a piezoelectric substrate according to a second embodiment will be described. In the following description, the same components as those of the piezoelectric substrate according to the first embodiment are denoted by the same reference numerals, and the redundant description will be omitted.

Second Embodiment
FIG. 6 shows a side view of the coaxial line structure constituting the piezoelectric base according to the second embodiment, and FIG. 7 shows a side view of the piezoelectric base according to the second embodiment.
As shown in FIG. 6, the coaxial line structure 10A constituting the piezoelectric base 100A (see FIG. 7) includes a long second piezoelectric member 14B, and a first piezoelectric member 14A. The second piezoelectric body 14B differs from the piezoelectric base 100 according to the first embodiment in that the second piezoelectric body 14B has a braided structure.
Specifically, as shown in FIG. 6, in the coaxial cable structure 10A, the first piezoelectric member 14A is helically wound in a counterclockwise direction from one end to the other at a helical angle β1 with respect to the axial direction G2 of the inner conductor 12A. , And the second piezoelectric body 14B is spirally wound in a right-handed manner from one end to the other at a helical angle β2, and the first piezoelectric body 14A and the second piezoelectric body 14B are alternately intersected. It has a braided structure. That is, the first piezoelectric body 14A and the second piezoelectric body 14B form a braid structure so that the inner conductor 12A can not be seen on the outer peripheral surface of the inner conductor 12A.
The “right-handed and spirally wound” means that the second piezoelectric body 14B is the coaxial wire structure 10A viewed from one end side (right end side in the case of FIG. 6) of the inner conductor 12A in the axial direction. This means that the right-handed winding is performed from the front side to the back side of the inner conductor 12A.
The “helical angle β2” is synonymous with the aforementioned helical angle β1.
Further, in the braid structure of the coaxial line structure 10A, the arrangement direction of the first piezoelectric body 14A is along the main orientation direction (double arrow E1) of the helical chiral polymer (A) contained in the first piezoelectric body 14A. ing. Similarly, the arrangement direction of the second piezoelectric body 14B is along the main alignment direction (double arrow E2) of the helical chiral polymer (A) contained in the second piezoelectric body 14B.

  As shown in FIG. 7, in the piezoelectric substrate 100A according to the second embodiment, the outer conductor 16 is spirally wound in one direction and disposed on the outer peripheral surface of the coaxial line structure 10A shown in FIG. There is. That is, the piezoelectric base 100A includes, in order from the inside, the elongated inner conductor 12A, the first piezoelectric body 14A and the second piezoelectric body 14B having a braided structure, and the outer conductor 16.

Hereinafter, the operation of the piezoelectric base 100A according to the second embodiment will be described.
For example, when tension is applied in the longitudinal direction of the piezoelectric substrate 100A, the helical chiral polymer (A) contained in the first piezoelectric body 14A and the helical chiral polymer (A) contained in the second piezoelectric body 14B. The shear stress is applied to both, and polarization occurs. It is considered that the polarization directions are all generated in the radial direction of the piezoelectric base 100A (the radial direction of the coaxial line structure 10A), and are generated with the phases aligned. This effectively detects a voltage signal proportional to the tension.
In particular, in the piezoelectric base 100A according to the second embodiment, the braid structure is formed by forming a braid structure by the first piezoelectric body 14A and the second piezoelectric body 14B along the outer peripheral surface of the internal conductor 12A. Even when a force that causes the piezoelectric substrate to be bent and deformed acts more flexibly than when not formed, the piezoelectric substrate is more easily bent and deformed. As a result, for example, the amount of charge generated when a tensile force is applied to the piezoelectric substrate is likely to increase.
Therefore, according to the piezoelectric base 100A, the piezoelectric sensitivity is excellent.

  Next, a piezoelectric substrate according to a third embodiment will be described. In the following description, the same components as those of the piezoelectric substrate according to the first and second embodiments are denoted by the same reference numerals, and the redundant description will be omitted.

Third Embodiment
The piezoelectric substrate (not shown) according to the third embodiment is a piezoelectric substrate in which the second piezoelectric body 14B of the piezoelectric substrate 100A according to the second embodiment is replaced with an insulator.
That is, in the piezoelectric substrate according to the third embodiment, the first piezoelectric body 14A is spirally wound in a left-handed manner from one end to the other at a helical angle β1 with respect to the axial direction G2 of the internal conductor 12A, The body is spirally wound in a right-handed manner from one end to the other at a helical angle β2 and the first piezoelectric body 14A and the insulator are alternately crossed to form a braid structure.

In the piezoelectric substrate according to the third embodiment, tension is applied, for example, in the longitudinal direction of the piezoelectric substrate by using, as the insulator, an insulator having flexibility equal to or higher than that of the first piezoelectric body 14A. Sometimes, shear stress is likely to be applied to the helical chiral polymer (A) contained in the first piezoelectric body 14A. That is, polarization is likely to occur. This effectively detects a voltage signal proportional to the tension.
Further, in the piezoelectric base according to the third embodiment, as in the piezoelectric base according to the second embodiment, the braid structure is not formed by forming the braid structure with the first piezoelectric body and the insulator. As compared with the case, even when a force that causes the piezoelectric substrate to be bent and deformed is applied, the piezoelectric substrate is easily bent and deformed easily. As a result, for example, the amount of charge generated when a tensile force is applied to the piezoelectric substrate is likely to increase.
Therefore, the piezoelectric substrate according to the third embodiment is also excellent in piezoelectric sensitivity.

  In addition, the piezoelectric base material which concerns on 3rd Embodiment is not limited to the said form. For example, the winding direction of the insulator is not limited to the above embodiment.

Piezoelectric Substrates of Fourth and Fifth Embodiments
The piezoelectric substrate of the present disclosure is not limited to the configuration in which the electric charge (electric field) generated when tension is applied is extracted as a voltage signal, and for example, the electric charge (electric field) generated when torsional force is applied The configuration may be taken out as

  The piezoelectric base 100B of the fourth embodiment and the piezoelectric base 100C of the fifth embodiment are, as shown in FIGS. 8 to 11, a long inner conductor 12A as an inner conductor and a long first inner conductor 12A. A piezoelectric layer 14A, an adhesive layer (not shown) disposed between the inner conductor 12A and the first piezoelectric member 14A, and an outer conductor 13 disposed on the outer surface of the first piezoelectric member 14A; Have. Further, in the piezoelectric base members 100B and 100C, the first piezoelectric body 14A is spirally wound on the internal conductor 12A in the main alignment direction (double arrow E1), and the first piezoelectric body 14A is wound on the first piezoelectric body 14A. The arrangement direction of the first piezoelectric body 14A is along the main orientation direction (double arrow E1) of the helical chiral polymer (A) contained.

  In the piezoelectric substrate 100B of the fourth embodiment, the helical chiral polymer (A) contained in the first piezoelectric body 14A is a homopolymer (PLLA) of L-lactic acid, while the piezoelectric substrate of the fifth embodiment In 100C, the helical chiral polymer (A) contained in the first piezoelectric body 14A is a homopolymer (PDLA) of D-lactic acid. The relationship between the twisting direction and the direction of polarization generated in the piezoelectric substrate 100B of the fourth embodiment is shown in FIGS. 8 and 9, and the relationship between the direction of torsion and the polarization generated in the piezoelectric substrate 100C of the fifth embodiment is shown in FIG. , Shown in FIG.

  In FIG. 8, when a twisting force in the direction of arrow X1 is applied to the piezoelectric base 100B with the helical axis as the central axis, shear stress is applied to the first piezoelectric body 14A wound helically, and a circular cross section is obtained. Polarization of PLLA occurs from the central direction to the outer direction. On the other hand, in FIG. 9, when a twisting force in the direction of arrow X2 opposite to the direction of arrow X1 is applied to piezoelectric base material 100B with the helical axis as the central axis, the first piezoelectric body 14A wound helically is sheared. Stress is applied to cause polarization of PLLA from the outside direction to the center direction of the circular cross section. Therefore, a charge (electric field) proportional to the twisting force is generated in the piezoelectric substrate 100B, and the generated charge is detected as a voltage signal (charge signal).

  Further, in FIG. 10, when a twisting force in the direction of arrow X1 is applied to the piezoelectric base 100C with the helical axis as the central axis, a shear stress is applied to the first piezoelectric body 14A wound helically, and a circle is formed. Polarization of PDLA occurs from the outer direction to the center direction of the cross section. On the other hand, in FIG. 11, when a twisting force in the direction of arrow X2 opposite to the direction of arrow X1 is applied to piezoelectric base 100C with the helical axis as the central axis, the first piezoelectric body 14A spirally wound is sheared. Stress is applied to cause polarization of PDLA from the center direction of the circular cross section to the outer direction. Therefore, in the piezoelectric base 100C, a charge (electric field) proportional to a twisting force is generated, and the generated charge is detected as a voltage signal (charge signal).

<Method of manufacturing piezoelectric substrate>
There is no particular limitation on the method of manufacturing the piezoelectric base material of the present disclosure, but for example, the first piezoelectric body is prepared, and the first piezoelectric body is preferably prepared for the separately prepared internal conductor (preferably signal line conductor). (Preferably spirally wound in one direction), and can be manufactured by disposing an outer conductor (preferably a ground conductor) on the outer periphery of the first piezoelectric body.
The first piezoelectric body may be manufactured by a known method or may be obtained.
In addition, when the piezoelectric base material of the present disclosure includes the second piezoelectric body and the insulator as needed, the piezoelectric base body is manufactured according to the method of spirally winding the first piezoelectric body. can do.
However, as described above, the winding directions of the first piezoelectric body and the second piezoelectric body, and the chirality of the helical chiral polymer (A) contained in the first piezoelectric body and the second piezoelectric body, It is preferable to select suitably according to the aspect of a piezoelectric base material.
In addition, between at least one of the inner conductor and the outer conductor and the first piezoelectric body, if necessary, between the members provided in the piezoelectric substrate of the present disclosure is adhered, for example, by the above-mentioned method via an adhesive. You may combine.

(Coaxial connector)
The coaxial connector unit of the present disclosure has a coaxial connector including a connection terminal electrically connected to the inner conductor of the piezoelectric substrate by applying pressure. Further, in the coaxial connector of the present disclosure, an insulating portion for holding the internal conductor of the piezoelectric substrate and the connection terminal in a state of being electrically connected, and a conductive shell for supporting the connection terminal via the insulating portion. It is preferable to further have

<Connection terminal>
The coaxial connector of the present disclosure includes a connection terminal electrically connected to the inner conductor of the piezoelectric substrate by applying pressure. The connection terminal is not particularly limited as long as it is electrically connected to the inner conductor by applying pressure. For example, the conductive plate spring is bent and has a pair of contact portions facing each other. It may be a connection terminal, and the internal conductor is held by the pair of contact portions by arranging the internal conductor inserted into the inside of the coaxial connector between the pair of contact portions described above. Good.
The pair of contact portions may be configured of one contact portion supported by an insulating portion main body described later, and the other contact portion positioned between the one contact portion and the insulating bent portion.

<Insulation part>
The coaxial connector of the present disclosure preferably includes an insulating portion that holds the internal conductor of the piezoelectric substrate and the connection terminal in a state of being electrically connected. Specifically, the insulating portion is held in a state where the internal conductor and the connection terminal are electrically connected by pressing the pair of contact portions constituting the connection terminal located on the inner side against the internal conductor. It may have a configuration. As a result, even when the coaxial connector unit is moved to a large extent, it is suppressed that the internal conductor is separated from the connection terminal and the electrical connection is released, and the electrical connection between the internal conductor and the connection terminal is It can be maintained for a long time.

  The insulating portion may be bendable, and the inner conductor may be held by the pair of contact portions by bending so that the inner conductor and the connection terminal are electrically connected. More specifically, the insulating portion may have an insulator body supporting one of the contact portions, and an insulating bent portion bent in the direction of the insulator body. By bending the insulating bent portion in the direction of the insulator main body, the other contact portion located between the one contact portion and the insulating bent portion is pressed in the direction of the one contact portion, whereby the pair of contact portions Alternatively, the internal conductor of the piezoelectric substrate may be gripped to electrically connect the internal conductor and the connection terminal.

<Shell>
The coaxial connector of the present disclosure preferably includes a conductive shell that supports the connection terminal through the insulating portion. For example, the shell may be bendable, and the inner conductor may be held by the pair of contact portions by bending so that the inner conductor and the connection terminal are electrically connected. More specifically, the shell may have a shell body that supports the insulator body, and a shell bend that is juxtaposed on the outside of the insulating bend and that is bent in the direction of the shell body. By bending the shell bent portion in the direction of the shell main body, the other contact portion is pressed in the direction of the one contact portion via the insulating bent portion, whereby the inner conductor of the piezoelectric substrate is gripped by the pair of contact portions. Thus, the internal conductor and the connection terminal may be electrically connected.

In addition, in the coaxial connector of the present disclosure, the shell bending portion may have a fixing portion that fixes the bent shell bending portion and the shell main body. Thus, when the insulating bent portion and the shell bent portion are bent, the bent shell bent portion and the shell main body are fixed by the fixing portion, so that the other contact portion is one contact through the insulating bent portion. It is possible to maintain a state of being pressed in the direction of the part, and preferably maintain a state in which the internal conductor of the piezoelectric substrate is gripped by the pair of contact parts and the internal conductor and the connection terminal are electrically connected. Can.
The shell bent portion may be configured to grip a protective layer covering the outer conductor of the piezoelectric substrate and the outer peripheral surface of the outer conductor. Thereby, since the piezoelectric base material and the coaxial connector are more firmly connected, the inner conductor of the piezoelectric base material is gripped by the pair of contact portions, and the inner conductor and the connection terminal are electrically connected. Can be suitably maintained.

<Application of coaxial connector unit>
The coaxial connector unit of the present disclosure is used for various ball games such as sensor applications (force sensors such as seating sensors, pressure sensors, displacement sensors, deformation sensors, vibration sensors, ultrasonic sensors, biological sensors, rackets, golf clubs, bats, etc.) Acceleration sensors and impact sensors when hitting sports equipment, touch and impact sensors for stuffed animals such as stuffed animals, security sensors for beds and windows, security sensors for glass and window frames, etc., actuators (sheet transport devices, etc.), energy harvesting applications (Power generation wear, power generation shoes, etc.), health care related applications (T-shirts, sports wear, spats, socks, various clothing, supporters, casts, diapers, baby wheelbarrow seats, wheelchair seats, medical incubators The mat, shoes, shoe insoles, watches etc. Provided service can be utilized as wearable sensors, etc.).
In addition, the coaxial connector unit of the present disclosure can be used in various clothing (shirts, suits, blazers, blouses, coats, jackets, jackets, jackets, jumpers, vests, dresses, pants, pants, underwear (slip, petticoat, camisole, bra), socks, gloves, Japanese clothes, belts, gold bands, cool clothes, neckties, handkerchiefs, scarves, scarves, stalls, eye masks, supporters (neck support, shoulder support, chest support, belly support, waist support, arm support, Foot supporters, elbow supporters, knee supporters, wrist supporters, ankle supporters, footwear (sneakers, boots, sandals, pumps, mules, slippers, ballet shoes, kung fu shoes), insoles, towels, rucksacks, hats (hat Caps, Casquettes, Hunting Caps, Ten Gallon Hats, Tulip Hats, Sun Visors, Berets), Hat Jaws, Helmets, Helmet Jaws, Hoods, Belts, Seat Covers, Sheets, Cushions, Cushions, Duvets, Duvets Covers, Blankets, Pillow, pillow cover, sofa, chair, desk, table, seat, seat, toilet seat, massage chair, bed, bed pad, carpet, basket, mask, bandage, rope, stuffed toy, various nets, bathtub, wall material, floor material, Window material, window frame, door, doorknob, PC, mouse, keyboard, printer, housing, robot, instrument, artificial hand, artificial leg, artificial foot, bicycle, skateboard, roller skate, rubber ball, shuttlecock, handle, pedal, fishing rod, fishing Floating, fishing reel, fishing rod holder, luer, switch, safe Fence, ATM, handle, dial, bridge, building, structure, tunnel, chemical reaction vessel and its piping, pneumatic equipment and its piping, hydraulic equipment and its piping, steam pressure equipment and its piping, motor, electromagnetic solenoid, gasoline It is disposed in various articles such as engines and used for sensors, actuators, and energy harvesting applications.
Examples of the arrangement method include various methods such as sewing the coaxial connector unit into the object, sandwiching the object with the object, and fixing the object with the adhesive.
For example, piezoelectric fabrics, piezoelectric knits, and piezoelectric devices can be applied to these applications.
Among the above applications, the coaxial connector unit of the present disclosure is preferably used as a sensor application or an actuator application.
Specifically, the coaxial connector unit of the present disclosure is preferably mounted on a force sensor, or mounted on an actuator.
Also, the coaxial connector unit, the piezoelectric fabric, the piezoelectric fabric, and the piezoelectric device described above can switch the FET by applying a voltage generated by stress between the gate and source of the field effect transistor (FET). It can also be used as an ON-OFF switch.
The coaxial connector unit of the present disclosure can also be used for other applications besides the applications described above.
Other applications include bedding for turning over, carpets for movement detection, insoles for movement detection, chest bands for respiration detection, masks for respiration detection, arm bands for detection of bruises, There are foot bands for detecting a reed, seating sheets for detecting a seating, and a stuffed toy and a stuffed toy-type social robot capable of determining a contact state. With a stuffed toy, a stuffed toy type social robot or the like that can determine the contact state, for example, a pressure sensor is detected by a contact sensor locally disposed on the stuffed toy or the like, and the person "struck" the stuffed toy etc. It is possible to determine each operation, such as whether it's "held" or not.
In addition, the coaxial connector unit according to the present disclosure is used, for example, in-vehicle applications; vehicle handle grip detection applications using vibration and acoustic sensing, in-vehicle device operation system applications using resonance spectrum using vibration and acoustic sensing, and touch sensor applications of in-vehicle displays It is particularly suitable for vibration body applications, automobile door and window pinch detection sensor applications, car body vibration sensor applications and the like.

[Force sensor]
A force sensor according to the present disclosure comprises the coaxial connector unit described above.
Since the force sensor according to the present disclosure includes the coaxial connector unit, a short circuit between the inner conductor and the outer conductor is suppressed, and an improvement in sensor sensitivity is expected.

  The force sensor of the present disclosure may be configured to take out a charge (electric field) generated when a tension is applied to the piezoelectric substrate as a voltage signal, and a charge generated when a twisting force is applied to the piezoelectric substrate The configuration may be such that the (electric field) is taken out as a voltage signal.

[Actuator]
An actuator according to the present disclosure comprises the coaxial connector unit described above.
Since the actuator according to the present disclosure includes the coaxial connector unit, a short circuit between the inner conductor and the outer conductor is suppressed, and an improvement in sensor sensitivity is expected.

DESCRIPTION OF SYMBOLS 2 connection terminal 4 insulation part 6 shell 10, 10A coaxial wire structure 12, 12A internal conductor 14, 14A piezoelectric material (1st piezoelectric material)
13, 16 Outer conductor 18 Protective layer 14B Second piezoelectric body 100, 100A, 100B, 100C Piezoelectric substrate 200 coaxial connector 300 coaxial connector unit

Claims (9)

A piezoelectric base material including a long inner conductor, a piezoelectric body covering an outer peripheral surface of the inner conductor, and an outer conductor disposed on the outer periphery of the piezoelectric body;
A coaxial connector having a connection terminal electrically connected to the inner conductor by applying pressure;
Coaxial connector unit. An insulating portion for holding the internal conductor and the connection terminal in a state of being electrically connected;
A conductive shell supporting the connection terminal through the insulating portion;
The coaxial connector unit according to claim 1, further comprising: The connection terminal has a pair of contact portions located inside the insulating portion and capable of gripping an internal conductor disposed therebetween,
The insulating portion and the shell are bendable, and by bending the insulating portion and the shell, the internal conductor is gripped by the pair of contact portions, and the internal conductor and the connection terminal are electrically connected. The coaxial connector unit according to claim 2. The insulating portion has an insulator body supporting one of the contact portions, and an insulating bent portion bent in the direction of the insulator body.
The shell has a shell main body for supporting the insulator main body, and a shell bend which is juxtaposed to the outside of the insulating bend and bent in the direction of the shell main body.
The other contact portion is disposed between the one contact portion and the insulating bent portion,
The coaxial according to claim 3, wherein the internal conductor is gripped by the pair of contact portions by bending the insulation bending portion and the shell bending portion, and the internal conductor and the connection terminal are electrically connected. Connector unit. The piezoelectric body includes a helical chiral polymer (A) having optical activity,
The main alignment direction of the helical chiral polymer (A) contained in the piezoelectric body is along the longitudinal direction of the piezoelectric body,
The coaxial connector unit according to any one of claims 1 to 4, wherein the orientation degree F of the piezoelectric body determined by the following formula (b) is in the range of 0.5 or more and less than 1.0.
Degree of orientation F = (180 ° -α) / 180 ° ··· (b)
(In formula (b), α represents the half width of the peak derived from the orientation measured by X-ray diffraction.)   The coaxial connector unit according to any one of claims 1 to 5, wherein the internal conductor is a tinsel wire. The piezoelectric body has a long flat plate shape,
The average thickness of the piezoelectric body is 0.001 mm to 0.2 mm,
The width of the piezoelectric body is 0.1 mm to 30 mm,
The coaxial connector unit according to any one of claims 1 to 6, wherein a ratio of a width of the piezoelectric body to an average thickness of the piezoelectric body is 2 or more.   A force sensor comprising the coaxial connector unit according to any one of claims 1 to 7.   An actuator comprising the coaxial connector unit according to any one of claims 1 to 8.