JP2012139066A - Overhead cable monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an overhead cable monitoring system applicable to a wide range of overhead cables, and in which the maintenance load is low.SOLUTION: The overhead cable monitoring system comprises a plurality of sensor nodes 100 installed in an overhead cable 200, detecting the information indicating the situation of the overhead cable and transmitting that information by radio, and a receiver which receives the information transmitted from the sensor node by radio. The sensor node includes a vibration power generator with an electrostatic induction power generation element as a power source. The electrostatic induction power generation element includes a first electrode, an electret provided on the first electrode, and a second electrode arranged separately from the electret, and is configured so that one of the electret or the second electrode moves relatively to the other by the vibration of an overhead cable. The electret is formed by injecting charges into (a) a fluorine-containing polymer having an aliphatic ring in the main chain or a resin film containing (a') a material derived from the (a)fluorine-containing polymer.

Description

  The present invention relates to an overhead cable monitoring system.

Since overhead cables such as overhead communication lines and overhead power transmission lines are affected in a wide range when a failure such as disconnection occurs, it is necessary to perform regular maintenance. In addition, when a failure occurs, it is necessary to quickly find the failure point. However, the overhead cable has a long track and a wide range of installation locations, so it takes manpower and time to find maintenance and trouble spots.
To solve such problems, a system configured to install a sensor device including a sensor and wireless communication means on an aerial cable, detect an abnormality (abnormal vibration, etc.) due to disconnection of the aerial cable, and transmit it wirelessly. Has been proposed.

The sensor device used in the system as described above usually includes a sensor, wireless communication means, control means for processing information from the sensor and controlling the operation of the wireless communication means, and power necessary for driving them. A battery is conventionally used as the power supply. However, in this case, it is necessary to periodically check and replace the battery. In recent years, the development of low-power-consumption wireless communication technology has progressed. For example, even if a lithium primary battery with a large battery capacity is used for over 5 years even if the communication frequency with high power consumption is reduced to about once / day. Stable and long-term operation is difficult. Moreover, the waste battery by replacement | exchange also becomes an environmental problem.
Thus, it has been proposed to use a solar cell that converts light energy into electrical energy as a power source for the sensor device (for example, Patent Documents 1 and 2).

On the other hand, electrostatic induction conversion elements using electrets in which electric charges are injected into an insulating material are conventionally used for condenser microphones and electrostatic induction vibration power generators. Conventionally, inorganic materials such as silicon dioxide have been mainly used as the insulating material constituting the electret (for example, Patent Document 3). In addition, chain polymer compounds such as polycarbonate, polypropylene, and polytetrafluoroethylene are also used as organic insulating materials.
Recently, it has been proposed to use a fluorine-containing polymer having an aliphatic ring structure in the main chain as an electret material (Patent Document 4). In addition, in order to improve the surface charge density of electrets using such a fluoropolymer, it has been proposed to blend a silane coupling agent having an amino group (Patent Document 5).

Japanese Patent No. 4155356 JP 2007-093342 A International Publication No. 2010/047076 JP 2006-180450 A International Publication No. 2008/114489

When a solar cell is used as a power source, light is necessary for the power generation, and it is necessary to install the solar cell in a place where the light hits. Therefore, applicable aerial cables are limited. For example, in a dark place such as under a roof or cover, underground space, etc., the solar cell cannot provide the power required for sensor drive and wireless transmission, so it cannot be applied to cables installed in such places. . In addition, there is a problem that even if the place is exposed to light, the amount of power generation is affected by the weather and stable power supply is not performed.
The present invention has been made in view of the above circumstances, and provides an aerial cable monitoring system that can be applied to a wide range of aerial cables with less maintenance load.

The present invention includes the following [1] to [7].
[1] An aerial system provided with a plurality of sensor nodes that are installed in an aerial cable and detect information indicating the status of the aerial cable and wirelessly transmit the information, and a receiving device that receives information wirelessly transmitted from the sensor node. A cable monitoring system,
The sensor node includes a vibration power generator as an independent power source,
The vibration power generator includes a first electrode, an electret provided on the first electrode, and a second electrode spaced apart from the electret, and the electret and the first by vibration of an aerial cable. Comprising an electrostatic induction power generating element configured such that one of the two electrodes moves relative to the other;
The electret is formed by injecting electric charge into a fluoropolymer (a) having an aliphatic ring in the main chain or a resin film containing a material (a ′) derived from the fluoropolymer (a). An aerial cable monitoring system characterized by being.
[2] One of the electret and the second electrode is arranged in parallel to the other, and is configured to reciprocate in a vertical direction toward the center direction of the overhead cable. The aerial cable monitoring system described.
[3] The aerial cable monitoring system according to [1] or [2], wherein a plurality of the electrostatic induction power generation elements are installed on an outer periphery of the aerial cable.
[4] The aerial cable monitoring system according to any one of [1] to [3], wherein the information indicating the status of the aerial cable is at least one selected from temperature, vibration, and acceleration.
[5] The aerial cable monitoring system according to any one of [1] to [4], wherein the aerial cable is a communication cable or a power transmission line.
[6] The aerial cable monitoring system according to any one of [1] to [5], wherein the fluoropolymer (a) has a carboxy group or an alkoxycarbonyl group as a terminal group.
[7] Any one of [1] to [6], wherein the material (a ′) includes a mixture or a reaction product of the fluoropolymer (a) and a silane coupling agent having an amino group. The overhead cable monitoring system described in the section.

  According to the present invention, it is possible to provide an aerial cable monitoring system that can be applied to a wide range of aerial cables with less maintenance load.

It is a conceptual diagram explaining schematic structure of the aerial cable monitoring system of one Embodiment of this invention. It is a block diagram which shows schematic structure of the sensor node 100 which comprises the aerial cable monitoring system shown in FIG. It is a block diagram which shows schematic structure of the power supply part of the sensor node 100 shown in FIG. FIG. 3 is a schematic side view showing a state where the vibration power generator of the sensor node 100 is installed on the overhead cable 200. It is a perspective exploded view showing one embodiment of a vibration power generator used for a power supply part. FIG. 4 is a partial cross-sectional view of the vibration power generator 1 shown in FIG. 3. It is a top view of the side by which the 1st electrode 11 and the electret 12 are provided of the movable electrode part 10 which comprises the vibration power generator 1 shown in FIG. It is a block diagram which shows the circuit structural example of a rectifier circuit.

The aerial cable monitoring system of the present invention is installed in an aerial cable, detects information indicating the status of the aerial cable and wirelessly transmits the information, and wirelessly transmits the information from the sensor node. An aerial cable monitoring system comprising a receiving device for receiving the received information, wherein the sensor node comprises a vibration power generator as a power source, the vibration power generator comprising a first electrode and a first electrode on the first electrode. And the second electrode spaced apart from the electret, and one of the electret and the second electrode is moved relative to the other by vibration of the overhead cable. A fluorinated polymer having an aliphatic ring in the main chain (a Or wherein the resin film containing the material (a ') derived from the fluoropolymer (a) is made by injecting the charge.
Here, in the present specification and claims, the “aerial cable” means a cable constructed in the air by a plurality of supports (electric poles, steel towers, etc.). The space where the overhead cable is installed may be on the ground or underground.
Examples of overhead cables include communication cables (wired telecommunication cables such as telephone lines, optical cables, etc.), power transmission lines (high voltage lines), and the like. Among these, a communication cable or a power transmission line is preferable in that constant monitoring is indispensable as a lifeline even during normal times and disasters.

According to the present invention, the status of an aerial cable (for example, whether there is abnormal vibration or overheating) can be monitored over a long period (for example, five years or more) without maintenance of the sensor node.
That is, there are low-frequency vibrations due to wind fluctuations, moving body vibrations, etc., so-called environmental vibrations in the environment. Since the aerial cable is installed with tension, it always vibrates to some extent due to environmental vibration. The vibration power generator including the electrostatic induction power generation element has high power generation efficiency at low-frequency vibration because a specific material is used for the electret. Therefore, by using the electrostatic induction power generation element as a power source, sufficient electric power for driving the sensor node can be obtained by the vibration of the overhead cable. For this reason, the sensor node is not limited in installation location as in the case of employing a solar cell as a power source, and can be applied to an aerial cable installed in a place where there is no light source such as underground.
In addition to the electrostatic induction type using an electret, an electromagnetic induction type and a piezoelectric type are known as vibration power generators. However, since the former requires a coil, It becomes heavier and there are restrictions on installation. The latter has a problem in the life of the generator because it is necessary to secure a space for the vibrator and the durability of the material is low. Furthermore, they have low power generation efficiency at low frequency vibration compared to electrostatic induction generators of the same volume, and sufficient power cannot be obtained when the vibration of the overhead cable is fine. Therefore, in order to obtain electric power necessary for driving the sensor node, it is necessary to provide an amplification mechanism that amplifies low-frequency vibrations and transmits the vibration to the generator, or to increase the size of the generator. Increase. Further, in the case of the piezoelectric type, power generation is performed by deforming the diaphragm to which the piezoelectric element is attached, so that the components are likely to deteriorate. On the other hand, when using an electrostatic induction type, particularly one equipped with an electret composed of the above specific material, a sufficient amount of power can be obtained with low-frequency vibration even without an amplification mechanism. Compared to the case of adopting, the weight can be reduced and the thickness can be reduced, and the cost is low. In addition, the electrostatic induction power generating element has a long life span (high charge retention stability), and it is not necessary to deform the electret or to contact other members. Is also excellent.

An embodiment of the overhead cable monitoring system of the present invention will be described with reference to the drawings.
In FIG. 1, the conceptual diagram explaining schematic structure of the aerial cable monitoring system of this embodiment is shown.
The aerial cable monitoring system of this embodiment includes a plurality of sensor nodes 100 that detect information indicating the status of an aerial cable and wirelessly transmit the information, and a plurality of relay nodes that receive the wirelessly transmitted information and wirelessly transmit the information. The wireless network includes a (receiving device) 110 and a gateway (receiving device) 120 that receives information transmitted from the relay node 110 by wire or wirelessly.
Each of the plurality of sensor nodes 100 is installed in an aerial cable 200 installed by a support (not shown).
The gateway 120 is connected to a server (not shown) via a wired or wireless communication line (not shown).

In the present embodiment, the status of the overhead cable 200 is monitored by the wireless network and the server.
First, the sensor node 100 detects information indicating the status of the overhead cable 30 at the location where the sensor node 100 is installed (hereinafter sometimes simply referred to as data) and wirelessly transmits the detected information. Data wirelessly transmitted from the sensor node 100 is wirelessly transmitted to the gateway 120 via the relay node 110. The data received by the gateway 120 is sent to the server via a wired or wireless communication line.
The server performs processing (recording, analysis, etc.) of the sent data, and activates peripheral devices (alarm devices, etc.) connected to the server as necessary. For example, the data sent from the sensor node 100 is recorded in correspondence with the installation position of the sensor node 100 that transmitted the data or the sensor identification number of the sensor node 100. In addition, when the data is analyzed and it is determined that the data is an abnormal value (for example, a value in which the temperature or vibration of the overhead cable 200 exceeds a preset value (threshold value), the fluctuation range from the immediately preceding data is a set value. The alarm device is activated and the alarm is notified by display (characters, images, light emission, etc.) or sound (alarm, voice, etc.). In addition, when the aerial cable 30 is disconnected, the data sent from the sensor node 100 installed at or near the disconnection location greatly fluctuates. Therefore, by analyzing the data from the plurality of sensor nodes 100, the disconnection location Can be detected early.
In the present embodiment, the configuration other than the sensor node 100 is not particularly limited, and those conventionally proposed as relay nodes, gateways, servers, and the like that configure the sensor network system can be used.

  According to the present invention, it is possible to monitor the status of an aerial cable over a long period of time. Also, abnormalities can be quickly discovered by using the power generation pattern itself in the vibration state of a normal overhead cable as a reference.

<< Sensor node 100 >>
FIG. 2 is a block diagram illustrating a schematic configuration of the sensor node 100.
The sensor node 100 includes a power supply unit 101, a sensor 102, a communication unit 103, an antenna 104, and a control unit 105 that processes an output signal from the sensor 102 and controls the communication unit 103.
In the sensor node 100, power necessary for driving each unit is supplied from the power supply unit 101 to the control unit 105. That is, the power required for driving the control unit 105 is directly supplied from the power supply unit 101, and the power required for driving the communication unit 103 is supplied via the control unit 105. When the sensor 102 requires power for driving, the power is also supplied via the control unit 105.

The power supply unit 101 includes three vibration power generators 1a, 1b, and 1c (hereinafter, collectively referred to as vibration power generator 1), a power control circuit 2, and power generated by the vibration power generator 1. And a power storage unit 5 for charging.
By providing the three vibration power generators 1, the single power supply unit 101 can be configured to recognize vibrations of all three axes. That is, as will be described later, when the vibration direction of the electret and the vibration direction of the overhead cable 200 coincide, the power generation efficiency is improved. When one vibration power generator 1 includes one electret, the three vibration power generators 1 are arranged so that the vibration directions of the respective electrets coincide with three directions (X axis, Y axis, Z axis) perpendicular to each other. As a result, even when the vibration direction of the aerial cable 200 changes, the power supply unit 101 recognizes the vibrations of all three axes and efficiently generates power.
In addition, although the example provided with the three vibration power generators 1 was shown here, this invention is not limited to this. The number of vibration power generators 1 included in the power supply unit 101 is not necessarily three, and may be one or more. The upper limit is not particularly limited, but is preferably 12 or less, more preferably 6 or less, in order to reliably recognize the vibrations of the three axes X, Y, and Z of the overhead cable 200. Three are particularly preferable from the viewpoint of cost.
When there are a plurality of vibration power generators 1, it is not necessary to use all of them, and any one or more may be used.

FIG. 3 is a block diagram illustrating a schematic configuration of the vibration power generator 1.
The vibration power generator 1 includes an electrostatic induction power generation element 3 and a power conversion circuit unit 4.
Although details will be described later with reference to FIGS. 5 to 6, the electrostatic induction power generating element 3 includes a first electrode 11 provided with the electret 12 and a second electrode 21 spaced from the electret 12. And the electret 12 is configured to move relative to the second electrode 21 by the vibration of the overhead cable 200. AC power is generated by this relative movement.
The power conversion circuit unit 4 includes a rectification circuit 41 and a voltage conversion circuit 42. The rectifier circuit 41 is a circuit that rectifies the AC power generated by the electrostatic induction power generation element 3 and converts it into DC power. The voltage conversion circuit 42 is a circuit that converts the voltage value of the direct current rectified by the rectification circuit 41 into an optimum voltage for charging the secondary battery to be used, and the voltage value of the direct current input from the rectification circuit 41. Is converted into an output voltage value from the vibration power generator 1.

  The power control circuit 2 mixes the DC power in order to supply power to the power storage unit 5 with high efficiency and safety according to the DC voltage value output from the one or more vibration power generators 1, 5 is a circuit for supplying power to the power source 5. For example, when three vibration power generators 1 are provided, the AC power generation amount of the electrostatic induction power generation element 3 varies greatly depending on the installed environmental conditions, and the voltage conversion circuit provided inside each vibration power generator 1. In 42, it cannot adjust and a big difference arises in the output voltage from each vibration power generator 1. FIG. The voltage output from each vibration power generator 1 is monitored by a voltage detection circuit configured in the power control circuit 2 to switch to a highly efficient and safe output circuit configuration.

The power storage unit 5 includes a secondary battery and a charge / discharge control circuit (not shown).
The charge / discharge control circuit is a control for preventing overcharge and overdischarge for protecting the secondary battery when the DC power output from the vibration power generator 1 is charged to the secondary battery or discharged from the secondary battery. A circuit and a control circuit for efficiently charging and discharging.

The sensor 102 detects information indicating the state of the aerial cable 200, converts the information into a signal that can be processed by the control unit 105 (the power generation output by vibration as it is or 0/1, etc.), and outputs the signal. .
Examples of the “information indicating the status of the aerial cable 200” detected by the sensor 102 include health monitoring (cable continuity, vibration, acceleration, temperature, humidity, etc.) of the aerial cable 200 and its surrounding environment (temperature, humidity). Etc.). Among these, in order to constantly sense and monitor the situation, it is preferable to detect at least the continuity of the cable and the ambient temperature. When health monitoring is vibration or acceleration, the vibration power generator 1 may also serve as the sensor 102.
The number of sensors 102 included in one sensor node 100 may be one or two or more. When a plurality of sensors 102 are provided, the type of each sensor 102 may be the same or different. By combining a plurality of types of sensors, a single sensor node 100 can be configured to detect a plurality of information.

The communication unit 103 and the antenna 104 are not limited to each other, and a communication device and an antenna conventionally used for wireless communication can be used.
The control unit 105 may be configured so that information based on the output signal from the sensor 102 is wirelessly transmitted from the communication unit 103 as it is, and an abnormal condition (for example, abnormal condition) of the overhead cable 200 based on the output signal from the sensor 102. A determination means for determining the presence or absence of vibration, overheating, etc. may be provided, and the determination result may be wirelessly transmitted from the communication unit 103.
Examples of the determination means for determining the presence or absence of abnormality include a comparator and a diode. For example, when a comparator is used, different signals are output depending on whether the input signal (voltage value or current value) is equal to or lower than a preset threshold value (normal value) and exceeds the threshold value (abnormal value). It can be configured as follows. When a diode is used, a signal can be output only when the threshold is exceeded (abnormal value). In addition, even when performing continuous sensing, when it is sufficient to sense at a rate of once every few seconds to several minutes, the sensor 102 and the circuit in the control unit 105 that processes the output signal from the sensor 102 are intermittently operated by a timer. As a result, power consumption can be reduced and the power supply unit can be further reduced in size.

The determination operation will be described by taking as an example a case where an electrostatic induction type acceleration sensor is employed as the sensor 102 and a comparator is employed as the determination means.
The electrostatic induction type acceleration sensor is a sensor that converts kinetic energy generated corresponding to acceleration into electric energy, and acceleration is obtained by utilizing the fact that the magnitude of the generated electric energy is proportional to the acceleration. The magnitude of electrical energy is expressed as a voltage value.
When a voltage value is input from the acceleration sensor to the comparator, the comparator compares the voltage value input from the acceleration sensor with a preset voltage value (threshold value). When the voltage value is less than or equal to the set voltage value (when the acceleration is normal), when the input voltage value exceeds the set voltage value (when the acceleration is abnormal), a signal corresponding to each is output. To do.

In the sensor node 100, the vibration power generator 1, the sensor 102, the communication unit 103, the control unit 105, the power control circuit 2, and the power storage unit 5 are housed in a housing 6. Note that the vibration power generator 1 may not be stored in the housing 6 for the convenience of installation. FIG. 2 shows an example in which the sensor node 100 includes one housing 6 that houses the vibration power generator 1, the sensor 102, the communication unit 103, the control unit 105, the power control circuit 2, and the power storage unit 5. However, a plurality of the casings 6 may be provided.
The sensor node 100 is installed on the aerial cable 200 by attaching the casing 6 to the aerial cable 200 and placing the vibration power generator 1 on the outer periphery of the aerial cable 200.
The vibration power generator 1 can generate power regardless of where it is attached to the overhead cable 200. However, in order to avoid wind noise due to the vibration power generator 1 acting as a wind resistance in strong winds, a utility pole or the like is used. It is preferable to be installed within 1 m, preferably within 0.5 m from the support.
A preferable installation location of the housing 6 is the same as the preferable installation location of the vibration power generator 1. In addition, the number of housings 6 is preferably 12 or less, and more preferably 6 or less, in order to reliably recognize the vibrations of the three axes X, Y, and Z of the overhead cable 200. From the viewpoint of cost, it is particularly preferable to install three. However, when the power supply unit 101 is configured to be able to recognize vibrations of all three axes, the number of housings 6 to be installed may be one. In this case, since the vibration of all three axes can be recognized with one, it is preferable that the number of housings 6 to be installed is one.

In FIG. 4, the sensor node 100 includes three cases 6 including the vibration power generator 1, the sensor 102, the communication unit 103, the control unit 105, the power control circuit 2, and the power storage unit 5. The schematic side view which shows the state which installed the housing | casing 6a, 6b, 6c of the overhead cable 200 is shown. In the embodiment shown in FIG. 4, the housings 6 a, 6 b, 6 c each house one vibration power generator 1.
The casings 6a, 6b, and 6c have the vibration directions of the electrets 12 included in the vibration power generator 1 housed in each of the casings 6a, 6b, and 6c (the direction of arrow D in FIGS. And the straight line La, Lb, Lc connecting the center P of the overhead cable 200. As a result, the electret 12 reciprocates (vibrates) in the vertical direction (perpendicular to the longitudinal direction of the aerial cable 200) toward the center P direction of the aerial cable 200. If the electret 12 is arranged so as to vibrate as described above, the vibration direction of the electret 12 and the vibration direction of the overhead cable 200 are likely to coincide. When these vibration directions coincide with each other, the vibration energy of the overhead cable 200 is efficiently transmitted to the vibration power generator 1 and the power generation efficiency is improved.
The casings 6a, 6b, and 6c are installed at equal intervals on the circumference of a cross section perpendicular to the longitudinal direction of the overhead cable 200. The direction of vibration of the overhead cable 200 is usually not constant. As described above, the plurality of casings 6a, 6b, and 6c are installed in different directions when viewed from the center P of the aerial cable 200, so that any of 6a to 6c can be obtained even if the vibration direction of the aerial cable 200 changes. Electric power is efficiently generated by the vibration power generator 1 housed in the casing. Therefore, power can be stably supplied to the control unit 105.

The external dimensions of the housing 6 are not particularly limited, and can be appropriately set according to the size and number of the vibration power generator 1 and the sensor 102 to be housed, the size of the overhead cable 200 to be attached, and the like.
Although FIG. 4 shows an example in which three housings 6a, 6b, and 6c are installed as the housing 6 as described above, the present invention is not limited to this.
For example, the number of housings 6 may be one or more. The upper limit is not particularly limited, but considering the cost and the like, it is preferably 12 or less, more preferably 6 or less, and particularly preferably 3 or less.
The plurality of housings 6 may not be installed on the circumference of a cross section perpendicular to the longitudinal direction of the aerial cable 200. For example, you may arrange | position helically on the outer peripheral surface of the overhead cable 200. FIG. However, even in this case, it is preferable that each housing 6 is installed in a different direction when viewed from the center P of the overhead cable 200.

A schematic structure of the vibration power generator 1 is shown in FIGS. FIG. 5 is an exploded perspective view of the vibration power generator 1, and FIG. 6 is a partial cross-sectional view of the vibration power generator 1.
In the present embodiment, the vibration power generator 1 includes an upper unit A including a first electrode 11 and an electret 12 and a lower unit B including a second electrode 21.
The upper unit A includes a movable electrode portion 10 including a first electrode 11, an electret 12 and a rectangular first substrate 13 having a smooth surface, a rectangular frame member 14, and a first substrate 13. It comprises spring members 15 a and 15 b attached to the member 14.
In the upper unit A, the movable electrode portion 10 is disposed in the frame of the frame member 14, and both side edges on the long side of the first substrate 13 are attached to the frame member 14 by spring members 15a and 15b, respectively. Thereby, the movable electrode part 10 can be reciprocated (vibrated) in a fixed direction (arrow D direction in FIGS. 5 to 6) within the frame of the frame member 14.
The lower unit B includes a fixed electrode portion 20 including a second electrode 21 and a rectangular second substrate 22 having a smooth surface, a power conversion circuit portion 4, and a fixing member 23.
In the present embodiment, the electrostatic induction power generating element 3 is configured by the movable electrode portion 10 and the fixed electrode portion 20.
The first electrode 11 and the second electrode 21 of the electrostatic induction power generating element 3 are each connected to a rectifier circuit 41 of the power conversion circuit unit 4.
The upper unit A and the lower unit B may be interchanged.

<Upper unit A>
In FIG. 7, the top view of the side by which the 1st electrode 11 and the electret 12 are provided of the movable electrode part 10 is shown.
As shown in FIG. 7, the first electrode 11 is a pattern electrode formed in a comb-like pattern, and a linear portion that connects a plurality of line-like comb-tooth portions 11 a and one end of each comb-tooth portion 11 a. 11b.
The comb tooth portion 11 a is formed such that the longitudinal direction of the line intersects the vibration direction D of the movable electrode portion 10.
The end of the straight line portion 11b is connected to the rectifier circuit 41 of the power conversion circuit portion 4 by a wiring (not shown).

The width (length in the vibration direction D) of the comb-tooth portion 11a is not particularly limited. However, the smaller the width, the smaller the relative motion (vibration), the more kinetic energy can be converted into electrical energy, and the conversion efficiency. Is preferable. Therefore, the width of each comb tooth portion 11a is preferably 1,000 μm or less, more preferably 500 μm or less, and even more preferably 300 μm or less. The lower limit of the width is not particularly limited, but in consideration of durability, productivity, characteristics as an electret (high surface charge density, its stability, electrostatic repulsion characteristics, parasitic capacitance, etc.), the width is 50 μm or more. Preferably, 100 μm or more is more preferable.
The first electrode 11 may be composed of a single layer, may be composed of a plurality of layers, or may form a structure having a distribution in composition.
The thickness of the first electrode 11 (total thickness in the case of a plurality of layers) is preferably 10 to 1,000 nm, and more preferably 100 to 500 nm. When the thickness is within the above range, the conductivity and productivity are excellent.
The thickness of the first electrode 11 can be measured by a stylus type surface shape measuring instrument (such as DEKTAK8 manufactured by ULVAC).

The material constituting the first electrode 11 is not particularly limited as long as it has conductivity. The resistance value of the material is preferably 0.1 Ωcm or less, more preferably 0.01 Ωcm or less in terms of volume resistivity.
Specific examples of the conductive material include gold, silver, copper, nickel, chromium, aluminum, titanium, tungsten, molybdenum, tin, cobalt, palladium, platinum, and alloys containing at least one of these as a main component. Can be mentioned. Moreover, organic conductive films made of metal oxide conductive films such as ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide), polyaniline, polypyrrole, polythiophene-based conductive polymer (PEDOT / PSS), carbon nanotubes, and the like can also be exemplified.

A method for forming the first electrode 11 is not particularly limited, and a known method can be used. Specifically, for example, there is a method of forming a conductive thin film on a substrate (first substrate 13 or second substrate 22) and patterning the conductive thin film.
The method for forming the conductive thin film is not particularly limited, and a known method such as physical vapor deposition or electroless plating can be used as a method for forming the conductive thin film.
Examples of physical vapor deposition include sputtering, vacuum vapor deposition, and ion plating.
The electroless plating method is selected on the surface of the substrate on which the catalyst has adhered by immersing the substrate with the catalyst on the surface in an electroless plating solution containing a metal salt, reducing agent, etc., and the reducing power of electrons generated from the reducing agent. In this method, a metal is deposited to form an electroless plating film.
As metal salts contained in the electroless plating solution, nickel salts (nickel sulfate, nickel chloride, nickel hypophosphite, etc.), cupric salts (copper sulfate, copper chloride, pyrophosphoric acid, etc.), cobalt salts ( Cobalt sulfate, cobalt chloride, etc.), noble metal salts (chloroplatinic acid, chloroauric acid, dinitrodiammine platinum, silver nitrate, etc.).
Examples of the reducing agent contained in the electroless plating solution include sodium hypophosphite, formaldehyde, sodium tetrahydroborate, dialkylamine borane, hydrazine and the like.
When forming a conductive thin film by an electroless plating method, it is preferable to attach a catalyst to the surface of the substrate in advance before forming the conductive thin film. Examples of the catalyst include metal fine particles, metal-supported fine particles, colloids, and organometallic complexes.

  The patterning of the conductive thin film can be performed by a combination of a photolithography method and a wet etching method, wiring formation by printing nanometal ink, or the like. For example, patterning by a combination of a photolithography method and a wet etching method is performed by applying a photoresist on a conductive thin film to form a resist film, and then exposing and developing the resist film (resist mask). And etching the conductive thin film using the resist mask as a mask. Etching of the conductive thin film can be performed by, for example, wet etching using a liquid (usually an acidic solution) that dissolves the conductive thin film as an etchant. Further, as a method for printing nano metal ink or the like, a screen printing method, an ink jet method, a micro contact printing method, or the like can be used. The nano metal ink refers to an ink in which nanoparticles of the conductive material described above are dispersed in an organic solvent, water, or the like.

The electret 12 is a resin film (hereinafter referred to as a resin film (A)) containing a fluoropolymer (a) having an aliphatic ring in the main chain or a material (a ′) derived from the fluoropolymer (a). And the resin film (A) is injected with electric charges.
Details of the resin film (A), its formation method, and charge injection method will be described later.
The electret 12 is formed in the pattern corresponding to the comb-tooth part 11a on the upper surface of each of the several comb-tooth part 11a of the 1st electrode 11. As shown in FIG. That is, the resin film (A) is formed by forming a pattern film having a line pattern having substantially the same width and length as the comb-tooth portion 11a and injecting electric charges into the pattern film.
Although the width | variety of each electret 12 is not specifically limited, It is preferable that it is the same as that of the comb-tooth part 11a of the 1st electrode 11, or it is larger than it, and it is more preferable that it is larger than the width | variety of the comb-tooth part 11a. When the width of the electret 12 is larger than the width of the comb tooth portion 11a, the surface potential value and the charge retention stability (both normal temperature stability and stability during heating) when electretized can be increased.
The thickness of the electret 12 (the shortest distance from the upper surface of the first electrode 11 to the top of the electret 12) is preferably 1 to 200 μm, more preferably 5 to 20 μm, taking into account the power generation output, ease of processing, and the like.
The thickness of the electret 12 can be measured by an optical interference type film thickness measuring device.

An insulating material is preferable as a material constituting the first substrate 13. The resistance value of the insulating material is preferably 10 ¹⁰ Ωcm or more, more preferably 10 ¹² Ωcm or more in terms of volume specific resistance.
Specific examples of the insulating material include inorganic materials such as glass, organic polymer materials such as polyethylene terephthalate, polyimide, polycarbonate, and acrylic resin.

The material of the frame member 14 is not particularly limited, and a conductive material such as a metal can be used, or an insulating material similar to that of the substrate 13 can be used. It is preferable to use an insulating material from the viewpoint of reducing the weight of the power generator and durability of the electret (difficult to discharge). It is particularly preferable to use an organic polymer material as the insulating material.
As for the material (spring material) of the spring members 15 a and 15 b, a conductive material such as a metal can be used like the frame member 14, or an insulating material similar to that of the substrate 13 can be used. When a metal material is used as the spring material, a spring material having a spring constant that can correspond to a resonance frequency matched to the frequency of vibration to be used is used. When an insulating material, particularly a polymer material, is used as the spring material, a spring having a resonance frequency that can accommodate a wide vibration frequency range can be produced.
As the polymer material, polyparaxylylene or a derivative thereof (also referred to as polyparaxylylene) is preferable. The polyparaxylylenes are special polymers that can be polymerized in a gas phase at room temperature. For example, the dimer shown below is sublimated at about 160 ° C., then thermally decomposed at 690 ° C. to form a monomer, introduced into a vacuum container (about 4 Pa) at room temperature, and polymerized on the solid surface. Xylylene) is obtained.

There are several types of polyparaxylylenes. A compound having a molecular structure in which chlorine is attached to a benzene ring (trade name: parylene-C) has high dielectric breakdown strength and chemical resistance and is suitable as a spring material.
Examples of polyparaxylylenes that can be used as a spring material, including the above-mentioned parylene-C, are shown below. The product name is shown below each structural formula.

  A conductive material may be introduced into the spring using polyparaxylylene by the method described in JP-A-2008-174811.

<Lower unit B>
The second electrode 21 is a comb-shaped pattern electrode formed in a pattern that is plane-symmetric with the first electrode 11. Like the first electrode 11, a plurality of line-shaped comb-tooth portions and each comb The linear part which connects the end of a tooth | gear part is comprised, and the terminal of a linear part is connected to the rectifier circuit 41 of the power converter circuit part 4 by the wiring which is not shown in figure.
The preferable ranges of the width of the comb tooth portion 11 a of the second electrode 21 and the thickness of the second electrode 21 are the same as those of the first electrode 11.
Examples of the material constituting the second electrode 21 include the same materials as those described in the description of the first electrode 11.
The second electrode 21 may be composed of a single layer, may be composed of a plurality of layers, or may form a structure having a distribution in composition.
The composition (material, layer configuration, etc.) of the second electrode 21 may be the same as or different from the composition of the first electrode 11.
A method for forming the second electrode 21 is not particularly limited, and the second electrode 21 can be formed by the same procedure as that for the first electrode 11.

Examples of the material constituting the second substrate 22 include the same materials as those described in the description of the first substrate 13.
The fixing member 23 has a concave portion corresponding to the fixed electrode portion 20 on one side, and a notch portion corresponding to the power conversion circuit portion 4 at one corner. However, the installation place of the power conversion circuit unit 4 is not limited, and may be installed on the back surface of the second substrate 22, for example.
The material of the fixing member 23 is not particularly limited, and a conductive material such as a metal can be used, or an insulating material similar to that of the substrate 13 can be used. It is preferable to use an insulating material from the viewpoint of reducing the weight of the power generator and durability of the electret (difficult to discharge). It is particularly preferable to use an organic polymer material as the insulating material.

As described above, the power conversion circuit unit 4 includes the rectification circuit 41 and the voltage conversion circuit 42.
The circuit structures of the rectifier circuit 41 and the voltage conversion circuit 42 are not particularly limited, and those conventionally used for electrostatic induction type vibration power generators can be used. For example, the circuit configuration of the rectifier circuit 41 may be the same as the circuit configuration of a general AC-DC converter. The circuit configuration of the voltage conversion circuit 42 may be the same as the circuit configuration of a general DC-DC converter.

FIG. 8 shows a circuit configuration example of the rectifier circuit 41. The rectifier circuit 41 of this example is constituted by a diode bridge constituted by diodes D1 to D4 and a capacitor Ch provided between output terminals _TOUT1 and _TOUT2 of the diode bridge. The first electrode 11 and the second electrode 21 of the electrostatic induction power generating element are connected to the input terminals T _IN1 and T _IN2 of the rectifier circuit, respectively.
In the rectifier circuit 41, AC power input from the electrostatic induction power generation element is full-wave rectified by a diode bridge, smoothed by a capacitor CH, and output as DC power.
Although an example of a circuit configuration for full-wave rectification is shown here, a circuit configuration for half-wave rectification may be used.

The lower unit B is configured by attaching the fixed electrode portion 20 to the concave portion of the fixing member 23 and attaching the power conversion circuit portion 4 to the notch portion. At this time, the fixed electrode portion 20 is arranged so that the longitudinal direction of the line of the comb tooth portion of the second electrode 21 intersects the vibration direction D of the movable electrode portion 20, that is, the comb tooth portion of the first electrode 11. It is attached so as to coincide with the longitudinal direction of the line.
As described above, the movable electrode portion 10 of the upper unit A can reciprocate (vibrate) in a fixed direction (the direction of arrow D in FIGS. 5 to 7) within the frame of the frame member 14. By fixing the frame member 14 of the upper unit A on the fixing member 23 of the lower unit B, the electret 12 and the second electrode 21 are opposed to each other with a certain interval.

  The external dimensions of the vibration power generator 1 are not particularly limited, and can be appropriately set according to the required electric energy, the maximum dimension that can be attached to the overhead cable 200, and the like. The thickness of the vibration power generator 1 (thickness of the fixing member 23 + thickness of the frame member 14) is preferably 1 to 20 mm, and the lateral width (length in the vibration direction D) and vertical width (perpendicular to the vibration direction D). The length in the direction is preferably 1 to 100 mm.

<Operation of Power Supply Unit 101>
In the power supply unit 101, when the vibration power generator 1 vibrates due to the vibration of the overhead cable 200, AC power is generated by the electrostatic induction power generation element 3. That is, when the aerial cable 200 vibrates, the entire vibration power generator 1 attached thereto vibrates. However, the movable electrode portion 10 of the upper unit A has a width of vibration larger than the fixed electrode portion 20 of the lower unit B. large. Therefore, relatively, the movable electrode part 10 is oscillating in a fixed direction (arrow D direction in FIGS. 5 to 7) in parallel with the fixed electrode part 20.
The second electrode 21 of the fixed electrode portion 20 is at a position facing the electret 12 of the movable electrode portion 10 when the movable electrode portion 10 is not vibrating. At this time, in the second electrode 21, a charge having a polarity opposite to the surface charge of the electret 12 is electrostatically induced by the surface charge of the electret 12 at the opposite position. When the movable electrode portion 10 vibrates and the electret 12 moves and the area of the overlapping portion of the electret 12 and the second electrode 21 decreases, the reverse charge opposite to the previously induced charge disappears, and the second electrode The amount of charge of 21 is reduced. When the position of the electret 12 returns to the original position and the area of the overlapping portion with the second electrode 21 increases, the charge is electrostatically induced again, and the amount of charge on the second electrode 21 increases. Thus, when the amount of charge in the second electrode 21 changes due to a change in the relative position between the second electrode 21 and the electret 12, a current flows to cancel the generated potential difference. AC power can be obtained by taking this repetition as a voltage wave.
The AC power generated by the electrostatic induction power generating element 3 is rectified by the rectifier circuit 41 of the power conversion circuit unit 4 and output from the power conversion circuit unit 4 as DC power. The output DC power is supplied to the control unit 105 via the power control circuit 2 and the power storage unit 5 and consumed as power (drive power) for driving the sensor 102, the communication unit 103, the control unit 105, and the like. The

According to the vibration power generator 1, even when the external dimensions are reduced to a size that can be installed on the overhead cable 200, sufficient power for driving the sensor node 100 can be obtained by the vibration of the overhead cable 200.
For example, when the aerial cable 200 is installed on the ground, the aerial cable 200 constantly vibrates at a frequency of several Hz or more and tens of Hz or less due to wind movement, vibration of the support, or the like. According to the vibration power generator 1 having the above configuration, electric power of about 10 to 100 μW can be obtained even with the above-described low-frequency vibration. Although it depends on the communication conditions, the power consumption of the sensor node 100 is about 1 to 50 μW, so that the sensor node 100 is sufficiently driven even if a power source other than the vibration power generator 1 is not provided.

Here, the maximum power generation output P _max of the vibration power generator 1 can be expressed by the following mathematical formula.
P _max = 2πσ ² nAf / {εε ₀ / d × (εg / d + 1)}
[In the formula, σ is the surface charge density of the electret 12, n is the number of poles (the number of the second electrodes 21 arranged in the vibration direction D of the first substrate 13 (that is, the number of the electrets 12)), and A is the electret. 12 is the maximum overlapping area of the second electrode 21, f is the frequency of the reciprocating motion of the electret 12, ε is the relative dielectric constant, ε ₀ is the vacuum dielectric constant, d is the thickness of the electret 12, and g is the electret 12. This is the distance from the second electrode 21. ]

As shown in the above formula, when the surface area of the electret 12 (the total surface area in the case of plural electrets) is the same, the higher the surface charge density of the electret 12, the larger the thickness d, or the vibration direction D. The greater the number of electrets 12, the greater the power generation output. Conventionally, inorganic materials such as silicon oxide films and silicon nitride films have been widely used as electret materials, but in the case of such inorganic materials, it is difficult to make the thickness d 2 μm or more from the viewpoint of strength and the like. Fine processing is also difficult. Therefore, it is difficult to increase the power generation output, and it is difficult to cover the power consumption of the sensor node 100 only by the electret.
On the other hand, the resin film (A) used in the present invention has high charge retention performance by containing the fluoropolymer (a) or the material (a ′), and the resin film (A) The electret formed by injecting electric charges into has a high surface charge density. For example, the electret 12 having a thickness of 10 μm or more can be easily formed. Further, finer processing is possible as compared with silicon oxide films and silicon nitride films. Therefore, a high power generation output can be obtained and the power necessary for driving the sensor node 100 can be sufficiently covered.

<Resin film (A)>
The resin film (A) contains a fluoropolymer (a) having an aliphatic ring in the main chain or a material (a ′) derived from the fluoropolymer (a).
The material (a ′), which will be described in detail later, is a mixture of the fluoropolymer (a) and other components other than the fluoropolymer (a), the fluoropolymer (a) and the fluoropolymer. The reaction product with other components other than (a), etc. are mentioned. When the resin film (A) contains the reaction product, the fluoropolymer (a) used for forming the reaction product or a part of other components is unreacted in the resin film (A). It may remain as it is.

[Fluoropolymer (a)]
The fluorinated polymer (a) is a fluorinated polymer having an aliphatic ring in the main chain.
Here, the “fluorinated polymer” is a polymer having a fluorine atom in its structure.
In the fluorine-containing polymer (a), the fluorine atom may be bonded to the carbon atom constituting the main chain or may be bonded to the side chain. The fluorine atom is preferably bonded to the carbon atom constituting the main chain because it is suitable for electretization with a low water absorption and low dielectric constant, high dielectric breakdown voltage, and high volume resistivity.

“Having an aliphatic ring in the main chain” means that at least one of the carbon atoms constituting the ring skeleton of the aliphatic ring is a carbon atom constituting the main chain of the fluoropolymer (a). means.
For example, when the fluoropolymer (a) is obtained by polymerization of a monomer having a polymerizable double bond, carbon derived from the polymerizable double bond of the monomer used for the polymerization At least one of the atoms becomes a carbon atom constituting the main chain. For example, when the fluorine-containing polymer (a) is a fluorine-containing polymer obtained by polymerizing a cyclic monomer as described later, two polymerizable double bonds constituting the cyclic monomer are included. The carbon atom becomes the carbon atom constituting the main chain. Further, in the case of a fluorinated polymer obtained by cyclopolymerizing a monomer having two polymerizable double bonds, among the four carbon atoms constituting the two polymerizable double bonds At least two are carbon atoms constituting the main chain.

“Aliphatic ring” refers to a ring having no aromaticity. The aliphatic ring may be saturated or unsaturated. The aliphatic ring may have a carbocyclic structure in which the ring skeleton is composed only of carbon atoms, and has a heterocyclic structure that includes atoms other than carbon atoms (heteroatoms) in the ring skeleton. Also good. Examples of the hetero atom include an oxygen atom and a nitrogen atom.
The number of atoms constituting the ring skeleton of the aliphatic ring is preferably 4 to 7, and more preferably 5 to 6. That is, the aliphatic ring is preferably a 4- to 7-membered ring, and more preferably a 5- to 6-membered ring.
The aliphatic ring may or may not have a substituent. The phrase “which may have a substituent” means that a substituent (an atom or group other than a hydrogen atom) may be bonded to an atom constituting the ring skeleton of the aliphatic ring.

The aliphatic ring may be a non-fluorinated aliphatic ring or a fluorinated aliphatic ring.
The non-fluorinated aliphatic ring is an aliphatic ring that does not contain a fluorine atom in the structure. Specifically, as the non-fluorinated aliphatic ring, a saturated or unsaturated aliphatic hydrocarbon ring, and a part of carbon atoms in the aliphatic hydrocarbon ring is substituted with a hetero atom such as an oxygen atom or a nitrogen atom. An aliphatic heterocyclic ring etc. are mentioned.
The fluorine-containing aliphatic ring is an aliphatic ring containing a fluorine atom in the structure. Examples of the fluorinated aliphatic ring include an aliphatic ring in which a substituent containing a fluorine atom (hereinafter referred to as a fluorinated group) is bonded to a carbon atom constituting the ring skeleton of the aliphatic ring. Examples of the fluorine-containing group include a fluorine atom, a perfluoroalkyl group, a perfluoroalkoxy group, and ═CF ₂ .
The fluorine-containing aliphatic ring or non-fluorine-containing aliphatic ring may have a substituent other than the fluorine-containing group.
As the aliphatic ring, a fluorine-containing aliphatic ring is preferable because of excellent charge retention performance.

Preferred fluorine-containing polymers (a) include the following fluorine-containing cyclic polymers (I) and fluorine-containing cyclic polymers (II).
Fluorinated cyclic polymer (I): a polymer having units based on a cyclic fluorinated monomer.
Fluorine-containing cyclic polymer (II): a polymer having units formed by cyclopolymerization of a diene fluorine-containing monomer.
“Cyclic polymer” means a polymer having a cyclic structure.
“Unit” means a repeating unit constituting a polymer.
Hereinafter, the compound represented by the formula (1) is also referred to as “compound (1)”. The same applies to units, compounds and the like represented by other formulas. For example, the unit represented by formula (3-1) is also referred to as “unit (3-1)”.

The fluorinated cyclic polymer (I) has units based on a cyclic fluorinated monomer.
“Cyclic fluorine-containing monomer” means a monomer having a polymerizable double bond between carbon atoms constituting a fluorine-containing aliphatic ring, or a carbon atom constituting a fluorine-containing aliphatic ring and a fluorine-containing fat. It is a monomer having a polymerizable double bond with a carbon atom outside the group ring.
As the cyclic fluorine-containing monomer, the following compound (1) or compound (2) is preferable.

［式中、Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｙ^１およびＹ^２は、それぞれ独立に、フッ素原子、酸素原子が介在してもよいペルフルオロアルキル基、または酸素原子が介在してもよいペルフルオロアルコキシ基である。Ｘ^３およびＸ^４は相互に結合して環を形成してもよい。］

[Wherein, X ¹ , X ² , X ³ , X ⁴ , Y ¹ and Y ² are each independently a fluorine atom, a perfluoroalkyl group that may be intervened by an oxygen atom, or an oxygen atom. A good perfluoroalkoxy group. X ³ and X ⁴ may be bonded to each other to form a ring. ]

The perfluoroalkyl group in X ¹ , X ² , X ³ , X ⁴ , Y ¹ and Y ² preferably has 1 to 7 carbon atoms, and more preferably 1 to 4 carbon atoms. The perfluoroalkyl group is preferably linear or branched, and more preferably linear. Specific examples include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and the like, and a trifluoromethyl group is particularly preferable.
Examples of the perfluoroalkoxy group in X ¹ , X ² , X ³ , X ⁴ , Y ¹ and Y ² include those in which an oxygen atom (—O—) is bonded to the perfluoroalkyl group, and a trifluoromethoxy group is particularly preferred. preferable.
When the perfluoroalkyl group or perfluoroalkoxy group has 2 or more carbon atoms, an oxygen atom (—O—) may be interposed between the carbon atoms of the perfluoroalkyl group or perfluoroalkoxy group.

In formula (1), X ¹ is preferably a fluorine atom.
X ² is preferably a fluorine atom, a trifluoromethyl group, or a perfluoroalkoxy group having 1 to 4 carbon atoms, and more preferably a fluorine atom or a trifluoromethoxy group.
X ³ and X ⁴ are each independently preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and more preferably a fluorine atom or a trifluoromethyl group.
X ³ and X ⁴ may be bonded to each other to form a ring. The number of atoms constituting the ring skeleton of the ring is preferably 4 to 7, and more preferably 5 to 6.
Preferable specific examples of compound (1) include compounds (1-1) to (1-5).

In formula (2), Y ¹ and Y ² are each independently preferably a fluorine atom, a C 1 -C 4 perfluoroalkyl group or a C 1 -C 4 perfluoroalkoxy group, and a fluorine atom or a trifluoromethyl group Is more preferable.
Preferable specific examples of compound (2) include compounds (2-1) to (2-2).

The fluorinated cyclic polymer (I) may be composed only of units formed by the cyclic fluorinated monomer, or may be a copolymer having the units and other units. Good.
However, the proportion of units based on the cyclic fluorinated monomer in the fluorinated cyclic polymer (I) is 20 mol% or more based on the total of all repeating units constituting the fluorinated cyclic polymer (I). Is preferable, 40 mol% or more is more preferable, and 100 mol% may be sufficient.
The other monomer is not particularly limited as long as it is copolymerizable with the cyclic fluorine-containing monomer. Specific examples include diene fluorine-containing monomers, monomers having a reactive functional group in the side chain, tetrafluoroethylene, chlorotrifluoroethylene, perfluoro (methyl vinyl ether), and the like. Examples of the diene-based fluorine-containing monomer include the same as those mentioned in the description of the fluorine-containing cyclic polymer (II) described later. Examples of the monomer having a reactive functional group in the side chain include monomers having a polymerizable double bond and a reactive functional group. The polymerizable double _{bond, CF 2 = CF-, CF 2} = CH-, CH 2 = CF-, CFH = CF-, CFH = CH-, CF 2 = C-, include CF = CF-, etc. . Examples of the reactive functional group include the same functional groups as those described in the explanation of the fluorine-containing cyclic polymer (II) described later.
A polymer obtained by copolymerization of a cyclic fluorine-containing monomer and a diene-based fluorine-containing monomer is considered as a fluorine-containing cyclic polymer (I).

The fluorinated cyclic polymer (II) has units formed by cyclopolymerization of a diene fluorinated monomer.
The “diene fluorine-containing monomer” is a monomer having two polymerizable double bonds and fluorine atoms. Although it does not specifically limit as this polymerizable double bond, A vinyl group, an allyl group, an acryloyl group, and a methacryloyl group are preferable.
As the diene fluorine-containing monomer, the following compound (3) is preferable.
_{CF 2 = CF-Q-CF} = CF 2 ··· (3).
In formula (3), Q may have an etheric oxygen atom, and a part of fluorine atoms may be substituted with a halogen atom other than fluorine atoms, preferably 1 to 5 carbon atoms, preferably 1 to 1 carbon atoms. 3 is a perfluoroalkylene group which may have a branch. Examples of halogen atoms other than fluorine include chlorine atom and bromine atom.
Q is preferably a perfluoroalkylene group having an etheric oxygen atom. In that case, the etheric oxygen atom in the perfluoroalkylene group may be present at one end of the group, may be present at both ends of the group, and is present between the carbon atoms of the group. It may be. From the viewpoint of cyclopolymerizability, it is preferably present at one end of the group.

Specific examples of the compound (3) include the following compounds.
CF ₂ = CFOCF ₂ CF = CF ₂ ,
CF ₂ = CFOCF (CF ₃ ) CF═CF ₂ ,
CF ₂ = CFOCF ₂ CF ₂ CF = CF ₂ ,
CF ₂ = CFOCF ₂ CF (CF ₃ ) CF═CF ₂ ,
CF ₂ = CFOCF (CF ₃ ) CF ₂ CF = CF ₂ ,
CF ₂ = CFOCFClCF ₂ CF = CF ₂ ,
_{CF 2 = CFOCCl 2 CF 2 CF} = CF 2,
CF ₂ = CFOCF ₂ OCF = CF ₂ ,
_{CF 2 = CFOC (CF 3)} 2 OCF = CF 2,
CF ₂ = CFOCF ₂ CF (OCF ₃ ) CF═CF ₂ ,
CF ₂ = CFCF ₂ CF = CF ₂ ,
CF ₂ = CFCF ₂ CF ₂ CF = CF ₂ ,
_{CF 2 = CFCF 2 OCF 2 CF} = CF 2.

  Examples of the unit formed by the cyclopolymerization of the compound (3) include the following units (3-1) to (3-4).

The fluorinated polymer (a) preferably has a reactive functional group.
The “reactive functional group” is bonded by reacting with other components blended between the molecules of the fluoropolymer (a) or together with the fluoropolymer (a) when heating or the like is performed. Means a reactive group capable of forming.
For example, as the other component, a silane coupling agent described later or a compound having a molecular weight of 50 to 2,000 having two or more polar functional groups (excluding the silane coupling agent) (hereinafter referred to as a polyvalent polar compound). When the fluorinated polymer (a) is reacted with the functional group possessed by the silane coupling agent or the polar functional group possessed by the polyvalent polar compound, It preferably has a functional group.
As the reactive functional group possessed by the fluoropolymer (a), in view of ease of introduction into the polymer, strength of interaction with the silane coupling agent or the polyvalent polar compound, etc., a carboxy group , An acid halide group, an alkoxycarbonyl group, a carbonyloxy group, a carbonate group, a sulfo group, a phosphono group, a hydroxy group, a thiol group, a silanol group, and an alkoxysilyl group, preferably at least one selected from the group consisting of a carboxy group or an alkoxy group A carbonyl group is particularly preferred.
The reactive functional group may be bonded to the end of the main chain of the fluoropolymer (a) or may be bonded to a side chain.

The relative dielectric constant of the fluoropolymer (a) is preferably 1.8 to 8, more preferably 1.8 to 5, further preferably 1.8 to 3, particularly preferably 1.8 to 2.7. .8 to 2.3 is most preferable. When the relative dielectric constant is not less than the lower limit of the above range, the amount of charge that can be stored as an electret is high, and when it is not more than the upper limit, the electrical insulation and the charge retention stability as an electret are excellent. The relative dielectric constant is measured at a frequency of 1 MHz in accordance with ASTM D150.
In addition, since the resin film (A) is a part responsible for charge retention as an electret, the fluoropolymer (a) preferably has a high volume resistivity and a high dielectric breakdown strength.
The volume resistivity of the fluoropolymer (a) is preferably 10 ¹⁰ to 10 ²⁰ Ωcm, and more preferably 10 ¹⁶ to 10 ¹⁹ Ωcm. The volume resistivity is measured according to ASTM D257.
The dielectric breakdown strength of the fluoropolymer (a) is preferably 10 to 25 kV / mm, and more preferably 15 to 22 kV / mm. The dielectric breakdown strength is measured according to ASTM D149.
The refractive index of the fluorinated polymer (a) is preferably 1.2 to 2 from the viewpoint of reducing the difference in refractive index from the substrate, suppressing light interference due to birefringence and the like, and ensuring transparency. 2-1.5 is more preferable.

The weight average molecular weight (Mw) of the fluoropolymer (a) is preferably 50,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, and particularly preferably 250,000 or more. When Mw is 50,000 or more, film formation is easy. In particular, when it is 200,000 or more, the heat resistance of the film is improved, and the thermal stability of the retained charge is improved when an electret is formed. On the other hand, if Mw is too large, it is difficult to dissolve in a solvent, and there is a possibility that problems such as limitation of the film forming process may occur. Therefore, Mw of the fluoropolymer (a) is preferably 1 million or less, more preferably 850,000 or less, further preferably 650,000 or less, and particularly preferably 550,000 or less.
In the present specification, Mw of the fluorine-containing polymer (a) is the chemical journal of the Chemical Society of Japan, 2001, NO. 12, p. It is a value calculated using the relational expression ([η] = 1.7 × 10 ⁻⁴ × Mw ^0.60 ) between Mw and intrinsic viscosity [η] (30 ° C.) described in 661.
Intrinsic viscosity [η] (30 ° C.) (unit: dl / g) is a value measured by an Ubbelohde viscometer at 30 ° C. using perfluoro (2-butyltetrahydrofuran) as a solvent.

As the fluoropolymer (a), one synthesized by polymerizing the above-described monomers may be used, or a commercially available product may be used.
CYTOP (registered trademark, manufactured by Asahi Glass Co., Ltd.) is a commercially available fluoropolymer having a fluorine-containing aliphatic ring containing an etheric oxygen atom in the main chain and having a carboxy group or an alkoxycarbonyl group at the end of the main chain. Is mentioned.

[Material (a ′)]
As the material (a ′), as described above, a mixture of the fluoropolymer (a) and other components other than the fluoropolymer (a), the fluoropolymer (a) and the fluoropolymer ( Reaction products with other components other than a) and the like can be mentioned.
As the reaction product, for example, when the coating liquid in which the fluoropolymer (a) and the other components are dissolved in a solvent is heated (e.g., when the solvent is evaporated to form a film), each component is What is produced | generated by reacting is mentioned.
As other components to be mixed or reacted with the fluoropolymer (a), a silane coupling agent or a polyvalent polar compound is preferable, and a silane coupling agent is particularly preferable. As a result, the charge retention performance (thermal stability of the retained charge, stability over time, etc.) of the formed resin film (A) is improved. The effect of improving the charge retention performance is particularly remarkable when the fluoropolymer (a) has a carboxy group or an alkoxycarbonyl group as a terminal group.
The effect of improving the charge retention performance is that the fluoropolymer (a) and the silane coupling agent or polypolar compound cause nanophase separation, and a nanocluster structure derived from the silane coupling agent or polypolar compound is formed. The nanocluster structure is presumed to function as a site for storing charges in the electret.
In the material (a ′), the silane coupling agent or the polyvalent polar compound may be present in a state in which molecules react with each other.

It does not specifically limit as a silane coupling agent, It can utilize over a wide range including a conventionally well-known or well-known thing.
As the silane coupling agent, a silane coupling agent having an amino group is preferable.
Considering availability, etc., particularly preferred silane coupling agents are γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, and N- (β-aminoethyl) -γ-aminopropyltriethoxy One or more selected from silane.

A silane coupling agent may be used individually by 1 type, and may use 2 or more types together.
0.1-20 mass% is preferable with respect to the total amount of a fluoropolymer (a) and a silane coupling agent, and, as for the compounding quantity of a silane coupling agent, 0.3-10 mass% is more preferable, 0.5-5 mass% is the most preferable. When it is in this range, when it is dissolved in a solvent together with the fluoropolymer (a) to form a coating solution, a uniform solution can be easily obtained.

The polyvalent polar compound is preferably a compound having a molecular weight of 50 to 2,000 having two or more polar functional groups (excluding the silane coupling agent). The molecular weight is more preferably 100 to 2,000. When the molecular weight of the polyvalent polar compound is not less than the lower limit of the above range, the molecular weight is high, so that it is difficult to volatilize and it is easy to remain in the film after film formation. Moreover, compatibility with a fluoropolymer (a) becomes favorable as it is below the upper limit of the said range.
The “polar functional group” is a functional group having one or both of the following properties (1a) and (1b).
(1a) Two or more types of atoms having different electronegativity are included, and the functional group has polarity due to polarization.
(1b) Polarization is caused by the difference in electronegativity with carbon bonded to the functional group.

Specific examples of the polar functional group having only the above characteristic (1a) include a hydroxyphenyl group.
Specific examples of the polar functional group having only the characteristic (1b) include a primary amino group (—NH ₂ ), a secondary amino group (—NH—), a hydroxyl group, and a thiol group.
Specific examples of the polar functional group having both the above characteristics (1a) and (1b) include sulfo group, phosphono group, carboxyl group, alkoxycarbonyl group, acid halide group, formyl group, isocyanate group, cyano group, carbonyl group. And an oxy group (—C (O) —O—) carbonate group (—O—C (O) —O—).

  Examples of the polyvalent polar compound include pentane-1,5-diamine, hexane-1,6-diamine, cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, cyclohexane-1,4-diamine, and 1,2. -Diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, triaminomethylamine, tris (2-aminoethyl) amine, tris (3-aminopropyl) amine, cyclohexane-1,3,5-triamine , Cyclohexane-1,2,4-triamine, 1,3,5-triaminobenzene, 1,2,4-triaminobenzene, 2,4,6-triaminotoluene, 1,3,5-tris (2 -Aminoethyl) benzene, 1,2,4-tris (2-aminoethyl) benzene, 2,4,6-tris (2-aminoethyl) to More preferred is at least one selected from the group consisting of ene, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and polyethyleneimine, and tris (2-aminoethyl) amine, tris (3-aminopropyl) amine, cyclohexane-1, Most preferred is at least one selected from the group consisting of 3-diamine, hexane-1,6-diamine, diethylenetriamine and polyethyleneimine.

A polyvalent polar compound may be used individually by 1 type, and may use 2 or more types together. For example, a compound having two polar functional groups and a compound having three or more polar functional groups may be mixed and used.
The blending amount of the polyvalent polar compound is preferably 0.01 to 30% by weight, more preferably 0.05 to 10% by weight, based on the blending amount of the fluoropolymer (a). The effect by mix | blending a polyvalent polar compound as this compounding quantity is 0.01 mass% or more is fully acquired. When the blending amount is 30% by mass or less, the miscibility with the fluoropolymer (a) is good, and the distribution in the coating liquid becomes uniform.

<Method for Forming Resin Film (A)>
It does not specifically limit as a formation method of a resin film (A), A well-known method can be utilized. For example, a coating film is formed on the surface of the first substrate 13 on which the first electrode 11 is formed on the first electrode 11 side, and the coating film is patterned into a pattern corresponding to the first electrode 11. The method of doing is mentioned.
As a method for forming the coating film, for example, a coating solution obtained by dissolving the fluoropolymer (a) in a solvent, or the fluoropolymer (a) and other components other than the fluoropolymer (a) There is a method of forming a coating film using a coating solution obtained by dissolving in a solvent. As said other component, as above-mentioned, a silane coupling agent or a polyvalent polar compound is preferable, and a silane coupling agent is especially preferable.

As the solvent, a solvent that dissolves at least the fluoropolymer (a) is used, and when it contains other components, the solvent that dissolves the fluoropolymer (a) dissolves the other components. If present, the solvent alone can be a uniform solution. Moreover, you may use together the other solvent which melt | dissolves this other component.
Specific examples of the solvent include a protic solvent, an aprotic solvent, and the like, and a solvent that dissolves a component to be blended in the coating liquid may be appropriately selected.
The “protic solvent” is a solvent having a proton donating property. An “aprotic solvent” is a solvent that does not have proton donating properties.

Examples of the protic solvent include the following protic non-fluorinated solvents and protic fluorinated solvents.
Methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, t-butanol, pentanol, hexanol, 1-octanol, 2-octanol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene Protic non-fluorinated solvents such as glycol monobutyl ether, propylene glycol, and methyl lactate.
Protic fluorine-containing solvents such as 2- (perfluorooctyl) ethanol and other fluorine-containing alcohols, fluorine-containing carboxylic acids, amides of fluorine-containing carboxylic acids, and fluorine-containing sulfonic acids.

Examples of the aprotic solvent include the following aprotic non-fluorinated solvents and aprotic fluorinated solvents.
Hexane, cyclohexane, heptane, octane, decane, dodecane, decalin, acetone, cyclohexanone, 2-butanone, dimethoxyethane, monomethyl ether, ethyl acetate, butyl acetate, diglyme, triglyme, propylene glycol monomethyl ether monoacetate (PGMEA), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), N-methylpyrrolidone, tetrahydrofuran, anisole, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, dichlorobenzene, benzene, toluene, xylene, ethylbenzene, Aprotic non-fluorine-containing solvents such as mesitylene, tetralin and methylnaphthalene.

  Polyfluoroaromatic compounds such as 1,4-bis (trifluoromethyl) benzene, polyfluorotrialkylamine compounds such as perfluorotributylamine, polyfluorocycloalkane compounds such as perfluorodecalin, perfluoro (2-butyltetrahydrofuran) Aprotic fluorine-containing solvents such as polyfluoro cyclic ether compounds such as), perfluoropolyethers, polyfluoroalkane compounds, and hydrofluoroethers (HFE).

Any one of these solvents may be used alone, or two or more thereof may be mixed and used. In addition to these, a wide range of compounds can be used.
Among these, the solvent used for dissolving the fluoropolymer (a) is preferably an aprotic fluorine-containing solvent because the solubility of the fluoropolymer (a) is large and a good solvent.
The solvent for dissolving the silane coupling agent or the polyvalent polar compound is preferably a protic fluorine-containing solvent.
The boiling point of the solvent is preferably 65 to 220 ° C., and preferably 100 to 220 ° C., because a uniform film can be easily formed during coating.

The solvent used for preparing the coating liquid preferably has a low water content. The moisture content is preferably 100 mass ppm or less, and more preferably 20 mass ppm or less.
The concentration of the fluoropolymer (a) in the coating liquid is preferably from 0.1 to 30% by mass, and more preferably from 0.5 to 20% by mass.
What is necessary is just to set the solid content concentration of a coating liquid suitably according to the film thickness to form. Usually, it is 0.1-30 mass%, and 0.5-20 mass% is preferable.
The solid content is calculated by heating the coating liquid whose mass was measured at 200 ° C. for 1 hour under normal pressure to distill off the solvent and measuring the mass of the remaining solid content.

The coating liquid may be obtained by preparing a composition containing each component in advance and dissolving it in a solvent, or by dissolving each component in a solvent and mixing each solution.
As a method for producing the composition in the case of preparing a composition containing each component in advance, the solid and the solid, or the solid and the liquid may be mixed by kneading, eutectic extrusion, etc. Each solution dissolved in may be mixed. Among these, it is more preferable to mix each solution.
For example, when the fluoropolymer (a) and a silane coupling agent are used in combination, the coating liquid comprises a polymer solution obtained by dissolving the fluoropolymer (a) in an aprotic fluorine-containing solvent, and a silane coupling agent. A silane coupling agent solution dissolved in a protic fluorine-containing solvent is preferably prepared, and the polymer solution and the silane coupling agent solution are preferably mixed.

The coating film can be formed, for example, by coating the surface of the substrate with a coating liquid and drying it by baking or the like.
As the coating method, a conventionally known method for forming a film from a solution can be used and is not particularly limited. Specific examples of such a method include a spin coating method, a roll coating method, a casting method, a dipping method, a water casting method, a Langmuir-Blodget method, a die coating method, an ink jet method, and a spray coating method. Printing techniques such as letterpress printing, gravure printing, lithographic printing, screen printing, and flexographic printing can also be used.
Drying may be performed by air drying at normal temperature, but is preferably performed by heating and baking. The baking temperature is preferably equal to or higher than the boiling point of the solvent, and particularly at a high temperature of 230 ° C. or higher, the reaction between the added silane coupling agent or polyvalent polar compound and the fluoropolymer (a) is sufficiently performed. It is particularly preferable in terms of completion.

The patterning method for the coating film is not particularly limited, and a known patterning technique can be used.
As a specific example, there is a method of forming a mask having a predetermined pattern on the coating film and performing etching.
The mask can be formed, for example, by the same method as that for the first electrode 11. However, the material constituting the mask only needs to have a certain etching selectivity with respect to the coating film, and may not be a conductive material. For example, a resist film patterned in a pattern corresponding to the first electrode 11 may be used as the mask. The resist film can be patterned by a known lithography method.

<Injection of charge>
The electret 12 can be formed by injecting electric charge into the resin film (A).
As a method for injecting electric charge, any method can be used as long as it is a method for charging an insulator. For example, the corona discharge method described in GMSessler, Electrets Third Edition, pp20, Chapter 2.2 “Charging and Polarizing Methods” (Laplacian Press, 1998), electron beam collision method, ion beam collision method, radiation irradiation method, light irradiation method, A contact charging method, a liquid contact charging method, or the like is applicable. In the present invention, it is particularly preferable to use a corona discharge method or an electron beam collision method.
The temperature condition for injecting the charge is maintained after the injection at a temperature equal to or higher than the glass transition temperature (Tg) of the fluoropolymer (a) or the material (a ′) contained in the resin film (A). It is preferable from the viewpoint of charge stability, and it is particularly preferable to carry out under a temperature condition of about Tg + 10 ° C. to Tg + 20 ° C.
As an applied voltage at the time of injecting electric charges, it is preferable to apply a high voltage as long as it is not higher than the dielectric breakdown voltage of the resin film (A). In the present invention, the applied voltage to the resin film (A) is 6 to 30 kV, preferably 8 to 15 kV for a positive charge, and -6 to -30 kV, preferably -8 to -15 kV for a negative charge.
Since the fluoropolymer (a) or the material (a ′) can hold a negative charge more stably than a positive charge, the applied voltage is preferably a negative charge. In this case, the surface potential of the electret 12 is negative.

Here, an example in which the resin film (A) is directly formed on the first electrode 11 of the first substrate 13 having the first electrode 11 formed on the surface and the charge is injected has been shown. The manufacturing method of 12 is not limited to this. For example, after the resin film (A) is formed on an arbitrary substrate and peeled off from the substrate, the resin film (A) is disposed on the first substrate 13 on the surface of which the first electrode 11 is formed. It is good. Moreover, after forming the resin film (A) on an arbitrary substrate and injecting electric charge into the electret 12, the electret 12 was peeled from the substrate, and the first electrode 11 was formed on the surface thereof. You may arrange | position on the 1st board | substrate 13. FIG.
In the case where the resin film (A) is formed on a substrate different from the first substrate 13 and no charge is injected on the substrate, the substrate can be used without any particular material. .
When the resin film (A) is formed on a substrate different from the first substrate 13 and the charge is injected on the substrate, the substrate is used when the charge is injected into the obtained laminate. A substrate that can be connected to ground is used. Preferred materials include, for example, conductivity such as gold, silver, copper, nickel, chromium, aluminum, titanium, tungsten, molybdenum, tin, cobalt, palladium, platinum, and an alloy containing at least one of these as a main component. These metals are mentioned. The substrate is made of an insulating material other than a conductive metal, for example, an inorganic material such as glass, a polymer compound material such as polyethylene terephthalate, polyimide, polycarbonate, or acrylic resin (insulating substrate). In addition, a metal film or a metal oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), zinc oxide, titanium dioxide, or tin oxide by a method such as sputtering, vapor deposition, or wet coating on the surface; polyaniline, polypyrrole , PEDOT / PSS, an organic conductive material made of carbon nanotubes, or the like may be used. Further, a semiconductor material such as silicon can be used as a substrate if the same surface treatment is performed or the semiconductor material itself has a low resistance value. The resistance value of the substrate material is preferably 0.1 Ωcm or less, more preferably 0.01 Ωcm or less, in terms of volume resistivity. With such a low resistance substrate material, it is possible to produce an electret by injecting a charge as it is into the laminate formed on the substrate.

As mentioned above, although the structure of the aerial cable monitoring system of this invention was demonstrated using FIGS. 1-8, this invention is not limited to this.
For example, in the above embodiment, a processing device (server) that performs data processing (recording, analysis, etc.) is provided separately from the receiving device (relay node 110, gateway 120) that receives data wirelessly transmitted from the sensor node 100. Although the example provided is shown, the present invention is not limited to this, and a reception device having the function of a processing device may be used.
The communication unit 103 of the sensor node 100 may also have a reception function. This function enables two-way communication, and it is possible to change a sensing condition (for example, a threshold for determining abnormality) from the processing device (server).
Further, although an example of a star-type network structure in which a plurality of sensor nodes 100 are arranged around one relay node 110 is shown, a network structure that synchronizes the sensor nodes 100 may be used. In this case, hopping communication between the sensor nodes is possible, thereby reducing the number of relay nodes 110. Alternatively, a more reliable system can be constructed by using a mesh type network structure.

The configuration of the sensor node provided in the aerial cable monitoring system of the present invention is not limited to the configuration of the sensor node 100 shown in the above embodiment. For example, the vibration power generator 1 is a known electrostatic induction vibration generator, except that an electrostatic induction power generation element is used which includes an electret containing a fluoropolymer (a) or a material (a ′). The configuration can be appropriately adopted.
For example, in the above embodiment, the relative movement between the electret 12 and the second electrode 21 is realized by the vibration of the first substrate 13, but is not limited thereto. For example, the first substrate 13 and the second substrate 22 may be interchanged so that the second substrate 22 vibrates.
Moreover, in this embodiment, although the electret 12 showed the example which coat | covers the upper surface of the 1st electrode 11, this invention is not limited to this, The electret 12 coat | covers the upper surface and side surface of the 1st electrode 11. May be.

Further, the first electrode and the second electrode are pattern electrodes (first electrode 11 and second electrode 21) each formed in a comb-shaped pattern, and the resin film (A) constituting the electret is Although the pattern film formed by the pattern corresponding to the comb-tooth portion of the first electrode 11, that is, the pattern formed by the pattern in which a plurality of lines are arranged in parallel is shown, the present invention is not limited to this. .
For example, the first electrode, the second electrode, and the electret may be formed in other patterns. As the other pattern, for example, the shape of a pattern electrode conventionally used for an electrostatic induction power generation element can be appropriately employed. Examples of shapes other than the comb shape and the line shape include a ring shape and a checkered pattern. The number of pattern electrodes and pattern films formed on the substrate surface may be one or plural, respectively.
The first electrode, the second electrode, and the electret may not be patterned, and may cover the entire surfaces of the first substrate 13 and the second substrate 22, respectively.

In the said embodiment, the 1st board | substrate 13 and the 2nd board | substrate 22 were respectively flat surfaces, and the example in which the 1st electrode 11 and the 2nd electrode 21 were each formed in the surface was shown. However, as the first substrate 13 or the second substrate 22, a substrate having irregularities formed on the surface may be used. For example, as the second substrate 22, a substrate having a surface with uneven patterns corresponding to the second electrode 21 may be used. The substrate may be provided with other pattern irregularities.
As a method for producing a substrate having a surface with unevenness, a conventionally known method such as a vacuum process or a wet process can be used, and is not particularly limited. Examples of the vacuum process include a sputtering method through a mask and a vapor deposition method through a mask. Examples of the wet process include a roll coater method, a cast method, a dipping method, a spin coat method, a water cast method, a Langmuir / Blodget method, a die coat method, an ink jet method, and a spray coat method. Printing techniques such as letterpress printing, gravure printing, lithographic printing, screen printing, and flexographic printing can also be used. Furthermore, examples of a method for manufacturing a substrate having fine unevenness on the surface include a nanoimprint method and a photolithography method.

  A guard electrode may be formed between the plurality of comb-tooth portions of the first electrode 11. When the second electrode 21 in which electrostatic induction has occurred by facing the electret 12 faces the guard electrode when the relative position fluctuates, a change in potential generated in the second electrode 21 increases. The amount of power generation increases. For the same reason, a guard electrode may be formed between the plurality of comb-tooth portions of the second electrode 21. The guard electrode can be formed in the same manner as the first electrode 11. The guard electrode is usually grounded.

  DESCRIPTION OF SYMBOLS 1 ... Vibration generator, 2 ... Power control circuit, 3 ... Electrostatic induction type power generation element, 4 ... Power conversion circuit part, 5 ... Power storage part, 6 ... Case, 10 ... Movable electrode part, 11 ... First electrode , 12 ... electret, 13 ... first substrate, 14 ... frame member, 15 ... spring member, 20 ... fixed electrode portion, 21 ... second electrode, 22 ... second substrate, 23 ... fixed member, 41 ... rectification Circuit, 42 ... Voltage conversion circuit, 100 ... Sensor node, 101 ... Power supply unit, 102 ... Sensor, 103 ... Communication unit, 104 ... Antenna, 105 ... Control unit, 110 ... Relay node, 120 ... Gateway, 200 ... Aerial cable

Claims (7)

An aerial cable monitoring system comprising a plurality of sensor nodes that are installed in an aerial cable, detect information indicating the status of the aerial cable, and wirelessly transmit the information, and a receiving device that receives information wirelessly transmitted from the sensor node Because
The sensor node includes a vibration power generator as an independent power source,
The vibration power generator includes a first electrode, an electret provided on the first electrode, and a second electrode spaced apart from the electret, and the electret and the first by vibration of an aerial cable. Comprising an electrostatic induction power generating element configured such that one of the two electrodes moves relative to the other;
The electret is formed by injecting electric charge into a fluoropolymer (a) having an aliphatic ring in the main chain or a resin film containing a material (a ′) derived from the fluoropolymer (a). An aerial cable monitoring system characterized by being.   The aerial according to claim 1, wherein one of the electret and the second electrode is arranged parallel to the other and configured to reciprocate in a vertical direction toward a center direction of the aerial cable. Cable monitoring system.   The aerial cable monitoring system according to claim 1, wherein a plurality of the electrostatic induction power generation elements are installed on an outer periphery of the aerial cable.   The aerial cable monitoring system according to any one of claims 1 to 3, wherein the information indicating the status of the aerial cable is at least one selected from temperature, vibration, and acceleration.   The aerial cable monitoring system according to claim 1, wherein the aerial cable is a communication cable or a power transmission line.   The aerial cable monitoring system according to any one of claims 1 to 5, wherein the fluoropolymer (a) has a carboxy group or an alkoxycarbonyl group as a terminal group.   The fictive according to any one of claims 1 to 6, wherein the material (a ') includes a mixture or a reaction product of the fluoropolymer (a) and a silane coupling agent having an amino group. Cable monitoring system.

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