JP5859370B2 - Energy conversion element and manufacturing method thereof - Google Patents

Description

  The present invention relates to an energy conversion element that converts mechanical energy into electrical energy, and a method for manufacturing the same, and more particularly to an energy conversion element that converts vibration energy of a vibration source having a large strain amount, such as a tire, into electrical energy. , And its manufacturing method.

  Conventionally, piezoelectric materials such as piezoelectric ceramics such as lead zirconate titanate (PZT), piezoelectric polymers such as PVDF (polyvinylidene fluoride), single crystals such as quartz (quartz), lithium niobate, etc. have been used for electrical energy. It is used in various piezoelectric sensors that convert energy, and conversely, various piezoelectric actuators that convert electrical energy into mechanical energy. Piezoelectric materials are also used in power generation elements that convert vibration energy such as tires into electrical energy. Currently, various types using the above-described piezoelectric materials have been proposed (see, for example, Patent Documents 1 and 2).

The dielectric rubber laminate of Patent Document 1 is obtained by providing electrode layers on the front and back surfaces of a dielectric rubber layer having a thickness of 10 to 200 μm. The dielectric rubber layer contains a dielectric filler having a relative dielectric constant of 200 or more, and the dielectric rubber layer itself has a relative dielectric constant of 5 to 30. In order to align the direction of spontaneous polarization of the dielectric filler dispersed in the dielectric rubber layer, electret treatment for applying a DC high voltage is performed. As a result, the power generation function is improved.
Examples of the high dielectric filler include barium titanate, lead zirconate titanate (PZT), lanthanum-doped lead zirconate titanate (PLZT), strontium titanate, lead titanate, bismuth titanate, and bismuth barium titanate. It has been.

Patent Document 2 discloses a multilayer capacitor, an ink jet recording head, a magnetic recording / reproducing head, a MEMS (Micro Electro-Mechanical Systems) device, a micro pump, a piezoelectric actuator mounted on an ultrasonic probe, and the like. An element is described.
The multilayer element includes a multilayer body in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked, and a pair of external electrodes formed on a side surface of the multilayer body. These external electrodes are alternately connected to each other, and are formed of a metal layer in which a pair of external electrodes and an internal electrode layer connected to each external electrode are continuous. The dielectric layer is a composite layer in which ceramic powder is dispersed in a resin mainly composed of cyanoethylated pullulan.

JP 2008-53527 A JP 2012-15152 A

  When a conventional piezoelectric material is attached to a vehicle tire and used to convert the vibration energy of the tire vibration generated during traveling into electrical energy, the amount of distortion generated with the vibration of the traveling vehicle tire is large. When the piezoelectric material is broken or peeled off from the tire, vibration energy may not be converted into electric energy. Further, the conventional piezoelectric material has a problem that deterioration with time occurs when the strain amount is large.

  In the dielectric rubber laminate of Patent Document 1 described above, the piezoelectric material is dispersed in the rubber. However, the rubber containing no resin alone is too soft, the particles are not loaded, and the power generation amount may be insufficient. is there. Further, even when the laminated element of Patent Document 2 is applied to a tire of a traveling vehicle, if the amount of distortion caused by the vibration of the traveling vehicle tire is large, the durability becomes low and the electrical energy is stable. There is a problem that it cannot be converted.

  An object of the present invention is to provide an energy conversion element that can stably convert mechanical energy into electrical energy even when the amount of strain is large, and a method for manufacturing the same.

  In order to achieve the above object, the present invention provides an energy conversion element for converting mechanical energy into electrical energy, and comprising a composite in which piezoelectric particles are uniformly dispersed and mixed in a matrix layer containing a resin and rubber. And the composite is provided with an energy conversion element characterized by being subjected to peroxide crosslinking treatment.

In this case, the resin preferably has a continuous heat resistant temperature of 160 ° C. or lower. The resin is, for example, a cyanoethyl resin. The rubber is, for example, nitrile butadiene rubber or silicon rubber, and preferably has a relative dielectric constant of 10 to 30.
The nitrile butadiene rubber is preferably contained in a mass ratio of 1% to less than 80% with respect to the cyanoethyl resin.
The silicon rubber is preferably contained in a mass ratio of 1% or more and less than 60% with respect to the cyanoethyl resin.
For example, the piezoelectric particles are made of particles having a perovskite crystal structure. In this case, the particles are preferably composed of lead zirconate titanate, lead lanthanum zirconate titanate, barium titanate, a solid solution of barium titanate and bismuth ferrite, or a relaxor piezoelectric material.

The composite is preferably formed with a stretchable conductive base material or conductive rubber base material. For example, a stretchable conductive substrate is composed of a composite composed of an organic polymer and conductive fine particles, and the conductive fine particles include C, Pd, Fe, Sn, Al, Ni, Pt, and Au. , Ag, Cu, Cr or Mo or an alloy thereof.
The composite is installed in, for example, a vibration source, and the mechanical energy is the vibration energy of the vibration source. The vibration source is, for example, a tire.

The present invention also includes a step of dissolving a resin and rubber in an organic solvent and dispersing piezoelectric particles in the organic solvent to obtain a coating solution containing piezoelectric particles, and applying the coating solution containing piezoelectric particles on a support substrate. Evaporating the organic solvent to obtain a film body to be a matrix layer, subjecting the film body to a peroxide crosslinking treatment, and obtaining a composite in which piezoelectric particles are uniformly dispersed and mixed in the matrix layer. The manufacturing method of the energy conversion element characterized by this is provided.
Furthermore, it is preferable to have a step of subjecting the composite to polarization treatment.

For example, the resin has a continuous heat resistance temperature of 160 ° C. or lower, and the peroxide crosslinking treatment is performed at 150 ° C. or lower. The resin is, for example, a cyanoethyl resin.
The rubber is, for example, nitrile butadiene rubber or silicon rubber, and preferably has a relative dielectric constant of 10 to 30.

The nitrile butadiene rubber is preferably contained in a mass ratio of 1% to less than 80% with respect to the cyanoethyl resin.
The silicon rubber is preferably contained in a mass ratio of 1% or more and less than 60% with respect to the cyanoethyl resin.
For example, the piezoelectric particles are made of particles having a perovskite crystal structure. In this case, the particles are preferably composed of lead zirconate titanate, lead lanthanum zirconate titanate, barium titanate, a solid solution of barium titanate and bismuth ferrite, or a relaxor piezoelectric material.

  The composite is preferably formed with a stretchable conductive base material or conductive rubber base material. For example, a stretchable conductive substrate is composed of a composite composed of an organic polymer and conductive fine particles, and the conductive fine particles include C, Pd, Fe, Sn, Al, Ni, Pt, and Au. , Ag, Cu, Cr or Mo or an alloy thereof.

According to the energy conversion element of the present invention, the vibration energy of a tire, which is a kind of mechanical energy, is converted into electric energy even when the amount of distortion generated by vibration of a tire of a traveling vehicle is large. Can do. In addition, mechanical energy such as vibration energy having a large amount of distortion can be stably converted into electric energy without a decrease in the generated voltage with time.
According to the method for manufacturing an energy conversion element of the present invention, an energy conversion element having the above-described performance can be manufactured.

It is typical sectional drawing which shows the energy conversion element of embodiment of this invention. It is typical sectional drawing which shows an example of the usage condition of the energy conversion element of embodiment of this invention. (A) is a schematic diagram which shows an example of the polling (polarization process) method used for manufacture of the energy conversion element of embodiment of this invention, (b) is a schematic diagram which shows an example of a polling (polarization process) method. FIG. It is a schematic diagram which shows the other example of the poling (polarization process) method used for manufacture of the energy conversion element of embodiment of this invention. It is a graph which shows the waveform of the voltage which generate | occur | produces in an energy conversion element with the example of a waveform of 3% of distortion, and the waveform of 3% of distortion. It is a graph which shows the maximum value of the voltage which generate | occur | produces when adding distortion amount 1% and distortion amount 3% continuously, in a time series.

Below, based on the preferred embodiment shown in an accompanying drawing, the energy conversion element of the present invention and its manufacturing method are explained in detail.
FIG. 1 is a schematic cross-sectional view showing an energy conversion element according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a usage pattern of the energy conversion element of the embodiment of the present invention.

The energy conversion element 10 shown in FIG. 1 converts mechanical energy into electrical energy, and is bonded to the vibration source 12 via an adhesive layer 14, for example. The mechanical energy is vibration energy, for example.
The energy conversion element 10 includes a composite 20, a lower electrode 22 connected to the lower surface 20 b of the composite 20, and an upper electrode 24 connected to the upper surface 20 a of the composite 20.
The composite 20 functions as a power generation member, and converts the mechanical energy of the vibration source 12 into electrical energy. The electrical energy obtained by conversion by the composite 20 is led out to the outside by the lower electrode 22 and the upper electrode 24.

  The vibration source 12 vibrates with a relatively large strain amount, for example, a strain amount of about 5%, and supplies the vibration energy to the energy conversion element 10 of the present invention as mechanical energy. The vibration source 12 has an upper surface 12a bonded to the energy conversion element 10 via the adhesive layer 14 in a direction parallel to the vibration direction indicated by an arrow a in the figure, and has, for example, a strain amount of about 5%. If there is, it will not be specifically limited. For example, examples of the vibration source 12 include various tires, floors, building dampers, vehicles such as automobiles, particularly suspensions, bridges, highways, waves, and the like.

  As the vibration source 12, a tire can be used as described above, and specifically, the tire 16 shown in FIG. 2 can be used. In this case, the energy conversion element 10 is provided via the adhesive layer 14 in the inside 16 b of the tire 16 corresponding to the inside of the tread portion 16 a of the tire 16. The electric power generated by the energy conversion element 10 can be used for, for example, a sensor that measures the temperature, air pressure, and the like of the inside 16b of the tire 16, and a transmitter that transmits the measurement result of the sensor to an external device.

The adhesive layer 14 is for joining the upper surface 12a of the vibration source 12 and the lower electrode 22, and an adhesive or the like is used.
The adhesive used for the adhesive layer 14 is not particularly limited as long as the energy conversion element 10 does not peel from the vibration source 12 due to vibration of the vibration source 12. Further, the thickness of the adhesive layer 14, that is, the thickness of the adhesive applied to the bonding surface may be any thickness, and the adhesive strength is not particularly limited. For the adhesive layer 14, an adhesive such as an epoxy adhesive or an acrylic adhesive is used.

The composite 20 of the energy conversion element 10 is obtained by uniformly dispersing and mixing piezoelectric particles 32 in a matrix layer 30.
The matrix layer 30 contains a resin and rubber and has been subjected to peroxide crosslinking treatment. The matrix layer 30 may include an inorganic material in addition to the resin and rubber.

  Resins constituting the matrix layer 30 are, for example, polypropylene resin, polyamide resin, fluorine resin (Teflon (registered trademark)), phenol resin, melamine / formaldehyde resin, silicone resin, diallyl phthalate resin, cyanoethyl resin, furan. Resin, xylene resin, epoxy resin, polyester resin and the like.

As described above, the matrix layer 30 has been subjected to peroxide crosslinking treatment. Of the resins constituting the matrix layer 30, the continuous heat resistance temperature of the soft and flexible resin having a high dielectric constant is often 160 ° C. or less. Since peroxide crosslinking is performed at 130 ° C. to 160 ° C., it is possible to perform crosslinking while determining the continuous heat-resistant temperature range of the resin, and improve mechanical properties and durability of the composite 20 thereafter. be able to. Further, since the dielectric constant of the resin is high, poling is facilitated, and the electrical characteristics of the composite 20 are improved.
On the other hand, in general sulfur bridge | crosslinking etc., since the crosslinking temperature of 160-200 degreeC or more is required, the said resin will raise | generate and the function as the composite_body | complex 20 cannot be exhibited.

Among the above-mentioned resins, resins having a continuous heat resistant temperature of 160 ° C. or lower are cyanoethyl resins, furan resins, xylene resins, epoxy resins, and polyester resins. In addition to the peroxide crosslinking treatment, when performing poling (polarization treatment), the resin constituting the matrix layer 30 is more preferably a cyanoethyl resin. The cyanoethyl resin is cyanoethylated polyvinyl alcohol (hereinafter also referred to as cyanoethylated PVA), cyanoethylated pullulan, cyanoethylated cellulose, or the like.
Here, the continuous heat-resistant temperature is an upper limit temperature defined by “the upper limit value of the operating temperature of the organic material” according to the Electrical Appliance and Material Safety Law.
In general sulfur cross-linking, the electrical characteristics of the composite 20 deteriorate due to the influence of vulcanization-specific auxiliary agents such as zinc oxide. Further, the resin often has a continuous heat resistance temperature of 160 ° C. or less, and sulfur crosslinking and the like that require 160 ° C. to 200 ° C. or more are often not suitable. On the other hand, peroxide crosslinking can be crosslinked at a low temperature and requires less additive, and therefore has less influence on the electrical properties of the composite 20.

As the rubber constituting the matrix layer 30, for example, nitrile butadiene rubber (NBR) or silicon rubber is used.
The rubber preferably has a relative dielectric constant of 10-30. If the relative dielectric constant of the rubber is less than 10, sufficient generated voltage may not be obtained. If the relative dielectric constant is 10 or more, sufficient poling can be performed. On the other hand, there is no rubber having a relative dielectric constant exceeding 30.

  When nitrile butadiene rubber is used as the rubber constituting the matrix layer 30 and cyanoethyl resin is used as the resin constituting the matrix layer 30, the nitrile butadiene rubber is 1% or more and less than 80% by mass ratio with respect to the cyanoethyl resin. It is preferable to contain. By containing the nitrile butadiene rubber in a mass ratio of 1% to less than 80% with respect to the cyanoethyl resin, a large generated voltage can be obtained even when the amount of strain is large. When the weight ratio of nitrile butadiene rubber is 80% or more, the matrix is soft and it is difficult to apply a load to the piezoelectric particles. Therefore, the decrease in generated voltage becomes significant. For example, the driving voltage of a standard circuit IC is 3V, which is likely to be lower than that, and the practicality becomes low.

  Further, when silicon rubber is used as the rubber constituting the matrix layer 30 and cyanoethyl resin is used as the resin constituting the matrix layer 30, the silicon rubber is 1% or more and less than 60% in mass ratio with respect to the cyanoethyl resin. It is preferable to contain. Silicon rubber, for example, has a dielectric constant lower than that of nitrile butadiene rubber, and if the silicone rubber has a mass ratio of 60% or more, poling becomes difficult, so the characteristics of the composite 20 are deteriorated. Therefore, by containing silicon rubber in a mass ratio of 1% to less than 60% with respect to the cyanoethyl resin, a large generated voltage can be obtained even when the amount of strain is large.

The piezoelectric particles 32 are made of particles having a perovskite crystal structure, for example. The particles constituting the piezoelectric particles 32 are, for example, lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), barium titanate (BaTiO ₃ ), sodium potassium niobate (KNN), titanate. It is composed of sodium bismuth (BNT), potassium bismuth titanate (BKT), a solid solution (BFBT) of barium titanate and bismuth ferrite (BiFeO ₃ ), or a relaxor piezoelectric material. As the relaxor piezoelectric material, for example, Pb (Mg, Nb) -PT, Pb (Ni, Nb) -PT, Pb (Zn, Nb) -PT, PMN-PZT, PNN-PZT, and the like are used. .
The particles constituting the piezoelectric particles 32 may be composed of ceramic particles. In this case, the ceramic particles may be single crystal particles or core-shell structured particles.

The lower electrode 22 and the upper electrode 24 are particularly limited as long as they can be electrically connected to the composite 20 and the electrical connection is not broken by the distortion of the composite 20 due to the vibration of the vibration source 12. is not. Various conductive materials such as metal materials such as gold, silver, copper, and aluminum, and conductive rubber can be used.
Further, it may be conductive so that a predetermined voltage can be applied to the composite 20 during the polarization treatment. In this case, the lower electrode 22 and the upper electrode 24 are, for example, C, Pd, Fe, Sn, Al, Ni, Pt, Au, Ag, Cu, Cr, Mo or the like or an alloy thereof can be used.

  The lower electrode 22 and the upper electrode 24 can be formed by, for example, a vapor deposition method such as a vacuum deposition method and a sputtering method, and a printing method such as screen printing and an inkjet method. Further, the lower electrode 22 and the upper electrode 24 are foil-like materials made of the above-mentioned C, Pd, Fe, Sn, Al, Ni, Pt, Au, Ag, Cu, Cr, Mo, etc., or alloys thereof. Also good.

The energy conversion element 10 is excellent in flexibility because the matrix layer 30 contains a resin and rubber. For this reason, it is preferable that the lower electrode 22 and the upper electrode 24 are also flexible. In this case, the lower electrode 22 and the upper electrode 24 are formed of, for example, a stretchable conductive base material, a conductive rubber base material, or a conductive elastomer base material.
When the lower electrode 22 and the upper electrode 24 are formed of a conductive rubber base material or a conductive elastomer base material, for example, the upper surface 20a and the lower surface 20b of the composite 20 are electrically conductive at a temperature equal to or higher than the softening temperature of the matrix layer 30. The lower electrode 22 and the upper electrode 24 are formed by pressure bonding a rubber base material or a conductive elastomer base material.

  The stretchable conductive base material is composed of a composite made of an organic polymer and conductive particles. For the organic polymer, at least one of a resin and an elastomer is used. As the conductive particles, the above-described C, Pd, Fe, Sn, Al, Ni, Pt, Au, Ag, Cu, Cr, Mo, or the like or an alloy thereof is used.

  The lower electrode 22 and the upper electrode 24 are not limited to those formed on the entire lower surface 20b and upper surface 20a of the composite 20. It may be formed on a part of the lower surface 20b and the upper surface 20a of the composite 20 as long as electrical energy can be efficiently extracted from the composite 20.

Next, a method for manufacturing the energy conversion element 10 of this embodiment will be described.
First, for example, nitrile butadiene rubber is dissolved as a rubber in an organic solvent such as methyl ethyl ketone, cyclohexanone, dimethylformamide (DMF), and further, for example, cyanoethylated PVA is dissolved as a resin. Next, for example, PZT particles are added to an organic solvent and dispersed using, for example, a propeller mixer to obtain a coating solution containing piezoelectric particles. The nitrile butadiene rubber dissolved in the piezoelectric particle-containing coating solution is in a polymer state before being crosslinked and contains a peroxide crosslinking component.

Next, a piezoelectric particle-containing coating solution is applied to a predetermined thickness on a conductive rubber substrate serving as a lower electrode using, for example, a slide coater. Then, the organic solvent is evaporated to obtain a film body to be a matrix layer. The conductive rubber substrate functions as a support substrate for the piezoelectric particle-containing coating solution.
Next, in order to crosslink the nitrile butadiene rubber in a polymer state, the film body is subjected to peroxide crosslinking treatment at a temperature of 150 ° C. or less, for example. Thereby, the composite 20 shown in FIG. 1 is formed. Then, the energy conversion element 10 can be manufactured by forming the upper electrode 24 on the upper surface 20 a of the composite 20.

If necessary, poling (polarization treatment) can be performed on the composite 20 on which the lower electrode is formed. In this case, as shown in FIGS. 3A and 3B, the upper surface 20a of the composite 20 is separated from the upper surface 20a of the composite 20 formed on the lower electrode 22 by a distance δ of several mm, for example, 1 mm. On the top, a rod-shaped or wire-shaped corona electrode 40 that can move along the upper surface 20a is provided. The corona electrode 40 and the lower electrode 22 are connected to a DC power source 42. Furthermore, a heating means for heating and holding the composite 20, for example, a hot plate is prepared.
Then, in a state where the composite 20 is heated and held at a temperature of 100 ° C., for example, a DC voltage of several kV, for example, 6 kV is applied between the lower electrode 22 and the corona electrode 40 from the DC power source 42 to corona discharge. Then, the corona electrode 40 is moved on the upper surface 20a of the composite body 20 along the upper surface 20a for poling. Then, the energy conversion element 10 can be manufactured by forming the upper electrode 24 on the upper surface 20a of the composite 20.
In addition, the frequency | count of a movement of the corona electrode 40 is not specifically limited, It sets suitably according to polling conditions.

Moreover, a known moving means can be used for the movement of the corona electrode 40. Moreover, it is not limited to what the corona electrode 40 moves, A movement mechanism which moves the composite_body | complex 20 may be provided, and this composite_body | complex 20 may be moved and polling may be carried out. Thus, the moving means of the corona electrode 40 is not particularly limited as long as it can move the corona electrode 40 relative to the composite 20.
In addition, the lower electrode 22 can also be removed after poling according to the aspect etc. which use the energy conversion element 10 after poling. Further, the number of corona electrodes 40 is not limited to one and may be plural.

  When the corona electrode 40 is used as in the polling method shown in FIGS. 3A and 3B, a roll-to-roll method is used, and a plurality of corona electrodes 40 are opposed to the upper surface 20a in the conveyance path of the composite 20. It is also possible to perform poling while transporting the composite 20 in the longitudinal direction. In this manner, the energy conversion element 10 having a large area can be manufactured. Hereinafter, the polling method shown in FIGS. 3A and 3B is also referred to as a corona polling method.

The polling is not limited to the polling method shown in FIGS. 3A and 3B, and the polling method shown in FIG. 4 can be used.
In this case, the upper electrode 24 is formed on the upper surface 20 a of the composite 20. The upper electrode 24 may be a conductive rubber substrate, or may be formed using, for example, a sputtering method.

Next, the lower electrode 22 and the upper electrode 24 are connected to a direct current DC power source 42. Furthermore, a heating means for heating and holding the composite 20, for example, a hot plate is prepared. Then, while the composite 20 is heated and held at a temperature of 100 ° C., for example, a DC electric field of several tens to several hundreds kV / cm, for example, 50 kV / cm between the lower electrode 22 and the upper electrode 24 from the DC power source 42. Apply cm for a predetermined time and poll.
In this poling, the piezoelectric particles 32 are polled by applying a DC electric field in the thickness direction of the composite 20 where the lower electrode 22 and the upper electrode 24 face each other. Thereby, the energy conversion element 10 can be obtained.

According to the energy conversion element 10 of the present embodiment, the mechanical properties are improved by adding a resin and rubber to the matrix layer 30 and performing a peroxide crosslinking treatment. Further, the matrix layer 30 is subjected to peroxide crosslinking treatment with a small amount of additives at a low temperature, thereby reducing the influence on the electrical characteristics of the composite 20. As a result, even when the amount of distortion of the vibration source is large, a sufficiently generated voltage can be obtained, and further, a decrease in the generated voltage with time can be suppressed. Thus, according to the energy conversion element 10 of the present embodiment, even when the amount of distortion of the vibration source is large, mechanical energy (vibration energy) can be stably converted into electric energy. Further, the breakage and peeling of the energy conversion element 10 due to the vibration of the vibration source 12 are also suppressed.
Furthermore, the energy conversion element 10 having the above-described performance can be obtained by the method for manufacturing the energy conversion element 10 described above.

  The present invention is basically configured as described above. As mentioned above, although the energy conversion element of this invention and its manufacturing method were demonstrated in detail, this invention is not limited to the said embodiment, You may make various improvement or change in the range which does not deviate from the main point of this invention. Of course.

Hereinafter, the effect of the energy conversion element of the present invention will be described in detail.
In this example, as shown below, cyanoethylated PVA and nitrile butadiene rubber (NBR) were used, and the energy conversion elements of Examples 1 and 2 were produced by changing the mixing ratio of nitrile butadiene rubber. The generated voltage was measured under each strain condition described in detail in FIG.

In Example 1, the nitrile butadiene rubber (NBR) contains 10% by mass ratio with respect to the total mass of the cyanoethylated PVA and the nitrile butadiene rubber (NBR), and in Example 2, the nitrile butadiene rubber (NBR) ) Is 80% by mass.
As Comparative Example 1, an energy conversion element not containing nitrile butadiene rubber (NBR) was produced, and the generated voltage was similarly measured under each strain condition described in detail below.

For Example 1 and Example 2, PZT particles, and cyanoethylated PVA (CR-V manufactured by Shin-Etsu Chemical Co., Ltd.) and nitrile butadiene rubber (NBR) as dimethylformamide (DMF) at the following composition ratio (mass ratio) were used. ) And dispersed with a propeller mixer (rotation speed: 2000 rpm) to prepare a coating solution containing piezoelectric particles.
PZT particles: 300 parts by mass Cyanethylated PVA: 27 parts by mass (Example 1), 6 parts by mass (Example 2)
NBR: 3 parts by mass (Example 1), 24 parts by mass (Example 2)
However, nitrile butadiene rubber (NBR) is a polymer that contains a cross-linking agent and the like and has not been subjected to cross-linking treatment at the time of preparing the piezoelectric particle-containing coating solution.

In addition, as PZT particle | grains, after sintering commercially available PZT raw material powder at 1000-1200 degreeC, what grind | pulverized and classified so that it might become an average particle diameter of 5 micrometers was used.
NBR is the state of the polymer before carrying out cross-linking and contains a peroxide cross-linking component.

Next, apply a piezoelectric particle-containing coating solution on a conductive rubber substrate (thickness 1 mm) with a coating area of A6 size (150 mm x 90 mm) so that the film thickness of the dried coating film becomes 90 μm using a slide coater. After that, DMF is evaporated by heating and drying on a 120 ° C. hot plate. Thereby, a film body is formed. Thereafter, a crosslinking treatment for crosslinking the nitrile butadiene rubber was performed on the film body at a temperature of 150 ° C. for 15 minutes.
Thereafter, using a corona poling method, a DC voltage of 6 kV was applied between the lower electrode 22 and the corona electrode 40 from the DC power source 42 shown in FIG. 3A, and a poling process was performed at a temperature of 100 ° C. Thereafter, a conductive rubber substrate was pressure bonded as an upper electrode.
Then, it cut out to the size of 30 mm x 30 mm, and produced the energy conversion element of Example 1 and Example 2.

  The energy conversion element of Comparative Example 1 was manufactured in the same manner as the energy conversion elements of Examples 1 and 2 except that nitrile butadiene rubber (NBR) was not included. For this reason, the detailed description about the manufacturing method of the energy conversion element of the comparative example 1 is abbreviate | omitted.

Each energy conversion element of Example 1, Example 2 and Comparative Example 1 was attached to a tensile rubber material having a thickness of 5 mm via an adhesive layer. As a result, the vibration source 12 shown in FIG. 1 is replaced with a tensile rubber substrate.
In this example, the tensile rubber material is 1 in the direction of arrow a shown in FIG. 1 in a sine wave shape of 10 Hz using a fatigue tester Micro Servo MMT-101NV-10 (manufactured by Shimadzu Corporation) with a strain _PP amount of 1%. After pulling for a period of time, the energy conversion elements of Example 1, Example 2 and Comparative Example 1 were vibrated by pulling for 1 hour with a strain _PP amount of 3% to give vibration energy. At that time, the maximum value of the voltage generated in each energy conversion element of Example 1, Example 2 and Comparative Example 1 was measured. FIG. 5 shows the waveform when the tensile rubber material is pulled, and FIG. 6 shows the measurement result of the maximum value of the generated voltage generated in each energy conversion element of Example 1, Example 2 and Comparative Example 1.

Specifically, the tensile rubber material was pulled with a waveform A of a sine wave shown in FIG. Waveform A represents one pulse (one period) minutes, strain _PP is 3%, the peak _{P 1} has a more than 5%.
In the present invention, the strain _PP amount is the difference St between the peak P ₁ and the peak P ₂ in the waveform A. If the peak difference St is 1%, the strain _PP amount is 1%, and if 3%, the strain _PP amount is 3%.
A waveform B in FIG. 5 shows an example of a waveform of a generated voltage generated in the energy conversion element 10 when the tensile rubber material is pulled by one pulse (one cycle). In the present embodiment, the maximum value of the generated voltage is the maximum value V _max of the generated voltage in the waveform B.

6, region _{D 1} is the strain _PP of 1% of the area, region _{D 2} is a strain _PP of 3% of the area. Energy conversion element of the present invention contemplates the use where the strain amount is large, strain _PP of 3% of the area D ₂ is applicable where the strain amount is large.
In FIG. 6, a waveform C ₁ indicates the first example, a waveform C ₂ indicates the _second example, and a waveform C ₃ indicates the first comparative example.

In Example 1, as the amount of strain increased, the generated voltage increased accordingly. In addition, the generated voltage did not decrease over time. In Example 2, although the generated voltage was small, when the amount of distortion increased, the generated voltage also increased with the increase, and the generated voltage did not decrease over time.
On the other hand, in Comparative Example 1, as the amount of strain increased, the generated voltage increased accordingly. However, in the region where the amount of distortion is large, the generated voltage greatly decreases with time.

As described above, in the first and second embodiments, the generated voltage does not decrease with time even in a region where the amount of strain is large, and even when the amount of strain of the vibration source is large, the vibration energy is stabilized to electrical energy. Since it can be converted, the effect of adding rubber to the matrix layer is clear.
In addition, Example 2 in which the addition amount of the rubber exceeds 70% by mass ratio with respect to the cyanoethyl resin has a low generated voltage and is not practical.

DESCRIPTION OF SYMBOLS 10 Energy conversion element 12 Vibration source 14 Adhesive layer 16 Tire 20 Composite body 22 Lower electrode 24 Upper electrode 30 Matrix layer 32 Piezoelectric particle D ₁ distortion amount 1% area | region D ₂ distortion amount 3% area | region

Claims (23)

An energy conversion element that converts mechanical energy into electrical energy,
Having a composite in which piezoelectric particles are uniformly dispersed and mixed in a matrix layer containing a resin and rubber;
The conjugate state, and are not treated peroxide crosslinking,
The energy conversion element , wherein the resin is a cyanoethyl resin .   The energy conversion element according to claim 1, wherein the resin has a continuous heat resistant temperature of 160 ° C. or less. The rubber, the energy conversion device according to claim 1 or 2 nitrile butadiene rubber or silicone rubber. The energy conversion element according to any one of claims 1 to 3 , wherein the rubber has a relative dielectric constant of 10 to 30. The energy conversion element according to claim 3 , wherein the nitrile butadiene rubber is contained in a mass ratio of 1% to less than 80% with respect to the cyanoethyl resin. The energy conversion element according to claim 3 , wherein the silicon rubber is contained in a mass ratio of 1% or more and less than 60% with respect to the cyanoethyl resin. The piezoelectric particles, the energy conversion device according to any one of claims 1 to 6, consisting of particles having a perovskite crystal structure. The energy conversion element according to claim 7 , wherein the particles are composed of lead zirconate titanate, lead lanthanum zirconate titanate, barium titanate, a solid solution of barium titanate and bismuth ferrite, or a relaxor piezoelectric material. Energy conversion device as claimed in any one of the complexes according to claim 1 stretchy conductive substrate or a conductive rubber substrate is formed on the 8. The stretchable conductive substrate is composed of a composite composed of an organic polymer and conductive fine particles, and the conductive fine particles include C, Pd, Fe, Sn, Al, Ni, Pt, and Au. , Ag, Cu, Cr or Mo, or energy conversion element according to configured claim 9 in these alloys. The complex is installed to the vibration source, the mechanical energy, the energy conversion device according to any one of claims 1 to 10, wherein a vibration energy of the vibration source. The energy conversion element according to claim 11 , wherein the vibration source is a tire. Dissolving a resin and rubber in an organic solvent, and dispersing piezoelectric particles in the organic solvent to obtain a coating solution containing piezoelectric particles;
The piezoelectric particle-containing coating solution is applied onto a support substrate, and the organic solvent is evaporated to obtain a film body to be a matrix layer. The film body is subjected to peroxide crosslinking treatment, and the piezoelectric layer is applied to the matrix layer. possess a step of the body particles get uniformly dispersed and mixed complexes,
The method for manufacturing an energy conversion element , wherein the resin is a cyanoethyl resin . Furthermore, the manufacturing method of the energy conversion element of Claim 13 which has the process of performing a polarization process to the said composite_body | complex. The method for producing an energy conversion element according to claim 13 or 14 , wherein the resin has a continuous heat resistance temperature of 160 ° C or lower, and the peroxide crosslinking treatment is performed at 150 ° C or lower. The method for manufacturing an energy conversion element according to any one of claims 13 to 15 , wherein the rubber is nitrile butadiene rubber or silicon rubber. The method for manufacturing an energy conversion element according to any one of claims 13 to 16 , wherein the rubber has a relative dielectric constant of 10 to 30. The said nitrile butadiene rubber is a manufacturing method of the energy conversion element of Claim 16 contained 1% or more and less than 80% by mass ratio with respect to the said cyanoethyl-type resin. The method of manufacturing an energy conversion element according to claim 16 , wherein the silicon rubber is contained in a mass ratio of 1% to less than 60% with respect to the cyanoethyl resin. The piezoelectric particles, method for producing energy transducer element according to any one of claims 13-19 consisting of particles having a perovskite crystal structure. The manufacturing method of the energy conversion element according to claim 20 , wherein the particles are composed of lead zirconate titanate, lead lanthanum zirconate titanate, barium titanate, a solid solution of barium titanate and bismuth ferrite or a relaxor piezoelectric material. Method. The method for manufacturing an energy conversion element according to any one of claims 13 to 21 , wherein the support substrate is a conductive base material having elasticity or a conductive rubber base material. The stretchable conductive substrate is composed of a composite composed of an organic polymer and conductive fine particles, and the conductive fine particles include C, Pd, Fe, Sn, Al, Ni, Pt, and Au. The manufacturing method of the energy conversion element of Claim 22 comprised by these, Ag, Cu, Cr, Mo, or these alloys.

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