JP2019006887A - Dielectric body particle-containing dielectric elastomer and manufacturing method therefor - Google Patents

Abstract

To provide a dielectric elastomer material for dielectric elastomer transducer with enhancing insulation voltage resistant performance and enhancing durability and efficiency by reducing leakage current, without mainly aiming enhancement of dielectric constant for solving conventional problems.SOLUTION: There is adopted a means consisting of a mixing process for mixing barium titanate, a surfactant, an organic dispersant, an organic solvent to obtain a barium titanate slurry; an ultrasonic wave treatment process for impacting the barium titanate slurry obtained in the mixing process to obtain a uniform shape of dispersion; a blending process for blending the barium titanate slurry obtained in the ultrasonic wave treatment process with a dielectric elastomer; and a drying process for drying the barium titanate slurry obtained in blending process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dielectric material used for a dielectric elastomer transducer, and more specifically, by dispersing barium titanate, which is a ferroelectric material, in a dielectric polymer polymer such as a dielectric elastomer, the dielectric strength is improved and leakage current is reduced. The present invention relates to a technique of a dielectric elastomer material used for a dielectric elastomer transducer which is reduced and has improved durability by preventing deterioration.

  Conventionally, research and development of dielectric elastomer transducers has been promoted. Such a dielectric elastomer transducer has a structure in which a dielectric elastomer is sandwiched between two electrodes. When a voltage is applied between the two electrodes, the electrodes are attracted to each other by Coulomb force, and the dielectric elastomer expands to stop the application. This is a converter that uses the action of contracting by the electric energy and converts electrical energy into mechanical energy. In recent years, it has come to be used for artificial muscles and the like, and it can be said that it will be used more and more in the future.

  However, the performance of dielectric elastomer transducers is greatly affected by the amount of expansion and contraction of the dielectric elastomer, and it is necessary to apply a high voltage to obtain a large mechanical energy, resulting in problems of durability and leakage current. . Even if the dielectric constant is increased, the elongation of the dielectric elastomer due to the application of voltage to the electrode does not increase so much, and in some cases, it may decrease.

  Therefore, various techniques have been proposed in the past to solve such problems. For example, Patent Document 1 discloses a technique in which the name of the invention is “dielectric actuator” (see Patent Document 1). Specifically, the object is to “provide a dielectric actuator having a large variation amount with respect to an applied voltage”, and the solution thereof is “an elastic high dielectric material portion is sandwiched between elastic insulating material portions and further from the outside. It has a structure sandwiched between electrodes, and the base material of the elastic high dielectric material portion is made of silicone rubber, and graphite powder is mixed to impart conductivity ”.

  Patent Document 2 discloses a technique in which the name of the invention is “dielectric film and transducer using the same” (see Patent Document 2). Specifically, the object is to “provide a flexible dielectric film having a high dielectric constant and a high dielectric breakdown even if the dielectric constant is large, and includes an elastomer and dielectric particles. The average value of the particle size and the area ratio of the elastomer per unit area are specified.

  Patent Document 3 discloses a technique in which the name of the invention is “insulating composition, insulating article, adjustment method thereof, and electrical cable accessory” (see Patent Document 3). Specifically, “about 70 to 100 parts by volume of polymer material, about 5 to 30 parts by volume of ceramic filler, about 0.1 to 5 parts by volume of crosslinking agent, and about 0 to 6 parts by volume of conductive material. Surface treatment with a bifunctional coupling agent in an amount of about 0.1 wt% to about 4 wt% of the ceramic filler. It has been said.

  However, any of the documents described above is a technique for increasing dielectric constant by mixing dielectric particles with dielectric elastomer. However, when dielectric particles are mixed with dielectric elastomer, the dielectric elastomer becomes hard and hardly stretched. In some cases, the amount of expansion and contraction is reduced, and none of the prior arts have been solved.

Japanese Patent No. 5374984 JP2015-189776 A JP-T-2006-511917

  The present invention does not have the main purpose of improving the dielectric constant in order to solve the conventional problems, but improves the dielectric breakdown voltage performance and reduces the leakage current, thereby improving the durability and efficiency. An object of the present invention is to provide a dielectric elastomer material for an elastomer transducer.

  The present invention employs a configuration in which dielectric particles surface-modified with an organic dispersant are contained in a dispersed state in a dielectric elastomer used in a dielectric elastomer transducer.

  The present invention can also employ a configuration in which the dielectric particles contained in a dispersed state in the dielectric elastomer are barium titanate.

  The present invention may also employ a configuration in which the barium titanate contained in the dielectric elastomer in a dispersed state has a particle diameter of 5 nm to 500 nm and an average particle diameter of 50 nm.

  In addition, the present invention may employ a configuration in which the blending ratio of the barium titanate contained in a dispersed state in the dielectric elastomer is in the range of 1.0 wt% to 50.0 wt%.

  The present invention also includes a mixing step of mixing a barium titanate, a surfactant, an organic dispersant, and an organic solvent to obtain a barium titanate slurry, and the barium titanate obtained in the mixing step. Obtained by an ultrasonic treatment step for applying an ultrasonic shock to the slurry to make the dispersion uniform, a blending step for blending the barium titanate slurry obtained in the ultrasonic treatment step with a dielectric elastomer, and the blending step. A means comprising a drying step of drying the obtained barium titanate slurry may be employed.

  Further, the present invention may employ a means in which the mixing condition in the mixing step uses a bead mill, uses beads of 5 mm or less, and the peripheral speed of the agitator is 3 m / s to 15 m / s.

  The present invention can also employ means for irradiating ultrasonic waves having a frequency of 18 kHz to 200 kHz for 10 seconds or more in the dispersion processing by the ultrasonic processing step.

  According to the dielectric particle-containing dielectric elastomer and the manufacturing method thereof according to the present invention, the dielectric elastomer contains dielectric particles such as barium titanate, thereby improving the dielectric withstand voltage performance, compared to the conventional dielectric elastomer. It exhibits an advantageous effect that makes it possible to significantly improve durability.

  In addition, according to the dielectric particle-containing dielectric elastomer and the method for producing the same according to the present invention, it is possible to obtain the expansion and contraction force of the dielectric elastomer at a lower voltage by improving the insulation voltage resistance. This makes it possible to suppress the current to a small value and to exhibit advantageous effects such as improving the energy conversion efficiency.

1 is a cross-sectional view of a basic configuration of a dielectric elastomer transducer using a dielectric elastomer containing dielectric particles according to the present invention. It is explanatory drawing which shows the non-electrically charged state of the dielectric particle containing dielectric elastomer transducer which concerns on this invention. It is explanatory drawing which shows the voltage application state in the dielectric elastomer containing dielectric particle | grains which concerns on this invention. 1 is a configuration explanatory diagram of an insulation withstand voltage performance test apparatus according to the present invention. FIG. 1 is a configuration explanatory diagram of a dielectric constant measuring apparatus according to the present invention. It is a flowchart which shows the manufacturing method of the dielectric particle containing dielectric elastomer which concerns on this invention.

  Hereinafter, embodiments of the dielectric particle-containing dielectric elastomer 1 according to the present invention will be described with reference to the drawings and tables. The dielectric particle-containing dielectric elastomer 1 and the dielectric particle-containing dielectric elastomer manufacturing method 2 according to the present invention are characterized by comprising barium titanate 12 in a dispersed state in the dielectric elastomer 10 in a dispersed state. . In the present invention, when numerical values and other ranges are expressed using “to”, both the upper limit and the lower limit of the numerical range are within the numerical range.

  FIG. 1 is a cross-sectional view of a basic configuration of a dielectric elastomer transducer 20 using a dielectric elastomer 1 containing dielectric particles according to the present invention. As shown in FIG. 1, a dielectric particle-containing dielectric elastomer 1 according to the present invention is obtained by dispersing dielectric particles 11 in a dielectric elastomer 10. Hereinafter, the dielectric elastomer 10 and the dielectric particles 11 used in the present invention will be described.

  The dielectric elastomer 10 has various types as a high dielectric constant material, but is generally an elastomer such as a rubbery substance or rubber having elasticity, and a silicone resin-based elastomer, an acrylic resin-based elastomer, and the like are conceivable. . Specifically, acrylic rubber, silicone rubber, natural rubber, polyurethane rubber, styrene butadiene rubber, chloroprene rubber, nitrile rubber, vinyl chloride elastomer, amide elastomer, polyvinyl chloride (PVC), etc. can be used as materials. .

  Moreover, when classifying the types of the dielectric elastomer 10, it is divided into a thermoplastic elastomer, a thermosetting elastomer, and an energy beam curable elastomer. It is not limited to any one of such classifications. For example, in thermoplastic elastomers, there are many styrene elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers, amide elastomers, and ester elastomers. There are types. The vinyl chloride elastomer is, for example, polyvinyl chloride (PVC).

  There are many types of thermosetting elastomers as well as the above thermoplastic elastomers, such as natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, and ethylene propylene rubber. , Urethane rubber, silicone rubber, chlorosulfonated polyethylene rubber, fluorine rubber, hydrogenated nitrile rubber, epichlorohydrin rubber, and the like, which are not particularly limited to any of these.

  The energy ray curable elastomer has elasticity by energy rays, such as silicone rubber, acrylic rubber, styrene butadiene rubber, ethylene propylene rubber, urethane rubber, etc. There are materials that can be applied. These are elastomers that are cured using any one or two or more of arbitrary energy rays, and the type of energy rays is not particularly limited, but is, for example, electromagnetic waves or radiation, and more specifically Specifically, they are ionizing radiation such as gamma rays and electron beams, and non-ionizing radiation such as radio waves, ultraviolet rays and infrared rays.

  The dielectric elastomer 10 has a thickness and size determined appropriately according to the purpose of use. For example, when used as an actuator, the dielectric elastomer 10 converts electrical energy necessary for output required as mechanical power. Thickness and size to function as a vessel are required. Further, regarding the durability of the dielectric elastomer 10, it is already confirmed that the dielectric elastomer 10 made by electron beam crosslinking has higher durability than the dielectric elastomer 10 made by thermal crosslinking, ultraviolet crosslinking, or the like before that. Confirmed by the inventors.

  The dielectric particles 11 mean all of the additives exhibiting ferroelectricity, and include not only barium titanate 12 but also ferroelectrics such as lead zirconate titanate (Pb (Zr, Ti) O 3). It is widely included and is not particularly limited to these, and refers to a substance in which electric dipoles are aligned even if there is no electric field outside and the direction of the dipoles can be changed by the electric field. However, in the description of the present invention, description will be made mainly using barium titanate 12.

  Barium titanate 12 is basically required to have particles having a constant particle size and shape (substantially spherical), a narrow particle size distribution, high crystallinity, and excellent dispersibility. However, since there is a problem of a decrease in crystallinity called a size effect with miniaturization, barium titanate 12 by a solid phase method or an oxalate method, which is a synthetic method in which crystallinity is relatively large, is more desirable.

  Barium titanate 12 is a compound composed of titanium (IV) oxide such as BaTiO3, BaTi2O5, Ba2TiO4 and barium oxide, and BaTiO3 is a tetragonal and ferroelectric substance at room temperature, but undergoes phase transition from room temperature to high temperature and is cubic. It becomes a crystal.

  In addition, the derivative of the dielectric particle 11 includes, for example, a compound in which some metal atoms in the barium titanate 12 are substituted with other metal atoms. , Part of barium (Ba) which is A site, or part of titanium (Ti) which is B site, and may be part of barium and titanium. The other metal atoms are metal atoms other than titanium and barium. For example, strontium (Sr), calcium (Ca), yttrium (Y), neodymium (Nd), samarium (Sm), dysprosium (Dy), Vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), germanium (Ge), selenium (Se), zirconium (Zr), niobium (Nb), Molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), tin (Sn), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), Examples thereof include osmium (Os), iridium (Ir), and platinum (Pt).

  The surface active agent 13 has the same characteristics as the surface active agent, and adheres to the surface of the dielectric particles 11 to reduce the interfacial tension, reduce the contact angle, and improve the wetting between the organic solvent 15 and the powder. This has the effect of improving dispersibility. Further, as the surface active agent 13, for example, a silicone system having excellent heat resistance is used, and preferably a polyether-modified silicone activator is used.

  The organic dispersant 14 is a generic name for agents that are added during dispersion and develop a dispersion function, and is an additive that plays an important role in facilitating dispersion and obtaining a stable and excellent slurry. In the present invention, the organic dispersant 14 is used, and the dispersant adsorbed on the surface of the particles prevents the particles from approaching each other and stabilizes the dispersion. The organic dispersant 14 is preferably an anionic one, and in particular, one having a carboxylic acid as an adsorbing group is preferable.

  The organic solvent 15 is a solution for taking in the dielectric particles 11, and is not particularly limited, but can indicate, for example, 2-propanol. Further, when a nonpolar elastomer such as styrene butadiene rubber, ethylene propylene rubber, or silicone rubber is used as the dielectric elastomer 10, a low polarity solvent represented by toluene, hexane, or the like is preferable. The solvent 15 is appropriately selected.

  FIG. 2 is an explanatory view showing a non-charged state in which no voltage is applied to the dielectric particle-containing dielectric elastomer 1 according to the present invention, and FIG. 3 is a voltage supply to the dielectric particle-containing dielectric elastomer 1 according to the present invention. It is explanatory drawing which shows the applied voltage application state.

  The dielectric elastomer transducer 20 uses the dielectric particle-containing dielectric elastomer 1 according to the present invention, in which the dielectric elastomer 10 contains dielectric particles 11, and includes electrodes 22 on both sides of the dielectric elastomer 10 as shown in the figure. It can also be used as a driving force for an actuator or the like as a transducer that converts electrical energy into mechanical energy by stretching by applying a voltage and contracting by removing the voltage. In contrast to this, the power generation device converts mechanical energy into electrical energy and has a possibility of practical use.

  As the voltage supply means 24, one that makes it possible to apply an appropriate voltage using a power source capable of controlling the voltage is used. Carbon can be suitably used as the material of the electrode 22, but it may be formed using a material that is usually used as the electrode 22, and is not particularly limited to carbon. An application example to an actuator or the like will be omitted, and the operation will be described below with reference to FIGS.

  The electrodes 22 are arranged on both sides of the dielectric elastomer 10 in the dielectric elastomer transducer 20 and are electrodes 22 for applying a voltage, and the Coulomb force K1 is applied to the dielectric elastomer 10 via the electrodes 22. As shown in FIG. 3, when the voltage is supplied from the voltage supply means 24 to the electrode 22, the two opposing electrodes 22 are attracted to each other by the Coulomb force K1 (force in the direction indicated by the arrow K1). Force is generated. As a result, the dielectric elastomer 10 is crushed by the two electrodes 22 and expands in the expansion direction K2.

  At this time, depending on the magnitude of the voltage applied to the two electrodes 22, the attracting force generated in the electrodes 22 also changes, and the amount by which the dielectric elastomer 10 extends also changes. Then, by stopping the supply of voltage from the voltage supply means 24, the attractive forces generated in the two electrodes 22 disappear. As a result, the dielectric elastomer 10 recovers its shape by its own elastic force and returns from the stretched state as shown in FIG. 3 to the state before the stretch as shown in FIG. The force obtained by such a change is inversely proportional to the distance between the two poles and is proportional to the square of the applied voltage. It is also proportional to the electrode area and the dielectric constant. Therefore, although it is necessary to improve the dielectric constant, the improvement of the withstand voltage by applying a large voltage is an important point for further improving the performance as a transducer.

  The relational expression between the pressure p generated to operate the dielectric polymer and the bias voltage Vb is shown below.

"Formula 1"

  Therefore, the bias voltage Vb can be increased, and the thickness t of the polymer can be reduced, so that the pressure p generated for operating the dielectric polymer is equal to the square of the bias voltage Vb and Since it increases in proportion to the square of the reciprocal of the thickness t, it is possible to drive with extremely good performance as compared with the prior art.

  Furthermore, as the power generation device, the power generation energy E is related to the change in the capacitance of the dielectric elastomer 10,

"Formula 2"

  It is represented by the following formula 2. Here, C1 and C2 are capacitances of the dielectric polymer in the stretched and contracted states, respectively, and Vb is a bias voltage. The power generation energy increases due to greater expansion / contraction, and increases with the square of the bias voltage Vb, so that it is possible to generate power with very good performance as compared with the prior art, and the dielectric breakdown voltage increases, so that the same bias as before In the case of operating with voltage, the burden is reduced and the life is improved.

  As described above, the dielectric elastomer transducer 20 can convert a change in voltage into a change in shape and can be applied to various products such as artificial muscles. However, in order to generate a large driving force, the bipolar electrode It is necessary to widen the distance to obtain the amount of expansion and contraction and to increase the applied voltage. However, when the voltage is increased, the dielectric elastomer 10 sandwiched between the two electrodes tends to cause dielectric breakdown, and the dielectric particles according to the present invention are contained in the dielectric elastomer 10 using barium titanate 12 as the dielectric particles 11. The excellent pressure resistance performance of the contained dielectric elastomer 1 is required.

  FIG. 4 is a configuration explanatory view showing the overall configuration of an insulation withstand voltage performance test apparatus 30 that performs an insulation withstand voltage performance test for the dielectric elastomer 1 containing dielectric particles according to the present invention.

  The insulation withstand voltage performance test apparatus 30 includes a high voltage voltmeter 31, a high voltage power source 32, a high voltage ammeter 33, an oscilloscope (voltage / current monitor) 34, a timer 35, and a high voltage switch 36. It discharges on the surface of the test piece and increases the voltage stepwise until a structural change occurs where the insulator becomes a conductor, and measures the highest voltage that is not destroyed.

  The high voltage voltmeter 31 is a device for measuring a voltage. Since the applied voltage is high, a high voltage voltmeter 31 is used.

  The high-voltage power supply 32 is a device that supplies necessary power to the insulation withstand voltage performance test device 30, and is a device that increases the voltage at 200V intervals until the test piece breaks.

  The high-voltage ammeter 33 is a device for measuring a current. Although the flowing current itself is low, the voltage is high. Therefore, it is necessary to measure the leakage current in a stable state. It is desirable to use an ammeter.

  The oscilloscope (voltage / current monitor) 34 is a measuring device that measures a state for determining that a dielectric breakdown has occurred, and is in a stable state for each voltage as the voltage from the high-voltage power supply 32 increases stepwise. It is a device that measures the presence or absence of dielectric breakdown measured from

  The timer 35 is a device that measures the time required to increase 200 V every predetermined time.

  The high voltage switch 36 is turned on to apply a voltage to the object to be measured, and determines that dielectric breakdown has occurred when an excessively large current flows, and turns off the power supply.

  The withstand voltage evaluation was performed by the dielectric breakdown voltage test by the step breakdown method using the dielectric withstand voltage performance test apparatus 30 described above. This test method measures by loading a high voltage on an insulator that has almost no charge carriers that can move around freely, so that the charge carriers suddenly increase in the insulator and the structure changes to become a conductor. Evaluation is performed by the test method. In order to evaluate the breakdown voltage, first, the voltage at which breakdown occurs in the short-time breakdown method is used as a reference. From about 40% of the voltage, the voltage is gradually increased every 200V until the breakdown occurs. It is evaluated from the maximum voltage that did not break, and as shown in Table 1 below, the dielectric elastomer 10 containing 5 wt% of barium titanate 12 compared with the one not containing barium titanate 12. It was confirmed that the pressure resistance performance was clearly improved.

  Table 1 below shows the experimental results of the dielectric withstand voltage performance of the silicone-based dielectric elastomer 10 containing the barium titanate 12 and the silicone dielectric elastomer 10 of the same type not containing the same. Table 3 shows. In the table, BT means barium titanate 12.

Main material: Silicone

  In Tables 1 to 3 above, the dielectric constant of each of the resins, which are the main components of the dielectric particle-containing dielectric elastomer 1 of the present invention, in which the blending ratio of the dielectric particles 11 is changed is measured. The results of whether or not the presence or absence of the dielectric particles 11 affects the withstand voltage performance are shown based on the results of experiments in which the dielectric particles 11 are not blended by such an apparatus and the other blending ratios are varied. In the actual experiment, the reference content of 0 wt% to 50 wt% was measured, and for 50 wt% or more, as shown in Table 3, the portion indicated by a broken line from the middle is shown as a predicted value. Next, a comparison is made between the case where silicone is used as the main material used in the pressure resistance test and 5 wt% of barium titanate 12 is contained in the dielectric particles and the case where the experiment is performed using only silicone which does not contain at all. Shown in

  As shown in Tables 1 to 3, when dielectric particles 11 are included in dielectric elastomer 10 using the characteristics of dielectric elastomer 10, the breakdown voltage is clearly improved as compared with the case where dielectric particles 11 are not included at all. I understand. Moreover, it turns out that the pressure | voltage resistance performance is improving also in the range of 1 wt% to 50 wt% about the mixture ratio. More specifically, as compared with the case where the blending ratio was 0%, the pressure resistance performance was greatly improved at any ratio of 5 wt%, 10 wt%, 30 wt%, and 50 wt%.

  More specifically, the inclusion of barium titanate 12 was as high as 5,400 V, and the breakdown was caused at 4,800 V without inclusion. Therefore, Tables 1 to 3 show that the withstand voltage performance is improved when the dielectric particles 11 are contained even in a slight amount. In addition, although 50 wt% or more is a result based on an expectation, when the compounding ratio of the barium titanate 12 is increased, the hardness of the barium titanate 12 itself affects the expansion and expansion of the main material, and the main material is deformed. It can also interfere. As a preferable result, in order to improve the withstand voltage, a good effect is exhibited in the range of at least 1 wt% to 50 wt%, and more preferably in the range of 10 wt% to 30 wt%. I can say that.

  FIG. 5 is a configuration explanatory diagram of a dielectric constant measuring device 40 used in the relative dielectric constant measurement of the dielectric particle-containing dielectric elastomer 1 according to the present invention.

  The dielectric constant measuring apparatus 40 includes an impedance analyzer 41, a test fixture 42, a main electrode 43, a device under test 44, and a counter electrode 45.

  The impedance analyzer 41 is a device that measures characteristics such as an inductor, a capacitor, or a resistance that is a two-terminal passive element, and is a device that is used when measuring the parasitic capacitance of a transistor that is an active element.

  The test fixture 42 is a terminal used for dielectric constant evaluation using the impedance analyzer 41.

  The main electrode 43 is a power supply device for operating the impedance analyzer 41 and a device for supplying a high voltage to the test fixture 42.

  As the device under test 44, a thin plate having an outer diameter of 50 mm × 50 mm and a thickness of 100 μm was used in this experiment.

  The counter electrode 45 used was a three-terminal configuration using a guard electrode to remove measurement errors caused by edge capacitance.

  The relative dielectric constant was evaluated from an experiment by a dielectric constant measurement method using a parallel plate using the impedance analyzer 41. In the parallel plate method, a capacitor is formed by sandwiching a test object 44 having an outer diameter of 50 mm × 50 mm and a thickness of 100 μm between two test fixture 42 electrodes, and the capacitance and loss measured by the impedance analyzer 41 are measured. From the vector component, the relative dielectric constant was calculated by the following (Equation 3).

"Formula 3"

  FIG. 6 is a flowchart showing a manufacturing method 2 of dielectric particle-containing dielectric elastomer according to the present invention.

  The mixing step A is a step of obtaining the barium titanate slurry 50 by mixing the barium titanate 12, the surfactant 13, the organic dispersant 14, and the organic solvent 15. For example, 300 g of barium titanate from Kyoritsu Material Co., Ltd. with the trade name “BT-HP9DX”, and Wako Pure Chemical Industries with the organization name “2-propanol molecular formula C3H8O, sexual formula CH3CHCH3”. Shin-Etsu Chemical Co., Ltd., a polyether-modified silicone consisting of 300 g of “2-propanol” and a copolymer having a polyoxyalkylene group which is a hydrophilic group and a hydrophobic polyorganosiloxane chain in the molecular structure. “AFB” of NOF Corporation, a dispersant composed of 0.6 g of “KF-6011” manufactured by the company and a polyfunctional comb polymer having an ionic group in the main chain and a polyoxyalkylene chain in the graft chain -1521 "9 g together with beads for grinding in a bead mill apparatus, and the average particle size is 0.03 micron to 0.1. Obtaining a barium titanate slurry 50 after the dispersion slurry process of the submicron level microns.

  In a production method in which dielectric particles 11 such as barium titanate 12 are contained in a dielectric elastomer 10 in a dispersed state with a uniform average particle diameter, which can be said to be a main part of the present invention, the adhesion between powders is reduced when the particle diameter is reduced. Becomes larger and the dispersibility becomes worse. Therefore, in the production method according to the present invention, it is necessary to weaken the adhesion and aggregation properties between the dielectric particles 11, and it is important to improve the particle surface using a polymer.

  As an example of such dispersion slurrying conditions for achieving a good dispersion state, a circulating operation is performed using a bead mill device with a peripheral speed of 8 m / s and an operation time of 180 minutes. In addition to the collision between the beads and the containment vessel wall, the average particle size was adjusted to be in the range of 0.03 microns to 0.8 microns by shearing or colliding with the beads. A barium titanate slurry 50 is obtained. The material of the container used in the apparatus is zirconia, the bead diameter is 1 mm, the bead material is partially stabilized zirconia, and the bead weight is 400 g. However, the dispersion slurrying treatment conditions are not limited to the above examples, and beads having a diameter of 5 mm or less may be used, and the peripheral speed of the agitator may be 3 m / s to 15 m / s.

  The ultrasonic treatment process B is performed immediately before the blending process C. In this step, the barium titanate slurry 50 obtained in the mixing step A is subjected to ultrasonic impact to solve particle sedimentation due to changes over time, thereby promoting homogenization. The barium titanate slurry 50 obtained in the mixing step A was irradiated with an ultrasonic wave of 20 kHz by an ultrasonic homogenizer at an output of 150 W for 120 seconds, and a shock wave by the ultrasonic wave was repeatedly applied to the substance in the solution, thereby causing a minute difference due to the pressure difference. Bubbles (cavitation) are generated and crushed so that the average particle size is in the range of 0.03 microns to 0.8 microns.

  The blending step C is a step of blending the barium titanate slurry 50 obtained in the ultrasonic processing step B with the dielectric elastomer 10. Taking film formation by a coating method as an example, the barium titanate slurry 50 obtained in the ultrasonic treatment step B is added to the dielectric elastomer 10 dissolved in a solvent and stirred uniformly, and then with a sieve having a predetermined size. Filter to obtain a coating solution. Here, the solvent used for dissolving the dielectric elastomer 10 is appropriately selected from those which do not solve the solubility of the dielectric elastomer 10 and the dispersion state of the barium titanate slurry 50, and includes, for example, toluene. Further, the stirring method is not particularly limited, and for example, it can be performed by stirring using a paddle type or propeller type impeller.

  The drying step D is a step of forming a film by drying the coating liquid (dispersed solution of the barium titanate slurry 50 and the dielectric elastomer 10) obtained in the blending step C. There is no limitation on the coating method, and coating is performed to an arbitrary thickness by a known coating method such as a roll coater, comma coater, knife coater, die coater, etc., and then introduced into an oven and dried. The drying conditions are selected depending on the base film, the type of coating liquid, and the like. For example, when PET (polyethylene terephthalate: PET) film is used as the base film and toluene is used as the solvent of the coating liquid, the drying conditions are 60 to 130 degrees. It is preferable to dry for 5 to 30 minutes.

DESCRIPTION OF SYMBOLS 1 Dielectric particle containing dielectric elastomer 2 Manufacturing method 10 of dielectric particle containing dielectric elastomer 10 Dielectric elastomer 11 Dielectric particle 12 Barium titanate 13 Surface active agent 14 Organic dispersing agent 15 Organic solvent 20 Dielectric elastomer transducer 22 Electrode 24 Voltage supply means 30 Insulation withstand voltage performance test equipment 31 High voltage voltmeter 32 High voltage power supply 33 High voltage ammeter 34 Oscilloscope (voltage current monitor)
35 Timer 36 High-voltage switch 40 Dielectric constant measuring device 41 Impedance analyzer 42 Test fixture 43 Main electrode 44 Test object 45 Counter electrode 50 Barium titanate slurry K1 Coulomb force K2 Stretching direction A Mixing process B Ultrasonic treatment process C Compounding process D Drying process

Claims (7)

The dielectric elastomer (10) used for the dielectric elastomer transducer (20) contains dielectric particles (11) surface-modified with an organic dispersing agent (14) in a dispersed state. (1). The dielectric elastomer (1) according to claim 1, wherein the dielectric particles (11) contained in a dispersed state in the dielectric elastomer (10) are barium titanate (12). The dielectric according to claim 2, wherein the barium titanate (12) contained in a dispersed state in the dielectric elastomer (10) has a particle diameter of 5 nm to 500 nm and an average particle diameter of 50 nm. Particle-containing dielectric elastomer (1). The blending ratio of the barium titanate (12) contained in the dielectric elastomer (10) in a dispersed state is in the range of 1.0 wt% to 50.0 wt%. Dielectric elastomer containing dielectric particles (1) described in 1. Barium titanate (12);
A surfactant (13);
An organic dispersant (14);
An organic solvent (15);
Mixing step (A) to obtain a barium titanate slurry (50) by mixing
An ultrasonic treatment step (B) for applying a shock by ultrasonic waves to the barium titanate slurry (50) obtained in the mixing step (A) to achieve uniform dispersion;
A blending step (C) for blending the barium titanate slurry (50) obtained in the ultrasonic treatment step (B) with a dielectric elastomer (10);
A drying step (D) for drying the barium titanate slurry (50) obtained by the blending step (C);
(2) A method for producing a dielectric elastomer containing dielectric particles. 6. The dielectric according to claim 5, wherein the mixing condition in the mixing step (A) is performed using a bead mill, using beads of 5 mm or less, and a peripheral speed of the agitator being 3 m / s to 15 m / s. Manufacturing method (2) of particle-containing dielectric elastomer. The dielectric particle-containing dielectric elastomer according to claim 5 or 6, wherein the dispersion treatment in the ultrasonic treatment step (B) is performed by irradiating ultrasonic waves having a frequency of 18 kHz to 200 kHz for 10 seconds or more. Method (2).