JP5156940B2 - Polymer actuator and manufacturing method thereof - Google Patents

Description

  The present invention relates to a polymer actuator and a method for producing the same, and in particular, includes a film made of a polymer compound and electrodes formed on both surfaces of the film, by applying a voltage between the electrodes. The present invention relates to a polymer actuator that bends and deforms the film and a method for manufacturing the same.

  At present, in the field of mechatronics, next-generation self-contained walking robots such as two-legged walking robots and healing robot toys are attracting attention. In these fields, control methods based on conventional electromagnetic motors are used, but the current situation is that the movement is awkward and the creature is still far from smooth movement. For example, in order to embody parts that require skillful and smooth movement without noise in home appliances and industrial products, true humanoid robots, general-purpose robots, etc. It is necessary to materialize next-generation actuators that can move smoothly and move smoothly.

  As such an actuator, there has been proposed a polymer actuator made of various polymer materials and causing electrochemical expansion and contraction or bending deformation by electrical stimulation. Compared with conventional electromagnetic motors, polymer actuators can be driven 1) smoothly, 2) no noise or noise when driven, 3) ultra-compact and lightweight, 4) mechanical failure 5) It has an excellent feature that it operates under a wide driving environment such as in the atmosphere, water, and organic medium.

  As such polymer actuators, various types of polymer actuators using ion conductive polymer compounds, electron conductive polymer compounds, nonionic gels, elastomers, and the like have been proposed. For example, a polymer actuator that causes bending deformation as shown in FIG. 1 has been reported. This type of polymer actuator includes a film 1 made of a polymer compound and electrodes 2a and 2b formed on both surfaces of the film, and the film is bent and deformed by applying a voltage between the electrodes. To do. As such polymer actuators, those using ionic polymer compounds (ion-conducting polymer compounds) are mainly used, but those using nonionic polymer compounds have also been reported.

  As an example of using an ionic polymer compound, for example, metal-composite polymers (IPMC: ionic polymeric-metal composites) provided with metal electrodes on both surfaces of an ion exchange resin film are disclosed (for example, Non-Patent Document 1). Etc.). The driving mechanism of this polymer actuator can be explained as follows for an anionic ion exchange resin membrane for cation exchange, for example. By applying voltage, cations that can move freely within the membrane move to the cathode side, and accompanying this ion, water molecules contained in the ion exchange resin also move to the cathode side, increasing the osmotic pressure on the cathode side. And the membrane expands. On the other hand, since the anion fixed to the ion exchange resin is not easily attracted to the anode side of the counter electrode, the concentration of the cation on the anode side decreases, the osmotic pressure decreases, and the membrane contracts. As a result, the membrane is bent and deformed by the expansion on the cathode side and the contraction on the anode side.

  As an example of using a nonionic polymer compound, the polymer film is bent and deformed by applying a voltage to the polymer film made of a nonionic polymer compound to which an ionic substance such as sodium acetate is added. A method is disclosed (see, for example, Patent Document 1).

In the conventional polymer actuator provided with electrodes on both surfaces of a film made of a polymer compound, a noble metal such as platinum or gold is plated as the electrode.
JP 2000-216448 A (released on August 4, 2000) M. Shahinpoor, Electrochimica Acta 48 (2003) 2343-2353

  However, in the above-described conventional polymer actuator, an electroless plating method is used for plating to form electrodes, but it takes time and effort (20 to 50 hours) to repeat the number of times of plating. In addition, there is a problem that the cost is increased because the noble metal is used.

  The present invention has been made in view of the above-mentioned problems, and its object is to provide a polymer that is inexpensive in cost and can be easily manufactured in a short time compared to a conventional polymer actuator using a noble metal. An object of the present invention is to provide an actuator and a manufacturing method thereof.

  As a result of intensive studies in view of the above problems, the present inventors have used an electrode comprising a polymer binder and carbon powder dispersed therein as an electrode of the polymer actuator. Contrary to the expectation that a mixture of carbon powder and polymer binder that has been hardened under pressure is hard and not suitable for an electrode that needs to bend in accordance with the bending deformation of the film, a flexible electrode is obtained. I found out that In addition, since such an electrode is required to be flexible, it must be fixed on both sides of the film without being reinforced with a support or the like, and it is difficult to obtain such an electrode only from a polymer binder and carbon powder. As expected, it was found that an electrode that does not collapse can be fixed on both sides of the film by balancing the amounts of the polymer binder and the carbon powder. Furthermore, since it is necessary for such an electrode to have high electrical conductivity, it was expected that the strength would be insufficient when the carbon powder content was increased, but the polymer actuator obtained had sufficient strength. And it discovered that it functions as a stable electrode even after impregnating an ionic liquid, and came to complete this invention.

  That is, the polymer actuator according to the present invention includes a film made of a polymer compound and electrodes formed on both surfaces of the film, and a voltage is applied between the electrodes in order to solve the above problems. In the polymer actuator for bending and deforming the film, the electrode includes a polymer binder and carbon powder dispersed therein. According to the above configuration, it is possible to realize a polymer actuator that is inexpensive in cost and can be easily manufactured in a short time as compared with a conventional polymer actuator using a noble metal.

  In the polymer actuator according to the present invention, the polymer compound may be an ion conductive polymer compound or a nonionic polymer compound.

  In the polymer actuator according to the present invention, the polymer compound preferably contains an ionic liquid. Since the polymer actuator contains an ionic liquid, it is possible to avoid the problem of deterioration of the function of the polymer actuator due to moisture evaporation, and therefore it can be used well in the atmosphere.

  In the polymer actuator according to the present invention, the carbon powder is preferably contained in an amount of 1 part by weight to 1000 parts by weight with respect to 100 parts by weight of the polymer binder. By including the carbon powder in the above proportion, there is an effect of functioning as a stable electrode having sufficient electrical conductivity and excellent strength.

  In the polymer actuator according to the present invention, the average particle size of the carbon powder is preferably greater than 0 nm and not greater than 10 μm. When the average particle diameter of the carbon powder is within the above range, there is a further effect of improving dispersibility and adhesion.

  In the polymer actuator according to the present invention, the polymer binder preferably comprises the same polymer compound as the polymer compound constituting the film. Since the polymer binder contains the same polymer compound as the polymer compound constituting the film, the compatibility with the film and the bondability and adhesion are higher. It can be configured.

  In the polymer actuator according to the present invention, the thickness of the film is preferably 10 μm or more and 5 mm or less. When the thickness of the film is within the above range, there is a further effect that the shape stability during molding is excellent.

  In the polymer actuator according to the present invention, the thickness of each of the electrodes is preferably 1 μm or more and 2 mm or less. When the thickness of the electrode is within the above range, there is a further effect that it has a sufficient electrical conductivity and functions as a flexible electrode that can bend and deform well together with the film.

  A method for producing a polymer actuator according to the present invention includes a film made of a polymer compound and electrodes formed on both surfaces of the film, and the film is bent and deformed by applying a voltage between the electrodes. A method of manufacturing a polymer actuator is characterized in that carbon powder is dispersed in a polymer binder solution to form a paste, and the film is heated and pressed with the paste interposed therebetween.

  According to said structure, compared with the conventional polymer actuator using a noble metal, it becomes cheap in cost and it becomes possible to manufacture a polymer actuator easily in a short time.

  As described above, the polymer actuator according to the present invention has a configuration in which the electrode includes a polymer binder and carbon powder dispersed therein. Compared with a molecular actuator, there is an effect that it is possible to realize a polymer actuator that is inexpensive and can be easily manufactured in a short time.

  Further, the electrode has an effect that it is excellent in flexibility without cracking as compared with a conventional electrode obtained by electroless plating of platinum or gold.

  Below, the polymer actuator concerning this invention and its manufacturing method are demonstrated in detail.

(1) Polymer actuator according to the present invention The polymer actuator according to the present invention includes a film made of a polymer compound and electrodes formed on both surfaces of the film, and a voltage is applied between the electrodes. Thus, in the polymer actuator for bending and deforming the film, the electrodes formed on both surfaces of the film comprise a polymer binder and carbon powder dispersed therein. Hereinafter, (1-1) an electrode and (1-2) a film made of a polymer compound will be described in this order.

(1-1) Electrode In the polymer actuator according to the present invention, the electrode includes a polymer binder and carbon powder dispersed therein. Such an electrode material in which carbon powder is dispersed and fixed in a polymer binder is an electrode material that can be used for all polymer actuators.

  It has been found that the electrode used in the present invention is very hydrophobic and repels water and floats on the water surface. A conventional electrode obtained by electroless plating of platinum or gold does not float on the water surface but gets wet. In the conventional electrode in which platinum or gold is electrolessly plated, water evaporates from the surface of the electrode and there is a problem that the bending fluctuation gradually decreases. However, the electrode used in the present invention is affected by this high hydrophobicity. It is thought that it has the effect of reducing the evaporation of water from the electrode surface.

Here, the polymer binder constituting the electrode of the polymer actuator according to the present invention is not particularly limited as long as it is a polymer binder having flexibility that can be deformed in accordance with the bending deformation of the film. It is preferable that it is less hydrolyzable and stable in the air. Such polymer binders include polyolefin polymers such as polyethylene and polypropylene; polystyrene; polyimide; polyarylenes such as polyparaphenylene oxide, poly (2,6-dimethylphenylene oxide), and polyparaphenylene sulfide (aromatic polymers). ); Polyolefin polymer, polystyrene, polyimide, polyarylenes (aromatic polymer), etc., sulfonic acid group (—SO ₃ H), carboxyl group (—COOH), phosphoric acid group, sulfonium group, ammonium group, pyridinium Fluorine-containing polymers such as polytetrafluoroethylene and polyvinylidene fluoride; sulfonate groups, carboxyl groups, phosphate groups, sulfonium groups, ammonium groups, Perfluorosulfonic acid polymer, perfluorocarboxylic acid polymer, perfluorophosphoric acid polymer, etc., in which a nium group is introduced, etc .; polybutadiene compounds; polyurethane compounds such as elastomers and gels; silicone compounds; polyvinyl chloride; polyethylene terephthalate; Nylon; and polyarylate.

  Moreover, as the polymer binder, a polymer having conductivity can be used. Such a polymer is not particularly limited, and examples thereof include polyaniline, polypyrrole, polythiophene, polyacetylene, and polyphenylene.

  Furthermore, as the polymer binder, a metal oxide having a polymer structure obtained by a sol-gel method or the like can also be used. The metal oxide is not particularly limited, and for example, manganese, nickel, cobalt, and vanadium pentoxide metal oxide can be used.

Among these polymer binders, a perfluorosulfonic acid / PTFE (polytetrafluoroethylene) copolymer, a perfluorocarboxylic acid / PTFE copolymer, or the like can be more suitably used as the polymer binder. More specifically, for example, Flemion ^TM (Asahi Glass), Nafion ^TM (manufactured by DuPont) and the like can be suitably used. Here, these polymer binders may be used alone or in combination of two or more. Furthermore, you may dilute and use with a suitable solvent. Further, instead of directly adding these polymers as binders, monomers corresponding to these polymers may be added to produce polymers from the polymerization reaction of the monomers, and as a result, they may function as polymer binders.

  The polymer binder is preferably a polymer having high compatibility with the film. Thereby, since compatibility and bondability with the said film are higher, it becomes possible to comprise a stronger electrode. For this purpose, the polymer binder may be a polymer having the same, similar or the same polymer structure as that of the polymer compound constituting the film, or a polymer having the same, similar or the same functional group. preferable. For example, when the film is perfluorosulfonic acid, the polymer binder is preferably perfluorosulfonic acid, perfluorocarboxylic acid, a polymer having a sulfonic acid group, a polymer having a carboxyl group, or the like.

  Further, the polymer binder may comprise the same kind, similar or the same polymer compound as the polymer compound constituting the film. Thereby, if compatibility and bondability with the said film become high, it will become possible to comprise a firm electrode. Further, from the viewpoint of compatibility and bonding properties, the higher the content of the same or the same polymer compound as the polymer compound constituting the film, the higher the polymer, and the same polymer as the polymer compound constituting the film. More preferably, it consists of a compound.

  The carbon powder dispersed in the electrode of the polymer actuator according to the present invention is not particularly limited as long as it can impart electrical conductivity by being dispersed in the polymer binder. Examples of such carbon powder include carbon black, activated carbon, carbon fiber, carbon tube, and graphite. Examples of carbon black include channel black, thermal black, furnace black, and acetylene black. Among these, the carbon powder is particularly preferably furnace black or acetylene black. Thereby, electrical conductivity can be provided more suitably.

  The average particle size of the carbon powder is not particularly limited, but is preferably greater than 0 and 10 μm or less, more preferably greater than 0 and 1 μm or less, and 0 or more and 500 nm or less. More preferably, it is particularly preferably 0 to 100 nm. Moreover, it is not preferable that the average particle diameter of the carbon powder is larger than 10 μm because the polymer actuator of the present invention may not be bent.

  The average particle size of the carbon powder can be measured using a dynamic light scattering particle size distribution measuring device, a scanning electron microscope or a transmission electron microscope.

  Further, the content of the carbon powder is preferably 1 part by weight or more and 1000 parts by weight or less, and more preferably 10 parts by weight or more and 500 parts by weight or less with respect to 100 parts by weight of the polymer binder. Preferably, it is 100 parts by weight or more and 200 parts by weight or less. It is preferable that the amount of the carbon powder is 1 part by weight or more with respect to 100 parts by weight of the polymer binder because electrical conductivity that can function as an electrode of the actuator can be provided. In addition, it is preferable that the amount of the carbon powder is 1000 parts by weight or less with respect to 100 parts by weight of the polymer binder because the strength of the actuator electrode can be imparted to the actuator electrode without collapsing.

  In the polymer actuator according to the present invention, the electrode is formed on both surfaces of the film. Here, the electrode is formed on both surfaces of the film as long as the electrode is bonded and fixed to both surfaces of the film. The carbon powder dispersed in the electrode may be dispersed to the surface and / or the inside of the film. Thus, when the carbon powder bites into the film and is dispersed, the contact area between the conductive carbon powder and the film is large, so that a voltage can be applied more efficiently. It is more preferable. In this way, in order to disperse the carbon powder to the surface and / or the inside of the film, for example, the carbon powder is dispersed in a polymer binder solution to form a paste, and the paste is used to form the film. In the case of using the method of heating and pressing with sandwiching the film, the film may be swollen in advance with an organic solvent such as alcohol, ketone, aromatic hydrocarbon or water before the heating and pressing.

  The thickness of the electrode is not particularly limited as long as it does not inhibit the bending deformation of the polymer actuator, but is preferably 1 μm or more and 2 mm or less, more preferably 1 μm or more and 500 μm or less, and more preferably 5 μm or more. It is more preferably 200 μm or less, and particularly preferably 5 μm or more and 100 μm or less. If the thickness of the electrode is less than 1 μm, it may be a problem in terms of electrical conductivity as an electrode of a polymer actuator, which is not preferable. In addition, if the thickness of the electrode is larger than 2 mm, the electrode is hard because it contains carbon, and it is liable to break, and it may not be bent along with the bending deformation of the film.

  As described above, the electrode of the polymer actuator according to the present invention is provided with conductivity by including a polymer binder and carbon powder dispersed therein. The electrical resistance value of the electrode is preferably 1000 Ω · cm or less, and more preferably 100 Ω · cm or less. When the electric resistance value of the electrode is 1000 Ω · cm or less, the polymer actuator of the present invention can be bent when a low voltage is applied to the electrode.

  Moreover, the said electrode should just contain a polymer binder and the carbon powder disperse | distributed in it, However, It is more preferable that the carbon powder is disperse | distributed uniformly. This is more preferable because the potential is applied uniformly.

  Moreover, the said electrode may contain other components other than a polymer binder and carbon powder, unless it has a bad influence on the function of a polymer actuator. Examples of such other components include ionic compounds and metal ions.

(1-2) Film made of polymer compound In the polymer actuator according to the present invention, the film made of the polymer compound is formed by applying a voltage between the electrodes formed on both surfaces of the film made of the polymer compound. The film is not particularly limited as long as it is a polymer compound film used in a polymer actuator of a type in which the film bends and deforms. Therefore, the polymer compound may be an ion conductive polymer compound or a nonionic polymer compound. Note that the ion conductive polymer compound is a polymer compound in which the charge carrier is an ion when an electric current moves and an electric current flows under an electric field, and is synonymous with the ionic polymer compound.

  When the polymer compound is, for example, an ion conductive polymer compound, the driving mechanism of the polymer actuator is, for example, the case where the ion conductive polymer compound is a polyanion in which an anionic functional group is introduced into a polymer. An example will be described as follows. By applying a voltage, cations that can move freely in the film move to the cathode side, and water molecules contained in the film also move to the cathode side with this cation, so the osmotic pressure on the cathode side increases. , The membrane expands. On the other hand, since the anion fixed to the ion conductive polymer compound is not easily attracted to the anode side of the counter electrode, the concentration of the cation on the anode side is lowered, the osmotic pressure is lowered, and the membrane is contracted. As a result, the film is bent and deformed by the expansion on the cathode side and the contraction on the anode side. In addition, when the said high molecular compound contains the ionic liquid mentioned later, a mobile species turns into the ion which comprises an ionic liquid. In this case, although the effect of osmotic pressure is unknown, a film made of a polymer compound is bent and deformed.

  In addition, when using a nonionic polymer compound, the mechanism is unknown, but by applying a voltage to a polymer film composed of a nonionic polymer compound to which an ionic substance such as sodium acetate is added, A method of bending and deforming a polymer film is known. When the nonionic polymer compound contains an ionic liquid described later, when a voltage is applied, the anion constituting the ionic liquid is attracted to the positive electrode and the cation is attracted to the negative electrode. Since the anion and the cation constituting the ionic liquid have different ion sizes, it is considered that the difference in the size of the ions causes a difference in the polarities of the film and the film bends and deforms.

As the ion conductive polymer compound, a polycation may be used, or a polyanion may be used. Examples of the polyanion are not particularly limited. For example, a known polymer having a basic skeleton such as polyethylene, polystyrene, polyimide, and polyarylenes (aromatic polymer) may be used as an anionic functional group. Acid group (—SO ₃ H), carboxyl group (—COOH), phosphoric acid group and the like introduced; anionic functional groups such as sulfonic acid group, carboxyl group and phosphoric acid group are added to the skeleton of the fluorine-containing polymer The introduced perfluorosulfonic acid polymer, perfluorocarboxylic acid polymer, perfluorophosphoric acid polymer and the like can be mentioned. Among these, as the polyanion, a perfluorosulfonic acid / PTFE (polytetrafluoroethylene) copolymer can be more suitably used. Here, as the perfluorosulfonic acid / PTFE copolymer, a commercially available one may be used, and for example, Flemion ^TM (Asahi Glass), Nafion ^TM (manufactured by DuPont) and the like can be suitably used.

  Also, examples of polycations are not particularly limited, but for example, a known functional polymer such as polyethylene, polystyrene, polyimide, polyarylenes (aromatic polymer), as a cationic functional group, sulfonium group, Examples thereof include an ammonium group and a pyridinium group introduced.

  The ion conductive polymer compound needs to be in a water-containing state at the time of operation, that is, at the time of applying a voltage to bend and deform. As a result, when a voltage is applied to the film made of the ion conductive polymer compound, water molecules move along with the moving ions, and the film can be bent and deformed. In addition, as a method of including water in the ion conductive polymer compound, for example, the ion conductive polymer compound may be impregnated in water, preferably ion exchange water. Similarly, when an ionic liquid described later is used, the ion conductive polymer compound needs to contain an ionic liquid in addition to water or in place of water during operation.

Further, when the ion conductive polymer compound is a polyanion, it is more preferable to use a compound obtained by exchanging a counter cation of an anionic functional group with Li ⁺ , Na ⁺ , K ⁺ , an alkyl ammonium ion, or the like. When the ion conductive polymer compound is a polycation, the counter anion of the cationic functional group is selected from F ⁻ , Cl ⁻ , Br ⁻ , aromatic or aliphatic sulfonic acids, aromatic or aliphatic It is more preferable to use those exchanged for carboxylic acids, aromatic or aliphatic phosphoric acids. This is preferable because the degree of bending and the bending speed of the polymer actuator can be improved. In addition, as a method for exchanging counter ions of the ion conductive polymer compound, for example, the ion conductive polymer compound may be impregnated in a salt solution containing the ions to be exchanged. Here, the solution may be an aqueous solution, an organic solvent, or a mixed solvent thereof.

  Examples of the nonionic polymer compound include fluorine-containing polymers such as tetrafluoroethylene and polyvinylidene fluoride; polyolefin polymers such as polyethylene and polypropylene; polybudadiene compounds; polyurethane compounds such as elastomers and gels. Silicone compounds; thermoplastic polystyrene; polyvinyl chloride; polyethylene terephthalate.

  The nonionic polymer compound needs to contain an ionic substance. Thereby, when a voltage is applied to the film made of the nonionic polymer compound, the film can be bent and deformed. In addition, as a method of including an ionic substance in the nonionic polymer compound, for example, a solution of the ionic substance may be impregnated with the nonionic polymer compound. Here, the solution may be an aqueous solution, an organic solvent, or a mixed solvent thereof.

  Examples of the ionic substance include lithium fluoride, lithium bromide, sodium bromide, magnesium chloride, copper sulfate, sodium acetate, sodium oleate, and sodium acetate.

  The polymer compound may contain an ionic liquid. Here, the ionic liquid refers to an organic compound salt composed of an anion and a cation and liquid at normal temperature. Such ionic liquids dissolve organic and inorganic compounds, are non-volatile, and are stable even at high temperatures. Therefore, when a polymer actuator having a conventional metal electrode containing water is used in the atmosphere, the problem that water is evaporated from the electrode surface and bending deformation is gradually lost is solved. Stability can be improved.

The ionic liquid is not particularly limited, and a conventionally known ionic liquid can be suitably used. Examples of the ionic liquid include CF ₃ SO ₃ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , NO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , and (CF ₃ SO ^{_{2) 3 C -, (CH}} 3) OSO 3 -, AlCl 4 -, ClO 4 -, RCOO -, RSO 3 -, NH 2 CHRCOO -, with _SO ^{4 2-or} the like counter anion, imidazolium cation, pyridinium A cation, a tetraalkylammonium cation or the like can be preferably used.

  As the imidazolium cation, a dialkyl imidazolium cation, a trialkyl imidazolium cation, or the like can be used. More specifically, for example, 1-butyl-3-methylimidazolium ion, 1-ethyl-3-methylimidazolium ion, 1,2-dimethyl-3-propylimidazolium ion, 1-butyl-2,3 -Dimethylimidazolium ion, 1-methyl-3- (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) imidazolium ion, 1- Butyl-3- (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) imidazolium ion, 1,3-dimethylimidazolium ion, 1 Examples include -hexyl-3 methylimidazolium ion, 1-methyl-3-octylimidazolium ion, 1-methyl-3-ethylimidazolium ion, and the like.

  Examples of the pyridinium cation include N-methylpyridinium ion, N-ethylpyridinium ion, N-propylpyridinium ion, N-butylpyridinium ion, 1-ethyl-2-methylpyridinium ion, and 1-butyl-2methyl. A pyridinium ion etc. can be mentioned.

  Examples of the tetraalkylammonium cation include trimethylpropylammonium, trimethylhexylammonium, and tetrapentylammonium.

  Examples of the ionic liquid include any combination of the anion and the cation. The ionic liquid may be used in combination of two or more ionic liquids.

  More specifically, examples of the ionic liquid include 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3- Examples thereof include methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, and the like.

  The ionic liquid may be polymerizable. Such a polymerizable ionic liquid is not particularly limited, and for example, an allylalkylimidazolium salt can be suitably used. More specifically, for example, 1-allyl-3-ethylimidazolim trifluoromethanesulfonate, 1-allyl-3-ethylimidazolim tetrafluoroborate, 1-allyl-3-ethylimidazolim hexafluorophosphate 1-allyl-3-ethylimidazolimyl chloride, 1-allyl-3-ethylimidazolim bromide, 1-allyl-3-ethylimidazolim iodide, 1-allyl-3-butylimidazolim trifluoromethanesulfur Phonate, 1-allyl-3-butylimidazolim tetrafluoroborate, 1-allyl-3-butylimidazolim hexafluorophosphate, 1-allyl-3-butylimidazolim chloride, 1-allyl-3-butyl Imidazolim bromide, 1-allyl-3 Butylimidazolim imidazolim iodide, 1,3-diallylimidazolium trifluoromethanesulfonate, 1,3-diallylimidazolium tetrafluoroborate, 1,3-diallylimidazolium hexafluorophosphate, 1,3- Examples include diallylimidazolium chloride, 1,3-diallylimidazolium bromide, and 1,3-diallylimidazolium iodide.

  When the polymer compound is an ion conductive polymer compound, as described above, it is necessary to be in a water-containing state at the time of operation. From the viewpoint of the stability of the polymer actuator in the air, the ion The conductive polymer compound preferably contains an ionic liquid in addition to or in place of water during operation. Further, when the polymer compound is a nonionic polymer compound, as described above, it is necessary to contain the ionic substance, but in addition to the ionic substance, or the ionic substance. It is preferable to contain an ionic liquid instead.

  The polymer compound containing the ionic liquid is, for example, impregnated in the ionic liquid or impregnated with a film of the polymer compound in a solution of the ionic liquid, and then the solvent is removed. Can be obtained. Here, the solution may be an aqueous solution, an organic solvent, or a mixed solvent thereof.

  The thickness of the film is, for example, preferably 10 μm or more and 5 mm or less, more preferably 100 μm or more and 5 mm or less, and further preferably 100 μm or more and 2 mm or less. When the thickness of the film is 10 μm or more, it is preferable in terms of moldability and dimensional stability. Moreover, it is preferable in terms of workability and flexibility that the thickness of the film is 5 mm or less.

  In addition, examples of the shape of the film include a rectangular flat plate shape as shown in FIG. 1, but are not limited thereto, and may be a flat plate shape such as a circle, a triangle, an ellipse, or a rod. It may be a film, a cylinder, a spiral, a coil, or the like.

  The polymer actuator according to the present invention may further include a power supply device that applies a voltage between the electrodes and a control device that controls the voltage.

  The actuator of the present invention is bent and deformed when a low voltage of about 0.1 to 10 V is applied between the electrodes. The direction of bending deformation, the amount of displacement, the displacement speed, and the like vary depending on the type of film made of the polymer compound, the composition of the electrode, the moving ion species, and the like. In general, when the polarity of the potential is reversed, the film bends and deforms in the opposite direction.

  Normally, in an actuator obtained by electroless plating of platinum, as shown in FIG. 5, in a state where the moisture content at a humidity of 90% is high (indicated by a in FIG. 5), the principle is strictly known. Although there is no backtracking of the displacement. When the humidity is lowered and the water content is lowered, as shown by b (humidity 30%) in FIG. In the polymer actuator according to the present invention, it was shown that the reverse phenomenon was hardly observed even at a humidity of 90%. Considering the applicability of the actuator, this property is considered important.

(2) Production method of polymer actuator according to the present invention The production method of the polymer actuator according to the present invention may be any method as long as it is a method capable of producing the polymer actuator, For example, a method in which carbon powder is dispersed in the polymer binder solution to form a paste, and the film is sandwiched with the paste and heated and pressed can be suitably used. Here, “heating and pressing” includes both methods of pressing while heating and raising the temperature in the pressed state.

  The paste can be obtained by adding the polymer binder, organic solvent, and carbon powder and mixing well. In addition, depending on the case, you may add water in addition to the said organic solvent. Here, since the polymer binder, the carbon powder, and the ratio thereof are as described above, the description thereof is omitted here. The order of adding the polymer binder, the organic solvent, and the carbon powder is not particularly limited. For example, the polymer binder is dissolved in the organic solvent, and the carbon powder is added to the obtained polymer binder solution. In addition, it is preferable to mix well.

  The organic solvent is not particularly limited as long as it can dissolve the polymer binder. The organic solvent has a boiling point of 150 ° C. or lower, more preferably 100 ° C. or lower. More preferred. Thereby, the said organic solvent can be removed favorably at the time of hot press. Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, and isopentyl alcohol; acetone, 2-butanone, 3-pentanone, and methylisopropyl. Ketones such as ketone, methyl ethyl ketone, methyl n-propyl ketone, 3-hexanone and methyl n-butyl ketone; ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and tetrahydropyran; lower saturated hydrocarbons such as pentane, hexane and cyclohexane; ethyl acetate Examples include esters such as esters.

  These organic solvents may be used alone or in combination. Furthermore, you may mix and use water.

  The polymer actuator according to the present invention can be bonded to the film in one step by sandwiching the film with the obtained paste and hot pressing.

The heating press may use a method of applying the paste to the film and then heating and pressing, or a method of heating and pressing the paste on two molds using a mold and sandwiching the film. It may be used. The temperature of the heating press may be any temperature necessary for evaporating the solvent of the polymer binder, and it is not particularly necessary for the polymer binder to melt. Further, it is not particularly limited as long as it is not lower than the melting temperature but not higher than the decomposition temperature of the polymer binder, and may be appropriately selected according to the polymer binder to be used, the polymer compound constituting the film, the moving ion species, and the like. That's fine. Further, the pressing pressure and time are not particularly limited, and may be appropriately selected according to the polymer binder to be used, the polymer compound constituting the film, the moving ion species, and the like. For example, the temperature of the hot press is preferably 30 to 150 ° C. Moreover, it is preferable that it is 1-100 kg / cm < ² >, and, as for a press pressure, it is more preferable that it is 10-50 kg / cm < ² >. In Examples to be described later, for example, a good polymer actuator could be produced at 90 ° C. to 95 ° C., 20 kg / cm ² and 30 minutes.

  When the film contains water, the ionic substance, the ionic liquid, or a mixture thereof, as described above, the solution may be impregnated with the film. Here, the concentration of the solution to be impregnated and the impregnation time are not particularly limited, and a conventionally known method may be used. The impregnation of the film with water, the ionic substance, the ionic liquid, or a mixture thereof may be performed after the electrodes are formed on both sides of the film.

Moreover, although the said film may be used as it is, you may perform the following processes.
i) The film is washed to remove adhering impurities and dust. As a method for washing the film, it is sufficient that the polymer compound constituting the film is not extremely eluted, and a method for washing with an acid, a method for ion exchange with ion-exchanged water, or the like can be used. For example, in the case of a perfluorosulfonic acid / PTFE copolymer, the film is preferably washed by boiling in an aqueous nitric acid solution and boiling in ion-exchanged water.
ii) When the film is an ion conductive polymer compound, the counter cation and the counter anion are ion-exchanged with the other ionic species described above. Such treatment is not essential, and even if it is a proton type, it operates as a polymer actuator, but it is more preferable to perform such treatment because the degree of bending and the bending speed of the polymer actuator can be improved. In addition, as a method of exchanging the counter ion of the ion conductive polymer compound, as described above, for example, the ion conductive polymer compound may be impregnated in a salt solution containing the ion to be exchanged. . Here, the solution may be an aqueous solution, an organic solvent, or a mixed solvent thereof.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by an Example.

  In the following examples, the bending deformation of the obtained polymer actuator was evaluated as follows.

  The amount of displacement of the polymer actuator was measured when a DC voltage of ± 1 V to ± 5 V was applied between the electrodes of the obtained polymer actuator at a switching interval of 30 seconds.

  The displacement amount of the polymer actuator is determined by fixing the short side end of the obtained rectangular flat polymer actuator and applying the above voltage to the deflection width (displacement amount) associated with bending using a CCD camera. It was followed by evaluation measurement by imaging.

[Example 1: Production of polymer actuator using film made of ion conductive polymer compound]
A film (proton type) made of 1 cm × 2 cm of perfluorosulfonic acid (thickness: about 200 μm, Flemion ^TM , manufactured by Asahi Glass Co., Ltd.) was boiled and heated in a 50% nitric acid aqueous solution for 1 hour. A film made of perfluorosulfonic acid that had been boiled and heated was thoroughly washed with ion exchange water, and then boiled in ion exchange water for about 1 hour. Next, in order to exchange the counter cation with lithium ion, it was immersed in 100 ml of 0.5 M lithium hydroxide solution for about 3 hours. The obtained film was thoroughly washed with ion exchange water.

Perfluorosulfonic acid membrane (Flemion ^TM , manufactured by Asahi Glass) as a polymer binder 0.1 g of carbon powder (acetylene black) (Denka Black, manufactured by Denki Kagaku Kogyo) is added to 1 ml of a lower alcohol solution (10 wt%) at 25 ° C. Kneaded well and mixed to obtain a paste. The paste obtained in each of two concave molds was placed, and a perfluorosulfonic acid film in which the counter cation was exchanged with lithium ions was sandwiched, and the pressure was applied with a heat press machine (manufactured by ASONE) (90 ° C to 95 ° C, 20 kg / cm ² , 30 minutes).

  In the obtained water-containing polymer actuator, electrodes having a carbon powder dispersed in perfluorosulfonic acid having a thickness of about 100 μm were formed on both sides of a perfluorosulfonic acid film having a thickness of about 200 μm. In addition, good bondability between the perfluorosulfonic acid film and the electrode in which carbon powder was dispersed in perfluorosulfonic acid was confirmed.

  About the obtained polymer actuator, the DC voltage of 1-5V was applied between both electrodes in air | atmosphere, and the bending deformation of the polymer actuator was confirmed.

  FIG. 2 shows the amount of displacement when a temperature of 25 ° C., a humidity of 30%, and a DC voltage of ± 5 V are applied (stepped) at a switching interval of 30 seconds. FIG. 4 shows the humidity effect of the displacement when a temperature of 25 ° C. and a DC voltage of ± 3 V are applied (stepped) with a switching interval of 30 seconds. In FIG. 4, a shows the result when the humidity is 90%, and b shows the result when the humidity is 30%.

  Normally, in an actuator obtained by electroless plating of platinum, as shown in FIG. 5, a reverse movement phenomenon of displacement is observed in a state where the moisture content is high at a humidity of 90%. In the polymer actuator obtained in this example, as shown in FIG. 4, the reverse phenomenon was hardly observed even under the condition of 90% humidity.

[Example 2]
A film (proton type) made of 1 cm × 2 cm of perfluorosulfonic acid (thickness: about 200 μm, Flemion ^TM , manufactured by Asahi Glass Co., Ltd.) was boiled and heated in a 50% nitric acid aqueous solution for 1 hour. The perfluorosulfonic acid film that had been boiled and heated was thoroughly washed with ion-exchanged water, and then boiled in ion-exchanged water for about 1 hour. Next, in order to exchange the counter cation with lithium ion, it was immersed in 100 ml of 0.5 M lithium hydroxide solution for about 3 hours. The obtained film was thoroughly washed with ion exchange water.

Perfluorosulfonic acid membrane as a polymer binder (Flemion ^TM , manufactured by Asahi Glass) 0.1 ml of carbon powder (carbon black (Denka Black, manufactured by Denki Kagaku Kogyo)) is added to 1 ml of lower alcohol solution (10 wt%) A paste was obtained by kneading and mixing, and the obtained paste was placed on two concave molds, and a perfluorosulfonic acid film in which counter cations were exchanged with lithium ions was sandwiched between them, and added with a heat press machine (manufactured by ASONE). Pressure (90 ° C. to 95 ° C., 20 kg / cm ² , 30 minutes).

  In order to exchange the water inside the film with an ionic liquid, the membrane was placed in an oven heated to about 110 ° C. to 120 ° C. and dried for about 15 hours, and then 1-ethyl-3-methylimidazolium trifluoro. It was impregnated with lomethanesulfonate and heated at 110 to 120 ° C. for 15 hours.

  In the polymer actuator in which the water in the membrane is replaced with an ionic liquid, electrodes having carbon powder dispersed in perfluorosulfonic acid of about 100 μm are formed on both sides of a perfluorosulfonic acid film having a thickness of about 250 μm. It was. In addition, good bondability between the perfluorosulfonic acid film and the electrode in which carbon powder was dispersed in perfluorosulfonic acid was confirmed.

  About the obtained polymer actuator, the DC voltage of 1-5V was applied between both electrodes in air | atmosphere, and the bending deformation of the polymer actuator was confirmed.

  FIG. 3 shows the amount of displacement when a temperature of 25 ° C., a humidity of 30%, and a DC voltage of ± 5 V are applied (stepped) at a switching interval of 30 seconds.

  The polymer actuator according to the present invention is less expensive than conventional polymer actuators using precious metals, and can be easily manufactured in a short time. It can be used for parts that require smooth movement, true humanoid robots, general-purpose robots, etc., and is very useful.

It is the schematic which shows one Embodiment of the conventional polymer actuator and the polymer actuator of this invention, (a) is the schematic before voltage application, (b) is the schematic which shows the polymer actuator at the time of voltage application. 3 is a graph showing the amount of bending deformation displacement due to voltage application of the polymer actuator obtained in Example 1. It is a graph which shows the displacement amount of the bending deformation by the voltage application of the polymer actuator obtained in Example 2. FIG. 3 is a graph showing the amount of bending deformation displacement due to voltage application of the polymer actuator obtained in Example 1. It is a graph which shows the displacement amount of the bending deformation by the voltage application of the conventional polymer actuator.

Explanation of symbols

1 Film 2a ・ 2b Electrode

Claims (7)

In a polymer actuator comprising a film made of a polymer compound and electrodes formed on both sides of the film, and bending and deforming the film by applying a voltage between the electrodes,
The electrode consists of a polymer binder and carbon powder dispersed therein ,
The polymer compound is a perfluorosulfonic acid / polytetrafluoroethylene copolymer,
The polymer binder, wherein the polymer binder comprises a perfluorosulfonic acid / polytetrafluoroethylene copolymer.   The polymer actuator according to claim 1, wherein the polymer compound contains an ionic liquid.   3. The polymer actuator according to claim 1, wherein the carbon powder is contained in an amount of 1 to 1000 parts by weight with respect to 100 parts by weight of the polymer binder.   4. The polymer actuator according to claim 1, wherein an average particle size of the carbon powder is greater than 0 nm and 10 μm or less.   5. The polymer actuator according to claim 1, wherein the film has a thickness of 10 μm to 5 mm.   The polymer actuator according to any one of claims 1 to 5, wherein each of the electrodes has a thickness of 1 µm or more and 2 mm or less. A method for producing a polymer actuator comprising a film made of a polymer compound and electrodes formed on both surfaces of the film, wherein the film is bent and deformed by applying a voltage between the electrodes,
In the polymer binder solution, carbon powder is dispersed into a paste, and the film is sandwiched with the paste and heated and pressed.
The polymer compound is a perfluorosulfonic acid / polytetrafluoroethylene copolymer,
The method for producing a polymer actuator, wherein the polymer binder comprises a perfluorosulfonic acid / polytetrafluoroethylene copolymer.

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