JPH0685339A - Polyurethane elastomer actuator - Google Patents

Abstract

PURPOSE:To provide an actuator which does not need so high voltage and hardly causes electrolysis or heat generation. CONSTITUTION:This is a polyurethane elastomer which has an inductive poIyol or a polyol which has a substituent having relatively strong bipolar moment, and polyol are oriented in the direction of an electric field by applying an DC electric field to the polyurethane elastomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane elastomer actuator utilizing the electric field orientation of a dielectric material of polyurethane elastomer material.

[0002]

2. Description of the Related Art Conventionally, the following piezoelectric materials have been known. A piezoelectric ceramic typified by lead zirconate titanate (PZT) system, a piezoelectric polymer typified by polyvinylidene fluoride (PVDF), or a composite of these. These are actually used as materials for speakers and headphones and have shown excellent performance for specific applications.

However, the piezoelectric material is usually about 10 k.
Since it requires a high voltage of V and the amount of electrostriction to be driven is not so large, it is not suitable for use as an actuator. On the other hand, recently, actuator materials using a specific chargeable gel have also been developed. However, this kind of material involves a chemical reaction, so that there is a problem that electrolysis and heat generation occur.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an actuator which does not require such high voltage and hardly causes electrolysis or heat generation.

[0005]

In order to solve the above-mentioned problems, a polyurethane elastomer actuator of the present invention is a polyurethane elastomer having a dielectric polyol or a polyol having a substituent having a relatively strong dipole moment. By applying a DC electric field to the polyurethane elastomer, the polyol is oriented in the direction of the electric field.

[0006]

When a DC electric field is applied to the polyurethane elastomer actuator of the present invention, the dielectric polyol of the polyurethane elastomer or the polyol having a substituent having a relatively strong dipole moment is oriented in the electric field direction. Then, the conformational change of the polymer constituting the polyurethane elastomer is induced.

In the present invention, it is necessary to apply a DC electric field in order to orient the above-mentioned polyol in the electric field direction, but as a voltage therefor, a voltage as high as that required by a conventional piezoelectric material (piezoelectric ceramics, etc.) is not obtained. do not need. Further, when the polyol is oriented in the direction of the electric field, no chemical reaction accompanies the electrolysis and heat generation. According to the configuration of the present invention, an anisotropic force is generated at an extremely high speed, which can be used for useful work and can be used for actuation. The mechanism of deformation or actuation in the present invention is based on the electric field orientation of the dielectric polyol and the change in the conformation of the polymer induced thereby.

Therefore, the higher-order structure such as anisotropy of the aggregated state of the polymer chains constituting the polyurethane elastomer is one of the factors that determine the magnitude of actuation.
The structural change occurs continuously and linearly by the electric field, and therefore the generated force and the amount of deformation can be linearly controlled by the electric field. This means that the action is constant, independent of the current, even when measured under conditions where a current is passed through the system.

Conditions under which virtually no current flows (eg 1 m
The fact that actuation can be performed at (about A) suggests that heat dissipation can be avoided and electrical energy can be converted into mechanical energy with high efficiency. That is, it is possible to change the shape of the polyurethane elastomer by only the molecular orientation with the effective current being practically close to zero, and the mechanical deformation energy generated during this shape change is used for actuation.

On the other hand, the fact that the driving performance can be brought out only by controlling the polymer structure in the state where the solvent required in the case of a gel material is not contained at all is
Considering that the elastomer material is a versatile material, this is a great advantage.

[0011]

EXAMPLES The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following embodiments. As described in the section of action, the mechanism of the polyurethane elastomer actuator of the present invention is due to the conformational change of the polymer chain, and it is more responsive than the conventional charged gel which involves a chemical reaction. Is extremely fast. Although the response speed depends on the inductive property of the polyurethane elastomer, it is generally on the order of milliseconds to 10 milliseconds. The amount of change depends most on the structure and physical properties due to the degree of crosslinking inherent to polyurethane / elastomer.

The chemical structure of the polyurethane elastomer was further sought in order to utilize the elastic function of the elastomer in the actuator. The structurally necessary components of the polyurethane elastomer are three components, a component constituting the soft segment and the hard segment, and a curing agent necessary for modifying the physical strength. Therefore, we investigated the driving performance of various related compounds and their combinations under an electric field.

The polyurethane elastomer can be obtained by the following method. That is, the reaction is carried out by a conventionally known method using the polymer polyol, the organic polyisocyanate and the chain extender. For example, a method of reacting the polymer polyol with an organic polyisocyanate to obtain a urethane prepolymer and then reacting it with a chain extender, or a so-called one-shot method in which the three components are simultaneously reacted in a predetermined ratio And so on. The NCO / OH molar ratio of the polymer polyol and the organic polyisocyanate is preferably in the range of 1.5-9.

As the polyisocyanate, 2 in the molecule
As long as it has more than one isocyanate group,
For example, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4
-Trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 4,
4'-methylenebis (cyclohexylisocyanate), 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexanediisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) ) Cyclohexane, m-phenylene diisocyanate, p-
Phenylene diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, dianidine diisocyanate, 4, 4'-
Diphenyl ether diisocyanate, 1,3-xylylene diisocyanate, ω, ω'-diisocyanate-
Examples thereof include 1,4-diethylbenzene, polymethylene polyfernyl polyisocyanate, and isocyanurate-modified products, carbodiimide-modified products, and burette-modified products of these polyisocyanates. These are 1
Only one species may be used, or two or more species may be used in combination.

As the polyol, one type or two types of polyester type polyol, polyether type polyol, polycarbonate type polyol and polybutadiene type polyol are used.
It is possible to use one composed of one or more kinds, or one obtained by appropriately blending the polyol with a polyolefin polyol. As the polyester-based polyol, for example, a condensate of a polycarboxylic acid and a low-molecular polyol,
Some have a molecular weight of 500 to 10,000. In particular,
Poly (ethylene adipate) (“PEA”), Poly (diethylene adipate) (“PDA”), Poly (propylene adipate) (“PPA”), Poly (tetramethylene adipate) (“PBA”), Poly (hexamethylene adipate) ) (“PHA”), poly (neopentylene adipate) (“PNA”), polyol consisting of 3-methyl-1,5-pentanediol and adipic acid, random copolymer of PEA and PDA, PEA and PPA. Random copolymer, random copolymer of PEA and PBA, PHA
And PNA random copolymers, or caprolactone polyols obtained by ring-opening polymerization of ε-caprolactone, polyols obtained by ring-opening β-methyl-δ-valerolactone with ethylene glycol, etc. (Molecular weight is preferably 500 to 10,000)
These may be used alone or in combination of two or more. Further, examples of the polyester-based polyol include a copolymer of at least one of the following acids and at least one of glycols.

Acids: terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (mixture), paraoxybenzoic acid, trimellitic anhydride, ε-caprolactone, β-methyl-δ valerolactone. Glycol: ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, penta Erythritol, 3-methyl-1,5-pentanediol.

Examples of the polyether-based polyols include those obtained by ring-opening addition polymerization using an alkylene oxide (eg, ethylene oxide or propylene oxide) as an initiator with a polyhydric alcohol (eg, diethylene glycol) which is an active hydrogen compound, specifically Examples include polypropylene glycol (“PPG”), polyethylene glycol (“PEG”), and a copolymer of propylene oxide and ethylene oxide. Further, there are those having a molecular weight of 500 to 5,000, which are provided by cationic polymerization of tetrahydrofuran. Specifically, it is polytetramethylene ether glycol (“PTMG”), and tetrahydrofuran is a copolymer with another alkylene oxide. Specifically, it is a copolymer of tetrahydrofuran and propylene oxide, or tetrahydrofuran. Examples thereof include copolymers with ethylene oxide (all of which preferably have a molecular weight of 500 to 10,000), and they can be used alone or in combination.

Polycarbonate polyols are obtained by condensation of conventionally known polyols (polyhydric alcohols) with phosgene, chloroformic acid esters, dialkyl carbonates or diallyl carbonates, and various molecular weights are known. Particularly preferred as such a polycarbonate-based polyol is one using 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, or 1,5-pentanediol as the polyol. And its molecular weight is in the range of about 500 to 10,000. Each can be used alone or in combination.

The following can be used as the polybutadiene-based polyol. The hydroxyl group-containing liquid diene polymer has a molecular weight of 600 to 3000, an average number of functional groups of 1.7 to 3.0, a diene polymer having 4 to 12 carbon atoms, a diene copolymer, and further, these diene monomer and carbon number. There are copolymers with 2 to 2.2 α-olefin addition polymerizable monomers. Specific examples thereof include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer and the like. These liquid diene-based polymers can be produced, for example, by reacting a conjugated diene monomer in a liquid reaction medium by heating in the presence of hydrogen peroxide.

Further, the polyol component may be used by blending the above-mentioned polyolefin polyol in which the double bond of the liquid diene polymer is saturated. As a curing agent,
It may be one that is commonly used in curing a urethane prepolymer to produce a polyurethane elastomer. Examples thereof include polyol compounds and polyamine compounds. As the polyol compound, any of primary polyol, secondary polyol, and tertiary polyol may be used. Specifically, trimethylolpropane (“TM
P "), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pecatanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3- Hexanediol, cyclohexanediol, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol and the like can be mentioned. As the polyamine compound, any of primary amines, secondary amines, and tertiary amines such as diamine, triamine, and tetraamine can be used. Specifically, an aliphatic amine such as hexamethylenediamine, 3,3′-dimethyl-4,
Alicyclic amines such as 4'-diaminodicyclohexylmethane, 4,4'-methylenebis-2-chloroaniline,
Aromatic amines such as 2,2'3,3'-tetrachloro-4,4'-diaminophenylmethane and 4,4'-diaminodiphenyl, and 2,4,6-tris (dimethylaminomethyl) phenol. To be These curing agents may be used alone or in combination of two or more.

As a method for mixing the above-mentioned curing agent and the urethane prepolymer obtained from the above composition to cure the urethane prepolymer, the mixing ratio of the curing agent to the urethane prepolymer, the curing temperature, the curing time, etc. Can be carried out by known methods. The polyurethane elastomer used in the present invention may contain additives and the like. Examples of additives include nonionic plasticizers, flame retardants, fillers, stabilizers, colorants, and the like.

Examples of the plasticizer include dioctyl phthalate (“DOP”), dibutyl phthalate (“DBP”),
Dioctyl adipate (“DOA”), triethylene glycol dibenzoate, tricresyl phosphate,
Dioctyl phthalate, fatty acid ester of pentaerythritol, dioctyl sebacate, diisooctyl azelate, dibutoxyethoxyethyl adipate and the like can be used.

A large number of polyurethane elastomers having a combination of the above compositions were molded into a plate having a thickness of 2 mm, and a DC electric field was applied to them to measure their mechanical response using a strain sensor. That is, the upper and lower surfaces of a polyurethane elastomer molded in a plate shape were sandwiched between electrode plates and a voltage was applied. The strain sensor was used to observe the thickness change of the polyurethane / elastomer, and the effects of potential and current were measured.

Specific examples will be shown below. Each example was performed by the following procedure. A polyisocyanate component (shown below in (2)) is added to 100 parts by weight of a polyol component (shown below in (1)) and reacted at 85 ° C. for 1 hour under a nitrogen stream to obtain a urethane prepolymer having a terminal isocyanate group. . Isocyanate group (“NCO”) content of the obtained urethane prepolymer, and 80 ° C.
Was measured (shown in Table 1 and Table 2). The viscosity of the urethane prepolymer was determined by using a Haake rotary viscometer, Rotovisco RV-12.

100 parts by weight of the urethane prepolymer obtained as described above was kept warm at 80 ° C. to obtain a curing agent (hereinafter (3)).
Was melted and mixed, poured into a mold having a thickness of 2 mm and kept at 110 ° C. in advance, and left in an oven at 110 ° C. for 16 hours to complete the curing reaction. And hardness (JIS-A) was measured (shown in Table 1 and Table 2).
Here, the melting temperature when using 4,4′-methylenebis (dichloroaniline) as the curing agent was 140 ° C., and the melting temperature when other curing agents were used was 80 ° C. Example 1 (1) Average molecular weight (refers to the number average molecular weight; the same applies hereinafter)
Is 1.979 polyethylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd., trade name PEG-2000) and polypropylene glycol having an average molecular weight of 2.007 (Sanyo Chemical Industry Co., Ltd., trade name Sanix PP2000) are 7:
Blend with 3. (2) Paraphenylene diisocyanate (manufactured by DuPont, the same applies below) ... 16.1 parts by weight. (3) 4,4'-methylenebis (dichloroaniline)
(Ihara Chemical Industry Co., Ltd., trade name TCDAM,
The same shall apply hereinafter) ... 12.7 parts by weight. Example 2 (1) Poly-β-methyl- having an average molecular weight of 1.042
δ-valerolactone polyol (Kuraray Co., Ltd., trade name Clapol L1010). (2) Paraphenylene diisocyanate ... 30.7 parts by weight. (3) 1,4-butanediol (manufactured by Kanto Chemical Co., Inc., the same applies below) ... 5.8 parts by weight. Example 3 (1) Poly-3-methyl- having an average molecular weight of 1.510
1,5-Pentane adipate polyol (Kuraray Co., Ltd., trade name CLAPOL P1510). (2) Paraphenylene diisocyanate ... 21.2 parts by weight. (3) 1,4-butanediol ... 1.5 parts by weight and trimethylolpropane (manufactured by Kanto Kagaku Co., Ltd .; hereinafter the same) ... 2.9 parts by weight. Example 4 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-Pentane adipate polyol (Kuraray Co., Ltd., trade name CLAPOL P3010, the same applies hereinafter). (2) Paraphenylene diisocyanate ... 10.9 parts by weight. (3) 1,2-propanediol (manufactured by Kanto Chemical Co., Inc., the same applies hereinafter) ... 1.0 part by weight and trimethylolpropane ... 1.4 parts by weight. Example 5 (1) A polypropylene glycol having an average molecular weight of 10.389 and capped with ethylene oxide (manufactured by Asahi Glass Co., Ltd., trade name X8202D, the same applies hereinafter). (2) Para-phenylene diisocyanate ... 3.1 parts by weight. (3) 0.2 parts by weight of 1,4-butanediol and 0.5 parts by weight of trimethylolpropane. Example 6 (1) A polypropylene glycol having an average molecular weight of 10.389 and capped with ethylene oxide. (2) 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Millionate MT, the same applies hereinafter) ... 4.8 parts by weight. (3) 0.2 parts by weight of 1,4-butanediol and 0.4 parts by weight of trimethylolpropane. Example 7 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-Pentane adipate polyol. (2) Paraphenylene diisocyanate ... 10.9 parts by weight. (3) Trimethylolpropane ... 2.8 parts by weight. Example 8 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-Pentane adipate polyol. (2) 4,4′-diphenylmethane diisocyanate ... 17.0 parts by weight. (3) Trimethylolpropane ... 2.8 parts by weight. Example 9 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-Pentane adipate polyol (Kuraray P3010, manufactured by Kuraray Co., Ltd.). (2) 4,4′-diphenylmethane diisocyanate ... 17.0 parts by weight. (3) Polyethylene adipate polyol having an average molecular weight of 993 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4002) ... 29.2 parts by weight. Example 10 (1) Poly-3-methyl- having an average molecular weight of 1.948
1,5-Pentane adipate polyol (Kuraray Co., Ltd., trade name CLAPOL P2010, the same applies hereinafter). (2) Paraphenylene diisocyanate ... 16.4 parts by weight. (3) 1,2-Propanediol ... 3.2 parts by weight. Example 11 (1) Poly-3-methyl- having an average molecular weight of 1.948
1,5-Pentane adipate polyol. (2) Paraphenylene diisocyanate ... 16.4 parts by weight. (3) 4,4'-methylenebis (dichloroaniline)
... 10.3 parts by weight and triisopropanolamine (manufactured by Kanto Chemical Co., Inc.) ... 1.1 parts by weight Example 12 (1) Polybutylene adipate polyol having an average molecular weight of 2.055 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4010). (2) Paraphenylene diisocyanate ... 15.6 parts by weight. (3) 0.8 parts by weight of 1,4-butanediol and 3.0 parts by weight of trimethylolpropane. Example 13 (1) Polybutylene adipate polyol having an average molecular weight of 2.477 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 3027). (2) Paraphenylene diisocyanate ... 12.9 parts by weight. (3) 0.8 parts by weight of 1,4-butanediol and 3.0 parts by weight of trimethylolpropane. Example 14 (1) Polycaprolactone polyol having an average molecular weight of 1.996 (manufactured by Daicel Chemical Industries, Ltd., trade name Praxel 220, and so on). (2) Paraphenylene diisocyanate ... 16.0 parts by weight. (3) 1,3-butanediol (manufactured by Kanto Chemical Co., Inc., the same applies hereinafter) ... 3.8 parts by weight. Example 15 (1) Polycaprolactone polyol having an average molecular weight of 1.996. (2) Paraphenylene diisocyanate ... 16.0 parts by weight. (3) 1,3-butanediol ... 2.8 parts by weight,
1,4-butanediol ... 1.0 part by weight. Example 16 (1) Polyol consisting of ethylene glycol having an average molecular weight of 1.993, butylene glycol, and adipic acid (manufactured by Sanyo Chemical Industry Co., Ltd., trade name Sun Ester 24)
620). (2) Paraphenylene diisocyanate ... 16.1 parts by weight. (3) 1,4-butanediol ... 2.5 parts by weight and trimethylolpropane ... 1.4 parts by weight. Example 17 (1) Polytetramethylene ether glycol having an average molecular weight of 1.986 (produced by Hodogaya Co., Ltd., trade name PTG)
2000SN). (2) Paraphenylene diisocyanate ... 16.1 parts by weight. (3) Trimethylolpropane ... 3.6 parts by weight. Example 18 (1) Polyethylene adipate polyol having an average molecular weight of 2.022 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4040). (2) Tolylene diisocyanate ... 17.2 parts by weight. (3) Trimethylolpropane ... 3.6 parts by weight.

The dimensions, shape and measurement conditions of the elastomer molded as described above are as follows. Elastomer dimensions: length 25 mm x width 25 mm x thickness 2 mm. Elastomer shape: A flat plate with a thickness and rubber-like elasticity. Applied voltage: 100 V to 1000 V, changed current value: 1 mA to 10 mA. When the applied voltage was less than 100V, the deformation of the elastomer could not be observed. The voltage is 100V
The amount of change in the elastomer in the direction of the electric field observed above increased monotonically with increasing voltage. The maximum change amount of the elastomer in the direction of the electric field is the same as in Example 4.
At a voltage of 500 V and a current of 1 mA at 23.2
It was μm (1.16%). Exotherm could not be observed under the conditions of 3 mA or less throughout the examples. The temperature of the elastomer was measured by a thermocouple inserted into the elastomer.

Tables 1 and 2 show the measurement results and the like of the polyurethane elastomer actuator in each example.

[0028]

[Table 1]

[0029]

[Table 2]

Next, each measurement result is evaluated. (Evaluation 1) In Example 4, a rapid contraction of 1.16% in the electric field direction was observed when an electric field of 500 V was applied. This is 100 times or more as compared with the driving amount of 0.1% or less under the equivalent condition of the polyvinylidene fluoride film which is a piezoelectric material. Although the response speed is slightly slower than the polyvinylidene fluoride film by several times, it is considered to be very fast considering that it is an elastic body having a hardness of JIS-A value of 65. By the way, when the response speed is compared with a PZT-fixed epoxy resin used as an electrostrictive material at the same driving amount, it is two to one third, which is fast.

In this embodiment, a large driving amount can be obtained by applying a low electric field as described above, and therefore under the condition that a dielectric breakdown does not occur and almost no current value is observed. (Evaluation 2) In Examples 10, 14 and 16 as well, large driving by the electric field is similarly observed. It is speculated that all of these have a relatively strong dipole moment in the soft segment, such as ester, as in the measurement result 4.

As for the type of polyol, the change amount of the ester type was the largest, followed by that of the ether type. In addition, in order to investigate the influence of the magnitude of the dipole moment, an experiment was conducted using only an olefin system having a weak dipole moment, but there was almost no change. (Evaluation 3) The structurally necessary components of the polyurethane elastomer are three components, that is, a component that constitutes the hard segment and the soft segment, and a curing agent that is necessary for modifying the physical strength. Harder to produce greater drive
It is considered that a curing agent that easily inhibits the formation of segments is preferable. As one of the embodiments, it is desirable to use a curing agent having a side chain. This is because the presence of the side chain makes it difficult for hydrogen bonds to be formed and therefore hard segments to be generated, so that the restriction by the hard segment on the structural change upon application of a DC electric field can be relaxed.

Polyurethane elastomer of this example
Actuators are not driven by grain boundaries like piezoceramics, but their principles are different,
This is due to the electric field orientation of the soft segment dipoles that make up the amorphous regions of the polyurethane elastomer. Therefore, it can be driven at a low voltage. In other words, the driving principle of this is the conventionally known oriented crystallized PVDF.
It is considered that this is based on a novel driving principle that is completely different from the phenomenon of distortion due to the electric field at the grain boundaries and the like.

Further, since the behavior of each soft segment becomes a strain of the entire polyurethane elastomer actuator, a large force can be generated. Furthermore, since it can be driven at a low voltage, that is, at a low energy, and the polyurethane elastomer is an elastic body and is soft, it is possible to obtain an actuator having excellent processability. Also,
When a polyurethane elastomer is used, an actuator having an extremely large driving amount can be manufactured by changing the combination of its chemical composition.

Since the polyurethane elastomer actuator obtained as described above can be micromachined by microfabrication, it can be applied to manipulators and the like used for microsurgery which requires high precision, softness and fine action. Is.

[0036]

As described above, according to the present invention, by utilizing the fact that the dielectric polyol component is oriented in the direction of the electric field by applying a DC electric field and the structure of the elastomer is anisotropically changed, It is possible to change the shape of the elastomer only by the molecular orientation with the effective current being practically close to zero (that is, while minimizing heat generation),
Furthermore, the mechanical deformation energy generated during this shape change can be effectively applied to actuation.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location C08J 7/00 7310-4F H01L 41/193 (72) Inventor Toshiaki Kasasaki Ikezawa Town, Yamatokoriyama City, Nara Prefecture 172 Nitta Stock Company Nara Factory

Claims (1)

[Claims] 1. A polyurethane elastomer having a dielectric polyol or a polyol having a substituent having a relatively strong dipole moment, wherein the polyol has an electric field direction by applying a direct electric field to the polyurethane elastomer. A polyurethane elastomer actuator characterized by being oriented in the direction of.