JPH07147785A - Electrostatic actuator - Google Patents

Abstract

PURPOSE:To improve the drivability of an electrostatic actuator by making a resistor layer in the mover of itself has an equal resistance value under the face. CONSTITUTION:In an electrostatic actuator, which comprises a stator 1 where a plurality of band-shape electrodes are wired on an electric insulating substrate 2 and a mover where a resistor layer 15 is tacked on a film-shape electric insulator layer, and floats and drives a mover 10 by the changeover of voltage to the band-shaped electrode, the low resistance layer 15 in this mover 10 consist of a charge transporting organic matter and a binder having compatibility with the change transporting organic matter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic actuator, and more particularly to an electrostatic actuator excellent in drivability.

[0002]

2. Description of the Related Art Recently, an electrostatic actuator has been developed as an electrostatic motor for converting electric field energy into mechanical energy. As shown in FIG. 1, the electrostatic actuator includes a stator 1 in which a plurality of strip electrodes 5 are wired on an electrically insulating substrate 2, and a film-shaped electrical insulator layer 13 placed on the stator 1. Moving element 1 in which a resistor layer 15 is laminated on
It consists of 0 and.

In the stator shown in FIG. 1, the strip electrode 5 is shown as being laminated on the electrically insulating substrate 2 and then further laminated with the electrically insulating film 3 to be embedded in the electrical insulator. As shown in FIG. 2, the strip electrode 5 has, for example, a width l ₁ of 0.4 mm, a pitch l ₂ of 1.27 mm, an overall width l ₃ of 126 where the strip electrode is arranged, and a length l _4.
Has a shape of 175 mm, and is composed of three types of electrode groups Φa, Φb, and Φc to which voltages are independently applied. Although the mover 10 is illustrated as being separated from the stator 1 in FIG. 1, the mover 10 is placed in contact with the stator 1.

The principle of operation of the electrostatic actuator will be described with reference to FIG. 3. First, as shown in FIG. 3A, the strip electrodes 5a ₁ and 5a ₂ of the electrode group Φa in the stator 1 have a positive voltage + V and the electrode group Φb. Strip electrodes 5b ₁ and 5b ₂ of 0
V, negative voltage −V on the strip electrodes 5c ₁ and 5c ₂ of the electrode group Φc
, Respectively, an image charge is induced in the resistor layer 15 in which no charge was initially present, and the electric insulator layer 11
It is induced at the interface with and becomes equilibrium. In this state, the mover is attracted to the stator. Next, the polarity of the voltage applied to each electrode group in the stator is switched. FIG. 2B is a diagram showing the moving state of the moving element. The strip electrodes 5a ₁ and 5a ₂ of the electrode group Φa are 0 V, and the strip electrode 5b of the electrode group Φb is 0V.
₁ , 5b ₂ negative voltage -V, electrode group Φc strip electrode 5
Positive voltage + V is applied to c ₁ and 5c ₂ , respectively. Then, the charge in the strip electrode instantaneously moves, but the mirror image charge induced in the resistor layer is not immediately erased because the resistor has a constant resistance value. As a result, the mirror image charges in the charge and the moving element of the band-shaped electrodes become the same sign, repulsive force is generated, the movable body 10 floats, electrodes 5b ₁ - charge and the electrode 5
The mover 10 moves by receiving the driving force in the right direction by the attraction with the mirror image charge + of a ₁ . When the mover 10 moves to the right by one pitch, the electric charge of the electrode and the image charge of the mover have different polarities, as shown in (c) of FIG. FIG. 4 shows the voltage application state to each electrode in FIGS. (A) -in FIG.
3C corresponds to the voltage application state at each time point of FIGS. 3A to 3C. Thereafter, this operation is generally 1/100
This is repeated in a switching order of 0 sec to move the mover. Further, by changing the voltage application method to the three types of electrode groups, it is possible to move the same in the left direction. The electrostatic actuator produces a repulsive force between the mover and the stator when it is driven, so the frictional force is small, and the attractive force works when the actuator is stopped, so a large holding force can be obtained. It has advantages that it is not required, thinning, large area, easy stacking, high output and low voltage driving.

In the moving element of such an electrostatic actuator, the resistor layer 15 has a volume resistance of 10 ⁸ Ω · cm.
It has 10 ¹² Ω · cm and is formed by using, for example, cellulose acetate, an antistatic agent, or by applying conductive ultrafine particles such as indium tin oxide dispersed in a binder. ing.

However, when the resistor layer 15 is formed by using cellulose acetate and an antistatic agent, there is a problem that the volume resistance changes with humidity, and conductive ultrafine particles such as indium tin oxide are used as a binder. When it is formed by the one dispersed in the inside, the dielectric property is affected by the dispersed state, and a uniform resistance value cannot be obtained in the resistor layer,
There is a problem in that accurate driveability cannot be obtained.

[0007]

SUMMARY OF THE INVENTION The present invention improves the drivability of an electrostatic actuator by making the resistor layer in the moving element of the electrostatic actuator have a uniform resistance value in its plane. An object is to provide the electrostatic actuator.

[0008]

SUMMARY OF THE INVENTION An electrostatic actuator of the present invention comprises a stator in which a plurality of strip electrodes are wired on an electrically insulating substrate, and a film-shaped electrical insulator layer placed on the stator. In an electrostatic actuator which comprises a moving element having a resistor layer laminated thereon, and which drives the moving element by levitating the moving element by switching the voltage to the strip electrode, the resistor layer in the moving element is made of a charge transporting organic substance. And a binder having compatibility with the charge transporting organic substance.

The moving element in the electrostatic actuator of the present invention comprises an electrically insulating film 13 and a resistor layer 15, as shown in FIG.

The electric insulating film 13 is made of the same material as that of the electric insulating film 3 which is a surface layer of the stator, which will be described later, in consideration of contact with the surface of the stator, and has a film thickness of 5 μm to 100 μm, preferably. Is 5 μm to 50 μ
It is preferable to use a plastic film such as polyethylene terephthalate or polyimide having a volume resistance of 10 ¹⁴ Ω · cm or more. The electrically insulating film 13 is intended to prevent the charges induced in the resistor layer from leaking in the direction of the stator and to have the support as a mover.

Next, the resistor layer 15 will be described. The resistor layer 15 is composed of a charge transporting organic substance and a binder. As the charge transporting organic substance, hydrazone derivatives,
Stilbene derivative, butadiene derivative, triphenylamine derivative, stilbene dimer (arylamine type),
Examples thereof include triphenylmethane derivatives, enamine derivatives, oxadiazole derivatives, azine derivatives, dibenzylaniline derivatives, pyrazoline derivatives and the like.

Examples of preferable charge transporting organic substances are shown below.

[0013]

[Chemical 1]

[0014]

[Chemical 2]

[0015]

[Chemical 3]

[0016]

[Chemical 4]

In the above general formula, preferable combinations of substituents are shown in Table 1.

[0018]

[Table 1]

[0019]

[Chemical 5]

[0020]

[Chemical 6]

[0021]

[Chemical 7]

[0022]

[Chemical 8]

[0023]

[Chemical 9]

[0024]

[Chemical 10]

Next, as the binder, a binder which is compatible with the charge transporting organic substance through the solvent described later, such as polycarbonate resin, silicone resin, vinyl formal resin, vinyl acetal resin, vinyl butyral resin, styrene resin, Styrene-butadiene copolymer resin, epoxy resin, acrylic resin, acrylic resin, saturated or unsaturated polyester resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, etc. may be used. However, a polycarbonate resin is particularly preferable from the viewpoint of moisture resistance and adjusting the volume resistance value of the resistor layer.

The binder is 5% by weight to 90% by weight, preferably 10% by weight to 50% by weight, based on the charge transporting organic substance.
Used in a weight percentage, the volume resistance value of the resistor layer is set to 10 ⁸
Ω · cm to 10 ¹² Ω · cm, preferably 10 ⁹ Ω · cm
It is advisable to adjust the range to -10 ¹¹ Ω · cm.

The charge transporting organic substance and the binder resin are, for example, dichloroethane, 1,1,2-trichloroethane, chlorobenzene, tetrahydrofuran, cyclohexane, dioxane, 1,2,3-trichloropropane, ethyl cellosolve, 1,1, It is important to dissolve it in 1-trichloroethane, methyl ethyl ketone, chloroform, toluene, xylene, etc., or a mixed solvent thereof to form a solution, and the solution is electro-formed by a spinner coating method, a blade coating method, a dip coating method or the like. Film thickness after drying on insulating film 1
The mover is prepared by applying the coating to a thickness of 20 μm to 20 μm, preferably 1 μm to 5 μm.

Further, the resistor layer may be laminated on the electrically insulating film in the same pattern as the strip electrode pattern of the stator. As a result, it is possible to prevent the leakage of charges in the lateral direction in the resistor layer and improve the drivability of the electrostatic actuator.

Next, the stator will be described with reference to FIG. 5A and 5B are views showing a laminated shape of strip electrodes, FIG. 5A is a perspective view thereof, and FIG. 5B is a sectional view thereof, in which 20 is an electrically insulating substrate and 21 is electrodeposition. Adhesive layer, 22 is an electrically insulating layer, 25 is a first electrode group, 26 is a second electrode group, 2
Reference numeral 7 is a third electrode group, and 25A to 27A are branch portions of each electrode group.

As shown in FIGS. 3A and 3B, the laminated shape of the strip electrodes is such that the electrodeposition adhesive layer 21 is formed on the electrically insulating substrate 20.
The first electrode group 25 and the second electrode group 26 are arranged through the above, then the insulating layer 22 is coated on the branching portion 26A of the second electrode group 26, and the third electrode group 27 is electrically insulated. The electrodes are laminated on the substrate 20 and the insulating layer 22, and the strip-shaped electrode portions in each electrode group are alternately laminated in parallel at regular intervals on the electrically insulating substrate.

Further, in FIG. 2, the strip electrodes 5 are arranged so as to be parallel to each other, but as shown in FIG. 6, the strip electrodes 5 are arranged on the electrically insulating substrate 2 in the shape of a donut in a radial pattern from the center of the circle. The strip electrode layer 5 may be arranged so as to extend.
An epoxy resin or the like is applied to the thus-prepared multilayer electrode plate, the surface is smoothed, and then 25 μm.
A stator is formed by laminating thick electrically insulating films such as polyethylene terephthalate film.

Next, an example of the manufacturing method of the stator will be described. First, in addition to the band-shaped electrode layer wiring stacking planned portion consisting of the first electrode group and the second electrode group on the transfer substrate made of stainless steel,
A polyimide-based resin ink is layered in a pattern by screen printing and heat-cured to form an insulating layer having a thickness of 5 μm. Then, a copper electrode layer is laminated by electroplating to a thickness of 5 μm on the transfer substrate on which the insulating layer is not formed.

An electrodeposition liquid for forming an electrodeposition adhesive layer on the copper electrode layer is prepared as follows.

(A) Cationic resin composition-Epoxy resin (Showa Polymer Co., Ltd., Epicoat 1004) ... 300 parts by weight-Diethanolamine ... 35 parts by weight-Butyl cellosolve ... 150 parts by weight-Ice Acetic acid: 13 parts by weight (B) Powder resin composition: Epoxy resin (Showa Polymer Co., Ltd., Epicoat 1007): 100 parts by weight Diphenyldiaminomethane: 5 parts by weight Two kinds of fine powder having an average particle size of 1.7 μm were prepared, and the powder resin powder (B) in solid content was added to 100 parts by weight of the cationic resin composition (A). 400 parts by weight is added, and pure water is added so that the total solid content is 15% by weight to prepare an electrodeposition solution.

In this electrodeposition solution, the stainless steel plate laminated with the patterned insulating layer prepared above was negatively electrodeposited on the copper electrode layer under the conditions of a liquid temperature of 25 ° C. and a voltage of 10 V for 3 seconds. The adhesive layer was electrodeposited with a thickness of 3 μm. After electrodeposition, it is washed with water, dried, and further heat-treated at 160 ° C. for 20 minutes to semi-cure the electrodeposition adhesive layer to prepare a transfer plate.

Next, the polyimide substrate having a film thickness of 25 μm and the transfer plate prepared as described above are superposed and roller-pressed at 180 ° C. for 20 minutes to transfer the electrode pattern on the transfer plate onto the polyimide substrate.

Next, the branch portion in the second electrode group is covered with a polyimide film having a film thickness of 25 μm using an adhesive.

On the other hand, an insulating layer was formed on another transfer substrate made of stainless steel in the same manner as in the above-mentioned transfer plate forming method except for the band electrode layer wiring stacking portion composed of the third electrode group, and a copper electrode layer was further formed. After similarly forming an electrodeposition adhesive layer to prepare a transfer plate, the respective electrode groups were aligned with the polyimide substrate having a strip electrode layer composed of the first electrode group and the second electrode group prepared above. And superimpose them, and press-roll the rollers as above.
Transferring a strip electrode layer composed of a first electrode group and a second electrode group,
The multilayer electrode wiring board shown in FIG. 5 is produced. The pitch between the obtained strip-shaped electrode layers can be 320 μm.

Further, after coating an epoxy resin with a film thickness of 2 μm on this multilayer electrode wiring board, a polyimide film with a film thickness of 25 μm is laminated using an adhesive to fix the total film thickness to 77 μm. I can have a child.

[0040]

In the electrostatic actuator, the resistor layer 15 in the moving element has a volume resistance of 10 ⁹ Ω.
By using the material having a cm to 10 ¹¹ Ω · cm, the fact that the image charge is induced depending on the voltage applied to the stator is utilized. Therefore, in the electrostatic actuator, in order to improve the drivability, the image charge in the moving element needs to be uniformly induced in the resistor layer.

According to the present invention, the resistor layer is formed by applying a solution containing a charge transporting organic substance and a binder to form a conductive inorganic substance such as indium tin oxide dispersed in the binder. In comparison, the inventors have found that the resistance value in the resistor layer can be made uniform.

A detailed description will be given below with reference to examples. still,
In the examples, "part" means part by weight and "%" means% by weight.

[0043]

Example 1-The following formula

[0044]

[Chemical 11]

Charge-transporting organic substance represented by: 5 parts by weight Polycarbonate (trade name Iupilon, manufactured by Mitsubishi Gas Chemical Co., Inc.) 1 part by weight with 2 parts of dichloromethane and 1, It was dissolved in a mixed solvent (weight ratio) with 3 parts of 1,2-trichloromethane so that the solid content was 15%, and then filtered through a mesh having a diameter of 0.2 mm to obtain a coating liquid.

This coating solution was spinner coated (700 rpm, 0.4 seconds) on a polyethylene terephthalate film having a film thickness of 25 μm. After coating, leave in the same solvent atmosphere for about 5 minutes and then in the air for 15 minutes, and then dry in an oven at 80 ° C. for 2 hours to obtain a film thickness of 5 after drying.
A resistor layer having a thickness of μm was laminated to manufacture a mover of the present invention.

An electrostatic actuator was produced using this mover and the stator produced as described above, and the stator having a pitch of 320 μm was driven at a maximum applied voltage of ± 1 kV. At a speed of about 10 mm / s. It was driven and showed good drivability.

[0048]

Example 2 The charge-transporting organic substance of Example 1
The following formula

[0049]

[Chemical 12]

Instead of using a film thickness after drying of 2 μm, a moving element was prepared in the same manner as in Example 1, and an electrostatic actuator was assembled in the same manner as in Example 1 and operated in the same manner. It was driven at a speed of / s and showed good drivability.

[0051]

Example 3 The charge transporting organic substance in Example 1
The following formula

[0052]

[Chemical 13]

In place of the film thickness after drying, instead of 2 μm, a moving element was prepared in the same manner as in Example 1, and an electrostatic actuator was assembled in the same manner as in Example 1 and operated in the same manner. It was driven at a speed of / s and showed good drivability.

[0054]

Example 4 The charge transporting organic substance in Example 1
The following formula

[0055]

[Chemical 14]

In place of the film thickness after drying, instead of 2 μm, a moving element was prepared in the same manner as in Example 1, and an electrostatic actuator was assembled in the same manner as in Example 1 and operated in the same manner. It was driven at a speed of / s and showed good drivability.

[0057]

[Comparative Example] ・ Ultrafine particles of indium tin oxide (primary particle size: 0.03 µm, specific resistance: 3 Ω · cm to 10 Ω ・ cm) ・ ・ ・ 0.1 parts by weight ・ Water-based resin (polyethylene-based resin, trade name MKO) -100, manufactured by Mitsui DuPont Chemical Co., Ltd. ...... 1 part by weight is dispersed in toluene so that the solid content is 15%,
It was used as a coating liquid.

This coating solution was wire-bar coated on a polyethylene terephthalate film having a film thickness of 25 μm.

After coating, at 40 ° C. for about 5 minutes, then at 80 ° C.
Was dried for 30 minutes, and a resistor layer having a film thickness of 2 μm after drying was laminated to prepare a moving element for comparison.

Using this moving element and the stator produced as described above, an electrostatic actuator was assembled in the same manner as in Example 1 and operated in the same manner, but the drivability could not be confirmed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electrostatic actuator including a moving element according to the present invention.

FIG. 2 is a perspective view of an electrostatic actuator.

FIG. 3 is an explanatory diagram of the operating principle of the electrostatic actuator.

FIG. 4 is an explanatory diagram of a voltage application sequence to each electrode group in the electrostatic actuator.

5 (a) and 5 (b) are a perspective view and a sectional view of an electrode wiring board in the electrostatic actuator stator.

FIG. 6 is a plan view of another electrostatic actuator.

[Explanation of symbols]

1 is a stator, 2 and 20 are electrically insulating substrates, 3 is an electrically insulating film, 5 is an electrode layer, 10 is a mover, 13 is an electrically insulating film, 15 is a resistor layer, and 21 is an electrodeposition adhesive layer. Two
2 is an insulating layer, 25 is a first electrode group, 26 is a second electrode group, 2
Reference numeral 7 is a third electrode group.

Claims (1)

[Claims] 1. A stator in which a plurality of strip electrodes are wired on an electrically insulating substrate, and a mover which is placed on the stator and has a resistor layer laminated on a film-shaped electrical insulator layer. In the electrostatic actuator that levitates and drives the mover by switching the voltage to the strip electrode, the resistor layer in the mover is compatible with the charge transporting organic substance and the charge transporting organic substance. An electrostatic actuator comprising a binder.