JPH08137476A - Sound wave suppressor for listening room and the like - Google Patents

Abstract

PURPOSE: To provide a sound wave suppressor for listening rooms, etc., capable of imparting desired acoustic characteristics to the listening rooms, etc., by absorbing the sound waves of desired oscillation frequencies according the applications of the listening rooms, etc., and changing sound absorption characteristics. CONSTITUTION: A sound wave absorption controller 10 consisting of a hollow panel having a pair of electrode plates on its front surface and rear surface, an electrosenstive type sound wave absorption controlling fluid compsn. which is prepd. by incorporating solid particle's having an electric field arranging effect into electrical insulating media and is housed between a pair of these electrode plates and a variable power source 16 for impressing a desired voltage between a pair of the electrode plates is mounted at a rectangular frame 6 and casters 6d are mounted at the lower part of this frame 6 to make the frame 6 freely movable. As a result, the acoustic characteristics meeting the kinds, etc., of the musical instruments to be played and the musical tones to be listened are imparted to the listening rooms, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound wave suppressing device for a listening room or the like for listening to music provided in a school or a general household. More specifically, the characteristic frequency is determined based on the electric field array effect. By attaching a sound wave absorption control device equipped with a fluid composition for controlling electro-sensitive sound wave absorption control to a rectangular frame, it is possible to absorb sound waves of a desired frequency.

[0002]

2. Description of the Related Art Conventionally, in a music practice room for practicing musical instruments, a listening room for listening to music, etc., it is necessary to provide acoustic characteristics such as sound absorption and reverberation time according to the main purpose of use. In order to block the sound wave (air vibration) generated from the sound source, for example, perforated gypsum board, A sound absorbing material composed of a perforated plate such as a sound absorbing cement plate and a porous sound absorbing plate such as rock wool, glass wool and sponge has been used as a wall material or a floor material.

[0003]

By the way, in the conventional listening room, it is possible to obtain a listening room having the desired acoustic characteristics after construction due to slight construction errors and changes in the surrounding environment. Not only that, the acoustic characteristics change depending on the placement position of furniture placed in the listening room, and the frequency of the sound wave to be blocked also differs depending on the kind of music to be listened to. For example, it is necessary to cut off sound waves in the low range, and for piano songs, etc. to cut off sound waves in the middle to high range. Therefore, it is possible to absorb sound waves having a desired frequency and change the sound absorbing properties according to the type of musical instrument to be played in the listening room and the kind of music to be listened to, so that the acoustic characteristics can be adjusted to have desired acoustic characteristics. It was desired to realize a sound absorbing material that can be used.

However, in the conventional sound wave absorbing material, since the natural frequency is constant depending on the material, only the sound wave of the component matching the natural frequency can be absorbed (removed), and the sound wave to be absorbed. When changing the component of, the sound wave absorbing material needs to be replaced with a different material according to the frequency of the sound wave. As described above, it is necessary to prepare a plurality of types of sound wave absorbers having different natural frequencies and select and use a predetermined sound wave absorber corresponding to the frequency of the sound wave component to be absorbed. However, the cost of the sound absorbing device is high and the handling thereof is complicated, resulting in low reliability.

By the way, the inventors of the present invention have developed a fluid composition for electro-sensitive sound wave absorption control (hereinafter referred to as "Electric Noise") having a novel electric field arrangement characteristic which has not been known.
-Control fluid composition is abbreviated as "ENC fluid composition"). This fluid composition is, for example, a fluid obtained by dispersing solid particles in an electrically insulating medium. When an electric field is applied to the fluid composition, the solid particles cause dielectric polarization, and electrostatic attraction based on the dielectric polarization causes the solid particles to undergo dielectric polarization. It has the property of forming a chain structure by aligning and aligning in the direction of the electric field. In addition, some solid particles exhibit the property of exhibiting an array lump structure by electrophoresis and array alignment. In this way, the alignment orientation of the particles under the electric field is determined by the electric field alignment effect (hereinafter, referred to as Electric A).
The "light effect" is abbreviated as "EA effect")
The solid particles having such properties are referred to as electric field arranging particles (hereinafter, electric field arranging particles are abbreviated as “EA particles”). Then, the present inventors arrived at the present invention by advancing research on the ENC fluid composition having this novel structure.

The present invention has been made in view of the above-mentioned problems of the prior art, and absorbs sound waves of a desired frequency to change the sound absorbing property according to the use of the listening room, etc. It is an object of the present invention to obtain a sound wave suppressing device for a listening room or the like that can impart desired acoustic characteristics to the etc.

[0007]

In order to achieve the above object, a sound wave suppressing device for a listening room or the like according to the present invention comprises a hollow panel having a pair of electrode plates on its front and back surfaces, and between the pair of electrode plates. A sound wave absorption control device comprising an ENC fluid composition housed and containing EA particles having an EA effect in an electrically insulating medium, and a variable power source for applying a desired voltage between the pair of electrode plates. It is characterized in that it is attached to a rectangular frame, wheels are attached to the lower part of the rectangular frame, and the rectangular frame is movable.

[0008]

In the sound wave absorption control device used in the sound wave suppression device for a listening room or the like of the present invention, EA particles having an EA effect in the ENC fluid composition when no voltage is applied between the pair of electrode plates. Are randomly dispersed and randomly dispersed in an electrically insulating medium. When a voltage is applied to the pair of electrode plates by the variable power source, the EA particles are arrayed and linked in a chain to form a chain (particle chain), and the chain is arrayed in parallel with the electric field direction. When a sound wave (air vibration) is applied to one of the electrode plates in this state, the electrode plate vibrates in the opposite direction, but the chain body itself has elasticity, so the chain body pulls. When the particles are opposed to each other, they attract each other to generate an attractive force, and when they are compressed, they bend to generate a repulsive force, which causes a viscous resistance due to the movement of the chain in the electrically insulating medium, which causes a sound wave. Loss of energy (dissipation) occurs.

That is, the ENC fluid composition containing the chain resonates with the electrode plate due to the sound wave incident on the electrode plate. The sound wave frequency that gives vibration to such a chain is determined by the characteristic frequency of the chain (which is presumed to be the so-called natural frequency, which is the balance between the elasticity of the chain and the inertia of the electrode plate). When a sound wave having a frequency matching the characteristic frequency is incident on the electrode plate, the chain resonates and absorbs the sound wave, and sound waves of other frequencies are reflected.

Since the attractive force (stress generated in the chain) acting between the particles increases as the voltage applied to the pair of electrode plates increases, the elastic modulus and viscosity of the chain itself are applied. The present invention takes advantage of this as the voltage increases as the voltage increases. In other words, by adjusting the applied voltage so that the characteristic frequency of the chain itself matches the frequency of the component of the incident sound wave (air vibration) that you want to remove, the chain resonates and absorbs sound. It consumes the energy of the component to be (removed) and reflects the other components.

Therefore, in the sound wave suppressing device for a listening room or the like of the present invention, the sound wave absorption control device as described above is attached to the rectangular frame, and the wheels are attached to the lower portion of the rectangular frame. Since the rectangular frame is movable, the applied voltage applied to the pair of electrodes of the sound wave absorption control device in order to set the characteristic frequency of the ENC fluid composition in accordance with the frequency of the component of the sound wave to be absorbed. By adjusting the value, it is possible to absorb sound waves of various frequencies without changing the ENC fluid composition, so that it becomes possible to impart acoustic characteristics according to the application to the listening room or the like. Further, the sound wave suppressing device for a listening room or the like of the present invention is movable because the wheels are attached to the lower part of the rectangular frame, and is easy to handle, and therefore the number and the arrangement position It is also possible to provide the listening room or the like with acoustic characteristics according to the application by adjusting the.

FIG. 1 is a graph showing the results of measuring the effect of the electric field strength on the EA characteristics for a 30 wt% EA particle dispersion system. It is clear from this graph that the stress acting on the chain increases as the applied voltage increases. EA
The characteristic is that the dielectrically polarized particles are arranged in the direction of the electric field by an electric attraction to form a chain structure. At low shear rates, electrical attraction dominates, resulting in a gradual cycle of breaking and reforming chain structures. The yield stress is the force that is generated when a chain arranged in the direction of the electric field undergoes shear failure in the direction perpendicular to it. Considering that the particles of all chains formed have the same diameter and connect the electrode plates in a straight line, the number of chains is proportional to the particle concentration.
The yield stress will also be proportional to the particle concentration. FIG. 2 shows an equivalent circuit of the vibration system of the present invention, that is, a coil spring 2 having an elastic modulus K and a dashpot 3 having a viscosity C are connected in parallel between a pair of electrode plates.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 3 is a schematic configuration diagram showing an embodiment of a sound wave suppression device for a listening room or the like of the present invention, and reference numeral 5 in FIG. 3 is a sound wave suppression device for a listening room or the like. FIG. 4 is a cross-sectional view taken along the line II of the sound wave suppressing device 5 for the listening room and the like shown in FIG. The sound wave suppression device 5 for the listening room or the like is roughly configured by a rectangular frame 6 and a sound wave absorption control device 10.

The rectangular frame 6 is made of metal such as aluminum or stainless steel or wood, and has a plurality of rectangular openings 6a (two in the drawing).
Inside each of the openings 6a, as shown in FIG. 4, concave grooves 6b are formed over the entire circumference. Both ends of the lower portion of the rectangular frame 6 are fixed to the central portions of a pair of frame support plates 6c, 6c which are arranged in parallel with each other with a gap, and casters are attached to both ends of each frame support plate 6c. (Wheels) 6d, 6d are attached so that the rectangular frame 6 is movable. Further, a voltage adjusting knob 6e is provided on the outer side of the rectangular frame 6. Further, a power source hole 6f for accommodating a variable power source described later is formed on the outer side of the rectangular frame 6.

A plurality of sound wave absorption control devices 10 (two in the drawing) are attached to such a rectangular frame 6, and a surface material 17 of the sound wave absorption control device 10 to be described later is provided through the plurality of openings 6a. Each side is visible. The sound wave absorption control device 10 is attached to the rectangular frame 6 by fitting the peripheral edge portion of each sound wave absorption control device 10 into the groove 6b formed in each opening 6a.

The sound wave absorption control device 10 is a plate-like member for absorbing sound waves having a desired frequency, and its appearance is a rectangular plate-like shape. As shown in FIG. It is a thing. The sound wave absorption control device 10 includes a hollow panel 11, a pair of electrode plates 12 and 13 provided on the hollow panel 11, an ENC fluid composition 15, and a variable power source 16.
It consists of The hollow panel 11 has a surface material 1
7, a backing material 18 that is arranged to face the surface material 17 with a gap, and a frame-shaped sealing member 19 fixed to the peripheral edges of the surface material 17 and the backing material 18. The surface material 17 is, for example, PE that is flexible against sound waves.
T (polyethylene terephthalate) film, PVC
Various plastic films such as (vinyl chloride) film, nylon film, polyethylene film, polypropylene film, and acrylic film are used. As the backing material 18, for example, a metal plate having conductivity is preferably used. When the backing material 18 is a metal plate, the backing material 18 also serves as the electrode plate 13.

The electrode plate 12 is uniformly adhered to the surface material 17 along the inner wall of the surface material 17, and a gap (composition containing space) is formed between the electrode plate 12 and the electrode plate 13. . The ENC fluid composition 15 containing the EA particles 21 having the EA effect described above in the electrically insulating medium 22 is housed in a sealed state between the pair of electrode plates 12 and 13. . Further, the one electrode plate 12 and the surface material 17 have their peripheral edges fixed, but are configured so that they can be vibrated in the opposing direction of the pair of electrode plates 12 and 13 (the vertical direction shown by the arrow X in FIG. 5). Has been done. Thereby, when the sound wave (air vibration) 24 is incident on the surface material 17, the surface material 17 and the one electrode plate 12 can vibrate vertically.

Reference numeral 16 is a variable power source for applying a desired voltage between the pair of electrode plates 12 and 13. The variable power source 1
A switch 27 is connected to 6 in series. By turning on the switch 27, the pair of electrode plates 12,
A voltage can be applied between 13. This variable power supply 1
6 is a power supply hole 6f formed in the rectangular frame 6
It is housed in.

The variable power source 16 of the sound wave absorption control device 10 is connected to a voltage adjusting knob 6e provided on the rectangular frame 6, and the voltage adjusting knob 6e is connected to the voltage adjusting knob 6e.
Thus, the voltage applied between the pair of electrode plates 12 and 13 can be adjusted.

In the sound wave suppressing device 5 for the listening room or the like of the above embodiment, the case where the sound wave absorption control device 10 has a rectangular plate-like appearance has been described, but it goes without saying that the appearance is a circular plate according to the place of installation. It may be in the form of a circle or any other suitable shape. Also, the hollow panel 11
Has been described as having a surface material 17, but when the electrode plate 12 is made of a material having a strength capable of containing the ENC fluid composition 15 and is made of a material that is flexible against sound waves, The material 17 may not be provided. Further, the backing material 1 made of a metal plate of the hollow panel 11
Although the case where 8 also serves as the electrode plate 13 has been described, when the backing material 18 is made of a material having no conductivity, the electrode plate 13 is uniformly fixed along the inner wall of the backing material 18. .

The EA particles 21 are composed of a core made of an organic polymer compound and an electric field aligning inorganic substance (hereinafter referred to as "EA").
Inorganic / organic composite particles formed by a surface layer containing an inorganic material). The EA inorganic substance is at least one selected from the group consisting of an inorganic ion exchanger, silica gel, and an electric semiconductor inorganic substance.

When the EA inorganic substance is an inorganic ion exchanger, the inorganic ion exchanger is a polyvalent metal hydroxide,
It is preferably at least one selected from the group consisting of hydrotalcites, polyvalent metal acid salts, hydroxyapatite, Nasicon type compounds, clay minerals, potassium titanates, heteropolyacid salts and insoluble ferrocyanides. .

When the EA inorganic substance is an electric semiconductor inorganic substance, the electric semiconductor inorganic substance is 10 ³ Ω at room temperature.
It is preferable ^-1 cm ^-1 to those having electrical conductivity in the range of 10 ^-11 Omega ^-1 cm ^-1. This electrically semiconductive inorganic substance is a metal oxide, a metal hydroxide, a metal oxide hydroxide, an inorganic ion exchanger, a metal-doped one or more of these, and whether or not metal-doped. It is preferable that it is at least one selected from the group consisting of at least one of these materials applied on another support as an electric semiconductor layer.

Next, an example of use of the sound wave suppressing device 5 for such a listening room will be described with reference to FIG. Figure 6
FIG. 4 is a diagram for explaining a listening room in which the sound wave suppressing device 5 for the listening room shown in FIG. 3 is used, in which reference numeral 28 denotes a side wall, 29 denotes a floor, 30 denotes a window, 31
Is an audio rack installed on the side wall 28, 32a is an analog player placed on the audio rack 31, 32b is a CD player, 32c is an amplifier to which the analog player 32a and the CD player 32c are respectively connected, and 32d and 32d are The above amplifier 32
It is a pair of speakers connected to c.

The pair of loudspeakers 32d and 32d are arranged with a gap in the window 30, and are arranged near the side wall 28 of the listening room. Then, since sound waves from the speakers 32d interfere with each other between the pair of speakers 32d and 32d, the acoustic effect may be deteriorated. Therefore, in this embodiment, between the pair of speakers 32d and 32d. A sound wave suppressing device 5 for a listening room or the like is arranged in the gap, and a sound wave is adjusted by a voltage adjusting knob 6e in order to set the characteristic frequency of the ENC fluid composition 15 in accordance with the frequency of the component of the sound wave to be absorbed. By adjusting the applied voltage value applied to the pair of electrodes 12 and 13 of the absorption control device 10 or moving the sound wave suppressing device 5 for the listening room or the like by the casters 6d, the desired acoustic effect can be obtained in the listening room. Can be granted. In addition, each speaker 32d, 3
Between the 2d and the side wall 28 (in the vicinity of the corner of the listening room), sound is likely to be gathered, so that the sound wave suppressing devices 5 and 5 for the listening room and the like are arranged in the vicinity of the corner, respectively, in the same manner as described above. , You can add your favorite sound effect to the listening room.

In the listening room shown in FIG. 6, in addition to the above-described sound wave suppressing device 5 for the listening room, a diffusing plate, a reflecting plate for adjusting the acoustic characteristics,
A conventionally used sound wave absorber or the like may be provided.

Next, FIG. 7 shows a specific example of the ENC fluid composition 15. In this ENC fluid composition 15, EA particles 21 which are solid particles are uniformly dispersed in an electrically insulating medium 22. The EA particles 21 include a core body 33 made of an organic polymer compound and particles 3 made of an EA inorganic substance.
And the surface layer 35 of 4 to form the inorganic-organic composite particles. In this specific example, the electrically insulating medium 22 is colorless and transparent silicone oil, the organic polymer compound forming the core body 33 of the inorganic / organic composite particles is polyacrylic ester, and the EA forming the surface layer 35.
The inorganic particles 34 are white titanium hydroxide that is both an inorganic ion exchanger and an electric semiconductor inorganic material. The color of the EA particles (inorganic / organic composite particles) 21 is, for example, white. The proportion of the EA particles 21 contained in the electrically insulating medium 22 is 7.5% by weight, for example.

As shown in FIG. 8, this ENC fluid composition 15 comprises a pair of electrode plates 12, 1 which are spaced apart and arranged in parallel.
It intervenes between 3. As shown in FIG. 9, when a voltage is applied to the pair of electrode plates 12 and 13 from the variable power source 16 via the switch 27, the EA particles 21 are generated by the EA effect.
Are arranged in a chain in a direction perpendicular to the surfaces of the electrode plates 12 and 13 to form a chain (particle chain) 36. At this time, the chain-like bodies 36 are spaced apart from each other and oriented in parallel.

Next, the operation of the sound wave absorption control apparatus 10 having the above structure will be described. As shown in FIG. 5, when no voltage is applied between the pair of electrode plates 12 and 13, E
The EA particles 21 of the NC fluid composition 15 are the electrically insulating medium 2
Floating / randomly distributed in 2 (see Fig. 8). When a voltage is applied to the pair of electrode plates 12 and 13, E
The EA particles 21 in the NC fluid composition 15 are arrayed and linked in a chain to form a chain (particle chain) 36, and the chain 36 is arrayed parallel to the electric field direction (see FIG. 9).

In this state, when a sound wave (air vibration) 24 is made incident on one of the electrode plates 12, (a) in FIG.
The states of (b), (c), and (d) sequentially occur, and the electrode plate 12 vibrates in the opposite direction as shown by the arrow X (see FIGS. 5 and 11) together with the surface material 17, but has a chain shape. Since the body 36 itself has elasticity, as shown in FIG. 10B, when the chain body 36 is compressed, the chain body 36 bends in, for example, a dogleg shape to generate a repulsive force. Occurs and FIG.
When the chain-shaped body 36 is pulled, the EA particles 21 facing each other attract each other to generate an attractive force, as shown in FIG. As a result, the movement of the chain-like body 36 in the ENC fluid composition 15 causes viscous resistance, resulting in loss of energy (dissipation) of the sound wave 24.

As the electrode plate 12 vibrates,
The chain 36 is repeatedly pulled and compressed, and as a result, the chain 36 itself vibrates.
That is, the chain member 3 is applied to the sound wave 24 incident on the electrode plate 12.
The ENC fluid composition 15 containing 6 resonates with the electrode plate structure composed of the electrode plate 12 and the surface material 17. The sound wave frequency that gives vibration to the chain 36 is determined by the characteristic frequency of the chain 36, and when the sound wave 24 having a frequency matching the characteristic frequency is incident on the electrode plate 12, the chain 36 is discharged. Resonates (see arrows A and B in FIG. 11)
The sound waves are absorbed and the sound waves 25 of other frequencies are reflected.

The force acting between the EA particles 21 (stress generated in the chain-like body 36) increases as the voltage applied to the pair of electrode plates 12 and 13 increases, so that the elasticity of the chain-like body 36 itself. The modulus and viscosity increase with increasing applied voltage. The present invention utilizes this fact to remove a desired component of a sound wave. That is, by adjusting the applied voltage to match the characteristic frequency of the particle chains 36 with the frequency of the component (sound wave having a specific wavelength) to be removed from the sound wave (air vibration) incident on the electrode plate 12, As shown in FIG. 11, the chain body 36 is resonated (resonated) by the action of inertial force as shown by the left and right arrows A and B, and the energy of the component of the incident sound wave 24 desired to be removed is consumed, and other sound wave components ( (Indicated by reference numeral 25) is reflected. In this way, the applied voltage can absorb the component of the desired specific wavelength of the incident sound wave 24.

The characteristic frequency of the sound wave absorption control device 10 is E
It changes depending on the size of the A particles (solid particles) 21, the elastic force acting between the EA particles 21, the natural frequency of the electrode plate 12, the distance between the pair of electrode plates 12 and 13, and the like. In the present invention, since the spherical EA particles 21 having a substantially uniform particle size are dispersed in the electrically insulating medium 22 (without using irregular particles), the above-mentioned repulsive force and attractive force are maintained under a constant voltage. Does not fluctuate, and the balance between the elastic force acting between the EA particles 21 and the inertial force of the electrode plate hardly fluctuates. In the above embodiment, the chain-like body 36 is supposed to be bent in a V shape, but in addition to this, for example, the S-shape as shown in FIG. W as shown in b)
It is considered that there is a case where it is bent into a letter shape.

In the above embodiment, the phenomenon in which the EA particles (inorganic / organic composite particles) 21 form a row of chain-like bodies 36 and are arranged in parallel by the application of an electric field has been described. If the number of the chains exceeds 30% by weight, the chains 36 are joined to each other in a plurality of rows instead of one row of the chains 36 to form a column 39 as shown in FIG. Come to do. In this column 39, the left and right chain-shaped EA particles 21 are shifted one by one and adjoin each other in a staggered manner. Regarding this, the present inventors have shown in FIG.
It is because it is more stable in terms of energy that the EA particles 21 that are dielectrically polarized in the + pole portion and the − pole portion are alternately adjacent to each other and the + pole portion and the − pole portion are attracted to each other, as shown in FIG. I'm estimating. Further, in the above embodiment, the ENC fluid composition 15 is directly accommodated between the pair of electrode plates 12 and 13, but the ENC fluid composition 15 is not limited to this.
A porous body sufficiently impregnated with the fluid composition 15 may be housed between the pair of electrode plates 12 and 13. In this case, the porous body preferably has open cells so as not to impair the EA effect.

The electrically insulating medium 22 used in the ENC fluid composition 15 of the present invention is, for example, diphenyl chloride,
Butyl sebacate, aromatic polycarboxylic acid higher alcohol ester, halophenyl alkyl ether, trans oil, chlorinated paraffin, fluorine oil, silicone oil, fluorosilicone oil, etc. Chemically stable and E
Any fluid or a mixture thereof can be used as long as it can stably disperse the A particles. The electrically insulating medium 22 can be colored according to the purpose. For coloring, it is preferable to use a type and amount of an oil-soluble dye or a dispersible dye that is soluble in the selected electrically insulating medium and does not impair its electrical properties. The electrically insulating medium 22 may further contain a dispersant, a surfactant, a viscosity modifier, an antioxidant, a stabilizer and the like.

The kinematic viscosity of this electrically insulating medium 22 is 1c.
It is preferably in the range of St to 30,000 cSt. When the kinematic viscosity is less than 1 cSt, the storage stability of the ENC fluid composition 15 is insufficient, and the kinematic viscosity is 300.
If it is larger than 00 cSt, it becomes difficult to uniformly disperse the EA particles, and bubbles are entangled during the adjustment to make it difficult for the bubbles to escape, which is unfavorable for handling. From this point of view, the kinematic viscosity is 10 cSt to 1000.
It is preferably in the range of cSt, particularly preferably in the range of 10 cSt to 100 cSt. Of course, the kinematic viscosity of the electrically insulating medium 22 changes with temperature, and this temperature effect can be suppressed by the applied voltage.

The EA particles 21 used in the present invention are EA particles.
Any material such as an element, an organic compound, an inorganic compound, or a mixture thereof can be used as long as it is an inorganic / organic composite particle having an effect. Examples thereof include particles of inorganic ion exchangers, metal oxides, silica gel, inorganic substances having electric semiconductors, carbon black, and particles having these as a surface layer.
However, the EA particles 21 are inorganic-organic composite particles formed by the core body 33 made of an organic polymer compound and the surface layer 35 made of the EA inorganic particles 34, as shown in the above-mentioned examples. Is particularly preferable. This inorganic
Organic composite particles are EA inorganic particles 3 having a relatively high specific gravity.
The surface layer 35 composed of 4 is carried on the core body 33 which is an organic polymer compound having a relatively low specific gravity, and the specific gravity of the whole particles can be adjusted so as to approximate to the electrical insulating medium 22. Therefore, the ENC fluid composition 15 obtained by dispersing this in the electrically insulating medium 22 has excellent storage stability.

Examples of the organic polymer compound that can be used as the core body 33 of the EA particles (inorganic / organic composite particles) 21 are poly (meth) acrylic acid ester, (meth) acrylic acid ester-styrene copolymer, One or a mixture or copolymer of polystyrene, polyethylene, polypropylene, nitrile rubber, butyl rubber, ABS resin, nylon, polyvinyl butyrate, ionomer, ethylene-vinyl acetate copolymer, vinyl acetate resin, polycarbonate resin and the like. Can be mentioned.

Various particles can be used as the particles 34 which are the EA inorganic material forming the surface layer 35, and preferred examples thereof include an inorganic ion exchanger, silica gel and an electrically semiconductive inorganic material. When the surface layer 35 is formed on the core body 33 made of an organic polymer using these particles 34, the obtained inorganic / organic composite particles are useful EA.
It becomes the particles 21.

Examples of the above inorganic ion exchanger include (1)
Hydroxide of polyvalent metal, (2) hydrotalcites,
(3) Acid salt of polyvalent metal, (4) Hydroxyapatite, (5) Nasicon type compound, (6) Clay mineral, (7)
Mention may be made of potassium titanates, (8) heteropolyacid salts, and (9) insoluble ferrocyanide.

The respective inorganic ion exchangers will be described in detail below. (1) Hydroxide of polyvalent metal. These compounds are represented by the general formula MO _x (OH) _y (M is a polyvalent metal, x is a number of 0 or more, and y is a positive number), and examples thereof include titanium hydroxide and hydroxide. zirconium,
Examples include bismuth hydroxide, tin hydroxide, lead hydroxide, aluminum hydroxide, tantalum hydroxide, niobium hydroxide, molybdenum hydroxide, magnesium hydroxide, manganese hydroxide, and iron hydroxide. Here, for example, titanium hydroxide refers to hydrous titanium oxide (also known as metatitanic acid or β-titanic acid, Ti
It contains both O (OH) ₂ ) and titanium hydroxide (also known as orthotitanic acid or α-titanic acid, Ti (OH) ₄ ), and the same applies to other compounds.

(2) Hydrotalcites. These compounds have the general formula M ₁₃ Al ₆ (OH) ₄₃ (C
O) ₃ · 12H ₂ O (M is a divalent metal),
For example, the divalent metal M is Mg, Ca or Ni. (3) Acid salt of polyvalent metal. These are, for example, titanium phosphate, zirconium phosphate, tin phosphate, cerium phosphate, chromium phosphate, zirconium arsenate, titanium arsenate, tin arsenate, cerium arsenate, titanium antimonate, tin antimonate, tantalum antimonate. , Niobium antimonate, zirconium tungstate, titanium vanadate, zirconium molybdate, titanium selenate, and tin molybdate.

(4) Hydroxyapatite. These are, for example, calcium apatite, lead apatite,
Examples include strontium apatite and cadmium apatite. (5) Nasicon type compound. These include, for example, (H ₃ O) Zr ₂ (PO ₄ ) ₃ but in the present invention, a Nasicon type compound in which H ₃ O is replaced with Na can also be used. (6) Clay mineral. These are, for example, montmorillonite, sepiolite, bentonite and the like, with sepiolite being particularly preferred.

(7) Potassium titanates. These general formula _{aK 2 O · bTiO 2 · nH} 2 O (a 0
<A is a positive number that satisfies a ≦ 1, b is a positive number that satisfies 1 ≦ b ≦ 6, and n is a positive number), for example, K ₂ ·
TiO ₂ · 2H ₂ O, K ₂ O · 2TiO ₂ · 2H ₂ O, 0.
5K ₂ O ・ TiO ₂・ 2H ₂ O, and K ₂ O ・ 2.5TiO
₂ · 2H ₂ O, and the like. In addition, among the above compounds, a compound in which a or b is not an integer is easily synthesized by subjecting a compound in which a or b is an appropriate integer to an acid treatment and replacing K with H.

(8) Heteropolyacid salt. These are represented by the general formula H ₃ AE ₁₂ O ₄₀ .nH ₂ O (A is phosphorus, arsenic, germanium, or silicon, E is molybdenum, tungsten, or vanadium, and n is a positive number), For example, ammonium molybdophosphate and ammonium tungstophosphate. (9) Insoluble ferrocyanide. These are compounds represented by the following general formula. M _b-pxa
A [E (CN) ₆ ] (M is an alkali metal or hydrogen ion, A is a heavy metal ion such as zinc, copper, nickel, cobalt, manganese, cadmium, iron (III) or titanium, E is iron (II), iron (III), cobalt (II) or the like, b is 4 or 3, a is a valence of A, and p is a positive number of 0 to b / a.) These include, for example, Cs. Insoluble ferrocyanine compounds such as ₂ Zn [Fe (CN) ₆ ] and K ₂ Co [Fe (CN) ₆ ] are included.

The inorganic ion exchangers (1) to (6) each have an OH group, and some or all of the ions present at the ion exchange sites of these inorganic ion exchangers are different ions. Those substituted with (hereinafter, referred to as a substitutional inorganic ion exchanger) are also included in the inorganic ion exchanger of the present invention. That, R-M ¹ inorganic ion exchanger described above (M ¹ represents an ion species of the ion exchange sites) is expressed as a part or all of M ¹ in the R-M ^1, the ion exchange reaction below A substituted inorganic ion exchanger in which an ionic species M ² different from M ¹ is substituted by
It is an inorganic ion exchanger in the present invention. xR−M ¹ + yM ² → Rx− (M ² ) y + xM ¹ (where x and y represent the valences of the ion species M ² and M ¹ , respectively). M ¹ varies depending on the type of the inorganic ion exchanger having an OH group, but when the inorganic ion exchanger exhibits a cation exchange property, M ¹ is generally H ⁺ , and in this case, M ² is an alkali metal or an alkali. Any metal ion other than H ⁺ , such as earth metals, polyvalent typical metals, transition metals or rare earth metals. When the inorganic ion exchanger having an OH group exhibits anion exchange property, M ¹ is generally OH ^−.
Where M ² is, for example, I, Cl, SCN, N
It is any of general anions other than OH ⁻ such as O ₂ , Br, F, CH ₃ COO, SO ₄ or CrO ₄ and complex ions.

Further, regarding the inorganic ion exchanger which has once lost the OH group due to the high temperature heat treatment but becomes to have the OH group again by an operation such as immersion in water, the inorganic ion exchanger after the high temperature heat treatment is used. Exchangers and the like are also a kind of inorganic ion exchangers that can be used in the present invention, and specific examples thereof include a Nasicon type compound such as (H ₃ O) Zr ₂
(PO ₄₎ HZr ₂ obtained by heating ₃ (PO _{4) 3} and high-temperature heat treatment of hydrotalcite (500 to 70
Heat treated at 0 ° C.) and the like. These inorganic ion exchangers can be used not only in one kind but also in many kinds simultaneously as a surface layer. It is particularly preferable to use a hydroxide of a polyvalent metal and an acid salt of a polyvalent metal as the above-mentioned inorganic ion exchanger.

EA particles (inorganic / organic composite particles) 21
An example of the electrically semiconductive inorganic material that can be used as the surface layer 35 of is an electric conductivity of 10 ³ to 10 ^-11 Ω ^-1 / cm at room temperature.
Metal oxides, metal hydroxides, metal oxide hydroxides, inorganic ion exchangers, or metal-doped ones of at least one of these, or at least any one of them regardless of the presence or absence of metal doping. For example, the seed is applied to another support as an electric semiconductor layer.

Examples of preferable electrically semiconducting inorganic substances are shown below. (A) Metal oxide: For example, SnO ₂ or amorphous titanium dioxide (manufactured by Idemitsu Petrochemical Co., Ltd.). (B) Metal hydroxide: For example, titanium hydroxide or niobium hydroxide. Here, titanium hydroxide means hydrous titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.), metatitanic acid (also known as β-titanic acid,
TiO (OH) ₂ ) and orthotitanic acid (also known as α-titanic acid, Ti (OH) ₄ ) are included. (C) Metal oxide hydroxide: For example, FeO
(OH) (goethite) and the like can be mentioned. (D) Hydroxide of polyvalent metal: equivalent to inorganic ion exchanger (1). (E) Hydrotalcites: Inorganic ion exchanger (2)
Equivalent to (F) Acid salt of polyvalent metal: equivalent to the inorganic ion exchanger (3). (G) Hydroxyapatite: Inorganic ion exchanger (4)
Equivalent to (H) Nashicon type compound: equivalent to the inorganic ion exchanger (5). (I) Clay mineral: equivalent to the inorganic ion exchanger (6). (J) Potassium titanate: equivalent to the inorganic ion exchanger (7). (K) Heteropolyacid salt: equivalent to the inorganic ion exchanger (8). (L) Insoluble ferrocyanide: equivalent to inorganic ion exchanger (9). (M) Metal-doped EA inorganic substance: This is obtained by doping the EA inorganic substance with a metal such as antimony (Sb) in order to increase the electric conductivity of the above-mentioned electric semiconductor inorganic substances (A) to (L). For example, antimony (S
b) Doping tin oxide (SnO ₂ ) and the like can be mentioned. (N) EA inorganic material applied as an electric semiconductor layer on another support: for example, titanium oxide, silica as a support,
Examples thereof include inorganic particles such as alumina and silica-alumina, or organic polymer particles such as polyethylene and polypropylene, to which antimony (Sb) -doped tin oxide (SnO ₂ ) is applied as an electric semiconductor layer. . The particles in which the EA inorganic substance is applied to the other support as described above can be regarded as the EA inorganic substance as a whole. These EA inorganic substances may be used not only in one kind but also in two kinds or more simultaneously as a surface layer.

The EA particles (inorganic / organic composite particles) 21 are
It can be manufactured by various methods. For example, there is a method in which a particulate core body 33 made of an organic polymer compound and fine particulate particles 34 are transported by a jet stream and collided with each other to produce the particles. In this case, the fine particles of the particles 34 collide with the surface of the particulate core body 33 at a high speed and are fixed to form the surface layer 35. As another example of the manufacturing method, there is a method in which the particulate core body 33 is suspended in a gas, and a solution of the particles 34 is atomized and sprayed on the surface thereof. In this case, the solution adheres to the surface of the core body 33 and is dried so that the surface layer 3
5 is formed.

A particularly preferred manufacturing method for manufacturing the EA particles (inorganic / organic composite particles) 21 is the core layer 33 and the surface layer 35.
Is a method of forming. This method is performed by, for example, the core body 33.
When emulsion-polymerizing, suspension-polymerizing, or dispersion-polymerizing a monomer of an organic polymer compound that forms a polymer, particles 34, which are finely divided EA inorganic substances, are present in the monomer or in the polymerization medium. Is.
Water is preferred as the polymerization medium, but a mixture of water and a water-soluble organic solvent can also be used, and an organic poor solvent can also be used. According to this method, the monomers are polymerized in the polymerization medium to form the core particles 33, and at the same time, the fine particle EA inorganic particles 34 are oriented in a layered manner on the surface of the core 33 to cover the particles. The surface layer 35 is formed.

When the EA particles (inorganic / organic composite particles) 21 are produced by emulsion polymerization or suspension polymerization, the particles of the EA inorganic material are combined by combining the hydrophobic property of the monomer and the hydrophilic property of the EA inorganic material. Most of 34 can be attached to the surface of the core 33. According to the method for simultaneously forming the core body 33 and the surface layer 35, the EA inorganic particle 34 is formed on the surface of the core body 33 made of an organic polymer compound.
Adhere to each other closely and firmly to form robust EA particles (inorganic / organic composite particles) 21.

The shape of the EA particles 21 used in the present invention does not necessarily have to be spherical, but the particle-shaped core body 33 is used.
In the case where the EA particles 21 are manufactured by the emulsion-suspension polymerization method in which is controlled, the shape of the obtained EA particles 21 is substantially spherical.
Although the particle size of the EA particles 21 is not particularly limited,
0.1 μm to 500 μm, especially 5 μm to 200
It is preferably within the range of μm. The particle size of the fine particles EA inorganic particles 34 at this time is not particularly limited, but is preferably 0.005 μm to 100 μm.
μm, more preferably 0.01 μm to 10 μm.

In the EA particles (inorganic / organic composite particles) 21, the weight ratio of the EA inorganic particles 34 forming the surface layer 35 to the organic polymer compound forming the core 33 is not particularly limited, In order to obtain the ENC fluid composition 15 with high storage stability, the particles 34 should be added to the total weight of the EA inorganic particles 34 and the organic polymer compound core 33.
Is preferably in the range of 1% to 60% by weight, particularly preferably in the range of 4% to 30% by weight. When the proportion of the core 33 is less than 1% by weight, the obtained EA particles 2
When the EA characteristic of 1 becomes insufficient and exceeds 60% by weight,
There is a possibility that the specific gravity of the EA particles 21 becomes excessive and the storage stability is impaired. The ENC fluid composition 15 of the present invention also comprises
The above-mentioned EA particles 21 can be manufactured by uniformly stirring and mixing in the electrically insulating medium 22 together with a dispersant and other components, if necessary. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used. The content of the EA particles 21 in the electrically insulating medium 22 is not particularly limited, but it is 0.
It is preferably from 5 to 75% by weight, particularly preferably from 5 to 50% by weight. If the content is less than 1%, a sufficient EA effect cannot be obtained, and if it is more than 75%, the initial viscosity of the ENC fluid composition 15 when a voltage is not applied becomes too large, which makes it difficult to use.

Various methods described above, particularly the core body 33 and the surface layer 35.
EA particles produced by a method of simultaneously forming and
In No. 1, the surface layer 35 is wholly or partially covered with a thin film of an organic polymer substance, a dispersant used in the manufacturing process, an emulsifier and other additive substances, and the EA effect as EA particles is not sufficiently exhibited. There are cases. This thin film of inert material can be easily removed by polishing the surface of the particles. Therefore, when the core body 33 and the surface layer 35 are simultaneously formed, it is preferable to polish the surfaces thereof.

The surface of the particles can be polished by various methods. For example, EA, which is an inorganic / organic composite particle
The method can be performed by dispersing the particles 21 in a dispersion medium such as water and stirring this. At this time, the EA particles 2 are mixed with an abrasive such as sand particles or balls in the dispersion medium.
It can also be carried out by a method of stirring with 1 or a method of stirring with a grinding wheel. For example, again
It is also possible to carry out dry stirring using the EA particles 21 and the above-mentioned abrasive or grinding stone without using the dispersion medium.

A more preferable polishing method is EA particle 21.
Is a method of stirring the air flow by a jet air flow or the like.
This is a method of polishing particles by violently colliding with each other in a gas phase, and is a preferable method in that the polished particles can be easily separated by classification without the need for another abrasive. In the above jet stream agitation, it is necessary to select polishing conditions depending on the type of equipment used, the agitation speed, the material of the EA particles 21, etc., but generally 0.5 min to 15 min at a stirring speed of 6000 rpm.
It is preferable to stir with a jet stream.

The ENC fluid composition 15 of the present invention can be produced by uniformly stirring and mixing the above EA particles 21 in the electrically insulating medium 21 together with other components such as a dispersant, if necessary. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used.

In the sound wave suppressing device 5 for the listening room and the like of the above embodiment, the sound wave absorption control device 10 is attached to the rectangular frame 6, and the caster 6d is attached to the lower part of the rectangular frame 6. Therefore, in order to set the characteristic frequency of the ENC fluid composition 15 in accordance with the frequency of the component of the sound wave 24 to be absorbed, the applied voltage value applied to the pair of electrodes 12, 13 of the sound wave absorption control device 10 is set. By adjusting with the voltage adjustment knob 6e, E
Since it is possible to absorb sound waves of various frequencies without changing the NC fluid composition 15, it is possible to provide the listening room or the like with acoustic characteristics according to the type of musical instrument to be played or music to be listened to. Further, the sound wave suppressing device 5 for the listening room or the like has a caster 6 on the rectangular frame 6.
Since d is attached, it can be moved and is easy to handle. Therefore, by changing the number and position of the arrangement, it is possible to change the number depending on the musical instrument to be played and the kind of music to be listened to. It is possible to give the acoustic characteristics to a listening room or the like.

Further, in the sound wave suppressing device 5 for the listening room or the like of the above embodiment, the backing material 18 is the electrode plate 1.
Sound wave absorption control device 1 provided with hollow panel 11 which also serves as 3
Although the case where 0 is used, the backing material 18 is flexible against sound waves, for example, various plastic films such as PET (polyethylene terephthalate) film, PVC (vinyl chloride) film, nylon film, polyethylene film, polypropylene film, acrylic film and the like. It is also possible to use a sound wave absorption control device 50 as shown in FIG. 14 that includes a hollow panel 11 that is composed of the above, and that has the electrode plate 13 uniformly fixed along the inner wall of the backing material 18. In the sound wave suppression device 5 for a listening room or the like in which the sound wave absorption control device 50 is attached to the rectangular frame 6, the surface material 1 of the sound wave absorption control device 50 is used.
Since it is possible to absorb sound waves of various frequencies on both the 7 side and the backing material 18 side, there is a large degree of freedom in the arrangement angle of the sound wave suppression device 5 for the listening room, etc. It is easy to give the listening room or the like acoustic characteristics according to the type of music played.

[0061]

The sound wave suppressing device for a listening room or the like according to the present invention is configured as described above, and therefore has the following effects. In order to set the characteristic frequency of the ENC fluid composition in accordance with the frequency of the component of the sound wave to be absorbed, the ENC fluid composition is adjusted by adjusting the applied voltage value applied to the pair of electrodes of the sound wave absorption control device. Since sound waves of various frequencies can be absorbed without any change, there is an advantage in that the listening room or the like can be provided with acoustic characteristics according to the kind of musical instrument to be played or music to be listened to. Further, the sound wave suppressing device for the listening room or the like is movable because the wheels are attached to the lower part of the rectangular frame and is easy to handle. Even by changing it, there is an advantage that the listening room or the like can be provided with acoustic characteristics according to the musical instrument to be played, the type of music to be listened to, and the like. Further, the sound wave absorption control device is a low-cost device using the ENC fluid composition, and as a result, the cost of the sound wave suppression device for a listening room or the like using the sound wave absorption control device increases. It is possible to avoid In particular, when the solid particles (EA particles) are inorganic-organic composite particles formed by a core body made of an organic polymer compound and a surface layer made of an EA inorganic substance, a practical ENC having high storage stability. A fluid composition is obtained, and as a result, the reliability of the sound wave absorption control device is further improved,
It is easy to give desired acoustic characteristics to the listening room.

[Brief description of drawings]

FIG. 1 is a graph showing the results of measuring the effect of electric field strength on EA characteristics in an EA particle dispersion system.

FIG. 2 is a diagram showing an equivalent circuit of a vibration system.

FIG. 3 is a schematic configuration diagram showing an embodiment of a sound wave suppressing device for a listening room or the like according to the present invention.

FIG. 4 is a cross-sectional view taken along the line II of the sound wave suppressing device for the listening room and the like shown in FIG.

5 is a cross-sectional view of a sound wave absorption control device of the sound wave suppression device for the listening room and the like shown in FIG.

6 is a diagram for explaining a listening room in which the sound wave suppressing device for the listening room and the like shown in FIG. 3 is used.

FIG. 7 is a cross-sectional view showing an example of the ENC composition according to the present invention.

FIG. 8 is a cross-sectional view showing an aspect of the ENC composition according to the present invention when the power is turned off.

FIG. 9 is a cross-sectional view showing an aspect of the ENC composition according to the present invention when the power is turned on.

FIG. 10 is a cross-sectional view showing a state in which a sound wave is incident and one of the electrode plates vibrates in the sound wave absorption control device used in the present invention.

FIG. 11 is a cross-sectional view showing a state where a chain and one of the electrode plates resonate when a sound wave is incident on the sound wave absorption control device used in the present invention.

FIG. 12 is a diagram showing another example of the bending state of the chain in the sound wave absorption control device used in the present invention.

FIG. 13 is a view showing a column in which a plurality of chains are joined to each other in the sound wave absorption control device used in the present invention.

FIG. 14 is a cross-sectional view showing another embodiment of the sound wave absorption control device used in the present invention.

[Explanation of symbols]

2 ... Coil spring, 3 ... Dash pot, 5 ... Sound wave suppressing device for listening room, 6 ... Rectangular frame,
6a ... opening, 6b ... groove, 6c ... frame support plate,
6d ... Casters (wheels), 6e ... Voltage adjustment knob, 6
f ... Power supply hole, 10 ... Sound wave absorption control device, 11 ... Hollow panel, 12 ... Electrode plate, 13 ... Electrode plate, 15 ... Electrosensitive sound wave absorption control fluid Composition (ENC fluid composition), 16 ... Variable power source, 17 ... Surface material, 18 ... Lining material, 19 ... Sealing member, 21 ... Electric field array particles (E
A particles, solid particles, inorganic / organic composite particles), 22 ... Electrical insulating medium, 24 ... Sound wave, 25 ... Sound wave, 27 ... Switch, 28 ... Side wall, 29 ... Floor, 30 ... Window, 31 ...
Audio rack, 32a ... Analog player, 32
b ... CD player, 32c ... Amplifier, 32d ... Speaker, 33 ... Core body (organic polymer compound), 34 ... Particles (particles of electric field aligning inorganic material), 35 ... Surface layer, 36 ... Chain-like Body (particle chain), 39 ... Column, 50 ... Sound wave absorption control device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Moritaka Goto 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Inventor Kenji Furuichi 1-1-5, Kiba, Koto-ku, Tokyo Shareholders Company Fujikura (72) Inventor Yasufumi Otsubo 9-21-1 Konakadai, Inage-ku, Chiba-shi, Chiba 206

Claims (1)

[Claims] 1. An electro-sensitive device comprising a hollow panel having a pair of electrode plates on a front surface and a back surface, and solid particles having an electric field array effect contained in an electrically insulating medium, the solid particles being housed between the pair of electrode plates. A sound wave absorption control device comprising a fluid composition for controlling sound wave absorption and a variable power source for applying a desired voltage between the pair of electrode plates is attached to a rectangular frame, and wheels are attached to the lower portion of the rectangular frame. The sound wave suppressing device for a listening room or the like, characterized in that the rectangular frame is movable.