JPH1144014A - Sound absorbing material, sound absorbing coating and manufacturing of sound absorbing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound absorbing material displaying fine sound absorbing characteristic even in a low frequency zone, causing no performance deterioration due to the omittance of powder or deflection, etc., and having lightweight, thin and workability equivalent to conventional porous material as well as execution efficiency. SOLUTION: A sound absorbing material formed by entering at least part of a powder layer 2 containing binder resin 5 of 0.5-40 pts.wt. of sol id content to powders 4 of 100 pts.wt. into a space part of a porous material 1 is manufactured. The powders 4 are held by the binder resin 5 to make it possible to form the powder layer 2 reducing the omission of the powders 4. Since ratio of the binder resin 5 to the powders 4 is small, the powder layer 2 having high sound absorbing characteristic in a low frequency zone by vibration of the powders 4 or viscous damping of surface muck stress air of the powders 4/resin 5 can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound-absorbing paint for forming a powder layer for obtaining a sound-absorbing effect.
Also, for sound treatment in listening rooms and musical instrument practice rooms, to reduce noise propagating in air-conditioning ducts, etc., and to enhance the sound insulation effect by filling between double structural walls such as walls and ceilings The present invention relates to a sound absorbing material used and a method for manufacturing the same.

[0002]

2. Description of the Related Art A sound-absorbing material is used in a listening room or a musical instrument practice room or the like where the acoustic characteristics of a room are problematic. Filling the walls and ceilings formed in the interior, lining material inside the air-conditioning duct or sound absorbing duct to prevent the propagation of noise, lining material inside the soundproof cover of equipment that generates noise, etc. Has been used as

As a sound absorbing material used in such applications, porous sound absorbing materials such as glass wool, rock wool, and polyurethane foam have been mainly used. These porous sound-absorbing materials have voids of complicated shape that communicate with each other, so that when sound waves enter the voids, viscous friction, etc., between the fiber surface and the urethane bubble wall during propagation in the voids Then, sound energy is absorbed in the porous material and sound is absorbed.

[0004] However, these porous sound absorbing materials generally have a sufficient sound absorption coefficient in a high frequency range, but the sound absorption coefficient decreases as the frequency decreases, and a sufficient sound absorption rate cannot be obtained in a low frequency range. There is. Increasing the thickness of the porous sound-absorbing material, or securing a sufficiently thick air layer behind the sound-incident surface of the porous sound-absorbing material (called the back air layer), can increase the sound absorption coefficient in the low frequency range. It is possible, but the sound absorbing material itself becomes very bulky, and the thickness of the sound absorbing material combined with the back air layer becomes very thick. For example, the room becomes narrow when used as an interior material of a room. This causes problems such as narrowing of the air passage when the duct is used as an inner paste.

On the other hand, as a sound absorbing material having excellent sound absorbing performance in a low frequency range even if it is thin, a sound absorbing material formed of a powder layer such as silica powder is provided. In this sound absorbing material,
When sound is incident on the powder layer, the powder particles vibrate, and the sound wave energy is absorbed by the vibration, thereby exhibiting a sound absorbing effect. However, the sound-absorbing material using this powder as a material is formed, for example, by filling a powder into a box-shaped container to form a powder layer, and covering with a film or the like having good sound wave transmission. However, there is a problem that even if the powder is uniformly filled in the container, the powder gradually moves in the course of use and the powder is biased, so that the sound absorbing performance may be changed.

Therefore, it has been proposed to form a sound-absorbing material by filling and holding a void in a very coarse porous material such as glass wool with a powder. However, even in this case, even if the powder is initially uniformly filled in the voids of the porous material, the problem that the powder is gradually moved and biased in the use process and the sound absorbing performance is changed cannot be solved. . In addition, in this one, the work of filling powder into the voids of a porous material such as glass wool is performed by spraying the powder on the porous material and vibrating to sink the powder into the voids between the fibers. However, this method has a problem that the powder soars into the air, which causes a deterioration in the working environment and a reduction in the working efficiency. Furthermore, when processing a sound absorbing material filled with powder in the voids of such a porous material, for example, when cutting to a desired size, the powder will leak from the cut surface of the porous material, and the usual A method of cutting a sound absorbing material, for example, a simple cutting method using a cutter knife, scissors, or the like, such as cutting foamed polyurethane, glass wool, rock wool, nonwoven fabric, felt, or the like, cannot be performed.

[0007]

Accordingly, the present invention shows good sound absorption characteristics even in a low frequency range, does not cause performance deterioration due to powder falling off or unevenness, and is light, thin and has a conventional porous structure. The object of the present invention is to provide a sound-absorbing material having the same workability and workability as a material and a method for manufacturing the same, and furthermore, a powder layer for improving sound-absorbing characteristics without causing deterioration of a working environment and the like. It is an object of the present invention to provide a sound-absorbing paint that can be formed on a substrate.

[0008]

The sound absorbing material according to the present invention comprises:
A powder layer containing 0.5 to 40 parts by weight of a solid content of a binder resin with respect to 100 parts by weight of a powder, at least a part of which is formed by entering a void portion of a porous material. Is what you do. The invention according to claim 2 is characterized in that the powder layer contains 1 to 6 parts by weight of a binder resin as a solid content with respect to 100 parts by weight of the powder.

The invention according to claim 3 is characterized in that the powder layer is formed so as to be exposed on the surface of the porous material. The invention according to claim 4 is characterized in that the powder layer is formed in a surface layer portion of a porous material. The invention according to claim 5 is characterized in that the powder layer is formed inside a porous material.

The invention according to claim 6 is characterized in that the porous material has continuous pores.
The invention according to claim 7 is characterized in that the porous material having continuous pores is selected from foamed polyurethane, glass wool, and nonwoven fabric. The invention according to claim 8 is characterized in that the powder layer has a weight per unit area of the powder of 0.3 to 3 kg / m ² .

The invention according to claim 9 is characterized in that the powder layer has a weight per unit area of the powder of 0.5 to ² kg / m ² . In the invention according to claim 10, the powder has a particle size of 0.1 to 1000 μm and a bulk density of 0.1 to 1000 μm.
It is characterized by being 1.5 g / cm ³ . The invention according to claim 11 is characterized in that the powder is at least one of talc, shirasu balloon and calcium carbonate.

In a twelfth aspect of the present invention, the powder is talc. According to a thirteenth aspect of the present invention, the binder resin is a phenol resin, an acrylic resin, a polyvinyl alcohol resin, or polyvinyl acetate.
One or more are selected. The invention according to claim 14 is characterized in that the powder layer is a free end.

[0013] The sound-absorbing paint according to the present invention contains 100 powders.
It is characterized by comprising 0.5 to 40 parts by weight of a binder resin in a solid content and 20 to 300 parts by weight of a solvent in a solid content. In the invention according to claim 16, the powder has a particle size of 0.1 to 1000 μm and a bulk density of 0.1 to 1.5 g.
/ Cm ³ .

The invention according to claim 17 is characterized in that the powder is at least one of talc, shirasu balloon and calcium carbonate. Also, in the invention according to claim 18, the binder resin is one of a phenol resin, an acrylic resin, a polyvinyl alcohol resin, and polyvinyl acetate.
One or more are selected.

The invention according to claim 19 is characterized in that the solvent is water. In the method for producing a sound absorbing material according to the present invention, 100 parts by weight of a powder, 0.5 to 40 parts by weight of a binder resin in solid content, and 20 to 300 parts by weight of a solvent are blended to prepare a sound absorbing paint. It is characterized in that a sound absorbing paint is applied to the surface of a porous material.

The invention of claim 21 is characterized in that the powder is 100 parts by weight, the binder resin is 0.5 to 40 parts by weight in solid content,
A sound absorbing paint is prepared by blending 20 to 300 parts by weight of a solvent, and the sound absorbing paint is impregnated into a porous material.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the sound absorbing material of the present invention will be described. The powder is made of an inorganic material and / or an organic material, for example, gold mica, silica, acrylic resin, talc, calcium silicate, fluororesin, perlite, shirasu balloon, fused silica, graphite, crystalline cellulose, silicon carbide, diatomaceous earth , Nylon, polyester,
Carbon fiber, titanium dioxide, calcium carbonate, polyvinyl chloride, polymethyl methacrylate, barium ferrite,
A powder such as silicone can be used.

As the powder, any one or more of these can be selected and used.
It is preferable to use talc, shirasu balloon or calcium carbonate. Talc powder has a particularly high sound absorption effect in the low frequency range, and Shirasu balloon powder has a lower sound absorption coefficient in the lower frequency range than talc powder under the same conditions, but has excellent sound absorption properties in a wide range in the mid-high range. . The sound absorbing properties of calcium carbonate show intermediate properties between talc and shirasu balloon. Talc powder and shirasu balloon powder are relatively inexpensive, and calcium carbonate is more inexpensive, which also helps to reduce costs. Talc powder, shirasu balloon powder, and calcium carbonate powder may be used alone or in combination of two or more.
Among them, talc is particularly preferable in terms of a sound absorbing effect in a low frequency range.

The powder has a particle size of 0.1 to 10
And the bulk density is 0.1 to 1.5 g /
It is preferable to use one having a range of cm ³ in order to improve the sound absorption characteristics. That is, powder having a particle size of less than 0.1 μm is practically difficult to use, and conversely, a particle size of 1000 μm
When m exceeds m, it becomes difficult to obtain the sound absorbing effect of the powder. If the bulk density is less than 0.1 g / cm ³ , the bulk becomes bulky, making it difficult to reduce the thickness of the powder layer and the sound absorbing material. Conversely, if the bulk density exceeds 1.5 g / cm ³ , Makes it difficult to obtain a sound absorbing effect.

As the binder resin, polyethylene resin, polystyrene resin, methacrylic resin, polyurethane resin, phenol resin, urea resin, acrylic resin, vinyl chloride resin, polyvinyl alcohol, polyvinyl acetate, etc. can be used. A water-soluble resin such as phenol resin, acrylic resin, polyvinyl alcohol, and polyvinyl acetate is preferable from the viewpoint of suppressing the discharge of the organic solvent or from the viewpoint of the working environment. In particular, phenolic resin is a thermosetting resin, which is effective in increasing the heat resistance of the sound absorbing material.In addition, phenolic resin and acrylic resin are insoluble in water after curing, so a sound absorbing material with good weather resistance can be used. It is something that can be obtained. Further, polyvinyl alcohol and polyvinyl acetate have a high affinity with inorganic powders and can obtain a high effect of retaining inorganic powders, and polyvinyl alcohol and polyvinyl acetate are relatively inexpensive. Yes, it is also useful for cost reduction. These binder resins can be used alone or in combination of two or more.

The porous material used in the present invention has a large number of voids inside as voids and interstices between fibers, and is made of foamed polyurethane, glass wool, rock wool, nonwoven fabric, or the like in which voids are formed as continuous pores. A material selected from felt can be used. The powder layer 2 is composed of the powder 4 and the binder resin 5, and the powder layer 2 is formed such that at least a part thereof enters the void portion of the porous material 1. By providing the powder layer 2 on the porous material 1 as described above,
The sound absorbing material A can be produced. In forming the powder layer 2 on the porous material 1, the porous material 1
The powder layer 2 may be formed so as to be exposed on the surface of the porous material 1 (see FIG. 4C), or the powder layer 2 may be formed in the surface layer of the porous material 1 (see FIG. a)), or the powder layer 2 may be formed inside the porous material 1 (see FIG. 4B). As the position where the powder layer 2 is provided is closer to the surface of the porous material 1, higher sound absorption characteristics in a low frequency range can be obtained. In addition, by providing the powder layer 2 inside the porous material 1, a higher frequency range can be obtained. Can be obtained with high sound absorption characteristics, and the required sound absorption characteristics can be satisfied by setting the position of the powder layer 2 provided on the porous material 1. The powder layer 2
In addition to providing one layer on the porous material 1, two layers may be provided by forming the porous material 1 on both surfaces (see FIG. 4D), or may be provided in multiple layers.

Here, the powder layer 2 is formed so as to contain 0.5 to 40 parts by weight of the binder resin 5 as a solid (that is, resin) with respect to 100 parts by weight of the powder 4. The binder resin 5 is blended for holding the powder 4, and in the present invention, by reducing the amount of the binder resin 5, the vibration of the powder 4 and the The sound absorbing characteristics due to the shear stress at the powder / resin interface and the viscous damping of air are developed, and it is possible to form the powder layer 2 having excellent sound absorbing characteristics particularly in a low frequency range. That is, the binder resin 5
Is set within the above range, the powder 4 is securely held without impairing the sound absorption characteristics due to the vibration of the powder 4, particularly the sound absorption characteristics in the low frequency range, and the powder 4 moves or flows out. In addition, even if the sound absorbing material A is cut, it is possible to minimize the falling of the powder 4 from the cut surface. From these points, the mixing amount of the binder resin 5 is 10
More preferably, the amount is in the range of 1 to 6 parts by weight with respect to 0 parts by weight.

Here, when producing the sound absorbing material A by providing the powder layer 2 on the porous material 1 as described above, the powder layer 2
The weight per unit area of the powder 4 contained in 0.3 to 3
It is preferable to form the powder layer 2 so as to be kg / m ² . The weight per unit area of the powder 4 is 0.3 kg / m ²
With the powder layer 2 of less than 2, the sound absorbing properties of the sound absorbing material A are close to the sound absorbing properties of the porous material 1, and high sound absorbing properties in a low frequency range cannot be obtained. Conversely, if the powder layer 2 having a weight per unit area of the powder 4 of more than 3 kg / m ² is formed, the weight of the sound absorbing material A cannot be reduced, and the powder layer 2 having more weight can be formed. It is practically difficult to do. Therefore, the weight per unit area of the powder 4 contained in the powder layer 2 is 0.3 to 3 kg / m ^{2 in} order to obtain high sound absorption characteristics in a low frequency range while maintaining the weight reduction of the sound absorbing material A. It is preferable to form the powder layer 2 so as to be as follows. From this point, the weight per unit area of the powder 4 contained in the powder layer 2 is 0.5
Forming the powder layer 2 so as to be ~ ² kg / m ²
More preferred.

Further, it is preferable that the sound absorbing material A is mounted on the surface opposite to the side on which the powder layer 2 is provided, so that the free end where the powder layer 2 is not fixed is provided. This is because, in addition to the vibration of the powder 4 and the sound absorption due to the shear stress at the powder / resin interface and the viscous damping of the air, the additional weight of the powder layer 2 and the spring vibration using the porous material 1 as a spring. This is because the sound absorbing effect of the above can also be used.

Next, a description will be given of a preferred sound absorbing paint for producing the powder layer of the above sound absorbing material. The types and amounts of the powder and the binder resin are as described above, but the sound absorbing paint requires a solvent in addition thereto. As the solvent, when a water-soluble binder resin is used, water can be used. In addition, alcohols such as toluene, THF, acetone, benzene, hexane, chloroform, dichloromethane, methanol, ethanol, and propanol can be used. Organic solvents such as organic solvents, halogen solvents, aromatic solvents and aliphatic hydrocarbons can also be used. In consideration of the environment, it is preferable to use water.

Then, 0.5 to 40 parts by weight of a binder resin in solids (that is, resin) is added to 100 parts by weight of the powder.
The sound-absorbing paint according to the present invention is prepared by mixing 20 to 300 parts by weight of a solvent, and further mixing and mixing additives such as a wetting agent, a dispersing agent, a thickener, and a preservative as needed. be able to. Here, in a normal coating material, the binder resin is compounded in a large amount greatly exceeding 40 parts by weight, but in the sound absorbing coating material of the present invention, as described above, 0.5 to 40 parts by weight with respect to 100 parts by weight of the powder. Very low. This is because the binder resin is not intended to form a coating film like ordinary paint, but is blended for holding powder, and thus reducing the amount of the binder resin. As described above, while retaining the powder, sound absorption characteristics due to the vibration of the powder, the shear stress at the powder / resin interface, and the viscous damping of the air can be exhibited, particularly in the low frequency range. This makes it possible to form a powder layer having excellent characteristics.

The solvent is used to adjust the fluidity of the sound absorbing paint to enhance the workability when applying the sound absorbing paint. The solvent is used in an amount of 20 parts by weight based on 100 parts by weight of the powder. If it is less than 10 parts, the viscosity of the sound-absorbing paint is so high that application becomes difficult. On the other hand, when the amount of the solvent exceeds 300 parts by weight with respect to 100 parts by weight of the powder, the viscosity of the sound absorbing paint becomes too low, so that the powder tends to settle, and the powder layer in which the powder is uniformly dispersed is formed. It becomes difficult to form. On the other hand, when the amount of the solvent is large, the drying load increases, which is not preferable for the environment.

An example of a procedure for preparing the sound absorbing paint of the present invention will be described. For example, using water as a solvent, the dispersibility of the powder and the affinity with the solvent or the porous material to which the sound absorbing paint is applied are described. In order to increase the content, necessary amounts of a wetting agent and a dispersing agent are added, and if necessary, an antifoaming agent is added and mixed with stirring. By adding and mixing a binder resin to the solution thus obtained and further adding and mixing a powder, a sound-absorbing paint can be obtained. When preparing the sound-absorbing paint, it may foam depending on the stirring method,
In such a case, it is desirable to add a defoaming agent or to remove the bubbles by vacuum defoaming or the like after stirring and mixing.

The powder layer can be formed by applying or impregnating the porous material with the sound absorbing paint according to the present invention obtained as described above. In addition, the adhesiveness of the sound-absorbing paint can be increased by selecting a binder resin or performing a pre-coating treatment on the surface to be coated. Next, a method for manufacturing the sound absorbing material will be described. As one of the methods, there is a method of applying a sound absorbing paint to the surface of a porous material. The application of the sound absorbing paint can be performed using a flow coater, a roll coater, a spray coat, or the like. There is also a method in which a part of a porous material, for example, a surface layer portion of the porous material is immersed in a sound absorbing paint to impregnate the porous material with the sound absorbing paint. By coating or impregnating the porous material with the sound absorbing paint as described above and allowing the powder to enter the voids of the porous material together with the binder resin, the sound absorbing paint is dried to solidify or cure the binder resin. The powder layer formed by holding the powder with the binder resin can be formed in the voids of the porous material. By forming the powder layer on the porous material as described above, the sound absorbing material according to the present invention can be manufactured. In this sound absorbing material, the powder is held in the porous material by the binder resin, so that it is possible to prevent the powder from moving or flowing out, thereby deteriorating the sound absorbing characteristics, and cut the sound absorbing material. This can prevent the powder from falling off from the cut surface during the cutting.

Further, a specific example of a method for producing a sound absorbing material will be described. FIG. 1 shows a structure in which a powder layer 2 is formed in a surface layer of a porous material 1 (Claim 4). After a sound absorbing paint 3 is applied to the surface of the porous material 1, a spatula 1 is formed.
When the sound absorbing paint 3 is rubbed on the surface of the porous material 1 at 0, the tip of the spatula 10 is moved along the surface of the porous material 1 as shown in FIG. The powder 4 is allowed to enter the voids in the surface layer of the porous material 1 together with the binder resin 5 and then dried to form a solidified or cured binder resin 5 as shown in FIG. A sound absorbing material A provided by embedding the powder layer 2 formed by holding in the surface layer portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 It is.

FIG. 2 shows a structure in which the powder layer 2 is formed inside the porous material 1 (Claim 5). After the sound absorbing paint 3 is applied to the surface of the porous material 1, the spatula 10 is formed. When the sound absorbing paint 3 is rubbed on the surface of the porous material 1 by using the porous material 1 as shown in FIG.
By moving the porous material 1 while pressing it, the powder 4 of the sound-absorbing paint 3 enters the void inside the porous material 1 together with the binder resin 5. As described above, when the porous material 1 is compressed by the spatula 10 and the powder 4 of the sound-absorbing paint 3 enters the void inside the porous material 1 together with the binder resin 5, the porous material 1 passes after the spatula 10 passes. When the elastic material 1 recovers elastically, a part of the binder resin 5 adheres to the porous material 1 and returns to the surface layer of the porous material 1, but the powder 4 is left in the void inside the porous material 1. It does not return to the surface layer of the porous material 1. Therefore, by drying this, as shown in FIG. 2B, the powder layer 2 formed by holding the powder 4 with the solidified or cured binder resin 5 is formed.
Is embedded in the porous material 1 to provide the sound absorbing material A.

FIG. 3 shows a structure in which a powder layer 2 is formed by exposing to the surface of a porous material 1 (claim 3).
After coating the sound absorbing paint 3 on the surface of the porous material 1 and then rubbing the sound absorbing paint 3 on the surface of the porous material 1 with the spatula 10, the tip of the spatula 10 is made porous as shown in FIG. By moving the powder 4 of the sound-absorbing paint 3 together with the binder resin 5 into a gap in the surface layer of the porous material 1 by moving the powder 4 of the sound-absorbing paint 3 together with the binder resin 5 by slightly moving the material 4 away from the surface of the material 1. At the same time, the other part of the powder 4 is exposed on the surface of the porous material 1 together with the binder resin 5 and then dried to solidify the powder 4 as shown in FIG. A part of the powder layer 2 formed by being held by the cured binder resin 5 is embedded in the surface layer of the porous material 1 and the other part is
The sound absorbing material A provided so as to be exposed from the surface can be obtained.

As described above, by operating the spatula 10, the powder layer 2 is formed in the surface layer of the porous material 1 as shown in FIG.
The powder layer 2 can be formed inside the porous material 1 as shown in FIG. 2, or the powder layer 2 can be formed so as to be exposed on the surface of the porous material 1 as shown in FIG. When the powder layer 2 is formed inside the porous material 1 as shown in FIG.
It is preferable to use a material in which the viscosity is adjusted to be low by increasing the amount of the solvent as the sound absorbing coating material 3. When the powder layer 2 is formed so as to be exposed on the surface of the porous material 1 as shown in FIG. It is preferable to use, as the sound-absorbing paint 3, a paint whose viscosity is adjusted to be high by reducing the amount of a solvent. When the powder layer 2 is formed in the surface layer portion of the porous material 1 as shown in FIG. 1, it is preferable to adjust the amount of the solvent so as to have an intermediate viscosity. Further, by utilizing the continuous pores of the porous material 1 and sucking it from the opposite surface of the porous material 1 on which the sound absorbing paint 3 is applied, the sound absorbing paint 3 is deeply embedded in the porous material 1. Infiltrate the powder layer 2 into the porous material 1
It is also possible to form deep inside.

As described above, the sound absorbing material A can be prepared by applying or impregnating the porous material 1 with the sound absorbing paint 3 and then drying it, but the surface properties of the sound absorbing material A are problematic. In such a case, a surface material such as paper, a resin film, or a non-woven fabric is laminated on the surface of the porous material 1, and the surface material is bonded to the porous material 1 by using a binder resin included in the sound absorbing paint 3. You may. At this time, when a thermosetting resin is used as the binder resin, the surface material is laminated on the surface of the porous material 1 and then hot pressed to cure the binder resin and simultaneously bond the surface material to the porous material 1. can do. Of course, the surface material may be adhered to the sound absorbing material A obtained by applying or impregnating the porous material 1 with the sound absorbing paint 3 and drying.

[0035]

Next, the present invention will be described specifically with reference to examples. Example 1 10 parts by weight of talc powder (bulk density: 0.4 g / cm ³ , average particle size: 20 μm), a binder resin containing polyvinyl alcohol and polyvinyl acetate as main components (liquid paste “Arabic Yamato manufactured by Yamato Corporation”) ": Polyvinyl alcohol solid content 11% by weight, polyvinyl acetate solid content 2
2% by weight of water, 82 to 84% by weight of water, and the remainder is 2 parts by weight of a fragrance and a preservative) and 9 parts by weight of water, and the resulting mixture is stirred and mixed to obtain a talc-polyvinyl alcohol-polyvinyl acetate-based sound absorbing material. Paint was prepared.

Next, a foamed polyurethane which is a porous material having continuous pores (density: 16 kg / m ³ , thickness: 30 m
m) The sound absorbing paint is applied to the surface of 1m in terms of the weight of talc powder.
g / m < ² >, and after applying a sound absorbing paint by operating a spatula as shown in FIG. 1 (a) and drying at room temperature for 24 hours, as shown in FIG. 4 (a). Then, a sound absorbing material A in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1 was obtained.

(Example 2) 10 parts by weight of the same talc powder as in Example 1, 2 parts by weight of the same binder resin as in Example 1, and 11 parts by weight of water were blended. A polyvinyl alcohol-polyvinyl acetate-based paint for sound absorption was prepared. Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 1 kg / m ^{2 in} terms of the weight of talc powder.
As shown in FIG. 4 (a), the spatula is operated to apply the sound absorbing paint, and then dried at room temperature for 24 hours.
As shown in (b), a sound absorbing material A provided with the powder layer 2 embedded in the porous material 1 was obtained.

(Example 3) 10 parts by weight of the same talc powder as in Example 1, 2 parts by weight of the same binder resin as in Example 1, and 7 parts by weight of water were mixed, and the mixture was stirred and mixed. A polyvinyl alcohol-polyvinyl acetate-based paint for sound absorption was prepared. Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 1 kg / m ^{2 in} terms of the weight of talc powder.
As shown in FIG. 4 (a), the spatula is operated to apply the sound absorbing paint, and then dried at room temperature for 24 hours.
As shown in (c), a sound absorbing material A was obtained in which a part was embedded in the surface layer of the porous material 1 and another part was exposed from the surface of the porous material 1 and the powder layer 2 was provided.

Example 4 10 parts by weight of the same talc powder as in Example 1, 2 parts by weight of the same binder resin as in Example 1, and 12 parts by weight of water were blended, and the mixture was stirred and mixed. A polyvinyl alcohol-polyvinyl acetate-based paint for sound absorption was prepared. Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and a sound-absorbing paint was applied to one surface of the foamed polyurethane at an application amount of 1 kg / m ^{2 in} terms of the weight of talc powder. As shown in FIG. 2 (a), a spatula was applied to apply the sound absorbing paint, dried at room temperature for 24 hours, and the other side of the foamed polyurethane was coated with the sound absorbing paint at a weight of 1 kg / m2 of talc powder. It was applied in ² of coating weight, after elaborate painted absorbing paints by operating the spatula as shown in FIG. 2 (a), by drying at room temperature for 24 hours, porous as shown in FIG. 4 (d) A sound absorbing material A provided with two powder layers 2 embedded in the material 1 was obtained.

Example 5 Talc powder (0.4 g bulk density)
/ Cm 3, average particle size 18 μm) and 10 parts by weight of a binder resin solution containing polyvinyl alcohol as a main component (“GH-17” manufactured by Chuo Rika Kogyo Co., Ltd .: polyvinyl alcohol solid content 10% by weight, water 90% by weight). 3 parts by weight and 8 parts by weight of water were blended, and 0.1 part by weight of a wetting agent (“Nopco Wet 50” manufactured by San Nopco) and 0.1 part by weight of a dispersant (“Hydropalat 1706” manufactured by San Nopco) were added.
Parts by weight, an antifoaming agent (Adecanate B-94 manufactured by Asahi Denka Co., Ltd.)
0 ") was blended, and the mixture was stirred and mixed to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound absorbing paint at a weight of 1 k of talc powder.
g / m ² , and after applying a sound-absorbing paint by operating a spatula as shown in FIG. As shown in a), a sound absorbing material A in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1 was obtained.

Example 6 5 parts by weight of shirasu balloon powder (bulk density: 0.26 g / cm ³ , average particle size: 220 μm), 3 parts by weight of the same binder resin solution as in Example 5, 8 parts by weight of water, 0.1 parts by weight, 0.1 parts by weight and 0.05 parts by weight of the same wetting agent, dispersing agent and defoaming agent as in Example 5 were blended, and the resulting mixture was stirred and mixed. Was prepared.

Next, the same foamed polyurethane as in Example 1 was used as a porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound absorbing paint to a coating amount of 0.5 kg / m ^{2 in} terms of weight of Shirasu balloon powder. As shown in FIG. 1 (a), after applying a sound absorbing paint by operating a spatula as shown in FIG. 1 (a), and drying for 1 hour with a dryer at 80 ° C., as shown in FIG. 4 (a). A sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1.

(Example 7) Silicone powder (having a bulk density of 0.1)
16 g / cm 3, average particle size 40 μm), 10 parts by weight, 3 parts by weight of the same binder resin solution as in Example 5, 8 parts by weight of water, and 0 parts each of the same wetting agent, dispersant and defoaming agent as in Example 5. .1 part by weight, 0.1 part by weight and 0.05 part by weight were mixed and stirred and mixed to prepare a silicone-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane so that the coating amount was 1 kg / m ^{2 in} terms of the weight of silicone powder. Apply, Fig. 1 (a)
After applying the sound absorbing paint by operating the spatula as shown in FIG. 4A, the material was dried for 1 hour with a drier at 80 ° C., so that the surface became substantially flush with the surface of the porous material 1 as shown in FIG. As a result, a sound absorbing material A provided by embedding the powder layer 2 in the surface layer of the porous material 1 was obtained.

Example 8 Fluororesin powder (having a bulk density of 0.1)
4 g / cm ³ , average particle size 47 μm), 10 parts by weight, 3 parts by weight of the same binder resin solution as in Example 5, 8 parts by weight of water, and the same wetting agent, dispersant and defoaming agent as in Example 5, respectively. 0.1 parts by weight, 0.1 parts by weight and 0.05 parts by weight are blended,
This was stirred and mixed to prepare a fluororesin-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 1 kg / m ^{2 in} terms of the weight of fluororesin powder. And then apply it to Fig. 1 (a)
After applying the sound absorbing paint by operating the spatula as shown in FIG. 4A, the material was dried for 1 hour with a drier at 80 ° C., so that the surface became substantially flush with the surface of the porous material 1 as shown in FIG. As a result, a sound absorbing material A provided by embedding the powder layer 2 in the surface layer of the porous material 1 was obtained.

Example 9 A talc-polyvinyl alcohol-based sound absorbing paint was prepared in the same manner as in Example 5. Next, a sound absorbing paint is applied to the surface of glass wool (a density of 32 kg / m ³ , a thickness of 25 mm), which is a porous material having continuous pores, so as to have an application amount of 1 kg / m ^{2 in} terms of talc powder weight. After the sound absorbing paint is applied by operating a spatula as shown in FIG. 1A, the porous material 1 is dried by a dryer at 80 ° C. for 1 hour as shown in FIG. A sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface.

Example 10 A binder resin solution containing 10 parts by weight of the same talc powder as in Example 5 and an acrylic resin ("SA-203" manufactured by Chuo Rika Kogyo Co., Ltd.):
0.75 parts by weight of an acrylic resin solid content of 40% by weight, water of 60% by weight, and a trace amount of a dispersing agent) and 9 parts by weight of water were blended. 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight were blended, respectively, and mixed by stirring to prepare a talc-acrylic resin-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound-absorbing paint by 1 k in terms of weight of talc powder.
g / m ² , and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for 1 hour in a dryer at 0 ° C., FIG.
As shown in (a), a sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1.

(Example 11) 10 parts by weight of the same talc powder as in Example 5 and a binder resin solution containing a water-soluble phenol resin as a main component (“CJ220” manufactured by Matsushita Electric Works, Ltd.)
2 ": 0.6 part by weight of phenolic resin solid content and 50 parts by weight of water) and 9 parts by weight of water are mixed and stirred and mixed to obtain a talc-phenolic resin-based sound absorbing paint. Prepared.

Next, the same glass wool as in Example 9 was used as a porous material having continuous pores, and a sound absorbing paint was applied on the surface of the glass wool in an amount of 1 kg / m 2 in terms of the weight of talc powder.
1 (a), and after applying a sound absorbing paint by operating a spatula as shown in FIG. 1 (a), followed by drying for 1 hour in a drier at 200 ° C. ), The powder layer 2 is embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1.
I got

(Example 12) 10 parts by weight of the same talc powder as in Example 5, and 1 part of the same binder resin solution as in Example 5
Parts by weight, 11 parts by weight of water, 0.1 part by weight, 0.1 part by weight and 0.05 part by weight of the same wetting agent, dispersing agent and defoaming agent as in Example 5, and mixing with stirring. In this way, a talc-polyvinyl alcohol-based sound absorbing paint was prepared.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound-absorbing paint by 1 k in terms of weight of talc powder.
g / m ² , and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for 1 hour in a dryer at 0 ° C., FIG.
As shown in (a), a sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1.

(Example 13) 10 parts by weight of the same talc powder as in Example 5, 10.7 parts by weight of the same binder resin solution as in Example 10, and 10 parts by weight of water, dispersed with the same wetting agent as in Example 5 0.1 part by weight, 0.1 part by weight and 0.05 part by weight of the agent and the defoaming agent were blended, respectively, and the mixture was stirred and mixed to prepare a talc-acrylic resin-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as a porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a weight of talc powder of 1 kN.
g / m ² , and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for 1 hour in a dryer at 0 ° C., FIG.
As shown in (a), a sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1.

Example 14 10 parts by weight of calcium carbonate powder (bulk density: 0.3 g / cm ³ , average particle size: 7 μm)
3 parts by weight of the same binder resin solution as in Example 5, 1.5 parts by weight of water, and 0.05 part by weight, 0.1 part by weight and 0 part by weight of the same wetting agent, dispersant and defoamer as in Example 5. .05 parts by weight and mixing with stirring to prepare a calcium carbonate-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 1 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 1 kg / m ^{2 in} terms of the weight of calcium carbonate powder. Apply to Fig. 1
As shown in FIG. 4A, the sound absorbing paint is applied by operating a spatula, and then dried for 1 hour with a dryer at 80 ° C., so that the surface of the porous material 1 is substantially removed as shown in FIG. A sound absorbing material A provided with the powder layer 2 embedded in the surface layer of the porous material 1 so as to be flush was obtained.

Example 15 10 parts by weight of calcium carbonate powder (bulk density: 0.8 g / cm ³ , average particle size: 7 μm)
4 parts by weight of the same binder resin solution as in Example 10, and 0.05 parts each of the same wetting agent, dispersant and defoamer as in Example 5.
Parts by weight, 0.1 part by weight and 0.05 part by weight were mixed and stirred and mixed to prepare a calcium carbonate-acrylic resin-based sound absorbing paint.

Next, foamed polyurethane which is a porous material having continuous pores (density 16 kg / m ³ , thickness 10 m
m) The sound absorbing paint is applied to the surface of 1m in terms of the weight of talc powder.
g / m ² , and after applying a sound-absorbing paint by operating a spatula as shown in FIG. As shown in a), a sound absorbing material A in which the powder layer 2 was embedded in the surface layer of the porous material 1 so as to be substantially flush with the surface of the porous material 1 was obtained.

(Example 16) 10 parts by weight of the same talc powder as in Example 5 and a binder resin solution containing polyvinyl alcohol as a main component ("GH-1" manufactured by Chuo Rika Kogyo Co., Ltd.)
7 ": polyvinyl alcohol solid content 15% by weight, water 85
% By weight) and 8 parts by weight of water,
The same wetting agent, dispersing agent and defoaming agent as in Example 5 were added in amounts of 0.1% each.
05 parts by weight, 0.1 parts by weight and 0.05 parts by weight were blended and stirred and mixed to prepare a talc-polyvinyl alcohol-based sound absorbing coating.

Next, a foamed polyurethane which is a porous material having continuous pores (density: 16 kg / m ³ , thickness: 10 m
m), the surface of the sound absorbing coating is coated with 0.1 g of talc powder in terms of weight.
By applying at a coating amount of 5 kg / m ² , applying a sound absorbing paint by operating a spatula as shown in FIG. 1 (a), and drying at 80 ° C. for 1 hour, Thus, a sound absorbing material A was provided in which the powder layer 2 was embedded in the surface layer portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1.

(Example 17) 10 parts by weight of the same talc powder as in Example 5, 1.33 parts by weight of the same binder resin solution as in Example 16, and 7 parts by weight of water were mixed, and the same wetness as in Example 5 was obtained. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.05 part by weight, 0.01 part by weight, and 0.05 part by weight of a dispersing agent, a dispersant, and an antifoaming agent, respectively, and stirring and mixing. .

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 0.5 kg / m 2 in terms of the weight of talc powder. After operating the spatula to apply the sound absorbing paint as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 18) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were blended. The same wetting agent, dispersing agent and defoaming agent were blended in an amount of 0.05 part by weight, 0.1 part by weight and 0.05 part by weight, respectively.
A polyvinyl alcohol-based paint for sound absorption was prepared.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 0.5 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 19) 10 parts by weight of the same talc powder as in Example 5, 4 parts by weight of the same binder resin solution as in Example 16, and 5 parts by weight of water were blended. The same wetting agent, dispersant, and defoamer were mixed in 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight, respectively, to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 15 was used as the porous material having continuous pores, and a sound-absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 0.5 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 20) 10 parts by weight of the same talc powder as in Example 5, 13.3 parts by weight of the same binder resin solution as in Example 16, and 5 parts by weight of water were blended. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.3 parts by weight, 0.1 part by weight, and 0.05 part by weight of an agent, a dispersant, and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 0.5 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 21) 10 parts by weight of the same talc powder as in Example 5, 26.7 parts by weight of the same binder resin solution as in Example 16, and 5 parts by weight of water were blended. 0.1 part by weight, 0.3 part by weight and 0.05 part by weight of an agent, a dispersant and an antifoaming agent were blended, respectively, to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as a porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 0.5 kg / m ^{2 in} terms of talc powder weight. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 22) 10 parts by weight of the same talc powder as in Example 5, 0.33 parts by weight of the same binder resin solution as in Example 16, and 8 parts by weight of water were blended. 0.1 part by weight, 0.1 part by weight and 0.05 part by weight of an agent, a dispersant and an antifoaming agent were blended, respectively, to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as that of Example 16 was used as the porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound-absorbing paint in an amount of 1 wt.
1 kg / m @ 2, and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for a time, the sound absorbing material A provided by embedding the powder layer 2 in the surface layer portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. I got

(Example 23) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were mixed, and the same wetting agent as in Example 5 was used. 0.05 parts by weight of a dispersant and 0.05 parts by weight of a defoamer were added.
2 parts by weight and 0.05 part by weight were mixed and stirred and mixed to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and the surface of the foamed polyurethane was coated with a sound-absorbing paint in an amount of 1 wt.
1 kg / m @ 2, and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for a time, the sound absorbing material A provided by embedding the powder layer 2 in the surface layer portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. I got

(Example 24) 10 parts by weight of the same talc powder as in Example 5, 26.7 parts by weight of the same binder resin solution as in Example 16, and 5 parts by weight of water were blended. 0.15 parts by weight, 0.1 parts by weight and 0.05 parts by weight of the agent, dispersant and defoaming agent were mixed to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as a porous material having continuous pores, and a sound-absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1% in terms of weight of talc powder.
1 kg / m ² , and after applying a sound absorbing paint by operating a spatula as shown in FIG.
By drying for a time, the sound absorbing material A provided by embedding the powder layer 2 in the surface layer portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. I got

(Example 25) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were mixed, and the same wetting agent as in Example 5 was used. 0.05 parts by weight of a dispersant and 0.05 parts by weight of a defoamer were added.
One part by weight and 0.05 part by weight were blended to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 0.3 kg / m ^{2 in} terms of talc powder weight. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 26) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were mixed, and the same wetting agent as in Example 5 was used. 0.1 parts by weight and 0.0 parts by weight of the dispersant and the defoamer
One part by weight and 0.05 part by weight were blended to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 0.8 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 27) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were blended. 0.1 parts by weight of the dispersant and 0.1 part by weight of the defoamer
The talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.05 parts by weight with the weight part.

Next, the same foamed polyurethane as in Example 16 was used as a porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at an application amount of 1.5 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Example 28) 10 parts by weight of the same talc powder as in Example 5, 2 parts by weight of the same binder resin solution as in Example 16, and 6 parts by weight of water were mixed, and the same wetting agent as in Example 5 was used. 0.01 parts by weight and 0.1 part by weight of the dispersant and the antifoaming agent, respectively.
One part by weight and 0.05 part by weight were blended to prepare a talc-polyvinyl alcohol-based sound absorbing paint.

Next, the same foamed polyurethane as in Example 16 was used as the porous material having continuous pores, and a sound absorbing paint was applied to the surface of the foamed polyurethane at a coating amount of 1.7 kg / m ^{2 in} terms of talc powder weight. Then, as shown in FIG.
By drying at 1 ° C. for 1 hour, the powder layer 2 was buried in the surface portion of the porous material 1 so as to be substantially flush with the surface of the porous material 1 as shown in FIG. Sound absorbing material A was obtained.

(Comparative Example 1) Foamed polyurethane of a porous material having continuous pores (density: 16 kg / m ³ , thickness: 30 m)
m) was used as a sound absorbing material. Comparative Example 2 A talc powder (bulk density: 0.4 g / cm @ 3, average particle diameter: 20 .mu.m) was filled into a container having an open top surface to a thickness of 30 mm to obtain a sound absorbing material.

Comparative Example 3 Foamed polyurethane of a porous material having continuous pores (density: 14 kg / m ³ , thickness: 30 m)
m), talc powder (bulk density: 0.4 g / cm ³ , average particle size: 20 μm) is uniformly sprayed at a spray rate of 1 kg / m ² to form a powder layer having a thickness of 3 mm.
A sound absorbing material was obtained.

Comparative Example 4 Glass wool (a density of 32 kg / m 3 and a thickness of 25 mm) as a porous material was used as a sound absorbing material. (Comparative Example 5) polyurethane foam porous material having continuous pores (density 16 kg / m ^3, thickness 10 mm) was used as a sound absorbing material.

With respect to the sound absorbing materials obtained in Examples 1 to 28 and Comparative Examples 1 to 5, the sound absorption coefficient was measured according to JIS A 1405.
The measurement was carried out based on "Method of measuring normal incidence sound absorption coefficient of building material by pipe method". For sound absorbing material coated with powder,
The measurement was performed with the application surface of the powder layer facing the sound source (the side not fixed by the end plate) so that the powder layer was at the free end. The results are shown in FIGS.

The sound absorbing materials obtained in Example 1 and Comparative Example 1 were
Two plywood sheets having a thickness of 2.5 mm were inserted into a double-structured panel arranged at an interval of 30 mm, and the sound transmission loss at a center frequency of 1/3 octave band was measured according to JIS A 1416.
The measurement was performed based on “Method of measuring sound transmission loss in laboratory”. However, the opening area was measured at 1.58 m ² . The results are shown in FIG.

Further, the sound-absorbing paint prepared in the same composition as in Example 1 was applied to the same foamed polyurethane as in Example 1 in the same manner as in Example 1 in terms of a talc powder weight of 0.5 kg / m 2.
² , using a sound absorbing material obtained by applying at an application amount of 1.0 kg / m ² or 2.0 kg / m ² , and a surface weight of 1.5 kg / m ²
This sound absorbing material was inserted into a double structure panel in which the two plywoods were arranged at an interval of 30 mm, and the sound transmission loss was measured in the same manner as described above. For comparison, a foamed polyurethane (density: 16 kg / m ³ , thickness: 30 mm) was inserted into the above-mentioned double-structure panel, and a case where the inside of the above-mentioned double-structure panel remained hollow (air layer) ), The sound transmission loss was measured in the same manner. The results are shown in FIG.

As shown in FIG. 4, in the case of the first embodiment, the whole of the powder layer 2 is held inside the porous material 1 while the upper surface of the porous material 1 is The upper surfaces are almost coincident. In the second embodiment,
The entirety of the powder layer 2 is held inside the porous material 1, and the upper surface of the powder layer 2 is located below the surface of the porous material 1. Furthermore, in the case of Example 3, the porous material 1
And a part thereof is held in the porous material 1. In the case of Example 4, two powder layers 2 exist in the porous material 1,
The position is slightly inside the upper and lower surfaces of the porous material 1.
Looking at the relationship between the amount of water in Examples 1 to 4 and the position of the powder layer 2 provided on the porous material 1, the amount of water (solvent) in the sound absorbing paint was changed in addition to the operation using a spatula. It can be seen that the position where the layer 2 is provided can be manipulated.

FIGS. 5, 6, and 7 show the results of the sound absorption characteristics of Examples 1, 2, and 3, respectively. In Example 1, the upper surface of the porous material 1 and the upper surface of the powder layer 2 almost coincide with each other, while exhibiting a sound absorption peak at the lowest frequency. When the characteristics are emphasized, it is understood that the configuration is particularly desirable. In each of the examples, the diameter was cut to 84 mm in order to measure the sound absorption coefficient by the normal incidence method, but no continuous powder leakage was observed.

Next, comparing the sound absorption characteristics and the powder holding state shown in FIGS.
Sample No. 28 shows excellent sound absorption characteristics in a low frequency range as compared with the conventional porous sound absorbing materials of Comparative Example 1, Comparative Example 4, and Comparative Example 5, which are foamed polyurethane or glass wool. In Comparative Example 2, the sound-absorbing material is composed of only the powder, but the sound-absorbing characteristic shows a sharp peak at a specific frequency, and the width of the sound-absorbing frequency is narrow. In contrast, Examples 1 to 5, Examples 9 to 13, and Examples 16 to
In the sound absorbing material of No. 28, the same talc powder as that of Comparative Example 2 was used, but the sound absorbing peak frequency was slightly higher, but the sound absorbing characteristics were over a wide frequency range.

In Comparative Example 2, since the powder was only filled in the container, the powder was skewed or scattered when the powder was tilted or shaken. No bias and scattering of the powder were observed, and stable sound absorption characteristics were obtained. Further, as described above, continuous outflow of the powder from the cut surface has not been observed. In Comparative Example 3, a sound absorbing material having a low sound absorption peak frequency was formed by laminating a talc powder layer on urethane to form a sound absorbing material. Has a wide frequency range. However, this powder layer remains in a scattered state, and when vibration or the like is applied, the powder easily scatters.

In Example 6, a shirasu balloon was used as the powder. However, compared to Comparative Example 1, a higher sound absorption coefficient was obtained, and a peak at 400 to 500 Hz was observed as in the case of using talc. Although not, it has a very wide sound absorption characteristic. The same applies to the case of using the fluororesin powder as the powder in Example 8. In Example 7, silicone powder was used as the powder, but as in the case of talc, a peak of sound absorption was shown at around 500 Hz, and a high sound absorption coefficient was obtained in a low frequency range.

In Examples 14 and 15, although calcium carbonate was used as the powder, a peak of sound absorption was shown at around 700 Hz, and a sound absorption characteristic intermediate between shirasu balloon and talc was obtained. In Examples 9 and 11, glass wool was used as the porous material. However, similar to the case where foamed polyurethane was used, characteristics showing a sound absorption peak in a low frequency range were obtained.

In Examples 10 and 13, an acrylic resin was used as the binder resin, but exhibited an excellent sound absorption coefficient in a low frequency range. Moreover, while having a thickness similar to that of the comparative example 1, a high sound absorption coefficient in a middle and high range is maintained in a wide frequency range. Also, when importance is placed on the sound absorption characteristics in a lower frequency range, it is confirmed that the smaller the amount of the binder resin, the better.

In Examples 16 to 21 and Examples 22 to 24, the mixing ratio of the polyvinyl alcohol resin as the binder resin was changed. The results are shown in FIGS. 20 to 25 and FIGS. 26 to 28. From these figures, it can be seen that in order to enhance the low-frequency sound absorption characteristics, the smaller the binder amount, the better. In Example 19, Example 23, and Examples 25 to 28, the weight of the powder layer was changed. The results are shown in FIGS. 23, 27, and 29 to 32. From this figure, it can be seen that it is better to increase the amount of powder in order to enhance the low frequency sound absorption characteristics.

Next, comparing the sound transmission loss measurement results of the panels using the sound absorbing material of Example 1 and Comparative Example 1 as a filler, as shown in FIG. 33, at 800 Hz or higher, both have almost the same performance. However, between 125 and 800 Hz, Example 1 is improved by about 5 dB at the maximum, and it is understood that Example 1 is useful for improving sound insulation in a low frequency range. Similarly, as shown in FIG. 34, the one using the sound absorbing material provided with the powder layer has a maximum of 5 d in the low frequency range up to 630 Hz as compared with the one using the foamed polyurethane.
An improvement in sound transmission loss of about B is recognized.

As can be seen from the results of the sound absorbing properties of the sound absorbing materials of Examples 1 to 28, the relationship between the sound absorbing coefficient and the frequency of the sound absorbing material of the present invention is determined by the type and amount of powder and the type and amount of binder resin. Since it varies depending on the type and density of the porous material, the position where the powder layer is formed in the porous material, and the like, it has been confirmed that tuning can be performed particularly in accordance with the frequency characteristics of the sound to be absorbed. You. In addition, the sound absorbing material of the present invention, which exhibits a high sound absorbing effect particularly at low frequency castles, exhibits a sound absorbing characteristic in which the film vibration is dominant, having a peak at a specific frequency, but the sound absorbing effect of the powder itself. And the sound absorption effect of the properties of the film formed by the powder layer, which is obtained by a synergistic effect. The film or plate vibration obtained from a normal sheet or plate having the same weight per unit area is obtained. It is possible to absorb sound at the lower frequency castle than the sound absorbing effect of the sound. In addition, those exhibiting broad sound absorption characteristics are a synergistic effect of the sound absorption effect of the powder itself, the property of the film formed by the powder layer, and the sound absorption effect of the property of the porous layer formed by the powder layer. It is obtained by the effect.

The sound absorbing coefficient of the sound absorbing material of Example 23 was set to JIS A by setting the powder coating surface to the end plate side (the side to be the fixed end).
1405 "Measurement method of normal incidence sound absorption coefficient of building material by pipe method". The result is shown in FIG. 35 as Comparative Example 6. From this figure, it is understood that it is necessary for sound absorption that the powder application surface be on the sound source side and the powder layer be free end and be capable of film vibration.

When the samples of Examples 1 to 28 were cut with a cutter knife after measuring the sound absorption coefficient, there was almost no powder falling off the cut surface, and the cutting method was the same as that for cutting the foamed polyurethane. Could be implemented. As described above, the sound-absorbing material of each embodiment shows good sound-absorbing characteristics even in a low frequency range without increasing the thickness and capacity, or has a high sound-absorbing coefficient in a middle-high range, compared to the conventional sound-absorbing material , And no deterioration in performance due to powder spilling, unevenness, etc., and the workability was equivalent to that of the base porous material.

[0105]

As described above, the sound-absorbing material according to the present invention has a binder resin content of 0.1% by weight based on 100 parts by weight of powder.
A powder layer containing 5 to 40 parts by weight, at least a part of which is formed by penetrating into voids of the porous material, so that the powder is held by a binder resin to reduce powder falling off. Powder that has a high sound absorption characteristic in the low frequency range due to the vibration of the powder and the viscous attenuation of the shear stress air at the powder / resin interface because the ratio of the binder resin to the powder is small due to the formation of the layer. A body layer can be formed. Therefore, it is possible to obtain a sound-absorbing material which does not cause performance degradation due to powder falling off or unevenness, and which is lightweight, thin and has the same workability and workability as a conventional porous material.

According to the second aspect of the present invention, the binder resin is contained in an amount of 1 to 6 parts by weight based on 100 parts by weight of the powder, so that the sound absorbing characteristics of the powder can be further improved. A powder layer can be formed, and a powder layer with reduced powder falling off can be formed. According to the third aspect of the present invention, since the powder layer is formed so as to be exposed on the surface of the porous material, it is possible to absorb low-frequency sound.

Further, according to the fourth aspect of the present invention, since the powder layer is formed in the surface layer of the porous material, sound in a lower frequency range can be absorbed. In the invention of claim 5, since the powder layer is formed inside the porous material, high frequency sound can be absorbed. According to the invention of claim 6, since the porous material has continuous pores, it is possible to obtain a sound-absorbing material in which a powder layer is provided in a void portion of the continuous pores.

In the invention of claim 7, since the porous material having continuous pores is selected from foamed polyurethane, glass wool, and nonwoven fabric, the sound absorbing material is reduced in weight, incombustibility, and low cost. It is possible to achieve the realization. The invention according to claim 8 is characterized in that the powder layer has a weight per unit area of 0.3 to 3 k.
Since it is formed so as to have a g / m ² , it is possible to form a powder layer in which the powder is held densely, and to improve the sound absorption characteristics in a lower frequency range.

According to the ninth aspect of the present invention, the powder is formed so that the weight per unit area is 0.5 to ² kg / m ² , so that it is lighter and has good sound absorbing characteristics in a low frequency range. Is possible. The invention according to claim 10 is characterized in that the powder has a particle size of 0.1 to 1000 μm,
Since a powder having a bulk density of 0.1 to 1.5 g / cm ³ is used, it is possible to obtain a powder layer capable of obtaining high sound absorption characteristics of the powder.

According to the eleventh aspect of the present invention, since at least one of talc, shirasu balloon and calcium carbonate is used as the powder, good sound absorption characteristics in a low frequency range can be obtained by using talc. It is possible to obtain a powder layer having good sound absorption characteristics in the middle and high frequency range by using a Shirasu balloon, and to obtain a good powder layer in the intermediate frequency range by using calcium carbonate A powder layer having excellent sound absorbing properties can be obtained.

According to the twelfth aspect of the present invention, since talc is used as the powder, a powder layer having good sound absorbing characteristics in a low frequency range can be obtained. Further, the invention of claim 13 uses, as the binder resin, at least one selected from a phenol resin, an acrylic resin, a polyvinyl alcohol resin, and polyvinyl acetate. A good powder layer can be obtained,
By using a phenolic resin or an acrylic resin, a powder layer having high water resistance can be obtained, and by using polyvinyl alcohol or polyvinyl acetate,
The powder layer can be formed at lower cost.

Further, according to the invention of claim 14, since the powder layer is a free end, good sound absorbing characteristics are exhibited by the spring vibration of the sound absorbing material. The sound-absorbing paint according to the present invention is characterized in that
00 parts by weight, 0.5 to 40 parts by weight of a solid content of a binder resin, and 20 to 300 parts by weight of a solvent. Powder having high sound absorption characteristics in a low frequency range due to the vibration of the powder and the viscous attenuation of the shear stress air at the powder / resin interface because the ratio of the binder resin to the powder is small. A body layer can be formed. Therefore, it is possible to obtain a sound-absorbing paint that can easily form a powder layer for improving sound-absorbing characteristics without deteriorating the working environment and the like.

The invention according to claim 16 is characterized in that the powder has a particle size of 0.1 to 1000 μm and a bulk density of 0.1 to 1000 μm.
Since 1.5 g / cm ³ is used, it is possible to form a powder layer capable of obtaining high sound absorption characteristics by the powder. Further, in the invention according to claim 17, since at least one of talc, shirasu balloon and calcium carbonate is used as the powder, powder having good sound absorption characteristics in a low frequency range by using talc is used. It is possible to form a layer, and it is possible to form a powder layer with good sound absorption characteristics in middle and high frequency ranges by using Shirasu balloon, and to use calcium carbonate to have good sound absorption characteristics in the intermediate frequency range It is possible to form a powder layer having the following.

Further, the invention of claim 18 uses at least one selected from phenol resin, acrylic resin, polyvinyl alcohol resin and polyvinyl acetate as the binder resin. It is possible to form a powder layer having good water resistance, and it is possible to form a powder layer having high water resistance by using a phenol resin or an acrylic resin, and to use polyvinyl alcohol or polyvinyl acetate. Thus, the powder layer can be formed at lower cost.

Further, in the invention of claim 19, since water is used as the solvent, the paint is environmentally friendly. The method for producing a sound absorbing material according to the present invention comprises:
Since 0.5 to 40 parts by weight of a binder resin and 20 to 300 parts by weight of a solvent were blended to prepare a sound-absorbing paint, and the sound-absorbing paint was applied to the surface of the porous material, powder was used. It is possible to form a powder layer with reduced powder shedding by holding the body with a binder resin, and because the ratio of binder resin to powder is small, vibration of powder and powder / resin It is possible to form a powder layer having a high sound absorption characteristic in a low frequency range due to the shear damping of the interface shear stress air.

The method for producing a sound-absorbing material according to the present invention comprises the steps of:
40 parts by weight and 20 to 300 parts by weight of a solvent were blended to prepare a sound-absorbing paint, and this sound-absorbing paint was impregnated into a porous material. It is possible to form a powder layer with reduced powder, and because the ratio of binder resin to powder is small, low frequency range due to vibration of powder and shear damping of shear stress air at powder / resin interface Can form a powder layer having high sound absorption characteristics.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of a sound absorbing material according to the present invention, in which (a) is a schematic diagram showing an operation of rubbing a sound absorbing paint into a porous material, and (b) is a schematic diagram of the sound absorbing material. It is.

FIG. 2 shows another example of the embodiment of the sound absorbing material of the present invention, wherein (a) is a schematic view showing an operation of rubbing a sound absorbing paint on a porous material, and (b) is a schematic view of the sound absorbing material. FIG.

FIGS. 3A and 3B show still another example of the embodiment of the sound absorbing material of the present invention, wherein FIG. 3A is a schematic view showing an operation of rubbing a sound absorbing paint on a porous material, and FIG. It is a schematic diagram.

FIG. 4 shows an embodiment of the sound absorbing material of the present invention,
(A) is a schematic diagram of the sound absorbing material of Example 1, (b) is Example 2
(C) is a schematic diagram of the sound absorbing material of Example 3, and (d) is a schematic diagram of the sound absorbing material of Example 4.

FIG. 5 is a graph showing normal incidence sound absorption characteristics of Example 1 and Comparative Examples 1 to 3.

FIG. 6 is a graph showing the normal incidence sound absorption characteristics of Example 2 and Comparative Examples 1 to 3.

FIG. 7 is a graph showing normal incidence sound absorption characteristics of Example 3 and Comparative Examples 1 to 3.

FIG. 8 is a graph showing normal incidence sound absorption characteristics of Example 4 and Comparative Examples 1 to 3.

FIG. 9 is a graph showing normal incidence sound absorption characteristics of Example 5 and Comparative Example 1.

FIG. 10 is a graph showing the normal incidence sound absorption characteristics of Example 6 and Comparative Example 1.

FIG. 11 is a graph showing the normal incidence sound absorption characteristics of Example 7 and Comparative Example 1.

FIG. 12 is a graph showing the normal incidence sound absorption characteristics of Example 8 and Comparative Example 1.

FIG. 13 is a graph showing normal incidence sound absorption characteristics of Example 9 and Comparative Example 1.

FIG. 14 is a graph showing the normal incidence sound absorption characteristics of Example 10 and Comparative Example 1.

FIG. 15 is a graph showing the normal incidence sound absorption characteristics of Example 11 and Comparative Example 1.

FIG. 16 is a graph showing normal incidence sound absorption characteristics of Example 12 and Comparative Example 1.

FIG. 17 is a graph showing the normal incidence sound absorption characteristics of Example 13 and Comparative Example 1.

FIG. 18 is a graph showing the normal incidence sound absorption characteristics of Example 14 and Comparative Example 5.

FIG. 19 is a graph showing the normal incidence sound absorption characteristics of Example 15 and Comparative Example 1.

FIG. 20 is a graph showing the normal incidence sound absorption characteristics of Example 16 and Comparative Example 1.

FIG. 21 is a graph showing normal incidence sound absorption characteristics of Example 17 and Comparative Example 1.

FIG. 22 is a graph showing the normal incidence sound absorption characteristics of Example 18 and Comparative Example 1.

FIG. 23 is a graph showing the vertical incidence sound absorption characteristics of Example 19 and Comparative Example 5.

FIG. 24 is a graph showing the normal incidence sound absorption characteristics of Example 20 and Comparative Example 5.

FIG. 25 is a graph showing the normal incidence sound absorption characteristics of Example 21 and Comparative Example 5.

FIG. 26 is a graph showing the normal incidence sound absorption characteristics of Example 22 and Comparative Example 1.

FIG. 27 is a graph showing the normal incidence sound absorption characteristics of Example 23 and Comparative Example 1.

FIG. 28 is a graph showing the normal incidence sound absorption characteristics of Example 24 and Comparative Example 1.

FIG. 29 is a graph showing the normal incidence sound absorption characteristics of Example 25 and Comparative Example 5.

FIG. 30 is a graph showing the normal incidence sound absorption characteristics of Example 26 and Comparative Example 5.

FIG. 31 is a graph showing the normal incidence sound absorption characteristics of Example 27 and Comparative Example 5.

FIG. 32 is a graph showing the normal incidence sound absorption characteristics of Example 28 and Comparative Example 5.

FIG. 33 is a graph showing the measurement results of the sound transmission loss of Example 1 and Comparative Example 1.

FIG. 34 is a graph showing the measurement results of sound transmission loss when the measurement is performed while changing the talc powder weight of the powder layer.

FIG. 35 is a graph showing the normal incidence sound absorption characteristics of Example 23 and Comparative Example 6.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Porous material 2 Powder layer 3 Sound absorbing paint 4 Powder 5 Binder resin

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kenji Onishi 1048 Kazumasa Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (21)

[Claims] 1. A powder layer containing 0.5 to 40 parts by weight of a binder resin in solid content with respect to 100 parts by weight of a powder, at least a part of which is formed by entering a void portion of a porous material. A sound absorbing material characterized by being formed. 2. The sound-absorbing material according to claim 1, wherein the powder layer contains 1 to 6 parts by weight of a binder resin as a solid content with respect to 100 parts by weight of the powder. 3. The sound-absorbing material according to claim 1, wherein the powder layer is formed so as to be exposed on the surface of the porous material. 4. The sound-absorbing material according to claim 1, wherein the powder layer is formed in a surface layer of a porous material. 5. The sound absorbing material according to claim 1, wherein the powder layer is formed inside a porous material. 6. The sound-absorbing material according to claim 1, wherein the porous material has continuous pores. 7. The sound-absorbing material according to claim 6, wherein the porous material having continuous pores is selected from foamed polyurethane, glass wool, and nonwoven fabric. 8. The powder layer according to claim 1, wherein the weight per unit area of the powder is 0.3 to 3 kg / m ^2.
8. The sound-absorbing material according to any one of items 1 to 7. 9. The powder layer according to claim 8, wherein the weight per unit area of the powder is 0.5 to ² kg / m ^2.
The sound-absorbing material described in 1. 10. The powder has a particle size of 0.1 to 1000 μm,
Sound absorbing material according to any one of claims 1 to 9 bulk density characterized in that it is of 0.1 to 1.5 g / cm ^3. 11. The sound absorbing material according to claim 1, wherein the powder is at least one of talc, shirasu balloon, and calcium carbonate. 12. The sound absorbing material according to claim 11, wherein the powder is talc. 13. The binder resin is a phenol resin,
13. The sound-absorbing material according to claim 1, wherein the sound-absorbing material is at least one selected from an acrylic resin, a polyvinyl alcohol resin, and polyvinyl acetate. 14. The sound absorbing material according to claim 1, wherein the powder layer has a free end. 15. A sound absorbing paint comprising 100 parts by weight of a powder, 0.5 to 40 parts by weight of a solid content of a binder resin and 20 to 300 parts by weight of a solvent. 16. The powder has a particle size of 0.1 to 1000 μm,
Absorbing paint according to claim 15, the bulk density is characterized in that it is of 0.1 to 1.5 g / cm ^3. 17. The sound absorbing paint according to claim 15, wherein the powder is at least one of talc, shirasu balloon, and calcium carbonate. 18. The binder resin is a phenol resin,
The sound-absorbing paint according to any one of claims 15 to 17, wherein the paint is at least one selected from an acrylic resin, a polyvinyl alcohol resin, and polyvinyl acetate. 19. The sound-absorbing paint according to claim 15, wherein the solvent is water. 20. A sound-absorbing paint is prepared by mixing 100 parts by weight of a powder, 0.5 to 40 parts by weight of a binder resin in solid content, and 20 to 300 parts by weight of a solvent. A method for producing a sound absorbing material, wherein the method is applied to a surface of a material. 21. A sound-absorbing paint is prepared by mixing 100 parts by weight of a powder, 0.5 to 40 parts by weight of a binder resin in solid content, and 20 to 300 parts by weight of a solvent. A method for producing a sound absorbing material, characterized by impregnating a sound absorbing material.