JP3482116B2 - Manufacturing method of sound absorbing material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to acoustic treatment of a listening room, a musical instrument practice room, etc., reduction of noise propagating in an air-conditioning duct, and the like. The present invention relates to a method for manufacturing a sound absorbing material that is used for filling and enhancing a sound insulation effect.

[0002]

2. Description of the Related Art Sound absorbing materials are a dual structure of an interior material for controlling the reverberation characteristics and reflection characteristics of a room in a listening room or musical instrument practice room where the acoustic characteristics of the room are a problem, and a room requiring sound insulation performance. Filling material that fills walls and ceilings that are formed on the inner wall, inner adhesive that stretches inside air-conditioning ducts and sound-absorbing ducts to prevent noise transmission, and inner adhesive that stretches inside sound-proof covers of devices that generate noise. Is used as.

Porous sound absorbing materials such as glass wool, rock wool, and foamed polyurethane have been mainly used as sound absorbing materials used for such applications. Since these porous sound-absorbing materials have voids of a complicated shape that communicate with the inside, when sound waves enter the voids, viscous friction or the like occurs between the fiber surface and the urethane bubble wall surface while propagating through the voids. Occurs, and the acoustic energy is absorbed in the porous material to absorb sound.

However, these porous sound absorbing materials generally have a sufficient sound absorption coefficient in the high frequency range, but the sound absorption coefficient decreases as the frequency decreases, and a sufficient sound absorption coefficient cannot be obtained in the low frequency range. There is. If the thickness of the porous sound absorbing material is increased, or if a sufficiently thick air layer (called a back air layer) is provided behind the sound incident surface of the porous sound absorbing material, the sound absorption coefficient in the low frequency range can be increased. 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, when it is used as an interior material for a room, the room becomes narrower. When used as an inner sticking of a duct, there arises a problem that the air passage becomes narrow.

On the other hand, there is provided a sound absorbing material formed of a powder layer such as silica powder as a sound absorbing material having excellent sound absorbing performance in a low frequency range even if the thickness is thin. With this sound absorbing material,
When sound is incident on the powder layer, the powder particles vibrate, and the sound wave energy is absorbed by this vibration to exhibit a sound absorbing effect.

However, the sound absorbing material made of this powder is
For example, powder is filled in a box-shaped container to form a powder layer,
It can be formed by covering it with a film that has good sound wave permeability, but even if the container is filled with powder evenly, the powder gradually moves during use and the powder is biased, causing noise absorption performance. There is a problem that may change.

Therefore, it has been proposed to form a sound absorbing material by filling and holding powder in the voids of a very coarse porous material such as glass wool. However, in this case as well, even if the voids of the porous material are initially uniformly filled with the powder, the problem that the powder gradually moves and is biased in the use process and the sound absorbing performance is changed cannot be solved. . Also, in this thing, the work of filling the voids of the porous material such as glass wool with the powder is performed by spraying the powder on the porous material and vibrating it so that the powder is submerged in the voids between the fibers. However, this method has a problem that the powder floats up in the air, which deteriorates the working environment and lowers the working efficiency. Furthermore, when processing the sound absorbing material in which the voids of such a porous material are filled with powder, for example, when cutting to a desired size, the powder will leak from the cut surface of the porous material, It has been impossible to carry out a method of cutting the sound absorbing material, for example, a simple cutting using a cutter knife, scissors, etc. such as cutting foamed polyurethane, glass wool, rock wool, nonwoven fabric, felt and the like.

[0008]

Therefore, the present invention shows good sound absorption characteristics even in a low frequency range, does not cause performance deterioration due to powder falling or deviation, and is lightweight, thin, and conventional porous. It is an object of the present invention to provide a method for manufacturing a sound absorbing material having workability and workability equivalent to those of the material.

[0009]

A method for manufacturing a sound absorbing material according to claim 1 of the present invention is a powder layer containing 0.5 to 40 parts by weight of a binder resin as a solid content based on 100 parts by weight of the powder. Sound absorption that is formed by entering the voids in the surface layer of the porous material so that they are almost flush with the surface of the porous material.
In manufacturing the material, 100 parts by weight of powder, vine
0.5 to 40 parts by weight of solid resin and 20 to 20 parts of solvent.
300 parts by weight was mixed to prepare a sound-absorbing paint.
It is characterized in that the coating material is applied to the surface of the porous material .

Further, the sound absorbing material according to claim 2 of the present invention is manufactured.
The manufacturing method is such that a powder layer containing 0.5 to 40 parts by weight of a binder resin as a solid content with respect to 100 parts by weight of the powder enters the void portion inside the porous material and is formed inside the porous material. In order to manufacture the sound absorbing material
00 parts by weight, 0.5 to 40 parts by weight of binder resin in solid content
20 to 300 parts by weight of a solvent and 20 to 300 parts by weight of a solvent to prepare a sound absorbing paint.
It is characterized in that it is prepared and the sound absorbing paint is applied to the surface of the porous material .

Further, the sound absorbing material according to claim 3 of the present invention is manufactured.
The manufacturing method is to add binder resin to 100 parts by weight of powder.
The powder layer containing 0.5 to 40 parts by weight in terms of solid content is porous.
Surface layer of porous material so that it is almost flush with the surface of the material
Manufactures a sound-absorbing material formed by entering the voids of
When adding 100 parts by weight of powder and binder resin
0.5-40 parts by weight of solids, 20-300 parts by weight of solvent
Parts to prepare a sound absorbing paint,
It is characterized by being impregnated with a quality material .

Further, the sound absorbing material according to claim 4 of the present invention is manufactured.
The manufacturing method is to add binder resin to 100 parts by weight of powder.
The powder layer containing 0.5 to 40 parts by weight in terms of solid content is porous.
Enter the voids inside the material and enter the interior of the porous material
In order to manufacture the sound absorbing material formed,
00 parts by weight, 0.5 to 40 parts by weight of binder resin in solid content
20 to 300 parts by weight of a solvent and 20 to 300 parts by weight of a solvent to prepare a sound absorbing paint.
It is characterized in that it is prepared and the porous material is impregnated with this sound absorbing paint .

Further, in the invention of claim 5, the solvent is water.
It is characterized by that.

In the invention of claim 6, the powder layer is a powder.
Binder resin is solid content of 1 to 6 with respect to 100 parts by weight.
It is characterized by containing parts by weight .

In the invention of claim 7, the porous material is continuous.
It is characterized by having continuous pores .

The invention of claim 8 has continuous pores
Porous materials such as polyurethane foam, glass wool,
It is characterized by being selected from woven cloth .

In the invention of claim 9, the powder layer is made of powder.
Weight per unit area and is characterized in this <br/> and a 0.3~3kg / m2.

In the invention of claim 10, the powder layer is a powder
The weight per unit area is 0.5 to 2 kg / m <2> .

According to the invention of claim 11, the powder has a particle size of
0.1-1000 μm, bulk density 0.1-1.5 g / c
It is characterized by being m3 .

In the invention of claim 12, the powder is talc.
And at least one of Shirasu balloon and calcium carbonate
It is characterized in that.

According to the invention of claim 13, the powder is talc.
It is characterized by being.

Further, the invention of claim 14 is a binder resin.
Fat is phenol resin, acrylic resin, polyvinyl alcohol
One or more selected from coal resin and polyvinyl acetate
It is characterized by being.

In the invention of claim 15, the powder layer is free.
It is characterized by being an edge .

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the sound absorbing material of the present invention will be described below.

The powder is made of an inorganic material and / or an organic material, and for example, gold mica, silica, acrylic resin, talc, calcium silicate, fluororesin, perlite, shirasu balloon, fused silica, graphite, crystalline cellulose, carbonization. Examples thereof include powders of silicon, diatomaceous earth, nylon, polyester, carbon fiber, titanium dioxide, calcium carbonate, polyvinyl chloride, polymethylmethacrylate, barium ferrite, silicone and the like.

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 low frequency range under the same conditions as talc powder, but has excellent sound absorption characteristics in a wide range in the middle and high range. . The sound absorption characteristics of calcium carbonate are intermediate between those of talc and Shirasu balloon. Talc powder and shirasu balloon powder are relatively inexpensive, and calcium carbonate is even cheaper, which helps reduce costs. The talc powder, the shirasu balloon powder, and the calcium carbonate powder may be used alone or in combination of two or more.
Among these, talc is particularly preferable in terms of sound absorbing effect in the low frequency range.

The powder has a particle size of 0.1 to 10
It is in the range of 00 μm and has a bulk density of 0.1 to 1.5 g /
It is preferable to use one having a range of cm ³ in order to improve the sound absorbing characteristics. That is, it is practically difficult to use a powder having a particle size of less than 0.1 μm, and conversely, a particle size of 1000 μm.
If it exceeds m, it becomes difficult to obtain the sound absorbing effect of the powder. Further, if the bulk density is less than 0.1 g / cm ³ , it becomes difficult to reduce the thickness of the powder layer or the sound absorbing material because it becomes bulky. Conversely, if the bulk density exceeds 1.5 g / cm ³ , the powder becomes powder. It becomes difficult to obtain the sound absorption effect due to.

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, but they are water-soluble. Water-soluble resins such as the above-mentioned phenol resin, acrylic resin, polyvinyl alcohol, and polyvinyl acetate are preferable from the viewpoint of suppressing the discharge of the organic solvent, or the working environment. In particular, since phenol resin is a thermosetting resin, it is effective in increasing the heat resistance of the sound absorbing material, and since phenol resin and acrylic resin are insoluble in water after curing, a sound absorbing material with good weather resistance should be used. It will be possible to obtain. In addition, polyvinyl alcohol and polyvinyl acetate have a high affinity with inorganic powders, and the effect of retaining the inorganic powder can be highly obtained. Moreover, polyvinyl alcohol and polyvinyl acetate are relatively inexpensive. Yes, it also helps reduce costs. These binder resins may 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, such as voids or voids between fibers. Polyurethane foam, glass wool, rock wool, non-woven fabric, 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 described above, and the powder layer 2 is formed such that at least a part of the powder layer 2 enters the void portion of the porous material 1. The sound absorbing material A can be manufactured by providing the powder layer 2 on the porous material 1 in this manner. In the formation of the powder layer 2 is a porous material 1, is also possible to form a powder layer 2 in the surface portion of the porous material 1 (see FIG. 3 (a)), the porous material 1
Even when the interior of the form a powder layer 2 (see FIG. 3 (b)
), Either is acceptable. The closer the position of the powder layer 2 is to the surface of the porous material 1, the higher the sound absorption characteristics in the low frequency range can be obtained, and the powder layer 2 inside the porous material 1 can be obtained.
It is possible to obtain high sound absorption characteristics in a high frequency range by providing the above, and it is possible to meet the required sound absorption characteristics by setting the position of the powder layer 2 provided on the porous material 1. The powder layer 2 may be formed on both surfaces of the porous material 1 in addition to providing one layer on the porous material 1 ( see FIG. 3C) . You may

Here, the powder layer 2 is formed so that the binder resin 5 is contained in a solid content (that is, a resin content) of 0.5 to 40 parts by weight 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 powder 4 can be reliably held, and the vibration of the powder 4 and The powder / resin interface is made to exhibit sound absorbing characteristics due to shear stress and viscous damping of air, 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
By setting the amount of the powder in the above range, the powder 4 is reliably 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. 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 amount of the binder resin 5 is 10
It is more preferable to set it in the range of 1 to 6 parts by weight with respect to 0 parts by weight.

When the sound absorbing material A is produced 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 is 0.3 to 3
It is preferable to form the powder layer 2 so that the powder layer 2 has a weight of ² kg / m ² . The weight per unit area of the powder 4 is 0.3 kg / m ²
In the powder layer 2 below, the sound absorbing property of the sound absorbing material A becomes close to the sound absorbing property of the porous material 1, and the sound absorbing property in the low frequency region cannot be obtained high. On the contrary, 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 reduction of the sound absorbing material A cannot be achieved, and more powder layers 2 are formed. It is practically difficult to do. Therefore, the weight per unit area of the powder 4 included in the powder layer 2 is 0.3 to 3 kg / m ^{2 in} order to obtain high sound absorbing characteristics in the low frequency range while maintaining the weight reduction of the sound absorbing material A. It is preferable to form the powder layer 2 so that From this point, the weight per unit area of the powder 4 contained in the powder layer 2 is 0.5.
It is necessary to form the powder layer 2 so that the powder layer 2 is about ² kg / m ² .
More preferable.

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

Next, a preferable sound absorbing paint for producing the powder layer of the above sound absorbing material will be described.

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 to it.

If a water-soluble binder resin is used as the solvent, water can be used. In addition, toluene, THF, acetone, benzene,
It is also possible to use an organic solvent such as hexane, chloroform, dichloromethane, methanol, ethanol, propanol and the like, such as alcohols, halogens, aromatics and aliphatic hydrocarbons. It is preferable to use water in consideration of the environment.

Then, 0.5 to 40 parts by weight of the binder resin in solid content (that is, resin content) is added to 100 parts by weight of the powder.
The sound absorbing paint according to the present invention is prepared by blending 20 to 300 parts by weight of a solvent, and further blending and mixing an additive such as a wetting agent, a dispersant, a thickener, and a preservative, if necessary. be able to.

Here, the binder resin is mixed in a large amount exceeding 40 parts by weight in a usual coating material, but in the sound absorbing coating material of the present invention, 0.5 to 40 parts by weight based on 100 parts by weight of the powder. It is very small with the weight part. This is because the binder resin is not intended to form a coating film like ordinary paints, but is blended for holding powder, and thus the amount of binder resin is reduced. As described above, while ensuring the retention of the powder, the sound absorption characteristics due to the vibration of the powder, the shear stress of the powder / resin interface and the viscous damping of the air are exhibited, and the sound absorption especially in the low frequency range is achieved. It is possible to form a powder layer having excellent characteristics.

The solvent is used to adjust the fluidity of the sound absorbing paint to improve workability in applying the sound absorbing paint, and the blending amount of the solvent is 20 parts by weight with respect to 100 parts by weight of the powder. When the amount is less than the range, the viscosity of the sound absorbing paint is high and the application becomes difficult. On the other hand, if the amount of the solvent blended with respect to 100 parts by weight of the powder exceeds 300 parts by weight, the viscosity of the sound absorbing coating becomes too low and the powder is liable to settle, and a powder layer in which the powder is uniformly dispersed is formed. Difficult to form. Further, if the amount of solvent is large, the drying load becomes large, which is not preferable for the environment.

An example of the procedure for preparing the sound absorbing coating 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 coating is applied are evaluated. To increase the amount, a wetting agent and a dispersant are added in the required amounts, and in some cases, a defoaming agent is added and the mixture is stirred and mixed. A sound absorbing paint can be obtained by adding a binder resin to the solution thus obtained and mixing them, and further adding a powder and mixing them. Depending on the stirring method, foaming may occur when preparing the sound absorbing paint,
In such a case, it is desirable to add a defoaming agent or to remove the bubbles by vacuum defoaming after stirring and mixing.

A powder layer can be formed by applying or impregnating the porous material with the sound absorbing paint of the present invention obtained as described above. Further, the adhesion of the sound absorbing paint can be improved by selecting the binder resin and pre-treating the surface to be coated.

Next, a method of 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 the porous material. The sound absorbing paint can be applied using a flow coater, a roll coater, a spray coater or the like. There is also a method in which a part of the porous material, for example, the surface layer portion of the porous material is dipped in the sound absorbing paint to impregnate the porous material with the sound absorbing paint. In this way, by applying or impregnating the porous material with the sound absorbing paint 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 thus forming the powder layer on the porous material, 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 it is possible to prevent the sound absorbing characteristics from deteriorating due to the movement or outflow of the powder, and cutting the sound absorbing material. It is possible to prevent the powder from falling off from the cut surface when performing.

Further, a concrete example of the method of manufacturing the sound absorbing material will be described.

FIG. 1 shows that the powder layer 2 is formed in the surface layer portion of the porous material 1 (claims 1 and 2 ).
After the sound absorbing paint 3 is applied to the surface of the porous material 1, when the sound absorbing paint 3 is rubbed 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 the voids in the surface layer portion of the porous material 1 by moving the material 1 along the surface of the material 1, and drying the powder 4 shown in FIG. As shown in b), the surface layer of the porous material 1 is formed so that the powder layer 2 formed by holding the powder 4 with the solidified or hardened binder resin 5 is substantially flush with the surface of the porous material 1. It is possible to obtain the sound absorbing material A embedded in the part.

FIG. 2 shows a structure in which the powder layer 2 is formed inside the porous material 1 (claims 3 and 4 ). After the sound absorbing paint 3 is applied to the surface of the porous material 1, Spatula 10
When rubbing the sound absorbing paint 3 on the surface of the porous material 1 by pressing the tip of the spatula 10 against the porous material 1 as shown in FIG. By the sound absorbing paint 3 powder 4
With the binder resin 5 are allowed to enter the void inside the porous material 1. In this way, the porous material 1 is compressed by the spatula 10 and the powder 4 of the sound absorbing paint 3 is allowed to enter the voids inside the porous material 1 together with the binder resin 5, and the porous material 1 is passed through after the spatula 10 has passed. When 1 is elastically restored, a part of the binder resin 5 adheres to the porous material 1 and returns to the surface layer portion of the porous material 1, but the powder 4 remains in the void inside the porous material 1. It remains as it is and does not return to the surface layer portion of the porous material 1. Therefore, by drying this, as shown in FIG. 2B, the powder layer 2 formed by being held by the binder resin 5 in which the powder 4 has been solidified or hardened is embedded in the porous material 1. The sound absorbing material A thus provided can be obtained.

By operating the spatula 10 as described above, the powder layer 2 is formed in the surface layer portion of the porous material 1 as shown in FIG.
The powder layer 2 was formed inside the porous material 1 as shown in FIG.
Squirrel Although Rukoto can, in the case of forming the powder layer 2 to the inside of the porous material 1 as shown in FIG. 2, a material obtained by adjusting the number and viscosity the amount of solvent lower sound-absorbing coatings 3 arbitrariness preferred to use. Further, by utilizing the continuous pores of the porous material 1 and sucking it from the surface of the porous material 1 on the opposite side to which the sound absorbing paint 3 is applied, the sound absorbing paint 3 is deeply placed inside the porous material 1. Permeate 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 produced by applying or impregnating the porous material 1 with the sound absorbing coating material 3 and then drying it, but the surface property of the sound absorbing material A becomes a problem. In some cases, a surface material such as paper, resin film, or non-woven fabric is placed on the surface of the porous material 1, and the surface material is adhered to the porous material 1 by using the binder resin contained in the sound absorbing paint 3. May be. At this time, when a thermosetting resin is used as the binder resin, the surface material is superposed on the surface of the porous material 1 and then hot pressed to cure the binder resin and at the same time 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 the same.

[0048]

EXAMPLES Next, the present invention will be specifically described with reference to examples.

Example 1 Talc powder (bulk density 0.4 g / cm ³ , average particle size 20 μ)
m) 10 parts by weight, 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% by weight, water) 8
A talc-polyvinyl alcohol-polyvinyl acetate-based sound absorbing paint was prepared by blending 2 to 84% by weight, 2 parts by weight of the balance of fragrance and preservative, and 9 parts by weight of water, and mixing the resulting mixture with stirring. did.

Next, foamed polyurethane (density 16 kg / m ³ , thickness 30 m) which is a porous material having continuous pores.
Sound absorbing paint on the surface of m) 1k in terms of weight of talc powder
Apply the coating amount of g / m ² , operate the spatula as shown in FIG. 1 (a), apply the sound absorbing paint, and then dry at room temperature for 24 hours, as shown in FIG. 3 (a). Then, a sound absorbing material A was obtained 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 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,
By mixing this with stirring, a talc-polyvinyl alcohol-polyvinyl acetate-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 sound absorbing paint was applied on the surface of the foamed polyurethane in an amount of 1 k in terms of the weight of talc powder.
It was coated at a coverage of g / m ^2, after elaborate painted absorbing paints by operating the spatula as shown in FIG. 2 (a), by drying for 24 hours at room temperature, as shown in FIG. 3 (b) A sound absorbing material A having 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 12 parts by weight of water were blended,
By mixing this with stirring, a talc-polyvinyl alcohol-polyvinyl acetate-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 sound absorbing paint was applied to one surface of the foamed polyurethane at a coating amount of 1 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 2 (a), after operating the spatula to apply the sound absorbing paint, it is dried at room temperature for 24 hours, and the sound absorbing paint is applied to the other side of the polyurethane foam in terms of the weight of the talc powder. It is applied at a coating amount of 1 kg / m ² , the spatula is operated by applying a spatula as shown in FIG. 2 (a), and then it is dried at room temperature for 24 hours, as shown in FIG. 3 (c) . Thus, a sound absorbing material A was obtained in which the two powder layers 2 were embedded in the porous material 1.

Example 4 Talc powder (bulk density 0.4 g / cm ³ , average particle size 18 μm)
10 parts by weight of m) and a binder resin solution containing polyvinyl alcohol as a main component (“GH” manufactured by Chuo Rika Kogyo Co., Ltd.
-17 ": polyvinyl alcohol solid content 10% by weight, water 90% by weight) 3 parts by weight, and water 8 parts by weight, and a wetting agent (" Nopco Wet 50 "manufactured by San Nopco Ltd.).
0.1 part by weight, 0.1 part by weight of a dispersant (“Hydroparat 1706” manufactured by San Nopco) and 0.05 part by weight of an antifoaming agent (“Adecanate B-940” manufactured by Asahi Denka Co., Ltd.). A talc-polyvinyl alcohol-based sound absorbing paint was prepared by stirring and mixing this.

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 1 k in terms of the weight of talc powder.
It was coated at a coverage of g / m ^2, after elaborate painted absorbing paints by operating the spatula as shown in FIG. 1 (a), by drying 1 hour at a 80 ° C. oven, FIG. 3 ( A sound absorbing material A was obtained 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 as in a).

Example 5 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 4 , 8 parts by weight of water, The same wetting agent, dispersant, and defoaming agent as in Example 4 were added in an amount of 0.1 part by weight and 0.1% by weight, respectively.
By mixing 1 part by weight and 0.05 part by weight and stirring and mixing them, a shirasu balloon-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 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 the shirasu balloon powder. 3), apply the sound-absorbing paint by operating the spatula as shown in FIG. 1 (a), and then dry for 1 hour in a dryer at 80 ° C., as shown in FIG. 3 (a). A sound absorbing material A was obtained 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 6 10 parts by weight of silicone powder (bulk density 0.16 g / cm ³ , average particle size 40 μm), 3 parts by weight of the same binder resin solution as in Example 4 and 8 parts by weight of water were used. The same wetting agent, dispersant, and defoaming agent as in Example 4 were blended in an amount of 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight, respectively. A coating material was prepared.

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 in an amount of 1 kg / m ^{2 in} terms of the weight of the silicone powder. Apply, Figure 1 (a)
After operating the spatula to apply the sound absorbing paint as shown in, dry it for 1 hour in a dryer at 80 ° C.
3 (a), the sound absorbing material A was obtained 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 7 Fluororesin powder (bulk density 0.4 g / cm ³ , average particle size 4
10 parts by weight of 7 [mu] m), 3 parts by weight of the same binder resin solution as in Example 4, water 8 parts by weight, the same wetting agent as in Example 4 dispersants and defoamer and respective 0.1 part by weight 0. By mixing 1 part by weight and 0.05 part by weight and stirring and mixing them, a fluororesin-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 sound absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1 kg / m ^{2 in} terms of the weight of the fluororesin powder. And then applied to Figure 1 (a)
After operating the spatula to apply the sound absorbing paint as shown in, dry it for 1 hour in a dryer at 80 ° C.
3 (a), the sound absorbing material A was obtained 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 8 A talc-polyvinyl alcohol-based sound absorbing coating material was prepared in the same manner as in Example 4 .

Next, the surface of glass wool (density 32 kg / m ³ , thickness 25 mm), which is a porous material having continuous pores, was coated with a sound absorbing paint at a weight of 1 kg / m in terms of the weight of talc powder.
The coating is ² coating amount after elaborate painted absorbing paints by operating the spatula as shown in FIG. 1 (a), by drying 1 hour at a 80 ° C. oven, FIG. 3 ( 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 in a).
Got

Example 9 10 parts by weight of the same talc powder as in Example 4 and a binder resin solution containing an acrylic resin as a main component (“SA-203” manufactured by Chuo Rika Kogyo Co., Ltd .: acrylic resin solid content 40% by weight) Of water, 60% by weight of water, 0.75 parts by weight of a dispersant, and 9 parts by weight of water, and 0.1 part by weight of the same wetting agent, dispersant, and defoaming agent as in Example 5, respectively. 0.1
A talc-acrylic resin-based sound absorbing paint was prepared by mixing 0.05 part by weight and 0.05 part by weight of the mixture.

Next, as a porous material having continuous pores
Using the same foamed polyurethane as in Example 1, foamed polyurethane
Sound absorbing paint on the surface of the tongue 1k in terms of weight of talc powder
g / m²So that the coating amount becomes as shown in Fig. 1 (a).
Operate the spatula to apply the sound absorbing paint, and then
Figure by drying for 1 hour in a 0 ° C dryerThree
It becomes almost flush with the surface of the porous material 1 as shown in (a).
Provided by embedding the powder layer 2 in the surface layer portion of the porous material 1
Sound absorbing material A was obtained.

Example 10 10 parts by weight of the same talc powder as in Example 4 and a binder resin solution containing a water-soluble phenol resin as a main component (Matsushita Electric Works, Ltd. “CJ2202”: phenol resin solid content 5)
0 wt%, water 50 wt%) 0.6 parts by weight, and water 9
A talc-phenol resin-based sound absorbing paint was prepared by blending parts by weight and stirring and mixing.

Next, the same glass wool as in Example 8 was used as the porous material having continuous pores, and the 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.
The coating is the coating amount after elaborate painted absorbing paints by operating the spatula as shown in FIG. 1 (a), by drying 1 hour at 200 ° C. dryer, Fig. 3 (a ), The sound absorbing material A is 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.
Got

[0069] (Example 11) Example 4 The same talc powder and 10 parts by weight, 1 part by weight of the same binder resin solution as in Example 4, water 11 parts by weight, the same wetting agent as in Example 4 and dispersing agents 0.1 defoamer each
A talc-polyvinyl alcohol-based sound absorbing paint was prepared by blending 1 part by weight, 0.1 part by weight, and 0.05 part by weight, and stirring and mixing them.

Next, as a porous material having continuous pores
Using the same foamed polyurethane as in Example 1, foamed polyurethane
Sound absorbing paint on the surface of the tongue 1k in terms of weight of talc powder
g / m²So that the coating amount becomes as shown in Fig. 1 (a).
Operate the spatula to apply the sound absorbing paint, and then
Figure by drying for 1 hour in a 0 ° C dryerThree
It becomes almost flush with the surface of the porous material 1 as shown in (a).
Provided by embedding the powder layer 2 in the surface layer portion of the porous material 1
Sound absorbing material A was obtained.

Example 12 10 parts by weight of the same talc powder as in Example 4 , 10.7 parts by weight of the same binder resin solution as in Example 9 , 10 parts by weight of water, and the same wetting agent and dispersion as in Example 4 were dispersed. 0.1 parts by weight, 0.1 parts by weight, and 0.05 parts by weight of an agent and an antifoaming agent, respectively,
By mixing this with stirring, a talc-acrylic resin-based sound absorbing paint was prepared.

Next, as a porous material having continuous pores
Using the same foamed polyurethane as in Example 1, foamed polyurethane
Sound absorbing paint on the surface of the tongue 1k in terms of weight of talc powder
g / m²So that the coating amount becomes as shown in Fig. 1 (a).
Operate the spatula to apply the sound absorbing paint, and then
Figure by drying for 1 hour in a 0 ° C dryerThree
It becomes almost flush with the surface of the porous material 1 as shown in (a).
Provided by embedding the powder layer 2 in the surface layer portion of the porous material 1
Sound absorbing material A was obtained.

Example 13 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 4, and 1.5 parts by weight of water. Parts, the same wetting agent, dispersant, and defoaming agent as in Example 4 were blended at 0.05 parts by weight, 0.1 parts by weight, and 0.05 parts by weight, respectively, and the mixture was stirred and mixed to give calcium carbonate-polyvinyl chloride. An 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 sound absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1 kg / m ^{2 in} terms of the weight of calcium carbonate powder. Applied to Figure 1
After operating the spatula as shown in (a) and applying the sound absorbing coating, it is dried in a dryer at 80 ° C. for 1 hour, so that the surface of the porous material 1 is almost as shown in FIG. 3 (a). A sound absorbing material A was obtained in which the powder layer 2 was embedded in the surface layer portion of the porous material 1 so as to be flush with each other.

Example 14 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 9 and the same wetting as in Example 4 0.05 parts by weight, 0.1 parts by weight and 0.0 parts by weight of an agent, a dispersant and an antifoaming agent respectively.
By mixing 5 parts by weight and stirring and mixing them, a calcium carbonate-acrylic resin-based sound absorbing paint was prepared.

Next, foamed polyurethane (density 16 kg / m ³ , thickness 10 m) which is a porous material having continuous pores.
Sound absorbing paint on the surface of m) 1k in terms of weight of talc powder
It was coated at a coverage of g / m ^2, after elaborate painted absorbing paints by operating the spatula as shown in FIG. 1 (a), by drying 1 hour at a 80 ° C. oven, FIG. 3 ( A sound absorbing material A was obtained 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 as in a).

(Example 15 ) 10 parts by weight of the same talc powder as in Example 4 and a binder resin solution containing polyvinyl alcohol as a main component ("GH-17" manufactured by Chuo Rika Kogyo Co., Ltd .: polyvinyl alcohol solid content 15% by weight) , 85% by weight of water) 0.33 parts by weight,
And 8 parts by weight of water, 0.05 part by weight, 0.1 part by weight and 0.05 part by weight of the same wetting agent, dispersant and defoaming agent as in Example 4 , respectively, and the mixture is stirred and mixed. Thus, a talc-polyvinyl alcohol-based sound absorbing paint was prepared.

Next, foamed polyurethane (density 16 kg / m ³ , thickness 10 m) which is a porous material having continuous pores.
The sound absorbing paint was applied to the surface of m.
Was coated at a coverage of 5 kg / m ^2, after elaborate painted absorbing paints by operating the spatula as shown in FIG. 1 (a), by drying 1 hour at 80 ° C., 3 of (a) Thus, a sound absorbing material A was obtained 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 16 10 parts by weight of the same talc powder as in Example 4 , 1.33 parts by weight of the same binder resin solution as in Example 15 , and 7 parts by weight of water were used.
0.05 part by weight and 0.01 part by weight of the same wetting agent, dispersant, and defoaming agent as in Example 4 , respectively.
A talc-polyvinyl alcohol-based sound absorbing paint was prepared by blending parts by weight and stirring and mixing this.

Next, the same foamed polyurethane as in Example 15 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 0.5 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

(Example 17 ) 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by blending 0.05 part by weight, 0.1 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 15 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 0.5 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

Example 18 10 parts by weight of the same talc powder as in Example 4 , 4 parts by weight of the same binder resin solution as in Example 15 and 5 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 14 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 0.5 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

Example 19 10 parts by weight of the same talc powder as in Example 4 , 13.3 parts by weight of the same binder resin solution as in Example 15 , and 5 parts of water were used.
Part by weight, the same wetting agent, dispersant, and defoaming agent as in Example 4 were added by 0.3 parts by weight, 0.1 parts by weight, and 0.05 parts by weight, respectively, and a talc-polyvinyl alcohol-based sound absorbing paint. Was prepared.

Next, the same foamed polyurethane as in Example 15 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 0.5 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

(Example 20 ) 10 parts by weight of the same talc powder as in Example 4 , 26.7 parts by weight of the same binder resin solution as in Example 15 , and 5 parts of water were added.
Part by weight, the same wetting agent, dispersant, and defoaming agent as in Example 4 were blended in 0.1 parts by weight, 0.3 parts by weight, and 0.05 parts by weight, respectively, and a talc-polyvinyl alcohol-based sound absorbing paint. Was prepared.

Next, the same foamed polyurethane as in Example 15 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 0.5 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

(Example 21 ) 10 parts by weight of the same talc powder as in Example 4 , 0.33 parts by weight of the same binder resin solution as in Example 15 , and 8 parts of water.
Talc-polyvinyl alcohol-based sound-absorbing paint by blending 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight of the same wetting agent, dispersant, and defoaming agent as in Example 4 , respectively. Was prepared.

Next, the same foamed polyurethane as in Example 15 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1 by weight of talc powder.
After applying the coating amount of kg / m ² and operating the spatula as shown in FIG.
As shown in FIG. 3 (a), 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 by drying for a time Got

Example 22 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by blending 0.05 part by weight, 0.2 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively, and stirring and mixing them.

Next, the same foamed polyurethane as in Example 15 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1 in terms of the weight of talc powder.
After applying the coating amount of kg / m ² and operating the spatula as shown in FIG.
As shown in FIG. 3 (a), 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 by drying for a time Got

(Example 23 ) 10 parts by weight of the same talc powder as in Example 4 , 26.7 parts by weight of the same binder resin solution as in Example 15 , and 5 parts of water were added.
Part by weight, and the same wetting agent, dispersant, and defoaming agent as in Example 4 were added in an amount of 0.15 parts by weight, 0.1 parts by weight, and 0.05 parts by weight, respectively, and a talc-polyvinyl alcohol-based sound absorbing paint. Was prepared.

Next, the same foamed polyurethane as in Example 15 was used as the porous material having continuous pores, and the sound absorbing paint was applied to the surface of the foamed polyurethane in an amount of 1 in terms of weight of talc powder.
After applying the coating amount of kg / m ² and operating the spatula as shown in FIG.
As shown in FIG. 3 (a), 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 by drying for a time Got

(Example 24 ) 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by blending 0.05 part by weight, 0.1 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 15 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 0.3 kg / m ^{2 in} terms of weight of talc powder. As shown in Fig. 1 (a), after operating the spatula to apply the sound absorbing paint,
As shown in FIG. 3 (a), the powder layer 2 is 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 by drying for 1 hour. Material A was obtained.

(Example 25 ) 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.1 part by weight, 0.01 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 15 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 0.8 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

Example 26 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by mixing 0.1 part by weight, 0.1 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 15 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 1.5 kg / m ^{2 in} terms of the weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

(Example 27 ) 10 parts by weight of the same talc powder as in Example 4 , 2 parts by weight of the same binder resin solution as in Example 15 and 6 parts by weight of water were blended to obtain the same wetting agent as in Example 4. A talc-polyvinyl alcohol-based sound absorbing paint was prepared by adding 0.01 part by weight, 0.1 part by weight, and 0.05 part by weight of a dispersant and an antifoaming agent, respectively.

Next, the same foamed polyurethane as in Example 15 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 1.7 kg / m ^{2 in} terms of weight of talc powder. Then, as shown in FIG. 1 (a), after operating the spatula to apply the sound absorbing paint,
By drying 1 hour at ° C., it was provided by the powder layer 2 so as to be substantially flush with the porous material first surface is embedded in the surface layer portion of the porous material 1 as shown in FIG. 3 (a) Sound absorbing material A was obtained.

Comparative Example 1 A foamed polyurethane (density 16 kg / m ³ , thickness 30 mm), which is a porous material having continuous pores, was used as a sound absorbing material.

Comparative Example 2 Talc powder (bulk density 0.4 g / cm ³ , average particle size 20 μm)
m) was filled into a container having an open top to a thickness of 30 mm to obtain a sound absorbing material.

(Comparative Example 3) A talc powder (bulk density 0.4 g / cm ³ , average particle size 20 μm) was placed on a foamed polyurethane (density 14 kg / m ³ , thickness 30 mm) which was a porous material having continuous pores. 1k
A sound absorbing material was obtained by uniformly spraying at a spraying amount of g / m ² to form a powder layer having a thickness of 3 mm.

(Comparative Example 4) Porous glass wool (density 32 kg / m ³ , thickness 25 mm) was used as a sound absorbing material.

Comparative Example 5 Foamed polyurethane (density 16 kg / m ³ , thickness 10 mm), which is a porous material having continuous pores, was used as a sound absorbing material.

With respect to the sound absorbing materials obtained in the above Examples 1 to 27 and Comparative Examples 1 to 5, the sound absorption coefficient was measured according to JIS A 1405.
The measurement was performed based on the "method of measuring the normal incidence sound absorption coefficient of building materials by the in-pipe method". For sound absorbing material coated with powder,
The measurement was performed with the coated surface of the powder layer on the sound source side (the side not fixed by the end plate) so that the powder layer had a free end. The results are shown in FIGS .

The sound absorbing materials obtained in Example 1 and Comparative Example 1 were
Two plywood sheets with a thickness of 2.5 mm were inserted into a double structure panel arranged at intervals of 30 mm, and the sound transmission loss at the 1/3 octave band center frequency was measured according to JIS A 1416.
It measured based on "the sound transmission loss measuring method in a laboratory". However, the opening area was measured at 1.58 m ² . The results are shown in Fig. 31 .

Further, the sound absorbing coating material prepared in the same composition as in Example 1 was added to the same foamed polyurethane as in Example 1 in the same manner as in Example 1 to convert the weight of talc powder to 0.5 kg / m.
² , plywood having a surface weight of 1.5 kg / m ² was arranged at an interval of 30 mm using the sound absorbing material obtained by applying the coating amount of ² , 1.0 kg / m ² , and 2.0 kg / m ² . The sound absorbing material was inserted into the double structure panel, and the sound transmission loss was measured in the same manner as above. For comparison, a foamed polyurethane (density 16 kg / m ³ , thickness 3
(0 mm) was inserted, and also for the above-mentioned double structure panel in which the inside of the double structure panel was hollow (air layer), the sound transmission loss was similarly measured. The results are shown in Fig. 32 .

As can be seen from FIG. 3 , in Example 1, while holding the entire powder layer 2 inside the porous material 1, the upper surface of the porous material 1 and the powder layer 2 are kept. The top surfaces are almost flush with each other. In addition, in the second embodiment,
The entire 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. Further, in Example 3 , the porous material 1
There are two powder layers 2 inside, and their positions are slightly inside the upper and lower surfaces of the porous material 1. Looking at the relationship between the amount of water and the position of the powder layer 2 provided on the porous material 1 in Examples 1 to 3 , in addition to the operation by the spatula, the powder was changed by the amount of water (solvent) of the sound absorbing paint. It will be appreciated that the location of the layer 2 can be manipulated.

Further, FIG. 4 and FIG. 5 show the results of the sound absorption characteristics of Example 1 and Example 2, respectively .
While holding the entire powder layer 2 inside, the porous material 1
The upper surface of the powder layer 2 and the upper surface of the powder layer 2 of Example 1 exhibit a sound absorption peak at the lowest frequency, and when the sound absorption characteristics in the low frequency range are emphasized,
It turns out that this is a particularly desirable configuration. Further, in any of the examples, in order to measure the sound absorption coefficient by the normal incidence method,
Although it is cut to φ84 mm, continuous leakage of powder is not recognized.

Next, comparing the sound absorption characteristics and the powder holding state of FIGS. 4 to 30 with Comparative Example, Examples 1 to 1 of the present invention will be described.
In No. 27 , the sound absorbing characteristics are superior in the 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 urethane foam or glass wool. In Comparative Example 2, the sound absorbing material is composed of only the powder, but the sound absorbing characteristic has a sharp peak at a specific frequency, and the range of the sound absorbing frequency is narrow. On the other hand, Examples 1 to 4 , Examples 8 to 12 and Examples 15 to
In the sound absorbing material of No. 27 , the same talc powder as in Comparative Example 2 was used, but the sound absorbing peak frequency was slightly higher, but the sound absorbing characteristics were in a wide frequency range.

Further, in Comparative Example 2, the powder is only filled in the container, so that the powder is biased or scattered when tilted or shaken. However, in the sound absorbing materials of Examples 1 to 25 , No unevenness or scattering of the powder was observed, and stable sound absorption characteristics were obtained. Furthermore, as described above, no continuous outflow of powder from the cut surface was observed.

In Comparative Example 3, a talc powder layer was laminated on urethane to form a sound absorbing material, whereby a sound absorbing material having a low sound absorbing peak frequency was produced. The range of sound absorption extends to a wider frequency range. However, this powder layer remains sprinkled,
When vibration is applied, the powder easily scatters.

In Example 5 , a shirasu balloon was used as the powder, but it showed a higher sound absorption coefficient as a whole than in Comparative Example 1, and a peak at 400 to 500 Hz was observed as in the case of using talc. It has no sound absorption characteristics. The same applies to the case of using the fluororesin powder as the powder in Example 7 .

In Example 6 , although silicone powder is used as the powder, as in the case of talc, a sound absorption peak is shown near 500 Hz, and a high sound absorption coefficient is obtained in the low frequency range.

In Examples 13 and 14 , calcium carbonate was used as the powder, but it showed a sound absorption peak near 700 Hz, and intermediate sound absorption characteristics of Shirasu balloon and talc were obtained.

In Examples 8 and 10 , glass wool was used as the porous material, but the characteristics showing a peak of sound absorption in the low frequency region were obtained as in the case of using polyurethane foam.

In Examples 9 and 12 , the acrylic resin was used as the binder resin, but it exhibited excellent sound absorption coefficient in the low frequency range. Moreover, while having the same thickness as that of Comparative Example 1, a high sound absorption coefficient is maintained in a wide frequency range in the mid-high range. Further, it is confirmed that when the sound absorption characteristics in the lower frequency range are emphasized, it is desirable that the amount of the binder resin is small.

In Examples 15 to 20 and Examples 21 to 23 , the compounding ratio of the polyvinyl alcohol resin as the binder resin was changed. The results are shown in FIGS.
And FIGS. 24 to 26 . From these figures, it is understood that the smaller the amount of the binder is, the better in order to enhance the low frequency sound absorption characteristics.

Example 18 , Example 22 and Example 24-
In No. 27 , the weight of the powder layer was changed. The result is shown in Figure 2.
1, FIG. 25, and FIGS. 27 to 30 . 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 the filler, as shown in FIG. 31 , both have almost the same performance at 800 Hz or higher. However, in the range of 125 to 800 Hz, the maximum improvement in Example 1 is about 5 dB, and it can be seen that the example 1 is useful for improving sound insulation in the low frequency range. Similarly, as seen in FIG. 32 , the one using the sound absorbing material provided with the powder layer has a maximum of 5d 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 characteristics of the sound absorbing materials of Examples 1 to 27 , the sound absorbing coefficient-frequency relationship of the sound absorbing material of the present invention is determined by the kind and amount of powder, the kind and amount of binder resin. It is confirmed that it is possible to tune according to the frequency characteristics of the sound to be absorbed, because it changes depending on the type and density of the porous material, the position where the powder layer is formed in the porous material, etc. It Further, the sound absorbing material of the present invention, which is designed to exhibit a high sound absorbing effect particularly in a low frequency castle, has a sound absorption characteristic in which the film vibration is dominant and has a peak at a specific frequency. And the sound absorption effect of the property of the powder layer to form a film, the film and plate vibrations obtained with ordinary sheets and plates having the same weight per unit area. It is possible to absorb sound in a castle with a lower frequency than the sound absorption effect of. In addition, a material that exhibits broad sound absorption characteristics is 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 absorption coefficient of the sound absorbing material of Example 22 was measured according to JIS A, with the powder coating surface on the end plate side (side to be the fixed end).
1405 "method of measuring normal incidence sound absorption coefficient of building material by in-pipe method". The result is shown in FIG. 33 as Comparative Example 6. From this figure, it is necessary for sound absorption that the coating surface of the powder should be on the sound source side and the powder layer should be the free end so that the film can vibrate.

Further, when each sample of Examples 1 to 27 was cut with a cutter knife after measuring the sound absorption coefficient, almost no powder fell off from the cut surface, and the cutting method was the same as in the case of cutting the foamed polyurethane. It was possible to carry out.

As described above, the sound absorbing materials of the respective examples show good sound absorbing characteristics even in the low frequency range without increasing the thickness and the capacity as compared with the conventional sound absorbing materials, or in the middle and high range. Sound absorption characteristics that maintain a high sound absorption coefficient are obtained,
In addition, performance deterioration due to powder spillage, unevenness, etc. does not occur,
Further, it had a workability equivalent to that of the porous material of the base.

[0128]

As described above , the manufacturing method according to claim 1 of the present invention is as follows.
The sound absorbing material is made of a porous material such that a powder layer containing 0.5 to 40 parts by weight of a binder resin as a solid content with respect to 100 parts by weight of the powder is substantially flush with the surface of the porous material. Since it is formed by entering into the voids in the surface layer, the powder is held by the binder resin to form a powder layer that reduces the loss of the powder, and the ratio of binder resin to powder Because of the small
Shear stress at the resin interface It is possible to form a powder layer having high sound absorption characteristics in a low frequency range due to viscous damping of air. Therefore, it is possible to obtain a sound-absorbing material which does not cause performance deterioration due to falling off of powder, uneven distribution, and the like, and which is lightweight, thin, and has workability and workability equivalent to those of conventional porous materials. Further, since the powder layer is formed in the surface layer portion of the porous material so as to be substantially flush with the surface of the porous material, it is possible to absorb the sound in the low frequency range. Furthermore, when manufacturing this sound absorbing material, powder
100 parts by weight, binder resin in solid content of 0.5 to 40
20 to 300 parts by weight of a solvent and 20 to 300 parts by weight of a solvent are mixed to produce a sound absorbing paint.
And apply this sound absorbing paint to the surface of the porous material.
Therefore, hold the powder with a binder resin and
What can form a powder layer with reduced body loss
And the ratio of binder resin to powder is small.
In order to avoid vibration of powder and shear stress at the powder / resin interface.
High sound absorption characteristics at low frequencies due to viscous damping of air
A powder layer can be formed.

Further , in the sound absorbing material manufactured according to claim 2 of the present invention, the powder layer containing 0.5 to 40 parts by weight of the binder resin as a solid content with respect to 100 parts by weight of the powder is a porous material. Since it is formed inside the porous material by entering the voids inside, it holds the powder with a binder resin to form a powder layer with reduced loss of the powder. Since the ratio of the binder resin to the powder is small, it is possible to form a powder layer having a high sound absorption characteristic in a low frequency region due to vibration of powder and shear stress at the powder / resin interface, viscous damping of air. Therefore, it is possible to obtain a sound-absorbing material which does not cause performance deterioration due to falling off of powder, uneven distribution, and the like, and which is lightweight, thin, and has workability and workability equivalent to those of conventional porous materials. Further, since the powder layer is formed inside the porous material, it can absorb high frequency sound. Furthermore, we manufacture this sound absorbing material
Powder, 100 parts by weight of powder, binder resin
0.5 to 40 parts by weight of solid content, 20 to 300 parts by weight of solvent
Prepare a sound-absorbing paint by blending parts by weight, and add this sound-absorbing paint.
Since it was applied to the surface of the porous material, the powder was
The powder layer is formed by holding the
It is possible to produce
Due to the small proportion of inder resin, powder vibration and powder
/ Shear stress at resin interface Low frequency range due to viscous damping of air
Can form a powder layer with high sound absorption characteristics
It is a thing.

Further, the sound absorption manufactured by claim 3 of the present invention.
The material is solid binder resin for 100 parts by weight of powder.
The powder layer containing 0.5 to 40 parts by weight is a porous material.
Of the surface of the porous material so that it is almost flush with the surface of the
Since it is formed by entering the gap part, the powder
A powder layer is formed by holding the powder with resin to reduce the loss of powder.
And the binder resin for the powder
Vibration of powder and powder / resin interface due to low fat content
Shear stress due to viscous damping of air
It is possible to form a powder layer with high sound characteristics.
It Therefore, the performance may be deteriorated due to the falling of powder or uneven distribution.
In addition, it is lightweight and thin, and is equivalent to conventional porous materials.
It is also possible to obtain a sound absorbing material with workability and workability.
Of. Also, the powder layer is substantially flush with the surface of the porous material.
Is formed in the surface layer of the porous material so that
Thus, it is possible to absorb low frequency sound.
Further, in manufacturing this sound absorbing material, 100
0.5 to 40 parts by weight of binder resin in solid content
Parts and 20 to 300 parts by weight of solvent to prepare a sound absorbing paint.
Made by impregnating the porous material with this sound absorbing paint
Therefore, hold the powder with a binder resin and remove the powder.
It is possible to form a powder layer with reduced
Moreover, the ratio of binder resin to powder is small.
Vibration of powder and shear stress of powder / resin interface, viscosity of air
A powder layer with high sound absorption characteristics in the low frequency range due to attenuation
It can be formed.

Further, the sound absorbing device manufactured according to claim 4 of the present invention.
The material is solid binder resin for 100 parts by weight of powder.
The powder layer containing 0.5 to 40 parts by weight is a porous material.
Enter the voids inside and form inside the porous material
Therefore, hold the powder with a binder resin
To form a powder layer that reduces the loss of
Because the ratio of binder resin to powder is small
Vibration of powder and shear stress of powder / resin interface, viscosity of air
A powder layer with high sound absorption characteristics in the low frequency range due to attenuation
It can be formed. Therefore, the fall of the powder
The performance is not deteriorated due to unevenness and unevenness, and it is lightweight and thin.
Has the same workability and workability as conventional porous materials.
It is possible to obtain a sound absorbing material. Also, powder layer
Is formed inside the porous material, so high frequency
The sound of can also be absorbed. Furthermore, we manufacture this sound absorbing material
Powder, 100 parts by weight of powder, binder resin
0.5 to 40 parts by weight of solid content, 20 to 300 parts by weight of solvent
Prepare a sound-absorbing paint by blending parts by weight, and add this sound-absorbing paint.
Since it was made to impregnate the porous material, the powder
-Forms a powder layer that is held by resin to reduce powder loss
The vine for powder
Due to the small proportion of resin, powder vibration and powder / wood
Shear stress at the oil interface In the low frequency range due to viscous damping of air
What can form a powder layer with high sound absorption characteristics
Is.

Further, the invention of claim 5 uses water as a solvent.
Therefore, it is an environmentally friendly paint.

[0133] The invention according to claim 6 uses 100 weights of powder.
1 to 6 parts by weight of binder resin in terms of solid content based on parts by weight
Since it is contained, the sound absorption characteristics of the powder are further added.
A powder layer that can get high can be formed,
It is possible to form a powder layer with less falling of powder.
It is a thing.

The invention according to claim 7 is the above porous material.
Since the material has open pores, the voids of open pores
It is possible to obtain a sound absorbing material with a powder layer provided on the part.
is there.

[0135] The invention according to claim 8 is the above continuous pores.
Polyurethane foam, glass
I chose to use wool and non-woven fabrics
In this way, it is possible to reduce the weight of the sound absorbing material, to make it incombustible and to reduce the cost.
It is possible.

Further, the invention of claim 9 relates to the above-mentioned powder layer.
The weight per unit area of the powder is 0.3 to 3 kg / m
Since it was formed to be 2, the powder that holds the powder tightly
Forming layers to improve sound absorption characteristics in the lower frequency range
It will be possible.

Further, the invention of claim 10 is the unit of powder.
The weight per area should be 0.5 to 2 kg / m2
Since it is formed, it is lighter and has better sound absorption characteristics in the low frequency range.
It is something that can be improved.

[0138] The invention of claim 11 relates to the above powder.
The particle size is 0.1 to 1000 μm and the bulk density is 0.1 to
Since the powder of 1.5 g / cm3 was used, powder
To obtain a powder layer with high sound absorption characteristics.
It is capable of

[0139] The invention of claim 12 relates to the above powder.
Then, talc, shirasu balloon, and a small amount of calcium carbonate
Since I decided to use at least one, I recommend using talc.
A powder with good sound absorption characteristics in the low frequency range due to
To obtain the body layer, and to use Shirasu balloon
Therefore, a powder layer with good sound absorption characteristics in the middle and high frequency range
Can be obtained by using calcium carbonate
A powder with good sound absorption characteristics in the intermediate frequency range
The layers can be obtained.

Further, the invention of claim 13 relates to the above powder and
Then, I used talc, so in the low frequency range
It is possible to obtain a powder layer having excellent sound absorption characteristics of
Of.

According to a fourteenth aspect of the present invention, there is provided the above-mentioned vine.
As the resin, phenol resin, acrylic resin, poly resin
Select one or more from vinyl alcohol resin and polyvinyl acetate
I chose to use a phenolic resin,
By using it, it is possible to obtain a powder layer with good heat resistance.
Yes, use phenol resin or acrylic resin.
A powder layer with high water resistance can be obtained by
By using livinyl alcohol or polyvinyl acetate
Therefore, the powder layer can be formed at a lower cost.
Of.

Further, according to the invention of claim 15, the powder layer itself is provided.
Since it is a good reason, the spring vibration of the sound absorbing material makes it
It shows sex.

[Brief description of drawings]

FIG. 1 is a view showing an example of an embodiment of a sound absorbing material of the present invention, (a) is a schematic view showing an operation of rubbing a sound absorbing paint into a porous material, and (b) is a schematic view of the sound absorbing material. Is.

2A and 2B show another example of the embodiment of the sound absorbing material of the present invention, FIG. 2A is a schematic view showing an operation of rubbing a sound absorbing paint on a porous material, and FIG. 2B is a schematic view of the sound absorbing material. It is a figure.

FIG. 3 shows an example of the sound absorbing material of the present invention,
(A) is a schematic view of the sound absorbing material of Example 1, (b) is Example 2
Of the sound absorbing material of Example 3, (c) is a schematic view of the sound absorbing material of Example 3 .
It is.

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

FIG. 5 is a graph showing the normal incident sound absorption characteristics of Example 2 and Comparative Examples 1 to 3.

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

7 is a graph showing the normal incident sound absorption characteristics of Example 4 and Comparative Example 1. FIG.

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

FIG. 9 is a graph showing the normal-incidence sound absorption characteristics of Example 6 and Comparative Example 1.

FIG. 10 is a graph showing the normal incidence sound absorption characteristics of Example 7 and Comparative Example 1.

11 is a graph showing the normal incident sound absorption characteristics of Example 8 and Comparative Example 4. FIG.

12 is a graph showing the normal incident sound absorption characteristics of Example 9 and Comparative Example 1. FIG.

FIG. 13 is a graph showing the normal incidence sound absorption characteristics of Example 10 and Comparative Example 4 .

FIG. 14 is a graph showing the normal incident sound absorption characteristics of Example 11 and Comparative Example 1.

FIG. 15 is a graph showing the normal incident sound absorption characteristics of Example 12 and Comparative Example 1.

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

FIG. 17 is a graph showing the normal incident sound absorption characteristics of Example 14 and Comparative Example 5.

FIG. 18 is a graph showing the normal incident sound absorption characteristics of Example 15 and Comparative Example 5 .

FIG. 19 is a graph showing the normal incident sound absorption characteristics of Example 16 and Comparative Example 5 .

FIG. 20 is a graph showing the normal incident sound absorption characteristics of Example 17 and Comparative Example 5 .

FIG. 21 is a graph showing the normal incidence sound absorption characteristics of Example 18 and Comparative Example 5 .

22 is a graph showing the normal incident sound absorption characteristics of Example 19 and Comparative Example 5. FIG.

FIG. 23 is a graph showing the normal incident sound absorption characteristics of Example 20 and Comparative Example 5.

FIG. 24 is a graph showing the normal incidence sound absorption characteristics of Example 21 and Comparative Example 5.

FIG. 25 is a graph showing the normal incident sound absorption characteristics of Example 22 and Comparative Example 5 .

FIG. 26 is a graph showing the normal incident sound absorption characteristics of Example 23 and Comparative Example 5 .

FIG. 27 is a graph showing the normal-incidence sound absorption characteristics of Example 24 and Comparative Example 5 .

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

FIG. 29 is a graph showing the normal incident sound absorption characteristics of Example 26 and Comparative Example 5.

FIG. 30 is a graph showing the normal incident sound absorption characteristics of Example 27 and Comparative Example 5.

FIG. 31 is a graph showing measurement results of sound transmission loss of Example 1 and Comparative Example 1.

FIG. 32 is a graph showing the measurement results of sound transmission loss when the talc powder weight of the powder layer was changed and measured.

FIG. 33 is a graph showing the normal incident sound absorption characteristics of Example 22 and Comparative Example 6.

[Explanation of symbols]

1 Porous material 2 powder layers 3 Sound absorbing paint 4 powder 5 Binder resin

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Nogami 1048 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Kenji Onishi, 1048 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Works, Ltd. (72) Inventor Kiyoshiro Yamakawa 1048, Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Works Co., Ltd. (JP, A) JP-A-2-228371 (JP, A) JP-A-2-227478 (JP, A) JP-A-50-18528 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) E04B 1/86

Claims (15)

(57) [Claims] 1. A porous material containing a binder resin in a solid content of 0.5 to 40 parts by weight based on 100 parts by weight of the powder so that the powder layer is substantially flush with the surface of the porous material. Made of sound absorbing material formed by entering the voids in the surface layer
When making, 100 parts by weight of powder, binder tree
0.5 to 40 parts by weight of fat in solid content, 20 to 300 in solvent
Prepare a sound absorbing paint by blending parts by weight, and use this sound absorbing paint.
The sound absorbing material, which comprises applying to the surface of the porous material
Manufacturing method . 2. A powder layer containing 0.5 to 40 parts by weight of a binder resin as a solid content based on 100 parts by weight of the powder enters the void portion inside the porous material and enters the inside of the porous material. When manufacturing the sound absorbing material that is formed , powder
100 parts by weight of the binder resin in a solid content of 0.5 to 4
0 parts by weight, 20 to 300 parts by weight of a solvent are mixed and applied for sound absorption.
Material and apply this sound absorbing paint to the surface of the porous material
A method of manufacturing a sound absorbing material , comprising: 3. A binder resin based on 100 parts by weight of powder.
A powder layer containing 0.5 to 40 parts by weight of fat as a solid content is often used.
The surface of the porous material should be approximately flush with the surface of the porous material.
Made of sound absorbing material formed by entering the voids of the layer
When making, 100 parts by weight of powder, binder tree
0.5 to 40 parts by weight of fat in solid content, 20 to 300 in solvent
Prepare a sound absorbing paint by blending parts by weight, and use this sound absorbing paint.
Production of sound absorbing material characterized by impregnating porous material
Way . 4. A binder resin based on 100 parts by weight of powder.
A powder layer containing 0.5 to 40 parts by weight of fat as a solid content is often used.
When entering the voids inside the porous material,
When manufacturing the sound absorbing material formed in the
100 parts by weight of the binder resin in a solid content of 0.5 to 4
0 parts by weight, 20 to 300 parts by weight of a solvent are mixed and applied for sound absorption.
A method for producing a sound absorbing material , which comprises: preparing a material; and impregnating a porous material with the sound absorbing paint . 5. The solvent is water.
5. The method for manufacturing the sound absorbing material according to any one of 1 to 4 . 6. The powder layer comprises a powder layer based on 100 parts by weight of the powder.
The sound absorbing material according to any one of claims 1 to 5, characterized in that the solid content of the inder resin is 1 to 6 parts by weight.
Manufacturing method . 7. The porous material has continuous pores.
The method according to any one of claims 1 to 6, characterized in that
Method for manufacturing sound absorbing material . 8. A porous material having continuous pores is a foamed material.
Selected from polyurethane, glass wool and non-woven fabric
The method for manufacturing the sound absorbing material according to claim 7, wherein
Law . 9. The powder layer has a weight per unit area of powder.
It is 0.3-3 kg / m <2>, It is characterized by the above-mentioned.
9. The method for manufacturing a sound absorbing material according to any one of 8 to 8. 10. The powder layer is the weight of the powder per unit area.
Is 0.5 to 2 kg / m2, The method for producing a sound absorbing material according to claim 9, wherein . 11. The powder has a particle size of 0.1 to 1000 μm,
The sound absorbing material according to any one of claims 1 to 10, which has a bulk density of 0.1 to 1.5 g / cm3.
Manufacturing method . 12. The powder is talc, shirasu balloon and carbonic acid.
It is at least one of calcium, The manufacturing method of the sound absorbing material in any one of Claim 1 thru | or 11 characterized by the above-mentioned. 13. The powder is talc.
The method for manufacturing the sound absorbing material according to claim 12 . 14. The binder resin is a phenol resin,
Acrylic resin, polyvinyl alcohol resin, poly vinyl acetate
Characterized by being selected from one or more of nil
A method for manufacturing the sound absorbing material according to any one of claims 1 to 13.
Law. 15. The method for producing a sound absorbing material according to claim 1 , wherein the powder layer has a free end.
Law .