JP2005338129A - Soundproof material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide soundproof fiber which is lightweight and has superior sound absorbing/proofing properties. <P>SOLUTION: Disclosed is a soundproof material made of a fiber structure using a fiber base body and fine powder particles stuck on the periphery of it. Silicon dioxide or activated carbon is used as the fine particle. The mean particle size of the fine powder particle is 0.1 nm to 100 μm. Soundproof fiber obtained by sticking the fine powder particle on the surface of fiber is made into non-woven fabric by a mechanical bonding method, an adhesion method, a fusing method, a wet method, etc., and the non-woven fabric is used as the fiber structure. The fiber is made into the non-woven fabric by the mechanical bonding method, adhesion method, fusing method, wet method, etc., and the fine powder particle is stuck on its surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a soundproofing material, and more specifically, excellent in sound absorption / sound insulation performance and light weight. Typically, a dash insulator, a ceiling base material, a floor insulator, a parcel board, a carpet, and a hood insulator. The present invention relates to a soundproofing material that can reduce noise of a vehicle or the like by being used for an engine cover, an undercover, a trim, and the like.

  In recent years, with increasing awareness of high-quality and high-performance automobiles, the requirements for quietness in the vehicle interior and noise outside the vehicle have become increasingly demanding. For this reason, various efforts have been made for soundproofing materials applied to vehicles for the purpose of obtaining a better soundproofing effect.

For example, as a technique related to a soundproof material for a vehicle, a technique for making the surface density of a nonwoven fabric a constant size is disclosed (for example, see Patent Document 1). Thus, although it is possible to obtain a soundproofing material having an excellent soundproofing performance, it is necessary to control the surface density of the fiber assembly in order to provide the desired soundproofing performance.
JP-A-8-241084

Further, as a technique related to a soundproof material for a vehicle, a technique using a double wall structure is disclosed as a technique related to the structure (see, for example, Patent Document 2). Although it is possible to obtain a soundproof structure with excellent soundproofing performance as a result, there is a possibility of occupying an excessive space for a vehicle, which is not satisfactory in terms of bulkiness.
Japanese Patent Laid-Open No. 10-247085

Furthermore, the technique regarding the soundproofing material which combined the fiber structure and the granular material is disclosed (for example, refer patent documents 3 and 4). Although it is possible to obtain a soundproofing material having excellent soundproofing performance by this, it is necessary to mix or apply a granular substance to the fiber portion, resulting in an increase in weight. In particular, it has not always been satisfactory for use in vehicle applications where weight reduction is essential.
JP-A-7-104762 JP 11-133980 A

  As described above, the weight per unit area of the soundproofing material is increased, and a device such as a double wall structure is known as a conventionally known technique. However, these methods improve the soundproofing effect, but increase the weight. In addition, there is a problem in that it is not preferable in terms of design as a vehicle component, because the volume of the soundproofing material or the soundproofing structure itself is restricted due to the volume.

  This invention is made | formed in view of the subject which such a prior art has, and the place made into the objective is to provide the soundproof material provided with the light weight and the more excellent sound absorption / sound insulation.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by surrounding fine particles on the surface of the fiber substrate, and have completed the present invention. .

  According to the present invention, since many fine powder particles are scattered on the surface of the fiber substrate, vibration energy from the outside is easily absorbed, and the vibration energy is moved by the vibration of the fiber substrate and the fine powder particles. It is converted into energy and heat energy and consumed.

  Hereinafter, the soundproofing material of the present invention will be described in detail. In the present specification and claims, “%” indicates a mass percentage unless otherwise specified.

The soundproofing material of the present invention is composed of a fiber structure, and the fiber structure is composed of a fiber substrate and fine powder particles that are attached to the fiber substrate. In other words, the fiber structure is a collection of fiber substrates attached (adhered) so that fine particles are dispersed on the surface.
With such a configuration, the soundproofing material absorbs vibration energy that has propagated in a solid or in the air, and a mass spring in which a part of the absorbed energy is constituted by a fiber base and fine particles or fine particles. By extinguishing it as thermal energy due to the kinetic energy or frictional resistance of the system, the sound generated by the vibration is absorbed or insulated. Moreover, it is lighter than conventional products and can exhibit the same or better soundproofing performance.

The soundproofing material of the present invention is preferably in the form of a nonwoven fabric. In this method for producing a nonwoven fabric, the step of surrounding the fine particles and the step of forming the nonwoven fabric can be performed regardless of the order. For example, after obtaining a soundproof fiber in which fine powder particles are wrapped around the surface of the fiber, a mechanical bonding method (such as a needle punch method), an adhesion method, a fusion method (spunbond method, etc.) ) Or a wet method (such as a papermaking method), and a method in which these are arbitrarily combined. Moreover, a fiber can be previously made into a nonwoven fabric by the said method, and a fine powder can also be put around the surface of the fiber which comprises this nonwoven fabric after that.
As a result, the weight of the conventional product is reduced, and the sound generated by the vibration is absorbed or insulated. Further, it can be manufactured at low cost and good productivity.
For the fibers and fine particles, the same material may be used, or materials having different properties may be used in appropriate combination. Moreover, as forms other than the nonwoven fabric of the said soundproofing material, fabric shape or string shape, such as a woven / knitted fabric, is mentioned, for example.

Further, the soundproofing material can be further improved in soundproofing performance by designing these techniques alone or in combination as appropriate, such as a double wall structure, control of surface density, and control of fineness and specific surface area of soundproofing fibers.
Furthermore, since the fine particles are fine, they are not easily separated from the surface of the fiber substrate by the vibration of the vehicle due to the adhesive force, but the surface density of the soundproof material is 0.02 if necessary. A thin non-woven fabric of about 0.05 kg / m ² can be bonded simultaneously in the sound absorbing material manufacturing process, or can be bonded in a separate process. At this time, the soundproofing material can be easily transported, and the soundproofing material can be prevented from being caught during the overlapping.

Here, the fiber may be either a synthetic fiber or a natural fiber, or a composite fiber thereof. For example, as synthetic fibers, rayon fibers, acetate fibers, polyester fibers, nylon fibers, acrylic fibers, modacrylic fibers, polypropylene fibers, polyethylene fibers, polyurethane fibers, aromatic nylon fibers, polybenz Examples include imidazole fiber and novoloid fiber. Examples of natural fibers include cellulosic fibers such as cotton and pulp, and animal fibers such as wool. The raw material type and fineness of these fibers are not particularly limited, but when used in vehicles, polyester fibers, cotton fibers, and clothing and fabric repellents, etc. from the viewpoint of cost, productivity, and stable supply of raw materials. It is desirable to use it.
Moreover, the said fiber may have special shapes, such as an irregular cross-section fiber, a conjugate fiber, and an ultrafine fiber. For example, it can be formed in a structure including air holes therein.

  The fine particles can be made of an inorganic material or an organic material, such as aluminum (Al), iron (Fe), copper (Cu), zinc (Zn), and nickel (Ni). Metals, talc, mica, gold mica, natural minerals such as silica, kaolin and talc, metal oxides such as silicon dioxide, titanium dioxide and alumina, metal hydroxides such as aluminum hydroxide, calcium carbonate, calcium silicate, calcium chloride And salts such as magnesium carbonate, graphite, activated carbon, carbon fiber, silicon carbide and diatomaceous earth, as well as polyethylene, polypropene, polyacrylonitrile, acrylic resin, fluororesin, nylon, polyester, polyvinyl chloride, polymethyl methacrylate and silicone resin Organic polymer particles such as These fine particles can be selected as appropriate, and may be used alone or in combination of two or more.

Furthermore, considering the use of the fine powder particles in a vehicle or the like, it is preferable that the fine particles are inorganic substances from the viewpoint of cost and supply stability. Furthermore, in consideration of the usage environment in vehicles such as heat, humidity and moisture, it is possible to adopt either or both of silicon dioxide and activated carbon that can maintain a fine powder state and a porous normal state more stably. More preferred.
In addition, although the said fiber and the said fine powder particle do not need to specifically limit, depending on a specification form, a weight increases or the soundproof material manufactured with this soundproof fiber becomes bulky, and is accompanied by restrictions on volume. Etc. may be undesirable in design.

Furthermore, the fine particles preferably have an average particle diameter of 0.1 nm to 100 μm. At this time, excellent absorption / sound insulation performance can be exhibited. On the other hand, for example, when the average particle diameter of silicon dioxide particles or activated carbon exceeds 100 μm, although it adheres to the surface of the fiber, stability may be deteriorated or clogging may occur.
In addition, as for the addition ratio of the said fiber and the said fine particle, it is good that a fine fiber is 2-39 parts with respect to 100 parts of fibers, More desirably, it is 2-10 parts.

Further, as the above-mentioned fine powder particle peripheral method, for example, a mixing stirring method, a spray method, a spray method, a paper making method, a contact method and the like can be appropriately employed in a dry or wet manner, and a fiber spinning process or a production of a fiber structure is possible. It can employ | adopt suitably as a process and the process after forming a fiber structure.
Furthermore, at least a part of the fine powder particles may be attached via a yield improver. That is, the fine particles can be attached to the surface of the fiber without using a yield improver, but depending on the method of surrounding the fine particles, it is costly to use a so-called yield improver in combination. It is preferable because of its advantages.
As the yield improver, for example, various anionic, nonionic, cationic or amphoteric water-soluble compounds, specifically, polyacrylamide-based cationic, nonionic, anionic and amphoteric resins, acrylic water-soluble compounds Resin, polyethyleneimine and derivatives thereof, polyethylene oxide, polyamine, polyamide, polyamide polyamine and derivatives thereof, cationic and amphoteric starch, oxidized starch, carboxymethylated starch, vegetable gum, polyvinyl alcohol, urea formalin resin, melamine formalin resin, Examples include hydrophilic cationic polymers and diallyldimethylammonium chloride polymers.
In addition, in the structure which apply | coated the fine particle to the fiber, an absorption / sound-insulation performance is easy to reduce, and in the structure which mixed the fiber and the fine particle, the dispersion | distribution density of a fine particle is easy to produce.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

(Example 1)
70% polyester fiber (fineness: 12 denier, diameter: about 35 μm, Teijin Fibers Co., Ltd., trade name “Teijin Tetron High Bulky”), polyester fiber with a core / sheath structure as a low melting point fusion fiber (fineness: 6 denier) , Diameter: about 25 μm, Teijin Fibers Co., Ltd., trade name “Teijin Tetron PET Binder”) 30%, and the resulting raw mat is heated and softened by heating with hot air, and then pressed to have a weight of 1 A plate-shaped nonwoven fabric having a thickness of 0.06 kg / m ² and a thickness of 30 mm was preliminarily produced.
Next, this plate-like nonwoven fabric was cut into a disk shape having a diameter of 200 mm, and placed on a papermaking filter having the same bottom surface of 200 mm in diameter (trade name “papermaking filter” manufactured by Fuji Corn Co., Ltd.). On the other hand, 40 g of silicon dioxide particles having an average particle diameter of 8 nm (trade name “AEROSIL 300” manufactured by Nippon Aerosil Co., Ltd.) are mixed in 1 liter of water and mixed in a mixer (trade name “Mixer BM-FS08” manufactured by Zojirushi Co., Ltd.). The suspension was stirred to prepare a suspension, which was poured evenly onto the upper surface of the nonwoven fabric set in the filtration device while paying attention to dispersion. Thereafter, the drainage port of the filtration device was opened, the mixture was passed through the non-woven fabric of water and suspension by its own weight, and further drained by depressurization. Furthermore, after drying in a hot air drying oven at 80 ° C. for 10 hours, removing moisture / constituting, and allowing to cool at room temperature, a disc-shaped soundproof material in which the silicon dioxide particles adhere to the polyester fiber surface is obtained. Obtained.
A test piece was cut out from the soundproofing material and evaluated. In addition, by the above series of operations, the fabric weight of the nonwoven fabric was 1.17 kg / m ² and the thickness was still 30 mm.

(Example 2)
Except that the basis weight of the prefabricated plate-shaped nonwoven fabric was 0.97 kg / m ^2, and 60 g of silicon dioxide particles having an average particle diameter of 8 nm in the suspension were mixed in 1 liter of water and mixed. The same operation as 1 was repeated to obtain a disk-shaped soundproof material.
A test piece was cut out from the soundproofing material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.08 kg / m ² and the thickness remained at 30 mm by the above series of operations.

(Example 3)
The basis weight of the prefabricated plate-shaped nonwoven fabric was 1.04 kg / m ^2, and 20 g of silicon dioxide particles having an average particle diameter of 40 nm in the suspension (trade name “AEROSIL TT600” manufactured by Nippon Aerosil Co., Ltd.) A disc-shaped soundproof material was obtained by repeating the same operation as in Example 1 except that the mixture was mixed in 1 liter.
A test piece was cut out from the soundproofing material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.06 kg / m ² and the thickness remained at 30 mm by the above series of operations.

Example 4
Except that the basis weight of the prefabricated plate-shaped nonwoven fabric was 0.98 kg / m ^2, and 40 g of silicon dioxide particles having an average particle diameter of 40 nm in the suspension were mixed in 1 liter of water and mixed. The same operation as 1 was repeated to obtain a disk-shaped soundproof material.
A test piece was cut out from the soundproofing material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.03 kg / m ² and the thickness remained at 30 mm by the above series of operations.

(Example 5)
The basis weight of the prefabricated plate-like nonwoven fabric was 1.03 kg / m ² , 10 g of silicon dioxide particles having an average particle diameter of 40 nm in the suspension were mixed in 1 liter of water, and this suspension The same operation as in Example 1 was repeated except that 2 g of acrylic water-soluble resin (trade name “FIREX RC-104” manufactured by Meisei Chemical Co., Ltd.) was added to the liquid and blended. Soundproof material was obtained.
A test piece was cut out from the soundproofing material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.21 kg / m < ² > by the above series of operations, and the thickness remained at 30 mm.

(Example 6)
The basis weight of the prefabricated plate-shaped nonwoven fabric was 0.95 kg / m ^2, and 20 g of silicon dioxide particles having an average particle diameter of 25 μm in the suspension (trade name “MK20 / 250” manufactured by Kyoritsu Material Co., Ltd.) A disc-shaped soundproof material was obtained by repeating the same operation as in Example 1 except that the mixture was mixed with 1 liter of water, and 2 g of the acrylic water-soluble resin was added to the suspension. .
A test piece was cut out from the soundproofing material and evaluated. In addition, by the above series of operations, the fabric weight of the nonwoven fabric was 1.19 kg / m ² and the thickness was still 30 mm.

(Example 7)
The basis weight of the prefabricated plate-shaped nonwoven fabric was 1.02 kg / m ^2, and 10 g of activated carbon particles having an average particle diameter of 20 μm in the suspension (trade name “Shirakaba” manufactured by Nippon Enviro Chemicals Co., Ltd.) were added to water 1 The same operation as in Example 1 was repeated except that 2 g of an acrylic water-soluble resin was added to the suspension and blended with this suspension to obtain a disc-shaped soundproof material.
A test piece was cut out from the soundproofing material and evaluated. In addition, by the above series of operations, the fabric weight of the nonwoven fabric was 1.16 kg / m ² and the thickness was still 30 mm.

(Example 8)
Example 1 except that the basis weight of the prefabricated plate-shaped nonwoven fabric was 0.92 kg / m ^2, and 20 g of activated carbon particles having an average particle size of 20 μm were mixed in 1 liter of water in the suspension. The operation was repeated to obtain a disk-shaped soundproof material.
A test piece was cut out from this soundproof material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.28 kg / m < ² > by the above series of operations, and the thickness remained at 30 mm.

Example 9
The basis weight of the prefabricated plate-shaped nonwoven fabric was 0.98 kg / m ^2, and 20 g of activated carbon particles having an average particle diameter of 85 μm in the suspension (trade name “powder activated carbon” manufactured by Matsuo Pharmaceutical Co., Ltd.) were added to water 1 The same operation as in Example 1 was repeated except that 2 g of an acrylic water-soluble resin was added to the suspension and blended with this suspension to obtain a disc-shaped soundproof material.
A test piece was cut out from this soundproof material and evaluated. In addition, the fabric weight of the nonwoven fabric became 1.22 kg / m < ² > by the above series of operations, and the thickness remained at 30 mm.

(Comparative Example 1)
70% polyester fiber (fineness 12 denier, diameter: about 35 μm) and 30% polyester fiber (fineness 6 denier, diameter: about 25 μm) having a core / sheath structure as a low melting point fusion fiber were obtained. The mat was softened by heating with hot air, and then pressed to produce a plate-like nonwoven fabric having a weight per unit area of 0.95 kg / m ² and a thickness of 30 mm. A test piece was cut out from this nonwoven fabric and evaluated.

(Comparative Example 2)
The same operation as in Comparative Example 1 was repeated to produce a plate-shaped nonwoven fabric having a basis weight of 1.21 kg / m ² and a thickness of 30 mm. A test piece was cut out from this nonwoven fabric and evaluated.

(Comparative Example 3)
The same operation as in Comparative Example 1 was repeated to produce a plate-shaped nonwoven fabric having a weight per unit area of 1.50 kg / m ² and a thickness of 30 mm. A test piece was cut out from this nonwoven fabric and evaluated.

(Comparative Example 4)
The same operation as in Comparative Example 1 was repeated to produce a plate-shaped nonwoven fabric having a basis weight of 1.78 kg / m ² and a thickness of 30 mm. A test piece was cut out from this nonwoven fabric and evaluated.

(Evaluation methods)
(1) Evaluation of basis weight of soundproofing material The soundproofing materials of Examples 1 to 9 and Comparative Examples 1 to 4 were allowed to stand for 24 hours at 23 ° C. and 50% RH for normal adjustment, and then placed on an electronic balance to measure the weight. Then, two decimal places were recorded as significant figures and divided by the area of the flat portion to calculate the basis weight of the soundproof material.
In addition, for the increased basis weight due to the particle adhesion operation, the weight of the test piece before and after the particle adhesion operation is measured by the same method as described above, and the weight of the test piece before the particle adhesion operation is determined from the weight of the test piece after the particle adhesion operation. Was calculated by dividing by the area of the flat part.

(2) Sound absorption measurement Measurement was performed in accordance with JIS A1405 “Measurement of normal incident sound absorption of building materials by pipe method”. Samples with a sample size of φ90 mm are used for measurements in the measurement range of 100 to 1.25 Hz, and samples with a sample size of φ40 mm are used for measurements with a measurement range of 1.6 to 5.0 kHz. The sound absorption coefficient of was displayed. As a reference, the sound absorption performance difference when the measurement result of Comparative Example 1 was used as a reference (0) was also calculated.

(3) Sound insulation measurement Measurement was performed in accordance with JIS A1416 "Measurement method of sound transmission loss in a laboratory". A simple reverberation box was used for the measurement. The measurement results were averaged in the range of 250 Hz to 4 kHz. For reference, the difference when the measurement result of Comparative Example 1 was used as the reference (0) was also calculated.

(4) Average particle diameter The particles used were observed with an optical microscope or an electron microscope, the average projected area of the particles was measured using the photographed image, and the diameter when converted into a circle was calculated as the average particle diameter. .
The results obtained in Examples 1 to 9 and Comparative Examples 1 to 4 are shown in Tables 1 to 3, respectively.

It is a scanning electron microscope image (magnification 500 times) which shows the particle | grains adhering to the fiber obtained by observing the test piece of Example 3, and the fiber surface. It is a scanning electron microscope image (500-times multiplication factor) which shows the fiber and fiber surface which were obtained by observing the test piece of the comparative example 1.

Claims (7)

A soundproofing material composed of a fiber structure,
The soundproofing material, wherein the fiber structure is made of a fiber base and fine powder particles around the fiber base.   A soundproof fiber obtained by surrounding fine particles on the surface of the fiber is made into a nonwoven fabric by at least one method selected from the group consisting of a mechanical bonding method, an adhesion method, a fusion method, and a wet method, and the nonwoven fabric The soundproofing material according to claim 1, wherein the soundproofing material is a fiber structure.   The fiber was made into a non-woven fabric by at least one method selected from the group consisting of a mechanical bonding method, an adhesion method, a fusion method and a wet method, and obtained by surrounding the fine particles on the surface of the non-woven fabric. The soundproof material according to claim 1.   The soundproof material according to any one of claims 1 to 3, wherein the fine powder is an inorganic substance.   The soundproof material according to any one of claims 1 to 4, wherein the fine particles are silicon dioxide and / or activated carbon.   The soundproof material according to any one of claims 1 to 5, wherein the fine particles have an average particle diameter of 0.1 nm to 100 µm.   The soundproof material according to any one of claims 1 to 6, wherein the fine powder particles are circumferentially attached via a yield improver.

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