JP3494332B2 - Soundproofing material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for sound absorption, sound insulation and the like. In particular, construction materials, civil engineering materials, aviation /
The present invention relates to materials such as sound absorbing and sound absorbing materials such as materials for vehicles and ships, and acoustic materials. 2. Description of the Related Art Generally, recycled felts are used as soundproofing materials.
Foamed polyurethane, foamed polyethylene and the like are used. These soundproofing materials can improve the soundproofing performance by increasing the basis weight, that is, increasing the weight. However, raising the weight increases the cost, and the weight increase goes against the demand for lighter, lighter and smaller in the age. In recent years, proposals have been made to use nonwoven fabrics as soundproofing materials instead of recycled felts. For example, Japanese Unexamined Patent Publication No. 7-97754 discloses that the fiber is made of a polyester fiber having a fiber diameter of 4 denier or less and has a spring constant of 80000 N / m.
The following nonwoven fabrics have been proposed. The spring constant correlates with the fiber diameter, and it is said that the use of a soundproofing material having a small fiber diameter improves the soundproofing performance. However, microfiber woven fabrics having a very small fiber diameter are not so excellent in soundproofing. Microfiber woven fabric alone has little sound insulation. Simply having a small fiber diameter does not improve soundproofing. SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive lightweight soundproofing material having excellent sound absorbing and sound insulating properties. The inventors of the present invention have studied various surface materials of the soundproofing material, and have found that the structure of the surface material in the sound incident direction has a great influence on sound absorption and sound insulation. I found it. In addition, as a result of further research, the pore diameter of the surface material has a large effect on sound absorption and sound insulation, and in particular, the number of holes with a hole area of 2000 μm ² or less per unit area has a large effect on sound absorption and sound insulation. It is clear that [0006] The present invention is a soundproof material having a porous layer having area of 2000 .mu.m ² below hole 200 / cm ² or more. If the number of holes is less than 200 / cm ² , the soundproof effect is poor. Preferably, the number is 1000 / cm ² or more. Also,
More preferably, the small holes, that is, the hole area is 1000 μm
² or less and the number is 200 pieces / cm ² or more. More preferably, the number is 500 / cm ² or more. [0007] The porous layer is a non-woven fabric, cloth, sponge, resin layer
And a combination thereof. When the nonwoven fabric or fabric is made of microfibers and has a high density, the interfiber gap can be reduced. These gaps correspond to holes in the present invention. The holes in this case are actually communicating. In addition, when each communicating part is taken, its sectional area is often not uniform. In the case of a communicating hole, if the cross-sectional area of the hole is partially smaller than the area defined above, it is calculated as one hole. In the present invention, pores on the surface of the porous layer are measured and used as representative values of the pores on the porous layer. The area and the number of holes were obtained by analyzing data input by a stereoscopic microscope with an image analyzer.
The image analysis software used was V10 manufactured by Toyobo Co., Ltd. The area of the holes was counted for every 500 μm ² such as 0 to 500 and 501 to 1000. In the case of a sponge, the holes are often independent. The independent holes are more preferable for soundproofing than the case where they are connected. Examples of sponge materials include polymers such as polyurethane, polyethylene, polystyrene, polyvinyl alcohol, polyvinyl acetate, and polyvinyl chloride.
There is a foam. [0010] Further, even if the diameter of the hole of the nonwoven fabric or the cloth itself is large, the hole can be closed and closed with an appropriate resin or the like. A porous layer formed in this way can also be used. The type of the resin referred to here is not particularly limited. Natural materials starch, modified starch, hemicellulose,
There are cellulose and polysaccharides, and proteins (eg, collagen, sericin, chitin) and the like. Further, there is a synthetic resin. For example, (meth) acrylic, vinyl acetate, vinyl chloride, ethylene, propylene, styrene, isoprene, chloroprene, butadiene, maleic acid, fumaric acid, polymers of (meth) acrylic acid and its esters and amides, and copolymers thereof. And nylon resin, polyester resin, polyurethane resin, epoxy resin, phenol resin and the like. The above resin can be applied to a nonwoven fabric or a fabric by a spray method, an impregnation method, a coating method, or the like. If the viscosity of the resin at the time of application is large, it is difficult to form holes. The lower the viscosity of the resin, the better. As the viscosity of the resin decreases, the amount of adhesion decreases, and it may be necessary to apply the resin in several degrees. It is economically undesirable to repeat the application, so it is necessary to select an appropriate viscosity. The resin may be a solution, an emulsion, or a melt. Among them, an emulsion having a small viscosity is preferable for the concentration. In the same sense, it is preferable that the molecular weight of the above resin is as small as possible without a problem in strength. The ease with which holes are formed also depends on the thickness of the fibers constituting the nonwoven fabric or the fabric. In other words, the thinner the constituent fibers are, the easier the resin adheres. Therefore, it is preferable because the viscosity of the resin can be reduced and holes are easily formed. The same is true for fiber wetting. That is, it is preferable to select a fiber oil agent that is easily wetted. In the case of a fabric, similar considerations are preferable for the knitting and weaving structures. A small hole can be formed in the film or resin by a known mechanical or electrical method, and such a processing method may be employed. However, it is not economically advantageous. If the porous layer is made of the nonwoven fabric itself and is not processed, the diameter of the pores will not be reduced unless the fiber diameters of the fibers constituting the nonwoven fabric are small, and no improvement in sound absorbing performance can be expected. At least the single fiber diameter of the fiber is 1
0 μm or less. Preferably it is 5 μm or less, more preferably 3 μm or less. As a method for producing a nonwoven fabric having a small fiber diameter, there is a melt blow method, and products such as polypropylene, polyethylene, polyester, and polyurethane are already commercially available. These are commercially available in a form laminated with a spunbonded nonwoven fabric, for example, commonly known as SMS. A non-woven fabric using split fibers can also produce a non-woven fabric having a small fiber diameter, and can be used as a porous layer. In this case, there is a method in which a nonwoven fabric is produced and then divided by chemical or heat treatment, and a method in which a nonwoven fabric is produced and divided at the same time by spunlace. [0017] A thermally bonded nonwoven fabric containing thermally fusible fibers can also be used as the porous layer. The fiber gap is crushed by the heat fusion, and the same effect as the resin processing can be obtained. The mixing ratio of the heat-fused fiber is preferably 50% by weight or more,
70% by weight or more is more preferable. More preferably 100
% By weight. Heat-fused fibers are already commercially available, and side-by-side and core-sheath heat-fusible fibers are often used. These are fibers in which polymers having different melting points are combined, and the melting points are different depending on the type of the polymer. 110, 13
There are also heat-fused fibers having low melting points of 0, 150, 170, and 200 ° C. As the type of polymer, polyolefin, copolymerized polyester, nylon and modified products thereof are often used as low melting point polymers. As the high melting point polymer, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon 6,
Nylon 66 and the like are often used. As the denier of the heat-fused fiber, 2 denier is usually used in many cases, but it is preferable that the fiber diameter is smaller because the fiber gap is smaller. If fibers other than the heat-fusible fibers are made of a polymer similar to the sheath component of the heat-fusible fibers, the number of bonding points increases, and the bonding effect is increased. As general synthetic fibers, for example, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, etc., as regenerated fibers, for example, viscose rayon,
As natural fibers such as acetate, there are, for example, cotton, hemp, wool, silk, and the like. The method for producing the above nonwoven fabric is, for example, a card,
A manufacturing method using cross lay, draw, and needle punch may be used. Alternatively, a manufacturing method using a random card or a needle punch may be used. In the present invention, these nonwoven fabrics can be used as a porous layer. The split fibers include a composite type, a multilayer type, and the like, which are composed of a component that separates, such as a sea-island type or a star shape, and a component that is divided into small portions. For example, there is a composite fiber in which the separating polymer is nylon 6 and the polymer to be split is polyethylene terephthalate. In recent years, in addition to nonwoven fabrics, multifilaments have recently been developed, and knitted fabrics composed of multifilaments having a small single fiber diameter are commercially available. Such a knitted fabric can also be used as a porous layer. In the case of ultra-fine fibers, denier of single fiber is manufactured up to about 0.5 denier. In the case of polyester, the fiber diameter is about 6 μm. Because of the multifilament, the weaving process is technically well established. Also, split fibers can be used in the same manner as nonwoven fabrics. A woven fabric having a higher density than a knitted fabric is preferred. The woven structure includes plain weave and twill weave, but a dense structure is preferable. The above-mentioned porous layer is preferably a dense layer because the pore size is small. Therefore, a higher density is preferable. That is, it is preferable to increase the density of the nonwoven fabric by embossing, calendering, or the like. The knitted fabric also preferably has a dense structure, and the density is preferably increased by embossing, calendering, or the like. The density of the porous layer is 0.1 g
/ Cm ³ or more, preferably 0.3 g / cm ³ or more, more preferably 0.5 g / cm ³ or more. The basis weight of the porous layer must be 20 g / m ² or more.
And more preferably 50 g / m ² . If the basis weight of the porous layer is less than 20 g / m ² , the improvement in the soundproofing effect of the soundproofing material cannot be expected to be large. The soundproofing material of the present invention comprises the above-described porous layer and the porous layer described below. For the porous layer, foamed polyurethane, foamed polyethylene, non-woven fabric and the like can be used. Also, a combination of these may be used. Foamed polyurethane foam or polyethylene foam is preferable because closed cells have better sound absorption and sound insulation performance than open cells. Levels and required performance soundproofing products varies depending soundproofing porous layer itself, the porous layer is sound absorbing performance if there is 5 g / m ² or more basis weight in the case of spongy alone can exert. Preferably it is 10 g / m ² or more. In the case of a nonwoven fabric layer alone, 300 g / m ²
Above, preferably 500 g / m ² or more. That is, since the effect of the present invention is improved in proportion to the sound absorption of the porous layer, if the single sound absorption of the porous layer is too small, the absolute value of the improvement of the sound absorption does not increase. However, the effects of the present invention cannot be sufficiently exhibited. 2kHz
The sound absorption coefficient is dramatically increased by laminating the porous layer having a sound absorption coefficient of 10% or more and the soundproofing material of the present invention. Therefore, the sound absorption coefficient of 10% or more alone is preferable for the porous layer, more preferably 25% or more, more preferably 40% or more.
%, It is preferable to use a porous layer having a sound absorption coefficient of not less than%. Further, it is preferable that the porous layer has low air permeability in order to improve the sound absorption coefficient. The porous layer has a density of 0.001 to 0.1 g /
cm ³ is preferred. As the density increases, the soundproofing performance tends to decrease. The density here means the apparent density. If the density is too high, the soundproofing is not improved for the basis weight and the cost increases. If the density is too low, the mechanical properties are reduced, and it is generally difficult to use. A feature of the present invention is that the soundproofing performance is remarkably improved by laminating the above porous layers. When using the soundproofing material of the present invention, it is necessary to use the porous layer facing the sound source. Therefore, back and front and 2
When there is a possibility that the sound source exists in the direction, it is preferable to laminate the porous layers on both sides of the porous layer. The lamination of the porous layer and the porous layer may be performed by using an adhesive. The effect of the present invention can be obtained by simply laminating. Examples of the adhesive include general emulsion type adhesives, for example, acrylic, eva, poval, and polyurethane adhesives. Also, a hot melt type adhesive can be used. There are polyester type, eva type and the like. Also, spray polyethylene powder, etc.,
Bonding can also be performed by heat treatment. Binder fibers can be used for the porous layer and the porous layer, and bonded by heat treatment. The porous layer and the porous layer may be held by another support and laminated mechanically. For example, when stored in a frame and laminated, or when laid on the floor, it is mechanically laminated, so it functions as the textile of the present invention without using an adhesive. be able to. Further, they may be bonded by needle punching. The soundproofing material of the present invention can be used in combination with other soundproofing materials. In addition, a film can be laminated and used in combination with the porous layer. It can also be used by sandwiching a film between a porous layer and a porous layer. When the soundproofing material is laminated in two or more layers, the effect of the porous layer can improve the soundproofing effect of the subsequent porous layer. Depending on the application, decorations such as coloring, embossing, patterning, and border decoration can be added. Moreover,
Performances such as deodorization, antibacterial deodorization, fragrance, mold prevention, and flame retardancy can be added by a known method. The soundproofing material of the present invention is particularly excellent in sound absorption in a high frequency range. Among them, it is excellent in sound absorption in a high frequency region of 500 Hz or more. In the present invention, the sound absorption was compared at 2 kHz as a representative value. The sound absorption was measured at 2 kHz with a sound absorption measurement device manufactured by Matsushita Intertechno Co., Ltd. In principle, it is a two-microphone system, but JIS-
This is based on the measurement of the normal incidence sound absorption coefficient similar to that of A1405. The soundproofing material of the present invention can be applied to light-weight textile products, and can provide rich design and drape properties. Can be granted. Also, it can be used as wallpaper and ceiling material in the same manner. These products are often required to have flame retardancy, but flame retardancy can be easily imparted by using a flame retardant material for the fiber material or by performing flame retardant processing. Further, it can be used as a part of a floor material and an inner material of a wall. Furthermore, it can be used as a sound-absorbing material for acoustic equipment, for automobiles, ships, and aircraft soundproof interior materials, and as a part thereof. Example 1 A plain dyed twill woven fabric (perforated layer 1, 2000 μm ² or less, made of Kanebo Co., Ltd., 100% split fiber Verima X, having a basis weight of 50 g / m ² and a density of 0.5 g / cm ³ ) 1, 5 holes
20, the number of 1000 .mu.m ² below holes 680 pieces / cm
² ) and a printed plain fabric having a density of 0.55 g / cm ³ (porous layer ² , the number of holes having 2000 μm ² or less is 1,760,
The density is 0.04 g / cm ³ , the thickness is 5 mm, and the basis weight is 20 while the number of pores having a size of 1000 μm ² or less is 720 / cm ² ).
A curtain, which is a soundproofing material of the present invention, was produced by sandwiching a foamed polyethylene (porous layer) of 0 g / m ² and a reactive crosslinkable polyurethane adhesive at an adhesion amount of 2 g / m ² . The sound absorption coefficients of the porous layers 1 and 2 and the porous layer alone were 3%, 3% and 38%, respectively. When the sound source was placed on the side of the twill fabric (porous layer 1) of the soundproofing material of the present invention in which these were laminated, the sound absorption coefficient was 81%. Also. The sound absorption coefficient when the sound source was placed on the plain fabric side (porous layer 2) was 79%. Example 2 Polypropylene melt-blown nonwoven fabric having a basis weight of 25 g / m ² and a single fiber diameter of 1 to 5 μm (porous layer, 2,230 pores of 2000 μm ² or less, 830 pores of 1000 μm ² or less) / Cm ² ) and a density of 0.04 g / c
A foamed polyurethane (porous layer) having an m ³ thickness of 9 mm and a basis weight of 360 g / m ² is adhered using a reactive cross-linkable polyurethane adhesive at an adhesion amount of 2 g / m ² to provide a sound-absorbing fiber product of the present invention. A curtain was manufactured. The sound absorption coefficients of the porous layer and the porous layer alone were 2% and 42%, respectively. The sound absorption coefficient measured by placing a sound source on the porous layer side of the soundproofing material of the present invention in which these were laminated was 88%. The sound absorption coefficient measured with the sound source placed on the porous layer side was 42%. Example 3 In the same manner as in Example 2, a porous layer was prepared by mixing 80% by weight of Polysil SD 1.4d, manufactured by Kanebo Co., Ltd., 51% by weight, and 2% by weight, 2 mm of Belcombi 2%, by fusion bonding, and carding and laminating. 1cm in thickness and compression thermoformed
00 g / m ² , density 0.05 g / cm ³ , sound absorption 33%
And the soundproofing material of the present invention was manufactured. The sound absorbing material of the present invention had a sound absorption of 66%. Example 4 In the same manner as in Example 2, only the sound absorption coefficient of the porous layer was changed by changing the density of foamed polyurethane, the size of cells, and the basis weight to produce a soundproofing material, and the sound absorption coefficient was measured. did. The results are shown in Table 1. [Table 1] Example 5 In the same manner as in Example 2, only the diameter of the single fiber of the polypropylene melt-blown nonwoven fabric (porous layer) was changed to change the distribution of pores, thereby producing a soundproofing material. The sound absorption coefficient was measured and the results are shown in Table 2. The single fiber diameter is an average value obtained by taking an SEM photograph and measuring the diameter. The number of holes is the number of holes of 2000 μm ² or less / cm ² . [Table 2] Example 6 An acrylic resin (acrylonitrile / methyl acrylate = 70: 30 weight ratio) was applied to the surface of the porous layer of Example 3 by spraying to form a porous layer of acrylic resin having a basis weight of 50 g / m ^2. did. This porous layer had 1,210 holes with 2000 μm ² or less and 530 holes / cm ² with 1000 μm ² or less. The sound absorbing material has a sound absorption of 8
3%. Example 7 In the same manner as in Example 2, the porous layer was coated with a commercially available basis weight of 50 g /
m ² , fiber diameter 20-30 μm, density 0.05 g / c
m ^3, the thickness is changed to a polypropylene spunbond 1 mm, were prepared two kinds of soundproofing materials untreated and those impregnated with phenolic resin emulsion in the same manner as in Example 6. The untreated porous layer had 110 holes of 2000 μm ² or less and 8 holes / c of 1000 μm ² or less.
m ² . The sound absorbing material of this reference example has a sound absorption of 42%.
Met. The resin-processed porous layer has a thickness of 2000 μm ²
The number of holes below was 310, and the number of holes below 1000 μm ² was 212 / cm ² . The sound absorbing material had a sound absorption rate of 52%. Example 8 In the same manner as in Example 7, the concentration of the phenol resin emulsion was changed to change the viscosity,
^The sound absorption coefficient was measured by changing the number 1 of the holes of ² or less and the number 2 of the holes of 1000 μm ² or less. Table 3 shows the results. 2
000Myuemu ² The following number of the number of 1000 .mu.m ² or less of the pores of the pores is correlated, and a viscosity of greater many number of 2000 .mu.m ² following holes, reduces the number of 1000 .mu.m ² following hole, 1000 .mu.m ² following The larger the number of holes, the better the sound absorption coefficient. [Table 3]

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-7-229049 (JP, A)                 JP-A-58-64290 (JP, A)                 JP-A-7-324400 (JP, A)                 JP-A-8-13764 (JP, A)                 Actual opening Hei 5-16964 (JP, U)

Claims (1)

(57) [Claims 1] Foamed polyurethane, foamed polyethylene,
A porous layer selected from a nonwoven fabric and a combination thereof, a basis weight of 20 g / m ² or more, and an area of 200 g / m ² or more;
Nonwoven having 0 .mu.m ² below hole 200 / cm ² or more, a fabric, a sponge, a resin layer and a porous layer formed is selected from these combinations are laminated, porous layer, the input of the sound
Soundproofing material near the launch surface .