JPH1161616A - Sound insulating laminated material and double-wall sound insulating structural material containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a sound insulating laminated material having excellent sound insulating property in a low frequency region and useful for an automotive, etc., by containing respectively specific high-density nonwoven fabric layer and low-density one and having a prescribed air permeable amount. SOLUTION: This sound insulating laminated material contains a high-density nonwoven fabric layer 4 and a low-density nonwoven fabric layer 3, respectively composed of thermoplastic synthetic fibers having 20-200 μm fiber diameter and 30-100 mm fiber length. The high-density layer 4 is composed of <=80 wt.% of high-softening point fibers (A) and >=20 wt.% of low-softening point fibers (B) having a softening point >=20 deg.C lower than a softening point of the fiber A and has 0.1-1.0 kg/cm<2> surface density, 1-10 mm thickness and 1,200-3,700 cc/cm<2> .min air permeability under 0.01 kg/cm<2> air pressure. The low-density layer 3 is composed of 70-90 wt.% of high- softening point fibers (C) and 10-30 wt.% of low-softening point fibers (B') having a softening point >=20 deg.C lower than a softening point of the fiber C and has 0.4-2.0 kg/cm<2> surface density, 15-50 mm thickness and 1,500-4,000 cc/cm<2> .min air permeability under 0.01 kg/cm<2> air pressure, and a difference of air permeability between the two layers 3 and 4 under 0.01 kg/cm<2> air pressure is 300-2,800 cc.cm<2> .min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-walled sound insulation structure installed to prevent external vibration and / or noise from entering, and more particularly to vibration and noise from floor steel plates of automobiles. Suitable for floor insulator carpets etc. installed to prevent / block noise. Further, the sound insulating laminate of the present invention is one in which air permeability is particularly controlled in order to improve sound insulating performance in a low frequency region.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a floor insulator for an automobile has a sound insulation laminate 2 located on the interior side of a floor panel 1 which partitions the interior of the automobile from the outside, so that noise from the exterior to the interior of the automobile is reduced. Has the role of preventing transmission. As shown in the figure, a conventional sound insulating laminate 2 includes a low-density layer 3 made of a porous base material such as felt, polyurethane foam, or nonwoven fabric.
And a high-density layer 4 formed of a material having no air permeability such as an EVA material sheet or a polyethylene sheet mixed with a filler.
Is composed of a laminate. The low-density layer 3 absorbs noise from outside the vehicle, and the floor panel 1
By forming a double-walled sound insulation structure in which the low-density layer 3 is interposed between the high-density layer 4 and the high-density layer 4, it is configured to exhibit good sound insulation performance in addition to the sound insulation effect. 5 is a carpet skin.

[0003]

In such a conventional double-walled sound insulating structure of a floor insulator, the high-density layer 4 does not have air permeability, so that it has excellent sound insulating performance in a high frequency range. In the low-frequency range, which is important for the sound insulation performance of automotive floor components, the performance is reduced near the resonance point, and the sound transmission loss (TL) determined by the mass of the entire laminate is superior to the sound insulation level of the mass rule. The nature is small.

[0004] The present invention has been made in view of such circumstances, and in a sound-insulating laminate made of a molded article, the performance near the resonance point is improved by controlling the air permeability. It is another object of the present invention to provide a sound insulating laminate having improved sound insulating performance in a low frequency range.

[0005]

The object of the present invention is to provide a high-density nonwoven fabric layer (1) and a low-density nonwoven fabric layer (2) each composed of thermoplastic synthetic fibers having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm. Wherein the high-density nonwoven fabric layer (1) has a high softening point fiber (fiber A) of at most 80% by weight and a low softening point having a softening point at least 20 ° C. lower than the softening point of the fiber A. Fiber (fiber B) at least 20% by weight, has an area density (basis weight) of 0.1 to 1.0 kg / cm ² , a thickness of 1 to 10 mm, and an air pressure of 0.01 kg / cm ² . Aeration rate of 1200-37
00 cc / cm ² · min. The low-density nonwoven fabric layer (2) has a high softening point fiber (fiber C) of 70 to 90% by weight,
Low softening point fiber (fiber B ′) having a softening point at least 20 ° C. lower than the softening point of the fiber C (10 to 30% by weight), an area density of 0.4 to 2.0 kg / cm ² ,
Having a thickness of 50 mm and an air pressure of 0.01 kg / c
The air flow rate in m ² is 1500 to 4000 cc / cm ²
-Min. And the air pressure of the two layers is 0.01 kg / c.
The difference in air flow rate in m ² is 300 to 2800 cc / cm
² min. This is achieved by the sound insulating laminate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION To improve the sound insulation performance by attaching the sound insulation laminate of the present invention to an external partition, for example, the interior side of an automobile floor panel, first, the high-density nonwoven fabric layer is It is effective to control and reduce the amount of ventilation to a required amount. The air permeability of the non-woven fabric layer depends on various factors such as the density of the layer determined by its surface density and thickness, the fiber diameter of the constituent fibers, and the fiber cross-sectional shape. Reducing the average diameter of the fibers to be formed is extremely effective in reducing air permeability. However, relying on mere increase in density leads to an increase in overall weight, which is disadvantageous in that it is not suitable for mounting on a vehicle, but also increases material costs.

Second, it is necessary that the outer partition walls and the high-density nonwoven fabric layer form a double-walled sound insulation structure via the low-density nonwoven fabric layer. It is already known that forming a double-walled sound insulation structure increases the effect of improving sound insulation performance. However, even in such a double-walled sound insulation structure, in order to further improve the sound insulation performance while avoiding the disadvantages such as the increase in weight described above, it is necessary to perform operations such as fiber blending, surface density, and thickness to improve the air permeability, rigidity, and the like. It is desirable to appropriately control the physical properties of the material. Therefore, the laminated body for sound insulation of the present invention, the air permeability of the high-density nonwoven fabric layer of the above-described constituent fibers, so that a double-walled sound insulation structure showing excellent sound insulation performance with the external partition can be formed. It is ideal to control the blending, the areal density and the thickness in a suitable range mainly by selecting the thickness.

Third, the airflow resistance, which is an index of air permeability, is:
It changes depending on the fiber diameter, area density and thickness.

[0009] Fourth, the sound insulation performance improves as the vibration transmission rate decreases. Here, the vibration transmissibility greatly depends on the dynamic spring constant of the object. Therefore, it is necessary to reduce the dynamic spring constant to improve the sound insulation performance. The spring constant changes depending on the fiber diameter.

Fifth, the higher the sound absorption coefficient of the low-density nonwoven fabric layer, the better the sound insulation performance. Sound absorption is the density of the layer determined by the surface density and thickness of the nonwoven fabric layer, the fiber diameter of the constituent fibers,
Although it depends on various factors such as the cross-sectional shape of the fiber, increasing the surface density and reducing the average diameter of the fibers constituting the nonwoven fabric are extremely effective for improving the sound absorption coefficient. However, relying on mere increase in density leads to an increase in overall weight, which is disadvantageous in that it is not suitable for mounting on a vehicle, but also increases material costs.

[0011] The present invention also provides a sound insulation laminated structure in which a low-density nonwoven fabric layer is sandwiched between an external partition and a high-density nonwoven fabric layer. By forming the sound insulation structure and arbitrarily shifting this resonance point to a lower frequency side, the entire sound insulation performance curve with respect to the frequency can be shifted to the lower frequency side to improve the performance. That is, the fiber composition, density,
Air permeability, rigidity, elastic modulus, tensile strength and spring hardness, as well as fiber composition, thickness, density,
The primary resonance frequency can be set to an arbitrary frequency of 50 to 300 Hz by manipulating the dynamic spring constant and the air flow rate.

In order to improve the sound insulation performance, it is necessary to form a double-walled sound insulation laminate by using the sound insulation laminate and an external partition. However, as a characteristic when the double-walled sound insulation structure is formed, a resonance phenomenon occurs at a certain frequency on the sound insulation performance curve. At this time, if the resonance point is shifted to a lower frequency side, the entire sound insulation performance curve with respect to the frequency is shifted to the lower frequency side, so that the performance can be improved. According to the present invention, the resonance point can be set arbitrarily, thereby achieving the goal of improving the sound insulation performance.

The primary resonance frequency (f) of a double-walled sound insulation structure having a low-density nonwoven fabric layer as an intermediate layer is generally approximated by the following equation (1).

F = 1 / 2π · [{(m ₁ + m ₂ ) / m ₁ · m ₂ } · E / d] _1/2 (1) where m ₁ and m ₂ are the outer partition and the high density The areal density of each nonwoven fabric layer, E is the Young's modulus of the low density nonwoven fabric layer, d is the thickness of the low density nonwoven fabric layer, and the Young's modulus is calculated from the elastic modulus and the like.

However, since the double-walled sound insulation structure constituted by the present invention does not form a complete double-walled structure, (1)
The primary resonance frequency cannot be determined only by the equation. Therefore, as a specific means for arbitrarily setting the resonance point, especially for setting to a low frequency, the fiber blending of the high-density nonwoven fabric layer within the above range,
Manipulating density, controlling air flow, manipulating stiffness, modulus, tensile strength, spring hardness, manipulating fiber composition and density of low-density nonwoven layer, increasing thickness, controlling air flow A method of reducing the dynamic spring constant is effective. Performing all of these at the same time enables more precise resonance point setting, but is not particularly limited.

In the sound insulation laminate of the present invention, the primary resonance frequency is preferably set to a frequency of 50 to 300 Hz.
If the resonance point is set to a frequency higher than 300 Hz, the sound insulation performance is reduced in a low frequency range of 1 kHz or less, and the object cannot be achieved. Setting the resonance point at less than 50 Hz is not preferable because the effect of the density increase particularly in the above operation increases the weight.

Next, comparison of sound insulation performance with the mass law will be described. In the double-walled sound-insulating structure using the sound-insulating structure of the present invention, the double-walled sound-insulating structure for the sound insulation level of the mass rule of sound transmission loss (TL) determined by the mass of the entire sound-insulating laminate. In the frequency range of 300 Hz to 1 kHz, the sound transmission loss is 1 to 3 dB on the average frequency.
improves.

The mass of the entire sound insulation laminate constituting the sound insulation structure is one of the factors that determine the sound insulation performance. The mass rule is that the sound insulation performance for each frequency is determined by the mass of the sound insulation laminate. However, when the sound insulation laminate forms a double-walled sound insulation structure together with the external partition, as described above, the sound insulation performance falls below the mass law in the resonance region, but exceeds the mass law in other regions. Therefore, by forming a double-walled sound insulation structure and operating the resonance point as described above, it is possible to improve the sound insulation performance in an arbitrary frequency region. By using the above means, the sound insulation laminate of the present invention can exceed the sound insulation level of the mass rule of sound transmission loss (TL) by 1 to 3 dB in the frequency range of 300 Hz to 1 kHz.

From the above viewpoints, first, the areal density of the entire laminate is preferably in the range of 0.5 to 3.0 kg / m ² . In order to ensure sound insulation performance, the surface density of the laminate is preferably as high as possible, but if it exceeds 3.0 kg / m ² , it is not preferable because it is too heavy for practical use. If the areal density is less than 0.5 kg / m ^2, it is difficult to achieve the purpose of improving sound insulation performance such as sound absorption performance, which is not preferable.

The thickness of the entire laminate is preferably in the range of 16 to 60 mm. If the area density is less than 16 mm in the above range, the air permeability becomes too small, and it is difficult to obtain sufficient sound insulation performance near the resonance point, especially in a low frequency region. The thickness is preferably as large as possible to improve the sound absorbing performance. However, if the thickness exceeds 60 mm, it is not preferable from the viewpoint of securing a space for practical use.

In order to impart sufficient sound insulation performance to the laminate,
The high-density nonwoven fabric layer secures the ventilation resistance required for forming the outer partition and the double-walled sound insulating structure, and controls the low-density nonwoven fabric layer to the ventilation resistance necessary for improving its sound absorption coefficient and reducing the spring constant. I need to do that. For this purpose, the difference in air permeability between the high-density non-woven fabric layer and the low-density non-woven fabric layer is determined by using an air pressure of 0.01 kg /
In cm ² 300~2800cc / cm ² · mi
n. Must be within the range. Aeration difference is 300
cc / cm ² · min. If it is less than the above, the structure becomes substantially the same as the single-layer structure, and the double-wall sound insulation structure is not formed. The difference in the amount of ventilation is 2800 cc / cm ² · min. If the ratio exceeds, the target of the sound insulation performance of the low-density nonwoven fabric layer cannot be achieved.

The amount of ventilation varies depending on the fiber diameter of the constituent fibers, the surface density and the thickness of the laminate. The smaller the fiber diameter,
That is, as the fiber surface area in the nonwoven fabric increases, the airflow resistance increases and the airflow decreases. However, fine denier fibers are expensive and have poor carding characteristics, making it difficult to form a nonwoven fabric. In addition, the number of fibers relatively increases under a constant surface density, and the mechanical strength increases, so that the fibers have a low mechanical strength in the low frequency range. Cannot achieve the target of sound insulation performance. In particular, fine denier fibers having a fiber diameter of less than 20 μm are difficult to manufacture technically, so that stable supply is difficult and cost increases, and it is difficult to mix with other fibers to obtain a uniform nonwoven fabric. Not preferred. On the other hand, if the fiber diameter exceeds 200 μm, sufficient airflow resistance cannot be obtained, and it is difficult to improve sound insulation performance.

The fiber length of the constituent fibers is from 30 to 30 from the viewpoints of controlling the air permeability of the nonwoven fabric, affecting the surface area of the fiber, improving the workability during production of the nonwoven fabric, such as carding characteristics, and improving the mechanical strength of the nonwoven fabric. It needs to be 100 mm. If the fiber length is less than 30 mm, the workability during the production of the nonwoven fabric is inferior.
If it exceeds 0 mm, it will be difficult to uniformly disperse it in the nonwoven fabric, and it will be difficult to form a nonwoven fabric layer of good and uniform quality.

As the thermoplastic synthetic fiber, polyester is suitable in terms of flowability, mechanical strength, rigidity and the like, and has high cost performance. However, polyamide-based polyamides such as nylon, polyvinyl-based polymers such as polyacrylonitrile, and polyethylene, a fiber-forming synthetic polymer such as polyolefins such as polypropylene or semi-synthetic polymers such as cellulose acetate can also be used. By producing the fiber and converting it into a nonwoven fabric, a material having substantially the same airflow resistance can be obtained.

Therefore, the high density nonwoven fabric layer will be described. The high-density nonwoven fabric layer comprises a fiber-forming linear polymer, preferably at most 80% by weight of a high softening point fiber (fiber A) having a fiber diameter of 25 to 200 μm, and a softening at least 20 ° C. lower than the softening point of the fiber A. Fiber diameter with points 20 to 200
It comprises at least 20% by weight of low softening point fibers (fiber B, hereinafter also referred to as binder fibers) of μm. Here, the high softening point fiber diameter is particularly preferably at least 25 μm. The smaller the fiber, the more difficult it is to operate the joint,
This is because it is difficult to control the mechanical strength. Also,
The fiber diameter must be less than 200 μm. Thicker fibers are unsuitable for obtaining the required airflow resistance. On the other hand, if the high softening point fiber A exceeds 80% by weight, it is difficult to control the thickness of the sound absorbing material, so that a sufficient density cannot be secured and the object cannot be achieved.

The high softening point fiber A is preferably a substantially homopolymer, and typically comprises a high melting point polyester having polyethylene terephthalate as a main component. The cross-sectional shape of the fiber may be circular or non-circular (irregular). The modified cross-section fibers further contribute to an increase in airflow resistance.

The low softening point fiber B has a fiber diameter of 20 to 200 μm.
m, a fiber having a fiber length of 30 to 100 mm and a high softening point fiber A
It is a fiber having a lower softening point of at least 20 ° C, and is blended in the high-density nonwoven fabric layer at a ratio of 20 to 100% by weight. The low softening point fiber B softens as a binder fiber by heat treatment and exhibits adhesiveness to the fiber A,
When the polymer having an affinity for the fiber A, for example, the fiber A is a homopolyester-based polymer fiber, the binder fiber is also made of polyester by copolymerizing or blending another dibasic acid component and / or a glycol component. Low softening point fibers composed of a modified or reduced softening point copolymer or blend polymer are preferably used.
More preferably, it is a core-sheath type or side-by-side type conjugate fiber conjugated with a homopolymer component having a high softening point such that at least a part of such a copolymer or blend polymer component is exposed on the fiber surface. . In such conjugate fibers, the high softening point component does not soften or melt, and performs a supporting function while the low softening point component controls the adhesive function.

When the blending amount of the low softening point fiber B is less than 20% by weight based on the weight of the high density nonwoven fabric layer, similarly, sufficient moldability cannot be imparted to the high density nonwoven fabric layer due to a decrease in the number of bonding points. The blending of the low softening point fiber B means that it is somewhat necessary to blend a fiber capable of imparting moldability into the high-density nonwoven fabric layer. The sound insulation laminate has a large factor in improving performance due to its adhesion to a portion where sound insulation is required, and it is necessary that the nonwoven fabric can be formed so as to follow various surface shapes. The use of the above-mentioned short fibers improves followability, but in order to maintain the shape, blending of binder fibers is required. At the time of heat molding, the binder fibers are softened while the fibers A are constrained in the shape of the mold, and the fibers adhere to each other, so that a fine surface shape can be maintained.

At this time, it is preferable that the binder fiber B has a size of 20 μm or more. Fibers having a fiber diameter of less than 20 μm are uncommon and costly, and are not preferable in terms of both economy and moldability. Also, if it is thinner than this, the binder fiber itself will be set (permanent crushing deformation) during heat molding,
Further, it becomes difficult to obtain a uniform nonwoven fabric when mixed with the fiber A. Further, the binder fiber preferably has a size of 200 μm or less. If a thicker fiber is used, the number of fibers is relatively reduced significantly, so that the number of bonding points between constituent fibers is reduced, shape stability and moldability are reduced, and it is difficult to maintain the shape.

When the difference between the softening points of the high softening point fiber A and the low softening point fiber B is less than 20 ° C., the strength and rigidity of the high softening point fiber A are prevented from lowering during heat molding, and the shape of the high density nonwoven fabric layer is reduced. In the maintained state, it is extremely difficult to control the temperature for softening only the low softening point fiber B to develop the adhesiveness, and the risk of softening the entire high-density nonwoven fabric layer increases. That is, while maintaining the shape of the nonwoven fabric, heating and press-forming, the difference in the softening point of the fiber itself, which is the minimum necessary for producing a product, is smaller than this, and when the difference in the softening point is smaller than this, Overall softening occurs.

Next, the areal density of the high-density nonwoven fabric layer required for forming the double-walled sound insulation structure together with the outer partition walls to secure the sound insulation performance is at least 0.1 kg /.
m ² . However, if the areal density exceeds 1.0 kg / m ² , it is not preferable from the viewpoint of an increase in material cost and weight. The preferred thickness of the high-density nonwoven fabric layer having an area density in the above range is in the range of 1 to 10 mm. It is difficult to form a high-density nonwoven fabric layer having the above-mentioned surface density with a thickness of less than 1 mm, and even if it can be molded, it is not preferable because the molded article has too high airflow resistance and, on the contrary, deteriorates sound insulation performance. On the other hand, if it exceeds 10 mm, it is difficult to obtain a sufficient ventilation resistance for exhibiting sound insulation performance in the above-mentioned area density range.

The application of the sound-insulating laminate of the present invention is that it can be molded in a state in which it adheres to and conforms to the shape of the uneven surface when used in addition to the uneven surface of, for example, a floor panel of an automobile. Not only is it important, but also a major factor in improving sound insulation performance. The sound insulation structure having the fiber A as a skeleton follows the shape of the mold well because the surface density and thickness are limited and the short fibers are used as described above. When heat molded at an appropriate temperature between the points, the binder fibers are softened and exhibit adhesiveness, and the intersections between the fibers are joined to stabilize the form of the nonwoven fabric.

The fiber formed by the above fiber type and fiber composition
The thermoformed high-density nonwoven fabric layer has an air pressure of 0.01 k
g / cm^TwoAir flow rate of 1200-3700cc /
cm ^Two-Min. Range.

Next, the low-density nonwoven fabric layer will be described. In order to further improve the sound insulation performance of the sound insulation laminate of the present invention, the air permeability control of the low density nonwoven fabric layer, the control of the air permeability of the low density nonwoven fabric layer, the reduction of the vibration transmissibility, the sound absorption Need to be improved.

The low-density nonwoven fabric layer has a fiber diameter of 20 to 200 μm.
m, preferably a fiber diameter of 40 to 200 μm, and a fiber length of 30 to
100-mm high softening point fiber C is 70-90% by weight, low softening point fiber having a softening point lower by at least 20 ° C. than said fiber C, having a fiber diameter of 20-200 μm and a fiber length of 30-90%.
It is characterized in that 100 mm fibers (fibers B 'or hereinafter also referred to as binder fibers) are constituted by 10 to 30% by weight.

The high softening point fiber C may be the same as or different from the fiber A, and the low softening point fiber B 'may be the same or different from the fiber B. As the fiber B ', a fiber having an affinity is used. In addition, the low-density nonwoven fabric layer mainly has a purpose of controlling air permeability and reducing a vibration transmissibility.

In order to improve the target sound insulation performance in the low frequency range, it is necessary to control the mechanical strength properties of the fibers to be used, depending on the thickness of the fibers used. However, the shape retention of the low-density nonwoven fabric layer is reduced depending on the fiber diameter, and sag occurs with the lapse of time, making it impossible to secure the thickness required to satisfy the required performance. Therefore, it is necessary to blend the same or relatively thick fiber as compared with the fiber A to be blended in the high-density nonwoven fabric layer. However, if it exceeds 200 μm, it is not suitable for obtaining the target sound insulation performance.

The blend of the high softening point fiber C must be 70% by weight or more to reduce the spring constant in order to improve the sound insulation performance. If the blending is further reduced, the ratio of the binder fiber increases, and it becomes difficult to reduce the spring constant to achieve the target performance. Further, it must be 90% by weight or less from the viewpoint of control of air permeability and securing of moldability. 90% by weight
When the ratio exceeds the above range, the amount of the binder fiber is reduced, and it becomes impossible to control the air permeability and secure the moldability.

The fibers constituting the low-density nonwoven fabric layer have an increased airflow resistance and a reduced air permeability as the fiber diameter is smaller within the range of 20 to 200 μm, that is, as the fiber surface area in the fiber nonwoven fabric is larger. At the same time, the smaller the fiber diameter is, the more the sound absorbing performance is improved. However, fine denier fibers having a fiber diameter of less than 20 μm are expensive, which leads to an increase in cost, and is inferior in carding properties and poor in formability to a nonwoven fabric. . On the other hand, when the thickness exceeds 200 μm, the ventilation resistance and the sound absorption performance are significantly reduced at the same time, so that it is difficult to improve the sound insulation performance.

Like the fiber A, the high softening point fiber C is preferably a substantially homopolymer, and is typically made of a high melting point polyester containing polyethylene terephthalate as a main component. The cross-sectional shape of the fiber may be circular or non-circular (irregular). The modified cross-section fibers further contribute to an increase in airflow resistance. Also,

The low softening point fiber B 'is a binder fiber which is softened by heat treatment and exhibits adhesiveness to the high softening point fiber C, and is a polymer having an affinity for the high softening point fiber C, for example, a high softening point fiber. When the point fiber C is a homopolyester polymer fiber, the binder fiber is also modified into a polyester system by copolymerizing or blending another dibasic acid component and / or a glycol component to lower the softening point. Alternatively, a low softening point fiber made of a blend polymer is preferably used. More preferably,
A core-sheath type or side-by-side type conjugate fiber conjugated with a homopolymer component having a high softening point such that at least a part of such a copolymer or blend polymer component is exposed on the fiber surface. In such conjugate fibers, the high softening point component does not soften or melt, and performs a supporting function while the low softening point component controls the adhesive function.

When the difference between the softening points of the high softening point fiber C and the low softening point fiber B ′ is less than 20 ° C., the strength and rigidity of the fiber C are prevented from lowering during heat molding, and the shape of the low density nonwoven fabric layer is maintained. In this state, it is extremely difficult to control the temperature at which only the low softening point fiber B 'is softened to exhibit adhesiveness, and the risk of softening the entire low density nonwoven fabric layer is increased.

As the low softening point fiber B ', a fiber having a fiber diameter of less than 20 .mu.m is not common and the cost is high, and the binder fiber itself is set (permanent crush deformation) during heat molding,
In addition, it is difficult to mix with the high softening point fiber C, and it is difficult to obtain a uniform fiber non-woven fabric. On the other hand, the fiber diameter of the binder fiber is 200 μm
If it exceeds, the number of fibers relatively decreases with an increase in the fiber diameter, so that the number of joining points between the constituent fibers decreases, and the shape stability and moldability decrease, which is not preferable. On the other hand, if the blending amount of the low softening point fiber B ′ is less than 20% by weight based on the weight of the high-density nonwoven fabric layer, similarly, it is not possible to impart sufficient moldability to the high-density nonwoven fabric layer due to a decrease in bonding points.

The areal density required for the low-density nonwoven fabric layer to ensure its sound insulation performance is in the range of 0.4 to 2.0 kg / m ² . If the areal density is less than 0.4 kg / m ^2, the improvement of the sound insulation performance is insufficient, while if it exceeds 2.0 kg / m ² , it is not preferable from the viewpoints of increase in material cost and weight.
Also, since the spring constant increases with the areal density of the nonwoven fabric layer and deteriorates the vibration transmissibility, it should be avoided to exceed 2.0 kg / m ² .

The low-density nonwoven fabric layer having a surface density in the above range needs to have a thickness of 15 to 50 mm. 15mm
If the thickness is less than 50 mm, the difference in density from the high-density nonwoven fabric layer becomes small and the double-walled structure is not substantially formed, so that the sound absorbing performance is reduced. On the other hand, if the thickness exceeds 50 mm, the space for practical use is secured. Is inappropriate.

The low-density nonwoven fabric layer formed by the above-mentioned fiber type and constitution has an air permeability of 1500 to 4000 cc / cm ² · mi at an air pressure of 0.01 kg / cm ² .
n. , Leading to excellent sound insulation performance. The ventilation rate is 1500 cc / cm ² · min. Too airflow resistance is increased when less than, the sound insulation performance degradation in the vicinity of the resonance point becomes remarkable, it is not preferable because it is difficult to overcome the conventional problems, and 4000cc / cm ² · min. On the other hand, if it exceeds, the ventilation resistance is insufficient, and it becomes difficult to form an effective double-walled sound insulation structure with the external partition, which is not preferable.

Next, application to a floor insulator for an automobile will be described. It is important in terms of required specifications to ensure sound insulation performance in a low frequency region, particularly 1 kHz or less, of floor components for automobiles. However, the sound insulation laminate of the present invention sufficiently meets such specifications required for floor insulators for automobiles. Can be satisfied. Further, since the resonance point can be set arbitrarily, it becomes possible to further improve the sound insulation performance in the important low frequency region.

In addition, polyester is often used for the carpet skin used for floor insulators for automobiles. By combining with the sound insulation laminate of the present invention, the whole floor insulator can be manufactured from polyester, and it is generated in the process. The recyclability of burrs and the like can be improved.

The sound-insulating laminate of the present invention has excellent air permeability and excellent sound insulation performance in a low-frequency region as compared with a conventional product having at least one high-density nonwoven layer having no air permeability and having the same shape and weight. And

The method for producing a sound insulating laminate according to the present invention comprises a short fiber web made of a high-density nonwoven fabric layer having low air permeability, preferably made of polyester, and a short fiber web made of a low-density nonwoven material layer having high air permeability, preferably made of polyester. Are separately formed, and both are laminated and integrated by needle punching and / or heat molding.

More specifically, the fiber diameter is 20 to 200 μm.
m, at most 8 of softening point short fibers having a fiber length of 30 to 100 mm
0% by weight and at least 20 ° C. below the softening point of the fiber
Fiber diameter 20-200 μm with low softening point, fiber length 3
0 to 100 mm binder fiber at least 20% by weight
The fiber raw material blended with is subjected to a carding and wrapping step by a conventional method to form a web for a high density nonwoven fabric layer having a predetermined basis weight. Similarly, the fiber diameter is 40 to 200 μm, and the fiber length is 3
70 to 90% by weight of a high softening point fiber having a softening point of 0 to 100 mm, and a fiber having a softening point lower by at least 20 ° C. than that of the fiber having a low softening point having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm is 10 to 30% by weight. Is subjected to a carding and wrapping process by a conventional method to form a web for a low density nonwoven fabric layer having a predetermined basis weight. Next, these short fiber webs were made into a web laminate by a plurality of continuous cross layers, and thereafter the whole was integrated by needle punching, and heat set as necessary,
0.5 ~ 3.0kg / cm ^{2 area} density and 16 ~ 60mm
Into a laminate having the following thickness.

Further, when the sound insulation laminate of the present invention is used by being attached to an uneven surface of, for example, a floor panel of an automobile, the sound insulating laminate can follow the uneven surface shape and can be formed in a state of being in close contact therewith. This is not only important in terms of sound quality, but also a major factor in improving sound insulation performance. The sound-insulating structure having the fiber A as a skeleton follows the shape of the mold well because the surface density and thickness are limited and short fibers are used as described above.
In this state, when heat-molded at an appropriate temperature between the softening points of the fibers A and the binder fibers, the binder fibers soften and exhibit adhesiveness, and join the intersections between the fibers to stabilize the form of the fiber aggregate. .

[0053]

The present invention will be described below in more detail with reference to Examples.

The measuring method of each characteristic value in the following examples and comparative examples is as follows. 1. Ventilation resistance For each sample, JIS L1004, L101
8, and the air permeability was measured according to the measurement method of the air permeability test specified in L1096. 2. Sound insulation performance For each sample, refer to JIS A1416 “Reverberation room-
Sound transmission loss measurement using a reverberation room ". At this time, the areal density is unified for each sample, and the sound transmission loss (T
The sound insulation performance difference was calculated using the sound insulation level of the mass rule of L) as a 0 dB reference. Further, this difference is set to 300-500 Hz, 50
The values were averaged at a frequency of 0 Hz to 1 kHz and summarized in a graph.

(Example 1) The high-density nonwoven fabric layer has an area density of 40.
0 g / cm^Two5mm thick, fiber diameter about 60μm, fiber
25% by weight of polyester fiber A having a length of about 50 mm
With a fiber diameter of 60 μm and a fiber length of about 50 mm, the softening point is higher than that of fiber
75% by weight of polyester fiber B 90 ° C lower
And air pressure 0.01kg / cm^TwoAirflow at 1900
cc / cm ^Two-Min. The low-density nonwoven fabric layer is dense
1000g / cm^Two, 35mm thick, about 12 fiber diameter
90 μm polyester fiber C having a fiber length of about 50 mm
Weight%, fiber diameter about 60μm, fiber length about 50mm
Polyester fiber B 'having a softening point lower by 90 [deg.] C. than C by 10
% By weight, air pressure 0.01 kg / cm^TwoAt
3400cc / cm ventilation volume^Two-Min. Fiber is
A sound insulation laminate (1) was produced using a woven fabric. Outside this
Primary resonance point is set to 200Hz by attaching to the partition wall
did.

Example 2 The high-density nonwoven fabric layer had an area density of 1
00g / cm ² , and air flow rate at an air pressure of 0.01 kg / cm ² is 2500 cc / cm ² · min. A sound insulation laminate (2) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 3 The high-density nonwoven fabric layer had an area density of 1
2,000 g / cm ² and an air pressure of 0.01 kg / cm ² at a flow rate of 1200 cc / cm ² · min. A sound insulation laminate (3) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 4 The high-density nonwoven fabric layer had a thickness of 1 m.
m, air flow rate at an air pressure of 0.01 kg / cm ² is 1300
cc / cm ² · min. A sound insulation laminate (4) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 5) The thickness of the high-density nonwoven fabric layer was 10
mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 200
0 cc / cm ² · min. A sound insulating laminate (5) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 6) The high-density nonwoven fabric layer has a fiber diameter of 25.
25% by weight of a polyester fiber A having a fiber length of 50 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C., and an air pressure of 0.01 kg / cm. The ventilation volume in ² is 1
800 cc / cm ² · min. A sound insulation laminate (6) was produced in exactly the same manner as in Example 1 except for the following.

Example 7 A high-density nonwoven fabric layer having a fiber diameter of 20
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than the fiber A, and an air pressure of 0.01 kg / cm. ² is 2800 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (7) was produced in exactly the same manner as described above.

(Example 8) The high-density nonwoven fabric layer has a fiber diameter of 60.
25% by weight of a polyester fiber A having a fiber length of 30 μm and a fiber length of 30 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C., and an air pressure of 0.01 kg / cm. The ventilation volume in ² is 1
700 cc / cm ² · min. A sound insulating structure (8) was produced in exactly the same manner as in Example 1 except for the following.

(Example 9) The high-density nonwoven fabric layer has a fiber diameter of 60.
25% by weight of a polyester fiber A having a fiber length of 100 μm and a fiber length of 100 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 2100 cc / cm ² · min. Example 1 except that
A sound insulation laminate (9) was produced in exactly the same manner as in the above.

Example 10 The high-density nonwoven fabric layer has a fiber diameter of 6
0% by weight of polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 100% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber A. The air pressure is 0.01 kg / cm ^2. 1 ventilation volume
500 cc / cm ² · min. A sound insulation laminate (10) was prepared in exactly the same manner as in Example 1 except for the following.

(Example 11) The high-density nonwoven fabric layer has a fiber diameter of 6
80% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 20% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 2200 cc / cm ² · min. Example 1 except that
A sound insulation laminate (11) was produced in exactly the same manner as described above.

(Example 12) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 20 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 1400 cc / cm ² · min. Example 1 except that
A sound insulation laminate (12) was produced in exactly the same manner as described above.

(Example 13) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of polyester fiber A having a fiber diameter of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 200 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C.
And an air flow rate of 3100 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (13) was produced in exactly the same manner as in Example 1 except for the following.

(Example 14) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 30 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 1600 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (14) was produced in exactly the same manner as described above.

(Example 15) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 100 mm and a softening point 90 ° C. lower than that of the fiber A.
And an air flow rate of 2400 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (15) was produced in exactly the same manner as in Example 1 except for the following.

Example 16 The low-density nonwoven fabric layer had an areal density of 400 g / cm ² and an air flow rate of 3800 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (16) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 17 The low-density nonwoven fabric layer had an areal density of 2000 g / cm ² and an air flow rate of 2400 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (17) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 18) The low-density nonwoven fabric layer had a thickness of 1
5 mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 26
00 cc / cm ² · min. A sound insulation laminate (18) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 19) The thickness of the low-density nonwoven fabric layer was 5
0 mm, air flow rate at air pressure 0.01 kg / cm ² is 35
00 cc / cm ² · min. A sound insulation laminate (19) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 20) The low-density nonwoven fabric layer
Polyester fiber C having a fiber length of 40 μm and a fiber length of 50 mm is 90
Weight%, fiber diameter 60μm, fiber length 50mm, fiber C
10% by weight of polyester fiber B 'having a softening point lower by 90 [deg.] C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
2800cc / cm^Two-Min. Implemented except for
A sound insulation laminate (20) was produced in exactly the same manner as in Example 1.

(Example 21) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 200 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 4000 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (21) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 22) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 30 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has an air permeability at an air pressure of 0.01 kg / cm ² of 3000 cc / cm ² · min. A sound insulation laminate (22) was produced in exactly the same manner as in Example 1, except that

Example 23 A low-density nonwoven fabric layer was made of 90% by weight of a polyester fiber C having a fiber diameter of 120 μm and a fiber length of 100 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. B 'is 10
% Air flow at an air pressure of 0.01 kg / cm ² at a flow rate of 3700 cc / cm ² · min. A sound-insulating laminate (23) was produced in exactly the same manner as in Example 1 except for the above.

(Example 24) A low-density nonwoven fabric layer was made of polyester fiber C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
30% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. and an air permeability at an air pressure of 0.01 kg / cm ² of 2900 cc / cm ² · min. A sound insulation laminate (24) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 25) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 20 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 3200 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (25) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 26) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 200 μm, a fiber length of 50 mm and a softening point lower than that of the fiber C by 90 ° C.
% Air flow at an air pressure of 0.01 kg / cm ² at 3900 cc / cm ² · min. A sound insulation laminate (26) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 27) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 60 μm, fiber length 30 mm and fiber C
10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. and an air flow rate of 3300 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (27) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 28) The low-density nonwoven fabric layer was composed of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, polyester fiber B ′ having a fiber diameter of 60 μm, a fiber length of 100 mm, and a softening point 90 ° C. lower than that of fiber C is 10%.
The sound insulating laminate (28) was produced in exactly the same manner as in Example 1 except that it was constituted by weight and the air flow rate at an air pressure of 0.01 kg / cm ² was 3600 cc / cm ² .

(Example 29) Forming a high-density nonwoven fabric layer
Difference in softening point between polyester fiber A and polyester fiber B
At 20 ° C and air pressure 0.01kg / cm^TwoAirflow
2050cc / cm ^Two-Min. Example 1 except that
A sound-insulating laminate (29) was produced in exactly the same manner as described above.

Example 30 The difference in softening point between the polyester fiber C and the polyester fiber B ′ forming the low-density nonwoven fabric layer was 20 ° C., and the air pressure was 0.01 kg / cm ² · min.
Air flow rate at 3550 cc / cm ² · min. A sound insulation laminate (30) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 1) The areal density of the high-density nonwoven fabric layer was 5
0 g / cm ² and an air pressure of 0.01 kg / cm ² at a ventilation rate of 2800 cc / cm ² · min. A sound insulation laminate (31) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Comparative Example 2 The high-density nonwoven fabric layer had an area density of 2
The air flow rate at 900 g / cm ² and air pressure of 0.01 kg / cm ² was 900 cc / cm ² · min. A sound insulation laminate (32) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 3) The thickness of the high-density nonwoven fabric layer was 1 m
An attempt was made to produce the sound insulation laminate (33) in exactly the same manner as in Example 1 except that the molding was carried out to m or less, but the fibers could not be compressed at the time of molding and could not be produced.

Comparative Example 4 A high-density nonwoven fabric layer having a thickness of 20
mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 240
0 cc / cm ² · min. A sound insulation laminate (34) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 5) A high-density nonwoven fabric layer having a fiber diameter of 5
Example 1 except that the polyester fiber A having a fiber length of 50 μm and a fiber length of 50 mm was 25% by weight, and the polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A was 75% by weight. An attempt was made to produce the sound insulation laminate (35) in exactly the same manner, but the fiber A was too thin to form a nonwoven fabric and could not be produced.

(Comparative Example 6) The high-density nonwoven fabric layer has a fiber diameter of 30.
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than the fiber A, and an air pressure of 0.01 kg / cm. ² is 3000 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (36) was produced in exactly the same manner as described above.

(Comparative Example 7) The high-density nonwoven fabric layer has a fiber diameter of 6
Example 1 except that polyester fiber A having a fiber length of 0 μm and a fiber length of 15 mm was 25% by weight and polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A was 50% by weight. An attempt was made to produce a sound-insulating laminate (37) in exactly the same manner, but the fiber A was too short to be a non-woven fabric and could not be produced.

(Comparative Example 8) A high-density nonwoven fabric layer having a fiber diameter of 6
0 μm, polyester fiber A having a fiber length of 200 mm
Weight%, fiber diameter 60μm, fiber length 50mm, fiber A
75% by weight of polyester fiber B whose softening point is 90 ° C lower
And air pressure 0.01 kg / cm ^TwoVentilation volume
Is 2500cc / cm^Two-Min. Examples other than
A sound insulation laminate (38) was produced in exactly the same manner as in Example 1.

(Comparative Example 9) A high-density nonwoven fabric layer having a fiber diameter of 6
An attempt was made to produce a sound-insulating laminate (39) in exactly the same manner as in Example 1 except that it was composed only of the polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, but the thickness could not be made sufficiently small and could not be produced. .

(Comparative Example 10) A high-density nonwoven fabric layer was composed of 25 polyester fibers A having a fiber diameter of 60 µm and a fiber length of 50 mm.
A sound insulation laminate (40) was produced in exactly the same manner as in Example 1 except that the fiber insulation layer (40) was constituted by 75% by weight of a polyester fiber B having a fiber diameter of 5 μm, a fiber length of 50 mm, and a softening point lower by 90 ° C. than the fiber A by 90 ° C. An attempt was made to fabricate it, but the fiber B was too thin to form a nonwoven fabric and could not be fabricated.

(Comparative Example 11) The high-density nonwoven fabric layer has a fiber diameter
Polyester fiber A having a length of 60 μm and a fiber length of 50 mm
Weight%, fiber diameter 300μm, fiber length 50mm and fiber A
25% by weight of polyester fiber B having a softening point lower by 90 ° C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
3200cc / cm^Two-Min. Except for
A sound insulation laminate (41) was produced in exactly the same manner as in Example 1.

(Comparative Example 12) A high-density nonwoven fabric layer was composed of 25 polyester fibers A having a fiber diameter of 60 µm and a fiber length of 50 mm.
75% by weight of a polyester fiber B having a fiber diameter of 60 μm, a fiber length of 15 mm, and a softening point lower than that of the fiber A by 90 ° C.
An attempt was made to produce the sound insulation laminate (42) in exactly the same manner as in Example 1, except that the fiber B was too short to be a non-woven fabric and could not be produced.

(Comparative Example 13) The high-density nonwoven fabric layer has a fiber diameter
Polyester fiber A having a length of 60 μm and a fiber length of 50 mm
Weight%, fiber diameter 60 μm, fiber length 200 mm, fiber A
75 weight of polyester fiber B having a softening point lower by 90 ° C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
The amount is 2700cc / cm^Two-Min. Except for
A sound insulation laminate (43) was produced in exactly the same manner as in Example 1.

(Comparative Example 14) The low-density nonwoven fabric layer had an areal density of 200 g / cm ² and an air flow rate of 0.01 kg / cm ² at a flow rate of 4100 cc / cm ² · min. A sound-insulating laminate (44) was produced in exactly the same manner as in Example 1 except for the above.

Comparative Example 15 The low-density nonwoven fabric layer had an areal density of 3000 g / cm ² and an air flow rate of 2000 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound-insulating laminate (45) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 16) The thickness of the low-density nonwoven fabric layer was 1
0 mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 28
00 cc / cm ² · min. A sound insulation laminate (46) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 17) The thickness of the low-density nonwoven fabric layer was 1
An attempt was made to produce the sound-insulating laminate (47) in exactly the same manner as in Example 1 except that the thickness was set to 00 mm, but the size did not become a realistic size in practical use.

(Comparative Example 18) A low-density nonwoven fabric layer was composed of 90% by weight of a polyester fiber C having a fiber diameter of 5 μm and a fiber length of 50 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. 10% by weight of B '
An attempt was made to produce the sound insulation laminate (48) in exactly the same manner as in Example 1 except that the fiber C was too thin to form a non-woven fabric and could not be produced.

(Comparative Example 19) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 300 μm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
The polyester fiber B ′ having a softening point lower by 90 ° C. is constituted by 10% by weight, and the air permeability at an air pressure of 0.01 kg / cm ² is 4800 cc / cm ² · min. A sound-insulating laminate (49) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 20) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 15 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
An attempt was made to produce the sound insulating structure (50) in exactly the same manner as in Example 1 except that 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. was used. And could not be produced.

(Comparative Example 21) A low-density nonwoven fabric layer was composed of 90% by weight of a polyester fiber C having a fiber diameter of 120 μm and a fiber length of 200 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. B 'is 10
% Air flow at an air pressure of 0.01 kg / cm ² at a flow rate of 3700 cc / cm ² · min. A sound insulation laminate (51) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 22) A low-density nonwoven fabric layer was made of 5 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 50% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 3200 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (52) was produced in exactly the same manner as in Example 1, except that

(Comparative Example 23) A low-density nonwoven fabric layer was made of polyester fiber C having a fiber diameter of 120 µm and a fiber length of 50 mm.
An attempt was made to produce the sound-insulating laminate (53) in exactly the same manner as in Example 1 except that the sound-insulating laminate (53) was constituted only by 00% by weight.

(Comparative Example 24) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
The sound insulation laminate (54) was made in exactly the same manner as in Example 1 except that the polyester fiber B ′ was composed of 0% by weight and 10% by weight of a polyester fiber B ′ having a fiber diameter of 5 μm, a fiber length of 50 mm, and a softening point 90 ° C. lower than that of the fiber C. ) Was attempted, but the fiber B was too thin to form a non-woven fabric and could not be produced.

(Comparative Example 25) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 μm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 300 μm, a fiber length of 50 mm, and a softening point 90 ° C. lower than that of fiber C.
% Air flow at an air pressure of 0.01 kg / cm ² at 4500 cc / cm ² · min. A sound insulation laminate (54) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 26) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 60 μm, fiber length 15 mm and fiber C
A sound insulation laminate (56) was prepared in exactly the same manner as in Example 1 except that the polyester fiber B 'having a softening point lower by 90 ° C. was constituted by 10% by weight. It could not be produced.

(Comparative Example 27) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 60 μm, a fiber length of 200 mm and a softening point lower by 90 ° C. than that of the fiber C.
% Air flow at an air pressure of 0.01 kg / cm ² at 4300 cc / cm ² · min. A sound insulation laminate (57) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 28) Forming a high-density nonwoven fabric layer
Difference in softening point between polyester fiber A and polyester fiber B
Is 10 ° C, air pressure 0.01kg / cm^TwoAirflow
2300cc / cm ^Two-Min. Example 1 except that
A sound insulation laminate (58) was produced in exactly the same manner as in the above.

(Comparative Example 29) Forming a low-density nonwoven fabric layer
Difference in softening point between polyester fiber C and polyester fiber B
Is 10 ° C, air pressure 0.01kg / cm^TwoAirflow
3800cc / cm ^Two-Min. Example 1 except that
A sound insulation laminate (59) was produced in exactly the same manner as in (1).

Tables 1, 2, 3 and 4 show test results of the structures and characteristic values of the samples obtained by the above Examples and Comparative Examples.

[0115]

[Table 1]

[0116]

[Table 2]

[0117]

[Table 3]

[0118]

[Table 4]

In the results shown in the above table, it was determined that a sound transmission loss difference of less than 1 dB in any of the frequency ranges of 300 to 500 Hz and 500 Hz to 1 kHz had no effect.

From these tables, it can be seen that each of the sound insulation laminates of the present invention produced in the examples has a lower frequency than the sound insulation level of the mass rule of sound transmission loss (TL) determined by the mass of the whole laminate. It was confirmed that the sound insulation performance in the region was improved. Moreover, the comparative example which does not correspond to the present invention could not obtain a satisfactory value for the sound insulation performance.

[0121]

As described above, the sound-insulating laminate of the present invention can control the air permeability of the high-density nonwoven fabric layer and is lower than the conventional sound-insulating laminate having a high-density nonwoven fabric layer having no air permeability. This has the effect of significantly improving the sound insulation performance in the frequency range.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a floor insulator mounted on a vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floor panel 2 Sound insulation laminated body 3 Low density nonwoven fabric layer 4 High density nonwoven fabric layer 5 Floor carpet

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[Procedure amendment]

[Submission date] August 28, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Sound insulation laminate and double-wall sound insulation structure including the same

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-walled sound insulation structure installed to prevent external vibration and / or noise from entering, and more particularly to vibration and / or vibration from floor steel plates of automobiles. Suitable for floor insulator carpets etc. installed to prevent / block noise. Further, the sound insulating laminate of the present invention is one in which air permeability is particularly controlled in order to improve sound insulating performance in a low frequency region.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a floor insulator for an automobile has a sound insulation laminate 2 located on the interior side of a floor panel 1 which divides the interior of the vehicle from the outside. Has the role of preventing transmission. As shown in the figure, a conventional sound insulating laminate 2 includes a low-density layer 3 made of a porous base material such as felt, polyurethane foam, or nonwoven fabric.
And a high-density layer 4 formed of a material having no air permeability such as an EVA material sheet or a polyethylene sheet mixed with a filler.
Is composed of a laminate. The low-density layer 3 absorbs noise from outside the vehicle, and the floor panel 1
By forming a double-walled sound insulation structure in which the low-density layer 3 is interposed between the high-density layer 4 and the high-density layer 4, the sound insulation performance is excellent and the sound insulation performance is excellent. 5 is a carpet skin.

[0003]

In such a conventional double-walled sound insulating structure of a floor insulator, the high-density layer 4 does not have air permeability, so that it has excellent sound insulating performance in a high frequency range. In the low-frequency range, which is important for the sound insulation performance of automotive floor components, the performance is reduced near the resonance point, and the sound transmission loss (TL) determined by the mass of the entire laminate is superior to the sound insulation level of the mass rule. The nature is small.

[0004] The present invention has been made in view of such circumstances, and in a sound-insulating laminate made of a molded article, the performance near the resonance point is improved by controlling the air permeability. It is another object of the present invention to provide a sound insulating laminate having improved sound insulating performance in a low frequency range.

[0005]

The object of the present invention is to provide a high-density nonwoven fabric layer (1) and a low-density nonwoven fabric layer (2) each composed of thermoplastic synthetic fibers having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm. Wherein the high-density nonwoven fabric layer (1) has a high softening point fiber (fiber A) of at most 80% by weight and a low softening point having a softening point at least 20 ° C. lower than the softening point of the fiber A. Fiber (fiber B) at least 20% by weight, has an area density (basis weight) of 0.1 to 1.0 kg / cm ² , a thickness of 1 to 10 mm, and an air pressure of 0.01 kg / cm ² . Aeration rate of 1200-37
00 cc / cm ² · min. The low-density nonwoven fabric layer (2) has a high softening point fiber (fiber C) of 70 to 90% by weight,
Low softening point fiber (fiber B ′) having a softening point at least 20 ° C. lower than the softening point of the fiber C (10 to 30% by weight), an area density of 0.4 to 2.0 kg / cm ² ,
Having a thickness of 50 mm and an air pressure of 0.01 kg / c
The air flow rate in m ² is 1500 to 4000 cc / cm ²
-Min. And the air pressure of the two layers is 0.01 kg / c.
The difference in air flow rate in m ² is 300 to 2800 cc / cm
² min. This is achieved by the sound insulating laminate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION To improve the sound insulation performance by attaching the sound insulation laminate of the present invention to an external partition, for example, the interior side of an automobile floor panel, first, the high-density nonwoven fabric layer is It is effective to control and reduce the amount of ventilation to a required amount. The air permeability of the non-woven fabric layer depends on various factors such as the density of the layer determined by its surface density and thickness, the fiber diameter of the constituent fibers, and the fiber cross-sectional shape. Reducing the average diameter of the fibers to be formed is extremely effective in reducing air permeability. However, relying on mere increase in density leads to an increase in overall weight, which is disadvantageous in that it is not suitable for mounting on a vehicle, but also increases material costs.

Second, it is necessary that the outer partition walls and the high-density nonwoven fabric layer form a double-walled sound insulation structure via the low-density nonwoven fabric layer. It is already known that forming a double-walled sound insulation structure increases the effect of improving sound insulation performance. However, even in such a double-walled sound insulation structure, in order to further improve the sound insulation performance while avoiding the disadvantages such as the increase in weight described above, it is necessary to perform operations such as fiber blending, surface density, and thickness to improve the air permeability, rigidity, and the like. It is desirable to appropriately control the physical properties of the material. Therefore, the laminated body for sound insulation of the present invention, the air permeability of the high-density nonwoven fabric layer of the above-described constituent fibers, so that a double-walled sound insulation structure showing excellent sound insulation performance with the external partition can be formed. It is ideal to control the blending, the areal density and the thickness in a suitable range mainly by selecting the thickness.

Third, the airflow resistance, which is an index of air permeability, is:
It changes depending on the fiber diameter, area density and thickness.

[0009] Fourth, the sound insulation performance improves as the vibration transmission rate decreases. Here, the vibration transmissibility greatly depends on the dynamic spring constant of the object. Therefore, it is necessary to reduce the dynamic spring constant to improve the sound insulation performance. The spring constant changes depending on the fiber diameter.

Fifth, the higher the sound absorption coefficient of the low-density nonwoven fabric layer, the better the sound insulation performance. Sound absorption is the density of the layer determined by the surface density and thickness of the nonwoven fabric layer, the fiber diameter of the constituent fibers,
Although it depends on various factors such as the cross-sectional shape of the fiber, increasing the surface density and reducing the average diameter of the fibers constituting the nonwoven fabric are extremely effective for improving the sound absorption coefficient. However, relying on mere increase in density leads to an increase in overall weight, which is disadvantageous in that it is not suitable for mounting on a vehicle, but also increases material costs.

[0011] The present invention also provides a sound insulation laminated structure in which a low-density nonwoven fabric layer is sandwiched between an external partition and a high-density nonwoven fabric layer. By forming the sound insulation structure and arbitrarily shifting this resonance point to a lower frequency side, the entire sound insulation performance curve with respect to the frequency can be shifted to the lower frequency side to improve the performance. That is, the fiber composition, density,
Air permeability, rigidity, elastic modulus, tensile strength and spring hardness, as well as fiber composition, thickness, density,
The primary resonance frequency can be set to an arbitrary frequency of 50 to 300 Hz by manipulating the dynamic spring constant and the air flow rate.

In order to improve the sound insulation performance, it is necessary to form a double-walled sound insulation laminate by using the sound insulation laminate and an external partition. However, as a characteristic when the double-walled sound insulation structure is formed, a resonance phenomenon occurs at a certain frequency on the sound insulation performance curve. At this time, if the resonance point is shifted to a lower frequency side, the entire sound insulation performance curve with respect to the frequency is shifted to the lower frequency side, so that the performance can be improved. According to the present invention, the resonance point can be set arbitrarily, thereby achieving the goal of improving the sound insulation performance.

The primary resonance frequency (f) of a double-walled sound insulation structure having a low-density nonwoven fabric layer as an intermediate layer is generally approximated by the following equation (1).

F = 1 / 2π · [{(m ₁ + m ₂ ) / m ₁ · m ₂ } · E / d] _1/2 (1) where m ₁ and m ₂ are the outer partition and the high density The areal density of each nonwoven fabric layer, E is the Young's modulus of the low density nonwoven fabric layer, d is the thickness of the low density nonwoven fabric layer, and the Young's modulus is calculated from the elastic modulus and the like.

However, since the double-walled sound insulation structure constituted by the present invention does not form a complete double-walled structure, (1)
The primary resonance frequency cannot be determined only by the equation. Therefore, as a specific means for arbitrarily setting the resonance point, especially for setting to a low frequency, the fiber blending of the high-density nonwoven fabric layer within the above range,
Manipulating density, controlling air flow, manipulating stiffness, modulus, tensile strength, spring hardness, manipulating fiber composition and density of low-density nonwoven layer, increasing thickness, controlling air flow A method of reducing the dynamic spring constant is effective. Performing all of these at the same time enables more precise resonance point setting, but is not particularly limited.

In the sound insulation laminate of the present invention, the primary resonance frequency is preferably set to a frequency of 50 to 300 Hz.
If the resonance point is set to a frequency higher than 300 Hz, the sound insulation performance is reduced in a low frequency range of 1 kHz or less, and the object cannot be achieved. Setting the resonance point at less than 50 Hz is not preferable because the effect of the density increase particularly in the above operation increases the weight.

Next, comparison of sound insulation performance with the mass law will be described. In the double-walled sound-insulating structure using the sound-insulating structure of the present invention, the double-walled sound-insulating structure for the sound insulation level of the mass rule of sound transmission loss (TL) determined by the mass of the entire sound-insulating laminate. In the frequency range of 300 Hz to 1 kHz, the sound transmission loss is 1 to 3 dB on the average frequency.
improves.

The mass of the entire sound insulation laminate constituting the sound insulation structure is one of the factors that determine the sound insulation performance. The mass rule is that the sound insulation performance for each frequency is determined by the mass of the sound insulation laminate. However, when the sound insulation laminate forms a double-walled sound insulation structure together with the external partition, as described above, the sound insulation performance falls below the mass law in the resonance region, but exceeds the mass law in other regions. Therefore, by forming a double-walled sound insulation structure and operating the resonance point as described above, it is possible to improve the sound insulation performance in an arbitrary frequency region. By using the above means, the sound insulation laminate of the present invention can exceed the sound insulation level of the mass rule of sound transmission loss (TL) by 1 to 3 dB in the frequency range of 300 Hz to 1 kHz.

From the above viewpoints, first, the areal density of the entire laminate is preferably in the range of 0.5 to 3.0 kg / m ² . In order to ensure sound insulation performance, the surface density of the laminate is preferably as high as possible, but if it exceeds 3.0 kg / m ² , it is not preferable because it is too heavy for practical use. If the areal density is less than 0.5 kg / m ^2, it is difficult to achieve the purpose of improving sound insulation performance such as sound absorption performance, which is not preferable.

The thickness of the entire laminate is preferably in the range of 16 to 60 mm. If the area density is less than 16 mm in the above range, the air permeability becomes too small, and it is difficult to obtain sufficient sound insulation performance near the resonance point, especially in a low frequency region. The thickness is preferably as large as possible to improve the sound absorbing performance. However, if the thickness exceeds 60 mm, it is not preferable from the viewpoint of securing a space for practical use.

In order to impart sufficient sound insulation performance to the laminate,
The high-density nonwoven fabric layer secures the ventilation resistance required for forming the outer partition and the double-walled sound insulating structure, and controls the low-density nonwoven fabric layer to the ventilation resistance necessary for improving its sound absorption coefficient and reducing the spring constant. I need to do that. For this purpose, the difference in air permeability between the high-density non-woven fabric layer and the low-density non-woven fabric layer is determined by using an air pressure of 0.01 kg /
In cm ² 300~2800cc / cm ² · mi
n. Must be within the range. Aeration difference is 300
cc / cm ² · min. If it is less than the above, the structure becomes substantially the same as the single-layer structure, and the double-wall sound insulation structure is not formed. The difference in the amount of ventilation is 2800 cc / cm ² · min. If the ratio exceeds, the target of the sound insulation performance of the low-density nonwoven fabric layer cannot be achieved.

The amount of ventilation varies depending on the fiber diameter of the constituent fibers, the surface density and the thickness of the laminate. The smaller the fiber diameter,
That is, as the fiber surface area in the nonwoven fabric increases, the airflow resistance increases and the airflow decreases. However, fine denier fibers are expensive and have poor carding characteristics, making it difficult to form a nonwoven fabric. In addition, the number of fibers relatively increases under a constant surface density, and the mechanical strength increases, so that the fibers have a low mechanical strength in the low frequency range. Cannot achieve the target of sound insulation performance. In particular, fine denier fibers having a fiber diameter of less than 20 μm are difficult to manufacture technically, so that stable supply is difficult and cost increases, and it is difficult to mix with other fibers to obtain a uniform nonwoven fabric. Not preferred. On the other hand, if the fiber diameter exceeds 200 μm, sufficient airflow resistance cannot be obtained, and it is difficult to improve sound insulation performance.

The fiber length of the constituent fibers is from 30 to 30 from the viewpoints of controlling the air permeability of the nonwoven fabric, affecting the surface area of the fiber, improving the workability during production of the nonwoven fabric, such as carding characteristics, and improving the mechanical strength of the nonwoven fabric. It needs to be 100 mm. If the fiber length is less than 30 mm, the workability during the production of the nonwoven fabric is inferior.
If it exceeds 0 mm, it will be difficult to uniformly disperse it in the nonwoven fabric, and it will be difficult to form a nonwoven fabric layer of good and uniform quality.

As the thermoplastic synthetic fiber, polyester is suitable in terms of flowability, mechanical strength, rigidity and the like, and has high cost performance. However, polyamide-based polyamides such as nylon, polyvinyl-based polymers such as polyacrylonitrile, and polyethylene, a fiber-forming synthetic polymer such as polyolefins such as polypropylene or semi-synthetic polymers such as cellulose acetate can also be used. By producing the fiber and converting it into a nonwoven fabric, a material having substantially the same airflow resistance can be obtained.

Therefore, the high density nonwoven fabric layer will be described. The high-density nonwoven fabric layer comprises a fiber-forming linear polymer, preferably at most 80% by weight of a high softening point fiber (fiber A) having a fiber diameter of 25 to 200 μm, and a softening at least 20 ° C. lower than the softening point of the fiber A. Fiber diameter with points 20 to 200
It comprises at least 20% by weight of low softening point fibers (fiber B, hereinafter also referred to as binder fibers) of μm. Here, the high softening point fiber diameter is particularly preferably at least 25 μm. The smaller the fiber, the more difficult it is to operate the joint,
This is because it is difficult to control the mechanical strength. Also,
The fiber diameter must be less than 200 μm. Thicker fibers are unsuitable for obtaining the required airflow resistance. On the other hand, if the high softening point fiber A exceeds 80% by weight, it is difficult to control the thickness of the sound absorbing material, so that a sufficient density cannot be secured and the object cannot be achieved.

The high softening point fiber A is preferably a substantially homopolymer, and typically comprises a high melting point polyester having polyethylene terephthalate as a main component. The cross-sectional shape of the fiber may be circular or non-circular (irregular). The modified cross-section fibers further contribute to an increase in airflow resistance.

The low softening point fiber B has a fiber diameter of 20 to 200 μm.
m, a fiber having a fiber length of 30 to 100 mm and a high softening point fiber A
It is a fiber having a lower softening point of at least 20 ° C, and is blended in the high-density nonwoven fabric layer at a ratio of 20 to 100% by weight. The low softening point fiber B softens as a binder fiber by heat treatment and exhibits adhesiveness to the fiber A,
When the polymer having an affinity for the fiber A, for example, the fiber A is a homopolyester-based polymer fiber, the binder fiber is also made of polyester by copolymerizing or blending another dibasic acid component and / or a glycol component. Low softening point fibers composed of a modified or reduced softening point copolymer or blend polymer are preferably used.
More preferably, it is a core-sheath type or side-by-side type conjugate fiber conjugated with a homopolymer component having a high softening point such that at least a part of such a copolymer or blend polymer component is exposed on the fiber surface. . In such conjugate fibers, the high softening point component does not soften or melt, and performs a supporting function while the low softening point component controls the adhesive function.

When the blending amount of the low softening point fiber B is less than 20% by weight based on the weight of the high density nonwoven fabric layer, similarly, sufficient moldability cannot be imparted to the high density nonwoven fabric layer due to a decrease in the number of bonding points. The blending of the low softening point fiber B means that it is somewhat necessary to blend a fiber capable of imparting moldability into the high-density nonwoven fabric layer. The sound insulation laminate has a large factor in improving performance due to its adhesion to a portion where sound insulation is required, and it is necessary that the nonwoven fabric can be formed so as to follow various surface shapes. The use of the above-mentioned short fibers improves followability, but in order to maintain the shape, blending of binder fibers is required. At the time of heat molding, the binder fibers are softened while the fibers A are constrained in the shape of the mold, and the fibers adhere to each other, so that a fine surface shape can be maintained.

At this time, it is preferable that the binder fiber B has a size of 20 μm or more. Fibers having a fiber diameter of less than 20 μm are uncommon and costly, and are not preferable in terms of both economy and moldability. Also, if it is thinner than this, the binder fiber itself will be set (permanent crushing deformation) during heat molding,
Further, it becomes difficult to obtain a uniform nonwoven fabric when mixed with the fiber A. Further, the binder fiber preferably has a size of 200 μm or less. If a thicker fiber is used, the number of fibers is relatively reduced significantly, so that the number of bonding points between constituent fibers is reduced, shape stability and moldability are reduced, and it is difficult to maintain the shape.

When the difference between the softening points of the high softening point fiber A and the low softening point fiber B is less than 20 ° C., the strength and rigidity of the high softening point fiber A are prevented from lowering during heat molding, and the shape of the high density nonwoven fabric layer is reduced. In the maintained state, it is extremely difficult to control the temperature for softening only the low softening point fiber B to develop the adhesiveness, and the risk of softening the entire high-density nonwoven fabric layer increases. That is, while maintaining the shape of the nonwoven fabric, heating and press-forming, the difference in the softening point of the fiber itself, which is the minimum necessary for producing a product, is smaller than this, and when the difference in the softening point is smaller than this, Overall softening occurs.

Next, the areal density of the high-density nonwoven fabric layer required for forming the double-walled sound insulation structure together with the outer partition walls to secure the sound insulation performance is at least 0.1 kg /.
m ² . However, if the areal density exceeds 1.0 kg / m ² , it is not preferable from the viewpoint of an increase in material cost and weight. The preferred thickness of the high-density nonwoven fabric layer having an area density in the above range is in the range of 1 to 10 mm. It is difficult to form a high-density nonwoven fabric layer having the above-mentioned surface density with a thickness of less than 1 mm, and even if it can be molded, it is not preferable because the molded article has too high airflow resistance and, on the contrary, deteriorates sound insulation performance. On the other hand, if it exceeds 10 mm, it is difficult to obtain a sufficient ventilation resistance for exhibiting sound insulation performance in the above-mentioned area density range.

The application of the sound-insulating laminate of the present invention is that it can be molded in a state in which it adheres to and conforms to the shape of the uneven surface when used in addition to the uneven surface of, for example, a floor panel of an automobile. Not only is it important, but also a major factor in improving sound insulation performance. The sound insulation structure having the fiber A as a skeleton follows the shape of the mold well because the surface density and thickness are limited and the short fibers are used as described above. When heat molded at an appropriate temperature between the points, the binder fibers are softened and exhibit adhesiveness, and the intersections between the fibers are joined to stabilize the form of the nonwoven fabric.

The fiber formed by the above fiber type and fiber composition
The thermoformed high-density nonwoven fabric layer has an air pressure of 0.01 k
g / cm^TwoAir flow rate of 1200-3700cc /
cm ^Two-Min. Range.

Next, the low-density nonwoven fabric layer will be described. In order to further improve the sound insulation performance of the sound insulation laminate of the present invention, the air permeability control of the low density nonwoven fabric layer, the control of the air permeability of the low density nonwoven fabric layer, the reduction of the vibration transmissibility, the sound absorption Need to be improved.

The low-density nonwoven fabric layer has a fiber diameter of 20 to 200 μm.
m, preferably a fiber diameter of 40 to 200 μm, and a fiber length of 30 to
100-mm high softening point fiber C is 70-90% by weight, low softening point fiber having a softening point lower by at least 20 ° C. than said fiber C, having a fiber diameter of 20-200 μm and a fiber length of 30-90%.
It is characterized in that 100 mm fibers (fibers B 'or hereinafter also referred to as binder fibers) are constituted by 10 to 30% by weight.

The high softening point fiber C may be the same as or different from the fiber A, and the low softening point fiber B 'may be the same or different from the fiber B. As the fiber B ', a fiber having an affinity is used. In addition, the low-density nonwoven fabric layer mainly has a purpose of controlling air permeability and reducing a vibration transmissibility.

In order to improve the target sound insulation performance in the low frequency range, it is necessary to control the mechanical strength properties of the fibers to be used, depending on the thickness of the fibers used. However, the shape retention of the low-density nonwoven fabric layer is reduced depending on the fiber diameter, and sag occurs with the lapse of time, making it impossible to secure the thickness required to satisfy the required performance. Therefore, it is necessary to blend the same or relatively thick fiber as compared with the fiber A to be blended in the high-density nonwoven fabric layer. However, if it exceeds 200 μm, it is not suitable for obtaining the target sound insulation performance.

The blend of the high softening point fiber C must be 70% by weight or more to reduce the spring constant in order to improve the sound insulation performance. If the blending is further reduced, the ratio of the binder fiber increases, and it becomes difficult to reduce the spring constant to achieve the target performance. Further, it must be 90% by weight or less from the viewpoint of control of air permeability and securing of moldability. 90% by weight
When the ratio exceeds the above range, the amount of the binder fiber is reduced, and it becomes impossible to control the air permeability and secure the moldability.

The fibers constituting the low-density nonwoven fabric layer have an increased airflow resistance and a reduced air permeability as the fiber diameter is smaller within the range of 20 to 200 μm, that is, as the fiber surface area in the fiber nonwoven fabric is larger. At the same time, the smaller the fiber diameter is, the more the sound absorbing performance is improved. However, fine denier fibers having a fiber diameter of less than 20 μm are expensive, which leads to an increase in cost, and is inferior in carding properties and poor in formability to a nonwoven fabric. . On the other hand, when the thickness exceeds 200 μm, the ventilation resistance and the sound absorption performance are significantly reduced at the same time, so that it is difficult to improve the sound insulation performance.

Like the fiber A, the high softening point fiber C is preferably a substantially homopolymer, and is typically made of a high melting point polyester containing polyethylene terephthalate as a main component. The cross-sectional shape of the fiber may be circular or non-circular (irregular). The modified cross-section fibers further contribute to an increase in airflow resistance. Also,

The low softening point fiber B 'is a binder fiber which is softened by heat treatment and exhibits adhesiveness to the high softening point fiber C, and is a polymer having an affinity for the high softening point fiber C, for example, a high softening point fiber. When the point fiber C is a homopolyester polymer fiber, the binder fiber is also modified into a polyester system by copolymerizing or blending another dibasic acid component and / or a glycol component to lower the softening point. Alternatively, a low softening point fiber made of a blend polymer is preferably used. More preferably,
A core-sheath type or side-by-side type conjugate fiber conjugated with a homopolymer component having a high softening point such that at least a part of such a copolymer or blend polymer component is exposed on the fiber surface. In such conjugate fibers, the high softening point component does not soften or melt, and performs a supporting function while the low softening point component controls the adhesive function.

When the difference between the softening points of the high softening point fiber C and the low softening point fiber B ′ is less than 20 ° C., the strength and rigidity of the fiber C are prevented from lowering during heat molding, and the shape of the low density nonwoven fabric layer is maintained. In this state, it is extremely difficult to control the temperature at which only the low softening point fiber B 'is softened to exhibit adhesiveness, and the risk of softening the entire low density nonwoven fabric layer is increased.

As the low softening point fiber B ', a fiber having a fiber diameter of less than 20 .mu.m is not common and the cost is high, and the binder fiber itself is set (permanent crush deformation) during heat molding,
In addition, it is difficult to mix with the high softening point fiber C, and it is difficult to obtain a uniform fiber non-woven fabric. On the other hand, the fiber diameter of the binder fiber is 200 μm
If it exceeds, the number of fibers relatively decreases with an increase in the fiber diameter, so that the number of joining points between the constituent fibers decreases, and the shape stability and moldability decrease, which is not preferable. On the other hand, if the blending amount of the low softening point fiber B ′ is less than 20% by weight based on the weight of the high-density nonwoven fabric layer, similarly, it is not possible to impart sufficient moldability to the high-density nonwoven fabric layer due to a decrease in bonding points.

The areal density required for the low-density nonwoven fabric layer to ensure its sound insulation performance is in the range of 0.4 to 2.0 kg / m ² . If the areal density is less than 0.4 kg / m ^2, the improvement of the sound insulation performance is insufficient, while if it exceeds 2.0 kg / m ² , it is not preferable from the viewpoints of increase in material cost and weight.
Also, since the spring constant increases with the areal density of the nonwoven fabric layer and deteriorates the vibration transmissibility, it should be avoided to exceed 2.0 kg / m ² .

The low-density nonwoven fabric layer having a surface density in the above range needs to have a thickness of 15 to 50 mm. 15mm
If the thickness is less than 50 mm, the difference in density from the high-density nonwoven fabric layer becomes small and the double-walled structure is not substantially formed, so that the sound absorbing performance is reduced. On the other hand, if the thickness exceeds 50 mm, the space for practical use is secured. Is inappropriate.

The low-density nonwoven fabric layer formed by the above-mentioned fiber type and constitution has an air permeability of 1500 to 4000 cc / cm ² · mi at an air pressure of 0.01 kg / cm ² .
n. , Leading to excellent sound insulation performance. The ventilation rate is 1500 cc / cm ² · min. Too airflow resistance is increased when less than, the sound insulation performance degradation in the vicinity of the resonance point becomes remarkable, it is not preferable because it is difficult to overcome the conventional problems, and 4000cc / cm ² · min. On the other hand, if it exceeds, the ventilation resistance is insufficient, and it becomes difficult to form an effective double-walled sound insulation structure with the external partition, which is not preferable.

Next, application to a floor insulator for an automobile will be described. It is important in terms of required specifications to ensure sound insulation performance in a low frequency region, particularly 1 kHz or less, of floor components for automobiles. However, the sound insulation laminate of the present invention sufficiently meets such specifications required for floor insulators for automobiles. Can be satisfied. Further, since the resonance point can be set arbitrarily, it becomes possible to further improve the sound insulation performance in the important low frequency region.

In addition, polyester is often used for the carpet skin used for floor insulators for automobiles. By combining with the sound insulation laminate of the present invention, the whole floor insulator can be manufactured from polyester, and it is generated in the process. The recyclability of burrs and the like can be improved.

The sound-insulating laminate of the present invention has excellent air permeability and excellent sound insulation performance in a low-frequency region as compared with a conventional product having at least one high-density nonwoven layer having no air permeability and having the same shape and weight. And

The method for producing a sound insulating laminate according to the present invention comprises a short fiber web made of a high-density nonwoven fabric layer having low air permeability, preferably made of polyester, and a short fiber web made of a low-density nonwoven material layer having high air permeability, preferably made of polyester. Are separately formed, and both are laminated and integrated by needle punching and / or heat molding.

More specifically, the fiber diameter is 20 to 200 μm.
m, at most 8 of softening point short fibers having a fiber length of 30 to 100 mm
0% by weight and at least 20 ° C. below the softening point of the fiber
Fiber diameter 20-200 μm with low softening point, fiber length 3
0 to 100 mm binder fiber at least 20% by weight
The fiber raw material blended with is subjected to a carding and wrapping step by a conventional method to form a web for a high density nonwoven fabric layer having a predetermined basis weight. Similarly, the fiber diameter is 40 to 200 μm, and the fiber length is 3
70 to 90% by weight of a high softening point fiber having a softening point of 0 to 100 mm, and a fiber having a softening point lower by at least 20 ° C. than that of the fiber having a low softening point having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm is 10 to 30% by weight. Is subjected to a carding and wrapping process by a conventional method to form a web for a low density nonwoven fabric layer having a predetermined basis weight. Next, these short fiber webs were made into a web laminate by a plurality of continuous cross layers, and thereafter the whole was integrated by needle punching, and heat set as necessary,
0.5 ~ 3.0kg / cm ^{2 area} density and 16 ~ 60mm
Into a laminate having the following thickness.

Further, when the sound insulation laminate of the present invention is used by being attached to an uneven surface of, for example, a floor panel of an automobile, the sound insulating laminate can follow the uneven surface shape and can be formed in a state of being in close contact therewith. This is not only important in terms of sound quality, but also a major factor in improving sound insulation performance. The sound-insulating structure having the fiber A as a skeleton follows the shape of the mold well because the surface density and thickness are limited and short fibers are used as described above.
In this state, when heat-molded at an appropriate temperature between the softening points of the fibers A and the binder fibers, the binder fibers soften and exhibit adhesiveness, and join the intersections between the fibers to stabilize the form of the fiber aggregate. .

[0053]

The present invention will be described below in more detail with reference to Examples.

The measuring method of each characteristic value in the following examples and comparative examples is as follows. 1. Ventilation resistance For each sample, JIS L1004, L101
8, and the air permeability was measured according to the measurement method of the air permeability test specified in L1096. 2. Sound insulation performance For each sample, refer to JIS A1416 “Reverberation room-
Sound transmission loss measurement using a reverberation room ". At this time, the areal density is unified for each sample, and the sound transmission loss (T
The sound insulation performance difference was calculated using the sound insulation level of the mass rule of L) as a 0 dB reference. Further, this difference is set to 300-500 Hz, 50
The values were averaged at a frequency of 0 Hz to 1 kHz and summarized in a graph.

(Example 1) The high-density nonwoven fabric layer has an area density of 40.
0 g / cm^Two5mm thick, fiber diameter about 60μm, fiber
25% by weight of polyester fiber A having a length of about 50 mm
With a fiber diameter of 60 μm and a fiber length of about 50 mm, the softening point is higher than that of fiber
75% by weight of polyester fiber B 90 ° C lower
And air pressure 0.01kg / cm^TwoAirflow at 1900
cc / cm ^Two-Min. The low-density nonwoven fabric layer is dense
1000g / cm^Two, 35mm thick, about 12 fiber diameter
90 μm polyester fiber C having a fiber length of about 50 mm
Weight%, fiber diameter about 60μm, fiber length about 50mm
Polyester fiber B 'having a softening point lower by 90 [deg.] C. than C by 10
% By weight, air pressure 0.01 kg / cm^TwoAt
3400cc / cm ventilation volume^Two-Min. Fiber is
A sound insulation laminate (1) was produced using a woven fabric. Outside this
Primary resonance point is set to 200Hz by attaching to the partition wall
did.

Example 2 The high-density nonwoven fabric layer had an area density of 1
00g / cm ² , and air flow rate at an air pressure of 0.01 kg / cm ² is 2500 cc / cm ² · min. A sound insulation laminate (2) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 3 The high-density nonwoven fabric layer had an area density of 1
2,000 g / cm ² and an air pressure of 0.01 kg / cm ² at a flow rate of 1200 cc / cm ² · min. A sound insulation laminate (3) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 4 The high-density nonwoven fabric layer had a thickness of 1 m.
m, air flow rate at an air pressure of 0.01 kg / cm ² is 1300
cc / cm ² · min. A sound insulation laminate (4) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 5) The thickness of the high-density nonwoven fabric layer was 10
mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 200
0 cc / cm ² · min. A sound insulating laminate (5) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 6) The high-density nonwoven fabric layer has a fiber diameter of 25.
25% by weight of a polyester fiber A having a fiber length of 50 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C., and an air pressure of 0.01 kg / cm. The ventilation volume in ² is 1
800 cc / cm ² · min. A sound insulation laminate (6) was produced in exactly the same manner as in Example 1 except for the following.

Example 7 A high-density nonwoven fabric layer having a fiber diameter of 20
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than the fiber A, and an air pressure of 0.01 kg / cm. ² is 2800 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (7) was produced in exactly the same manner as described above.

(Example 8) The high-density nonwoven fabric layer has a fiber diameter of 60.
25% by weight of a polyester fiber A having a fiber length of 30 μm and a fiber length of 30 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C., and an air pressure of 0.01 kg / cm. The ventilation volume in ² is 1
700 cc / cm ² · min. A sound insulating structure (8) was produced in exactly the same manner as in Example 1 except for the following.

(Example 9) The high-density nonwoven fabric layer has a fiber diameter of 60.
25% by weight of a polyester fiber A having a fiber length of 100 μm and a fiber length of 100 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 2100 cc / cm ² · min. Example 1 except that
A sound insulation laminate (9) was produced in exactly the same manner as in the above.

Example 10 The high-density nonwoven fabric layer has a fiber diameter of 6
0% by weight of polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 100% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber A. The air pressure is 0.01 kg / cm ^2. 1 ventilation volume
500 cc / cm ² · min. A sound insulation laminate (10) was prepared in exactly the same manner as in Example 1 except for the following.

(Example 11) The high-density nonwoven fabric layer has a fiber diameter of 6
80% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 20% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 2200 cc / cm ² · min. Example 1 except that
A sound insulation laminate (11) was produced in exactly the same manner as described above.

(Example 12) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 20 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 1400 cc / cm ² · min. Example 1 except that
A sound insulation laminate (12) was produced in exactly the same manner as described above.

(Example 13) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of polyester fiber A having a fiber diameter of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 200 μm and a fiber length of 50 mm and a softening point lower than that of the fiber A by 90 ° C.
And an air flow rate of 3100 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (13) was produced in exactly the same manner as in Example 1 except for the following.

(Example 14) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 30 mm and a softening point 90 ° C. lower than that of the fiber A, and an air pressure of 0.01 kg / cm. ² is 1600 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (14) was produced in exactly the same manner as described above.

(Example 15) The high-density nonwoven fabric layer has a fiber diameter of 6
25% by weight of polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 100 mm and a softening point 90 ° C. lower than that of the fiber A.
And an air flow rate of 2400 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (15) was produced in exactly the same manner as in Example 1 except for the following.

Example 16 The low-density nonwoven fabric layer had an areal density of 400 g / cm ² and an air flow rate of 3800 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (16) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Example 17 The low-density nonwoven fabric layer had an areal density of 2000 g / cm ² and an air flow rate of 2400 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (17) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 18) The low-density nonwoven fabric layer had a thickness of 1
5 mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 26
00 cc / cm ² · min. A sound insulation laminate (18) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 19) The thickness of the low-density nonwoven fabric layer was 5
0 mm, air flow rate at air pressure 0.01 kg / cm ² is 35
00 cc / cm ² · min. A sound insulation laminate (19) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 20) The low-density nonwoven fabric layer
Polyester fiber C having a fiber length of 40 μm and a fiber length of 50 mm is 90
Weight%, fiber diameter 60μm, fiber length 50mm, fiber C
10% by weight of polyester fiber B 'having a softening point lower by 90 [deg.] C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
2800cc / cm^Two-Min. Implemented except for
A sound insulation laminate (20) was produced in exactly the same manner as in Example 1.

(Example 21) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 200 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 4000 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (21) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 22) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 30 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has an air permeability at an air pressure of 0.01 kg / cm ² of 3000 cc / cm ² · min. A sound insulation laminate (22) was produced in exactly the same manner as in Example 1, except that

Example 23 A low-density nonwoven fabric layer was made of 90% by weight of a polyester fiber C having a fiber diameter of 120 μm and a fiber length of 100 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. B 'is 10
% Air flow at an air pressure of 0.01 kg / cm ² at a flow rate of 3700 cc / cm ² · min. A sound-insulating laminate (23) was produced in exactly the same manner as in Example 1 except for the above.

(Example 24) A low-density nonwoven fabric layer was made of polyester fiber C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
30% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. and an air permeability at an air pressure of 0.01 kg / cm ² of 2900 cc / cm ² · min. A sound insulation laminate (24) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 25) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 20 μm, fiber length 50 mm and fiber C
It is composed of 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 3200 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (25) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 26) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 200 μm, a fiber length of 50 mm and a softening point lower than that of the fiber C by 90 ° C.
% Air flow at an air pressure of 0.01 kg / cm ² at 3900 cc / cm ² · min. A sound insulation laminate (26) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 27) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 60 μm, fiber length 30 mm and fiber C
10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. and an air flow rate of 3300 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (27) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Example 28) The low-density nonwoven fabric layer was composed of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, polyester fiber B ′ having a fiber diameter of 60 μm, a fiber length of 100 mm, and a softening point 90 ° C. lower than that of fiber C is 10%.
The sound insulating laminate (28) was produced in exactly the same manner as in Example 1 except that it was constituted by weight and the air flow rate at an air pressure of 0.01 kg / cm ² was 3600 cc / cm ² .

(Example 29) Forming a high-density nonwoven fabric layer
Difference in softening point between polyester fiber A and polyester fiber B
At 20 ° C and air pressure 0.01kg / cm^TwoAirflow
2050cc / cm ^Two-Min. Example 1 except that
A sound-insulating laminate (29) was produced in exactly the same manner as described above.

Example 30 The difference in softening point between the polyester fiber C and the polyester fiber B ′ forming the low-density nonwoven fabric layer was 20 ° C., and the air pressure was 0.01 kg / cm ² · min.
Air flow rate at 3550 cc / cm ² · min. A sound insulation laminate (30) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 1) The areal density of the high-density nonwoven fabric layer was 5
0 g / cm ² and an air pressure of 0.01 kg / cm ² at a ventilation rate of 2800 cc / cm ² · min. A sound insulation laminate (31) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

Comparative Example 2 The high-density nonwoven fabric layer had an area density of 2
The air flow rate at 900 g / cm ² and air pressure of 0.01 kg / cm ² was 900 cc / cm ² · min. A sound insulation laminate (32) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 3) The thickness of the high-density nonwoven fabric layer was 1 m
An attempt was made to produce the sound insulation laminate (33) in exactly the same manner as in Example 1 except that the molding was carried out to m or less, but the fibers could not be compressed at the time of molding and could not be produced.

Comparative Example 4 A high-density nonwoven fabric layer having a thickness of 20
mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 240
0 cc / cm ² · min. A sound insulation laminate (34) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 5) A high-density nonwoven fabric layer having a fiber diameter of 5
Example 1 except that the polyester fiber A having a fiber length of 50 μm and a fiber length of 50 mm was 25% by weight, and the polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A was 75% by weight. An attempt was made to produce the sound insulation laminate (35) in exactly the same manner, but the fiber A was too thin to form a nonwoven fabric and could not be produced.

(Comparative Example 6) The high-density nonwoven fabric layer has a fiber diameter of 30.
25% by weight of a polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, and 75% by weight of a polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than the fiber A, and an air pressure of 0.01 kg / cm. ² is 3000 cc / cm ² · min. Example 1 except that
A sound-insulating laminate (36) was produced in exactly the same manner as described above.

(Comparative Example 7) The high-density nonwoven fabric layer has a fiber diameter of 6
Example 1 except that polyester fiber A having a fiber length of 0 μm and a fiber length of 15 mm was 25% by weight and polyester fiber B having a fiber diameter of 60 μm and a fiber length of 50 mm and a softening point 90 ° C. lower than that of the fiber A was 50% by weight. An attempt was made to produce a sound-insulating laminate (37) in exactly the same manner, but the fiber A was too short to be a non-woven fabric and could not be produced.

(Comparative Example 8) A high-density nonwoven fabric layer having a fiber diameter of 6
0 μm, polyester fiber A having a fiber length of 200 mm
Weight%, fiber diameter 60μm, fiber length 50mm, fiber A
75% by weight of polyester fiber B whose softening point is 90 ° C lower
And air pressure 0.01 kg / cm ^TwoVentilation volume
Is 2500cc / cm^Two-Min. Examples other than
A sound insulation laminate (38) was produced in exactly the same manner as in Example 1.

(Comparative Example 9) A high-density nonwoven fabric layer having a fiber diameter of 6
An attempt was made to produce a sound-insulating laminate (39) in exactly the same manner as in Example 1 except that it was composed only of the polyester fiber A having a fiber length of 0 μm and a fiber length of 50 mm, but the thickness could not be made sufficiently small and could not be produced. .

(Comparative Example 10) A high-density nonwoven fabric layer was composed of 25 polyester fibers A having a fiber diameter of 60 µm and a fiber length of 50 mm.
A sound insulation laminate (40) was produced in exactly the same manner as in Example 1 except that the fiber insulation layer (40) was constituted by 75% by weight of a polyester fiber B having a fiber diameter of 5 μm, a fiber length of 50 mm, and a softening point lower by 90 ° C. than the fiber A by 90 ° C. An attempt was made to fabricate it, but the fiber B was too thin to form a nonwoven fabric and could not be fabricated.

(Comparative Example 11) The high-density nonwoven fabric layer has a fiber diameter
Polyester fiber A having a length of 60 μm and a fiber length of 50 mm
Weight%, fiber diameter 300μm, fiber length 50mm and fiber A
25% by weight of polyester fiber B having a softening point lower by 90 ° C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
3200cc / cm^Two-Min. Except for
A sound insulation laminate (41) was produced in exactly the same manner as in Example 1.

(Comparative Example 12) A high-density nonwoven fabric layer was composed of 25 polyester fibers A having a fiber diameter of 60 µm and a fiber length of 50 mm.
75% by weight of a polyester fiber B having a fiber diameter of 60 μm, a fiber length of 15 mm, and a softening point lower than that of the fiber A by 90 ° C.
An attempt was made to produce the sound insulation laminate (42) in exactly the same manner as in Example 1, except that the fiber B was too short to be a non-woven fabric and could not be produced.

(Comparative Example 13) The high-density nonwoven fabric layer has a fiber diameter
Polyester fiber A having a length of 60 μm and a fiber length of 50 mm
Weight%, fiber diameter 60 μm, fiber length 200 mm, fiber A
75 weight of polyester fiber B having a softening point lower by 90 ° C.
%, Air pressure 0.01 kg / cm ^TwoVentilation in
The amount is 2700cc / cm^Two-Min. Except for
A sound insulation laminate (43) was produced in exactly the same manner as in Example 1.

(Comparative Example 14) The low-density nonwoven fabric layer had an areal density of 200 g / cm ² and an air flow rate of 0.01 kg / cm ² at a flow rate of 4100 cc / cm ² · min. A sound-insulating laminate (44) was produced in exactly the same manner as in Example 1 except for the above.

Comparative Example 15 The low-density nonwoven fabric layer had an areal density of 3000 g / cm ² and an air flow rate of 2000 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound-insulating laminate (45) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 16) The thickness of the low-density nonwoven fabric layer was 1
0 mm, the air flow rate at an air pressure of 0.01 kg / cm ² is 28
00 cc / cm ² · min. A sound insulation laminate (46) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 17) The thickness of the low-density nonwoven fabric layer was 1
An attempt was made to produce the sound-insulating laminate (47) in exactly the same manner as in Example 1 except that the thickness was set to 00 mm, but the size did not become a realistic size in practical use.

(Comparative Example 18) A low-density nonwoven fabric layer was composed of 90% by weight of a polyester fiber C having a fiber diameter of 5 μm and a fiber length of 50 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. 10% by weight of B '
An attempt was made to produce the sound insulation laminate (48) in exactly the same manner as in Example 1 except that the fiber C was too thin to form a non-woven fabric and could not be produced.

(Comparative Example 19) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 300 μm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
The polyester fiber B ′ having a softening point lower by 90 ° C. is constituted by 10% by weight, and the air permeability at an air pressure of 0.01 kg / cm ² is 4800 cc / cm ² · min. A sound-insulating laminate (49) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 20) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 15 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
An attempt was made to produce the sound insulating structure (50) in exactly the same manner as in Example 1 except that 10% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C. was used. And could not be produced.

(Comparative Example 21) A low-density nonwoven fabric layer was composed of 90% by weight of a polyester fiber C having a fiber diameter of 120 μm and a fiber length of 200 mm, and a polyester fiber having a fiber diameter of 60 μm and a fiber length of 50 mm and having a softening point 90 ° C. lower than that of the fiber C. B 'is 10
% Air flow at an air pressure of 0.01 kg / cm ² at a flow rate of 3700 cc / cm ² · min. A sound insulation laminate (51) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 22) A low-density nonwoven fabric layer was made of 5 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0 wt%, fiber diameter 60 μm, fiber length 50 mm and fiber C
It is composed of 50% by weight of a polyester fiber B ′ having a softening point lower by 90 ° C., and has a ventilation volume of 3200 cc / cm ² · min. At an air pressure of 0.01 kg / cm ² . A sound insulation laminate (52) was produced in exactly the same manner as in Example 1, except that

(Comparative Example 23) A low-density nonwoven fabric layer was made of polyester fiber C having a fiber diameter of 120 µm and a fiber length of 50 mm.
An attempt was made to produce the sound-insulating laminate (53) in exactly the same manner as in Example 1 except that the sound-insulating laminate (53) was constituted only by 00% by weight.

(Comparative Example 24) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
The sound insulation laminate (54) was made in exactly the same manner as in Example 1 except that the polyester fiber B ′ was composed of 0% by weight and 10% by weight of a polyester fiber B ′ having a fiber diameter of 5 μm, a fiber length of 50 mm, and a softening point 90 ° C. lower than that of the fiber C. ) Was attempted, but the fiber B was too thin to form a non-woven fabric and could not be produced.

(Comparative Example 25) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 μm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 300 μm, a fiber length of 50 mm, and a softening point 90 ° C. lower than that of fiber C.
% Air flow at an air pressure of 0.01 kg / cm ² at 4500 cc / cm ² · min. A sound insulation laminate (54) was produced in exactly the same manner as in Example 1 except that the above conditions were satisfied.

(Comparative Example 26) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight, fiber diameter 60 μm, fiber length 15 mm and fiber C
A sound insulation laminate (56) was prepared in exactly the same manner as in Example 1 except that the polyester fiber B 'having a softening point lower by 90 ° C. was constituted by 10% by weight. It could not be produced.

(Comparative Example 27) A low-density nonwoven fabric layer was made of 9 polyester fibers C having a fiber diameter of 120 µm and a fiber length of 50 mm.
0% by weight and 10% of polyester fiber B ′ having a fiber diameter of 60 μm, a fiber length of 200 mm and a softening point lower by 90 ° C. than that of the fiber C.
% Air flow at an air pressure of 0.01 kg / cm ² at 4300 cc / cm ² · min. A sound insulation laminate (57) was produced in exactly the same manner as in Example 1 except for the above.

(Comparative Example 28) Forming a high-density nonwoven fabric layer
Difference in softening point between polyester fiber A and polyester fiber B
Is 10 ° C, air pressure 0.01kg / cm^TwoAirflow
2300cc / cm ^Two-Min. Example 1 except that
A sound insulation laminate (58) was produced in exactly the same manner as in the above.

(Comparative Example 29) Forming a low-density nonwoven fabric layer
Difference in softening point between polyester fiber C and polyester fiber B
Is 10 ° C, air pressure 0.01kg / cm^TwoAirflow
3800cc / cm ^Two-Min. Example 1 except that
A sound insulation laminate (59) was produced in exactly the same manner as in (1).

Tables 1, 2, 3 and 4 show test results of the structures and characteristic values of the samples obtained by the above Examples and Comparative Examples.

[0115]

[Table 1]

[0116]

[Table 2]

[0117]

[Table 3]

[0118]

[Table 4]

In the results shown in the above table, it was determined that a sound transmission loss difference of less than 1 dB in any of the frequency ranges of 300 to 500 Hz and 500 Hz to 1 kHz had no effect.

From these tables, it can be seen that each of the sound insulation laminates of the present invention produced in the examples has a lower frequency than the sound insulation level of the mass rule of sound transmission loss (TL) determined by the mass of the whole laminate. It was confirmed that the sound insulation performance in the region was improved. Moreover, the comparative example which does not correspond to the present invention could not obtain a satisfactory value for the sound insulation performance.

[0121]

As described above, the sound-insulating laminate of the present invention can control the air permeability of the high-density nonwoven fabric layer and is lower than the conventional sound-insulating laminate having a high-density nonwoven fabric layer having no air permeability. This has the effect of significantly improving the sound insulation performance in the frequency range.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a floor insulator mounted on a vehicle.

[Description of Signs] 1 Floor panel 2 Sound insulation laminate 3 Low density nonwoven layer 4 High density nonwoven layer 5 Floor carpet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kyoichi Watanabe Nissan Motor Co., Ltd. (2) Nissan Motor Co., Ltd. (72) Inventor Yoshikazu Nemoto Nissan Motor Co., Ltd.

Claims (10)

[Claims] 1. A laminate comprising a high-density nonwoven fabric layer (1) and a low-density nonwoven fabric layer (2) each composed of thermoplastic synthetic fibers having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm. The high-density nonwoven fabric layer (1) comprises at most 80% by weight of the high softening point fiber (fiber A) and at least 20% by weight of the low softening point fiber (fiber B) having a softening point at least 20 ° C. lower than the softening point of the fiber A % And 0.1
And a thickness of ~1.0kg / cm ² surface density and 1 to 10 mm, and aeration amount in the air 0.01 kg / cm ² is 1200~3700cc / cm ² · min. And the low-density nonwoven fabric layer (2) has a high softening point fiber (fiber C) 7
0 to 90% by weight, at least 2% from the softening point of the fiber C
Low softening point fiber (fiber B ') 10 having a low softening point of 0 ° C
0.4 to 2.0 kg / cm
^{2 having} a surface density of 15 to 50 mm and an air flow rate of 1500 to ^{4 at} an air pressure of 0.01 kg / cm ² .
000 cc / cm ² · min. And the difference in air flow rate at an air pressure of 0.01 kg / cm ² of the two layers is 300 to
2800 cc / cm ² · min. A sound-insulating laminate, characterized in that: 2. The areal density of the whole laminate is 0.5 to 3.0 k.
g / cm ^2, sound insulation laminate according to claim 1, wherein the thickness of 16～60Mm. 3. The sound insulation laminate according to claim 1, wherein the fibers A of the high density nonwoven fabric layer (1) and the fibers C of the low density nonwoven fabric layer (2) are mainly composed of polyester. body. 4. The fiber B and the fiber B ′ are obtained by compounding a high softening point component composed mainly of polyester and a low softening point component composed of copolyester such that the low softening point component is exposed on the fiber surface. The sound insulation laminate according to claim 3, which is a conjugate fiber. 5. A high-density nonwoven fabric comprising a high-density nonwoven fabric layer (1) and a low-density nonwoven fabric layer (2) each composed of thermoplastic synthetic fibers having a fiber diameter of 20 to 200 μm and a fiber length of 30 to 100 mm. Layer (1) is a high softening point fiber (fiber A)
At most 80% by weight, at least 2% lower than the softening point of the fiber A
0.1 to 1.0 kg / c, comprising at least 20% by weight of a low softening point fiber (fiber B) having a low softening point of 0 ° C.
and a surface density and 1~10mm thickness of m ^2, and aeration amount in the air 0.01 kg / cm ² is 1200-3
700 cc / cm ² · min. The low-density nonwoven fabric layer (2) has a high softening point fiber (fiber C) of 70 to 90% by weight,
Low softening point fiber (fiber B ′) having a softening point at least 20 ° C. lower than the softening point of the fiber C (10 to 30% by weight), an area density of 0.4 to 2.0 kg / cm ² ,
Having a thickness of 50 mm and an air pressure of 0.01 kg / c
The air flow rate in m ² is 1500 to 4000 cc / cm ²
-Min. And the air pressure of the two layers is 0.01 kg / c.
The difference in air flow rate in m ² is 300 to 2800 cc / cm
² min. The low-density nonwoven fabric layer (2) is provided between an outer partition and the high-density nonwoven fabric layer (1).
Is formed by the high-density nonwoven fabric layer (1) and the external partition by being attached to the external partition so as to intervene, and the primary resonance frequency is set to a frequency in the range of 50 to 300 Hz. Double wall sound insulation structure. 6. The surface density of the entire sound insulating laminate is 0.5
~ 3.0kg / cm ^TwoAnd the thickness is 16-60mm
6. The double-wall sound insulation structure according to claim 5, wherein
body. 7. The fiber according to claim 5, wherein the fibers A of the high-density nonwoven fabric layer (1) and the fibers C of the low-density nonwoven fabric layer (2) are mainly composed of polyester.
Heavy wall sound insulation structure. 8. The fiber B and the fiber B ′ are compounded with a high softening point component composed mainly of polyester and a low softening point component composed of copolyester such that the low softening point component is exposed on the fiber surface. The double-walled sound insulation structure according to any one of claims 5 to 7, wherein the conjugate fiber is a conjugated fiber. 9. The sound insulation level according to the mass rule of sound transmission loss (TL) determined by the mass of the entire sound insulation laminate,
9. A sound transmission loss (TL) improved by 1 to 3 dB on the average frequency in a frequency range of 300 Hz to 1 kHz.
Heavy wall sound insulation structure. 10. The external wall is a floor panel of an automobile, and the double-walled sound insulation structure is formed on the vehicle interior side.
The double-walled sound insulation structure according to any one of claims 5 to 9, wherein the double-walled sound insulation structure is applied as a car floor insulator in a state where a carpet is installed on the laminate.