JP3188598B2 - Sound insulation structure and method of manufacturing the same - Google Patents

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 a method of manufacturing the same. The present invention relates to a sound insulation structure suitable for a floor insulator carpet installed to prevent and block the incidence of vibration and noise of the vehicle, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG. 13, a conventional car floor insulator carpet generally has a carpet skin layer 1 made of tufted carpet or the like, a backing layer 2 mainly made of polyethylene or the like, a cushioning material layer 3, and a normal melt sheet. The asphalt sheet layer 4 and the floor steel plate 5 are laminated in this order. That is, a floor insulator carpet for an automobile usually has a sound insulation structure having a double wall structure in which a flexible cushioning material layer is interposed between a carpet layer and a melt sheet layer or a floor steel plate.

[0003] Felt is often used for the cushioning material layer of such a conventional floor insulator carpet. As a generally applied felt, for example, one obtained by disintegrating used clothing into a cotton form and subjecting to needle punching or adding a binder such as a phenol resin and heat-curing is usually used. However, such a felt has poor adhesion to a floor steel sheet (or a melt sheet) due to poor shapeability.
Generally, the sound insulation performance is poor. In addition, complicated irregularities due to a wire harness, a heater duct, or the like laid on the floor steel plate cannot be completely absorbed, and irregularities may occur on the carpet skin, which may cause inconvenient appearance. In addition, there is a drawback that the set between the fibers is weakened over time (permanent crush deformation) due to weak bonding between the fibers.

In order to improve such a defect, a cushioning material using a urethane foam as a cushioning material instead of felt has been proposed in, for example, Japanese Patent Application Laid-Open No. 3-176241. By shaping this urethane foam and using it as a cushioning material, the adhesiveness between the cushioning material and the floor steel sheet is improved, and not only the sound insulation performance is improved, but also the urethane foam can be molded. Above can be absorbed, and the uniformity of the carpet surface can be maintained. Therefore, the carpet skin layer becomes uniform and flat, so that the appearance is excellent, and further, there is an effect of preventing deterioration over time and instability of quality.

However, when a urethane foam is used as a cushioning material, the material cost is high, and in addition to a carpet molding step, a liquid polyol and isocyanate injection step, a foaming step and a bonding step are required. Therefore, the process requires a long time, and a large-scale facility including an exhaust facility is also required, which is disadvantageous in that productivity and economic efficiency are poor. In addition, since the spring constant is higher and the resonance point is higher than felt having the same thickness, as shown in FIG. 1, the vibration isolation region above the resonance point is narrowed, and the overall value of the transmission loss is poor. There is.

[0006] In an attempt to solve the drawbacks and problems associated with the conventional felt and urethane foams as described above,
The following proposals have been made. (1) Improvement of the material of the buffer material layer, that is, the use of a nonwoven fabric capable of being formed by mixing a heat-adhesive fiber with a synthetic fiber such as polyester or the like for the buffer material layer (JP-A-62-223357)
And JP-A-4-272263). (2) In order to increase the number of layers of the cushioning material layer, that is, to improve the sound absorption performance and the sound vibration performance such as tuning of the resonance point, a cushioning material layer having a multilayer structure including a different hardness layer is provided. 61-70
085 and JP-A-3-233).

[0007]

Therefore, the present inventors intend to obtain a cushioning material layer which is a compromise between the above (1) and (2), that is, a cushioning material layer made of a synthetic fiber having a multilayer structure. First, as in the method (a) shown in FIG. 2A, a hard layer 3-a having a high apparent density and a soft layer 3-b made of a synthetic fiber non-woven fabric having a relatively low apparent density are press-formed. Were separately prepared, and these were laminated and bonded using an adhesive or the like to produce a buffer material layer 3 having a different hardness layer. However, according to this method, there is a disadvantage that the number of steps is increased and the cost is significantly increased.

On the other hand, as shown in the method (b) shown in FIG. 2B, a plurality of fiber aggregates laminated in advance and having different apparent densities, for example, a nonwoven fabric 3-a 'having a high apparent density and a relatively non-woven fabric having a high apparent density When the low nonwoven fabric 3-b 'is simultaneously pressed and formed into a cushioning material layer 3 composed of a soft layer 3-b and a hard layer 3-a, the soft layer 3-b becomes a hard layer 3-a.
As a result, the cushioning material layer was compressed more and became harder, and the hardness of each layer became close to each other, so that it was not possible to obtain a cushioning material layer having a clearly multilayered structure.

An object of the present invention, which has been made in view of the above-mentioned problems, is to provide both good sound insulation performance and moderate cushioning property, and to reduce the vibration transmissibility when a load is applied under the feet. A sound-insulating structure that is lightweight, economically advantageous, and easy to manufacture, with sufficient repulsion and formability that can conform to the complicated shape of the vibration and noise incident body such as a floor steel plate, especially a car floor insulator carpet. To offer.

[0010]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
In a sound insulation structure laminated on a partition wall on which vibration and / or noise is incident, the sound insulation structure includes a buffer material layer including at least two different hardness layers of a hard layer 3-a and a soft layer 3-b. The hard layer 3-a is composed of a fiber aggregate having morphological stability and high apparent density due to inter-fiber bonding, and the soft layer 3-b is mainly composed of free entangled fibers and has a high compression elastic recovery rate and a low apparent density. This is achieved by a sound insulation structure comprising a fiber aggregate having a high density and the soft layer 3-b disposed on the partition wall side. When the cushioning material layer constituting the sound insulation structure is attached to the floor surface of a living space such as a house or a vehicle ship, the cushioning material layer is usually laminated on the upper surface thereof via a backing layer mainly composed of a thermoplastic resin. The carpet comprises a skin layer.

The high apparent density fiber aggregate is formed by using a high melting point thermoplastic synthetic fiber F ₁ as a matrix fiber and a low melting point thermoplastic synthetic fiber F ₂ as a binder fiber, and by entanglement bonding with the binder fiber. A nonwoven fabric provided with stability, wherein the low apparent density fiber aggregate is at least 20 ° C. higher than the low melting point thermoplastic synthetic fiber F _2.
Is preferably a nonwoven fabric mainly made of thermoplastic synthetic fibers F ₃ having a melting point, more preferably, the synthetic fiber F ₁ is polyethylene terephthalate fiber, said synthetic fiber F ₂ is a polyethylene terephthalate polymers It is a core-sheath conjugate fiber having a polyester component having a melting point of 110 to 200 ° C. as a core component.

Further, the low apparent density fiber aggregate includes:
Synthetic fiber F ₃ , preferably polyethylene terephthalate-based side-by-side conjugate fiber
-100% by weight.

Further, the hard layer 3-a is 10 to 40 kg.
f, and the soft layer 3-b has a hardness of 1 to 10 k.
gf, and the ratio of the hard layer 3-a to the 25% hardness of the soft layer 3-b is preferably in the range of 3: 2 to 30: 1. The preferred thickness of -b is 0.5 mm to 10 mm and 5% to 50% of the thickness of the cushioning material layer. The apparent density of the hard layer is preferably 0.02 g / cm ^{3 to} 0.1 g / cm ³ .
in the range of cm ^3, an apparent density of the soft layer is preferably in the range of ^{0.005g / cm 3 ~0.04g / cm 3} .

The weight (area density) of the buffer layer 3 in which the hard layer 3-a and the soft layer 3-b are combined is preferably 0.5
in the range of ^{kg / m 2 ~2.5kg / m 2} .

The sound insulation structure of the present invention is particularly effective when used as a car floor insulator carpet attached to a car floor steel plate.

The method for producing a sound insulating structure according to the present invention comprises the steps of: forming a matrix composed of a high melting point thermoplastic synthetic fiber F ₁ and a low melting point thermoplastic synthetic fiber F ₂ substantially uniformly distributed and mixed in the matrix; Fiber assembly layer 3-a '
At least two layers including a thermoplastic synthetic fiber (F ₃ ) having a melting point at least 20 ° C. higher than the melting point of the low melting thermoplastic synthetic fiber F ₂ and a fiber aggregate layer 3-b ′ mainly composed of and, by the laminate was heated to a temperature between the melting point of the synthetic fiber F ₂ and synthetic fibers F ₃ of the melting point, compression molding from a direction perpendicular to the plane of the laminate, the low melting point synthetic fibers the fiber intersections fusion of F ₂ fibrous assembly layer 3-a 'converts the form stability comprises and apparent high hard layer 3-a dense, fibrous assembly layer 3-b'
Is maintained in a free state to provide a soft layer 3-b having a high compression elastic recovery rate and a low apparent density.

In the method of the present invention, at least two fibers including the fiber assembly layer 3-a 'and the fiber assembly layer 3-b'
When laminating the layers, it is preferable that a thermoplastic sheet material that melts at the above-mentioned heating temperature and exhibits adhesiveness is inserted between the layers in advance.

In a preferred embodiment of the method for manufacturing a sound insulating structure according to the present invention, the fibers are arranged such that the fiber assembly layer 3-b 'is arranged on the partition wall side on which vibration and / or noise is incident. Aggregate layer 3-a 'and fiber aggregate layer 3-
b ') and a carpet skin layer is laminated on the upper surface thereof via a backing layer which melts at the heat molding temperature and exhibits adhesiveness, and is thus formed. is the overall laminate structure was heated to a temperature between the melting point of the synthetic fiber F ₂ of the melting point and synthetic fiber F _3, by integral molding by compressing from the direction perpendicular to the surface of the laminated structure, a buffer The material layer is shaped along the surface shape of the partition.

Hereinafter, the present invention will be described in more detail based on a specific embodiment mainly when the present invention is laid on a floor surface in a vehicle, particularly, a floor insulator carpet for an automobile.

The most important point in the present invention is that (1) the cushioning material layer constituting the sound insulating structure comprises a different hardness layer including at least two hard layers having a high apparent density and a soft layer having a low apparent density. The point where the soft layer is disposed on the partition wall side of a steel plate or the like where vibration and noise are incident, and (2) the buffer material layer composed of at least two layers having different apparent densities and hardness are formed by simultaneous integral molding. On the point.

First, the point (1) will be described with respect to a typical example of the present invention comprising a cushioning material layer having a carpet skin layer on the upper surface via a backing layer. Generally, when a buffer material having a uniform hardness is used, the resonance point f ₀ in the sound transmission loss is one place. Anti-vibration and sound insulation areas

[Outside 1] It is desired that the resonance point f ₀ be shifted to a lower frequency side in order to effectively use. Shifting the resonance point to the lower frequency side can be achieved by increasing the mass of the carpet skin layer and the backing layer and reducing the spring of the cushioning material layer. However, an increase in mass not only increases costs but also results in a reduction in weight for automobiles. on the other hand,
If the cushioning material layer is lowered, the carpet sinking increases, and sufficient cushioning properties cannot be obtained.

In the configuration of the sound insulation structure of the present invention, such a problem is solved by the appearance of two resonance points as shown in FIG. That is, as shown in FIG.
The resonance point on the low frequency side is a vibration mode in which the soft layer with a low apparent density is a spring and a damper, and the part including the hard layer with high apparent density, the carpet skin layer and the backing layer becomes a mass, while The resonance point on the high frequency side uses the hard layer as a spring and a damper, and the carpet skin layer and the backing layer become masses. Therefore, two resonance points as shown in FIG. 3 appear. In particular, by adopting the configuration of the present invention, in addition to the mass of the carpet skin layer at the resonance point on the low frequency side, the hard layer is also included as a mass, so that the same effect as in the case where the mass is increased is achieved, and the mass line has a lower Since it rises from the side, the effect of improving the sound insulation performance can be obtained.
If this configuration is reversed, a vibration mode in which the mass is increased cannot be obtained, and no improvement in sound insulation performance can be obtained.

Next, the point (2) will be described. BACKGROUND ART Floor insulator carpets for automobiles are required to have formability in conformity with complex irregularities due to bead shapes of floor steel sheets, laid wire harnesses, heater ducts, and the like. However, the cushioning material layer made of a synthetic fiber nonwoven fabric has poor shapeability, and cannot be formed by absorbing such irregularities. However, according to the method of the present invention, it is possible to make the buffer material layer made of a synthetic fiber nonwoven fabric into an appropriate shape by mixing an appropriate amount of a thermoadhesive fiber or an adhesive. That is, a synthetic fiber nonwoven fabric mixed with a heat-adhesive fiber or an adhesive is heated to express their adhesiveness and adhere at least a part of the fiber intersection, and compression molding / cooling is performed to suppress the compression elastic recovery rate. Thereby, the cushioning material layer can be formed in accordance with the uneven shape of the steel sheet.

In the method (a) for obtaining a buffer material layer having a multilayer structure as shown in FIG. 2 (a), a fiber assembly to be a hard layer,
For example, an appropriate amount of heat-adhesive fibers or an adhesive is mixed in advance in the nonwoven fabric layer 3-a ', and the mixture is put into a mold and heated to fuse the heat-adhesive fibers and the like in the nonwoven fabric 3-a'. Pressed, cooled and formed into a hard layer 3 with high apparent density
-A, and on the other hand, a non-woven fabric layer substantially free of other fiber aggregates to be a soft layer, for example, fused fibers.
It is possible to obtain the sound insulation structure of the present invention composed of a layer of different hardness by separately forming b ′ to form a soft layer 3-b having a low apparent density and then laminating and bonding with the hard layer 3-a. is there. However, as described above, such a method (a) causes a significant increase in cost due to an increase in the number of steps, so that the method (b) shown in FIG. However, in the method (b), the nonwoven fabric 3-b 'to be a soft layer and the nonwoven fabric 3-a' to be a hard layer are preliminarily laminated, then put into a mold, and simultaneously heated, pressed and cooled. In this case, the nonwoven fabric 3-b 'is often softer and has a lower apparent density than the nonwoven fabric 3-a', and is more likely to be compressed during pressing. Therefore, the layer that would normally be a soft layer is formed in a compressed state, and the hardness of the soft layer 3-b and the hardness of the hard layer 3-a are close to each other, so that a cushioning material layer having a distinctly different hardness layer is obtained. I can't.

However, according to the present invention, the nonwoven fabric layer 3-
By mixing a specific adhesive fiber or adhesive into a 'and applying simultaneous integral molding by the method (b) under specific conditions, a buffer material layer having a different hardness layer with an effective hardness ratio can be obtained at low cost. You can do it. In the present invention, the formability of the cushioning material layer is ensured by the hard layer 3-a, and the soft layer 3-b lowers the formability by suppressing or eliminating the amount of the heat-adhesive fiber or adhesive mixed therein. Set. For this reason, the soft layer compressed at the time of pressing returns to the original shape by springback after molding, and maintains desired hardness and apparent density. "Simultaneous integrated pressure molding" in this document refers to the above (b)
As shown in the method, it means a method of obtaining a buffer layer having a different hardness layer in a simplified process without separately forming a soft layer and a hard layer.

In the present invention, as a material of the fiber aggregate constituting the cushioning material layer, it is desirable that at least the soft layer is a nonwoven fabric made of synthetic fibers. Of course, the entire cushioning layer including the hard layer can be made of a synthetic fiber nonwoven fabric. Such nonwoven consists matrix fibers F ₁ were intertwined, at least a hard layer comprises a binder fibers F ₂ for shaping the whole was further entangled heat-sealed to the matrix fibers, the matrix fibers fibers The hardness can be easily changed by changing the diameter, the blending amount of the binder fiber, the apparent density, and the like. Conventionally applied felts and urethane foams are not preferred because they increase the cost for obtaining a cushioning material layer with changed hardness.

The constituent fibers of the non-woven fabric can be appropriately selected from known fibers, and the use of thermoplastic polyester fibers typified by polyethylene terephthalate is costly, moldable,
It is preferable from the viewpoint of the stability of performance after processing and the like. Hard layer 3-a that constitute the buffer material layer according to the present invention includes a high-melting-point polyester fiber as the matrix fibers F _1, as binder fibers i.e. heat Chakusen'i F ₂ and the low-melting polyester fibers, low When heated to above the melting point of the high-melting polyester fiber and below the melting point of the high-melting polyester fiber, by bonding at least a portion of the intersections of the fibers that the low-melting polyester fiber contacts, by bonding the fibers together, It is possible to provide a sound insulation structure that can be shaped along a partition wall shape such as a floor steel plate. Further, the nonwoven fabric may be subjected to a needle punching treatment in order to enhance its cohesiveness.

The thermoplastic polyester matrix fiber F ₁ is preferably composed of a polyethylene terephthalate polymer, and more preferably a side-by-side conjugate composed of a polyethylene terephthalate homopolymer component and a copolymer component. Fiber. Such conjugate fibers have latent crimp properties,
A crimp is developed by heating during the simultaneous integral pressure molding. The thermoplastic polyester binder fiber F ₂ has a core component of a polyethylene terephthalate polymer and a sheath component of a melting point of 1.
It is preferable that the core-sheath conjugate fiber be a polyester copolymer at 10 to 200 ° C. Such in fiber aggregate structure, when heated to a temperature below the melting point of and matrix fibers above the melting point of the polyester copolymer sheath of the binder fiber F _2, fiber intersections contacting a polyester copolymer sheath At least partially fuse to bond the fibers. The reason why the melting point of the polyester copolymer in the sheath is 110 to 200 ° C. is that if the melting point is lower than 110 ° C., the polyester is melted by heat from a floor steel plate or the like,
This is because the bond between fibers may be damaged.
If the temperature exceeds 0 ° C., the melting point of polyethylene terephthalate is too close, and the heating condition control during molding becomes strict.

In the present invention, the soft layer 3-b includes
Indah fiber F_TwoHas a melting point at least 20 ° C higher
Thermoplastic polyester fiber F_Three95 to 100% by weight
Most preferably, it is a non-woven fabric. This non-woven fabric
Needle punched to increase its cohesiveness
You may. Here, fiber F_ThreeThe melting point of binder fiber F _Two
More than at least 20 ° C higher than 20 ° C
And the heating conditions during molding are strictly controlled, and the soft layer 3-b
Polyester fiber F_ThreeMelts and forms the soft layer 3-b
And the apparent density may increase,
This is because the desired performance may not be obtained. Ma
The above thermoplastic polyester fiber F_ThreeContent of 95
The reason why the weight of the other low melting point fiber is
If it exceeds 5% by weight, the moldability of the soft layer 3-b and the
And the apparent density is high,
It is difficult to obtain.

The polyester fiber F ₃ is preferably a crimped fiber. This is because the crimped fiber has a higher compression elastic recovery rate, that is, springback after molding, and also has better cohesion as a nonwoven fabric. Further, the polyester fiber F ₃ is preferably polyethylene terephthalate. Accordingly, the thermoplastic polyester fibers F _3, preferably side-by-side type conjugate fibers of homopolymers and copolymers of polyethylene terephthalate. Such a conjugate fiber has latent crimping properties, and develops crimping by heating during simultaneous integral pressure molding. Further, when a single component fiber is used, using a low-melting-point copolymerized polyester obtained by copolymerizing isophthalic acid or the like not only causes an increase in cost, but also from the viewpoint of obtaining the performance intended for the present invention. Not a good idea.

In the cushioning material layer having at least two different hardness layers (for example, the hard layer 3-a and the soft layer 3-b in FIG. 5) constituting the car floor insulator carpet of the present invention, the hard layer 3- a and the soft layer 3-b
Is bonded is composed of polyester fiber F ₂ contained in the hard layer 3-a, if necessary, a thermoplastic resin such as EVA and low density polyethylene between the hard layer 3-a and the soft layer 3-b A film or heat bonded nonwoven may be inserted.

In the cushioning material layer having at least two different hardness layers constituting the floor insulator carpet for an automobile of the present invention, the hardness of the hard layer is 5 kgf to 50 kg.
It is preferably in the range of f. If it is less than 5 kgf, sufficient resilience cannot be obtained, and if it exceeds 50 kgf, it is too hard to exhibit its function as a cushioning material. More preferably, it is in the range of 10 kgf to 40 kgf. The ratio of the 25% hardness of the hard layer 3-a to the soft layer 3-b is 3: 2 to 3
It is preferably in the range of 0: 1. When the 25% hardness of the hard layer is less than 1.5 times that of the soft layer, only one resonance point appears, and the significance of providing a different hardness layer is lost. If it exceeds 30 times, the soft layer becomes too soft, while the hard layer becomes too hard, making it difficult to form a nonwoven fabric, and also loses the cushioning effect as a cushioning material. A more preferred 25% hardness ratio is in the range of 2: 1 to 20: 1.

In the cushioning material layer of the car floor insulator carpet, the preferred thickness of the soft layer 3-b disposed on the floor steel plate side is 0.5 mm to 10 mm, and the entire cushioning material layer (3-a The ratio of the thickness of the soft layer 3-b to the thickness of +)-(3-b) is preferably 5%.
５０50%. If the thickness of the soft layer is less than 0.5 mm, the soft layer is compressed by the weight of the carpet skin layer and the hard layer, and the function of the soft layer may be lost. On the other hand, 10
If it exceeds mm, the resilience decreases, the sinking under the feet increases, and it becomes difficult to fulfill the function as a carpet. In addition, the ability to follow the hard layer 3-a is deteriorated, and the cushioning material layer is applied to the floor steel sheet. Of the fitting deteriorates. The thickness of the soft layer is 5% of the thickness of the entire cushioning material layer.
If it is less than 50%, the function of the soft layer will not be sufficiently exhibited, and if it exceeds 50%, the resilience will be reduced, and the function as a carpet will not be sufficiently achieved.

In the cushioning material layer, the apparent density of the nonwoven fabric of the soft layer 3-b disposed on the floor steel plate side is preferably in the range of 0.005 g / cm ^{3 to} 0.040 g / cm ³ . If this value is less than 0.005 g / cm ^3, it is too soft and easily sagged (permanently crushed easily), and it is difficult to form a nonwoven fabric. If it exceeds 0.040 g / cm ³ , the nonwoven fabric becomes hard and the function as a soft layer is not sufficiently exhibited. The apparent density of the nonwoven fabric of the hard layer 3-a is as follows:
Preferably in the range of ^{0.02g / cm 3 ~0.1g / cm 3} . If this value is less than 0.02 g / cm ³ , cushioning properties cannot be obtained. ^{On the other hand} , if it exceeds 0.1 g / cm ³ , it becomes too hard, which is disadvantageous in sound vibration performance and increases the weight. Further, the basis weight (area density) of the buffer material layer is 0.5 to
It is preferably 2.5 kg / m ² . If the basis weight (area density) is less than 0.5 kg / m ^2, it is too soft and easily sags, and it is difficult to form a nonwoven fabric. If it exceeds 2.5 kg / m ² , the nonwoven fabric becomes hard and the function as a buffer material layer cannot be sufficiently exhibited.

The cushioning material layer having at least two layers of different hardness constituting the car floor insulator carpet of the present invention can be obtained by simultaneous integral pressure molding. More specifically, the 'non-woven fabric 3-b corresponding with the soft layer 3-b' nonwoven fabric 3-a that corresponds to the hard layer 3-a laminated, the resulting laminate of the binder fiber F ₂ mp After heating to a temperature not higher than the melting point of the thermoplastic polyester fiber F ₃ and above, the laminate is put into a mold, press-formed from a direction perpendicular to the layer surface, and cooled to a temperature equal to or lower than the melting point of the binder fiber F _2. Thus, an intended buffer material layer having at least two different hardness layers is obtained. At this time, it goes without saying that the carpet skin layer 1 can also be laminated on the cushioning material layer via the backing layer 2 and molded at the same time.

[0036]

The present invention will be described below in more detail with reference to Examples. In the examples, "parts" represents parts by weight.

The measuring method of each characteristic place is as follows. 1.25% hardness According to the method described in JIS K 6382-1978,
The load value when the cushioning material was compressed by 25% using an aluminum disk loader having a diameter of 200 mm and a thickness of 5 mm was read. The thickness of the cushioning material was evaluated by laminating as necessary so that the thickness was 50 mm or more. 2. Sound transmission loss Measured according to JIS A 1416 "Method of measuring sound transmission loss in laboratory". 3. Underfoot vibration transmissibility A 5 kgf iron disk loader with a diameter of 150 mm (underfoot load, equivalent to underfoot area) is placed on the sample and forcedly vibrated with a constant force of 5 N to measure the vibration transmission gain at 30 Hz. A comparison was made. 4. Cushioning property evaluation Using a hardness tester described in JIS K 6382-1987, the sinking amount of the cushioning material when a load of 5 kgf was applied using an iron disk loader of φ150 was measured, and the cushioning property was measured. An evaluation was performed.

Examples 1 to 3 show examples in which the hardness is changed by making a difference between the surface densities of the hard layer and the soft layer. Embodiment 1 FIG. 6 is a sectional view showing Embodiment 1 of the present invention. In FIG. 6, the sound insulation structure of the present invention includes a carpet skin layer 1, a backing layer 2 mainly composed of a thermoplastic resin attached to the back surface of the carpet skin layer, and cushioning material layers 3-a and 3-b. The buffer material layer includes at least two different hardness layers (hard layer 3-a and soft layer 3-b), and the soft layer 3-b is arranged on the floor steel plate side where vibration and noise enter. You.

As the carpet skin layer, any of needle-punched carpets, tufted carpets and the like usually used for automobiles can be applied. In this embodiment, a toughness of pile weight (area density) of 580 g / m ² is used. The ted carpet is used as the skin layer 1 and has a basis weight (area density) of 600 g /
A polyethylene sheet of m ² was obtained and used as a backing material 2 beforehand.

The fiber assembly 3-a 'to be the hard layer 3-a of the cushioning material layer has a basis weight (area density) of 900 g / m ² (20
mm thick) of a polyethylene terephthalate-based non-woven fabric (apparent density: 0.045 g / cm ³ )
The fiber assembly 3-b 'to be -b has a basis weight (area density) of 1
00 g / m ² (6 mm thick) non-woven fabric made of polyethylene terephthalate fiber (apparent density: 0.017 g / cm
³ ) Prepared. As the fiber composition of these non-woven fabrics, non-woven fabric 3-a 'is made of 2 denier × 51 mm solid side-by-side conjugate type: 60 parts, 6 denier × 51 mm hollow side-by-side conjugate type: 20 parts, 2 denier × 51 mm core-sheath conjugate type heat-fused fiber (sheath component: melting point 110
° C copolymerized polyester): 20 parts, non-woven fabric 3-
b 'is 2 denier x 51 mm solid side-by-side conjugate type: 70 parts, 6 denier x 51
mm hollow side-by-side conjugate type: 30 parts. These nonwoven fabrics were laminated, the laminate was heated in an oven until the temperature reached 175 ° C., and then formed by a press machine so that the nonwoven fabric 3-a ′ became a hard layer 3-a having a thickness of 15 mm ( At this time, the total thickness is 20 mm). The apparent density of the entire cushioning material layer is 0.05 g / cm ³ (area density: 1000 g / m ² ),
(The apparent density of the hard layer 3-a: 0.06 g / cm ³ and the apparent density of the soft layer 3-b: 0.02 g / cm ³ ). The 25% hardness of the hard layer thus obtained is 15%.
kgf, the 25% hardness of the soft layer was 2 kgf, and the ratio of the hard layer: the 25% hardness of the soft layer was 7.5: 1.

As a melt sheet, an asphalt sheet having a thickness of 2.5 mm (area density: 4.0 kg / m ² ), and a floor steel sheet having a thickness of 0.8 mm (area density: 6.3 kg / m ² ).
² ) were prepared and laminated in the order shown in FIG. The bonding between the backing material 2 and the cushioning material layer should be
Keep the polyethylene sheet used for the backing material in a molten state at 30 ° C, and place a hard layer on it,
Cooled and glued. There is no particular problem even if a spunbond base fabric or a heat-sealing fiber nonwoven fabric is used as the bonding method here.

In general, floor steel sheets for automobiles are given a bead shape in order to obtain rigidity, or have irregularities for passing heater ducts, wire harnesses and the like.
For the purpose of measuring the 25% hardness, the sound transmission loss, and the vibration transmissibility of the feet, the flat plate was used for convenience. Of course, it is needless to say that the polyester nonwoven fabric used in the present embodiment can be processed into a shape corresponding to the shape of the floor steel plate by applying a shape to the press machine mold.

The samples obtained by the above method were evaluated for sound transmission loss, vibration transmissibility under foot, and cushioning property. The results were compared with those of Comparative Examples 1 to 4. All the performances were equal to or higher than Comparative Examples 1 to 4. It turned out that it was obtained.

Example 2 The fiber assembly 3-a 'had a basis weight (area density) of 820 g / m ^2.
(20 mm thick) non-woven fabric (apparent density: 0.041 g / cm ³ ) made of polyethylene terephthalate-based fiber, and the fiber assembly 3-b ′ has a basis weight (area density) of 180 g / m 2.
^{A 2} (6 mm thick) nonwoven fabric made of polyethylene terephthalate fiber (apparent density: 0.03 g / cm ³ ) was prepared. As a fiber composition of these nonwoven fabrics, a fiber aggregate 3-
Both a 'and 3-b' were the same as in Example 1. When a laminate of these nonwoven fabrics was formed in the same manner as in Example 1, a buffer layer having an area density of 1.0 kg / m ² and an overall thickness of 20 mm was obtained. The apparent density of the hard layer 3-a was 0%. 0.055g
/ Cm ³ , the apparent density of the soft layer 3-b is 0.036 g
/ Cm ³ . The 25% hardness of the hard layer 3-a is 1
2.5 kgf, 25% hardness of the soft layer 3-b is 4.0 kg
f, the ratio of the 25% hardness of the hard layer to the soft layer is about 3:
It was one.

The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

Example 3 The fiber assembly 3-a 'had a basis weight (area density) of 945 g / m.^Two
(20mm thick) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.0473 g / cm ^Three),
The fiber assembly 3-b 'has a basis weight (area density) of 55 g / m.
^Two(6mm thick) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.0092 g / cm^Three)
Prepared. As the fiber composition of these nonwoven fabrics, nonwoven fabric 3
Both -a 'and 3-b' were the same as in Example 1. These
When the laminate of woven fabric was molded in the same manner as in Example 1,
1.0kg / m^Two, The whole thickness of the buffer material layer 20mm
The hard layer 3-a has an apparent density of 0.063.
g / cm^ThreeThe apparent density of the soft layer 3-b is 0.011.
g / cm^ThreeMet. The 25% hardness of the hard layer 3-a is
17.5 kgf, 25% hardness of the soft layer 3-b is 1.0 k
gf, and the ratio of the 25% hardness of the hard layer to the soft layer is about 1
7.5: 1.

The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel plate 5 were the same as those in Example 1 and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

In Example 4, the melting point of the binder fiber was changed.
An example in the case of the above will be described. Example 4 The weight (area density) of the fiber assembly 3-a 'was 900 g / m.
^Two(20mm thickness) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.045 g / cm ^Three),
The weight of the fiber assembly 3-b 'is 100 g / m.^Two(6mm
Thick) polyethylene terephthalate nonwoven fabric
(Apparent density: 0.017 g / cm^Three) Was prepared. This
As a fiber composition of these nonwoven fabrics, nonwoven fabric 3-a '
Neil x 51mm solid side-by-side type conduit
Gate type: 60 parts, 6 denier x 51 mm hollow
Side-by-side conjugate type: 20
Part, 2 denier x 51mm core-sheath conjugate tie
Heat-fused fiber (sheath component: copolymerized polyethylene with a melting point of 170 ° C)
Stell): 20 parts, non-woven fabric 3-b 'is 2 denier ×
51mm solid side-by-side conjugate
Type: 70 parts, 6 denier x 51 mm hollow side
Buy-side conjugate type: 30 parts.
These nonwoven fabrics are laminated, and the laminate is heated to a temperature of 195 ° C.
Heated in an oven until it is
The woven fabric 3-a 'becomes a hard layer 3-a having a thickness of 15 mm.
(At this time, the total thickness is 20 mm.
). The apparent density of the entire cushioning material layer is 0.05 g /
cm^Three(Area density: 1000 g / m^Two). like this
Cut one corner of the cushioning material layer obtained in
a and the soft layer 3-b.
When the 25% hardness was measured, the apparent denseness of the hard layer 3-a was found.
The degree is 0.06 g / cm^Three, Apparent density of the soft layer 3-b
Is 0.02 g / cm^ThreeMet. The hard layer 3-a
25% hardness of the soft layer 3-b is 15kgf, 25% hardness of the soft layer 3-b
Is 2 kgf, and the ratio of hard layer: soft layer is 25% hardness
Was 7.5: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel plate 5 were the same as in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

Example 5 The fiber assembly 3-a 'had a basis weight (area density) of 750 g / m.^Two
(20mm thick) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.0375 g / cm ^Three),
The fiber assembly 3-b 'has a basis weight (area density) of 150 g / m.^Two
(6 mm thick) polyethylene terephthalate fiber
Non-woven fabric (apparent density: 0.025 g / cm^ThreePrepare)
Was. As the fiber composition of these nonwoven fabrics, nonwoven fabric 3-
a 'is 6 denier x 51mm hollow side by size
Deformed conjugate type: 40 parts, 2 denier x 51
mm core-sheath conjugate type heat-fused fiber (sheathed
Min: copolymerized polyester having a melting point of 110 ° C.): 60 parts
Then, the nonwoven fabric 3-b 'is solid denier of 2 denier × 51 mm.
Dubai side type conjugate type: 70 parts, 6
Denier × 51mm hollow side-by-side type
The conjugate type was 30 parts. Each nonwoven
Laminate and laminate in oven until temperature reaches 175 ° C
Then, the non-woven fabric layer 3-a 'is formed by a press machine.
It was formed so as to be a 15 mm hard layer 3-a. this
At this time, the total surface density of the buffer material layers 3-a and 3-b is
0.9kg / m^Two, And the total thickness is 20 mm. this
Cut off one corner of the cushioning material layer obtained in
3-a and the soft layer 3-b.
When the hardness and 25% hardness were measured, the apparent appearance of the hard layer 3-a was
Density is 0.05g / cm^ThreeThe appearance of the soft layer 3-b
Density is 0.03 g / cm^ThreeMet. In addition, the hard layer 3
-A has a hardness of 36.0 kgf and a soft layer 3-b of 2
The 5% hardness is 3 kgf, and the hard layer: 25% hardness of the soft layer
The length ratio was 12: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel plate 5 were the same as in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

Example 6 The fiber assembly 3-a 'had a basis weight (area density) of 750 g / m ^2.
(20 mm thick) non-woven fabric made of polyethylene terephthalate fiber (apparent density: 0.0375 g / cm ³ )
For the fiber assembly 3-b 'is 150 g /
An m ² (6 mm thick) polyethylene terephthalate-based fiber nonwoven fabric (apparent density: 0.025 g / cm ³ ) was prepared. As the fiber composition of these nonwoven fabrics, nonwoven fabric 3
-A 'is a 6 denier x 51 mm hollow side-by-
Side conjugate type: 60 parts, 2 denier ×
51 mm core-sheath conjugate type heat-fused fiber (sheath component: copolymerized polyester having a melting point of 110 ° C.): 40
Department. Non-woven fabric 3-b 'is 2 denier x 51 mm solid side-by-side conjugate type: 70
Part, 6 denier × 51 mm hollow side-by-side conjugate type: 30 parts. When a laminate of these nonwoven fabrics was molded in the same manner as in Example 5, the obtained buffer material layer had an areal density of 0.9 kg / m ² and a total thickness of the buffer material layer of 20 mm. One corner of the cushioning material layer thus obtained was cut out, separated into a hard layer 3-a and a soft layer 3-b, and the apparent density and 25% hardness of each were measured. Has an apparent density of 0.05 g / cm
^3. The apparent density of the soft layer 3-b is 0.03 g / cm ³
Met. The 25% hardness of the hard layer 3-a is 26.0.
kgf, the 25% hardness of the soft layer 3-b was 3.0 kgf, and the ratio of the 25% hardness of the hard layer to the soft layer was 8.5: 1.

The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

In Example 7, the thickness of the matrix fiber was changed.
The following shows the case where the hardness is changed. Example 7 The weight (area density) of the fiber assembly 3-a 'was 750 g / m.^Two
(20mm thick) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.0375 g / cm ^Three),
The fiber assembly 3-b 'has a basis weight (area density) of 150 g / m.^Two
(6 mm thick) polyethylene terephthalate fiber
Non-woven fabric (apparent density: 0.025 g / cm^ThreePrepare)
Was. As the fiber composition of these nonwoven fabrics, nonwoven fabric 3-
a 'is a 13 denier x 51 mm hollow side-by-
Side conjugate type: 80 parts, 2 denier ×
51mm core-sheath conjugate type heat-fused fiber
(Sheath component: copolymerized polyester having a melting point of 110 ° C.): 20
Department. Non-woven fabric 3-b 'is 2 denier × 51 mm
Solid side-by-side conjugate type: 7
0 parts, 6 denier × 51mm hollow side-by-side
Conjugate type: 30 parts.

The nonwoven fabric is laminated, and the laminate is heated in an oven until the temperature reaches 175 ° C., and then the nonwoven fabric layer 3-a ′ is formed into a 15 mm thick hard layer 3 by a press.
-A, a soft layer 3-b having a thickness of 5 mm with a nonwoven fabric layer 3-b '
(Apparent density: 0.05 g / cm ³ ). One corner of the cushioning material layer thus obtained was cut out, separated into a hard layer 3-a and a soft layer 3-b, and the apparent density and 25% hardness of each were measured. apparent density 0.05 g / cm ^3, an apparent density of the soft layer 3-b was 0.036 g / cm ³ (at this time, the surface density of the entire cushioning layer is 0.9 kg / m ^2, the thickness of the Is 20 mm,
The apparent density is 0.045 g / cm ³ ). The 25% hardness of the hard layer was 20.0 kgf, the 25% hardness of the soft layer was 3.0 kgf, and the ratio of the hard layer to the soft layer was 25: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning properties of the samples were compared with those of Comparative Examples 1 to 4, and it was found that the same or better performance was obtained for all the performances.

Example 8 The fiber assembly 3-a 'had a basis weight (area density) of 1250 g.
/ M ² (30 mm thickness) non-woven fabric made of polyethylene terephthalate fiber (apparent density: 0.0417 g / c)
m ³ ) to the fiber assembly 3-b ′
0 g / m ² (6 mm thick) non-woven fabric made of polyethylene terephthalate fiber (apparent density: 0.025 g / c)
m ³ ) was prepared. As the fiber composition of these nonwoven fabrics,
The fiber aggregate 3-a ′ is a hollow side-by-side conjugate type of 6 denier × 51 mm: 60 parts,
2 denier × 51 mm core-sheath conjugate type heat-fused fiber (sheath component: copolymerized polyester having a melting point of 110 ° C.): 40 parts. The fiber aggregate 3-b 'was a solid side-by-side conjugate type of 2 denier × 51 mm: 70 parts, and a hollow side-by-side conjugate type of 6 denier × 51 mm: 30 parts.

These nonwoven fabrics are laminated, and the laminate is heated at a temperature.
Heat in oven until 175 ° C, then press
The fiber assembly 3-a 'is formed into a 25 mm hard layer 3-
a was formed. At this time, the entire eye of the cushioning material layer
With (Area density is 1.4 kg / m ^TwoAnd the total thickness is 3
0 mm. One corner of the cushioning material layer thus obtained
And separated into a hard layer 3-a and a soft layer 3-b,
When each apparent density and 25% hardness were measured,
The apparent density of the hard layer 3-a is 0.05 g / cm. ^Three, Soft
The apparent density of the layer 3-b is 0.036 g / cm.^ThreeSo
Was. The 25% hardness of the hard layer is 26.0 kgf, and the soft layer is
Has a 25% hardness of 3.0 kgf.
The 25% hardness ratio was 8.5: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. For the samples, the results of evaluating the sound transmission loss, the transmission of vibration under the feet, and the cushioning properties were compared with Comparative Examples 9 to 12 having the same thickness, and it was found that the same or better performance was obtained for any of the performances. did.

Example 9 The fiber assembly 3-a 'had a basis weight (area density) of 2250 g / m.
^Two(50mm thickness) polyethylene terephthalate fiber
Nonwoven fabric (apparent density: 0.045 g / cm ^Three),
The fiber assembly 3-b 'has a basis weight (area density) of 150 g / m.^Two
(6 mm thick) polyethylene terephthalate fiber
Non-woven fabric (apparent density: 0.025 g / cm^ThreePrepare)
Was. As a fiber composition of these nonwoven fabrics, a fiber aggregate 3-
a 'is a 6 denier x 51 mm hollow side-by-side support
Id type conjugate type: 60 parts, 2 denier × 5
1 mm core-sheath conjugate type heat-fused fiber (sheath
Ingredients: copolymerized polyester having a melting point of 110 ° C.): 40 parts
did. The fiber aggregate 3-b ′ is 2 denier × 51 mm.
Solid side-by-side conjugate type: 7
0 parts, 6 denier × 51mm hollow side-by-side
Conjugate type: 30 parts.

These nonwoven fabrics are laminated and heated in an oven until the temperature of the laminate becomes 185 ° C., and thereafter, the fiber assembly 3-a ′ is turned into a 45 mm thick hard layer 3-a by a press. It was molded as follows. At this time, the basis weight (area density) of the buffer material layer is 2.4 kg / m ² , and the thickness is 50 mm. One corner of the cushioning material layer thus obtained was cut out, separated into a hard layer 3-a and a soft layer 3-b, and the apparent density and 25% hardness of each were measured.
-A has an apparent density of 0.05 g / cm ³ , and the soft layer 3-b
Had an apparent density of 0.036 g / cm ³ . The 25% hardness of the hard layer was 26.0 kgf, the 25% hardness of the soft layer was 3.0 kgf, and the ratio of the 25% hardness of the hard layer to the soft layer was 8.5: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel sheet 5 were the same as in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. For the sample, the results of evaluating the sound transmission loss, the transmissibility of underfoot vibration, and the cushioning property were compared with Comparative Examples 15 to 18 having the same thickness, and it was found that the same or better performance was obtained for any of the performances. did.

Comparative Example 1 This example shows a case where urethane foam is used for the cushioning material layer. Urethane foam was prepared by the following method. 20m
Liquid A comprising 100 parts of propylene oxide-1,2,6-hexanetriol as a polyol, 2 parts of water, 1 part of a surfactant, and 0.5 part of carbon black in a casting foaming mold having a clearance of m And solution B consisting of 100 parts of tolylene diisocyanate and 0.5 part of silicone oil with respect to polyol and isocyanate 1.
It was obtained by injecting at a low pressure and foaming with 25 equivalents. The obtained urethane foam sheet had a thickness of 20 mm and an apparent density of 0.06 g / cm ³ . The bonding between the buffer layer 3 and the backing layer 2 was performed by applying a spray-type adhesive.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of evaluating the sound transmission loss, the vibration transmission under the feet, and the cushioning properties of the obtained samples were compared with Comparative Examples 2 to 4, and Comparative Examples 3 and 4 particularly using felt.
For sound transmission loss (medium and high frequency over 400Hz)
It turned out that the performance was inferior.

[0065] In the case of Comparative Example 2, Comparative Example 1, as a backing layer, an ethylene calcium carbonate having a basis weight (areal density) 1500 g / m ² in place of the polyethylene sheet having a basis weight of 600 g / m ² was fillers - vinyl acetate Except for using the copolymer sheet, all had the same configuration as Comparative Example 1. The results of evaluating the sound transmission loss, the vibration transmission under foot, and the cushioning property of the obtained sample were compared with Comparative Examples 1, 3, and 4, and the results were improved with respect to Comparative Example 1 because of the increased weight. However, it was found that the performance was inferior to the comparative example 4 of the felt using the backing material of the same weight in the middle to high frequency region of 400 Hz to 1000 Hz.

Comparative Example 3 In this example, felt (trade name: Feltop, manufactured by Howa Textile Industry Co., Ltd., thickness: 20 mm, apparent density:
0.06 g / cm ³ ), the backing material 2 is bonded to the cushioning material in advance by melting the polyethylene sheet used for the backing material at 130 ° C., and placing the cushioning material layer on the polyethylene sheet. , Cooled and glued. Carpet skin layer 1, backing layer 2, melt sheet layer 4, floor steel sheet 5
Was used in the same manner as in Example 1, and was laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the vibration transmission under foot, and the cushioning property of the obtained sample were compared with Comparative Examples 1, 2, and 4, and the performance was almost equal to or lower than most of the evaluated properties.

Comparative Example 4 Here, in Comparative Example 3, the backing layer was replaced with a polyethylene sheet having a basis weight (area density) of 600 g / m ² instead of a calcium carbonate having a basis weight (area density) of 1500 g / m ² . Except for using the ethylene-vinyl acetate copolymer sheet, all had the same configuration as Comparative Example 3. About the obtained sample, sound transmission loss, vibration transmission rate under foot,
When the results of the evaluation of the cushioning property were compared with Comparative Examples 1 to 3, although the sound transmission loss was improved as compared with Comparative Example 3 due to the increase in weight, Comparative Examples 1 and 2 using urethane foam were used. It was found that the performance was inferior to the vibration transmission rate and cushioning properties of the feet.

Comparative Example 5 A nonwoven fabric made of polyethylene terephthalate fiber having a basis weight (area density) of 1000 g / m ² was prepared for the buffer layer 3.
The fiber composition of the polyethylene terephthalate fiber non-woven fabric is 6 denier x 51 mm hollow side-by-side conjugate type: 60 parts, 2 denier x 51 m
m of the core-sheath type conjugate type heat-fused fiber (sheath component: copolymerized polyester having a melting point of 110 ° C.): 40 parts. The nonwoven fabric is heated in an oven until the temperature of the nonwoven fabric reaches 175 ° C., and then the buffer material layer 3 is pressed by a press machine to 20 mm
(Apparent density: 0.05 g / cm ³ ). The 25% hardness of the cushioning material layer thus obtained is 26.0 k.
gf.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the vibration transmission under foot, and the cushioning property of the obtained sample are compared with those of Comparative Examples 1 to 4. As a result, since the sample is hard and has a high resonance frequency, the sound transmission loss (particularly, 400 Hz or more) is obtained. (Medium frequency) was found to be inferior in performance.

Comparative Example 6 A nonwoven fabric made of polyethylene terephthalate fiber having a basis weight (area density) of 1000 g / m ² was prepared for the buffer layer 3.
The fiber composition of the polyethylene terephthalate-based nonwoven fabric is a solid side-by-side conjugate type of 2 denier x 51 mm: 60 parts, 6 denier x 51 m
m of hollow side-by-side conjugate type: 20 parts, 2 denier × 51 mm core-sheath conjugate type heat-fused fiber (sheath component: copolymerized polyester having a melting point of 110 ° C.): 20 parts. Nonwoven fabric temperature 17
The mixture was heated in an oven until the temperature reached 5 ° C., and then the buffer material layer 3 was made 20 mm (apparent density: 0.05 g) using a press machine.
/ Cm ³ ). The 25% hardness of the cushioning material layer thus obtained was 10.0 kgf.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. About the obtained sample, the sound transmission loss, the vibration transmission under foot, and the results of evaluating the cushioning property were compared with Comparative Examples 1 to 4, because the sample was soft.
It became clear that the sinking under the foot was large and sufficient cushioning property could not be obtained.

Comparative Examples 7 and 8 show examples in which the cushioning material has two different hardness layers and the hard layer is disposed on the floor steel plate side. Comparative Example 7 The weight (area density) of the fiber assembly 3-b ′ was 667 g / m ^2.
(18 mm thick) non-woven fabric made of polyethylene terephthalate-based fiber, and a fiber aggregate 3-a 'having a basis weight (area density) of 3
A 33 g / m ² (5 mm thick) nonwoven fabric made of polyethylene terephthalate fiber was prepared. The fiber composition of these non-woven fabrics is as follows: non-woven fabric 3-a 'is 2 denier × 51 mm solid side-by-side conjugate type: 60 parts,
6 denier x 51 mm hollow side-by-side conjugate type: 20 parts, 2 denier x 51 mm core-sheath conjugate type heat-fused fiber (sheath component: copolymerized polyester having a melting point of 170 ° C): 20 parts The nonwoven fabric 3-b 'was a solid side-by-side conjugate type of 2 denier × 51 mm: 70 parts, and a hollow side-by-side conjugate type of 6 denier × 51 mm: 30 parts. Laminate those nonwovens,
The laminate is heated in an oven until the temperature reaches 175 ° C., and then the non-woven fabric 3-a ′ has a thickness of 5 m by a pressing machine.
The non-woven fabric 3-b 'was formed into a 15-mm thick soft layer 3-b on the m hard layer 3-a. One corner of the cushioning material layer thus obtained was cut out, separated into a hard layer 3-a and a soft layer 3-b, and the apparent density and 25% hardness of each were measured. Is 0.067
g / cm ³ , the apparent density of the soft layer is 0.044 g / cm ^3
3 , and the 25% hardness of the hard layer is 17.5 kgf,
The 25% hardness of the soft layer was 6.5 kgf, and the ratio of the hard layer: the 25% hardness of the soft layer was 2.69: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning property of the obtained sample were compared with Comparative Examples 1 to 4. The sound transmission loss (particularly 400 Hz) was obtained because the first resonance point was higher. It turned out that the performance was inferior at the above (medium frequency).

Comparative Example 8 The fiber assembly 3-b 'had a basis weight (area density) of 150 g / m ^2.
(6 mm thick) non-woven fabric made of polyethylene terephthalate-based fiber, and a weight (area density) of 75
A non-woven fabric made of polyethylene terephthalate-based fiber of 0 g / m ² (20 mm thickness) was prepared. The fiber composition of these nonwoven fabrics is as follows: nonwoven fabric 3-a 'is a hollow side-by-side conjugate type of 13 denier x 51 mm: 80
Core-sheath conjugate type heat-fused fiber of 2 denier x 51 mm (sheath component: copolymerized polyester having a melting point of 110 ° C): 20 parts, non-woven fabric 3-b 'is 2 denier x 51 mm solid side -The by-side conjugate type: 70 parts, 6 denier x 51 mm hollow side-by-side conjugate type: 30 parts. These nonwoven fabrics are laminated, and the laminate is heated at a temperature of 175 ° C.
The nonwoven fabric 3-a 'was formed into a hard layer 3-a having a thickness of 15 mm by a press machine. At this time, the basis weight (area density) of the entire cushioning material layer is 0.1.
9 kg / m ² and the thickness is 20 mm. One corner of the cushioning material layer thus obtained was cut out and separated into a hard layer 3-a and a soft layer 3-b, each having an apparent density of 25%.
When the hardness was measured, the apparent density of the hard layer was 0.05
g / cm ³ , the apparent density of the soft layer is 0.036 g / cm ^3
3 , and the 25% hardness of the hard layer is 20.0 kgf,
The 25% hardness of the soft layer was 8.0 kgf, and the ratio of the hard layer to the 25% hardness of the soft layer was 2.5: 1.

The carpet skin layer 1, the backing layer 2, the mel sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. About the obtained sample, sound transmission loss,
The results of evaluating the vibration transmission rate under foot and cushioning property are
In comparison with Comparative Examples 1 to 4, it was found that the first resonance point was higher, and the performance was inferior in sound transmission loss (especially middle frequency of 400 Hz or more).

In Comparative Examples 9 to 14, the thickness of the cushioning material layer was 3
The case of 0 mm is shown. Comparative Example 9 In this example, the layers were laminated in the order shown in FIG. 11 in the same manner as in Example 1 except that the urethane foam of 30 mm obtained by the method of Comparative Example 1 was used as a buffer. The results of the evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning property of the obtained samples were compared with those of Comparative Examples 10 to 12. It was found that the transmission loss (medium frequency of 400 Hz or more) was inferior in performance.

Comparative Example 10 In this example, the backing layer had a basis weight (area density) of 1500 g.
Except for using an ethylene-vinyl acetate copolymer sheet containing calcium carbonate / m ² as a filler, all had the same configuration as Comparative Example 9. The results of evaluation of the sound transmission loss, the vibration transmission under the feet, and the cushioning properties of the obtained samples were compared with Comparative Examples 9, 11, and 12, and the results were improved with respect to Comparative Example 9 because the weight was increased. However, it was found that the performance was inferior to the comparative example 12 of the felt using the backing material of the same weight in the middle to high frequency region of 400 Hz to 1000 Hz.

Comparative Example 11 In this example, a felt (trade name: Feltop, manufactured by Howa Textile Industry Co., Ltd., thickness: 30 mm) was used as a buffer material layer.
The apparent density: 0.06 g / cm ³ ) was used, and the backing material 2 and the cushioning material were bonded in advance by melting the polyethylene sheet used for the backing material at 130 ° C. and forming a cushioning material layer thereon. After placing, it was cooled and adhered.
The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. With respect to the obtained samples, the results of evaluation of sound transmission loss, vibration transmissibility under foot, and cushioning property are shown in Comparative Examples 9 and 1.
When compared with 0 and 12, most of the performances evaluated were below the equivalent level.

Comparative Example 12 In this example, the basis weight (area density) was 150 as the backing layer.
Ethylene-filled with 0 g / m ² calcium carbonate
Comparative Example 1 except that a vinyl acetate copolymer sheet was used.
The configuration was the same as that of No. 1. For the obtained sample, the results of evaluating the sound transmission loss, the transmission of vibration under the feet, and the cushioning property were compared with Comparative Examples 9 to 11. As a result, the sound transmission loss was higher than that of Comparative Example 11 due to the increase in weight. Although it was improved, it was found that Comparative Examples 9 and 10 using foamed urethane were inferior in performance due to vibration transmission coefficient and cushioning property under the feet.

Comparative Example 13 The basis weight (area density) of the fiber blend used in Comparative Example 5 was 1500 g.
/ M ² of a non-woven fabric made of polyethylene terephthalate fiber. The nonwoven fabric was heated in an oven until the temperature of the nonwoven fabric reached 175 ° C., and then formed into a size of 30 mm (apparent density: 0.075 g / cm ³ ) by a press machine. The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel sheet 5 were the same as in Example 1 and were laminated in the same manner as in Example 1 in the order shown in FIG. The results of evaluating the sound transmission loss, the transmissibility of underfoot vibration, and the cushioning property of the obtained sample were compared with those of Comparative Examples 9 to 12. As a result, the sample was hard and the resonance frequency was high, and the sound transmission loss (particularly, 400 Hz or more) was obtained. (Medium frequency) was found to be inferior in performance.

Comparative Example 14 The fiber weight used in Comparative Example 6 (area density) was 1500 g.
/ M ² of a non-woven fabric made of polyethylene terephthalate fiber. The nonwoven fabric was heated in an oven until the temperature of the nonwoven fabric reached 175 ° C., and then formed into a size of 30 mm (apparent density: 0.075 g / cm ³ ) by a press machine. The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel sheet 5 were the same as in Example 1 and were laminated in the same manner as in Example 1 in the order shown in FIG. For the obtained sample, the results of evaluation of sound transmission loss, vibration transmission under foot, and cushioning property were compared with Comparative Examples 9 to 12. As the sample was soft, sinking under the foot was large and sufficient cushioning property was obtained. It turned out that it could not be obtained.

In Comparative Examples 15 to 20, the case where the thickness of the cushioning material layer is 50 mm is shown. Comparative Example 15 A 50 mm urethane foam obtained by the method described in Comparative Example 1 was used as a buffer material. The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. When the results of evaluation of the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning property of the obtained samples were compared with Comparative Examples 16 to 18, in particular, Comparative Examples 17 and 18 using felts exhibited acoustic noise. It turned out that the performance was inferior in transmission loss (especially middle frequency of 400 Hz or more).

Comparative Example 16 In this example, the basis weight (area density) was 150 as the backing layer.
Ethylene-filled with 0 g / m ² calcium carbonate
Comparative Example 1 except that a vinyl acetate copolymer sheet was used.
The same configuration as that of No. 5 was adopted. The results of evaluating the sound transmission loss, the vibration transmission under foot, and the cushioning property of the obtained samples were compared with Comparative Examples 15, 17, and 18, and the results were improved with respect to Comparative Example 15 because the weight was increased. However, it was found that the performance was inferior to the comparative example 18 of the felt using the same weight of the backing material in the middle to high frequency region of 400 Hz to 1000 Hz.

Comparative Example 17 In this example, felt (trade name: Feltop, manufactured by Howa Textile Industry Co., Ltd., thickness: 50 mm) was used as a buffer material layer.
The apparent density: 0.06 g / cm ³ ) was used, and the backing material 2 and the cushioning material were bonded in advance by melting the polyethylene sheet used for the backing material at 130 ° C. and forming a cushioning material layer thereon. After placing, it was cooled and adhered.
The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel plate 5 were the same as those in Example 1, and were laminated in the same manner as in Example 1 in the order shown in FIG. About the obtained sample, the result of having evaluated the sound transmission loss, the vibration transmissibility of the feet, and the cushioning property was compared with Comparative Example 15,
As compared with Nos. 16 and 18, most of the evaluated performances were below the equivalent level.

Comparative Example 18 In this example, the basis weight (area density) was 150 as the backing layer.
Ethylene-filled with 0 g / m ² calcium carbonate
Comparative Example 1 except that a vinyl acetate copolymer sheet was used.
The same configuration as in No. 7 was adopted. For the obtained sample, the results of evaluating the sound transmission loss, the transmissibility of the vibration under the feet, and the cushioning property were compared with Comparative Examples 15 to 17. As a result, the sound transmission loss was higher than that of Comparative Example 17 because of the increase in weight. Although it was improved, it was found that Comparative Examples 15 and 16 using urethane foam were inferior in performance due to the vibration transmission rate and cushioning property under the feet.

Comparative Example 19 The fiber weight used in Comparative Example 5 (area density) was 2500 g.
/ M ² of a non-woven fabric made of polyethylene terephthalate fiber. The nonwoven fabric was heated in an oven until the temperature of the nonwoven fabric reached 175 ° C., and then formed into 50 mm by a press. The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1 and were laminated in the same manner as in Example 1 in the order shown in FIG. About the obtained sample, the sound transmission loss, the vibration transmissibility under foot, and the cushioning property were evaluated.
When compared with 5 to 18, it was found that the sample was hard and the resonance frequency was high, and the performance was inferior in sound transmission loss (especially middle frequency of 400 Hz or more).

Comparative Example 20 A nonwoven fabric made of polyethylene terephthalate fiber having a basis weight of 2500 g / m ² and a fiber blend used in Comparative Example 6 was prepared. The nonwoven fabric was heated in an oven until the temperature of the nonwoven fabric reached 175 ° C., and then formed into 50 mm by a press. The carpet skin layer 1, the backing layer 2, the melt sheet layer 4, and the floor steel sheet 5 were the same as those in Example 1 and were laminated in the same manner as in Example 1 in the order shown in FIG. About the obtained sample, the sound transmission loss, the vibration transmission rate under foot, and the cushioning property were evaluated.
In comparison with No. 8, it was found that since the sample was soft, sinking under the foot was large and sufficient cushioning property could not be obtained.

Tables 1 to 3 summarize the respective structures of the samples obtained in the above Examples and Comparative Examples.
Shown in

[0089]

[Table 1]

[0090]

[Table 2]

[0091]

[Table 3]

Tables 4 to 6 show comparison results of evaluation of the sound transmission loss, the vibration transmissibility under the feet, and the cushioning properties of the samples.

[0093]

[Table 4]

[0094]

[Table 5]

[0095]

[Table 6]

[0096]

【The invention's effect】

1. When the sound transmission loss is compared between the above example and the comparative example with respect to the same thickness, the example of the present invention performs at low frequency of 400 Hz or less, medium frequency of 400 to 1000 Hz, high frequency of 1000 Hz or more and the overall value. Excellent. 2. When comparing the sound transmission loss for the same thickness of the inventive example and a comparative example using urethane foam,
Even if the basis weight (area density) of the backing material is reduced from 1500 g / m ² to 600 g / m ² , the embodiment of the present invention can be performed at a low frequency of 400 Hz or less, a medium frequency of 400 to 1000 Hz, a high frequency of 1000 Hz or more and an overall value. It is excellent in performance and can be reduced in weight. 3. When comparing the sound transmission loss of the example of the present invention and the comparative example using felt with the same thickness, the example of the present invention is superior in performance in terms of the vibration transmissibility and cushioning property under the feet. 4. Since a buffer layer having at least two different hardness layers having the above-described effects can be obtained with the same number of steps as a single buffer layer, productivity and economy are excellent. 5. As described above, the sound-insulating structure of the present invention has good sound-insulating performance and moderate cushioning properties, can reduce the vibration transmissibility at the time of applying a load under the feet, and can move along a complicated shape such as a floor steel plate. It has many advantages over the conventional sound insulation structure that it can be easily formed and reduced in weight, and the productivity is increased by streamlining the process, and it is particularly suitable as a car floor insulator carpet.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the performance required of a car floor insulator carpet.

FIG. 2 (a) is a process flow sheet showing a control method in which different hardness layers are individually formed to form a laminate. (B)
Is a process flow sheet showing a method of forming a different hardness layer in a single step by the method of the present invention.

FIG. 3 is a graph showing a relationship between a sound transmission loss characteristic and an acoustic frequency of a multi-layered cushioning material and a single-layered cushioning material of a sound insulation structure.

FIG. 4 is a graph showing a relationship between an increase in the mass of the sound insulation structure or a reduction in the spring of the cushioning material and the sound transmission loss characteristics.

FIG. 5 is a cross-sectional view illustrating a structure of a floor insulator carpet according to the first to seventh embodiments of the present invention.

FIG. 6 is a cross-sectional view showing a structure of a floor insulator carpet according to Embodiment 8 of the present invention.

FIG. 7 is a cross-sectional view illustrating a structure of a floor insulator carpet according to Embodiment 9 of the present invention.

FIG. 8 is a cross-sectional view illustrating a structure of a floor insulator carpet of Comparative Examples 1 to 6.

FIG. 9 is a cross-sectional view illustrating a structure of a floor insulator carpet of Comparative Example 7.

FIG. 10 is a cross-sectional view illustrating a structure of a floor insulator carpet of Comparative Example 8.

FIG. 11 is a cross-sectional view illustrating a structure of a floor insulator carpet of Comparative Examples 9 to 14.

FIG. 12 is a cross-sectional view illustrating a structure of a floor insulator carpet of Comparative Examples 15 to 20.

FIG. 13 is a sectional view showing the structure of a conventional automobile floor insulator carpet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carpet skin layer 2 Backing layer 3 Buffer layer 3-a Hard layer 3-b Soft layer 3-c Intermediate hardness layer 4 Mel sheet layer 5 Floor steel plate

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jin Ito 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Hiroshi Sugawara 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-8-108810 (JP, A) JP-A-8-104164 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35 / 00 D04H 1/00-18/00 G10K 11/16 B60N 3/00-5/00

Claims (17)

(57) [Claims] 1. A sound insulation structure laminated on a partition wall on which vibration and / or noise is incident, wherein the sound insulation structure has at least two different layers of a hard layer (3-a) and a soft layer (3-b). The hard layer comprises a fiber aggregate having morphological stability and a high apparent density due to bonding between entangled fibers, and the soft layer comprises a high compression elastic recovery rate mainly composed of free entangled fibers. And a fiber layer having a low apparent density and the soft layer (3-b) is arranged on the partition wall side. 2. The sound insulation structure according to claim 1, further comprising a carpet skin layer laminated on a top surface of the cushioning material layer via a backing layer mainly composed of a thermoplastic resin. 3. The fiber aggregate having a high apparent density is formed by using a thermoplastic synthetic fiber (F ₁ ) having a high melting point as a matrix fiber and a thermoplastic synthetic fiber (F ₂ ) having a low melting point as a binder fiber. A nonwoven fabric provided with form stability by confounding point bonding, wherein the low apparent density fiber aggregate is a thermoplastic synthetic fiber (F) having a melting point at least 20 ° C. higher than the low melting thermoplastic synthetic fiber (F ₂ ). ₃ )
The sound insulation structure according to claim 1 or 2, which is a nonwoven fabric mainly composed of: 4. The synthetic fiber (F ₁ ) is a polyethylene terephthalate-based fiber, and the synthetic fiber (F ₂ ) is a polyethylene terephthalate-based polymer whose core component is a polyester-based copolymer having a melting point of 110 to 200 ° C. The sound insulation structure according to claim 3, which is a core-sheath conjugate fiber used as a sheath component. 5. The fiber aggregate having a low apparent density contains 95 to 100% by weight of synthetic fiber (F ₃ ).
Sound insulation structure. 6. The sound insulation structure according to claim 3, wherein the synthetic fiber (F ₃ ) is a polyethylene terephthalate-based side-by-side conjugate fiber. 7. The hard layer (3-a) has a weight of 10 to 40 kg.
f, and the soft layer (3-b) has a hardness of 1 to 1
It has a 25% hardness of 0 kgf and a hard layer (3-
a) The ratio of the 25% hardness of the soft layer (3-b) to 3: 2-3.
The sound insulation structure according to any one of claims 1 to 6, which is in a range of 0: 1. 8. The thickness of the soft layer (3-b) is 0.5 m.
m to 10 mm and 5% to 5% of the thickness of the cushioning material layer.
The sound insulation structure according to any one of claims 1 to 5, which is 0%. 9. The hard layer has an apparent density of 0.02 / c.
m ³ is in the range of to 0.1 g / cm ^3, an apparent density of the soft layer is 0.005g / cm ³ ~0.04g / cm ³
The sound insulation structure according to any one of claims 1 to 8, wherein 10. The sound insulation structure according to claim 1, wherein the partition wall is a steel plate of an automobile floor, and the sound insulation structure is used as a car floor insulator carpet. 11. A high-melting thermoplastic synthetic fiber (F)₁)
And substantially uniform throughout the matrix.
Low melting thermoplastic synthetic fibers (F_Two)When
Fiber assembly layer (3-a ') made of
Plastic synthetic fiber (F_Two) At least 20 ° C above the melting point
Thermoplastic synthetic fiber (F _Three)
At least two layers including a fiber assembly layer (3-b ').
After layering, synthetic fibers (F_Two) And synthetic fiber (F_Three)
Heating to a temperature between the melting point of
Compression molding from different directions,
Wei (F_Two), The fiber assembly layer (3-
a ′) is a hard layer having morphological stability and high apparent density
(3-a) and the fiber assembly layer (3-
b ') keeps the entangled fiber in a free state and has high compression elastic recovery
A soft layer (3-b) provided with a ratio and having a low apparent density.
The hard layer (3-a) and the soft layer (3-
b) A method for producing a sound insulating structure comprising a cushioning material layer comprising: 12. The synthetic fiber (F ₁ ) is a polyethylene terephthalate-based fiber, and the synthetic fiber (F ₂ ) is a polyethylene terephthalate-based polymer whose core component is a polyester-based copolymer having a melting point of 110 to 200 ° C. The method for producing a sound insulating structure according to claim 11, which is a core-sheath conjugate fiber used as a sheath component. 13. The method according to claim 11, wherein the fiber aggregate (3-b ′) contains 95 to 100% by weight of the synthetic fiber (F ₃ ). 14. The sound insulation structure according to claim 11, wherein the synthetic fiber (F ₃ ) is made of polyethylene terephthalate-based side-by-side conjugate fiber, and develops crimp by the heating. Manufacturing method. 15. When laminating at least two layers including the fiber assembly layer (3-a ') and the fiber assembly layer (3-b'), the layers are fused at the heating temperature and exhibit adhesiveness. 12. A thermoplastic sheet material to be inserted in advance.
15. The method for producing a sound insulating structure according to any one of items 14 to 14. 16. The method for manufacturing a sound insulating structure according to claim 11, wherein the fiber assembly layer (3-b ′) is arranged on the partition wall side on which vibration and / or noise is incident. Layer (3-a ') and the fiber assembly layer (3-
b '), and a carpet skin layer is laminated on the upper surface thereof via a backing layer which melts at the heating temperature and exhibits adhesiveness, and thus formed on the upper surface. The entire laminated structure is heated to a temperature between the melting point of the synthetic fiber (F ₂ ) and the melting point of the synthetic fiber (F ₃ ), and is compressed from a direction perpendicular to the surface of the laminated structure to be integrally formed. Thereby shaping the cushioning material layer along the surface shape of the partition wall. 17. The method for manufacturing a sound insulating structure according to claim 11, wherein the sound insulating structure is a car floor insulator carpet.