JP2002061026A - Binder fiber and fiber assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cheap and light fiber assembly capable of saving the space therefor, having both a vibration-damping performance and a sound insulating performance, therefore suitable as a sound insulator for automobiles and the like, and to provide a cheap binder fiber for the fiber assembly. SOLUTION: This sheath/core-type binder fiber composed of two components differing in softening point from each other as the sheath and the core respectively; wherein a resin 2a as the core component contains a piezoelectric material 2b, and a resin 3a as the sheath component is lower in softening point than the resin 2a as the core component and contains substantially no component other than resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder fiber suitably used for a vibration damping material, a sound absorbing material, a sound insulating structure, or the like used in, for example, an automobile floor, a dash, or a part of a building. The present invention relates to a fiber assembly using the binder fiber.

[0002]

Heretofore, as a sound insulation structure used for an automobile, a building or the like, a structure in which a sound absorbing material and a plate-like material represented by metal or resin are laminated (for example, a laminated structure) has been used. And JP-A-07-223478.

Further, as a development system of these sound insulation structures, Japanese Patent Application Laid-Open No.
A sound insulating material represented by 246573 has been proposed. The sound insulating material described in the publication is proposed in view of an increase in weight and an occupied volume of the sound insulating structure. However, when a ferroelectric material is used as a film, the capacitance (C) Is proportional, it is necessary to reduce the external resistance value (R) when used in a large area, and there is a problem that a real external resistance value (R) cannot be combined depending on the area. Usually, the sound insulation structure is not composed of a single film, but is used in combination with an appropriate sound absorbing material.In this case, however, it is necessary to prepare a sound absorbing material in addition to the film, so that the final product cannot be used. There is a problem that a certain sound insulating structure becomes expensive, and at the same time, the manufacturing process becomes complicated by combining the sound absorbing material and the film, and it is difficult to obtain a realistic sound insulating material.

It is also conceivable to directly knead a piezoelectric material or the like into a resin to form a fiber. However, in this case, there is a problem that the toughness of the kneaded resin is significantly reduced, and the fiberization itself becomes difficult as well as a reduction in diameter. As a result, solving these problems has been a problem in the sound insulating material.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the conventional sound insulating material. The object of the present invention is to reduce the weight and space and to achieve high vibration and sound insulation performance. The object of the present invention is to provide a fiber assembly suitable for a sound insulation structure of an automobile or the like and a binder fiber having high vibration damping performance and sound insulation performance as a material thereof at low cost.

[0006]

The binder fiber according to the first aspect of the present invention is a core-sheath type binder fiber having components having different softening points in the core and the sheath, and the resin of the core component contains a piezoelectric material. It is characterized by having a configuration in which the softening point of the resin of the sheath component is lower than the softening point of the resin of the core component. Means.

In one embodiment of the binder fiber according to the present invention, the binder fiber according to the second aspect has a configuration in which the core component resin contains a conductive material in addition to the piezoelectric material. In the binder fiber, the resin of the sheath component is substantially composed of only the resin, and in the binder fiber according to the fourth aspect, the piezoelectric material is a polyvinylidene fluoride (PVDF) piezoelectric material or a poly (fluorinated) material. Vinylidene / trifluoroethylene) (P
6. The binder fiber according to claim 5, wherein the binder fiber is a (VDF / TrFE)) copolymer, and the resin of the core component is a non-piezoelectric portion of the PVDF or P (VDF / TrFE) copolymer. In the above, at least the resin of the core component has a solubility coefficient (SP value) of 1.60 × 1
^{0 4 ~2.78 × 10 4 (J} / m 3) is characterized in that a structure is a resin having a polarity ^0.5.

[0008] The fiber assembly according to claim 6 of the present invention comprises:
The sound insulating structure according to claim 7, comprising the binder fiber according to the above claim, wherein the sheath component of the binder fiber is softened and thermally bonded. The present invention is characterized in that such a configuration in the fiber assembly and the sound insulation structure is used as means for solving the above-mentioned conventional problems.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The binder fiber according to the present invention comprises:
For example, as shown in FIG. 1, a core 2 having a core-sheath type cross-sectional shape having components having different softening points in a core and a sheath, and a core 2 made of a resin 2 a containing a piezoelectric material 2 b and an outer surface of the core 2 And a sheath 3 made of a resin 3a having a softening point lower than that of the resin 2a forming the core 2. Therefore,
The sound pressure and / or vibration or both are efficiently absorbed by the electric loss due to the electric interaction between the piezoelectric material 2b and the resin 2a which is generated by the sound pressure and / or vibration input to the binder fiber 1 as described above. Will be done. Further, since the softening point of the resin 3a forming the sheath 3 is lower than the softening point of the resin 2a of the core 2, the binder fiber 1
They are easily thermally bonded to each other, and easily form a fiber aggregate.

In order to impart vibration damping properties to a nonwoven fabric (fiber aggregate) containing such binder fibers 1, it is desirable to reduce the diameter in order to receive as much sound pressure and vibration energy as possible. Therefore, as described in claim 3,
In the case where the binder fiber 1 is melt-spun or drawn after the melt-spinning, the sheath component resin 3a is made of substantially only the resin without including the piezoelectric material.
The sheath component resin 3a, which does not substantially contain anything other than the resin and has high ductility, bears the spinning tension and the stretching tension,
A further reduction in the diameter of the binder fiber is achieved. Note that “substantially composed of only resin” means that the composition of the sheath component is clearly smaller than that of the core component including the piezoelectric material 2b, except for a component other than the resin. It refers to a state that can be approximated without including anything other than resin.

The resin 3a used as the sheath component is not particularly limited even if it is a homopolymer, but it is preferable to use a copolymer from the viewpoint of controlling the softening point, that is, the heat bonding temperature. As such a copolymer resin, a copolymer of polyethylene terephthalate (PET) and polyethylene isophthalate (PEI) (PET / P
In addition to EI), PET in which the ethylene glycol component is substituted with another different glycol component (for example, polyhexamethylene terephthalate (PHT)), and terephthalic acid component in which another different dibasic acid component is substituted (for example, , Polybutylene isophthalate (PBI)) and PET
Or a copolymer of substituted ones, and in addition to the substituted ones, a polymer of an aliphatic lactone having 4 to 11 carbon atoms such as polyεcaprolactone (PCL), or It may be a copolymer of polydiol and the above-mentioned substituted product or PET, and is not particularly limited. In any case, by substantially not mixing the piezoelectric material with the sheath component, stable spinning (thinning of the fiber diameter) and stable thermal bonding can be performed.

As the piezoelectric material 2b, an inorganic piezoelectric material such as barium titanate (TiBaO ₃ ) or lead zirconate titanate (PZT) is desirable in terms of availability on the market and high piezoelectric characteristics. It is. The mixing ratio of the piezoelectric material 2b to the resin 2a is not particularly limited as long as the moldability of the mixed resin 2a is not impaired.
It has been found that the range of 0 parts by volume is a good mixing ratio from the viewpoint of moldability.

In the binder fiber according to the present invention,
As described in claim 2, the core portion 2 may further contain a conductive material in addition to the piezoelectric material in the binder fiber according to claim 1. That is, as shown in FIGS. 2A and 2B, the binder fiber 1 according to the second aspect has the core 2 having a mixed resin composed of the piezoelectric material 2b, the conductive material 2c, and the resin 2a. Forming resin 2
a core portion 2 made of a resin 3a having a softening point lower than
Is composed of a sheath portion 3 that covers the outer surface of the housing.

Accordingly, the electric charge generated in the piezoelectric material 2b by the sound pressure or vibration input to the binder fiber 1 is efficiently consumed by the electric resistance (R) composed of the resin 2a and the conductive material 2c, Sound pressure and / or vibration will be more efficiently absorbed. In addition,
Also in this case, it is needless to say that stable spinning and heat bonding can be performed as described above by forming the sheath portion 3 substantially containing only the resin 3a without containing the piezoelectric material.

In the binder fiber according to the present invention, the sound pressure and vibration frequency (f) to be absorbed can be reduced by changing the electric resistance R, that is, by adjusting the mixing ratio of the conductive component. It is possible to change the frequency, so that sound and vibration of a desired arbitrary frequency can be mainly absorbed.

In order to adjust the frequency f, the LC resonance of a circuit composed of a capacitance (C) composed mainly of a piezoelectric material and a pseudo inductance component (L) composed of other parts. Formula for establishing: f = 1 /
It is necessary to change (2π (LC) ^0.5 ), but it is difficult to change this pseudo inductance component arbitrarily. Therefore, utilizing the fact that the L component changes by changing R, the target frequency f is determined by the change in R, that is, the amount of the conductive material 2c mixed.
It is a practical means to shift the peak of the vibration damping property.

As the conductive material 2c, carbon fiber or carbon powder can be preferably used, but metal powder can also be used. For any conductive component, the frequency f
Is desired, and the mixing ratio is not particularly limited, but is preferably in the range of 5 to 20 parts by volume with respect to 100 parts by volume of the resin from the viewpoint of moldability.

[0018] In the present invention, claim 4 is provided.
As described above, the piezoelectric material 2b is made of polyvinylidene fluoride (PVD).
F) Piezoelectric material or poly (vinylidene fluoride / trifle)
Oroethylene) (P (VDF / TrFE)) copolymer
Then, the resin 2a as the core component is replaced with the PVDF or P (VD
F / TrFE) copolymer can be a non-piezoelectric part
You. By using such an organic piezoelectric material,
Mechanical piezoelectric material TiBaO _ThreeAnd using PZT
Although the sound pressure and vibration absorption performance deteriorates slightly,
At a high speed during spinning.
In addition to being able to take up, in winding at low speed
The operation will also be stable.

The core component resin 2a has a solubility coefficient (SP value) of 1.60 × 10 ^{4 to} 2.78 × 10 ⁴ (J / m ³ ). It is desirable to use a resin of ^0.5 , whereby the electric interaction with the piezoelectric material becomes large, and the vibration damping performance of the binder fiber becomes higher. Here, the solubility coefficient (SP value) of the resin 2a is set to 1.60 × 10 ^{4 to} 2.78 × 1.
The reason for setting the range of 0 ⁴ (J / m ³ ) ^0.5 is that when a resin in this range is used, the electric interaction with the piezoelectric material is large,
This is because it was confirmed that the obtained vibration damping performance was significantly improved as compared with a resin having an SP value of less than 1.60 × 10 ⁴ . Such SP value is polyethylene as an example of the lower resin, inventor SP value 1.60 × 10 ⁴ ~
It has been confirmed that the vibration damping performance is slightly inferior to the resin in the range of 2.78 × 10 ⁴ (J / m ³ ) ^0.5 . The upper limit of the SP value does not need to be particularly limited in terms of performance, but is preferably 2.78 × 10 ^{4 in} terms of availability on the market.

By hot-pressing the binder fiber 1 as described above, the resin 3a of the sheath component is softened and thermally bonded to other fibers, and the fiber assembly shown in FIGS. 3 (a) and 3 (b) is obtained. 5 can be set. At this time, the binder fiber 1 can be thermoformed after being mixed with fibers generally available in the market, such as a fiber mainly composed of polyethylene terephthalate (PET), in addition to molding the fiber alone. Thus, the raw material cost is reduced, and the economy is improved.

Further, as shown in FIG. 4, for example, the fiber assembly 5 formed as described above is bonded to a plate-like material 6 to form a sound insulation structure 7. It can be used as a member for blocking noise, such as a part or a floor, and an excellent sound insulating effect can be economically obtained in a small space. In addition, as the plate-shaped material 6, a material made of metal or resin can be used, and is not particularly limited.

[0022]

The binder fiber according to the first aspect of the present invention has the above-mentioned structure, that is, a piezoelectric material is contained in a resin of a core component of a core-sheath type binder fiber having components having different softening points in a core and a sheath. Since the softening point of the component resin is lower than that of the core component resin, vibration damping performance can be improved by an electrical interaction between the piezoelectric material and the resin, and the binder fiber according to claim 2 of the present invention. In, since the core component resin contains a conductive material in addition to the piezoelectric material, the electric charge generated in the piezoelectric material is consumed by the resin and the conductive material to heat, and the vibration damping performance can be further improved. This provides an extremely excellent effect that the vibration damping property can be controlled for a desired frequency.

Further, in the binder fiber according to the third aspect of the present invention, since the resin of the sheath component does not include the piezoelectric material and is substantially composed of only the resin, the spinning and the stretching after the spinning are stabilized. In the binder fiber according to the fourth aspect, the piezoelectric material is made of polyvinylidene fluoride (PVDF) piezoelectric material or poly (fluoride). Vinylidene / trifluoroethylene) (P (VDF / TrFE))
Since the core component resin is a non-piezoelectric portion of the PVDF or P (VDF / TrFE) copolymer, the winding operation at the time of spinning is smaller than that using an inorganic piezoelectric material. Can be fast and stable,
In the binder fiber according to the fifth aspect, the resin of the core component has a solubility coefficient (SP value) of 1.60 × 10 ^{4 to} 2.78.
Since it is a resin having a polarity of × 10 ⁴ (J / m ³ ) ^0.5 , the electric interaction with the piezoelectric material can be increased, and the vibration damping performance can be further improved. Is brought.

Further, the fiber aggregate according to claim 6 of the present invention contains the binder fiber according to the present invention, and the sheath component of the binder fiber is softened and thermally bonded.
The vibration damping performance can be enhanced, and the sound insulating structure according to claim 7 of the present invention has the above-mentioned fiber assembly stuck to a plate-like material, and thus has excellent space saving and sound insulating properties. Thus, for example, an excellent effect that it can be suitably used as a sound insulation member of an automobile is provided.

[0025]

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

[Dynamic Viscoelasticity Test] Example 1 Polyamide 6 resin (PA6: SP value = 2.78 × 10 ⁴⁾
(J / m ³ ) ^0.5 , softening point = 225 ° C.) 100 parts by volume of barium titanate (TiBa) as a piezoelectric material
A resin was prepared by mixing 100 parts by volume of O ₃ ). Then, a core-sheath type binder fiber (outer diameter 40 μm) having a core portion of this mixed resin and a PET / PEI copolymer resin (copolymerization ratio 67/33, softening point = 150 ° C.) in a sheath portion was prepared.

Then, the obtained fiber is cut into a length of 40 mm to form a sample, and as shown in FIG. 5, both ends of the sample fiber 8 are fixed to fixing portions 9 and 9 by 10 mm each, and are moved. Viscoelasticity test. In the dynamic viscoelasticity test, the frequencies were 10, 50 and 100 Hz and 25
The loss tangent (tan δ) at 10 ° C. and a strain of 10 μm was measured.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 8 described later. This is considered to be due to the high SP value of polyamide 6 used as the resin for the core.

EXAMPLE 2 The core was changed to a resin in which 100 parts by volume of the polyamide 6 resin, 100 parts by volume of barium titanate, and 20 parts by volume of carbon fiber were further mixed. Under the conditions, a core-sheath type binder fiber (outer diameter: 40 μm) was prepared, and tan δ was similarly measured by a dynamic viscoelasticity test.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 1. This is considered to be because the efficiency was improved by further mixing carbon fibers.

EXAMPLE 3 The same conditions as in Example 1 were used except that the core was changed to a resin in which 100 parts by volume of the polyamide 6 resin, 100 parts by volume of barium titanate, and 10 parts by volume of carbon fiber were mixed. To prepare a core-sheath type binder fiber (outer diameter: 40 μm), and tan δ was measured in the same manner by a dynamic viscoelasticity test.

As a result, as shown in Table 1, a higher tan δ was observed as compared with Example 1, and
By comparing with the results of the above, it was confirmed that the frequency at which the peak of tan δ was obtained could be changed.

Example 4 The core was made of polyethylene terephthalate resin (PET: SP
Value = 2.19 × 10 ⁴ (J / m ³ ) ^0.5 , softening point = 255
C) 100 parts by volume, a resin obtained by mixing 100 parts by volume of barium titanate and 20 parts by volume of carbon fiber was used, and the core-sheath type binder fiber (outer diameter 40 μm ), And by dynamic viscoelasticity test,
Similarly, tan δ was measured.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 8. This is considered to be because the SP value of polyethylene terephthalate used as the resin for the core was higher than that of polyethylene.

Example 5 A core portion was made of a polypropylene resin (PP: SP value = 1.64 ×
For 100 parts by volume of 10 ⁴ (J / m ³ ) ^0.5 , softening point = 170 ° C.), 100 parts by volume of barium titanate and 20 parts by volume of carbon fiber were changed to a mixed resin. Under the same conditions as above, the core-sheath type binder fiber (outer diameter 40μ)
m), and a dynamic viscoelasticity test was performed in the same manner to obtain ta
nδ was measured.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 8. This is considered to be because the SP value of the polypropylene used as the resin for the core was higher than that of polyethylene.

Example 6 Polyvinylidene fluoride (PVDF: softening point = 165 ° C.)
To the core, PET / PEI copolymer resin (copolymerization ratio 67 /
33) was provided in the sheath portion, and a core-sheath type binder fiber (outer diameter: 40 μm) in which the ratio of β crystal in the PVDF crystal was 20% was prepared. Then, a dynamic viscoelasticity test was similarly performed, and ta
nδ was measured.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 8.

The ratio of the β crystal is calculated according to the following equation.
It was calculated from the scattering intensity based on α- and β-crystals in wide-angle X-ray scattering.

Ratio of β crystal = scattering intensity of β crystal / (scattering intensity of α crystal + scattering intensity of β crystal)

Example 7 A resin obtained by mixing 20 parts by volume of carbon fiber with 100 parts by volume of polyvinylidene fluoride (PVDF) was used as a core, and PET was used.
/ PEI copolymer resin (copolymerization ratio 67/33) in the sheath part, to produce 20% core-sheath type binder fiber (outer diameter 40 μm) in PVDF crystal, By the test, tan δ was measured similarly.

As a result, as shown in Table 1, a higher tan δ was observed than in Example 6. This is considered to be because the efficiency was improved by further mixing carbon fibers.

Example 8 A core was made of a high-density polyethylene resin (HDPE: SP value =
1.58 × 10 ⁴ (J / m ³ ) ^0.5 , softening point = 130 ° C.)
A core-sheath type binder fiber (outer diameter: 40 μm) was prepared under the same conditions as in Example 1 except that the resin was changed to a resin in which 100 parts by volume of barium titanate was mixed with 100 parts by volume. In an elasticity test, tan δ was measured similarly.

As a result, as shown in Table 1, a lower tan δ was observed as compared with the results of Examples 1 to 7. This is SP of HDPE used as core resin.
This is considered to be due to the small value.

Comparative Example 1 A core / sheath type binder fiber (outer diameter: 40 μm) having the above polyamide 6 resin in the core and the above PET / PEI copolymer resin in the sheath.
m) was prepared, and tan δ was similarly measured by a dynamic viscoelasticity test.

As a result, as shown in Table 1, lower tan δ was observed as compared with the results of Examples 1 to 8.

[0047]

[Table 1]

[Transmission Loss Test] As a reduced form of the transmission loss measuring device specified in JIS A1416, an apparatus having a structure shown in FIG. 6 was used, and the transmission loss of the sound insulation structure prepared in the following manner was compared. .

The transmission loss measuring apparatus 10 shown in the figure has two reverberation boxes, ie, an input-side reverberation box 11 and an output-side reverberation box 12, and a speaker 13 as a sound source is attached to the input-side reverberation box 11. With both reverberation boxes 11 and 1
A sample as a measurement target can be mounted on the partition wall 14 that partitions the two. An input-side sound pressure gauge 11a for measuring sound pressure is provided in both reverberation boxes 11 and 12.
And an output-side sound pressure gauge 12a. The transmission loss TL (dB) is obtained by comparing the input-side sound pressure value I (dB) measured by the input-side sound pressure meter 11 a with the output-side sound pressure meter 1.
The difference is given by the following equation as the difference between the output-side sound pressure values O (dB) measured in 2a.

TL (dB) = I (dB) -O (dB)

Example 9 Short fibers made of polyethylene terephthalate (PET) (H38F, manufactured by Unitika Ltd., fiber diameter 36 μm)
The binder fiber prepared in Example 4 was mixed with the binder fiber at a mass ratio of 7%.
After mixing at 0:30, the heat-formed nonwoven fabric was sandwiched between metal plates to form a sound insulation structure, and this sound insulation structure was mounted on the transmission loss measuring apparatus 10 and transmission loss TL (dB) was set for each frequency. Was measured.

Comparative Example 2 The above short fibers made of polyethylene terephthalate (PET) and a polyester-based binder fiber (Unitika Co., Ltd.)
, 4080, fiber diameter 39 μm) in a mass ratio of 70: 3.
After being mixed to 0, the non-woven fabric formed by heating is sandwiched between metal plates to form a sound insulation structure, and this sound insulation structure is mounted on the transmission loss measuring device 10, and similarly the transmission loss TL (dB)
Was measured.

FIG. 7 shows the transmission loss TL of the sound insulating structure according to the ninth embodiment based on the result of the comparative example 2, that is, the transmission loss T L of the sound insulating structure according to the ninth embodiment.
9 is a diagram in which a value obtained by subtracting the transmission loss TL of the sound insulating structure according to Comparative Example 2 from L is plotted for each frequency, and FIG.
At all frequencies exceeded the result of Comparative Example 2, and it was confirmed that the sound insulation performance was particularly excellent at frequencies around 200 Hz.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a structural example of a binder fiber according to the present invention.

FIG. 2A is a schematic view showing another example of the structure of the binder fiber according to the present invention. FIG. 3B is an enlarged cross-sectional view illustrating a structure of a core portion of the binder fiber illustrated in FIG.

FIG. 3 (a) is a schematic view showing an example of a shape of a fiber aggregate including a binder fiber according to the present invention. (B) It is an enlarged view of the fiber assembly shown in FIG.

FIG. 4 is a schematic cross-sectional view showing an example of the shape of a sound insulation structure made of a fiber aggregate including binder fibers according to the present invention.

FIGS. 5A and 5B are a plan view and a front view showing a method for fixing a sample fiber in a dynamic viscoelasticity test.

FIG. 6 is a schematic diagram showing a structure of a measuring device used for a transmission loss test.

FIG. 7 is a graph showing the measurement results of the transmission loss of the sound insulating structure according to the present invention based on the measurement results of Comparative Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Binder fiber 2a Resin (core part) 2b Piezoelectric material 2c Conductive material 3a Resin (sheath part) 5 Fiber assembly 6 Plate-like material 7 Sound insulation structure 8 Sample (fiber) 9 Sample fixing part 10 Transmission loss measuring device 11 Input side Reverberation box 11a Input side sound pressure measurement device 12 Output side reverberation box 12a Output side sound pressure measurement device 13 Sound source (speaker) 14 Partition wall (sample mounting position)

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[Procedure amendment]

[Submission date] August 25, 2000 (2008.2
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

FIG. 7 is a graph showing the measurement results of the transmission loss of the sound insulating structure according to the present invention based on the measurement results of Comparative Example 2.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) E04B 1/98 E04B 1/98 H E04C 2/10 E04C 2/10 2/20 2/20 Z 2/24 2/24 R 2/26 2/26 V (72) Inventor Katsumi Moroboshi 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture F-term in Nissan Motor Co., Ltd. (reference) 2E001 DF02 DF07 DG01 FA24 GA12 GA29 HB01 HD11 JD04 2E162 CB01 CD04 CD15 4L041 BA02 BA05 BA21 BA49 BC09 BD03 BD11 BD20 CA06 CA12 CA21 CA37 CA47 CB02 CB06 CB27 CB28 DD01 DD03 DD05 DD14 DD15 DD21 4L047 AA21 AA23 AA27 AA29 BA09 BB06 BB07 CB03

Claims (7)

[Claims] 1. A core-sheath type binder fiber having components having different softening points in a core and a sheath, wherein the resin of the core component contains a piezoelectric material and the softening point of the resin of the sheath component is A binder fiber having a lower softening point than a resin. 2. The binder fiber according to claim 1, wherein the core component resin contains a conductive material in addition to the piezoelectric material. 3. The resin according to claim 1, wherein the resin of the sheath component is substantially composed of only the resin.
A binder fiber as described. 4. The piezoelectric material is made of polyvinylidene fluoride (PVD).
F) a piezoelectric material or a poly (vinylidene fluoride / trifluoroethylene) (P (VDF / TrFE)) copolymer, wherein the resin of the core component is PVDF or P (VDF)
The binder fiber according to any one of claims 1 to 3, wherein the binder fiber is a non-piezoelectric portion of a (/ TrFE) copolymer. 5. A resin having at least a core component having a solubility coefficient (SP value) of 1.60 × 10 ^{4 to} 2.78 × 10 ⁴ (J / m).
³ ) The binder fiber according to any one of claims 1 to 3, wherein the binder fiber is a resin having a polarity of ^0.5 . 6. A fiber assembly comprising the binder fiber according to any one of claims 1 to 5, wherein a sheath component of the binder fiber is softened and thermally bonded. 7. A sound insulating structure, wherein the fiber aggregate according to claim 6 is attached to a plate-like material.