JP2002202780A - Fire-retardant acoustic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive fire-retardant acoustic material which is light in weight and has superior sound absorption characteristics and fire retardance in combination. SOLUTION: This fire-retardant acoustic material is formed by adhering a nonwoven fabric of extremely fine fibers of >=50 g/m2 in surface density mainly, composed of fibers of <=1.0 dtext by a thermoplastic adhesive of a melting point lower than the melting point of the nonwoven fabric of the extremely fine fibers to one surface of the nonwoven fabric of organic fibers of 100 to 500 g/m2 in surface density, formed by using the organic fibers of 1.0 to 12 dtext and is self-extinguishable in fire retardance standards for automobiles (FMVSS. No.302).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant sound-absorbing material which is lightweight, has high performance, is recyclable, and is suitable for low-cost automobiles.

[0002]

2. Description of the Related Art At present, good sound absorbing performance is required for high performance sound absorbing applications, and as a conventionally used sound absorbing material, thermoplastic fibers (mainly,
Patents such as polyester-based fibers) and core-sheath type (core; high melting point, sheath; low melting point) fiber blends, and thermoformed (heat-fused) nonwoven fabrics have been proposed.

However, the required level of the sound absorbing performance of the sound absorbing material for automobiles has been increasing year by year, and particularly, an improvement in the performance level in the mid-high range (800 to 2000 Hz) is required. To meet this demand, it is possible to increase the basis weight, but this will lead to an increase in weight. Also,
2-7 dt for thermoformed non-woven fabric using thermoplastic fiber
If a relatively thin fiber ex is used, the level of sound absorption performance can be increased, but the weight is still inevitable.

[0004] Therefore, the inventors of the present invention have found that 1.0 to 10 dt.
the nonwoven fabric areal density 100 to 1000 g / m ² in ex organic fibers, the sound absorption excellent structure is lightweight when laminating microfibrous non-woven fabric by a melt blow method a surface density of 20 to 100 g / m ² is obtained However, when flame retardancy is required, it has been found that further improvement is required. As a countermeasure, it is conceivable to use a flame-retardant fiber for the organic fiber nonwoven fabric, but there is a problem of an increase in cost and weight.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been found to solve the above-mentioned problems, and is intended to be used for an inexpensive automobile having both excellent sound absorption and flame retardancy while suppressing an increase in weight. It is intended to obtain a suitable flame-retardant sound absorbing material.

[0006]

That is, the present invention provides a method for manufacturing a semiconductor device comprising:
Surface density using organic fiber of ~ 12 dtex is 100 ~ 5
1.0 g mainly on one side of the organic fiber non-woven fabric of 00 g / m ^2.
A nonwoven fabric made of fibers having a surface density of 50 g / m ² or more and having a surface density of 50 g / m ² or more is bonded with a thermoplastic adhesive having a melting point lower than the melting point of the fine fiber nonwoven fabric. No. 302) is a flame-retardant sound-absorbing material characterized by being self-extinguishing.

Further, the amount of the thermoplastic adhesive is 10 to
The flame-retardant sound-absorbing material according to the above, wherein the weight is 30 g / m ² .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The material of the melt-blown nonwoven fabric in the present invention is not particularly limited as long as it is a thermoplastic resin having a melting point higher than that of the thermoplastic resin adhesive. However, from the viewpoint of improving the flame retardancy due to the improvement in drip properties and the stability of spinnability, the melting point is about 120 to 200 ° C. Preferably, there is.

The fineness of the constituent fibers of the melt blown nonwoven fabric is 1 dtex or less. If it exceeds 1 dtex, a sufficient decrease in air permeability is unlikely to occur. Preferably 0.5d
tex or less, and 0.0001 dte from the viewpoint of spinnability.
x or more is preferable.

The thermoplastic resin adhesive is not particularly limited as long as it has a melting point lower than the melting point of the material of the melt-blown non-woven fabric. C. or lower is preferred. In particular, a polyolefin-based thermoplastic resin is preferable, and a polyethylene-based thermoplastic resin adhesive is more preferable because it has a low melting point and is inexpensive.

For laminating and bonding the organic fiber nonwoven fabric and the melt-blown nonwoven fabric, a melt bonding method can be adopted. In this case, the heating temperature is not problematic as long as it is higher than the melting point of the thermoplastic resin adhesive. It is necessary to melt the adhesive uniformly from the viewpoint of adhesive strength, and the softening / melting (olefin type), shrinkage (polyester type), etc. of the organic fiber nonwoven fabric become a problem. Optimal. In this case, it does not matter whether a load is applied or not, but in order to prevent an excessive decrease in the thickness of the laminate, a clearance having a predetermined thickness is set at the time of laminating, and heating and melting are performed.
It is desirable to bond.

[0012] The organic fiber non-woven fabric is 1.0 to 10 dtex.
A short fiber having a surface density of 100 to 500 g / m ² may be used, but a short fiber having a sound absorption of ² to 7 dtex is desirable, and a fiber having a higher melting point than a melt blown nonwoven fabric is more preferable. desirable. Further, it is desirable that the needle-punched nonwoven fabric has fewer restraining points. still,
Processing is possible even if the areal density of the organic fiber nonwoven fabric is less than 100 g / m ² , but in this case, sufficient sound absorbing properties cannot be obtained.

Next, the flame-retardant mechanism according to the present invention will be briefly described as follows. First, if the areal density of the organic fiber nonwoven fabric of the laminate of the melt blown nonwoven fabric and the organic fiber nonwoven fabric is 500 g / m ² or more, sufficient flame retardancy can be obtained due to the basis weight effect without particularly performing flame retardancy treatment.

However, the areal density of the organic fiber nonwoven fabric is 1
In the range of 00 to 500 g / m ² , the basis weight effect is small, and the flame retardancy of the laminate of the melt-blown nonwoven fabric and the organic fiber nonwoven fabric is reduced. No. 302 (self-extinguishing) is not passed. Or, even if it passes, it becomes unstable (evaluation results of pass and reject are mixed depending on the object).

Therefore, when the melt-blown nonwoven fabric and the organic fiber non-woven fabric are melt-bonded using a thermoplastic resin adhesive such as polyethylene resin having a melting point lower than the melting point of the melt-blown nonwoven fabric, the drip effect of the melt-blown nonwoven fabric alone is insufficient. While a low-melting thermoplastic resin adhesive is melt-bonded (interposed) to the organic fiber non-woven fabric, the drip effect of both is large and the viscosity is small, while the flame effect is not obtained. Because the flame that ignited each fiber quickly dropped with the drip,
It is considered that a synergistic effect due to both drip is obtained, and the flame retardancy is further improved and stabilized.

By the above processing, flame retardancy is improved, and organic
Surface density of fiber non-woven fabric is 500g / m ^TwoLess than a car
FMVSS. No. Stabilize the 302 method
You can pass. In addition, regulations for home interior use
45 degree tilt method (micro burner method)
You can pass at the same time.

[0017]

The present invention will be described in more detail with reference to the following examples and comparative examples. In addition, the evaluation method in the Example and the comparative example was based on the following method.

(Evaluation method) Sound absorption coefficient: Normal incidence method; JIS A 1405 method. Flame retardancy: Automotive flame retardancy standard FMVSS. No. 302
And a 45-degree tilt method (micro burner method).

(Example 1) The single yarn dtex is 0.0001.
A ～0.2Dtex, basis weight creates a polypropylene meltblown nonwoven fabric is 70 g / m ^2. Furthermore, using a polyester short fiber mixed with 2.2 dtex 70% and 6.7 dtex 30%, a basis weight of 200 g / m
^2. A non-woven fabric having a thickness of 5 mm is prepared by a needle punch method, and the above two types of non-woven fabric are laminated, and a polyethylene-based adhesive powder (UM8510 manufactured by Ube Industries, melting point 104)
° C) is uniformly dispersed and interposed at 25 g / m ² ,
The sample was melt-bonded at an adhesion clearance of 4 mm and a temperature of 120 ° C. for 30 seconds to obtain an evaluation sample. Table 1 shows the evaluation results.

(Example 2) The single yarn dtex is 0.0001.
A ～0.2Dtex, basis weight creates a polypropylene meltblown nonwoven fabric is 50 g / m ^2. Further, using a polyester short fiber mixed with 2.2 dtex 70% and 6.7 dtex 30%, a basis weight of 300 g / m
^2. A non-woven fabric having a thickness of 6 mm is prepared by a needle punch method, and the above two types of non-woven fabrics are laminated.
° C) is uniformly dispersed and interposed at 25 g / m ² ,
The sample was melt-bonded at an adhesion clearance of 5 mm at a temperature of 120 ° C. for 30 seconds to obtain an evaluation sample. Table 1 shows the evaluation results.

(Comparative Example 1) Single yarn dtex is 0.0001
A ～0.2Dtex, basis weight creates a polypropylene meltblown nonwoven fabric is 70 g / m ^2. Furthermore, using a polyester short fiber mixed with 2.2 dtex 70% and 6.7 dtex 30%, a basis weight of 200 g / m
^2. A nonwoven fabric having a thickness of 5 mm was prepared by a needle punch method, the above two types of nonwoven fabrics were laminated, and bonded by a needle punch method to obtain an evaluation sample. Table 1 shows the evaluation results.

(Comparative Example 2) The single yarn dtex is 0.0001.
A ～0.2Dtex, basis weight creates a polypropylene meltblown nonwoven fabric is 70 g / m ^2. Further, using a polyester short fiber mixed with 2.2 dtex 70% and 6.7 dtex 30%, a basis weight of 300 g / m
^2. A non-woven fabric having a thickness of 6 mm was prepared by a needle punch method, and the above two types of non-woven fabric were laminated and bonded by a needle punch method to obtain an evaluation sample. Table 1 shows the evaluation results.

(Comparative Example 3) Single yarn dtex is 0.0001
A ～0.2Dtex, basis weight creates a polypropylene meltblown nonwoven fabric is 70 g / m ^2. Further, a nonwoven fabric having a basis weight of 500 g / m ² and a thickness of 6 mm was prepared using a 2.2 dtex polyester short fiber by a needle punch method, and the above two types of nonwoven fabrics were laminated.
Lamination was performed using a needle punch method, and used as an evaluation sample. Table 1 shows the evaluation results.

[0024]

[Table 1]

[0025]

[Table 2]

Example 3 An evaluation sample was prepared in the same manner as in Example 1 except that the polyethylene-based adhesive was changed to Danfuse 7211 (manufactured by Nitto Boss Co., Ltd., melting point: 85 ° C.). The evaluation result was FMVSS No. The 302 method was self-extinguishing and the 45-degree tilt method (micro-Hauerner method) passed. The sound absorption coefficient (%) by the vertical incidence method showed the same pattern as in Example 1, and it was confirmed that the sound absorption was good.

As described above, the example has the same basis weight as the comparative example, but also has the FMVS flame retardant standard for automobiles.
S. No. You can pass 302. Not only that, it can also pass the 45-degree tilt method (micro burner method) used in interior applications. In addition, the sound absorbing property is maintained at the same level or more as the sound absorbing product, and it is understood that the sound absorbing material is a good sound absorbing material.

[0028]

The present invention provides a method for laminating and adhering a microfiber non-woven fabric to one side of an organic fiber non-woven fabric having a specific surface density.
It is a lightweight laminate bonded with a thermoplastic adhesive having a melting point lower than the melting point of the ultrafine fiber nonwoven fabric.
MVSS. No. 302) is self-extinguishing,
It is possible to provide an inexpensive sound absorbing material having excellent sound absorbing properties and flame retardancy and suitable for an inexpensive automobile.

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Claims (2)

[Claims] 1. An organic fiber nonwoven fabric having an area density of 100 to 500 g / m ^{2 using} an organic fiber of 1.0 to 12 dtex has an area density of 50 g / m2 mainly composed of fibers of 1.0 dtex or less. the microfibrous non-woven fabric is m ² or more, and is bonded with a thermoplastic adhesive of lower than the melting point of the ultra-fine fiber nonwoven melting point, automotive flame retardancy rating (FMVSS.Nanba3
02) A flame-retardant sound-absorbing material characterized by being self-extinguishing. 2. The amount of the thermoplastic adhesive is 10 to 30 g / g.
The flame-retardant sound-absorbing material according to claim 1, wherein m ² .