KR20160081609A - Composite fiber aggregate of micro-fiber having good adhesion and sound-absorption, Manufacturing method thereof and Sound-absorbing materials containing the same - Google Patents

Abstract

The present invention relates to a micro-fibrous conjugate fiber assembly and a method of manufacturing thereof, and more specifically, to a micro-fibrous conjugate fiber assembly introducing polyethylene terephthalate (PET) short fibers to melt-blown conjugate fibers with bulky properties to enhance adhesive properties and sound-absorbing properties, a method of manufacturing thereof, and sound-absorbing materials containing the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microfiber composite fiber aggregate excellent in adhesiveness and sound absorption properties, a method for producing the same, and a sound absorbing material containing the same,

The present invention relates to a composite fiber aggregate having a bulky structure which improves the adhesion between fibers in the composite fiber to improve the defective rate and the sound absorption property, a method for producing the composite fiber aggregate, and further relates to an application product thereof.

Such as a vacuum cleaner, a dishwasher, a washing machine, an air conditioner, an air purifier, a computer, a projector, and the like, and the problem of noise pollution becomes more serious. Therefore, efforts to block or reduce the noise generated from various noise sources in the modern life are continuing, and in the developed countries, the legal regulations to regulate the noise level between the interlayer and the generation of apartment houses and apartments are increasingly strict . In addition, the noise introduced into the automobile interior is typically generated by the engine, such as the engine noise transmitted through the vehicle body or the air, and the friction sound with the wheel and the ground. In order to suppress such noise, the engine cover and the hood insulation are used The effect of reducing the noise is insignificant, and the dash outer, the dash inner, and the floor carpet attached to the outside of the vehicle play a role of removing most of the noise.

There are two ways to improve the noise. One is to improve the sound absorption performance and the other way to improve the sound insulation performance. Sound absorption is the sound energy that is transmitted through the inner path of the material and is converted into heat energy and disappears. And is reflected and shielded by the shield.

Felt, sponge, polyurethane foam and the like are conventionally used as suction and sound insulating materials conventionally used. In addition, sound absorbing materials impregnated with a thermoplastic resin or a thermosetting resin in compressed fiber, glass fiber, rock surface, or regenerated fiber are listed . However, most of the sound absorbing materials described above have insufficient soundproofing ability, and most of the sound absorbing materials contain harmful components to the human body.

In recent years, regulations on the environment-friendly and recyclability have been gradually strengthened, and the use ratio of the thermoplastic resin-based fiber-absorbing material is increasing. In order to reduce carbon dioxide, the regulation of fuel efficiency of the vehicle is gradually increasing. The improvement of fuel efficiency can be attained through the weight reduction of parts, so it is necessary to develop lightweight sound absorbing material with improved performance.

Accordingly, research and development on a sound absorbing material which is harmless to the human body and excellent in the sound absorbing function capable of effectively absorbing and reducing the noise while reducing the thickness has been actively conducted.

As a sound absorbing material which has been conventionally researched and developed, there is disclosed a sound absorbing material (U.S. Patent Publication No. 1954-433600) which is a web type in which general short fibers having a diameter of 10 탆 or more are crimped to a general meltblown fiber in an amount of 10% Discloses a sound absorbing material and a heat insulating material which are webs formed of a meltblown fiber containing bulky fibers that are crimped. However, since the porosity of a web made of a general meltblown fiber is very large, the structure of the web is insufficient and the durability of the sound absorbing material is insufficient There is a problem that the thickness of the sound absorbing material must be greatly increased in order to provide a sufficient sound absorbing effect as well as not providing a sufficient sound absorbing effect.

Although a three-dimensional nonwoven web made of a meltblown microfine fiber is disclosed, a three-dimensional nonwoven web has a large porosity and thus is not densely structured to have a poor durability. It is necessary to increase the thickness of the three-dimensional nonwoven web significantly, and it is difficult to manufacture the nonwoven web composed of three dimensions as described above, which increases the manufacturing cost significantly. In addition, a sound absorbing material is also disclosed, which includes staple fibers that can be fused to the meltblown fibers by heat to impart three-dimensional stability. However, such a sound absorbing material still has a problem of insufficient sound insulation performance. In addition, a sound absorbing material using a honeycomb structure having a plurality of spaces together with meltblown fibers has been disclosed. However, such a sound absorbing material is insufficient in soundproof performance and has a problem in that it is limited in its application because of lack of flexibility.

In addition, the existing micro-acoustic sound absorbing material is problematic in that, when it is subjected to trimming or the like, the adhesive force between the fibers in the sound absorbing material is so weak that the fibers constituting the sound absorbing material adhere to the device and cause defective products, .

U.S. Published Patent Application No. 1954-433600 Korean Patent Publication No. 10-2011-0122566

Disclosure of the Invention The present invention has been conceived to solve the problems as described above, and an object of the present invention is to provide a composite fiber aggregate which not only improves the adhesion between the fibers in the composite fiber aggregate to improve the defective rate and merchantability, And a sound absorbing material using the same.

In order to solve the above-mentioned problems, the present invention relates to a microfine fiber aggregate comprising melt blown conjugate fibers and polyethylene terephthalate short fibers.

In one preferred embodiment of the present invention, the meltblown conjugate fiber of the microfine fiber composite aggregate of the present invention is in a side-by-side form, and the polypropylene-based compound and the polyethylene- Side-by-side type composite fiber comprising a polypropylene fiber and a polypropylene fiber in a ratio of 9: 1 to 5: 1 by weight.

In a preferred embodiment of the present invention, the polypropylene-based compound of the microfine fiber composite aggregate of the present invention may be characterized by containing at least one selected from polypropylene and polypropylene random copolymers.

Further, in a preferred embodiment of the present invention, the polypropylene-based compound of the microfine fiber composite according to the present invention is characterized by being a polypropylene having a melt index (MI) of 800 to 1,500 g / 10 min (230 ° C) .

As a preferred embodiment of the present invention, in the microfine fiber composite aggregate of the present invention, the polyethylene compound may be characterized by containing low density polyethylene (LDPE).

The LLDPE has a melt index (MI) in the range of 140 to 160 g / 10 min, and the LLDPE of the polyethylene micro- (190 DEG C).

Also, as a preferred embodiment of the present invention, the LLDPE may have a specific gravity of 0.90 to 0.95.

In one preferred embodiment of the present invention, the meltblown composite fibers of the microfine fiber composite aggregate of the present invention may have an average diameter of 1 탆 to 8 탆.

In one preferred embodiment of the present invention, the polyethylene terephthalate staple fibers of the inventive microfine fiber composite aggregate have an average fineness of 5 to 10 denier, an average number of crimps of 12 to 17 fibers / inch and an average fiber length of 50 to 30 mm, 80 mm.

Also, as a preferred embodiment of the present invention, the polyethylene terephthalate staple fiber may have a strength of 4.8 g / d to 6.5 g / d and an elongation of 35% to 45%.

In one preferred embodiment of the present invention, the microfine fiber composite aggregate of the present invention comprises the meltblown conjugate fiber and the polyethylene terephthalate fiber in a weight ratio of 3 to 9: 1 to 7.

In one preferred embodiment of the present invention, the microfine fiber composite aggregate of the present invention is a nonwoven fabric and may have a surface area of 250 g / m ² to 400 g / m ² .

In one preferred embodiment of the present invention, the microfine fiber aggregate according to the present invention has an absorption coefficient at a frequency of 1,000 g / m < ² > at a frequency of 300 g / m < Of 0.80 or more and a sound absorption coefficient at 2,000 Hz of 0.90 or more.

As a preferred embodiment of the present invention, when the density of the microfine fiber composite of the present invention is 300 g / m ² , the absorption coefficient at 3,150 Hz is measured according to the alpha cabin method of ISO R 354, Is 0.95 or more, and the absorption coefficient at 5,000 Hz is 1.05 or more.

Further, as a preferred embodiment of the present invention, when the microfine fiber composite aggregate of the present invention has a surface density of 300 g / m ² and an adhesion strength of 5.5 N / 25 mm to 14 N / 25 mm.

Another object of the present invention is to provide a method for producing the various types of microfine fiber assemblies described above, wherein the polypropylene-based compound-containing resin and the polyethylene-based compound-containing resin are melt-knitted together with a side- It is possible to prepare a microfiber composite fiber aggregate by mixing a meltblown composite fiber and a polyethylene terephthalate fiber by mixing a meltblown air stream with a polyethylene terephthalate fiber through a blowing device and a nozzle have.

In one preferred embodiment of the present invention, the meltblown composite spinning is performed at a hot air temperature of 260 ° C to 290 ° C.

Another object of the present invention is to provide a sound absorbing material of various types of composite fiber aggregates as described above.

The present invention also relates to an interior material, an automobile interior material, an electric product or an electronic product using the sound absorbing material.

INDUSTRIAL APPLICABILITY The composite fiber aggregate of the present invention has an excellent sound absorption coefficient for not only a high frequency but also a low frequency, and is excellent in adhesion force between the composite fiber aggregate fibers. Therefore, when the composite fiber aggregate is used as a sound absorption material, workability is easy, It is suitable for use as a lightweight material such as a bar, an interior material of a moving means such as a car, an airplane, a ship, an electronic product part such as a cell phone, a notebook computer, a TV, and a building interior material.

Fig. 1 is a SEM photograph of the composite fiber aggregate produced in Example 1. Fig.
Fig. 2 is a schematic view in which support layers are introduced on both sides of the composite fiber assembly of the present invention.
3 is a photograph showing an apparatus for measuring the adhesive strength of the composite fiber fabric prepared in Example 1 performed in Experimental Example 1. FIG.
4 is a photograph of a wheel house of a vehicle to which the sound absorbing material of the present invention manufactured in Production Example 1 is applied.
FIG. 5 is a photograph of a c-pillar to which a sound absorbing material of the present invention manufactured in Production Example 2 is applied. The c-pillars play an important role not only in supporting the roof of an automobile but also in improving the rigidity and safety of the vehicle body It is located between the rear glass and the side glass of the pillar.
FIG. 6 is a photograph of a luggage side, which is a trunk side built-in part of a vehicle to which the sound absorbing material of the present invention manufactured in Production Example 3 is applied.

Hereinafter, the present invention will be described in more detail.

The composite fiber aggregate of the present invention is characterized in that when a polypropylene-based compound-containing resin and a polyethylene-based compound-containing resin are melt-blended in a side-by-side composite spinneret, a blowing facility is provided in the melt- 1, the meltblown conjugate fiber 12 and the polyethylene phthalate short fiber (PET) 11 are mixed together by mixing the meltblown conjugate fiber and the polyethylene terephthalate short fiber by mixing the polyethylene terephthalate short fiber through the nozzle, To produce a microfine fiber aggregate.

At this time, the meltblown composite spinning is preferably performed at a hot air temperature of 260 to 290 ° C, preferably 260 to 280 ° C, and when the hot air temperature is less than 260 ° C, Since the thickness of the fiber of the polypropylene compound constituting one side of the side composite fibers becomes thick, the porosity of the fiber aggregate decreases, and the amount of air contained therein is relatively reduced, thereby reducing the flow resistance of sound energy caused by the microfine fibers and the air layer The effect may be deteriorated, and as a result, the sound absorption performance may be deteriorated. When the hot air temperature is higher than 290 ° C, the fibers of the polypropylene-based compound component are not stably focussed and blown, and the fibers of the polyethylenic component constituting the other side of the sheath-by- There is a problem that the structure of the composite fiber aggregate is deteriorated because the bonding property is deteriorated.

In the present invention, the polyethylene terephthalate (hereinafter referred to as PET) staple fiber is produced by spinning a PET resin at a spinning temperature of 270 ° C. to 285 ° C. and a spinning speed of 1,000 to 1,400 m / min to produce staple fibers; Stretching the staple fibers at a temperature in the range of 2.5 to 4.0 times at 70 to 85 캜; And heat treating the stretched staple fibers at 130 ° C to 150 ° C.

In the production of PET staple fibers, the spinning temperature in the step of producing the staple fibers is preferably 270 ° C to 285 ° C, and preferably 272 ° C to 278 ° C. It is preferable that the spinning speed is 1,000 to 1,400 m / min, preferably 1,100 to 1,300 m / min, and more preferably 1,150 to 1,250 m / min when producing staple fibers.

In the production of PET staple fibers, the stretching step can be carried out at 70 ° C to 85 ° C, preferably at 75 ° C to 80 ° C, and the stretching ratio is 2.5 to 4.0 times, preferably 3.0 to 3.5 times It is better to stretch it. In the production of PET staple fibers, the heat treatment temperature is preferably 130 占 폚 to 150 占 폚, and preferably 135 占 폚 to 145 占 폚, which is advantageous from the viewpoint of securing elongation.

The PET resin used for producing the PET staple fiber may have a melting point of 250 ° C to 270 ° C, preferably a melting point of 255 ° C to 265 ° C.

It is advantageous from the viewpoint of moldability that the PET resin has an intrinsic viscosity (IV) of 0.60 to 0.70, preferably 0.62 to 0.68.

The thus prepared PET staple fibers preferably have an average fineness of 4 to 10 denier, preferably 4 to 9 denier, and when the staple fiber is less than 4 denier, Carding process, there may be a problem of lowering the running efficiency and lowering the uniformity. When the density exceeds 10 denier, the thickness of the composite fiber aggregate itself becomes thick and the gap between the fiber and the fiber becomes large, There is a problem that the performance is deteriorated, so it is better to use the one within the above range.

The PET staple fiber preferably has an average fiber length of 50 mm to 80 mm, preferably 55 mm to 75 mm, and more preferably 60 mm to 70 mm. When the fiber length is less than 50 mm It may be difficult to maintain the homogeneity of the composite fiber aggregate because it is difficult to uniformly quantitatively supply the short fibers, and when the length exceeds 80 mm, the composite fiber aggregate in which the single fibers are mixed at a constant weight ratio is relatively thick There may be a problem of maintaining the target horn performance because the number of short fibers increases.

The PET staple fiber preferably has an average crimp number of 12 to 17 crimps per inch, preferably an average crimp count of 13 to 16 crimps per inch, more preferably 13.5 to 15 pcs / inch, If the average number of crimps is smaller than 12 / inch, there is a problem that the thickness of the fiber aggregate becomes thinner and the sound absorption performance is lowered. If the average crimp number exceeds 17 / inch, the process of opening and carding PET staple fibers There is a problem that the uniformity of the fibrous aggregate becomes poor in the final product, and as a result, the sound absorption performance and the compressive recovery ability are deteriorated.

The PET staple fiber may have a strength of 4.8 to 6.5 g / d, preferably 5.0 to 6.2 g / d, and an elongation of 35% to 45%, preferably an elongation of 37% to 43% .

In the microfine composite fiber aggregate of the present invention, the meltblown composite fiber is a side-by-side composite fiber comprising a polypropylene-based compound and a polyethylene-based compound in a weight ratio of 5 to 9: 1 to 5, If the content of the polyethylene compound is less than 1 part by weight, there may be a problem that the adhesive property and the bulky property are lowered. If the amount is more than 5 parts by weight, There may be a problem that the defects increase in the whole.

The side-by-side type meltblown conjugate fiber preferably has an average diameter of 1 to 8 탆, preferably 1 to 5 탆, more preferably 2 to 4 탆, If the average diameter of the fibers is less than 1 탆, there is a problem that the manufacturing cost is greatly increased due to the lowering of the productivity, the sound absorption performance is decreased due to the reduction of the thickness and the compression recovery rate, and when the diameter exceeds 8 탆, The structure is not formed densely, which may result in problems of sound absorption performance and durability deterioration.

In the conjugated fiber of the present invention, the polypropylene-based compound (or the polypropylene-based compound-containing resin) may include at least one selected from a polypropylene and a random copolymer of polypropylene, have. The polypropylene preferably has an MI (melt index) of 800 to 1,500 g / 10 minutes (230 ° C), preferably 1100 to 1,400 g / 10 minutes (230 ° C) If the MI is less than 800 g / 10 min (230 ° C), the fineness of the meltblown fibers becomes thick and the processing temperature is increased to 290 ° C There is a problem in that the nozzle replacement cycle may be shortened due to an increase in the process cost and an increase in the polypropylene carbide, and when the temperature is higher than 1,500 g / 10 min (230 ° C), the melt strength is weakened, There may be a problem that the occurrence frequency of shots occurs during the spinning due to the deterioration. Therefore, it is preferable to use one having an MI within the above range.

In the conjugated fiber of the present invention, the polyethylene-based compound (or the polyethylene-based compound-containing resin) is preferably a low density polyethylene (LDPE), preferably a linear low density polyethylene (LLDPE) Is advantageous in terms of securing the adhesion of the side-by-side composite fiber to the polypropylene-based compound.

The linear low density polyethylene has a melt index (MI) of 140 to 160 g / 10 min (190 캜), preferably 145 to 160 g / 10 min (190 캜) If the MI of the LLDPE resin is less than 140 g / 10 min (190 DEG C), the flowability is lowered and the fineness of the meltblown fibers becomes thicker There is a problem, and when the MI is used in excess of 160 g / 10 min (190 캜), the meltblown fiber filing phenomenon during spinning increases, which may be a disadvantage in controlling the uniformity of composite nonwoven fabric uniformity.

The LLDPE resin preferably has a specific gravity of 0.90 to 0.95, more preferably 0.92 to 0.94, from the viewpoint of ensuring the lightweight property and adhesion of the composite fiber aggregate.

As described above, the composite fiber aggregate of the present invention has a wide surface area and an air layer formed by the presence of the side-by-side type meltblown conjugate fiber 12 and the PET staple fiber 11 together at a specific ratio, Not only high frequencies but also excellent sound absorption performance can be realized even in a low frequency band. In addition, adhesion between PET short fibers and polypropylene fibers of the composite fibers can be improved, thereby minimizing the defect rate in the processing of the composite fiber assembly and improving the merchantability. The meltblown conjugate fibers 12 and the PET staple fibers 11 are contained in a weight ratio of 3: 7 to 9: 1, preferably 4: 6 to 8: 2, If less than 9: 1 by weight of meltblown conjugated fibers and PET staple fibers are used, the sound absorption property is significantly lowered, and the meltblown conjugated fibers and the PET short fibers 3: use less meltblown conjugate fiber in a weight ratio of 7 to less than 3 weight ratio when it may be the adhesion of the composite fiber aggregate significantly less problem.

The meltblown composite nonwoven fabric produced by the above-described method has an average thickness of 5 mm to 35 mm, preferably 10 mm to 20 mm, which is advantageous for sound absorption and thinning. The meltblown composite nonwoven fabric may have a surface density of 100 to 400 g / m ² , preferably a surface density of 150 to 350 g / m ² , more preferably 280 to 330 g / m ² . However, it is possible to optimize by adjusting the area density according to the area where the noise is generated and the appropriate size of the applied part.

If the surface density of the meltblown composite nonwoven fabric is 100 g / m ² , there may be a problem in that it does not have sufficient mechanical properties such as strength and compression resilience. If it exceeds 400 g / m ² , It is preferable to have the area density within the above range because the improvement rate of the sound absorption performance is insufficient as compared with the increase in manufacturing cost caused by the increase in the area density, which is difficult to adhere to the parts.

And such a composite fiber aggregate of the present invention, area density 300 g / m ² in the case, as determined sound absorption coefficients on the basis of the alpha cabin (alpha cabin) method in ISO R 354, the low-frequency logarithmic the sound absorption coefficient at 1,000 Hz 0.80, Preferably 0.82 or more, and a sound absorption coefficient at 2,000 Hz of 0.90 or more, preferably 0.96 or more. When the area density of the composite fiber aggregate is 300 g / m ² , the sound absorption coefficient is 0.95 or more, preferably 0.96 or more at 3,150 Hz in accordance with the alpha cabin method of ISO R 354 And a sound absorption coefficient at a high frequency of 5,000 Hz of 0.95 or more, preferably 1.00 or more, more preferably 1.05 or more.

The composite fiber aggregate of the present invention has a surface density of 300 g / m < ² > and has an adhesive strength of 5.5 N / 25 mm to 14 N / 25 mm, preferably 6.5 N / 25 mm to 12 N / 25 mm.

As shown in FIG. 2, the composite fiber assembly 10 of the present invention can be applied to various kinds of known materials which are applied to the surface of an interior cover such as a nonwoven fabric, a woven fabric, a knitted fabric, a foam, A spun bond fabric, a meltblown fabric, a staple web or the like may be used alone or in combination of two or more of the support layers 20 and 30. The support layers 20 and 30 cover the surface of the sound absorbing material to be installed inside the vehicle or inside the building to maintain the shape of the sound absorbing material and to provide strength and also to prevent the short fibers 12 from being detached as the seal passes So that the sound absorption function can be maintained continuously.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Preparation Example  One : Polyethylene phthalate Staple  Produce

A polyethylene terephthalate resin having a melting point of 260 DEG C and an intrinsic viscosity of 0.65 was spinnig filed at a spinning temperature of 275 DEG C and a spinning speed of 1,200 m / min, followed by stretching at 3.3 DEG C at 77 DEG C to prepare staple fibers.

Next, stretched staple fibers were heat treated at 140 ° C to produce PET staple fibers.

The obtained PET staple fibers had an average fineness of 7 deniers, an intensity of 5.7 g / d, an elongation of 40%, an average number of crimps of 14.5 / inch and an average fiber length of 64 mm.

Preparation Example  2

Using the same PET resin as in Preparation Example 1, but with different spinning and post-treatment conditions, PET staple fibers having an average fineness of 5.5 denier, a strength of 5.3 g / d, an elongation of 44%, an average number of crimps of 13.5 / inch and an average fiber length of 60 mm were produced.

Preparation Example  3

Using the same PET resin as in Preparation Example 1, except that the spinning conditions and post- PET staple fibers having an average fineness of 8.5 denier, a strength of 5.2 g / d, an elongation of 43%, an average crimp number of 14.8 pcs / inch and an average fiber length of 69 mm were produced.

Example of comparison preparation  One

Using the same PET resin as in Preparation Example 1, except that the spinning conditions and the post- PET staple fibers having an average fineness of 12 denier, an intensity of 5.8 g / d, an elongation of 42%, an average crimp number of 14.5 pcs / inch and an average fiber length of 64 mm were produced.

Example  One

The PET staple fibers prepared in Preparation Example 1 were subjected to an opening and a carding process and then passed through a LLDPE resin (Linear Low Density Polyethylene (DNDA-1082 NT 7, manufactured by Dow Chemical Company) PP resin (Polypropylene, HP 461Y melt blowing resin) was uniformly and quantitatively mixed in the process of producing the meltblown fibers by the side-by-side composite radiation method.

The MI (melt index) of the LLDPE used was 155 g / 10 min (190 캜) and the MI (Melt Index) of PP was 1,300 g / 10 min (230 캜). At this time, the meltblown spinning temperature and the hot air temperature were 270 ° C, and the average diameter of the obtained meltblown composite fibers was 2.9 μm.

Then, the PET staple fibers were mixed with each other in a vertically descending meltblown air stream so that the PET staple fibers were 40% by weight and the LLDPE / polypropylene meltblown conjugate fibers were mixed so as to have a balance of 60% A total area of 300 g / m < ² > and a thickness of 16 mm. FIG. 1 shows a photograph of the composite fiber aggregate in the form of a nonwoven fabric and its SEM measurement photograph.

Example  2 ~ Example  3

A composite fiber aggregate (total area density of 300 g / m ² ) in the form of a meltblown nonwoven fabric having 20% by weight of PET staple fibers and 80% by weight of polypropylene meltblown fibers was prepared and carried out in the same manner as in Example 1 Example 2 was carried out.

A composite fiber aggregate in the form of a meltblown nonwoven fabric having a staple fiber content of 60% by weight and a polypropylene meltblown fiber content of 40% by weight was prepared in the same manner as in Example 1, m ² ) was performed

Example  4

Except that the PET staple fibers of Preparation Example 2 were used in place of the PET staple fibers of Preparation Example 1 and 40 wt% of PET staple fibers and 80 wt% of LLDPE / polypropylene meltblown conjugate fibers were used, (Total area density of 300 g / m < ² >) of a nonwoven fabric-type nonwoven fabric was prepared and Example 4 was carried out.

Example  5

Except that PET staple fibers of Preparative Example 3 were used in place of PET staple fibers of Preparation Example 1 and 40 wt% of PET staple fibers and 80 wt% of LLDPE / polypropylene meltblown conjugated fibers were used, (Total area density of 300 g / m < ² >) in the form of a non-woven fabric was prepared.

Example  6

A composite fiber aggregate in the form of a nonwoven fabric was prepared in the same manner as in Example 1 except that the average diameter of the meltblown composite fibers was 5 占 퐉, and Example 3 (total area density of 300 g / m ² ) was performed.

Example  7

The LLDPE resin constituting the meltblown composite fiber had an MI (Melt Index) of 148 g / 10 min (190 ° C), and the PP resin had an MI (Melt Index) (Total area density of 300 g / m ² ) of 1,400 g / 10 min (230 ° C).

Comparative Example  One

A composite fiber assembly in the form of a nonwoven fabric was produced under the same conditions as in Example 1 except that PP resin (HP 461Y of Polyfuse Co., Ltd.) was applied solely as meltblown fibers so that the PET staple fiber was 40% And the trowel PP fibers were mixed in an amount of 60% by weight to prepare a composite fiber aggregate having a nonwoven fabric shape having a total area density of 300 g / m ² .

Comparative Example  2

Except that the PET staple fibers of Comparative Preparation Example 1 were used in place of the PET staple fibers of Preparation Example 1, 20 wt% of PET staple fibers and 80 wt% of LLDPE / polypropylene meltblown conjugated fibers (Total area density of 300 g / m < ² >) in the form of a non-woven fabric was prepared.

Comparative Example  3

(Total area density 300 g / m ² ) in the form of a nonwoven fabric so that the LLDPE / polypropylene meltblown conjugate fiber and the PET staple fiber were contained in an amount of 95 wt% and 5 wt%, respectively, .

Comparative Example  4

(Total area density of 300 g / m ² ) in the form of a nonwoven fabric so that the LLDPE / polypropylene meltblown conjugate fiber and the PET staple fiber each contain 20 wt% and 80 wt%, respectively, in the same manner as in Example 1 .

Comparative Example  5

A composite fiber aggregate (total area density of 300 g / m ² ) in the form of a nonwoven fabric was produced in the same manner as in Example 1 except that the average diameter of the meltblown composite fibers was 10 μm.

Experimental Example  : By frequency Hz ) Sound absorption coefficient and adhesive strength measurement experiment

The sound absorption coefficient and adhesive strength (Hz) of the composite fiber assemblies prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 1 below.

(1) Sound absorption coefficient measurement by frequency

For the measurement of the sound absorption coefficient, three samples each of which is applicable to the ISO R 354, Alpha Cabin method were prepared, and the sound absorption coefficient was measured after leaving for 30 minutes at the external temperature of 0 ° C and 25 ° C, and the average value of the measured sound absorption coefficient is shown in Table 1 .

(2) Measurement of adhesion strength

The bonding strength was measured using a measuring apparatus shown in FIG. 3. The bonding strength was determined by bonding a fibrous aggregate to a fibrous aggregate using a hot-air drier and then applying a UTM (universal testing machine) The strength was measured. At this time, the experimental temperature was 150 ° C. for 8 minutes, the cooling time was 3 minutes, and the pressing load was 22.40 g / cm 2.

division Sound absorption coefficient by frequency Adhesive strength
(N / 25 mm) 1,000 Hz 2,000 Hz 3,150 Hz 5,000 Hz Example 1 0.89 0.98 1.05 1.16 9.8 Example 2 0.91 1.00 1.06 1.19 9.4 Example 3 0.87 0.98 1.03 1.11 9.3 Example 4 0.89 0.99 0.99 1.08 9.7 Example 5 0.84 0.94 1.01 1.12 9.2 Example 6 0.82 0.93 1.02 1.12 9.4 Example 7 0.88 0.97 1.01 1.11 9.2 Comparative Example 1 0.83 0.92 0.94 0.98 4.6 Comparative Example 2 0.85 0.95 0.99 1.02 8.9 Comparative Example 3 0.88 0.94 0.98 1.01 9.2 Comparative Example 4 0.75 0.81 0.89 0.95 4.9 Comparative Example 5 0.82 0.93 1.02 1.08 7.5

The results of Table 1 show that Examples 1 to 7 have an excellent adhesive strength of 5.5 N / 25 mm or more and have a high sound absorption coefficient at all frequencies as compared with Comparative Example 1 there was.

However, in Comparative Example 1 prepared using only polypropylene single fibers and PET staple fibers rather than composite fibers, it was confirmed that the bonding strength was low and the absorption coefficient at high frequencies was greatly reduced, as compared with Example 1 I could.

In addition, in Comparative Example 2 produced using PET short fibers having an average fineness of 12 deniers, the sound absorption coefficient in the high frequency region was low. As the fineness of PET short fibers increased, It is considered that this is because the size of the inner cavity is increased and this is an obstacle to reducing the sound energy in the high frequency region.

In the case of Comparative Example 3 in which less than 10% by weight of PET staple fiber was used, the sound absorption performance was lowered as compared with Example 1, and in Comparative Example 4 in which the conjugated fiber content was less than 30% by weight Compared with Example 1, there was a problem that the sound absorption performance was excellent but the adhesive strength was greatly decreased.

In the case of Comparative Example 5, which is a sound absorbing material formed of composite fibers having an average diameter exceeding 8 mu m exceeding 8 mu m, the structure of the composite fiber aggregate was not formed densely, It is judged that the strength has decreased.

Manufacturing example  One

A PET composite meltblown nonwoven sound absorbing material was prepared by cutting the sound absorbing material prepared in Example 1 according to the shape of a wheel house of a car and attaching it using a double-sided tape. This is shown in FIG. 4 as a photograph.

Manufacturing example  2

The c-pillar (c-pillar) located between the rear glass and the side glass of the pillar, which plays an important role in not only supporting the roof of the automobile but also improving the rigidity and safety of the vehicle body, pillar), which is shown in FIG. 5 as a photograph.

Manufacturing example  3

The sound-absorbing material prepared in Example 1 was cut and applied to a luggage side, which is a trunk side internal part of a car, to produce a sound-absorbing automobile part, which is pictured in FIG.

It can be seen from the above Examples and Experimental Examples that the composite fiber aggregate of the present invention has an excellent sound absorption ability not only in a high frequency band but also in a low frequency band, and further confirmed that the adhesive strength is excellent. The present invention can be widely applied to a material requiring sound absorption, for example, an interior part of a moving means such as an automobile, an airplane, a ship, an electronic product part such as a cell phone, a notebook computer, a TV, .

10: composite fiber aggregate 11: PET staple fiber
12: meltblown composite fiber 20, 30: support layer

Claims (21)

A composite of microfiber composite fibers having excellent adhesive and sound absorption properties, comprising melt blown conjugate fibers and polyethylene terephthalate fibers in side by side form.
The composite of microfiber composite fibers according to claim 1, wherein the composite fiber comprises a polypropylene-based compound and a polyethylene-based compound in a weight ratio of 5-9: 1 to 5: 1.
The polypropylene resin composition according to claim 2, wherein the polypropylene-based compound comprises at least one selected from a polypropylene and a polypropylene random copolymer,
Wherein the polyethylene-based compound includes low-density polyethylene (LDPE).
The polypropylene resin composition according to claim 3, wherein the polypropylene-based compound is polypropylene having a melt index (MI) of 800 to 1,500 g / 10 min (230 ° C)
Wherein the polyethylene-based compound is linear low density polyethylene (LLDPE) having a melt index (MI) of 140 to 160 g / 10 min (190 캜).
The microfine fiber aggregate according to claim 4, wherein the linear low density polyethylene has a specific gravity of 0.90 to 0.95.
The composite of microbial fibers according to claim 1, wherein the meltblown conjugate fiber has an average diameter of 1 탆 to 8 탆.
The polyethylene terephthalate staple fiber according to claim 1, wherein said polyethylene terephthalate staple fibers have an average fineness of 5 to 10 denier, an average number of crimps of 12 to 17 fibers / inch and an average fiber length of 50 to 80 mm. Microfiber composite fiber aggregate with excellent properties.
8. The microfine fiber composite according to claim 7, wherein the polyethylene terephthalate staple fiber has a strength of 4.8 to 6.5 g / d and an elongation of 35 to 45%.
The composite of microfiber composite fibers according to claim 1, wherein the composite fiber aggregate comprises meltblown composite fibers and polyethylene terephthalate fibers in a weight ratio of 3: 9: 1 to 7: 1.
10. The absorbent article according to any one of claims 1 to 9, wherein the composite fiber assembly is a nonwoven fabric,
And a surface density of from 250 g / m ² to 400 g / m ² .
The composite fiber aggregate according to claim 10, wherein the composite fiber aggregate has a surface density of 300 g / m < ² >, and a sound absorption coefficient is 0.80 or more at 1,000 Hz, And a sound absorption coefficient of 0.90 or more.
The composite fiber aggregate according to claim 10, wherein the composite fiber aggregate has a surface density of 300 g / m < ² > and an absorption coefficient of at least 0.95 at 3,150 Hz, Wherein the sound absorption coefficient is 1.05 or more.
The composite fiber aggregate according to claim 10, wherein the composite fiber aggregate has a surface density of 300 g / m ² ,
Characterized in that the adhesive strength is 5.5 N / 25 mm to 14 N / 25 mm when measured according to the KS M ISO 36 method.
When the polypropylene compound-containing resin and the polyethylene-based compound-containing resin are melt-blended in a side-by-side composite spinning spinneret, a melt blown air stream to be radiated is blown through a facility and a nozzle to form a polyethylene terephthalate layer A method for producing a microfine fiber aggregate by incorporating fibers into a meltblown composite fiber and a polyethylene terephthalate short fiber.
15. The method of claim 14, wherein the meltblown composite spinning is performed at a hot air temperature of from 260 DEG C to 290 DEG C.
15. The method of claim 14, wherein the polyethylene terephthalate staple fibers comprise
Spinning a polyethylene terephthalate resin at a spinning temperature of 270 ° C. to 285 ° C. and a spinning speed of 1,000 to 1,400 m / min to produce staple fibers;
Stretching the staple fibers at a temperature in the range of 2.5 to 4.0 times at 70 to 85 캜; And
And heat treating the drawn short fibers at 130 ° C to 150 ° C.
The method according to claim 16, wherein the polyethylene terephthalate resin has a melting point of 250 ° C to 270 ° C and an intrinsic viscosity (IV) of 0.60 to 0.70.
A sound absorbing material comprising the microfine composite fiber aggregate according to any one of claims 1 to 13.
An automobile interior material comprising the sound absorbing material of claim 18.
A building interior material for construction comprising the sound absorbing material of claim 18.
An electronic product comprising the sound absorbing material of claim 18.

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