KR101720162B1 - Sound-absorbing materials of micro-fiber having good compression-elasticity rate and sound-absorption and Manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-acoustic absorbent material and a method of manufacturing the same, more specifically, to a method of manufacturing a micro-acoustic absorbent material by manufacturing polyethylene terephthalate (PET) staple fibers into meltblown fibers and / or meltblown conjugate fibers having bulky properties The present invention relates to a micro-fiber sound absorbing material having a coating layer formed on a meltblown composite nonwoven fabric and then forming pores to improve sound absorption properties, adhesive strength and compressive elasticity, and a method for producing the same.

Description

TECHNICAL FIELD The present invention relates to a micro-fiber sound absorbing material having excellent compression recovery and sound absorption properties, a method for producing the same, and a sound-

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 a conventional absorbent / sound insulating material. In addition, sound absorbing materials impregnated with a thermoplastic resin or a thermosetting resin in a compressed fiber, a glass fiber, a rock surface, . 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 above-mentioned problems. It is an object of the present invention to provide a sound absorbing material which is excellent in adhesion between fibers in a composite nonwoven fabric constituting a sound absorbing material, And also to provide a sound absorbing material having excellent sound absorbing performance and a manufacturing method thereof.

In order to solve the above problems, the present invention relates to a microbubble absorbent material comprising a meltblown composite nonwoven fabric and a coating layer coated on a surface of the composite nonwoven fabric with a UV curable coating resin.

As one preferred embodiment of the present invention, the micro-acoustic absorbent of the present invention may further include a support, and the support, the meltblown composite nonwoven fabric and the coating layer may be laminated in order.

In one preferred embodiment of the present invention, the meltblown composite nonwoven fabric of the microfine sound absorbing material of the present invention is characterized by containing fine pores having an average depth of 40 탆 to 150 탆 and an average diameter of 10 탆 to 40 탆 toward the coating layer .

In one preferred embodiment of the present invention, the meltblown composite nonwoven fabric of the microfabric sound absorbing material of the present invention has an average distance between the center of the pores and the center of the neighboring pores of 5 mu m to 50 mu m.

In one preferred embodiment of the present invention, the meltblown composite nonwoven fabric may have a surface density of 100 g / m ² to 400 g / m ² .

In one preferred embodiment of the present invention, the coating layer has an average thickness of 20 μm to 70 μm, and the meltblown composite nonwoven fabric has an average thickness of 5 mm to 35 mm .

In a preferred embodiment of the present invention, the meltblown composite nonwoven fabric may include melt blown fibers and polyethylene terephthalate fibers.

In one preferred embodiment of the present invention, in the micro-acoustic absorbent material of the present invention, the meltblown fibers constituting the meltblown composite nonwoven fabric include polypropylene fibers; Or a side-by-side composite fiber comprising a polypropylene-based compound and a polyethylene-based compound.

As a preferred embodiment of the present invention, in the microfabric sound absorbing material of the present invention, the propylene-based fiber may include at least one selected from a polypropylene and a polypropylene random copolymer, and a melt index of 800 g / 10 min (230 캜) to 1,500 g / 10 min (230 캜).

As a preferred embodiment of the present invention, in the micro-acoustic absorption material of the present invention, the meltblown conjugate fiber is a side-by-side conjugate fiber, and the polypropylene-based compound and the polyethylene- In a weight ratio of 5: 5 to 9: 1.

As a preferred embodiment of the present invention, the polypropylene-based compound of the meltblown conjugate fiber constituting the meltblown composite nonwoven fabric may be characterized in that it comprises at least one selected from a polypropylene and a polypropylene random copolymer And the polypropylene-based compound is a polypropylene having a melt index (MI) of 800 g / 10 min (230 ° C) to 1,500 g / 10 min (230 ° C).

Further, as a preferred embodiment of the present invention, the polyethylene compound of the meltblown conjugate fiber constituting the meltblown composite nonwoven fabric may be characterized in that it comprises low density polyethylene (LDPE), preferably linear (LLDPE) having a melt index (MI) of 140 g / 10 min (190 캜) to 160 g / 10 min (190 캜) and a specific gravity of 0.90 to 0.95 .

As a preferred embodiment of the present invention, in the present invention, the meltblown fibers may have an average diameter of 1 탆 to 8 탆.

In one preferred embodiment of the present invention, the polyethylene terephthalate staple fiber of the present invention has an average fineness of 5 to 10 denier, an average number of crimps of 12 / inch to 17 / inch and an average fiber length of 50 mm To 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 sound absorbing material of the present invention comprises the meltblown conjugate fiber and the polyethylene terephthalate short fiber at a weight ratio of 3 to 9: 1 to 7.

In one preferred embodiment of the present invention, the UV curable coating resin used for forming the coating layer of the micro-acoustic absorbent of the present invention contains 4 to 10 parts by weight of a photoinitiator based on 100 parts by weight of the UV curable hydrophilic nonporous polymer resin .

In one preferred embodiment of the present invention, the UV curable hydrophilic nonporous polymer resin of the microfine sound absorbing material of the present invention may comprise a water-dispersed polyurethane acrylate resin containing 20 to 50% by weight of solid content have.

As a preferred embodiment of the present invention, in the microphase sound absorber according to the present invention, the photoinitiator is selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, 1-hydroxy-2-methyl-1-phenyl- And dimethyl 2,4,6-trimethylbenzoylphosphine oxide.

In one preferred embodiment of the present invention, the photoinitiator may be characterized in that it comprises - hydroxycyclohexyl phenyl ketone and dimethyl 2,4,6-trimethylbenzoylphosphine oxide in a weight ratio of 6: 4 to 8: 2 have.

As a preferred embodiment of the present invention, the microfine sound absorbing material of the present invention is characterized in that when the melt density of the meltblown composite nonwoven fabric is 300 g / m ² , the absorption coefficient is measured according to the alpha cabin method of ISO R 354, A sound absorption coefficient of at least 0.83 at 1,000 Hz, and a sound absorption coefficient of at least 0.93 at 2,000 Hz.

As a preferred embodiment of the present invention, the microfine sound absorbing material of the present invention is characterized in that when the melt density of the meltblown composite nonwoven fabric is 300 g / m ² , the absorption coefficient is measured according to the alpha cabin method of ISO R 354, A sound absorption coefficient at 3,150 Hz is 0.95 or more, and a sound absorption coefficient at 5,000 Hz is 1.00 or more.

As a preferred embodiment of the present invention, the micro-acoustic absorption material of the present invention is characterized in that the compression recovery rate is 43% to 55% when measured according to ASTM D6571 when the melt density of the meltblown composite nonwoven fabric is 300 g / m ² .

In a preferred embodiment of the present invention, the meltblown composite nonwoven fabric of the microfiber sound absorbing material of the present invention has a melt density of 300 g / m < ² > 36, the adhesive strength may be 5.5 N / 25 mm to 14 N / 25 mm.

Another object of the present invention is to provide a method of manufacturing the various types of micro-acoustic absorbents described above, which comprises: preparing a meltblown composite nonwoven fabric having a surface density of 250 to 400 g / m ² ; Coating a surface of the meltblown composite nonwoven fabric with a UV curable coating resin including a UV curable hydrophilic nonporous polymer resin and a photoinitiator to form a coating layer; Performing a pin press process in the direction in which the coating layer is formed to form micropores in the meltblown composite nonwoven fabric having the coating layer formed thereon; And irradiating UV light to UV cure to produce a micro-acoustic absorbent material.

As a preferred embodiment of the present invention, the meltblown composite nonwoven fabric may be a meltblown fiber or a meltblown conjugate fiber; When meltblown fibers are used, the meltblown composite nonwoven fabric may be produced by melt-spinning a polypropylene-based compound-containing resin by melt spinning, A meltblown composite nonwoven fabric can be prepared by mixing a meltblown fiber and a polyethylene terephthalate staple fiber by mixing a polyethylene terephthalate staple fiber with a blowing device through a blowing device and a nozzle.

In a preferred embodiment of the present invention, in the case of using the meltblown conjugated fiber in the production of the meltblown composite nonwoven fabric, the resin containing the polypropylene compound and the resin containing the polyethylene compound are mixed with the side- When the meltblown composite spinning is carried out by spinning, the meltblown air stream is mixed with the polyethylene terephthalate staple fiber through a blowing device and a nozzle to mix the meltblown conjugate fiber and the polyethylene terephthalate staple fiber, Triblock composite nonwoven fabric can be produced.

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

In a preferred embodiment of the present invention, the pin press process is a press process in which a pin having an average diameter of 10 mu m to 40 mu m and an average length of 40 mu m to 150 mu m is attached at 5,000 to 15,000 per unit area And the like.

As a preferred embodiment of the present invention, the step of UV curing may be performed by irradiating UV energy of 1.5 to 4.0 J / cm 2.

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.

The micro-acoustic absorption material of the present invention has excellent sound absorption coefficient for low frequency as well as high frequency, excellent mechanical properties such as compression recovery rate, excellent adhesive force between fibers, easy workability, It is suitable for use as a sound-absorbing material such 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.

1 is a SEM photograph of the meltblown composite nonwoven fabric produced in Example 1. Fig.
Fig. 2 is a schematic view of a meltblown composite nonwoven fabric prior to finishing processing. Fig. 2 shows a composite fiber assembly 10 of a support 30, meltblown fibers or meltblown composite fibers 12 and PET short fibers 11, (20) are stacked.
3 is a photograph showing an apparatus for measuring the adhesive strength of the meltblown composite nonwoven fabric of Example 3 performed in Experimental Example 2. 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.
5 is a photograph of a c-pillar of a vehicle to which a sound absorbing material of the present invention manufactured in Production Example 2 is applied.
6 is a photograph showing a luggage side of a vehicle to which the sound absorbing material of the present invention manufactured in Production Example 3 is applied.
7 is a photograph of a headliner of a vehicle to which the sound absorbing material of the present invention manufactured in Production Example 4 is applied.
8 is a photograph of a c-pad of a vehicle to which the sound absorbing material of the present invention manufactured in Production Example 4 is applied.

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

The micro-acoustic absorbent material of the present invention includes a meltblown composite nonwoven fabric and a coating layer coated on the upper surface of the composite nonwoven fabric with a UV curable coating resin. The composite nonwoven fabric may further include a support on the lower surface thereof, Is as follows.

The micro-acoustic absorption material of the present invention comprises the steps of: preparing a meltblown composite nonwoven fabric; Coating a surface of the meltblown composite nonwoven fabric with a UV curable coating resin including a UV curable hydrophilic nonporous polymer resin and a photoinitiator to form a coating layer; Performing a pin press process in the direction in which the coating layer is formed to form micropores in the meltblown composite nonwoven fabric having the coating layer formed thereon; And irradiating ultraviolet light to UV curing the ultraviolet light absorbing material.

In the step of preparing the meltblown composite nonwoven fabric, the meltblown composite nonwoven fabric may include meltblown fibers (12) composed of discontinuous fibers or meltblown conjugate fibers (12) composed of two or more fibers; And a polyethylene terephthalate staple fiber (11). At this time, it is preferable that the average diameter of the meltblown conjugate fiber is 1 mu m to 8 mu m, preferably 1 mu m to 5 mu m, more preferably 2 mu m to 4 mu m, If the diameter is less than 1 탆, the manufacturing cost may be greatly increased due to the lowering of the productivity, the sound absorption performance may be decreased due to the reduction of the thickness and compression recovery rate, and if the diameter exceeds 8 탆, Which may result in problems of sound absorption performance and durability degradation.

In the production of the meltblown composite nonwoven fabric, in the production of the meltblown composite nonwoven fabric composed of the meltblown fibers and the polyethylene terephthalate short fibers composed of the discontinuous fibers, the polypropylene-based compound- When melt-blown yarn is blown into the meltblown air stream, the meltblown fibers and the polyethylene terephthalate staple fibers are mixed with a polyethylene terephthalate staple fiber through a blowing device and a nozzle to melt-melt the composite nonwoven fabric The composite fiber aggregate 10 comprising the meltblown conjugate fiber 12 and the polyethylene phthalate short fiber (PET) 11 as shown in Fig. 2 can be produced.

The polypropylene-based compound-containing resin used for producing the meltblown fiber composed of the discontinuous fibers is preferably a polypropylene-based compound-containing resin (or a polypropylene-based compound-containing resin), preferably a polypropylene- And may include at least one selected from the group consisting of polypropylene and polypropylene. The polypropylene preferably has an MI (melt index) of 800 to 1,500 g / 10 minutes (230 DEG C), preferably MI of 1,100 to 1,400 g / 10 minutes (230 DEG C) (230 deg. C) can be used. If the MI is less than 800 g / 10 min (230 deg. C), the meltblown fiber becomes thicker and the processing temperature If the temperature is higher than 290 ° C, there is a problem that the nozzle replacement cycle is shortened due to an increase in the process cost and an increase in the polypropylene carbide. If the temperature is higher than 1,500g / 10 min (230 ° C), the melt strength becomes weak, There is a possibility that the occurrence frequency of shots in the spinning may increase due to the decrease in the formability, so it is preferable to use one having an MI within the above range.

The die, nozzle temperature and hot air temperature of the meltblown spinning are preferably performed at 250 ° C to 290 ° C, preferably 260 ° C to 280 ° C, , And when the hot air temperature is less than 250 ° C, the thickness of the fiber of the polypropylene compound component becomes thick, so that 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 fiber and the air layer The effect may be deteriorated, and as a result, the sound absorption performance may be deteriorated. If the hot air temperature exceeds 290 ° C, the nozzle replacement period may be shortened due to an increase in the process cost and the polypropylene carbide increase, and the fibers of the polypropylene compound may not be stably focussed.

In the production of the meltblown composite nonwoven fabric, in producing a meltblown composite nonwoven fabric composed of two or more non-discontinuous fibers of meltblown conjugate fiber and polyethylene terephthalate short fiber, a polypropylene-based compound-containing resin and a polyethylene- When the compound-containing resin is melt-blended with the side-by-side composite spinneret, the spinning meltblown stream is mixed with the polyethylene terephthalate staple fiber through a blowing device and a nozzle to form a meltblown composite The composite fiber aggregate (PET) 11 comprising the meltblown conjugate fiber 12 and the polyethylene phthalate short fiber (PET) 11 shown in Fig. 2 constituting the meltblown composite nonwoven fabric was obtained by mixing the fibers and the polyethylene terephthalate short fibers 10) can be produced.

The die and nozzle of the meltblown composite spinning are preferably performed at a hot air temperature of 250 ° C to 290 ° C, preferably 260 ° C to 280 ° C, If the air temperature is lower than 250 ° C, the fiber content of the polypropylene-based compound component, which is a part of the side-by-side composite fiber, becomes thicker and the porosity of the fiber aggregate lowers and the amount of air contained therein is relatively reduced. The effect of reducing the flow resistance of the sound energy may be deteriorated. As a result, the sound absorption performance may deteriorate. When the hot air temperature exceeds 290 ° C, the nozzle replacement cycle is shortened due to an increase in the process cost and the polypropylene carbide increase, and the fiber of the polypropylene compound component is not stably focused, -Side conjugated fibers may deteriorate in bonding properties with the fibers of the polyethylene-based compound constituting the other side, resulting in a problem of poor composite fiber aggregate structure.

The meltblown conjugate fiber is a side-by-side composite fiber comprising a polypropylene-based compound and a polyethylene-based compound in a weight ratio of 1: 0.5 to 2, preferably 1: 0.7 to 1.5, If the content of the polyethylene compound is less than 0.5 parts by weight, there may be a problem that the adhesiveness and the bulky property are deteriorated. If the proportion is more than 2 parts by weight, there is a problem that the fineness is increased due to the decrease in radioactivity and the defects are increased in the fiber aggregate as a whole .

In the meltblown conjugated fiber, the polypropylene-based compound (or the polypropylene-based compound-containing resin) may include at least one member selected from a polypropylene and a random copolymer of polypropylene, . The polypropylene preferably has an MI (melt index) of 800 to 1,500 g / 10 minutes (230 DEG C), preferably MI of 1,100 to 1,400 g / 10 minutes (230 DEG C) (230 deg. C) can be used. If the MI is less than 800 g / 10 min (230 deg. C), the meltblown fiber becomes thicker and the processing temperature If the temperature is higher than 290 ° C, there is a problem that the nozzle replacement cycle is shortened due to an increase in the process cost and an increase in the polypropylene carbide. If the temperature is higher than 1,500g / 10 min (230 ° C), the melt strength becomes weak, There is a possibility that the occurrence frequency of shots in the spinning may increase due to the decrease in the formability, so it is preferable to use one having an MI within the above range.

In the meltblown conjugated fiber, the polyethylene compound (or the resin containing the polyethylene compound) may be 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 securing the lightweight property and the adhesiveness of the composite fiber aggregate.

In the step of producing the meltblown composite nonwoven fabric according to the production method of the present invention, the polyethylene terephthalate (hereinafter referred to as " PET ") short staple fibers are produced by melt kneading a PET resin at a spinning temperature of 270 DEG C to 285 DEG C and a spinning speed of 1,000 to 1,400 m / To prepare a staple fiber; 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% .

As described above, the meltblown composite nonwoven fabric can be produced by combining the meltblown fibers 12 or the meltblown conjugate fibers 12 in the side-by-side configuration and the PET short fibers 11 in a specific ratio, And an air layer can be formed to improve the sound absorption coefficient. In addition to achieving excellent sound absorption performance in a low frequency range as well as high frequencies, adhesion between the polypropylene fibers of the PET short fibers (11) and the melt blown fibers (12) The meltblown fibers 12 and / or the meltblown conjugate fibers 12 and the PET staple fibers 11 are mixed at a ratio of 3: 7 to 9: 1, 1 weight ratio, preferably 4: 6 ~ 8: 2 weight ratio, is advantageous in terms of sound absorption properties and adhesive strength, and the use of less amount of PET staple fibers at less than 9: 1 by weight of meltblown fibers and PET staple fibers Sound significantly dropping, the meltblown fibers and PET monofilament 3: Using less meltblown conjugate fiber in a weight ratio of 7 to less than 3 weight ratio 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 has a surface density of 100 g / m ² to 400 g / m ² , preferably a surface density of 150 g / m ² to 350 g / m ² , more preferably 280 g / m ² 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.

Further, the produced meltblown composite nonwoven fabric area density 300 g / m as ^2, when measured according to KS M ISO 36 method, 5.5 N / 25㎜ ~ 14 the bonding strength N / 25㎜, preferably 7.5 And an adhesive strength of N / 25 mm to 12 N / 25 mm.

Hereinafter, a step of forming a coating layer will be described.

The upper surface of the meltblown composite nonwoven fabric manufactured through the above-described processes is coated with a UV curable coating resin to form a coating layer. The coating layer is formed on both sides or in one side to improve the poor surface characteristics of the short fiber composite meltblown fiber aggregate. In place of the conventional spunbonded nonwoven fabric that has been requested to be provided on the surface, and at the same time enhancing the sound absorption performance through fine pores formed on the surface, and has an average thickness of 20 mu m to 70 mu m, preferably 35 mu m to 60 mu m It is good.

The UV-curable coating resin may include a UV-curable hydrophilic polymeric resin and a photoinitiator, and may further include a photo-initiator, a functional additive such as an exothermic agent, an antibacterial agent, and a deodorant.

The UV-curable hydrophilic nonporous polymer resin is preferably a water-dispersed polyurethane acrylate resin having a solid content of 20 to 50 wt%, preferably a water-dispersed polyurethane acrylate resin having a solid content of 30 to 48 wt% If the solid content is less than 20% by weight, the thickness of the coating layer may be insufficient to improve the poor surface properties and may be problematic in the formation of micropores. If the content exceeds 50% by weight, the UV curing time may increase There may be problems such as deterioration of productivity and formation of fine pores.

Also, the photoinitiator may be a UV photo-curable photoinitiator generally used in the art, preferably 1-hydroxycyclohexyl phenyl ketone, 1-hydroxy-2-methyl-1-phenyl- 1-one and dimethyl 2,4,6-trimethylbenzoylphosphine oxide can be used in combination, and 1-hydroxycyclohexyl phenyl ketone and dimethyl 2,4,6-trimethyl Benzoylphosphine oxide may be mixed in a weight ratio of 6: 4 to 8: 2.

The photoinitiator may be used in an amount of 4 to 10 parts by weight, preferably 5 to 8 parts by weight, based on 100 parts by weight of the UV curable hydrophilic polymer. When the amount of the photoinitiator is less than 4 parts by weight, The time may be too long, and if it is used in excess of 10 parts by weight, it is advisable to use it within the above range in an uneconomical manner.

The step of forming the coating layer may further include a step of coating the UV curable coating resin on the meltblown composite nonwoven fabric and then drying at 100 ° C to 150 ° C for 30 seconds to 2 minutes.

Next, pores are formed in the meltblown composite nonwoven fabric through a pin pressing process using a pin press plate with a pin attached from the direction in which the coating layer is formed from the meltblown composite nonwoven fabric having the coating layer formed thereon, The effect can be increased.

At this time, the press plate may be a press plate having 5,000 to 15,000, preferably 8,000 to 12,000, and more preferably 9,000 to 11,000 pins per unit area. The fins attached to the press plate may have an average diameter of 10 mu m to 40 mu m, preferably an average diameter of 15 mu m to 25 mu m, and an average length of pins of 40 mu m to 150 mu m, preferably 45 mu m To 120 [mu] m. If the average diameter of the fin is less than 10 mu m, the size of the pores formed in the composite nonwoven fabric may be too small to increase the sound absorption effect. If the average diameter of the fins exceeds 40 mu m, There is a problem that the compression recovery rate is greatly reduced. If the average length of the pin is less than 40 mu m, the sound absorption effect may be insufficient. If the average length of the pin exceeds 150 mu m, the sound absorption effect may increase, but the compression recovery rate and mechanical strength may be significantly reduced.

Next, the step of completely curing the coating layer by UV-curing the melt-blown composite nonwoven fabric having fine pores is performed. In this case, the UV curing method may be a general UV curing method used in the art. For example, The curing can be performed by irradiating UV energy of 1.5 J / cm 2 to 4.0 J / cm 2, preferably 1.5 J / cm 2 to 3.0 J / cm 2.

The microfiber sound absorbing material of the present invention thus manufactured was measured at a frequency of 1,000 g / m ² , which is a low frequency logarithm, when the melt density of the meltblown composite nonwoven fabric was 300 g / m ² and the absorption coefficient was measured according to the ISO cabin method of ISO 354 A sound absorption coefficient of 0.83 or more, preferably 0.85 or more, and a sound absorption coefficient of 0.93 or more, preferably 0.95 or more at 2,000 Hz. Further, when the surface density of the meltblown composite nonwoven fabric is 300 g / m ² , the absorption coefficient is measured to be 0.95 or more at 3,150 Hz in accordance with the alpha cabin method of ISO R 354, And may have a sound absorption coefficient of 1.00 or more, preferably 1.05 or more, and more preferably 1.10 or more at a high frequency of 5,000 Hz.

In addition, the micro-fiber sound-absorbing material of the present invention is melt when the surface density of the meltblown composite nonwoven fabric is 300 g / m ² day, the compression recovery rate is 43-55% when measured according to ASTM D6571 is preferably between 45% and 50% .

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. The support layers 20 and 30 cover the surface of the sound absorbing material installed in the interior of the vehicle or inside the building to maintain the shape of the sound absorbing material and provide strength and prevent the PET staple fibers from being detached as the seal passes, You can keep the function constant.

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 1: Preparation of polyethylene phthalate staple fiber

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

PET staple fibers having an average fineness of 5.5 denier, a strength of 5.3 g / d, an elongation of 44%, an average crimp number of 13.5 / inch and an average fiber length of 60 mm were prepared using the same PET resin as in Preparation Example 1 above.

Preparation Example 3

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 prepared using the same PET resin as in Preparation Example 1 above.

Comparative Preparation Example 1

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 prepared using the same PET resin as in Preparation Example 1 above.

Example  One

(1) Production of meltblown composite nonwoven fabric comprising PET staple fiber and PP fiber

After the PET staple fibers prepared in Preparation Example 1 were subjected to an opening and a carding process, a PP resin (Polypropylene, HP 461Y meltblown resin of Polyfusa) was melted through a blowing facility, The carded PET staple fibers were uniformly and quantitatively mixed in the process of producing the triblock fibers.

The MI (Melt Index) of the PP resin 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 m.

Then, the PET staple fibers were mixed with each other in a vertically descending meltblown air stream so that the PET staple fibers were made to be 40% by weight and the PP meltblown fibers were mixed so that the remaining amount became 60% / m < ² > and an average thickness of 16 mm.

(2) Coating layer and pore formation

Next, the meltblown composite nonwoven fabric was spin-coated, hot-air dried, and UV-cured, and then wound in an inline manner.

A UV curable coating resin mixed with 95% by weight of a water-dispersed polyurethane acrylate having a solid content of 35% by weight and 5% by weight of 1-hydroxycyclohexyl phenyl ketone (Igacure 184, photoinitiator) was prepared.

Next, the UV curable coating resin was coated on the upper surface of the meltblown composite nonwoven fabric using a spray coating method to have a coating film having an average thickness of 50 탆, and the coated composite nonwoven fabric was dried at 120 캜 for 1 minute .

Next, the dried composite nonwoven fabric was contacted with a press plate attached with 10,000 fins having an average diameter of 20 m per unit area (1 cm2) on the top of the coating film, and then a microporous press was applied to the coating film to a depth of 100 mu m, And further separated to form micropores having an average diameter of 20 mu m and an average depth of 100 mu m.

Next, the coating film was fully cured by irradiating UV energy of 2.0 J / cm 2 in a UV curing machine equipped with a metal halide lamp to prepare a microfiber sound absorbing material.

Example 2

The microporous sound absorbing material was prepared in the same manner as in Example 1 except that 93% by weight of water-dispersed polyurethane acrylate having a solid content of 45% by weight and 1-hydroxy-2-methyl- (Darocur 1173, photoinitiator) in an amount of 7% by weight was used.

Example 3

A microfiber sound absorbing material was prepared in the same manner as in Example 1, except that a press plate having 10,000 fins each having an average diameter of 50 탆 per unit area (1 cm 2) was contacted, and then a microporous press was applied Thereafter, they were separated again to prepare a micro-porous sound absorbing material having fine pores having an average diameter of 50 μm and an average depth of 100 μm.

Comparative Example 1

A microfiber sound absorbing material was prepared in the same manner as in Example 1, except that the pin pressing process was omitted, thereby producing a microporous sound absorbing material having no pores.

Example 4

(1) Production of meltblown composite nonwoven fabric comprising PET staple fiber and PP / LLDPE conjugate fiber

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 the 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. 2 shows a photograph of the composite fiber aggregate of the nonwoven fabric type and the SEM measurement photograph thereof.

(2) Coating layer and pore formation

Next, the meltblown composite nonwoven fabric was spin-coated, hot-air dried, and UV-cured, and then wound in an inline manner.

A UV curable coating resin mixed with 95% by weight of a water-dispersed polyurethane acrylate having a solid content of 35% by weight and 5% by weight of 1-hydroxycyclohexyl phenyl ketone (Igacure 184, photoinitiator) was prepared.

Next, the UV-curable coating resin was coated on the upper surface of the meltblown composite nonwoven fabric using a spray coating method so as to have a coating film having an average thickness of 50 μm, and the coated composite nonwoven fabric was dried at 120 ° C. for 1 minute .

Next, the dried composite nonwoven fabric was contacted with a press plate having 10,000 fines having an average diameter of 20 mu m per unit area (1 cm < 2 >) on the top of the coating film. Then, a microporous press was applied to the coating film to a depth of 100 mu m, And further separated to form fine pores having an average diameter of 20 mu m and an average depth of 100 mu m.

Next, the coating film was fully cured by irradiating UV energy of 2.0 J / cm 2 in a UV curing machine equipped with a metal halide lamp to prepare a microfiber sound absorbing material.

Examples 5 to 6

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

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

Example 7

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 8

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 >) of a nonwoven fabric-like nonwoven fabric was prepared and Example 5 was carried out.

Example 9

A composite fiber aggregate 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 5 占 퐉 to thereby prepare Example 3 (total area density of 300 g / m ² ) .

Example 10

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 DEG C).

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 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 were 95% by weight and 5% by weight, 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 composite fiber and the PET staple fiber contained 20 wt% and 80 wt%, respectively, .

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: Measurement of sound absorption coefficient and adhesive strength by frequency (Hz)

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 and 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.

 (3) Measurement of compression recovery rate

Compression recovery rate was measured according to ASTM D6571 method.

division Sound absorption coefficient by frequency Adhesive strength
(N / 25 mm) Compression recovery rate
(%) 1,000 Hz 2,000 Hz 3,150 Hz 5,000 Hz Example 1 0.87 0.97 1.01 1.11 7.6 48 Example 2 0.83 0.95 0.99 1.05 7.5 47 Example 3 0.84 0.93 0.98 1.03 7.8 47 Example 4 0.89 0.98 1.05 1.16 9.8 46 Example 5 0.91 1.00 1.06 1.19 9.4 47 Example 6 0.87 0.98 1.03 1.11 9.3 50 Example 7 0.89 0.99 0.99 1.08 9.7 44 Example 8 0.84 0.94 1.01 1.12 9.2 45 Example 9 0.83 0.93 1.02 1.12 9.4 43 Example 10 0.88 0.97 1.01 1.11 9.2 43 Comparative Example 1 0.81 0.92 0.99 1.02 9.3 54 Comparative Example 2 0.85 0.95 0.99 1.02 8.9 46 Comparative Example 3 0.88 0.94 0.98 1.01 9.2 32 Comparative Example 4 0.75 0.81 0.89 0.95 4.9 50 Comparative Example 5 0.81 0.92 1.00 1.05 7.0 42

The results of the tests of Table 1 show that Examples 1 to 10 have an excellent adhesive strength of 5.5 N / 25 mm or more and an excellent compression recovery rate of 43% or more, And it was confirmed that it had a sound absorption coefficient.

In the case of Comparative Example 1, the adhesive strength was very high, which means that the adhesive strength of the sound absorbing material was higher than those of the other Examples and Comparative Examples.

Examples 4 to 10, in which PP / LLDPE conjugated fibers and PET staple fibers were used, were superior to those of Examples 1 to 3 prepared using only polypropylene single fibers and PET staple fibers, Sound absorption.

Compared with Example 4, in Comparative Example 2 produced using PET staple fibers having an average fineness of 12 deniers, the sound absorption coefficient in the high frequency range was low, which means that as the fineness of the PET staple fibers increases The thickness of the fibrous aggregate is somewhat thickened, and it is considered that the size of the pores inside the fibrous aggregate becomes larger, thereby causing interference to reduce the sound energy in the high frequency region.

In the case of Comparative Example 3 using less than 10% by weight of PET staple fibers, the sound absorption performance was generally lower as compared with Examples 1 and 4.

In Comparative Example 4 using less than 30% by weight of the conjugated fiber, there was a problem that the sound absorption performance was excellent but the adhesive strength was greatly reduced as compared with Example 4.

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 of 10 mu m, the structure of the meltblown composite fibers was not densely formed. As compared with Example 10, It is judged that the sound absorption performance and the adhesive strength of the product are deteriorated.

Production Example 1

A PET composite meltblown nonwoven sound absorbing material was prepared by cutting the sound absorbing material prepared in Example 4 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.

Production Example 3

The sound absorbing material prepared in Example 4 was cut and applied to a luggage side of a trunk side of a vehicle to produce a sound absorbing automobile part, which is pictured in FIG.

Production Example 4

The sound absorbing material prepared in Example 4 was cut and applied to a headliner of an automobile to produce a sound absorbing automobile part, which is pictured in FIG.

Manufacturing example  5

The sound-absorbing material prepared in Example 4 was cut and applied to a c-pad of an automobile to produce a sound-absorbing automobile part, which is illustrated 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 fiber or meltblown conjugate fiber
20: Coating layer 30: Support

Claims (22)

Meltblown composite nonwoven fabric comprising side by side melt blown fibers and polyethylene terephthalate fibers in a weight ratio of 3 to 9: 1 to 7; And
And a coating layer coated on the one surface of the composite nonwoven fabric with a UV curable coating resin,
Wherein the UV curable coating resin comprises a UV curable hydrophilic nonporous polymer resin and a photoinitiator,
The meltblown fibers include a polypropylene-based compound and at least one low-density polyethylene (LDPE) containing at least one member selected from the group consisting of polypropylene and polypropylene random copolymers at a weight ratio of 1: 0.5 to 2,
Wherein the meltblown fibers have an average diameter of 1 占 퐉 to 8 占 퐉,
The meltblown composite nonwoven fabric has an adhesive strength of 5.5 N / 25 mm to 14 N / 25 mm when measured according to the KS M ISO 36 method when the surface density of the meltblown composite nonwoven fabric is 300 g / m ² ,
Characterized in that the compression recovery rate of the sound absorbing material is 43% to 55% when measured according to the ASTM D6571 method when the surface area of the meltblown composite nonwoven fabric is 300 g / m < ² >.
2. The method of claim 1, further comprising a support comprising a polypropylene spunbond,
Characterized in that the support, the meltblown nonwoven fabric, and the coating layer are laminated in order. The microfabricated sound absorbing material is excellent in compression recovery rate and sound absorption property.
2. The microbubble-absorbing composite material according to claim 1, wherein the meltblown composite nonwoven fabric comprises micropores having an average depth of 40 탆 to 150 탆 and an average diameter of 10 탆 to 40 탆 in the direction of the coating layer. .
delete delete delete The polypropylene resin composition according to claim 1, wherein the polypropylene compound is a polypropylene having a melt index (MI) of 800 g / 10 min (230 ° C) to 1,500 g / 10 min
Wherein the low density polyethylene (LDPE) is a linear low density polyethylene (LLDPE) having a MI index of 140 g / 10 min (190 캜) to 160 g / 10 min (190 캜) and a specific gravity of 0.90 to 0.95. Ultrasonic absorption material with excellent characteristics.
delete The polyethylene terephthalate staple fiber according to claim 1, wherein said polyethylene terephthalate staple fiber has an average fineness of 5 to 10 denier, an average number of crimps of 12 / inch to 17 / inch and an average fiber length of 50 to 80 mm,
Wherein the polyethylene terephthalate staple fiber has a strength of 4.8 g / d to 6.5 g / d and an elongation of 35% to 45%.
delete delete The nonwoven fabric of claim 1, wherein the meltblown composite nonwoven fabric has a surface density of from 250 g / m ² to 400 g / m ² ,
Wherein the coating layer has an average thickness of 20 탆 to 70 탆 and the meltblown composite nonwoven fabric has an average thickness of 5 mm to 35 mm.
The UV curable coating resin according to claim 1, wherein the UV curable coating resin comprises 4 to 10 parts by weight of a photoinitiator based on 100 parts by weight of the UV curable hydrophilic nonporous polymer resin,
The UV curable hydrophilic nonporous polymer resin is a water-dispersed polyurethane acrylate resin containing 20 to 50% by weight of solid content,
The photoinitiator may include at least one selected from 1-hydroxycyclohexyl phenyl ketone, 1-hydroxy-2-methyl-1-phenyl-propan-1-one and dimethyl 2,4,6-trimethylbenzoylphosphine oxide Wherein the compression recovery ratio and the sound absorption property are excellent.
delete 14. The process of claim 13, wherein the photoinitiator comprises 1-hydroxycyclohexyl phenyl ketone and dimethyl 2,4,6-trimethylbenzoylphosphine oxide in a weight ratio of 6: 4 to 8: 2. Ultrasonic absorption material with excellent sound absorption characteristics.
The sound absorbing material according to any one of claims 1 to 3, 7, 9, 12, 13, and 15, wherein the sound absorbing material has a surface density of not less than 300 g / m ² , the sound absorption coefficient is not less than 0.83 at 1,000 Hz and the sound absorption coefficient is not less than 0.93 at 2,000 Hz in the measurement of the sound absorption coefficient according to the alpha cabin method of ISO R 354, This excellent micro-acoustic absorption material.
The sound absorbing material according to any one of claims 1 to 3, 7, 9, 12, 13, and 15, wherein the sound absorbing material has a surface density of not less than 300 g / m ² , the sound absorption coefficient is 0.95 or more at 3,150 Hz and the sound absorption coefficient is 1.00 or more at 5,000 Hz in accordance with the alpha cabin method of ISO R 354, and the compression recovery rate and the sound absorption characteristic This excellent micro-acoustic absorption material.
delete Preparing a meltblown composite nonwoven fabric having a surface density of 250 g / m ² to 400 g / m ² ;
Coating a surface of the meltblown composite nonwoven fabric with a UV curable coating resin including a UV curable hydrophilic nonporous polymer resin and a photoinitiator to form a coating layer;
Performing a pin press process in the direction in which the coating layer is formed to form micropores in the meltblown composite nonwoven fabric having the coating layer formed thereon; And
Irradiating UV light to UV cure,
The meltblown composite nonwoven fabric in the step of producing the meltblown composite nonwoven fabric is characterized in that when the resin containing the polypropylene compound and the resin containing the low-density polyethylene compound are melt-blended in a side-by-side composite spinneret, A meltblown air current is prepared by mixing a meltblown conjugate fiber and a polyethylene terephthalate short fiber at a ratio of 3 to 9: 1 to 7 by mixing a polyethylene terephthalate staple fiber through a blowing device and a nozzle,
Wherein the meltblown composite fiber comprises a polypropylene-based compound and a low-density polyethylene (LDPE) in a weight ratio of 5-9: 1 to 5: 5.
delete delete A vehicle interior material characterized by comprising a microfiber absorptive material according to any one of claims 1 to 3, 7, 9, 12, 13 and 15.

Images