Sound-absorption and insulation material having excellent radio frequency band sound absorbing characteristics, and sound-absorption and insulation components for vehicle comprising same

Abstract

The present invention relates to a sound-absorption and insulation material and, more particularly, to a sound-absorption and insulation material having excellent mechanical properties while having excellent sound-absorption properties with respect to a radio frequency band as well as a low frequency band. In addition, the sound-absorption and insulation material of the present invention may be widely applied to materials requiring sound-absorption and insulation properties, for example, interior materials for transportation means such as vehicles, airplanes, ships, etc., components for electronic devices such as mobile phones, laptop computers, PCs, TVs, etc., materials for building interiors, etc., and preferably, may be used as sound-absorption and insulation components for the interior and exterior of a vehicle.

Description

Sound-absorbing and sound-insulating material with excellent high-frequency band sound absorption characteristics and automotive sound-absorbing and sound-insulating component including the same

[0001] The present invention relates to a sound-absorbing and sound-insulating material having excellent sound absorption characteristics not only in the low-frequency band but also in the high-frequency band, as well as excellent mechanical properties and chemical resistance, and to an automotive sound-absorbing and sound-insulating component using the same.

[0002] Materials used to reduce noise and vibration inside and outside a vehicle are called soundproofing materials. Soundproofing materials are broadly classified into sound-absorbing materials, sound-insulating materials, and vibration-damping materials. Sound-absorbing materials include glass fiber (glass wool) and felt (resin, needle, PET), while sound-insulating materials include PU foam and PE foam, felt, EVA, and H / Layer. Vibration-damping materials include asphalt sheets and RSS (asphalt + H / Layer).

[0003] Because the noise characteristics generated by different parts of a vehicle vary, the methods and materials used to reduce noise and vibration differ. For example, to reduce engine noise, sound isolation or absorption methods are employed. Fiberglass is used as a sound-absorbing material, while PU foam is used as a sound-insulating material for the hood. The headliner is an interior component attached to the vehicle's ceiling; it houses the assist handle, overhead console, room lamp, map lamp, and coat hanger, providing passenger comfort and convenience while also possessing the function of absorbing and shielding against external vibrations and noise.

[0004] Materials such as PU, PP, and glass fiber are difficult to recycle and pose problems regarding the release of regulated substances, such as dioxins, during incineration. Consequently, recent technological trends in automotive interior materials are focused on developing eco-friendly products to comply with environmental regulations. In particular, as environmental regulations are becoming stricter globally—including European laws requiring high recycling rates—the development of products that meet these regulations is urgently needed.

[0005] Furthermore, as automobiles have recently evolved from conventional internal combustion engines to hybrid, electric, and fuel cell vehicles (hydrogen cars), vehicles currently being developed and marketed that use electric motors as their primary power source generate significant noise in the high-frequency range; consequently, existing sound-absorbing and sound-insulating materials have limitations in sufficiently reducing the noise generated by these vehicles.

[0006] Generally, increasing the thickness of sound-absorbing materials increases the sound absorption rate; however, in the high-frequency range, there is a problem in that sufficient sound absorption is not achieved even with increased thickness, and in the case of electric vehicles, high-frequency noise significantly affects the occupant's sensory quality.

[0007] The present invention has been devised to solve the aforementioned problems. The objective of the present invention is to provide a sound-absorbing and sound-insulating material for automobiles using the same, which has excellent sound absorption in low-frequency bands as well as high-frequency bands by optimizing the fineness and density of fibers within the nonwoven fabric constituting the core layer and the skin layer, while maintaining appropriate adhesive strength by additionally incorporating hollow staple fibers of an eco-friendly material within the core layer.

[0008] To solve the above-mentioned problem, the present invention relates to a sound-absorbing and sound-insulating material having excellent high-frequency band sound absorption characteristics, comprising: a core layer including a meltblown composite nonwoven fabric; and a skin layer including a spunbond nonwoven fabric provided on at least one surface of the core layer; wherein the meltblown composite nonwoven fabric comprises 10 to 50 weight percent of polyester (PE) hollow staple fibers and the remaining amount of meltblown polyester (MB-PE) fibers in the total weight.

[0009] As a preferred embodiment of the present invention, a skin layer may be further included on the other side of one side of the meltblown composite nonwoven fabric.

[0010] As a preferred embodiment of the present invention, the meltblown composite nonwoven fabric may have a thickness of 10 to 50 mm and an areal density of 100 to 900 gsm.

[0011] As a preferred embodiment of the present invention, the spunbond nonwoven fabric may have a thickness of 0.1 to 1.5 mm and an areal density of 13 to 100 gsm.

[0012] As a preferred embodiment of the present invention, the PE hollow staple fibers among the meltblown composite nonwoven fabric components may satisfy a hollowness ratio of 5 to 50%, preferably 10 to 20%, measured according to Formula 1 below.

[0013] [Equation 1]

[0014] Hollowness (%) = Area of ​​hollow parts / (Area of ​​hollow parts + Area of ​​fibers)

[0015] As a preferred embodiment of the present invention, the PE hollow staple fiber may have a fiber diameter of 10 to 50 μm, a fiber length of 30 to 40 mm, and an average crimp count of 6.0 to 9.0 pieces / inch.

[0016] As a preferred embodiment of the present invention, the MB-PE fibers among the meltblown composite nonwoven fabric components may have a fiber diameter of 1 to 8 μm.

[0017] As a preferred embodiment of the present invention, the PE hollow staple fiber and MB-PE fiber may be a spinneret of a resin containing a chelate represented by the following chemical formula 1.

[0018] [Chemical Formula 1]

[0019]

[0020] In the above chemical formula 1, R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkyl group having 1 to 5 carbon atoms.

[0021] As a preferred embodiment of the present invention, the PE hollow staple fiber is a spinneret of a molten resin prepared by performing a polymerization reaction of a composition comprising an ester reaction product and a chelate represented by the following chemical formula 1, or a polyester resin prepared by melting a polyester chip, wherein the ester resin comprises an acid component and a diol component in a molar ratio of 1:1.0 to 2.0, the acid component comprises one or more selected from an aromatic polycarboxylic acid having 6 to 14 carbon atoms, an aliphatic polycarboxylic acid having 2 to 14 carbon atoms, and a metal sulfonic acid salt, and the diol component may comprise one or more selected from ethylene glycol and a diol represented by the following chemical formula 2.

[0022] [Chemical Formula 2]

[0023]

[0024] In Chemical Formula 2, R 1 is a C1 to C5 straight-chain alkylene group, and n is an integer from 1 to 20.

[0025] As a preferred embodiment of the present invention, the MB-PE fiber is a spinneret of a molten resin prepared by performing a polymerization reaction of a composition comprising an ester reaction product and a chelate represented by Formula 1, or a polyester chip, wherein the ester resin comprises an acid component and a diol component in a molar ratio of 1:1.0 to 2.0, the acid component comprises one or more selected from an aromatic polycarboxylic acid having 6 to 14 carbon atoms, an aliphatic polycarboxylic acid having 2 to 14 carbon atoms, and a metal sulfonic acid salt, and the diol component may comprise one or more diols selected from ethylene glycol, diethylene glycol, polyethylene glycol, and neopentyl glycol (NPG).

[0026] As a preferred embodiment of the present invention, the core layer and the skin layer may be joined through thermal fusion, ultrasonic fusion, or hot melt bonding.

[0027] As a preferred embodiment of the present invention, the sound-absorbing and sound-insulating material of the present invention can satisfy a sound absorption coefficient of 0.92 or higher at 5,000 Hz when measuring the sound absorption coefficient according to the MS 341-12 Alpha Cabin method.

[0028] As a preferred embodiment of the present invention, the sound-absorbing material of the present invention can satisfy an adhesive strength of 3.5 to 16.0 N / 25 mm when measured according to the KS M ISO 36 method, when the areal density of the meltblown composite nonwoven fabric is 600 to 800 gsm.

[0029] As a preferred embodiment of the present invention, the sound-absorbing material of the present invention can satisfy an adhesive strength of 7.5 to 14.0 N / 25 mm when measured according to the KS M ISO 36 method when the areal density of the meltblown composite nonwoven fabric is 700 gsm.

[0030] As a preferred embodiment of the present invention, the sound-absorbing material of the present invention can satisfy a compressive modulus of 45% or more when the areal density of the meltblown composite nonwoven fabric is 700 gsm.

[0031] Another objective of the present invention is to provide a sound-absorbing and sound-insulating component for automobiles using the sound-absorbing and sound-insulating material described above.

[0032] As a preferred embodiment of the present invention, the sound-absorbing material may be a sound-absorbing component for an electric vehicle.

[0033] As a preferred embodiment of the present invention, the sound-absorbing and sound-insulating component for an automobile may be a sound-absorbing and sound-insulating material applied to an automobile wheelhouse (wheel guard), cow side trim, pillar trim, package tray, def-nozzle, luggage side, headliner, C-pad, engine mount, or door trim, etc.

[0034] The microfiber sound-absorbing material of the present invention exhibits excellent sound absorption not only for high frequencies but also for low frequencies, and possesses superior physical properties such as adhesive strength and bending strength, making it suitable for use as a sound-absorbing and sound-insulating component in automobiles.

[0035] FIG. 1 is a schematic cross-sectional view of the sound-absorbing and sound-insulating material of the present invention.

[0036] Figure 2 shows A as a cross-sectional photograph of the sound-absorbing and sound-insulating material prepared in Example 1, and B and C as SEM measurement images of a part of the sound-absorbing and sound-insulating material.

[0037] The present invention will be explained in more detail below.

[0038] As shown schematically in FIG. 1, the sound-absorbing material of the present invention comprises a core layer (10) comprising a meltblown composite nonwoven fabric (5) and a skin layer (20) comprising a spunbond nonwoven fabric (7) provided on at least one surface of the core layer.

[0039] In addition, a skin layer (20') may be further included on the other side of one side of the core layer.

[0040] First, the core layer is explained as follows.

[0041] [Core layer]

[0042] The above core layer is composed of a meltblown composite nonwoven fabric, and the meltblown composite nonwoven fabric comprises 10 to 50 weight% of polyester (PE) hollow staple fibers (1) and the remaining amount of meltblown polyester (MB-PE) fibers (2) of the total weight. Preferably, it may comprise 20 to 50 weight% of PE hollow staple fibers and the remaining amount of MB-PE fibers of the total weight, and more preferably, 30 to 46 weight% of PE hollow staple fibers and the remaining amount of MB-PE fibers of the total weight. At this time, if the PE hollow staple fiber content in the meltblown composite nonwoven fabric is less than 10 weight%, there may be a problem of insufficient sound absorption effect in the high-frequency band, and if the PE hollow staple fiber content exceeds 50 weight%, there may be a problem of too low adhesive strength; therefore, it is preferable to include PE hollow staple fibers within the above range.

[0043] In addition, the core layer (or meltblown composite nonwoven fabric) is preferably 10 to 50 mm thick and 100 to 900 gsm, preferably 15 to 25 mm thick and 500 to 800 gsm, more preferably 18 to 25 mm thick and 600 to 800 gsm, where, if the thickness is less than 10 mm, there may be a problem with low sound absorption effect in the low frequency range, and if the areal density is less than 100 gsm, it may be difficult to obtain a sufficient sound absorption effect in the high frequency range. In addition, if the core layer thickness exceeds 50 mm or the areal density exceeds 900 gsm, the solidification speed inside the polymer constituting the PE hollow staple fibers and / or MB-PET fibers due to residual heat during the manufacturing process slows down, and a difference in shrinkage rate between the inner surface and the surface of the nonwoven fabric occurs. This is because if the outer polymer has already fully solidified and hardened while shrinkage occurs during the internal polymer's solidification process, the internal polymer becomes subjected to tensile stress, resulting in the formation of internal emptiness. Since this can lead to a decrease in physical properties such as adhesive strength, it is preferable for the core layer to have a thickness and areal density within the aforementioned range.

[0044]

[0045] The PE hollow staple fibers constituting the meltblown composite nonwoven fabric may satisfy a hollowness of 5 to 50%, preferably 10 to 20%, and more preferably 10 to 18% as measured according to Formula 1 below. At this time, if the hollowness is less than 5%, sound absorption performance is reduced not only in the high frequency band but also in the low frequency band, and if the hollowness exceeds 50%, the hollow shape collapses during the manufacture of the meltblown composite nonwoven fabric or the manufacture of the sound-absorbing material, making it difficult to maintain the shape and causing problems such as reduced sound absorption performance in the high frequency band.

[0046] [Equation 1]

[0047] Hollowness (%) = Area of ​​hollow parts / (Area of ​​hollow parts + Area of ​​fibers)

[0048] In addition, the PE hollow staple fiber may have a fiber diameter of 10 to 50 μm, a fiber length of 30 to 40 mm, and an average crimp count of 6.0 to 9.0 pieces / inch, preferably a fiber diameter of 20 to 40 μm, a fiber length of 30 to 40 mm, and an average crimp count of 6.0 to 9.0 pieces / inch, more preferably a fiber diameter of 24 to 36 μm, a fiber length of 32 to 38 mm, and an average crimp count of 6.8 to 8.2 pieces / inch, and even more preferably a fiber diameter of 28 to 32 μm, a fiber length of 34 to 36 mm, and an average crimp count of 7.2 to 7.8 pieces / inch. If the fiber diameter of the above PE hollow staple fiber is less than 10 μm, manufacturing costs increase significantly due to reduced productivity, and there may be a problem of reduced sound absorption performance due to reduced thickness and compression recovery rate. If the fiber diameter exceeds 50 μm, the tissue structure of the nonwoven fabric is not formed densely, which may ultimately lead to problems with reduced sound absorption performance and durability. In addition, if the fiber length of the PE hollow staple fiber is less than 30 mm, fiber shedding becomes severe during the manufacture of the meltblown composite nonwoven fabric, resulting in uneven mixing with MB-PE fibers and causing variations in the sound absorption performance of the sound-absorbing and sound-insulating material. If the fiber length exceeds 40 mm, the exposure of the fiber cross-section relative to the same weight decreases, which may lead to a problem of reduced sound absorption performance. Therefore, it is preferable to have a fiber length within the above range. In addition, if the average crimp of PE hollow staple fibers is less than 6.0 fibers / inch, there may be a problem where the contact points are reduced and the adhesive strength of the nonwoven fabric is reduced, and if the average crimp exceeds 9.0 fibers / inch, there may be a problem where the bulkiness of the fibers is reduced and the thickness of the nonwoven fabric is reduced at the same weight.

[0049] The above PE hollow staple fiber is a spinneret of a resin containing a chelate represented by the following chemical formula 1.

[0050] The above PE hollow staple fiber is a spinneret of a molten resin produced by melting a polyester resin or polyester chips, prepared by performing a polymerization reaction of a composition comprising an ester resin (ester reaction product) and a chelate represented by the following chemical formula 1.

[0051] [Chemical Formula 1]

[0052]

[0053] In the above chemical formula 1, R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkylene group having 1 to 5 carbon atoms, preferably R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkylene group having 1 to 3 carbon atoms, and more preferably R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkylene group having 1 to 2 carbon atoms.

[0054] Among the above compositions, the ester resin (ester reaction product) may be an ester reaction product obtained by esterifying an acid component and a diol component in a molar ratio of 1:1.0 to 2:0, preferably in a molar ratio of 1:1.0 to 1:1.8. At this time, if the diol component is included in a molar ratio of less than 1.0 with respect to the acid, a problem may occur in which the acidity becomes excessively high and side reactions are promoted, and if it is included in a molar ratio exceeding 2.0, a problem may occur in which the degree of polymerization does not increase.

[0055] The above acid component may include one or more selected from aromatic polycarboxylic acids having 6 to 14 carbon atoms, aliphatic polycarboxylic acids having 2 to 14 carbon atoms, and metal sulfonate salts, and preferably may include one or more selected from aromatic polycarboxylic acids having 6 to 12 carbon atoms, aliphatic polycarboxylic acids having 3 to 14 carbon atoms, and metal sulfonate salts, and more preferably, terephthalic acid that does not reduce the heat resistance of the polyester may be used as the above acid component.

[0056] In addition, the above diol component may include one or more selected from ethylene glycol and diols represented by the following chemical formula 2.

[0057] [Chemical Formula 2]

[0058]

[0059] In Chemical Formula 2, R 1 is a C1 to C5 straight-chain alkylene group, preferably a C2 to C4 straight-chain alkylene group, and more preferably a C2 to C3 straight-chain alkylene group. In addition, n in Formula 2 is an integer from 0 to 20, preferably an integer from 0 to 10.

[0060] The acid component in the above composition may further include one or more selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, souveric acid, citric acid, pimmeric acid, azelaic acid, sebacic acid, nonanoic acid, decanoic acid, dodecanoic acid, and hexanodecanoic acid.

[0061] In addition, the esterification reaction of the acid component and the diol component can be carried out under esterification reaction conditions commonly used in the industry, and as a preferred example, it can be carried out at a speed of 40 to 80 rpm for 150 to 240 minutes at 200 to 260°C, and more preferably at a speed of 50 to 70 rpm for 180 to 210 minutes at 210 to 250°C.

[0062] In the above composition, the chelate acts as a polymerization catalyst. Since the chelate is stable even in the presence of water molecules, it is not deactivated even when added prior to the ester reaction, which generates a large amount of water as a byproduct. As a result, the polycondensation reaction can be performed in a shorter time than conventional methods, thereby suppressing discoloration. Furthermore, the polymerization reactivity is excellent even at low polymerization temperatures, and the generation of carboxyl groups (-COOH) at the ends of the polyester resin produced by a relatively high degree of polymerization is reduced. This reduces contamination of the nozzle surface by oligomers and monomers during the spinning process. Additionally, the number of times the nozzle surface is cleaned (wiping cycle) can be reduced, leading to improved production yield and reduced defect rates. Moreover, the uniformity of hollow staple fibers can be improved, and the resulting variation in sound absorption properties of the sound-absorbing and sound-insulating material can be reduced. Furthermore, this enables the production of a friendly polymer with reduced acetaldehyde content.

[0063] In addition, the chelate content in the above composition may be 250 to 480 ppm, more preferably 250 to 400 ppm, and even more preferably 250 to 380 ppm of the total weight of the composition. At this time, if the chelate content is less than 250 ppm, the content is too low so that the polymerization reaction does not proceed well, which may result in a problem of reduced polymerization processability and insufficient effect of extending the wiping cycle; and if the chelate content exceeds 480 ppm, due to excessive use, the molecular weight distribution in the polymerization process may be uneven due to residual chelate in the PE hollow staple fiber, which may lead to reduced spinning workability due to viscosity differences during spinning and spinning defects. Therefore, it is preferable to manufacture a polyester resin by performing a polymerization reaction using the above range in the composition.

[0064] The polyester resin, which is a polyester compound produced by polymerizing the composition described above, may also be manufactured into a resin (or chip) for forming hollow PE staple fibers by further adding additives such as heat stabilizers, color correctors, and matting agents.

[0065] The above heat stabilizer may include one or more selected from triphenylphosphate (TPP), triethylphosphate (TEP), phosphate (H3PO4), trimethylphosphate (TMP), tributylphosphate, tribubutoxyethylphosphate, tricresylphosphate, triarylphosphate isopropylated, and hydroquinone bis-(diphenyl phosphate), and preferably may include one or more selected from TPP, TEP, H3PO4, and TMP. Furthermore, the content of the heat stabilizer in the composition may be 60 to 370 ppm, preferably 62 to 250 ppm, and more preferably 70 to 220 ppm. At this time, the content of the heat stabilizer in the composition If the content is less than 60 ppm, the thermal stabilization effect resulting from its use may be insufficient due to the low amount; if the amount used exceeds 370 ppm, it inhibits the reaction, prolonging the reaction time, and due to the long operating time, the fiber's b * Since there may be a problem with the value rising, it is recommended to use it within the above range.

[0066] The polyester resin or polyester chip produced from the composition used in the manufacture of the above PE hollow staple fiber may have an intrinsic viscosity (IV) of 0.35 to 0.55 dl / g, preferably an intrinsic viscosity (IV) of 0.45 to 0.55 dl / g, and more preferably an intrinsic viscosity (IV) of 0.48 to 0.55 dl / g, and having an intrinsic viscosity in this range is desirable in terms of meltability and processability for manufacturing hollow staple fibers.

[0067]

[0068] [Meltblown fiber]

[0069] Next, among the fibers constituting the meltblown composite nonwoven fabric, the meltblown polyester (MB-PE) fiber (2) may have a fiber diameter of 1 to 8 μm, preferably 1.5 to 6 μm, and more preferably 1.8 to 5.5 μm.

[0070] In addition, the above MB-PE fiber may have a fiber length of 20 to 40 mm, preferably 25 to 38 mm, and more preferably 27 to 38 mm. At this time, if the diameter of the MB-PE fiber is less than 1 μm, the supporting strength of the fiber itself is insufficient, which may result in a decrease in the bending strength of the sound-absorbing material, and if the diameter exceeds 8 μm, the areal density of the sound-absorbing material decreases, and the sound absorption performance in the high-frequency band may decrease. In addition, if the fiber length of the MB-PE fiber is less than 30 mm, there may be a problem in maintaining the uniformity of the fiber aggregate within the nonwoven fabric, and if the fiber length of the MB-PE fiber exceeds 40 mm, there may be a problem in maintaining the target sound absorption performance because the number of relatively thick short fibers increases.

[0071] The above MB-PE fiber is a spinneret of a molten resin produced by melting a polyester resin or polyester chips, prepared by performing a polymerization reaction of a composition comprising an ester resin (ester reaction product) and a chelate represented by Chemical Formula 1.

[0072] Among the compositions used for manufacturing MB-PE fibers, the ester resin (ester reaction product) may be an ester reaction product obtained by esterifying an acid component and a diol component in a molar ratio of 1:1.0 to 2:0, preferably 1:1.0 to 1:1.8. At this time, if the diol component is included in a molar ratio of less than 1:0 with respect to the acid, the acidity may become excessively high, which may cause problems in promoting side reactions, and if it is included in a molar ratio exceeding 2:0, the degree of polymerization may not increase.

[0073] The above acid component may include one or more selected from aromatic polycarboxylic acids having 6 to 14 carbon atoms, aliphatic polycarboxylic acids having 2 to 14 carbon atoms, and metal salts of sulfonates, and preferably may include one or more selected from aromatic polycarboxylic acids having 6 to 12 carbon atoms, aliphatic polycarboxylic acids having 3 to 14 carbon atoms, and metal salts of sulfonates, and more preferably may use terephthalic acid alone or a mixture of terephthalic acid and isophthalic acid as the acid component, which does not reduce the heat resistance of the polyester, and preferably may include 2 to 14 mol% isophthalic acid and 86 to 98 mol% terephthalic acid, and more preferably 4 to 12 mol% isophthalic acid and 88 to 96 mol% terephthalic acid.

[0074] In addition, the above diol component may include one or more diols selected from ethylene glycol, diethylene glycol, polyethylene glycol, and neopentyl glycol (NPG).

[0075] In addition, the esterification reaction of the acid component and the diol component can be carried out under esterification reaction conditions commonly used in the industry, and as a preferred example, it can be carried out at a speed of 40 to 80 rpm for 150 to 240 minutes at 200 to 260°C, and more preferably at a speed of 50 to 70 rpm for 180 to 210 minutes at 210 to 250°C.

[0076] In the above composition, the chelate acts as a polymerization catalyst. Since the chelate is stable even in the presence of water molecules, it is not deactivated even when added prior to the ester reaction, which generates a large amount of water as a byproduct. As a result, the polycondensation reaction can be performed in a shorter time than conventional methods, thereby suppressing discoloration. Furthermore, the polymerization reactivity is excellent even at low polymerization temperatures, and the generation of carboxyl groups (-COOH) at the ends of the polyester resin produced by a relatively high degree of polymerization is reduced. This reduces contamination of the nozzle surface by oligomers and monomers during the spinning process. Additionally, the number of times the nozzle surface is cleaned (wiping cycle) can be reduced, leading to improved production yield and reduced defect rates. Moreover, the uniformity of hollow staple fibers can be improved, and the resulting variation in sound absorption properties of the sound-absorbing and sound-insulating material can be reduced. Furthermore, this enables the production of a friendly polymer with reduced acetaldehyde content.

[0077] The polyester resin, which is a polyester compound prepared by polymerizing the composition described above, may also be manufactured into a resin (or chip) for forming MB-PE by further adding additives such as heat stabilizers, color correctors, and matting agents.

[0078] The above heat stabilizer may include one or more selected from triphenylphosphate (TPP), triethylphosphate (TEP), phosphate (H3PO4), trimethylphosphate (TMP), tributylphosphate, tribubutoxyethylphosphate, tricresylphosphate, triarylphosphate isopropylated, and hydroquinone bis-(diphenyl phosphate), and preferably may include one or more selected from TPP, TEP, H3PO4, and TMP. Furthermore, the content of the heat stabilizer in the composition may be 60 to 370 ppm, preferably 62 to 250 ppm, and more preferably 70 to 220 ppm. At this time, the content of the heat stabilizer in the composition If the content is less than 60 ppm, the thermal stabilization effect resulting from its use may be insufficient due to the low amount; if the amount used exceeds 370 ppm, it inhibits the reaction, prolonging the reaction time, and due to the long operating time, the fiber's b * Since there may be a problem with the value rising, it is recommended to use it within the above range.

[0079]

[0080] [Composite Nonwoven Fabric]

[0081] In relation to meltblown composite nonwoven fabrics applied as sound-absorbing materials, conventionally, polyolefin fibers, such as polypropylene (PP) fibers, were used as MB fibers to manufacture composite nonwoven fabrics and applied as sound-absorbing materials. However, PP fibers have a glass transition temperature (-10 to 0°C, Tg), crystallization temperature (110 to 120°C, Tc), and melting temperature (165 to 170°C, Tm), which is lower than that of polyester fibers such as PET (Tg=70~80°C, Tc=190~200°C, Tm=250~260°C), and there are disadvantages in terms of material recycling.

[0082] The meltblown composite nonwoven fabric of the present invention can be manufactured using the previously described PE hollow staple fibers and MB-PE fibers through the following method.

[0083] The above meltblown composite nonwoven fabric can be manufactured by mixing the MB-PE fibers and the PE hollow staple fibers by incorporating PE hollow staple fibers into the meltblown airflow through a blowing facility and nozzle when the molten resin is extruded to form MB-PE fibers using a spinneret.

[0084] In addition, the die and nozzle temperatures and the hot air temperature of the meltblown spinning process are preferably performed at 250°C to 290°C, and more preferably at 260°C to 280°C. At this time, if the hot air temperature is below 250°C, the thickness of the MB-PE fiber increases, which lowers the porosity of the fiber assembly and relatively reduces the amount of air contained. Consequently, the effect of reducing the flow resistance of sound energy by the fiber and air layer may decrease, and as a result, a problem of reduced sound absorption performance may occur. Furthermore, if the hot air temperature exceeds 290°C, problems such as increased process costs and a shortened nozzle replacement cycle due to increased carbonization may occur, and PE hollow staple fibers may not be stably aggregated and may fly away.

[0085] In addition, the above PE hollow staple fiber can be manufactured by performing a process comprising: a step of manufacturing hollow staple fibers by spinning a polyester resin at a spinning temperature of 270°C to 285°C and a spinning speed of 1,000 to 1,400 m / min; a step of stretching the hollow staple fibers by 2.5 to 4.0 times at 70°C to 85°C; and a step of heat-treating the stretched hollow staple fibers at 130°C to 150°C.

[0086] When manufacturing PE hollow staple fibers, the spinning temperature of the step of manufacturing the staple fibers is preferably 270°C to 285°C, and more preferably 272°C to 278°C. Also, when manufacturing the staple fibers, the spinning speed is preferably 1,000 to 1,400 m / min, preferably 1,000 to 1,300 m / min, and more preferably 1,150 to 1,250 m / min.

[0087] When manufacturing PE hollow staple fibers, the stretching treatment step can be performed at 70°C to 85°C, preferably at 75°C to 80°C, and the stretching ratio is preferably 2.5 to 4.0 times, preferably 3.0 to 3.5 times. In addition, when manufacturing PET staple fibers, the heat treatment temperature is 130°C to 150°C, preferably 135°C to 145°C, which is advantageous in terms of securing appropriate elongation.

[0088] In addition, the PE hollow staple fiber may have a strength of 4.8 to 6.5 g / d, preferably 5.0 to 6.2 g / d, and may also have an elongation of 35 to 45%, preferably 37 to 43%.

[0089]

[0090] [Skin layer]

[0091] A skin layer formed on at least one surface of the core layer of the present invention comprises a spunbond nonwoven fabric.

[0092] The skin layer (20, 20') covers the surface of the sound-absorbing material to maintain the shape of the sound-absorbing material and provide strength, while also preventing the short fibers within the core layer from detaching over time, thereby allowing the sound-absorbing function to be continuously maintained.

[0093] The above skin layer may have a thickness of 0.1 to 1.5 mm and an areal density of 13 to 100 gsm, preferably a thickness of 0.1 to 1.5 mm and an areal density of 15 to 40 gsm, more preferably a thickness of 0.3 to 1.2 mm and an areal density of 20 to 40 gsm, and even more preferably a thickness of 0.5 to 1.2 mm and an areal density of 25 to 40 gsm. At this time, if the skin layer thickness is less than 0.1 mm or the areal density is less than 13 gsm, the appropriate bending strength of the sound-absorbing and sound-insulating material may not be secured. Also, if the skin layer thickness exceeds 1.5 mm, the areal density of the skin layer decreases, which may cause a problem where the low-frequency sound absorption performance actually decreases, and if the areal density of the skin layer exceeds 100 gsm, the adhesive strength of the sound-absorbing and sound-insulating material may decrease.

[0094]

[0095] A sound-absorbing material can be manufactured in the form of a laminated skin layer-core layer or skin layer-core layer-skin layer by heat-fusion or ultrasonically fusing the spunbond nonwoven fabric described above to one or both sides of the meltblown composite nonwoven fabric described above.

[0096] The sound-absorbing and sound-insulating material of the present invention can satisfy a sound absorption coefficient of 0.92 or higher at 5,000 Hz, preferably 0.95 to 1.25, and more preferably 1.00 to 1.20 when measuring the sound absorption coefficient according to the MS 341-12 alpha cabin method.

[0097] In addition, the sound-absorbing material of the present invention can satisfy an adhesive strength of 7.5 to 14.0 N / 25 mm when measured according to the KS M ISO 36 method when the areal density of the meltblown composite nonwoven fabric is 700 gsm.

[0098] In addition, the sound-absorbing material of the present invention can satisfy a compressive modulus of 45% or more when the areal density of the meltblown composite nonwoven fabric is 700 gsm.

[0099] The present invention will be explained in more detail below through examples, but the following examples are not intended to limit the scope of the invention and should be interpreted as being for the purpose of aiding understanding of the invention.

[0100] [Example]

[0101] Preparation Example 1-1: Preparation of Polyester (PE) Hollow Staple Fibers

[0102] Terephthalic acid (acid component) and ethylene glycol (diol component) were subjected to an esterification reaction (temperature 230°C, stirring speed 60 rpm, 200 min) in a molar ratio of 1:1.2 to obtain an ester reaction product.

[0103] Next, a polyester compound was prepared by polymerizing 300 ppm of a chelate represented by the following chemical formula 1-1 as a polymerization catalyst and the ester reaction product.

[0104] Next, a resin for forming polyester hollow staple fibers (melting point = 260°C, intrinsic viscosity = 0.50 dl / g) was prepared by mixing 150 ppm of H3PO4 (heat stabilizer), 3.2 ppm of a complementary colorant mixed with blue and red dyes (solvent blue 122:solvent red 195 = 1:1.8~2.0 weight ratio), 2,300 ppm of TiO2 (matting agent), and the remainder of the above polyester compound.

[0105] [Chemical Formula 1-1]

[0106]

[0107] In the above chemical formula 1-1, R 1 and R 2 is a hydrogen atom.

[0108] Next, the above-mentioned polyester hollow staple fiber forming resin was spun using a spinneret for manufacturing hollow fibers at a spinning temperature of 275°C and a spinning speed of 1,200 m / min, and then stretched 3.3 times at 77°C.

[0109] Then, PE hollow staple fibers were manufactured through opening and carding processes.

[0110] The obtained PE hollow staple fibers had a fiber diameter of 29 µm, a fiber length of 34 to 36 mm, and an average crimp count of 7.5 fibers / inch, with a hollowness of 12.0%, a strength of 5.7 g / d, and an elongation of 40%.

[0111]

[0112] Preparation Example 2-1: Preparation of resin for forming meltblown fibers (MB-PE)

[0113] An esterification reaction product was obtained by esterifying terephthalic acid and a diol component in a molar ratio of 1:1.2 (temperature 230℃, stirring speed 60 rpm, 200 min) as acid components.

[0114] At this time, the above diol component used was ethylene glycol.

[0115] Next, a polyester resin (compound) was prepared by mixing dimethyl terephthalate, 320 ppm of a chelate represented by the following chemical formula 1-1 as a polymerization catalyst, and the remaining amount of the ester reaction product and performing a polymerization reaction.

[0116] [Chemical Formula 1-1]

[0117]

[0118] In the above chemical formula 1-1, R 1 and R 2 is a hydrogen atom.

[0119] Next, a resin for forming meltblown fibers was prepared by mixing 170 ppm of H3PO4 (heat stabilizer), 3.2 ppm of a complementary colorant mixed with blue and red dyes (solvent blue 122:solvent red 195 = 1:1.8~2.0 weight ratio), 2,500 ppm of TiO2 (matting agent), and the remaining amount of the polyester resin.

[0120]

[0121] Preparation Examples 2-2 to 2-6 and Comparative Preparation Examples 2-1 to 2-3

[0122] A resin for forming MB-PE fibers was prepared with the same composition as in Preparation Example 2-1 above, but with different acid and / or diol components as shown in Table 1 below, and an ester reaction product was synthesized, and then the resin for forming MB-PE fibers was prepared using the product to carry out Preparation Examples 2-2 to 2-6 and Comparative Preparation Examples 2-1 to 2-3, respectively.

[0123] In Table 1 below, TPA means terephthalic acid, IPA means isophthalic acid, EG means ethylene glycol, and DEG means diethylene glycol.

[0124] Classification (Molar%) Preparation Example 2-1 Preparation Example 2-2 Preparation Example 2-3 Preparation Example 2-4 Preparation Example 2-5 Preparation Example 2-6 Acidic Component TPA 100 96 928 89 688 IPA 04 81 24 12 Diol Component EG 100 97 94 91 91 7DEG 03 69 93 Classification (Molar%) Comparison Preparation Example 2-1 Comparison Preparation Example 2-2 Comparison Preparation Example 2-3 --- Acidic Component TPA 85 96 85 --- IPA 15 4 15 --- Diol Component EG 95 88 88 --- DEG 5 12 12 ---

[0125]

[0126] Example 1: Preparation of sound-absorbing and sound-insulating material

[0127] (1) Manufacture of meltblown composite nonwoven fabric

[0128] During the process of manufacturing fibers using the meltblown fiber-forming resin prepared in Preparation Example 2-1, the above-mentioned carded PE hollow staple fibers were uniformly and quantitatively incorporated through a blowing facility.

[0129] At this time, the meltblown spinning temperature and hot air temperature were 270°C, and the PE hollow staple fibers prepared in Preparation Example 1 were mixed together in a vertically descending meltblown air stream, such that the PE hollow staple fibers accounted for 35% by weight and the MB-PE fibers accounted for the remainder, i.e., 65% by weight, to produce a meltblown composite nonwoven fabric with an areal density of 700 gsm and a thickness of 50 mm.

[0130] In addition, a cross-sectional photograph of the manufactured meltblown composite nonwoven fabric is shown in Fig. 2A, and SEM measurement images of the same are shown in Fig. 2B and C.

[0131] (2) Preparation of spunbond nonwoven fabric

[0132] A spunbond nonwoven fabric with an areal density of 25 gsm and a thickness of 0.8 mm was prepared by melt-spinning PET resin.

[0133] (3) Manufacturing of sound-absorbing and sound-insulating materials

[0134] A sound-absorbing material in the form of a support layer-core layer laminated was manufactured by heat-fusing the spunbond nonwoven fabric onto one side of the meltblown composite nonwoven fabric.

[0135]

[0136] Examples 2 to 6 and Comparative Examples 1 to 3

[0137] Sound-absorbing and sound-insulating materials were prepared in the same manner as in Example 1, but with different content of the resin for MB-PE fiber formation, different diameters of the MB-PE fibers, or different surface densities of the meltblown nonwoven fabric as shown in Tables 2 and 3 below, and Examples 2 to 6 and Comparative Examples 1 to 3 were carried out, respectively. The difference in thickness of the composite nonwoven fabric is due to the difference in the composition of the resin for MB-PE fiber formation, which alters the solidification behavior and thus results in a difference in thickness.

[0138]

[0139] Comparative Example 4

[0140] A sound-absorbing and sound-insulating material was prepared in the same manner as in Example 1, but instead of the MB-PE fiber-forming resin of Preparation Example 2-1, a polypropylene (PP) resin with an MI of 1500 (230°C, 2.16 kg) was used as the MB fiber-forming resin, and the mixture was prepared such that PE hollow staple fibers accounted for 35% by weight and MB fibers (PP fibers) accounted for 65% by weight to produce a meltblown composite nonwoven fabric with an areal density of 700 gsm and a thickness of 50 mm.

[0141] Classification Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Preparation of resin for MB-PE fiber forming Example 2-1 Preparation Example 2-2 Preparation Example 2-3 Preparation Example 2-4 Preparation Example 2-5 Preparation Example 2-6 MB-PE fiber diameter (㎛) 85 32 33 Planar density (gsm) 700 700 600 800 700 700 Thickness (mm) 50 40 30 20 30 25

[0142] Classification Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 MB-PE Fiber-forming Resin Comparison Preparation Example 2-1 Comparison Preparation Example 2-2 Comparison Preparation Example 2-3 PP Resin MB-PE Fiber Diameter (㎛) 53 13.5 Planar Density (gsm) 700 700 700 700 Thickness (mm) 10 15 10 50

[0143]

[0144] Experimental Example 1: Measurement of Sound Absorption Coefficient and Adhesion Strength by Frequency (Hz)

[0145] The frequency (Hz) sound absorption coefficient and adhesive strength of the sound-absorbing and sound-insulating materials prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were measured by the following method, and the results are shown in Table 4 below.

[0146] (1) Measurement of sound absorption coefficient by frequency

[0147] To measure the sound absorption coefficient, three specimens each were prepared as specimens applicable to the MS 341-12 alpha cabin method, and after leaving them at external temperatures of 0°C and 25°C for 30 minutes, the sound absorption coefficient was measured, and the average values ​​of the measured sound absorption coefficients are shown in Table 4.

[0148] (2) Measurement of adhesive strength

[0149] Adhesive strength was measured by bonding fiber assemblies using a hot air dryer and then measuring the adhesive strength using a universal testing machine (UTM) according to the KS M ISO 36 method. The experiment was conducted at a temperature of 150℃ for 8 minutes, with a cooling time of 3 minutes and an applied load of 22.40 g / ㎠.

[0150] (3) Measurement of compressive modulus (%)

[0151] For the evaluation of compressive modulus, a test specimen measuring 100 mm × 100 mm (thickness varies depending on product specifications) was randomly selected and placed between steel plates measuring 100 mm × 100 mm × 0.8 mm (width, length, thickness), and a weight of 500 g (40 pi) was placed on the steel plates. At this time, the atmosphere around the specimen was maintained at 120°C (±2°C) for 1 hour, and the compressive modulus was calculated. To ensure reproducibility, the measurement was performed five times, and the average value was calculated.

[0152] Classification Sound Absorption Coefficient by Frequency Adhesion Strength (N / 25mm) Compressive Modulus (%) 1,000Hz 2,000Hz 3,150Hz 4,000Hz 5,000Hz Example 10.87 0.97 1.01 1.05 1.107.547 Example 20.88 0.95 0.99 1.02 1.068.746 Example 30.86 0.92 0.97 1.001 1.027.746 Example 40.88 0.97 1.04 1.11 1.159.745 Example 50.90 0.99 1.05 1.101 1.189.346 Example 60.86 0.97 1.02 1.06 1.109.249 Comparative Example 10.700.780.840.860.868.842 Comparative Example 20.720.800.880.900.918.445 Comparative Example 30.700.800.880.900.919.142 Comparative Example 40.901.001.051.151.2010.545

[0153] Looking at the experimental results in Table 3, it was confirmed that Examples 1 to 6 had high sound absorption coefficients across the entire frequency range from low to high, excellent adhesive strength of 7.5 N / 25 mm or more, and excellent compressive modulus of 45% or more. However, compared to Comparative Example 1, in which an excessive amount of IPA was used as the acid component, there was a problem of having relatively high sound absorption coefficients at all frequencies and relatively low compressive modulus.

[0154] In addition, in Comparative Example 2, in which 12 mol% of DEG was used as a diol component exceeding 10 mol% when synthesizing the resin for forming MB-PE fibers, the sound absorption coefficient at low frequencies tended to be lower compared to Example 2.

[0155] In addition, in Comparative Example 3, in which an excess amount of IPA was used as the acid component and 12 mol% of DEG was used as the diol component exceeding 10 mol%, the sound absorption coefficient at low frequencies was relatively low and the compressive modulus was poor.

[0156] In addition, in the case of Comparative Example 4, which uses a composite nonwoven fabric made using PP resin as the MB fiber, the overall sound absorption and adhesion are good, but as shown in the following evaluation, it is difficult to use in a high-temperature environment.

[0157]

[0158] Experimental Example 2: Thermal Stability Measurement Experiment

[0159] The thermal stability of the composite nonwoven fabric, i.e., the sound-absorbing material, prepared in Example 1 and Comparative Example 4 was evaluated based on the heat shrinkage rate, and the results are shown in Table 5 below.

[0160] The heat shrinkage rate was measured by exposing the composite nonwoven fabric to 150℃ (±2℃) for 200 hours, then removing it and letting it cool for 60 minutes, and then measuring the MD (machine direction) and CD (cross direction) shrinkage rates of the composite nonwoven fabric according to Equation 3 below.

[0161] [Equation 3]

[0162] Heat shrinkage rate (%) = (Initial length - Final length) / Initial length × 100%

[0163] In Equation 3, the initial length is the length of the composite nonwoven fabric before exposure to heat, and the later length is the length of the composite nonwoven fabric cooled after exposure to 150°C (±2°C) for 200 hours.

[0164] Classification MD Shrinkage Rate (%) CD Shrinkage Rate (%) Example 1 2.3 2.8 Comparative Example 4 5.9 10.8

[0165] Looking at the change in heating shrinkage rate in Table 5 above, it can be confirmed that Comparative Example 4 has a problem of showing a relatively higher shrinkage change of 2 to 3 times or more compared to Example 1.

[0166] Through the above examples and experimental examples, it was confirmed that the sound-absorbing and sound-insulating material of the present invention possesses excellent sound absorption capabilities not only in the high-frequency range but also in the low-frequency range, and that it exhibits excellent sound absorption coefficients at all frequencies. The present invention can be widely applied to materials requiring sound absorption and sound insulation, such as interior materials for means of transportation like automobiles, airplanes, and ships; components for electronic products like mobile phones, laptops, computers, and TVs; and interior materials for construction. Preferably, it can be used as a sound-absorbing and sound-insulating material component for the interior and exterior of automobiles.

[0167] [Explanation of the symbol]

[0168] 1 : PE hollow staple fiber 2 : Meltblown fiber

[0169] 5 : Meltblown composite nonwoven fabric 7 : Spunbond nonwoven fabric

[0170] 10 : Core layer 20 : Support

Claims

A core layer comprising a melt-blown composite nonwoven fabric having a thickness of 10 to 50 mm and an areal density of 100 to 900 gsm; A skin layer comprising a spun bond nonwoven fabric having a thickness of 0.1 to 1.5 mm and an area density of 13 to 100 gsm, provided on at least one surface of a core layer; The above meltblown composite nonwoven fabric is a sound-absorbing and sound-insulating material with excellent high-frequency sound absorption properties, characterized by comprising 10 to 50 weight percent of polyester (PE) hollow staple fibers and the remaining amount of meltblown polyester (MB-PE) fibers in the total weight. In claim 1, the sound-absorbing and sound-insulating material having excellent high-frequency band sound absorption characteristics is characterized in that the PE hollow staple fiber satisfies a hollow ratio of 5 to 50% measured according to Formula 1 below; [Equation 1] Hollowness (%) = Area of ​​hollow parts / (Area of ​​hollow parts + Area of ​​fibers) In claim 1, the PE hollow staple fiber has a fiber diameter of 10 to 50 μm, a fiber length of 30 to 40 mm, and an average crimp count of 6.0 to 9.0 pieces / inch, and The above MB-PE fiber is characterized by having a fiber diameter of 1 to 8 μm and is a sound-absorbing and sound-insulating material with excellent high-frequency band sound absorption properties. A sound-absorbing and sound-insulating material with excellent high-frequency band sound absorption characteristics, characterized in that, in claim 1, a skin layer is further included on the other side of one side of the core layer on which the skin layer is formed. A sound-absorbing and sound-insulating material with excellent high-frequency band sound absorption properties, characterized in that, in claim 1, the core layer and the skin layer are bonded through thermal fusion, ultrasonic fusion, or hot melt bonding. In paragraph 3, the PE hollow staple fiber is a spinneret of a polyester resin or a molten resin obtained by melting polyester chips, prepared by performing a polymerization reaction of a composition comprising an ester reaction product and a chelate represented by the following chemical formula 1. The above ester reaction product contains an acid component and a diol component in a molar ratio of 1:1.0 to 2.0, and The above acid component comprises one or more selected from aromatic polycarboxylic acids having 6 to 14 carbon atoms, aliphatic polycarboxylic acids having 2 to 14 carbon atoms, and metal sulfonate salts, and A sound-absorbing and sound-insulating material with excellent high-frequency sound absorption properties, characterized in that the above-mentioned diol component comprises one or more types selected from ethylene glycol and diols represented by the following chemical formula 2; [Chemical Formula 1] In the above chemical formula 1, R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkylene group having 1 to 5 carbon atoms, and [Chemical Formula 2] In Chemical Formula 2, R 1 is a C1 to C5 straight-chain alkylene group, and n is an integer from 0 to 20. In paragraph 3, the MB-PE fiber is a spinneret of a molten resin prepared by performing a polymerization reaction of a composition comprising an ester reaction product and a chelate represented by the following chemical formula 1, or a polyester resin prepared by melting polyester chips. The above ester reaction product contains an acid component and a diol component in a molar ratio of 1:1.0 to 2.0, and The above acid component comprises one or more selected from aromatic polycarboxylic acids having 6 to 14 carbon atoms, aliphatic polycarboxylic acids having 2 to 14 carbon atoms, and metal sulfonate salts, and A sound-absorbing and sound-insulating material with excellent high-frequency sound absorption properties, characterized in that the above-mentioned diol component comprises one or more diols selected from ethylene glycol, diethylene glycol, polyethylene glycol, and neopentyl glycol (NPG). [Chemical Formula 1] In the above chemical formula 1, R 1 and R 2 Each is independently a hydrogen atom or a straight-chain alkylene group having 1 to 5 carbon atoms. In any one of claims 1 to 7, when measuring the sound absorption coefficient based on the MS 341-12 alpha cabin method, A sound-absorbing and sound-insulating material with excellent high-frequency band sound absorption characteristics, characterized by satisfying a sound absorption value of 0.92 or higher at 5,000 Hz. An automotive sound-absorbing component characterized by including a sound-absorbing material selected from any one of claims 1 to 7. In claim 9, the sound-absorbing and sound-insulating component for an automobile is characterized in that the above-mentioned sound-absorbing and sound-insulating material is a sound-absorbing and sound-insulating component for an electric vehicle.

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