KR20140086190A - Sound-absorbing materials having excellent sound absorption performance and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a sound-absorbing material having an excellent sound absorption performance and a manufacturing method thereof. In particular, the sound-absorbing material having an excellent sound absorption performance includes an air layer which can maximize viscosity loss and a dissipation pathway of incident sound energy; ultimately has excellent properties to reduce vibration by sound energy transferred inside a matrix, resulted from an increased rebound elasticity; and has an increased absorption rate. In addition, the sound-absorbing material can adjust the temperature even when the temperature of the outside changes; can prevent deterioration of the sound absorption performance even during the winter when the temperature of the outside is low; has the excellent sound absorption performance which is effective to block noisy sound transmitted to the inside of a vehicle; has a temperature adjusting function so that the sound-absorbing material can be used as an interior material, which can increase energy efficiency and quality of a future electric vehicle that is driven by a battery and has a separate heating system.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a sound absorbing material having excellent sound absorbing performance,

The present invention relates to a sound absorbing material having excellent sound absorbing performance and a method of manufacturing the same, and more particularly, to a sound absorbing material having an excellent sound absorbing performance that can be adjusted not only to a sound absorption rate but also to a temperature change with an external temperature change.

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

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

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

In recent years, regulations on environmental friendliness and recyclability have gradually been strengthened, and the use ratio of fiber-absorbing materials based on thermoplastic resin such as PET or PP (polypropylene) 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.

 In addition, the conventional fiber-absorbing products have a problem that they are greatly influenced by the sound absorption performance due to external temperature changes. In the winter when the outside temperature is lower than in the summer when the temperature is high, there is a problem that the fiber aggregate becomes hard and the viscoelasticity deteriorates due to the lowering of the external temperature.

 Furthermore, unlike gasoline vehicles that are heated by the waste heat from the internal combustion engine, electric vehicles, which are expected to increase in demand in the future, are driven by the battery and are heated separately, It is required to develop an interior material capable of enhancing the quality of the interior.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to improve the sound absorption rate by forming an air layer capable of maximizing viscous loss and dissipation path of incident sound energy, Which is capable of preventing deterioration of the sound absorption performance even in the winter when the external temperature is lowered.

Further, it is an object of the present invention to provide a sound absorbing material capable of maintaining a sufficient bonding force between fibers while improving moldability and rebound modulus, and ultimately having excellent vibration damping ability against sound energy transmitted to the matrix.

 In order to solve the above-described problems,

Staple fibers comprising phase change material (PCM); And a binder fiber for partially bonding a plurality of short fibers including the phase change material (PCM).

According to a preferred embodiment of the present invention, the staple fibers may include a polyolefin-based polymer and a dispersed phase change material (PCM).

According to another preferred embodiment of the present invention, the weight ratio of the polyolefin-based polymer and the phase change material (PCM) may be from 9: 1 to 3: 7.

According to another preferred embodiment of the present invention, the staple fiber may be a conjugated fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a single component.

According to another preferred embodiment of the present invention, the staple fiber is a sheath including a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component - It may be a sheath-core type conjugated fiber.

According to another preferred embodiment of the present invention, the weight ratio of the core component and the sheath component may be 7: 3 to 3: 7 in the sheath-core type conjugate fiber.

According to another preferred embodiment of the present invention, the phase change material (PCM) may be a paraffinic phase change material (PCM) having 14 to 22 carbon atoms.

According to another preferred embodiment of the present invention, the phase change material (PCM) is selected from the group consisting of n-octanoic acid, n-heptanoic acid, n-hexanoic acid, n-octadecane, n-heptadecane, n-hexadecane, n-pentadecane, n-tetradecane and n-tridecane from the group consisting of n-heptanoic acid, It can be any one or more selected.

According to another preferred embodiment of the present invention, the melting point of the phase change material (PCM) may be 5 to 44 캜.

According to another preferred embodiment of the present invention, the fiber length of the short fibers is 22 to 64 mm and the fineness may be 1 to 10 D.

According to another preferred embodiment of the present invention, the binder fiber may include a low melting point (LM) elastomer having an elastic recovery rate of 50 to 80%.

According to another preferred embodiment of the present invention, the binder fibers may be composite fibers obtained by spinning the low melting point (LM) elastomer as a single component.

According to another preferred embodiment of the present invention, the low melting point (LM) elastomer may include at least one selected from the group consisting of polyester, polyamide and polyurethane.

According to another preferred embodiment of the present invention, the low melting point (LM) elastomer is selected from the group consisting of dimethyl terephthalate (DMT), dimethyl isophthalate (DMI), terephthalic acid 1,4-butanediol (1,4-BD), polytetramethyleneglycol (PTMG) as a diacid, isophthalic acid (IPA) as a diacid, diol ) By esterification and polymerization steps.

According to another preferred embodiment of the present invention, the sound absorbing material may include 50 to 80% by weight of short fibers including phase change material (PCM) and 20 to 50% of binder fibers.

The present invention also relates to a staple fiber comprising a phase change material (PCM); And a binder fiber for partially bonding short fibers including a plurality of phase change materials (PCM), wherein the reduction rate of the sound absorption ratio measured at 0 DEG C with respect to the absorption coefficient measured at 25 DEG C by the Alpha Cabin method Is 5% or less.

According to a preferred embodiment of the present invention, the staple fiber is a cis-fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component, And may be a sheath-core type conjugated fiber.

The present invention also relates to a staple fiber comprising a phase change material (PCM); And a binder fiber for partially bonding short fibers including a plurality of the phase change materials (PCM) to a nonwoven fabric.

According to another preferred embodiment of the present invention, the staple fiber is a sheath including a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component - It may be a sheath-core type conjugated fiber.

According to another preferred embodiment of the present invention, the sound absorbing material may include 50 to 80% by weight of short fibers containing phase change material (PCM) and 20 to 50% of binder fibers.

The sound absorbing material having excellent sound absorbing performance of the present invention forms an air layer capable of maximizing the viscous loss and dissipation path of incident sound energy, and has an improved rebound resilience, and ultimately the sound energy transmitted to the inside of the matrix The sound absorption rate is improved due to the excellent vibration damping ability and the temperature can be adjusted even when the external temperature is changed, so that the decrease of the sound absorption performance can be prevented even in the winter when the external temperature is low. In addition, it is effective not only to prevent noise coming into the automobile due to excellent sound absorbing effect but also to be used as an interior material that can be energy-efficient for a future electric vehicle driven by a battery, It can contribute to improvement.

FIG. 1 is a cross-sectional photograph of a staple fiber including a phase change material (PCM) produced by composite spinning in the form of a sheath-core included in a sound absorbing material according to a preferred embodiment of the present invention.
FIG. 2 is a cross-sectional photograph of a low melting point (LM) polyester elastomer fiber prepared by composite spinning in the form of an eccentric sheath-core included in a sound absorbing material according to a preferred embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

As described above, the conventional sound absorbing product has a problem of increasing the area density and thickness of the fiber aggregate in order to improve the sound absorption performance and the sound insulation performance by increasing the porosity and the sound dissipation path. The influence of the sound absorption performance There is a problem that the fiber aggregate becomes hard and the viscoelasticity decreases due to the lowering of the external temperature in the winter when the external temperature is lower than that of the summer, where the temperature is high.

Accordingly, the present invention provides a staple fiber comprising a phase change material (PCM); And a binder fiber for partially bonding a plurality of short fibers including the phase change material (PCM). It is possible to improve the sound absorption rate by forming an air layer to maximize the viscous loss and dissipation path of incident sound energy, and it is possible to control the temperature even when the external temperature changes. Therefore, even in the winter when the external temperature is low, A sound absorbing material having excellent sound absorbing performance and a manufacturing method thereof can be provided.

 The staple fiber included in the sound absorbing material of the present invention includes a phase change material (PCM).

 Phase Change Material (PCM) is a material that repeatedly shows heat storage and heat dissipation characteristics that absorb heat while melting when the ambient temperature rises, and crystallize as the ambient temperature lowers.

The present invention can improve the energy efficiency by adding a temperature control function in addition to a sound absorption effect by using a short fiber including a phase change material (PCM), and the temperature can be adjusted even when the external temperature changes, It is possible to prevent the sound absorbing performance from decreasing due to the stiffness of the film and the deterioration of the viscoelasticity.

The staple fiber of the present invention may include a polyolefin-based polymer and a phase change material (PCM) dispersed in the polyolefin-based polymer.

The polyolefin-based polymer is excellent in compatibility with a phase change material (PCM) and can be included as a main component of a short fiber including a phase change material (PCM). The type of the polyolefin-based polymer is not particularly limited, And may be at least one polyolefin polymer selected from the group consisting of polypropylene, polyisobutylene, and copolymers thereof. Most preferably, it is excellent in physical properties such as abrasion resistance and chemical resistance, ≪ / RTI > It is more preferable that the polypropylene has a melt flow index (MFI) of 10 to 40 g / 10 min and a melting point (Tm) measured by DSC of 160 to 165 캜. The lower the melt flow index of polypropylene, the stiffness, chemical resistance and low elongation of the fiber can be given, but the viscosity is lowered and the processability is deteriorated. When the melt flow index is too high, not only the stiffness of the fiber is lowered, It is most preferable to have a melt flow index of 10 to 40 g / 10 min.

In addition, the melting point of the phase change material (PCM) contained in the staple fibers of the present invention may preferably be 5 to 44 캜. The melting point of the phase change material (PCM) is preferably within the above-mentioned range in consideration of the seasonal factors and the temperature range of the ordinary automobile room, and most preferably 21 to 34 ° C.

It is more preferable that the phase change material (PCM) is a paraffinic phase change material (PCM) having 14 to 22 carbon atoms even among those satisfying the melting point range. Paraffinic phase change materials (PCM) are highly compatible with polyolefin systems and are harmless to humans. The paraffinic phase change material (PCM) may be selected from the group consisting of n-octanoic acid, n-heptanoic acid, n-hexanoic acid, n-tetracholic acid, n- N-heptadecane, n-hexadecane, n-pentadecane, n-tetradecane, or n-tridecane, and the like.

The weight ratio of the polyolefin-based polymer and the phase change material (PCM) contained in the staple fibers of the present invention may be from 9: 1 to 3: 7. If the phase change material (PCM) is contained in the range below the above range, there may be a disadvantage that the temperature control function is insufficient. If the phase change material (PCM) is included in the range above the above range, the fiber forming ability of the core part is lowered, There may be a downside drawback.

Further, the staple fibers may be conjugated fibers obtained by spinning a polyolefin-based polymer and a dispersed phase change material (PCM) as one component.

The composite fiber may be a sheath-core type or a side by side type. When the sheath-core type conjugate fiber is formed, the polyolefin-based polymer and / A sheath-core type composite fiber comprising a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component. The polyester-based polymer contained as a sheath component has a space formed therebetween due to the interface property with the polyolefin-based polymer as a core component, which maximizes the formation of the air layer, And the dissipation path can be maximized, and the sound absorption performance can be remarkably improved. The polyester-based polymer contained as a sheath component is not particularly limited as long as it is a general-purpose polyester-based polymer, but it is more preferable to use a polyethyleneterephthalate, polybutyleneterephthalate or polytrimethylene Terephthalate (Polytrimethyleneterephthalate), or the like. FIG. 1 is a cross-sectional photograph of a short fiber prepared by composite spinning in the form of a sheath-core included in a fiber aggregate according to a preferred embodiment of the present invention, wherein the core component comprises polypropylene and a paraffinic phase change material (PCM) And polyethylene terephthalate as a sheath component, and a space is formed between the core component and the sheath component due to their interfacial properties.

The weight ratio of the core component and the sheath component of the sheath-core type conjugate fiber may be 7: 3 to 3: 7. When the core component is included in the range below the above range, the temperature control function is insufficient, and the space formed between the sheath and the core portion is reduced, and the sound absorption performance is deteriorated. If the content is in excess of the above-mentioned range, the sheath component may be too small to cause deterioration of the physical properties of the composite spinning fiber.

The fiber length of the short fibers may be from 22 to 64 mm, and if the fiber length is less than 22 mm, the gap between the fibers is widened to form and produce into a fibrous aggregate, and sound absorption and sound insulation performance may be deteriorated due to excessive porosity If it exceeds 64 mm, the gap between the fibers becomes too narrow to decrease the porosity, which may lower the sound absorption rate. Furthermore, the fineness of the staple fibers may be 1 to 10 D, and the smaller the fineness, the more effective the improvement of the scratching performance. If the fineness of the fibers is less than 1 D, there may be a problem in controlling the optimum shape of the target cross-section. If the fiber density exceeds 10 De, difficulties arise in the manufacturing process of the nonwoven fabric, felled There may be a problem.

In addition, the sound absorbing material of the present invention includes binder fibers for partially joining short fibers including a plurality of the phase change materials (PCM).

The binder fiber may be a binder fiber commonly used in the production of a fiber structure, and may be used in the form of a powder as well as the fiber, and more preferably a low melting point (LM) elastomer. Elastomer refers to a polymer material having a remarkable elasticity such as rubber, that is, a polymer having elongation when applied with an external force and returning to its original length when an external force is removed. A preferred low melting point (LM) elastomer used in the present invention may exhibit an elastic recovery rate of 50 to 80%. If the elastic recovery rate is less than 50%, the fiber aggregate may become hard and the flexibility may be insufficient to lower the sound absorption performance. If the elastic recovery rate is more than 80%, the manufacturing cost of the polymer material itself may increase, .

Conventionally, when binder fibers are melted and main fibers are bound, the fibrous aggregates are hardened, so that the vibration transmitted to the matrix structure due to the transmission of sound waves can not sufficiently attenuate and the sound absorption rate is lowered. However, (ASTM D 3574) of the fabric structure is increased to 50 to 80%, and ultimately to the inside of the matrix, by adjusting the binder fiber of the fiber structure to include a low melting point (LM) elastomer having an elastic recovery rate of 50 to 80% The vibration damping ability to be transmitted is improved and the sound absorption rate and transmission loss can be improved.

The low melting point (LM) elastomer may be a polyester, a polyamide, a polystyrene, a polyvinyl chloride, or a polyurethane.

More preferably, the low melting point (LM) elastomer is selected from the group consisting of dimethyl terephthalate (DMT), dimethyl isophthalate (DMI), terephthalic acid (TPA) and isophthalic acid Acid (IPA) is used as an acid component (Diacid), 1,4-butanediol (1,4-BD) and polytetramethyleneglycol (PTMG) Can be prepared through polymerization steps.

 The acidic component (Diacid) is obtained by using dimethyl terephthalate (DMT), dimethyl isophthalate (DMI) or terephthalic acid (TPA) and isophthalic acid (IPA), and dimethyl terephthalate (DMT) and terephthalic acid (TPA) react with the diol component to form a crystalline region. Dimethylisophthalate (DMI) and isophthalic acid (IPA) react with the diol component to form an amorphous region to give low melting point function and elasticity .

The molar ratio of dimethyl terephthalate (DMT) to dimethyl isophthalate (DMI) is preferably in the range of 0.65 to 0.80: 0.2 to 0.35, and the molar ratio of terephthalic acid (TPA) to isophthalic acid (IPA) 0.2 to 0.35. The molar ratio of dimethyl isophthalate (DMI) to isophthalic acid (IPA) is less than the above range, the elastic recovery rate may be lowered, the low melting point function may not be exhibited and dimethyl isophthalate (DMI) and isophthalic acid ) Is more than the above range, the physical properties may be lowered.

The diol component is 1,4-butanediol (1,4-BD), and polytetramethyleneglycol (PTMG). 1,4-butanediol reacts with an acid component to form crystals (PTMG) forms an amorphous region by reacting with an acid component to give a low melting point function and an elastic force.

The mixing ratio of 1,4-butanediol (1,4-BD) and polytetramethylene glycol (PTMG) is preferably in a molar ratio of 0.85 to 0.95: 0.05 to 0.15. The molar ratio of the polytetramethylene glycol (PTMG) is less than the above range, the elastic recovery rate may be lowered, the low melting point function may not be exhibited, and the molar ratio of dipotetramethylene glycol (PTMG) The physical properties may be deteriorated. 1,4-butanediol (1,4-BD) can be mixed with ethylene glycol (EG) within the above range.

The polytetramethylene glycol (PTMG) preferably has a molecular weight of 1,500 to 2,000. When the polytetramethylene glycol (PTMG) is out of the above range of molecular weight, the elasticity and physical properties of a low melting point (LM) elastomer may not be suitable for use.

It is preferable that the acid component and the diol component are mixed and polymerized at a molar ratio of 0.9 to 1.1: 0.9 to 1.1. If the acid component and the diol component are mixed too much, the acid component and the diol component are preferably used in a similar amount.

As described above, dimethyl terephthalate (DMT) and dimethyl isophthalate (DMI) can be used as an acid component as 1,4-butanediol (1,4-BD), polytetramethylene glycol (PTMG) as a diol component The resulting low melting point (LM) elastomer is prepared with a melting point of 150 to 180 DEG C and an elastic recovery rate of 50 to 80%.

Also. The binder fiber of the sound-absorbing material of the present invention may be a conjugated fiber obtained by spinning the low melting point (LM) elastomer as one component. More preferably, it may be a sheath-core type or a side by side type conjugated fiber, and in the case of forming a sheath-core type conjugated fiber, the low melting point ( LM) elastomer as a sheath component, and a general polyester as a core component. The general polyester has the function of lowering the manufacturing cost and supporting the fiber, and the low melting point (LM) elastomer enables the elasticity and the low melting point function to be expressed.

The weight ratio of the low melting point (LM) elastomer to the general polyester is preferably 40:60 to 60:40. If the weight ratio of the low melting point (LM) elastomer is less than 40, the elasticity and the low melting point function may be deteriorated. If the weight ratio is more than 60, the manufacturing cost is increased.

The sound absorbing material may include 50 to 80% by weight of short fibers containing phase change material (PCM) and 20 to 50% by weight of binder fibers. When the content of staple fibers containing phase change material (PCM) is less than 50% by weight, the temperature control function against external temperature change may be insufficient, while the content of staple fibers including phase change material (PCM) If the content of the binder fiber is more than 10% by weight, the content of the binder fiber becomes less than 20%, the sufficient bonding force between the fibers can not be maintained. Therefore, it is difficult to form the sound absorbing material into an arbitrary shape, The vibration transmitted to the matrix structure caused by the transmission of the vibration wave is not sufficiently attenuated and the sound absorption rate of the low frequency wave may be lowered. As the content of the binder fiber increases from 20 to 50% by weight, the rebound resilience (ASTM D 3574) increases to 50 to 80%.

Such a sound absorbing material having excellent sound absorption performance includes a staple fiber including a phase change material (PCM); And a binder fiber for partially bonding short fibers including a plurality of the phase change materials (PCM) to a nonwoven fabric.

In order to manufacture a sound-absorbing material, a fiber aggregate containing short fibers and binder fibers including the above-mentioned phase change material (PCM) is subjected to a conventional fiber structure sound absorbing material manufacturing process such as a needle punching process or a heat bonding process, And the like. Detailed description of the short fibers and binder fibers including the above-mentioned phase change material (PCM) applied to the method of manufacturing the sound absorbing material of the present invention will be omitted herein.

The sound-absorbing material having excellent sound-absorbing performance of the present invention can prevent the deterioration of sound-absorbing performance even in the winter when the external temperature is lowered, The reduction rate of the sound absorption rate measured at 0 ° C is less than 5% as compared with the absorption rate measured at 0 ° C. Accordingly, the sound-absorbing material of the present invention can be used not only for a sound absorbing material for automobiles or a train, a ship, an airplane, etc. which blocks external noises from entering the vehicle interior, but also a future electric vehicle Can be used as an interior material that can enhance energy efficiency, thereby contributing to quality improvement.

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 1 >

core-type composite fiber comprising n-octadecane (melting point: 28 to 30 占 폚) and polypropylene as one component and a polyester-based low melting point (LM) elastomer as a binder fiber, Shaped composite fiber having a thickness of 20 mm and a surface density of 1600 g / m < ² > through a conventional heat-bonding process after being physically entangled through a needle punching process with constant weight adjustment after mixing to a weight ratio of 8: . The rebound resilience of the manufactured sound absorbing material was 55%.

The cis-core type conjugate fiber comprising n-octadecane has a melting point of 260 占 폚 and an intrinsic viscosity of 0.65 g / dl, polyethyleneterephthalate as a sheath component. The melt flow index (Melt Flow Index) (MFI) of 24 to 26 g / 10 min and n-octadecane as a phase transfer material at a weight ratio of 7: 3 and kneaded at a processing temperature of 230 ° C. to be used as a core component. Using a composite spinneret capable of spin-spinning the PP and n-octadecane (core component) and general PET (sheath component), the weight ratio of the core component and the sheath component was adjusted to 5: 5, Density, 3.0g / D, elongation 80%, number of crimps 12 / inch, fiber length 64mm, temperature control function at a speed of 1,000 m / min, and 3.3 times of stretching at 77 DEG C and final heat treatment at 140 DEG C A composite staple fiber was prepared.

The cis-core type conjugate fiber including the polyester low melting point (LM) elastomer as the binder fiber has a polyester low melting point (LM) elastomer as a sheath component, and the polyester low melting point (LM) A mixture obtained by mixing 75 mol% of terephthalic acid and 25 mol% of isophthalic acid as an acid component and 8.0 mol% of poly (tetramethylene ether) glycol and 92.0 mol% of 1,4-butanediol as a diol component was used The acid component and the diol component were mixed at a molar ratio of 1: 1 and polymerized. The low melting point (LM) elastomer thus prepared has a melting point of 150 캜, an intrinsic viscosity of 1.4, and an elastic recovery of 80%. Polyethylene terephthalate (PET) having a melting point of 260 캜 and an intrinsic viscosity of 0.65 g / dl was used as the core component, and a composite radiation The weight ratio of the core component and the sheath component was adjusted to 6: 4 Density, 2.7g / D, elongation of 70%, number of crimps of 13 / inch, finishing temperature of 140 deg. C, spinning at a spinning temperature of 275 deg. A composite fiber having a fiber length of 64 mm was produced.

≪ Example 2 >

Was prepared in the same manner as in Example 1, except that heptadecane (melting point: about 21 ° C) was used instead of n-octadecane as a phase change material.

≪ Example 3 >

Except that n-octadecane was replaced by nonadecane (melting point: about 32 to 34 DEG C) as a phase change material.

<Example 4>

Except that the thermosensitive functional staple fibers were made of a single fiber prepared by kneading polypropylene with n-octadecane (melting point 28 to 30 ° C) instead of conjugated fibers containing PET. 1.

&Lt; Example 5 >

The procedure of Example 1 was repeated except that the low melting point PET fiber was used as the binder fiber. The rebound resilience of the manufactured sound absorbing material was 30%.

&Lt; Comparative Example 1 &

Same as Example 1 except that short fibers prepared by using polytetrafluoroethylene terephthalate alone having a melting point of 260 占 폚 and an intrinsic viscosity of 0.6 g / Lt; / RTI &gt;

&Lt; Comparative Example 2 &

A polyethyleneterephthalate having a melting point of 260 占 폚 and an intrinsic viscosity of 0.6 g / dl and containing no n-octadecane in a short fiber was used as a sheath component and a melt flow index (MFI) of 24 to 26 g / 10 min was used instead of the conjugated fiber of PP (polypropylene) as a core component.

<Experimental Example>

The sound absorption performance, compression recovery rate, and temperature control functionality of the sound absorbing materials prepared according to Examples 1 to 5 and Comparative Examples 1 and 2 were tested according to the following measurement methods, and the results are shown in the table.

1. Thickness

The average value was measured 20 times over the entire width using a thickness gauge.

2. Elasticity recovery rate

The elastic recovery rate was measured by measuring the elongated length after recovering 200% of the specimen of 2 mm thickness and 10 cm length at the speed of 200% / minute using Dumbbell (Instron) And was obtained by the following formula.

Elastic recovery rate (%) = {[20- (L-10)] / 20]} x100

(L: elongated length)

3. Ball Rebound

The height of the rebound was measured by dropping iron beads on a test piece at a constant height. (JIS K-6301, unit:%) Test specimens were made with a length of 50 mm or more and a thickness of 50 mm or more. A steel ball with a weight of 16 g and a diameter of 16 mm was dropped on a test piece at a height of 500 mm, After the measurement, the rebound value was measured at least three times in succession within one minute in each of the three test pieces, and the median value was determined as the rebound resilience (%).

4. Absorption rate

To measure the sound absorption rate, three specimens were prepared for each test piece applicable to ISO R 354 and Alpha Cabin method. The absorptivity was measured after leaving at 0 ° C and 25 ° C for 30 minutes, and the average values of the measured absorption coefficients are shown in the table.

5. Temperature control functional test

In order to test the temperature control function of the sound absorbing materials prepared in Examples and Comparative Examples, the specimens were heated in an oven set at 50 ° C for 30 minutes, and the surface temperature of the nonwoven fabric specimens was measured at intervals of 10 minutes using an infrared camera Respectively. The sample was allowed to stand in the oven for 30 minutes, then taken out and allowed to stand in the air for 30 minutes. The surface temperature of the nonwoven fabric sample was measured using an infrared camera at intervals of 10 minutes. All tests were conducted 5 times and mean values were used.

division Heating time (min) Cooling time (minutes) 0 10 20 30 0 10 20 30 Example 1 16.7 24.7 30.7 42.2 42.2 37.8 29.1 18.9 Example 2 16.4 25.1 31.5 42.4 42.4 37.4 28.8 18.5 Example 3 16.5 24.2 30.3 41.3 41.3 37.6 28.7 18.8 Example 4 16.7 25.9 33.3 43.3 43.3 36.9 27.4 16.6 Example 5 16.6 24.8 30.2 42.1 42.1 37.1 29.0 18.7 Comparative Example 1 16.5 26.4 33.9 43.7 43.7 37.0 28.3 17.1 Comparative Example 2 16.4 26.2 33.5 43.6 43.6 37.0 27.9 16.8

division Frequency (Hz) Sound absorption coefficient 1000Hz 2000Hz 3150Hz 5000Hz 25 ℃ 0 ℃ Decrease (%) 25 ℃ 0 ℃ Decrease (%) 25 ℃ 0 ℃ Decrease (%) 25 ℃ 0 ℃ Decrease (%) Example 1 0.73 0.71 3.49 0.84 0.81 4.04 0.84 0.80 4.95 0.93 0.89 4.42 Example 2 0.69 0.66 3.70 0.80 0.77 4.26 0.78 0.76 2.13 0.89 0.86 3.67 Example 3 0.68 0.65 5.00 0.82 0.78 4.17 0.81 0.77 4.12 0.91 0.88 3.60 Example 4 0.69 0.61 11.11 0.81 0.71 12.63 0.81 0.71 11.34 0.84 0.76 9.71 Example 5 0.72 0.70 3.53 0.83 0.81 3.06 0.84 0.79 5.94 0.93 0.88 6.14 Comparative Example 1 0.67 0.58 13.92 0.77 0.65 14.44 0.77 0.67 12.90 0.83 0.72 12.87 Comparative Example 2 0.70 0.63 9.76 0.78 0.69 11.96 0.81 0.71 12.37 0.86 0.78 9.52

As can be seen from the above table, Examples 1 to 5 using short fibers containing phase change material (PCM) are superior in sound absorption performance as compared with the comparative examples, and have a remarkably small reduction rate of sound absorption performance when the external temperature is decreased appear.

 Specifically, Comparative Example 2 using cis-core conjugated staple fibers without a phase change material (PCM) showed no significant difference in the sound absorption performance at 25 ° C, but the decrease rate of the sound absorption rate when the external temperature decreased to 0 ° C 1000 ~ 5000Hz on average, which is about 11% larger. In contrast, in the embodiments using the cis-core composite short fibers including the phase change material (PCM), the reduction rate of the sound absorption rate is less than 5% even when the external temperature is decreased to 0 ° C, The sound absorption performance was still excellent. However, in Example 4, which was made of a single fiber rather than a composite fiber, there was no space forming effect between the sheath core portions, so that the sound absorption performance was deteriorated and the PCM component was vaporized and exited.

 Further, by comparing the performance measurement results of Example 5 using low-melting-point PET fibers with binder fibers and Examples 1 to 4 using low-melting-point elastomers, a flexible structure having a rebound resilience of 55% was obtained by using a low melting point elastomer as a binder fiber And it was found that the sound absorption performance was improved due to the improvement of the vibration damping ability transmitted through the matrix structure.

Claims (20)

Staple fibers comprising phase change material (PCM); And
And a binder fiber partially bonding the plurality of short fibers including the phase change material (PCM). The method according to claim 1,
Wherein the staple fiber comprises a polyolefin-based polymer and a dispersed phase change material (PCM).

3. The method of claim 2,
Wherein the weight ratio of the polyolefin-based polymer and the phase change material (PCM) is from 9: 1 to 3: 7. The method according to claim 1,
Wherein the staple fiber is a conjugated fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a single component. The method according to claim 1,
The short fiber is a sheath-core type conjugated fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component And a sound absorbing material. 6. The method of claim 5,
Wherein the sheath-core type conjugate fiber has a weight ratio of a core component and a sheath component of 7: 3 to 3: 7. The method according to claim 1,
Wherein the phase change material (PCM) is a paraffinic phase change material (PCM) having 14 to 22 carbon atoms. The method according to claim 1,
Wherein said phase change material (PCM) is selected from the group consisting of n-octanoic acid, n-heptanoic acid, n-hexanoic acid, n-tetracholic acid, n- n-nonadecane, n-octadecane, n-heptadecane, n-hexadecane, n-pentadecane, n-tetradecane and n-tridecane. The method according to claim 1,
Wherein the melting point of the phase change material (PCM) is 5 to 44 占 폚. The method according to claim 1,
Wherein the short fibers have a fiber length of 22 to 64 mm and a fineness of 1 to 10 D. The method according to claim 1,
Wherein the binder fiber comprises a low melting point (LM) elastomer having an elastic recovery rate of 50 to 80%. 12. The method of claim 11,
Wherein the binder fiber is a composite fiber obtained by spinning the low melting point (LM) elastomer as a single component. 12. The method of claim 11,
Wherein the low melting point (LM) elastomer comprises at least one selected from the group consisting of polyester, polyamide and polyurethane. 12. The method of claim 11,
The low melting point (LM) elastomer may be prepared by dissolving dimethyl terephthalate (DMT), dimethyl isophthalate (DMI) or terephthalic acid (TPA) and isophthalic acid (IPA) Is prepared by esterification and polymerization steps using 1,4-butanediol (1,4-BD), polytetramethyleneglycol (PTMG) as a diol component (Diol) And a sound absorbing material. The method according to claim 1,
Wherein the sound absorbing material comprises 50 to 80% by weight of short fibers containing phase change material (PCM) and 20 to 50% of binder fibers. Staple fibers comprising phase change material (PCM); And
And a binder fiber for partially bonding short fibers including a plurality of the phase change materials (PCM)
Characterized in that the rate of decrease of the sound absorption rate measured at 0 占 폚 is 5% or less as measured by the Alpha Cabin method at 25 占 폚. 17. The method of claim 16,
The short fiber is a sheath-core type conjugated fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component And a sound absorbing material. Staple fibers comprising phase change material (PCM); And
A method of manufacturing a sound absorbing material for forming a fiber aggregate including a plurality of phase change materials (PCM) in a nonwoven fabric. 19. The method of claim 18,
The short fiber is a sheath-core type conjugated fiber comprising a polyolefin-based polymer and a dispersed phase change material (PCM) as a core component and a polyester-based polymer as a sheath component Wherein the sound absorbing material is a sound absorbing material. 19. The method of claim 18,
Wherein the sound absorbing material comprises 50 to 80% by weight of short fibers including phase change material (PCM) and 20 to 50% of binder fibers.

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