Laminates, sound-absorbing materials, and automotive interior components

Abstract

The present invention provides a laminate, a sound-absorbing material, and an automotive interior component that can improve the sound absorption coefficient on the low-frequency side. [Solution] One embodiment of the present invention is a laminate 1. The laminate 1 includes a resin fiber layer 20 made of an olefin resin with a thickness of 10 mm or more, and a surface layer 10 laminated on the resin fiber layer 20. The air permeability of the surface layer 10 is 50 cm 3 / (cm 2 The weight of the resin fiber layer 20 is 300 g / m² or less, and the basis weight of the resin fiber layer 20 is 300 g / m². 2 The following applies: The crystallization temperature of olefin resins is 80°C or higher.

Description

[Technical Field]

[0001] This invention relates to laminates, sound-absorbing materials, and automotive interior components. [Background technology]

[0002] Conventionally, soundproof covers for automobiles have been provided to absorb noise generated from noise sources such as the transmission of an automobile. For example, Patent Document 1 discloses a soundproof cover structure for automobiles comprising a cover body positioned facing the noise source, a sound-absorbing material provided on the noise source side of the cover body, and a rear air layer formed between the cover body and the sound-absorbing material. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-162769 [Overview of the project] [Problems that the invention aims to solve]

[0004] By the way, in the soundproof cover structure for automobiles described in Patent Document 1, plate-shaped ribs are required to secure an air layer. However, the weight increases with the addition of the ribs, and there is a limit to the height of the ribs, so there is a problem in that it is not possible to create an air layer large enough to improve the sound absorption coefficient on the low-frequency side.

[0005] Therefore, the present invention aims to provide a laminate, a sound-absorbing material, and an automotive interior component that can improve the sound absorption coefficient on the low-frequency side. [Means for solving the problem]

[0006] The inventors conducted diligent research and discovered that the above problems can be solved by a laminate having a structure (layer) formed from specific components, and thus completed the present invention. That is, the present invention is as follows.

[0007] One aspect of the present invention is a laminate. The laminate has a resin fiber layer with a thickness of 10 mm or more formed of an olefin resin, and a surface layer laminated on the resin fiber layer. The air permeability of the surface layer is 50 cm

[0013] , , , , , ,

[0012] , / (cm 2 ·s) or less, the basis weight of the resin fiber layer is 300 g / m 2 or less, and the crystallization temperature of the olefin resin is 80°C or higher.

[0008] Another aspect of the present invention is a sound-absorbing material. The sound-absorbing material includes the laminate according to any of the above aspects.

[0009] Another aspect of the present invention is an automotive interior member. The automotive interior member includes the laminate according to any of the above aspects.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a laminate, a sound-absorbing material, and an automotive interior member that can improve the sound absorption rate on the low-frequency side.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a conceptual side view of the laminate according to the present embodiment. [Figure 2] FIG. 2(a) is a graph showing the sound absorption rates of Examples 1, 2, and Comparative Example 1. FIG. 2(b) is a graph showing the sound absorption rates of Examples 3, 4, and Comparative Example 2. [Figure 3] FIG. 3 is a graph showing the sound absorption rates of Examples 5 to 8 and Comparative Example 2.

Modes for Carrying Out the Invention

[0012] Hereinafter, the laminate, the sound-absorbing material, the automotive interior member, etc. will be specifically described, but the present invention is not limited thereto.

[0013] In this specification, if multiple upper limits and multiple lower limits are described separately, all numerical ranges that can be set by freely combining these upper and lower limits are described herein.

[0014] 1. Structure of the laminate Figure 1 is a conceptual side view of the laminate 1 according to this embodiment. As shown in Figure 1, the laminate 1 is composed of a surface layer 10 and a resin fiber layer 20. In addition to the surface layer 10 and the resin fiber layer 20, the laminate 1 may also have a base material 30. In this case, the resin fiber layer 20 is laminated on one side of the base material 30. The following describes each component.

[0015] 1-1. Resin fiber layer 1-1-1. Ingredients The resin fiber layer 20 is a fibrous structure formed from hot-melt resin (also called hot-melt adhesive).

[0016] Hot melt resin primarily contains thermoplastic resin components. It may also contain other components.

[0017] 1-1-1-1.Thermoplastic resin component The thermoplastic resin component, which is the main component of the hot-melt resin constituting the resin fiber layer 20, can be an olefin-based, ester-based, urethane-based, amide-based, vinyl alcohol-based resin, etc. Among these, olefin-based resins are preferred. In other words, the thermoplastic resin component is preferably an olefin-based hot-melt resin. Using an olefin-based hot-melt resin as the thermoplastic resin component can improve the sound absorption and workability of the fiber structure.

[0018] Examples of olefin resins include polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, ethylene-α-olefin copolymer, and polymer blends thereof.

[0019] The olefin resin is more preferably polypropylene.

[0020] 1-1-1-2. Other ingredients Other known additives include tackifiers, plasticizers, fillers, pigments, dyes, antioxidants, antioxidants, antistatic agents, flame retardants, antibacterial agents, light stabilizers, stabilizers, dispersants, solvents, hydrophilic agents, waxes, and crystal nucleating agents.

[0021] Other components may be present in amounts of, for example, 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, 5 parts by mass or less, 1 part by mass or less, or 0.1 parts by mass or less per 100 parts by mass of hot melt resin.

[0022] 1-1-2.Physical properties / properties 1-1-2-1. Melt viscosity The melt viscosity of the hot-melt resin constituting the resin fiber layer 20 at 180°C is preferably 200,000 mPa·s or less, 100,000 mPa·s or less, 50,000 mPa·s or less, 30,000 mPa·s or less, or 20,000 mPa·s or less.

[0023] Furthermore, the melt viscosity of the hot melt resin at 180°C is preferably 1,000 mPa·s or more, 2,000 mPa·s or more, or 5,000 mPa·s or more.

[0024] The melt viscosity of the hot-melt resin constituting the resin fiber layer 20 at 200°C is preferably 100,000 mPa·s or less, 50,000 mPa·s or less, 25,000 mPa·s or less, 20,000 mPa·s or less, or 18,000 mPa·s or less, 15,000 mPa·s or less, or 10,000 mPa·s or less.

[0025] Furthermore, the melt viscosity of the hot melt resin at 200°C is preferably 500 mPa·s or higher, 1,000 mPa·s or higher, 1,500 mPa·s or higher, or 3,000 mPa·s or higher.

[0026] By setting the melt viscosity of the hot melt resin within this range, spray application of the hot melt resin becomes easy, and a resin fiber layer 20 with excellent sound absorption properties can be easily obtained. In this embodiment, "spray application" refers to spraying the molten hot melt resin in a fibrous form using compressed air.

[0027] The melt viscosity was measured using a parallel plate rheometer with a swing angle of 10% and an angular frequency of 1 rad / s for a hot melt resin heated to a predetermined temperature.

[0028] 1-1-2-2. Crystallization Temperature / Crystallization Energy The crystallization temperature of the hot-melt resin constituting the resin fiber layer 20 is preferably 80°C or higher, and more preferably 80 to 150°C, or 80 to 135°C. By setting the crystallization temperature of the hot-melt resin within this range, it is possible to improve ease of workability, sound absorption, and other properties in a well-balanced manner.

[0029] The crystallization energy (heat of crystallization) of the hot-melt resin constituting the resin fiber layer 20 is preferably 50 mJ / mg or more, and particularly preferably 50 to 200 mJ / mg, or 50 to 100 mJ / mg. By setting the crystallization energy of the hot-melt resin within this range, it is possible to improve ease of workability, sound absorption, and other properties in a well-balanced manner.

[0030] The crystallization temperature and crystallization energy shall be measured in accordance with JIS K 7121.

[0031] 1-1-2-3. Storage modulus, loss modulus, loss tangent, glass transition temperature The lower limit of the storage modulus G' of the hot melt resin is preferably 10 MPa or more, 20 MPa or more, 50 MPa or more, 75 MPa or more, 90 MPa or more, 100 MPa or more, 200 MPa or more, or 500 MPa or more. The upper limit of the storage modulus G' of the hot melt resin is, for example, 2,000 MPa or less, 1,500 MPa or less, 1,000 MPa or less, or 900 MPa or less.

[0032] The loss modulus G'' of the hot melt resin is preferably 50 MPa or less, or 40 MPa or less.

[0033] The loss tangent tanδ (loss modulus G'' / storage modulus G') of the hot melt resin is preferably 1.00 or less, or 0.50 or less.

[0034] The hot melt resin preferably has a glass transition temperature of -30 to 60°C or -25 to 40°C.

[0035] The storage modulus G' and the loss modulus G'' are measured as follows. Measurement method: rheometer Device name: MCR302 (Anton Paar) Swing angle: 0.8° Frequency: 10Hz Deformation mode: Shear mode Temperature: -50~110℃ Sample size: 5mm (width) x 20mm (depth) x 1mm (thickness) The storage modulus G' and loss modulus G'' are the values ​​obtained at 23°C.

[0036] The temperature corresponding to the peak value of the loss tangent tanδ mentioned above is defined as the glass transition temperature.

[0037] By setting the storage modulus G', loss modulus G'', loss tangent tanδ, or glass transition temperature of the hot melt resin within these ranges, it is easy to obtain a resin fiber layer 20 with excellent sound absorption, shape retention, and ease of workability.

[0038] In particular, by setting the storage modulus G' of the hot-melt resin within this range, it is easier to obtain a resin fiber layer 20 that has higher sound absorption properties and significantly better shape retention.

[0039] 1-1-2-4. Air permeability The air permeability of the resin fiber layer 20 is 10.0 cm 3 / (cm2 above 15.0 cm ( / s) 3 / (cm 2 above 20.0 cm ( / s) 3 / (cm 2 above 30.0 cm ( / s) 3 / (cm 2 above 40.0 cm3 / (cm ( / s) 2 above or 45.0 cm ( / s) 3 / (cm 2 above or 55.0 cm ( / s) 3 / (cm 2 It is preferably above ( / s).

[0040] Also, the air permeability of the resin fiber layer 20 is 200 cm 3 / (cm 2 below ( / s), 150 cm 3 / (cm 2 below ( / s), 100 cm 3 / (cm 2 below ( / s), 95.0 cm 3 / (cm 2 below ( / s), 85.0 cm 3 / (cm 2 below ( / s), or 80.0 cm 3 / (cm 2 It is preferably below ( / s). By setting the air permeability of the resin fiber layer 20 within such a range, excellent sound absorption can be obtained.

[0041] In particular, in the resin fiber layer 20 formed of a hot melt resin, by using fibers having a preferred fiber diameter and setting the air permeability within such a range, the distribution of voids and fibers becomes appropriate, and very excellent sound absorption can be obtained.

[0042] The air permeability of the resin fiber layer 20 is measured according to the air permeability test of JIS L 1096.

[0043] Furthermore, if the resin fiber layer 20 is bonded to the base material 30, the air permeability of the resin fiber layer 20 can be determined by forming an identical resin fiber layer (a resin fiber layer with the same components, structure, thickness, etc.) on a release film, removing the release film to produce a single layer of resin fiber, and measuring the value for this resin fiber layer.

[0044] 1-1-2-5. Weight average molecular weight The weight-average molecular weight of the surface layer 10 and the resin fiber layer 20 is preferably 5,000 to 200,000, more preferably 25,000 to 150,000, and even more preferably 50,000 to 100,000. By setting the weight-average molecular weight of the surface layer 10 within this range, the sound absorption coefficient on the low-frequency side can be improved.

[0045] The measurement conditions for weight-average molecular weight are as follows: Measurement method: GPC (Gel Permeation Chromatography) measurement Device name: HLC-8321GPC / HT (manufactured by Tosoh Corporation) Detector: RI detector Solvent: Orthodichlorobenzene (ODCB) Autosampler: 24 vials Temperature: 140°C (Measurement begins after confirming that the substance has melted after heating for 1 hour) Columns: Waters Styragel HT6E, HT4, HT3 Analysis program: 8321GPC-WS

[0046] The polystyrene-equivalent molecular weight is measured using the GPC method by determining the number-average molecular weight (Mn), weight-average molecular weight (Mw), and Z-average molecular weight (Mz). Note that the weight-average molecular weight is calculated on a polystyrene basis.

[0047] 1-1-3. Structure 1-1-3-1. Fiber diameter The fiber diameter of the fibers constituting the resin fiber layer 20 can be, for example, 1 to 100 μm, 3 to 30 μm, or 5 to 20 μm. Excellent sound absorption can be obtained when the fiber diameter is within this range. The method for calculating the fiber diameter is as follows: First, the resin fiber layer 20 is photographed with an SEM, and the fiber diameter (width of the short axis) of 10 fibers included in the obtained image is measured, and the average of these measurements is taken as the fiber diameter.

[0048] 1-1-3-2. Thickness As will be described in detail later, the laminate 1 of this embodiment can be formed with a substantially uniform thickness of the resin fiber layer 20. Therefore, it can fully exhibit stable sound absorption.

[0049] The thickness of the resin fiber layer 20 can be, for example, 0.1 to 100 mm, 1 to 50 mm, 5 to 40 mm, or 10 to 30 mm. By setting the thickness of the resin fiber layer 20 within this range, excellent sound absorption can be obtained while maintaining ease of manufacturing.

[0050] 1-1-3-3. Measuring weight The basis weight of the resin fiber layer 20 is, for example, 50 to 1,000 g / m². 2 75-750g / m 2 , or 100-500g / m 2 This can be done. The basis weight of the resin fiber layer 20 is 300 g / m². 2 The following is also possible. By setting the basis weight of the resin fiber layer 20 within this range, excellent sound absorption can be obtained.

[0051] Fiber diameter, basis weight, thickness, air permeability, etc., can be adjusted by the melt viscosity of the hot melt resin, the type of nozzle used when spraying the hot melt resin, and the spray application conditions (pressure, temperature, time, etc.).

[0052] The resin fiber layer 20 according to this embodiment has excellent sound absorption properties and can therefore be preferably used as a sound-absorbing material.

[0053] 1-2. Base material 1-2-1.Shape Furthermore, when the laminate 1 has a base material 30, the shape of the base material 30 is not particularly limited, and any suitable shape can be used. In addition, the resin fiber layer 20 can be formed simply by spray-coating hot melt resin onto the base material 30. Thus, even when a component with a complex shape is used as the base material 30, the resin fiber layer 20 can be easily manufactured on the base material 30, and excellent sound absorption properties can be provided.

[0054] 1-2-2.Material The material of the base material 30 can be a resin, a metal, or a composite containing these. Among these, it is preferable to use an olefin resin as the resin.

[0055] Examples of olefin resins include polyethylene, polypropylene, polybutene-1, ethylene-propylene copolymer, ethylene-α-olefin copolymer, and polymer blends thereof. These materials may be used individually or as composites of two or more materials.

[0056] As described above, in this embodiment, the laminate 1 has a resin fiber layer 20 made of an olefin-based hot melt resin. If the laminate 1 also has a base material 30 in addition to the resin fiber layer 20, and both the resin fiber layer 20 and the base material 30 are made of the same olefin-based material, the bonding strength between the resin fiber layer 20 and the base material 30 can be increased.

[0057] Furthermore, the base material 30 and the resin fiber layer 20 are often made of different materials, requiring separation of the base material 30 and the resin fiber layer 20 during recycling. In contrast, when the resin fiber layer 20 and the base material 30 are made of the same olefin-based material, separation of the resin fiber layer 20 and the base material 30 during recycling becomes unnecessary, simplifying the process.

[0058] 1-3. Surface layer 1-3-1. Ingredients The surface layer 10 is made of a nonwoven fabric. Examples of nonwoven fabrics constituting the surface layer 10 include spunbond nonwoven fabric, air-through nonwoven fabric, meltblown nonwoven fabric, and electrospinned nonwoven fabric. The resin constituting these nonwoven fabrics is not particularly limited in type, as long as it has fiber-forming ability. For example, olefin resins and ester resins can be used. Examples of nonwoven fabrics include MB BTS0040EM from Kuraray Kuraflex Co., Ltd., PS0023EMEL from Kuraray Kuraflex Co., Ltd., and HOP-60HCF(120)S from Daiwabo Co., Ltd.

[0059] Furthermore, the surface layer 10 can also be made of a hot melt resin. The melt viscosity of the hot melt resin constituting the surface layer 10 at 140°C is preferably 20,000 mPa·s or less, 15,000 mPa·s or less, and 10,000 mPa·s or less, and preferably 1,000 mPa·s or more, 2,000 mPa·s or more, and 4,000 mPa·s or more. Furthermore, the melt viscosity of the hot melt resin at 150°C is preferably 15,000 mPa·s or less, 10,000 mPa·s or less, and 6,000 mPa·s or less, and preferably 500 mPa·s or more, 1,000 mPa·s or more, and 2,000 mPa·s or more.

[0060] 1-3-2.Physical properties / properties 1-3-2-1. Air permeability The air permeability of the surface layer 10 is 5.0 cm 3 / (cm 2 / s) or more, 10.0cm 3 / (cm 2 / s) or more, 15.0cm 3 / (cm 2 It is preferable that the air permeability of the surface layer 10 is 100 cm² or more. 3 / (cm 2 / s) or less, 50.0cm 3 / (cm 2 / s) or less, or 30.0cm 3 / (cm 2 It is preferable that the air permeability of the surface layer 10 is 50.0 cm² or less. 3 / (cm 2 It can also be set to less than / s. By setting the air permeability of the surface layer 10 within this range, excellent sound absorption can be obtained.

[0061] 1-3-2-2. Crystallization Temperature / Crystallization Energy The crystallization temperature of the hot-melt resin constituting the surface layer 10 is preferably 50°C or lower, and more preferably 40°C or lower. By setting the crystallization temperature of the hot-melt resin constituting the surface layer 10 within this range, it is possible to improve ease of workability, sound absorption, and other properties in a well-balanced manner.

[0062] The crystallization energy (heat of crystallization) of the hot melt resin constituting the surface layer 10 is preferably 100 mJ / mg or less, more preferably 75 mJ / mg or less, and even more preferably 50 mJ / mg or less. Furthermore, the crystallization energy of the hot melt resin is preferably 10 mJ / mg or more, more preferably 15 mJ / mg or more, and even more preferably 20 mJ / mg or more. By setting the crystallization energy of the hot melt resin within this range, it is possible to improve breathability, curability, workability, and sound absorption.

[0063] 1-3-3. Structure 1-3-3-1. Thickness The thickness of the surface layer 10 can be, for example, 0.01 to 10.0 mm, 0.05 to 5.0 mm, or 0.1 to 3.0 mm. By setting the thickness of the surface layer 10 within this range, excellent sound absorption can be obtained while maintaining ease of manufacturing. In this embodiment, a commercially available nonwoven fabric was used, but a surface layer with similar physical properties may be formed using hot melt resin.

[0064] The crystallization temperature and crystallization energy shall be measured in accordance with JIS K 7121.

[0065] 1-3-3-2. Measuring weight The basis weight of the surface layer 10 is, for example, 100 g / m². 2 Below 80g / m 2 Below 60g / m2 The following can be achieved. By setting the basis weight of the surface layer 10 within this range, excellent sound absorption can be obtained. The basis weight of the surface layer 10 is 5 g / m². 2 It is preferable that the amount be greater than 10g / m 2 It is more desirable to have a value greater than or equal to 15g / m². 2 It is desirable that the above be the case.

[0066] 2. Method for manufacturing laminates If the laminate 1 has a base material 30, the laminate can also be obtained by directly spray-coating a hot-melt resin, held in a molten state, onto the base material 30. The hot-melt resin, which has become fibrous due to the spray coating, comes into contact with the base material 30 in a molten and / or softened state, fusing with the base material 30, and a resin fiber layer is formed when the hot-melt resin cools and solidifies. Alternatively, the surface layer 10 may be formed by directly spray-coating the resin fiber layer after its molding.

[0067] As for the spraying method, known methods such as curtain spray, omega spray, spiral spray, summit spray, etc., can be applied.

[0068] When forming the laminate, the surface layer is fixed to any point on the edge of the resin fiber layer. Methods for fixing include, for example, adhesive bonding and heat fusion (e.g., heat treatment, ultrasonic fusion, etc.), but ultrasonic fusion is preferred considering workability.

[0069] The hot melt resin used for spray coating can be manufactured by known methods. For example, the aforementioned raw materials can be put into a continuous mixer such as a single-screw or twin-screw extruder, or a batch mixer such as a roll mixer, Banbury mixer, kneader, planetary mixer, or high-shear Z-wing mixer, and mixed at a predetermined temperature for a predetermined time.

[0070] Surface treatment (such as cleaning, smoothing, roughening, electrical discharge treatment, or UV treatment) may be performed on the substrate 30 for purposes such as increasing the bonding strength of the resin fiber layer to the substrate 30.

[0071] The laminate of this embodiment can be constructed by simply covering the formed resin fiber layer with a nonwoven fabric (there is no need for steps to heat-weld the nonwoven fabric or to apply adhesive to the nonwoven fabric). Therefore, a resin fiber layer with excellent sound absorption properties derived from hot-melt resin can be easily formed, and peeling is unlikely to occur because the resin fiber layer is adhered to the surface in a substantially uniform manner.

[0072] 3.Applications The application locations of the laminate and sound-absorbing material in this embodiment are not particularly limited and can be any location where sound absorption is required. For example, they can be applied to interior and exterior components of buildings, airplanes, ships, vehicles (automobiles, railway cars), and other vehicles. [Examples]

[0073] The laminates of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0074] <<Manufacturing of laminates / resin fiber layers>> The following olefin-based hot-melt resins were used to constitute the resin fiber layer. PP-2 (manufactured by Tosho Chemical Co., Ltd., polypropylene, MFR 1800g / 10min) PR100 (TEX YEAR, α-olefin)

[0075] (Example 1) A hot-melt resin, maintained at 190°C and molten, was spray-applied onto a release paper. The hot-melt resin (PP-2) was then cooled and solidified at room temperature to form a resin fiber layer. A nonwoven fabric was then placed over the formed resin fiber layer to obtain the laminate according to Example 1. An Auto Supply (manufactured by ITW) (nozzle: AE3) was used for spray application.

[0076] The thickness, basis weight, average fiber diameter, and air permeability of the resin fiber layer were adjusted by changing the spray application conditions (application time) and air temperature.

[0077] (Example 2) Example 2 is identical to Example 1 except for differences in surface weight, plate thickness, and air permeability.

[0078] (Example 3) Example 3 is the same as Example 1 except for the average fiber diameter and air temperature.

[0079] (Example 4) Example 4 shares the same conditions as Example 1, except for the average fiber diameter and air temperature.

[0080] (Example 5) Example 5 shares the same conditions as Example 1, except for the average fiber diameter and air temperature.

[0081] (Example 6) Release paper was prepared, and olefin resin, held at 150°C and molten, was spray-coated onto the release paper. The olefin resin (manufactured by TEX YEAR) listed in Table 1 was then cooled and solidified at room temperature to form a surface layer. Subsequently, the release paper was peeled off the surface layer, and the laminate according to Example 6 was obtained by attaching it to the resin fiber layer so that the surface layer covered the resin fiber layer when viewed from above. Auto Supply (manufactured by ITW) (nozzle: AE3) was used for spray coating. In other words, the surface layer was formed on the hot melt resin layer.

[0082] Furthermore, a hot melt resin, maintained at 190°C and molten, was spray-coated onto the release paper under the conditions described in Table 1. The hot melt resin was then cooled and solidified at room temperature to form a resin fiber layer.

[0083] The surface layer thickness, basis weight, average fiber diameter, and air permeability were adjusted by changing the spray application conditions (application time) and air temperature.

[0084] (Example 7) As shown in Table 1, the laminate of Example 7 was prepared in the same manner as in Example 6, except that the basis weight, plate thickness, and air permeability of the surface layer were changed.

[0085] (Example 8) Example 8 differs from Example 6 in that the basis weight, thickness, and air permeability of the surface layer are changed, and a release film is used instead of release paper. An olefin resin, held at 150°C and molten, is spray-coated onto the release film, and the olefin resin is cooled and solidified at room temperature to form the surface layer. The procedure after peeling off the release film, such as a PET film, from the surface layer is the same as in Example 6.

[0086] (Comparative Example 1) A laminate according to Comparative Example 1 was obtained using the same manufacturing method as in Example 1, except that a surface layer was not provided.

[0087] (Comparative Example 2) A laminate according to Comparative Example 2 was obtained using the same manufacturing method as in Example 1, except that a surface layer was not provided and the amount of resin fiber layer applied, the basis weight, and the plate thickness were varied.

[0088] (Comparative Example 3) A laminate according to Comparative Example 3 was obtained using the same manufacturing method as in Example 1, except that a surface layer was not provided and the material properties, coating amount, basis weight, and plate thickness of the resin fiber layer were varied.

[0089] <<Rating>>

[0090] Table 1 shows the components (hot melt resin) of the resin fiber layer, the thickness of the resin fiber layer, the basis weight, the average fiber diameter, the air permeability, the storage modulus G', the loss modulus G'', the loss tangent tanδ, and the glass transition temperature for each example and comparative example. The measurement conditions for each physical property are as follows.

[0091] <mfr> The MFR was measured and evaluated for each laminate in Examples 1-8 and Comparative Examples 1 and 2. The MFR was measured in accordance with JIS K 7121.

[0092] <Melting point> The melting points of each laminate in Examples 1-8 and Comparative Examples 1-3 were measured and evaluated. The melting points were measured in accordance with JIS K 7121.

[0093] <Crystallization temperature> The crystallization temperature of each laminate in Examples 1-8 and Comparative Examples 1-3 was measured and evaluated. The crystallization temperature was measured in accordance with JIS K 7121.

[0094] <Crystallization energy> The crystallization energy was measured and evaluated for each laminate in Examples 1-8 and Comparative Examples 1-3. The crystallization energy was measured in accordance with JIS K 7121.

[0095] <Storage modulus G', loss modulus G'', loss tangent tanδ> For each laminate in Examples 1-8 and Comparative Examples 1-3, the storage modulus G', loss modulus G'', and loss tangent tanδ were measured and evaluated. These were measured according to the procedure in accordance with JIS-K7198, under conditions of heating from -80°C to 150°C at a rate of 5°C / min and a frequency of 1 Hz.

[0096] <Glass transition temperature> The glass transition temperature was measured and evaluated for each laminate in Examples 1-8 and Comparative Examples 1-3. The glass transition temperature was defined as the peak value of tanδ measured under the conditions of heating from -80°C to 150°C at a rate of 5°C / min and a frequency of 1 Hz, in accordance with JIS K 7198.

[0097] <Sound absorption coefficient> The sound absorption coefficient was measured and evaluated for each laminate in Examples 1-8 and Comparative Examples 1 and 2. The sound absorption coefficient was measured from the surface side according to the transfer function method of JIS A 1405-2.

[0098] As shown in Figure 2(a), it was confirmed that in Examples 1 and 2, the sound absorption coefficient in the low frequency range (generally below 2000 Hz) was significantly improved compared to Comparative Example 1. In particular, in Examples 1 and 2, the improvement in sound absorption coefficient was remarkable in the 1000-2000 Hz frequency range compared to Comparative Example 1.

[0099] As shown in Figure 2(b), in Examples 3 and 4, it was confirmed that the sound absorption coefficient in the low frequency range (generally below 2000 Hz) was significantly improved compared to Comparative Example 2. In particular, in Examples 3 and 4, the improvement in sound absorption coefficient was remarkable in the frequency range of 1600 to 3150 Hz compared to Comparative Example 2.

[0100] As shown in Figure 3, in Examples 5 to 8, it was confirmed that the sound absorption coefficient in the low frequency range (generally below 2000 Hz) was significantly improved compared to Comparative Example 2. In particular, in Examples 5 to 8, the improvement in sound absorption coefficient was remarkable in the frequency range of 1600 to 3150 Hz compared to Comparative Example 2.

[0101] [Table 1] The details of the components shown in Table 1 are as follows: Antioxidant: Songwon Co., Ltd., Songnox 11B FF

[0102] From the above results, it can be understood that the laminates comprising the resin fiber layer and the surface layer according to each embodiment have sufficient sound absorption in the low frequency range. [Industrial applicability]

[0103] As described above, the present invention is extremely useful and has high industrial applicability because it can improve the sound absorption coefficient on the low-frequency side. [Explanation of symbols]

[0104] 1: Laminate 10: Surface layer 20: Resin fiber layer 30: Base material< / mfr>

Claims

1. A resin fiber layer with a thickness of 10 mm or more, formed from an olefin resin, The surface layer laminated on the aforementioned resin fiber layer, Equipped with, The air permeability of the surface layer is 50 cm ３ / (cm ２ s) is less than or equal to, The basis weight of the aforementioned resin fiber layer is 300 g / m². ２ The following: A laminate in which the olefin resin has a crystallization temperature of 80°C or higher.

2. The laminate according to claim 1, wherein the thickness of the surface layer is 3.0 mm or less.

3. The surface layer has a basis weight of 100 g / m². ２ The laminate according to claim 1, which is as follows:

4. A sound-absorbing material comprising a laminate according to any one of claims 1 to 3.

5. An automotive interior component comprising a laminate according to any one of claims 1 to 3.

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