JP2010284986A - Sound absorbing laminated material and sound absorbing laminated material mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight laminated material rich in sound absorptivity. <P>SOLUTION: This sound absorbing laminated material 8 is provided so that the laminated material is formed of a base material 7 and a skin material 6 thermally adhered to a surface of the base material 7, and the base material 7 is formed of mixed fiber formed of vegetable fiber and low melting point thermoplastic resin fiber having a melting point of 180°C or less, and the skin material 6 is formed by bonding a porous fiber sheet 1 to a reverse surface of a fiber sheet 3 via a gas permeable adhesive layer 5A, and an bonding strength enhancing sheet 2 is also bonded to a reverse surface of the porous fiber sheet 1 via a gas permeable adhesive layer 5B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to a sound-absorbing laminate used for interior materials such as automobile door trims, floor trims, door linings, trunk boards, and package trays, and molded articles of the above-mentioned sound-absorbing laminate.

Interior materials such as automobile door trims, floor trims, door linings, trunk boards, and package trays are required to be lightweight for the purpose of improving fuel economy in order to counter recent increases in the price of petroleum resources and global warming. However, at the same time, rigidity is required to stabilize the molding shape.
The interior material generally has a structure in which a fiber mat in which fibers are bound with a thermoplastic resin is used as a base material, and a skin material is adhered to the surface thereof, but kenaf fiber, palm fiber, hemp fiber, bamboo fiber, pulp fiber, etc. Because plant fiber is a natural resource, it does not depend on petroleum resources, and the fiber mat made by binding the plant fiber with a thermoplastic resin binder such as polyethylene, polypropylene, polyester, etc. is useful as a lightweight and rigid interior material It is.

  As described above, an automobile interior material has a configuration in which a skin material such as a nonwoven fabric or a moquette is bonded to the surface of the fiber mat as a base material. In order to bond the skin material to the base material, the entanglement (anchor effect) at the joint surface between the fibers of the fiber mat and the fibers of the skin material is used, or the thermoplastic resin binding contained in the fiber mat is used. A hot melt adhesive made of the same kind of thermoplastic resin as the adhesive is used.

JP 2002-371455 A JP 2001-179716 A JP 2006-95918 A JP 2000-015612 A JP 2001-058382 A JP-A-9-277216 JP 7-246657 A JP 2001-0388857 A

As described above, for the adhesion between the base material and the skin material, entanglement between the fibers of the base material and the skin material and a hot melt adhesive are used, but the use of the adhesive takes time and effort for the bonding work, In addition, the adhesive cost is increased, and the air permeability of the resulting interior material is hindered and the sound absorption performance deteriorates. Therefore, without using an adhesive, the skin material is thermocompression bonded to the base material, and the base material and the skin material fiber It is desirable to bond by tangling each other.
In order to firmly bond the skin material to the base material by thermocompression bonding the base material and the skin material, it is necessary to increase the content of the thermoplastic resin contained in the fiber mat, When the content of the thermoplastic resin in the fiber mat is increased, the air permeability is hindered, and the sound absorbing performance of the resulting interior material is adversely affected. In addition, there is a problem in the treatment of the waste of the interior material, which is not desirable from the environmental viewpoint.
Furthermore, in order to improve the sound absorption performance, it is necessary to increase the thickness of the fiber mat that is the base material. As a result, there is a problem that the lightness and compactness are hindered.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a laminated material that is lightweight and has high rigidity and excellent sound absorption. In the present invention, a fiber sheet, A porous fiber sheet bonded to the back surface of the fiber sheet via a breathable adhesive layer, and a fine fiber-containing nonwoven fabric further bonded to the back surface of the porous fiber sheet via a breathable adhesive layer The porous fiber is made of a fiber laminated material obtained by thermally bonding a sound-absorbing skin material composed of an adhesive strength reinforcing sheet to a surface of a base material which is a fiber mat composed of a mixed fiber of vegetable fibers and thermoplastic resin fibers. The sheet is composed of porous fibers having a large number of pores opened on the surface, and is set to a thickness of 0.05 to 1.0 mm and a ventilation resistance of 0.08 to 2.0 kPa · s / m, The above-mentioned adhesion strengthening sheet has fineness .3dtex the following fine fibers comprise more than 50 wt%, a fine fiber-containing nonwoven fabrics which are set in the basis weight 20 to 100 g / ^{m 2,} the ventilation resistance of the sound absorbing surface material 0.6～2.5KPa · A sound-absorbing laminate that is s / m is provided.
The sound-absorbing laminate material may be molded into a predetermined shape to form a sound-absorbing laminate material.

[Action / Effect]
In the sound-absorbing skin material 6 used for the sound-absorbing laminated material 8 of the present invention, the back surface of the fiber sheet 3 is backed with a sheet made of porous fibers having a large number of pores opening on the surface, that is, the porous fiber sheet 1. . The porous fiber sheet 1 is used as the base material 7 because it exhibits a very excellent sound absorbing performance by the air layer contained in the whole porous fiber and the air layer contained in the gap between the porous fibers. It is possible to reduce the thickness of a fiber mat made of a mixed fiber of vegetable fibers and thermoplastic resin fibers. In order to obtain good sound absorption performance, the porous fiber sheet 1 has a thickness of 0.05 to 1.0 mm and a ventilation resistance of 0.08 to 2.0 kPa · s / m.
In the present invention, in the sound-absorbing skin material 6, an adhesive strength reinforcing sheet 2 that is a fine fiber-containing nonwoven fabric is further bonded to the back surface of the porous fiber sheet 1 through a breathable adhesive layer. The fine fiber-containing non-woven fabric as the adhesive strength-enhancing sheet 2 contains 50% by mass or more of fine fibers having a fineness of 3.3 dtex or less, and is set to a basis weight of 20 to 100 g / m ^2. Has a myriad of blemishes on its surface, and the above-mentioned sound-absorbing skin material 6 is polymerized and pressure-bonded toward the surface of the heat-softened fiber mat that is the base material 7 on the side of the adhesive reinforcing sheet 2 that is the fine fiber-containing nonwoven fabric. When molded, the numerous fibers on the surface of the fine fiber-containing nonwoven fabric as the adhesive strength reinforcing sheet 2 bite into the heat-softened surface of the fiber mat, and the plant fibers in the fiber mat as the substrate 7 and The heat-absorbing thermoplastic resin fibers are entangled with each other, and the sound-absorbing skin material 6 is firmly bonded to the surface of the base material 7 that is the fiber mat without using an adhesive.
The ventilation resistance of the sound absorbing skin material 6 as a whole is set to 0.6 to 2.5 kPa · s / m from the viewpoint of sound absorbing performance.
In the fiber mat that is the base material 7 used in the present invention, it is composed of mixed fibers composed of vegetable fibers and thermoplastic resin fibers, and a fibrous material is used as the thermoplastic resin binder. The plant fiber and the thermoplastic resin fiber are entangled in the base material 7, and the fibers are firmly bound to each other. Therefore, the fiber sheet is rich in rigidity, and the molded product of the fiber mat has a stable molded shape.

It is explanatory drawing explaining the measuring method of ventilation resistance R. FIG. 3 is a longitudinal side view of the sound-absorbing laminated material 8. FIG.

The present invention is described in detail below.
〔Base material〕
As a material of the fiber mat which is a base material used in the present invention, a mixed fiber composed of vegetable fibers and low melting point thermoplastic resin fibers is used.
Examples of the vegetable fiber include pulp, cotton, mulberry, Mitsumata, straw, bagasse, palm fiber, hemp fiber, bamboo fiber, and kenaf fiber. The above plant fibers are used alone or in combination of two or more. Among these plant fibers, kenaf fibers are desirable as a material for the substrate from the viewpoint of rigidity, availability, and price.

  Examples of the low-melting point thermoplastic resin fiber include polyolefin fibers such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer having a melting point of 180 ° C. or lower, polyvinyl chloride fibers, and thermoplastic polyurethane fibers. Polyester fiber, polyester copolymer fiber, polyamide fiber, polyamide copolymer fiber, and the like. These thermoplastic resin fibers are used alone or in combination of two or more. The fineness of the thermoplastic resin fiber is preferably in the range of 0.1 to 60 dtex. Desirable thermoplastic resin fibers used in the present invention include polypropylene fibers having a softening point of about 130 ° C. and a relatively low temperature, which are inexpensive and easily available. For example, high melting point polyester fibers or polyamides having a melting point of 180 ° C. or higher. A core-sheath type composite fiber having a high melting point fiber such as a fiber as a core component and a low melting point thermoplastic resin having a melting point of 100 to 180 ° C., for example, a low melting point polyester resin or a low melting point polyamide resin, is also a desirable fiber. When the core-sheath type composite fiber is used, the rigidity and heat resistance of the obtained base material are not lowered.

  The vegetable fiber and the thermoplastic resin fiber are uniformly mixed by, for example, a defibrator, a mixer, a card machine, etc., and the obtained mixed fiber is deposited on a support to form a mat, and the mat is desired. If it is subjected to needle punching, it is heated to a temperature equal to or higher than the softening point of the low-melting point thermoplastic resin fiber to be contained and cold-pressed or higher than the softening point of the low-melting point thermoplastic resin fiber. The fiber mat is hot-pressed at a temperature, and the fiber mat is used as the substrate of the present invention.

When the mixing ratio of the low-melting point thermoplastic resin fibers in the mixed fiber of the base material exceeds 70% by mass, the flexibility of the base material becomes poor, and when molded into a predetermined shape, the low-melting point thermoplastic resin fiber mutual As a result, it is difficult to obtain a uniform molded product, and the density becomes high and the sound absorption is lowered.
On the other hand, when the mixing ratio of the low-melting-point thermoplastic resin fiber in the mixed fiber is less than 30% by mass, the rigidity of the base material is lowered, and when the base material is molded, the molding shape is stable. May be worse. Therefore, as the mixed fiber used as the material of the base material, it is desirable that the mixed ratio is 30 to 70% by mass of vegetable fiber and 70 to 30% by mass of low melting point thermoplastic resin fiber.

Furthermore, it is desirable to set the thickness of the base material in a range of 1 to 20 mm.
If the thickness of the base material is less than 1 mm, the sound absorbing performance is deteriorated.
Further, when the thickness of the base material exceeds 20 mm, the mass of the laminated material becomes large, and the thickness is too large to be molded into a predetermined shape.

Here, the ventilation resistance (Pa · s / m) is a scale representing the degree of ventilation of the breathable material. This ventilation resistance is measured by a steady flow differential pressure measurement method. As shown in FIG. 1, the test piece T is arranged in the cylindrical air passage W, and the air passage W in the air passage W on the starting point side of the arrow in the figure in a state of a constant air flow V (the direction of the arrow in the figure). By measuring the pressure difference between the pressure P1 and the end point P2 of the arrow in the figure, the ventilation resistance R can be obtained from the following equation.
R = ΔP / V
Here, ΔP (P1−P2): pressure difference (Pascal: Pa), and V: air flow per unit area (m ³ / m ² · sec).
The ventilation resistance can be measured by, for example, an air permeability tester (product name: KES-F8-AP1, manufactured by Kato Tech Co., Ltd., steady flow differential pressure measurement method).

[Fiber sheet]
Examples of the fiber material of the fiber sheet used in the present invention include polyester fibers, polyethylene fibers, polypropylene fibers, polyamide fibers, acrylic fibers, urethane fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, synthetic fibers such as acetate fibers, and corn. Biodegradable fibers made of starch extracted from plants such as sugarcane and sugarcane, or inorganic fibers such as vegetable fibers, glass fibers, carbon fibers, ceramic fibers and asbestos fibers used in the above-mentioned base materials, or these fibers One type or two or more types of recycled fibers obtained by defibrating scraps of used fiber products are used. For example, inorganic fibers such as glass fibers, carbon fibers, ceramic fibers, asbestos fibers, and stainless fibers. And polymetaphenylene isophthalamide fiber, poly-p-phenylene terf Aramid fibers such as Ruamido fibers, polyarylate fibers, polyether ether ketone fibers, preferably such as polyphenylene sulfide fibers With a melting point of 250 ° C. or more heat-resistant synthetic fibers, the heat resistance of a very high skin material is obtained. Among them, carbon fiber is a useful inorganic fiber because it can be incinerated and is difficult to disperse fine pieces, and aramid fiber is a useful synthetic fiber because it is relatively inexpensive and easily available.
Using a low melting point thermoplastic resin fiber having a melting point of 180 ° C. or lower or a core-sheath type composite fiber, similar to the low melting point thermoplastic resin fiber of the base material, for a part or all of the fibers used in the fiber sheet. Also good.

The fiber sheet is formed by a method in which the fiber web sheet or mat is entangled by needle punching, a spunbond method, the fiber web sheet or mat is made of the low-melting-point thermoplastic resin fiber, or the low A thermal bond method in which the low-melting point thermoplastic resin fibers are softened by heating a sheet or mat of the above-described fiber web when the melting point thermoplastic resin fibers are mixed; The low-melting point thermoplastic resin fiber is softened by heating after entanglement of the fiber sheet or mat by needle punching or by chemical bond method in which a synthetic resin binder is impregnated or mixed with the sheet or mat Stitches that tie together or sew with thread Spunlace entangle with command method or high-pressure water, a method of forming wear impregnated with the synthetic resin binder into a sheet or mat subjected to the needle punching, it is further produced by a method in which woven knitted the fibers.
In addition, the basis weight and thickness of the fiber sheet according to the present invention can be arbitrarily set in principle, but are preferably set to a basis weight of 10 to 200 g / m ² and a thickness of 0.01 to 10 mm.

[Porous fiber sheet]
In the sound-absorbing skin material of the present invention, the porous fiber sheet adhered to the back surface of the fiber sheet is a sheet made of porous fibers having a large number of pores opened on the surface, and such porous fibers are For example, it is obtained by beating pulp appropriately.
From the viewpoint of sound absorption and light weight, the porous fiber sheet preferably has a basis weight of 10 to 60 g / m ² , a thickness of 0.05 to 1.0 mm, and a ventilation resistance of 0.08 to 2. Set to 0 kPa · s / m.
Examples of the pulp that is a raw material of the porous fiber used for the porous fiber sheet include hardwood wood pulp, softwood wood pulp, hemp pulp, kenaf pulp, bamboo pulp, esbalt pulp, bagasse pulp, and straw pulp.

[Adhesion Strengthening Sheet]
In the present invention, the adhesive strength reinforcing sheet bonded to the back surface of the porous fiber sheet is made of a fine fiber-containing nonwoven fabric. The fine fiber is generally obtained by discharging a thermoplastic resin melt into a thread form from a nozzle, blowing hot air on the thread-like discharge object, and stretching, and has a fiber cut length of 2.0 to 80.0 mm. The fineness is 3.3 dtex or less. In order to make such fine fibers into a non-woven fabric, known methods such as a method of entanglement of the fine fibers by needle punching and a method of entanglement and fusion of fibers in a molten state are applied.
From the viewpoint of sound absorption performance, the basis weight of the adhesive strength reinforcing sheet is set to ²⁰ to 100 g / m ² . And from a viewpoint of sound-absorbing performance, in the said adhesive force reinforcement sheet, 50 mass% or more of fine fibers are contained in a fine fiber containing nonwoven fabric.

(Breathable adhesive layer)
In the present invention, a breathable adhesive is applied to the fiber sheet and the porous fiber sheet, and the porous fiber sheet and the adhesive strength reinforcing sheet. As the adhesive used in the air-permeable adhesive, a normal solution type or aqueous emulsion type adhesive, a powder type, a web type, a solution type, or an aqueous emulsion type hot melt adhesive, etc. are used. The In the case of a hot melt adhesive in the form of a powder or a web, a porous adhesive layer is used, so that air permeability can be ensured and the air permeability of the sound-absorbing skin material is not impaired.
In the case of a solution-type or aqueous emulsion-type adhesive, the adhesive is applied in the form of dots by spray coating, silk printing coating, offset printing coating, or the like to ensure the breathability of the sound-absorbing skin material.

[Sound-absorbing skin material]
The sound-absorbing skin material laminated on the surface of the substrate that is the fiber mat has a porous fiber sheet adhered to the back surface of the fiber sheet via a breathable adhesive layer, and further has a breathable adhesive layer on the back surface. The adhesive strength reinforcement sheet which is a fine fiber containing nonwoven fabric is adhere | attached through.
In order to produce the sound-absorbing skin material, the breathable adhesive layer is formed on the back surface of the fiber sheet and / or the surface of the porous fiber sheet, and further, the back surface of the porous fiber sheet and / or the adhesion is formed. The breathable adhesive layer is formed on the surface of the force reinforcing sheet, and the three layers of the fiber sheet, the porous fiber sheet, and the adhesive strength reinforcing sheet are bonded together, or the fiber sheet and the above A method of first bonding the porous fiber sheet or the porous fiber sheet and the adhesive strength reinforcing sheet and then bonding the adhesive strength reinforcing sheet or the fiber sheet may be employed. In any case, when a hot melt adhesive is used, heat bonding is applied.
The entire ventilation resistance of the sound-absorbing skin material manufactured as described above is set to 0.6 to 2.5 kPa · s / m from the viewpoint of sound absorption performance.

[Sound-absorbing laminate]
The sound-absorbing laminate of the present invention is produced by adhering the base material that is the fiber mat and the sound-absorbing skin material.
In order to bond the fiber mat and the sound-absorbing skin material, the surface of the fiber mat is heated, and the heating temperature at that time is set to a temperature equal to or higher than the softening point of the thermoplastic resin fibers contained in the fiber mat. Then, the thermoplastic resin fiber is put in a softened state. The sound-absorbing skin material is polymerized on the surface of the base material, and the sound-absorbing skin material is pressure-bonded to the surface of the base material by a cold press and formed into a predetermined shape. The base material is breathable and porous. Therefore, the thermoplastic resin fiber in the base material has a heat storage property, and can maintain the softened state up to the time when the sound-absorbing skin material is pressed.

  In this way, the sound-absorbing laminated material 8 as shown in FIG. 2 is manufactured. In the sound-absorbing laminated material 8 shown in FIG. 2, 7 is a base material, and 6 is a sound-absorbing skin material adhered to the surface of the base material 7. The sound-absorbing skin material 6 includes a fiber sheet 3, a porous fiber sheet 1 bonded to the back surface of the fiber sheet 3 via a breathable adhesive layer 5 A, and a gas flow through the back surface of the porous fiber sheet 1. The adhesive strength reinforcing sheet 2 is bonded to the adhesive adhesive layer 5B.

  Examples for describing the present invention more specifically will be described below, but the present invention is not limited to these examples.

[Example 1]
A fiber sheet, which is a needle punched nonwoven fabric having a basis weight of 160 g / m ² and a thickness of 1.5 mm, was prepared by a normal needle punching method using a web made of polyester fibers as a material.
Further, pulp fibers made of conifers are processed into a pulp fiber having a large number of pores opened on the surface through a disaggregation-beating step, and a paper weight of the pulp fiber slurry is made to 23 g / m ² , thickness 0.13 mm. A porous fiber sheet having a ventilation resistance of 1.015 kPa · s / m was produced.
Next, copolymer polyester particles (particle size: 200 to 300 μm, softening point: 155 ° C.) as a hot melt adhesive are sprayed on the back surface of the fiber sheet at a coating amount of 5 g / m ² , and then the porous fiber sheet is polymerized. Then, the hot melt adhesive is melted while being pressed against the surface of a hot roll at 180 ° C., and then cooled and bonded and laminated with the fiber sheet and the porous fiber sheet, and further, the porous fiber sheet of the laminate Copolymerized polyamide particles (particle size: 200 to 300 μm, softening point 125 ° C.) are spread on the side at a coating amount of 5 g / m ² and heated at 140 ° C. in a heating chamber to soften and melt the copolymerized polyamide particles. 70% by mass of polyester fiber (fineness: 2.2 dtex, fiber cut length: 75 mm) and polyester fiber (fineness: 6.6 dtex, fiber cut) : 75 mm) was mixed fiber web consisting of 30 wt% and the material, basis weight 50 g / ^{m 2} by a conventional needle punching method, a cohesive strengthening sheet made of needle punched nonwoven fabric is a ventilation resistance 0.031kPa · s / m polymerization Then, pressure-bonding was performed with two cooled rolls, and a sound-absorbing skin material having an overall airflow resistance of 1.056 kPa · s / m made of a fiber sheet-porous fiber sheet-adhesion strengthening sheet laminate was produced. .
Next, a fiber mat having a thickness of 4.5 mm and a basis weight of 1200 g / m ² composed of 50% by mass of kenaf fibers and 50% by mass of polypropylene fibers is used as a base material, and the base material is placed in a hot air circulation thermostat at 200 ° C. After heating for 2 minutes to soften the polypropylene fiber which is the thermoplastic resin fiber in the base material, it is taken out from the hot air circulating thermostat and the adhesive strength reinforcing sheet side of the sound-absorbing skin material is polymerized on the base material. Then, it was immediately pressed by a cooling press machine to produce a sound-absorbing laminated material having a thickness of 5.5 mm.
The adhesive strength between the base material and the skin material of the above sound-absorbing laminated material is 8.9 N / 25 mm (180 ° peeling test in normal state, tensile speed 20 mm / min, sample width 25 mm), high rigidity and resin on the surface of the skin material No oozing, wrinkles, etc., and appearance was good.

[Example 2]
A fiber sheet, which is a needle punched nonwoven fabric having a basis weight of 140 g / m ² and a thickness of 1.2 mm, was prepared by a normal needle punching method using a web made of polyester fibers.
In addition, pulp fibers composed of 70 parts by weight of softwood pulp and 40 parts by weight of hardwood pulp are subjected to a disaggregation-beating process to obtain pulp fibers having a large number of pores opened on the surface. A porous fiber sheet having a thickness of 0.18 mm / m ² and a ventilation resistance of 1.207 kPa · s / m was produced.
Next, copolymer polyester particles (particle size: 200 to 300 μm, softening point: 155 ° C.) as a hot melt adhesive are sprayed on the back surface of the fiber sheet at a coating amount of 5 g / m ² , and then the porous fiber sheet is polymerized. Then, the hot melt adhesive is melted while being pressed against the surface of a hot roll at 180 ° C., and then cooled and bonded and laminated with the fiber sheet and the porous fiber sheet, and further, the porous fiber sheet of the laminate Copolymerized polyamide particles (particle size: 200 to 300 μm, softening point 125 ° C.) are spread on the side at a coating amount of 5 g / m ² and heated at 140 ° C. in a heating chamber to soften and melt the copolymerized polyamide particles. In addition, the surface of the fiber sheet is fluffed by further punching a polyester fiber (fineness: 2.2 dtex) sheet by a spunbond method. Myself understood, basis weight 40 g / ^{m 2,} by polymerizing a cohesive strengthening sheet comprising fiber sheet is a pressure drop 0.046kPa · s / m, and pressed in the cooled two rolls, the fiber sheet - porous fiber A sound-absorbing skin material having an overall ventilation resistance of 1.285 kPa · s / m made of a sheet-adhesion-strengthened sheet laminate was produced.
Next, a fiber mat with a thickness of 5.0 mm and a basis weight of 1000 g / m ² consisting of 55% by mass of kenaf fibers and 45% by mass of polypropylene fibers was used as a substrate, and the substrate was placed in a hot air circulating thermostat at 210 ° C. After heating for 2 minutes to soften the polypropylene fiber which is the thermoplastic resin fiber in the base material, it is taken out from the hot air circulating thermostat and the adhesive strength reinforcing sheet side of the sound-absorbing skin material is polymerized on the base material. Then, it was immediately pressed with a cooling press to produce a sound-absorbing laminated material having a thickness of 5.2 mm.
The sound-absorbing laminate has excellent adhesive strength between the base material and the skin material, has high rigidity and good appearance, and the adhesive strength between the base material and the skin material of the sound-absorbing laminate material is 8.1 N / It was 25 mm (by the same peel test as in Example 1), and the sound absorption rate by the reverberation chamber method was 41% at 1000 Hz, 78% at 2000 Hz, and 91% at 4000 Hz.

Example 3
A fiber sheet, which is a needle punched nonwoven fabric having a basis weight of 160 g / m ² and a thickness of 1.2 mm, was prepared by a normal needle punching method using a web made of polyester fibers as a material.
Further, a pulp fiber composed of 80 parts by mass of softwood pulp and 20 parts by mass of hardwood pulp is subjected to a disaggregation-beating process to obtain pulp fibers having a large number of pores opened on the surface, and a slurry of the pulp fibers is made to make a porous fiber. A porous fiber made of creped paper having a basis weight of 18 g / m ² , a thickness of 0.12 mm, a crepe rate of 20%, and a ventilation resistance of 1.170 kPa · s / m by forming a sheet and creping the porous fiber sheet A sheet was produced.
Next, copolymer polyamide particles (particle size: 80 to 200 μm, softening point: 135 ° C.) as a hot melt adhesive are sprayed on the back surface of the fiber sheet at a coating amount of 7 g / m ² , and then the porous fiber sheet is polymerized. Then, the hot melt adhesive is melted while being pressed against the surface of a hot roll at 160 ° C., then cooled and bonded and laminated to the fiber sheet and the porous fiber sheet, and then the porous fiber sheet of the laminate Copolymerized polyamide particles (particle size: 80-200 μm, softening point 120 ° C.) are sprayed on the side at a coating amount of 5 g / m ² and heated at 130 ° C. in a heating chamber to soften and melt the copolymerized polyamide particles. 60% by mass of polyester fiber (fineness: 1.7 dtex, fiber cut length: 70 mm) and polyester fiber (fineness: 6.6 dtex, fiber cut length: 7) mm) was mixed fiber web consisting of 40 wt% and the material, basis weight 60 g / ^{m 2} by a conventional needle punching method, the cohesive strengthening sheet polymerization consisting of needle punched nonwoven fabric is a ventilation resistance 0.035kPa · s / m Thus, a sound-absorbing skin material having an overall ventilation resistance of 1.245 kPa · s / m made of a fiber sheet-porous fiber sheet-adhesion-strengthened sheet laminate was produced by pressure bonding with two cooled rolls.
Next, a fiber mat having a thickness of 4.0 mm and a basis weight of 900 g / m ² consisting of 55% by mass of kenaf fibers and 45% by mass of polypropylene fibers is used as a substrate, and the substrate is placed in a hot air circulation thermostat at 210 ° C. After heating for 2 minutes to soften the polypropylene fiber which is the thermoplastic resin fiber in the base material, it is taken out from the hot air circulating thermostat and the adhesive strength reinforcing sheet side of the sound-absorbing skin material is polymerized on the base material. Then, it was immediately molded into a predetermined shape with a cooling press to produce a sound-absorbing laminated material molded product.
The obtained sound-absorbing laminate molding is excellent in sound-absorbing property and rigidity, and is useful for automobile package trays, door boards, trunk room trims, and the like.

  The sound-absorbing laminated material of the present invention is lightweight and excellent in sound-absorbing performance, and the molded product has high rigidity and a stable molded shape, so that it is particularly useful as an automobile interior material and can be used industrially.

DESCRIPTION OF SYMBOLS 1 Porous fiber sheet 2 Adhesive strength reinforcement sheet 3 Fiber sheet 5A, 5B Breathable adhesive layer 6 Sound-absorbing skin material 7 Base material 8 Sound-absorbing laminated material

Claims (2)

A fiber sheet, a porous fiber sheet bonded to the back surface of the fiber sheet via a breathable adhesive layer, and a fine sheet bonded to the back surface of the porous fiber sheet via a breathable adhesive layer A sound-absorbing skin material comprising an adhesive strength reinforcing sheet that is a fiber-containing nonwoven fabric,
It consists of a fiber laminate material that is thermally bonded to the surface of the substrate, which is a fiber mat composed of mixed fibers of vegetable fibers and thermoplastic resin fibers,
The porous fiber sheet is made of a porous fiber having a large number of pores opened on the surface, and is set to a thickness of 0.05 to 1.0 mm and a ventilation resistance of 0.08 to 2.0 kPa · s / m. Because
The adhesive strength reinforcing sheet is a fine fiber-containing non-woven fabric containing 50% by mass or more of fine fibers having a fineness of 3.3 dtex or less, and having a basis weight of 20 to 100 g / m ² .
The sound-absorbing laminated material according to claim 1, wherein the sound-absorbing skin material has a ventilation resistance of 0.6 to 2.5 kPa · s / m. A sound-absorbing laminate material molded product obtained by molding the sound-absorbing laminate material according to claim 1 into a predetermined shape.