JP2010064361A - Sound absorbing material component, sound absorbing material and manufacturing method of sound absorbing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorbing material component and a sound absorbing material wherein the sound absorbing material component can easily form a resin film having a uniform thickness and permeability on a surface of the sound absorbing layer composed of a non-woven fabric, and the sound absorbing material is moldable, hardly exfoliate the resin film and excellent in sound absorption and durability. <P>SOLUTION: The sound absorbing material component has a permeable resin film spray coated by a hot melt spray method on a release-treated surface of a releasing paper wherein the resin film is composed of a synthetic resin with a melting point of 80-200°C. A moldable sound absorbing material is manufactured by transferring and cementing the resin film on the non-woven fabric by heat-pressing them after superimposing the sound absorbing material component on the surface of non-woven fabric so that the resin film and the non-woven fabric may contact with each other wherein the non-woven fabric has a bulk density of 0.01-0.2 g/cm<SP>3</SP>and a basis weight of 100-2,500 g/m<SP>2</SP>. A molded article of the sound absorbing material has neither wrinkle nor tear on the surface and looks nice. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sound absorbing material constituting member and a sound absorbing material. More specifically, the present invention relates to a sound absorbing material constituting member provided with a uniform resin film for transfer and a moldable sound absorbing material using the same.

  Engines and drive systems mounted on vehicles and the like generate noise when driven. In order to prevent this noise from causing discomfort to the occupant, sound absorbing materials are laminated in layers on the wall surfaces of wall materials such as engine hoods, dash panels, ceiling materials, door trims, cab floors, etc. There are many cases.

  For this reason, a sound-absorbing material can be obtained by laminating and integrating a breathable non-woven fabric or a skin material layer such as a resin film on a sound-absorbing layer made of a porous material such as non-woven fabric or urethane foam to form a laminated structure. It is known (for example, Patent Documents 1 to 6).

  In Patent Document 1, a hot melt film or a low melting point resin non-woven fabric is laminated between a fiber layer and a thermoplastic resin sheet layer, and is laminated by heating and pressurizing to integrate an automobile interior base material. Manufacturing is disclosed. Patent Document 2 discloses a vehicle carpet in which a sound absorbing layer made of a nonwoven fabric and a skin material layer are bonded by heating and melting thermoplastic resin powder. Patent Document 3 discloses a method in which a short fiber nonwoven fabric is combined and integrated by a needle punch method into a layer obtained by combining a nonwoven fabric obtained by a melt blown method or a spunbond method and a film layer by an extrusion laminating method. Yes.

  In these methods, the porous material layer and the skin material layer are bonded with the third substance, and the skin material layer is wrinkled during bonding, or the porous material layer and the skin material layer during heating and fusing. The third material has different melting and deformation levels, resulting in problems such as deformation of the resulting laminate and peeling of the skin material layer.

  As a method of laminating a porous body layer and a skin material layer without using a third substance, Patent Document 4 discloses that a sound absorbing layer made of felt, urethane foam, or the like is made of a thermoplastic resin such as polypropylene, polyethylene, or polyester. A method of thermally fusing a nonwoven fabric or a resin film is disclosed. However, there is a problem that the low melting point resin film adheres to the hot platen at the time of heat fusion and cannot be detached from the hot platen.

  Therefore, in Patent Document 5, as a method for improving the problems of Patent Document 4, a polyester film or the like is superimposed on urethane foam, release paper is laminated thereon, and pressure heating is performed from the release paper side with a hot platen. A method of obtaining a breathable sound-absorbing material by melt-bonding urethane foam and a polyester film and then removing the release paper is disclosed.

  However, even these methods cannot completely improve the adhesive displacement between the porous body layer and the skin material layer during thermocompression bonding. In Patent Document 5, a slippage between the release paper and the polyester film causes a misalignment between the urethane foam and the polyester film, and there is a problem with the formation of a uniform laminate surface.

  Furthermore, the above-described conventional technology cannot solve the economical problem of lightweight and bulky products. That is, in the case of a sound absorbing material, it is often stored as a final product (sound absorbing material) and transported to the place of use at the time of use, and since it is light and bulky, the cost required for storage and transport is high. In order to reduce storage or transport costs, if a large amount is pushed in or loaded, the skin layer tends to be broken or wrinkled due to storage conditions or vibration during transport, etc. May fall.

  On the other hand, in order to improve the problem when the sound absorbing layer and the skin material layer are separately manufactured, Patent Document 6 discloses a method of directly forming a skin material layer by spraying molten resin on a nonwoven fabric (sound absorbing layer). It is disclosed. However, since the melted resin is impregnated into the voids in the nonwoven fabric, a large amount of resin is required to obtain a skin material layer having a predetermined thickness. Thus, there is a problem that it is difficult to obtain sufficient air permeability.

Furthermore, there is a method of roll-coating an adhesive resin on the release paper, but it is difficult to control the coating amount and obtain a resin film with a uniform thickness when applying a highly viscous molten resin. The sound-absorbing material produced by transferring and adhering to the sound-absorbing layer has a problem that the thin part of the resin film is easily peeled off.
JP 2005-226178 A (Claim 5) JP 2002-219989 A (Claim 1) JP 2006-47628 A (Claim 4) JP 2005-263118 A (Claim 1) Japanese Patent Laid-Open No. 10-119220 (Japanese Patent No. 3,388,681) JP 2007-279649 A

  The present invention has been made in view of the above circumstances, and a sound-absorbing material constituting member that can easily form a resin film having a uniform thickness and air permeability on the surface of a sound-absorbing layer made of a nonwoven fabric, and It is an object of the present invention to provide a sound-absorbing material which is difficult to peel off, has excellent sound-absorbing properties and durability, and can be molded.

  As a result of diligent research, the inventors of the present invention have applied the molten synthetic resin by spray coating to the release-treated surface of the release paper by a hot melt spray method, thereby achieving a uniform thickness with a smaller amount of resin than roll coating. It has been found that a resin film having air permeability is formed, and that the resin film is hardly peeled off by transferring the resin film to the surface of the nonwoven fabric, and that a sound-absorbing material having excellent shape retention can be obtained. Reached.

  That is, the present invention is characterized in that a resin film having air permeability made of a synthetic resin having a melting point of 80 to 200 ° C., which is spray-coated by a hot melt spray method, is provided on a release treatment surface of a release paper. A sound absorbing material constituting member is provided.

  The resin film having air permeability made of the synthetic resin may be a resin film that has been subjected to crushing processing after the molten resin is spray-coated by a hot melt spray method.

In the sound-absorbing material forming member of the present invention, the synthetic resin preferably has a melt viscosity at 200 ° C. of 40000 mPa · s or less, and the resin film having air permeability made of the synthetic resin has a thickness of 10 to 100 μm, The air permeability of the resin film is preferably 0.01 to 50 cc / cm ² / sec. The synthetic resin is preferably a polyethylene resin, a polypropylene resin, or a polyester copolymer resin.

Moreover, this invention is resin provided in the above-mentioned sound-absorbing-material structural member of this invention on the surface of the nonwoven fabric whose bulk density is 0.01-0.2 g / cm < ³ > and a fabric weight is 100-2500 g / m < ² >. A sound-absorbing material is provided in which a film is transferred and bonded.

  In the sound absorbing material of the present invention, the nonwoven fabric is preferably a needle punched nonwoven fabric, an airlaid nonwoven fabric or a melt blown nonwoven fabric. Moreover, it is preferable that the fiber which comprises the said nonwoven fabric is 1 type, or 2 or more types of fibers chosen from a thermoplastic fiber and a heat resistant fiber whose melting temperature or thermal decomposition temperature is 370 degreeC or more.

  Recycling is easy when the fibers constituting the nonwoven fabric and the resin constituting the transferred resin film are made of the same material.

In the sound-absorbing material of the present invention, the air flow rate measured based on JIS L 1096 is preferably 0.01 to 50 cc / cm ² / sec. Thereby, it becomes a sound-absorbing material excellent in sound-absorbing property.

  Since the sound-absorbing material of the present invention has the above characteristics, it can be suitably used particularly for a vehicle interior material.

Furthermore, the present invention provides the sound absorbing material according to any one of claims 1 to 5 on the surface of a nonwoven fabric having a bulk density of 0.01 to 0.2 g / cm ³ and a basis weight of 100 to 2500 g / m ^2. The constituent members are superimposed so that the resin film provided on the sound absorbing material constituent member and the nonwoven fabric are in contact with each other, and then heat-pressed to transfer and bond the resin film to the surface of the nonwoven fabric. A method for producing a sound absorbing material is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the sound-absorbing material excellent in the sound-absorbing property, durability, and a moldability which has few tears, wrinkles, and peeling of a skin, and few deformation | transformation and heat shrink of a nonwoven fabric can be provided. Moreover, if there is a nonwoven fabric and a sound absorbing material constituting member, it is also possible to manufacture the sound absorbing material in a demand place where an automobile production factory or the like exists, and it is possible to suppress the transfer cost and the deterioration in the quality of the sound absorbing material accompanying the transfer as much as possible. . And since a manufacturing method is simple, a sound-absorbing material can be manufactured at low cost. The manufactured sound-absorbing material has a soft skin and is thermoplastic, so that it can be easily stretched during molding and can be deep drawn. The molded product of the sound-absorbing material has good appearance without wrinkles or tearing of the skin.

  Further, according to the present invention, if a coloring material, a flame retardant, a water repellent and the like are blended with a synthetic resin, a sound absorbing material having a colored, flame retardant or water repellent skin is processed in one step. The skin can be easily colored. Even when water-repellent treatment is performed in post-processing, the skin and the nonwoven fabric are less likely to peel off.

  Hereinafter, the present invention will be described in detail.

  The hot melt spray method in the present invention is a method using a curtain spray which is generally used for adhesives, and a large number of small holes are arranged in a line in a molten resin pumped from a molten resin tank by a pump or the like. This is a method of forming a resin film by extruding from a spray nozzle and spinning and stretching by a high-temperature high-speed air stream from a slit provided so as to sandwich a row of small holes, and directly spraying and laminating on a coated surface.

When the resin film is formed by the hot melt spray method, it may be applied by a known method using a known hot melt coating apparatus. In this case, the coated amount of the molten resin is preferably in a 40 to 100 g / ^{m 2,} more preferably 40 and 80 g / ^{m 2.} If the coating amount of the molten resin is too small, it is difficult to form a uniform resin film. If the coating amount is too large, the air permeability of the resin film is lowered, and as a result, the sound absorbing property of the sound absorbing material is impaired. The thickness of the resin film is preferably in the range of 10 to 200 μm, more preferably 30 to 120 μm.

In addition, the resin film having air permeability made of a synthetic resin having a melting point of 80 to 200 ° C. may be subjected to crushing after the molten resin is sprayed and applied by a hot melt spray method. After coating the molten resin, the thickness of the resin film and the air flow rate can be appropriately changed by crushing the resin film by pressurizing the coated surface. A preferable air flow rate is 0.01 to 50 cc / cm ² / sec. When the air flow rate of the resin film is larger than 50 cc / cm ² / sec, the sound absorption property is inferior because the air flow rate of the sound absorbing material after the resin film is transferred and bonded to the nonwoven fabric is too large. Moreover, when the air flow rate of the resin film is smaller than 0.01 cc / cm ² / sec, the air flow rate of the sound-absorbing material after the resin film is transferred and bonded to the nonwoven fabric is too small. Sound absorption in the frequency domain becomes extremely low. The resin film thus formed has fine pores, is thin, flexible, and air permeable.

  When crushing the resin film, after forming the resin film on the release treated surface of the release paper by the hot melt spray method, the resin film may be immediately sandwiched between rolls and continuously pressed or melted. A method in which resin is once sprayed and laminated directly onto the release-treated surface of the release paper, the release paper on which the resin film is formed is rolled up, and then the resin film is crushed while being heated and pressed with a calender roller or the like But you can. In this case, since the resin surface easily adheres to the heat roll, it is preferable to further overlap the release paper on the resin film and heat and press with the heat roll. As calendering conditions, 100 to 150 ° C. and linear pressure of 100 to 200 kg / cm are preferable.

  FIG. 1 is a side view schematically showing a method for producing a sound absorbing material constituting member of the present invention. In FIG. 1, 1 is a resin coating line, 2 is a release paper (the upper surface is a release treatment surface), 3 is a molten resin, R is a molten resin flow, 4 is pressurized air, and A is a pressurized heated air flow. There is a heater 5 in the coating device. While moving the coating line 1 in the direction of the arrow, a molten resin flow and a heated and pressurized air flow are sprayed to form a resin film made of the molten resin on the release paper.

  The synthetic resin spray-coated by the hot melt spray method is not particularly limited as long as it is a meltable resin. For example, polyester resin, polyamide resin, acrylic resin, polyethylene resin, polypropylene resin, ethylene-vinyl acetate resin , Polyester polyol resin, ethylene propylene copolymer resin, polyester copolymer resin and the like.

  As the above synthetic resin, those having a melting point of 80 to 200 ° C. are used from the viewpoint of work efficiency at the time of coating and transfer, etc., with little peeling in the use environment of the sound absorbing material. More preferably, the melting point is 120 to 200 ° C. The lower the melting point of the resin, the better the workability. However, when the operating temperature of the sound absorbing material is increased, the resin film may be melted or peeled off. On the other hand, when the melting point of the resin is too high, the resin viscosity at the time of spray coating becomes high, so that the coating property to the release paper is deteriorated.

  Among the synthetic resins, a synthetic resin having a melt viscosity at 200 ° C. of 40000 mPa · s or less is preferable. The viscosity of the synthetic resin at the time of coating is preferably as low as possible, whereby the coating time can be shortened and a resin film having a uniform thickness is easily formed. As such a resin having a low melt viscosity, a polyethylene resin, a polypropylene resin, a polyester copolymer resin, or the like is preferable.

  You may mix | blend at least 1 sort (s) of a coloring material, a flame retardant, and a water repellent with said synthetic resin by a conventionally well-known compounding quantity. Known colorants such as pigments and dyes are used as the colorants, and known flame retardants such as phosphate esters, halogens, and hydrated metal compounds are used as the water repellent. Known water- and oil-repellent agents such as fluorine and silicone can be used.

  The release paper used in the present invention is not particularly limited, and examples thereof include release paper having a surface coated with a silicone coat or the like.

As the nonwoven fabric used in the present invention, one having a bulk density of 0.01 to 0.2 g / cm ³ and a basis weight of 100 to 2500 g / m ² is desirable. If the bulk density of the nonwoven fabric is too small, the sound absorption is lowered, and if it is too large, the wear resistance and workability are lowered. Therefore, it is more preferably in the range of 0.01 to 0.1 g / cm ³ . If the fabric weight of the nonwoven fabric is too small, the shape retention will be poor, and if it is too large, the energy required for fiber entanglement will increase, or the entanglement will be inadequate, resulting in inconveniences such as deformation during nonwoven fabric production, more preferably. 100 to 1000 g / m ² .

  The thicker the nonwoven fabric, the better the sound absorbing property, but it is preferably 2 to 100 mm, more preferably 3 to 50 mm, from the viewpoints of economy, ease of handling, securing a space as a sound absorbing material, and the like.

  As a fiber constituting the nonwoven fabric, one kind selected from synthetic fibers, chemical fibers such as rayon, natural fibers such as cotton, hemp, jute, and wool, or fibers such as anti-hairs (recovered and recycled fibers), or Two or more types can be used. Of these, synthetic fibers are preferred from the viewpoints of heat resistance, wear resistance, and the like.

  Examples of such synthetic fibers include thermoplastic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polypropylene fibers, and polyethylene fibers, and aramid fibers, polyarylate fibers, polybenzoxazole (PBO) fibers, polybenzthiazole fibers, and polybenz. Melting temperature or thermal decomposition temperature of imidazole (PBI) fiber, polyimide fiber, polyetherimide fiber, polyetheretherketone fiber, polyetherketone fiber, polyetherketoneketone fiber, polyamideimide fiber, flameproof fiber, etc. is 370 ° C. The heat resistant fiber which is the above can be mentioned. As these synthetic fibers, those conventionally known and those manufactured according to a known method or a method analogous thereto can be used. The flame-resistant fiber is a carbon fiber precursor mainly produced by firing acrylic fiber at 200 to 500 ° C. in an active atmosphere such as air. For example, the product name “LASTAN” (registered by Asahi Kasei Corporation) Trademark), and trade name “Pyromex” (registered trademark) manufactured by Toho Tenax Co., Ltd.

  Among the above thermoplastic fibers, polyester fibers, polypropylene fibers, and polyamide fibers are preferable from the viewpoint of excellent durability and wear resistance, and these fibers may be used alone or mixed in an arbitrary ratio. it can. Polyethylene terephthalate, polybutylene terephthalate, biodegradable polyester, especially because raw polyester can be easily recycled by heat melting of waste nonwoven fabric, and it has excellent economic efficiency, good nonwoven fabric texture, and excellent moldability. Most preferred are polyester fibers such as fibers. These thermoplastic fibers may be subjected to a flame retardant treatment.

  Moreover, even if it is the same material, it is preferable to mix fibers having different melting points as appropriate because the nonwoven fabric shape-forming property during heat setting and the shape retention property during molding are improved.

  Among the above heat-resistant fibers, aramid fibers, polyarylate fibers and polybenzoxazole fibers which do not melt at high temperatures are preferred from the viewpoint of low shrinkage and good processability, and aramid fibers and polybenzoxazole fibers are most preferred. It is possible to improve the durability and heat resistance of the sound-absorbing material by mixing the heat-resistant fiber with the thermoplastic fiber at an arbitrary mixing ratio, and high heat resistance is required by using only the heat-resistant fiber. A sound-absorbing material suitable for the intended use can be obtained.

  The aramid fibers include para-aramid fibers and meta-aramid fibers. Para-aramid fibers are preferred from the viewpoint of less heat shrinkage. Examples of para-aramid fibers include polyparaphenylene terephthalamide fibers (US DuPont, manufactured by Toray DuPont, trade name “KEVLAR” (registered trademark)), copolyparaphenylene-3,4′-oxydi. Commercial products such as phenylene terephthalamide fiber (manufactured by Teijin Techno Products Co., Ltd., trade name “Technola” (registered trademark)) can be used.

  The form of the fiber constituting the nonwoven fabric used in the present invention is not particularly limited, and may be a filament or a staple. In the case of staples, the fiber length is preferably 10 to 100 mm, particularly preferably 20 to 80 mm. If the fiber length of the staple is 10 mm or more, the entangled staple will not easily fall off the nonwoven fabric. On the other hand, when the fiber length of the staple is long, the card passing property tends to be inferior. As for the fineness of the fiber, the thickness of the single fiber is preferably 0.5 to 30 dtex, more preferably 1.0 to 10 dtex. Staples can be used alone or in combination of two or more, and the same or different kinds of fibers having different fineness and fiber length can also be used in combination.

  Nonwoven fabrics used in the present invention include long-fiber nonwoven fabrics such as meltblown nonwoven fabrics and spunbond nonwoven fabrics, and airlaid nonwoven fabrics in which low-melting fibers in the web are melted by high-temperature hot air and welded to surrounding fibers, and others. Needle punch nonwoven fabrics, water jet punch nonwoven fabrics and the like can be used, and miscellaneous felts can also be used as nonwoven fabrics.

  Among these non-woven fabrics, air-laid non-woven fabrics, needle punched non-woven fabrics, and melt blown non-woven fabrics are preferred because the air permeability of the sound absorbing material can be easily adjusted. In addition, these nonwoven fabrics can use what was produced in accordance with the conventional method using the apparatus similar to the past.

  In the nonwoven fabric used in the present invention, among the constituent fibers, low melting point fibers (preferably fibers that melt at 150 ° C. or lower) are 15 to 80% by mass (hereinafter “%”), more preferably 15 to 60%, It is preferably contained. By using the low-melting-point fiber in the above amount range, the sound-absorbing material after molding has an appropriate hardness (waist) and shape retention is improved. The low-melting fiber may be selected from the above-described thermoplastic fibers or may be a known thermoplastic short fiber. Examples of the thermoplastic short fibers include one or more selected from polyester fibers, polypropylene fibers, polyethylene fibers, linear low density polyethylene fibers, ethylene-vinyl acetate copolymer fibers, and the like.

The sound absorbing material of the present invention has a sound absorbing material constituting member provided on the surface of a nonwoven fabric having a bulk density of 0.01 to 0.2 g / cm ³ and a basis weight of 100 to 2500 g / m ^2. The resin film and the non-woven fabric are laminated so that they are in contact with each other, and then these are heat-pressed to transfer and adhere the resin film to the surface of the non-woven fabric. For thermocompression bonding, an apparatus for heat treatment such as calendaring or roll processing can be used. The apparatus may or may not include a heating plate, and an external heating device such as an infrared heater may be used in combination with an apparatus that does not include a heating plate.

  After solidifying the resin film adhered to the non-woven fabric, the release paper is removed, whereby a sound absorbing material is easily produced in a short time. The resin film transferred and adhered to the nonwoven fabric forms the skin of the sound absorbing material. After the resin film is transferred to the nonwoven fabric, it can be further pressure-bonded with a hot roll. In this case, an appropriate air flow rate can be obtained by transferring a resin film prepared with a small amount of resin applied to the release paper.

  When producing a sound-absorbing material, it is preferable that the non-woven fabric used as the sound-absorbing layer is previously compressed with a heat roll or the like to smooth the surface, because uneven adhesion of the resin on the skin is reduced.

  In the above production method, the thermocompression bonding temperature may be equal to or higher than the melting point of the synthetic resin, but heat energy loss, impregnation of the molten resin into the nonwoven fabric, disappearance of the fine pores of the transferred resin film, It is preferable that the melting point is in the vicinity of the melting point. The thermocompression bonding time varies depending on the thermocompression bonding method, but it is 0.5 to 3 minutes in the batch press method and 1 second or less in the continuous calendar method. Moreover, you may transfer by the method of transferring, running continuously between a hot plate and a roll.

  When airlaid nonwoven fabric (thermal bond type), miscellaneous felt or the like is used, the coating method such as roll coating may not adhere to the nonwoven fabric, but the transfer method of the present invention has selectivity for the nonwoven fabric. There is an advantage that the adhesive strength to the nonwoven fabric is good compared to the coating method.

The sound-absorbing material of the present invention has an air flow rate measured in accordance with JIS L 1096 of 0.01 to 50 cc / cm ² / sec, preferably 0.05 to 30 cc / cm ² / sec. If the air flow rate is less than 0.01 cc / cm ² / sec, the permeability of gas such as engine gas becomes low, and if it exceeds 50 cc / cm ² / sec, the sound absorption performance is deteriorated.

  The sound absorbing material is easy to recycle if the resin constituting the nonwoven fabric and the resin constituting the resin film to be transferred are made of the same material. In other words, for example, a large amount of sound-absorbing materials used as vehicle interior materials such as automobiles are required and must be recyclable. If different materials are used, it will be necessary to disassemble and recycle. It becomes difficult.

  The sound absorbing material of the present invention can be attached in close contact with a site where the sound absorbing material is required by further molding. Molding is performed by heating a sound-absorbing material that has been used in the past, placing it in a mold, hot pressing and then cooling, or heating and then placing it in a male or female mold, and then using a vacuum device to male or female. Vacuum forming or the like in which the mold is brought into close contact with the mold and cooled may be used. Moreover, the method of shape | molding, applying a heat | fever from a vacuum bag during a driving | operation of a vacuum pump may be used. The molding temperature is appropriately determined in consideration of the melting point of the sound absorbing material.

  The sound-absorbing material of the present invention is a surface layer usually used as an interior material for vehicles, in which one layer or two or more layers of air permeable film, paper, woven fabric, knitted fabric, etc. are laminated on one or both sides as required. By laminating materials and the like, it can be preferably applied to automotive interior materials such as automobile ceiling materials, floor materials, option mats, rear packages, door trims and the like.

  The above surface material is preferably laminated on the skin side so as not to impair the water repellency, water resistance, and sound absorption properties of the sound absorbing material, but when the surface material is laminated on the skin, the surface material on the skin May be laminated directly or via another layer (for example, a gray layer). Examples of the surface layer material include non-woven fabric, woven fabric, moquette, tricot, jersey, carpet, leather, artificial leather, and synthetic resin sheet.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited only to a following example. In addition, the measuring method of each characteristic value in the following examples and comparative examples is as follows.

[Air flow rate]
Based on the JIS L-1096 fragile method, the measurement was performed using FX3300 manufactured by TEXTEST, Switzerland.

[Sound absorption rate]
Using an automatic normal incidence sound absorption measurement device (manufactured by Sotec Co., Ltd.), the normal incidence sound absorption coefficient at each frequency was measured according to JIS-A-1405 “Method for measuring normal incidence sound absorption coefficient of building material in pipe method”. The measurement was performed with the sound-absorbing material attached so that the skin was on the sound source side.

[Example-1]
On the release surface of release paper SL-73 manufactured by Koa Shoji Co., Ltd., a copolymer polyester resin having a melting point of 146 ° C. and a viscosity at 180 ° C. of 22400 mPa · s, a molten resin temperature of 200 ° C., a spray head temperature of 210 ° C., hot air After applying at a rate of 5 m / min so that the amount applied to the release paper is 50 g / m ^{2 under} the conditions of a temperature of 210 ° C. and a distance between the release paper and the nozzle of 60 mm, place the release paper on the resin surface. The sound absorbing material constituting member was obtained by immediately pressing with a metal roll with the resin surface sandwiched between release papers. When the resin film after pressurization is peeled off from the release paper and observed, the coated surface is in a state having fine holes on the entire surface of the resin film, the thickness of the resin film is 55 μm, and the air flow rate is 30 cc / cm ² / sec.

[Example-2]
In the same manner as in Example 1, the resin, the spray head temperature, the hot air temperature, the distance between the release paper and the nozzle were set, and the sound absorbing material applied at a speed of 5 m / min so that the amount applied to the release paper was 70 g / m ^2. A component was obtained.
The thickness of the resin film peeled from the release paper was 85 μm, and the air flow rate was 27 cc / cm ² / sec.

[Example-3]
An airlaid nonwoven fabric having a thickness of 15 mm, a weight per unit area of 600 g / m ² , and a bulk density of 0.04, made of a polyester staple containing 20% of a low-melting-point component at 110 ° C. Was heat-pressed under the conditions of a calendar temperature of 185 ° C., a calendar roll gap of 8 mm, and a speed of 5 m / min to transfer the resin film onto the surface of the nonwoven fabric, and the release paper was peeled off to obtain a sound absorbing material. The sound absorbing material had a thickness of 13.5 mm and an air permeability of 20 cc / cm ² / sec. The normal incident sound absorption coefficient was as shown in FIG.
The sound absorbing material was heated at 145 ° C. on the resin surface and the non-woven fabric surface at 180 ° C. for 3 minutes at the same time, and then immediately placed in a mold consisting of a concave surface and a convex surface. A molded product was obtained. This molded product was free from wrinkling and tearing of the skin, and was excellent in form retention. Further, the air flow rate measured at the flat portion of the molded product was 15 cc / cm ² / sec, and the normal incident sound absorption coefficient was as shown in FIG.

[Example-4]
A resin surface of the resin film with release paper obtained in Example 2, an airlaid nonwoven fabric having a thickness of 10 mm, a basis weight of 400 g / m ² , and a bulk density of 0.04 made of polyester staple containing 20% of a low melting point component at 110 ° C. Are placed in a hot press machine with a width of 1 m and a length of 2 m, and a spacer is inserted so that the distance between the upper and lower hot plates is 8 mm. The resin film was transferred to and bonded to the surface of the nonwoven fabric by hot pressing for a minute, and the release paper was peeled off to obtain a sound absorbing material. The sound absorbing material had a thickness of 9 mm and an air permeability of 18 cc / cm ² / sec. The normal incident sound absorption coefficient was as shown in FIG.
Further, the obtained sound absorbing material was molded in the same manner as in Example 3 to obtain a molded product with no skin wrinkle tearing and excellent shape retention. The air permeability of this molded product was 13 cc / cm ² / sec, and the normal incident sound absorption coefficient was as shown in FIG.

[Comparative Example-1]
According to the roll coating method described in JP-A-2008-146001, the same as in Example 4, a polyester staple containing 20% of a low melting point component at 110 ° C. having a thickness of 10 mm, a basis weight of 400 g / m ² , a bulk density of 0. The polyester copolymer resin used in Example 1 was applied to the airlaid nonwoven fabric of 04 at a roll temperature of 210 ° C. at a resin coating amount of 60 g / m ² , and immediately thereafter the surface temperature of the resin surface was 160 ° C. with a far infrared heater. Thus, the sound absorbing material was obtained by processing at a speed of 5 m / min while pressing with a roll. This sound absorbing material had a thickness of 8 mm and an air permeability of 65 cc / cm ² / sec. The normal incident sound absorption coefficient was as shown in FIG.

[Comparative Example-2]
According to the roll coating method described in Japanese Patent Application Laid-Open No. 2008-146001, the polyester copolymer resin used in Example 1 is applied to the release surface of the release paper used in Example 1 at a roll temperature of 210 ° C. applied in m ² was obtained sound absorbing material component. The air permeability of the resin film of the sound absorbing material constituting member was 150 cc / cm ² / sec. This sound-absorbing material constituting member was hot-pressed on the same airlaid nonwoven fabric as in Example 4 under the same conditions as in Example 4, and the release paper was peeled off to obtain a sound-absorbing material. This sound absorbing material had a thickness of 9 mm and an air permeability of 85 cc / cm ² / sec. The normal incident sound absorption coefficient was as shown in FIG.
When the obtained sound absorbing material was molded in the same manner as in Example 3, there was no skin wrinkle, but a portion where the skin was partially broken was observed. The air permeability after molding was 82 cc / cm ² / sec, and the normal incident sound absorption coefficient of this molded product was as shown in FIG.

[Comparative Example-3]
An EVA resin powder having a melting point of 110 ° C. is sprinkled over 25 g / m ^{2 on} one side of a nonwoven fabric having a basis weight of 600 g / m ² , a thickness of 15 mm, and a bulk density of 0.04 as in Example 3, and an air flow rate of 18 cc / cm ² / sec A polyester paper having a thickness of 80 μm and a basis weight of 40 g / m ² was placed thereon, and a sound absorbing material in which the paper and the nonwoven fabric were integrated while being suppressed with a heat roll at 150 ° C. was obtained. The sound absorbing material had a thickness of 14.5 mm and an air permeability of 17 cc / cm ² / sec.
The sound absorption coefficient of the sound absorbing material was as shown in FIG. In the same manner as in Example 3, after heating for 3 minutes at an upper and lower hot plate temperature of 200 ° C., it was placed in a mold consisting of a concave surface and a convex surface, and cold pressed with a press for 3 minutes to obtain a molded product. This molded product had good shape retention, but the skin could not shrink, so many wrinkles were generated and the appearance was poor.

  The sound-absorbing material of the present invention can be used in various applications where sound-absorbing properties are required by processing it into an appropriate size, shape, etc. by applying a known method according to the purpose and application. Insulators for automobiles, trains, aircraft interior dashboards, automobiles, trains, aircraft and other dashboards; electrical appliances such as refrigerators, vacuum cleaners and air conditioners; speaker diaphragms; lawn mowers It can be used for various applications such as electric tools such as electric drills and electric excavators, and wall materials and materials for civil engineering and construction.

It is a side view which shows roughly the manufacturing method of the sound-absorbing material component of the present invention. It is a figure which shows the normal incidence sound absorption coefficient of the sound-absorbing-material structural member of this invention, a sound-absorbing material, a molded article, and a comparative product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin coating line 2 Release paper 3 Molten resin 4 Pressurized air 5 Heater R Molten resin flow A Pressurized heating air flow

Claims (12)

  A sound-absorbing material constituting member characterized in that a breathable resin film made of a synthetic resin having a melting point of 80 to 200 ° C., which is spray-coated by a hot melt spray method, is provided on a release-treated surface of a release paper .   The sound-absorbing material constituting member according to claim 1, wherein the breathable resin film made of the synthetic resin is subjected to crushing after the molten resin is spray-coated by a hot melt spray method.   The sound absorbing material constituting member according to claim 1 or 2, wherein the synthetic resin has a melt viscosity at 200 ° C of 40000 mPa · s or less. The sound-absorbing material according to any one of claims 1 to 3, wherein the air-permeable resin film made of the synthetic resin has a thickness of 10 to 100 µm and an air flow rate of 0.01 to 50 cc / cm ² / sec. Constituent member.   The sound absorbing material constituting member according to any one of claims 1 to 4, wherein the synthetic resin is a polyethylene resin, a polypropylene resin, or a polyester copolymer resin. It is provided in the sound-absorbing material constituting member according to any one of claims 1 to 5 on the surface of the nonwoven fabric having a bulk density of 0.01 to 0.2 g / cm ³ and a basis weight of 100 to 2500 g / m ^2. A moldable sound-absorbing material, wherein a resin film is transferred and bonded.   The formable sound-absorbing material according to claim 6, wherein the nonwoven fabric is a needle punched nonwoven fabric, an airlaid nonwoven fabric or a meltblown nonwoven fabric.   The formable sound absorbing material according to claim 6 or 7, wherein the fibers constituting the nonwoven fabric are one or more fibers selected from thermoplastic fibers and heat resistant fibers having a melting temperature or a thermal decomposition temperature of 370 ° C or higher. Wood.   The formable sound-absorbing material according to any one of claims 6 to 8, wherein the fiber constituting the nonwoven fabric and the resin constituting the resin film to be transferred are made of the same material. The moldable sound-absorbing material according to any one of claims 6 to 9, wherein the air flow rate measured based on JIS L 1096 is 0.01 to 50 cc / cm ² / sec.   The formable sound-absorbing material according to any one of claims 6 to 10, which is used as a vehicle interior material. The sound absorbing material constituting member according to any one of claims 1 to 5 is applied to the surface of the nonwoven fabric having a bulk density of 0.01 to 0.2 g / cm ³ and a basis weight of 100 to 2500 g / m ^2. After superimposing the resin film provided on the component and the non-woven fabric in contact with each other, they are thermocompression-bonded to transfer and adhere the resin film to the surface of the non-woven fabric. Method.