JP7198709B2 - METHOD FOR MANUFACTURING MULTILAYER STRUCTURE SOUND INSULATION MATERIAL FOR VEHICLE, AND THERMOPLASTIC RESIN FILM USED FOR MULTILAYER STRUCTURE SOUND INSULATION MATERIAL FOR VEHICLE - Google Patents

Description

The present invention is a multi-layer soundproof material (dash silencer, To provide a multi-layer soundproof material for a vehicle, which is a floor silencer, etc., excellent in soundproof performance such as sound absorption performance and sound insulation performance, lightweight, excellent in moldability and productivity, and capable of reducing manufacturing cost.

Conventionally, in order to suppress the propagation of noise outside the vehicle interior into the vehicle interior, a soundproofing material is attached to each side of the vehicle interior, such as the dash panel, floor panel, ceiling, or door panel.

As such a soundproof material, as shown in FIG. 1, Patent Document 1 discloses a soundproof material (dash silencer) 10 disposed facing a dash panel separating an engine room and a passenger compartment of a vehicle. ing. That is, the soundproof material 10 has a structure in which a dash panel side sound absorbing layer 11, a sound insulating layer 13 made of a thermoplastic resin film, and a skin sound absorbing layer 12 are laminated in this order. It has a decorative layer 121 . The thermoplastic resin film 13 is composed of three layers, for example, an outer layer and an inner layer made of polyethylene resin and an intermediate layer made of a synthetic resin having a melting point higher than that of the outer layer and the inner layer.

Furthermore, in Patent Document 1, as a manufacturing method of the soundproof material 10 that is excellent in productivity and effective in cost reduction, the thermoplastic resin film 13 is arranged on the molded body of the dash panel side sound absorbing layer 11, and the It is disclosed that an air-permeable skin sound absorbing layer 12 is placed on the side of the film facing the dash panel side sound absorbing layer 11, and the layers are bonded to each other by pressing using a mold to form a laminated structure.

In Patent Document 2, in order to efficiently improve the intelligibility of conversation in the vehicle interior, a multi-layer structure soundproofing material for a vehicle is used for the body of a vehicle for the purpose of selectively reducing the noise level of a specific frequency band. A first sound absorbing layer, a first adhesive layer, a non-air-permeable sound insulating layer (thermoplastic resin film), a second adhesive layer, and a second sound absorbing layer are applied in this order from the outside of the passenger compartment to the interior surface of a dash panel. A multi-layered vehicle acoustic insulation arrangement is disclosed. This multi-layer structure soundproof material for vehicles has excellent performance that the balance between sound insulation and sound absorption can be adjusted by changing the adhesion area ratio of the second sound absorption layer and the non-air-permeable sound insulation layer. When it is desired to effectively improve the sound insulation, the area is adhered to 75 to 100%, and when it is desired to effectively improve the sound absorption, the area is adhered to 1 to 25%. As the adhesion method, the second adhesive layer selected from resins such as EVA, urethane, chloroprene latex, styrene-butadiene polymer (SBR), acrylic, olefin, etc. is equivalent to 1 to 50 dots / cm ² Alternatively, a second adhesive layer may be formed in the form of threads to join the second sound absorbing layer and the non-breathable sound insulating layer.

However, in the case of manufacturing a multi-layer soundproof material by partially adhering the interface between the sound absorbing layer and the film constituting the air-impermeable sound-insulating layer, the air-impermeable sound-insulating layer must be formed in advance. Both sides of the film to be bonded had to be coated with adhesive that was patterned all over and/or in dots or lines. In addition, in such a configuration and manufacturing method, the technical difficulty of coating the adhesive on both sides of the film and the difficulty of handling the film coated with the adhesive on both sides lead to an increase in the manufacturing cost. It was.

For this reason, a multi-layer soundproof material for vehicles in which the interface between the sound absorbing layer and the film constituting the non-air-permeable sound insulating layer is partially adhered is press-molded as disclosed in Patent Document 1. has been desired to develop a method that can be manufactured more easily and at a lower cost.

Japanese Unexamined Patent Application Publication No. 2004-90532 Japanese Patent Application Laid-Open No. 2005-227747

The present invention partially divides the interface between the sound absorbing layer and the sound insulating layer (non-breathable film), which can selectively reduce the noise level of specific frequency bands to efficiently improve speech intelligibility in the vehicle interior. To provide a method for manufacturing an adhered multi-layer soundproofing material for vehicles by press molding with high productivity at a low cost, and a thermoplastic resin film used for the method.

That is, according to the present invention, in order to solve the above problems, a passenger compartment-side sound absorbing member, a thermoplastic resin film, and a passenger compartment-side sound absorbing member are prepared, and at least one surface of the thermoplastic resin film is heat-fused. The thermoplastic resin film is partially coated with ink that inhibits adhesion, and the interior-side sound absorbing member is laminated on one surface of the thermoplastic resin film, and the exterior-side sound absorbing member is laminated on the other surface to form a laminate, There is provided a method for manufacturing a multi-layer soundproof material for a vehicle, comprising heating the laminate so as to melt at least a portion of the thermoplastic resin film, followed by press working.

In addition, one surface of the thermoplastic resin film is partially coated with an ink that inhibits heat fusion, and the interior-side sound absorbing member is provided on the surface partially coated with the ink that inhibits heat fusion. and a vehicle-outdoor-side sound absorbing member laminated on the other surface.

Further, the thermoplastic resin film is a multilayer film in which a heat-sealing layer made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin of the sound insulating layer is laminated on both surfaces of a sound insulating layer made of a thermoplastic resin. There is provided a method for manufacturing the multi-layer structure soundproofing material for vehicles.

Further, there is provided a thermoplastic resin film for use as a multi-layer structure soundproofing material for vehicles, characterized in that at least one surface is partially coated with an ink that inhibits thermal adhesion.

Further, the heat-sealing layer made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin of the sound insulating layer is laminated on both surfaces of the sound insulating layer made of a thermoplastic resin. A plastic resin film is provided.

The method for producing a multi-layer soundproofing material for vehicles and the thermoplastic resin film used in the multi-layered soundproofing material for vehicles according to the present invention select a noise level in a specific frequency band in order to efficiently improve the intelligibility of conversation in the vehicle interior. It is possible to produce a multi-layered soundproofing material with high productivity and low cost by press molding, in which the interface between the sound absorbing member and the soundproofing layer (impermeable soundproofing film) is partially adhered. That is, the thermoplastic resin film used in the method for producing a multi-layered soundproofing material for vehicles and the multi-layered soundproofing material for vehicles of the present invention does not use an adhesive for adhering the film constituting the sound insulation layer and the sound absorbing material. In addition, it is not necessary to apply an adhesive patterned in the form of dots or lines to both surfaces of the non-air-permeable film that constitutes the sound insulation layer in advance. For this reason, it is difficult to apply adhesive to both sides of the air-impermeable film that constitutes the sound insulation layer, and it is difficult to handle the adhesive-coated film on both sides, resulting in an increase in manufacturing costs. It has the advantage of not inviting.

FIG. 1 is a schematic diagram showing a conventional vehicle multi-layer structure soundproof material (dash silencer) and an example of its arrangement. FIG. 2 shows a heat-sealing layer made of a thermoplastic resin having a melting point lower than the melting point of the sound insulation layer, which is laminated on both surfaces of a sound insulation layer made of a thermoplastic resin according to an embodiment of the present invention. FIG. 2A is a cross-sectional view and a plan view of a multilayer thermoplastic resin film partially coated with an ink that inhibits heat-sealing on the surface. FIG. 3 shows a heat-sealing layer made of a thermoplastic resin having a melting point lower than that of the sound insulation layer, and a heat-sealing layer made of a thermoplastic resin having a melting point lower than that of the sound insulation layer. FIG. 2A is a cross-sectional view and a plan view of a multilayer thermoplastic resin film partially coated with an ink that inhibits heat-sealing on the surface. FIG. 4 shows a heat-sealing layer made of a thermoplastic resin having a melting point lower than that of the sound insulation layer, which is laminated on both surfaces of a sound insulation layer made of a thermoplastic resin according to an embodiment of the present invention. FIG. 2A is a cross-sectional view and a plan view of a multilayer thermoplastic resin film partially coated with an ink that inhibits heat-sealing on the surface. FIG. 5 is a diagram showing the outline of the manufacturing method of the present invention.

Hereinafter, an embodiment of a method for manufacturing a multi-layer soundproof material for vehicles according to the present invention will be described. It should be noted that the present invention is not limited to the following forms, and can take various forms within the range where similar effects can be achieved.

The sound absorbing member on the exterior side and the sound absorbing member on the interior side of the vehicle according to the present invention are made of, for example, a fiber assembly such as felt or glass wool, or a porous synthetic resin such as urethane foam. The exterior sound absorbing member is arranged on the exterior side of the vehicle, such as the dash panel side or the floor panel side, and has a density of, for example, 0.01 to 0.1 g/cm ³ , particularly 0.02 to 0.07 g/cm ³ , or more. It is preferably 0.02 to 0.05 g/cm ³ . Further, the passenger compartment-side sound absorbing member is arranged inside the passenger compartment, and has a density of 0.1 to 0.8 g/cm ³ , particularly 0.2 to 0.5 g/cm ³ , more preferably 0.25 to 0.4 g/cm 3 . cm ³ is preferred. The thickness of the exterior sound absorbing member is preferably 1 to 60 mm, more preferably 2 to 50 mm, more preferably 3 to 40 mm. Furthermore, it is preferable that the thickness of the sound absorbing member on the passenger compartment side is 1 to 15 mm, particularly 2 to 10 mm, further preferably 3 to 7 mm. From the viewpoint of design, a decorative layer made of non-woven fabric or the like may be laminated on the passenger compartment side of the passenger compartment side sound absorbing member.

The thermoplastic resin film in the present invention may be a single layer or multiple layers. When the thermoplastic resin film is a single layer, the thermoplastic resin to be used is preferably a polyolefin such as polyethylene or polypropylene having a melting point of 90 to 140° C. or a modification thereof. The single-layer thermoplastic resin film should preferably have a thickness of 20 to 200 μm because it is necessary to maintain a constant thickness even after heating and pressing.

Further, the thermoplastic resin film is a multilayer film in which heat-sealable layers made of a thermoplastic resin having a lower melting point than the thermoplastic resin of the sound insulation layer are laminated on both surfaces of a sound insulation layer made of a thermoplastic resin. In this case, the thermoplastic resin constituting the sound insulation layer can be appropriately selected from thermoplastic resins such as polyester, polyamide, and ethylene-vinyl alcohol copolymer. The thickness of the sound insulation layer is preferably 7 to 50 μm. The thermoplastic resin constituting the heat-sealing layer is not particularly limited as long as it has a lower melting point than the thermoplastic resin constituting the sound insulation layer. is preferably modified. The thickness of the thermal adhesive layer is preferably 7 to 50 μm. An adhesive layer made of an adhesive resin such as modified polyolefin may be provided between the sound insulation layer and the heat-sealable layer.

The method for producing the thermoplastic resin film in the present invention is not particularly limited, but an inflation film-forming method, a flat die-cast film-forming method, or the like can be appropriately selected. Moreover, in the case of a multilayer film, it may be manufactured by adhering separately formed films with an adhesive or a molten resin, or by heat-sealing them.

In the present invention, the ink that is partially coated on the surface of the thermoplastic resin film and inhibits thermal adhesion is used as a part of the sound insulating film and the passenger compartment inner sound absorbing member and/or the passenger outer sound absorbing member during press working. The ink is not particularly limited as long as it can inhibit the thermal fusion of the interface between the two. Examples thereof include inks in which the melting point of the resin component of the binder is higher than the melting point of the thermoplastic resin forming the heat-sealing layer, heat- or UV-curing inks, and two-component curing inks. The pattern coating of the ink can be carried out using commonly used printing methods such as gravure printing, flexographic printing, and inkjet printing.

2 to 4 show examples of a multilayer thermoplastic resin film 20 pattern-coated with a heat-seal inhibiting layer on one surface. Needless to say, the heat-sealing inhibition layer may be pattern-coated on both surfaces of the thermoplastic resin film. The coating pattern and the ratio of the coating area to the entire interface are determined by the types of the interior and exterior sound absorbing members, the sound absorption performance, thickness, etc., and the type of thermoplastic resin that constitutes the sound insulation layer. , sound insulation performance, thickness, etc. are taken into account to achieve the sound insulation performance required for multi-layer structure sound insulation materials for vehicles.

FIG. 5 shows a schematic diagram of the manufacturing method of the present invention. First, the passenger compartment side sound absorbing member 31, the multilayer thermoplastic resin film 33 pattern-coated with a heat-sealing inhibiting layer on one surface, and the passenger compartment side sound absorbing member 32 are laminated in this order to form a laminate 34. Next, the laminated body 34 is press-worked by heating, pressurizing, and cooling to form a vehicle exterior sound absorbing member 31, a multilayer thermoplastic resin film 33 pattern-coated with a heat-sealing inhibition layer on one surface, and a vehicle. The interior-side sound absorbing member 32 is adhered to each other by heat-sealing with the heat-sealing layer on the surface of the multilayer thermoplastic resin film, except for the portion coated with the heat-sealing inhibition layer, to form a multi-layer soundproofing material for vehicles. get

In the pressing process, the vehicle interior side sound absorbing member 31, the multilayer thermoplastic resin film 33 pattern-coated with a heat-sealing inhibiting layer on one surface, and the vehicle interior side sound absorbing member 32 are placed in the above-described arrangement relationship. As long as they are arranged, the arrangement order, method, etc. are not particularly limited. Moreover, this pressing process may also serve as a molding process using a mold. In the case of press working using a mold, for example, first, the sound absorbing member on the interior side and the thermoplastic resin film pattern-coated with a heat-sealing inhibition layer on the surface are sucked and held by the suction function of the mold. Then, the passenger compartment-side sound absorbing member is moved into the molding die and placed therein, and then press working can be performed. As a result, it is possible to efficiently arrange the passenger compartment-side sound absorbing member, the thermoplastic resin film pattern-coated with the heat-sealing inhibiting layer on the surface, and the passenger compartment-side sound absorbing member in the mold.

In order to efficiently adhere the thermoplastic resin film having a heat-sealing inhibition layer pattern-coated on the surface and the vehicle exterior sound absorbing member and the vehicle interior sound absorbing member, the temperature at the time of press working is 90 to 200 ° C. , particularly preferably 110 to 180°C, more preferably 120 to 160°C. Also, the press pressure, press time, cooling temperature, cooling time, etc. during press working can be appropriately designed.

10 soundproof material (dash silencer)
11 Dash panel side sound absorbing layer 12 Skin sound absorbing layer 13 Sound insulating layer 121 made of thermoplastic resin film Decorative layer 20 Multilayer thermoplastic resin film 21 pattern-coated with a heat-sealing inhibition layer on one surface Heat-sealing layer 22 Sound insulation layer 23 made of thermoplastic resin Heat fusion inhibition layer 31 Exterior-side sound absorbing member 32 Interior-side sound absorption member 33 Multilayer thermoplastic resin film 34 pattern-coated with heat fusion inhibition layer on one surface Laminate

Claims (5)

A sound absorbing member on the interior side, a thermoplastic resin film, and a sound absorbing member on the exterior side are prepared, and at least one surface of the thermoplastic resin film is partially coated with an ink that inhibits heat sealing, and the heat is applied. A laminate is formed by laminating the passenger compartment-side sound absorbing member on one surface of a plastic resin film and the passenger compartment-side sound absorbing member on the other surface, and at least part of the thermoplastic resin film is applied to the laminate. A method for manufacturing a multi-layer soundproofing material for vehicles, characterized in that the material is heated so as to be melted and then pressed. One surface of the thermoplastic resin film is partially coated with an ink that inhibits heat fusion, and the surface partially coated with the ink that inhibits heat fusion is provided with a passenger compartment inner sound absorbing member, 2. The method for producing a multi-layer soundproof material for vehicles according to claim 1, wherein the vehicle exterior sound absorbing member is laminated on the other surface. The thermoplastic resin film is a multi-layer film in which heat-sealable layers made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin of the sound insulation layer are laminated on both surfaces of a sound insulation layer made of a thermoplastic resin. 3. The method for producing a multi-layer structure soundproofing material for vehicles according to claim 1 or 2, characterized in that: 1. A thermoplastic resin film used as a multi-layer structure soundproofing material for a vehicle, wherein at least one surface is partially coated with an ink that inhibits thermal adhesion. 5. The method according to claim 4, characterized in that thermal adhesive layers made of a thermoplastic resin having a melting point lower than that of the thermoplastic resin of the sound insulating layer are laminated on both surfaces of the sound insulating layer made of the thermoplastic resin. thermoplastic resin film.

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