Soundproof laminate, soundproof film used in its manufacture, and soundproof film sheet

Abstract

To provide a sound insulation film which is thin and does not cause variation in sound insulation depending on the location where the sound insulation is measured, and which always exhibits desired sound insulation, a sound insulation laminate using the same, and a sound insulation film sheet suitable for manufacturing the sound insulation laminate. [Solution] The soundproof laminate 11 includes a sound-insulating film 2 characterized by containing at least resin, metal particles, and cellulose nanofibers, and a sound-absorbing body 4, and the sound-insulating film 2 is formed on both sides of the sound-absorbing body 4.

Description

[Technical field]

[0001] The present invention relates to a sound insulation film, a sound insulation sheet, and a soundproof laminate. [Background technology]

[0002] Conventionally, soundproofing materials using sound-insulating materials with sound-proofing properties (function to prevent sound transmission) and sound-absorbing materials with sound-absorbing properties (function to convert the kinetic energy of sound into thermal energy and attenuate it) have been developed as soundproofing materials with sound-insulating properties (function to reflect sound and not transmit it). For example, sound-insulating materials include sound-insulating sheets using heavy materials with high specific gravity such as steel plates, and sound-absorbing materials include porous sound-absorbing materials with cushioning properties that are foamed by adding a foaming agent to a resin. Alternatively, soundproofing materials that combine these sound-insulating materials and sound-absorbing materials are known. These soundproofing materials are used for the walls of buildings, moving objects such as automobiles, electronic devices, etc.

[0003] However, when trying to obtain sufficient sound insulation using conventional sound-insulating materials, in accordance with the mass law, sufficient sound insulation may not be obtained unless heavy materials are used. In addition, sufficient sound insulation may not be obtained only with conventional porous sound-absorbing materials. In particular, in recent years, with the spread of electric vehicles, there is a demand for reducing the weight of vehicles to improve energy efficiency. With the weight reduction of automobiles, there is a demand to replace steel plates having sound insulation properties with lighter sound-insulating materials from the viewpoint of weight. Furthermore, from the viewpoint of design freedom, it is considered preferable that the sound-insulating material has flexibility to follow a three-dimensional shape.

[0004] Patent Document 1 discloses a soundproof sheet formed by integrally bonding a first sheet member made of one of paper, cloth, nonwoven fabric, metal foil, and resin sheet, which are used for sound insulation panels, vibration damping materials, etc., and a second sheet member (soundproofing film) formed into a sheet by mixing metal powder with an organic binder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 7-266488 Summary of the Invention [Problem to be solved by the invention]

[0006] The soundproof sheet described in Patent Document 1 was lighter than a steel plate and exhibited a certain degree of soundproofing, but when the second sheet member (soundproofing film) was made thinner to reduce its weight, it was difficult to achieve a uniform thickness using the conventional method of forming a sheet by rolling or the like. In addition, when only metal particles were mixed with an organic binder and rolled, the metal particles were sometimes localized. Another method for thinning the soundproofing film is to add a dilution solvent and form the soundproofing film by a coating method. However, even with the coating method, there were drawbacks such as the metal particles being precipitated in the resin and not being uniformly dispersed in the soundproofing film, the fact that the film could not be formed with a uniform thickness, or the fact that the soundproofing film was formed in a state in which no metal particles were present. Therefore, the obtained soundproofing film had a drawback that the soundproofing property varied depending on the location where the soundproofing property was measured, and did not always exhibit the desired soundproofing property. The present invention aims to provide a soundproofing film which is a thin film and does not cause variation in soundproofing properties depending on the location where the soundproofing properties are measured, and which always exhibits the desired soundproofing properties, a soundproofing laminate using the same, and a soundproofing film sheet suitable for manufacturing the soundproofing laminate. [Means for solving the problem]

[0007] The present invention comprises the following aspects. (Section 1) A sound insulation film characterized by containing at least a resin, metal particles, and cellulose nanofibers.

[0008] By using the sound insulation film described in item 1, the metal particles are uniformly and stably dispersed in the sound insulation film by containing cellulose nanofibers in the sound insulation film, and sound insulation can be imparted to the sound insulation film without variation, and continuous processing by the roll-to-roll method is possible. Therefore, the sound insulation film of the present invention is excellent in productivity. By using the sound insulation film of the present invention, the sound insulation property of the sound insulation film can be easily imparted to the soundproof laminate of the present invention described later, and in combination with the sound absorption property of the sound absorber, the soundproof property of the soundproof laminate can be further improved.

[0009] (Section 2) A soundproof laminate having at least one or more layers of sound absorbing material and two or more layers of sound insulation film formed thereon, the soundproof laminate having at least a structure in which a sound insulation film is formed on both sides of a sound absorbing body including one or more layers of sound absorbing material, and the sound insulation film is the sound insulation film according to item 1.

[0010] By using the soundproof laminate described in item 2, it is possible to impart excellent sound insulation properties to the sound absorbing material, and it is possible to improve the soundproof properties of the soundproof laminate.

[0011] (Section 3) Item 1. A sound insulation film sheet having at least the sound insulation film according to item 1 formed on a substrate.

[0012] By using the sound insulation film sheet according to item 3, the sound insulation film of the present invention can be easily formed on the sound absorbing body. Therefore, by using the sound insulation film sheet of the present invention, the soundproof laminate of the present invention can be easily obtained. Effect of the Invention

[0013] The sound insulation film of the present invention is characterized by containing at least a resin, metal particles, and cellulose nanofibers, so that when the film is applied to a substrate described later, the metal particles do not settle in the resin, and the metal particles are uniformly dispersed in the sound insulation film, and the film can be formed with a uniform thickness. Therefore, the obtained sound insulation film is a thin film, and the sound insulation property does not vary depending on the measurement point, so that the sound insulation film always exhibits the desired sound insulation property, and the sound insulation laminate using the sound insulation film of the present invention also always exhibits the desired sound insulation property. And, by using the sound insulation film sheet of the present invention, the sound insulation laminate of the present invention can be easily obtained. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a cross-sectional structure of one embodiment of a sound insulation film sheet of the present invention in which a sound insulation film is formed on a substrate. [Diagram 2] FIG. 1 is a schematic diagram of the cross-sectional structure of one embodiment of the soundproof laminate of the present invention in which sound-insulating film sheets (substrate / sound-insulating film) are formed on two opposing surfaces (both surfaces) of a sound absorber (one layer of sound-absorbing material). [Diagram 3] FIG. 1 is a schematic diagram of a cross-sectional structure of one embodiment of a soundproof laminate of the present invention in which sound insulation films are formed on two opposing surfaces (both surfaces) of a sound absorber (one layer of sound absorbing material). [Figure 4] FIG. 1 is a schematic diagram of a cross-sectional structure of one embodiment of a soundproof laminate of the present invention in which a plurality of sound absorbers (each of which is a layer of sound-absorbing material) and a plurality of sound-insulating films are formed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Soundproof laminate) The soundproof laminate of the present invention has a soundproofing film, which will be described later, formed on at least two opposing surfaces (both surfaces) of a sound absorbing body, which will be described later. By forming a laminate having such a configuration, sound can be efficiently absorbed within the sound absorbing body sandwiched between the two soundproofing films, and an excellent soundproofing effect can be obtained. In the following, the adhesive layer, which will be described later, may be omitted, and the soundproof laminate may be described as "soundproofing film / sound absorbing body / soundproofing film" in a schematic manner.

[0016] The method for bonding the sound-insulating film of the present invention to the sound-absorbing body is not particularly limited as long as it is a method that can bond the sound-insulating film of the present invention to the sound-absorbing body, but a method in which the sound-insulating film of the present invention and the sound-absorbing body are bonded via an adhesive layer is preferred because it can easily bond them. Furthermore, the sound insulating film and the sound absorbing body may be bonded to each other by a method such as thermocompression bonding without using an adhesive layer.

[0017] The soundproof laminate of the present invention has at least a first soundproofing film formed on a first surface of a sound absorber, and a second soundproofing film formed on a second surface of the sound absorber opposite to the first surface. That is, the soundproofing films are formed on both surfaces of the sound absorber. The soundproof laminate of the present invention can have, for example, the following configurations. · Sound insulation film / sound absorber (sound absorbing material) / sound insulation film ·Base material / soundproofing film / sound-absorbing body (sound-absorbing material) / soundproofing film / base material · Sound insulation film / adhesive layer / sound absorbing body (sound absorbing material) / adhesive layer / sound insulation film · Sound insulation film / sound absorbing body (sound absorbing material / sound absorbing material) / sound insulation film · Sound insulation film / sound absorbing body (sound absorbing material / adhesive layer / sound absorbing material) / sound insulation film · Sound insulation film / sound absorbing body (sound absorbing material) / sound insulation film / sound absorbing material (sound absorbing material) · Sound insulation film / sound absorber (sound absorbing material) / sound insulation film / sound absorbing material (sound absorbing material) / sound insulation film Among the above exemplary configurations, in order for the soundproof laminate of the present invention to have excellent soundproofing properties, a configuration in which the soundproofing film of the present invention is formed on at least the first surface of the sound absorbing body and the second surface opposite to the first surface, i.e., on both surfaces, is preferred. Each soundproofing film, sound absorbing material, and sound absorbing body may be made of the same material or different materials, and in addition to these, the soundproofing properties of a specific frequency (for example, sounds of 1000 Hz or less) can be improved by changing the composition of the soundproofing film, the thickness of the soundproofing film, the number of sound absorbing materials, the type of sound absorbing material, or a combination thereof.

[0018] (Adhesive layer) The adhesive layer is a layer formed between the sound insulation film of the present invention and the sound absorbing material in order to bond the sound insulation film of the present invention to the sound absorbing material. The adhesive layer may be an adhesive layer made of a conventionally known resin. Examples of the resin used in the adhesive layer include polyamide resins (nylon resins), acrylic resins, chlorinated polypropylene resins, vinyl chloride acetate resins, and polyester resins. When the adhesive layer is made of a resin, it may be formed on one or both of the sound insulation film side and the sound absorbing material side. Alternatively, an adhesive core in which the resin has been sprayed onto a nonwoven fabric or the like in advance may be used as the adhesive layer.

[0019] (Functional layer) In addition, the soundproof laminate of the present invention may be formed with one or more layers having any desired function (functional layers), such as a printed layer, a metal vapor deposition layer, a design layer, a protective layer, etc., within the scope of the object of the present invention. The material used for the functional layer, the thickness of the functional layer, and the position where the functional layer is formed may be appropriately selected within a range that meets the object of the present invention.

[0020] (Sound insulation film) The sound insulation film of the present invention is composed of at least a resin, metal particles, and cellulose nanofibers. Furthermore, known additives such as dispersants, viscosity modifiers, stabilizers, dyes, and pigments can be added within a range that does not impair the effects of the present invention. The thickness of the sound insulation film is preferably 5 μm to 100 μm, and more preferably 20 μm to 80 μm. If the thickness of the sound insulation film of the present invention is thinner than 5 μm, there is a risk that sufficient sound insulation cannot be obtained. If the thickness of the sound insulation film of the present invention is thicker than 100 μm, there is a risk that the metal particles are not uniformly dispersed in the sound insulation film of the present invention.

[0021] (resin) The resin used in the sound insulation film of the present invention serves as a binder for holding the metal particles, and various conventionally known resins that can be processed into a thin film can be used. In order to obtain the effects of the present invention, thermoplastic resins such as urethane resins, olefin resins, acrylic resins, and epoxy resins are suitable, and urethane resins are particularly suitable from the viewpoint of flexibility.

[0022] (metal particles) The metal particles used in the sound-insulating film of the present invention may have any shape, such as a spherical shape, a flake shape, or an irregular shape. The particle size of the metal particles may be 1 μm to 50 μm, or may be 2 μm to 40 μm. If the particle size of the metal particles is smaller than 1 μm, the metal particles are expensive, and there is a risk that the cost of producing the sound-insulating film of the present invention is too high. If the particle size of the metal particles is larger than 50 μm, there is a risk that the metal particles are not sufficiently dispersed when producing the sound-insulating film of the present invention. Materials that can be used for the metal particles used in the sound insulation film of the present invention include conventionally known metals such as aluminum, iron, lead, tungsten, copper, silver, silicon, or metal compounds such as silicon oxide, iron oxide, silicon carbide, or mixtures thereof (e.g., stainless steel). In particular, by using a metal with a high density, the sound insulation of the sound insulation film of the present invention can be improved. As the metal particles of the present invention, metal particles made of iron, lead, tungsten, copper, or silver are suitable, and from the viewpoint of cost and ease of handling, metal particles made of iron or tungsten are particularly suitable. The amount of the metal particles is preferably 100 parts by mass to 2000 parts by mass, more preferably 500 parts by mass to 1500 parts by mass, relative to 100 parts by mass of the resin. If the amount is 100 parts by mass or less, the sound insulation at frequencies of 2000 Hz or less may be weakened. If the amount is 2000 parts by mass or more, the flexibility of the film may be impaired, resulting in a brittle film.

[0023] (Cellulose nanofiber) The cellulose nanofibers used in the sound-insulating film of the present invention serve as a dispersant for uniformly dispersing metal particles in the sound-insulating film. By incorporating cellulose nanofibers, metal particles can be uniformly and stably dispersed in the sound-insulating film. Therefore, the obtained sound-insulating film is a thin film, and does not vary in soundproofing depending on the location where it is measured, and always exhibits the desired sound-insulating properties. Furthermore, the sound-insulating film of the present invention can be continuously manufactured by a roll-to-roll method. As the cellulose nanofibers used in the sound-insulating film of the present invention, conventionally known cellulose nanofibers can be used. In particular, from the viewpoint of dispersibility, lignocellulose nanofibers containing lignin are suitable. General cellulose nanofibers having a fiber width of about 3 to 200 nm and a fiber length of about 100 μm or less can be used. The amount of cellulose nanofiber is preferably 10 to 40 parts by mass, more preferably 20 to 30 parts by mass, relative to 100 parts by mass of resin. If it is 10 parts by mass or less, there is a risk that the metal particles will not be sufficiently dispersed depending on the amount of metal particles, particle size, etc. If the amount is more than 40 parts by mass, the flexibility of the film is lost, and the film may become brittle.

[0024] (composition) The composition of the present invention is prepared by adding a conventionally known solvent to at least the resin, metal particles, and cellulose nanofibers to prepare a state suitable for a coating method. The composition is formed into a thin film by a coating method or the like and dried to obtain the sound insulation film of the present invention. As described above, by using the composition in the production of a sound insulation film by a coating method, the metal particles can be uniformly and stably dispersed in the sound insulation film. Therefore, the sound insulation properties of the sound insulation film and soundproof laminate of the present invention can be made uniform, and they can be produced with good productivity.

[0025] (Formation of sound insulation film) In order to form the sound insulation film of the present invention into a thin film, a method (coating method) of coating the above-mentioned composition on a substrate described later can be mentioned. By using the coating method, the sound insulation film of the present invention can be easily formed into a thin film. As the coating method, for example, a conventionally known coating method such as a die coating method, a gravure coating method, or a reverse coating method can be used. In addition, the coating method may be a batch method or a roll-to-roll method, but the roll-to-roll method is particularly preferable because it can continuously produce the sound insulation film and has excellent productivity.

[0026] (Sound absorbing body) The sound absorbing material used in the soundproof laminate of the present invention may be any material that exhibits sound absorbing properties. The sound absorbing material of the present invention includes one or more layers of sound absorbing material, and when the sound absorbing material has two or more layers, different or the same types of sound absorbing materials are laminated, for example, by bonding via an adhesive layer, bonding by thermocompression, or simply overlapping. The sound absorbing material may be, for example, a conventionally known sound absorbing material such as chip cushion, glass wool, rock wool, porous urethane, or polyester fiber. The thickness, material, and shape of the sound absorbing material and sound absorbing material may be appropriately selected depending on the purpose of using the soundproof laminate of the present invention.

[0027] (Sound insulation sheet) The sound insulation film sheet of the present invention is at least a substrate on which the sound insulation film of the present invention is formed, and by laminating the sound insulation film sheet of the present invention on the sound absorbing material, the sound insulation film of the present invention can be easily and productively formed on the sound absorbing material. It is also used to easily obtain the soundproof laminate of the present invention. The sound insulation film sheet of the present invention may contain the above-mentioned functional layer within a range that meets the object of the present invention. By using the sound insulation film sheet of the present invention on which the functional layer is formed, the functional layer can be formed on the sound absorbing material at the same time as the sound insulation film of the present invention, and the soundproof laminate of the present invention having the functional layer can be easily obtained. When the substrate, which will be described later, is a substrate without releasability, the soundproof laminate of the present invention obtained by using the sound insulation film sheet of the present invention has the substrate formed on the sound absorbing body together with the sound insulation film, as shown in Fig. 2. When the substrate, which will be described later, is a substrate with releasability, the soundproof laminate of the present invention obtained by using the sound insulation film sheet of the present invention has only the sound insulation film formed on the sound absorbing body, as shown in Fig. 3, by removing the substrate from the sound insulation film sheet.

[0028] (base material) The substrate used in the sound insulation film sheet of the present invention may be any substrate capable of applying the composition, and may be any conventionally known substrate such as a plastic film, a nonwoven fabric, or paper. However, a plastic film is preferred from the viewpoint of processability. The thickness and material of the substrate may be appropriately selected according to the purpose. As described above, when the substrate is a substrate having releasability, the sound insulation film can be transferred onto the sound absorber by removing the substrate after forming the sound insulation film sheet of the present invention on the sound absorber. At this time, any of the functional layers can be transferred at the same time. By transferring the sound insulation film from the sound insulation film sheet onto the sound absorber, the soundproof laminate of the present invention does not include a substrate and can be made lighter. The substrate having releasability may be a substrate on which a release layer having releasability, such as a silicon-based resin layer, a fluorine-based resin layer, a wax layer, or a melamine-based resin layer, is formed. In this case, the release layer is removed together with the substrate when the sound insulation film of the present invention is transferred onto the sound absorber and formed, and is not formed on the sound absorber. EXAMPLES

[0029] The present invention will be described in detail below with reference to examples, but the technical scope of the present invention is not limited to the following examples.

[0030] (Preparation of composition for obtaining sound insulation film) (Composition A) A polyurethane-based resin was used as the resin, and 100 parts by mass of the resin were mixed with 1,000 parts by mass of iron (Fe) particles having a median diameter of 4 to 8 μm as the metal particles, 30 parts by mass of lignocellulose nanofibers (aspect ratio 525, fiber length 45 μm) as the cellulose nanofibers, a diluting solvent, and a stabilizer to obtain composition A for obtaining the sound-insulating film of the present invention.

[0031] (Composition B~G) Compositions B to G were obtained in the same manner as composition A, except that the aspect ratio, fiber length, and amount of the cellulose nanofibers in composition A, and the material and amount of the metal particles were as shown in Table 1. The tungsten (W) particles used in composition F had a median diameter of 2 to 9 μm. [Table 1]

[0032] (Creating soundproofing membrane sheets) (Examples 1 to 8 and Comparative Example 1) A film in which a release layer made of a melamine-based resin having a thickness of 1 μm was formed on a polyethylene terephthalate film having a thickness of 50 μm and a width of 1100 mm was used as a substrate, and the composition A was continuously applied onto the release layer using a roll-to-roll die coating method, and dried to form a sound insulation film of the present invention having a thickness of 50 μm, thereby obtaining a sound insulation film sheet of the present invention of Example 1. In addition, sound insulation film sheets of the present invention of Examples 2 and 3 were obtained by forming a sound insulation film in the same manner as in Example 1, except that the thickness of the sound insulation film of Example 1 was changed as shown in Table 2. In addition, sound insulation film sheets of Examples 4 to 8 of the present invention and Comparative Example 1 were obtained by forming a sound insulation film in the same manner as in Example 1, except that compositions B to G were used instead of composition A. In the sound insulation film sheet of Comparative Example 1, iron particles were precipitated in the composition, and a sound insulation film made of only a polyurethane-based resin without iron particles was formed in the sound insulation film. In addition, a soundproof laminate was not produced or evaluated using the sound insulation film sheet of Comparative Example 1.

[0033] (Creating soundproof laminates) The sound insulation laminate of the present invention was obtained by the following procedure using the sound insulation film sheet obtained in each of the above examples. First, a double-sided adhesive core (adhesive layer) made of a nylon-based resin was placed between the sound insulation film of the sound insulation film sheet and a chip cushion having a thickness of 10 mm, which is a sound absorbing material, and heat-pressed to form a sound insulation film sheet on the sound absorbing material. Then, the base material of the sound insulation film sheet was removed. Further, a sound insulation film was similarly formed on the other side of the sound absorbing material, and the sound insulation laminate of the present invention of Examples 1 to 8 having a layer structure of sound insulation film / adhesive layer / sound absorbing material / adhesive layer / sound insulation film was obtained. Furthermore, as Example 1-2, a double-sided adhesive core made of a nylon-based resin was placed between the side of one of the sound insulation films of Example 1 on which the sound absorbing material was not formed and the same chip cushion having a thickness of 10 mm, which is a second sound absorbing material, and heat-pressed to form a sound insulation film sheet on the sound absorbing material. Furthermore, a sound-insulating film was formed on the side of the second sound-absorbing material on which the sound-insulating film was not formed, in the same manner as in Example 1, to obtain the soundproof laminate of the present invention of Example 1-2 having a laminate structure of sound-insulating film / sound-absorbing material / sound-insulating film / (second) sound-absorbing material / sound-insulating film.

[0034] (Soundproofing evaluation - sound transmission loss) For the soundproof laminates of Examples 1 to 8 and 1-2 obtained above, normal incidence sound transmission loss was measured by a 16-microphone method using a 102 mm diameter sound tube (WinZac MTX manufactured by Nihon Onkyo Engineering Co., Ltd.) to evaluate soundproofing properties. Furthermore, as Comparative Example 2, a soundproofing material consisting of only a 0.8 mm thick iron plate was used. As Comparative Example 3, a sound absorbing material consisting of only a 10 mm thick chip cushion was used. The soundproofing properties were evaluated as follows. The results of each Example and Comparative Example are shown in Table 2. Note that the measurement results in Table 2 were obtained by using the center in the width direction at the end of processing in the length direction of the sound insulation film sheet for the soundproof laminates of Examples 1 to 8 and 1-2. (Soundproofing evaluation criteria) The transmission loss at frequencies of 500Hz, 1000Hz, 2000Hz and 4000Hz is ○: 10 dB or more at all frequencies. △: 10 dB or more at any frequency. ×: Less than 10 dB at all frequencies.

[0035] (Weight Rating-Area Density) The weights of the samples cut into a circle having a diameter of 102 mm were measured and the surface density (kg / m2) was calculated for the soundproof laminates of Examples 1 to 8 and 1-2, the sound-insulating material of Comparative Example 2, and the sound-absorbing material of Comparative Example 3 obtained above. The results are shown in Table 2.

[0036] (Evaluation of processability) By continuously applying compositions A to F by a roll-to-roll method, sound insulation film sheets of Examples 1 to 8 each having a coating width of 1050 mm (substrate 1100 mm) and a length of 50 m were obtained. The sound insulation film of the present invention was formed in which metal particles (iron particles or tungsten particles) were uniformly dispersed in the sound insulation film in both the length direction and the width direction. As described above, in the sound insulation film sheet of Comparative Example 1 using composition G, the metal particles precipitated in the composition, and a sound insulation film consisting only of polyurethane resin without iron particles was formed in the sound insulation film, and the desired sound insulation properties were clearly not obtained. [Table 2]

[0037] As shown in Table 2, the soundproof laminate of the present invention had a lower surface density, i.e., was lighter, than the soundproof material of Comparative Example 2. Furthermore, a larger transmission loss could be obtained, i.e., it exhibited better soundproofing properties, compared to the sound-absorbing material alone of Comparative Example 3. Compositions A to F for producing the soundproof film of the present invention contained cellulose nanofibers, and thus the metal particles were uniformly and stably dispersed. Therefore, even when continuous coating was performed by the roll-to-roll method, the soundproof film of the present invention in which the metal particles were uniformly dispersed could be continuously obtained. Therefore, the soundproof film sheet of the present invention has excellent productivity. Furthermore, the soundproof laminate of the present invention can be easily obtained by using the soundproof film sheet of the present invention for producing the soundproof laminate of the present invention. [Explanation of symbols]

[0038] 1 Base material 2. Sound insulation membrane 3 Adhesive layer 4 Sound absorbing body (1 layer of sound absorbing material) 10 Soundproofing membrane sheet 11 Soundproof laminate

Claims

[Claim 1] A soundproof laminate comprising at least one layer of a sound absorbing material and two or more layers of a sound insulating film, The sound absorbing body includes one or more layers of sound absorbing material, and the sound insulating film is formed on both sides of the sound absorbing body. The soundproof laminate is characterized in that the soundproof film contains at least a resin, metal particles, and cellulose nanofibers.

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