JP7547168B2 - Laminate - Google Patents

Description

The present invention relates to a laminate with excellent soundproofing properties.

Traditionally, efforts have been made to reduce the weight of automobiles, trains, and other vehicles in order to improve fuel efficiency. As the weight of vehicles has been reduced, it has become easier for noise from the outside to enter the interior space of the vehicle, so efforts have been made to improve soundproofing to make the interior space more comfortable. In buildings such as buildings and houses, too, efforts have been made to improve soundproofing to suppress the intrusion of noise from the outdoors and adjacent rooms and to improve the comfort of the living space.

Furthermore, as mentioned above, as the weight of vehicles is reduced, the vehicle body is more susceptible to vibration, and the vibration noise caused by this vibration can cause noise, so there is a demand for vibration-damping properties for the vehicle body. Also, in the living space of a building, vibrations generated on the upper floors are transmitted to the rooms on the floors below, and the vibration noise caused by these transmitted vibrations causes noise, so there is a demand for suppressing vibrations in the structural members that make up the building, such as flooring and wall materials.

A variety of soundproofing materials are available to meet these demands. Soundproofing materials made from a single material have the problem that, although they provide excellent soundproofing at certain frequencies, they provide insufficient soundproofing at other frequencies.

In order to solve the above problems, a soundproofing material formed using a plurality of materials has been proposed. Specifically, the soundproofing material includes a base layer made of a normal sound absorbing and insulating material, a nonwoven fabric containing 30 to 100% by mass of heat resistant fibers, and a surface layer that is located in the same layer as the nonwoven fabric and contains a binder that is contained in a form that maintains the three-dimensional shape inside the nonwoven fabric, and the surface layer is laminated on one side of the base layer (see, for example, Patent Document 1).
Also, a soundproofing material has been proposed which includes a first sound-absorbing material disposed facing a sound source, a first soft sound-insulating layer laminated on the surface of the first sound-absorbing material opposite the sound source and having an air permeability measured in accordance with JIS L1018 of 10 cc/ ^cm2 ·sec or less, a second sound-absorbing material laminated on the first soft sound-insulating layer, and a second soft sound-insulating layer laminated on the second sound-absorbing material and having an air permeability measured in accordance with JIS L1018 of ¹⁰ cc/cm2·sec or less and a Young's modulus measured in accordance with JIS K7127 that is at least five times greater than that of the first soft sound-insulating layer, within the range in which the second sound-absorbing material can vibrate and deform integrally with the second sound-absorbing material, and in which at least the second soft sound-insulating layer and the second sound-absorbing material are bonded partially or entirely (see, for example, Patent Document 2).

Special table 2017-509004 publication Patent No. 5715163

However, the soundproofing materials proposed in Patent Documents 1 and 2 have insufficient soundproofing properties, and when the thickness is increased in order to improve the soundproofing properties, there arises a problem that the light weight is lost.
Generally, soundproofing performance at low frequencies is inferior to that at high frequencies, and therefore there is a demand for improved soundproofing performance at low frequencies in the fields of vehicles and buildings.

Therefore, the present invention aims to provide a laminate that has excellent soundproofing properties, particularly soundproofing and vibration damping properties at low frequencies, and is also lightweight.

The present invention has been made to solve the above problems, and the gist of the present invention is as follows.
[1] A laminate comprising: a first surface material; a second surface material laminated on one side of the first surface material; and a first connection portion provided between the first surface material and the second surface material and partially connecting the first surface material and the second surface material, wherein the thickness of the first connection portion is 0.05 mm or more, the total area projected in the stacking direction of the first connection portion is 20 to 80% of an overlapping area where the first surface material and the second surface material overlap in the stacking direction, and the first connection portion contains a viscoelastic resin having a loss sine tan δ of 1.0 or more at 10 to 30°C.
[2] The laminate described in [1], wherein the first surface material includes a synthetic resin foam sheet.
[3] The laminate according to [2], wherein the synthetic resin foam sheet has an expansion ratio of 2 to 50 times.
[4] The laminate described in any one of [1] to [3], wherein the first face material and the second face material include at least one selected from the group consisting of a metal sheet, a fiber-reinforced plastic sheet, and a gypsum board.
[5] The laminate described in any one of [1] to [4], wherein the first connection portion includes an adhesive layer or a pressure-sensitive adhesive layer that integrates the first surface material and the second surface material.
[6] A laminate described in any one of [1] to [5], further comprising a third surface material laminated on the other surface of the first surface material, and a second connection portion provided between the first surface material and the third surface material and partially connecting the first surface material and the third surface material, wherein the thickness of the second connection portion is 0.05 mm or more, and the total area projected in the stacking direction of the second connection portion is 20 to 80% of the overlapping area where the first surface material and the third surface material overlap in the stacking direction.
[7] The laminate described in [6], wherein the second connection portion contains a viscoelastic resin having a loss sine tan δ of 1.0 or more at 10 to 30° C.

The present invention provides a laminate that is excellent in soundproofing, particularly in soundproofing and vibration damping at low frequencies, and is also lightweight.

1 is a cross-sectional view showing a laminate according to a first embodiment of the present invention. 1 is a cross-sectional view showing how to use a laminate according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view showing a laminate according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view showing a laminate according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view showing a laminate according to a fourth embodiment of the present invention.

Below, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are represented by the same or similar symbols. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc. differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. In addition, it goes without saying that the drawings include parts with different dimensional relationships and ratios.

First Embodiment
1, a laminate A according to a first embodiment of the present invention comprises a first face material 1, a second face material 2 laminated on one surface 1a of the first face material 1, and a first connection portion 3 provided between the first face material 1 and the second face material 2 and partially connecting the first face material 1 and the second face material 2. In the laminate A according to the first embodiment, the thickness of the first connection portion 3 is 0.05 mm or more, the total area of the first connection portion 3 projected in the stacking direction is 20 to 80% of the overlapping area where the first face material 1 and the second face material 2 overlap in the stacking direction, and the first connection portion 3 contains a viscoelastic resin having a loss sine tan δ of 1.0 or more at 10 to 30°C.

<First surface material>
The first face material 1 constitutes the main body that is the base of the laminate A. The first face material 1 exerts a soundproofing effect that prevents outside sounds from entering the vehicle or building in which the laminate A is arranged, and prevents sounds inside the vehicle or building from leaking out. In the present invention, "soundproofing" refers to preventing the intrusion of sound waves propagating through the air, and includes sound absorption that prevents the reflection and transmission of noise by absorbing sound, and sound insulation that prevents the transmission of noise by blocking sound. In the present invention, "vibration control" refers to converting vibration energy entering from the outside into thermal energy and absorbing or attenuating it.

The first face material 1 is not particularly limited, and examples thereof include a synthetic resin foam sheet and a rubber sheet. Since the first face material 1 has excellent sound insulation and vibration damping properties and also has heat insulation properties, it is preferable to include a synthetic resin foam sheet. From the viewpoint of improving sound insulation and vibration damping performance, it is preferable that the synthetic resin foam sheet has a bending modulus (measured according to JIS 7171) in the range of 1 to 100 MPa. Since the first face material 1 is composed of an apparent restraint type vibration damping material with the first connection part 3 and the second face material 2, it is necessary to increase the loss sine value of the first connection part 3 and to increase the bending modulus of the first face material 1 and the second face material 2 according to the principle of the restraint type vibration damping material. On the other hand, if the bending modulus of the first face material 1 is too high, the resonance frequency shifts higher and the sound insulation and vibration damping performance at low frequencies decreases, so it is desirable that the bending modulus of the synthetic resin foam sheet is within the above range.

The resin constituting the synthetic resin foam sheet is not particularly limited, and examples thereof include polyolefin resins such as polyethylene resins and polypropylene resins, polyester resins, polyurethane resins, etc., with polyolefin resins being preferred, and polypropylene resins being more preferred. The resins may be used alone or in combination of two or more.
The polyethylene resin is not particularly limited, and examples thereof include low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene.
The polypropylene resin is not particularly limited, and examples thereof include homopropylene and copolymers of propylene and other olefins. The copolymers of propylene and other olefins may be any of block copolymers, random copolymers, and random block copolymers. Examples of the olefins copolymerized with propylene include α-olefins such as ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene, and 1-decene.
The polyester resin is not particularly limited, but examples thereof include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).
Examples of polyurethane resins include polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins.

The synthetic resin foam sheet may be either a closed-cell foam sheet or an open-cell foam sheet, with the closed-cell foam sheet being preferred.
The expansion ratio of the synthetic resin foam sheet is preferably 2 to 50, more preferably 3 to 50, and even more preferably 5 to 30. When the expansion ratio of the synthetic resin foam sheet is within the above range, the synthetic resin foam is appropriately expanded, resulting in good flexibility and good soundproofing and vibration damping properties.
In the present invention, the expansion ratio refers to a value obtained by dividing the density of the synthetic resin as a raw material by the density of the synthetic resin foam sheet.

The rubber constituting the rubber sheet is not particularly limited, and examples include styrene-butadiene rubber, butadiene rubber, chloroprene rubber, isoprene rubber, ethylene-propylene rubber, acrylonitrile-butadiene rubber, acrylic rubber, urethane rubber, and thermoplastic elastomers.

The thickness of the first facing material 1 is preferably 5 to 30 mm, and more preferably 10 to 20 mm. When the thickness of the first facing material 1 is within the above range, the laminate A exhibits excellent soundproofing and vibration damping properties.

A cloth member (not shown) may be laminated to one or both sides of the first panel 1. In the first panel 1, it is preferable that a cloth member is laminated to the laminated surface (one surface 1a) of the second panel 2. As will be described later, when a third panel is laminated to the other surface 1b of the first panel 1, it is preferable that a cloth member is laminated to the other surface 1b of the first panel 1. By laminating a cloth member to the first panel 1, for example, even if the adhesion between the first panel 1 and the first connection portion 3 is not good, the adhesion between the first panel 1 and the first connection portion 3 can be strengthened by the cloth member. By strengthening the adhesion between the first panel 1 and the first connection portion 3, peeling between the first panel 1 and the first connection portion 3 can be prevented, and good soundproofing performance can be achieved. The cloth member is not particularly limited, and examples include nonwoven fabric, woven fabric, knitted fabric, etc., and nonwoven fabric is preferable.

The second face material 2 is laminated and integrated onto one surface 1a of the first face material 1 via a first connection portion 3, and an air layer 4 is formed between the first face material 1 and the second face material 2. The laminate A has excellent soundproofing and vibration damping properties due to the presence of the air layer 4. Furthermore, the laminate A has excellent lightweight properties due to the presence of the air layer 4.

<Second surface material>
The second face material 2 is not particularly limited as long as it can impart soundproofing and vibration-damping properties to the laminate A, and examples thereof include a metal sheet, a fiber-reinforced plastic sheet, a gypsum board, a synthetic resin sheet, etc., with a metal sheet, a fiber-reinforced plastic sheet, and a gypsum board being preferred.

The rigidity of the second face material 2 is preferably 1 N·m to 5×10 ⁴ N·m, more preferably 5 N·m to 3.5×10 ⁴ N·m, and even more preferably 8 N·m to 2×10 ⁴ N·m. Furthermore, when the rigidity of the second face material 2 is within the above range, excellent soundproofing and vibration damping properties can be exhibited, and soundproofing and vibration damping properties can be imparted to the laminate A.
The rigidity of the second panel 2 can be obtained by multiplying the Young's modulus of the second panel 2 by the cube of the thickness of the second panel 2 .

The acoustic impedance of the second face material 2 is preferably from 1× ¹⁰ Pa·s/m to 100× ¹⁰ Pa·s/m, more preferably from 10× ¹⁰ Pa·s/m to 75× ¹⁰ Pa·s/m, and even more preferably from 15× ¹⁰ Pa·s/m to 50× ¹⁰ Pa·s/m. When the acoustic impedance of the second face material 2 is within the above range, excellent soundproofing properties can be exhibited, and soundproofing properties can be imparted to the laminate A.
The acoustic impedance of the second panel 2 is defined as the density of the second panel 2 multiplied by the propagation speed of sound waves in the second panel 2 .

<First Connection Part>
The first connecting portion 3 is partially present on one surface 1a of the first surface material 1, and supports the second surface material 2 on the first surface material 1. In other words, the first surface material 1 is laminated and integrated with the second surface material 2 via the first connecting portion 3.
The first connecting parts 3 may be present regularly, for example in a checkerboard pattern, or may be present irregularly on one surface 1a of the first face material 1, but are preferably present regularly. The regular presence of the first connecting parts 3 forms a regular air layer 4 between the opposing surfaces of the first face material 1 and the second face material 2, which reliably absorbs or attenuates sound waves entering the laminate A from all directions, and the laminate A exhibits excellent soundproofing properties.

The first connection portion 3 is partially disposed between the first surface material 1 and the second surface material 2 on one surface 1a of the first surface material 1. Since the first surface material 1 and the second surface material 2 are partially connected via the first connection portion 3, the second surface material 2 is not entirely restrained by the first surface material 1. Therefore, the second surface material 2 maintains its degree of deformation freedom, and the vibration energy that enters the laminate A can be smoothly absorbed or attenuated by the deformation of the second surface material 2, and the laminate A exhibits excellent soundproofing and vibration damping properties. In addition, since the first surface material 1 and the second surface material 2 are not entirely connected but are partially connected, the laminate A can effectively absorb or attenuate sound waves and vibration energy having a frequency higher than the resonant frequency of the mass-spring system, and has excellent soundproofing and vibration damping properties.

The first connection portion 3 is partially disposed between the first face material 1 and the second face material 2, and an air layer 4 is formed in the remaining portion between the first face material 1 and the second face material 2. By providing the air layer 4 in the laminate A, excellent sound insulation and vibration damping properties are exhibited, and the laminate A is also made lighter. In addition, by providing the air layer 4 in the laminate A, a difference in acoustic impedance is generated at the interfaces between the air layer 4 and the first face material 1 and the second face material 2, and sound waves, which are airborne sound that propagate through the air and enter the laminate A, are reflected by the first face material 1 or the second face material 2, and the laminate A exhibits excellent sound insulation properties.

The total area of the first connection parts 3 projected in the stacking direction is 20 to 90% of the overlapping area where the first surface material 1 and the second surface material 2 overlap in the stacking direction. Here, in this specification, "the total area of the first connection parts 3 projected in the stacking direction" refers to the total area of the multiple first connection parts 3 projected when viewed from the stacking direction of the laminate A. Also, "the overlapping area where the first surface material 1 and the second surface material 2 overlap in the stacking direction" refers to the area of the portion where the first surface material 1 and the second surface material 2 overlap when viewed from the stacking direction of the laminate A. If the total area of the first connection parts 3 projected in the stacking direction is less than 20% of the overlapping area where the first surface material 1 and the second surface material 2 overlap in the stacking direction, the bond between the first surface material 1 and the second surface material 2 becomes insufficient, making it difficult to maintain the bond and resulting in poor vibration damping. Furthermore, if the total area of the first connection portion 3 projected in the stacking direction is more than 90% of the overlapping area of the first face material 1 and the second face material 2 in the stacking direction, the degree of deformation freedom of the second face material 2 is restricted, and the vibration energy that has entered the laminate A is not smoothly absorbed or attenuated by the deformation of the second face material 2, making it difficult for the laminate A to exhibit excellent soundproofing properties. In view of the above, the total area of the first connection portion 3 projected in the stacking direction is preferably 25 to 85% of the overlapping area of the first face material 1 and the second face material 2, more preferably 27 to 80%, and even more preferably 30 to 75%.

The thickness of the first connection part 3 is 0.05 mm or more. Here, in this specification, the "thickness of the first connection part 3" refers to the distance between both ends of the first connection part 3 in the stacking direction of the laminate A. In other words, the thickness of the first connection part 3 is synonymous with the thickness of the air layer 4. If the thickness of the first connection part 3 is less than 0.05 mm, the air layer 4 cannot be sufficiently secured, and the soundproofing performance due to the air layer 4 cannot be obtained, so that the laminate A has difficulty in exhibiting excellent soundproofing properties. From the viewpoint of securing the air layer 4 sufficiently and obtaining the soundproofing performance due to the air layer 4, the thickness of the first connection part 3 is preferably 0.08 mm or more, more preferably 0.1 mm or more, and even more preferably 0.12 mm or more. Furthermore, the thickness of the first connection portion 3 is preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less, and even more preferably 3 mm or less, because an increase in the thickness of the air layer 4 reduces the mechanical strength of the laminate A and makes it difficult to exhibit vibration damping properties.

The first connection part 3 may have either double-sided adhesiveness or double-sided adhesion. The first connection part 3 may have double-sided adhesiveness or double-sided adhesion, for example, at least one selected from the group consisting of adhesives, pressure-sensitive adhesives, and double-sided adhesive tapes. Among these, double-sided adhesive tapes without a base layer are preferred because they have a high loss sine tan δ at 10 to 30°C.

For reasons of the principle of the constrained vibration damping material described above, the first connecting part 3 has a higher loss sine tan δ (loss modulus E"/storage modulus E') at 10 to 30°C, and it is preferably 0.5 or more, more preferably 0.8 or more, even more preferably 1 or more, and particularly preferably 1.5 or more. In order to ensure that the loss sine tan δ at 10 to 30°C is equal to or greater than the above lower limit, the first connecting part 3 contains a viscoelastic resin having a loss sine tan δ at 10 to 30°C of 1.0 or more.
The loss sine tan δ of the viscoelastic resin at 10 to 30° C. is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 1.8 or more.
Examples of viscoelastic resins include rubber-based resins such as polybutadiene and butyl rubber, chlorine-containing resins such as polyvinyl chloride and chlorinated polyethylene, acrylic resins such as polybutyl acrylate and poly(2-ethylhexyl acrylate), and highly polar resins such as epoxy resins and nylon resins. Viscoelastic resins may be used alone or in combination of two or more. In addition, in order to improve properties such as vibration damping, processability, adhesion, and long-term stability, plasticizers, stabilizers, tackifiers, fillers, ultraviolet absorbers, antioxidants, and the like may be added to the viscoelastic resin. Among these, plasticizers, fillers, ultraviolet absorbers, and antioxidants are additives that are effective in improving vibration damping.

<Production Method>
The method for producing the laminate A will be described below. The method for producing the laminate A is not particularly limited, and examples thereof include the following production method.
First, a viscoelastic resin sheet is partially attached at a predetermined thickness to one surface 1a of the first face material 1. Then, the second face material is laminated and integrated onto the viscoelastic resin sheet attached to the first face material 1, and then cured to produce the laminate A by laminating the second face material 2 onto the first face material via the first connection portion 3, which is a viscoelastic resin sheet.

<How to use the laminate>
The usage of the laminate A will be described. As shown in Fig. 2, the laminate A is used by adhering and integrating with a target member B (hereinafter referred to as "construction member") using a viscoelastic resin. The construction member B is not particularly limited, and examples thereof include components of transport equipment such as automobiles, railways, ships, and aircraft, components of buildings (e.g., exterior wall components, interior components, ceiling components, etc.), components of industrial equipment such as industrial machines, components of office automation equipment such as computers, and components of home appliances such as washing machines and refrigerators.

When adhering the laminate A to the construction member B, the other surface 1b of the first surface material 1 of the laminate A, i.e., the surface of the laminate A on which the second surface material 2 is not laminated, is preferably adhered and integrated onto the construction member B facing the construction member B.
By adhering and integrating the laminate A onto the construction member B, the laminate A can absorb or attenuate sound waves propagating through the air before and after passing through the construction member B, and the laminate A exhibits excellent soundproofing properties.
Furthermore, even when the construction member B is a vibrating body, the laminate A adhered and integrated onto the construction member B can absorb or attenuate the vibration energy generated in the construction member B and absorb or attenuate the noise caused by the vibration of the construction member B, and the laminate A exhibits excellent soundproofing and vibration-damping properties.

When the laminate A is bonded and integrated onto the construction member B using the viscoelastic resin C, the viscoelastic resin C may be disposed over the entire surface of the opposing surfaces of the laminate A and the construction member B, but this maintains the degree of freedom of deformation of the first facing material 1 and forms an air layer 4 between the opposing surfaces of the laminate A and the construction member B, improving the soundproofing and vibration damping properties of the laminate A through the same action as described above. Therefore, it is preferable to partially dispose the viscoelastic resin C on the opposing surfaces of the laminate A and the construction member B.

The thickness of the viscoelastic resin C disposed on the opposing surfaces of the laminate A and the construction member B is 0.05 mm or more, preferably 0.1 mm or more, more preferably 0.2 mm or more, and particularly preferably 0.3 mm or more. The thickness of the viscoelastic resin C disposed on the opposing surfaces of the laminate A and the construction member B is preferably 20 mm or less, more preferably 10 mm or less, more preferably 5 mm or less, and particularly preferably 3 mm or less. When the thickness of the viscoelastic resin C is 0.05 mm or more, the sound insulation and vibration damping properties of the laminate A are improved. When the thickness of the viscoelastic resin C is 10 mm or less, the sound insulation and vibration damping properties of the laminate A are improved. The "thickness of the viscoelastic resin C" refers to the distance between both ends of the viscoelastic resin C in the stacking direction of the laminate A on the construction member B.

The total area of the viscoelastic resin C is 20-80%, preferably 20-50%, of the overlapping area between the laminate A and the opposing construction member B. When the total area of the viscoelastic resin C is within the above range, the degree of deformation freedom of the first face material 1 is maintained, vibration energy that has entered the laminate A is smoothly absorbed or attenuated by the deformation of the first face material 1, and sound waves are effectively reflected by the first face material 1, so that the laminate A exhibits excellent soundproofing and vibration damping properties.
"Total area of viscoelastic resin C" refers to the total area of viscoelastic resin C when viewed from the stacking direction of laminate A on construction member B. "Overlapping area of laminate A and construction member B facing it" refers to the area of the overlapping portion between laminate A and construction member B when viewed from the stacking direction of laminate A on construction member B.

Second Embodiment
The second embodiment differs from the first embodiment in that, as shown in Fig. 3, a third surface material 6 is also laminated and integrated onto the other surface 1b of the first surface material 1 via a second connection portion 5. The differences between the first embodiment and the second embodiment will be described below. In the following description of different embodiments, the same reference numerals will be used to designate members having the same configuration.

The second connection portion 5 and the third surface material 6 may have the same configuration and material as the first connection portion 3 and the second surface material 2, respectively. The arrangement of the second connection portion may also have the same configuration as the arrangement of the first connection portion 3. Note that the second connection portion 5 and the third surface material 6 do not need to be the same as the first connection portion 3 and the second surface material 2, respectively.

Third Embodiment
The third embodiment differs from the first embodiment in that, as shown in Fig. 4, the first face material 1 is a multi-layer face material formed by laminating and integrating a plurality of (two or more) divided face materials 11 with each other via a third connection portion 7. The following describes the third embodiment and the differences from the first embodiment. In the following description of different embodiments, the same reference numerals are used for members having the same configuration.

The multiple dividing panel members 11 do not need to be identical to each other. Even if there are multiple third connection parts 7, they do not need to be identical to each other.

In FIG. 4, the second panel 2 is laminated to one surface 1a of the first panel 1 via the first connecting portion 3, and the third panel 6 is laminated to the other surface 1b of the first panel 1 via the second connecting portion 5. However, the third panel 6 does not have to be laminated to the other surface 1b of the first panel 1. In addition, at least one of the second panel 2 laminated to one surface 1a of the first panel 1 and the third panel 6 laminated to the other surface 1b of the first panel 1 may be a multi-layer panel, as described below.

The dividing panel 11 and the third connecting portion 7 may have the same structure and material as the first panel 1 and the first connecting portion 3, respectively. The third connecting portion 7 may also be disposed in the same manner as the first connecting portion 3. It is not necessary that the dividing panel 11 and the third connecting portion 7 are the same as the first panel 1 and the first connecting portion 3, respectively.

Fourth Embodiment
The fourth embodiment differs from the first embodiment in that, as shown in Fig. 5, the second face material 2 is a multi-layer face material formed by laminating and integrating a plurality (two or more) of divided face materials 21 with each other via a fourth connecting portion 8. The following describes the differences between the first embodiment and the fourth embodiment. In the following description of different embodiments, the same reference numerals are used for members having the same configuration.

The multiple dividing panel members 21 do not need to be identical to each other. Even if there are multiple fourth connection parts 8, they do not need to be identical to each other.

Figure 5 shows a case where a multi-layer second panel 2 is laminated and integrated onto one surface 1a of the first panel 1 via a first connection portion 3, but a single-layer or multi-layer third panel 6 may also be laminated and integrated onto one surface 1b of the first panel 1 via a second connection portion.

The dividing panel 21 and the fourth connecting portion 8 can be made of the same structure and material as the second panel 2 and the first connecting portion 3, respectively. The fourth connecting portion 8 can be arranged in the same structure as the first connecting portion 3. The multi-layer third panel 6 can be made of the same structure as the multi-layer second panel 2.

The following describes examples of the present invention, but the present invention is not limited to these examples.

Example 1
As the first surface material, a polypropylene resin closed cell foam sheet (thickness: 15 mm, expansion ratio: 13 times, manufactured by Sekisui Chemical Co., Ltd., product name "Zettron") was prepared.
A chlorinated polyethylene viscoelastic resin sheet (thickness: 0.5 mm, manufactured by Sekisui Chemical Co., Ltd., product name "Calmoon Sheet (product number KS690)") was prepared as the first connecting portion. Three chlorinated polyethylene viscoelastic resin sheets (width: 20 mm, length: 50 mm) were attached to one surface 1a of the polypropylene resin foam sheet in a regular, evenly spaced manner in a checkerboard pattern.
Thereafter, an aluminum sheet (thickness: 0.6 mm) having the thickness shown in Table 1 was laminated as a second surface material on one surface 1a of the polypropylene resin closed cell foam sheet via a chlorinated polyethylene viscoelastic resin.
On the other surface 1b of the polypropylene resin foam sheet, three sheets of chlorinated polyethylene viscoelastic resin sheets (width: 20 mm, length: 50 mm) were attached as second connecting parts at equal intervals and uniformly in a regular grid pattern.
Thereafter, an aluminum sheet (thickness: 0.6 mm) having the thickness shown in Table 1 was laminated as a third surface material on the other surface 1b of the polypropylene resin closed cell foam sheet via the chlorinated polyethylene viscoelastic resin sheet to produce a laminated sheet.

The chlorinated polyethylene viscoelastic resin sheet of the laminated sheet was cured, and an aluminum sheet (second face material 2) was laminated and integrated with one surface 1a of the polypropylene resin closed-cell foam sheet, which is the first face material 1 constituting the main body, via a chlorinated polyethylene viscoelastic resin sheet (first connection part 3), and an aluminum sheet (third face material 6) was laminated and integrated with the other surface 1b of the polypropylene resin closed-cell foam sheet 1 via a chlorinated polyethylene viscoelastic resin sheet (second connection part 5), to obtain a laminate A. The laminate A was a flat rectangular shape measuring 20 mm in length and 250 mm in width.

In laminate A, the thickness and total area of the first and second connection parts are shown in Table 1. In laminate A, air layers 4 were formed between both sides of the polypropylene resin closed cell foam sheet and the opposing surfaces of the aluminum sheet.

Example 2
A laminate A was obtained in the same manner as in Example 1, except that an acrylic adhesive tape (thickness: 0.6 mm, manufactured by Sekisui Chemical Co., Ltd., product name "SJ Tape") was used instead of the chlorinated polyethylene viscoelastic resin sheet.

(Comparative Example 1)
A laminate A was obtained in the same manner as in Example 1, except that a polyethylene foam double-sided tape (thickness: 1 mm, manufactured by Sekisui Chemical Co., Ltd., "Product No. 536") was used instead of the chlorinated polyethylene viscoelastic resin sheet.

(Comparative Example 2)
A laminate A was obtained in the same manner as in Example 1, except that a urethane foam (thickness: 10 mm, manufactured by Sekisui Chemical Co., Ltd., product name "FFU") was used instead of the polypropylene-based resin foam sheet.

The thickness and area of the first and second connection parts of the laminates obtained in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

The loss factor and resonance frequency of the resulting laminate were measured as described below. The results are shown in Table 1.
In addition, the loss sine of the viscoelastic resin, adhesive tape, and double-sided tape used in the connection was measured in the manner described below. The results are shown in Table 1.
The flexural modulus of the polypropylene resin foam sheet and the urethane foam was measured as described below. The results are shown in Table 1.

(Loss factor and resonance frequency)
The loss factor of the laminate was measured by the central excitation method in accordance with JIS G0602. Specifically, the loss factor was measured at the frequency of the primary resonance at 23° C. with the second face of the laminate facing down. The higher the loss factor and the lower the resonance frequency, the more excellent the vibration damping properties of the laminate A at low frequencies (50 Hz to 315 Hz).

(Loss sine)
The storage modulus E' and loss modulus E'' of the viscoelastic resin, adhesive tape, and double-sided tape used in the connection were measured at a frequency of 50 Hz using a viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd., product name "Dynamic Viscoelasticity Apparatus DVA-200"), and the loss sine (tan δ) at room temperature (approximately 23°C) was calculated.

(Flexural modulus)
The flexural modulus of the polypropylene resin foam sheet and the urethane foam was measured in accordance with JIS 7171.

The laminate has excellent sound insulation, especially at low frequencies, and vibration damping properties, and is also lightweight. Therefore, the laminate can be suitably applied to construction materials such as transportation equipment, buildings, industrial equipment, office automation equipment, and home appliances.

Reference Signs List 1 First face material 2 Second face material 3 First connection portion 4 Air layer 5 Second connection portion 6 Third face material 7 Third connection portion 8 Fourth connection portion A Laminate B Construction member C Viscoelastic resin

Claims (6)

A first surface material including a synthetic resin foam sheet ;
A second face material laminated on one surface of the first face material;
a first connection portion provided between the first surface material and the second surface material and partially connecting the first surface material and the second surface material;
The thickness of the first connection portion is 0.05 mm or more,
a total area of the first connection portion projected in a stacking direction is 20 to 80% of an overlapping area between the first surface material and the second surface material in the stacking direction;
The first connecting portion comprises a viscoelastic resin having a loss sine tan δ of 1.0 or more at 23 to 30° C. 2. The laminate according to claim 1 , wherein the synthetic resin foam sheet has an expansion ratio of 2 to 50 times. 3. The laminate according to claim 1, wherein the first face material and the second face material comprise at least one selected from the group consisting of a metal sheet, a fiber-reinforced plastic sheet, and a gypsum board. The laminate according to claim 1 , wherein the first connection portion includes an adhesive layer or a pressure-sensitive adhesive layer that integrates the first surface material and the second surface material. A third surface material laminated on the other surface of the first surface material;
A second connection portion is provided between the first surface material and the third surface material and partially connects the first surface material and the third surface material,
The thickness of the second connection portion is 0.05 mm or more,
The laminate according to any one of claims 1 to 4 , wherein a total area of the second connection portion projected in the stacking direction is 20 to 80% of an overlapping area where the first surface material and the third surface material overlap in the stacking direction. The laminate according to claim 5 , wherein the second connection portion contains a viscoelastic resin having a loss sine tan δ of 1.0 or more at 23 ° C. to 30° C.