CN118043882A - Sound-insulating sheet and sound-insulating structure - Google Patents

Sound-insulating sheet and sound-insulating structure Download PDF

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Publication number
CN118043882A
CN118043882A CN202280065949.2A CN202280065949A CN118043882A CN 118043882 A CN118043882 A CN 118043882A CN 202280065949 A CN202280065949 A CN 202280065949A CN 118043882 A CN118043882 A CN 118043882A
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China
Prior art keywords
sound
convex portion
linear
insulating sheet
dot
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CN202280065949.2A
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Chinese (zh)
Inventor
中山真成
松冈毅
越峠晴贵
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Mitsubishi Chemical Corp
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Mitsubishi Chemical Corp
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Priority claimed from PCT/JP2022/036444 external-priority patent/WO2023054587A1/en
Publication of CN118043882A publication Critical patent/CN118043882A/en
Pending legal-status Critical Current

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  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

The present invention provides a sound-insulating sheet exhibiting a high sound-insulating effect exceeding the law of mass in a plurality of frequency bands. The sound-insulating sheet is formed by having at least a sheet portion and convex portions A and B having different shapes. The arrangement of the convex portions and the like are configured such that at least 2 peaks are obtained in a graph having a horizontal axis of frequency X and a vertical axis of Δtl (dB) obtained by the following formula (1) and obtained by measuring the acoustic transmission loss of the acoustic insulator, and at least 2 of the peaks have a height of 3dB or more. Δtl=tl 1-TL2 (1) (in the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, and TL 2 is the sound transmission loss (dB) of the flat sheet having no irregularities, which has the same mass as the sound-insulating sheet and the same area as the area of the sheet portion.

Description

Sound-insulating sheet and sound-insulating structure
Technical Field
The present invention relates to a sound insulating sheet and a sound insulating structure.
Background
In buildings such as apartments, office buildings, and hotels, silence is required that is suitable for indoor use by blocking outdoor noise from automobiles, railways, airplanes, ships, and the like, equipment noise generated inside the buildings, and human noise. In vehicles such as automobiles, railways, airplanes, and ships, it is necessary to reduce indoor noise in order to block wind noise and engine noise and provide passengers with a quiet and comfortable space.
Accordingly, studies and developments have been made on a means for blocking transmission of noise or vibration from the outside to the inside of the room or from the outside to the inside of the vehicle, that is, a sound insulation means. In recent years, in order to increase the building height, improve the energy efficiency of vehicles, and improve the degree of freedom in design of buildings, vehicles, and devices thereof, flexible soundproof members capable of coping with complex shapes have been demanded.
Conventionally, in order to improve sound insulation performance, a sound insulation member, particularly a sheet-like member, has been improved in component structure.
For example, a method is known in which a plurality of rigid flat materials such as gypsum board, concrete, steel sheet, glass sheet, and resin sheet are combined and used (patent document 1); a method of producing a hollow double-wall structure and a hollow triple-wall structure using gypsum board or the like (patent document 2); a method of using a flat plate material in combination with a plurality of independent stump-like projections (patent documents 3, 4 and 5), a method of using a sound absorbing material in combination with a plurality of independent stump-like projections in addition to a flat plate material (patent document 4), and the like.
Prior art literature
Patent literature
Patent document 1: japanese patent application laid-open No. 2013-231316
Patent document 2: japanese patent laid-open No. 2017-227109
Patent document 3: international publication No. 2017/135409
Patent document 4: japanese patent laid-open No. 2000-265593
Patent document 5: japanese patent laid-open No. 2019-208727
Disclosure of Invention
In recent years, along with the electric driving of automobiles, there has been an increasing demand for lightweight noise reducing materials that simultaneously reduce the weight of the vehicle body and reduce the noise in the vehicle, but conventional noise reducing materials made of iron, rubber, or the like have a mass law that the weight per unit area is increased, and thus the noise reducing performance is in a trade-off with the weight.
On the other hand, in the above-described conventional sound insulating members, the sound insulating members described in patent documents 3 and 5 are members having a form in which cylindrical protrusions arranged in a plurality of rows and columns or linear protrusions arranged in a unidirectional manner are provided on the surface of a sheet, and the protrusions and the sheet vibrate in response to the incidence of sound, whereby a high sound insulating performance exceeding the law of mass is obtained in a specific frequency band. Artificial structural materials so designed as to produce vibrations or resonance modes in response to sound waves of a target frequency band are known as acoustic metamaterials and are expected to be the most advanced sound technology beyond mass laws.
However, since the acoustic metamaterial-based sound insulation technology uses vibration or resonance in a specific frequency band, the sound insulation technology has a single sound insulation frequency and is narrow-band, and thus has limited application.
In practice, noise generated from automobiles, electric appliances, and the like is rarely sound of a single frequency, but sounds of different frequency bands are generated simultaneously, and thus, a novel sound insulating material capable of insulating sound for a plurality of frequency bands is demanded.
In order to improve the sound-insulating effect in a plurality of frequency bands, countermeasures such as lamination of different acoustic meta-materials, lamination of sound-insulating materials and sound-absorbing materials, and increase in weight or thickness of sound-insulating materials are considered, but the sound-insulating member is inevitably thick, large in size, and heavy, and the requirement of noise shielding by a miniaturized and lightweight member cannot be satisfied.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a sound-insulating sheet having a high sound-insulating effect exceeding the law of mass in different design frequency bands.
The present inventors have conducted intensive studies to solve the above problems, and as a result, they have clarified: when a structure in which projections having different shapes are combined is applied to a sheet-like substrate, vibration modes effective for sound insulation are exhibited in different frequency bands. The use of the soundproof sheet has been confirmed to block incident sound in a plurality of frequency bands, and the above problems have been solved.
Namely, the gist of the present invention is as follows.
A sound-insulating sheet is characterized by comprising a sheet portion and a convex portion,
The convex part includes at least a convex part A and a convex part B having different shapes,
On either side of the sheet, there are more than 2 convex part areas where the convex part A exists,
On either side of the sheet, there are more than 2 convex part areas where the convex part B exists,
In a graph obtained by measuring the acoustic transmission loss, in which the frequency X is on the horizontal axis and Δtl (dB) is on the vertical axis, which is obtained by the following formula (1), at least 2 peaks are obtained, and the height of at least 2 of these peaks is 3dB or more.
ΔTL＝TL1-TL2 (1)
(In the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, TL 2 is the sound transmission loss (dB) of a flat sheet having no irregularities and having the same mass and area as the sound-insulating sheet and the area of the sheet portion at the frequency X.)
The soundproof sheet according to item [ 2 ], wherein the convex portion A is a linear convex portion.
The sound-insulating sheet according to [1 ] or [ 2 ], wherein a plurality of the convex portions B are present in the convex portion region B, and the convex portions B are dot-shaped convex portions.
[ 4] A sound-insulating sheet, characterized in that it comprises a sheet portion and a convex portion,
The convex portion includes at least a linear convex portion and a plurality of dot-shaped convex portions,
On either side of the sheet portion, there are at least 2 convex portion regions where the linear convex portions exist,
The sheet has 2 or more convex regions on either side thereof, in which a plurality of the dot-like convex portions are present.
The soundproof sheet according to any one of [ 2 ] to [4 ], wherein the dot-like convex portions in the convex portion region where the plurality of dot-like convex portions are present are arranged in a column structure composed of 1 or more columns, and a longitudinal direction of the column structure is substantially parallel to a longitudinal direction of the column structure composed of the linear convex portions.
The soundproof sheet according to item [ 6 ], wherein the linear convex portions and the dot convex portions are alternately arranged in a planar view.
The soundproof sheet according to item [ 7 ] above, wherein the linear convex portions and the dot convex portions are alternately arranged at equal intervals in a plan view.
The soundproof sheet according to any one of [ 5 ] to [ 7 ], wherein the dot-like projections in the column structure are arranged at equal intervals.
The soundproof sheet according to any one of [2 ] to [ 8 ], characterized in that the value represented by (total mass of linear convex portion/mass of sheet portion) is 0.8 or more, the value represented by (total mass of dot convex portion/mass of sheet portion) is 0.15 or more, and the value represented by (total mass of linear convex portion/total mass of dot convex portion) is 3.5 to 15.
The sound-insulating sheet according to any one of [ 3 ] to [ 9 ], wherein the dot-like convex portion has a cylindrical shape.
The soundproof sheet according to any one of [ 3 ] to [ 9 ], wherein the dot-like convex portions have a prismatic shape.
The sound-insulating sheet according to [ 12 ] or [ 4 ] above, wherein the convex portion B is a linear convex portion having a length different from that of the linear convex portion a, and the plurality of convex portions B are arranged in series as linear convex portions in each convex portion region where the convex portion B exists.
The sound-insulating sheet according to any one of the above [4 ] to [ 12 ], wherein at least 2 peaks are obtained in a graph having a horizontal axis of frequency X and a vertical axis of ΔTL (dB) obtained by the following formula (1) and the height of at least 2 of the peaks is 3dB or more.
ΔTL＝TL1-TL2 (1)
(In the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, TL 2 is the sound transmission loss (dB) of a flat sheet having no irregularities and having the same mass and area as the sound-insulating sheet and the area of the sheet portion at the frequency X.)
The soundproof sheet according to any one of [1] to [ 13 ], wherein the convex portion contains at least one selected from the group consisting of a photocurable resin and a thermoplastic resin.
A sound-insulating sheet comprising a sheet portion and a convex portion,
The convex portion includes a plurality of linear convex portions A and a plurality of convex portions B having a shape different from that of the linear convex portions A,
At least one of the linear protrusions A is disposed between the plurality of protrusions B,
At least one of the convex portions B is disposed between the plurality of linear convex portions a.
The sound-insulating sheet according to [ 16 ] above [15 ], wherein the convex portion B is a convex portion having a shape not having a side longer than the longitudinal length of the linear convex portion A.
The soundproof sheet according to [ 15 ] or [ 16 ], wherein the value represented by (total mass of the linear convex portion a/mass of the sheet portion) is 0.8 or more and the value represented by (total mass of the convex portion B/mass of the sheet portion) is 0.15 or more.
The soundproof sheet according to item [ 18 ], wherein the convex portion B is a convex portion having a shape not having a longer side than the longitudinal length of the linear convex portion A in a plan view.
The soundproof sheet according to item [ 19 ] above [ 18 ], wherein the convex portion B is constituted by a plurality of linear rows of the convex portions B, and the linear rows are substantially parallel to the longitudinal direction of the linear convex portions a.
The soundproof sheet according to item [ 20 ], wherein the linear protrusions A are alternately arranged with the column structure of the protrusions B in a plan view.
The soundproof sheet according to [ 21 ] above, wherein the convex portion B is a dot-like convex portion.
The soundproof sheet according to [ 22 ] above [ 21 ], wherein the value represented by (total mass of the linear convex portion A/total mass of the dot-like convex portion B) is 3.2 to 15.
[ 23 ] The soundproof sheet according to the above [ 22 ], wherein the value represented by (total mass of the linear convex portion A/total mass of the dot-shaped convex portion B) is 3.5 to 15.
The soundproof sheet according to [ 24 ] above, wherein the convex portion B is a linear convex portion shorter than the linear convex portion a.
The soundproof sheet according to item [ 25 ] above, wherein the convex portions B are formed in a plurality of rows in which the convex portions B are linearly arranged in the longitudinal direction.
The soundproof sheet according to item [ 26 ] above, wherein,
When the linear convex portion a is the "1 st linear convex portion" and the linear convex portion B shorter than the linear convex portion a is the "2 nd linear convex portion",
The ratio of the length of the linear protrusion B to the linear protrusion a, which is represented by (1 st linear protrusion)/(2 nd linear protrusion), is in the range of 0.1 to 0.99.
The sound insulation structure of [ 27 ], wherein the sound insulation sheet of any one of [ 1 ] to [ 26 ] is laminated on a sound absorbing material.
According to the present invention, a lightweight sound-insulating sheet that can exhibit a sound-insulating effect exceeding the mass law for noise in a plurality of frequency bands, despite being a single sheet, can be provided.
Drawings
Fig. 1 is a schematic perspective view of an embodiment of a sound insulation sheet according to an embodiment of the present invention.
Fig. 2 is a schematic perspective view of an embodiment of a sound insulation sheet according to an embodiment of the present invention.
Fig. 3 is a schematic perspective view of an embodiment of a sound insulation sheet according to an embodiment of the present invention.
Fig. 4 is a schematic perspective view of an embodiment of a sound insulation sheet according to an embodiment of the present invention.
Fig. 5 is a schematic perspective view of an embodiment of a sound insulation structure according to an embodiment of the present invention.
Fig. 6 is a schematic perspective view of a sound insulating sheet having only linear protrusions.
Fig. 7 is a schematic perspective view of a sound insulating sheet having only dot-like projections.
Fig. 8 is a diagram showing an example of a process for manufacturing the soundproof member.
Fig. 9 is a diagram showing an example of a process for manufacturing the soundproof member.
Fig. 10 is a graph showing the relationship between Δtl of the first peak and the linear protrusion/piece mass ratio in the example.
Fig. 11 is a graph showing the relationship between Δtl of the second peak and the dot-like convex portion/piece mass ratio in the example.
Fig. 12 is a graph showing the relationship between the absolute value of the difference between the Δtl of the first peak and the Δtl of the second peak and the linear convex portion/dot convex portion mass ratio in the example.
Detailed Description
The present invention will be described in detail below. The following description is an example (representative example) of the present invention, and the present invention is not limited to these. The present invention can be arbitrarily modified and implemented within a range not exceeding the gist thereof.
In the present specification, the expressions "to" indicate ranges including the numbers before and after the expressions. In the present specification, "a plurality of" means 2 or more.
< Sound insulation sheet >)
Embodiment 1 of the present invention is characterized in that,
A sound-insulating sheet comprising a sheet portion and a convex portion, wherein the convex portion has at least a convex portion A and a convex portion B having different shapes, wherein the convex portion has at least 2 convex portion areas where the convex portion A is present on either side of the sheet portion, the convex portion has at least 2 convex portion areas where the convex portion B is present on either side of the sheet portion,
In a graph obtained by measuring the acoustic transmission loss, in which the frequency X is on the horizontal axis and Δtl (dB) obtained by the following formula (1) is on the vertical axis, at least 2 peaks are obtained, and the height of at least 2 of these peaks is 3dB or more.
The shapes of the convex portions a and B are not particularly limited as long as they are different from each other, and from the viewpoint of exhibiting a sound-insulating effect in a low frequency band, one convex portion (for example, convex portion a) is preferably a linear convex portion (linear convex portion), and from the viewpoint of exhibiting a sound-insulating effect in a high frequency band, one convex portion (for example, convex portion B) is preferably a dot-like convex portion (dot-like convex portion), and from the viewpoint of exhibiting a high sound-insulating effect exceeding the law of mass in a different design frequency band in a single piece, it is preferable to have these 2 convex portions as convex portions.
In the case of having a dot-like convex portion as the convex portion, for example, in the case of the convex portion B being a dot-like convex portion, the number of dot-like convex portions in each convex portion region is not particularly limited, and is preferably present in a plurality from the viewpoint that a single sheet exhibits a high sound-insulating effect exceeding the law of mass in different design frequency bands.
Further, one of the projections may be a linear projection (hereinafter, also referred to as "1 st linear projection") and the other projection may be a2 nd linear projection having a shape different from that of the 1 st linear projection. By setting the length of the 2 nd linear protrusion shorter than the length of the 1 st linear protrusion, the sound-insulating effect can be exhibited in a lower frequency band in the same manner as the above-described linear protrusion and dot-shaped protrusion. The method using these 2 linear protrusions may be considered as a method in which the shape of the dot-shaped protrusion is deformed from a dot shape to a linear shape, among the above-described linear protrusions and dot-shaped protrusions.
The sound-insulating sheet may have a convex portion region (hereinafter, also referred to as "other convex portion region") having a convex portion other than the convex portion a and the convex portion B, but is preferably only 2 shapes, particularly preferably only linear convex portions and dot-shaped convex portions, from the viewpoint that a single sheet exhibits a high sound-insulating effect exceeding the law of mass in different design frequency bands.
In the sound-insulating sheet according to the present embodiment, at least 2 peaks, particularly at least 2 peaks having a height of 3dB or more are obtained in a graph having a horizontal axis of frequency X and a vertical axis of Δtl (dB) obtained by the following formula (1) and obtained by measuring sound transmission loss of the sound-insulating sheet. When ΔTL is 3dB or more, a sufficient noise reduction effect can be obtained.
ΔTL＝TL1-TL2 (1)
(In the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, TL 2 is the sound transmission loss (dB) of a flat sheet having no irregularities and having the same mass and area as the sound-insulating sheet and the area of the sheet portion at the frequency X.)
Details regarding this property are set forth later.
The 2 nd sound-insulating sheet according to another embodiment of the present invention is a sound-insulating sheet including a sheet portion and a convex portion,
The convex portion includes at least a linear convex portion and a plurality of dot-shaped convex portions, and has 2 or more convex portion regions in which the linear convex portion is present on any one surface of the sheet portion, and has 2 or more convex portion regions in which the plurality of dot-shaped convex portions are present on any one surface of the sheet portion.
Since the sound insulating sheet according to each of the embodiments described above includes the plurality of convex portions having the convex portions with different shapes, the sound insulating sheet can insulate a plurality of frequency bands, and the sound insulating material to be mounted as a countermeasure against noise can be made lightweight and compact.
Further, by adjusting the shape or material of the protruding portions, the distance between the protruding portions, the thickness or material of the sheet portion, or the like, different sound-deadening frequencies can be adjusted.
Hereinafter, the following soundproof sheet will be described in detail: the convex portions in the convex portion region a (the convex portion a in the 1 st sound-insulating sheet) are in a column structure composed of linear convex portions, and the convex portions in the convex portion region B (the convex portion B in the 1 st sound-insulating sheet) are dot-like convex portions, in particular, are in a column structure composed of one or more columns in which a plurality of dot-like convex portions are present.
The following description is applicable to any embodiment of the 1 st sound-insulating sheet and the 2 nd sound-insulating sheet. In this case, the above-described "projection region in which the linear projections are present" and "projection region in which the plurality of dot projections are present" may be referred to as "linear projection row structure in which the linear projections are present" and "dot projection row structure in which the plurality of dot projections are present", respectively.
Further, embodiments of the present invention will be described below with reference to the drawings. The following embodiments are examples for illustrating the present invention, and the present invention is not limited to the embodiments.
In the case of the above-described system having the 1 st linear convex portion and the 2 nd linear convex portion, the conditions of the linear convex portion in the following description of the embodiment may be applied to the conditions of the 1 st linear convex portion. On the other hand, unless otherwise specified, the condition of the 2 nd linear convex portion may be applied in combination with the conditions of the linear convex portion and the dot-shaped convex portion in the following description of the embodiment.
[ Component Structure of Sound-insulating sheet ]
Fig. 1 to 3 are schematic perspective views of sound insulating sheet 1.
The sound insulating sheet 1 of the illustrated embodiment has a shape in which a plurality of 2 types of protrusion rows are provided on a surface 2a of one side of the sheet portion 2, and the 2 types of protrusion rows are: a column structure (linear protrusion column structure) 5 composed of linear protrusions 3 extending in 1 direction; and a row structure (dot-like convex portion row structure) 6 formed by arranging the dot-like convex portions 4 scattered on the surface 2a in 1 or more rows. In this case, the linear convex portion row structures 5 are each 1 convex portion region, and the dot convex portion row structures 6 are each 1 convex portion region.
Fig. 4 is a schematic perspective view of sound-insulating sheet 1 having 1 st linear convex portion 3a and 2 nd linear convex portion 3 b.
The sound insulating sheet 1 of the illustrated embodiment has a shape in which a plurality of 2 types of protrusion rows are provided on a surface 2a of one side of the sheet portion 2, and the 2 types of protrusion rows are: a1 st column structure (1 st linear protrusion column structure) 5a constituted by 1 st linear protrusions 3a extending in 1 st direction; and a 2 nd column structure (2 nd linear convex portion) 5b formed by arranging a plurality of 2 nd linear convex portions 3b in series in each convex portion region where the linear convex portions 3b exist.
In this case, the linear convex portion 3b has a different length from the linear convex portion 3 a. The 1 st linear convex portion row structures 5a are each 1 convex portion region, and the 2 nd linear convex portion row structures 5b are each 1 convex portion region.
In the sound insulating sheet 1 having the 1 st linear protrusion 3a and the 2 nd linear protrusion 3b, as shown in fig. 4, the 1 st linear protrusion row structure 5a is a structure including 1 linear protrusion 3a, and the 2 nd linear protrusion row structure 5b is a structure including a plurality of linear protrusions 3b arranged in series.
(Sheet portion)
The sheet portion 2 supports the linear protrusions 3 and the dot-shaped protrusions 4.
The material constituting the sheet portion 2 is not particularly limited as long as it can support the linear protrusions 3 and the dot-shaped protrusions 4, and may be the same as or different from the material constituting the linear protrusions 3 and the dot-shaped protrusions 4. Therefore, the conditions of the material constituting the convex portion described later are applicable not only to the convex portion but also to the conditions of the material of the entire sound-insulating sheet including the sheet portion 2.
Specific examples of the material constituting the sheet portion 2 include: polyacrylonitrile, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyvinyl chloride, polyvinylidene chloride, polychlorotrifluoroethylene, polyethylene, polypropylene, polystyrene, cyclic polyolefin, polynorbornene, polyethersulfone, polyetheretherketone, polyphenylene sulfide, polyarylate, polycarbonate, polyamide, polyimide, cellulose triacetate, polystyrene, epoxy, acrylic, orOrganic materials such as oxazine resins; metallic materials such as aluminum, stainless steel, iron, copper, zinc, or brass; inorganic materials such as inorganic glass; or a composite material including particles of the inorganic material and fibers in the organic material, but is not particularly limited thereto. Among these, polyethylene terephthalate is preferable from the viewpoints of sound insulation, rigidity, moldability, cost and the like.
The sheet 2 may be formed of 1 layer, or may be formed of a plurality of layers of 2 or more layers, and in the case of a plurality of layers of 2 or more layers, the conditions of the sheet 2 in the present specification are conditions as a laminate unless otherwise specified.
The thickness of the sheet portion 2 is preferably 30 μm to 500. Mu.m, more preferably 35 μm to 400. Mu.m, still more preferably 40 μm to 300. Mu.m. When the thickness of the sheet portion 2 is equal to or greater than the lower limit, the operability is excellent, and when the thickness is equal to or less than the upper limit, the sound insulation performance is improved by providing the linear protrusions 3 and the dot-like protrusions 4.
The Young's modulus of the sheet portion 2 at 25℃is not limited as long as the sound-insulating property is exhibited, but from the viewpoints of mechanical strength, flexibility, handleability, productivity, and the like, a Young's modulus of preferably 10MPa or more, more preferably 500MPa or more is preferable, and a Young's modulus of preferably 50GPa or less, more preferably 20GPa or less is preferable. The preferable condition of the young's modulus can also be applied as a preferable condition of the young's modulus of the convex portion described later.
Here, the young's modulus in the present specification means a ratio of a force (stress) applied to a sample per unit cross-sectional area to a deformation ratio (strain) when an external force is applied in a uniaxial direction, and can be evaluated by measuring young's modulus using a dynamic viscoelasticity device DMS6100 (manufactured by SII corporation), and preparing a resultant viscoelasticity curve of 1Hz to 10kHz according to a time-temperature conversion rule, and calculating young's modulus at 25 ℃. As the sample for measurement, a product obtained by cutting a long sample having a width of 5mm, a length of 50mm, and a thickness of 1mm from the sheet portion 2, or a product obtained by producing a long sample having a width of 5mm, a length of 50mm, and a thickness of 1mm from the same material as the sheet portion 2 may be used. In the case where the sheet portion 2 is made of the same material as the convex portion, a value measured as the young's modulus of the convex portion may be used as the young's modulus of the sheet portion 2.
Measurement mode: stretching
Measurement temperature: 70 ℃ to 50 DEG C
Temperature increase rate: 2 ℃/min
Measurement frequency: 1Hz, 10Hz, 50Hz
The specific gravity of the sheet portion 2 is not particularly limited, but is usually 0.1 or more, preferably 0.3 or more, more preferably 0.5 or more, and is usually 25 or less, preferably 15 or less, more preferably 10 or less, from the viewpoint of operability and weight reduction.
The sheet portion 2 has an areal density of not particularly limited, but is usually 0.01kg/m 2 or more, preferably 0.05kg/m 2 or more, more preferably 0.1kg/m 2 or more, and is usually 20kg/m 2 or less, preferably 10kg/m 2 or less, more preferably 5kg/m 2 or less, from the viewpoint of handling property and weight reduction.
The shape of the sheet portion 2 is not limited to the form shown in fig. 1 to 3. The setting may be appropriately made according to the installation surface of the soundproof sheet 1. For example, the sheet may be flat, curved, or processed into a special shape such as a curved surface portion or a bent portion. In addition, from the viewpoints of mountability, weight saving, and the like, a cutout, a punched portion, and the like may be provided at any portion of the sheet portion 2.
(Convex portion)
The linear protrusions 3 and the dot-shaped protrusions 4 provided on the surface of the sheet portion 2 exert a local (preferably local and periodic) mass function on the sheet portion 2.
The following functions are exerted by (preferably periodically) imparting a local mass: when an acoustic wave is incident from the acoustic source, a vibration mode effective for sound insulation corresponding to the acoustic wave of the target frequency is excited in the sheet portion 2. In the present specification, when the description is simply referred to as "convex portion", the description applies to all the convex portions without distinguishing the linear convex portion 3, the dot-like convex portion 4, and other convex portions unless otherwise specified.
The method for forming the linear protrusions 3 and the dot-shaped protrusions 4 is not particularly limited, and the sheet may be formed by deforming, for example, by pressing a mold having a concave cavity against a sheet having no protrusions, or may be formed integrally with a member of the sheet 2 using a material different from that of the member of the sheet 2, for example, by molding by flowing a material into a mold having a cavity, or may be formed by bonding a separately manufactured protrusion member and a member of the sheet 2 with an adhesive material. The linear protrusions 3 and the dot-shaped protrusions 4 may be made of different materials or by different methods.
The linear convex portion 3 and the dot-shaped convex portion 4 may be formed on one surface 2a of the sheet portion 2, or may be formed on both surfaces of one surface (surface of the sheet portion 2) 2a and the opposite surface (surface of the sheet portion 2) 2b of the sheet portion 2, and the present inventors have estimated that it is preferable to form only one surface 2a of the sheet portion 2 from the viewpoint of obtaining a stable sound insulation effect.
The shape of the cross section of the linear protrusion 3 orthogonal to the longitudinal direction, that is, the cross section of the linear protrusion 3 may be a polygonal shape such as a substantially square, rectangle, or trapezoid, a semicircular shape, or a semi-elliptical shape, or the like, so long as a local (preferably local and periodic) mass can be imparted to the sheet portion 2. The cross-sectional shape of the linear protrusion 3 may be appropriately selected depending on the application, from the viewpoints of sound insulation performance, manufacturing cost, operability, and the like.
The shape of the cross section of the dot-shaped protruding portion 4 orthogonal to the longitudinal direction of the column structure, that is, the cross section of the dot-shaped protruding portion 4 may be a polygonal shape such as a substantially square, rectangle, trapezoid, or the like, a semicircular shape, a semi-elliptical shape, or the like, and the shape of the entire dot-shaped protruding portion 4 may be a prismatic shape such as a triangular prism shape or a quadrangular prism shape, a cylindrical shape, or an elliptic cylindrical shape, or the like, as long as a local (preferably local and periodic) quality can be imparted to the sheet portion 2. The cross-sectional shape of the dot-shaped protruding portion 4 can be appropriately selected from the viewpoints of sound insulation performance, manufacturing cost, operability, and the like, depending on the application.
The ratio of the maximum width (the maximum line segment that is preferable in the cross section) of the linear protrusion 3 in the cross section orthogonal to the longitudinal direction to the length of the pitch between the linear protrusion row structures 5 (the maximum width/the length of the pitch) is preferably 0.8 or less, more preferably 0.7 or less, still more preferably 0.6 or less, and generally 0.05 or more. When the vibration modes are within the above range, vibration modes effective for sound insulation are excited in the sound insulation sheet 1, and the sound insulation sheet 1 excellent in sound insulation performance at a plurality of sound insulation frequencies can be obtained.
The ratio of the maximum width (the maximum line segment that is preferable in the cross section) of the dot-shaped protruding portion 4 in the cross section orthogonal to the longitudinal direction of the row structure to the length between the central axes of the dot-shaped protruding portions 4 constituting the dot-shaped protruding portion row structure 6 is preferably 0.8 or less, more preferably 0.7 or less, still more preferably 0.6 or less, and generally 0.1 or more. When the vibration modes are within the above range, the sound-insulating sheet 1 is excited with vibration modes effective for sound insulation, and a sound-insulating sheet excellent in sound-insulating performance at a plurality of sound-insulating frequencies can be obtained.
The ratio of the maximum width (the maximum line segment that is preferable in the cross section) of the dot-shaped protruding portion 4 in the cross section orthogonal to the longitudinal direction of the row structure to the length of the pitch between the dot-shaped protruding portion row structures 6 is preferably 0.8 or less, more preferably 0.7 or less, still more preferably 0.6 or less, and usually 0.05 or more. When the vibration modes are within the above range, vibration modes effective for sound insulation are excited in the sound insulation sheet 1, and the sound insulation sheet 1 excellent in sound insulation performance at a plurality of sound insulation frequencies can be obtained.
The lengths of the linear convex portion array structure 5 and the dot convex portion array structure 6 are not particularly limited, but are each independently usually 30mm or more, preferably 50mm or more, more preferably 100mm or more, and are usually 20000mm or less, and may be 10000mm or less from the viewpoint of the sound insulation effect. In addition, these column structures may each be independently provided in an end-to-end manner existing in the sheet portion 2.
In the case of the soundproof sheet 1 having the 1 st linear convex portion 3a and the 2 nd linear convex portion 3b shown in fig. 4, the length of the 2 nd linear convex portion 3b needs to be at least half the length of the 1 st linear convex portion 3a because at least 2 or more 2 nd linear convex portions 3b need to be arranged in series in the longitudinal direction of the wire. Specifically, from the viewpoint of the sound insulation effect, the length of each of the 2 nd linear protrusions 3b is usually 50mm or more, preferably 100mm or more, more preferably 300mm or more, and is usually 1000mm or less, preferably 800mm or less, more preferably 500mm or less, independently of each other. In addition, these column structures may each be independently provided in an end-to-end manner existing in the sheet portion 2. In the above, the condition of the length of the 1 st linear protrusion 3a can be applied to the length of the linear protrusion row structure 5.
The ratio of the length of the 2 nd linear protrusion 3b to the length of the 1 st linear protrusion 3a, which is expressed by (length of the 1 st linear protrusion 3 a)/(length of the 2 nd linear protrusion 3 b), is preferably 0.1 to 0.99, and more preferably 0.12 to 0.5. By setting the ratio of the length of the 2 nd linear convex portion 3b to that of the 1 st linear convex portion 3a within this range, 3 or more soundproof peaks having soundproof strength exceeding the mass law can be exhibited in a low frequency region of 800Hz or less.
The mass ratio of the entire linear convex portion 3 to the sheet portion 2 expressed by (total mass of the linear convex portion 3/mass of the sheet portion 2) is preferably 0.8 or more, more preferably 1 or more, and further preferably 1.5 or more. The upper limit of the mass ratio is not particularly limited, and from the viewpoint of the light weight of the soundproof sheet 1, for example, 20 or less is exemplified. By setting the mass ratio of the entire linear protruding portion 3 to the sheet portion 2 within this range, a local mass sufficient to excite a vibration mode effective for sound insulation can be provided to the sheet portion 2, and the sound insulation performance of the sound insulation sheet 1 can be effectively improved. The total mass of the linear protrusions 3 is a total value of all the masses of the plurality of linear protrusions 3 existing in 1 sound-insulating sheet, and the mass of the sheet portion 2 is a mass of the entire sheet portion 2 constituting 1 sound-insulating sheet 1.
The mass ratio of the entire convex portion B other than the linear convex portion 3 to the sheet portion 2 represented by (the total mass of the dot-shaped convex portion 4/the mass of the sheet portion 2) or (the total mass of the linear convex portion 3B (the 2 nd linear convex portion) 3B shorter than the linear convex portion 3) is preferably 0.15 or more, more preferably 0.3 or more, and still more preferably 1 or more. The upper limit of the mass ratio is not particularly limited, and from the viewpoint of the light weight of the soundproof sheet 1, for example, 6 or less is exemplified. By setting the mass ratio of the entire protruding portion B other than the linear protruding portion 3 to the sheet portion 2 within this range, a local mass sufficient to excite a vibration mode effective for sound insulation can be provided to the sheet portion 2, and the sound insulation performance of the sound insulation sheet 1 can be effectively improved. The total mass of the dot-shaped convex portions 4 is the total value of all the masses of the plurality of dot-shaped convex portions 4 present in 1 sound-insulating sheet 1, the total mass of the linear convex portions (2 nd linear convex portions) 3b shorter than the linear convex portions 3 is the total value of all the masses of the plurality of 2 nd linear convex portions 3b present in 1 sound-insulating sheet 1, and the mass of the sheet 2 is the mass of the entire sheet 2 constituting 1 sound-insulating sheet 1.
The mass ratio of the entire linear convex portion 3 to the entire dot-shaped convex portion 4, which is expressed by (total mass of the linear convex portion 3/total mass of the dot-shaped convex portion 4), is preferably 3.2 to 15, more preferably 3.5 to 15, and even more preferably 5 to 12. By setting the mass ratio of the entire linear convex portion 3 to the entire dot-shaped convex portion 4 within this range, a sound-insulating effect exceeding the mass law can be obtained in each of the different sound-insulating frequency bands. The total mass of the linear protrusions 3 refers to the total value of all the masses of the plurality of linear protrusions 3 present in 1 sound-insulating sheet 1, and the total mass of the dot-shaped protrusions 4 refers to the total value of all the masses of the plurality of dot-shaped protrusions 4 present in 1 sound-insulating sheet 1.
As described above, the above-described value (total mass of the dot-shaped convex portion 4/mass of the sheet portion 2) is applicable to a linear convex portion (2 nd linear convex portion) shorter than the linear convex portion, in addition to the case where the convex portion B is a dot-shaped convex portion.
The linear convex portion row structures 5 and the dot-like convex portion row structures 6 are generally arranged in plural on the sound insulating sheet 1, and from the viewpoint of sound insulating effect, it is preferable that these convex portion rows be arranged (in the longitudinal direction) in parallel with the convex portion row structures, that is, the longitudinal direction of these convex portion rows be substantially parallel with the longitudinal direction of the convex portion row structures. The substantially parallel means that the inclination may not be completely parallel, may be within ±5°, may be within ±3°, or may be within ±1°. However, the projections may be arranged not only in parallel but also at an appropriate angle as long as they do not impair the sound insulation effect and do not overlap with other projections and projections. The rows of the dot-like projections 4 in the projection row structure are generally arranged in a straight line, but may be arranged in a folded line or a curved line as long as they do not impair the sound insulation effect and do not overlap the dot-like projections 4 in the linear projections 3 or other projection row structures.
From the viewpoint of the sound insulation effect, it is preferable that 1 dot-like convex portion row structure 6 is arranged between 2 linear convex portion row structures 5 in a plan view, and 1 linear convex portion row structure 5 is preferably arranged between 2 dot-like convex portion row structures 6, more preferably the linear convex portion row structures 5 and the dot-like convex portion row structures 6 are alternately arranged, and even more preferably the linear convex portion row structures and the dot-like convex portion row structures 6 are alternately arranged at equal intervals. These alternate, alternate and equally spaced arrangements may be local or integral, preferably integral, with respect to the entirety of the sound insulating sheet 1. In this case, the arrangement of the convex portions in plan view means the arrangement of the convex portions observed so as to omit the sheet portion 2, that is, irrespective of which surface of the sheet portion 2 the convex portions are arranged. Further, from the same viewpoint, when the projections are observed in the entire sound-insulating sheet 1, it is further preferable to arrange the projections periodically.
The dot-like convex portion row structure 6 is a structure in which the arrangement of the dot-like convex portions 4 is made up of 1 or more rows, and the number of rows constituting the row structure 6 (2 in fig. 1 and 1 in fig. 2) is not particularly limited, but is usually 1 or more, may be 2 or more, may be 3 or more from the viewpoint of the sound insulation effect, and is usually 20 or less, preferably 15 or less, more preferably 10 or less, may be 8 or less, may be 5 or less, and particularly preferably 1 from the viewpoint of the light weight.
In the present specification, one dot-shaped convex portion row structure 6 is a collection of rows of the largest dot-shaped convex portions 4 that can be obtained without the dot-shaped convex portions 4 being separated by convex portions of a shape other than the dot-shaped convex portions such as the linear convex portions 3 in a plan view. That is, in fig. 1, the dot-shaped convex portion row structures 6 between the 2 linear convex portion structures 5 are not regarded as having 2 dot-shaped convex portion row structures 6 each consisting of 1 row, but are regarded as having 1 dot-shaped convex portion row structures 6 each consisting of 2 rows. The 1 linear convex portion row structure 5 is similarly a collection of rows of largest linear convex portions 3 that can be obtained without the linear convex portions 3 being separated by convex portions of a shape other than the linear convex portions 3 such as dot-shaped convex portions in a plan view.
The number of the dot-like projections 4 in each row constituting the dot-like projection row structure 6 (6 in fig. 1, 3 in fig. 2) is not particularly limited, but is usually 2 or more, may be 5 or more, may be 10 or more from the viewpoint of the sound-insulating effect, and is usually 100 or less, preferably 80 or less, more preferably 50 or less from the viewpoint of the light weight.
The intervals between the dot projections 4 constituting the dot projection array structure 6 are not particularly limited, and are preferably arranged at equal intervals (periodically) from the viewpoint of the sound insulation effect.
The number of rows constituting the linear convex portion row structure 5 (1 in fig. 1 and 2) is not particularly limited, but is usually 1 or more, may be 2 or more, may be 3 or more from the viewpoint of the sound insulation effect, and is usually 20 or less, preferably 15 or less, more preferably 10 or less, may be 8 or less, may be 5 or less, and preferably 1 from the viewpoint of the light weight.
The types of materials contained in the linear protrusions 3 and the dot-shaped protrusions 4 are not particularly limited, and examples thereof include resins and elastomers. Examples of the resin include a thermosetting or photocurable resin; the thermoplastic resin may be, for example, a heat-curable or light-curable elastomer or a thermoplastic elastomer.
In addition, not only the resin or the elastomer, but also: metals such as aluminum, stainless steel, iron, tungsten, gold, silver, copper, lead, or zinc; alloys such as brass, and inorganic glasses such as soda glass, quartz glass, and lead glass; or a composite obtained by adding a powder of such a metal or alloy, an inorganic glass, or the like to a resin material.
1 Of these materials may be used alone, and 2 or more materials may be used in combination in any combination and ratio from the viewpoint of sound insulation performance and manufacturing cost. The linear protrusions 3 and the dot-shaped protrusions 4 may be porous bodies including pores (gas such as air) or may not be porous bodies within a range that does not cause a decrease in sound insulation.
Examples of the resin contained in the linear protrusions 3 and the dot-shaped protrusions 4 include thermosetting resins such as phenol resins, epoxy resins, urethane resins, and rosin-modified maleic resins; photocurable resins such as homopolymers or copolymers of monomers such as epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, or modified products thereof; or a homo-or copolymer of a vinyl monomer such as vinyl acetate, vinyl chloride, vinyl alcohol, vinyl butyral, or vinyl pyrrolidone, or a thermoplastic resin such as an acrylic resin such as a homo-or copolymer of a monomer such as a saturated polyester resin, a polycarbonate resin, a polyamide resin, a polyolefin resin, a polyarylate resin, a polysulfone resin, a polyphenylene ether resin, or an acrylic acid ester or a methacrylic acid ester, or a modified product thereof.
Among these, from the viewpoints of shaping property and transparency, at least one selected from the group consisting of a photocurable resin and a thermoplastic resin is preferable, and an acrylic resin, a homopolymer of urethane (meth) acrylate, a homopolymer of polyester (meth) acrylate or a copolymer thereof, or a polyether (meth) acrylate resin is more preferable, and an acrylic resin or a urethane (meth) acrylate is particularly preferable. These may be used alone or in combination of 2 or more.
Examples of the elastic bodies contained in the linear convex portion 3 and the dot-shaped convex portion 4 include: a chemically crosslinked thermosetting elastomer such as a vulcanized rubber such as a natural rubber or a synthetic rubber, a urethane rubber, a silicone rubber, a fluororubber, or a thermosetting resin-based elastomer such as an acrylic rubber; thermoplastic elastomers such as olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, polyurethane-based thermoplastic elastomer, ester-based thermoplastic elastomer, amide-based thermoplastic elastomer, silicone rubber-based thermoplastic elastomer, acrylic-based thermoplastic elastomer, etc., photocurable elastomers such as acrylic-based photocurable elastomer, silicone-based photocurable elastomer, or epoxy-based photocurable elastomer, etc.; or a silicone-based thermosetting elastomer, an acrylic-based thermosetting elastomer, an epoxy-based thermosetting elastomer, or the like.
Among these, a silicone-based thermosetting elastomer, an acrylic-based thermosetting elastomer, or an acrylic-based photocurable elastomer, or a silicone-based photocurable elastomer is preferable. These may be used alone or in combination of 2 or more.
The photocurable resin refers to a resin polymerized by light irradiation. For example, a photo radical polymerizable resin or a photo cation polymerizable resin may be mentioned, and among them, a photo radical polymerizable resin is preferable.
The radical polymerizable resin preferably has at least 1 or more (meth) acryloyl groups in a molecule. The photoradical polymerizable elastomer having 1 or more (meth) acryloyl groups in the molecule is not particularly limited, and from the viewpoint of the elastic modulus of the cured product, for example, examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-methyl butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, 2-methyl hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-butyl hexyl (meth) acrylate, isooctyl (meth) acrylate, isoamyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxy (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, morpholin-4-yl (meth) acrylate, and the like, and resins of homopolymers or copolymers of monomers such as urethane (meth) acrylate.
Among these, homopolymers of urethane (meth) acrylates are preferable from the viewpoints of formability and transparency. These may be used alone or in combination of 2 or more.
The resin contained in the linear protrusions 3 and the dot-shaped protrusions 4 may contain a compound having an ethylenically unsaturated bond.
Examples of the compound having an ethylenically unsaturated bond include: aromatic vinyl monomers such as styrene, α -methylstyrene, α -chlorostyrene, vinyltoluene, and divinylbenzene; vinyl ester monomers such as vinyl acetate, vinyl butyrate, N-vinylformamide, N-vinylacetamide, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, or divinyl adipate; vinyl ethers such as ethyl vinyl ether and phenyl vinyl ether; allyl compounds such as diallyl phthalate, trimethylolpropane diallyl ether, or allyl glycidyl ether; (meth) acrylamides such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-t-butyl (meth) acrylamide, (meth) acryloylmorpholine, or methylenebis (meth) acrylamide; mono (meth) acrylates such as (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, morpholinyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl (meth) acrylate, allyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, isobornyl (meth) acrylate, or phenyl (meth) acrylate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate (number of repeating units: 5 to 14), propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate (number of repeating units: 5 to 14), 1, 3-butanediol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, polybutylene glycol di (meth) acrylate (number of repeating units: 3 to 16), poly (1-methylbutanediol) (number of repeating units: 5 to 20), 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hydroxypivalate di (meth) acrylate, dipentadiol di (meth) acrylate, caprolactone (n=2-m+2-butyrolactone of hydroxypivalate (n=5 to 2+m-butyrolactone of di (meth) acrylate, n=2+m+2-butyrolactone of di (meth) acrylate, A di (meth) acrylate of a caprolactone adduct of neopentyl glycol (n+m=2 to 5), a di (meth) acrylate of a caprolactone adduct of butanediol (n+m=2 to 5), a di (meth) acrylate of a caprolactone adduct of cyclohexanedimethanol (n+m=2 to 5), a di (meth) acrylate of a caprolactone adduct of dicyclopentanediol (n+m=2 to 5), a di (meth) acrylate of a caprolactone adduct of bisphenol a (n+m=2 to 5), a di (meth) acrylate of a caprolactone adduct of bisphenol F (n+m=2 to 5), a di (meth) acrylate of a bisphenol a ethylene oxide adduct (p=1 to 7), a di (meth) acrylate of a bisphenol F propylene oxide adduct (p=1 to 7), a tri (meth) acrylate, a tri (propylene oxide adduct (p=1 to 7), a tri (meth) acrylate (p=1 to 5) A tri (meth) acrylate of glycerol ethylene oxide adduct (p=1 to 5), a ditrimethylolpropane tetra (meth) acrylate, a tetra (meth) acrylate of ditrimethylolpropane ethylene oxide adduct (p=1 to 5), a pentaerythritol tri (meth) acrylate, a pentaerythritol tetra (meth) acrylate, a tri (meth) acrylate of pentaerythritol ethylene oxide adduct (p=1 to 5), a tetra (meth) acrylate of pentaerythritol ethylene oxide adduct (p=1 to 15), a tri (meth) acrylate of pentaerythritol propylene oxide adduct (p=1 to 5), a tetra (meth) acrylate of pentaerythritol propylene oxide adduct (p=1 to 15), a penta (meth) acrylate of dipentaerythritol ethylene oxide adduct (p=1 to 5), a hexa (meth) acrylate of dipentaerythritol ethylene oxide adduct (p=1 to 15), a poly (meth) acrylate such as N, N', N "-tri (meth) acryloyloxy poly (p=1 to 4) (ethoxy) ethyl) isocyanurate, a tri (meth) acrylate of pentaerythritol caprolactone (4 to 8 mole) adduct, a pentaerythritol lactone (4 to 8 mole) acrylate A multifunctional (meth) acrylate such as dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, penta (meth) acrylate of dipentaerythritol caprolactone (4 to 12 moles) adduct, hexa (meth) acrylate of dipentaerythritol caprolactone (4 to 12 moles) adduct, N '-tris (acryloyloxyethyl) isocyanurate, N' -bis (acryloyloxyethyl) -N "-hydroxyethyl isocyanurate, isocyanuric acid ethylene oxide modified (meth) acrylate, isocyanuric acid propylene oxide modified (meth) acrylate, or isocyanuric acid ethylene oxide-propylene oxide modified (meth) acrylate; or epoxy poly (meth) acrylates obtained by the addition reaction of a polyepoxide compound having a plurality of epoxy groups in the molecule, such as bisphenol a glycidyl ether, bisphenol F glycidyl ether, phenol novolac type epoxy resin, cresol novolac type epoxy resin, pentaerythritol polyglycidyl ether, trimethylolpropane triglycidyl ether, or triglycidyl tris (2-hydroxyethyl) isocyanurate, with (meth) acrylic acid.
Among these, phenoxyethyl acrylate, benzyl acrylate, 2-ethylhexyl (meth) acrylate, and methoxypolyethylene glycol acrylate having a low elastic modulus of the cured product are preferable, and 2-ethylhexyl (meth) acrylate or methoxypolyethylene glycol acrylate is more preferable. These may be used alone or in combination of 2 or more.
Examples of the material other than the resin and/or the elastomer which can be contained in the linear protrusions 3 and the dot-shaped protrusions 4 include metals such as aluminum, stainless steel, iron, copper, and zinc; alloys such as brass, aluminum alloy, and magnesium alloy; metal oxides such as alumina, zirconia, and barium titanate; hydroxides such as hydroxyapatite; carbides such as silicon carbide; carbonates such as calcium carbonate; nitride such as silicon nitride; halides such as calcium fluoride; ceramics such as glass, cement, or gypsum; or a composite material comprising particles or fibers of these metals or ceramics in the above resin and/or elastomer.
In addition to such an inorganic filler, for example, resin particles such as an acrylic resin, a styrene resin, a silicone resin, a melamine resin, or an epoxy resin and a copolymer thereof may be compounded with the above resin and/or elastomer to be used.
These materials may be used singly or in combination of 2 or more.
In the case where the resin included in the formation of the linear protrusions 3 and the dot-shaped protrusions 4 includes a photocurable resin or an elastomer, it is preferable to include a photopolymerization initiator from the viewpoints of improving moldability, mechanical strength, reducing manufacturing cost, and the like, and examples thereof include a photopolymerization initiator such as benzoin-based, acetophenone-based, thioxanthone-based, phosphine oxide-based, or peroxide-based.
Specific examples of the photopolymerization initiator include benzophenone, 4-bis (diethylamino) benzophenone, 2,4, 6-trimethylbenzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2-ethylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] phenyl } -2-methyl-propane-1-one, benzil dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, benzoin methyl ether, benzoin diethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methyl- [4- (methylthio) phenyl ] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, diethylthioxanthone, isopropylthioxanthone, 2,4, 6-trimethylbenzoyl phosphine oxide, bis (2, 6-dimethylbenzoyl) -2, 6-dimethylbenzoyl phosphine oxide, and the like.
These may be used alone, or 2 or more kinds of materials may be used in combination in any combination and ratio.
The content of the photopolymerization initiator in the resin for forming the linear protrusions 3 and the dot-shaped protrusions 4 is not particularly limited, and in terms of improving the mechanical strength and maintaining an appropriate reaction rate, the mass of the material constituting the linear protrusions 3 and the dot-shaped protrusions 4 is usually 0.1 mass% or more, preferably 0.3 mass% or more, and more preferably 0.5 mass% or more, based on 100 mass%. In addition, the content is usually 3% by mass or less, preferably 2% by mass or less.
The resins contained in the linear protrusions 3 and the dot-shaped protrusions 4 may contain various additives such as flame retardants, antioxidants, plasticizers, defoaming agents, and mold release agents as other components as long as they do not inhibit the sound insulation performance, and these may be used alone or in combination of 1 or 2 or more.
Flame retardants are additives that are used to blend flammable raw materials that are not easily burned or ignited. Specific examples thereof include bromine compounds such as pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol a, hexabromocyclododecane, and hexabromobenzene; phosphorus compounds such as triphenyl phosphate; chlorinated compounds such as chlorinated paraffin; antimony compounds such as antimony trioxide; metal hydroxides such as aluminum hydroxide; nitrogen compounds such as melamine cyanurate; or a boron compound such as sodium borate, etc., but is not particularly limited thereto.
The antioxidant is an additive blended to prevent oxidative degradation. Specific examples thereof include phenol antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like, but are not particularly limited thereto.
Plasticizers are additives blended for improving flexibility and weather resistance. Specific examples thereof include phthalic acid esters, adipic acid esters, trimellitic acid esters, polyesters, phosphoric acid esters, citric acid esters, sebacic acid esters, azelaic acid esters, maleic acid esters, silicone oils, mineral oils, vegetable oils, modified products thereof, and the like, but are not particularly limited thereto.
[ Method of Forming Sound-insulating sheet ]
The molding method of the soundproof sheet 1 is not particularly limited, and a generally known sheet molding method can be employed. In the case of a thermosetting or thermoplastic resin or elastomer, for example, a melt molding method such as press molding, extrusion molding, or injection molding is given, and molding conditions such as temperature and pressure for performing melt molding in this case may be appropriately changed depending on the type of material used.
In the case of a photocurable resin or an elastomer, for example, the resin or the like may be injected into an active energy ray-transparent plate-shaped molding die, and the resin or the like may be cured by irradiation with active energy rays.
The active energy ray used for curing the photocurable resin or the like may be a ray for curing the photocurable resin or the like used, and examples thereof include ultraviolet rays, electron beams, and the like.
The irradiation amount of the active energy ray may be an amount for curing the photocurable resin or the like used, and for example, ultraviolet rays having a wavelength of 200 to 400nm are usually irradiated in the range of 0.1 to 200J, considering the types and amounts of the monomer and the polymerization initiator.
As the light source of the active energy ray, a chemical lamp, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, or the like can be used. The irradiation with the active energy ray may be performed in 1 stage, and in order to obtain a photocurable resin sheet having good surface properties, it is preferable to perform the irradiation in multiple stages or at least 2 stages. In the case of using a photocurable resin, a curing accelerator may be contained.
The method of molding the linear protrusions 3 and the dot-shaped protrusions 4 on the sheet 2 is not particularly limited, and the sheet 2 may be molded simultaneously with the linear protrusions 3 and the dot-shaped protrusions 4 by using a mold having a cavity, or may be molded by compounding the sheet 2 with the linear protrusions 3 and the dot-shaped protrusions 4.
Hereinafter, a method of forming the sheet portion 2 by compounding the linear convex portion 3 and the dot-shaped convex portion 4 will be described in detail, but the present invention is not limited to this method.
The method of compounding the sheet portion 2 with the linear protrusions 3 and the dot-shaped protrusions 4 is not particularly limited, and any method may be used, such as a method of forming the linear protrusions 3 and the dot-shaped protrusions 4 on the sheet portion 2, or a method of bonding the linear protrusions 3 and the dot-shaped protrusions 4 to the sheet portion 2 after molding. In the case of the bonding method, an adhesive is preferably used, and the type of adhesive is not limited as long as the linear protrusions 3 and the dot-shaped protrusions 4 can be bonded to the sheet portion 2.
Next, an example of a method of molding the soundproof sheet 1 using the photocurable resin will be described.
Fig. 8 shows a schematic cut end surface of a die used for molding the soundproof sheet 1. The illustrated mold 9 has a plurality of cavities (grooves) 9a formed in the upper surface thereof, the cavities corresponding to the outer shapes of the convex structures of the sound-insulating sheet 1, that is, the surfaces of the cavities being recessed in a shape corresponding to the outer shapes of the linear convex portions 3 and the dot-shaped convex portions 4.
Using this mold 9, the sound insulating sheet 1 can be molded in the following steps.
First, the mold 9 is placed with the surface of the side where the cavity 9a is formed facing upward, and the photocurable resin is flowed into each cavity 9a to fill the cavity, and the sheet 2 made of a material that transmits a specific light such as ultraviolet rays or electron beams that can cure the photocurable resin is superimposed thereon.
Then, with the sheet portion 2 pressed against the upper surface of the mold 9, a specific light is irradiated from above, passed through the sheet, and the photocurable resin in the cavity 9a is cured, and fixed to the surface of the sheet portion 2.
Then, when the photocurable resin is cured, as shown in fig. 9, the sheet portion 2 having the linear protrusions 3 and the dot-shaped protrusions 4 fixed to the surface thereof is peeled off from the mold 9, whereby the soundproof sheet 1 can be obtained.
< Acoustic Transmission loss >)
As the evaluation of the sound insulation characteristics of the sound insulation sheet 1, an evaluation based on measurement of the sound transmission loss can be performed.
When white noise is generated in one of the two spaces defined by the sound insulating sheet 1, the sound Transmission Loss (TL) is obtained from the difference between the sound pressure level (L in) at a predetermined portion of the space (sound source chamber) where sound is generated and the sound pressure level (L out) at a predetermined portion of the other space (sound receiving chamber) at each center frequency of the 1/12 times (octave) frequency band of 72.8 to 10900Hz based on the following expression (2).
TL[dB]＝Lin-Lout-3 (2)
L in: sound pressure level of sound source chamber (dB)
L out: sound pressure level of sound receiving chamber (dB)
Incident sound: white noise (for example, sound pressure having an average sound pressure value of about 0.94Pa in a frequency region of 72.8 to 10900 Hz)
Sample-microphone spacing: 10mm of
The 1 st sound-insulating sheet 1 described above is required to have at least 2 or more peaks (peak-shaped waveforms) on a graph having a horizontal axis of frequency X and a vertical axis of Δtl (dB) obtained by the following formula (1), which is obtained by measuring the sound transmission loss, and this requirement is preferably applied to another embodiment. It was confirmed by the present inventors that 2 or more peaks were not observed in a manner that 2 linear protrusions were arranged at both ends of the sheet portion 2, a plurality of dot-like protrusions 4 were arranged between them, and no other protrusions were present.
ΔTL＝TL1-TL2 (1)
(In the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, TL 2 is the sound transmission loss (dB) of a flat sheet having no irregularities and having the same mass and area as the sound-insulating sheet and the area of the sheet portion at the frequency X.)
The arrangement of the sound insulating sheet 1 with respect to the sound source is not particularly limited, as long as the sound insulating sheet 1 can be arranged along the outer periphery of the opening between the sound source chamber and the sound receiving chamber without a gap. The arrangement of the sound-insulating sheet 1 in the measurement of the acoustic transmission loss is not particularly limited, and the requirement of satisfying the peak is that at least one of the above-described requirements is satisfied in any arrangement, and the sound-insulating sheet 1 is preferably arranged along the outer periphery of the opening between the sound source chamber and the sound receiving chamber so that no gap is formed as the arrangement of the peak is easily observed.
The height of the peak in the graph obtained by measuring the acoustic transmission loss is not particularly limited, but is preferably 3dB or more, more preferably 5dB or more, further preferably 15dB or more, from the viewpoint of enabling the noise reduction effect to be perceived, and the upper limit is not particularly limited, and is usually 25dB or less. The number of peaks satisfying it is not particularly limited, and is preferably satisfied with at least one of the above-mentioned at least 2 peaks, more preferably with at least 2 peaks, from the viewpoint that a single sheet exhibits a high sound-insulating effect exceeding the law of mass in different design frequency bands.
In the case where the peak with the lowest frequency among the 2 or more peaks is referred to as a first peak and the peak with the lowest frequency next to the first peak is referred to as a second peak, the absolute value of the difference between Δtl of the first peak and Δtl of the second peak is not particularly limited, and is usually 20dB or less, preferably 15dB or less, more preferably 10dB or less, still more preferably 5dB or less, particularly preferably 3dB or less, from the viewpoint of achieving a balanced sound insulation effect at a plurality of frequencies, and the preferable lower limit is not particularly limited, but is usually 0dB or more and may be 1dB or more.
< Sound insulation Structure >)
Another embodiment of the present invention is a sound insulation structure in which the sound insulation sheet 1 is laminated on a sound absorbing material. In the present specification, the sound insulation structure means a structure in which the sound insulation sheet 1 and the sound absorbing material are laminated.
Fig. 5 shows, as an example of the sound insulation structure, a sound insulation structure 7 having a sound insulation sheet 1 and a sound absorbing material 8, but is not limited to this embodiment. The shape of the sound absorbing material 8 is not particularly limited as long as it can be provided so as to be laminated on the sound insulating sheet 1, and is preferably a sheet shape.
The sound insulating sheet 1 may be attached to the sound absorbing material 8 by an adhesive, a double-sided tape, or a tape (gum), or may be physically fixed by a nail gun (tacker) or a stapler. Further, the fixing may be not fixed, and may be in a state of being closely adhered to each other. The sound absorbing material 8 may be located on the one surface 2a side of the sheet portion 2 where the convex portion of the sound insulating sheet 1 exists, or may be located on the surface 2b where the convex portion does not exist, as shown in fig. 5, or may be disposed on both surfaces thereof. Further, a sound insulating material, a nonflammable material, or the like may be further laminated on the surface of the sound absorbing material 8 other than the surface on which the sound insulating sheet 1 is laminated, depending on the application.
In the sound absorbing material 8, a material that is easily deformed and can follow the vibration displacement of the sheet portion 2 is preferably used in order not to interfere with the vibration even when the sound absorbing material is in contact with the sound insulating sheet 1.
For example, glass wool, asbestos, felt, rubber cloth, nonwoven fabric, fibrous polymer, or a fibrous sound absorbing material formed of inorganic fibers; or a foam of a polymer such as polyurethane, various rubbers, polyethylene, polystyrene, or polypropylene, or an inorganic porous material, a metal foam, or a porous material obtained by curing and molding a pulverized product, fiber chips, or the like with various binders, and these may be used alone or in combination of two or more. Among these, a foam such as a nonwoven fabric, a polymer foam, or a metal foam, glass wool, felt, or rubber cloth is preferable, and a nonwoven fabric or a foam is particularly preferable from the viewpoint of obtaining a high sound insulation effect.
Examples
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded. The various conditions and values of the evaluation results in the examples represent the preferred ranges of the present invention in the same manner as the preferred ranges in the above-described embodiments of the present invention. The preferred ranges of the present invention can be determined in consideration of ranges represented by the preferred ranges in the above-described embodiments and values of the following examples or combinations of values of the examples with each other.
Example 1
The raw materials were weighed in terms of mass ratio and mixed for 20 minutes and 10 minutes using Awatori Rentaro (product of THINKY Co., AR-250) so as to obtain EBECRYL230 (product of Daicel-Allnex Co., ltd., urethane acrylate, weight average molecular weight: 5000)/Aronix M-120 (product of east Asian Synthesis Co., ltd., special acrylate)/IRGACURE 184 (product of BASF Co., 1-hydroxycyclohexylphenyl ketone)/IRGACURE.TPO (product of BASF Co., ltd., 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide) =50/50/1/0.1), and the mixture BL was obtained by stirring.
By the method shown in fig. 8 and 9, the sound-insulating sheet 1 having the arrangement shown in fig. 1, i.e., the arrangement in which 1 linear convex portion row and 2 columnar dot convex portion rows are alternately arranged, is obtained.
Specifically, after the above mixture BL was poured into a rectangular mold 9 of A4 size (in which the longitudinal direction of the column is the short side direction of the sheet portion 2) in which aluminum concave grooves (cavities) corresponding to the convex portions of the soundproof sheet 1 were arranged, a PET film having a short side direction length of 250mm, a long side direction length of 340mm, a thickness of 250 μm, a young's modulus at 25 ℃ of 5GPa, a specific gravity of 1.2, and an areal density of 0.3kg/m 2 was placed on the mold 9, and the soundproof sheet 1 was molded by ultraviolet irradiation with an energy of 1000mJ/m 2 at a wavelength of 200nm to 450nm using a high-pressure mercury lamp 21 as a material of the sheet portion 2. Then, the soundproof sheet 1 cured in the mold 9 is peeled off from the mold 9.
The resulting soundproof sheet 1 had the following structure: a film having a thickness of 0.05mm, which was formed by solidifying the mixture BL, was laminated on a PET film having a thickness of 250 μm, and linear protrusion row structures 5 each having linear protrusions 3 each having a width of 6mm, a height of 5mm, and a length of 210mm were arranged on the film at a pitch of 90mm, and dot-shaped protrusion row structures 6 (each having dot-shaped protrusions 4 each having a diameter of 6mm and a height of 5mm and each having a linear shape at a pitch of 30 mm) were arranged between the linear protrusion row structures 5 in 2 rows so that the distance between the dot-shaped protrusion row structures 6 and the central line of the linear protrusion row structures 5 became 30 mm. In the sheet portion 2, each of the convex portion rows is arranged such that, when a plurality of line segments are drawn at any position along the short side direction of the sheet portion 2, the center of the linear convex portion row and the center of the dot-shaped convex portion row exist on a straight line connecting the midpoints of the line segments. That is, in this embodiment, the convex portion is formed in the region of 210mm×297mm in the center of the 250mm×340mm PET film.
The number of linear and dot-shaped protrusion rows is the number at which the total number of protrusion rows stored in the length direction 297mm of the A4 region is the largest among the specified inter-protrusion row pitches, and the positioning of the protrusion rows in the sheet length direction is arranged on the sheet section 2 such that when a plurality of line segments are drawn at any position along the length direction of the sheet section 2, the midpoints of the line segments are connected to form a straight line, and the straight line is line-symmetrical.
In addition, regarding the number and arrangement of the dot-like projections 4 in the dot-like projection row, the projection row is arranged such that the center of the dot-like projection row is located on a straight line connecting the midpoints of the plurality of line segments when the line segments are drawn out at arbitrary positions along the short side direction of the sheet 2, and the maximum number of dot-like projections 4 stored in the short side direction 210mm of the A4 region at a predetermined inter-projection pitch is arranged such that the center of the line-like projection row is located on a straight line connecting the midpoints of the plurality of line segments when the line segments are drawn out at arbitrary positions along the short side direction of the sheet 2. The same applies to the following examples and comparative examples as to the number and positioning method of the protrusions.
The film of 0.05mm is a part of the sheet 2, but since the surface density of the film is very small compared with the surface density of the PET film, the young's modulus, specific gravity and surface density of the sheet 2 can be used, and the presence or absence of the film has very little influence on the sound insulation performance. The same applies to examples and comparative examples described later.
Example 2
The sound-insulating sheet 1 was molded in the same manner as in example 1, except that the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 1 was changed to the mold 9 in which the sound-insulating sheet 1 having the arrangement shown in fig. 2, i.e., the arrangement in which 1 linear convex portion row and 1 columnar dot convex portion row were alternately arranged, was obtained.
The resulting soundproof sheet 1 had the following structure: a film of 0.05mm in thickness formed by solidifying the mixture BL was laminated on a PET base material of 125 μm in thickness, and linear projection row structures 5 composed of linear projections 3 of 6mm in width and 5mm in height were arranged at 30mm intervals on the film, 1 row of dot projection row structures 6 were arranged between the linear projection row structures 5 so that the interval from the linear projection row structures 5 became 15mm, and the dot projection row structures 6 were formed by arranging dot projections 4 of 6mm in diameter and 5mm in height in a straight line at 15mm intervals.
Example 3
The soundproof sheet 1 of example 3 is the soundproof sheet 1 of the configuration shown in fig. 3, that is, the configuration in which 1 column of linear convex portions and 1 column of quadrangular prism-like dot convex portions are alternately arranged, and is the following configuration: on a PET substrate having a thickness of 250 μm, linear protrusion row structures 5 each composed of linear protrusions 3 having a prism shape of 6mm in width, 10mm in height and 210mm in length cut out from an acrylic plate as linear protrusions 3 were fixed to a substrate (sheet) surface 2a at 42mm intervals using an adhesive, and dot-shaped protrusion row structures 6 (each of which is formed by linearly arranging dot-shaped protrusions 4 having a prism shape of 7.1mm in width and 6mm in height cut out from an acrylic plate at 38mm intervals) were arranged 1 row between the linear protrusion row structures 5 so that the distance between the dot-shaped protrusion row structures 6 and the center line of the linear protrusion row structures 5 became 21 mm.
Example 4
The sound-insulating sheet 1 was molded in the same manner as in example 1, except that the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 1 was changed to the mold 9 in which the sound-insulating sheet 1 having the arrangement shown in fig. 5, i.e., the arrangement in which 1 linear convex portion row and 1 columnar dot convex portion row were alternately arranged, was obtained.
The resulting soundproof sheet 1 had the following structure: a film of 0.05mm in thickness, which is formed by solidifying the mixture BL, was laminated on a PET base material of 125 μm in thickness, and on the film, linear protrusion row structures 5 composed of linear protrusions 3 of 6mm in width and 5mm in height were arranged at 35mm intervals, and dot-shaped protrusion row structures 6 (which are formed by linearly arranging dot-shaped protrusions 4 of 6mm in diameter and 5mm in height at 35mm intervals) were arranged 1 row between the linear protrusion row structures 5 such that the distance between the dot-shaped protrusion row structures 6 and the center line of the linear protrusion row structures 5 became 17.5 mm. The sound-insulating sheet 1 was formed by attaching each side of the sound-insulating sheet 1 to the surface of a sound-absorbing material 8 made of ultrafine acrylic fiber XAI (registered trademark) (weight per unit area: 360g/m 2, thickness: 25 mm) using a double-sided tape, and a sound-insulating structure 7 was produced in a manner similar to that of fig. 5.
Comparative example 1
The sound-insulating sheet 1 was molded in the same manner as in example 1, except that the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 1 was changed to the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 6 was obtained, that is, the shape in which only the linear convex portions 3 were arranged as convex portions.
The resulting soundproof sheet 1 had the following structure: on a PET substrate having a thickness of 250 μm, a film having a thickness of 0.05mm formed by curing the above-mentioned mixture BL was laminated, and on the film, only linear convex portion array structures 5 composed of linear convex portions 3 having a width of 6mm and a height of 5mm were arranged at a pitch of 30 mm.
Comparative example 2
The sound-insulating sheet 1 was molded in the same manner as in example 1, except that the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 1 was changed to the mold 9 in which the sound-insulating sheet 1 having the shape shown in fig. 7, that is, the shape in which only the columnar dot-like convex portions 4 were arranged as the convex portions, was obtained.
The resulting soundproof sheet 1 had the following structure: on a PET substrate having a thickness of 250 μm, a film having a thickness of 0.05mm obtained by curing the mixture BL was laminated, and on the film, only dot-shaped convex portions 6 each composed of dot-shaped convex portions 4 each having a diameter of 6mm and a height of 5mm were arranged at intervals of 30mm in the longitudinal and transverse directions.
[ Measurement of Acoustic Transmission loss ]
The sound-insulating sheet 1 or the sound-insulating structure 7 produced in examples 1 to 4 and comparative examples 1 to 2 was used to measure the sound transmission loss.
In this measurement, the surface having the irregularities is disposed toward the sound receiving chamber. In each of the examples and comparative examples, the measured value of the acoustic transmission loss when the acoustic insulator sheet 1 was replaced with a flat sheet having the same mass as the acoustic insulator sheet 1 and the same area as the sheet portion 2 and having no irregularities was measured as the value in the mass law. In this case, a difference obtained by subtracting the acoustic transmission loss in the mass law from the acoustic transmission loss in the case of using the acoustic insulator sheet 1 is calculated. Table 1 summarizes the frequencies of peaks (frequencies at the maximum values of peaks) and Δtl at the frequencies (the "difference between the transmission loss at the sound-deadening frequency and the mass law" in table 1) observed in a graph having the frequency X on the horizontal axis and the Δtl (dB) obtained by the following formula (1) on the vertical axis. In examples 1 to 4, 2 peaks having a height of 3dB or more were observed, and thus 2 differences are shown in Table 1.
ΔTL＝TL1-TL2 (1)
(In the above formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, TL 2 is the sound transmission loss (dB) of a flat sheet having no irregularities and having the same mass and area as the sound-insulating sheet and the area of the sheet portion at the frequency X.)
The measurement conditions of the acoustic transmission loss are shown below.
When white noise is generated in one of the two spaces defined by the sound insulating sheets 1 and the sound insulating structures 7 produced in examples 1 to 4 and comparative examples 1 to 2, the sound Transmission Loss (TL) is obtained from the difference between the sound pressure level (L in) at the predetermined portion of the space where sound is generated (sound source chamber) and the sound pressure level (L out) at the predetermined portion of the other space (sound receiving chamber) at each center frequency of the 1/12 th-fold frequency band of 72.8 to 10900Hz based on the following formula (2).
TL[dB]＝Lin-Lout-3 (2)
L in: sound pressure level of sound source chamber (dB)
L out: sound pressure level of sound receiving chamber (dB)
Incident sound: white noise (average sound pressure value in frequency region of 72.8-10900 Hz is 0.94 Pa)
Sample-microphone spacing: 10mm of
Simulation
Example 5
An infinite plane model to which a cycle boundary condition applies is constructed by reproducing a unit cell portion having substantially the same shape as in fig. 2 in which linear protrusion row structures 5 and dot protrusion row structures 6 are arranged in parallel and alternately with each other and are always arranged in 1 direction at equal intervals with each other on a sheet portion 2a on simulation software COMSOLMultiphysics (registered trademark). The sheet 2 was made of PET, and had a density of 1200kg/m 2, an elastic modulus of 5GPa, a Poisson's ratio of 0.39, a loss factor of 0.1, and a thickness of 250. Mu.m. Further, a film of a photocurable resin having a thickness of 0.05mm was present on the surface of the sheet portion 2 on which the convex portions were disposed, and the convex portions formed of the photocurable resin were disposed thereon, the photocurable resin had a density of 1050kg/m 2, a poisson ratio of 0.49, and a loss factor of 0.1. The elastic modulus of the photocurable resin is calculated by the following formula (3).
E: elastic modulus of photocurable resin (Pa)
F: frequency (Hz)
The acoustic transmission loss when plane waves having a sound pressure of 1Pa were incident from the surface 2a side of the sheet 2 of the shape models 1 to 20 produced on the simulation software in example 5 described in table 2 was obtained by the acoustic structure joint calculation based on the finite element method. At this time, the sound transmission loss simulation of each of the shape models 1 to 20 of table 2 was performed with the width of the linear convex portion 3 being W, the height being hl, the pitch of the linear convex portion row structure 5 being pl, the diameter of the dot convex portion 4 being Φ, the height being hd, the pitch of the dot convex portion in the dot convex portion row structure 6 being pd, the thickness of the sheet portion 2 being T.
The mass of the sheet was compared with the mass law value of a flat sheet having no irregularities and having the same mass as the sound-insulating sheet 1 of each shape and the same area as the sheet portion 2. In this case, a difference obtained by subtracting the mass law value from the acoustic transmission loss when the acoustic insulator 1 is used is calculated, and a graph is created in which the frequency X is on the horizontal axis and Δtl (dB) obtained by the above formula (2) is on the vertical axis.
As a result, in all shape models, 2 or more peaks were observed. The peak with the lowest frequency among the 2 or more peaks is referred to as a first peak, and the peak with the lower frequency next to the first peak is referred to as a second peak. Fig. 10 is a graph showing a graph of Δtl of the first peak (maximum value of the first peak) plotted on the vertical axis and the mass ratio of linear convex portion 3/segment 2 plotted on the horizontal axis, fig. 11 is a graph showing a graph of Δtl of the second peak (maximum value of the second peak) plotted on the vertical axis and the mass ratio of dot-shaped convex portion 4/segment 2 plotted on the horizontal axis, and fig. 12 is a graph showing a graph of the absolute value of the difference between Δtl of the first peak and Δtl of the second peak plotted on the vertical axis and the mass ratio of linear convex portion 3/dot-shaped convex portion 4 plotted on the horizontal axis. In fig. 12, the plot is made in a manner other than the value of Δtl for the first peak being less than 3 dB.
As shown in examples 1 to 4 of table 1, the sound insulating sheet 1 having the linear convex portion array structure 5 and the dot convex portion array structure 6 exhibits a transmission loss exceeding the mass law in sound waves of different frequency bands.
On the other hand, as shown in comparative examples 1 to 2 of table 1, the soundproof sheet 1 having only the linear convex portion row structure 5 and the soundproof sheet 1 having only the dot convex portion row structure 6 exhibit a soundproof effect exceeding the mass law only in one frequency band.
Therefore, it is shown that the shape of the linear convex portion array structure 5 and the dot convex portion array structure 6 arranged is indispensable for designing the sound insulating sheet 1 exhibiting the sound insulating effect in a plurality of frequency bands.
As is clear from the simulation results shown in fig. 10 to 11, in the design of the soundproof sheet 1 capable of blocking a plurality of frequency bands, the first peak is likely to occur when the mass ratio of the linear convex portion 3 to the sheet portion 2 is 0.8 or more, and the second peak is likely to occur when the mass ratio of the dot convex portion 4 to the sheet portion 2 is 0.15 or more. As shown in fig. 12, when the mass ratio of the linear convex portion 3 to the dot-like convex portion 4 is also in the range of 3.2 to 15, it is found that both of the different soundproof peaks easily show a transmission loss value exceeding the mass law.
Example 6
An infinite plane model to which a cycle boundary condition applies is constructed by reproducing a unit cell portion having substantially the same shape as in fig. 4 on simulation software COMSOLMultiphysics (registered trademark), wherein in fig. 4, on a surface 2a of a sheet portion 2, 1 st linear convex portion row structures 5a and 2 nd linear convex portion row structures 5b different from the 1 st linear convex portion row structures 5a are arranged in parallel and alternately with each other, and 1 st linear convex portion rows 3a and 2 nd linear convex portion rows 3b are always arranged at equal intervals in 1 direction with each other.
Specifically, the soundproof sheet 1 of example 6 has the following configuration: on the sheet portion 2a, 1 st linear protrusion row structures 5a constituted by 1 st linear protrusions 3a having a width of 10mm and a height of 10mm are arranged such that the distance between the central lines is 60mm, and 2 nd linear protrusion row structures 5b (which are formed by 2 nd linear protrusions 3b having a width of 5mm, a height of 8mm, and a length of 285mm being arranged linearly at a pitch of 330 mm) are arranged in 1 st row between the 1 st linear protrusion row structures 5a such that the distance between the central lines of the 1 st linear protrusion row structures 5a and the 2 nd linear protrusion row structures 5b is 30 mm. The sheet 2 was PET having a density of 1200kg/m 2, an elastic modulus of 5GPa, a Poisson's ratio of 0.39, a loss factor of 0.1 and a thickness of 250. Mu.m. The protruding portion formed of polymethyl methacrylate having a density of 1180kg/m 2, an elastic modulus of 3GPa, a poisson's ratio of 0.39, and a loss factor of 0.1 was disposed on the sheet portion 2.
Example 7
The soundproof sheet 1 of example 7 is a soundproof sheet 1 in which the 1 st linear protrusion row structures 5a and the 2 nd linear protrusion row structures 5b different from the 1 st linear protrusion row structures 5a are arranged in parallel with each other and alternately on the surface 2a of the sheet portion 2, and the 1 st linear protrusion row 3a and the 2 nd linear protrusion row 3b are always arranged at equal intervals in 1 direction, and is configured as shown in fig. 4, and is configured as follows: on a PET film having a Young's modulus of 5GPa, a specific gravity of 1.2, and an areal density of 0.3kg/m 2 at a temperature of 25 ℃ and a length of 1000mm in the short side direction, 1000mm in the long side direction, a thickness of 250 μm, and a length of 900mm, 1 st linear convex portions 3a cut out from an acrylic plate were fixed to a base (sheet) surface 2a at intervals of 60mm by using an adhesive, thereby forming 1 st linear convex portion row structures 5a, and similarly 2 nd linear convex portions 3b cut out from an acrylic plate, having a width of 5mm, a height of 8mm, and a length of 267mm, were fixed between the 1 st linear convex portion row structures 5a at intervals of 310mm on the base (sheet) surface 2a by using an adhesive, thereby forming 2 nd linear convex portion row structures 5b, and arranged such that the center line distance between the 1 st linear convex portion row structures 5a and the 2 nd linear convex portion row structures 5b becomes 30 mm.
The convex portion rows are arranged on the sheet portion 2 such that the center of the 1 st linear convex portion row and the center of the 2 nd linear convex portion row are present on a straight line connecting midpoints of a plurality of line segments when the line segments are drawn at any position along the short side direction of the sheet portion 2. That is, in this embodiment, a convex portion is formed in a 900mm×900mm region in the center of a 1000mm×1000mm PET film.
[ Measurement of Acoustic Transmission loss ]
The sound-insulating sheet of example 6 was evaluated for acoustic transmission loss by simulation.
The sound-insulating sheet 1 produced in example 7 was used, and the sound transmission loss was measured by the same method as the sound-insulating sheet 1 or the sound-insulating structure 7 produced in examples 1 to 4 and comparative examples 1 to 2.
In measurement, when white noise is generated in one of the two spaces defined by the sound insulating sheet 1, the sound Transmission Loss (TL) is obtained from the difference between the sound pressure level (L in) at the predetermined portion of the space where sound is generated (sound source chamber) and the sound pressure level (L out) at the predetermined portion of the other space (sound receiving chamber) at each center frequency of the 1/3 times the frequency band of 100 to 10000Hz based on the above formula (2).
The evaluation and measurement results are shown in Table 3.
TABLE 3
As shown in table 3, by changing from the dot-shaped convex portion 4 to the 2 nd linear convex portion 3b, the number of sound-insulating peaks at frequencies of 800Hz or less increases from 2 to 3 or 4. It is thus found that by adjusting the shape of the projection, the sound-insulating panel can exhibit high sound-insulating properties over a wide frequency band for low-frequency noise which is generally difficult to mute in a sound-absorbing material or a lightweight sound-insulating panel.
Symbol description
1. Sound insulation sheet
2. Sheet part
2A surface of the sheet portion
2B face of sheet portion
3. Linear convex part
3A 1 st linear convex part
3B No. 2 linear protrusion
4. Punctiform convex part
5. Linear convex part array structure
5A 1 st linear convex part array structure
5B No. 2 linear convex part array structure
6. Point-like convex part array structure
7. Sound insulation structure
8. Sound absorbing material
9. Mould
9A cavity.

Claims (27)

1. A sound-insulating sheet is characterized by comprising a sheet portion and a convex portion,
The convex part includes at least a convex part A and a convex part B having different shapes,
On either side of the sheet, there are more than 2 convex part areas where the convex part A exists,
On either side of the sheet, there are more than 2 convex part areas where the convex part B exists,
In a graph obtained by measuring the acoustic transmission loss, in which the frequency X is on the horizontal axis and the DeltaTL (dB) obtained by the following formula (1) is on the vertical axis, at least 2 peaks are obtained, and the height of at least 2 of the peaks is 3dB or more,
ΔTL＝TL1-TL2 (1)
In the formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, and TL 2 is the sound transmission loss (dB) of the flat sheet having no irregularities, which has the same mass as the sound-insulating sheet and the same area as the sheet portion, at the frequency X.
2. The sound insulating sheet according to claim 1, wherein the convex portion a is a linear convex portion.
3. Sound insulating sheet according to claim 1 or 2, characterized in that a plurality of protrusions B are present in the protrusion area B, the protrusions B being punctiform protrusions.
4. A sound-insulating sheet is characterized by comprising a sheet portion and a convex portion,
The convex part is provided with at least a linear convex part and a plurality of point-shaped convex parts,
At least 2 convex part areas with the linear convex parts are arranged on any surface of the sheet part,
The sheet portion has 2 or more convex portion regions on either side thereof, in which a plurality of the dot-like convex portions are present.
5. The sound-insulating sheet according to any one of claims 2 to 4, wherein the dot-like convex portions in the convex portion region where the plurality of dot-like convex portions are present are arranged in a column structure composed of 1 or more columns, and a longitudinal direction of the column structure is substantially parallel to a longitudinal direction of the column structure composed of the linear convex portions.
6. The sound insulating sheet according to claim 5, wherein the column structures formed of the linear protrusions and the column structures formed of the dot-like protrusions are alternately arranged in a plan view.
7. The sound insulating sheet according to claim 5, wherein the linear protrusions are arranged alternately and at equal intervals from the dot protrusions in a plan view.
8. The sound insulating sheet according to any one of claims 5 to 7, wherein the dot-like projections in the column structure are arranged at equal intervals from each other.
9. The soundproofing sheet according to any one of claims 2 to 8, wherein,
The value expressed by (total mass of linear convex portion/mass of piece portion) is 0.8 or more,
A value represented by (total mass of dot-like convex portions/mass of sheet portion) of 0.15 or more, and
The value expressed by (total mass of linear convex portion/total mass of dot convex portion) is 3.5 to 15.
10. The sound insulating sheet according to any one of claims 3 to 9, wherein the dot-like convex portion has a cylindrical shape.
11. Sound insulating sheet according to any one of claims 3 to 9, characterized in that the shape of the dot-like protruding portion is a prismatic shape.
12. A sound-insulating sheet as claimed in claim 2 or 4, wherein,
The convex portion B is a linear convex portion having a length different from that of the linear convex portion A,
In each convex portion region where the convex portion B exists, the convex portion B as a linear convex portion is arranged in series in a plurality of numbers.
13. The sound-insulating sheet according to any one of claims 4 to 12, wherein at least 2 peaks are obtained in a graph having a horizontal axis of frequency X and a vertical axis of ΔTL (dB) obtained by the following formula (1) and the heights of at least 2 of the peaks are 3dB or more,
ΔTL＝TL1-TL2 (1)
In the formula (1), TL 1 is the sound transmission loss (dB) of the sound-insulating sheet at the frequency X, and TL 2 is the sound transmission loss (dB) of the flat sheet having no irregularities, which has the same mass as the sound-insulating sheet and the same area as the sheet portion, at the frequency X.
14. The sound-insulating sheet according to any one of claims 1 to 13, wherein the convex portion contains at least one selected from a photocurable resin and a thermoplastic resin.
15. A sound-insulating sheet comprising a sheet portion and a convex portion,
The convex part comprises a plurality of linear convex parts A and a plurality of convex parts B with different shapes from the linear convex parts A,
At least any one of the linear protrusions A is disposed between the plurality of protrusions B,
At least one of the convex portions B is disposed between the plurality of linear convex portions a.
16. The sound-insulating sheet according to claim 15, wherein the convex portion B is a convex portion having a shape not having a longer side than the longitudinal length of the linear convex portion a.
17. The sound-insulating sheet according to claim 15 or 16, wherein,
The value expressed by (total mass of linear convex portion a/mass of piece portion) is 0.8 or more,
The value expressed by (total mass of the convex portion B/mass of the piece) is 0.15 or more.
18. The sound-insulating sheet according to claim 17, wherein the convex portion B is a convex portion having a shape not having a side longer than a longitudinal length of the linear convex portion a in a plan view.
19. The sound-insulating sheet according to claim 18, wherein the convex portions B constitute a plurality of column structures in which the plurality of convex portions B are arranged in a line, the column structures being substantially parallel to the longitudinal direction of the linear convex portions a.
20. The sound insulating sheet according to claim 19, wherein the column structure of the convex portions B is alternately arranged with the linear convex portions a in a plan view.
21. The sound-insulating sheet according to claim 20, wherein the convex portion B is a dot-like convex portion.
22. The sound-insulating sheet according to claim 21, wherein a value expressed by (total mass of linear convex portion a/total mass of dot convex portion B) is 3.2 to 15.
23. The sound-insulating sheet according to claim 22, wherein a value expressed by (total mass of the linear protrusions a/total mass of the dot-shaped protrusions B) is 3.5 to 15.
24. The sound-insulating sheet according to claim 20, wherein the convex portion B is a linear convex portion shorter than the linear convex portion a.
25. The sound-insulating sheet according to claim 24, wherein the convex portion B constitutes a plurality of column structures in which a plurality of the convex portions B are arranged in a line in the longitudinal direction.
26. The sound-insulating sheet of claim 25, wherein,
When the linear convex portion a is the "1 st linear convex portion" and the linear convex portion B shorter than the linear convex portion a is the "2 nd linear convex portion",
The ratio of the length of the linear protrusion B to the length of the linear protrusion a, which is represented by (1 st linear protrusion)/(2 nd linear protrusion), is in the range of 0.1 to 0.99.
27. A sound insulation structure comprising a sound absorbing material and the sound insulation sheet according to any one of claims 1 to 26 laminated on the sound absorbing material.
CN202280065949.2A 2021-09-30 2022-09-29 Sound-insulating sheet and sound-insulating structure Pending CN118043882A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2021-161875 2021-09-30
JP2022-052035 2022-03-28
JP2022052035 2022-03-28
PCT/JP2022/036444 WO2023054587A1 (en) 2021-09-30 2022-09-29 Sound-blocking sheet and sound-blocking structure

Publications (1)

Publication Number Publication Date
CN118043882A true CN118043882A (en) 2024-05-14

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202280065949.2A Pending CN118043882A (en) 2021-09-30 2022-09-29 Sound-insulating sheet and sound-insulating structure

Country Status (1)

Country Link
CN (1) CN118043882A (en)

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