Sound insulation sheet and sound insulation structure

Abstract

The present invention aims to provide a sound-insulating sheet with excellent sound-insulating performance. The sound-insulating sheet (1) has a substrate (10) and an uneven structure arranged on at least one surface of the substrate. The uneven structure has uneven unit shapes (11), each of which has a weight per unit of 20 mg to 900 mg, a thickness of the substrate of 30 μm to 250 μm, and a Young's modulus of 1 GPa or more.

Description

[Technical field]

[0001] The present invention relates to a sound insulation sheet and a sound insulation structure. This application claims priority based on Japanese Patent Application No. 2019-023812, filed on February 13, 2019, Japanese Patent Application No. 2019-023813, filed on February 13, 2019, and Japanese Patent Application No. 2019-020879, filed on February 7, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] In buildings such as apartment buildings, office buildings, and hotels, quietness suitable for indoor use is required by blocking outdoor noise from automobiles, trains, airplanes, ships, etc., and equipment noise and human voices generated inside the building. In addition, in vehicles such as automobiles, trains, airplanes, and ships, it is necessary to reduce indoor noise by blocking wind noise and engine noise to provide a quiet and comfortable space for passengers. For this reason, research and development of means for blocking the transmission of noise and vibration from the outdoors to the indoors, or from the outside of a vehicle to the indoors, that is, sound insulation means, has been promoted. In recent years, sound insulation members that can be applied to complex shapes are required in order to increase the height of buildings, improve the energy efficiency of vehicles, and further increase the design freedom of buildings, vehicles, and their facilities.

[0003] Conventionally, improvements have been made to the structure of sound insulation members, particularly sheet-like members, in order to improve sound insulation performance. For example, a method of combining and using multiple rigid flat plate materials such as gypsum board, concrete, steel plate, glass plate, and resin plate (Patent Document 1), a method of forming a hollow double-wall structure or a hollow triple-wall structure using gypsum board or the like (Patent Document 2), and a method of combining a flat plate material with multiple independent stump-like protrusions (Patent Documents 3 and 4 and Non-Patent Document 1) are known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-231316 A [Patent Document 2] JP 2017-227109 A [Patent Document 3] JP 2000-265593 A [Patent Document 4] International Publication No. 2017 / 135409 [Non-patent literature]

[0005] [Non-Patent Document 1] M. Oudich, Y. Li, MB Assouar, and Z. Hou, A sonic band gap based on the locally resonant phononic plates with stubs, New Journal of Physics, 2010, volume 12, pp 083049. Summary of the Invention [Problem to be solved by the invention]

[0006] In the sound insulation sheets in the above Patent Documents 1 to 4, the shielding performance has been examined when the material and size of the stump-shaped protrusions (resonators) are changed. However, there is a problem that sufficient improvements have not been made in terms of the configuration conditions of the stump-shaped protrusions and the thickness of the base material.

[0007] Furthermore, there is a problem in that sufficient improvements have not been made in terms of moldability in actual production.

[0008] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a sound insulation sheet and a sound insulation structure having excellent sound insulation performance.

[0009] Another object of the present invention is to provide a sound insulation sheet and a sound insulation structure that are excellent in formability. [Means for solving the problem]

[0010] As a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems could be solved by setting the thickness of the stump-shaped protrusion (resonator) and the substrate within a specific range, and thus completed the present invention.

[0011] Furthermore, as a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems could be solved by providing a tapered portion within a specific range at the bottom of the stump-shaped protrusion (resonator), and thus completed the present invention.

[0012] That is, the present invention provides various specific embodiments as shown below. [1] A sound-proofing sheet having a substrate and a concave-convex structure arranged on at least one surface of the substrate, the concave-convex structure having a concave-convex unit shape, the concave-convex unit shape having a weight per unit of 20 mg or more and 900 mg or less, the thickness of the substrate being 30 μm or more and 250 μm or less, and the Young's modulus of the substrate being 1 GPa or more. [2] The sound-proofing sheet according to [1], characterized in that the thickness of the substrate is 30 μm or more and 230 μm or less. [3] The sound-proof sheet according to [2], characterized in that the ratio of the area of ​​the concave-convex structure to the area of ​​one side of the base material is 5% or more and 80% or less. [4] A sound-proofing sheet having a substrate and a concave-convex structure arranged on at least one surface of the substrate, wherein the concave-convex structure has a concave-convex unit shape, the concave-convex unit shape has a weight per unit of 20 mg or more and 900 mg or less, the ratio of the area of ​​the concave-convex structure to the area of ​​one surface of the substrate is 5% or more and 80% or less, and the Young's modulus of the substrate is 1 GPa or more. [5] The sound-proofing sheet according to [4], characterized in that the thickness of the substrate is 30 μm or more and 250 μm or less. [6] The sound-proofing sheet according to any one of [1] to [5], characterized in that the uneven structure has a plurality of convex portions, and the value expressed as the weight (mg) of the convex portions divided by the thickness (μm) of the substrate is 0.1 or more and 5.0 or less. [7] A sound-proofing sheet described in any one of [1] to [6], characterized in that the uneven unit shapes are repeatedly arranged in at least two different directions along the surface on the uneven structure side. [8] A sound-proofing sheet as described in any one of [1] to [7], characterized in that the maximum width of the cross section of the uneven unit shape parallel to the one surface is 0.5 mm or more and 50 mm or less. [9] The sound-proofing sheet according to any one of [1] to [8], characterized in that the height of the unit uneven shapes is 0.5 mm or more and 50 mm or less.

[10] The sound-proof sheet according to any one of [1] to [9], characterized in that the spacing between the concave and convex unit shapes is 1 mm or more and 100 mm or less.

[11] A sound-proofing sheet having a substrate and a plurality of protrusions arranged on at least one surface of the substrate, wherein a value expressed as the weight (mg) of the protrusions divided by the thickness (μm) of the substrate is 0.1 or more and 5.0 or less, and the Young's modulus of the substrate is 1 GPa or more.

[12] A sound-proofing sheet having a substrate and a plurality of protrusions arranged on at least one surface of the substrate, wherein the protrusions have a weight per unit of 20 mg or more and 900 mg or less, and the thickness of the substrate is 30 μm or more and 250 μm or less, and the substrate is made of an organic material selected from the group consisting of 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, triacetyl cellulose, polystyrene, epoxy resin, acrylic resin, and oxazine resin, or a composite material containing metal, inorganic glass, inorganic particles, or fibers in these organic materials.

[13] The sound-proof sheet according to

[11] or

[12] , characterized in that the ratio of the area of ​​the concave-convex structure to the area of ​​one side of the base material is 5% or more and 80% or less.

[14] A sound-proofing sheet as described in any one of

[11] to

[13] , characterized in that the uneven unit shapes are repeatedly arranged in at least two different directions along the surface on the uneven structure side.

[15] A sound-proofing sheet as described in any one of

[11] to

[14] , characterized in that the maximum width of the cross section parallel to the one surface of the uneven unit shape is 0.5 mm or more and 50 mm or less.

[16] The sound-proof sheet according to any one of

[11] to

[15] , characterized in that the height of the unit uneven shapes is 0.5 mm or more and 50 mm or less.

[17] The sound-proof sheet according to any one of

[11] to

[16] , characterized in that the interval between the concave and convex unit shapes is 1 mm or more and 100 mm or less.

[18] A sound-proofing sheet having a substrate and a plurality of protrusions arranged on at least one surface of the substrate, wherein the protrusions have a tapered portion at a base portion connected to the substrate.

[19] The sound-proof sheet according to

[18] , characterized in that the ratio of the height of the tapered portion to the maximum height of the protrusion is 3% or more and 40% or less.

[20] The sound-proofing sheet according to

[18] or

[19] , characterized in that the taper angle of the tapered portion is greater than or equal to 20 degrees and less than or equal to 70 degrees.

[21] A sound-insulating structure comprising the sound-insulating sheet according to any one of [1] to

[20] and a support that supports the other surface of the base material. Effect of the Invention

[0013] The present invention can provide a sound insulation sheet and a sound insulation structure having excellent sound insulation performance. Also, the present invention can provide a sound insulation sheet and a sound insulation structure having excellent moldability. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view of a sound insulation sheet having a concave-convex structure according to one embodiment of the present invention. [Diagram 2] 1 is a perspective view of a sound insulation sheet having a concave-convex structure and a support body according to one embodiment of the present invention. [Diagram 3] 1 is a perspective view of a sound insulation sheet having a concave-convex structure according to one embodiment of the present invention. [Figure 4] 1 is a perspective view of a sound insulation sheet having a concave-convex structure according to one embodiment of the present invention. [Diagram 5] 1 is a perspective view of a sound insulation sheet having a concave-convex structure and rib-shaped protrusions according to one embodiment of the present invention. [Figure 6] 1 is a perspective view of a sound insulation sheet having a concave-convex structure and rib-shaped protrusions according to one embodiment of the present invention. [Figure 7] FIG. 13 is a diagram showing a model of protrusion vibration. [Figure 8] FIG. 4 is a schematic front view of a protrusion having a tapered portion. [Figure 9] FIG. 13 is a schematic front view of a protrusion of Example 4 having no tapered portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Note that each of the following embodiments is an example for explaining the present invention, and the present invention is not limited to only the embodiment. In addition, unless otherwise specified, the positional relationship such as up, down, left, right, etc. is based on the positional relationship shown in the drawings. In addition, the dimensional ratio of the drawings is not limited to the illustrated ratio. In this specification, for example, the expression of a numerical range such as "1 to 100" includes both the lower limit value "1" and the upper limit value "100". The same applies to the expression of other numerical ranges.

[0016] A sound-insulating sheet according to an embodiment of the present invention has a substrate and an uneven structure arranged on at least one surface of the substrate, the uneven structure having an uneven unit shape, the uneven unit shape having a weight per unit of 20 mg or more and 900 mg or less, the thickness of the substrate being 30 μm or more and 250 μm or less, and the Young's modulus of the substrate being 1 GPa or more. A sound-insulating sheet according to an embodiment of the present invention has a substrate and a plurality of convex portions arranged on at least one surface of the substrate, wherein a value expressed as the weight (mg) of the convex portions / thickness (μm) of the substrate is 0.1 or more and 5.0 or less, and the Young's modulus of the substrate is 1 GPa or more. A sound-insulating sheet according to an embodiment of the present invention is a sound-insulating sheet having a substrate and a plurality of convex portions arranged on at least one surface of the substrate, the convex portions having a weight per unit of 20 mg or more and 900 mg or less, and the substrate having a thickness of 30 μm or more and 250 μm or less, the substrate being an organic material selected from the group consisting of 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, triacetyl cellulose, polystyrene, epoxy resin, acrylic resin, and oxazine resin, or a composite material containing metal, inorganic glass, inorganic particles, or fibers in these organic materials.

[0017] [First embodiment of sound insulation sheet] First, the sound insulation sheet of the first embodiment will be described with reference to Figs. 1 is a schematic perspective view showing a sound insulation sheet 1 of a first embodiment. The sound insulation sheet 1 has a sheet-like substrate 10 and an uneven structure including a plurality of protrusions (convex portions) 11 as uneven unit shapes.

[0018] 2 is a schematic perspective view showing a sound insulation structure 100 of this embodiment. The sound insulation structure 100 includes a sound insulation sheet 1 and a support 2. The support 2 supports the base material 10 from a surface (other surface) 10b opposite to a surface (one surface) 10a on which the protrusions 11 are arranged.

[0019] [Uneven structure] The protrusions 11 that constitute the uneven structure act as resonating parts. A resonating part functions as an oscillator (dynamic vibration absorber) that vibrates at a certain frequency when sound waves are incident from a noise source. By having a resonating part, the effective mass increases when sound waves are incident from the noise source, and high sound insulation performance that surpasses the mass law can be obtained.

[0020] The protrusion 11 may be configured as a single structure as shown in Fig. 1 and Fig. 2, or may be configured as a composite structure including a base 20 and a weight 21 supported by the base 20 and having a mass larger than that of the base 20 as shown in Fig. 3. Furthermore, the protrusion 11 may be configured as a composite structure in which the weight 21 is embedded in the base 20 as shown in Fig. 4. In such a composite structure, when the concave-convex structure acts as a resonating part, the protrusion 11 effectively functions as a dynamic vibration absorber having a resonance frequency determined by the mass of the weight 21 acting as a weight and the spring constant of the base acting as a spring. Moreover, the protrusion 11 may be a porous body containing pores (gas such as air).

[0021] Also, as shown in FIG. 5, the sound insulation sheet 1 may have a configuration in which rib-shaped protrusions 3 are provided on the surface 10a. The rib-shaped protrusions 3 are arranged in pairs on both edges of the base material 10 in a first direction (left-right direction in FIG. 5) parallel to one side of the base material 10, sandwiching a plurality of protrusions 11 between them. Each rib-shaped protrusion 3 is provided in a rectangular plate shape extending in a second direction parallel to the surface 10a and perpendicular to the first direction. The rib-shaped protrusions 3 have a maximum height higher than the maximum height of the protrusions 11 in the normal direction of the base material 10. When the base material 10 is manufactured by, for example, cutting out a long sheet material on which the protrusions 11 are provided, so-called roll-to-roll, the second direction is set to the long direction (sheet flow direction) of the sheet material, so that even if the sound insulation sheet 1 is wound into a sheet or multiple sheets are stacked, the rib-shaped protrusions 3 function as spacers, and thus the contact of the protrusions 11 with the back surface of the stacked base material 10 is suppressed. Therefore, by providing the rib-shaped protrusions 3, it becomes easy to manufacture and store the sound-insulating sheet 1 by so-called roll-to-roll production without causing manufacturing problems such as deformation, deviation, cracking, falling off, and breakage of the protrusions 11.

[0022] In addition, the rib-shaped protrusions 3 are not limited to the rectangular plate-like configuration shown in Fig. 5, and may be configured to be formed into a substantially cylindrical shape and arranged at intervals to form a row along the second direction at the edges on both sides in the first direction, as shown in Fig. 6. By adopting this configuration, the same action and effect as the rectangular plate-like rib-shaped protrusions 3 shown in Fig. 5 can be obtained, and in addition, the conformability (flexibility) of the sound insulation sheet 1 is improved by arranging the multiple rib-shaped protrusions 3 at intervals. Therefore, even for an attachment surface with a more complex shape, the flexible and stretchable base material 10 can conform to the surface shape, and as a result, the base material 10 can be stably attached to the support 2.

[0023] The uneven structure may be formed by modifying the sound insulation sheet 1, or may be formed as protrusions 11 using a material different from that of the sound insulation sheet 1. Furthermore, the uneven structure may be formed on one surface of the sound insulation sheet 1, or on multiple surfaces. In a form having a support 2, the surface 10a opposite to the laminated surface of the support 2 has unevenness. These can be appropriately selected depending on the application from the viewpoints of sound insulation performance, manufacturing costs, handleability, etc.

[0024] The uneven structure has protrusions 11, which are uneven unit shapes, and the protrusions 11 are repeatedly arranged in at least two different directions along the surface 10a on the uneven structure side. In Fig. 1 to Fig. 4, the protrusions 11 are arranged along perpendicular sides of the substrate 10, which is rectangular in plan view. The protrusions 11 may have roughly a cylindrical shape, a prismatic shape, a conical shape, a truncated conical shape, a pyramidal shape, a truncated pyramidal shape, a hemispherical shape, an ellipsoidal shape, or the like, which may be appropriately selected according to the application from the viewpoints of sound insulation performance, manufacturing cost, handleability, and the like.

[0025] When sound waves enter a material, the material vibrates and emits sound waves behind the material. This is the mechanism of sound transmission. In other words, in order to improve sound insulation, it is necessary to suppress the vibration of the material in response to the sound waves entering it.

[0026] Conventionally, the mechanism of sound insulation by sound insulation sheets with a concave-convex structure has been considered to be "protrusion vibration," in which each protrusion 11 vibrates and acts as a dynamic vibration absorber. Figure 7 is a diagram showing a model of protrusion vibration. In this model, multiple weights m are connected to M, which represents the base material 10, via springs, or springs and dampers (not shown). Here, weights m and springs (and dampers) represent the protrusions. In response to noise, weights m vibrate with a phase difference relative to the base material 10, thereby exerting an effect as a dynamic vibration absorber, and reducing the vibration of the base material 10 improves sound insulation.

[0027] The inventors have discovered that in addition to the above-mentioned effect of "protrusion vibration," protrusion 11 acts by "imparting localized rigidity and mass." Protrusion 11 has high rigidity relative to base material 10 and can impart localized mass to the base material, thereby locally suppressing the vibration of base material 10 and, as a result, reducing the vibration of the entire base material 1, thereby providing a sound insulation effect ("imparting localized rigidity and mass"). Note that "high rigidity" here refers to the rigidity that arises when protrusions are thicker than other areas (areas without protrusions).

[0028] The inventors also discovered that by adjusting the uneven structure and base material, it is possible to adjust the degree of "protrusion vibration" and "imparting of local rigidity and mass", and that the sound insulation strength can be increased by the synergistic effect of "protrusion vibration" and "imparting of local rigidity and mass".

[0029] Below are details of the structure that provides high sound insulation from the perspective of "localized rigidity and mass."

[0030] In the above uneven structure, the ratio of the area of ​​the protrusions 11 to the area of ​​the surface 10a on the uneven structure side is preferably 5% to 80% (5% or more and 80% or less), more preferably 5.5% to 70% (5.5% or more and 70% or less), and even more preferably 6% to 60% (6% or more and 60% or less). When the ratio is within the above range, sound insulation due to vibration of the base material is exhibited, and sound insulation is dramatically improved. The area of ​​the protrusions 11 refers to the cross-sectional area of ​​the protrusions 11 at the point (base) where they are connected to the surface 10a of the base material 10.

[0031] In the above-mentioned uneven structure, the weight (per unit) of each protrusion 11 is 20 mg or more and 900 mg or less, and the thickness of the base material 10 is 30 μm or more and 250 μm or less. In this case, when sound waves are incident from a noise source, the effective mass of the protrusion 11 increases, and the protrusion 11 functions as an oscillator (dynamic vibration absorber) that vibrates at a certain frequency, and the protrusion 11 also serves as a weight or a function to suppress the vibration of the base material 10 by being more rigid than the base material 10.

[0032] When sound waves are incident from a noise source, membrane vibration occurs in which the base material 10 vibrates. The protrusions 11 act as local weights to inhibit the membrane vibration. As a result, the sound insulation effect is higher than when the protrusions 11 function only as dynamic vibration absorbers.

[0033] As described above, the weight of each unit shape of the protrusion 11 is preferably 20 mg to 900 mg, more preferably 22 mg to 700 mg, further preferably 24 mg to 600 mg, and particularly preferably 25 mg to 500 mg. When the weight of each unit shape of the protrusion 11 is 20 mg to 900 mg, the sound insulation performance is dramatically improved by the synergistic effect of the sound insulation property due to the "protrusion vibration" of the uneven unit shape and the sound insulation property due to the "imparting of localized rigidity and mass".

[0034] Furthermore, the maximum width of protrusion 11 in a cross section parallel to face 10a (hereinafter simply referred to as maximum width), i.e., the diameter when protrusion 11 is cylindrical, and the maximum width across when protrusion 11 is prismatic, is preferably 0.5 mm to 50 mm, more preferably 1.0 mm to 30 mm, even more preferably 1.5 mm to 20 mm or less, and particularly preferably 2.0 mm to 10 mm. When protrusion 11 has a maximum width of 0.5 mm or more, it provides excellent sound insulation performance, and when it is 50 mm or less, it provides excellent moldability and handleability.

[0035] The height (maximum height) of the protrusions 11 is preferably 0.5 mm to 50 mm, more preferably 0.7 mm to 30 mm, further preferably 0.9 mm to 20 mm, and particularly preferably 1.2 mm to 10 mm. When the height of the protrusions 11 is 0.5 mm or more, the sound insulation performance is excellent, and when it is 50 mm or less, the moldability and handling properties are excellent.

[0036] The interval between the protrusions 11 is preferably 1 to 100 mm, more preferably 1.4 to 80 mm, even more preferably 1.8 to 60 mm, and particularly preferably 2 to 50 mm. When the interval between the uneven unit shapes is 1 mm or more, excellent moldability is achieved, and when it is 100 mm or less, excellent sound insulation performance is achieved. The interval between the uneven unit shapes is the distance (arrangement pitch) when a straight line is drawn between the center of one uneven unit shape and the center of an adjacent uneven unit shape.

[0037] In the above uneven structure, the ratio of the area of ​​the protrusions 11 to the area of ​​the surface 10a on the uneven structure side is preferably 5% to 80% (5% or more and 80% or less), more preferably 5.5% to 70% (5.5% or more and 70% or less), and even more preferably 6% to 60% (6% or more and 60% or less). When the ratio is within the above range, sound insulation due to "localized rigidity and mass" is realized, and the sound insulation is dramatically improved. The area of ​​the protrusions 11 is the cross-sectional area of ​​the protrusions 11 at the point (base) where they are connected to the surface 10a of the substrate 10.

[0038] The value expressed as the weight per protrusion 11 relative to the thickness of the base material 10 (weight per protrusion (mg / piece) / thickness of base material 10 (μm)) is 0.1 or more and 5.0 or less, more preferably 0.6 or more and 4.0 or less, and most preferably 1.0 or more and 3.0 or less. If the weight of the protrusions 11 is small relative to the thickness of the base material 10, protrusion vibration will be the main source of vibration, but if the protrusions 11 are heavy to a certain extent, a sound insulation effect is achieved by effectively suppressing vibration through "imparting local rigidity and mass".

[0039] The number of protrusions 11 per unit area is 40 to 1,000,000 / m 2 , more preferably 100 to 500,000 pieces / m 2 , and more preferably 300 to 100,000 pieces / m 2 , and particularly preferably 500 to 30,000 pieces / m 2 , 1000~10000 pieces / m 2 It is preferable that the number of protrusions 11 is sufficient to effectively block noise.

[0040] [Materials used for uneven structures] The type of material used to form the uneven structure (protrusions 11) is not particularly limited as long as it has rubber elasticity and allows measurement of dynamic viscoelasticity, and examples thereof include resins and elastomers. Examples of the resin include a thermosetting or photosetting resin and a thermoplastic resin, and examples of the elastomer include a thermosetting or photosetting elastomer and a thermoplastic elastomer. Among these, a photosetting resin or a photosetting elastomer is preferred, and a photosetting resin is particularly preferred because it has good shape transferability and exhibits excellent sound insulation function. When a thermosetting or thermoplastic resin or a thermosetting or thermoplastic elastomer is used as the material for the protrusion 11, bubbles tend to form in the molded protrusion 11 because a curing reaction by heat is required when molding the protrusion 11. When bubbles form, resonance becomes difficult and sound insulation performance is reduced. On the other hand, when a photosetting resin or a photosetting elastomer is used as the material for the protrusion 11, the problem of bubbles as described above does not occur, and sound insulation performance is less likely to be reduced. The resin or elastomer may be used as a single material, or as a mixture of two or more materials in any combination and ratio. From the viewpoint of being able to control properties such as storage modulus and tensile elongation at break, it is preferable to combine two or more materials.

[0041] Examples of resins used to form the uneven structure (protrusions 11) include thermosetting resins such as unsaturated polyester resins, phenolic resins, epoxy resins, urethane resins, and rosin-modified maleic acid resins, photocurable resins such as homopolymers or copolymers of monomers such as epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and modified versions thereof, homopolymers and copolymers of vinyl monomers such as vinyl acetate, vinyl chloride, vinyl alcohol, vinyl butyral, and vinyl pyrrolidone, and thermoplastic resins such as saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins, and polyphenylene ether resins. Among these, urethane (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate, which have a low elastic modulus of the cured product, are preferred, and urethane (meth)acrylate is particularly preferred.

[0042] Examples of elastomers used to form the uneven structure (projection portion 11) include vulcanized rubber such as chemically crosslinked natural rubber or synthetic rubber, thermosetting elastomers such as urethane rubber, silicone rubber, fluororubber, and acrylic rubber; thermoplastic elastomers such as olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, PVC-based thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, amide-based thermoplastic elastomers, silicone rubber-based thermoplastic elastomers, and acrylic-based thermoplastic elastomers; photocurable elastomers such as acrylic-based photocurable elastomers, silicone-based photocurable elastomers, and epoxy-based photocurable elastomers; silicone-based thermosetting elastomers, acrylic-based thermosetting elastomers, and epoxy-based thermosetting elastomers. Among these, silicone-based thermosetting elastomers and acrylic-based thermosetting elastomers, which are thermosetting elastomers, and acrylic-based photocurable elastomers and silicone-based photocurable elastomers, which are photocurable elastomers, are preferred.

[0043] A photocurable resin is a resin that polymerizes by irradiation with light. Examples include photoradical polymerizable resins and photocationic polymerizable resins. Among them, photoradical polymerizable resins are preferred. The photoradical polymerizable resin preferably has at least one (meth)acryloyl group in the molecule. The photoradical polymerizable elastomer having one or more (meth)acryloyl groups in the molecule is not particularly limited, but from the viewpoint of the elastic modulus of the cured product, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, 2-methylhexyl (meth)acrylate, 2-ethyl ... ) acrylate, 2-butylhexyl (meth)acrylate, isooctyl (meth)acrylate, isopentyl (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, hexadecyl (meth)acrylate, stearyl (meth)acrylate, morpholin-4-yl (meth)acrylate, urethane (meth)acrylate, etc. Among these, urethane (meth)acrylate is preferable from the viewpoint of the elastic modulus of the cured product.

[0044] The resin used to form the uneven structure (protrusions 11) 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, and divinyl adipate; vinyl ethers such as ethyl vinyl ether and phenyl vinyl ether; diallyl phthalate, trimethylolpropane diallyl ether, and allyl glycidyl. Allyl compounds such as ethers; (meth)acrylamides such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, Nt-butyl (meth)acrylamide, (meth)acryloylmorpholine, and methylene bis (meth)acrylamide; (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and n-butyl (meth)acrylate. acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, morpholyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, (meth)acrylic acid Mono(meth)acrylates such as diethylaminoethyl, 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, and phenyl (meth)acrylate; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate;Tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate (number of repeating units: 5-14), 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: 5-14), 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, polybutylene glycol di(meth)acrylate (number of repeating units: 3-16), poly(1-methylbutylene glycol) di(meth)acrylate (number of repeating units: 5-20), 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, di(meth)acrylate of dicyclopentanediol, di(meth)acrylate of neopentyl glycol hydroxypivalate caprolactone adduct (n+m=2-5), di(meth)acrylate of hydroxypivalate Di(meth)acrylic acid ester of γ-butyrolactone adduct of neopentyl glycol (n+m=2-5), di(meth)acrylic acid ester of caprolactone adduct of neopentyl glycol (n+m=2-5), di(meth)acrylic acid ester of caprolactone adduct of butylene glycol (n+m=2-5), di(meth)acrylic acid ester of caprolactone adduct of cyclohexanedimethanol (n+m=2-5), di(meth)acrylic acid ester of caprolactone adduct of dicyclopentanediol (n+m=2-5), caprolactone adduct of bisphenol A (n+m=2-5), Di(meth)acrylic acid ester of prolactone adduct (n+m=2-5), di(meth)acrylic acid ester of caprolactone adduct of bisphenol F (n+m=2-5), di(meth)acrylic acid ester of ethylene oxide adduct of bisphenol A (p=1-7), di(meth)acrylic acid ester of propylene oxide adduct of bisphenol A (p=1-7), di(meth)acrylic acid ester of ethylene oxide adduct of bisphenol F (p=1-7), di(meth)acrylic acid ester of propylene oxide adduct of bisphenol F (p=1-7),Trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide adduct (p=1-5) tri(meth)acrylate, trimethylolpropane propylene oxide adduct (p=1-5) tri(meth)acrylate, glycerin tri(meth)acrylate, glycerin ethylene oxide adduct (p=1-5) tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ditrimethylolpropane ethylene oxide adduct (p=1-5) ) tetra(meth)acrylic acid ester, pentaerythritol tri(meth)acrylic acid ester, pentaerythritol tetra(meth)acrylic acid ester, tri(meth)acrylic acid ester of pentaerythritol ethylene oxide adduct (p=1-5), tetra(meth)acrylic acid ester of pentaerythritol ethylene oxide adduct (p=1-15), tri(meth)acrylic acid ester of pentaerythritol propylene oxide adduct (p=1-5), pentaerythritol propylene oxide adduct (p=1-15) tetra(meth)acrylic acid ester of dipentaerythritol ethylene oxide adduct (p=1-5), penta(meth)acrylic acid ester of dipentaerythritol ethylene oxide adduct (p=1-15), hexa(meth)acrylic acid ester of dipentaerythritol ethylene oxide adduct (p=1-15), tri(meth)acrylic acid ester of poly(meth)acrylate pentaerythritol caprolactone (4-8 moles) adduct such as N,N',N"-tris((meth)acryloxypoly(p=1-4)(ethoxy)ethyl)isocyanurate, pentaerythritol caprolactone (4-8 moles) adduct, tetra(meth)acrylic acid ester of dipentaerythritol caprolactone (4 to 12 mol) adduct, dipentaerythritol penta(meth)acrylic acid ester, dipentaerythritol hexa(meth)acrylic acid ester, penta(meth)acrylic acid ester of dipentaerythritol caprolactone (4 to 12 mol) adduct, hexa(meth)acrylic acid ester of dipentaerythritol caprolactone (4 to 12 mol) adduct, N,N',N"-tris(acryloxyethyl)isocyanurate, N,N'-bis(acryloxyethyl)-N"-hydroxyethyl isocyanurate,Polyfunctional (meth)acrylates such as ethylene oxide-modified (meth)acrylate isocyanurate, propylene oxide-modified (meth)acrylate isocyanurate, and ethylene oxide-propylene oxide-modified (meth)acrylate isocyanurate; epoxy poly(meth)acrylates obtained by addition reaction of polyepoxy compounds having multiple epoxy groups in the molecule such as bisphenol A glycidyl ether, bisphenol F glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, pentaerythritol polyglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl tris(2-hydroxyethyl)isocyanurate with (meth)acrylic acid, etc. Among these, phenoxyethyl acrylate, benzyl acrylate, 2-ethylhexyl (meth)acrylate, and methoxypolyethylene glycol acrylate are preferred, and 2-ethylhexyl (meth)acrylate and methoxypolyethylene glycol acrylate are more preferred, because they give a low elastic modulus of the cured product. These can be used alone or in combination of two or more.

[0045] The content of the resin and / or elastomer used to form the uneven structure (projection portion 11) can be appropriately adjusted from the viewpoint of sound insulation performance, manufacturing cost, other functions, etc., and is not particularly limited. For example, it is usually 70% by weight or more, and preferably 80% by weight or more. It may also be 100% by weight, and preferably 99% by weight or less.

[0046] When the uneven structure (protrusion 11) is formed by including a photocurable resin or elastomer, it is preferable for the resin or elastomer to include a photopolymerization initiator from the viewpoints of improving moldability and mechanical strength, reducing manufacturing costs, and the like. Examples of such photopolymerization initiators include benzoin-based, acetophenone-based, thioxanthone-based, phosphine oxide-based, and peroxide-based photopolymerization initiators. Specific examples of the photopolymerization initiator include benzophenone, 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylbenzophene, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2-ethylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, benzyl dimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, benzoin methyl ether, Examples of such compounds include benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, diethylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, methylbenzoyl formate, etc. These compounds may be used alone as one type of material, or two or more types of materials may be used in any combination and ratio.

[0047] The content of the photopolymerization initiator in the resin used to form the uneven structure (protrusions 11) is not particularly limited, but from the viewpoint of improving mechanical strength and maintaining an appropriate reaction rate, it is usually 0.1% by weight or more, preferably 0.3% by weight or more, and more preferably 0.5% by weight or more. Also, it is usually 3% by weight or less, and preferably 2% by weight or less.

[0048] The resin used to form the uneven structure (protrusions 11) may contain particles, plates, spheres, etc. in order to improve sound insulation and other functions, etc. The materials for these are not particularly limited, and examples thereof include metal, inorganic, organic, etc. From the viewpoint of improving mechanical strength and reducing material costs, the protrusions 11 may contain inorganic fine particles, such as transparent inorganic fine particles of silicon oxide, aluminum oxide, titanium oxide, soda glass, diamond, etc. In addition to such inorganic fine particles, resin particles such as acrylic resin, styrene resin, silicone resin, melamine resin, epoxy resin, and copolymers thereof can also be used as the fine particles.

[0049] The resin used to form the uneven structure (protrusion 11) may contain various additives such as flame retardants, antioxidants, plasticizers, defoamers, and release agents as other components, as long as the sound insulation performance is not impaired. These may be used alone or in combination of two or more. Flame retardants are additives that are blended to make flammable materials less flammable or to prevent them from catching fire. Specific examples of flame retardants include, but are not limited to, bromine compounds such as pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol A, hexabromocyclododecane, and hexabromobenzene, phosphorus compounds such as triphenyl phosphate, chlorine compounds such as chlorinated paraffin, antimony compounds such as antimony trioxide, metal hydroxides such as aluminum hydroxide, nitrogen compounds such as melamine cyanurate, and boron compounds such as sodium borate. The antioxidant is an additive that is blended to prevent oxidative deterioration. Specific examples thereof include, but are not limited to, phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. The plasticizer is an additive that is blended to improve flexibility and weather resistance. Specific examples of the plasticizer include, but are not limited to, phthalates, adipates, trimellitates, polyesters, phosphates, citrates, sebacates, azelates, maleates, silicone oils, mineral oils, vegetable oils, and modified products thereof.

[0050] [Base material] The substrate 10 is used to support the uneven structure (protrusions 11). There are no particular limitations on the material constituting the substrate 10 as long as it is capable of supporting the uneven structure, but from the viewpoint of suppressing vibration of the substrate itself and supporting the protrusions 11, it is preferable that the material is more rigid than the resin used to form the uneven structure. Specifically, the substrate preferably has a Young's modulus of 1 GPa or more, more preferably 1.5 GPa or more. There is no particular upper limit, but an example of this is 1000 GPa or less. By having a Young's modulus of 1.0 GPa or more, it is possible to suppress vibration of areas where the protrusions 11 are not provided. In addition, when the substrate 10 is directly installed on an apparatus, a structure, or the like, the surface (member) on which the substrate 10 is installed should have a resistance of 20 kg / m from the viewpoint of supporting the substrate 10 and enhancing sound insulation performance. 2 Less than 10 kg / m 2 Less than 5 kg / m, more preferably 2 The following is better.

[0051] Specific examples of materials constituting the substrate 10 include organic materials such as 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, triacetyl cellulose, polystyrene, epoxy resin, acrylic resin, oxazine resin, and the like, and composite materials containing metals such as aluminum, stainless steel, iron, copper, zinc, brass, inorganic glass, inorganic particles, and fibers in these organic materials, but are not particularly limited thereto. Among these, polyethylene terephthalate is preferred from the viewpoints of sound insulation, rigidity, moldability, cost, and the like.

[0052] The thickness of the substrate 10 is preferably 30 μm to 250 μm, more preferably 30 μm to 230 μm, more preferably 40 μm to 220 μm, and particularly preferably 45 μm to 210 μm. When the substrate thickness is 30 μm or more, the substrate has excellent handleability, and when the substrate thickness is 250 μm or less, particularly 230 μm or less, the substrate has excellent sound insulation performance due to the provision of protrusions.

[0053] The shape of the substrate 10 is not limited to the embodiment shown in Fig. 2, and can be appropriately set depending on the installation surface. For example, it may be a flat sheet, a curved sheet, or a special shape processed to have curved or bent portions. Furthermore, from the viewpoint of weight reduction, etc., cuts, punched portions, etc. may be provided at any location of the support.

[0054] The substrate 10 may have an adhesive layer or the like on a surface of the substrate in order to attach it to another member. The surface of the substrate having an adhesive layer or the like is not particularly limited, and may have one or more surfaces.

[0055] [Second embodiment of sound insulation sheet] Next, a sound insulation sheet according to a second embodiment will be described with reference to FIGS. In these figures, the same elements as those in the first embodiment shown in FIGS. 1 to 7 are designated by the same reference numerals, and the description thereof will be omitted.

[0056] FIG. 8 is a schematic front view of a substrate 10 having protrusions 11 provided on a surface 10a thereof. 8, the protrusions 11 constituting the uneven structure have a tapered portion 12 at the base portion connected to the substrate 10. The tapered portion 12 is formed in a skirt shape in which the diameter gradually increases toward the substrate 10, and the tapered shape may be either straight or curved.

[0057] The height of tapered portion 12 (the length in the normal direction of surface 10a (hereinafter simply referred to as the normal direction)) can be obtained by measuring the upper part of tapered portion 12 in the vertical direction from the boundary with surface 10a when protrusion 11 is viewed in cross section of a plane including the center of the planar view. The ratio of the height of tapered portion 12 to the maximum height of protrusion 11 is preferably 3% to 40%, more preferably 4% to 35%, and even more preferably 5% to 30%. When the ratio is 3% or more, excellent releasability during molding is achieved, and when it is 40% or less, excellent sound insulation is achieved.

[0058] The taper angle of the tapered portion 12 can be determined using as a reference plane the intersecting plane (hereinafter referred to as the bottom plane) with the surface 10a of the protrusion 11 when the protrusion 11 is viewed in the above cross section. The taper angle of the tapered portion 12 is preferably 20 degrees to 70 degrees, more preferably 25 degrees to 65 degrees, and even more preferably 30 degrees to 60 degrees. When the taper angle is 20 degrees or more, excellent sound insulation properties are achieved, and when it is 70 degrees or less, excellent mold releasability during molding is achieved.

[0059] It is preferable that the diameter of the protrusion 11 from the tip to the boundary with the tapered portion 12 is the same or is formed in a skirt shape with the diameter gradually increasing toward the substrate 10. If it is formed in a skirt shape, the angle is preferably larger (70 to 90 degrees) than the angle of the tapered portion 12. This makes it possible to achieve both the characteristics of the resonator and the ease of removal from the mold during molding.

[0060] [Forming method] The molding method of the sound insulation sheet 1 of the first and second embodiments is not particularly limited, and a general known sheet molding method can be adopted. In the case of a thermosetting or thermoplastic resin or elastomer, for example, a melt molding method such as press molding, extrusion molding, injection molding, etc. can be mentioned, and the molding conditions such as temperature and pressure for melt molding in this case can be appropriately changed depending on the type of material used. In addition, in the case of a photocurable resin or elastomer, for example, these resins can be injected into a plate-shaped mold that is transparent to active energy rays, and photocured by irradiating active energy rays.

[0061] The active energy rays used for curing the photocurable resin may be any that cures the photocurable resin, and examples of such rays include ultraviolet rays and electron beams. The amount of irradiation of the active energy rays may be any amount that cures the photocurable resin, and is usually irradiated in the range of 0.1 to 200 J, taking into consideration the type and amount of the monomer and polymerization initiator. As a light source for the active energy rays, a chemical lamp, a xenon lamp, a low pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, etc. are used. In addition, the irradiation of the active energy rays may be performed in one step, but in order to obtain a photocurable resin sheet with good surface properties, it is preferable to perform it in multiple steps, at least two steps. In addition, when a photocurable resin is used, a curing accelerator may be contained.

[0062] The method for combining the protrusions 11 and the substrate 10 is not particularly limited, and may be any method of forming the protrusions 11 on the substrate 10, or a method of adhering the molded protrusions 11 to the substrate 10. In the case of an adhesive method, it is preferable to use an adhesive, but there is no limitation on the type of adhesive as long as it can adhere the protrusions 11 to the substrate 10.

[0063] [Sound insulation properties] The sound transmission loss of the sound insulation sheet 1 is preferably 3 dB or more, more preferably 5 dB or more, in terms of the difference in sound transmission loss at the peak frequency between the sound insulation sheet 1 and a flat sheet having the same mass as the sound insulation sheet 1. Here, the sound transmission loss in the present invention refers to the difference between the sound pressure level at a predetermined location in the space where the sound is generated (the sound source room) and the sound pressure level at a predetermined location in the other space (the sound receiving room) when sound is generated in one of two spaces separated by the sound insulation sheet 1. The peak frequency refers to the frequency at which sound insulation is most improved by the effect of the sound insulation sheet 1. EXAMPLES

[0064] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. Note that the various conditions and values ​​of the evaluation results in the following examples indicate the preferred ranges of the present invention, as well as the preferred ranges in the embodiments of the present invention, and the preferred ranges of the present invention can be determined by taking into consideration the preferred ranges in the above-mentioned embodiments and the ranges indicated by the values ​​in the following examples or a combination of the values ​​of the examples.

[0065] First, an example of the sound insulation sheet of the first embodiment will be described.

[0066] [Raw materials used] The following materials were used as raw materials: (Material for forming protrusion 11) EBECRYL 230 (manufactured by Daicel Allnex Co., Ltd., urethane acrylate, weight average molecular weight Mw: 5000) Aronix M-120 (Toagosei Co., Ltd., special acrylate) IRGACURE 184 (BASF, 1-hydroxy-cyclohexyl-phenyl-ketone) ·IRGACURE TPO (BASF, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) (Base material 10) PET film (Diamond Foil, manufactured by Mitsubishi Chemical Corporation) Film thickness: 50μm, 100μm, 125μm, 200μm, 250μm, 400μm

[0067] [Sound transmission loss] The sound transmission loss was measured using the above sound insulation sheet 1. The measured value of Comparative Example 2 was used as a reference, and the differences between this measured value and each of the Examples and Comparative Examples were summarized in Table 1. The conditions for measuring the sound transmission loss are as follows: White noise was generated from inside the small reverberation box to which the sound-proofing sheet 1 was attached, and the sound transmission loss (TL) was calculated from the difference in sound pressure between the microphones attached inside and outside the small reverberation box based on the following formula (1). Sound pressure difference between microphones placed inside and outside the reverberation box

number

[0068] Lin ; Sound pressure level of the internal microphone (dB) Lout ; Sound pressure level of external microphone (dB) Incident sound: White noise Sample-microphone distance: 10mm

[0069] [Production Example 1] The mixture was weighed out in a ratio of EBECRYL230 / Aronix M-120 / IRGACURE.184 / IRGACURE.TPO = 50 / 50 / 1 / 0.1% by weight, and stirred using a foaming mixer (AR-250, manufactured by Thinky Corporation) for 20 minutes and degassing for 10 minutes to obtain mixture A.

[0070] [Example 1] Mixture A obtained in Production Example 1 was poured into an A4-sized aluminum mold with concave shapes of 6 mm in diameter and 5 mm in height at a pitch of 10 mm, and then a PET film with a thickness of 125 μm and a Young's modulus of approximately 4 GPa was placed on the mold as a substrate. A high-pressure mercury lamp was used to illuminate the film with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The soundproof sheet was then cured by exposure to ultraviolet light at 100° C. Thereafter, the soundproof sheet cured in the mold was peeled off from the mold. The obtained sound insulation sheet is the sound insulation sheet shown in the embodiment 1, and has a convex resonating part with a diameter of 6 mm, a height of 5 mm, and a pitch of 10 mm on a PET substrate with a thickness of 125 μm, and the weight per unit shape was 150 mg. In addition, the ratio of the area (cross-sectional area) of the base of the concave-convex structure to the area of ​​the substrate surface to which the concave-convex structure (protrusions) is applied (hereinafter referred to as the filling rate) was 28%. The value of the weight per protrusion 11 relative to the thickness of the substrate 10 (weight per protrusion (mg / piece) / thickness (μm) of the substrate 10) (hereinafter referred to as the value of weight (mg / piece) / thickness (μm)) was 1.2.

[0071] [Example 2] A sound insulation sheet was produced in the same manner as in Example 1, except that a PET film with a thickness of 100 μm was used. The weight per unit shape of the obtained sound insulation sheet was 150 mg. The filling rate of the uneven structure was 28%. The value of weight (mg / piece) / thickness (μm) was 1.5. [Example 3] A sound insulation sheet was produced in the same manner as in Example 1, except that a PET film with a thickness of 50 μm was used. The weight per unit shape of the obtained sound insulation sheet was 150 mg. The filling rate of the uneven structure was 28%. The value of weight (mg / piece) / thickness (μm) was 3. [Example 4] A sound insulation sheet was produced in the same manner as in Example 1, except that a PET film with a thickness of 250 μm was used. The weight per unit shape of the obtained sound insulation sheet was 150 mg. The filling rate of the obtained sound insulation sheet was 28%. The value of weight (mg / piece) / thickness (μm) was 0.6.

[0072] [Example 5] Mixture A obtained in Production Example 1 was poured into an A4-sized aluminum mold with concave shapes of 6 mm in diameter and 2 mm in height at a pitch of 10 mm, and then a 125 μm-thick PET film was placed on the mold as a substrate. A high-pressure mercury lamp was used to illuminate the mold with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The soundproof sheet was then cured by exposure to ultraviolet light at 100° C. Thereafter, the soundproof sheet cured in the mold was peeled off from the mold. The obtained soundproof sheet had a convex resonating part with a diameter of 6 mm, a height of 2 mm, and a pitch of 10 mm on a PET substrate with a thickness of 125 μm, and the weight per unit shape was 60 mg. The filling rate of the concave-convex structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.48.

[0073] [Example 6] Mixture A obtained in Production Example 1 was poured into an A4-sized aluminum mold with concave shapes of 6 mm in diameter and 5 mm in height at a pitch of 7 mm, and then a PET film with a thickness of 250 μm and a Young's modulus of approximately 4 GPa was placed on the mold as a substrate. A high-pressure mercury lamp was used to illuminate the film with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The sound-proof sheet member cured in the mold was then peeled off from the mold. The obtained sound-proof sheet member had a convex resonating part with a diameter of 6 mm, a height of 5 mm, and a pitch of 7 mm on a PET substrate with a thickness of 250 μm, and the weight per unit shape was 150 mg. The filling rate of the concave-convex structure was 58%. The value of weight (mg / piece) / thickness (μm) was 0.6.

[0074] [Example 7] A sound-insulating sheet member was produced in the same manner as in Example 6, except that a mold with a pitch of the uneven structure (protrusions) of 15 mm was used. The weight per unit shape of the obtained sound-insulating sheet member was 150 mg. The filling rate of the uneven structure was 14%. The value of weight (mg / piece) / thickness (μm) was 0.6.

[0075] [Example 8] A sound-insulating sheet member was produced in the same manner as in Example 6, except that a mold with a pitch of the uneven structure (protrusions) of 20 mm was used. The weight per unit shape of the obtained sound-insulating sheet member was 150 mg. The filling rate of the uneven structure was 7%. The value of weight (mg / piece) / thickness (μm) was 0.6.

[0076] [Example 9] A sound-insulating sheet member was produced in the same manner as in Example 6, except that a mold with a pitch of the uneven structure (protrusions) of 30 mm was used. The weight per unit shape of the obtained sound-insulating sheet member was 150 mg. The filling rate of the uneven structure was 3%. The value of weight (mg / piece) / thickness (μm) was 0.6.

[0077] [Comparative Example 1] Mixture A obtained in Production Example 1 was poured into an A4-sized aluminum mold with concave shapes of 1.2 mm in diameter and 2 mm in height at a pitch of 2 mm, and then a 125 μm-thick PET film was placed on the mold. A high-pressure mercury lamp was used to emit light with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The soundproof sheet was then cured by exposure to ultraviolet light at 100° C. Thereafter, the soundproof sheet cured in the mold was peeled off from the mold. The obtained soundproof sheet had a convex resonating part with a diameter of 1.2 mm, a height of 2 mm, and a pitch of 2 mm on a PET substrate with a thickness of 125 μm, and the weight per unit shape was 2.5 mg. The filling rate of the concave-convex structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.02.

[0078] [Comparative Example 2] A sound insulation sheet was produced in the same manner as in Comparative Example 1, except that a PET film with a thickness of 250 μm was used. The weight per unit shape of the obtained sound insulation sheet was 2.5 mg. The filling rate of the uneven structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.01.

[0079] [Comparative Example 3] A sound insulation sheet was produced in the same manner as in Example 1, except that a silicon sheet (Sylgard 184, manufactured by Toray Dow Corning Co., Ltd.) with a thickness of 200 μm and a Young's modulus of approximately 0.01 GPa was used. The weight per unit shape of the obtained sound insulation sheet was 150 mg. The filling rate of the uneven structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.75.

[0080] [Comparative Example 4] A sound insulation sheet was produced in the same manner as in Example 1, except that a silicon sheet (Sylgard 184, manufactured by Dow Corning Toray Co., Ltd.) with a thickness of 400 μm and a Young's modulus of approximately 0.01 GPa was used. The weight per unit shape of the obtained sound insulation sheet was 150 mg. The filling rate of the uneven structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.375.

[0081] [Comparative Example 5] Mixture A obtained in Production Example 1 was poured into an A4-sized aluminum mold with concave shapes of 1.2 mm in diameter and 2 mm in height at a pitch of 2 mm, and then a 250 μm-thick PET film was placed on the mold. A high-pressure mercury lamp was used to emit light with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The sound-proof sheet member cured in the mold was then peeled off from the mold. The obtained sound insulation sheet member had a convex resonating portion (protrusion) with a diameter of 1.2 mm, a height of 2 mm, and a pitch of 2 mm on a PET substrate with a thickness of 250 μm, and the weight per unit shape was 2.5 mg. The filling rate of the concave-convex structure was 28%. The value of weight (mg / piece) / thickness (μm) was 0.01.

[0082] [Comparative Example 6] A sound-insulating sheet member was produced in the same manner as in Comparative Example 5, except that a mold with a pitch of the uneven structure (protrusions) of 10 mm was used. The weight per unit shape of the obtained sound-insulating sheet member was 2.5 mg. The filling rate of the uneven structure was 1%. The value of weight (mg / piece) / thickness (μm) was 0.01.

[0083] [Comparative Example 7] A sound insulation sheet member was produced in the same manner as in Comparative Example 5, except that a mold with a 4 mm pitch for the uneven structure (projections) was used. The weight per unit shape of the obtained sound insulation sheet member was 2.5 mg. The filling rate of the uneven structure was 7%. The value of weight (mg / piece) / thickness (μm) was 0.01.

[0084] The sound transmission loss was evaluated by the method described above using the sound insulation sheets produced in the above-mentioned Examples 1 to 9 and Comparative Examples 1 to 7. The evaluation results are shown in Table 1.

[0085] [Table 1]

[0086] From a comparison between Examples 1 to 9 and Comparative Examples 1 to 7 in Table 1, it can be seen that the sound insulation peak frequency intensity is improved in a configuration in which the weight per unit shape is 20 mg or more and 900 mg or less, the Young's modulus of the substrate is 1 GPa or more d, and the substrate thickness is 30 μm or more and 250 μm or less. It can also be seen that the sound insulation peak frequency is shifted to a lower frequency band. This is because the substrate thickness is set to 250 μm or less, resulting in a synergistic effect between the sound insulation performance due to the vibration of the stump-shaped protrusion (dynamic vibration absorber) and the sound insulation performance due to "localized rigidity and mass addition". In addition, in Examples 1 to 3 in which the substrate thickness is 30 μm or more and 230 μm or less, the sound insulation peak frequency exceeds 8, which is a particularly excellent result. In Comparative Examples 1-2 and 5-7, the weight per unit shape is 20 mg or less, and it can be seen that the sound insulation peak frequency intensity does not improve even if the substrate thickness is thin. This is because the weight of the resonating part is small, so the sound insulation performance by "localized stiffness and mass" is not realized.

[0087] From the comparison of Examples 1 to 9 and Comparative Examples 1 to 7 in Table 1, it can be seen that the sound insulation peak frequency intensity is significantly improved in a configuration in which the Young's modulus of the substrate is 1 GPa or more and the value of weight (mg / piece) / thickness (μm) is 0.1 or more and 5.0 or less, particularly 1.0 or more and 3.0 or less. This is because the sound insulation effect is created by effectively suppressing the sound by "imparting local rigidity and mass" by setting the value of weight (mg / piece) / thickness (μm) in this range. In addition, considering that the sound insulation strength decreases from Examples 1 to 3, it is estimated that the sound insulation effect decreases when the value of weight (mg / piece) / thickness (μm) is too high. For example, if the substrate is too thin, vibrations may occur in places where no convex parts are provided, resulting in a decrease in sound insulation strength. Similarly, when a substrate with a low Young's modulus is used as in Comparative Examples 3 and 4, it is considered that vibrations occur in places where no convex parts are provided because the substrate is soft, resulting in a decrease in sound insulation strength.

[0088] From a comparison between Examples 1 to 8 and Comparative Examples 6 to 7 in Table 1, it can be seen that the sound insulation peak frequency intensity is improved in a configuration in which the filling rate, which is the ratio of the area of ​​the uneven structure to the area of ​​one side of the base material, is 5% or more and 80% or less. This is because a synergistic effect of the sound insulation performance due to the vibration of the stump-shaped protrusions (dynamic vibration absorbers) and the sound insulation performance due to "localized rigidity and mass impartation" is expressed by setting the filling rate to 5% or more and 80% or less. It can be seen that in Comparative Examples 1 to 2 and 5 to 7, the weight per unit shape is 20 mg or less, and the sound insulation peak frequency intensity is not improved even when the filling rate is within a specific range (filling rate is 5% or more and 80% or less). This is because the weight of the resonating part is small, so the sound insulation performance due to "localized rigidity and mass impartation" is not expressed.

[0089] The results in Table 1 confirm that sound insulation performance can be improved by keeping the stump-shaped protrusions (dynamic vibration absorbers) and base material thickness within a specific range.

[0090] Next, examples of the sound insulation sheet of the second embodiment will be described.

[0091] [Shape transferability] The photocurable resin prepared in the above-mentioned Manufacturing Example 1 was poured into the mold prepared in the following Examples and Comparative Examples, and then a PET film was placed on top. A high-pressure mercury lamp was used to illuminate the mold with a wavelength of 200 to 450 nm and an energy amount of 1000 mJ / m. 2 The soundproofing sheet was then cured by exposure to ultraviolet light at 40°C. The soundproofing sheet cured in the mold was then peeled off from the mold. A ratio of the number of convex parts obtained by transfer to the total number of convex parts on the mold of 90% or more was evaluated as "○", and a ratio of less than 90% was evaluated as "×".

[0092] [Example 10] A sound-proofing sheet was produced in the same manner as in Example 4, except that a mold was used made of aluminum and had concave shapes with a diameter of 6 mm, a height of 5 mm, a taper angle of 45 degrees, and a taper height of 0.5 mm, with a pitch of 10 mm. The shape transfer rate of the obtained sound insulation sheet was 99.5%.The acoustic band gap obtained by the method described in Non-Patent Document 1 was 2223 to 2864 Hz.

[0093] [Example 11] A sound-proofing sheet was produced in the same manner as in Example 4, except that a mold was used made of aluminum and had concave shapes with a diameter of 6 mm, a height of 5 mm, a taper angle of 45 degrees, and a taper height of 1.0 mm, with a pitch of 10 mm. The shape transfer rate of the obtained sound insulation sheet was 100%. Moreover, the acoustic band gap obtained by the method described in Non-Patent Document 1 was 2382 to 3024 Hz. [Example 12] A sound-proofing sheet was produced in the same manner as in Example 4, except that a mold was used made of aluminum and had concave shapes with a diameter of 6 mm, a height of 5 mm, a taper angle of 45 degrees, and a taper height of 3.0 mm, with a pitch of 10 mm. The shape transfer rate of the obtained sound insulation sheet was 100%. Moreover, the acoustic band gap obtained by the method described in Non-Patent Document 1 was 3306 to 4093 Hz.

[0094] [Example 4] 9, the sound insulation sheet of Example 4 had protrusions 11 without tapered portions 12 formed thereon, and the shape transfer rate was 89%. The acoustic band gap obtained by the method described in Non-Patent Document 1 was 2133 to 2768 Hz.

[0095] Table 2 shows the shape transferability and the acoustic band gap calculation results for the sound insulation sheets produced in Examples 10 to 12 and Example 4 above.

[0096] [Table 2]

[0097] A comparison of Examples 10 to 12 with Example 4 in [Table 2] shows that the transferability of the concave-convex structure (protrusions) having tapered portions is good. Also, a comparison of Examples 10 and 11 with Example 12 shows that a high ratio of taper height / convex-convex structure height (maximum height of protrusions) results in excellent transferability, but the acoustic band gap shifts to the high frequency band, so that from the viewpoint of sound insulation performance in the low frequency band, it is more preferable to adjust the ratio of taper height / convex-convex structure height (maximum height of protrusions).

[0098] The results in [Table 2] show that providing a tapered section to the base connected to the substrate improves shape transferability. In other words, it was found that the rate at which the protrusions fall off when the sound insulation sheet is removed from the mold is reduced. This is thought to be because the tapered section reduces the stress that occurs between the base of the protrusions and the mold when the sound insulation sheet is removed from the mold, preventing the sheet from falling off due to stress. It was also found that when the ratio of the height of the tapered portion to the maximum height of the protrusion is 3% or more and 40% or less, the protrusion can sufficiently act as a weight to further improve the sound insulation performance in the low frequency band.

[0099] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention. [Industrial Applicability]

[0100] The present invention can be applied to a sound insulation sheet and a sound insulation structure. [Explanation of symbols]

[0101] REFERENCE SIGNS LIST 1...sound insulation sheet, 2...support, 10...base material, 10a...surface (one surface), 10b...surface (other surface), 11...projection (convex portion), 12...tapered portion, 100...sound insulation structure

Claims

1. A sound-proof sheet having a base material and a concave-convex structure disposed on at least one surface of the base material, The uneven structure has an uneven unit shape including a protrusion, the weight per unit of the uneven unit shape is 20 mg or more and 900 mg or less, when the base material is the bottom surface, the protrusion does not have a weight having a larger mass than the uneven unit shape on the tip side than the center in the height direction of the protrusion, and the thickness of the base material is 30 μm or more and 250 μm or less, A sound-proof sheet characterized in that the Young's modulus of the substrate is 1 GPa or more.

2. 2. The sound insulation sheet according to claim 1, wherein the thickness of the substrate is 30 μm or more and 230 μm or less.

3. 3. The soundproof sheet according to claim 2, wherein the ratio of the area of ​​the concave-convex structure to the area of ​​one surface of the base material is 5% or more and 80% or less.

4. A sound-proof sheet having a base material and a concave-convex structure disposed on at least one surface of the base material, The uneven structure has an uneven unit shape including a protrusion, the uneven unit shape has a weight per unit of 20 mg or more and 900 mg or less, when the base material is the bottom surface, there is no weight having a larger mass than the uneven unit shape on the tip side of the center in the height direction of the protrusion, and the ratio of the area of ​​the uneven structure to the area of ​​one surface of the base material is 5% or more and 80% or less, A sound-proof sheet characterized in that the Young's modulus of the substrate is 1 GPa or more.

5. 5. The sound insulation sheet according to claim 4, wherein the thickness of the substrate is 30 μm or more and 250 μm or less.

6. The uneven structure has a plurality of protrusions, The sound-proof sheet according to any one of claims 1 to 5, characterized in that the value expressed by the weight (mg) of the convex portion / the thickness (μm) of the substrate is 0.1 or more and 5.0 or less.

7. The soundproof sheet according to any one of claims 1 to 6, characterized in that the uneven unit shapes are repeatedly arranged in at least two different directions along the surface on the uneven structure side.

8. 8. The soundproof sheet according to claim 1, wherein the maximum width of the uneven unit shape in a cross section parallel to the one surface is 0.5 mm or more and 50 mm or less.

9. 9. The soundproof sheet according to claim 1, wherein the height of the unit uneven shapes is 0.5 mm or more and 50 mm or less.

10. 10. The soundproof sheet according to claim 1, wherein the interval between the concave and convex unit shapes is 1 mm or more and 100 mm or less.

11. A sound-insulating sheet having a concave-convex structure, the sound-insulating sheet having a base material and a plurality of convex portions arranged on at least one surface of the base material, The uneven structure has an uneven unit shape, a value expressed by weight (mg) of the protrusions / thickness (μm) of the base material is 0.1 or more and 5.0 or less, When the base material is used as a bottom surface of the uneven unit shape, the uneven unit shape does not have a weight having a larger mass than the uneven unit shape at a tip side of the center in a height direction of the protrusion, A sound-proof sheet characterized in that the Young's modulus of the substrate is 1 GPa or more.

12. A sound-insulating sheet having a concave-convex structure, the sound-insulating sheet having a base material and a plurality of convex portions arranged on at least one surface of the base material, The uneven structure has an uneven unit shape, When the base material is used as a bottom surface of the uneven unit shape, the uneven unit shape does not have a weight having a larger mass than the uneven unit shape at a tip side of the center in a height direction of the protrusion, The convex portion has a weight per unit of 20 mg or more and 900 mg or less, and the thickness of the base material is 30 μm or more and 250 μm or less, The sound-proofing sheet is characterized in that the substrate is an organic material selected from the group consisting of 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, triacetyl cellulose, polystyrene, epoxy resin, acrylic resin, and oxazine resin, or a composite material containing metal, inorganic glass, inorganic particles, or fibers in these organic materials.

13. 13. The soundproof sheet according to claim 11, wherein the ratio of the area of ​​the concave-convex structure to the area of ​​one surface of the base material is 5% or more and 80% or less.

14. The soundproof sheet according to any one of claims 11 to 13, characterized in that the uneven unit shapes are repeatedly arranged in at least two different directions along the surface on the uneven structure side.

15. The soundproof sheet according to any one of claims 11 to 14, characterized in that the maximum width of the cross section of the uneven unit shape parallel to the one surface is 0.5 mm or more and 50 mm or less.

16. The soundproof sheet according to any one of claims 11 to 15, characterized in that the height of the unit uneven shapes is 0.5 mm or more and 50 mm or less.

17. The soundproof sheet according to any one of claims 11 to 16, characterized in that the interval between the concave and convex unit shapes is 1 mm or more and 100 mm or less.

18. The sound insulation sheet according to any one of claims 1 to 17, A sound-insulating structure comprising: a support body that supports the other surface of the base material.

Images