Vibration control damper

Abstract

Provided is a vibration control damper with which the deterioration of damping characteristics can be suppressed.　This vibration control damper includes a layered structure in which a metal layer, an adhesive layer composed of an adhesive containing a crosslinking agent, and an uncrosslinked viscoelastic body layer composed of a rubber composition containing the following (A) component and (B) component are laminated in this order, wherein said vibration control damper has a cured portion having an elastic modulus of greater than 1.2 MPa and formed of the crosslinking agent migrated from the adhesive layer into the uncrosslinked viscoelastic body layer, and the thickness of the cured portion is in a range of at most 75 μm.　(A) is at least one among a styrene-isoprene-styrene copolymer and a styrene-butadiene-styrene copolymer. (B) is at least one selected from the group consisting of an ethylene-propylene-diene terpolymer, an ethylene-butene-diene terpolymer, and a butadiene rubber.

Description

Vibration damping damper

[0001] This invention relates to a vibration damping damper. More specifically, it relates to a vibration damping damper suitable for applications such as vibration control and seismic isolation in the civil engineering and construction fields.

[0002] In the fields of civil engineering and construction, vibration control devices and seismic isolation devices, particularly vibration dampers (also called seismic dampers) used in large structures such as bridges and buildings, are required to absorb vibration energy caused by earthquakes and other events. This requires that vibration control performance be achieved not only through the mechanical structural elements of the vibration damper, but also through the viscoelastic material (rubber material) used in the vibration damper.

[0003] Furthermore, with the inclusion of measures to address long-period ground motion (convergence time of 600 seconds) for high-rise buildings in the 2016 Ministry of Land, Infrastructure, Transport and Tourism guidelines, there is a growing need for vibration control dampers that do not experience a decrease in damping characteristics even with long-convergence tremors.

[0004] Conventional vibration damping dampers primarily use viscoelastic materials mainly composed of styrene-isoprene-styrene (SIS) copolymers (see, for example, Patent Documents 1 and 2). In addition, to induce friction damping, it has been considered to incorporate ethylene-propylene-diene ternary copolymers or small-particle fillers such as silica or calcium carbonate into the SIS copolymer.

[0005] Japanese Patent Publication No. 2014-227521 Japanese Patent Publication No. 2015-183110

[0006] In the manufacture of vibration damping dampers, adhesives are used to bond the viscoelastic material that constitutes the damper to the metal. However, depending on the storage period and environment of the damping damper after manufacture, there is a concern that crosslinking agents and crosslinking accelerators (hereinafter sometimes collectively referred to as "crosslinking agents") contained in the adhesive may migrate or diffuse into the uncrosslinked viscoelastic material, increasing the crosslink density near the adhesive interface of the viscoelastic material and potentially degrading the damping characteristics of the damping damper.

[0007] This invention has been made in view of these circumstances, and provides a vibration damping damper that can suppress the deterioration of damping characteristics.

[0008] The present inventors conducted extensive research from the viewpoint of suppressing the deterioration of damping characteristics of vibration damping dampers caused by the migration of crosslinking agents. Surprisingly, they found that the deterioration of damping characteristics can be suppressed by using an uncrosslinked viscoelastic body made of a rubber composition comprising (A) at least one of styrene-isoprene-styrene (SIS) copolymer and styrene-butadiene-styrene (SBS) copolymer and (B) one or more selected from the group consisting of ethylene-propylene-diene terpolymer (EPDM), ethylene-butene-diene terpolymer (EBT), and butadiene rubber (BR), and an adhesive made of an adhesive containing a crosslinking agent, and by controlling the thickness of the hardened portion formed by the crosslinking agent that migrated from the adhesive layer into the uncrosslinked viscoelastic body layer to a specific range.

[0009] In other words, the gist of the present invention is as follows: [1] A vibration damping damper comprising a layer structure in which a metal layer, an adhesive layer made of an adhesive containing a crosslinking agent, and an uncrosslinked viscoelastic layer made of a rubber composition containing the following components (A) and (B) are laminated in this order, wherein the damping damper has a hardened portion with an elastic modulus of more than 1.2 MPa formed by the crosslinking agent that has migrated from the adhesive layer into the uncrosslinked viscoelastic layer, and the thickness of the hardened portion is in the range of 75 μm or less. (A) At least one of styrene-isoprene-styrene copolymer and styrene-butadiene-styrene copolymer (B) One or more selected from the group consisting of ethylene-propylene-diene terpolymer, ethylene-butene-diene terpolymer, and butadiene rubber [2] The vibration damping damper according to [1], wherein the thickness of the hardened portion is in the range of 50 μm or less. [3] The vibration damping damper according to [1] or [2], wherein the rubber composition further contains at least one of calcium carbonate and silica. [4] The vibration damping damper according to any one of [1] to [3], wherein the crosslinking agent is an aromatic nitroso compound, and the content of the aromatic nitroso compound is 0.1 to 50% by mass relative to the total solid content in the adhesive. [5] The vibration damping damper according to any one of [1] to [4], wherein the thickness of the uncrosslinked viscoelastic layer is 3 to 40 mm, and the thickness of the adhesive layer is 5 to 40 μm.

[0010] According to the present invention, it is possible to suppress the decrease in damping characteristics in a vibration damping damper.

[0011] According to one embodiment of the present invention, the decrease in damping characteristics of a vibration damping damper can be suppressed by suppressing the increase in crosslinking density of the uncrosslinked viscoelastic material caused by the crosslinking agent contained in the adhesive, i.e., by suppressing the formation of a hardened portion.

[0012] More specifically, according to one embodiment of the present invention, by suppressing the thickness of the hardened portion formed due to the migration of the crosslinking agent contained in the adhesive to the uncrosslinked viscoelastic layer, depending on the storage period and storage environment of the vibration damping damper after manufacturing, to a range of 75 μm or less, it is possible to effectively suppress the deterioration of the damping characteristics of the vibration damping damper, and more preferably, it is very useful in that it is possible to maintain good interlayer adhesion characteristics between the metal layer and the uncrosslinked viscoelastic layer.

[0013] This is a front view showing an example of a vibration damping damper. This is a cross-sectional view showing an example of a vibration damping damper. This is a cross-sectional view showing another example of a vibration damping damper. This is a schematic diagram showing the installation state of the vibration damping damper. This is a schematic diagram of the apparatus used to perform the evaluation method described in the embodiment. This is a diagram showing the load-strain loop curve in the evaluation method described in the embodiment. This is a schematic partial cross-sectional view to explain the layer structure of the vibration damping damper.

[0014] Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to these embodiments.

[0015] In this specification, "X or / and Y (where X and Y are any configuration)" means at least one of X and Y, and can mean X only, Y only, or X and Y. Furthermore, in the numerical ranges described in steps in this specification, the upper or lower limit of one step in the numerical range can be arbitrarily combined with the upper or lower limit of another step in the numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit of that numerical range can be replaced with the values ​​shown in the examples.

[0016] A vibration damping damper according to one embodiment of the present invention (hereinafter sometimes referred to as "this vibration damping damper") is a vibration damping damper that includes a layer structure in which a metal layer, an adhesive layer made of an adhesive containing a crosslinking agent (hereinafter sometimes referred to as "this adhesive layer"), and an uncrosslinked viscoelastic layer made of a rubber composition containing the following components (A) and (B) (hereinafter sometimes referred to as "this rubber composition") are laminated in this order, and is characterized in that it has a hardened portion with an elastic modulus of more than 1.2 MPa formed by the crosslinking agent that has migrated from the adhesive layer into the viscoelastic layer, and the thickness of the hardened portion is in the range of 75 μm or less. (A) At least one of styrene-isoprene-styrene copolymer and styrene-butadiene-styrene copolymer (B) One or more selected from the group consisting of ethylene-propylene-diene terpolymer, ethylene-butene-diene terpolymer, and butadiene rubber

[0017] As mentioned above, when the crosslinking agent in the adhesive layer migrates into the viscoelastic layer, the crosslinking density near the adhesive interface of the viscoelastic layer increases, forming a hardened portion, which may reduce the damping characteristics of the vibration damper. In one embodiment of this vibration damper, the thickness of the hardened portion formed by the crosslinking agent migrated into the viscoelastic layer is controlled to a specific range of 75 μm or less, resulting in excellent damping characteristics. If the thickness of the hardened portion is outside this range, it is not possible to obtain the excellent damping characteristics of the present invention. For example, if the thickness of the hardened portion exceeds 75 μm, it is not possible to obtain the excellent damping characteristics of the present invention.

[0018] Furthermore, according to a preferred embodiment of this vibration damping damper, the thickness of the hardened portion formed by the crosslinking agent migrated from the adhesive layer into the viscoelastic layer is controlled to a specific range of 75 μm or less. This results in excellent interlayer adhesion characteristics, making it extremely useful in that it is excellent in both damping characteristics and interlayer adhesion characteristics.

[0019] Although the reason why the above-mentioned excellent effects are obtained by this vibration damping damper is not entirely clear, the inventors speculate that by suppressing the thickness of the hardened portion (sometimes called the "crosslinking agent migration layer") formed by the migration of the crosslinking agent in the adhesive layer to a specific thinness, it is possible to exhibit an excellent spring effect while maintaining interlayer adhesion characteristics, and that each layer in the layer structure consisting of the hardened portion, viscoelastic layer, and metal layer can be functionally separated, resulting in excellent damping characteristics as each layer operates efficiently.

[0020] The hardened portion described above is formed when the crosslinking agent contained in the adhesive migrates into the viscoelastic layer, resulting in an increase in crosslink density near the adhesive layer interface of the viscoelastic material. This hardened portion has the characteristic of having a higher elastic modulus than the viscoelastic material itself. In this invention, the hardened portion refers to the portion between the adhesive layer interface and the viscoelastic layer with an elastic modulus exceeding 1.2 MPa, and its thickness is defined as the thickness of the hardened portion. The upper limit of the elastic modulus is not particularly limited, but it is usually 2.5 MPa or less.

[0021] The thickness of the hardened portion described above can be determined by the following method, following conventional procedures. A smooth cross-section is prepared by cutting the portion containing the metal layer, adhesive layer, and viscoelastic layer that constitute the vibration damping damper, and the elastic modulus is measured using a microhardness tester. The thickness of the hardened portion is defined as the thickness of the region in the thickness direction where the elastic modulus is greater than 1.2 MPa, from the adhesive layer interface to the viscoelastic layer. The measurement of the elastic modulus using a microhardness tester is performed, for example, under the following measurement conditions: [Measurement conditions for elastic modulus] Microhardness tester: Fischer Instruments FISCHERSCOPE HM2000 Vickers diamond indenter: square pyramidal Load: 0 to 200 mN Indentation time: 2 seconds Maximum load holding (creep) time: 5 seconds Load release time: 2 seconds

[0022] In one embodiment of this vibration damping damper, it includes a layer structure consisting of "metal layer / adhesive layer / viscoelastic layer / adhesive layer / metal layer," and hardened portions (two hardened portions) are formed near each interface of the two adhesive layers. However, it is sufficient that the thickness of at least one hardened portion is controlled to a specific range of 75 μm or less, and it is more preferable that the thickness of both hardened portions is controlled to a specific range of 75 μm or less.

[0023] The following provides a detailed explanation of each layer that makes up the vibration damping damper.

[0024] [Viscoelastic Layer] The viscoelastic layer constituting this vibration damping damper is formed from a viscoelastic material made of the rubber composition containing component (A) and component (B).

[0025] In one embodiment of this vibration damping damper, the rubber composition contains at least component (A) and component (B) as polymer components. Preferably, the polymer component is a polymer component mainly composed of component (A).

[0026] The term "main component" of the above polymer component means that component (A) accounts for 50% by mass or more of the total amount (100% by mass) of the above polymer component, and may be 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more.

[0027] Furthermore, in one embodiment of this vibration damping damper, from the viewpoint of damping characteristics, it is preferable that the polymer component consists only of component (A) and component (B), but it is not limited thereto. For example, the content ratio of component (A) and component (B) in the total amount (100% by mass) of the polymer component may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, etc.

[0028] (A) At least one of styrene-isoprene-styrene (SIS) copolymer and styrene-butadiene-styrene (SBS) copolymer. This rubber composition contains at least one of styrene-isoprene-styrene (SIS) copolymer and styrene-butadiene-styrene (SBS) copolymer. Styrene-isoprene-styrene (SIS) copolymer and styrene-butadiene-styrene (SBS) copolymer are styrene-based elastomers, and those conventionally known in the art can be used as appropriate.

[0029] (Styrene-isoprene-styrene (SIS) copolymer) The diblock content of styrene-isoprene in the SIS copolymer is not particularly limited, but is preferably 50 to 95% by mass, and more preferably 60 to 90% by mass. Such a diblock content is superior in obtaining high damping characteristics. The above diblock amount is a value measured by gel permeation chromatography (GPC).

[0030] The styrene content in the SIS copolymer is not particularly limited, but is preferably 10 to 30% by mass, and more preferably 13 to 25% by mass. The above styrene content is a value measured by nuclear magnetic resonance (NMR) spectrometer.

[0031] The number-average molecular weight (Mn) of the SIS copolymer is not particularly limited, but is preferably 100,000 to 200,000, and more preferably 100,000 to 150,000. In other words, such a small molecular weight is preferable from the viewpoint of decay characteristics. The above number-average molecular weight (Mn) was measured according to gel permeation chromatography (GPC).

[0032] Mooney viscosity of SIS copolymer (ML) 1+4 The temperature (100°C) is not particularly limited, but for example, it is preferably 10 to 50°C, and more preferably 13 to 40°C.

[0033] In addition, the Mooney viscosity in this specification complies with the provisions of JIS K6300-1:2013, uses an L-shaped rotor, and is measured under the conditions of a preheating time of 1 minute, a rotor rotation time of 4 minutes, and a test temperature of 100°C.

[0034] (Styrene-butadiene-styrene (SBS) copolymer) The diblock content of styrene-butadiene in the SBS copolymer is not particularly limited. For example, 50 to 95% by mass is preferable, and more preferably 60 to 90% by mass. With such a diblock amount, it becomes more excellent in obtaining high damping characteristics and the like. The above diblock amount is a value measured by gel permeation chromatography (GPC).

[0035] The styrene content in the SBS copolymer is not particularly limited. For example, it is preferably 10 to 30% by mass, and more preferably in the range of 13 to 25% by mass. The above styrene amount is a value measured by a nuclear magnetic resonance apparatus (NMR).

[0036] The number average molecular weight (Mn) of the SBS copolymer is not particularly limited. For example, a range of 100,000 to 200,000 is preferable, and more preferably a range of 100,000 to 150,000. That is, it is preferable that the molecular weight is small in this way from the viewpoint of damping characteristics. The above number average molecular weight (Mn) is a value measured according to gel permeation chromatography (GPC).

[0037] The Mooney viscosity (ML 1+4 (100°C)) is not particularly limited. For example, 10 to 50 is preferable, and more preferably 13 to 40.

[0038] Incidentally, the rubber composition may contain components other than the above as polymer components. For example, styrene-based elastomers such as styrene-butadiene (SB) copolymer, styrene-isoprene (SI) copolymer, styrene-ethylene-butylene (SEB) copolymer, styrene-ethylene-butylene-styrene (SEBS) copolymer, styrene-ethylene-propylene (SEP) copolymer, styrene-ethylene-propylene-styrene (SEPS) copolymer, and hydrogenated copolymers thereof can be mentioned. These can be used alone or in combination of two or more.

[0039] Examples of commercially available products of component (A) include Quintac 3390, Quintac 3433N, Quintac 3270 (manufactured by Nippon Zeon Co., Ltd.), D1161 (manufactured by Clayton Polymer Co.), VECTOR 4411 (manufactured by TSRC Co.), and the like.

[0040] 《One or more selected from the group consisting of (B) ethylene-propylene-diene terpolymer, ethylene-butene-diene terpolymer, and butadiene rubber》 The rubber composition contains one or more selected from the group consisting of ethylene-propylene-diene terpolymer, ethylene-butene-diene terpolymer, and butadiene rubber.

[0041] (Ethylene-propylene-diene terpolymer (EPDM)) As the EPDM, those conventionally known in the art can be appropriately used. The ethylene content of the EPDM is not particularly limited, but for example, from the viewpoint of damping characteristics, it is preferably 5 to 60% by mass, more preferably 10 to 40% by mass.

[0042] s The propylene content of the EPDM is not particularly limited, but for example, from the viewpoint of damping characteristics, it is preferably 5 to 60% by mass, more preferably 10 to 40% by mass.

[0043] The diene content of the EPDM is not particularly limited, but for example, from the viewpoint of damping characteristics, it is preferably 3 to 25% by mass, more preferably 5 to 15% by mass.

[0044] The diene (third component) of EPDM is preferably a diene monomer having 5 to 20 carbon atoms. Specifically, examples include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene, 1,4-octadiene, 1,4-cyclohexadiene, cyclooctadiene, dicyclopentadiene (DCP), 5-ethylidene-2-norbornene (ENB), 5-butylidene-2-norbornene, 2-methallyl-5-norbornene, and 2-isopropenyl-5-norbornene.

[0045] Mooney viscosity of EPDM (ML) 1+4 The temperature (100°C) is not particularly limited, but is preferably in the range of 30 to 100°C, and more preferably in the range of 35 to 85°C.

[0046] (Ethylene-butene-diene terpolymer (EBT)) Any EBT conventionally known in the art can be used as appropriate. The ethylene content of the EBT is not particularly limited, but is preferably 55% by mass or less, more preferably 35 to 55% by mass, and even more preferably 40 to 53% by mass.

[0047] The butene content in EBT is not particularly limited, but is preferably 35% by mass or more, more preferably 35 to 55% by mass, and even more preferably 38 to 50% by mass.

[0048] The diene content of EBT is not particularly limited, but from the viewpoint of damping characteristics, for example, it is preferably 3 to 25% by mass, and more preferably 5 to 15% by mass.

[0049] The diene (third component) of EBT is preferably a diene monomer having 5 to 20 carbon atoms. Specifically, examples include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene, 1,4-octadiene, 1,4-cyclohexadiene, cyclooctadiene, dicyclopentadiene (DCP), 5-ethylidene-2-norbornene (ENB), 5-butylidene-2-norbornene, 2-methallyl-5-norbornene, and 2-isopropenyl-5-norbornene.

[0050] (Butadiene Rubber (BR)) The butadiene rubber (BR) used in this rubber composition may be any that is conventionally known in the art. Butadiene rubber (BR) is a rubber obtained by polymerizing butadiene as a raw material monomer, and can be obtained, for example, by polymerizing butadiene using a Ziegler catalyst or an alkyllithium initiator.

[0051] The microstructure of butadiene rubber (BR) is not particularly limited, but low-cis-BR with a cis-1,4 bond unit content of 50% by mass or less, for example, 30-40% by mass, or high-cis-BR with 90% by mass or more, can be used as appropriate.

[0052] Butadiene rubber (BR) Mooney viscosity (ML 1+4 (100°C) is not particularly limited, but for example, it is around 30-60, 30-55, or 30-50.

[0053] Examples of commercially available components (B) include EPT 4045M (manufactured by Mitsui Chemicals, Inc.), EP104E, EP35, EP65, EP33, and EP98 (manufactured by JSR Corporation).

[0054] The mixing ratio of component (A) and component (B) in this rubber composition is preferably (A):(B) = 95:5 to 50:50 by mass ratio, and more preferably (A):(B) = 90:10 to 55:45.

[0055] A preferred embodiment of this rubber composition is the combined use of styrene-isoprene-styrene (SIS) copolymer and ethylene-propylene-diene terpolymer (EPDM). The ratio of styrene-isoprene-styrene (SIS) copolymer to ethylene-propylene-diene terpolymer (EPDM) is preferably SIS:EPDM = 95:5 to 50:50 by mass ratio, and more preferably SIS:EPDM = 90:10 to 55:45.

[0056] <Other Optional Components> In addition to components (A) and (B), this rubber composition may appropriately contain fillers such as calcium carbonate, silica, and carbon black, processing aids, antioxidants, crosslinking agents, and crosslinking accelerators, to the extent that they do not hinder the effects of the present invention. These may be used alone or in combination of two or more. However, from the viewpoint of significantly achieving the effects of the present invention, it is preferable that this rubber composition does not contain crosslinking agents and crosslinking accelerators.

[0057] The total content of component (A) and component (B) in this rubber composition is not particularly limited, but is, for example, 30 to 70% by mass, preferably 40 to 68% by mass, and more preferably 45 to 65% by mass, based on the total amount of the rubber composition (100% by mass).

[0058] (Calcium carbonate) From the viewpoint of suppressing the migration of the above crosslinking agent, it is preferable to use calcium carbonate. As the calcium carbonate, those conventionally known in the art can be used as appropriate. Although not particularly limited, calcium carbonate that has undergone surface treatment such as hydrophobic treatment may be used. Specifically, for example, stearic acid-treated calcium carbonate, rosin acid-treated calcium carbonate, lignin-treated calcium carbonate, fatty acid quaternary ammonium salt-treated calcium carbonate, etc. may be used.

[0059] The average particle size (average primary particle size) of calcium carbonate used in this rubber composition is, for example, 10 to 300 nm. From the viewpoint of significantly achieving the effects of the present invention, the average particle size (average primary particle size) of calcium carbonate is preferably, for example, 30 to 100 nm, and more preferably 30 to 70 nm. The average particle size (average primary particle size) can be calculated using a scanning transmission electron microscope.

[0060] Furthermore, the particle shapes of the calcium carbonate used in this rubber composition include, for example, cubic, spindle-shaped, disc-shaped, hexagonal plate-shaped, and spherical. Among these, the cubic shape is preferred from the viewpoint of further improving the damping characteristics. Examples of the cubic shape include a regular hexahedron and a cube shape that approximates a regular hexahedron. Specifically, for example, a hexahedron in which the difference in length of each piece is ±8 nm can be cited.

[0061] The BET specific surface area of calcium carbonate is not limited hereinafter, but for example, it is 4.0 to 60 m 2 / g, preferably 10 to 40 m 2 / g, more preferably 20 to 35 m 2 / g. The BET specific surface area of calcium carbonate can be measured, for example, by a BET specific surface area measuring device (manufactured by Micro Data Co., Ltd., 4232-II) using a mixed gas (N2: 70%, He: 30%) as an adsorption gas after degassing the sample at 200 °C for 15 minutes.

[0062] The DBP (dioctyl phthalate) oil absorption amount of calcium carbonate is not limited hereinafter, but for example, it is 15 to 75 cc / 100 g, preferably 20 to 45 cc / 100 g, more preferably 20 to 30 cc / 100 g.

[0063] From the viewpoint of effectively suppressing the migration of the above crosslinking agent, the content of calcium carbonate is, for example, 25 to 80 parts by mass, preferably 28 to 70 parts by mass, more preferably 30 to 60 parts by mass with respect to 100 parts by mass in total of the components (A) and (B).

[0064] (Silica) From the viewpoint of suppressing the migration of the above crosslinking agent, it is preferable to use silica. As the silica, those conventionally known in the technical field can be appropriately used. Although not particularly limited, for example, wet silica, dry silica, colloidal silica, etc. can be mentioned. These may be used alone or in combination of two or more.

[0065] Further, the surface of the above silica may be subjected to a hydrophobization treatment as necessary. As the hydrophobized silica, dimethylsilyl-treated silica and trimethylsilyl-treated silica surface-treated with dimethylsilane or trimethylsilane are preferable.

[0066] The BET specific surface area of silica is not particularly limited, but for example, 350 m 2 / g or less is preferable, 80 to 320 m 2 / g, 100 to 300 m 2It is approximately / g. The BET specific surface area of ​​silica can be measured, for example, by degassing the sample at 200°C for 15 minutes, and then using a mixed gas (N2: 70%, He: 30%) as the adsorbed gas, with a BET specific surface area measuring device (Microdata Corporation, 4232-II).

[0067] Furthermore, while the amount of DBA adsorbed by silica is not particularly limited, it is preferably in the range of 10 to 350 mmol / kg, and more preferably in the range of 20 to 300 mmol / kg. The amount of DBA adsorbed can be measured from the amount of dibutylamine (DBA) adsorbed onto the unreacted silanol groups on the silica surface.

[0068] From the viewpoint of effectively suppressing the migration of the crosslinking agent, the silica content is preferably, for example, 20 to 80 parts by mass, and more preferably 30 to 60 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0069] In one embodiment of the rubber composition, it is preferable to include at least one of calcium carbonate and silica, from the viewpoint of significantly exhibiting the effects of the present invention. That is, by including calcium carbonate and / or silica together with components (A) and (B), the formation of hardened areas tends to be effectively suppressed, and the deterioration of damping characteristics can be suppressed.

[0070] (Carbon Black) As carbon black, conventionally known types in this art can be used as appropriate. For example, various grades of carbon black such as SAF, ISAF, HAF, MAF, FEF, GPF, SRF, FT, and MT can be used. These can be used alone or in combination of two or more types.

[0071] The specific surface area for nitrogen adsorption of carbon black is not particularly limited, but for example, it is 10 to 150 m². 2 A value of / g is preferred, and more preferably 15 to 100 m 2 / g, more preferably 20 to 76m 2 / g, particularly preferably 25 to 65m 2The value is / g. The specific surface area of ​​nitrogen adsorption of carbon black can be measured, for example, by degassing the sample at 200°C for 15 minutes, and then using a mixed gas (N2: 70%, He: 30%) as the adsorbed gas, with a specific surface area measuring device (Microdata Corporation, 4232-II).

[0072] The amount of iodine adsorbed by carbon black is not particularly limited, but is preferably 10 to 150 mg / g, more preferably 10 to 75 mg / g, and even more preferably 20 to 65 mg / g. The amount of DBP (dibutyl phthalate) absorbed by carbon black is preferably 20 to 180 mL / 100 g, and more preferably 20 to 150 mL / 100 g. The iodine adsorbed amount of carbon black was measured in accordance with JIS K6217-1 (Method A), and the DBP absorbed amount of carbon black was measured in accordance with JIS K6217-4.

[0073] The carbon black content is not particularly limited, but is preferably 0.5 to 15 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0074] When silica and carbon black are used in combination, the content ratio of the two (silica:carbon black) is, for example, 98:2 to 70:30, and preferably 97:3 to 80:20.

[0075] (Anti-aging agents) Examples of anti-aging agents include aromatic secondary amine-based anti-aging agents, special wax-based anti-aging agents, amine-ketone-based anti-aging agents, phenol-based anti-aging agents, and imidazole-based anti-aging agents. These can be used alone or in combination of two or more. The content of the anti-aging agent is not particularly limited, but for example, it is 0.5 to 5 parts by mass, preferably 1 to 4 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0076] (Processing aids) Examples of processing aids include stearic acid, paraffin wax, polyethylene, and peptiders. The content of processing aids is not particularly limited, but is preferably 0.5 to 5 parts by mass, and 1 to 4.5 parts by mass, per 100 parts by mass of the total of components (A) and (B).

[0077] [Adhesive Layer] In one embodiment of the present invention, the adhesive forming this adhesive layer (hereinafter sometimes referred to as "this adhesive") contains a polymer component and a crosslinking agent (including a crosslinking accelerator). As the polymer component, those conventionally known in the present art can be used as appropriate. Examples include, but are not limited to, halogenated polymers, phenolic resins, epoxy resins, and graphite polymers. Among these, halogenated polymers are preferred from the viewpoint of adhesion to the metal layer. Examples of halogenated polymers include chlorinated natural rubber, chlorinated polyethylene, chlorosulfonated polyethylene, chlorinated polybutadiene, and brominated polymers.

[0078] From the viewpoint of significantly achieving the effects of the present invention, the content of the polymer component is 15 to 60% by mass, preferably 20 to 55% by mass, and more preferably 25 to 50% by mass, relative to the total solid content in the adhesive. Here, "solid content" refers to the solid content in the adhesive excluding the solvent component. Examples of the solvent component include water, xylene, ethylbenzene, and methyl isobutyl ketone.

[0079] Examples of crosslinking agents include aromatic nitroso compounds, aromatic dioximes, aliphatic bis-nitrosamines, and maleimide compounds. Specifically, but not limited to, examples of aromatic dinitroso compounds include m-dinitrosobenzene, p-dinitrosobenzene, m-dinitrosonaphthalene, p-dinitrosonaphthalene, 2,5-dinitroso-p-cymene, 2-methyl-1,4-dinitrosobenzene, 2-methyl-5-chloro-1,4-dinitrosobenzene, 2-fluoro-1,4-dinitrosobenzene, 2-methoxy-1,3-dinitrosobenzene, 5-chloro-1,3-dinitrosobenzene, and 2-benzyl-1,4-dinitrosobenzene.Also, for example, N,N'-(1,3-phenylene)bismaleimide, N,N'-(4-methyl-1,3-phenylene)bismaleimide, N,N'-(1,4-phenylene)bismaleimide, N,N'-(1,2-phenylene)bismaleimide, N,N'-(1,5-naphthylene)bismaleimide, N,N'-(4-chloro-1,3-phenylene)bismaleimide, N,N'-(methylenedi-p-phenylene)bismaleimide, N,N'-(4,4' N,N'-(biphenylene)bismaleimide, N,N'-(sulfonyldi-p-phenylene)bismaleimide, N,N'-(oxydi-p-phenylene)bismaleimide, N,N'-(3,3'-dimethyl-4,4'-biphenylene)bismaleimide, N,N'-(benzylidenedi-p-phenylene)bismaleimide, N,N'-[methylenebis(3-chloro-4-phenylene)]bismaleimide, N,N'-[methylenebis(3-methyl-4-phenylene) ]bismaleimide, N,N'-[methylenebis(3-methoxy-4-phenylene)]bismaleimide, N,N'-(thiodi-p-phenylene)bismaleimide, N,N'-3,3'-benzophenonebismaleimide, N,N'-[methylenebis(3-methyl-5-ethyl-4-phenylene)]bismaleimide, N,N'-[tetramethylenebis(oxy-p-phenylene)]bismaleimide, 2,2-bis[4-(4-maleimidephenoxy)phen Aromatic bismaleimide compounds such as nyl]propane, bis[4-(4-maleimidophenoxy)phenyl]sulfone, 1,4-phenylenebis(4-maleimidophenoxy), bis[3-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ketone, 1,3-phenylenebis(4-maleimidophenoxy), and bis[4-(4-maleimidophenylthio)phenyl]ether are examples.

[0080] From the viewpoint of significantly achieving the effects of the present invention, the content of the crosslinking agent is preferably 0.1 to 60% by mass, more preferably 0.1 to 50% by mass, even more preferably 1 to 50% by mass, and particularly preferably 3 to 40% by mass, relative to the total solid content of the adhesive. Furthermore, when a crosslinking agent and a crosslinking accelerator are used in combination, the total content of both is preferably 0.1 to 85% by mass, more preferably 0.1 to 50% by mass, even more preferably 1 to 50% by mass, and particularly preferably 3 to 40% by mass, relative to the total solid content of the adhesive, from the viewpoint of significantly achieving the effects of the present invention.

[0081] In addition to the components listed above, the adhesive may optionally contain fillers, thickeners, acid acceptors, other additives, and auxiliary components.

[0082] The adhesive layer may be either a one-component or two-component type. If it is a two-component type, the adhesive layer will consist of two layers: an undercoat adhesive layer (also called a primer) formed in contact with the surface of the metal layer, and a topcoat adhesive layer (also called a covercoat) formed in contact with the undercoat adhesive layer. The topcoat adhesive layer (also called a covercoat) will be formed using this adhesive.

[0083] [Metal layer] The metal forming the metal layer is not particularly limited, but examples include iron, stainless steel, copper, brass, and composite alloys thereof.

[0084] (Method for preparing this viscoelastic material) This viscoelastic material can be obtained, for example, by kneading components (A) and (B), and other components as needed, using a kneader, planetary mixer, mixing roll, twin-screw agitator, etc.

[0085] Specifically, in a manufacturing method comprising, but not limited to, a first step of kneading at least component (A) and component (B) to prepare a first kneaded product, and a second step of adding and kneading calcium carbonate or the like to the first kneaded product to obtain a second kneaded product, wherein the first step is kneaded at 80 to 150°C for 3 to 15 minutes (preferably 100 to 120°C for 7 to 12 minutes), and the second step is preferably a method in which calcium carbonate is added to the kneaded product obtained in the first step under conditions where the temperature is adjusted to the range of 50 to 110°C, kneaded for 2 to 10 minutes (preferably 3 to 8 minutes), and then kneaded at 80 to 150°C for 3 to 15 minutes (preferably 100 to 120°C for 7 to 12 minutes).

[0086] (Method for manufacturing vibration damping dampers) As a method for manufacturing vibration damping dampers, for example, a rubber composition (viscoelastic material) is prepared as described above, and several metal plates of a predetermined size are prepared. The rubber composition (viscoelastic material) is layered on the metal plates, and finally, a metal plate is placed on top to create a laminate. Adhesive is applied to the laminated surface of the metal plates in advance.

[0087] As described above, this vibration damping damper uses an uncrosslinked viscoelastic body made of a rubber composition containing components (A) and (B), and an adhesive made of an adhesive containing a crosslinking agent. Furthermore, by controlling the thickness of the hardened portion formed by the crosslinking agent that has migrated from the adhesive layer into the uncrosslinked viscoelastic body layer to a specific range, the deterioration of damping characteristics can be suppressed.

[0088] The manufacturing method for controlling the thickness of the hardened portion to a specific range is not particularly limited, but is suitable for, for example, a method of adding calcium carbonate and / or silica in addition to components (A) and (B), a method of adjusting the type of adhesive used to form the adhesive layer, the type of crosslinking agent, and their respective contents, or a method of heating and pressurizing the laminate under conditions of 120 to 155°C for 30 to 100 minutes (preferably 130 to 145°C for 60 to 90 minutes).

[0089] Here, Figure 1 shows an example of this vibration damping damper. In the figure, 1 is the vibration damping damper, 2 is the viscoelastic body (viscoelastic layer), and 4 and 5 are metal plates (metal layers). The viscoelastic body 2 (viscoelastic layer) is sandwiched between the two metal plates 4 and 5 and is bonded to the two metal plates 4 and 5 with an adhesive. Figure 2 is a cross-sectional view (A-A' cross-section in Figure 1) showing an example of this vibration damping damper. In Figure 2, the viscoelastic body 2 in the vibration damping damper has a single-layer structure. Although not shown, in this vibration damping damper, an adhesive (adhesive layer) is applied and interposed at the interface between the viscoelastic body 2 (viscoelastic layer) and the metal plate 4 (metal layer), and an adhesive (adhesive layer) is also applied and interposed at the interface between the viscoelastic body 2 (viscoelastic layer) and the metal plate 5 (metal layer). Figure 3 is a cross-sectional view showing another example of the vibration damping damper. Figure 3 shows a vibration damping damper in which the viscoelastic body 2 has a two-layer structure. Although not shown in the figure, in this vibration damping damper, an adhesive (adhesive layer) is applied and interposed at the interface between the viscoelastic body 2 (viscoelastic layer) and the metal plate 4 (metal layer), and an adhesive (adhesive layer) is also applied and interposed at the interface between the viscoelastic body 2 (viscoelastic layer) and the metal plate 5 (metal layer).

[0090] Figure 4 shows an example of the installation of the vibration damping damper 1. In Figure 4, 1 is the vibration damping damper, 2 is the viscoelastic body, 4 and 5 are metal plates, 6 is a bolt, 7 and 8 are panels, 10 is a beam, and 11 is a foundation. As shown in the figure, the metal plates 4 and 5 of the vibration damping damper 1 are attached to panels 7 and 8, respectively, by bolts 6. The viscoelastic body 2 sandwiched between the metal plates 4 and 5 functions to dampen vibrations between the beam 10 and the foundation 11.

[0091] Figure 7 is a schematic partial cross-sectional view illustrating the layer structure of the vibration damping damper. Referring to Figure 7, the thickness 2t of the viscoelastic layer 2 in this vibration damping damper is not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, it is preferably 3 to 40 mm, and more preferably 10 to 25 mm. The thickness at of the adhesive layer a in this vibration damping damper (thickness of the top adhesive layer (cover coat) in the case of two layers) is not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, it is preferably 5 to 40 μm, and more preferably 10 to 25 μm. As mentioned above, it is important to control the thickness 2h of the hardened portion in this vibration damping damper to a specific range of 75 μm or less. More preferably 10 to 70 μm, even more preferably 20 to 60 μm, even more preferably 20 to 50 μm, particularly preferably 20 to 40 μm, and may also be 20 to 30 μm. The thickness 2h of the hardened portion is a part of the thickness of the viscoelastic layer 2, and is the thickness of the portion where the crosslinking agent of the adhesive layer a migrates, increasing the crosslinking density and resulting in an elastic modulus exceeding 1.2 MPa. Specifically, as shown in Figure 7, it is the portion of the thickness region in the direction of the viscoelastic layer 2, starting from the interface s of the adhesive layer a, where the elastic modulus exceeds 1.2 MPa. The thickness of the metal layer 4 in this vibration damping damper is not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, it is preferably 10 to 40 mm, and more preferably 15 to 25 mm. Note that Figure 7 is a schematic explanatory diagram, and the layer structure and layer thickness ratios in Figure 7 are not intended to limit the interpretation of the present invention.

[0092] The vibration damper of the present invention is not limited to the shape described above, and can exhibit excellent functionality as a vibration damper (also called a seismic damper) for civil engineering and construction, as well as for home appliances and electronic devices. In particular, it can exhibit even better functionality as a vibration damper (also called a seismic damper) used in large structures such as bridges and buildings, and especially as a vibration damper for high-rise buildings.

[0093] Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples unless it exceeds the essence of the invention.

[0094] First, the following viscoelastic material was prepared. In addition, the following adhesive was prepared.

[0095] <Viscoelastic material> ・Viscoelastic material a A rubber composition was prepared by blending each component shown in Table 1 in the proportions shown in the same table. Specifically, the rubber composition was prepared through a first step of kneading components (A) and (B) to prepare a masterbatch, and a second step of adding the remaining materials to the masterbatch and kneading. The first step was carried out by kneading in a kneader at 130°C for 10 minutes. The second step was carried out by adding the remaining materials to the masterbatch prepared in the first step and kneading in a kneader at 130°C for 10 minutes.

[0096] Viscoelastic material b was prepared in the same manner as viscoelastic material a, except that it did not contain silica and calcium carbonate.

[0097]

[0098] <Adhesives> ・Adhesive a: Chlorinated natural rubber adhesive [Adhesive containing 10% by mass of DNB (dinitrosobenzene) as a crosslinking agent] ・Adhesive b: Chlorinated natural rubber adhesive [Adhesive containing 30% by mass of DNB (dinitrosobenzene) as a crosslinking agent] ・Adhesive c: Chlorinated natural rubber adhesive [Adhesive containing 10% by mass of bismaleimide compound as a crosslinking agent]

[0099] (Example 1) Multiple iron plates [20 mm thick, 1200 mm long, 800 mm wide] were prepared. A viscoelastic material a [10 mm thick, 900 mm long, 700 mm wide] and an intermediate iron plate (located between the two iron plates) were alternately layered on one of the iron plates, and finally the other iron plate was placed on top to create a laminate. Adhesive a was applied to the laminated surface of the iron plates beforehand before creating the laminate.

[0100] The resulting laminate was hot-press molded at 140°C for 70 minutes to prepare samples. The thickness of the adhesive layer in each of the obtained samples was 10 μm.

[0101] (Example 2) A sample according to Example 2 was obtained in the same manner as in Example 1, except that adhesive a was replaced with adhesive b. The thickness of the adhesive layer in the obtained sample was 20 μm.

[0102] (Example 3) A sample according to Example 3 was obtained in the same manner as in Example 1, except that adhesive a was replaced with adhesive c. The thickness of the adhesive layer in the obtained sample was 10 μm.

[0103] (Example 4) A sample according to Example 4 was obtained in the same manner as in Example 1, except that viscoelastic material a was replaced with viscoelastic material b (calcium carbonate-free and silica-free) [thickness 10 mm, length 900 mm, width 700 mm]. The thickness of the adhesive layer of the obtained sample was 10 μm.

[0104] (Comparative Example 1) A sample according to Comparative Example 1 was obtained in the same manner as in Example 1, except that the obtained laminate was hot-press molded at 170°C for 110 minutes. The thickness of the adhesive layer of the obtained sample was 10 μm.

[0105] [Measurement of Elastic Modulus of Hardened Part] The portion of the sample obtained above that contains the laminated structure of the metal layer, adhesive layer, and viscoelastic layer was cut with a metal cutter, embedded in resin, and polished to create a smooth cross-section. The elastic modulus of the viscoelastic layer was measured using a microhardness tester, and the thickness of the hardened part was determined. The results are shown in Table 2. [Measurement Conditions for Elastic Modulus] Microhardness tester: Fischer Instruments, FISCHERSCOPE HM2000 Vickers diamond indenter: square pyramidal Load: 0 to 200 mN Indentation time: 2 seconds Maximum load holding (creep) time: 5 seconds Load release time: 2 seconds

[0106] In this embodiment, the elastic modulus was measured near the interface between the intermediate iron plate and the viscoelastic layer. For convenience, the measurement interval for the elastic modulus in this embodiment was set to every 20 μm from the interface between the adhesive layer and the viscoelastic layer. Specifically, the elastic modulus was measured at the following points to determine the thickness of the hardened portion: (1) the interface between the adhesive layer and the viscoelastic layer, (2) a distance of 20 μm from the interface in the direction of the viscoelastic layer, (3) a distance of 40 μm from the interface in the direction of the viscoelastic layer, (4) a distance of 60 μm from the interface in the direction of the viscoelastic layer, (5) a distance of 80 μm from the interface in the direction of the viscoelastic layer, and (6) a distance of 100 μm from the interface in the direction of the viscoelastic layer. For example, in Example 1, the modulus of elasticity is greater than 1.2 MPa in step (2), and less than or equal to 1.2 MPa in step (3), so the thickness of the hardened portion is 20 μm.

[0107] The method for measuring the elastic modulus is not limited to the measurement intervals described above; for example, the elastic modulus can also be measured at smaller intervals (e.g., every 10 μm). In this case as well, measurements are taken sequentially, and the thickness position where the elastic modulus exceeds 1.2 MPa is defined as the thickness of the hardened portion. For example, if the elastic modulus at a position 30 μm away from the interface in the direction of the viscoelastic layer is greater than 1.2 MPa, and the elastic modulus at a position 40 μm away from the interface in the direction of the viscoelastic layer is 1.2 MPa or less, then the thickness of the hardened portion is set to 30 μm.

[0108] [Damping Characteristics Test] The sample was vibrated in the direction of the arrow in Figure 5 (adhesive layer and cured portion are not shown), and the dynamic shear characteristics were evaluated based on the load-strain loop curve shown in Figure 6. Specifically, the apparatus shown in Figure 5 was subjected to vibration (shear strain rate: 200% (200% of sample thickness), frequency (f): 0.33 Hz, measurement temperature: 20°C) simulating a major earthquake, using a vibration exciter (Washinomiya Seisakusho Co., Ltd., DYNAMIC SERVO), an input signal oscillator (Yokogawa Electric Corporation, Synthesized Function Generator FC320), and an output signal processor (Ono Sokki Co., Ltd., Portable FFT Analyzer CF-3200). From the analysis of the shear strain value (δ) and load value (Qd) with respect to the vibration time, the equivalent stiffness (Ke) and equivalent damping coefficient (Ce) were determined according to the following equations (1) to (3), and the damping constant (he) was determined from these values. In the following equation, ω = 2πf and W = Keδ 2 / 2, ΔW represents the load-strain loop area (absorbed energy). Equivalent stiffness: Ke (N / mm) = Qd / δ …(1) Equivalent damping coefficient: Ce (kN・s / m) = ΔW / πωδ 2 …(2) Damping constant: he = ΔW / 4πW …(3)

[0109] The attenuation constant in Comparative Example 1 was set to 1.0 (reference), and the exponential values ​​of the attenuation constants in each example and comparative example were calculated and evaluated according to the following criteria. The results are shown in Table 2. ◎ (very good) ... Attenuation constant (exponential value) is 1.20 or higher 〇 (good) ... Attenuation constant (exponential value) is 1.05 or higher and less than 1.20 × (poor) ... Attenuation constant (exponential value) is less than 1.05

[0110]

[0111] From the results in Table 2 above, it can be seen that the samples of the examples satisfy the requirements of the present invention and exhibit excellent damping characteristics. Specifically, it can be seen that examples in which the thickness of the cured portion is controlled to 75 μm or less exhibit excellent damping characteristics.

[0112] In contrast, the results in Table 2 above show that the comparative example samples do not satisfy the requirements of the present invention and therefore have insufficient damping characteristics. Specifically, Comparative Example 1, which has a cured portion thickness of 80 μm, outside the range of 75 μm or less, exhibited inferior damping characteristics.

[0113] Furthermore, a comparison of Example 1 and Example 4 shows that by incorporating calcium carbonate and / or silica, the thickness of the hardened portion can be further suppressed, resulting in superior damping characteristics.

[0114] Furthermore, the interlayer adhesion properties between the metal layer and the uncrosslinked viscoelastic layer were evaluated for the samples in the examples. Excellent results were obtained in terms of interlayer adhesion properties for the samples in Examples 1 to 4.

[0115] From the above, it can be seen that the requirements of the present invention are met, namely, a vibration damping damper having a layer structure in which a metal layer, an adhesive layer made of an adhesive containing a crosslinking agent, and an uncrosslinked viscoelastic layer made of a rubber composition containing component (A) and component (B) are laminated in this order, and having a hardened portion with an elastic modulus of more than 1.2 MPa formed by the crosslinking agent that has migrated from the adhesive layer into the uncrosslinked viscoelastic layer, and the thickness of the hardened portion is in the range of 75 μm or less, can suppress a decrease in damping characteristics.

[0116] While the above embodiments illustrate specific forms of the present invention, these embodiments are merely illustrative and should not be interpreted restrictively. Various modifications that are obvious to those skilled in the art are intended to fall within the scope of the present invention.

[0117] The vibration damper of the present invention can exhibit excellent functionality as a vibration damper for civil engineering, construction, home appliances, and electronic devices. In particular, it can exhibit even better functionality as a vibration damper used in large structures such as bridges and buildings, and especially as a vibration damper for high-rise buildings. Furthermore, vibration damping devices and seismic isolation devices such as vibration damping walls for buildings, vibration damping materials and shock absorbers for home appliances and electronic devices, and vibration damping materials and shock absorbers for automobiles, which are equipped with the viscoelastic material that is a component of the vibration damper of the present invention, can also be used as vibration dampers of the present invention.

[0118] 1. Vibration damper 2. Viscoelastic material 4, 5. Metal plate 6. Bolt 7, 8. Panel 10. Beam 11. Base a. Adhesive

Claims

1. A vibration damping damper comprising a layer structure in which a metal layer, an adhesive layer made of an adhesive containing a crosslinking agent, and an uncrosslinked viscoelastic layer made of a rubber composition containing the following components (A) and (B) are laminated in this order, wherein the damper has a hardened portion with an elastic modulus of more than 1.2 MPa formed by the crosslinking agent that has migrated from the adhesive layer into the uncrosslinked viscoelastic layer, and the thickness of the hardened portion is in the range of 75 μm or less. (A) At least one of styrene-isoprene-styrene copolymer and styrene-butadiene-styrene copolymer (B) One or more selected from the group consisting of ethylene-propylene-diene terpolymer, ethylene-butene-diene terpolymer, and butadiene rubber 2. The vibration damping damper according to claim 1, wherein the thickness of the hardened portion is in the range of 50 μm or less.

3. The vibration damping damper according to claim 1 or 2, wherein the rubber composition further contains at least one of calcium carbonate and silica.

4. The vibration damping damper according to any one of claims 1 to 3, wherein the crosslinking agent is an aromatic nitroso compound, and the content of the aromatic nitroso compound is 0.1 to 50% by mass relative to the total solid content contained in the adhesive.

5. The vibration damping damper according to any one of claims 1 to 4, wherein the thickness of the uncrosslinked viscoelastic layer is 3 to 40 mm and the thickness of the adhesive layer is 5 to 40 μm.

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