Damping rubber composition and viscoelastic damper

Abstract

The present invention provides a damping rubber composition that can form a damping member with excellent damping properties in low-strain areas such as wind sway, while suppressing adhesion to rolls and having good processability. [Solution] The damping rubber composition contains (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler with a particle size of 3 μm or more as measured by the air permeability method, and (e) a fatty acid derivative as a lubricant, wherein the (a) base rubber contains at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber, and the amount of (b) tackifier is 70 to 110 parts by mass, the amount of (c) carbon black is 100 to 160 parts by mass, the amount of (d) inorganic filler is 5 to 100 parts by mass, and the amount of (e) lubricant is 0.5 to 10 parts by mass per 100 parts by mass of the (a) base rubber.

Description

[Technical Field]

[0001] The present invention relates to a damping rubber composition and a viscoelastic damper comprising a damping member using the same. [Background technology]

[0002] Conventionally, buildings such as houses and office buildings, as well as bridges, have been equipped with means to absorb vibration energy generated by earthquakes, traffic vibrations, wind sway, etc. Among these, tuned mass dampers (TMDs) are known as a means to suppress vibrations in the low-strain range, such as wind sway. However, TMDs are large and expensive to install and maintain. On the other hand, viscoelastic dampers equipped with damping members (viscoelastic materials) are relatively inexpensive and have excellent vibration damping performance against intense vibrations such as those of large earthquakes, while also exhibiting vibration suppression effects against minute vibrations such as wind sway. For this reason, they are widely used as a means of providing seismic isolation, vibration control, vibration damping, and vibration isolation.

[0003] For example, Patent Document 1 discloses a high-damping rubber composition containing carbon black, silica, and rosin-modified phenol and / or rosin ester for rubber containing natural rubber and / or isoprene rubber.

[0004] Patent Document 2 discloses a high-damping rubber composition comprising at least a rubber component and a metal rosinate salt.

[0005] Patent Document 3 discloses a silica-containing high-damping rubber composition obtained by adding 30 to 200 parts by weight of silica to 100 parts by weight of a base rubber having CC bonds in its main chain, and then kneading a specific silane compound at a concentration of 5 to 50% by weight relative to the silica.

[0006] Patent Document 4 discloses a highly damping rubber composition containing (A) butyl rubber, (B) at least one of styrene-isobutylene block copolymer (SIB) and styrene-isobutylene-styrene block copolymer (SIBS), (C) a nonpolar alicyclic saturated hydrocarbon resin, and (D) sulfur. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-003014 [Patent Document 2] Japanese Patent Publication No. 2007-063425 [Patent Document 3] Japanese Patent Application Publication No. 07-041603 [Patent Document 4] Japanese Patent Publication No. 2011-190397 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Regarding rubber compositions, methods for increasing the damping rate (heq) in low-strain areas such as wind sway include incorporating fine carbon particles or incorporating tackifiers such as rosin derivatives. However, in methods that incorporate fine carbon particles into a rubber composition, there is a problem that if the amount of fine carbon particles is increased, the viscosity and hardness of the rubber composition become too high. Also, in methods that incorporate tackifiers into a rubber composition, if the amount of tackifier increases, the adhesiveness of the rubber composition to metals such as rolls becomes stronger, worsening the processability for discharge and sheet extrusion, leading to problems such as reduced mass production capacity or even the inability to manufacture the product.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a damping rubber composition that can form a damping member with excellent damping properties in the low strain range, such as wind sway, and that suppresses adhesion to rolls and has good processability. [Means for solving the problem]

[0010] The damping rubber composition of the present invention that has solved the above problems contains (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler, and (e) a lubricant. The (a) base rubber contains at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber. The blending amount of the (b) tackifier is 70 parts by mass or more and 110 parts by mass or less with respect to 100 parts by mass of the (a) base rubber. The blending amount of the (c) carbon black is 100 parts by mass or more and 160 parts by mass or less with respect to 100 parts by mass of the (a) base rubber. The particle size of the (d) inorganic filler measured by the air permeability method is 3 μm or more. The blending amount of the (d) inorganic filler is 5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the (a) base rubber. The (e) lubricant is a fatty acid derivative, and the blending amount of the (e) lubricant is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the (a) base rubber.

Effect of the Invention

[0011] According to the present invention, a damping member excellent in damping performance in a low strain region such as wind sway can be formed, and a damping rubber composition that suppresses adhesiveness to a roll and has good processability can be obtained.

Brief Description of the Drawings

[0012] [Figure 1] An exploded perspective view showing the disassembly of a test piece as a model of the damping member, which is produced to evaluate the damping performance and the like of the damping member using the rubber compositions of the examples and comparative examples of the present invention. [Figure 2] A diagram explaining the outline of a testing machine for obtaining the relationship between the displacement amount and the load by displacing the test piece. [Figure 3] A graph showing an example of a hysteresis loop indicating the relationship between the displacement amount and the load, which is obtained by displacing the test piece using the testing machine.

Modes for Carrying Out the Invention

[0013] <Damping Rubber Composition> The damping rubber composition of the present invention contains (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler, and (e) a lubricant. Furthermore, the damping rubber composition of the present invention is characterized in that (a) the base rubber contains at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber, (b) the amount of tackifier is 70 parts by mass or more and 110 parts by mass or less per 100 parts by mass of (a) the base rubber, (c) the amount of carbon black is 100 parts by mass or more and 160 parts by mass or less per 100 parts by mass of (a) the base rubber, (d) the particle size of the inorganic filler measured by the air permeability method is 3 μm or more, the amount of inorganic filler is 5 parts by mass or more and 100 parts by mass or less per 100 parts by mass of (a) the base rubber, and (e) the lubricant is a fatty acid derivative, and the amount of lubricant is 0.5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of (a) the base rubber. In this specification, the amount of blending refers to the amount added when preparing the damping rubber composition.

[0014] The reason why the damping rubber composition of the present invention can suppress adhesion to the roll and form a damping member with excellent damping properties in the low strain range is not entirely clear, but it is thought to be as follows. In the damping rubber composition, hysteresis loss occurs due to the interaction of (a) base rubber, (b) tackifier, and (c) carbon black. In the damping rubber composition, (b) tackifier is added to increase damping performance, which tends to increase the adhesion of the rubber composition to metal parts such as rolls that are part of the processing machine, thus worsening processability. Here, it is predicted that tackiness is determined by the surface tack force, the size of the contact area, and the green strength of the rubber composition. Therefore, by incorporating (e) a lubricant into the rubber composition, the surface free energy can be reduced by the lubricant bleeding onto the surface of the rubber composition, thereby reducing tackiness. Furthermore, by adding an inorganic filler with a certain particle size or larger as (d) an inorganic filler to the rubber composition, the surface roughness of the rubber composition can be increased, reducing the contact area between the rubber composition and the metal, and the green strength of the rubber can be increased by the reinforcing properties of the inorganic filler. Thus, it is considered that by using both (d) an inorganic filler and (e) a lubricant in combination, tackiness can be reduced while maintaining damping performance.

[0015] The following describes each component used in the damping rubber composition of the present invention.

[0016] (a) Base rubber The damping rubber composition contains (a) base rubber. The content of (a) base rubber in the damping rubber composition is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0017] The (a) base rubber contains at least one selected from the group consisting of polyisoprene-based rubber and polybutadiene-based rubber. By containing a specific rubber in the (a) base rubber, the necessary processability and durability can be ensured.

[0018] The total content of polyisoprene rubber and polybutadiene rubber in the base rubber (a) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. If the total content of polyisoprene rubber and polybutadiene rubber is within the above range, the damping performance in the low strain range will be further improved. Note that the base rubber (a) may contain only polyisoprene rubber, only polybutadiene rubber, or both polyisoprene rubber and polybutadiene rubber.

[0019] (Polyisoprene rubber) The polyisoprene-based rubber is not particularly limited as long as it is rubber having constituent units derived from isoprene (preferably rubber containing 50% by mass or more of constituent units derived from isoprene). Examples of the polyisoprene-based rubber include natural rubber (NR) and synthetic rubber. Natural rubber is derived from rubber-containing plants and contains pure cis-1,4-polyisoprene. Synthetic polyisoprene-based rubber is synthesized by polymerizing isoprene or a monomer composition containing isoprene (preferably a monomer composition containing 50% by mass or more of isoprene). The natural rubber and synthetic polyisoprene-based rubber may also be modified rubber. These polyisoprene-based rubbers may be used individually or in combination.

[0020] Examples of the aforementioned natural rubber include various grades of natural rubber such as SMR (Standard Malaysian Rubber)-CV60, and various types of deproteinized natural rubber.

[0021] Examples of the synthetic polyisoprene-based rubber include polyisoprene rubber (IR) and copolymer rubber of isoprene and other monomer components.

[0022] Other monomer components that can constitute the synthetic polyisoprene rubber include, for example, butadiene, styrene, ethylene, propylene, acrylonitrile, and chloroprene. These other monomer components may be used individually or in combination of two.

[0023] The content of isoprene-derived structural units in the synthetic polyisoprene rubber is preferably more than 50% by mass, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit for the isoprene-derived structural units is 100% by mass.

[0024] Among the synthetic polyisoprene rubbers, polyisoprene rubber (IR) is preferred, and high-cis-1,4-polyisoprene rubber containing 90% or more (preferably 95% or more by mass) of cis-1,4-bonds is more preferred. Using high-cis-1,4-polyisoprene rubber results in better damping in the low-strain range.

[0025] Specific examples of the aforementioned synthetic polyisoprene rubber include commercially available products such as the Nipol® IR series (e.g., IR2200) manufactured by Nippon Zeon Co., Ltd.

[0026] Mooney viscosity (ML) of the aforementioned polyisoprene rubber 1+4 The Mooney viscosity (ML) in this invention is preferably 40 or higher, more preferably 45 or higher, even more preferably 50 or higher, preferably 120 or lower, more preferably 110 or lower, and even more preferably 100 or lower. The effects of the present invention can be obtained more favorably if the Mooney viscosity of the polyisoprene rubber is within the above range. Note that the Mooney viscosity (ML) in this invention refers to the Mooney viscosity (ML). 1+4 (100℃)) refers to the value measured in accordance with JIS K6300, using an L rotor, with a preheating time of 1 minute, a rotor rotation time of 4 minutes, and under conditions of 100℃.

[0027] (Polybutadiene rubber) The polybutadiene-based rubber is not particularly limited as long as it is a rubber having constituent units derived from butadiene (preferably a rubber containing 50% by mass or more of constituent units derived from butadiene). Examples of the polybutadiene-based rubber include those synthesized by polymerizing butadiene or a monomer composition containing butadiene (preferably a monomer composition containing 50% by mass or more of butadiene). The polybutadiene-based rubber may also be a modified rubber. The polybutadiene-based rubber may be used alone or in combination of two types.

[0028] Examples of the polybutadiene-based rubber include polybutadiene rubber (BR) and copolymer rubber of butadiene and other monomer components.

[0029] Other monomer components that can constitute the polybutadiene-based rubber include, for example, isoprene, styrene, ethylene, propylene, acrylonitrile, and chloroprene. These other monomer components may be used alone or in combination of two. Styrene-butadiene rubber is an example of a copolymer rubber of butadiene and other monomer components.

[0030] The polybutadiene-based rubber preferably has a butadiene-derived constituent unit content of more than 50% by mass, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit for the butadiene-derived constituent unit content is 100% by mass.

[0031] As the polybutadiene rubber (BR), high-cis-1,4-polybutadiene rubber containing 90% or more (preferably 95% or more by mass) of cis-1,4-bonds is more preferable. High-cis-1,4-polybutadiene rubber exhibits less variation in physical properties due to temperature (especially at low temperatures). By using high-cis-1,4-polybutadiene rubber, the damping performance of the damping member in the low-strain region is improved, and the temperature dependence of the damping performance and equivalent shear modulus can be further reduced.

[0032] The styrene-butadiene rubber is a copolymer of styrene and 1,3-butadiene. As the styrene-butadiene rubber, high-styrene type, medium-styrene type, and low-styrene type SBRs, classified according to their styrene content, can all be used. The styrene content of the styrene-butadiene rubber is preferably 15% by mass or more, more preferably 20% by mass or more, preferably 45% by mass or less, and more preferably 35% by mass or less.

[0033] Specific examples of the aforementioned polybutadiene-based rubber include commercially available products such as the UBEPOL® BR series manufactured by Ube Industries, Ltd. (e.g., BR130B, BR360B, BR150B, BR150L, ​​BR360L) and the Nipol® SBR series manufactured by Nippon Zeon Corporation (e.g., SBR1502, SBR1723).

[0034] Mooney viscosity of the aforementioned polybutadiene-based rubber (ML) 1+4 The Mooney viscosity (at 100°C) is preferably 15 or higher, more preferably 20 or higher, even more preferably 25 or higher, preferably 80 or lower, more preferably 70 or lower, and even more preferably 60 or lower. The effects of the present invention can be obtained more favorably if the Mooney viscosity of the polybutadiene rubber is within the above range.

[0035] The (a) base rubber may contain at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber, but it is also preferable that it contains both polyisoprene rubber and polybutadiene rubber.

[0036] When the base rubber (a) contains polyisoprene rubber and polybutadiene rubber, the content of polyisoprene rubber in the base rubber (a) is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. If the content of polyisoprene rubber is 40% by mass or more, the damping performance in the low strain range is improved, and if it is 80% by mass or less, the damping performance in the low strain range is improved, and the temperature dependence of the damping performance and equivalent shear modulus is further suppressed.

[0037] When the base rubber (a) contains polyisoprene rubber and polybutadiene rubber, the content of polybutadiene rubber in the base rubber (a) is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less. If the content of polybutadiene rubber is 20% by mass or more, the damping performance in the low strain range is improved, and if it is 60% by mass or less, the damping performance in the low strain range is even better, and the temperature dependence of the damping performance and equivalent shear modulus is further suppressed.

[0038] When the base rubber (a) contains polyisoprene rubber and polybutadiene rubber, the mass ratio of polyisoprene rubber to polybutadiene rubber (polyisoprene rubber / polybutadiene rubber) is preferably 0.5 or more, more preferably 1.0 or more, even more preferably 1.2 or more, preferably 4.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. If the mass ratio (polyisoprene rubber / polybutadiene rubber) is within the above range, the damping performance in the low strain region is further improved, and the temperature dependence of the damping performance and equivalent shear modulus is further suppressed.

[0039] (Other types of rubber) The (a) base rubber may contain other rubber components in addition to the polyisoprene rubber and / or polybutadiene rubber. Examples of these other rubber components include butyl rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, and modified rubbers thereof. These other rubber components may be used individually or in combination of two or more.

[0040] Furthermore, each rubber component (polyisoprene-based rubber, polybutadiene-based rubber, and other rubber components) contained in the damping rubber composition may be either an oil-expanded type with added spreader oil or a non-oil-expanded type without added spreader oil. When using the oil-expanded type, the rubber content and mass ratio are calculated based on the rubber content excluding the spreader oil.

[0041] It is preferable that each rubber component contained in the damping rubber composition is solid at 25°C. In other words, it is preferable that the base rubber (a) does not contain liquid rubber that is liquid at 25°C and is commonly used as a softening agent.

[0042] (b) Tackifier The damping rubber composition contains (b) a tackifier. Examples of the tackifiers in (b) above include petroleum-based resins, terpene-based resins, coumarone-based resins, styrene-based resins, rosin-based resins, etc. These tackifiers may be used individually or in combination of two or more types.

[0043] (Petroleum-based resin) The aforementioned petroleum-based resins are resins polymerized using aliphatic (cyclic) diolefin unsaturated hydrocarbon fractions (C5 fraction (isoprene, 1,3-pentadiene, cyclopentene, cyclopentadiene, etc.)) or aromatic olefin unsaturated hydrocarbon fractions (C9 fraction (styrene, vinyltoluene, α-methylstyrene, indene, alkylindene, dicyclopentadiene, etc.)) obtained by the thermal decomposition of petroleum naphtha as raw materials.

[0044] Examples include aliphatic (cyclic) petroleum resins obtained by copolymerizing the C5 fraction (or a high-purity component extracted from the C5 fraction), aromatic petroleum resins obtained by copolymerizing the C9 fraction (or a high-purity component extracted from the C9 fraction), aliphatic (cyclic)-aromatic petroleum resins obtained by copolymerizing the C5 fraction and the C9 fraction (or a high-purity component extracted from these fractions), and hydrogenated versions thereof. These petroleum resins may be used individually or in combination of two or more types.

[0045] Specific examples of the aforementioned petroleum-based resins include commercially available products such as the Quinton® 1000 series (e.g., Quinton 1920, Quinton 2940) and 100 series (e.g., Quinton E200SN) manufactured by Nippon Zeon Corporation, the Petocol® series (e.g., Petocol 120, Petocol 130, Petocol LX) and Petrotac® series (e.g., Petrotac 60, Petrotac 70) manufactured by Tosoh Corporation, the Structol® series (e.g., Structol 40MS, Structol 60NS) manufactured by Structol Corporation, the Marcaretz® M series (e.g., Marcaretz M-890A) manufactured by Maruzen Petrochemical Co., Ltd., and the SYLVATRAXX® series (e.g., SYLVATRAXX 4401) manufactured by Kraton Corporation.

[0046] (Terpene resin) The terpene resins mentioned above are resins having constituent units mainly derived from terpene compounds, and examples include polyterpene resins obtained by (co)polymerizing terpene compounds, terpene-aromatic resins obtained by copolymerizing terpene compounds and aromatic compounds, aromatically modified polyterpene resins obtained by modifying polyterpene resins with aromatic compounds, and hydrogenated versions thereof. These terpene resins may be used individually or in combination of two or more types.

[0047] The terpene compound is a hydrocarbon represented by the composition (C5H8)n and its oxygen-containing derivative, and is a monoterpene (C 10 H 16 ), sesquiterpenes (C15 H 24 )), diterpenes (C 20 H 32 )), etc., and are compounds having a terpene as a basic skeleton. Examples include α-pinene, β-pinene, dipentene, limonene, myrcene, allo-ocimene, ocimene, α-farnesene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, etc. These terpene compounds may be used alone or in combination of two or more.

[0048] Examples of the aromatic compound include phenolic compounds such as phenol, alkylphenol, alkoxyphenol, and phenol containing an unsaturated hydrocarbon group; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and naphthol containing an unsaturated hydrocarbon group; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and styrene containing an unsaturated hydrocarbon group, etc. These aromatic compounds may be used alone or in combination of two or more.

[0049] Specific examples of the terpene resin include commercially available products such as the SYLVATRAXX (registered trademark) series (e.g., SYLVATRAXX 4150, SYLVATRAXX 4125), SYLVARES (registered trademark) series (e.g., SYLVARES TR B115, SYLVARES TR M1115) manufactured by Clayton, and the YS resin series (e.g., YS resin TO85) manufactured by Yasuhara Chemical Co., Ltd.

[0050] (Coumarone resin) The coumarone resin is a resin having a structural unit mainly derived from coumarone. Examples include coumarone resin, coumarone-indene resin, copolymer resin mainly composed of coumarone, indene, and styrene, etc. These coumarone resins may be used alone or in combination of two or more.

[0051] Specific examples of the aforementioned coumaron-based resins include commercially available products such as the Nitto Chemical Co., Ltd.'s

[0052] (Styrene resin) The styrene-based resin is a polymer containing styrene monomers as constituent monomers. Examples include a homopolymer obtained by polymerizing one type of styrene monomer alone, a copolymer obtained by copolymerizing two or more types of styrene monomers, and a copolymer of a styrene monomer and other monomers that can copolymerize it.

[0053] Examples of styrene monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene. These may be used individually or in combination of two or more. Among these, styrene and α-methylstyrene are more preferred.

[0054] To obtain better results, the styrene-based resin is preferably an α-methylstyrene-based resin (α-methylstyrene homopolymer, copolymer of styrene and α-methylstyrene, etc.), and more preferably a styrene-α-methylstyrene resin (polymer of styrene and α-methylstyrene)).

[0055] (Rosin-based resin) Examples of the rosin-based resins include rosin esters, hydrogenated rosin esters, disproportionated rosin esters, and polymerized rosin esters. These may be used individually or in combination of two or more types.

[0056] Specific examples of the aforementioned rosin-based resins include commercially available products such as the Pine Crystal® series (e.g., Pine Crystal KR-85) manufactured by Arakawa Chemical Industries, Ltd.

[0057] The amount of the tackifier (b) is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, even more preferably 80 parts by mass or more, preferably 110 parts by mass or less, more preferably 105 parts by mass or less, and even more preferably 100 parts by mass or less, per 100 parts by mass of the base rubber (a). If the amount of the tackifier (b) is 70 parts by mass or more, the damping performance will be good, and if it is 110 parts by mass or less, the temperature dependence of the damping performance and the equivalent shear modulus will be suppressed.

[0058] The (b) tackifier preferably contains (b1) at least one selected from the group consisting of petroleum resins, terpene resins, and coumarone resins, and (b2) a rosin resin. By using these tackifiers in combination, it is possible to achieve both improved damping performance in the low strain range and suppression of the temperature dependence of damping performance and equivalent shear modulus.

[0059] When (b) a tackifier is used in combination with (b1) at least one selected from the group consisting of petroleum resins, terpene resins, and coumarone resins, and (b2) a rosin resin, the mass ratio of these ((b1) / (b2)) is preferably 4 or more, more preferably 5 or more, even more preferably 6 or more, preferably 15 or less, more preferably 12 or less, and even more preferably 10 or less.

[0060] (c) Carbon Black The damping rubber composition contains (c) carbon black. The (c) carbon black is, for example, produced by thermal decomposition or incomplete combustion of hydrocarbons such as petroleum-based or coal-based oil or natural gas as raw materials. As the carbon black, any of furnace carbon black, thermal carbon black, channel carbon black, or acetylene black, which are classified according to the manufacturing method, may be used.

[0061] Examples of the carbon blacks mentioned in (c) above include furnace carbon blacks such as SAF (Super Abrasion Furnace Black), ISAF (Intermediate Super Abrasion Furnace Black), IISAF (Intermediate ISAF), HAF (High Abrasion Furnace Black), MAF (Medium Abrasion Furnace Black), FEF (Fast Extruding Furnace Black), SRF (Semi-Reinforcing Furnace Black), GPF (General Purpose Furnace Black), FF (Fine Furnace Black), and CF (Conductive Furnace Black); thermal carbon blacks such as FT (Fine Thermal Black) and MT (Medium Thermal Black); channel carbon blacks such as EPC (Easy Processing Channel Black) and MPC (Medium Processing Channel Black); and acetylene black. The carbon blacks may be used individually or in combination of two or more types.

[0062] Specific examples of the carbon black mentioned in (c) above include commercially available products such as the Seast series (e.g., Seast 3) manufactured by Tokai Carbon Co., Ltd.

[0063] The arithmetic mean particle diameter (primary particle diameter) of the carbon black (c) is preferably 15 nm or more, more preferably 20 nm or more, even more preferably 25 nm or more, preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less. If the arithmetic mean particle diameter of the carbon black (c) is within the above range, processability and damping performance in the low strain region will be better. The arithmetic mean particle diameter can be determined, for example, by measuring the diameter of each carbon black particle using an electron microscope image and calculating their arithmetic mean values.

[0064] The nitrogen adsorption specific surface area of ​​the carbon black (c) is 30 m². 2 Preferably 50 m / g or more, and more preferably 50 m 2 / g or more, more preferably 70m 2 It is 150m or more / g 2 Preferably less than / g, and more preferably 130m 2 / g or less, more preferably 110m 2 (c) If the nitrogen adsorption specific surface area of ​​carbon black is within the above range, processability and damping performance in the low strain range will be better. The nitrogen adsorption specific surface area can be measured, for example, by a gas phase adsorption method using nitrogen gas as the adsorbent gas.

[0065] The amount of iodine adsorbed by the carbon black (c) is preferably 30 mg / g or more, more preferably 50 mg / g or more, even more preferably 70 mg / g or more, preferably 150 mg / g or less, more preferably 130 mg / g or less, and even more preferably 110 mg / g or less. If the amount of iodine adsorbed by the carbon black (c) is within the above range, processability and damping performance in the low strain range will be better. The amount of iodine adsorbed can be measured, for example, in accordance with JIS K6217-1.

[0066] The amount of DBP (dibutyl phthalate) absorbed by the carbon black (c) above is 40 cm 3 Preferably 100g or more, and more preferably 60cm 3 / 100g or more, more preferably 80cm 3 / 100g or more, 150cm 3 Preferably 100g or less, and more preferably 140cm 3 / 100g or less, more preferably 130cm 3 (c) If the DBP absorption amount of carbon black is within the above range, processability and damping performance in the low strain range will be better. The DBP absorption amount can be measured, for example, in accordance with the oil absorption amount method A of JIS K6217-4.

[0067] The amount of carbon black (c) added is preferably 100 parts by mass or more, more preferably 110 parts by mass or more, even more preferably 120 parts by mass or more, preferably 160 parts by mass or less, more preferably 150 parts by mass or less, and even more preferably 140 parts by mass or less, per 100 parts by mass of the base rubber (a). If the amount of carbon black (c) added is 100 parts by mass or more, the discharge of the rubber composition after kneading becomes easier and the damping performance of the damping member in the low strain range is improved, and if it is 160 parts by mass or less, the kneading of the rubber composition becomes easier and the processability is good.

[0068] (d) Inorganic fillers The damping rubber composition contains (d) an inorganic filler having a particle size of 3 μm or more as measured by the air permeability method. By adding an inorganic filler having a particle size of a certain size or more as (d) an inorganic filler to the damping rubber composition, the green strength of the rubber can be increased by the reinforcing properties of the (d) inorganic filler, and the surface roughness of the rubber composition can be increased, thereby reducing the contact area between the rubber composition and the metal members of the kneader used to prepare the rubber composition.

[0069] Examples of the inorganic filler (d) include calcium carbonate, magnesium carbonate, barium sulfate, talc, clay, and silica. These inorganic fillers (d) may be used individually or in combination of two or more. Among these, calcium carbonate is preferred as the inorganic filler (d).

[0070] The inorganic filler (d) described above has a particle size of 3 μm or more, preferably 4 μm or more, more preferably 5 μm or more, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less, as measured by the air permeability method. The measurement by the air permeability method shall conform to JIS M8511 (2014).

[0071] The amount of the inorganic filler (d) is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of the base rubber (a). If the amount of the inorganic filler (d) is 5 parts by mass or more, the processability will be good, and if it is 100 parts by mass or less, adverse effects on the physical properties of the damping member can be suppressed.

[0072] The damping rubber composition may contain, in addition to the inorganic filler (d), an inorganic filler having a particle size of less than 3 μm as measured by the air permeability method, to an extent that does not impair the effects of the present invention.

[0073] (e) lubricant The damping rubber composition contains (e) a fatty acid derivative as a lubricant. The lubricant (e) may be used alone or in combination of two or more types. The fatty acid derivative is preferably at least one selected from the group consisting of fatty acid metal salts, fatty acid amides, and fatty acid esters. In particular, it is preferable that the (e) lubricant contains fatty acid metal salts and fatty acid amides.

[0074] Examples of the lubricant (e) above include fatty acid metal salts such as calcium stearate, magnesium stearate, and zinc stearate; fatty acid amides such as stearamide, oleamide, and erucamide; and fatty acid esters such as alkyl stearate.

[0075] The amount of the lubricant (e) is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the base rubber (a). If the amount of the lubricant (e) is 0.5 parts by mass or more, the processability will be good, and if it is 10 parts by mass or less, adverse effects on the physical properties of the damping member can be suppressed.

[0076] (Vulcanizing agent) Preferably, the damping rubber composition further contains a vulcanizing agent.

[0077] It is preferable to use a sulfur-based vulcanizing agent as the vulcanizing agent. Examples of sulfur-based vulcanizing agents include powdered sulfur, oil-treated powdered sulfur, precipitated sulfur, colloidal sulfur, and dispersible sulfur. These sulfur-based vulcanizing agents may be used individually or in combination of two or more.

[0078] Specific examples of the aforementioned vulcanizing agent include commercially available products such as 5% oil-treated sulfur powder manufactured by Tsurumi Chemical Industries Co., Ltd.

[0079] The amount of the vulcanizing agent blended is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, even more preferably 1.0 part by mass or more, preferably 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, and even more preferably 2.0 parts by mass or less, per 100 parts by mass of the base rubber. If the amount of the vulcanizing agent blended is within the above range, the vulcanization performance can be good while suppressing the occurrence of bloom. When using, for example, oil-treated powdered sulfur or dispersible sulfur as the vulcanizing agent, the blending amount refers to the amount of sulfur itself as an active ingredient contained in each.

[0080] (Vulcanization accelerator) Preferably, the damping rubber composition further contains a vulcanization accelerator.

[0081] The aforementioned vulcanization accelerators include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole (MBT) and 2-benzothiazolyl disulfide (MBTS); dithiocarbamate-based accelerators such as zinc dimethyldithiocarbamate (ZnMDC), zinc diethyldithiocarbamate (ZnEDC), and zinc dibutyldithiocarbamate (ZnBDC); and tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD), and tetrabenzylthiuram disulfide. Examples of such agents include thiuram-based vulcanization accelerators such as t-(TBzTD); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiadylsulfenamide (CBS), N-tert-butyl-2-benzothiazolesulfenamide (TBBS), N-oxydiethylene-2-benzothiazolesulfenamide (OBS), and N,N′-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine (DPG), diorthototrilguanidine, and orthototrilbiguanidine. These may be used individually or in combination of two or more.

[0082] Specific examples of the aforementioned vulcanization accelerators include, for example, the Axel® series manufactured by Kawaguchi Chemical Industry Co., Ltd. (e.g., Axel CZ, Axel TET) and the Noxellar® series manufactured by Ouchi Shinko Chemical Co., Ltd.

[0083] The amount of the vulcanization accelerator blended is preferably 0.3 parts by mass or more, more preferably 0.4 parts by mass or more, even more preferably 0.5 parts by mass or more, preferably 2.0 parts by mass or less, more preferably 1.8 parts by mass or less, and even more preferably 1.5 parts by mass or less, per 100 parts by mass of the base rubber. If the amount of the vulcanization accelerator blended is within the above range, it is possible to suppress the occurrence of bloom while maintaining good vulcanization acceleration.

[0084] (Other ingredients) In addition to the above-mentioned components, the damping rubber composition of the present invention may further contain various additives that can be used in damping rubber compositions, such as vulcanization aids, antioxidants, and softeners, selected as appropriate within a range that does not impair the objectives of the present invention.

[0085] (Vulcanization aid) Examples of the aforementioned vulcanization aids include metal compounds such as zinc oxide, and fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid. These vulcanization aids may be used individually or in combination of two or more.

[0086] Specific examples of the aforementioned vulcanization aids include commercially available products such as two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. and Tsubaki manufactured by NOF Corporation.

[0087] The amount of the vulcanization aid blended is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, preferably 10 parts by mass or less, more preferably 9 parts by mass or less, and even more preferably 8 parts by mass or less, per 100 parts by mass of the base rubber. If the amount of the vulcanization aid blended is within the above range, the vulcanization properties of the rubber composition will be better.

[0088] (Anti-aging agent) Examples of the aforementioned anti-aging agents include various anti-aging agents such as benzimidazole-based, quinone-based, polyphenol-based, and amine-based agents. These anti-aging agents may be used alone or in combination of two or more. Of these, benzimidazole-based and quinone-based anti-aging agents are preferred, and the combination of benzimidazole-based and quinone-based anti-aging agents is more preferred.

[0089] Specific examples of the benzimidazole-based antioxidant include, for example, commercially available products such as the Nocrack® series (e.g., Nocrack MB) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Specific examples of the quinone-based antioxidant include, for example, Antigen FR [aromatic ketone-amine condensate] manufactured by Maruishi Chemical Co., Ltd.

[0090] The amount of the anti-aging agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, preferably 8 parts by mass or less, more preferably 6 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the base rubber. If the amount of the anti-aging agent is within the above range, the anti-aging effect of the rubber composition will be good.

[0091] Furthermore, when a benzimidazole-based antioxidant and a quinone-based antioxidant are used in combination as the aforementioned anti-aging agent, the mass ratio of these (benzimidazole-based / quinone-based) is preferably 0.2 or higher, more preferably 0.5 or higher, even more preferably 0.8 or higher, preferably 5 or lower, more preferably 4 or lower, and even more preferably 2 or lower. If the mass ratio (benzimidazole-based / quinone-based) is within the above range, the anti-aging effect of the rubber composition will be better.

[0092] The damping rubber composition can be prepared, for example, by blending and kneading (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler, (e) a lubricant, a vulcanizing agent, a vulcanization accelerator, and other components added as needed. The kneading method is not particularly limited and can be carried out using known kneaders such as a closed-type kneader, kneading rolls, a Banbury mixer, or a kneader.

[0093] <Damping rubber> The present invention includes a damping rubber obtained by curing the damping rubber composition. The damping rubber can be obtained, for example, by pressing the kneaded damping rubber composition at a temperature of 130°C to 170°C for 20 minutes to 10 hours, thereby simultaneously molding and vulcanizing it.

[0094] The aforementioned damping rubber exhibits excellent damping properties in low-strain areas, such as wind-induced vibrations. For example, it can be suitably used as a vibration-damping material to absorb vibrations in low-strain areas, such as wind-induced vibrations.

[0095] The damping rubber preferably has an equivalent damping constant heq(23°C) of 0.25 or higher, more preferably 0.26 or higher, and even more preferably 0.27 or higher, measured under conditions of a temperature of 23°C and a strain of 2%. If the equivalent damping constant heq(23°C) is 0.25 or higher, the damping properties of the damping rubber are good. There is no particular upper limit to the equivalent damping constant heq(23°C), but it is 0.60.

[0096] The damping rubber preferably has a deformation amount (strain rate) of 300% or more, more preferably 400% or more, and even more preferably 500% or more at the limit deformation, measured at a temperature of 23°C and a deformation speed of 1 mm / s. If the deformation amount at the limit deformation is 300% or more, the durability against vibrations with large amounts of strain is improved.

[0097] <Viscoelastic damper> The present invention includes a viscoelastic damper equipped with the aforementioned damping rubber as a damping member. The viscoelastic damper of the present invention exhibits excellent damping properties in low-strain regions, such as wind-induced vibrations. For example, it can be suitably used as a viscoelastic damper for absorbing vibrations in low-strain regions, such as wind-induced vibrations (particularly a viscoelastic damper installed in buildings). [Examples]

[0098] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples, and any modifications and embodiments that do not depart from the spirit of the present invention are all included within the scope of the present invention.

[0099] [Evaluation Method] <Tackiness> The rubber composition was subjected to sheet dispensing using a metal roll, and its tackiness to the metal roll was evaluated according to the following evaluation criteria. ◎(Pass): The rubber composition does not adhere to metal and can be easily dispensed as a sheet. ○ (Pass): The rubber composition adheres to the metal, but the sheet can be dispensed without stopping the roll. × (Failure): The rubber composition adheres to metal and requires the roll to be fixed in place and then peeled off.

[0100] <damping> (Preparation of test specimens) Each rubber composition was extruded into a sheet and then punched out to form a rectangular flat plate 1 (8 mm thick × 40 mm long × 40 mm wide) as shown in Figure 1. Next, rectangular flat steel plates 2, 6 mm thick × 50 mm long × 50 mm wide, were stacked on both sides of the flat plate 1 via vulcanizing adhesive to form a laminate. Then, the laminate was heated to 140°C while applying pressure in the lamination direction to crosslink the rubber composition forming the flat plate 1, and the flat plate 1 was vulcanized and bonded to the two steel plates 2 to create a test specimen 3 as a model of a damping member.

[0101] (Displacement test) Two of the above-mentioned test specimens 3 were prepared as shown in Figure 2(a). Each of these two test specimens 3 was bolted to a central fixing jig 4 via one of the steel plates 2, and one left / right fixing jig 5 was bolted to the other steel plate 2 of each test specimen 3. Next, the central fixing jig 4 was bolted to the upper fixing arm 6 of the testing machine (not shown) via a joint 7, and the two left / right fixing jigs 5 were bolted to the lower movable plate 8 of the testing machine via a joint 9. Both test specimens 3 were fixed as described above, with two parallel sides of the flat plate 1 aligned parallel to the displacement direction described below. Next, the hysteresis loop H (see Figure 3) was determined, which shows the relationship between the displacement (mm) of the plate 1 in the direction perpendicular to its thickness and the load (N) when the plate 1 was repeatedly subjected to strain deformation, i.e., vibration, with the operations (I), (II), (III), and (IV) described below as one cycle. (I): The movable platen 8 is displaced so as to push it upward in the direction of the fixed arm 6, as shown by the white arrow in Figure 2(a), causing the flat plate 1 to be distorted and deformed in a direction perpendicular to the thickness direction, as shown in Figure 2(b). (II): From the state shown in Figure 2(b), the movable platen 8 is displaced by pulling it down in the opposite direction to the fixed arm 6, as indicated by the white arrow in Figure 2(b), returning it to the state shown in Figure 2(c). (III): Displace the movable plate 8 so as to pull it down in the opposite direction to the fixed arm 6, as shown by the white arrow in Figure 2(c), so that the flat plate 1 is distorted and deformed in the direction perpendicular to the thickness direction, as shown in Figure 2(d). (IV): From the state shown in Figure 2(d), the movable platen 8 is displaced by pushing it upward in the direction of the fixed arm 6, as indicated by the white arrow in Figure 2(d), returning it to the state shown in Figure 2(a).

[0102] The measurements were performed under conditions of 23°C, with the above operations (I) to (IV) carried out for 150 cycles, and the value at the 100th cycle was recorded. In each cycle, the maximum displacement was set such that the displacement of the two steel plates 2 sandwiching the flat plate 1 in the direction perpendicular to the thickness direction of the flat plate 1 was 2% of the thickness of the flat plate 1. In the displacement test, the deformation frequency was set to 1 Hz.

[0103] From the hysteresis loop H in Figure 3, obtained by measurement, the equivalent shear modulus Geq(N / mm²) can be calculated using the following equation (1). 2 ) was sought.

[0104]

number

[0105] In equation (1), Keq (N / mm) is the slope of the straight line L1, shown as a thick solid line in Figure 3, which connects the point of maximum displacement and the point of minimum displacement of the hysteresis loop H. T (mm) is the thickness of plate 1. A(mm 2 ) is the cross-sectional area of ​​plate 1.

[0106] Furthermore, the equivalent damping constant heq was obtained from the hysteresis loop H in Figure 3 using the following equation (2).

[0107]

number

[0108] In equation (2), ΔW is the amount of absorbed energy represented by the total surface area of ​​the hysteresis loop H, which is shown as a shaded area in Figure 3. W is the elastic strain energy represented by the surface area of ​​the triangular region enclosed by the line L1, the horizontal axis of the graph (load is 0N), and the perpendicular L2 drawn from the intersection of line L1 and the hysteresis loop H to the horizontal axis of the graph, as shown by the shaded line in Figure 3.

[0109] (evaluation) The equivalent damping constant heq(23°C), measured in an environment at 23°C, was used as an indicator of damping performance. A larger equivalent damping constant heq(23°C) indicates superior damping performance. Products with an equivalent damping constant heq(23°C) of 0.25 or higher were marked "○" (pass), and those with a value less than 0.25 were marked "×" (fail).

[0110] <Limit Deformation Test> (Preparation of test specimens) Two test specimens 3 were prepared in the same manner as the damping test described above.

[0111] (Limit deformation test) Two of the above-mentioned test specimens 3 were prepared as shown in Figure 2(a) and similarly fixed to the testing machine used in the damping test.

[0112] Next, under conditions of 23°C, the movable platen 8 was displaced at a speed of 1 mm / s so as to push it upward in the direction of the fixed arm 6, as indicated by the white arrow in Figure 2(a), and the point at which the stress significantly decreased was measured as the critical deformation strain. The critical deformation strain (%) was calculated using the following formula, based on the displacement amount D (mm) of the two steel plates 2 sandwiching the flat plate 1, in the direction perpendicular to the thickness direction of the flat plate 1, and the thickness of the flat plate 1 T (mm). Limit deformation strain (%) = (D / T) × 100

[0113] (evaluation) The critical deformation strain (%) measured at a temperature of 23°C was used as the index of critical deformation. Products with a critical deformation strain (23°C) of 300% or more were marked "○" (pass), and those with a critical deformation strain (23°C) of less than 300% were marked "×" (fail).

[0114] <Overall Rating> If the evaluation results for adhesion, damping, and limit deformation were all "pass," the overall evaluation was set to "○." If any one of the evaluation results for adhesion, damping, or limit deformation was "fail," the overall evaluation was set to "×."

[0115] A rubber composition was prepared by kneading each component of the formulation shown in Table 1 using a closed-type kneader.

[0116] [Table 1]

[0117] The components listed in Table 1 are as follows: IR2200: Manufactured by Zeon Corporation, made of polyisoprene rubber (product name: Nipol IR2200, Mooney viscosity (ML) 1+4 (100℃): 82) BR130B: Manufactured by Ube Industries, Ltd., made of polybutadiene rubber (product name: UBEPOL BR130B), Mooney viscosity (ML) 1+4 (100℃): 26) SBR1502: Manufactured by Zeon Corporation, styrene-butadiene rubber (product name: NiPOL_1502, Mooney viscosity (ML) 1+4 (100℃): 52, Styrene content: 23.5% by mass Terpene resin: Aromatic modified terpene resin manufactured by Yasuhara Chemical Co., Ltd. (Product name: YS Resin TO85) Coumaron-based resin: Coumaron indene resin (product name: Nitto Chemical Co., Ltd., Coumaron G-90) Petroleum-based resin: Kraton Corporation, SYLVATRAXX4401 Rosin-based resin: Arakawa Chemical Industries, Ltd. ultra-pale rosin (product name: Pine Crystal KR-85) Seest 3: Manufactured by Tokai Carbon Co., Ltd. (Carbon black, product name: Seest 3, arithmetic mean particle size: 28 nm, nitrogen adsorption specific surface area: 79 m²) 2 / g, Iodine adsorption amount: 80mg / g, DBP absorption amount: 101cm³ 3 (100g) Calcium carbonate (13.0 μm): Manufactured by Bihoku Powder Chemical Industry Co., Ltd., product name BF400, average particle size 13.0 μm as determined by air permeability method. Calcium carbonate (5μm): Manufactured by Bihoku Powdering Industry Co., Ltd., product name BF200, average particle size 5μm according to air permeability method. Calcium carbonate (0.70 μm): Manufactured by Bihoku Powder Chemical Industry Co., Ltd., product name Softon 3200, average particle size 0.70 μm according to air permeability method. Structol® WB16: Manufactured by Structol, a fatty acid derivative (a mixture of fatty acid metal salts and fatty acid amides). Sulfur: 5% oil-treated powdered sulfur manufactured by Tsurumi Chemical Industry Co., Ltd. AXEL (registered trademark) CZ: Sulfenamide-based vulcanization accelerator, manufactured by Kawaguchi Chemical Industry Co., Ltd. Accel (registered trademark) TET: Thiuram-based vulcanization accelerator, manufactured by Kawaguchi Chemical Industry Co., Ltd. Zinc oxide: Manufactured by Mitsui Mining & Smelting Co., Ltd., 2 types of zinc oxide Stearic acid: Manufactured by NOF Corporation, Camellia Nocrack (registered trademark) MB: Manufactured by Ouchi Shinko Chemical Industry Co., Ltd., a benzimidazole-based antioxidant. Antigen FR: Manufactured by Sanshin Chemical Industry Co., Ltd., a quinone-based anti-aging agent.

[0118] As shown in Table 1, rubber compositions No. 1 to 7 contain predetermined amounts of (a) a base rubber selected from the group consisting of polyisoprene-based rubber and polybutadiene-based rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler with a particle size of 3 μm or more as measured by the air permeability method, and (e) a fatty acid derivative as a lubricant. These rubber compositions No. 1 to 7 have suppressed tackiness and good processability. Furthermore, damping members formed from these rubber compositions No. 1 to 7 exhibited excellent damping in the low strain range.

[0119] Rubber composition No. 8 is the case where (d) inorganic filler and (e) lubricant are not included. Rubber composition No. 9 is the case where (e) lubricant is not included. Rubber composition No. 10 is the case where (e) the amount of lubricant is too high. Rubber composition No. 11 is the case where (d) inorganic filler is not included. Damping members formed from these rubber compositions No. 8 to 11 showed excellent damping in the low strain range, but all of these rubber compositions No. 8 to 11 had high tackiness and poor processability.

[0120] Rubber composition No. 12 is the case where (d) the amount of inorganic filler is too high. The damping member formed from this rubber composition No. 12 had poor damping properties in the low strain range.

[0121] Rubber composition No. 13 uses an inorganic filler with a particle size of less than 3 μm as measured by the air permeability method. The damping member formed from this rubber composition No. 13 exhibited excellent damping in the low strain range, but this rubber composition No. 13 had high tackiness and poor processability.

[0122] The present invention (1) is a damping rubber composition containing (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler, and (e) a lubricant, wherein the (a) base rubber contains at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber, the amount of the (b) tackifier is 70 parts by mass or more and 110 parts by mass or less per 100 parts by mass of the (a) base rubber, and the amount of the (c) carbon black is The damping rubber composition is characterized in that, per 100 parts by mass of (a) the base rubber, the amount of (d) inorganic filler is 100 parts by mass or more and 160 parts by mass, the particle size of the inorganic filler measured by the air permeability method is 3 μm or more, the amount of (d) inorganic filler is 5 parts by mass or more and 100 parts by mass per 100 parts by mass of (a) base rubber, the (e) lubricant is a fatty acid derivative, and the amount of (e) lubricant is 0.5 parts by mass or more and 10 parts by mass per 100 parts by mass of (a) base rubber.

[0123] The present invention (2) is the damping rubber composition according to the present invention (1), wherein the base rubber (a) contains polyisoprene rubber and polybutadiene rubber.

[0124] The present invention (3) is a damping rubber composition according to the present invention (1) or (2), which contains a fatty acid metal salt and a fatty acid amide as the lubricant (e).

[0125] The present invention (4) is a damping rubber composition according to any one of the present inventions (1) to (3), wherein the tackifier (b) is at least one selected from the group consisting of petroleum resins, terpene resins and coumarone resins, and a rosin-based tackifier.

[0126] The present invention (5) is a damping rubber characterized by being obtained by curing a damping rubber composition described in any one of the present inventions (1) to (4).

[0127] The present invention (6) is a viscoelastic damper characterized by comprising a damping member obtained by curing a damping rubber composition described in any one of the present inventions (1) to (4). [Explanation of symbols]

[0128] 1: Flat plate, 2: Steel plate, 3: Test specimen, 4: Central fixing jig, 5: Left and right fixing jigs, 6: Fixing arm, 7: Joint, 8: Movable plate, 9: Joint, H: Hysteresis loop, L1: Straight line, L2: Perpendicular line, W: Elastic strain energy, ΔW: Absorbed energy, Keq: Slope of straight line L1

Claims

1. A damping rubber composition comprising (a) a base rubber, (b) a tackifier, (c) carbon black, (d) an inorganic filler, and (e) a lubricant, The (a) base rubber contains at least one selected from the group consisting of polyisoprene rubber and polybutadiene rubber, The amount of the tackifier (b) blended is 70 parts by mass or more and 110 parts by mass or less per 100 parts by mass of the base rubber (a), The amount of carbon black in (c) is 100 parts by mass or more and 160 parts by mass or less per 100 parts by mass of the base rubber (a), The particle size of the inorganic filler measured by the air permeability method is 3 μm or larger, and the amount of the inorganic filler blended is 5 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the base rubber (a). A damping rubber composition characterized in that the (e) lubricant is a fatty acid derivative, and the amount of the (e) lubricant blended is 0.5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the (a) base rubber.

2. The damping rubber composition according to claim 1, wherein the base rubber (a) contains polyisoprene rubber and polybutadiene rubber.

3. The damping rubber composition according to claim 1, further comprising a fatty acid metal salt and a fatty acid amide as the lubricant (e).

4. The damping rubber composition according to claim 1, wherein the (b) tackifier comprises (b1) at least one selected from the group consisting of petroleum resins, terpene resins, and coumarone resins, and (b2) a rosin resin.

5. A damping rubber characterized by being obtained by curing a damping rubber composition according to any one of claims 1 to 4.

6. A viscoelastic damper characterized by comprising a damping member obtained by curing a damping rubber composition according to any one of claims 1 to 4.

Images